JP2000310823A - Reflection type projector device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector device capable of reducing misregistration caused by positional deviation between optical parts, projecting a high-resolution video, improving yield and being realizes at low cost. SOLUTION: Polarizing prisms 9 to 11 are housed and held in brackets 31 to 33. Holding plates 15 to 17 holding reflection type liquid crystal elements 12 to 14 are fixed on the brackets 31 to 33. Spacers 34 to 36 are stuck and fixed on a combined prism. By fastening the brackets 31 to 33 to the spacers 34 to 36 with screws, the prisms 9 to 11, the elements 12 to 14 and the combined prism are formed as one block 50'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type projector using a reflection type liquid crystal element.

[0002]

2. Description of the Related Art Since there is an increasing demand for displaying images on a large screen, projector devices for projecting images on a screen have become widespread. FIG. 5 and FIG.
FIG. 5 is a diagram showing a configuration of a conventional reflection type projector device using a reflection type liquid crystal element. FIG. 5 is a top view and FIG. 6 is a side view. Note that the left-right direction in FIG. 6 corresponds to a direction orthogonal to the paper surface in FIG.

For example, white light emitted from a lamp 1 which is a xenon arc lamp is condensed by lenses 2 and 3 and is incident on a color separation mirror 4. Of the white light incident on the color separation mirror 4, the blue (B) light is
, And the yellow light is reflected by the color separation mirror 4 and enters the color separation mirror 5. Of the yellow light incident on the color separation mirror 5, red (R) light passes through the color separation mirror 4 and is incident on the polarizing prism 9. Of the yellow light incident on the color separation mirror 5, green (G) light is reflected by the color separation mirror 5 and is incident on the polarizing prism 10.

[0004] The B light transmitted through the color separation mirror 4 is incident on the color separation mirror 7 via the relay lens 6. This B
The light is reflected by the color separation mirror 7 and enters the polarizing prism 11 via the relay lens 8. Relay lens 6,8
Is for adjusting the optical path length of B light to the optical path length of R light and G light. Since the B light has already been separated at the time when it has passed through the color separation mirror 4, a normal reflection mirror may be used instead of the color separation mirror 7.

[0005] In the R light incident on the polarizing prism 9, only the S-wave component is reflected at the joint surface thereof, and is incident on the reflection type liquid crystal element 12. The S-wave component incident on the liquid crystal element 12 is reflected by the liquid crystal element 12 to become a P-wave component, passes through the joint surface of the polarizing prism 9, and is incident on the combining prism 22. Only the S-wave component of the G light incident on the polarizing prism 10 is reflected on the joint surface thereof, and is incident on the reflective liquid crystal element 13. The S-wave component incident on the liquid crystal element 13 is reflected on the liquid crystal element 13 to become a P-wave component, passes through the joint surface of the polarizing prism 10, and is incident on the combining prism 22.

[0006] In the B light incident on the polarizing prism 11, only the S-wave component is reflected at the joint surface thereof, and is incident on the reflection type liquid crystal element 14. The S-wave component incident on the liquid crystal element 14 is reflected by the liquid crystal element 14 to become a P-wave component,
The light is transmitted through the joining surface and is incident on the combining prism 22. As is well known, a voltage corresponding to an image is applied to the liquid crystal elements 12 to 14 to modulate the incident R, G, and B light, respectively.

[0007] R, G, B incident on the combining prism 22
The light is combined by the combining prism 22 and the projection lens 2
3 is projected on a screen (not shown). Thus, an image is displayed on the screen.

Next, the mounting structure of each optical component will be described. Each of the liquid crystal elements 12 to 14 has a holding plate 1
5-17. These holding plates 15 to 17
Are mounted on brackets 18 to 20, respectively. That is, holes 15a to 17a are formed at four corners of the rectangular holding plates 15 to 17, respectively. The arms 18a to 20a of the brackets 18 to 20 are inserted into the holes 15a to 17a, and the periphery of the holes 15a to 17a and the arms 18a to 20a are fixed by, for example, solder 21. The holding plates 15 to 17 holding the liquid crystal elements 12 to 14 are adjusted after the focus position of the projection lens 23 and the relative position between the liquid crystal elements 12 to 14 are adjusted.
Bracket 18 bonded and fixed to polarizing prisms 9 to 11
Fixed to ２０20.

The brackets 18 to 20 holding the liquid crystal elements 12 to 14 in this manner are adhered and fixed to the polarizing prisms 9 to 11, respectively. As shown in FIG. 6, the polarizing prisms 9 to 11 are bonded and fixed to a pedestal 24, and the combining prism 22 is bonded and fixed to a pedestal 25. Pedestal 2
The polarizing prisms 9 to 11 and the synthetic prism 22 adhered and fixed to the base plates 4 and 25 are provided with a base 30 made of, for example, an aluminum die-cast so that relative positions between these components do not shift.
It is fixed with screws. Projection lens 23 is also base 3
0.

The lamp 1 to the projection lens 23 and the base 30 are positioned as a whole on the optical base 100 and fixed by screws or the like. If all of these optical components are correctly positioned, FIG.
As shown in (1), the R, G, B light is not shifted, and an image without registration shift is projected on the screen.

[0011]

However, the difference in the linear expansion coefficient between the polarizing prisms 9 to 11 and the synthetic prism 22 made of glass and the pedestals 24 and 25, and the linear expansion coefficient between the pedestals 24 and 25 and the base 30. The relative positions of the polarizing prisms 9 to 11, the liquid crystal elements 12 to 14, or the combining prism 22 are shifted due to the difference between them. Then, FIG.
As shown in (1), the R, G, and B lights are shifted, and a registration shift occurs in the image projected on the screen. FIG. 8 shows, as an example, a case where the liquid crystal element 12 for R light shifts from the position indicated by the solid line to the position indicated by the broken line, and the polarizing prism 11 for B light shifts from the position indicated by the solid line to the position indicated by the broken line. Is shown.

Such a misregistration becomes more problematic as the size of the liquid crystal elements 12 to 14 is reduced or the required resolution is increased. In recent projector apparatuses, higher resolution without registration deviation has been required more than before, and positional deviation between optical components has been a serious problem. Generally, when trying to eliminate the displacement between the optical components, the yield decreases, the production cost increases, and the projector apparatus becomes expensive. Therefore, it is required that the yield can be improved and the displacement between the optical components is eliminated by using an inexpensive configuration.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and it is possible to improve a registration shift due to a positional shift between optical components, to display a high-resolution image, and to increase a yield. It is an object of the present invention to provide a reflection type projector device which can be realized at a low cost.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the prior art, the present invention provides a separating means (4, 5) for separating white light from a light source (1) into three primary colors. First to third polarizing prisms (9) for polarizing the three primary color lights, respectively.
11) and the first to third polarization prisms polarized by the first to third polarization prisms are incident, and the first to third polarization prisms modulate the three primary color lights and reflect them to the first to third polarization prisms.
In a reflection type projector apparatus comprising: a third reflective liquid crystal element (12 to 14); and a combining prism (22) for combining the three primary color lights transmitted through the first to third polarizing prisms. A bracket (31 to 33) for holding first to third polarizing prisms, and members (34 to 36) fixed to the combining prism; the first to third polarizing prisms; A reflection type liquid crystal element and the synthetic prism are formed as one block (50 '), and the bracket is screwed to the member to provide a reflection type projector device. is there.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a reflection type projector according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a top view showing one embodiment of the reflection type projector apparatus of the present invention, FIG. 2 is a side view showing one embodiment of the reflection type projector apparatus of the present invention, FIG. 3 is a top view showing a comparative example, FIG. FIG. 4 is a side view showing a comparative example. 1 to 4, the same parts as those in FIGS. 5 and 6 are denoted by the same reference numerals. In addition,
The horizontal direction in FIGS. 2 and 4 corresponds to a direction orthogonal to the paper surface in FIGS.

First, a comparative example shown in FIGS. 3 and 4 will be described. The comparative examples shown in FIGS. 3 and 4 are proposed by the present applicant in Japanese Patent Application No. 10-357338. 3 and 4, white light emitted from a lamp 1, for example, a xenon arc lamp, is condensed by lenses 2 and 3 and is incident on a color separation mirror 4. Of the white light that has entered the color separation mirror 4, blue (B) light passes through the color separation mirror 4, and yellow light is reflected by the color separation mirror 4 and enters the color separation mirror 5. Of the yellow light incident on the color separation mirror 5, red (R) light passes through the color separation mirror 4 and is incident on the polarizing prism 9. Of the yellow light incident on the color separation mirror 5, green (G) light is reflected by the color separation mirror 5 and is incident on the polarizing prism 10.

The B light transmitted through the color separation mirror 4 is incident on the color separation mirror 7 via the relay lens 6. This B
The light is reflected by the color separation mirror 7 and enters the polarizing prism 11 via the relay lens 8. Relay lens 6,8
Is for adjusting the optical path length of B light to the optical path length of R light and G light. Since the B light has already been separated at the time when it has passed through the color separation mirror 4, a normal reflection mirror may be used instead of the color separation mirror 7.

The R light incident on the polarizing prism 9 reflects only the S-wave component on the joint surface thereof, and is incident on the reflection type liquid crystal element 12. The S-wave component incident on the liquid crystal element 12 is reflected by the liquid crystal element 12 to become a P-wave component, passes through the joint surface of the polarizing prism 9, and is incident on the combining prism 22 via the spacer glass 41. G incident on the polarizing prism 10
In the light, only the S-wave component is reflected at the joint surface, and is incident on the reflective liquid crystal element 13. The S-wave component incident on the liquid crystal element 13 is reflected by the liquid crystal element 13 to become a P-wave component, passes through the joint surface of the polarizing prism 10, and is incident on the combining prism 22 via the spacer glass 42.

The B light that has entered the polarizing prism 11 reflects only the S-wave component at its junction surface, and enters the reflective liquid crystal element 14. The S-wave component incident on the liquid crystal element 14 is reflected by the liquid crystal element 14 to become a P-wave component,
And enters the synthetic prism 22 via the spacer glass 43. As is well known, a voltage corresponding to an image is applied to the liquid crystal elements 12 to 14 to modulate the incident R, G, and B light, respectively.

R, G, B incident on the combining prism 22
The light is combined by the combining prism 22 and the projection lens 2
3 is projected on a screen (not shown). Thus, an image is displayed on the screen.

Next, the mounting structure of each optical component will be described. Each of the liquid crystal elements 12 to 14 has a holding plate 1
5-17. These holding plates 15 to 17
Are mounted on brackets 18 to 20, respectively. That is, holes 15a to 17a are formed at four corners of the rectangular holding plates 15 to 17, respectively. The arms 18a to 20a of the brackets 18 to 20 are inserted into the holes 15a to 17a, and the periphery of the holes 15a to 17a and the arms 18a to 20a are fixed by, for example, solder 21. The holding plates 15 to 17 holding the liquid crystal elements 12 to 14 are adjusted after the focus position of the projection lens 23 and the relative position between the liquid crystal elements 12 to 14 are adjusted.
Bracket 18 bonded and fixed to polarizing prisms 9 to 11
Fixed to ２０20.

The brackets 18 to 20 holding the liquid crystal elements 12 to 14 as described above are bonded and fixed to the polarizing prisms 9 to 11, respectively. Polarizing prism 9-11
And the combining prism 22 are bonded and fixed via spacer glasses 41 to 43, respectively, so that the relative positions between the polarizing prisms 9 to 11 and the combining prism 22 do not shift. That is, the liquid crystal elements 12 to 14 and the polarizing prisms 9 to
11 and the combining prism 22 are formed as one block 50 in which all are integrated.

In this configuration example, components other than the liquid crystal elements 12 to 14, the polarizing prisms 9 to 11, and the combining prism 22, that is, the brackets 18 to 20 and the spacer glass 41
To 43, but are not limited to this.
It also includes a configuration in which only the liquid crystal elements 12 to 14, the polarizing prisms 9 to 11, and the combining prism 22 are configured as one block. That is, the liquid crystal elements 12 to 14 are connected to the polarizing prisms 9 to 11.
The polarizing prisms 9 to 11 may be directly bonded and fixed to the synthetic prism 22, or the liquid crystal elements 12 to 14 may be bonded and fixed indirectly to the polarizing prisms 9 to 11 to form a polarizing prism. 9 to 11 may be indirectly bonded and fixed to the synthetic prism 22. You may combine the direct adhesive fixing between each component and the indirect adhesive fixing.

Up and down (left and right in FIG. 4) of the combining prism 22
, A holding plate 44 is adhesively fixed to the holding plate 4.
The fourth flange portion 44a is screwed and fixed to a base 60 made of, for example, aluminum die cast. Projection lens 2
3 is also fixed to the base 60 with screws.

The lamp 1 to the projection lens 23 and the base 60 described above are further positioned as a whole on the optical base 100 and fixed by screws or the like. In this comparative example, the liquid crystal elements 12 to 14 and the polarizing prisms 9 to
11 and the combining prism 22 are configured as one block 50, so that the relative positions between these optical components hardly deviate. Therefore, as shown in FIG. 7, the R, G, B light is not shifted, and an image without registration shift is projected on the screen.

In the comparative examples shown in FIGS. 3 and 4 described above, registration deviation due to positional deviation between optical parts can be improved, and a high-resolution image can be displayed. However, since the liquid crystal elements 12 to 14, the polarizing prisms 9 to 11, and the combining prism 22 are configured as one block 50 by bonding and fixing,
For example, even if there is a defect in any one of the polarizing prisms 9 to 11, it is difficult to separate and replace it, and the entire block 50 becomes defective. Therefore, the yield decreases and the production cost increases. Also,
Precisely positioning and bonding the optical components requires special skills, which increases costs.

It is possible to improve the yield and reduce the production cost without deteriorating the registration deviation due to the positional deviation between the optical components, and without impairing the feature that a high-resolution image can be displayed. This is the configuration of the present invention shown in FIGS. 1 and 2, the same parts as those in FIGS. 3 and 4 are denoted by the same reference numerals, and the description thereof will be appropriately omitted.

1 and 2, the liquid crystal elements 12 to 14
Are fixed to the holding plates 15 to 17, respectively. These holding plates 15 to 17 are respectively provided with brackets 31.
~ 33. That is, the four corners of the rectangular holding plates 15 to 17 have holes 15a to 1 respectively.
7a are formed. The arms 31a to 33a of the brackets 31 to 33 are inserted into the holes 15a to 17a, and the periphery of the holes 15a to 17a and the arms 31a to 33a are fixed by, for example, solder 21. Arms 31a to 33
“a” may be provided by cutting and raising a part of the brackets 31 to 33. The holding plates 15 to 17 holding the liquid crystal elements 12 to 14 are adjusted by adjusting the focus position of the projection lens 23 and the relative position between the liquid crystal elements 12 to 14, and then the brackets 31 to 31 holding the polarizing prisms 9 to 11. 33.

The brackets 31 to 33 holding the liquid crystal elements 12 to 14 sandwich and hold the polarizing prisms 9 to 11, respectively. Brackets 31-33
Is formed in a box shape having an opening in a direction in which the R, G, and B light passes, and accommodates and holds the polarizing prisms 9 to 11 therein. Polarizing prism 9 of synthetic prism 22
Frame-shaped spacers 34 to 36 are bonded and fixed to the surface facing 11. Synthetic prism 22 and spacer 34-
36 may be integrally formed by a separate member to integrate the two.

The composite prism 22 of the brackets 31 to 33
The flanges 31b to 33b (flange 32b
Only shown in FIG. 2), and brackets 31 to 31 are formed.
33 are spacers 34-36.
It is screwed to. Some of the brackets 31 to 33 have projecting portions 31c to 31
33c (only the protrusion 32c is shown in FIG. 2). An elastic body 37 is provided between the protrusions 31c to 33c and the polarizing prisms 9 to 11. By providing the elastic body 37, the polarizing prisms 9 to 11 are pressed against the spacers 34 to 36, and the polarizing prisms 9 to 11 and the combining prism 22 are firmly integrated.

Up and down (left and right in FIG. 2) of the combining prism 22
, A holding plate 44 is adhesively fixed to the holding plate 4.
The fourth flange portion 44a is screwed and fixed to a base 60 made of, for example, aluminum die cast. Projection lens 2
3 is also fixed to the base 60 with screws. Lamp 1
The projection lens 23 and the base 60 are further
It is positioned on the optical base 100 and fixed by screws or the like.

As described above, in the configuration of the present invention, similarly to the comparative example described above, the liquid crystal elements 12 to 14, the polarizing prisms 9 to 11, and the synthesizing prism 22 are all integrated into one unit. It is formed as a block 50 '. Therefore, registration deviation due to positional deviation between optical components can be improved, and a high-resolution image can be displayed. Moreover, the polarizing prisms 9 to 11
With spacers 34 to 36 fixed to the synthetic prism 22.
To the polarizing prisms 9 to 11
If any one of the above is defective, it can be separated and replaced. In addition, since accurate positioning of the optical component by screwing is easier than bonding and fixing, the yield can be improved and the production cost can be reduced.

In this embodiment, the brackets 31 to 33
The holding plates 15 to 17 holding the liquid crystal elements 12 to 14 are fixed and the polarizing prisms 9 to 11 are stored and held. The bracket for fixing the holding plates 15 to 17 and the polarizing prisms 9 to 11 are stored and held. Alternatively, the bracket to be fixed may be a separate member, and these two brackets may be screwed to the spacers 34 to 36 fixed to the synthetic prism 22. In the present embodiment, the base 60
, A clamping plate 44 for clamping and holding the synthetic prism 22
And the brackets 31 to 33 are combined with the synthetic prism 2
The synthetic prism 22 is screwed or clamped to the spacers 34 to 36 fixed to the base 2, but fixed to the base 60 by screwing or the like. Alternatively, the polarizing prisms 9 to 11 may be screwed.

[0034]

As described in detail above, the reflection type projector apparatus of the present invention has the bracket holding the first to third polarizing prisms and the member fixed to the combining prism. The third to third polarizing prisms, the first to third reflective liquid crystal elements, and the synthetic prism were formed as one block, and a bracket for holding the polarizing prism was screwed to a member fixed to the synthetic prism. Therefore, it is possible to improve the registration shift due to the positional shift between the optical components, to display a high-resolution image, to improve the yield, and to realize a low cost.

[Brief description of the drawings]

FIG. 1 is a top view showing one embodiment of the present invention.

FIG. 2 is a side view showing one embodiment of the present invention.

FIG. 3 is a top view showing a comparative example.

FIG. 4 is a side view showing a comparative example.

FIG. 5 is a top view showing a conventional example.

FIG. 6 is a side view showing a conventional example.

FIG. 7 is a diagram showing a state where there is no registration deviation;

FIG. 8 is a diagram illustrating a state in which a registration shift has occurred due to a position shift of an optical component.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lamp (light source) 4, 5, 7 Color separation mirror (separation means) 9-11 Polarizing prism 12-14 Reflective liquid crystal element 22 Synthetic prism 23 Projection lens 31-33 Bracket 34-36 Spacer (member) 37 Elastic body 50 , 50 'block 60 base 100 optical base

Claims (1)

[Claims] 1. A separating means for separating white light from a light source into three primary color lights, first to third polarizing prisms for respectively polarizing the three primary color lights, and polarized light by the first to third polarizing prisms. The three primary color lights are incident, and the three primary color lights are modulated to form the first primary light.
A reflective projector comprising: first to third reflective liquid crystal elements that reflect light to third to third polarizing prisms; and a combining prism that combines the three primary color lights transmitted through the first to third polarizing prisms. An apparatus, comprising: a bracket holding the first to third polarizing prisms; and a member fixed to the combining prism, wherein the first to third polarizing prisms and the first to third reflecting prisms are provided. A reflective liquid crystal device and the synthetic prism are formed as one block, and the bracket is screwed to the member.