WO2014127556A1

WO2014127556A1 - Phase retardation device, driving method thereof, and display device

Info

Publication number: WO2014127556A1
Application number: PCT/CN2013/073493
Authority: WO
Inventors: 张洪术
Original assignee: 京东方科技集团股份有限公司; 北京京东方显示技术有限公司
Priority date: 2013-02-25
Filing date: 2013-03-29
Publication date: 2014-08-28
Also published as: CN103149707A; CN103149707B

Abstract

A phase retardation device, a driving method therefor, and a display device. The phase retardation device comprises multiple electro-optical crystal plates (10) and multiple electrode plates (20) which are arranged alternately. The electrode plates (20) are connected with a driving circuit, and electric fields may be formed therebetween. The polarizing character of the phase retardation device is uniform, and dispersion and oblique chromatic aberration are reduced.

Description

Phase delay device, driving method thereof and display device

Embodiments of the present invention relate to a phase delay device, a driving method thereof, and a display device. Background technique

Three-dimensional (3D) display technology has developed rapidly and has become a research hotspot in the field of display technology. The basic principle of 3D display is to use the two-eye parallax of the observer to provide different images to the two eyes to produce a stereo effect. Three-dimensional display technology is usually divided into eyepiece mirrors and non-glasses. For the glasses type, the display device displays the left eye image and the right eye image in a time division manner in different polarization directions, and the observer needs to wear the polarized glasses or the shutter glasses to obtain a three-dimensional display effect. Glasses-type three-dimensional technology includes active shutter glasses, polarized glasses, and the like.

The current 3D display technology PR (Patterned Retarder) (also known as polarized 3D technology) has a higher cost of polarizing lenses; and FPR (Film Patterned Retarder) technology replaces lenses with thin films. , reducing costs.

The principle of FPR technology is as follows:

1. A phase delay device (retardation) through which the light of the original image of the odd-even line pixel passes forms left-handed circularly polarized light and right-handed circularly polarized light;

Different regions of the phase delay device correspond to each row of pixels of the display panel, and the light rays perpendicularly from the parity row pixels of the display panel are 45-degree linearly polarized light, and are converted into left-handed circularly polarized light after passing through respective corresponding phase delay device regions ( Left-handed circularly polarized light and right-handed circularly polarized light (right-handed circularly polarized light), such as the light from the odd-numbered rows of pixels is converted into left-handed circularly polarized light, and the light from the even-numbered rows of pixels is converted into right-handed circularly polarized light.

2. A lens of 3D (Three-Dimensional, 3D) glasses worn by the observer, the right-handed circularly polarized light becomes 90°. The linearly polarized light passes through the polarizer in the glasses, and the left-handed circularly polarized light becomes 0°. The polarizer in the glasses absorbs; similarly, in the other lens, the left-handed circular polarization becomes 90° The polarized light passes through the polarizer in the glasses, and the right-handed circularly polarized light becomes 0°. The linearly polarized light is absorbed by the polarizer in the glasses.

3. The observer's left and right eyes receive different images to achieve 3D display.

The phase retardation device of the prior art employs a liquid crystal retarder. In the manufacturing process, the coating curing of the liquid crystal layer is difficult to ensure, affecting the uniformity of the delay of each line, the dispersion of the different wavelengths is large, and the chromatic aberration of the squint is obvious. Summary of the invention

Embodiments of the present invention provide a phase delay device, a driving method thereof, and a display device, which can solve the above technical problems.

An embodiment of the present invention provides a phase delay device comprising a plurality of electro-optic crystal plates and a plurality of electrode sheets spaced apart from each other, wherein the electrode sheets are applied with a voltage, and an electric field can be formed between the electrode sheets.

A driving method of the phase delay device provided by an embodiment of the present invention includes: inputting different voltages to adjacent electrode sheets such that opposite electric field crystal plates are in opposite directions; and causing adjacent electro-optical crystal sheets to become A quarter-wave phase retarder and a negative quarter-wave phase retarder.

A display device according to an embodiment of the present invention includes a display panel, and further includes a phase delay device provided by an embodiment of the present invention; the phase delay device is disposed on a light emitting surface side of the display panel; The electrode sheets are arranged in parallel with the pixel rows in the display panel. DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below. It is obvious that the drawings in the following description relate only to some embodiments of the present invention, rather than to the present invention. limit.

1 is a schematic structural diagram of a phase delay device according to an embodiment of the present invention; 2 is a schematic structural diagram of a display device according to an embodiment of the present invention; FIG. 3 is a schematic structural diagram of an electro-optical crystal chip according to an embodiment of the present invention; A schematic diagram of a driving method of a phase delay device; FIG. 5 is a schematic diagram of a principle of a display device according to an embodiment of the present invention. detailed description

The technical solutions of the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings. It is apparent that the described embodiments are part of the embodiments of the invention, rather than all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the described embodiments of the present invention without departing from the scope of the invention are within the scope of the invention.

Unless otherwise defined, technical terms or scientific terms used herein shall be of the ordinary meaning understood by those of ordinary skill in the art to which the invention pertains. The words "first", "second" and similar terms used in the specification and claims of the present invention are not intended to indicate any order, quantity or importance, but merely to distinguish different components. Similarly, the words "a" or "an" do not mean a quantity limitation, but rather mean that there is at least one. The words "including" or "comprising", etc., are intended to mean that the elements or objects preceding "including" or "comprising" are intended to encompass the elements or Component or object. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to indicate the relative positional relationship, and when the absolute position of the object to be described is changed, the relative positional relationship may also change accordingly.

Embodiments of the present invention provide a phase delay device, a driving method therefor, and a display device which can be used to fabricate phase delay devices having uniform polarization characteristics, reduce dispersion for different wavelengths, and reduce squint chromatic aberration.

Referring to FIG. 1, a phase delay device provided by an embodiment of the present invention includes an interval setting. A plurality of electro-optical crystal sheets 10 and a plurality of electrode sheets 20 are connected to the driving circuit so that a voltage can be applied, and an electric field can be formed between the electrode sheets.

Preferably, the material of the electro-optic crystal wafer 10 may be an electro-optic crystal having inversion symmetry, such as potassium dihydrogen phosphate KDP crystal, barium titanate BaTiO ₃ crystal, lithium niobate LiNbO ₃ crystal, ammonium dihydrogen phosphate (NH) ₄ ) H ₂ P0 ₄ (also known as ADP) crystal. The inversion symmetry may be a central inversion symmetry or an axial inversion symmetry or the like.

A driving method of a phase delay device provided by an embodiment of the present invention includes: inputting different voltages to adjacent electrode sheets 20 such that electric fields of adjacent electro-optic crystal sheets 10 are opposite in direction; and causing adjacent electro-optic crystals by electric field action The sheets 10 are respectively a quarter-wave phase retarder and a negative quarter-wave phase retarder.

Preferably, the input voltage V ₊ and the voltage V of the adjacent electrode sheets 20 respectively satisfy the following conditions:

Γ = . - c 2 D 2 r = . - c " _{e) +} K 2 D)] = - 2

Where Γ is the phase difference; “is the angular frequency; L is the thickness of the electro-optic crystal piece, the thickness direction is the same as the direction of light propagation through the phase delay device; c is the speed of light; „ is the ordinary refractive index; n _e is very The refractive index; is the electro-optic tensor, that is, the r ₆₃ component in the 6 x 3 matrix; V V_ is the voltage applied to the electro-optic crystal plate; ) is the width of the electro-optic crystal plate, and the width direction is parallel to the direction of the electric field.

The magnitude of the electric field applied to the electro-optic crystal piece 10 is determined by the difference in the input levels of the metal electrodes across the electro-optical crystal piece 10 and the width of the electro-optical crystal piece 10.

An embodiment of the present invention provides a display device, including a display panel 60, and a phase delay device 50 according to the above embodiment of the present invention. The phase delay device 50 is disposed on a light emitting surface side of the display panel. The sheet 10 and the electrode sheet 20 are arranged in parallel with the pixel row 30 in the display panel 60, as shown in FIGS. 2 and 5.

Preferably, for example, the electro-optic crystal wafer 10 has a thickness ranging from 0.5 mm to 2 mm; The thickness direction of the crystal piece 10 is the same as the light propagation direction by the phase delay device 50. Preferably, for example, the length of the electro-optic crystal wafer 10 is the length of the pixel row 30 in the display panel 60; the length direction is parallel to the pixel row 30 in the display panel 60.

Preferably, for example, the width of the electro-optic crystal wafer 10 is a pixel row in the corresponding display panel 60.

30 width.

The size selection of the electro-optic crystal wafer 10 in one embodiment of the invention includes, but is not limited to, the above dimensions, which are related to the manner in which the pixels in the display device 60 are used. For example, the original image may be set to correspond to one quarter-wave phase retarder or negative quarter-wave phase delay sheet every two rows of pixels, and the width of the electro-optic crystal wafer 10 may be designed to be the width of two rows of pixels.

For example, the display panel may be a TN (Twisted Nematic) type panel, or the display panel may also be an IPS (In-Plane Switching) type or an ADS (ADvanced Super Dimension). Swtich, advanced super-dimensional field conversion type panel; the ADS type panel may also be an improved ADS type panel such as high transmittance I-ADS, high aperture ratio H-ADS, high resolution S-ADS.

Preferably, for example, the angle between the transmission axis direction of the polarizer and the analyzer in the in-plane conversion type or advanced super-dimensional field conversion type liquid crystal panel and the pixel row direction are positive 45 degrees and negative 45 degrees, respectively.

Preferably, for example, the display device sequentially inputs the voltage V ₊ and the voltage V_ to the electro-optic crystal wafer 10 through the electrode sheet 20, so that the electro-optical crystal wafers are in different electric fields, so that the electro-optical crystal wafer 10 becomes a quarter-wave phase retarder and Negative quarter-wave phase retarder. The quarter-wave phase retarder is used to make incident light into right-handed circularly polarized light; and the negative quarter-wave phase retarder is used to make incident light into left-handed circularly polarized light. The quarter-wave phase retarder and the negative quarter-wave phase retarder are alternately arranged, and the user can receive the 3D image using the FPR 3D circular polarized glasses.

An example of the fabrication of the phase delay device 50 of the present invention is given below:

For convenience of description, the vertical direction of the panel is the y direction, the parallel direction of the pixel row is the X direction, and the z direction is perpendicular to the X direction and the y direction at the same time. The phase delay device fabrication process is as follows:

a. Cut the KDP into strips with the same width D as the pixels; the thickness L ranges from 0.5 mm (mm) to 2 mm (mm); where D is in the z direction and L is in the y direction, as shown in FIG. ;

b. cutting and splicing the crystal strip according to the length of the pixel row, and the single crystal strip is an electro-optic crystal sheet;

c, the electro-optic crystal wafer is assembled into a phase delay device, wherein each electro-optic crystal wafer has a metal electrode on both sides of the z-direction, and the electrode width is L;

d. The metal electrodes at both ends of each electro-optic crystal piece are connected to the driving circuit, and the high voltage and the low voltage are sequentially input to the metal electrodes of the electro-optical crystal piece, so that the electric field strengths of the adjacent electro-optical crystal plates are the same, and the electric field direction is opposite.

Specifically, the electro-optical crystal pieces are connected to the input voltage in parallel at the adjacent metal electrodes, and the input voltages of the respective metal electrodes are alternately V/2 and -V/2, as shown in FIG. Then, the electric field voltage applied to the electro-optical crystal piece 10 is V/2-(-V/2)=V, (-V/2)-V/2=-V.

Debugging of the phase delay device:

The magnitude of the input voltage of the metal electrode is adjusted such that the electro-optic crystal plates corresponding to the adjacent two rows of pixels become a quarter-wave phase retarder and a negative quarter-wave phase retarder, respectively. The negative quarter-wave phase retarder is for making the incident light into a left-handed circularly polarized light; the quarter-wavelength phase retarder is for making the incident light into a right-handed circularly polarized light. Adjusted voltage of electro-optic crystal piece

V+ and _ just meet the following electro-optic effect formula:

coL V π o)L , ι V π

Γ =— [(n ₀ - ^ ) +— 3⁄4 (—)] = - , Γ =— [(η ₀ - ^ ) +— r ₆₃ (—)] = -- c 2 D 2 c 2 D 2

M. It is an ordinary refractive index, which is an extraordinary refractive index, and r ₆₃ is an electro-optic tensor, which are inherent parameters of the crystal. For KDP crystals, ". =1.5115, =1.4698, r ₆₃ = 10.3 pm/V. As shown in FIG. 5, after the linearly polarized light emitted from the display panel 60 passes through the electro-optical crystal piece 10, the left-handed circularly polarized light and the right-handed circularly polarized light are alternately formed row by row, and the two respectively pass through the FPR 3D circularly polarized glasses, respectively, respectively. Presented in the eye, so that the user receives different images from both eyes, reaching 3D display effect.

According to the above technical solution, a phase delay device according to an embodiment of the present invention includes a plurality of electro-optic crystal sheets and a plurality of electrode sheets disposed at intervals, and the electrode sheets are connected with a driving circuit, and an electric field can be formed between the electrode sheets. Since the polarization characteristics of each electro-optic crystal piece can be adjusted according to the input electric field, the embodiment of the present invention has at least the following advantages: the uniformity of the polarization characteristics of the phase delay device is ensured, the dispersion to different wavelengths is reduced, and the dispersion is reduced. Small squint color difference.

Compared with the prior art FPR display device, the FPR display device of the present invention solves the problem of chromatic dispersion and squint chromatic aberration of the FPR display device by using a phase delay device having uniform polarization characteristics. Users can get a better experience when receiving images through FPR 3D circular polarized glasses.

The phase delay device of the present invention can also be applied to other fields. Instead of the wave plate in the prior art, the electro-optical crystal is made into a quarter wave plate and a negative quarter by controlling the electric field between the electrode sheets in the phase delay device. A wave plate or other form of wave plate, such as a half wave plate.

The above is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims.

Claims

Claim

1. A phase delay device comprising:

a plurality of electro-optic crystal sheets and a plurality of electrode sheets arranged at intervals,

A voltage is applied to the electrode sheets, and an electric field can be formed between the electrode sheets.

The phase delay device according to claim 1, wherein the material of the electro-optical crystal piece is an electro-optical crystal having inversion symmetry.

3. The phase delay device according to claim 2, wherein the electro-optic crystal is preferably selected from one or more of potassium dihydrogen phosphate crystal, barium titanate crystal, lithium niobate crystal, ammonium dihydrogen phosphate crystal. .

4. The phase delay device according to any one of claims 1 to 3, wherein

The thickness of the electro-optic crystal piece ranges from 0.5 mm to 2 mm;

The thickness direction of the electro-optic crystal piece is the same as the direction of light propagation by the phase delay means.

5. A method of driving a phase delay device, the phase delay device comprising a plurality of electro-optic crystal plates and a plurality of electrode pads disposed at intervals, the method comprising:

Inputting different voltages to adjacent electrode sheets, so that the electric fields of adjacent electro-optical crystal sheets are opposite in direction; the adjacent electro-optic crystal sheets are respectively made into quarter-wave phase retarders and negative quarter-wave phase retarders by electric field action .

6. The driving method according to claim 5, wherein the input voltage V ₊ and the voltage of the adjacent electrode sheets respectively satisfy the following conditions:

n V π

Γ =— +— 3⁄4(—)] = - c 2 D 2, r = . - c 4 φ] =

2 D 2

Wherein, Γ is a phase difference; “is an angular frequency; L is the thickness of the electro-optic crystal piece, the thickness direction is the same as the direction of light propagation through the phase delay device; c is the speed of light; „ is the ordinary refractive index; It is an extraordinary refractive index; r ₆₃ is an electro-optic tensor; V ₊ and V- are voltages applied to the electro-optic crystal piece; ) is an electro-optical crystal piece width, and the width direction is parallel to the electric field direction.

7. A display device comprising:

The display panel and the phase delay device according to any one of claims 1 to 4, wherein the phase delay device is disposed on a light emitting surface side of the display panel, the electro-optic crystal piece, the electrode sheet, and the display panel The rows of pixels are arranged in parallel.

8. The display device according to claim 7, wherein

The length of the electro-optic crystal piece is the length of the pixel row in the display panel; the length direction is parallel to the pixel row in the display panel.

9. The display device according to claim 7 or 8, wherein

The width of the electro-optic crystal piece is the width of the pixel row in the display panel.

10. The display device according to any one of claims 7-9, wherein

The display panel is a twisted nematic liquid crystal panel.

11. The display device according to any one of claims 7-9, wherein

The display panel is one of an in-plane conversion type liquid crystal panel and an advanced super-dimensional field conversion type liquid crystal panel;

The angle between the transmission axis direction of the polarizer and the analyzer and the pixel row direction in the display panel is positive 45 degrees and negative 45 degrees, respectively.