JPH11237601A - Liquid crystal projector device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-luminance liquid crystal projector for a large screen. SOLUTION: In the figure, units 30 (r, g, b) are write reflection, image formation optical systems for R light, G light and B light and are provided with a semiconductor laser light emission part 31 forming a first light source, a beam expander part 32 expands laser light outputted from the semiconductor laser light emission part 31 by a parallel light beam and a multi-lens array 33 which converges the laser light expanded by the beam expander part 32 on a write panel 34. The write panel 34 modulates its transmitted light with an image signal by making a color signal to be projected as a driving signal to project it on a projection panel 36 through an image forming lens 35. The projection panel 36 is provided with photosensitive type conductive film, a reflecting mirror, a liquid crystal plate etc., and the resistance value of the photosensitive type conductive film varies according to the modulated light of an incident write image to modulate the light of a 2nd light source inputted trough a polarization beam splitter 37(r, g, b) and a dichroic 38 composes color image projection light beams and projects the composite image on a screen, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector, and more particularly to a liquid crystal projector suitable for projecting a large-screen image with high luminance.

[0002]

2. Description of the Related Art Projector devices using a liquid crystal panel as an image forming means have become widespread as relatively small devices, but it is necessary to use a high-intensity lamp in order to obtain a projected image on a larger screen. Is done. In addition, a transmissive liquid crystal panel, for example, a liquid crystal panel using a semiconductor element such as a TFT as a driving electrode can have a relatively high resolution. When the number increases, a problem arises in that a photocon leak or the like occurs due to heat generation of the liquid crystal panel and the image is deteriorated.

In view of this, a liquid crystal projector device has been developed in which a reflection type liquid crystal panel which is hardly affected by drive electrodes and the like is used as an image forming means, and a relatively large screen image can be obtained by supporting a high-luminance light source. There's something you can do.

FIG. 15 shows an outline of such a reflection type liquid crystal projector device, in which 21 is a first light source of a writing optical system, and 22 is an image signal which is written and irradiated with an electric signal (not shown). A writing panel 23 for modulating the output light in accordance with the image signal and outputting the modulated light;
Is a lens for forming an image of the output light on the projection panel 24.

[0005] As shown in the enlarged view, the projection panel 24 has a transparent electrode IT on the incident side via a glass substrate 24t.
Photosensitive conductive film 2 made of O, amorphous silicon, etc.
4a is provided. Then, the photosensitive conductive film 2
The resistance value of 4a changes according to the intensity of the incident light. Behind the photosensitive conductive film 24a modulated by the incident light, the liquid crystal plate 2 is connected via a reflection mirror 24b.
4c is arranged so that light that enters from the front glass substrate 24t, passes through the liquid crystal plate 24c, and is reflected by the reflection mirror 24b is polarized at a predetermined angle.

Reference numeral 25 denotes a second light source (lamp) serving as projection light.
The light output from the second light source 25 is converted into parallel light via a lens 26 and is applied to a polarizing beam splitter 27. And the polarizing beam splitter 2
For example, the S-polarized wave is reflected by the projection panel 24 side, and the P-polarized wave is separated so as to pass. The S-polarized wave reflected on the projection panel 24 side is the liquid crystal plate 24c described above.
And the P-polarized wave component is reflected by the rotation of the polarization plane, the polarization beam splitter 2
7 and is input to the projection lens 28.

[0007] Such a projector device uses the video signal supplied to the writing panel 22 to generate the first light source 2.
1 is modulated, and the transmitted light is transmitted through the lens 23 to the photosensitive conductive film 24a of the projection panel 24.
, The driving voltage applied to the liquid crystal panel 24c changes due to the resistance change of the photosensitive conductive film 24a,
When the polarization plane of the light from the second light source 25 incident on the projection panel 24 rotates in accordance with the written image, the projection light input from the polarization beam splitter 27 to the projection lens 28 changes. The written image can be directly projected on a screen or the like.

A liquid crystal projector of this type includes a writing optical system extending from a first light source 21 to a writing panel 23;
The projection light can be divided into a projection optical system including a second light source 25, a polarization beam splitter 27, and a projection panel 24. The projection light projected on the screen is projected by the first light source 21 projected on the writing panel 23. Since the second light source 25 is modulated, light having extremely high brightness can be used as the second light source 25, and the second light source 25 has a feature that it can be applied to a projection device having a large screen.

Further, since the projection panel 24 is of a reflection type, there is also an effect that the aperture ratio of light is improved and light can be irradiated effectively. The writing optical system is shown in FIG.
As shown in FIG. 1, for example, the first light source 21 and the writing panel 22
Instead, a cathode ray tube 29 that directly modulates an electron beam with a video signal may be used, and an image on the tube surface of the cathode ray tube 29 may be irradiated on the projection panel 24.

[0010]

By the way, when a device for projecting a color image by a liquid crystal projector device as shown in FIG. 15 is made, the structure actually becomes as shown in FIG. That is, first, a filter 2 for blocking ultraviolet rays (UV) and infrared rays (IR) is arranged on the front surface of a discharge lamp 1 serving as a first light source, and the output light of the filter 2 is irradiated on a glass pipe 4 by a condenser lens 3. The light from the discharge lamp 1 is converged by the glass pipe 4 so as to have an angle of view of the liquid crystal plate, and is incident on the lens 5.

The light that has passed through the lens 5 is modulated by three primary color video signals, and is incident on three dichroic mirrors or half mirrors 6 and 7 for separating the light into three optical paths. In order to form an image, the light is incident on the writing panel 10r via the field lens 8r and the polarizing plate 9r. Further, in order to form a G light write image, light input to the field lens 8g, the polarizing plate 9g, and the writing panel 10g and forming a B light write image is also input to the field lens 8b, the polarizing plate. 9b, and enters the writing panel 10b.

The write panels 10r, 10g, and 10b are supplied with drive signals corresponding to the color image signals R, G, and B signals to be projected, respectively. ) Are transmitted through the writing lens 11 (r, g, b), respectively, and the reflection type projection panel 13 described with reference to FIG.
(R, g, b). Each reflective projection panel 1
3 (r, g, b) includes a polarizing beam splitter 14
Light corresponding to the R, G, and B lights is emitted from the second light source via (r, g, b), and the projection panel 13 (r,
The modulated light reflected by g, b) passes through the polarizing beam splitter 14 (r, g, b), is synthesized by the dichroic prism 15, and is projected on a screen (not shown) via the projection optical system lens 16. . 12, 1
Reference numeral 2 denotes a total reflection mirror, and a second light source (not shown) is a polarizing beam splitter 1 from above or below the paper surface.
4 (r, g, b), the reflected light is modulated by the projection panel 13 (r, g, b) and irradiated in the direction of the dichroic prism 15 as described with reference to FIG.

In the case of the color liquid crystal projector described above, the following structural problems occur. (1) Since the discharge lamp 1 is required to have a relatively high output and its size becomes large, the discharge lamp 1 is controlled by a dichroic mirror (half mirror) 6 (a, b), 7, etc. from a single light source.
The light path until the light is divided into the paths and enters the projection panels 13 (r, g, b) for the R, G, and B images becomes longer. (2) When adjusting the position of the projection panel 13 (r, g, b) for obtaining the R, G, B projection light, an optical path common to the optical path of the discharge lamp 1 serving as the first light source. Since the system exists, the degree of freedom for adjustment cannot be increased. (The adjustment range is limited.)

(3) As shown by the dotted line in FIG. 17, the writing lens 11 (r, g, b) and the writing panel 10 (r, g, b)
b) and the distance y1 and x1 between the projection panel 13 (r, g, b) and the writing lens 11 (r, g, b).
And the like are in a common relation, so that, for example, the projection panel 13
Is moved to the left, the writing lens 11 is lowered or the mirror 12 for bending the optical path
Must be moved to the left, and in any case, it is necessary to translate all parts on the ramp side from the part to be moved, and if these are moved too much, it is necessary to move the entire writing system. The problem of becoming very difficult arises. (4) Although the luminance of the discharge lamp 1 deteriorates relatively quickly, adjusting the luminance of this lamp changes the spectrum of the emitted light, and tends to cause chromatic aberration. Further, a lens for correcting chromatic aberration needs to combine at least two or more lens units having different dispersions, and thus there is a problem that the lens becomes expensive and becomes large. (5) The light applied to the writing panel 10 is preferably linearly polarized light as incident light. However, since the output light from the discharge lamp is a non-polarized wave, the light use efficiency is not improved.

[0015]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a first invention is to form an image screen by modulating light emitted from a first light source. Writing image forming means, projection image forming means for modulating light emitted from a second light source using light emitted from the writing image forming means as a drive signal, and the light modulated by the projection image forming means. A liquid crystal projector having a projection lens for projecting a second light source;
Are integrally formed by a laser light source and other optical devices.

A liquid crystal projector device according to a second aspect of the present invention is a writing reflection image forming optical system in which a semiconductor laser light emitting portion serving as a first light source and a writing and projection panel are integrally formed via an optical device. Are individually arranged in three primary color optical paths to constitute a color liquid crystal projector.

Since the first light source for forming the image for writing is constituted by a semiconductor laser or the like, the registration of each optical system becomes easy, and the light of the writing system is linearly polarized. Chromatic aberration can be reduced. Also,
It is easy to adjust the brightness of each optical system, and it is easy to adjust the uniformity (uneven brightness) and the registration.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 30 denotes a writing / reflecting image forming optical system. In the case of FIG. 1, a writing / reflecting image forming optical system for R light is used to project a color image. 30r, a write reflection image forming optical system 30g for G light, and a write reflection image forming optical system 30b for B light are arranged (the insides of 30g and 30b are the same as 30r and are not shown). ing). Each writing reflection image forming optical system 30
(R, g, b) denotes a semiconductor laser light emitting portion 31 forming a first light source, a beam expander portion 32 for expanding a laser beam output from the semiconductor laser light emitting portion 31 by parallel light beams, and a beam expander The laser beam spread by the panda section 32 is converted into a light flux for each of a plurality of areas, and the writing panel 34
Is provided with a multi-lens array 33 for converging with respect to.

As described above, the writing panel 34 can be constituted by a reflective liquid crystal panel of the TFT type, and supplies a color signal to be projected as a drive signal, thereby modulating the transmitted light by an image signal. It is. Reference numeral 35 denotes an imaging lens, which is formed by an optical lens that irradiates the transmitted light modulated by the writing panel 34 onto the surface of the projection panel 35 at a focal point.

As shown in the projection panel 24 of FIG. 15, the projection panel 36 is held by a glass substrate or the like having transparent electrodes formed on both sides, and is made of a photosensitive conductive film, a dielectric, etc. from the incident side. It has a reflection mirror, a liquid crystal plate, and a transparent electrode layer. When the resistance value of the photosensitive conductive film changes in accordance with the incident modulated light of the written image, the drive voltage applied to the liquid crystal plate changes, and the second light source incident from the other side The reflectance is changed by controlling the polarization rotation angle of the light.

Reference numerals 37r, 37g, and 37b denote light of three primary colors (R, G, and B) such as a discharge lamp (not shown) that is incident from above (or below) in the drawing.
6 illustrates a polarization beam splitter that reflects light toward the 6 (r, g, b) side, for example, by reflecting an S-polarized wave and transmitting a P-polarized wave to thereby reflect the P reflected by the projection panel 36 (r, g, b). The polarization wave is arranged to be incident on the dichroic prism 38. The dichroic prism 38 synthesizes color image projection light by outputting light incident from the three projection panels 36 (r, g, b) to the projection lens 39 side, and projects the light onto a screen or the like (not shown). It is.

FIGS. 2 and 3 show a plan view and a side view of the multi-lens array.
(A, b) are a plurality of small lenses 33-1, 33-2, 33-3,... Having a shape corresponding to the angle of view of the writing panel 34.
... 33-n are provided as openings. As shown in FIG. 2 in which the write reflection image forming optical system 30 of each color (also called a fly-eye lens) is enlarged,
The laser light emitted from the semiconductor laser light emitting unit 31 includes two lenses 32a. 32b widens the laser beam width. Then, the light is incident on the two multi-lens arrays 33 (a, b) in a parallel light state. A second multi-lens array 33b is installed near the focal point of the first multi-lens array 33a closer to the laser light source side, and the opening of each small lens emitted from the second multi-lens array 33b. A convex lens 33c is provided to combine the light beams emitted from the writing panel 34 so as to overlap on the writing panel 34. In this manner, by superimposing the laser beam by the small lens group, it is possible to eliminate the luminance unevenness on the writing panel 34.

In the case of the color projector of the present invention, since the semiconductor laser light is used as the first light source as described above, the light source itself can be reduced in size and the R, G, B light can be used. It is easy to independently write and write the reflection image forming optical system 30 for each color, in which the image is written and the modulated light for the written image is projected light.
Therefore, the adjustment of the registration as described above becomes extremely simple, and the whole apparatus can be made compact.

Further, the laser light has essentially higher efficiency and longer life than the light emitted from the discharge lamp. Furthermore, since the brightness of the output light can be easily adjusted by controlling the applied voltage, it is easy to balance the color and easily cope with the aging. Furthermore, since laser light can be essentially linearly polarized light output at a single wavelength, it is extremely advantageous for chromatic aberration of each lens system, and the polarizer itself is omitted for a liquid crystal panel using a polarizer. This makes it possible to perform image writing that is extremely compatible.

FIG. 4 shows a writing reflection image forming optical system 3 of the present invention.
0 shows another embodiment. In the case of this embodiment, a convex lens 40 having a positive power is arranged at an intermediate portion between the multi-lens array 33 and the writing panel 34 so that the pupil position of the incident light on the writing panel 34 becomes infinite. A system optical system can be formed, and the resolution of a written image can be improved.

As shown in FIG. 5, the writing panel 34 can be of a reflection type. That is, the output light of the multi-lens array 33 is input to the polarization beam splitter 42, and for example, a specific polarization wave (P wave) of laser light is incident on the reflection type liquid crystal plate 43. The reflection type liquid crystal plate 43 is driven by the signal of the projected image, so that the reflected light is rotated corresponding to the image signal, and the polarization beam splitter 42 is rotated.
The polarization wave (P wave) modulated by the laser beam may enter the imaging lens 35 and irradiate the projection panel 36.

FIG. 6 shows still another embodiment of the writing reflection image forming optical system 30.
It is constituted by up to four semiconductor laser element portions 31a to 31b. Then, the plurality of semiconductor laser element units 31 (a, b) are supplied to the multi-lens array 33 via the beam expander 32. The other parts are indicated by the same reference numerals as in FIGS.

FIG. 7 shows still another embodiment of the writing reflection image forming optical system, in which the semiconductor laser light emitting section 31 is replaced by a number of small semiconductor laser elements 31-1, 31-2, 31.
-3,... 31-n. In other words, semiconductor laser elements are provided corresponding to the number of small lenses serving as openings of the multi-lens array. With such a configuration, each semiconductor element can be directly disposed so as to face the small lens of the multi-lens array, so that the beam expander can be omitted and the size can be further reduced.

Further, as shown in FIG. 8, two to four semiconductor laser light emitting portions 31a and 31b may be expanded by different beam expanders 32a and 32b, respectively, and irradiated to the multi-lens array 33. In addition, as shown in FIG. 9, as in the case of the first multi-lens array 33P1 and the second multi-lens array 33P2, the shape and brightness of the overall emitted light of the laser light source and the angle of view of the writing panel are different. Thus, the outer shape of the small lens and the arrangement of the small lens can be changed.

FIG. 10 shows a write reflection image forming optical system 30 formed by the multi-lens array shown in FIG. 9, and the second multi-lens array 33P1 in which the elements of each lens are not arranged at equal intervals. , 33P2 can be further miniaturized.

FIG. 11 shows still another embodiment of the writing reflection image forming optical system of the present invention. In the case of this embodiment, directional light output from the semiconductor laser unit 31 is input to the diffusion lens 44 to diverge the direction of the light, and the dispersed light is a mirror having a high reflection surface formed therein. Input to the cylinder 45. The writing panel 34 faces the output window of the lens barrel 45.

The laser beam transmitted through the lens 44 is
A different divergence angle is given according to the transmission part of No. 4, and the divergence angle is input to the writing panel 34 while repeating internal reflection in accordance with the divergence angle. Therefore, even when the light intensity has a Gaussian distribution in the laser spot, the lens barrel 45 is not affected.
At the exit side, the light beam is converted into a light beam having a light distribution of uniform intensity, and uniform light can be supplied to the writing panel 34. In this case, designing the outer shape of the lens barrel 45 in accordance with the angle of view of the writing panel efficiently supplies light, and appropriately designing the length of the lens barrel 45 and the divergence angle of the lens 44. This makes it possible to irradiate the writing panel 34 with uniform light.

FIG. 12 shows an embodiment adapted to the case where the light emission output of the semiconductor laser light emitting section 31 used in FIG. 11 is small, and the laser light emitting section is formed by two to four laser light emitting sections 32a to 32b. The following is an embodiment of the present invention. The reference numerals of the other parts are the same as those of FIG.

FIG. 13 shows an embodiment in which a glass rod 46 is used for the lens barrel 45 used in the case of FIG. In this case, the divergence angle of the lens 44 is designed so that the laser light is totally reflected within the side surface of the rod.
There is an advantage that light transmission efficiency can be increased as compared with the case of a lens barrel. Further, when the writing panel 34 is small, there is an effect that the writing panel 34 can be made smaller than using a lens barrel. Further, when the glass rod 46 is used, as shown in FIG. 14, the diverging lens 47a is formed by a curved surface that is convex on the laser incident side, and can be integrated with the glass rod 47b to reduce the number of parts. can do.

In the above embodiment, the case where a semiconductor laser is used as the first light source has been described. However, a small and light gas laser or another laser device may be used as the light source. In particular, in the case of a light emitting diode (LED) in which a single wavelength cannot be obtained in terms of the emission spectrum, but the emission spectrum exists only within a comparatively narrow range, when a certain level of light output is obtained, It may be used in place of laser light.

[0036]

As described above, the liquid crystal projector device of the present invention uses laser light as the first light source for writing, so that it is possible to reduce the luminance deterioration and to reduce the size. The weight can be reduced. In addition, in the case of a projector that projects a color image, the adjustment of registration is facilitated by integrating the write reflection image forming optical systems of the respective color systems, and a projector device with excellent color balance is constructed. It becomes possible.

In addition, since laser light essentially outputs light having a single wavelength and light having a linear polarization plane, it is extremely advantageous in terms of chromatic aberration of the optical system. There is an effect that a beautiful screen without the image can be projected. In particular, since the light incident on the liquid crystal panel can be efficiently used, the light modulation efficiency is improved, and it is easy to achieve an improvement in contrast and an increase in luminance. In addition, since unnecessary ultraviolet rays, infrared rays, and electromagnetic waves as noise are not generated as projection light, a filter or an optical element that blocks these rays is not required, and a great contribution can be obtained in terms of power consumption and miniaturization. .

[Brief description of the drawings]

FIG. 1 is a plan view showing an outline of a liquid crystal projector device of the present invention.

FIG. 2 is an explanatory diagram of a multi-lens array.

FIG. 3 is an explanatory diagram of a writing reflection image forming optical system using a semiconductor laser as a first light source.

FIG. 4 is an explanatory view showing another embodiment of the writing reflection image forming optical system.

FIG. 5 is an explanatory diagram of a writing reflection image forming optical system using a reflection type liquid crystal panel.

FIG. 6 is an explanatory diagram of a writing reflection image forming optical system in which a laser light emitting unit is a plurality of semiconductor lasers.

FIG. 7 is an explanatory diagram of an embodiment using the same number of semiconductor lasers as the numerical aperture of the multi-lens array.

FIG. 8 is an explanatory diagram showing an embodiment when the number of beam expanders is increased.

FIG. 9 is an explanatory diagram of a modified multi-lens array.

FIG. 10 shows an embodiment of a writing reflection image forming optical system using the multi-lens array of FIG.

FIG. 11 is an explanatory diagram showing an embodiment using a lens barrel as a beam expander.

FIG. 12 is a diagram illustrating a lens barrel as an example as a beam expander corresponding to a plurality of semiconductor lasers.

FIG. 13 is an explanatory diagram showing an embodiment using a glass rod as a beam expander.

FIG. 14 is an explanatory diagram showing an embodiment using a glass rod whose input surface is lens-processed as a beam expander.

FIG. 15 is a schematic diagram for explaining the principle of a reflective liquid crystal projector.

FIG. 16 shows a schematic diagram of a reflection type liquid crystal projector using a cathode ray tube.

FIG. 17 is a configuration diagram illustrating an example of a color liquid crystal projector device.

[Explanation of symbols]

Reference Signs List 30 writing reflection image forming optical system, 31 semiconductor laser emitting section, 32 beam expander, 33 multi-lens array, 34 writing panel, 34 imaging lens, 36
Projection panel

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toruyuki Miyawaki 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Junichi Iwai 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (9)

[Claims] 1. A writing image forming means for modulating light emitted from a first light source to form an image screen, and the light emitted from the writing image forming means is emitted from a second light source as a drive signal. A liquid crystal projector device comprising: a projection image forming unit that modulates the reflected light; and a projection lens that projects reflected light of the second light source modulated by the projection image forming unit. A liquid crystal projector device comprising a light emitting source. 2. The liquid crystal projector according to claim 1, wherein the first light source is constituted by a beam expander and an optical element converged by a multi-lens array. 3. The liquid crystal projector according to claim 1, wherein an optical system having a negative power (concave lens) is provided between the first light source and the writing image forming unit. apparatus. 4. The liquid crystal projector according to claim 1, wherein the first light source is configured to be focused by two or more semiconductor laser beams and a multi-lens array. 5. The apparatus according to claim 1, wherein said writing image forming means is constituted by a reflection type liquid crystal device.
5. The liquid crystal projector device according to 2, 3, or 4. 6. The liquid crystal projector according to claim 1, wherein the first light source is formed by a semiconductor laser, a lens that diverges the output light thereof, and a lens barrel. 7. The liquid crystal projector according to claim 1, wherein the first light source is formed of a semiconductor laser, a lens that diverges output light from the semiconductor laser, and a glass rod. 8. The liquid crystal projector according to claim 8, wherein a lens for diverging the laser light and a glass rod are integrated. 9. A writing image forming means for modulating a first light source to form a writing type image, and a projection image forming means for modulating a second light using emission light of the writing image as a drive signal. The write-reflection image forming optical system arranged integrally is
A color projection image formed by combining the projection images output from the optical paths of the R, G, and B lights with a dichroic prism, disposed before the optical system of light, G light, and B light. Liquid crystal projector device.