WO2013069387A1

WO2013069387A1 - Display device, and drive method and manufacturing method for same

Info

Publication number: WO2013069387A1
Application number: PCT/JP2012/074685
Authority: WO
Inventors: 結城　昭正; 佐竹　徹也; 明男中山; 真彦宇野; 石川　淳
Original assignee: 三菱電機株式会社
Priority date: 2011-11-07
Filing date: 2012-09-26
Publication date: 2013-05-16
Also published as: JP2014160282A; JPWO2013069387A1

Abstract

The present invention relates to a display device such as a parallax barrier type three-dimensional display for the unaided eye and a multi-image display that displays different images for each direction of observation, the display device being provided with a display panel (10) on which are disposed a plurality of pixels in a matrix shape that form a light transmitting part or light emitting part and a parallax barrier (12) that is disposed on an image visual contact side or rear side of the display panel (10) and in which light transmitting parts are disposed in a plurality of matrix shapes. The plurality of pixels for the display panel (10) constitutes pixel sets, each of which comprises at least two pixels each displaying an image for observation from a different direction. One of the light transmitting parts of the parallax barrier (12) and one pixel set are disposed with a positional relationship such that the same correspond vertically. Of the parallax barrier (12) and the display panel (10) the one disposed on the image visual contact side is provided along the left and right sides of the light transmitting part and has a semi-transmissive part that transmits part of the light.

Description

Display device and driving method and manufacturing method thereof

The present invention relates to a display device, and more particularly to a display device such as a parallax barrier type naked-eye three-dimensional display or a multi-image display that displays different images for each observation direction.

Conventionally, an autostereoscopic image display device capable of stereoscopic viewing without requiring special glasses has been proposed.

For example, Patent Document 1 discloses a barrier generating unit that generates a parallax barrier stripe by electronic control using a transmissive display element, and a display screen that is spaced a predetermined distance backward from the position at which the parallax barrier stripe is generated. Image display means arranged and capable of outputting and displaying a multi-directional image in which strips of the left image and the right image are alternately arranged corresponding to the parallax barrier stripe when displaying a three-dimensional image There is disclosed a three-dimensional image display device characterized by comprising:

In such a 3D image display device, barrier stripes are generated electronically, and the shape (number of stripes, width, interval), position (phase), density, etc. of the generated barrier stripes can be variably controlled. Since it has been made possible, it can be used as a two-dimensional image display device and method and also as a three-dimensional image display device and method, and a compatible image display device and method can be realized. Yes.

Furthermore, in Patent Document 1, the position of the observer's head is detected, and the position (phase) of the electronic barrier is detected by the detection signal, and the phase inversion (barrier is performed each time the head moves in the left-right direction by the distance of the pupil interval. By reversing the positional relationship between the transmission part and the transmission part, it is said that the reverse viewing phenomenon in the binocular parallax stereogram can be solved and the stereoscopic observation range can be expanded.

Patent Document 2 discloses that image display means for alternately displaying a striped left-eye image and right-eye image, and the position of the light-shielding part that causes the binocular parallax effect are moved at a pitch of 1/4 mm of the light-shielding part pitch. A light-shielding means configured to be able to detect the movement of the observer's head in the left-right direction and a sensor that detects whether the position of the observer's head deviates back and forth from the appropriate viewing range. Is divided into regions in the left-right direction, and the movement and non-moving control of the position of the light-shielding part of the light-shielding means is performed in each region divided according to the state in which the observer's head position moves back and forth from the appropriate viewing range. There is disclosed a 3D image display apparatus without glasses, which is provided with a region division movement control means.

In the stereoscopic image display device disclosed in Patent Document 2, when the observer's head moves to a shifted position, the movement of the light shielding unit and the display control of the image display means are performed, so that the right eye of the observer An eye image can be supplied, and at this time, since the left eye image is supplied to the left eye of the observer, the observer can recognize a stereoscopic image.

Patent Document 2 includes a black mask portion having at least two different widths between the right-eye pixel and the left-eye pixel of the display portion adjacent to the horizontal direction of the pixel corresponding to the opening of the barrier, It is disclosed that a black mask portion between pixels constituting a parallax image pair is made larger than other portions.

As a result, the crosstalk at the boundary between the areas for displaying the right-eye image and the left-eye image can be reduced, and the observer has no double image generated by the original image light and crosstalk in a wider range. 3D images can be recognized. If different images are displayed instead of the parallax images, it is possible to recognize multi-directional images without double images generated by crosstalk in a wider range for each observation direction.

Japanese Patent No. 2857429 Japanese Patent No. 3668116 JP 2011-76095 A

Generally, in an autostereoscopic display or a multi-image display that displays different images for each observation direction, there is a luminance difference of the display image depending on the observation direction. Therefore, in the three-dimensional display devices of Patent Document 1 and Patent Document 2, even if the movement control of the barrier light shielding unit and the display control of the image display means are performed by electronic control according to the movement of the observer's head, the control is performed. Because of the inevitable movement delay, the observer's eyes may perceive a change in the brightness of the image, or may enter the boundary region and view a double image due to crosstalk.

◎ When the observer's head moves quickly or frequently, it feels uncomfortable. Therefore, it is desirable that there is no change in luminance depending on the position in the observation area of each image, and that the area where crosstalk occurs at the boundary with the image viewing area in other directions is narrow.

The present invention has been made to solve the above-described problems, and is a parallax barrier system that can continue stereoscopic viewing in a wide range without feeling flicker of luminance even when an observer moves. An object of the present invention is to provide a naked-eye three-dimensional image display device and to provide a multi-image display capable of visually recognizing an image without a double image due to a change in luminance or crosstalk in a wide range.

The display device according to the present invention includes a display panel in which a plurality of pixels each having a light transmission part or a light emission part are arranged in a matrix, and an image viewing side or a rear side of the display panel, and the light transmission part is in a matrix. A plurality of pixels of the display panel, each of which includes at least two pixels for displaying images to be observed from different directions, forming a set of pixels One of the light transmission portions of the parallax barrier and the one set of pixels are arranged in a corresponding positional relationship in the vertical direction, and the one arranged on the image viewing side of the parallax barrier and the display panel is , Provided along the left and right sides of the light transmission part, and having a semi-transmission part that partially transmits light.

A display device driving method according to the present invention includes a display panel in which a plurality of pixels are arranged in a matrix, and a parallax that is arranged on the image viewing side of the display panel and dynamically forms a parallax barrier by driving a liquid crystal layer A driving method of a display device including a barrier shutter panel, wherein the plurality of pixels of the display panel are a set of at least two or more pixels each displaying a left-eye parallax image and a right-eye parallax image. The parallax barrier shutter panel constituting a pixel set is divided into a plurality of states in which the liquid crystal layer is electrically insulated, and each has a plurality of sub-openings that are individually driven, The opening forms a light transmission part, a light shielding part, and a semi-transmission part that partially transmits light depending on the driving state of the liquid crystal layer, and the plurality of sub-openings and the one pixel set correspond vertically. In the parallax barrier shutter panel, the sub-openings serving as the semi-transmissive portions are positioned on the left and right of the array of the sub-openings serving as the light-transmitting portions among the plurality of sub-openings. The liquid crystal layer is driven.

According to the display device according to the present invention, of the parallax barrier and the display panel, the one disposed on the image viewing side is provided along the left and right sides of the light transmission unit, and transmits the light partially. Therefore, the brightness gradient of each image can be made steep at the boundary between the display areas of the two images, and the boundary area where the double image occurs due to the change in brightness or crosstalk can be narrowed. For this reason, even when the observation position of the observer moves to the left and right, a good image without occurrence of a double image due to a change in luminance or crosstalk can be visually recognized in a wide range.

According to the display device driving method of the present invention, the parallax barrier shutter panel includes sub-openings serving as semi-transmissive portions on the left and right sides of the array of sub-openings serving as the light transmissive portions among the plurality of sub-openings. Since the liquid crystal layer is driven so as to be positioned, the luminance gradient of each image can be made steep at the boundary between the display areas of the two images, and a double image is generated due to a change in luminance or crosstalk. The boundary area can be narrowed. For this reason, even when the observation position of the observer moves to the left and right, a good image without occurrence of a double image due to a change in luminance or crosstalk can be visually recognized in a wide range.

It is a figure which shows the measured value of the left-right direction light distribution characteristic of a parallax barrier system autostereoscopic display, a geometric optical calculation result, and a wave optical calculation result. It is an enlarged view of the low-intensity part of the measured value of the left-right direction light distribution characteristic of a parallax barrier system autostereoscopic display, a geometric optical calculation result, and a wave optical calculation result. It is a schematic diagram which shows the model of the wave optical calculation for calculating the light distribution characteristic of the display apparatus which has a parallax barrier. It is a perspective view which shows the structure of the display apparatus of Embodiment 1 which concerns on this invention. It is sectional drawing which shows the structure of the display apparatus of Embodiment 1 which concerns on this invention. It is a figure which shows the measured value and wave optical calculation result of the left-right direction light distribution characteristic of 2 image display apparatuses. It is the enlarged view of the boundary part of the measured value of the left-right direction light distribution characteristic of 2 image display apparatuses, and a wave optical calculation result. It is a figure which shows the wave optical calculation result of the light distribution characteristic of the left-right direction at the time of changing the width | variety of the semi-transmissive part of the display apparatus of Embodiment 1 which concerns on this invention. It is an enlarged view of the wave optical calculation result of the light distribution characteristic of the left-right direction at the time of changing the width | variety of the semi-transmissive part of the display apparatus of Embodiment 1 which concerns on this invention. It is a figure which shows the wave optical calculation result of the light distribution characteristic of the left-right direction at the time of changing the transmittance | permeability of the semi-transmissive part of the display apparatus of Embodiment 1 which concerns on this invention. It is a schematic diagram which shows the manufacturing method of the parallax barrier of the display apparatus of Embodiment 1 which concerns on this invention. It is a schematic diagram which shows the manufacturing method of the parallax barrier of the display apparatus of Embodiment 1 which concerns on this invention. It is a schematic diagram which shows the manufacturing method of the parallax barrier of the display apparatus of Embodiment 1 which concerns on this invention. It is a schematic diagram which shows the optical path difference used as the necessary condition of the structure pitch of a semi-transmissive part. It is sectional drawing which shows the structure of the display apparatus of Embodiment 2 which concerns on this invention. It is a schematic diagram which shows operation | movement of the semi-transmissive part of the barrier liquid crystal of the display apparatus of Embodiment 2 which concerns on this invention. It is a schematic diagram explaining the movement operation | movement of the barrier of the display apparatus of Embodiment 2 which concerns on this invention. It is a schematic diagram explaining the movement operation | movement of the barrier of the display apparatus of Embodiment 2 which concerns on this invention. It is a schematic diagram explaining the movement operation | movement of the barrier of the display apparatus of Embodiment 2 which concerns on this invention. It is a figure which shows the geometric optical calculation result and wave optical calculation result of the light distribution characteristic of the left-right direction of a parallax barrier system autostereoscopic display. It is a figure which shows the light distribution characteristic of the left-right direction normalized of the parallax barrier system autostereoscopic display by wave optical calculation. It is a figure which shows how the difference of wave optical calculation and geometric optical calculation changes with structural dimensions. It is a figure which shows the wave optical calculation result of the light distribution characteristic of the left-right direction of the display apparatus of Embodiment 2 which concerns on this invention. It is a figure which shows the wave optical calculation result of the light distribution characteristic of the left-right direction of the display apparatus of Embodiment 2 which concerns on this invention. It is a perspective view which shows the structure of the display apparatus of Embodiment 3 which concerns on this invention. It is a figure which shows the wave optical calculation result of the light distribution characteristic of the left-right direction of the display apparatus of Embodiment 3 which concerns on this invention. It is a figure which shows the wave optical calculation result of the light distribution characteristic of the left-right direction of the display apparatus of Embodiment 3 which concerns on this invention. It is a figure which shows the structure of the permeation | transmission part of the liquid crystal panel of the display apparatus of Embodiment 4 which concerns on this invention. It is a figure which shows typically the optical path of the light which passes the opening of the upper and lower barriers of Embodiment 4 which concerns on this invention. It is a figure which shows thickness distribution of the high refractive index film | membrane in the permeation | transmission part of the liquid crystal panel of Embodiment 4 which concerns on this invention. It is a figure which shows the calculation result of the left-right direction light distribution characteristic by wave optical calculation in case there exists distribution of an average refractive index in the transmission part of the liquid crystal panel of Embodiment 4 which concerns on this invention. It is a figure which shows the structure of the permeation | transmission part of the liquid crystal panel of the display apparatus of Embodiment 4 which concerns on this invention. It is a figure which shows the structure of the permeation | transmission part of the liquid crystal panel of the display apparatus of Embodiment 4 which concerns on this invention. It is a figure which shows the structure of the permeation | transmission part of the liquid crystal panel of the display apparatus of Embodiment 4 which concerns on this invention. It is a perspective view which shows the structure of the permeation | transmission part of the liquid crystal panel of Embodiment 5 which concerns on this invention. It is sectional drawing which shows the structure of the permeation | transmission part of the liquid crystal panel of Embodiment 5 which concerns on this invention. It is a figure which shows the structure undesirable as a permeation | transmission part of a liquid crystal panel. It is a figure which shows the ITO film thickness distribution which produces the phase difference in the case of taking an undesirable structure as a transmission part of a liquid crystal panel. It is a figure which shows the structure of the permeation | transmission part of the liquid crystal panel of Embodiment 5 which concerns on this invention.

<Optical performance prediction by wave optics calculation>
Conventionally, in a parallax barrier type autostereoscopic display and a two-image display device, optical design of light distribution characteristics has been performed by geometrical optical calculation.

FIG. 1 shows measured values of light distribution characteristics in the left-right direction and calculation results by geometric optical calculation of a naked-eye stereoscopic display device having a liquid crystal shutter panel on the front side (image viewing side) of the liquid crystal display panel. It shows the light distribution characteristics when a white image and a black image are displayed in the right eye image and the left eye image, respectively.

Here, the pitch (arrangement interval) of the pixels of the liquid crystal display panel is 0.096 mm, the pitch of the openings of the liquid crystal shutter panel is 0.192 mm, and the distance between the openings of the liquid crystal shutter panel and the pixels is 0.62 mm. is there.

Also, the width of the pixel light emitting portion of the liquid crystal panel is 0.051 mm, the center of the right eye pixel is on the left side -0.048 mm, and the center of the right eye pixel is on the right side of 0.048 mm. The opening width of the liquid crystal shutter panel is 0.062 mm, and is positioned approximately at the center of the right eye pixel and the right eye pixel of the liquid crystal panel. The refractive index of the member is 1.5.

In FIG. 1, the horizontal axis indicates the left-right angle (degrees), and the vertical axis indicates the relative luminance (au .: arbitrary unit), and the measured values and the geometric optical calculation results are almost the same. The shape of the luminance profile is triangular, and the luminance peak is in the direction of 6.5 degrees. The position in the left-right direction of the luminance peak at the viewing distance of 280 mm is close to half of the average interocular distance of 65 mm and is a reasonable value.

Here, the base of the luminance profile is shown in detail in FIG. In FIG. 2, in the geometrical optical calculation, the luminance is 0 in the direction of −1 degree, while the measured value has a base, and there is leakage light. The cause of this mismatch is presumed to be the influence of light scattering and diffraction of the members that are not taken into account in the geometric optical calculation. However, it was not clear to what extent the effect of diffraction.

In view of this situation, a wave optical calculation model was newly created in order to investigate the effect of diffraction on the light distribution characteristics of a display device including a display panel and a parallax barrier panel. A basic principle model of the calculation is shown in FIG.

In FIG. 3, the parallax barrier panel 20 is mounted on the front-side main surface of the display panel 10, and the two openings provided in the display panel light-shielding portion 25 on the front-side main surface of the display panel 10 By transmitting backlight light BL from a backlight (not shown) provided on the back side, a right pixel light emitting portion 11a and a left pixel light emitting portion 11b are formed, and the backlight light BL transmitted through these light emitting portions is transmitted. The parallax barrier panel 20 passes through the transparent glass substrate 24 and is observed on the observation surface 3 through the barrier transmission part 21 provided on the barrier light shielding part 22 on the front main surface of the parallax barrier panel 20. .

The newly devised wave optical calculation model is based on Kirchhoff's diffraction theory, and a wave spreading in a cylindrical plane from a minute region of the right pixel light emitting part 11a and the left pixel light emitting part 11b which are pixels of the display panel 10 This is a two-dimensional model in which secondary element waves are generated from each minute region of the 20 barrier transmission parts 21 and these element waves interfere at one point on the observation surface 3. Here, the wavelength was 550 nm.

The calculation result by this wave optical calculation model is shown by a solid line in FIG. 1 as the wave optical calculation. As shown in FIG. 1, the luminance profile obtained from the wave optical calculation has a triangular shape similar to the measurement value and the geometric optical calculation result, and the angles at which the peaks are made coincide.

Also in FIG. 2 showing the base of the luminance profile in detail, it can be seen that the result of the wave optical calculation indicated by the solid line is the base as in the measurement value, and the influence of diffraction is reproduced.

From the above, it has been found that geometrical optical calculations are insufficient to elucidate the behavior of leaked light in the vicinity of the boundary, and wave optical calculations based on a newly devised wave optical calculation model are effective. In the following, embodiments of the present invention will be described using this wave optical calculation.

<Embodiment 1>
<Device configuration>
FIG. 4 is a schematic perspective view of a two-image display 100 that displays different images depending on the observation direction of the first embodiment according to the present invention. The display panel may be an organic EL panel, a plasma display panel, or a liquid crystal panel, but a liquid crystal panel is shown as an example below.

As shown in FIG. 4, a parallax barrier 12 is disposed on the front surface (image viewing side) main surface of the display panel 10 in which a plurality of pixels are arranged in a matrix. A backlight 30 is provided on the back side of the display panel 10.

In the parallax barrier 12, a plurality of openings of the barrier light-shielding part 122 provided on the front-side main surface of the display panel 10 serve as a barrier transmission part 121. Each of the barrier transmission parts 121 is arranged so that the plan view has a stripe shape and the long sides are arranged in parallel. A barrier semi-transmissive portion 123 is provided along each long side. The configuration of the parallax barrier 12 will be further described with reference to FIG.

Further, in the display panel 10, the plurality of openings of the light shielding portion 115 provided on the liquid crystal layer 114 serve as the pixel light emitting portion 111. Each of the pixel light emitting units 111 is arranged so that the plan view has a stripe shape and the long sides are arranged in parallel. The right-direction pixel light-emitting portions 111a and the left-direction pixel light-emitting portions 111b are alternately arranged. The configuration of the display panel 10 will be further described with reference to FIG.

4 is a schematic diagram for explaining the positional relationship between the backlight, the pixel light emitting unit 111 of the display panel 10 and the opening 121 of the parallax barrier 12, and the position where the semi-transmissive portion 123 is provided. It is the figure which abbreviate | omitted the transparent electrode, transparent glass substrate, etc. which are provided. The pixel light emitting unit 111 of the display panel 10 and the opening 121 of the parallax barrier 12 may be arranged at a predetermined distance, and a medium such as air or glass may exist between them.

FIG. 5 is a cross-sectional view along the arrangement direction of the pixel light emitting units 111 in FIG. As shown in FIG. 5, the display panel 10 is a liquid crystal panel, and is provided on the liquid crystal layer 114 sandwiched between two

transparent glass substrates

14 and 15, and on the back surface side (light source side) main surface of the transparent glass substrate 14. The back polarizing plate 116 and the front polarizing plate 126 provided on the front main surface of the transparent glass substrate 15 are provided.

A transparent electrode 112 divided for each pixel is disposed on the back surface side main surface of the liquid crystal layer 114, and a counter transparent electrode integrally provided over the entire front surface side main surface of the liquid crystal layer 114. 113 is provided, and an electric field is applied to each pixel between both electrodes.

The opening of the light shielding part 115 provided on the counter transparent electrode 113 forms the pixel light emitting part 111. The light shielding portion 115 is provided so as to cover the boundary portion between the adjacent transparent electrodes 112, and prevents leakage light from the pixel boundary.

The parallax barrier 12 is arranged on the main surface on the front side of the transparent glass substrate 15, and a semi-transmissive film 122b having an energy transmittance of 4 to 64% is arranged at an interval. By providing the light-shielding film 122a having a narrow energy transmittance of 0%, the barrier semi-transmissive part 123 and the barrier light-shielding part 122 are formed, and the barrier transmissive part 121 is formed between the adjacent semi-transmissive films 122b. is doing. The front polarizing plate 126 is formed so as to cover the parallax barrier 12.

Here, the barrier light-shielding portions 122 of the parallax barrier 12 are provided at a pitch equal to the arrangement width of the right-side pixel light-emitting portions 111a and the left-direction pixel light-emitting portions 111b of the liquid crystal panel 10.

The width W1 of the barrier semi-transmissive portion 123 extending on the barrier transmissive portion 121 is 0.5 μm to 10 μm, the transmittance is 20 to 80% amplitude transmittance, and 4 to 64% energy transmittance.

The barrier semi-transmissive portion 123 of the parallax barrier 12 is configured so that an additional phase difference of Δnd from 0 to half wavelength (λ / 2) is generated between the barrier semi-transmissive portion 123 and the barrier transmissive portion 121, unlike the barrier transmissive portion 121. You may do it. Here, the additional phase difference Δnd can be set by a combination of the refractive index difference Δn between the semi-transmissive film 121 and the peripheral member and the thickness d of the semi-transmissive film.

In addition, by configuring the barrier semi-transmissive portion 123 to generate an additional phase difference, an effect of steepening the luminance gradient in the boundary direction between the two left and right images can be obtained. Further explanation will be given.

<Optimization of structure by wave optics calculation>
In the two-image display 100 described above, different images are displayed in the left and right directions of 30 degrees, and the wave optical calculation results and measured values for the light distribution characteristics are shown in FIG.

Here, the pitch W2 of the pixels of the liquid crystal panel 10 is 0.064 mm, the pitch W3 of the openings of the parallax barrier 12 is 0.128 mm, and the distance T between the openings of the parallax barrier 12 and the pixels of the liquid crystal panel 10 is 0. It is set to 09 mm. The distance from the liquid crystal panel 10 to the observation surface 31 is 50 mm.

Further, the width W4 of the pixel light emitting unit 111 of the liquid crystal panel is 0.032 mm, the center of the right eye pixel is left-0.032 mm, the center of the right eye pixel is 0.032 mm right, and the parallax barrier 12 The opening width W5 is 0.032 mm, and the opening of the parallax barrier 12 is provided almost above the center of the pair of right-eye pixels and right-eye pixels of the liquid crystal panel 10. Further, the width W6 of the light shielding portion 115 is 0.032 mm.

In FIG. 6, the horizontal axis indicates the left-right angle (degrees), and the vertical axis indicates the relative luminance. The calculated value of the right pixel light-emitting portion obtained by wave optical calculation is calculated R, and the measured value is The measurement value R is the calculated light value of the left pixel light emitting unit L, the measurement value is the measurement L, the light distribution characteristic of the backlight 30 used for the wave optics calculation is also calculated BL, and the measurement value is measured Shown as BL. Here, the calculation is performed on the assumption that the parallel light beams according to the actually measured light distribution characteristics of the backlight light BL of the liquid crystal panel 10 are uniformly incident on the light emitting portion of the liquid crystal panel 10.

As shown in FIG. 6, it can be seen that the actually measured luminance profile and the luminance profile obtained from the wave optics calculation are almost the same.

FIG. 7 shows the profile of the low luminance region (1 × 10 ⁻¹ to 1 × 10 ⁻⁴ ) with the vertical axis as a logarithmic display. It is obtained from the actually measured luminance profile and wave optical calculation in the low luminance region. It can be seen that the obtained luminance profile is almost the same.

Note that the luminance of the wave optical calculation result is lower than the measured value in the direction where the angle is higher than 30 degrees on the left and right. In the actual device, the light emitting pixels of the liquid crystal panel 10 and the opening of the parallax barrier 12 are in the horizontal direction. This is because, in the wave optical calculation, only a single light emitting pixel and the opening of the parallax barrier are taken into consideration.

Therefore, considering that the light passing through the opening of another parallax barrier is superimposed on the result of the wave optical calculation in a direction with an angle higher than 30 degrees on the left and right, the measured value and the result of the wave optical calculation are It matches well.

In this way, the brightness profile obtained from the wave optics calculation reproduces the brightness profile of the measured boundary area well, and this wave optics calculation is effective for analyzing the brightness profile of the boundary area and the low brightness area. I understand.

Generally, in the two-image display, the following two characteristics are important. The first is to make the boundary area where two images appear to be mixed as narrow as possible, and the second is to eliminate the reflection of the image in the other direction even when a dark image is displayed in the image in the observation direction. In other words, the ratio of leakage light to the peak luminance of the original display image is suppressed to about 1/1000 or less.

As shown in FIG. 7, the leakage light luminance due to diffraction of the image in the other direction is about 1/1000 of the peak luminance even in the 30 ° right and left direction near the peak of the display light. It has been found necessary to suppress this.

FIG. 8 shows a calculation result of the light distribution characteristics of the two-image display 100 according to the first embodiment of the present invention by wave optical calculation. In FIG. 8, the width of the opening of the parallax barrier 12 is 32.2 μm. The brightness profiles calculated by changing the width of the barrier semi-transmissive portion 123 in various ways assuming that the barrier semi-transmissive portion 123 having an energy transmittance of 16% is provided on the left and right of the barrier transmissive portion 121 are shown.

In FIG. 8, the horizontal axis indicates the left-right angle (degrees), and the vertical axis indicates the leakage light luminance. When the width of the barrier semi-transmissive portion 123 is 0, 0.5 μm, 1.0 μm, The luminance profiles for 2.5 μm, 5.0 μm, 7.5 μm, and 10 μm are shown.

8 that the leakage light intensity in the left and right 30 directions is halved when the width of the barrier semi-transmissive portion 123 is 0.5 μm or more, compared to the case where the barrier semi-transmissive portion 123 indicated by the solid line is not provided.

FIG. 9 shows an enlarged view of the left and right borders. From FIG. 9, the luminance gradient at the left and right boundary portions becomes steeper as the width of the barrier semi-transmissive portion 123 increases, and becomes maximum when the width is 5 μm. It can be seen that when the width of the barrier semi-transmissive portion 123 is further increased, the maximum luminance gradient gradually decreases, and at the same time, the angle at which the maximum luminance gradient is generated is shifted in the display direction of other images, and the luminance gradient in the front direction is decreased.

Therefore, in order to increase the luminance gradient in the front direction when the width of the barrier semi-transmissive portion 123 is wider than 5 μm, the width of the barrier transmissive portion 121 is reduced to about the width of the barrier semi-transmissive portion 123. Is required.

Next, FIG. 10 shows the calculation result of the luminance profile by wave optical calculation when the width of the barrier semi-transmitting portion 123 is fixed to 5 μm and the energy transmittance is variously changed.

In FIG. 10, the horizontal axis indicates the left-right angle (degrees), and the vertical axis indicates the leakage light luminance. When the energy transmittance of the barrier semi-transmissive portion 123 is 0, 0.04 (4%), The brightness profiles in the case of 0.16 (16%), 0.36 (36%), and 0.64 (64%) are shown, respectively.

As shown in FIG. 10, the leakage light luminance in the direction of 30 degrees to the left and right is the minimum when the energy transmittance is between 16% and 36%, and the maximum luminance gradient in the boundary direction is the steepest around 16%. I understand.

As described above, in the two-image display 100 according to the first embodiment, the parallax barrier 12 is provided with the barrier semi-transmissive portion 123. The barrier semi-transmissive portion 123 has a width of 0.5 μm or more and an energy transmittance of 4 to 64%. By doing so, it is possible to suppress the leakage light luminance in the left and right directions by 30 degrees, and to make the luminance gradient in the boundary direction between the left and right images steep. For this reason, it is possible to narrow a boundary region where a double image is generated due to a change in luminance or crosstalk, and even if the observer's observation position moves to the left or right, a double image due to a change in luminance or crosstalk over a wide range. It is possible to visually recognize a good image without occurrence of. It is most preferable that the barrier semi-transmissive portion 123 has a width of 2.5 to 5 μm and an energy transmittance of 16 to 36%.

<Barrier translucent part manufacturing method 1>
Next, the manufacturing method of a barrier semi-transmissive part is demonstrated using FIG. First, as shown in part (a) of FIG. 11, a sputtering mask 151 is disposed above the main surface of the transparent glass substrate 15. Then, from the upper side of the sputtering mask 151, chromium oxide or graphite, which is a material of the barrier semi-transmissive portion 123, is blown by a sputtering method and adhered onto the main surface of the transparent glass substrate 15, thereby forming the semi-transmissive film 122 b. The transmissivity of the semipermeable membrane 122b is 4 to 64%. The energy transmittance is controlled by controlling the film thickness of the semi-transmissive film 122b.

Here, the sputtering mask 151 has a pattern in which the upper part of the transparent glass substrate 15 that becomes the barrier transmission part 121 is masked and the part where the semi-transmissive film 122b is formed becomes an opening.

Next, after removing the sputtering mask 151, a sputtering mask 152 is formed above the main surface of the transparent glass substrate 15 as shown in FIG. Then, from above the sputtering mask 152, chromium oxide serving as the material of the barrier light-shielding portion 122 is blown off by a sputtering method and deposited on the semi-transmissive film 122b, thereby forming a light-shielding film 122a having an energy transmittance of 0%. Here, the sputtering mask 152 has a pattern in which only a portion where the light shielding film 122a is formed becomes an opening, and the other portion is masked.

Through the above steps, the barrier semi-transmissive portion 123 and the barrier light-shielding portion 122 are formed, and the barrier transmissive portion 121 is formed between the adjacent barrier semi-transmissive portions 123. Here, the mask sputtering method has been described as an example of the method for forming the light shielding film 122a and the semi-transmissive film 122b. However, the method is not limited to this, and the light shielding film 122a and the semi-transmissive film 122b can also be formed by a pad printing method or the like.

<Manufacturing method 2 of a barrier translucent part>
In the method for manufacturing the barrier semi-transmissive portion described with reference to FIG. 11, an example in which two sputtering masks are used for forming the barrier semi-transmissive portion 123 has been described. Is required.

Therefore, as another example of the manufacturing method of the barrier semi-transmissive portion, a method of forming the barrier semi-transmissive portion 123 with one sputtering mask will be described with reference to FIG.

First, as shown in part (a) of FIG. 12, a sputtering mask 153 is formed on the main surface of the transparent glass substrate 15. Then, from the diagonally upper side of the sputtering mask 153, chromium oxide serving as the material of the barrier semi-transmissive portion 123 is blown off by a sputtering method and deposited on the main surface of the transparent glass substrate 15, thereby forming the semi-transmissive film 122c. The energy transmittance of the semipermeable membrane 122c is 4 to 64%. The energy transmittance is controlled by controlling the film thickness of the semi-transmissive film 122c.

In this case, the semi-transmissive film 122c extends to below the edge of the sputtering mask 153 in the flying direction of the sputtering material. On the other hand, the semi-transmissive film 122c does not extend below the edge of the sputtering mask 153 in the direction opposite to the direction in which the sputtering material comes in.

Next, from the diagonally upper side opposite to the sputtering mask 153, chromium oxide, which is a material of the barrier semi-transmissive portion 123, is blown by a sputtering method to adhere to the main surface of the transparent glass substrate 15, thereby forming the semi-transmissive film 122d. To do. The energy transmittance of the semipermeable membrane 122d is 4 to 64%, which is the same as that of the semipermeable membrane 122c. The energy transmittance is controlled by controlling the film thickness of the semi-transmissive film 122d.

In this case, the semi-transmissive film 122d is formed on the semi-transmissive film 122c and extends to below the edge portion of the sputtering mask 153 in the flying direction of the sputtering material. On the other hand, the semi-transmissive film 122d does not extend below the edge of the sputtering mask 153 in the direction opposite to the flying direction of the sputtering material.

As a result, it has a central portion where the semipermeable membrane 122c and the semipermeable membrane 122d overlap each other and an edge portion where only the semipermeable membrane 122c or the semipermeable membrane 122d is formed. The central portion serves as a barrier light shielding portion 122 and the edge portion serves as a barrier semi-transmissive portion 123.

As described above, the barrier light-shielding part 122 and the barrier semi-transmissive part 123 can be formed with one sputtering mask by performing the sputtering twice from the oblique direction.

In this case, since the sputtering mask 153 is common, the problem of alignment accuracy can be solved, and the manufacturing cost can be reduced by reducing the types of masks.

However, since the restriction that the film thickness of the barrier semi-transmissive portion 123 is only half the film thickness of the light shielding portion 122 occurs, the transmittance of the light shielding portion 122 is only the square of the barrier semi-transmissive portion 123. For example, when the transmittance of the barrier semi-transmissive portion 123 is 0.1 (10%), the transmittance of the light shielding portion 122 is 0.01 (1%).

<Method 3 for producing a barrier semi-transmissive portion>
The manufacturing method of the barrier semi-transmissive portion described above is a manufacturing method for a configuration in which the barrier semi-transmissive portion 123 is provided along the long side of the stripe-shaped barrier transmissive portion 121, and the shape of the barrier semi-transmissive portion 123 is also configured. It was striped.

However, as shown in FIG. 13, a barrier semi-transmissive portion 124 in which fine openings and barrier light shielding portions 122 are alternately arranged may be employed.

In FIG. 13, in the light shielding film that forms the barrier light shielding part 122, when the arrangement direction of the barrier transmissive part 121 is the left-right direction, a plurality of fine openings 125 arranged in the vertical direction perpendicular to the barrier transmissive part 121 are arranged. Are formed along the two long sides. As a result, a barrier semi-transmissive portion 124 in which the structure in which the fine opening 125 is a concave portion and the barrier light-shielding portion 122 is a protrusion is alternately obtained is obtained.

At this time, if the pitch P of the fine openings 125 is sufficiently small, the effective energy transmittance of the semi-transmissive portion can be adjusted to the average value of the light shielding area and the opening area.

Here, the required pitch P will be described with reference to FIG. As shown in FIG. 14, when considering a model in which light emitted from a pixel point G of the display panel 10 travels in the Z-axis direction (vertical direction) and reaches the point B of the parallax barrier 12, the light goes straight to the vertical direction. The optical path difference dL when reaching the point B ′ shifted by the pitch P in the X-axis direction is T when the distance between the pixel point G of the liquid crystal display panel 10 and the parallax barrier 12 is T, and the refractive index of the optical path is n. It is approximately expressed by the following formula (1).

dL = 4 × P × P / T (1)
Here, in order for the barrier semi-transmissive portion 124 to be regarded as a region having a uniform transmittance, the phase difference is small, that is, the optical path difference dL is sufficiently smaller than the wavelength of light (for example, about 1/10). is necessary. In order to satisfy this, it is necessary to satisfy the following formula (2).

P <2 × (wavelength / refractive index / 10 × T) ^0.5 (2)
In the above formula, for example, when the wavelength is 550 nm (0.55 μm), T = 80 μm, and n = 1.5 are substituted, the following formula (3) is obtained.

P <2 × (0.55 / 1.5 / 10 × 80) ^0.5 = 3.4 μm (3)
That is, when the pitch P of the fine openings 125 is 2 μm or less, the barrier semi-transmissive portion 124 functions as a semi-transmissive portion having an effectively uniform transmittance. Similarly, when the distance T between the pixel point G of the liquid crystal display panel 10 and the parallax barrier 12 is as thick as 720 μm, if the pitch P of the fine openings 125 is 10 μm or less, the barrier semi-transmissive portion 124 is effectively transmitted. It will function as a semi-transmissive part with a uniform rate.

With such a barrier semi-transmissive portion 124, it is not necessary to form a semi-transmissive film on the transparent glass substrate 15, and it is only necessary to form the barrier light-shielding portion 122. Therefore, the thickness of the semi-transmissive film and the alignment of the mask are adjusted. High accuracy is not required, and the manufacturing process can be simplified.

Note that the pitch P of the fine openings 125 only needs to satisfy the above formulas (1) to (3), and does not need to be uniform and may be random. Further, the openings may be in the form of polka dots isolated from each other.

<Embodiment 2>
<Device configuration>
FIG. 15 shows a cross-sectional configuration of the autostereoscopic display 200 according to the second embodiment of the present invention. As shown in FIG. 15, the autostereoscopic display 200 includes a display panel 210, a parallax barrier shutter panel 220 disposed on the front surface (image viewing side) main surface of the display panel 210, and the rear surface side of the display panel 210 ( A backlight 23 is provided on the light source side.

Although the display panel 210 is a matrix type display panel, the display panel 210 may be an organic EL panel, a plasma display panel, or a liquid crystal panel, but a liquid crystal panel is shown below as an example.

As shown in FIG. 15, the display panel 210 is a liquid crystal panel, a liquid crystal layer 214 sandwiched between two transparent glass substrates 204 and the transparent glass substrate 205, and the back side (light source side) of the transparent glass substrate 204. A back polarizing plate 216 provided on the surface and an intermediate polarizing plate 217 provided on the front main surface of the transparent glass substrate 205 are provided.

In addition, a counter transparent electrode 215 that is integrally provided over the entire surface is disposed on the main surface on the back surface side of the liquid crystal layer 214, and is divided for each pixel on the main surface on the front surface side of the liquid crystal layer 114. A sub-pixel transparent electrode 212 is provided, and an electric field is applied to each pixel between both electrodes.

The subpixel transparent electrode 212 is divided by a light shielding wall 218, and the subpixel upper polarizing plate 219 is provided on the subpixel transparent electrode 212, but the subpixel upper polarizing plate 219 is also divided by the light shielding wall 218. ing.

Corresponding to the subpixel transparent electrode 212 divided by the light shielding wall 218, subpixels 2110 to 2114 are formed in the horizontal direction (horizontal direction). Then, for example, by combining two sub-pixels of the adjacent sub-pixel 2111 and sub-pixel 2112, a sub-pixel pair 241 that displays different parallax images in the right direction and the left direction is configured. Further, by combining two sub-pixels of the adjacent sub-pixel 2113 and sub-pixel 2114, a sub-pixel pair 242 that displays different parallax images in the right direction and the left direction is configured.

The parallax barrier shutter panel 220 is provided on the liquid crystal layer 224 sandwiched between the transparent glass substrate 222 (first transparent substrate) and the transparent glass substrate 226 (second transparent substrate), and the front-side main surface of the transparent glass substrate 222. And a display surface polarizing plate 228. Note that a polarizing plate is also provided on the main surface of the transparent glass substrate 226 on the display panel 210 side, but is omitted here as being also used as the intermediate polarizing plate 217.

Here, as the mode of the liquid crystal layer 224, twisted nematic (TN), super twisted nematic (STN), in-plane switching (IPS), optically compensated bend (OCB), or the like can be used.

Further, a transparent electrode 225 (second transparent electrode) provided integrally on the entire rear surface side of the liquid crystal layer 224 is disposed, and a transparent electrode 225 (second transparent electrode) is provided over the entire surface. An electrode 223 is provided.

The reference parallax barrier pitch is defined by a length corresponding to the arrangement width of each sub-pixel pair, and the transparent electrode 223 is divided into a plurality of electrically insulated states within the reference parallax barrier pitch. Although FIG. 15 shows an example of eight divisions, the present invention is not limited to this, and the number of divisions may be larger. Each of the divided transparent electrodes 223 becomes a sub opening 301, and the width of the sub opening 301 becomes a sub opening pitch.

Here, the virtual light LO that has exited from the center of the light shielding wall 218 in the middle of the sub-pixels 2111 and 2112 constituting the sub-pixel pair 241 and passed through the center point within the corresponding reference parallax barrier pitch is the present display device. The reference parallax barrier pitch is set so as to gather at the design visual recognition point Q set in front of.

In the parallax barrier shutter panel 220 configured in this manner, by applying an electric field to the liquid crystal layer 224 using the transparent electrode 223 and the transparent electrode 225, the plurality of sub-openings 301 are alternately set in a light transmission state, a light shielding state, and a half state. It can be switched to a transparent state.

An example of the operation state of the parallax barrier shutter panel 210 will be described with reference to FIG. 16 further schematically illustrates the autostereoscopic display 200 illustrated in FIG.

In FIG. 16, four of the eight sub-openings 301 within the reference parallax barrier pitch are in a transmissive state to form a transmissive portion 321, and two on both sides thereof are in a semi-transmissive state to form a semi-transmissive portion 323. The liquid crystal is controlled by applying an electric field to the liquid crystal layer 224 using the respective transparent electrodes 223 so that the remaining two are in a light-shielding state to form the light-shielding portion 322. Note that a light emitting portion in the liquid crystal layer 214 in the display panel 210 is shown as a display pixel light emitting portion 211. Note that a light shielding portion (not shown) is disposed on the liquid crystal layer 214 with an interval therebetween, and no light is emitted from the light shielding portion, so that the display pixel light emitting portion 211 exists in a scattered manner.

Here, in addition to the birefringence due to the alignment state of the liquid crystal layer in the semi-transmissive portion 323, if the refractive index change Δn and the thickness d of the liquid crystal layer are appropriately selected, the transmittance of the semi-transmissive portion 323 is lowered and the transmissive portion 321 is also obtained. It is also possible to generate a phase difference (additional phase difference) of Δnd as a phase difference from the light that has passed through.

Next, an example of the operation pattern of the sub opening 301 of the parallax barrier shutter panel 220 will be described with reference to FIGS.

17 to 19 show an arrangement of twelve sub-openings 301 as a part of the plurality of sub-openings 301, and reference numerals 1 to 8 are given in order from the left side in the drawing. The code is repeated from the sub-opening 301 on the right side of the eighth sub-opening 301.

FIG. 17 shows a pattern in which all the sub-openings 301 are in a transmissive state. In part (a) of FIG. 18, as pattern 1, four consecutive 1 to 4 of the eight sub-openings 301 within the reference parallax barrier pitch are in a light transmission state, and 5 and 8 are in a semi-transmission state. In addition, by making 6 and 7 light-shielded, a pattern having transmissive portions 321 on the left and right is formed.

18B shows a pattern 2 in which

patterns

7 and 8 are in a light-shielded state, 1 and 6 are in a semi-transmissive state, and the rest are in a transmissive state.

18C shows a pattern 3 in which 8 and 1 are in a light-shielding state, 7 and 2 are in a semi-transmissive state, and the rest are in a transmissive state.

18D shows a pattern 4 in which 1 and 2 are in a light-shielding state, 8 and 3 are in a semi-transmissive state, and the rest are in a transmissive state.

19A shows a pattern 5 in which 2 and 3 are in a light-shielded state, 1 and 4 are in a semi-transmissive state, and the rest are in a transmissive state.

19B shows a pattern 6 in which 3 and 4 are in a light-shielding state, 5 and 2 are in a semi-transmissive state, and the rest are in a transmissive state.

19C shows a pattern 7 in which 4 and 5 are in a light-shielding state, 6 and 3 are in a semi-transmissive state, and the rest are in a transmissive state.

19D shows a pattern 8 in which 5 and 6 are in a light shielding state, 4 and 7 are in a semi-transmissive state, and the rest are in a transmissive state.

As in the patterns 2 to 8 described above, the position of the transmission part 321 can be moved at the pitch of the sub-opening part 301 by selecting the sub-opening part 301 to be in the light transmission state and the semi-transmission state.

<Light distribution characteristics in general autostereoscopic displays>
In a typical autostereoscopic display using a parallax barrier, the results of geometric and wave optics calculations for the light distribution characteristics when a white image and a black image are displayed on the image for the right eye and the image for the left eye, respectively. It shows in FIG.

Here, the pitch of the pixels of the liquid crystal panel is 0.069 mm, the pitch of the openings of the liquid crystal shutter panel is 0.138 mm, and the distance between the openings of the liquid crystal shutter panel and the pixels is 1.224 mm.

Further, the center of the right-eye pixel of the liquid crystal panel is at the left of −0.034 mm, the center of the right-eye pixel is at the right of 0.034 mm, and the opening width of the liquid crystal shutter panel is 0.069 mm. Is located approximately above the center of the pair of right-eye pixels and left-eye pixels of the liquid crystal panel.

FIG. 20 shows the result of calculating the light distribution characteristics with various aperture widths of the pixels of the display panel, the refractive index of the transparent glass member is 1.5, and the wavelength at the time of wave optical calculation is It is 550 nm. The calculation result is a relative luminance distribution on a screen located at a design observation distance of 750 mm from the liquid crystal shutter panel. In the figure, the geometric optical calculation result appears as a straight line, and the wave optical calculation result appears as a curve.

In FIG. 20, the horizontal axis represents the observation position (mm) on the screen, and the vertical axis represents the relative luminance. When the aperture width of the pixel of the display panel is 34.2 μm, 27.3 μm, 20. The geometric optical calculation result and the wave optical calculation result are shown for the cases of 5 μm, 13.7 μm, and 6.8 μm, respectively.

From FIG. 20, it is expected from the geometric optical calculation result that the luminance peak is lowered and the flat portion of the luminance is widened as the aperture width of the pixel of the display panel is reduced, so that the viewing area with uniform luminance is expanded. Furthermore, it is expected that the light leakage area to the other direction image display area on the left side of the boundary portion is narrowed and the boundary area is reduced.

However, the results of wave optics calculations are different. Although the luminance peak decreases as the aperture width of the pixel of the display panel decreases, a large distribution occurs because a plurality of peaks appear, and the width of the luminance peak area is also narrower than the geometric optical calculation result.

Here, FIG. 21 shows a profile obtained by normalizing the luminance profile in FIG. 20 with the peak luminance, and the vertical axis represents the normalized relative luminance.

From FIG. 21, it is found that the light leaking range to the other direction image display area on the left side of the boundary portion does not differ as much as expected from geometric optical calculation even if the aperture width of the pixel is narrowed to 6.8 μm. did.

FIG. 22 shows the calculation results obtained by examining how the difference between the wave optical calculation and the geometric optical calculation differs depending on the structural dimensions. As calculated in FIG. 20, the pixel pitch of the liquid crystal panel is 0.069 mm, the pitch of the opening of the liquid crystal shutter panel is 0.138 mm, and the distance between the opening of the liquid crystal shutter panel and the pixel is 1.224 mm. The center of the pixel for the right eye of the panel is at the left -0.034 mm, the center of the pixel for the right eye is at the right of 0.034 mm, the opening width of the liquid crystal shutter panel is 0.069 mm, and the opening is formed in the liquid crystal panel. The reference structure is assumed to be located approximately above the center of the pair of right-eye pixels and left-eye pixels, and the display panel pixel aperture width is 34.2 μm. FIG. 22 shows calculation results when the reference structure is similarly changed to 1/2 times, 2 times, and 4 times.

In FIG. 22, the refractive index of the transparent glass member is 1.5, and the wavelength of light is 550 nm. The calculation result is a relative luminance distribution (au) on the screen at a design observation distance of 750 mm from the liquid crystal shutter panel. In the figure, the geometric optical calculation result appears as a straight line, and the wave optical calculation result appears as a curve.

As shown in FIG. 22, in the structure that is similarly magnified 4 times, the result of the wave optical calculation is greatly different from the result of the geometric optical calculation indicated by the solid line in terms of the luminance at the 0 mm point and the flatness of the peak. However, it can be seen that the difference between the result of the wave optical calculation and the result of the geometric optical calculation becomes larger as the size is similarly reduced. In a similar doubled structure, the results of wave optics calculations show that the peak brightness variation exceeds 10%, and the brightness at the geometrical optics calculation is 0—the brightness at the 10 mm point exceeds 10% of the peak. ing. Therefore, a structure that is similarly magnified four times eliminates the difference from geometric optical calculation and loses the merit of using wave optical calculation. In other words, if the similar dimension is less than 4 times, it can be said that there is an advantage of using wave optical calculation. In terms of specific dimensions, in view of 0.138 mm, which is twice the 0.069 mm liquid crystal shutter panel opening width behind the optical path, which is more influenced by the principle of wave optics, the opening width closer to the observer is smaller. If it is smaller than 0.138 mm, it is effective to adjust the luminance profile using wave optics calculation.

Therefore, in view of the above, a method for adjusting a luminance profile in consideration of diffraction will be described below.

<Light distribution characteristics in autostereoscopic display according to the present invention>
Next, wave optical calculation results of light distribution characteristics in the autostereoscopic display 200 according to the second embodiment of the present invention will be described with reference to FIG.

In the following, the pitch of the sub-openings 301 was calculated for the case where the reference parallax barrier pitch was divided into 16 (in FIGS. 15 and 16, the case of 8 equal parts was shown). The pixel pitch W12 of the liquid crystal display panel 210 is 0.069 mm, the pitch of the transmission part 321 of the liquid crystal shutter panel 220 is 0.138 mm, and the distance DB between the transmission part 321 of the liquid crystal shutter panel 220 and the pixel of the liquid crystal panel 210 is 1.224 mm.

The width of the display pixel light emitting section 211 of the liquid crystal panel 210 is 20.5 μm, the center of the right eye pixel is at the left end of −0.034 mm, and the center of the right eye pixel is at 0.034 mm on the right.

The width W13 (barrier opening width) of the transmissive portion 321 of the liquid crystal shutter panel 220 is 0.069 mm (68.5 μm), which is the sum of the widths of the eight

sub-openings

301, and 8 on one side of the sub-opening portion. A semi-transmissive portion 323 of .5 μm exists, and is positioned almost above the center of the pair of right-eye pixels and right-eye pixels of the liquid crystal panel 210.

FIG. 23 shows the results of calculating the light distribution characteristics by changing the transmittance and additional phase of the semi-transmissive portion 323 in various ways. The refractive index of the transparent glass member is 1.5, and the wave optical calculation is performed. The wavelength at that time is 550 nm. The light distribution characteristics when a white image and a black image are displayed in the right-eye image and the left-eye image, respectively, are shown. The calculation result is at a design observation distance DS = 750 mm away from the liquid crystal shutter panel 220. It is a relative luminance distribution on a certain screen.

In FIG. 23, the horizontal axis represents the observation position (mm) on the screen, and the vertical axis represents the relative luminance. In the figure, the phase of light passing through the semi-transmissive portion 323 (width 8.5 μm) is the transmissive portion. Various calculation results when the energy transmittance is 6%, 25%, and 56% are assumed to travel a distance longer by 1/4 wavelength as an additional phase difference than when passing through 321 (width 68.5 μm). Shown with a chain line. Further, the case where there is no semi-transmissive portion 323 and the transmissive portion 321 is correspondingly wide (barrier opening width is 85.6 μm) is indicated by a thick chain line, and the semi-transmissive portion 323 is absent and the transmissive portion 321 remains 68.5 μm. The profile of the case is shown by a solid line.

In FIG. 23, compared to the case where the semi-transmissive portion 323 indicated by the solid line is not present, the luminance gradient is steep in both cases when the semi-transmissive portion 323 is present, and the leakage light at the −10 mm point can be suppressed. You can see that However, when the transmittance is 56%, the amount of light leaked at a point of −30 mm is increased. Under this condition, it can be seen that a transmittance of about 25% is suitable.

FIG. 24 shows the calculation result showing the effect of the additional phase difference generated when passing through the semi-transmissive portion 323 when the energy transmittance of the semi-transmissive portion 323 is 25%, when there is no additional phase difference. It is shown together with (in the case of 0).

In FIG. 24, the horizontal axis indicates the observation position (mm) on the screen, and the vertical axis indicates the relative luminance, and the case where the phase advances by a quarter wavelength (−λ /) as compared with the case where it passes through the transmission part 321. 4) shows a case where the phase advances by 1/2 wavelength (-λ / 2), a case where the phase advances by 3/4 wavelength (-λ3 / 4), and a case where the phase difference is zero.

From FIG. 24, it can be seen that when the light advances by λ / 4 as compared with the case where the light passes through the transmission part 321 (when the phase difference is 0), the gradient of the boundary part is steep and the luminance of the leaked light in the direction of 20 degrees is low. I understand.

As described above, in the autostereoscopic display 200 according to the second embodiment, the liquid crystal shutter panel 220 is provided with the semi-transmissive portion 323, the transmittance of the semi-transmissive portion 323 is about 25%, and the light passes through the transmissive portion 321. By configuring the semi-transmissive portion 323 so as to proceed by λ / 4 as compared with the above, it is possible to suppress the leakage light luminance in the right and left 20 degrees direction and to make the luminance gradient in the boundary direction steep. For this reason, it is possible to narrow a boundary region where a double image is generated due to a change in luminance or crosstalk, and a double image due to a change in luminance or crosstalk over a wide range when the observer's observation position moves to the left or right. It is possible to visually recognize a good image without occurrence of.

In the above calculation, the preferred size is discussed for green light with a wavelength of 550 nm. However, red light (wavelength 650 nm) and blue light (wavelength 450 nm) have different wavelengths and are suitable for controlling leakage light. The size is different. Therefore, it is also possible to eliminate the color of leakage light by changing the size of the semi-transmissive portion of the parallax barrier according to the color of the target pixel.

In the above description, the configuration of the parallax barrier is an elongated stripe shape and the long sides are arranged in parallel. However, it is needless to say that the parallax barrier can be applied to a staggered arrangement (checker flag pattern shape). . In the case of the staggered arrangement, the resolution of the stereoscopic image is improved.

In addition, the number of direction-specific images has been described by taking the case of two as an example. However, the present invention is not limited to this, and even when there are three or more parallax images, the luminance of the leaked light is suppressed at each image boundary. There is an effect to.

<Embodiment 3>
<Device configuration>
In Embodiment 1 according to the present invention described above, a display device including a display panel in which pixels are arranged in a matrix and a parallax barrier formed on the front side (image viewing side) of the display panel will be described as an example. However, when the display panel is a liquid crystal display panel, the present invention can also be applied to an apparatus having a parallax barrier on the back side of the display panel.

FIG. 25 is a schematic perspective view of a two-image display 300 that displays different images depending on the observation direction according to the third embodiment of the present invention.

As shown in FIG. 25, a parallax barrier 42 is disposed on the back side of the display panel 41 in which a plurality of pixels are arranged in a matrix. A backlight 43 is provided on the back side of the parallax barrier 42.

Further, in the display panel 41, a plurality of openings of the light shielding part 412 provided on the liquid crystal layer 410 serve as a pixel transmission part 411. All of the pixel transmission portions 411 are arranged so that the plan view has a stripe shape and the long sides are arranged in parallel. A semi-transmissive portion 413 is provided along each long side.

In the parallax barrier 42, a plurality of openings of the barrier light shielding part 422 are barrier transmission parts 421. All of the barrier transmission parts 421 are arranged so that the plan view has a stripe shape and the long sides are arranged in parallel.

FIG. 25 is a schematic diagram for explaining the positional relationship between the backlight 43, the pixel transmission unit 411 and the parallax barrier transmission unit 421 of the display panel 41, and omits transparent electrodes, transparent glass substrates, and the like provided in the display panel. It has become the figure. In addition, the pixel transmission unit 411 and the parallax barrier transmission unit 421 of the display panel 41 are arranged at a predetermined distance from each other, and a medium such as air or glass may be present therebetween.

FIG. 25 is a schematic diagram for explaining the positional relationship between the backlight, the display panel, and the parallax barrier, and the position where the semi-transmissive portion is provided, in which the transparent electrode and the transparent glass substrate provided on the display panel are omitted. It has become. Further, the backlight, the display panel, and the parallax barrier may be in close contact with each other, or a medium such as air or glass may be present therebetween.

The width of the semi-transmissive portion 413 of the liquid crystal display panel 41 is 0.5 μm to 10 μm, the transmittance is 20 to 80% amplitude transmittance, and the energy transmittance is about 4 to 64%. Further, the semi-transmissive portion 413 has a refractive index different from that of the transmissive portion 411, and is configured such that a phase difference of Δnd from 0 to a half wavelength is generated between the semi-transmissive portion 413 and the transmissive portion 411.

Thus, also in the display panel 41 in which pixels are arranged in a matrix and the display device in which the parallax barrier 42 is formed on the back surface side of the display panel 41, the semi-transmissive portion 413 is provided on the long side of the transmissive portion 411 of the display panel 41. By providing, the luminance gradient at the boundary portion of the image can be made steep.

FIG. 26 shows a wave optical calculation result of the light distribution characteristics in the two-image display 300 according to the third embodiment of the present invention.

In the following, the pixel pitch of the display panel 41 is 0.069 mm, the pitch of the barrier transmission part 421 of the parallax barrier 42 is 0.138 mm, and the transmission part 411 of the display panel 41 and the barrier transmission part 421 of the parallax barrier 42 are The distance between is 1.224 mm.

The center position of the transmissive portion 411 of the display panel 41 is -0.034 mm for the left eye pixel and 0.034 mm for the right eye pixel. The width of the barrier transmission part 421 of the parallax barrier 42 is 0.069 mm.

In FIG. 26, the energy transmittance of the semi-transmissive portion 413 provided on the left and right of the transmissive portion 411 and the additional phase difference added compared to the case where the phase of the light passing through the semi-transmissive portion 413 passes through the transmissive portion 411. The light distribution characteristics when Δnd is varied are calculated, the refractive index of the transparent glass member is 1.5, and the wavelength in the wave optical calculation is 550 nm. The calculation result is a relative luminance distribution on a screen located at a design observation distance of 750 mm from the liquid crystal shutter panel. FIG. 27 shows a normalized relative luminance profile obtained by normalizing each luminance profile with peak luminance.

Here, the additional phase difference Δnd can be set by a combination of the refractive index change Δn and the thickness d of the liquid crystal layer. Since the thickness d of the liquid crystal layer is fixed, in order to make the refractive index of the semi-transmissive portion 413 different from that of the transmissive portion 411, the thickness of the ITO (Indium Tin Oxide) electrode having a larger refractive index than that of the liquid crystal. What is necessary is just to employ | adopt the structure that it is set as a different value by the semi-transmissive part 413 and the transmissive part 411.

26 and 27, the horizontal axis indicates the observation position (mm) on the screen, and the vertical axis indicates the relative luminance. In the drawing, there is no transflective portion 413, and the transmitting portion 411 is 34.3 μm). The case is indicated by a thick chain line, the case where there is no transflective portion 413 and the transmission portion 411 is 27.4 μm is indicated by a solid line, the width of the transflective portion 413 is 5 μm, the transmittance is 25%, and an additional phase difference (Δnd) Λ / 4 is indicated by a broken line, and a case where the width of the semi-transmissive portion 413 is 5 μm, the transmittance is 25%, and the additional phase difference (Δnd) is 0 is indicated by a chain line.

In FIG. 27, when the transmittance is 25% and the additional phase difference (Δnd) is λ / 4, the luminance gradient at the boundary portion is not greatly reduced as compared with the case where the semi-transmissive portion 413 indicated by the solid line is not provided. Is steep, and it can be seen that leakage light at a point of −10 mm can be suppressed.

Further, when the transmissivity of the semi-transmissive portion 413 is 25% and the additional phase difference (Δnd) is 0, the peak luminance is not greatly reduced as compared with the case where the semi-transmissive portion 413 indicated by the solid line is not present, at the point of −30 mm. It can be seen that the leakage light of the light can be suppressed.

As described above, suitable light leakage characteristics can be obtained by appropriately setting the transmittance of the semi-transmissive portion 413 and the additional phase difference (Δnd) according to the configuration of the display device.

<Embodiment 4>
In Embodiment 4 according to the present invention, a specific configuration of the liquid crystal display panel in the apparatus described in Embodiment 3 in which the display panel is a liquid crystal display panel and the parallax barrier is on the back side of the display panel will be described. To do.

FIG. 28 is a diagram showing an example of a specific configuration of the transmissive portion 411 of the display panel 41 shown in FIG. 25. FIG. 28 (a) is a plan view, and FIG. 28 (b) is a plan view. FIG. 2 is a cross-sectional view taken along line AA in the plan view.

As shown in part (a) of FIG. 28, the planar shape of the transmission part 411 is a vertically long rectangular shape, and a semi-transmissive film 1413 is provided along the two long sides. A light shielding film 1412 is formed around the transmission part 411 including the semi-transmissive film 1413.

As shown in FIG. 28B, the liquid crystal layer 1422 is sandwiched between the lower transparent substrate 1400 and the upper transparent substrate 1450, and the pixel electrode 1423 is disposed on the lower transparent substrate 1400. A counter electrode 1421 is disposed on the upper transparent substrate 1450, and both are disposed to face each other with a liquid crystal layer 1422 therebetween. The pixel electrode 1423 is provided independently for each transmissive portion (also referred to as an upper opening) 411 and is provided at least in a region corresponding to the lower portion of the upper opening 411. The counter electrode 1421 is provided on the entire upper transparent substrate 1450. Further, on the lower main surface of the lower transparent substrate 1400 (the main surface opposite to the side on which the pixel electrode 1423 is provided), the barrier light shielding portion 422 and the barrier transmission portion (also referred to as a lower barrier opening) of the parallax barrier 42 are also referred to. ) 421 is provided.

By adopting such a structure, an appropriate voltage can be applied to the pixel electrode 1423 to form an electric field with the counter electrode 1421, and the orientation of the liquid crystal layer 1422 can be controlled by the electric field, and the upper opening 411 can be controlled. The light transmittance can be changed.

Here, the normal pixel electrode 1423 is formed of a transparent conductive film such as ITO having a refractive index of about 2.1 and is formed of a thin film having a uniform thickness. In addition, a high refractive index film 1424 having a curved shape in which the cross-sectional shape is thickest at the center of the transmission part 411 and becomes thinner toward the edge part is provided. This high refractive index film 1424 is also made of ITO and functions as a pixel electrode.

The pixel electrode 1423 is formed on the lower transparent substrate 1400. As a method for forming the pixel electrode 1423, a transparent conductive film such as ITO is formed on the entire surface of the lower transparent substrate 1400, and the transparent conductive film is formed. The pixel electrode 1423 can be provided by patterning with photolithography. Note that the patterned pixel electrode 1423 is covered with a transparent insulating film 1401, and the transparent insulating film 1401 is planarized to the thickness of the pixel electrode 1423.

The formation method of the counter electrode 1421 is also the same. After forming the semi-transmissive film 1413 and the light-shielding film 1412 in which the part corresponding to the transmissive part 411 is an opening on the upper transparent substrate 1450, the transparent electrode 1421 is transparent together with the opening. The insulating film 1402 is covered, the transparent insulating film 1402 is flattened to the thickness of the semi-transmissive film 1413 and the light-shielding film 1412, and a transparent conductive film is formed over the entire surface on the transparent insulating film 1402, the semi-transmissive film 1413 and the light-shielding film 1412. Thus, the counter electrode 1421 is obtained. Note that the method described with reference to FIGS. 11 and 12 can be employed as a method of forming the semi-transmissive film 1413 and the light shielding film 1412.

After the high refractive index film 1424 is formed on the pixel electrode 1423, the upper transparent substrate 1450 and the lower transparent substrate 1400 are disposed to face each other so that the pixel electrode 1423 and the counter electrode 1421 face each other, and a liquid crystal material is interposed therebetween. Is sealed to form a liquid crystal layer 1422.

Next, the thickness distribution of the high refractive index film 1424 will be described with reference to FIG. FIG. 29 schematically shows an optical path of light passing through the pixel transmission part 411 (upper opening 411) of the display panel 41 and the barrier transmission part 421 (lower barrier opening 421) of the parallax barrier 42 shown in FIG. FIG. 9 shows a state in which the upper opening 411 is opposed to the lower barrier opening 421 in the observation direction with a distance D0.

The light emitted from the point P in the lower barrier opening 421 propagates radially toward the upper opening 411. At this time, the light Lx passing through the position x in the upper opening 411 has a phase determined by the optical path difference ΔDx = (Dx−D0) and the surrounding refractive index na, as compared with the light L0 traveling right above the point P. Delay (ΔDx−D0) · na occurs.

Here, in order for the light emitted from the point P in the lower barrier opening 421 and passing through the upper opening 411 to be focused and imaged at the position of the observer, the phases immediately after passing through the upper opening 411 may be aligned. It is valid. In order to compensate for the phase lag of the light Lx with respect to the light L0, a high refractive index film 1424 having a refractive index nh having a refractive index larger than the surrounding refractive index na is disposed at the center in the opening, and its thickness t It is effective to form so as to satisfy the following formula (4).

ΔDx · na = (nh−na) · t (4)
In FIG. 30, the horizontal axis represents the left / right position (mm) representing the position from the central axis in the width direction (left / right direction) of the high refractive index film 1424, and the vertical axis represents the film thickness t (mm). The film thickness distribution of the rate film 1424 is shown. And the ideal film thickness distribution of the high refractive index film | membrane 1424 which satisfy | fills the said Numerical formula (4) is shown with the broken line.

Here, the distance D0 between the upper opening 411 and the lower barrier opening 421 is 0.9 mm, the width of the upper opening 411 is 0.030 mm, the width of the lower barrier opening 421 is 0.050 mm, and the surrounding refractive index na is the refractive index of the liquid crystal layer 1422. It is assumed that na = 1.5, and the refractive index of the high refractive index film 1424 is the refractive index of ITO nh = 2.1. In this case, the film thickness distribution of the ideal high refractive index film 1424 is 0 μm at the end of the upper opening 411, and the maximum thickness at the center of the upper opening 411 is about 0.35 μm. Since the thickness is thinner than 3-5 μm, the influence on the light shielding effect of the liquid crystal panel is negligible.

FIG. 31 shows the calculation result of the light distribution characteristic by the wave optical calculation when the film thickness distribution of the high refractive index film 1424 is ideal. In FIG. 31, the horizontal axis indicates the light distribution angle as the left and right angle (degrees), and the vertical axis indicates the relative luminance (au: arbitrary unit), and the characteristic plotted by the white circle is the film thickness. This is a calculation result when the distribution is ideal, and this is referred to as “phase compensation ideal distribution”. Under this condition, there is no semi-transmissive region.

In FIG. 31, the calculation result when the ITO film thickness of the pixel electrode 1423 is uniform, does not have the high refractive index film 1424, and does not have a semi-transmissive region is shown as “conventional aperture”. In the ideal distribution, both the minimum leakage light luminance appearing in the −2.5 degree direction and the leakage light luminance in the −1 degree direction are decreased. This represents that the observer can observe a stereoscopic image without a double image due to crosstalk in a wider range in a wider viewing range.

Further, in the state of ideal phase guarantee distribution, a calculation result when a semi-transmission region with an amplitude transmittance of 50% is formed at the end of the opening with a width of 4 μm is expressed as “phase guarantee ideal distribution + semi-transmission region 4 μm. As a characteristic plotted with a filled diamond. With this characteristic, it can be seen that both the minimum leakage light luminance appearing in the −2.5 degree direction and the leakage light luminance in the −1 degree direction are further reduced.

As described above, a film having a higher refractive index than the surroundings is formed in the vicinity of the upper opening 411 so that the film thickness (t) has a distribution satisfying Equation (4), thereby narrowing the width of the boundary region where the crosstalk is large. In addition, light distribution characteristics with low minimum leakage luminance can be realized, and furthermore, by providing a semi-transmissive region at the end of the upper opening 411 in the width direction (left-right direction), the width of the boundary region where crosstalk is large can be achieved. It can be seen that it is possible to realize a light distribution characteristic that is further narrowed and has a lower minimum leakage luminance.

However, such an improvement in the leakage light luminance distribution is not limited to the ideal distribution in which the film thickness distribution of the high refractive index film 1425 satisfies Expression (4). That is, a plurality of high-refractive-index thin films having a uniform thickness may be laminated to form a multilayer high-refractive-index film having a film thickness distribution that approximates the phase guarantee ideal distribution. FIG. 32 shows an example of a multilayer high refractive index film.

32 is a view corresponding to FIG. 28. FIG. 32 (a) shows a plan view, and FIG. 32 (b) shows a cross-sectional view taken along line BB in the plan view. Note that the same components as those in FIG. 28 are denoted by the same reference numerals, and redundant description is omitted.

In FIG. 32, on the pixel electrode 1423, the cross-sectional shape has the first thickness that is the thickest at the center of the upper opening 411, and the other portion has the second thickness that is thinner than the first thickness. A two-stage high refractive index film 1425 is provided. The high refractive index film 1425 includes a high refractive index film 14251 provided along the long side of the opening at the center of the upper opening 411 and a high refractive index film 14252 provided so as to cover the high refractive index film 14251. The high

refractive index films

14251 and 14252 at the center have a first thickness, and the thickness of the high refractive index film 14252 corresponds to the second thickness.

In FIG. 30, as an example of the multilayer high refractive index film, in addition to the above-described two-stage high refractive index film, a three-stage high refractive index film and a one-stage high refractive index film are used. The film thickness distribution is also shown. That is, the single-stage high-refractive index film has a uniform thickness of 0.2 μm, and the two-stage high-refractive index film has a thickness of 0.3 μm at the center and 0 on both sides. The three-stage high refractive index film having a thickness of 2 μm has a thickness of 0.3 μm at the center, a thickness of 0.2 μm on both sides, and a thickness of 0.2 μm on the outer side. It has a thickness of 1 μm.

FIG. 31 shows the light distribution characteristic when a one-stage high refractive index film is used as a characteristic plotted as a solid circle with a phase compensation of one stage 0.2 μm. The light distribution characteristics when using a refractive index film are shown as characteristics plotted with white triangles as two stages of phase compensation 0.2 μm & 0.3 μm. The light distribution characteristics when using a three-stage high refractive index film are shown. , Phase compensation is shown as a characteristic plotted with solid triangles as three stages 0.1 μm & 0.2 μm & 0.3 μm. In any condition, it is assumed that there is no semi-transmissive region.

From these characteristics, in all cases, the effect of reducing the leakage light luminance is inferior compared to the case of an ideal film thickness distribution, but the leakage light luminance in the direction of −1 degree is reduced compared to the case of “conventional opening”. You can see that you can.

That is, by forming a film having a higher refractive index near the upper opening 411 with a film thickness distribution that is thicker at the center of the opening and thinner at the end, the gradient at which leakage light decreases can be increased. That is, it is possible to narrow the width of the boundary area where the crosstalk close to the observation area boundary is large and to widen the three-dimensional viewing area.

Furthermore, a high refractive index film in which a refractive index is higher in the vicinity of the upper opening 411 than in the surroundings and a thicker central part than at both ends, and a semi-transmissive region is provided at the end of the upper opening 411 in the width direction. In addition, it is possible to reduce the width of the boundary region where crosstalk is large and realize light distribution characteristics with low minimum leakage luminance.

<Modification>
FIG. 33 and FIG. 34 show another configuration of a high refractive index film having a refractive index higher in the vicinity of the upper opening 411, thicker at the center of the opening, and thinner at the end, in the vicinity of the upper opening 411. That is, the high refractive index film 1424 shown in FIG. 28 and the high refractive index film 1425 shown in FIG. 32 were provided in the liquid crystal layer 1422, but the high refractive index film 1426 and the high refractive index film 1426 shown in FIG. 33 and FIG. 1427 is formed in the transparent insulating film 1401 provided on the lower transparent substrate 1400. Here, the thickness of the general liquid crystal layer 1422 is 3 to 5 μm, and the thickness of the thin film layer on the substrate 1400 is about 1 to 3 μm. The distance between the lower barrier opening 421 and the upper opening 411 is about 1 mm. Since it is thinner than DO, the high refractive index layer 1427 can be said to be in the vicinity of the liquid crystal layer 1422.

More specifically, the high refractive index film 1426 shown in FIG. 33 has a width wider than that of the high refractive index film 14262 formed of a silicon nitride film (SiN, nh = 1.8 to 2.2). The high refractive index film 14261 made of a narrow silicon nitride film is laminated, and the high refractive index film 1426 is disposed below the pixel electrode 1423. Here, if the transparent insulating film 1401 is a silicon oxide film (SiO ₂ , na = 1.5), the refractive index of the high refractive index film 1426 is higher, so that the condition is satisfied.

Also, the high refractive index film 1427 shown in FIG. 34 is disposed above the high refractive index film 14272 made of a silicon nitride film, and a high refractive index film 14271 made of a silicon nitride film having a narrower width than that. The transparent insulating film 1401 is interposed between the two, but since the distance between the two is narrow, the phase delay of the light passing therethrough is the delay in the high refractive index film 1427 and the delay in the high refractive index film 14272. Since it becomes a sum, it is substantially the same as the case of the two-stage shape.

Here, if the position of the high

refractive index films

1426 and 1427 is within a few μm from the liquid crystal layer 1422, it is about 1/10 of the width of the upper opening 411. Has the same effect as the case.

In general TFT (thin film transistor) driven liquid crystal displays, a transparent conductive film (ITO), a silicon oxide film (SiO ₂ ), a silicon nitride film (SiN), and an oxide semiconductor are used to form TFTs and color filters. A plurality of transparent thin films having different refractive indexes are deposited and patterned by a photoengraving process.

Therefore, the high

refractive index films

1426 and 1427 are made of a material (liquid crystal, silicon oxide film, organic film) having a relatively low refractive index (1.5 to 1.6) among these plural materials. Can be formed by leaving a relatively high (1.9 or more) material (silicon nitride film, ITO, oxide semiconductor) by changing the pattern shape of the conventional mask, so that there is no increase in process cost. A refractive index film can be formed.

In addition, Embodiment 4 and its modification can be paraphrased as follows. That is, the average refractive index of the light transmission part 411 including the liquid crystal layer 1422, the surrounding electrodes, and the insulating film on the substrate is high at the center part in the width direction (left-right direction) and low at the end part side (center part) (Below the end side), the gradient in which light leakage decreases in the light distribution characteristics can be increased, and the width of the boundary region where crosstalk close to the boundary of the observation region is large is narrowed and three-dimensional viewing is possible. The area can be expanded.

<Embodiment 5>
In Embodiment 5 according to the present invention, in the apparatus described in Embodiment 3 in which the display panel is a liquid crystal display panel and the parallax barrier is on the back side of the display panel, FFS (Frings Field Switching) is used as the liquid crystal display panel. A specific configuration when a mode liquid crystal display panel is used will be described.

FIG. 35 is a diagram showing an example of a specific configuration immediately below the transmission portion (also referred to as an upper opening) 411 of the display panel 41 shown in FIG. As shown in FIG. 35, the planar shape of the transmission part 411 is a vertically long rectangular shape, and a light shielding film 2412 is formed on the outside thereof.

The liquid crystal layer 2422 is driven by an electric field generated between the common electrode 2421 on the flat plate and the comb-like pixel electrode 2423 provided above the common electrode 2421 and extending in the width direction of the upper opening 411. . The pixel electrode 2423 is provided independently for each upper opening 411, and is provided at least in a region corresponding to the lower part of the upper opening 411.

By adopting such a structure, a voltage can be appropriately applied to the pixel electrode 2423 to form an electric field with the common electrode 2421, the orientation of the liquid crystal layer 2422 is controlled by the electric field, and each upper opening 411 is controlled. The light transmittance can be changed.

Here, in the liquid crystal layer 2422, a liquid crystal layer insulating film 2424 made of a silicon oxide film or a silicon nitride film is disposed in a region corresponding to two end portions in the width direction of the upper opening 411. In the region corresponding to the end portion, the thickness of the liquid crystal layer 2422 is thinner than the central portion. That is, as shown in FIG. 35, a pair of liquid crystal layer insulating films 2424 is disposed above the pixel electrode 2423, and the liquid crystal layer insulating film 2424 is thin at the center side of the upper opening 411, and is on the end side. Therefore, the thickness of the liquid crystal layer 2422 is substantially reduced at the end of the upper opening 411 in the width direction.

That is, since the maximum thickness of the liquid crystal layer insulating film 2424 is about half of the thickness of the liquid crystal layer 2422, the thickness of the liquid crystal layer 2422 is as thin as about half of the central portion at the end in the width direction of the upper opening 411. It can be said that

Next, the operation of the liquid crystal layer 2422 in the case of having the above configuration will be described with reference to a cross-sectional view shown in FIG. The FFS mode liquid crystal display panel is a normally black panel in which the transmittance is 0 when no voltage is applied. Therefore, as shown in part (a) of FIG. 36, all light passing through the polarizing plate 2400 and the lower transparent substrate 2401 is transmitted through the upper transparent substrate 2450 when no voltage is applied to the pixel electrode 2423. The rubbing direction of the liquid crystal layer 2422 and the polarization directions of the

polarizing plates

2400 and 2300 are determined so as to be absorbed by 2300.

Here, when maximizing the transmittance of the upper opening 411, as shown in FIG. 36B, a voltage is applied to the pixel electrode 2423 to form an electric field with the common electrode 2421. The orientation angle of liquid crystal molecules in the liquid crystal layer 2422 is rotated. Then, by applying a voltage in which the polarization direction of the incident light passing through the center of the upper opening 411 is rotated by 90 degrees, most of the incident polarized light is transmitted without being absorbed by the polarizing plate 2300. The transmittance of the upper opening 411 is maximized.

It is the liquid crystal layer insulating film 2424 that makes it possible to control the orientation angle of the liquid crystal molecules. In other words, due to the presence of the insulating film 2424 in the liquid crystal layer, the thickness of the liquid crystal layer 2422 is about half of the central portion at the end in the width direction of the upper opening 411. Therefore, the rotation of the polarization direction of incident light passing therethrough is rotated. It becomes smaller than 90 degrees, and the transmittance at the polarizing plate 2300 is lower than that at the center. Thereby, the area | region where the transmittance | permeability is low compared with a center part at the both ends of the width direction of the upper opening 411, ie, a semi-transmissive area | region, is realizable. Thereby, a low leakage light luminance distribution as shown in FIG. 31 can be realized.

In addition, by disposing the liquid crystal layer insulating film 2424 near the pixel electrode 2423, there is an effect that the electric field applied to the liquid crystal layer 2422 is reduced. For this reason, since the change in the orientation angle of the liquid crystal molecules is also reduced, the rotation of the polarization direction of the incident light becomes smaller and the absorption by the polarizing plate 2300 increases.

The liquid crystal layer insulating film 2424 may be provided at a position near the light shielding film 2412. However, the liquid crystal layer insulating film 2424 is arranged at a position near the pixel electrode 2423 to effectively reduce the thickness of the thinner liquid crystal layer insulating film 2424. The transmittance can be lowered, and the step in the liquid crystal layer 2422 can be reduced, so that the rubbing process is facilitated.

Further, if the thickness of the liquid crystal layer 2422 can be reduced to about half of the central portion at the widthwise end portion of the upper opening 411, the transmittance is not limited to this method, and the transmittance is at the central portion at both widthwise end portions of the upper opening 411. Similarly, it is possible to realize a low region, that is, a semi-transmissive region.

In FIG. 35, the pixel electrode 2423 has a comb-like shape extending in the width direction of the upper opening 411. However, the pixel electrode 2423 is not arranged in this manner, but in the longitudinal direction of the upper opening 411 as shown in FIG. In the case of an extended arrangement, the following problems occur.

That is, in FIG. 37, the comb-like pixel electrode 2423a is arranged to be inclined with respect to the longitudinal direction of the upper opening 411. Since the pixel electrode 2423a is usually formed of an ITO film having a thickness of about 0.1 μm, the thickness of the pixel electrode 2423a protrudes into the liquid crystal layer 2422 by about 0.1 μm. The refractive index of the ITO thin film is 1.9 to 2.1, which is larger than the refractive index (1.5 to 1.6) of the liquid crystal layer 2422. Therefore, an uneven phase delay distribution in the width direction in the upper opening 411 (Δnd phase lag distribution) occurs.

In FIG. 38, the horizontal axis indicates the width direction position (mm) in the upper opening 411, and the vertical axis indicates the film thickness (mm). The pixel electrode 2423a has a thickness (0 It is shown that a phase delay of .0001 mm) occurs.

This is unevenness that is not negligible compared to the ideal film thickness distribution of the high refractive index film shown in FIG. 30. Diffraction occurs in the width direction and leakage light in the width direction increases.

On the other hand, in the case of a shape that extends in the width direction of the upper opening 411 like the pixel electrode 2423 shown in FIG. 35, the diffracted light spreads in the longitudinal direction of the upper opening 411 but does not spread in the width direction. The leak light in the width direction does not increase.

Here, in the IPS mode and the FFS mode, the comb-like electrode fine wires are arranged so as to be inclined by about ± 5 to 10 degrees with respect to the width direction or the longitudinal direction of the opening. This is to align the direction of rotation of the molecular orientation. Therefore, even when the pixel electrode 2423 has a comb-like shape extending in the width direction, it can be considered that the pixel electrode 2423 is disposed with an inclination of about ± 5 to 10 degrees with respect to the width direction. 39 (a) shows a configuration in which the comb-like pixel electrode 2423b is inclined with respect to the width direction of the upper opening 411. FIG. In the case of adopting such a configuration, the diffracted light from the pixel electrode 2423b travels in a direction tilted by ± 5 to 10 degrees with respect to the longitudinal direction of the upper opening 411, so that an increase in leakage light from the width direction of the opening is suppressed. Is done.

Note that when the configuration shown in FIG. 39A is employed, the planar shape of the light shielding film 2412a is as shown in FIG. 39B. In other words, a concavo-convex structure is formed at both ends in the width direction of the upper opening 411, and a convex portion that blocks light is formed at a portion corresponding to the pixel electrode 2423b formed of an ITO film, and light is transmitted between the pixel electrodes 2423b. It is a concave part. As a result, a region having an average transmittance lower than that of the central portion of the upper opening 411 is formed at the end in the width direction of the upper opening 411.

Further, at the end portion in the width direction of the upper opening 411, only a portion not corresponding to the pixel electrode 2423b formed of the ITO film is a transmission portion, and is not affected by the high refractive index of the pixel electrode 2423b. The average transmittance is lower than the central portion of the upper opening 411. Therefore, it is easy to realize the film thickness distribution of the high refractive index film as shown in FIG.

35, the high refractive index film 1424 shown in FIG. 28, the high refractive index film 1425 shown in FIG. 32, the high refractive index film 1426 shown in FIG. 33, and the high refractive index film 1424 shown in FIG. Alternatively, the high refractive index film 1427 may be provided so that the average refractive index of the light transmission portion is lower on the end side than the central portion in the left-right direction of the light transmission portion.

In the above description, the number of images to be displayed for each direction has been described using two examples. However, the present invention is not limited to this, and it goes without saying that the same holds true in the case of three images or four images. Yes.

It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

10 display panel, 12 parallax barrier, 121 barrier transmissive part, 122 barrier light shielding part, 123 barrier semi-transmissive part, 220 parallax barrier shutter panel, 321 transmissive part, 322 light shielding part, 323 semi-transmissive part.

Claims

A display panel (10) in which a plurality of pixels each having a light transmission part or a light emitting part are arranged in a matrix;
A display device including a parallax barrier (12.42) arranged on the image viewing side or the rear of the display panel and having a plurality of light transmission parts (121, 421) arranged in a matrix,
The plurality of pixels of the display panel are:
A set of pixels is composed of at least two pixels each displaying an image for observation from different directions,
One of the light transmission parts of the parallax barrier and the one set of pixels are arranged in a corresponding positional relationship in the up and down direction,
Of the parallax barrier and the display panel, the one arranged on the image viewing side has semi-transmissive portions (123, 413) provided along the left and right sides of the light transmissive portion and partially transmitting light. A display device characterized by that.
The parallax barrier is disposed on the image viewing side of the display panel,
The display device according to claim 1, wherein the semi-transmissive portion is provided along left and right sides of the light transmissive portion of the parallax barrier.
The parallax barrier is disposed behind the display panel,
The display device according to claim 1, wherein the semi-transmissive portion is provided along the left and right sides of the light transmissive portion of the display panel, partially transmits light, and absorbs the rest.
Of the parallax barrier and the display panel, the semi-transmissive portion provided on the side arranged on the image viewing side is
The display device according to any one of claims 1 to 3, wherein the display device is configured so that a predetermined phase difference is added as compared with light passing through the light transmission section.
A liquid crystal display panel in which a plurality of pixels having a light transmission portion are arranged in a matrix;
A parallax barrier disposed behind the liquid crystal display panel and having a plurality of light transmission portions arranged in a matrix;
A backlight disposed behind the parallax barrier, and a display device comprising:
The plurality of pixels of the liquid crystal display panel constitute a pixel set of at least two pixels that respectively display images for display in different directions,
One of the light transmission parts of the parallax barrier and the one set of pixels are arranged in a corresponding positional relationship in the up and down direction,
The display device, wherein an average refractive index of the light transmission part of the liquid crystal display panel is lower on an end side than a central part in the left-right direction of the light transmission part.
The liquid crystal display panel is
The display device according to claim 5, further comprising at least one thin film (1424) having a refractive index higher than that of the liquid crystal layer in a central portion in a left-right direction of a region corresponding to the light transmission portion.
The at least one thin film comprises:
A multilayer film in which a plurality of uniform thickness films are laminated,
The multilayer film is
The display device according to claim 6, wherein the number of stacked layers at the center is larger than the number of stacked layers at the end.
Each of the plurality of pixels of the liquid crystal display panel has a comb-like electrode (2423),
The display device according to claim 2, wherein the comb-like electrode extends in a left-right direction of the light transmission portion.
The liquid crystal panel is a normally black mode panel,
The display device according to claim 5, wherein the liquid crystal display panel has an insulating film (2424) at an end portion in a left-right direction in a liquid crystal layer (2422) corresponding to the light transmission portion.
A display panel (210) in which a plurality of pixels are arranged in a matrix;
A display device driving method comprising a parallax barrier shutter panel (220) disposed on the image viewing side of the display panel and dynamically forming a parallax barrier by driving a liquid crystal layer,
The plurality of pixels of the display panel are:
A set of pixels is formed by at least two or more pixels that display parallax images for the left eye and the right eye,
The parallax barrier shutter panel is:
The liquid crystal layer is divided into a plurality of electrically insulated states, each having a plurality of sub-openings (301) that are individually driven,
The plurality of sub-openings, depending on the driving state of the liquid crystal layer, constitutes a light transmissive portion, a light shielding portion, and a semi-transmissive portion that partially transmits light,
The plurality of sub-openings and the one set of pixels are arranged in a corresponding positional relationship in the vertical direction,
The parallax barrier shutter panel is:
The liquid crystal layer is driven such that, among the plurality of sub-openings, the sub-openings serving as the semi-transmissive portions are positioned on the left and right of the arrangement of the sub-openings serving as the light transmissive portions. And driving method of display device.
The sub opening serving as the semi-transmissive portion is
The display device driving method according to claim 10, wherein the refractive index is adjusted so that a predetermined phase difference is added as compared with light passing through the sub-opening serving as the light transmitting portion.
A manufacturing method of a display device according to claim 1,
Among the parallax barrier and the display panel, in the formation of the semi-transmissive portion provided on the side arranged on the image viewing side,
A method for manufacturing a display device, comprising: a step of forming a semi-transmissive film and a light-shielding film on top of a main surface of a transparent layer (15) serving as a substrate.