JPH08327808A - Optical prism device and projector device - Google Patents

Abstract

PURPOSE: To provide such an optical prism and a projector device in a simple structure as being capable of forming a stable thin air layer between optical mating faces and easily manage an optical system. CONSTITUTION: Two prisms 2A, 2B are opposed each other on the preset optical faces 3A, 3B to form a thin air layer therebetween. The prisms 2A, 2B have mutual contact between each other opposing areas 8, 10 at a space except in a light passage so that both can be adhered each other and integrally held between the areas 8, 10 with thrusting holder members 4A, 4B.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Field of Industrial Application Conventional Technology Problems to be Solved by the Invention Means for Solving the Problems Action Examples (FIGS. 1 to 5) (1) TIR prism device (FIGS. 1 and 2) (2) TIR prism Application example of the device (FIGS. 3 to 6)

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical prism device and a projector device, and is preferably applied to, for example, an internal total reflection prism or a projector device using an internal total reflection prism.

[0003]

2. Description of the Related Art Conventionally, for example, a prism has been used as an optical device for selectively transmitting or reflecting incident light according to the incident angle in an optical system. One of them is total internal reflection ( TIR: Total Internal Reflection) There is a prism. The TIR prism has the effect of reflecting 100% of the light incident on the boundary surface between the inside air and glass at an angle larger than the critical angle, regardless of the deflection state before the incidence. Incident light and reflected light can be separated.

This TIR prism is, for example, a DMD (Digital Micromirror Device) consisting of a specular polarization type optical modulator.
It is used for projector devices using display panels.
The TIR prism is used in the projector device to guide the irradiation light to the DMD display panel, separate the light reflected by the DMD display panel according to the incident angle to the prism, and select the effective light. The DMD display panel controls each of microscopic mirror elements (DMD elements) arranged in a plane according to pixels in accordance with an image signal and modulates image light by reflecting effective light ( JP-A-60-179781, JP-A-3-40693, and JP-A-3-174112).

The TIR prism is formed by two triangular prisms, but in order to avoid astigmatism, a thin air layer (0 or more, preferably 2 to 20) is formed between the two triangular prisms.
[Μm] or less) is required. As the structure of the prism that forms such a thin air layer,
There are the following. For example, with a thin film formed by vapor deposition on the optical mating surface of one prism,
An enclosing area is provided, and the thin film is inserted between the two, and the optical mating surface of the other prism is bonded with an adhesive. As a result, an air layer is formed in the area surrounded by the thin film. Further, instead of the thin film, a thin spacer having an opening in the optical path portion of the optical mating surface is inserted between the optical mating surfaces of the two prisms. As a result, an air layer is formed in the opening of the spacer inserted between the two prisms.

[0006]

However, in the TIR prism having such a structure, the adhesive for adhering the two prisms penetrates into the air layer and changes the thickness (gear cup) of the air layer. I got it. Further, when the two prisms are fixed together, when a stress due to thermal expansion is applied, the spacer inserted between them is deformed to change the gap of the air layer. For this reason, when the TIR prism is installed, only one prism can be supported, and the handling is troublesome. Further, due to the reasons as described above, it is difficult to control the air gap, and it is difficult to form an air layer having a predetermined thickness so as not to give astigmatism to the projected image and to keep the gear constant. Atsuta Furthermore, the projector apparatus using the TIR prism, which is difficult to control the air gap and difficult to handle, has a problem that astigmatism is generated and it is difficult to manage the optical system.

The present invention has been made in consideration of the above points, and uses an optical prism device capable of forming a stable thin air layer between optical mating surfaces with a simple structure and the optical prism device. We are going to propose a projector device with easy optical system management.

[0008]

In order to solve such a problem, in the present invention, a prism is formed by making two prisms face each other at predetermined optical surfaces with a thin air layer therebetween. This holder is provided with a holder member that abuts between the opposing portions excluding the optical path between them and presses between the portions to bring the two prisms into close contact with each other and hold them together.

Further, according to the present invention, a specular spatial light modulator element structure for converting emitted light emitted from a light source into at least two color separated lights and modulating each separated light with a color image signal corresponding to each color light. In the projector device which irradiates each display panel of No. 1, each color image light obtained through each display panel is combined, and is enlarged and projected through the projection lens, it is formed by facing predetermined optical surfaces of two prisms to each other. And a holder member that holds the two prisms in close contact with each other by bringing them into contact with each other between the opposing parts except for the optical path and pressing between these parts. Form a prismatic device. The optical prism device guides the incident light to the display panel and selectively transmits the effective light reflected by the display panel.

[0010]

[Operation] Two prisms are provided with predetermined optical surfaces,
A thin air layer is formed between the prisms by facing each other, and the prisms are brought into contact with each other between the opposing parts except the optical path, and the prisms are pressed by the two parts so that the two prisms are brought into contact with each other. By closely contacting and holding them together, an air layer between the prisms which is easy to disassemble or assemble and stable can be formed. Further, the stable formation of the air layer makes it possible to obtain a good projection image without astigmatism.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

(1) TIR Prism Device In FIGS. 1 and 2, reference numeral 1 indicates the T according to the present invention as a whole.
Shows an IR prism device, two prisms 2A and 2B
Are mechanically pressed between the mating surfaces 3A and 3B, which are optical surfaces, to form a prism, which is integrally held by the holders 4A and 4B. Each of the prisms 2A and 2B is a triangular prism formed by three optical surfaces. Each prism 2A and 2B is a columnar member made of optical glass having a triangular side surface.

The TIR prism device 1 forms a thin air layer between the mating surfaces 3A and 3B for laminating the prisms 2A and 2B in accordance with the surface accuracy of the mating surfaces 3A and 3B. This TIR prism device 1 has a function of reflecting light incident on the boundary surface between the air and the glass at an angle larger than the critical angle by 100% regardless of the deflection state before the incidence. And reflected light can be separated.

Next, the holders 4A and 4B for holding the two prisms 2A and 2B will be described. First, the holder 4A holding one prism 2A includes a bottom surface portion 6 having an opening 5 for guiding incident light to the prisms 2A and 2B and a side surface portion 8 supporting a side surface portion 7 of the prism 2A. Has been formed. The other holder 4B, which is paired with the holder 4A, is screwed to the holder 4A by a screw attached to the peripheral end portion of the upper surface portion 9. Holder 4B
Is to fix the TIR prism device 1 from the upper surface by means of the upper surface portion 9 and to provide the oblique side portion 10A of the obliquely cut side surface portion 10 at the corresponding position inside the side surface portion 8 of the holder 4A. The portion is brought into contact with 8A. At this time, the protruding guide pin 11 provided on the upper end of the side surface 8 of the holder 4A is fitted into the guide hole 12 provided on the peripheral end of the upper surface 9 of the holder 4B, whereby the holders 4A and 4
B is assembled together.

The holder 4A assembled in this way
4B are screwed into screw holes 14 provided at the upper end of the side surface portion 8 of the holder A by means of a contact screw 13 attached next to the guide hole 12 of the upper surface portion 9 of the holder 4B. As a result, the prisms 2A and 2B incorporated in the holders 4A and 4B are pressed and fixed by tightening the contact screw 13 between the upper surface portion 9 of the holder 4B and the bottom surface portion 6 of the holder 4A. An adjusting screw 15 used to widen the gear is provided beside the contact screw 13.

Further, in order to fix the prisms 2A and 2B from the side surface, between the side surface portion 7 on one side of the prisms 2A and 2B and the side surface portions 8 and 10 on one side of the holders 4A and 4B which face the prisms 2A and 2B, respectively. Insert a spacer (not shown). Each of the spacers is tightened by screws (not shown) from three screw holes 16 provided in the lower portion of the side surface portion 8 and the upper portion of the side surface portion 10, respectively, whereby the prisms 2A and 2B are provided on the opposite side surface. The parts 8 and 10 are pressed and fixed. In this way, the prisms 2A and 2
Combine the two holders 4A and 4B with B in between,
By tightening the contact screw 13 and the adjusting screw 15 from above and below, the gap between the prisms can be reduced to almost zero.
It can be fixed in the state of approaching [μm].

The TIR prism device 1 assembled in this manner does not use an adhesive or the like and therefore can be manufactured at a relatively low cost because the bonding step is omitted. Also,
By protecting the peripheries of the prisms 2A and 2B with the holders 4A and 4B, it is difficult for oil or the like of a finger to adhere to the optical surface of the prism. Further, even if oily fingers or the like adhere to the optical surface, they can be easily decomposed, so that they can be washed with a solvent and the like, and the handling becomes easy. Incidentally, the gap of the air layer that does not give astigmatism to the projected image is 0.
The thickness is set to [μm] or more, preferably 2 to 20 [μm] or less, but by using this TIR prism device 1, the gap of the air layer can be stably maintained,
As a result, a good projection image without astigmatism can be obtained without controlling the air gap.

(2) Application Example of TIR Prism Device In FIGS. 3 to 6, reference numeral 20 indicates a T according to the present invention as a whole.
1 shows a projector device using the IR prism device 1.
The projector device 20 is composed of a main body block 21 composed of a color separation block and a color composition block, and a lamp block 22 accommodating a light source.

The lamp block 22 is provided with a light source 23 for emitting high-intensity white light and a folding mirror 24 for reflecting the projection light L1 emitted from the light source 23. This lamp block 22 is integrally constructed by sheet metal, and the inside is hermetically sealed and a cooling system (not shown).
Is cooled by. Further, a UV (Ultra Violet) filter 25 for removing unnecessary ultraviolet rays is provided in a window of the lamp block 22 for emitting the projection light L1. The position of the lamp block 22 is set by a positioning pin 26 provided on the rear portion of the main body block 21 for positioning.

At the center of the main body block 21, there is provided a main base 27 that serves as a mounting reference for each optical component, and the main body block 21 is divided into a color separation block 21A and a color synthesis block 21B at this center portion. Figure 5
As shown in, a sub-base 28 whose position is adjustable by sliding in the optical axis direction is attached to the main base 27. On this sub-base 28, the prism mounting bracket 29 to which the TIR prism device 1 is mounted, and the DMD
Display panel 30 (30R, 30B, 30G) and DMD
A mounting block 31 which is a mechanism for aligning the reflection position of the display panel 30 is installed. The attachment block 31 emits 3 light emitted from the color separation block 21A.
DMD display panels 30R, 30B, 3 for the colored lights R, B, G
TIR prism devices 1R, 1B, and 1G which are incident on 0G are arranged.

DMD display panels 30R, 30B, 30G
Mounting block 31 (31R, 31G, 3
1B) is a plate 3 whose lower end is fixed to the sub base 28.
2 moving plates 33 each supported by 2,
It is formed by superimposing 34 and 35. With respect to each plate, the plate 33 moves in the horizontal direction, the plate 34 moves in the vertical direction, and the plate 35 moves in the rotational direction with respect to the plate 32. Adjust the reflection position of.

In practice, the projection light L1 emitted from the light source 23 is bent in the direction of the main body block 21 by the mirror 24, unnecessary UV rays are removed by the UV filter 25, and then the color separation of the main body block 21 is performed. Block 21
It is incident on A. The projection light L1 incident on the color separation block 21A is converted into parallel light through the condenser lens 36, bent by the folding mirror 37, and separated by the dichroic mirrors 38R and 38B.
38G is irradiated.

Disassembly dichroic mirrors 38R, 38
B and 38G decompose the procedure light L1 composed of white light into red light LR, blue light LB, and green light LG. The red light LR, the blue light LB and the green light LG are reflected by the mirror 3
It is bent upward at an angle of 45 ° by 9R, 39B, and 39G. The red light LR, the blue light LB and the green light LG are
Opening windows 40R provided on the main base 27,
40B, 40G, through the TIR prism device 1R, 1
Guided to B and 1G.

The light reflected by the TIR prism devices 1R, 1B, and 1G is applied to the reflecting surfaces of the DMD display panels 30R, 30B, and 30G at an angle of 20 [°], and is spatially modulated, and then the relay lens. 41R, 41B and 41G are enlarged and projected, and the combined dichroic mirror 42R,
An image is formed at a virtual image formation point A through 42B and 42G. In this way, the incident light from the mirrors 39R, 39B, 39G is made incident on the DMD display panels 30R, 30B, 30G by the TIR prism devices 1R, 1B, 1G, so that the entire optical path length in the alignment mechanism is short. Therefore, the entire alignment mechanism can be arranged in a narrow range.

DMD display panels 30R, 30B, 30G
Are pixel arrays of video data (for example, 768 × 57
The number of micro mirror surface elements is about 17 [μm] square, for example.
A reflective surface having a size similar to that of a 2-inch CCD (solid-state image sensor) is formed. This micro mirror surface element is arranged corresponding to each memory cell of the frame memory according to the arrangement of the pixels of the video data, and the inclination state of the corresponding micro mirror surface element changes individually according to the state of each memory cell. Has been done.

In reality, each micro mirror element is tilted by +10 [°] as shown in FIG. 6A when the memory cell is in the ON state, that is, when the memory cell is effective as a pixel with respect to the neutral state, and conversely Is in an off state, that is, when the pixel is invalid, it is inclined by +10 [°] as shown in FIG. 6 (B). As a result, the reflected light reflected by the mirror surface with respect to the incident light is switched to have an optical path difference of 20 [°] between the effective reflected light necessary for forming an image and the invalid reflected light that is ineffective.

In the case of this projector device 1, each DMD
By setting image data for one frame of red, green, and blue in the frame memories corresponding to the display panels 30R, 30B, and 30G, red, green, and blue image lights are formed as effective reflected light. The red, green, and blue image lights correspond to the corresponding relay lenses 41R, 41B, 41.
The dichroic mirror for synthesis 42R, 42
It is guided to B and 42G and is combined as color image light.
This is a projection lens 43 with a zoom lens configuration.
Through, a magnified projection is carried out on a screen (not shown) which is arranged outside the projector device 1.

In the projector device 20, the combined light imaged at the virtual image formation point A in this manner is operated by the attachment block 31 of the DMD display panel 30 so that the DMD display panel 30 (30R, 30B, 30G) is displayed. By making small movements in the vertical direction, the rotation direction, and the focus direction, the respective image positions of the red light LR, the blue light LB, and the green light LG at the virtual image formation point A can be corrected.

In the above arrangement, the projection light L1 emitted from the light source 23 is the color separation block 21A.
Guided to the disassembly dichroic mirror 38R, 38
The red light LR, the blue light LB, and the green light LG are separated by B and 38G. The red light LR, the blue light LB and the green light LG are obliquely reflected by the mirrors 39R, 39B and 39G.
45 [°] Bent upwards, 2 main bases each
7 through the opening windows 40R, 40B, 40G, the TIR prism device 1R of the color synthesis block 21B,
Guided to 1B and 1G.

The light reflected by the TIR prism devices 1R, 1B, 1G is applied to the reflecting surfaces of the DMD display panels 30R, 30B, 30G at an angle of 20 [°], is spatially modulated, and is again TIR prism device. It is incident on 1R, 1B and 1G. In this way, the incident light from the mirrors 39R, 39B, 39G is made incident on the DMD display panels 30R, 30B, 30G by the TIR prism devices 1R, 1B, 1G, so that the entire optical path length in the alignment mechanism is short. Therefore, the entire alignment mechanism can be arranged in a narrow range.

The TIR prism device 1 selectively transmits incident light according to the spatial light modulation by each of the DMD display panels 2R, 30B and 30G. That is, as shown in FIG. 6B, the off-state light incident on the boundary surface of the TIR prism device 1 at an angle larger than the critical angle is reflected,
As shown in (A), light in an ON state with an incident angle of 0 [°] is transmitted. The modulated light of each color light is relay lenses 41R, 41
B, 41G magnify and project, pass through the composite dichroic mirrors 42R, 42B, 42G, combine at the virtual image forming point A, and project on the screen through the projection lens.

According to the above configuration, the DMD display panel 3
In the projector device 20 using the 0R, 30B, and 30G, the color-separated color lights are separated by the TIR prism device 1.
DMD display panels 30R, 30 using R, 1B, 1G
By making the light incident on B and 30G, the entire optical path length in the alignment mechanism can be shortened, and thus the entire alignment mechanism can be arranged in a narrow range.
Further, according to the above-mentioned configuration, a T formed by mechanically incorporating the holders 4A and 4B around the prisms 2A and 2B.
By using the IR prism device 1, the arrangement of the TIR prism device 1 in the optical system can be easily changed. Further, since the TIR prism device 1 formed by mechanically incorporating the holders 4A and 4B does not use an adhesive or the like, it can be easily disassembled and washed, and an optically good state can be maintained.

Further, according to the above-mentioned configuration, by using the TIR prism device 1, the air layer gear trap can be stably maintained, and a good projection image without astigmatism can be controlled by the air layer gear trap. This can be obtained without performing the above, and the labor of adjusting the optical system in the projector device 20 can be greatly saved.

In the above-mentioned embodiment, the case where the two prisms 2A and 2B are assembled between the holders 4A and 4B and adhered to each other and fixed so that they do not move is described, but the present invention is not limited to this. The two prisms forming the TIR prism device 1 may be slid along the hypotenuse portion 10A and the step portion 8A of the holders 4A and 4B so that they can move along the mating surfaces 3A and 3B. As a result, the thickness of the two prisms is slightly changed while the DMD display panel mounting position is fixed, and the magnification is adjusted by changing the effective optical path length between the DMD display panel, the relay lens, and the projection lens. The size of the image of each color light can be adjusted at the time of image matching.

Further, in the above-mentioned embodiment, the projector device 20 using the DMD display panel for decomposing the white light emitted from the light source 23 into the three-color light is described, but the present invention is not limited to this, and the white light is emitted. A projector device capable of decomposing into at least two-color light may be used.

In the above-mentioned embodiment, the case where the TIR prism is formed by using two prisms has been described, but the present invention is not limited to this, and a thin air layer is formed between the mating surfaces of the prisms. This is applicable to general prism devices that require the above.

Further, in the above-mentioned embodiment, the projector devices 40 and 50 using the DMD display panel 30 as the spatial light modulator have been described, but the present invention is not limited to this, and for example, a transmission type liquid crystal display panel or a reflection type. It may be used for a projector device using a liquid crystal display panel or the like.

[0038]

As described above, according to the present invention, the two prisms are brought into close contact with each other by mechanically pressing by the holder member abutting between the opposed portions except the optical path, By forming a prism that forms a thin air layer between the optical mating surfaces by holding them together, an optical prism device is obtained that can be easily assembled or disassembled for easy handling. Further, by using an optical prism device having a stable air layer between the prisms, a projector device having no astigmatism and easy management of the optical system can be realized.

[Brief description of drawings]

1 is a schematic diagram showing a perspective view (FIG. 1 (A)) and (FIG. 1 (C)) of a holder of a TIR prism device according to the present invention, and a perspective view (FIG. 1 (B)) of a prism.

2 is a front view of the TIR prism device shown in FIG.
FIG. 3A is a schematic diagram showing a side view (FIG. 2B).

FIG. 3 is a side view (FIG. 3A) and a top view (FIG. 3) of a projector device using a specular polarization type optical modulator according to the present invention.
It is an approximate line figure showing (B) and a side view (Drawing 3 (C)).

4 is a schematic diagram showing a rear view of the main body block of FIG. 3. FIG.

FIG. 5 is a schematic diagram showing a front view of a TIR prism device and an alignment mechanism mounted on a main base.

FIG. 6 is a schematic diagram for explaining the operation of the DMD element of the specular deflection type optical modulator.

[Explanation of symbols]

1 ... TIR prism device, 1R, 1B, 1G ... TI
R prism, 2A, 2B …… Prism, 4A, 4B ……
Holder, 5 ... Opening part, 6 ... Bottom part, 7, 8, 10 ...
… Side part, 9 …… Top part, 11 …… Guide pin, 12…
… Guide hole, 13… Adhesion screw, 15… Adjusting screw, 20… Projector device, 21… Main unit block, 21A… Color separation block, 21B… Color composition block, 22… Lamp block, 23 ... light source, 24,
37, 39R, 39B, 39G ... Mirror, 25 ... U
V filter, 26 ... Locating pin, 27 ... Main base, 30R, 30B, 30G ... DMD display panel,
38R, 38B, 38G ... Separation dichroic mirror, 40R, 40B, 40G ... Opening window, 41 ... Positioning pin, 41R, 41B, 41G ... Relay lens,
42R, 42B, 42G ... Synthetic dichroic mirror, 43 ... Projection lens.

Front page continuation (72) Inventor Junichi Iwai 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (3)

[Claims] 1. A prism formed by facing predetermined optical surfaces of two prisms with a thin air layer in between, and between a facing portion excluding an optical path with the prism interposed therebetween. An optical prism device comprising: a holder member that abuts and presses between the parts to bring the two prisms into close contact with each other and hold them together. 2. The optical prism device according to claim 1, wherein the two prisms are movable along the optical surface to change the thickness of the air layer. 3. Light emitted from a light source is reduced to 2
Converting to separate light of each color, irradiating each separate light on each display panel of the mirror surface spatial light modulation element configuration that modulates with the color image signal according to each color light, each color image light obtained through each corresponding display panel. In a projector device for synthesizing and magnifying and projecting through a projection lens, a prism formed by facing predetermined optical surfaces of two prisms, and a facing portion excluding an optical path with the prism interposed therebetween. An optical prism device formed by a holder member that holds the two prisms in close contact with each other by bringing them into contact with each other and pressing the two prisms together is provided. A projector device characterized in that incident light is guided to a panel and effective light reflected by the display panel is selectively transmitted. .