JPH08149493A - Image projector - Google Patents

Abstract

PURPOSE: To reduce the dimensions and weight of the image projector by forming plural write images corresponding to two colors at least with one write image forming device. CONSTITUTION: An incidental beam 35 made incident from the lower surface of a polarizing beam splittter 5 is splitted into an S polarized component and a P polarized component, and the S polarized component is bent at 90 deg. and emitted to SLM 4A, 4B and 4C as a read beam 40. On the other hand, the respective write images due to signals for red, green and blue formed by a CRT 1 are respectively formed on the correspondent SLM 4A, 4B and 4C by a fiber plate 3 and read images corresponding to the respective colors are formed on the SLM 4A, 4B and 4C. For example, the effect of birefringence is received corresponding to the read images for respective colors formed on the SLM 4B and 4C and those images are respectively emitted as modulated beams 41B and 41C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image projection device using a spatial light modulator.

[0002]

2. Description of the Related Art FIG. 5 shows a spatial light modulator (Spatial Light
It is a figure which shows schematic structure of the conventional image projection apparatus using t Modulator: It describes with SLM hereafter. Reference numeral 30 denotes a CRT that constitutes a writing image forming apparatus, and an SLM 31 is arranged on the front surface of the CRT 30 via a fiber plate 32. Reference numeral 33 is a light source that generates light 35, and 34 is an optical system that guides the light 35 of the light source 33 to the polarization beam splitter 36. An optical system 37 forms an image of the P-polarized component 38 emitted from the polarization beam splitter 36 on the screen 39. The P polarization component 38 will be described later.

The light 35 guided to the polarization beam splitter 36 by the optical system 34 is a polarization beam splitter 36.
Is separated into an S-polarized light component and a P-polarized light component which are linearly polarized light components, and the S-polarized light component is bent 90 degrees with respect to the incident direction and is emitted to the SLM 31 as read light 40. On the other hand, the P-polarized light component goes straight through the polarization beam splitter 36 and is emitted. The written image formed by the CRT 30 is SL by the fiber plate 32.
The image is formed on the M31, and the SLM3 is formed according to the written image.
A read image is formed at 1. The read light 40 that has entered the SLM 31 undergoes a birefringence effect in accordance with the read image, and is emitted as modulated light 41 from the SLM 31 to the polarization beam splitter 36. The P-polarized component 38 included in the modulated light 41 travels straight through the polarization beam splitter 36, and the optical system 37 forms an image of the P-polarized component 38 on the screen 39.

In the full-color image projection apparatus, the structure shown in FIG.
As shown in FIG. 3, three CRTs, SLMs, fiber plates and polarization beam splitters are used for red images, green images and blue images, respectively. In FIG. 6, other devices related to the full-color image projection device are omitted. 51A, 51B and 51C are CRTs,
52A, 52B and 52C are SLMs, 53A, 53
B and 53C indicate fiber plates, respectively. The written image corresponding to the red signal formed by the CRT 51A is formed on the SLM 52A by the fiber plate 53A. Similarly, the written images corresponding to the green signal and the blue signal are SLM52B.
And 52C. On the SLMs 52A, 52B, and 52C, respective read images are formed corresponding to the write images of each of the three colors. The modulated lights corresponding to the read images of these three colors are SLMs 52A, 52B and 5 respectively.
It is emitted from 2C, and each P-polarized component is separated by the polarization beam splitter as in the case of FIG.
Since the P-polarized components are combined and formed on the screen by the optical system, a full-color display image is obtained.

[0005]

However, as shown in FIG. 6, in the conventional full-color image projection apparatus, three sets of CRTs corresponding to a red image, a green image and a blue image are provided.
Since the SLM and the fiber plate are required, there is a problem that the size and weight of the image projection device become large.

It is an object of the present invention to provide a full-color image projection device that is small in size and weight.

[0007]

Description will be made in association with FIGS. 1 and 2 showing an embodiment. To explain in association with FIG. 1, the invention of claim 1 is applied to an image projection apparatus that projects an image of at least two colors, and a plurality of spatial light modulation elements 4A and 4B corresponding to each color and a spatial light modulation element 4A. And one writing image forming apparatus 1 that forms an image to be written in each of 4B, an image forming apparatus 3 that forms an image in each of spatial light modulating elements 4A and 4B, and a plurality of spatial light modulating elements 4A. And image reading means 5, 33 and 34 for reading the respective images formed by 4B.
And the optical system 6 for synthesizing the images read by the image reading means 5, 33 and 34 to form an image on the screen 39, thereby achieving the above-mentioned object. When described in association with FIG. 2, the writing image forming apparatus is the liquid crystal image forming apparatus 16 like the image projecting apparatus of the invention of claim 2.
It may be configured by.

[0008]

In the image projecting device of the present invention, each of the writing images formed by one writing image forming device 1 passes through the image forming device 3 and each of the plurality of spatial light modulation elements 4A and 4B. Written in. In the image projection apparatus of the second aspect of the present invention, the liquid crystal image forming element 16 forms each written image to be written in each of the plurality of spatial light modulation elements 4A and 4B.

Incidentally, in the section of means and action for solving the above-mentioned problems for explaining the constitution of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. It is not limited to.

[0010]

Embodiments of the present invention will be described below with reference to FIGS. First Embodiment FIG. 1 is a perspective view showing a schematic configuration of a full-color image projection device according to the present invention. 1, the same parts as those in FIG. 5 are designated by the same reference numerals. Reference numeral 1 denotes a CRT that constitutes a writing image forming apparatus. In this embodiment, an image signal input to the CRT 1 is digitally processed, and the screen of the CRT 1 is divided into four in a square shape, and each divided screen is for red. An image based on a signal, an image based on a signal for green color, an image based on a signal for blue color, and a full-color display image using the signals of the three colors are formed. Reference numeral 101 denotes a screen for outputting the above-described full-color display image, which can be used as a monitor for the projection image displayed in full-color. On the front surface of the screen of CRT1, SLM4 corresponding to the respective written images of the red signal, the green signal and the blue signal of CRT1.
A, 4B and 4C are arranged via the fiber plate 3. Reference numeral 5 is a polarization beam splitter, which is a surface 5
A, 5B, 5C and 5D. 6 is screen 3
9 is an optical system including lenses 6A, 6B, and 6C for forming a projected image on the display unit 9. The light 35 generated by the light source 33 is incident on the lower surface of the polarization beam splitter 5 by the optical system 34.

FIG. 2 is a view seen from the direction of G (arrow) in FIG. 1, and the operation will be described with reference to this figure. It should be noted that the portion that cannot be seen in the vertical direction of the paper surface, that is, the SLM4
A, the screen 101, the surfaces 5A and 5D of the polarization beam splitter 5, and the lens 6A are omitted in the description. The light 35 incident from the lower surface of the polarization beam splitter 5 is separated into an S-polarized component and a P-polarized component, the S-polarized component is bent 90 degrees with respect to the incident direction, and the SLMs 4A, 4 as the read light 40.
Emitted to B and 4C. On the other hand, each of the written images by the red signal, the green signal and the blue signal formed by the CRT 1 is imaged by the fiber plate 3 on the corresponding SLMs 4A, 4B and 4C, respectively, and is formed on the SLMs 4A, 4B and 4C. A read image corresponding to each color is formed. Hereinafter, the SLMs 4B and 4C will be described.
And 4C are subjected to the birefringence effect according to the read-out images for the respective colors, and the modulated lights 41B and 41C
Is emitted as.

FIG. 3 shows the polarization beam splitter 5. When images 45A, 45B, 45C and 45D (including S-polarized component and P-polarized component, respectively) divided into four are incident on the rear surface facing the surfaces 5A, 5B, 5C and 5D as shown in the figure, the surfaces 5A, 5B , 5C and 5D output images 46A, 46B, 46C and 46D of P-polarized components, respectively. Then, the emitted image 46
A, 46B, 46C and 46D are focused at one point on the axis connecting the polarization beam splitter 5 and the screen 39 (not shown), and the surfaces 5A, 5B of the polarization beam splitter 5 are arranged so that their respective images overlap. , 5C and 5D are processed.

Returning to FIG. 2, when the modulated light 41B is incident on the polarization beam splitter 5, the P polarization component 38B contained in the modulated light 41B is converted into the surface 5B of the polarization beam splitter 5.
Is emitted to the lens 6B from which the image of the green signal is formed on the screen 7 by the lens 6B. Similarly, the P-polarized component 38C included in the modulated light 41C is imaged as a blue signal image on the screen 39 via the surface 5C and the lens 6C. The same applies to the SLM 41A (not shown), and an image of a red signal is formed on the screen 39. In this way, red on the screen 39,
The three images of green and blue are combined to form a full-color display image on the screen 39.

In the conventional full-color image projection apparatus, three sets of CRs are provided for red, green and blue images.
Using T, fiber plate and SLM,
According to the full-color image projection apparatus of this embodiment, one C
By RT1, the above three images are converted into three SLM4A,
Since the data is written in 4B and 4C, respectively, the size and weight of the image projection apparatus can be reduced, and further, the manufacturing cost can be reduced.

-Modification of First Embodiment- In FIG. 1, a CRT 1 is used as a writing image forming apparatus, but as shown in FIG. 4, a liquid crystal display device with a backlight (hereinafter, referred to as a liquid crystal image forming apparatus instead of the CRT 1) Then LC
16) may be used. FIG. 4 shows the writing image forming apparatus, fiber plate and S in FIG.
The LM portion is shown. The same parts as those in FIG. 1 are designated by the same reference numerals, and the description will be focused on the parts different from those in FIG.

Similar to the first embodiment, the image signal input to the LCD 16 is digitally processed and the screen of the LCD 16 is divided into four screens. Image by red signal is S
The images written in the LM 4A and by the green signal and the blue signal are written in the SLMs 4B and 4C, respectively. Note that reference numeral 161 denotes a screen for outputting a full-color display image, which can be used as a monitor for a projected image.

Also in the modification of the first embodiment shown in FIG. 4, since the above three images are written in the three SLMs 4A, 4B and 4C by one LCD 16, the same effect as in the first embodiment can be obtained. Obtainable.

In the embodiment described above, three images corresponding to three colors have been described, but the number of images is not limited to three and may be two or four or more. The written image was written to the SLM using a fiber plate, but other optical systems such as lenses may be used.

In the correspondence between the embodiment described above and the claims, the CRT 1 and the LCD 16 compose a writing image forming apparatus, and the polarization beam splitter 5, the light source 33 and the optical system 34 compose image reading means.

[0020]

As described above, according to the present invention,
Since a plurality of writing images corresponding to at least two colors are formed by one writing image forming apparatus, the size and weight of the image projection apparatus can be reduced. Further, the cost can be reduced because only one image forming apparatus is required.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a full-color image projection apparatus according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an operation of the full-color image projection device in FIG.

FIG. 3 is a diagram illustrating the polarization beam splitter of FIG.

FIG. 4 is a diagram showing a part of a full-color image projection device according to a modification of the first embodiment.

FIG. 5 is a diagram showing an operation of a conventional image projection device.

FIG. 6 is a diagram showing a part of a conventional full-color image projection device.

[Explanation of symbols]

1, 30, 51A, 51B, 51C CRT 3, 32, 53A, 53B, 53C Fiber plate 4A, 4B, 4C, 31, 52A, 52B, 52C Spatial light modulator 5, 36 Polarizing beam splitter 5A, 5B, 5C, 5D surface 6,34,37 Optical system 6A, 6B, 6C Lens 39 Screen 33 Light source 16 Liquid crystal display device with backlight

Claims (2)

[Claims] 1. An image projection apparatus for projecting an image of at least two colors, a plurality of spatial light modulation elements corresponding to the respective colors, and one written image forming a written image to be written in each of the spatial light modulation elements. A forming device; an image forming device that forms the written image on each of the spatial light modulators; an image reading unit that reads out each read image formed by the plurality of spatial light modulators; An image projection apparatus, comprising: an optical system that synthesizes the read images read by the reading unit and forms an image on a screen. 2. The image projection apparatus according to claim 1, wherein the writing image forming apparatus is a liquid crystal image forming apparatus.