JP3328238B2 - High-brightness projector using single-plate reflective element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention separates white light into monochromatic light by a double disk type dichroic mirror having a color filter that reflects or transmits each color by, for example, 120 °, and separates the separated monochromatic lights from each other. The present invention relates to a high-brightness projector using a single-plate reflective element configured to input an angle to a reflective element.

[0002]

2. Description of the Related Art As a flat panel display which is smaller and lighter than a CRT display device, a liquid crystal display device and a plasma light emitting display device have attracted attention. These flat panel displays are provided with a light source separately from a self-luminous type that emits light by itself, and a display device itself is largely a non-light emitting type of a transmittance control type that performs display by controlling light transmittance. Separated.

[0003] A liquid crystal display device which is being put to practical use in various fields as a favorite of the next-generation flat panel display is a representative of the latter transmittance control type. Further, a color liquid crystal projector is known as a flat panel display for displaying a large screen. In this technique, light from a lamp is condensed and incident on a liquid crystal panel, and transmitted light or reflected light is projected on a screen by a projection lens to display an image.

A liquid crystal panel can modulate the intensity of light two-dimensionally, so that it can modulate transmitted light and use an optical system to enlarge and project it to obtain a large-screen color image. . In recent years, rear type liquid crystal projectors incorporating this color liquid crystal projector have been developed.
These rear liquid crystal projectors are smaller and lighter than conventional CRT projectors.
Future development is expected.

[0005] In particular, such a rear-type liquid crystal projector is required to have high luminance and low cost. Conventionally, a three-panel type liquid crystal projector has been known as a color display system in such a color liquid crystal projector. The three-panel liquid crystal projector uses red, green, and blue light (hereinafter, light in the red wavelength range is called R, light in the green wavelength range is called G, and light in the blue wavelength range is called B for simplicity). The three primary colors,
A liquid crystal panel is made to correspond to each one, and color separation and synthesis are performed using an optical system such as a dichroic mirror.

On the other hand, in a single-panel liquid crystal projector, a single liquid crystal panel is used, and a color absorption filter (color filter) for each color is provided for each pixel. The three-panel type liquid crystal projector can display with high brightness because the reduction in light efficiency is small due to color separation and synthesis, whereas the single-panel type liquid crystal projector uses one liquid crystal panel. Therefore, it has the feature that a low-cost system can be realized.

[0007]

On the other hand, in recent years, a single-panel type liquid crystal projector which does not use a color filter has been developed. According to this display method, after spectroscopy is performed using a dichroic mirror, the separated light of each color is guided to a corresponding pixel on a liquid crystal panel using a microlens array. By adopting this display system, a display system with high brightness and low cost is realized to some extent.

However, since the single-panel type color liquid crystal projector having the above-described configuration uses a dichroic mirror to perform spectral separation, the reduction in light efficiency at the time of spectral separation is small, and the single-panel type liquid crystal projector has a simple structure. ,
Although there is an advantage that the manufacturing cost is low and the light condensing effect by the micro lens array can be expected, the luminance modulation is performed for each monochromatic light R
Since only one color of G and B can be effectively modulated, high luminance cannot be realized.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a double disk-type dichroic mirror having a color filter that reflects or transmits each monochromatic light, and separates white light into monochromatic light. It is an object of the present invention to obtain a high-brightness projector by inputting a plurality of monochromatic lights having an angle to each other to a reflective element.

[0010]

The present invention employs the following configuration to achieve the above object. Primarily,
White light is separated into monochromatic light by a double-disk type dichroic mirror having a color filter, and the separated monochromatic lights are input to a reflective element at an angle to each other. That is,
Equipped with a plate reflection type element and a double disk type dichroic mirror
The double disk type dichroic mirror is
The white light is R,
A color filter that separates into monochromatic light of G and B respectively
Are those provided, the double disc-type dichroic
Multiple monochromatic lights separated by a mirror have an angle to each other
It is configured to be input to the single-plate reflection type element.

Second, among the monochromatic lights separated by the double disk type dichroic mirror having the color filter,
One monochromatic light is perpendicular to the reflective element, and one of the other monochromatic lights is input to the reflective element at an angle. Third, the reflective element is formed by a microlens array having a band-like lens having a width of two columns of pixels.

Fourthly, the double disk type dichroic mirror having the color filters for reflecting or transmitting the respective colors is constituted by the color filters for reflecting or transmitting the respective colors by 120 °. Fifth, the microlens array is configured such that the central axis of the lens coincides with the central axis of every two pixels of the reflective element.

Sixth, when the input light to the microlens array is converged by the microlens array, a focus is formed after being reflected by the pixels of the reflective element. Seventh, if the light output from the microlens array is extended toward the reflective element assuming that there is no microlens array, the optical system is adjusted to focus on the pixels of the reflective element The configuration is as follows.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a high-brightness projector using a single-plate reflective element according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory view showing a structure of a high-brightness projector using a single-plate reflective element according to the present invention as viewed from the side, FIG. 2 is an explanatory view showing a structure also viewed from above, and FIG. FIG. 4 is an explanatory diagram showing the state of output from the pattern element as viewed from above, FIG. 4 is an explanatory diagram showing an input state of monochromatic light to the pixel of the reflective element, and FIG. 5 is also reflected by the pixel of the reflective element FIG. 6 is an explanatory view showing an output state of monochromatic light, and FIG. 6 is an explanatory view of output light from the microlens viewed from the output side.

When viewed from the side, a high-brightness projector using the single-plate reflection type element according to the present invention is configured as shown in FIG. In the figure, reference numeral 1 denotes white light.
Is a double disk type dichroic mirror 2 to be placed in front
Is separated into monochromatic light. By the way, the double-disk tie-croic mirror 2 converts the white light 1 into red, green, and blue light (hereinafter, for simplicity, light in the red wavelength range is R, light in the green wavelength range is G, and blue light is blue. This is for separating the light in the wavelength range into the three primary colors (referred to as B), and the configuration is configured as disclosed in FIG.

That is, the double-disk tie-croic mirror 2 is composed of a color filter 2a that reflects or transmits each color at 120 °, and a motor unit 2 provided at the center.
It is configured to be rotated at b. As shown in FIG. 2, the color filter 2a has an inner color filter and an outer color filter has R transmission and G transmission, G transmission and B transmission, and B transmission and R transmission for an image. It is configured to be able to switch synchronously.

The double-disk type dichroic mirror 2 separates one monochromatic light of the separated red light R, green light G, and blue light B perpendicularly to the reflection type element 3 and to another monochromatic light. It is configured such that one of the lights can be input at a predetermined angle with respect to the reflective element 3. That is, one of the monochromatic lights (R, G, B) transmitted through the inside of the double disk type dichroic mirror 2 is:
The monochromatic light transmitted through the color filter 2a inside the double-disk dichroic mirror 2 and input to the reflective element 3 at a predetermined angle and not able to pass through the inside of the double-disk dichroic mirror 2 ( R, G, B)
Are reflected by the total reflection mirror 4 disposed on the front side of the double disk type dichroic mirror 2 and again pass through the outside of the disk of the double disk type dichroic mirror 2 and are reflected. It is configured to be input perpendicular to the element 3.

The reflection type element 3 reflects each monochromatic light (R, G, B) transmitted through the double disk type dichroic mirror 2 to the optical insulator 5 in a dark state and projects it in a bright state. It is configured to reflect toward the lens 6. Each monochromatic light (R, G, B) passing through the projection lens 6 is configured to irradiate a screen 7 disposed in front as shown in FIG.

Hereinafter, the operation of the high-brightness projector using the single-plate reflection type element according to the present invention based on the above configuration will be described in detail. With reference to the state viewed from above in FIG. 2, a description will be given of how white light 1 is separated into monochromatic light (R, G, B) by the double-disk dichroic mirror 2 and input to the reflective element 3.

First, the white light 1 is disposed inside the color filter 2, for example, toward the transmission filter R. Then, the monochromatic red light R transmitted through the transmission filter R proceeds to the reflection element 3 as it is. At this time, the other green monochromatic light G light and blue monochromatic light B light reflected by the double disk dichroic mirror 2 are reflected by the total reflection mirror 4, and the green monochromatic light G reflected by the total reflection mirror 4. , The green monochromatic light G of the blue monochromatic light B goes to the green monochromatic light G light transmission filter disposed outside the double disk dichroic mirror 2.

The monochromatic green light G transmitted through the G light transmission filter travels toward the reflection type element 3 and is reflected by the total reflection mirror 4.
The blue monochromatic light B reflected again is not inputted to the reflective element 3 and is discarded. Note that the traveling directions of the monochromatic red light R and the monochromatic green light G input to the reflective element 3 have an angle in the horizontal direction and no angle in the vertical direction.

The rotation of the double disk dichroic mirror 2 for R transmission and G transmission, G transmission and B transmission, and B transmission and R transmission is controlled by a video signal and switched in synchronization. By the way, as described above, the light (G light) vertically input to the reflective element 3 passes through the microlens 8 and is located on the center line of the microlens 8 as shown in an enlarged view in FIG. Pixel 3 of reflective element 3
is input to a.

On the other hand, the monochromatic red light R input to the reflective element 3 at a predetermined angle is input by the microlens 8 to the pixel 3b of the reflective element 3 located on an extension between adjacent microlenses 8. . As a result, one monochromatic light (R, G, B) input perpendicularly to the reflective element 3 and the other monochromatic light (R, G, B) input at an angle have independent luminance. Modulation can be performed.

By the way, different monochromatic lights inputted to the predetermined pixels 3a and 3b as described above, as shown in FIG.
The light is reflected by the reflective element 3 and output. That is, one monochromatic light which is vertically input to the reflective element 3 and reflected is then focused and input by the microlens 8
Output through The monochromatic light output from the microlens 8 is adjusted so as to focus on the position of the reflective element 3 as shown in FIG.

On the other hand, one monochromatic light which is input to the reflective element 3 at a predetermined angle and reflected is output from the microlens 8 located next to the input microlens 8 having a focus. . Also in this case, the monochromatic light output from the microlens 8 is adjusted so as to focus on the position of the reflective element 3 assuming that the microlens 8 does not exist.

As described above, a plurality of monochromatic lights outputted after being subjected to luminance modulation by the reflection type element 3 are focused on the screen 7 through the projection lens 6 as shown in FIG.

[0027]

According to the present invention, as described in detail above,
The white light is separated into monochromatic light by a double disk type dichroic mirror having a color filter, and the separated monochromatic lights are input to a reflective element at an angle to each other, and one of the separated monochromatic lights is separated. Perpendicular to the reflective element
One of the reflection type elements is provided with an angle, and the reflection type element is configured as a microlens array having a band-shaped lens having a width of two columns of pixels. When the input light is converged by the microlens array, the focal point is formed after being reflected by the pixels of the reflective element while the central axis of the pixels of the reflective element is aligned with the pixels of every two columns of the pixels. ,
If the light output from the lens array of the reflective element is extended toward the reflective element, assuming that there is no microlens, the optical system is adjusted to focus on the pixel of the reflective element. In contrast to a projector using a conventional reflective element that can effectively use only one of the R, G, and B light components, a device that effectively uses two of the R, G, and B light components. Therefore, the projector using the single-plate reflection type element according to the present invention can realize high luminance.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a structure of a high-brightness projector using a single-plate reflection type element according to the present invention as viewed from the side.

FIG. 2 is an explanatory diagram showing a structure of a high-brightness projector using a single-plate reflection type element according to the present invention as viewed from above.

FIG. 3 is an explanatory diagram of an output from a reflective element of a high-brightness projector using a single-plate reflective element according to the present invention, as viewed from above.

FIG. 4 is an explanatory diagram showing an input state of monochromatic light to pixels of a reflective element of a high-brightness projector using a single-plate reflective element according to the present invention.

FIG. 5 is an explanatory diagram showing an output state of monochromatic light reflected by pixels of a reflective element of a high-brightness projector using a single-plate reflective element according to the present invention.

FIG. 6 is an explanatory diagram of output light from a microlens by a high-brightness projector using a single-plate reflective element according to the present invention as viewed from an output side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 White light 2 Double disk type dichroic mirror 2a Color filter 2b Motor part 3 Reflection type element 3a, 3b Pixel 4 Total reflection mirror 5 Optical insulator 6 Projection lens 7 Screen

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G03B 21/00 G02F 1/13 505 G03B 33/12 H04N 5/74 H04N 9/31

Claims (7)

(57) [Claims] (1)Single-plate reflective element and double disk type dichroic
A high-brightness projector having a back-up mirror and The double disk type dichroic mirror is on the same surface
R, G, B white light at the inner and outer positions
Color filters that separate light into monochromatic light
Was A plurality separated by the double disk type dichroic mirror
Monochromatic lights enter the single-plate reflective element at an angle to each other.
Configured to be empowered High brightness screen
Logecta. 2. Separation by a double disk type dichroic mirror
Perpendicularly to one monochromatic light reflective element of the monochromatic light, another one of a monochromatic light against the reflective element
2. The high-brightness projector according to claim 1, wherein the projector is configured to be input with an angle. 3. The double disk type dichroic mirror comprises:
High brightness projector according to claim 1, characterized in that it is constituted by a color filter which reflects or transmits the respective colors by 20 °. 4. The high-brightness projector according to claim 1, wherein the reflection-type element is constituted by a microlens array having a band-like lens having a width of two columns of pixels. 5. The high-brightness projector according to claim 4, wherein in the micro lens array, the central axis of the lens is aligned with the central axis of the pixel of every two pixels of the reflective element. 6. When the input light to the microlens array you converged by the microlens array, is constructed such that the focal point is formed after being reflected on the pixel of the reflective element
High brightness projectors of claim 5, characterized in that it was. 7. An optical system adjusted to focus on a pixel of a reflective element when light output from the microlens array is extended toward a reflective element assuming that there is no microlens array. A high-brightness projector characterized by having: