JPH1020395A - Lcd projector device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To spectrally split and synthesize light by dichroic mirrors and to eliminate the omission of an image by specifying the arrangement of plural dichroic films separating the incident white light and plural dichroic films individually modulating separated color components by LCDs and synthesizing the modulated color components. SOLUTION: The dichroie mirrors for spectrally splitting light 21 and 22 are arranged in parallel by inclining the film surfaces thereof by 45 deg. with respect to the incident light A. By the mirror 21, the color component R of red is reflected. By the mirror 22 separating the color component of the transmitted light thereof, the color component B of blue is reflected. A total reflection mirror 25 is arranged in the reflecting direction of the mirror 21. The LCD 28 and the dichroic mirror for synthesizing 23 are arranged in the reflecting direction of the mirror 22 and the LCD 27 and a total reflection mirror 29 are arranged in the transmitting direction thereof. Besides, the LCD 26 and the dichroic mirrors for synthesizing 23 and 24 are arranged in the reflecting direction of the mirror 25 and the mirror 24 is arranged in the reflecting direction of the mirror 29. Then, all of the mirrors including the total reflection mirrors are arranged so that the surfaces thereof become in parallel with the surfaces of the mirrors 21 and 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention disperses a video signal consisting of incident white light into three primary color components, and modulates each color component using a liquid crystal display (LCD). The present invention relates to an LCD projector device that recombines and projects a full-color image.

[0002]

2. Description of the Related Art In a conventional LCD projector of this type, as shown in FIG. 3, two dichroic mirrors having different properties are used as means for separating parallel incident light A, which is white light, into three primary colors. The dichroic mirrors 1 and 2 provided are crossed with each other. For example, a dichroic mirror 1 that reflects a blue color component B and a dichroic mirror 2 that reflects a red color component R is used. The three color components R, G, B separated by the intersecting dichroic mirrors 1, 2
Among them, R is reflected by the total reflection mirrors 3 and 4, and the color component G
Goes straight as it is, and the color component B is the total reflection mirrors 5 and 6.
LCDs 7, 8, 9 corresponding to
Is incident on. Since the images of the red, green, and blue color components are projected on the LCDs 7, 8, and 9, when the light passes therethrough, the change in the transmittance due to the images of the LCDs 7, 8, and 9 causes the intensity of the light to change. Modulated.

That is, in FIG. 3, red, green, and blue color components R, G, and B are modulated by video signals of LCDs 7, 8, and 9 to become color components R ', G', and B ', respectively. The light is recombined by the dichroic prism 10 and output as output light A '. The emitted light A 'is projected onto a screen by a projection lens (not shown) as is well known, and a full-color image is projected on the screen.

[0004]

However, in the conventional example, since two types of dichroic mirrors 1 and 2 are used in a crossed state as shown in FIG. 4, one dichroic mirror 1 has one reflecting surface. There is a disadvantage that the image is partially missing due to the lack of the portion. For example, assuming that the dichroic mirrors 1 and 2 cross each other at a right angle in FIG. 4, the relationship between the thickness t of the dichroic mirror 1 and the dimension t 'of the portion where the reflecting surface is missing is expressed by the following equation. t '= t / 2 ^1/2 ... (1)

[0005] t 'in the equation (1) is a value that cannot be ignored, and there is an inconvenience that, for example, the center of blue is lost in a stripe shape. Further, the cross dichroic prism 10 used for synthesizing the modulated color components in the conventional example has a complicated structure, and is expensive and heavy.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art by dispersing and synthesizing light with only a dichroic mirror. In addition, an object of the present invention is to provide an LCD projector device that can be made thinner in a projection direction of emitted light that is color image light.

[0007]

In order to achieve the above object, an LCD projector according to the present invention comprises a first spectral device for separating incident white light into one color component of three primary colors and the remaining color components. A dichroic film for separation, a second dichroic film for spectral separation for separating the remaining color components into two color components, three LCDs for individually receiving and modulating the separated three color components, and 3 modulated by LCD
A first color synthesizing dichroic film for synthesizing two of the two color components, and a second color synthesizing light synthesized by the first color synthesizing dichroic film and the remaining one color component
And the first and second dichroic films for color synthesis.
The first and second dispersive dichroic films are arranged along a direction perpendicular to the projection direction of the combined light by the combining dichroic film, and the first and second dichroic films are arranged along a direction perpendicular to the projection direction. Characterized in that a dichroic film for synthesis is arranged.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the illustrated embodiment. FIG. 1 shows an LCD projector device on which the present invention is based, and 11 is, for example, a red and blue color component R,
B: First spectral dichroic mirror for reflecting B, 12
Is a second spectral dichroic mirror for separating the reflected color components R and B. The second spectral dichroic mirror 12 has a property of reflecting the blue color component B. . The first and second spectroscopic dichroic mirrors 11 and 12 are arranged in parallel to the incident light A in the direction of 45 °.
These dichroic mirrors 11 on both sides of
Total reflection mirrors 13 and 14 are arranged in parallel with 12. Further, the first and second spectral dichroic mirrors 1
A first combining dichroic mirror 15 that reflects the blue color component B and a second combining dichroic mirror 16 that reflects the red color component R are arranged in the direction in which the surfaces 1 and 12 are extended, and are totally reflected. L in the direction parallel to the incident light A between the mirror 13 and the first synthesizing dichroic mirror 15.
A CD 17 is arranged, and L is set in a direction orthogonal to the incident light A between the first and second dichroic mirrors 11 and 12 for dispersion.
A CD 18 is disposed, and L is set in a direction parallel to the incident light A of the second spectral dichroic mirror 12 and the total reflection mirror 14.
A CD 19 is provided.

The incident light A is incident on the first spectral dichroic mirror 11, and the green color component G transmitted therethrough is reflected by the total reflection mirror 13 before being incident on the LCD 17. The blue color component B reflected by the dichroic mirror 11 and reflected by the second spectral dichroic mirror 12 is transmitted to the LCD 18, and the red color component R transmitted through the second spectral dichroic mirror 12 is transmitted to the LCD 1.
9 respectively. LCDs 17, 15, and 16 display images corresponding to green, blue, and red color components G, B, and R, respectively.
16, each color component G, B, R is modulated by the intensity of the respective light, and the color components G ′, B ′, R ′ are changed.
Becomes These modulated color components G ', B', R 'are recombined and projected on the screen as full-color emission light A'.

The green color component G 'modulated by the LCD 17 is transmitted through the first synthesizing chromatic mirror 15 and the second synthesizing dichroic mirror 16 and output. Also,
The blue color component B ′ modulated by the LCD 18 is reflected by the first synthesizing dichroic mirror 15 and becomes a green color component G ′.
Is synthesized with Further, the red color component R 'modulated by the LCD 19 is reflected by the total reflection mirror 14 and then reflected by the second dichroic mirror 16 for synthesis, where it is synthesized with the green and blue color components G' and B '. The emitted light becomes A '. The optical path length of each color component is the same.

However, in the case of this example, the green color component G
Is transmitted through the two dichroic mirrors 15 and 18 after an image is formed by the LDC 17, and is greatly affected by aberration.

FIG. 2 shows an embodiment of the present invention.
The spectroscopic dichroic mirrors 21 and 22 tilt the dichroic film surface in the direction of 45 degrees with respect to the incident light A,
They are arranged in parallel along the incident direction of the incident light A. The first spectral dichroic mirror 21 has a characteristic of reflecting the red color component R, and the second spectral dichroic mirror 21 separates the green and blue color components transmitted through the first spectral dichroic mirror 21.
The spectroscopic dichroic mirror 22 has a characteristic of reflecting the blue color component B. A total reflection mirror 25 is disposed in the reflection direction of the first spectral dichroic mirror 21, and the LCD 28 and the first combining dichroic mirror 2 are disposed in the reflective direction of the second spectral dichroic mirror 22.
3 is disposed, and the second spectral dichroic mirror 22
The LCD 27 and the total reflection mirror 29 are arranged in the transmission direction. The direction of reflection of the total reflection mirror 25 is LC
D26, first combining dichroic mirror 23, second
Are arranged, and a second dichroic mirror 24 is sequentially arranged in the reflection direction of the total reflection mirror 29. All mirrors including the total reflection mirror have their surfaces arranged in parallel with the surfaces of the first spectral dichroic mirror 21 and the second spectral dichroic mirror 22.

The incident light A is incident on a first spectral dichroic mirror 21, and a component transmitted therethrough is reflected by a second dichroic mirror 22 to a blue color component B and a green color component G is transmitted. The green color component G transmitted through the second dichroic mirror 22 enters the LCD 27. Also,
The red color component R reflected by the first spectral dichroic mirror 21 is reflected by the total reflection mirror 25, and then reflected by the LCD.
26. Further, the blue color components B reflected by the second spectral dichroic mirror 22 enter the LCD 28, respectively. LCDs 27, 26, and 28 display images corresponding to green, red, and blue color components G, R, and B, respectively, and these images are displayed on LCDs 27, 26, and 28, respectively.
, Each of the color components G, R, and B is modulated into the intensity of each light to become color components G ′, R ′, and B ′.

The green color component G 'modulated by the LCD 27 is transmitted through the second synthesizing dichroic mirror 24 and output. The red color component R modulated by the LCD 26 passes through the first dichroic mirror 23 for synthesis and
To the combining dichroic mirror 24, where it is reflected and combined with the green color component G '. Also, the LCD 28
Are reflected by the first dichroic mirror for synthesis 23 and reach the second dichroic mirror for synthesis 24, where they are reflected and converted into green and red color components G ′ and R ′. The light is synthesized and projected on the screen as a full-color outgoing light A 'from a direction orthogonal to the incident light A.

In this embodiment, the red color component R 'is reflected once by the spectral dichroic mirror, is transmitted once by the combining dichroic mirror and is reflected once, and the green color component G' is spectrally reflected. Penetrates the dichroic mirror twice and penetrates the dichroic mirror for synthesis once,
The blue color component B 'transmits once and reflects once through the spectral dichroic mirror, reflects twice through the synthesizing dichroic mirror, and does not transmit through the dichroic mirror at all.

As described above, since the number of times of transmission of each dichroic mirror is zero or one at the time of color synthesis after image formation, the influence of image aberration by the dichroic mirror for synthesis is reduced. Is done. Also, the two dichroic mirrors 21 and 22 for spectroscopy and the two dichroic mirrors 23 and 24 for synthesis are arranged along the direction orthogonal to the projection direction of the emission light A ′, that is, the color image (light). With this configuration, the thickness of the projector device is reduced in the projection direction.

In the embodiment, for example, the red and blue light paths may be reversed. In this case, various combinations are possible by appropriately selecting each dichroic mirror and LCD so as to match each color component.

[0018]

As described above, the LCD according to the present invention is described.
The projector device can be configured so as to be able to separate and combine light by using a dichroic mirror instead of the conventionally used dichroic prism. Further, since there is no need to cross the dichroic mirrors for spectroscopy as in the related art, the problem of image loss in the related art is completely eliminated. Further, it is possible to reduce the thickness of the device with respect to the projection direction.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an LCD projector device as a premise of the present invention.

FIG. 2 is an optical layout diagram of an embodiment of the LCD projector device according to the present invention.

FIG. 3 is a layout diagram of a conventional example.

FIG. 4 is an enlarged view of a crossed state of a dichroic mirror in a conventional example.

[Explanation of symbols]

 21, 22 Dichroic mirror for spectrum 23, 24 Dichroic mirror for synthesis 25, 29 Total reflection mirror 26, 27, 28 LCD

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location H04N 9/31 H04N 9/31 C

Claims (3)

[Claims] 1. A first dichroic film for splitting incident white light into one color component of three primary colors and a remaining color component, and a second dichroic film splitting the remaining color component into two color components. A dichroic film for spectroscopy, three LCDs for individually receiving and modulating the three separated color components, and a second LCD for synthesizing two of the three color components modulated by these LCDs. (1) the dichroic film for color synthesis, the light synthesized by the first dichroic film for color synthesis, and the remaining 1
A second dichroic film for synthesizing two color components, and the first and second dichroic films are arranged along a direction orthogonal to a projection direction of synthetic light by the first and second dichroic films for synthesis. Along with placing a spectroscopic dichroic film,
LC wherein the first and second dichroic films for synthesis are arranged along a direction orthogonal to the projection direction.
D projector device. 2. Each of two color components of the three primary colors passes through only one dichroic film and is reflected by another dichroic film, and the remaining one color component is subjected to two dichroic films during color separation. , And then the optical path is 9
2. The LCD projector device according to claim 1, wherein the LCD projector device is configured so as to be bent by 0 degrees and to pass through one dichroic film disposed on the optical path bent by 90 degrees in color synthesis. 3. The LCD projector according to claim 2, wherein the one remaining color component is green.