JP3081973U - Transmissive liquid crystal projection display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmissive liquid crystal projection display which is efficient, low in manufacturing cost and simplifies manufacturing difficulty. SOLUTION: An incident light source is a single polarized light, and the polarized light is divided into three primary colors by a color separation device, and three transmission liquid crystal pieces respectively correspond to the three primary colors, and adjusting means using an optical path. Guides the three primary colors of light, passes through each of the liquid crystal pieces, and then enters the L-shaped polarized light splitting prism device,
The three primary color lights are combined into one output light beam, and the projection lens projects the output light beam.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a type of liquid crystal projection system, and more particularly, to a transmission type liquid crystal projection display employing a type of L-shaped polarized light color separation prism device.

[0002]

[Prior art]

 The transmissive liquid crystal projection display has the advantages of high image quality, small volume, and easy portability, and can produce a large-area display device. However, there are differences in the degree of difficulty in manufacturing due to the difference in the design of the optical system, because the working principle of the liquid crystal piece modulates the polarization mode of light, modifies the intensity of output light, and changes This is because different gray scales appear, and it is necessary to adjust the light intensity by providing a vibrating piece before and after the liquid crystal piece.

The well-known transmissive liquid crystal projection display employs a single liquid crystal piece and a three-piece liquid crystal piece. The three-piece liquid crystal projection device is more complicated than the single-piece liquid crystal projection device. Liquid crystal projectors have a space for development in brightness and resolution, and for this reason, three-piece liquid crystal projectors are currently the mainstream of high quality liquid crystal projectors. In general, a three-piece liquid crystal projection apparatus combines polarized light beams of three primary colors into one using a cross dichroic prism. For example, the projection devices described in U.S. Pat. Nos. 5,073,131 and 5,075,798 have relatively high manufacturing costs, and the crossed colorimetric prism used is relatively complicated in structure and manufacturing, and the difficulty is high. Was high.

[0004]

[Problems to be solved by the invention]

 An object of the present invention is to provide a kind of transmissive liquid crystal projection display, which overcomes the above-mentioned disadvantages of the prior art.

That is, the main object of the present invention is to provide a transmission type liquid crystal projection display equipped with a kind of L-shaped polarized light splitting prism device, thereby achieving the function of high efficiency and low manufacturing cost. It is in.

[0006] Another object of the present invention is to simplify the difficulty of the polarized light splitting prism device used in the transmissive liquid crystal projection display and the difficulty in manufacturing the device.

[0007]

[Means for Solving the Problems]

 The invention according to claim 1 includes: an incident light source that is a single polarized light; a colorimetric device that divides the polarized light into three primary colors; three transmissive liquid crystal pieces respectively corresponding to the three primary colors; And an L-shaped polarized light splitting prism device that forms one output light beam, and guides the three primary color lights from the color separating device to the L-shaped polarized light splitting prism device via the corresponding liquid crystal piece. A transmission type liquid crystal projection display, comprising: an optical path adjusting means for performing the operation; and a projection lens for projecting the output light beam. The invention according to claim 2 is the transmissive liquid crystal projection display according to claim 1, wherein the single polarized light is one of vertical polarized light and horizontal polarized light. According to a third aspect of the present invention, the colorimetric device reflects a first primary color light of the polarized light and projects the other two primary color lights, a first polarized light color separation piece, and a second primary color light. 2. A transmissive liquid crystal projection display according to claim 1, further comprising: a second polarized light separating piece for projecting light of three primary colors. The invention according to claim 4 is characterized in that the L-shaped polarized light splitting prism device is composed of two adjacent polarized light splitting prisms and one vertically interconnected equivalent glass block. 1 is a transmissive liquid crystal projection display. The invention according to claim 5 is characterized in that one wave piece is installed between the two adjacent polarized light color separating prisms to modify the polarized state of incident primary color light. It is a transmissive liquid crystal projection display. The invention according to claim 6 is the transmission type liquid crystal projection display according to claim 1, characterized in that the optical path adjusting means adjusts the march path of the three primary colors by a plurality of reflecting mirrors. The invention of claim 7 is that in the transmissive liquid crystal projection display, two sets of polarized light splitting prisms are respectively formed between two joined first and second prisms, and between the first and second prisms. The transmissive liquid crystal projection display according to claim 1, further comprising a dielectric film.

[0008]

[Embodiment of the invention]

 The transmissive liquid crystal projection display of the present invention has an incident light source, uses two polarized light splitting pieces and three reflecting mirrors, divides the incident polarized light into three bundles of primary color light, and After each passing through one liquid crystal piece, it is made incident on one L-shaped polarized light splitting prism apparatus, which is composed of two polarized light splitting prisms and one equivalent glass block. Then, the three primary color lights are combined into one light beam, and the light beam is transmitted through one projection lens and projected on the screen.

[0009]

【Example】

 The main feature of the present invention is to use the L-shaped polarized light color separation prism device instead of the well-known cross-type color separation prism device, effectively solve the well-known problem and achieve the function of the present invention. It is in.

As shown in FIG. 1, the transmissive liquid crystal projection display 10 of the present invention comprises an incident light source 12 which provides a parallel beam of single polarized light, which is a single vertical polarized light. Light (S-polarization) or single parallel polarized light (P-polization). The color separating device 14 includes a first polarized light separating piece 16 and a second polarized light separating piece 18, and the first polarized light separating piece 16 converts the polarized light into red, blue, and green (R, B, and G). ) Is divided into two bundles, the first primary color light is reflected, and the other two primary color lights are projected. The second polarized light separation piece 18 converts the two primary color lights into two single light beams. The second primary color light is reflected, and the third primary color light is projected. The L-shaped polarized light splitting prism device 20 is composed of two adjacent polarized light splitting prisms 22 and 24 and one equivalent glass block 26 which is vertically connected to each other. One transmissive liquid crystal piece 28, 30, 32 is provided on each of the entrance surface of the polarized light color separation prism 22 and one entrance surface of the equivalent glass block 26, and the three primary colors are respectively provided. It is made to correspond to light. In addition, the three primary color lights guided by the optical path adjusting means pass through the corresponding liquid crystal pieces 28, 30, and 32 from the color separation device 14 and enter the L-shaped polarized light color separation prism device 20, and the first primary color light, The second primary color light and the third primary color light are combined to form one light flux.

In other words, the first primary color light reflected by the first polarized light color separating piece 16 is first controlled in its traveling path by using the reflection of the reflecting mirror 34, and enters the equivalent glass block 26 through the liquid crystal piece 28. After passing through the equivalent glass block 26 and entering the polarized light color separation prism 24, it is reflected therefrom. The second primary color light reflected by the second polarized light separating piece 18 is emitted after passing through the liquid crystal piece 30, the polarized light separating prism 22 and the polarized light separating prism 24 in this order. After being reflected by the two reflecting mirrors 34 and 38, the third primary color light is first transmitted through the liquid crystal piece 32, is reflected by the polarized light color separating prism 22, and is transmitted through the polarized light separating prism 22 to form the third primary color. The light, the first primary color light, and the second primary color light are combined to form one output light beam, and the output light beam is projected via the projection lens 40, whereby the light beam is projected on the screen to display an image.

[0012] Of the two sets of polarized light splitting prisms described above, each of the two polarized light splitting prisms is a first prism and a second prism joined together into one, and a first prism. And a dielectric thin film formed between the first prism and the second prism. The characteristic of the dielectric film is to reflect or project primary color light.

Although the present invention describes the structure of the whole transmissive liquid crystal projection display and the primary color light path according to the above embodiments, the present invention has other different embodiments. For example, in the embodiment shown in FIG. 2, the liquid crystal piece 32 is installed on another incident surface of the polarized light color separating prism 22, and the second polarized light separating piece 18 is placed on the first polarized light separating piece 16. And a reflecting mirror 34, corresponding to the liquid crystal piece 32, and using only two reflecting mirrors 34 and 36 to adjust the traveling path of the primary color light. Is completely different from that shown in FIG. As a result, the first primary color light transmitted through the first polarized light color separating piece 16 is first reflected by the reflecting mirror 36, then enters the polarized light color separating prism 22 via the liquid crystal piece 30, and is subjected to the polarized light color separating. The light passes through the prisms 22 and 24 in order and is emitted. The second primary color light reflected by the second polarized light color separating piece 18 first passes through the liquid crystal piece 32, is reflected by the polarized light color separating prism 22, and then passes through the polarized light color separating prism 24 and is emitted. Is done. The third primary color light is first reflected by the reflecting mirror 34, then transmitted through the liquid crystal piece 28 and the equivalent glass block 26, and then is reflected via the polarized light color separation prism 24, and the first primary color light and the second primary color The light and the third primary color light are combined into one output light flux.

The present invention can also modify the structure of the L-shaped polarized light splitting prism device 20, and as shown in FIG. 3, there are two horizontally adjacent polarized light splitting prisms 22, 24. A rectangular glass block 42 is connected to one side of the polarized light color separating prism 24, and one liquid crystal piece 28, 30 is provided on each of the two incident surfaces of the polarized light separating prism 22 and the rectangular glass block 42. 32, that is, the first polarized light reflected by the first polarized light separating piece 16 is reflected by the reflecting mirror 34, and then passes through the liquid crystal piece 28 and the polarized light separating prism 22 to be further deflected. The light is reflected by the color prism 24. The second primary color light reflected by the second polarized light color separating piece 18 passes through the liquid crystal piece 30 and is reflected and emitted by the polarized light separating prism 22 and the polarized light separating prism 24 and emitted. After being reflected by the reflecting mirrors 36 and 38, the third primary color light is transmitted through the liquid crystal piece 32, reflected by the rectangular glass block 42 and transmitted through the polarized light color separating prism 24, and the three primary colors are combined to form one output light flux. It is said.

In addition, in the present invention, the equivalent glass block 26 can be used instead of the square glass block 42 of the L-type polarized light splitting prism device 20 shown in FIG. 3, and as in the embodiment shown in FIG. In addition, a liquid crystal piece 32 is provided on the incident surface of the equivalent glass block 26, and the path of the third primary color light is adjusted by one reflecting mirror 36, and the other parts are the same as the above described optical path of FIG. Therefore, the description is omitted.

[0016]

[Effect of the invention]

 As described above, the present invention makes use of the features of the L-shaped polarized light splitting prism apparatus, and simplifies the difficulty and manufacturing difficulty of the polarized light splitting prism apparatus used in the transmission type liquid crystal projection display. This achieves the effects of high efficiency and low manufacturing costs.

The embodiments described above are provided for explaining the present invention, and do not limit the scope of the claims of the present invention. It shall belong to the claims of the invention.

[Brief description of the drawings]

FIG. 1 is a structural view of the present invention.

FIG. 2 is a schematic view showing another embodiment of the present invention.

FIG. 3 is a schematic view showing another embodiment of the present invention;

FIG. 4 is a schematic view showing another embodiment of the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 10 transmissive liquid crystal projection display 12 incident light source 14 color separation device 16 first polarized light color separating piece 18 second polarized light separating color piece 20 L-shaped polarized light separating prism apparatus 22 polarized light separating prism 24 polarized light separating prism 26 Equivalent glass block 28 Liquid crystal piece 30 Liquid crystal piece 32 Liquid crystal piece 34 Reflecting mirror 36 Reflecting mirror 38 Reflecting mirror 40 Projection lens 42 Square glass block

Claims (7)

[Utility model registration claims] 1. An incident light source having a single polarized light, a colorimetric device for dividing the polarized light into three primary colors, three transmission liquid crystal pieces respectively corresponding to the three primary colors, and combining the three primary colors. An L-shaped polarized light splitting prism device that forms one output light beam; and an optical path for guiding the three primary color lights from the color separating device to the L-shaped polarized light splitting color prism device via the corresponding liquid crystal piece. A transmissive liquid crystal projection display, comprising: adjusting means; and a projection lens for projecting the output light beam. 2. The transmissive liquid crystal projection display according to claim 1, wherein the single polarized light is one of vertical polarized light and horizontal polarized light. 3. A color separation device for reflecting a first primary color light of polarized light and projecting the other two primary color lights, a first polarized light color separation piece, and reflecting a second primary color light to form a third primary color light. 2. The transmissive liquid crystal projection display according to claim 1, further comprising: a second polarized light separating piece for projecting light. 4. The apparatus according to claim 1, wherein the L-shaped polarized light separating prism apparatus is composed of two adjacent polarized light separating prisms and one vertically connected equivalent glass block. A transmissive liquid crystal projection display as described. 5. The transmission type liquid crystal according to claim 4, wherein one wave piece is disposed between the two adjacent polarized light color separating prisms to change the polarized state of the incident primary color light. Projection display. 6. The transmissive liquid crystal projection display according to claim 1, wherein said optical path adjusting means adjusts a march path of said three primary colors by a plurality of reflecting mirrors. 7. The transmission type liquid crystal projection display, wherein two sets of polarized light splitting prisms are respectively connected to the first and second prisms, and a dielectric formed between the first and second prisms. 2. The transmissive liquid crystal projection display according to claim 1, further comprising a film.