JP2000267046A - Color picture projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a color picture projection device, which composites pictures of B, R and G displayed at LCDs(reflection type liquid crystal display panels) for B, R and G, and magnifys and displays them on a screen by a projection lens, small in size and low in piece. SOLUTION: This device is provided with a color separation element 36 separating the components of B, R and G from incident light (S-polarized light), a first PBS(polarizing beam splitter) 48 reflecting either of the separated components of B and R and transmitting the other component so as to irradiate the LCDs 22 and 30 and transmitting either of the reflected light and reflecting and outputting the other component, a second PBS 50 reflecting the component of G so as to irradiated the LCD 26 and transmitting and outputting the reflected light and a color synthesizing element 52 synthesizing the components of B, R and G outputted from the PBS 48 and the PBS 50 and outputting them to the projection lens 34. Then, the element 36, the PBS 48, the PBS 50, the LCDs 22, 30 and 26 and the element 52 are arranged so that the length of optical paths that the components of B, R and G separated by the element 36 arrive at the LCDs 22, 30 and 26 become equal to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image projection apparatus which combines red, blue and green images displayed on three reflection type liquid crystal display panels and enlarges and displays them on a screen by a projection lens.

[0002]

2. Description of the Related Art Conventionally, this type of color image projection apparatus has been configured as shown in FIG. That is, the light source 10
(Hereinafter simply referred to as R), green (hereinafter referred to as R)
Simply G. ) And blue (hereinafter simply referred to as B), after condensing S-polarized light (or P-polarized light) containing the three color components by the condensing lens 12, the first and second dichroic mirrors 14, 1
In step 6, the R and G components are sequentially reflected and separated, and the B component is transmitted and separated. The separated R component is reflected by a total reflection mirror 18 via a relay lens 17, and further led to a first polarizing beam splitter (hereinafter simply referred to as a first PBS) 20 via a relay lens 19, and this first PBS 2
A reflection type liquid crystal display panel (hereinafter, simply referred to as an R LCD) 22 that reflects the image at 0 and displays the R image is irradiated with the reflected light (this reflected light is converted from S-polarized light to P-polarized light). Output through. The separated G component is used as a second polarization beam splitter (hereinafter simply referred to as a second PBS) 24.
A reflective liquid crystal display panel (hereinafter, simply referred to as an LCD for G) 26 that has displayed a G image by being reflected by the LCD is irradiated with the reflected light (this reflected light is converted from S-polarized light to P-polarized light).
And output. A reflection type liquid crystal display panel (hereinafter simply referred to as a reflection type liquid crystal display panel) displaying a B image by reflecting the separated B component transmitted through the first and second dichroic mirrors 14 and 16 by a third polarization beam splitter (hereinafter simply referred to as a third PBS) 28. The LCD 30 irradiates the reflected light (this reflected light is converted from S-polarized light to P-polarized light) and outputs the reflected light. The cross prism 32 reflects the R and B components output from the first and third PBSs 20 and 28, transmits the G component output from the second PBS 24, combines the R, G, and B components, and combines the combined light into a projection lens. At 34, the image was enlarged and projected on a screen (not shown).

[0003]

However, FIG.
Has the following problems. (1) From the light source 10 to the LCD 22 for R, the LCD 26 for G,
Since the optical path lengths of the R, G, and B components reaching each of the B LCD 30 are different, an extra lens for individually adjusting the focal length is required. (2) Since the expensive cross prism 32 is used as the color synthesizing element, the price of the device becomes high. This is because the cross prism 32 is made by combining four parts, so that the yield is low and the cost is high. (3) Since the first PBS 20, the second PBS 24, and the third PBS 28 are also required as the polarizing beam splitters, it is not possible to reduce the size of the entire apparatus in combination with the above (1).

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has no need for an extra lens by equalizing the optical path lengths of the R, G, and B components from the light source to the R, G, and B LCDs. It is an object of the present invention to provide a color image projection apparatus which eliminates the need for an expensive cross prism, reduces the number of required polarization beam splitters, and can downsize the entire apparatus.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a color image projection apparatus for synthesizing red, blue and green images displayed on three reflective liquid crystal display panels and enlarging and displaying the images on a screen with a projection lens. While separating the three color components of red, blue and green from the incident light polarized to the P-polarized light,
A color separation element that outputs one of the second color components as S-polarized light, the other as P-polarized light, and the third color component as S-polarized light (or P-polarized light);
One of the first and second color components separated by the color separation element is reflected and transmitted through the other to irradiate the corresponding first and second reflective liquid crystal display panels, while transmitting one of the reflected light. A first polarizing beam splitter that reflects and outputs the other, and reflects (or transmits) the third color component separated by the color separation element to irradiate the corresponding third reflection type liquid crystal display panel and to reflect the reflected light. A second polarizing beam splitter that transmits (or reflects), the first and second color components output from the first polarizing beam splitter, and the third color component output from the second polarizing beam splitter are combined and output to the projection lens. And a first, second, and third color components respectively corresponding to the first, second, and third color components separated by the color separation element.
The color separation element, the first and second polarization beam splitters, the first, second and third reflection type liquid crystal display panels, and the color combining element are arranged so that the optical path lengths up to the reflection type liquid crystal display panel are equal. It is characterized by becoming.

The first, second, and third color separation elements separated by a color separation element
Since the optical path lengths to the first, second, and third reflective liquid crystal display panels corresponding to the respective color components are equal, an extra lens for individually adjusting the focal length is not required. The color separation element separates the incident light into three color components of red, blue, and green, and one of the first and second color components (for example, the first color component) is S-polarized light and the other (for example, the second color component). Component) becomes P-polarized light, and the third color component becomes S-polarized light (or P-polarized light).
Each of the second and third color components irradiates the corresponding first, second and third reflection type liquid crystal display panel, and outputs the reflected light, and is output from the first and second polarization beam splitters by the color combining element. The output first, second, and third color components are combined and output to a projection lens, and a color image is displayed on a screen. Therefore, an expensive cross prism is not required.
Only two polarization beam splitters are required.

In order to simplify the structure of the color separation element, the color separation element is formed by sequentially stacking a first retardation layer, a first dichroic layer, a second retardation layer, and a second dichroic layer on a transparent substrate. And separating the first, second, and third color components from the incident light by the first and second dichroic layers.
One of the first and second color components (for example, the first color component) is S-polarized light and the other (for example, the second color component) is P by the second retardation layer.
The polarized light and the third color component are S-polarized (or P-polarized).

In order to reduce the angle dependence of the third color component due to the first retardation layer and to allow the third color component to reach the third reflective liquid crystal display panel in a state of high polarization, A separating element, a retardation plate having a first retardation layer formed on a transparent substrate, a first dichroic layer on a transparent substrate,
A second phase difference layer and a second dichroic layer are sequentially laminated to form a color separation plate, and first, second, and third color components are separated from incident light by the first and second dichroic layers. One of the first and second color components (for example, the first color component) is S-polarized light and the other (for example, the second color component) by the second retardation layer.
Is P polarized light, and the third color component is S polarized light (or P polarized light).

[0009] The third embodiment eliminates displacement of the irradiation position due to refraction.
In order to efficiently irradiate the third reflection type liquid crystal display panel with color components, a color separation element is formed by forming a first right-angle prism having a first dichroic layer formed on a slope and a second dichroic layer on a slope. And the second right-angle prism are integrally fixed with the second retardation layer interposed between the first and second dichroic layers, and formed by a color separation prism in which the first retardation layer is fixed to the horizontal plane of the first right-angle prism. , First,
The second, dichroic layer separates the first, second,
The third color component is separated, and one of the first and second color components (for example, the first color component) is S-polarized by the first and second retardation layers.
The other (for example, the second color component) is P-polarized light, and the third color component is S-polarized light (or P-polarized light).

In order to reduce a substantial difference in optical path length between the first and second color components due to an optical property that light having a longer wavelength has a longer focal length, the first and second color separation elements have the same structure. The second dichroic layer separates the first and second color components such that the color component having the shorter optical path length at the time of color separation becomes the color component having the shorter wavelength.

The first, second, and third color separation elements separated by the color separation element
First, second, and third reflective liquid crystals corresponding to first, second, and third color components separated by a color separation element in order to remove unnecessary color components included in each of the color components. An unnecessary light removing element that transmits a corresponding color component and removes other color components is provided in an optical path leading to the display panel. For example, the unnecessary light removing element is constituted by first, second, and third absorption filters, and the first absorption filter is provided between the first reflection type liquid crystal display panel and the first polarization beam splitter.
Absorbs color components other than the color component and sets the second absorption filter to the second
It is provided between the reflective liquid crystal display panel and the first polarizing beam splitter to absorb color components other than the second color component, and a third absorption filter is provided between the third reflective liquid crystal display panel and the second polarizing beam splitter. To absorb color components other than the third color component.

Alternatively, the unnecessary light removing element is constituted by first and second dichroic mirrors, and the first dichroic mirror is provided between the color separating element and the first polarizing beam splitter to separate the first and second color components. Transmits and reflects color components other than the first and second color components. A second dichroic mirror is provided between the color separation element and the second polarizing beam splitter to transmit the third color component and to transmit the third color component. Reflects color components other than the components.

When the third color component output from the second polarizing beam splitter is S-polarized light, a color synthesizing element is formed by a dichroic mirror in order to widen a wavelength range usable as projection light and increase luminance. A half-wave plate (half-wave plate) for converting the third color component from S-polarized light to P-polarized light is provided between the dichroic mirror and the second polarization beam splitter.

In order to prevent dust and dirt from adhering to the image display surfaces of the first, second and third reflective liquid crystal display panels, the first and second polarizing beam splitters are formed by polarizing beam splitter prisms. Forming a space between the corresponding surfaces of the first and second reflective liquid crystal display panels and the first polarizing beam splitter prism in a hermetically sealed state, and forming a space between the third reflective liquid crystal display panel and the second polarizing beam splitter prism. The space formed between the corresponding surfaces is formed in a sealed state.

In order to further reduce the size, to facilitate assembly, adjustment and replacement, and to improve the brightness, one surface sandwiching the respective right angles is on the color separation element side and the slope is substantially coplanar. The first and second right-angle prisms are integrated with the third and fourth right-angle prisms having one surface sandwiching each right angle in contact with the slopes of the first and second right-angle prisms and the other surfaces contacting each other. Equipped with a prism block,
A polarizing film forming a first polarizing beam splitter is provided between contact surfaces of the first right-angle prism and the third right-angle prism, and a second polarizing beam splitter is provided.
A polarizing film forming a second polarizing beam splitter is provided between the contact surfaces of the right-angle prism and the fourth right-angle prism, and a dichroic film forming a color combining element is formed between the contact surfaces of the third and fourth right-angle prisms. Provide.

In order to further reduce the size, facilitate assembly, adjustment and replacement, and improve the luminance, one surface sandwiching each right angle is on the side of the color separation element and the inclined surface is substantially coplanar. The first and second right-angle prisms are integrated with the third and fourth right-angle prisms having one surface sandwiching each right angle in contact with the slopes of the first and second right-angle prisms and the other surface in contact with each other. The formed prism block is integrated with the color separation element to form a unit, and a space formed between the first, second, and third reflective liquid crystal display panels and the corresponding surface of the prism block is formed in a sealed state. A polarizing film forming a first polarizing beam splitter is provided between the contact surfaces of the first right-angle prism and the third right-angle prism, and the second polarizing beam splitter is provided between the contact surfaces of the second right-angle prism and the fourth right-angle prism. Form The polarizing film is provided, the third, providing a dichroic film for forming a color combining element between the abutment surface of the fourth rectangular prism.

In order to further reduce the size, facilitate assembly, adjustment and replacement, improve the luminance and prevent the irradiation position from shifting due to the refractive index, one surface sandwiching the right angle is in contact, and the other surface is The first and second right-angle prisms, which are substantially coplanar, and the third right-angle prism having one surface sandwiching the right angle abutting on the slope of the first right-angle prism and part of the slope being on the incident light side, sandwiching the right angle. One surface is in contact with the inclined surface of the second right-angle prism, and a part of the inclined surface is on the projection lens side, and one surface sandwiching the right angle is in contact with the other surface sandwiching the right angle of the third right-angle prism. A prism block that integrates a fifth right-angle prism that is in contact with the other surface and abuts the other surface sandwiching the right angle of the fourth right-angle prism;
The space formed between the third reflective liquid crystal display panel and the corresponding surface of the prism block is formed in a sealed state, and the first and second
A first retardation layer is provided between the contact surfaces of the right-angle prism,
A first dichroic layer, a second retardation layer, and a second dichroic layer are provided between the contact surfaces of the right-angle prism and the third right-angle prism, and the first dichroic layer is provided between the contact surfaces of the third right-angle prism and the fifth right-angle prism. A polarizing film for forming a polarizing beam splitter is provided, a polarizing film for forming a second polarizing beam splitter is provided between contact surfaces of the second right-angle prism and the fourth right-angle prism, and a fourth right-angle prism and a fifth right-angle prism are provided. A dichroic film for forming a color combining element is provided between the contact surfaces.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of a color image projection apparatus according to the present invention. The same parts as those in FIG. 15 are denoted by the same reference numerals, and the description is omitted or simplified. In FIG.
Reference numeral 10 denotes a light source that outputs S-polarized light as incident light to the device;
Reference numeral 2 denotes a condensing lens, and reference numeral 22 denotes a first displaying a blue (B) image.
LCD for B as an example of reflective liquid crystal display panel, 30
R is an R LCD as an example of a second reflective liquid crystal display panel displaying a red (R) image, and 26 is a G L as an example of a third reflective liquid crystal display panel displaying a green (G) image.
CD and 34 are projection lenses.

Reference numeral 36 denotes a color separation element.
Is placed on a transparent substrate (eg, a glass substrate) 38 disposed at an angle of 45 ° with respect to the incident light (S-polarized light).
The phase difference layer 40, the first dichroic layer 42, the second phase difference layer 44, and the second dichroic layer 46 are sequentially laminated, and are formed by the first and second dichroic layers 42 and 46 from incident light (S-polarized light). The B, R, and G components as the first, second, and third color components are separated, and the B component is S-polarized (referred to as Bs in the drawing) and R by the first and second retardation layers 40, 44. The component is referred to as P-polarized light (referred to as Rp in the figure), and the G component is referred to as S-polarized light (referred to as Gs in the figure). More specifically, the second dichroic layer 46 reflects and separates the B component, transmits the R and G components, and transmits the first and second dichroic layers 42 and 42.
Reflects and separates the R component and transmits the G component. In addition, by setting the optical path length of the R component passing through the second retardation layer 44 to a half wavelength (（wavelength), the R component is reduced to S
Convert from polarized light to P-polarized light. That is, since the R component transmits through the second retardation layer 44, is reflected by the first dichroic layer 42 and transmits again through the second retardation layer 44, the optical path length of the R component transmitted through the second retardation layer 44 is obtained. Is a half wavelength.
Further, by setting the optical path length of the G component passing through the second retardation layer 44 and the first retardation layer 40 to one wavelength, the G component is reduced to S.
Return to polarized light. For this reason, the thickness of the first retardation layer 40 is
Although the thickness is three times the thickness of the retardation layer 44, the thickness is shown to be substantially the same for convenience of illustration. Also, the first and second retardation layers 40,
44, the first and second dichroic layers 42 and 46 are thin layers (for example, thin films), but are enlarged for convenience of illustration.

Reference numeral 48 denotes a first polarization beam splitter prism (hereinafter simply referred to as a first PBS) as an example of a first polarization beam splitter, and 50 denotes a second polarization beam splitter prism (hereinafter simply referred to as a first PBS) as an example of a second polarization beam splitter. Reference numeral 52 denotes a dichroic prism as an example of a color combining element. The first PB
S48 is formed in a state where a polarizing film is provided between the inclined surfaces of the two right-angle prisms and fixed. The second PBS 50
Are formed similarly to the first PBS 48. The dichroic prism 52 is formed in a form in which a dichroic film is provided and fixed between the slopes of two right-angle prisms.

The first PBS 48 is provided with the color separation element 3.
The B component separated at 6 is reflected and radiated to the B LCD 22, and the reflected light (which has been converted from S-polarized light to P-polarized light with this reflection) is transmitted and output. LCD for R through R component separated by
30 and the reflected light (P due to this reflection)
It has been converted from polarized light to S-polarized light. ) Is reflected and output. The second PBS 50 reflects the G component separated by the color separation element 36 and irradiates the G LCD 26 with the reflected light (which is converted from S-polarized light to P-polarized light with this reflection). Output. The dichroic prism 52 outputs the B output from the first PBS 48.
The component, the R component, is transmitted, the G component output from the second PBS 50 is reflected, the B component, the R component, and the G component are combined and output to the projection lens 34. The color separation element 36,
First and second PBSs 48 and 50, LCD 22 for B, L for R
The CD 30, the G LCD 26, and the dichroic prism 52 are optical path lengths to the B LCD 22, R LCD 30, and G LCD 26 corresponding to the B, R, and G components separated by the color separation element 36, respectively. Are arranged to be equal.

Next, the operation of FIG. 1 will be described. (1) The incident light (S-polarized light) output from the light source 10 and collected by the condenser lens 12 is B, R,
The light is separated into three color components of G, the B component is S-polarized light, the R component is P-polarized light, and the G component is S-polarized light. (2) The B component is reflected by the first PBS 48 and irradiates the corresponding LCD 22 for B, and the reflected light (P polarization) is reflected by the first PB 48.
The output is transmitted through S48. The R component is transmitted through the first PBS 48 and irradiates the corresponding R LCD 30 with the reflected light (S
(Polarized light) is reflected by the first PBS 48 and output. The G component is reflected by the second PBS 50 and irradiates the corresponding G LCD 26, and the reflected light (P-polarized light) is transmitted through the second PBS 50 and output. (3) The B and R components output from the first PBS 48 and the G component output from the second PBS 50 are combined by the dichroic prism 52 and output to the projection lens 34, where a color image is displayed on a screen (not shown). (4) B component, R component, and G separated by the color separation element 36
LCD for B and R for each component
30, since the optical path lengths up to the G LCD 26 are equal, an extra lens for focusing is not required. Further, an expensive cross prism as in the conventional example is not required, and the polarizing beam splitter is also provided with the first PBS 48 and the second PBS 48.
Only two of PBS 50 are required.

In the embodiment, the B component, the R component, and the G component separated by the color separation element 36 are combined with the first PBS 48,
The input is made directly to the corresponding B LCD 22, the R LCD 30, and the G LCD 26 via the second PBS 50. However, the present invention is not limited to this, and an absorption filter or a dichroic mirror as an unnecessary light removing element is provided in the middle. LCD 22 for B, LCD 30 for R, LCD 26 for G
It is also possible to use an arrangement in which unnecessary color components (that is, noise) are prevented from being input.

For example, as shown in FIG.
8 and the LCD 22 for B, a first absorption filter 54 for absorbing a color component other than the B component is provided, and a second absorption filter 56 for absorbing a color component other than the R component is provided between the first PBS 48 and the LCD 30 for R. , Second PBS50 and LCD2 for G
6, a third absorption filter 58 for absorbing a color component other than the G component is provided, and the B component and the R component separated by the color separation element 36 are provided.
Unnecessary color components contained in each of the component and the G component can be removed. In this case, the third absorption filter 5
The same effect can be obtained by providing between the color separation element 36 and the second PBS 50 instead of providing the 8 between the second PBS 50 and the G LCD 26. Alternatively, as shown in FIG. 3, a first dichroic mirror 60 that transmits the B component and the R component and reflects the components other than the B component and the R component is provided between the color separation element 36 and the first PBS 48. 2nd PBS50
A second dichroic mirror 62 that transmits the G component and reflects the components other than the G component is provided between them, and unnecessary color components included in each of the B component, the R component, and the G component separated by the color separation element 36. Can be removed. In this case, instead of the first and second dichroic mirrors 60 and 62,
First and second dichroic layers are fixed to the surfaces of the first and second PBSs 48 and 50 on the color separation element 36 side, and the B and R components separated by the color separation element 36 by the first and second dichroic layers. , And G components, the same effect can be obtained by removing unnecessary color components contained in each of the G components.
In FIG. 3, the transparent substrate 38 of the color separation element 36 is shown.
Is omitted for convenience of illustration.

In the above embodiment, the LCD 22 for B, the R
The space formed between the LCD 30 for G and the corresponding surface of the first PBS 48 is formed in an unsealed state, and the LCD 26 for G and the second
Although the case where the space formed between the corresponding surface of the PBS 50 and the corresponding surface of the PBS 50 is formed in an unsealed state has been described, the present invention is not limited to this, and can be used in a case where the space is formed in a closed state. For example, as shown in FIG. 4, the peripheral portion on the image display side of the LCD 22 for B is fixed to the corresponding surface of the first PBS 48 with a sealing material 66b, and the space formed therebetween is sealed. Similarly, LCD for R
30, the peripheral portion on the image display side of the G LCD 26 is fixed to the corresponding surfaces of the first PBS 48 and the second PBS 50 with the sealing materials 66r and 66g, and the space formed between them is sealed. When formed in such a sealed state,
It is possible to prevent dust and dirt from adhering to the image display surfaces of the LCD 22 for B, the LCD 30 for R, and the LCD 26 for G. LCD 22 for B, LCD 30 for R, L for G
The cooling fins 68b and 6 are provided on the side of the CD 26 opposite to the image display side.
8r, 68g, and the cooling fins 68b, 68
By exposing cooling air to r and 68g, heat generated by the B LCD 22, the R LCD 30, and the G LCD 26 accompanying the sealing is radiated. It should be noted that in FIG.
The transparent substrate 38 is omitted for convenience of illustration.

In the above-described embodiment, the case where the first PBS 48, the second PBS 50, and the dichroic prism 52 are separate bodies has been described. However, the present invention is not limited to this. it can. For example, as shown in FIG. 5, the first and second right-angle prisms 701 and 702 are arranged such that one surface sandwiching the respective right angles is on the color separation element 36 side and the slopes are substantially coplanar.
And third and fourth right-angle prisms 703, 704 in which one surface sandwiching the respective right angles is in contact with the slopes of the first and second right-angle prisms 701, 702, and the other surface is in contact with each other.
And a polarizing film 72 forming a first polarizing beam splitter between contact surfaces of the first right-angle prism 701 and the third right-angle prism 703. Fourth right angle prism 70
4, a polarizing film 74 forming a second polarizing beam splitter is provided between the contact surfaces of the third and fourth right-angle prisms 703, 7
The present invention can also be applied to a case where a dichroic film 76 for forming a color synthesizing element is provided between the contact surfaces 04. In this case, the size can be further reduced by the integration, the assembling, adjustment, and replacement can be facilitated, and the reflection and scattering at the interface can be eliminated to improve the luminance. In FIG. 5, the transparent substrate 38 of the color separation element 36 is omitted for convenience of illustration.

Alternatively, as shown in FIG. 6, the prism block 70 is integrated with the color separation element 36 to form a unit 78, and the LC for B is formed by sealing materials 66r, 66b, 66g.
It can also be used when the space formed between the corresponding surfaces of the D22, R LCD 30, G LCD 26 and the prism block 70 is sealed. In this case, the same effects as in the case of FIG. 5 can be obtained, and the adjustment of the projection image position can be facilitated, and the assembly, adjustment, and replacement can be facilitated by reducing the number of parts. In addition,
6, the transparent substrate 38 of the color separation element 36 is omitted for convenience of illustration.

In the above embodiment, in order to simplify the structure of the color separation element, the color separation element is provided on a transparent substrate by a first retardation layer, a first dichroic layer, a second retardation layer and a second retardation layer.
The dichroic layer is formed by sequentially laminating the dichroic layers. However, the present invention is not limited to this, and the three color components of blue, red, and green are separated from the incident light polarized as the S-polarized light or the P-polarized light. , One of the second color components is S-polarized light, the other is P-polarized light,
What is necessary is just to output the third color component as S-polarized light (or P-polarized light).

For example, as shown in FIG.
6a, a retardation plate 80 having a first retardation layer 40a formed on a transparent substrate 38a and a first dichroic layer 42, a second retardation layer 44, and a second dichroic layer 46 laminated on a transparent substrate 38b in this order. The first and second dichroic layers 42 and 46 separate the B, R, and G components from the incident light, and the first and second retardation layers 40a and 44 separate the B component. It can also be used when the S component, the R component is P polarized light, and the G component is S polarized light. In this case, the angle dependence of the retardation layers 40a and 44 can be reduced, and the G component can reach the G LCD 26 in a state of high polarization. That is, since the incident surface of the color separation element 36a is set at 45 ° to the traveling direction of the incident light, the incident angles θ1 (45 °) and θ2 (
When the difference (θ1−θ2) increases by 45 °, the first retardation layer 40 disposed at 45 ° with respect to the traveling direction of the incident light.
In the case of FIG. 1, the incident angle difference (θ1−θ2) is further enlarged, and the color (G component) balance may be lost at both ends of the display screen, so that the display screen may look different. On the other hand, the first retardation layer 40a provided at 90 ° to the traveling direction of the incident light
In the case of FIG. 7, the incident angle difference (θ
1−θ2) can be suppressed, and the color (G component) balance at both ends of the display screen can be prevented from being lost. Further, since the position of the first retardation layer 40a is closer to the G LCD 26 than in the case of FIG. 1 (the first retardation layer 40), the G component is allowed to reach the G LCD 26 in a state of high polarization to improve the brightness and the brightness. The contrast can be improved.
The thickness of the first retardation layer 40a in FIG. 7 is about √2 times the thickness of the first retardation layer 40 so that the G component incident on the second PBS 50 is converted into S-polarized light.

Alternatively, as shown in FIG.
b, a first right-angle prism 84 having a first dichroic film (an example of a first dichroic layer) 42a formed on a slope.
And a second right-angle prism 86 having a second dichroic film (an example of a second dichroic layer) 46a formed on the slope, and a second right-angle prism 86 between the first and second dichroic films 42a and 46a.
The first and second dichroic films 42a and 46a are formed by a color separation prism in which the first phase difference layer 40a is fixed to the horizontal plane of the first right-angle prism 84 while being integrally fixed with the phase difference layer 44 interposed therebetween. , B, R, and G components are separated from each other, and the first and second retardation layers 40a and 44 convert the B component into S-polarized light, the R component into P-polarized light, and the G component into S-polarized light.
In this case, the irradiation position shift due to the refraction of the color separation element 36b can be almost eliminated, and the incident light can be converted to the B, R, and G LCs.
D22, 30, and 26 can be efficiently irradiated to the surface. That is, in the color separation element 36 shown in FIG.
As shown in FIG. 9, the first and second dichroic layers 42,
46, the first and second retardation layers 40 and 44 all cause an irradiation position shift due to refraction. However, in the color separation element 36b shown in FIG. Does not cause displacement.

FIG. 10 shows another embodiment of the present invention. In this figure, reference numeral 88 denotes an integrally formed prism block. The prism block 88 has first and second right-angle prisms 881 and 882 in which one surface sandwiching a right angle is in contact and the other surface is substantially the same, and one surface sandwiching a right angle is a first right-angle prism 881. A third right-angle prism 883 in contact with the slope, one side of the slope being the incident light side, and a third side in which one side sandwiching the right angle is in contact with the slope of the second right-angle prism 882 and one side of the slope is the projection lens 34 side. Fourth right-angle prism 884 and a fifth surface where one surface sandwiching the right angle abuts the other surface sandwiching the right angle of third right-angle prism 883 and the other surface abuts the other surface sandwiching the right angle of fourth right-angle prism 884. The first phase difference layer 40 is formed between the contact surfaces of the first and second right angle prisms 881 and 882.
a, and the first dichroic film 42a, the second retardation layer 44, and the second dichroic film 46a are provided between the contact surfaces of the first right-angle prism 881 and the third right-angle prism 883. 5 right angle prism 885
And a polarizing film 74 forming a second polarizing beam splitter between the contact surfaces of the second right-angle prism 882 and the fourth right-angle prism 884. And the fourth right-angle prism 884
And a dichroic film 76 for forming a color combining element is provided between the contact surface of the first rectangular prism 885 and the fifth rectangular prism 885. Seal material 66
r, 66b, and 66g determine the LCD 22 for B and the L for R
The space formed between the CD 30, the LCD 26 for G, and the corresponding surface of the prism block 88 is formed in a sealed state. With such a configuration, it is possible to achieve the same effect as in the case of FIG. 6 and to prevent the irradiation position from being shifted due to the refraction of the color separation element. Further, as shown by a dotted line T in FIG.
A vertical angle of 5 ° and third, fourth and fifth right angle prisms 883,
The apex angle of 90 ° of 884 and 885 is integrated (assumed as 360 °), and the apex angle portion indicated by the dotted line T is a portion where light rays (B, R, G components) do not transmit or reflect. Since strict precision is not required, fabrication can be facilitated.

In the above embodiment, the case where the incident light is the S-polarized light has been described. The present invention is not limited to this.
It can also be used when the incident light is P-polarized light. For example, as shown in FIG. 11, a first retardation layer 40b and a first dichroic layer 4 are formed on a transparent substrate (not shown).
2, the second retardation layer 44 and the second dichroic layer 46 are sequentially stacked to form the color separation element 36c. 1st, 2nd
Incident light (P-polarized light) by dichroic layers 42 and 46
, The B, R, and G components as the first, second, and third color components are separated from each other, and the B component is P-polarized (referred to as Bp in the drawing) and R by the first and second retardation layers 40b and 44. The component is defined as S-polarized light (referred to as Rs in the figure), and the G component is defined as S-polarized light (referred to as Gs in the figure). That is, the first retardation layer 40b and the second retardation layer 44 have the same thickness, and the G component first retardation layer 4
The G component is changed from P-polarized light to S-polarized light by setting the optical path length in Ob and the second retardation layer 44 to a half wavelength (１ ／ wavelength) of the G component. Then, the B component (Bp) is transmitted by the first PBS 48 and the R component (Rs) is transmitted.
Is reflected to irradiate the corresponding B LCD 22 and R LCD 30, and one of the reflected light (Bs) is reflected and the other (Rp) is transmitted and output, and the G component (Gs) is reflected by the second PBS 50. Then, while irradiating the corresponding G LCD 26, the reflected light (Gp) is transmitted and output.

In the above-described embodiment, the case where the third color component (G component) is converted into S-polarized light by the color separation element when the incident light is S-polarized light or P-polarized light has been described, but the present invention is not limited to this. However, the present invention can also be applied to a case where the third color component (G component) is changed to P-polarized light by the color separation element when the incident light is S-polarized light or P-polarized light. For example, as shown in FIG. 12, a first phase difference layer 40b, a first dichroic layer 42, a second phase difference layer 44, and a second dichroic layer 46 are sequentially stacked on a transparent substrate (not shown) to form a color separation element. 36c is formed, the G LCD 26 is disposed on the opposite side of the incident surface of the second PBS 50, and B, R, and G components are separated from the incident light (S-polarized light) by the first and second dichroic layers 42 and 46. 1, the second retardation layer 40b,
44, the B component is converted into S-polarized light (denoted as Bs in the drawing), R
The component is P-polarized light (denoted by Rp in the figure), the G component is P-polarized light (denoted by Gp in the figure), and the G component is the second retardation layer 4.
4. The G component is converted from S-polarized light to P-polarized light by setting the optical path length passing through the first retardation layer 40b to a half wavelength.
For this reason, the thickness of the first retardation layer 40b is
4 and the same thickness. Also, the G LCD 26 is set to the second P
Since it is located on the opposite side of the entrance surface of BS50, FIG.
The width of the device can be reduced as compared with the case of FIG.

Further, in the embodiment shown in FIG. 12, between the second PBS 50 and the dichroic prism 52, a 1/2 phase difference plate (that is, 1/2) that converts the G component output from the second PBS 50 from S-polarized light to P-polarized light. 2 wavelength plate) 90
Is provided, the wavelength range that can be used as projection light is widened and the luminance is increased. That is, the transmittance characteristic of the dichroic prism 52 is S
Polarization (shown by a solid line) and P-polarization (shown by a dotted line)
B component (380 nm to 490 nm) and R component (560 n
m to 780 nm), the S-polarized light
The usable wavelength range is wider than that of polarized light. Further, the reflectance characteristic of the dichroic prism 52 is such that the transmittance characteristic shown in FIG. 13 is upside down (0% on the upper side and 100% on the lower side), so that the G component (490 nm to 490 nm). 560
nm), the wavelength range of use of P-polarized light is wider than that of S-polarized light. Therefore, the wavelength range of the transmitted light of the B component (Bp) and the R component (Rs) in the dichroic prism 52 is the hatched area in FIG. 14A, and the wavelength range of the reflected light of the G component (Gp) is Since the region is indicated by hatching in FIG. 9B, the wavelength band used as a whole is the region indicated by hatching in FIG. On the other hand, when the 1/2 phase difference plate 90 is not provided in FIG. 12, the G component is input to the dichroic prism 52 as S-polarized light, so that the wavelength region of the G component (Gs) using reflected light is as shown in FIG. As shown in (d), the wavelength becomes narrower, an unused wavelength region is generated between the G component (Gs) and the B component (Bp), and the luminance is reduced accordingly. In the case where the half-wave plate 90 is provided, such an unused wavelength region does not occur, so that the incident light can be effectively used to improve the luminance.
In the embodiment shown in FIGS. 1 to 7, 10 and 11, the G component output from the second PBS 50 is input to the dichroic prism 52 as P-polarized light.
Even without providing the two phase difference plates 90, the wavelength range of use as a whole can be widened as in FIG. 12, and the incident light can be effectively used to improve the luminance.

In the above embodiment, the substantial difference in the optical path length between the B component and the R component separated in the same direction is reduced based on the optical property that the longer the wavelength, the longer the focal length. The case where the first and second dichroic layers are formed so that the color component having the shorter optical path length at the time of color separation becomes the color component having the shorter wavelength (B component) has been described. The color component having the shorter optical path length in the color separation of the B component and the R component separated in the same direction is the color component having the longer wavelength (R component).
It can also be used when the first and second dichroic layers are formed such that

In the above embodiment, the first of the color separation elements,
A color separation element is formed such that one of the first and second color components separated by the second dichroic layer in the same direction is a B component, the other is an R component, and the third color component is a G component. Although a case has been described in which the wavelength ranges of the first and second color components to be separated are separated so that interference is unlikely to occur, the present invention is not limited to this, and the first and second color components separated in the same direction are not limited to this. The present invention can also be applied to a case where a color separation element is formed such that any two of the B component, the R component, and the G component are the color components, and the third color component is the remaining color component.

[0037]

According to the present invention, there is provided a color image projection apparatus which combines red, green, and blue images displayed on three reflective liquid crystal display panels and enlarges and displays the images on a screen with a projection lens. A second polarizing beam splitter and a color combining element are provided, and the incident light is red, green, and
While separating into three color components of blue, one of the first and second color components is S-polarized, the other is P-polarized, and the third color component is S-polarized (or P-polarized). Reflecting one of the first and second color components and transmitting the other to irradiate the corresponding first and second reflective liquid crystal display panels, transmitting one of the reflected light and reflecting and outputting the other, The second color beam splitter reflects (or transmits) the third color component to irradiate the corresponding third reflective liquid crystal display panel, transmits (or reflects) the reflected light, and outputs the reflected light. The first and second color components output from the first polarization beam splitter and the third color component output from the second polarization beam splitter are combined and output to the projection lens, and the first and second color components separated by the color separation element are output. Each of the second and third color components corresponds The color separation element, the first and second polarization beam splitters, and the first, second and third reflection type liquid crystal display panels so that the optical path lengths to the first, second and third reflection type liquid crystal display panels are equal. Was placed. For this reason,
It does not require an extra lens for equalizing the optical path lengths of the first, second, and third color components for focusing, does not require an expensive cross prism, and requires only two polarization beam splitters. Therefore, the cost and size of the device can be reduced.

A color separation element is formed by sequentially laminating a first retardation layer, a first dichroic layer, a second retardation layer, and a second dichroic layer on a transparent substrate, and the first and second dichroic layers are used to enter the light. The first, second, and third color components are separated from light, and one of the first and second color components is S-polarized, the other is P-polarized, and the third color component is S-polarized by the first and second retardation layers. (Or P-polarized light), the structure of the color separation element can be simplified.

The color separation element is a color separation plate in which a first retardation layer is formed on a transparent substrate, and a first dichroic layer, a second retardation layer, and a second dichroic layer are sequentially laminated on a transparent substrate. The first and second dichroic layers separate the first, second and third color components from the incident light, and the first and second retardation layers separate one of the first and second color components. When the S-polarized light, the other is P-polarized light, and the third color component is S-polarized light (or P-polarized light), the angle dependence of the third color component by the first retardation layer is reduced, and the color balance on the display screen is reduced. And the third color component can be made to reach the third reflective liquid crystal display panel in a state of high polarization to improve the brightness and contrast.

The color separation element is composed of a first right-angle prism having a first dichroic layer formed on a slope and a second right-angle prism having a second dichroic layer formed on a slope.
The second phase difference layer is interposed between the dichroic layers and fixed together, and the first phase difference layer is fixed to the horizontal plane of the first right-angle prism with a color separation prism. The first and second dichroic layers separate the incident light. The first, second, and third color components are separated, and one of the first and second color components is S-polarized light, the other is P-polarized light, and the third color component is S-polarized light (or In the case of P-polarized light, the third color component can be efficiently radiated to the third reflective liquid crystal display panel without displacement of the irradiation position due to refraction.

The first and second dichroic layers of the color separation element convert the color component of the first and second color components (for example, the B and R components) having the shorter optical path length at the time of color separation into the one having the shorter wavelength. When the color components are separated so as to have the same color component (for example, the B component), a substantial difference between the first and second color components generated based on the optical property that the focal length becomes longer as the wavelength becomes longer. Optical path length difference can be reduced.
The first and second reflective liquid crystal display panel surfaces can be efficiently irradiated with the color components.

The first, second and third colors separated by the color separation element
When an unnecessary light removing element that transmits the corresponding color component and removes other color components is provided in the optical path to the first, second, and third reflective liquid crystal display panels corresponding to the color components, Unnecessary color components included in each of the first, second, and third color components separated by the color separation element can be removed.

For example, the unnecessary light removing element is composed of first, second, and third absorption filters, and the first absorption filter is provided between the first reflection type liquid crystal display panel and the first polarization beam splitter, and the first color filter is provided. A second absorption filter is provided between the second reflective liquid crystal display panel and the first polarizing beam splitter to absorb color components other than the second color component, and the third absorption filter is provided for the third absorption filter. The first, second, and third reflection type liquid crystal display panels are provided between the three reflection type liquid crystal display panel and the second polarization beam splitter to absorb color components other than the third color component. Unnecessary color components included in each of the second and third color components can be removed. Alternatively, the unnecessary light removing element is constituted by first and second dichroic mirrors, and the first dichroic mirror is provided between the color separation element and the first polarization beam splitter to transmit the first color component and the second color component. Reflecting the color components other than the first color component and the second color component, and providing a second dichroic mirror between the color separation element and the second polarizing beam splitter to transmit the third color component and to excluding the third color component. By reflecting the above color components, unnecessary color components included in each of the first, second, and third color components reaching the first, second, and third reflective liquid crystal display panels can be removed. it can.

A color synthesizing element is formed by a dichroic mirror, and a third color component is converted from S-polarized light to P-polarized light between the dichroic mirror and the second polarizing beam splitter.
In the case where a / 2 phase difference plate is provided, when the third color component output from the second polarization beam splitter is S-polarized light, the wavelength range usable as projection light can be widened to increase the luminance.

The first and second polarization beam splitters are formed by polarization beam splitter prisms, and the space formed between the first and second reflection type liquid crystal display panels and the corresponding surface of the first polarization beam splitter prism is sealed. When the space formed between the third reflective liquid crystal display panel and the corresponding surface of the second polarizing beam splitter prism is formed in a closed state, the first, second, and third reflective liquid crystal displays are formed. It is possible to prevent dust and dirt from attaching to the image display surface of the panel.

First and second right-angle prisms having one surface sandwiching each right angle on the color separation element side and the slopes being substantially coplanar, and one surface sandwiching each right angle being a first and second right angle prism. A prism block in which third and fourth right-angle prisms are integrated with each other, and the first and third right-angle prisms are in contact with each other. A polarizing film for forming a polarizing beam splitter is provided, a polarizing film for forming a second polarizing beam splitter is provided between contact surfaces of the second right-angle prism and the fourth right-angle prism, and a contact between the third and fourth right-angle prisms is provided. When a dichroic film for forming a color synthesizing element is provided between the surfaces, it is possible to further reduce the size, facilitate assembly, adjustment and replacement, and improve the luminance.

First and second right-angle prisms having one surface sandwiching each right angle on the color separation element side and the inclined surfaces being substantially coplanar, and one surface sandwiching each right angle being a first and second right angle prism. The prism block formed by integrating the third and fourth right-angle prisms, which abut on the inclined surface and the other surface abut each other, is integrated with the color separation element to form a unit, and the first, second, and third prisms are integrated. Polarization forming a space formed between the reflective liquid crystal display panel and the corresponding surface of the prism block in a sealed state, and forming a first polarization beam splitter between the contact surfaces of the first right-angle prism and the third right-angle prism. Providing a polarizing film for forming a second polarizing beam splitter between the contact surfaces of the second right-angle prism and the fourth right-angle prism;
When a dichroic film for forming a color combining element is provided between the contact surfaces of the third and fourth right-angle prisms, further miniaturization is achieved, and assembling, adjustment and replacement are facilitated, and luminance is improved. be able to.

The first and second right-angle prisms having one surface abutting the right angle and the other surface being substantially coplanar, and one surface abutting the right angle abutting on the slope of the first right-angle prism, and A third right-angle prism part of which is on the incident light side, and one surface sandwiching the right angle is in contact with the slope of the second right-angle prism, and the fourth right-angle prism part of which is on the projection lens side sandwiches the right angle. A prism block in which one surface abuts the other surface sandwiching the right angle of the third right angle prism and the other surface abuts on the other surface sandwiching the right angle of the fourth right angle prism and a fifth right angle prism integrated with the prism block; A space formed between the first, second, and third reflective liquid crystal display panels and the corresponding surface of the prism block is formed in a sealed state, and a space is formed between the contact surfaces of the first and second right-angle prisms. One phase difference layer is provided, and a first right-angle prism and a third right-angle prism are provided. First dichroic layer between the contact surface,
A second retardation layer and a second dichroic layer are provided, a polarizing film for forming a first polarizing beam splitter is provided between contact surfaces of the third right-angle prism and the fifth right-angle prism, and the second right-angle prism and the fourth right-angle are provided. When a polarizing film forming a second polarizing beam splitter is provided between the contact surfaces of the prisms, and a dichroic film forming a color combining element is provided between the contact surfaces of the fourth right-angle prism and the fifth right-angle prism. Can further reduce the size, facilitate assembly, adjustment and replacement, improve the luminance, and prevent displacement of the irradiation position due to the refractive index.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram showing an embodiment of a color image projection apparatus according to the present invention.

FIG. 2 shows LCDs 22 and 30 for B, R and G in FIG.
An absorption filter 54, 56, 58 for absorbing unnecessary light components between the corresponding surfaces of the first PBS 48 and the second PBS 50.
FIG. 9 is a basic configuration diagram of a main part showing an example in which is provided.

FIG. 3 is a main part showing an example in which dichroic mirrors 60 and 62 for transmitting necessary light components and reflecting unnecessary light components are provided on the color separation element 36 side of the first PBS 48 and the second PBS 50 in FIG. It is a basic block diagram.

FIG. 4 shows LCDs 22, 30, for B, R, and G in FIG.
FIG. 4 is a basic configuration diagram of a main part showing an example in which a space formed between corresponding surfaces of a first PBS 48 and a second PBS 50 in a sealed state is formed.

FIG. 5 is a basic configuration diagram showing a second embodiment of the color image projection apparatus according to the present invention.

FIG. 6 is a basic configuration diagram showing a third embodiment of a color image projection apparatus according to the present invention.

FIG. 7 is a basic configuration diagram showing a second embodiment of a color separation element.

FIG. 8 is a basic configuration diagram showing a third embodiment of a color separation element.

FIG. 9 is an explanatory diagram of a position shift due to refraction of the color separation element of FIG. 1;

FIG. 10 is a basic configuration diagram showing a fourth embodiment of a color image projection apparatus according to the present invention.

FIG. 11 is a basic configuration diagram showing an embodiment example in which input light is replaced with S-polarized light in the embodiment example of FIG. 1;

FIG. 12 is a basic configuration diagram showing a fifth embodiment of the color image projection apparatus according to the present invention.

FIG. 13 is a characteristic diagram showing transmittance characteristics of the dichroic prism 52.

14A and 14B are diagrams for explaining a wavelength range used in the dichroic prism 52 in FIG. 12, wherein FIG.
And Rs) Explanatory diagram of the use wavelength range, (b) is reflected light (Gp)
(C) Explanatory diagram of the use wavelength range of transmitted light (Bp and Rs) and reflected light (Gp), (d) Comparative example (1/2 phase difference plate 90 is provided in FIG. 12) FIG. 7 is an explanatory diagram of a use wavelength range of transmitted light (Bp and Rs) and reflected light (Gs) in the case where there is no light.

FIG. 15 is a basic configuration diagram showing a conventional example.

[Explanation of symbols]

10: Light source, 12: Condensing lens, 22: LCD for B
(Example of First Reflective Liquid Crystal Panel), 26 ... LCD for G
(Example of Third Reflective Liquid Crystal Panel), 30 ... LCD for R
(An example of a second reflective liquid crystal panel), 34: a projection lens, 36, 36a, 36b, 36c: a color separation element,
38, 38a, 38b: transparent substrate, 40, 40a, 4
0b: first retardation layer, 42: first dichroic layer,
42a: a first dichroic film, 44: a second retardation layer, 46: a second dichroic layer, 46a: a second dichroic film, 48: a first PBS (an example of a first polarizing beam splitter), 50: a second PBS (a second PBS) 52: a dichroic prism (an example of a color combining element); 54: a first absorption filter;
56: second absorption filter, 58: third absorption filter, 60: first dichroic mirror, 62: second
Dichroic mirror, 66b, 66r, 66g: sealing material, 68b, 68r, 68g: cooling fin,
70: prism block, 701: first right angle prism, 702: second right angle prism, 703: third right angle prism, 704: fourth right angle prism, 72, 74
... polarizing film, 76 ... dichroic film, 78 ... unit, 80 ... retardation plate, 82 ... color separation plate, 84 ... first right angle prism, 86 ... second right angle prism, 88 ...
Prism block, 881 ... first right angle prism, 8
82 ... second right-angle prism, 883 ... third right-angle prism,
884: Fourth right-angle prism, 885: Fifth right-angle prism, 90: 1/2 retardation plate, Bp: P-polarized blue component (an example of the first color component), Bs: S-polarized blue component (No. Gp ... P-polarized green component (an example of a third color component), Gs ... S-polarized green component (an example of a third color component), P ... P-polarized incident light,
Rp: P-polarized red component (an example of a second color component), R
s: S-polarized red component (an example of a second color component);
S-polarized incident light.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H088 EA15 EA16 EA18 HA13 HA19 HA20 HA24 MA06 2H099 AA12 BA09 CA01 DA05 5C058 EA11 EA12 EA26 5C060 BA03 BC01 EA01 HC01 HC09 HC14 HC21 JB06 5G435 AA00 AA12 DD12 BB12 CC GG01 GG02 GG03 GG04 GG11 GG28 GG44 GG46 HH02 LL15

Claims (28)

[Claims] 1. A color image projection apparatus for synthesizing red, blue, and green images displayed on three reflective liquid crystal display panels and enlarging and displaying the images on a screen by a projection lens.
In addition to separating the three color components of red, blue and green from the incident light polarized as polarized light, one of the first and second color components is S-polarized, the other is P-polarized, and the third color component is S-polarized (or P-polarized light)
And a color separation element that outputs one of the first and second color components separated by the color separation element and transmits the other to irradiate the corresponding first and second reflection type liquid crystal display panels, A first polarizing beam splitter that transmits one of the reflected lights and reflects and outputs the other, and a third polarizing beam splitter that reflects (or transmits) the third color component separated by the color separation element to correspond to the third light component;
A second polarizing beam splitter for irradiating the reflective liquid crystal display panel and transmitting (or reflecting) the reflected light; a first and a second color components output from the first polarizing beam splitter; and a second polarizing beam splitter. Third output
A color synthesizing element for synthesizing a color component and outputting the synthesized color component to the projection lens, wherein the first, second, and
The color separation element, the first and second polarization beam splitters, and the first and second polarization beam splitters are so arranged that the optical path lengths of the third color components to the corresponding first, second and third reflective liquid crystal display panels are equal. , A second reflection type liquid crystal display panel and a color combining element are arranged. 2. A color separation element comprising: a first retardation layer on a transparent substrate;
A first dichroic layer, a second retardation layer, and a second dichroic layer are sequentially stacked, and the first and second dichroic layers separate first, second, and third color components from incident light, and The color image projection according to claim 1, wherein one of the first and second color components is S-polarized light, the other is P-polarized light, and the third color component is S-polarized light (or P-polarized light) by the first and second retardation layers. apparatus. 3. A color separation element comprising: a retardation plate having a first retardation layer formed on a transparent substrate; and a first dichroic layer, a second retardation layer, and a second dichroic layer laminated on the transparent substrate in this order. A first, second, and third color components separated from incident light by the first and second dichroic layers; and the first and second phase difference layers by the first and second retardation layers.
2. The color image projector according to claim 1, wherein one of the color components is S-polarized light, the other is P-polarized light, and the third color component is S-polarized light (or P-polarized light). 4. A color separation element comprising: a first right-angle prism having a first dichroic layer formed on a slope and a second right-angle prism having a second dichroic layer formed on a slope.
The second dichroic layer includes a color separation prism having a second retardation layer sandwiched therebetween and integrally fixed thereto, and a first retardation layer fixed to a horizontal plane of the first right-angle prism. The first and second dichroic layers form a color separation prism. First, second, and third color components are separated from incident light, one of the first and second color components is S-polarized, the other is P-polarized, and the third color is separated by the first and second retardation layers. 2. The color image projector according to claim 1, wherein the component is S-polarized light (or P-polarized light). 5. The first and second dichroic layers of the color separation element, wherein the color component having the shorter optical path length of the first and second color components upon color separation becomes the color component having the shorter wavelength. 5. The color image projection device according to claim 2, wherein the color components are separated as described above. 6. The first, second, and third color separation elements separated by a color separation element.
2. An unnecessary light removing element which transmits a corresponding color component and removes other color components in an optical path leading to the first, second, and third reflective liquid crystal display panels corresponding to the color components. 5. The color image projection device according to 2, 3, or 4. 7. The first, second, and third color separation elements separated by a color separation element.
6. An unnecessary light removing element for transmitting a corresponding color component and removing other color components in an optical path leading to the first, second, and third reflective liquid crystal display panels corresponding to the color components.
The color image projection device according to claim 1. 8. An unnecessary light removing element comprising first, second and third absorption filters, wherein said first absorption filter is provided between a first reflection type liquid crystal display panel and a first polarization beam splitter. The second absorption filter is provided between the second reflective liquid crystal display panel and the first polarizing beam splitter to absorb color components other than the second color component; 7. The color image projector according to claim 6, wherein the absorption filter is provided between the third reflection type liquid crystal display panel and the second polarization beam splitter and absorbs a color component other than the third color component. 9. An unnecessary light removing element comprising first, second and third absorption filters, wherein said first absorption filter is provided between a first reflection type liquid crystal display panel and a first polarization beam splitter. The second absorption filter is provided between the second reflective liquid crystal display panel and the first polarizing beam splitter to absorb color components other than the second color component; 8. The color image projection device according to claim 7, wherein the absorption filter is provided between the third reflection type liquid crystal display panel and the second polarization beam splitter and absorbs a color component other than the third color component. 10. An unnecessary light removing element comprising first and second dichroic mirrors, wherein said first dichroic mirror is provided between a color separation element and a first polarization beam splitter, and includes a first color component and a second polarization beam splitter. Transmitting the color component and reflecting a color component other than the first color component and the second color component, wherein the second dichroic mirror is provided between the color separation element and the second polarization beam splitter; 7. The color image projection device according to claim 6, wherein the color image projection device transmits three color components and reflects color components other than the third color component. 11. An unnecessary light removing element comprising first and second dichroic mirrors, wherein said first dichroic mirror is provided between a color separation element and a first polarization beam splitter, and includes a first color component and a second polarization beam splitter. Transmitting the color component and reflecting a color component other than the first color component and the second color component, wherein the second dichroic mirror is provided between the color separation element and the second polarization beam splitter; 8. The color image projection device according to claim 7, wherein the color image projection device transmits three color components and reflects color components other than the third color component. 12. A method for converting a third color component from S-polarized light to P-polarized light between a color combining element and a second polarizing beam splitter.
5. The color image projection device according to claim 1, further comprising a retardation plate. 13. A す る converter for converting a third color component from S-polarized light to P-polarized light between a color combining element and a second polarizing beam splitter.
The color image projection device according to claim 5, further comprising a retardation plate. 14. A す る converter for converting a third color component from S-polarized light to P-polarized light between a color combining element and a second polarizing beam splitter.
7. The color image projection device according to claim 6, further comprising a retardation plate. 15. A converter for converting a third color component from S-polarized light to P-polarized light between a color combining element and a second polarizing beam splitter.
12. The method according to claim 7, wherein a retardation plate is provided.
The color image projection device according to claim 1. 16. The first and second polarization beam splitters are formed by first and second polarization beam splitter prisms, and are disposed between the first and second reflection type liquid crystal display panels and corresponding surfaces of the first polarization beam splitter prism. 3. A space formed between the third reflection type liquid crystal display panel and the corresponding surface of the second polarizing beam splitter prism is formed in a closed state. , 3 or 4
The color image projection device according to claim 1. 17. The first and second polarizing beam splitters are formed by first and second polarizing beam splitter prisms, and are provided between the first and second reflective liquid crystal display panels and corresponding surfaces of the first polarizing beam splitter prism. 6. A space formed between the third reflection type liquid crystal display panel and the corresponding surface of the second polarizing beam splitter prism is formed in a closed state, and a space formed in the space is formed in a closed state. Color image projection device. 18. A first and second polarizing beam splitter, comprising first and second polarizing beam splitter prisms, between a first and second reflective liquid crystal display panel and a corresponding surface of the first polarizing beam splitter prism. 7. A space formed between the third reflection type liquid crystal display panel and the corresponding surface of the second polarizing beam splitter prism is formed in a closed state, and a space formed in the space is formed in a closed state. Color image projection device. 19. A polarizing beam splitter comprising first and second polarizing beam splitter prisms, wherein a first polarizing beam splitter is provided between the first and second reflective liquid crystal display panels and a corresponding surface of the first polarizing beam splitter prism. The space formed between the third reflection type liquid crystal display panel and the corresponding surface of the second polarizing beam splitter prism is formed in a closed state. , 9,1
15. The color image projector according to 0, 11, 13 or 14. 20. First and second polarizing beam splitters are formed by first and second polarizing beam splitter prisms, and the first and second reflection type liquid crystal display panels and corresponding surfaces of the first polarizing beam splitter prisms. 13. The space formed between the third reflection type liquid crystal display panel and the corresponding surface of the second polarizing beam splitter prism is formed in a closed state, and the space formed in the space is formed in a closed state. Color image projection device. 21. First and second polarizing beam splitters are formed by first and second polarizing beam splitter prisms, and the first and second reflection type liquid crystal display panels and corresponding surfaces of the first polarizing beam splitter prisms. 16. The space formed between the third reflection type liquid crystal display panel and the corresponding surface of the second polarizing beam splitter prism is formed in a closed state, and the space formed in the third reflection type liquid crystal display panel is formed in a closed state. Color image projection device. 22. First and second right-angle prisms having one surface sandwiching each right angle and being on the same side as the color separation element side, and the slopes being substantially coplanar, and one surface sandwiching each right angle being the first and second prisms. A prism block in which third and fourth right-angle prisms are integrated with each other, wherein the third and fourth right-angle prisms are in contact with each other on the inclined surface of the two right-angle prisms, and the contact surface between the first right-angle prism and the third right-angle prism is provided. A polarizing film that forms a first polarizing beam splitter is provided between the third polarizing beam splitter and a polarizing film that forms a second polarizing beam splitter between contact surfaces of the second right-angle prism and the fourth right-angle prism; 5. The color image projection apparatus according to claim 1, further comprising a dichroic film for forming a color combining element between the contact surfaces of the fourth right-angle prism. 23. First and second right-angle prisms having one surface sandwiching each right angle and having a slope substantially on the same side on the color separation element side, and one surface sandwiching each right angle being the first and second prisms. A prism block in which third and fourth right-angle prisms are integrated with each other, wherein the third and fourth right-angle prisms are in contact with each other on the inclined surface of the two right-angle prisms, and the contact surface between the first right-angle prism and the third right-angle prism is provided. A polarizing film that forms a first polarizing beam splitter is provided between the third polarizing beam splitter and a polarizing film that forms a second polarizing beam splitter between contact surfaces of the second right-angle prism and the fourth right-angle prism; 6. A color image projection apparatus according to claim 5, wherein a dichroic film for forming a color combining element is provided between the contact surfaces of the fourth right-angle prism. 24. First and second right-angle prisms having one surface sandwiching each right angle and being on the same plane as the color separation element side, and one surface sandwiching each right angle being the first and second prisms. A prism block in which third and fourth right-angle prisms are integrated with each other, wherein the third and fourth right-angle prisms are in contact with each other on the inclined surface of the two right-angle prisms, and the contact surface between the first right-angle prism and the third right-angle prism is provided. A polarizing film that forms a first polarizing beam splitter is provided between the third polarizing beam splitter and a polarizing film that forms a second polarizing beam splitter between contact surfaces of the second right-angle prism and the fourth right-angle prism; 7. The color image projector according to claim 6, further comprising a dichroic film for forming a color combining element between the contact surfaces of the fourth right-angle prism. 25. First and second right-angle prisms having one surface sandwiching each right angle and being on the same plane as the color separation element side, and one surface sandwiching each right angle being the first and second prisms. A prism block in which third and fourth right-angle prisms are integrated with each other, wherein the third and fourth right-angle prisms are in contact with each other on the inclined surface of the two right-angle prisms, and the contact surface between the first right-angle prism and the third right-angle prism is provided. A polarizing film that forms a first polarizing beam splitter is provided between the third polarizing beam splitter and a polarizing film that forms a second polarizing beam splitter between contact surfaces of the second right-angle prism and the fourth right-angle prism; 12. The color image projection device according to claim 7, wherein a dichroic film for forming a color combining element is provided between the contact surfaces of the fourth right-angle prism. 26. First and second right-angle prisms having one surface sandwiching each right angle and being on the same plane as the color separation element side, and one surface sandwiching each right angle being the first and second prisms. A prism block formed integrally with the third and fourth right-angle prisms, which abuts on the inclined surface of the two right-angle prisms and the other surfaces abut each other, is integrated with the color separation element to form a unit, and 2. The space formed between the third reflective liquid crystal display panel and the corresponding surface of the prism block is formed in a closed state, and the first right-angle prism and the third
A polarizing film for forming a first polarizing beam splitter is provided between contact surfaces of right-angle prisms, and a polarizing film for forming a second polarizing beam splitter between contact surfaces of the second right-angle prism and the fourth right-angle prism. 5. The color image projection device according to claim 1, wherein a dichroic film for forming a color combining element is provided between contact surfaces of the third and fourth right-angle prisms. 27. First and second right-angle prisms having one surface sandwiching each right angle and being on the same plane as the color separation element side, and one surface sandwiching each right angle being the first and second prisms. A prism block formed integrally with the third and fourth right-angle prisms, which abuts on the inclined surface of the two right-angle prisms and the other surfaces abut each other, is integrated with the color separation element to form a unit, and 2. The space formed between the third reflective liquid crystal display panel and the corresponding surface of the prism block is formed in a closed state, and the first right-angle prism and the third
A polarizing film for forming a first polarizing beam splitter is provided between contact surfaces of right-angle prisms, and a polarizing film for forming a second polarizing beam splitter between contact surfaces of the second right-angle prism and the fourth right-angle prism. 6. A color image projection apparatus according to claim 5, wherein a dichroic film for forming a color combining element is provided between the contact surfaces of said third and fourth right-angle prisms. 28. First and second right-angle prisms having one surface abutting a right angle and having substantially the same plane on the other surface, and one surface abutting a right angle abutting on a slope of the first right-angle prism. A third right-angle prism having a part of the slope facing the incident light side;
One surface sandwiching the right angle is in contact with the slope of the second right angle prism, and a portion of the slope is on the projection lens side, and one surface sandwiching the right angle sandwiches the right angle of the third right angle prism. A prism block integrated with a fifth right-angle prism that abuts the other surface and the other surface abuts the other surface sandwiching the right angle of the fourth right-angle prism; A space formed between the liquid crystal display panel and the corresponding surface of the prism block is formed in a closed state, and a first retardation layer is provided between contact surfaces of the first and second right-angle prisms. A first dichroic layer, a second retardation layer, and a second dichroic layer are provided between the contact surfaces of the first right-angle prism and the third right-angle prism, and the first dichroic layer, the second retardation layer, and the second dichroic layer are provided between the third right-angle prism and the fifth right-angle prism. First polarization beam splitter formed between A polarizing film for forming a second polarizing beam splitter is provided between the contact surfaces of the second right-angle prism and the fourth right-angle prism, and the contact surface of the fourth right-angle prism and the fifth right-angle prism is provided. 2. The color image projection device according to claim 1, further comprising a dichroic film for forming a color combining element therebetween.