JP2000347137A - Projector device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust the light quantity by changing the polarization axis of incident light to correct luminance. SOLUTION: Polarizing means 2R:3R, 2G:3G and 2B:3B are arranged in front and behind liquid crystal display panels 1R, 1G and 1B, and an image is formed by image signals in three primary colors from input terminals 4R, 4G and 4B. The polarization axis of the light emitted from a light source means 5 is converter into one way by a polarized beam splitter 6, a mirror 7 and a half-wave plate 8. The light is made incident, for example, on a polarization axis varying means 9 made from a half-wave plate and the polarization axis varying means 9 is rotated, for example, by a motor 10 to vary the polarization axis of the incident light. The exit light is reflected by the dichroic mirrors 11R, 11G and 11B and mirrors 12R and 12B so as to be made incident on the liquid crystal panels 1R, 1G and 1B, and then, the formed image light is synthesized by a cross-dichroic prism 13, and then, projected on a screen 15 through a projecting lens 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projector device for displaying an image by projecting display light from a transmitted light amount control means (for example, a liquid crystal display device) onto a screen. More specifically, the display brightness can be adjusted by arbitrarily changing the polarization axis of the light beam incident on the transmitted light amount control means. Thereby, for example, when a large-sized display is performed by combining the displays by a plurality of transmitted light amount control means, the brightness of each display can be adjusted uniformly.

[0002]

2. Description of the Related Art For example, in a projector apparatus for projecting display light formed by a video signal, instead of a conventional cathode ray tube as a display light forming means, a transmitted light amount control means which is not affected by geomagnetism or the like, for example, a liquid crystal. Devices using display devices have been put to practical use. In this case, this kind of transmitted light amount control means is generally not self-luminous,
Light source means (lamp) for obtaining display light is separately required. That is, the light from the light source means is incident on the transmitted light amount control means to form display light.

When a lamp is used as the light source, the output light quantity of the lamp generally fluctuates greatly. Also, such lamps have a short life and need to be replaced after a certain period of use. When such lamp replacement is performed, the output light amount described above is greatly changed, and the luminance of the display light to be formed is greatly changed. However, such a change in the display luminance may cause the reliability of the device to be significantly impaired.

Further, a display of a large screen is formed by combining, for example, four to sixteen displays formed by the display light vertically and horizontally as described above. In such a case, if the display brightness changes as described above, the brightness and color tone change for each part of the large screen to be formed, and the entire screen becomes extremely unsightly.
That is, when a large-screen display is formed by combining the displays in this way, it is necessary to adjust the brightness and the color tone particularly between the adjacent displays.

Therefore, in order to make the brightness and the color tone of such a display uniform, means for correcting the above-mentioned fluctuation of the display light is required. However, correcting such an adjustment by a liquid crystal display device by adjusting the level of a video signal, for example,
This is difficult because the dynamic range of the liquid crystal display is narrow. On the other hand, it is conceivable to adjust the light amount of the light source means, but in the case of a discharge lamp generally used in terms of luminous efficiency and the like, it is difficult to adjust the light amount by, for example, a lighting circuit. Is what it is.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and the problem to be solved is that when the luminance of a display fluctuates in a conventional device, for example, Have not been invented.

[0007]

According to the present invention, there is provided a polarization axis changing means for arbitrarily changing a polarization axis of a light beam incident on a transmitted light quantity control means. For example, by controlling the polarization axis of the light beam, the light quantity can be adjusted in cooperation with the polarization means provided on the incident side of the transmitted light quantity control means.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a projector apparatus comprising a light source means and a transmitted light quantity control means, wherein the transmitted light quantity control means has a polarization means having a predetermined polarization axis at least on a light incident side from the light source means. And a polarization conversion means for converting the light into linearly polarized light which coincides with the polarization axis of the polarization means in the path of the light from the light source means, and the polarization axis of the light ray is arbitrary between the polarization conversion means and the polarization means. Is provided with a polarization axis changing means.

Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of a projector apparatus to which the present invention is applied. The embodiment described here shows a so-called liquid crystal projector device using a liquid crystal display device as a transmitted light amount control unit, for example. Therefore, in FIG. 1, for example, three liquid crystal display devices corresponding to the three primary colors of red (R), green (G), and blue (B) are provided.

These liquid crystal display devices include, for example, liquid crystal display panels 1R, 1R in which liquid crystal pixels are provided in a matrix.
G, 1B, and polarizing means 2R: 3R, 2G: 3G, 2B: 3B, whose polarization axes are crossed in a crossed Nicols before and after G, 1B. And these liquid crystal display panels 1R, 1G,
1B is supplied with video signals (R, G, B) of three primary colors from input terminals 4R, 4G, 4B, for example.
The polarization axis of the light beam passing through each liquid crystal pixel is changed according to these signals, and the polarization means 2R: 3R, 2G: 3G,
B: Bright and dark images are formed between 3B.

A light source means 5 composed of, for example, a discharge lamp is provided. The light beam generated by the light source means 5 is incident on a polarization beam splitter 6 which separates, for example, a vertical polarization component and a horizontal vertical polarization component of the light beam. For example, the vertical polarization component of the light beam passes through the polarization beam splitter 6, and The horizontal component of the light beam is reflected by the polarizing beam splitter 6 and extracted to the right in the drawing. Further, the horizontal component of the light beam extracted to the right is reflected by the mirror 7 in the same direction as the vertical polarization component, and passes through the half-wave plate 8 so that the polarization axis of the light beam changes from horizontal to vertical. Is converted.

The light beams having passed through the polarization beam splitter 6 and the half-wave plate 8 are combined (combining means is omitted), and is incident on, for example, a polarization axis varying means 9 composed of a half-wave plate. . Further, this polarization axis changing means 9
For example, it is rotated by a motor 10 on a rotation axis parallel to the light beam. Here, the half-wave plate is, for example, a crystal obtained by cutting a crystal such as mica into a plate shape so that the optical axis is included in the cutting axis. The polarization axis of the light beam is 0 ± 9 with respect to the original axis.
It can be changed to 0 degrees.

Further, the light beam emitted from the polarization axis changing means 9 is incident on a dichroic mirror 11R for separating, for example, a red light beam, and a red reflected light beam from the dichroic mirror 11R is reflected by a mirror 12R to form a red primary color. The light is incident on the liquid crystal panel 1R supplied to the signal (R).
In the liquid crystal panel 1R, the polarization axis of the incident light beam is changed according to the primary color signal (R), and the change in the polarization axis is changed between light and dark between the polarization means 2R: 3R, and the primary color signal (R ) Is formed.

Further, the dichroic mirror 1 which separates the green light from the light transmitted through the dichroic mirror 11R
1G, and the green reflected light from the dichroic mirror 11G is incident on a liquid crystal panel 1G displaying a green primary color signal (G). In the liquid crystal panel 1G, the polarization axis of the incident light beam is changed in accordance with the primary color signal (G), and the change in the polarization axis is changed between light and dark between the polarization means 2G and 3G, and the primary color signal (G ) Is formed.

Further, the dichroic mirror 1 which separates the blue light from the light transmitted through the dichroic mirror 11G
2B and the liquid crystal panel 1B that reflects the mirror 12B and displays a blue primary color signal (B). In the liquid crystal panel 1B, the polarization axis of the incident light beam is changed in accordance with the primary color signal (B), and the change in the polarization axis is changed between light and dark between the polarization means 2B and 3B, and the primary color signal (B ) Is formed. In this way, video light modulated according to the primary color signals (R, G, B) is formed.

Further, the image light of the primary color signals (R, G, B) formed by the liquid crystal panels 1R, 1G, 1B is incident on the cross dichroic prism 13, and these image lights are combined. Then, the synthesized image light is projected on the screen 15 through the projection lens 14. In this manner, for example, video light corresponding to the three primary color signals (R, G, B) of red, green, and blue supplied to the input terminals 4R, 4G, and 4B is formed on the liquid crystal panels 1R, 1G, and 1B. Then, the formed image light is synthesized and projected on the screen 15.

In this apparatus, the polarization axis of the passing light beam is rotated by rotating the polarization axis changing means 9 by, for example, a motor 10, thereby changing the luminance of the image light formed thereby.

That is, in FIG.
Is rotated, for example, by a motor 10 on a rotation axis parallel to the light beam. Therefore, for example, when the polarization axis of the light beam incident on the polarization axis varying means 9 is vertical and this axis coincides with the optical axis of the polarization axis varying means 9 (the high-speed axis or the low-speed axis of the half-wave plate). Are emitted from the polarization axis varying means 9 without changing the polarization axis of the light beam. And, for example, the liquid crystal panel 1R,
Polarizing means 2R, 2G, 2B provided before 1G, 1B
If the polarization axis is perpendicular, the light beam is
G and 2B are passed 100%.

On the other hand, when the optical axis of the polarization axis changing means 9 is rotated by the angle θ, the polarization axis of the light beam emitted from the polarization axis changing means 9 is changed by the angle 2θ. Then, for example, the polarizing means 2 provided in front of the liquid crystal panels 1R, 1G, 1B
If the polarization axes of R, 2G and 2B are perpendicular, the light beam is reduced by the above-mentioned angle 2θ and passes through the polarization means 2R, 2G and 2B. That is, when the angle 2θ is 0 degree, the light beam passes through the polarizing means 2R, 2G, and 2B 100%, and the angle 2θ
Is 90 degrees, no light beam is passed through the polarizing means 2R, 2G, 2B.

For example, by rotating the optical axis of the polarization axis changing means 9 by 0 to 45 degrees by the above-described motor 10, the polarization axis of the emitted light beam is changed to 0 to 90 degrees, and the polarization means 2R, The light amount of the light beam passing through 2G and 2B can be controlled from 100% to 0%. By controlling the amount of light passing through the polarizing means 2R, 2G, and 2B, the luminance of the formed image light can be changed.

Therefore, in this apparatus, by providing a polarization axis varying means for arbitrarily changing the polarization axis of the light beam incident on the transmitted light quantity control means, the polarization axis of the light ray is controlled to thereby control the incident side of the transmitted light quantity control means. The amount of light can be adjusted in cooperation with the polarizing means provided in the light source. With this, for example, when the luminance of the display fluctuates in the conventional device, it cannot be appropriately corrected,
According to the present invention, these problems can be easily solved.

Further, in the above-described apparatus, the display formed as described above is, for example, as shown in FIG.
A large-screen display can be formed by combining six pieces vertically and horizontally. In this case, the change in the display luminance is corrected as described above, so that the change in the luminance and the color tone of each part of the large screen to be formed can be corrected, and the uniformity of the entire screen can be improved. You can do it.

In the case of FIG. 3, for example, the light source lamp is replaced for the display at the bottom of the second column from the right where the brightness is lowest. Then, the adjustment is performed so that the luminance of the lowest luminance among the remaining displays is maximized, and further, the luminance of each of the other displays is adjusted in accordance with the luminance thus obtained. In this way, the brightness of the entire screen can be made uniform.

That is, when a large-screen display is formed by combining the displays in this manner, the entire large screen can be easily viewed by adjusting the brightness and the color tone particularly between adjacent displays. . According to the above-described apparatus, the correction of such a change in display luminance can be realized with an extremely simple configuration having only a half-wave plate and a polarization axis changing unit 9 provided by a rotating unit (motor 10). Can be done.

According to the projector apparatus described above, the light source means and the transmitted light quantity control means are provided, and the transmitted light quantity control means has a polarization means having a predetermined polarization axis at least on the light incident side from the light source means. In the path of the light beam from the means, a polarization conversion means for converting the light beam into linearly polarized light that matches the polarization axis of the polarization means is provided, and a polarization axis for arbitrarily changing the polarization axis of the light beam between the polarization conversion means and the polarization means. By providing the variable means, it is possible to arbitrarily correct the display brightness by adjusting the light amount.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0027]

Therefore, according to the first aspect of the present invention, the polarization axis of the light beam is controlled by providing the polarization axis variable means for arbitrarily changing the polarization axis of the light beam incident on the transmitted light amount control means. The light quantity can be adjusted in cooperation with the polarization means provided on the incident side of the transmitted light quantity control means.

Thus, according to the present invention, these problems can be easily solved, for example, in the case where the brightness of the display fluctuates in the conventional device, which cannot be appropriately corrected. You can do it.

According to the second aspect of the present invention, the amount of light of the light source is adjusted by adjusting the polarization axis changing means, and the brightness of the display is adjusted by the transmitted light amount control means, so that the amount of light is adjusted. Can be adjusted.

Further, according to the third aspect of the present invention, the amount of light incident on the plurality of transmitted light quantity control means is adjusted by performing a single display by combining the displays by the plurality of transmitted light quantity control means. Can be done.

According to the fourth aspect of the present invention, when a single display is performed by combining the displays by the transmitted light amount control means, the light amount of each light source means is adjusted by adjusting the polarization axis changing means. Thus, the brightness of a single display can be adjusted uniformly.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an embodiment of a projector device to which the present invention is applied.

FIG. 2 is a diagram for explaining the operation.

FIG. 3 is a diagram for explaining a large-screen display using the projector device of the present invention.

[Explanation of symbols]

1R, 1G, 1B: liquid crystal display panel, 2R, 2G, 2
B, 3R, 3G, 3B ... polarizing means, 4R, 4G, 4B ...
Input terminal, 5: light source means, 6: polarizing beam splitter,
7 mirror, 8 half-wave plate, 9 polarization axis changing means,
Reference numeral 10: motor, 11R, 11G, 11B: dichroic mirror, 12R, 12B: mirror, 13: cross dichroic prism, 14: projection lens, 15: screen

Claims (4)

[Claims] 1. A projector device comprising a light source unit and a transmitted light amount control unit, wherein the transmitted light amount control unit has a polarizing unit having a predetermined polarization axis at least on a light incident side of the light from the light source unit. Along with providing a polarization conversion unit that converts the light beam into linearly polarized light that matches the polarization axis of the polarization unit in the path of the light beam from the light source unit, the polarization axis of the light beam is set between the polarization conversion unit and the polarization unit. A projector device, comprising: a polarization axis changing unit that arbitrarily changes the polarization axis. 2. The projector device according to claim 1, wherein the polarization axis changing unit is adjusted to adjust the light amount of the light source unit, and the display light amount is adjusted by the transmitted light amount control unit. Projector device. 3. The projector device according to claim 1, wherein a single display is performed by combining the displays by the plurality of transmitted light amount control means. 4. The projector device according to claim 3, wherein, when a single display is performed by combining the displays by the transmitted light amount control unit, the polarization axis variable unit is adjusted to adjust the light amount of each of the light source units. Adjusting, a projector device.