JP2008197185A - Image forming unit, image composition unit and image projection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form an image without deviating red, blue and green light beams by reducing distortion, deformation or stress due to a difference of the thermal expansion coefficients of parts caused by temperature change with a simple configuration. <P>SOLUTION: An optical path separation element 2, a reflection type optical modulation element 3 and a light transmissive member 4 are fixed to a pair of supporting members 5 formed of optical glass or ceramic or low expansion alloy having a linear expansion coefficient nearly the same as that of the optical glass in the shape of a triangle pole, so that the rigidity of an image forming unit 1 is made higher to secure stable holding accuracy, and also the distortion, the deformation and the stress due to the difference of the thermal expansion coefficients of respective component parts are reduced, and the stable holding accuracy is maintained. Image light obtained by making illumination light of different wavelength bands incident on three sets of image forming units 1 and optically modulating it is emitted, and the emitted image light is combined by a light combining prism 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming unit used for a front projector, a rear projector, and the like, an image composition unit for synthesizing image light of each color, and an image projection apparatus using the image formation unit, and in particular, to increase rigidity of the image formation unit and optically change due to temperature change. The present invention relates to obtaining a high-quality image by preventing deterioration of characteristics.

  As shown in Patent Document 1, optical means that separates light from a light source into red, blue, and green light, and the light of each separated color is transmitted and incident on a reflective liquid crystal panel, and modulated by the reflective liquid crystal panel 2. Description of the Related Art An image projection apparatus is used that includes a reflective polarizing element that reflects the incident light and enters a light combining prism, and a projection lens that projects an image combined by the light combining prism onto a screen and displays an image.

  In this image projection apparatus, the positions of the reflective polarizing element, the reflective liquid crystal panel, and the light combining prism are adjusted and fixed with an adhesive or the like so that the image light 2 of red, blue and green colors overlap on the screen. Yes. If the positions of the reflective polarizing element, the reflective liquid crystal panel, and the light combining prism that have been adjusted and fixed are shifted due to temperature changes such as outside air, the superimposition of images projected on the screen is shifted.

In order to prevent the misalignment of the projected images, the optical device disclosed in Patent Document 2 is a glass material having a linear expansion coefficient of 10 × 10 ⁻⁶ (/ K) or less as shown in FIG. Among the three side surfaces of the fixed plate 100 formed of triangular or stainless steel or Kovar (FeNiCo), the first side surface is a bonding surface to the light incident surface of the light combining prism 101, and the second side surface is the reflective polarizing element 102. And a third side surface as a mounting surface of the reflective liquid crystal panel 103, and the reflective polarizing element 102 and the reflective liquid crystal panel 103 are separated by a fixed distance from each other through two upper and lower fixed plates 100. 101 is fixed to the corresponding light incident surface.
JP 2006-98881 A JP 2006-99086 A

  The optical device disclosed in Patent Document 1 uses a glass material, stainless steel, or Kovar for the fixed plate 100. However, the reflective polarizing element 102 and the reflective liquid crystal panel 103 corresponding to red, blue, and green light are combined. In order to fix to the prism 101, six fixing plates 100 are required. If the linear expansion coefficients of the respective fixing plates 100 are different, there is a possibility that a color shift occurs in an image synthesized by the light combining prism due to a change in temperature.

  In addition, when the reflective polarizing element 102, the reflective liquid crystal panel 103, and the light combining prism 101 are fixed to the mounting surfaces of the two fixed plates 100, it is necessary to perform accurate alignment for each fixed plate 100, Assembling is not easy, and many fixing plates 100 are used, resulting in high costs.

  Further, since the light combining prism 101 attaches the light incident surface to the mounting surface of the fixed plate 100, it is necessary to provide an adhesive region on the light incident surface, and the light combining prism becomes large and expensive.

  The present invention improves such disadvantages and reduces distortion, deformation, or stress due to differences in the coefficient of thermal expansion of components due to temperature changes with a simple configuration, causing red, blue, and green light to shift. SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming unit, an image synthesizing unit, and an image projection apparatus that can be easily assembled together without being combined.

  The image forming unit according to the present invention includes a reflection type light modulation element having an image forming unit that modulates or deflects light in pixel units according to an image signal, and transmits the illumination light of a predetermined wavelength band and transmits the reflection type light modulation. An optical path separating element that reflects the image light that is incident on the element and modulated and reflected by the reflective light modulating element; a translucent member that transmits and emits the image light reflected by the optical path separating element; and an angle of 45 A pair of support members formed in a triangular prism shape having two apex angles of degrees, and both ends of the optical path separation element are fixed to the inclined surfaces of the pair of support members, and the pair of support members Both ends of the reflective light modulation element are fixed to one orthogonal surface of the member, and both ends of the translucent member are fixed to the other surface.

  A second image forming unit according to the present invention includes a reflective light modulation element having an image forming unit that modulates or deflects light in units of pixels in accordance with an image signal, and translucency that transmits illumination light in a predetermined wavelength band. A member, an optical path separating element that reflects the illumination light transmitted through the translucent member, enters the reflective light modulation element, and transmits the image light that is modulated and reflected by the reflective light modulation element; A pair of support members formed in a triangular prism shape having two apex angles of 45 degrees, and both ends of the optical path separation element are fixed to the inclined surfaces of the pair of support members, and the pair of support members Both ends of the reflective light modulation element are fixed to one orthogonal surface of the support member, and both ends of the translucent member are fixed to the other surface.

  The support member is preferably made of optical glass or ceramic or low expansion alloy having a linear expansion coefficient substantially the same as that of optical glass.

  Further, any one, two or all of the reflection type light modulation element, the optical path separation element and the translucent member may be fixed to the pair of support members via an intermediate support member. Furthermore, an intermediate support member that supports the optical path separation element may be used.

  The internal space surrounded by the reflective light modulation element, the optical path separation element, the translucent member, and the pair of support members is preferably sealed. This sealed internal space may be filled with a light-transmitting liquid.

  Further, a polarizer may be disposed on the light incident surface side or the light exit surface of the translucent member.

  A third image forming unit according to the present invention includes a reflective light modulation element having an image forming unit that modulates or deflects light in pixel units according to an image signal, and transmits the illumination light in a predetermined wavelength band to reflect the light. An optical path separation element that reflects image light that is incident on the reflective light modulation element and modulated and reflected by the reflective light modulation element, and a translucent prism formed in a triangular prism shape having two apex angles of 45 degrees The optical path separating element is fixed to the inclined surface of the translucent prism member, and both end portions of the reflective light modulation element are fixed to one orthogonal surface of the translucent prism member. It is characterized by. A polarizer may be disposed on the light exit surface side of the translucent prism member.

  A fourth image forming unit of the present invention includes a reflection type light modulation element having an image forming unit that modulates or deflects light in pixel units according to an image signal, and reflects the illumination light in a predetermined wavelength band to reflect the reflection light. An optical path separating element that transmits the image light that is incident on the reflection type light modulation element and modulated and reflected by the reflection type light modulation element, and a translucent prism formed in a triangular prism shape having two apex angles of 45 degrees The optical path separating element is fixed to the inclined surface of the translucent prism member, and both end portions of the reflective light modulation element are fixed to one orthogonal surface of the translucent prism member. It is characterized by. A polarizer may be disposed on the incident surface side of the translucent prism member.

  The image composition unit of the present invention has at least two sets of any one of the image forming units and a light combining prism, and illumination lights having different wavelength bands are incident on the at least two sets of image forming units. Illumination light is modulated to emit image light, and the light combining prism combines and emits image light emitted from the image forming units.

  It is desirable to connect the image forming unit and the light combining prism with a fixing member.

  The image projection apparatus of the present invention includes the image synthesis unit, separates the illumination light emitted from the light source into light of different wavelength bands, and enters the separated light of each color into the image synthesis unit, and the image synthesis The light of each color incident on the unit is modulated, the modulated light of each color is synthesized and emitted, and an image is displayed on the projection surface.

  The present invention has a pair of support members formed in a triangular prism shape, and fixes the optical path separation element, the reflective light modulation element, and the translucent member to the pair of support members formed in a triangular prism shape, Since the optical path separation element and the reflective light modulation element are fixed to the translucent prism member formed in a triangular prism shape, the rigidity can be increased and stable holding accuracy can be ensured.

  In addition, the support member is made of optical glass or ceramic having a linear expansion coefficient substantially the same as that of optical glass or a low expansion alloy, so that the distortion, deformation, and stress caused by the difference in thermal expansion coefficient of each component can be achieved. Can be reduced, and stable holding accuracy can be secured.

  In addition, by sealing the internal space surrounded by the reflective light modulation element, the optical path separation element, the translucent member, and the pair of support members, dust floating in the air is prevented from entering the inside. It can prevent dust from adhering to the surface that plays an important role in image formation of the optical path separation element and the reflection type light modulation element, and can prevent a decrease in light quantity and flare, and emit high quality image light. Can do.

  Furthermore, by filling the inside of the sealed image forming unit with a light-transmitting liquid, it is more certain that dust will adhere to the surface of the optical path separation element or the reflection type light modulation element that has an important function for image formation. Can be prevented.

  In addition, by providing a polarizer on the exit surface side of the image forming unit, the illumination light is disturbed in polarization, or the light that should return without being modulated by the reflective light modulation element is converted into image light. The component which drops can be cut, and contrast can be improved more.

  In addition, illumination light of different wavelength bands is incident on at least two sets of image forming units that ensure stable holding accuracy, and the incident illumination light is modulated to emit image light. By combining with the light combining prism, it is possible to combine image light of different wavelength bands with high accuracy.

  Furthermore, by connecting the image forming unit and the light combining prism with a fixing member, it is possible to increase the rigidity of the image combining unit and maintain stable holding accuracy and emit high-quality image light without positional deviation. it can.

  By using this image synthesizing unit in the image projection apparatus, it is possible to stably project a good quality image on the projection surface.

  1A and 1B show a configuration of an image forming unit according to the present invention, in which FIG. 1A is a perspective view and FIG. 1B is a side view. As shown in the figure, the image forming unit 1 includes an optical path separation element 2, a reflective light modulation element (light valve) 3, a translucent member 4 and a pair of support members 5. The optical path separation element 2 has an optical path separation unit 201 formed on a substrate 202 formed of a half mirror having a polarization separation film or an induced multilayer film, a wire grid polarization element, or the like. The reflection type light modulation element 3 includes a liquid crystal panel sealed with a backplane on which pixel electrodes are formed and a cover glass, which is arranged on a ceramic substrate or a glass epoxy substrate, and is configured by a holder for holding the substrate.

Each support member 5 is formed in a triangular prism shape having two apex angles with an angle of 45 degrees. This support member 5 is made of a ceramic having a linear expansion coefficient of 5.0 to 8.0 × 10 ⁻⁶ (/ K) which is almost the same as the linear expansion coefficient of optical glass (BK7) or optical glass 7.5 × 10 ⁻⁶ (/ K), or a linear expansion coefficient of 6.0. It is formed of a low expansion alloy of ˜8.0 × 10 ⁻⁶ (/ K).

  The pair of support members 5 are arranged at a predetermined interval, and both ends of the optical path separation element 2 are fixed to the inclined surfaces of the pair of support members 5 so as not to interrupt an effective optical path, and one orthogonal surface is formed. Both ends of the reflective light modulation element 3 are fixed, and both ends of the translucent member 4 are fixed to the other orthogonal surface. As a method of fixing the optical path separation element 2, the reflection type light modulation element 3, and the translucent member 4 to the support member 5, mechanical bonding by screwing may be used, but bonding by an adhesive is preferable. Further, mechanical bonding and bonding with an adhesive may be used in combination.

  When illumination light enters the optical path separation element 2 of the image forming unit 1, the optical path separation element 2 transmits the incident illumination light and enters the reflective light modulation element 3. The reflective light modulation element 3 modulates incident illumination light in units of pixels according to an image signal, reflects the modulated image light, and enters the optical path separation element 2. The optical path separation element 2 reflects the incident image light and emits it toward the translucent member 4. The translucent member 4 transmits and emits incident image light.

  As described above, since the optical path separation element 2, the reflective light modulation element 3, and the translucent member 4 are fixed to the respective side surfaces of the pair of support members 2 formed of triangular prisms, the rigidity of the image forming unit 1 is increased. be able to. FIG. 1 shows the case where the optical path separation element 2, the reflection type light modulation element 3 and the end of the translucent member 4 are fixed to the support member 2 apart from each other. It may be configured in close contact. As described above, when the optical path separation element 2, the reflection type light modulation element 3, and the ends of the translucent member 4 are brought into close contact with each other, the rigidity can be further increased. Further, a frame configuration may be used to increase the strength of the support member 5.

  Further, by forming the support member 5 from optical glass having a small linear expansion coefficient or ceramic or low expansion alloy having a linear expansion coefficient substantially the same as that of optical glass, the shape change due to temperature is small, and the heat of each component is reduced. Distortion, deformation, and stress due to expansion can be avoided and stable holding accuracy can be secured.

  In the above description, the case where the optical path separation element 2, the reflective light modulation element 3 and the translucent member 4 are directly fixed to the side surfaces of the pair of support members 5 has been described. Alternatively, any or all of the translucent member 4 may be fixed to the support member 5 via an intermediate support member. For example, as shown in FIG. 2, the outer peripheral surface of the optical path separation element 2 is held by a frame-shaped first intermediate support member 6 having an opening at the center, and the reflective light modulation element 3 is formed by a second intermediate support member. The first intermediate support member 6 is fixed to the inclined surfaces of the pair of support members 5, and the second intermediate support member 7 is fixed to one orthogonal surface of the support member 5. The first intermediate support member 6 and the second intermediate support member 7 are made of the same material as that of the support member 5.

  Thus, by fixing the optical path separation element 2 and the reflective polarizing element 3 to the pair of support members 2 via the intermediate support members 6 and 7, the rigidity of the image forming unit 1 can be further increased. In addition, stress is not directly applied to important functional components such as the optical path separating element 2 and the reflective polarizing element 3, and the stable image forming unit 1 can be formed. Further, although the optical path separation element 2 and the reflective polarizing element 3 are generally different in material, they are bonded to the intermediate support members 6 and 7 by using an adhesive according to the material, and the intermediate support members 6 and 7 are used. An appropriate adhesive can also be used for joining the support member 5 and the image forming unit 1 with higher reliability. Further, since the optical path separating element 2 and the reflective polarizing element 3 are fixed to the supporting member 5 via the intermediate supporting members 6 and 7, the optical path separating element 2 and the reflective polarizing element 3 can be exchanged. It can also be structured.

  In the above description, the case where the outer peripheral surface of the optical path separation element 2 is held by the frame-shaped first intermediate support member 6 has been described. As shown in the front view of FIG. 3A and the side view of FIG. The outer periphery of the optical path separation element 2 that does not block the effective optical path may be supported by a frame-shaped first intermediate support member 6, and the first intermediate support member 6 may be fixed to the pair of support members 5. Thus, by holding the outer periphery of the optical path separation element 2 with the frame-shaped first intermediate support member 6, when a polarization beam splitter is adopted as the optical path separation element 2, it has the minimum necessary optical function. It is only necessary to form a polarization separation section, and the cost can be reduced by reducing the expensive optical path separation element 2. The first intermediate support member 6 is not limited to the frame shape, and the periphery of the optical path separation element 2 may be held within a range in which effective light does not affect the image.

  Also, the first intermediate support member 6 and the second intermediate support member 7 are formed of the same linear expansion coefficient as that of the support member 5 by forming the first intermediate support member 6 and the second intermediate support member 7. 7 can avoid distortion, deformation, and stress due to thermal expansion of the support member 5 and the support member 5, and can ensure stable holding accuracy.

  Further, as shown in the front view of FIG. 4A and the side view of FIG. 4B, the optical path separation element 2, the reflective light modulation element 3, and the translucent member 4 fixed to a pair of support members 5 are mutually connected. Or an optical path separation element 2 fixed to a pair of support members 5 via a first intermediate support member 6 and reflective light fixed to a pair of support members 5 via a second intermediate support member 7 The space between the modulation element 3 and the translucent member 4 may be sealed with a sealing member 8. As the sealing member 8, for example, a silicon-based relatively soft rubber sealant is used. Here, the sealing member 8 is not limited to the sealing agent, and each component may be intimately joined to serve as an adhesive.

  Thus, by forming the image forming unit 1 in a sealed structure, dust floating in the air can be prevented from entering the inside, and image formation of the optical path separation element 2 and the reflective light modulation element 3 can be prevented. By preventing dust from adhering to the surface performing important functions, it is possible to prevent a decrease in light quantity and flare, and to emit high-quality image light.

  Further, the image forming unit 1 sealed with the sealing member 8 may be filled with a light-transmitting liquid. As the liquid to be filled, for example, silicon resin or glycerin may be used, but a liquid that can withstand the temperature change required for the image forming unit 1 is preferable. In order to cope with this temperature change, bubbles may be provided as long as the optical path is not interrupted to serve as an expansion / contraction buffer, or an expansion / contraction mechanism using a sealant may be provided.

  In this way, by filling the image forming unit 1 sealed with the sealing member 8 with a light-transmitting liquid, the surface of the optical path separation element 2 and the reflective light modulation element 3 that plays an important function in image formation is dusty. Can be reliably prevented.

  Further, a polarizer 9 may be provided on either the incident side or the emission side of the translucent member 4, for example, on the emission side of the translucent member 4 as shown in FIG. 4. By providing the polarizer 9 in this way, the illumination light is disturbed in polarization, or light that is not modulated by the reflective light modulation element 3 and should return in the same direction as the illumination light becomes image light. The component that drops the light can be cut by the polarizer 9, and the contrast can be further improved.

  In the above description, the case where the optical path separation element 2, the reflective light modulation element 3, and the translucent member 4 are fixed to the pair of support members 5 has been described, but the front view of FIG. 5A and the side surface of FIG. As shown in the figure, a light transmitting prism member 10 formed in a triangular prism shape having two apex angles of 45 degrees is used, and the optical path separation element 2 is fixed to the inclined surface of the light transmitting prism member 10, The reflective light modulation element 3 may be fixed to one orthogonal surface, and the other orthogonal surface may be used as a display surface.

  By fixing the optical path separation element 2 and the reflective light modulation element 3 to the translucent prism member 10 in this way, the rigidity of the image forming unit 1 can be further increased.

  Further, when the reflective light modulation element 3 is fixed to the translucent prism member 10, the reflective light modulation element 3 usually has a cover glass, so that the reflective light modulation element 3 is in close contact with the translucent prism member 10 through the cover glass. As shown in FIG. 6, the optical path separation surface 201 of the optical path separation element 2 is formed on the inclined surface of the translucent prism member 9, and is sandwiched between the glass plates 11 to eliminate the air interface with an adhesive or the like. In addition, it is possible to completely prevent dust and the like from being mixed into the fixing portion with the translucent prism member 10. Further, when a wire grid polarizer is used as the optical path separation element 2 and the optical path separation surface 201 functions at the air interface, the substrate 202 side that is the opposite side of the optical path separation surface 201 is transmitted through as shown in FIG. What is necessary is just to arrange | position closely and adhere to the optical prism member 10. FIG. In this way, by eliminating the air interface and mixing dust and the like, polarization disturbance, irregular reflection, and multiple reflection can be prevented, and the contrast can be further improved.

  Further, when a liquid crystal is used as the reflection type light modulation element 3, a phase modulation element 12 such as a phase difference plate may be required on the front surface of the reflection type light modulation element 3. In such a case, as shown in FIG. 8, it is preferable that the reflective light modulation element 3, the phase modulation element 12, and the translucent prism member 10 are closely arranged.

  If the polarizer 9 is disposed on the display surface of the translucent prism member 10, the illumination light included in the image light can be cut by the polarizer 9, and the contrast of the image light can be further improved.

  Next, an image composition unit using the image forming unit 1 will be described. As shown in the block diagram of FIG. 9, the image composition unit 20 includes two sets of image forming units 1a and 1b and a light composition prism 21 such as a dichroic prism. The image forming unit 1a receives illumination light of the first wavelength band, optically modulates the incident light of the first wavelength band according to an image signal, and emits the modulated light as image light. The image forming unit 1b receives illumination light having a wavelength band different from the first wavelength band, optically modulates the incident illumination light according to an image signal, and emits the modulated image light. The light combining prism 21 combines and emits the image light emitted from the image forming unit 1a and the image light emitted from the image forming unit 1b. In this manner, the image light of the first wavelength band and the image light of the second wavelength band can be synthesized and the image light of the color image can be emitted. For example, when green (G) illumination light is incident on the image forming unit 1a and blue (B) and red (R) illumination light is incident on the image forming unit 1b in a time-sharing manner, full-color image light is converted into a light combining prism. 21 can be emitted.

  The image composition unit 20 shown in FIG. 9 has been described as having two sets of image forming units 1a, 1b. However, as shown in the configuration diagram of FIG. 10, three sets of image forming units 1a, 1b, 1c are provided. Opposite to the three incident surfaces of the light combining prism 21, illumination light of different wavelength bands, for example, green (G) color, blue (B) color, and red (R) color is applied to each of the image forming units 1 a to 1 c. Incident light may be modulated, and the light-modulated image light may be combined by the light combining prism 21.

  Further, the image forming units 1a to 1c are positioned on the respective incident surfaces of the light combining prism 21, and as shown in the configuration diagram of FIG. 11A, the linear expansion is substantially the same as that of a glass member having a small linear expansion coefficient or a glass member. The display surface of the translucent member 4 or translucent prism member 10 of each of the image forming units 1a to 1c and the respective incident surfaces of the light combining prism 21 are used as image light by a fixing member 22a such as ceramic or low expansion alloy having a coefficient. As shown in FIG. 11B, the pair of support members 5 and the translucent prism member 10 of each of the image forming units 1a to 1c are fixed with an adhesive within a range that does not affect the used light flux. The image forming units 1a to 1c may be fixed to the light combining prism 21 with a fixing member 22b sandwiched therebetween. By fixing the image forming units 1a to 1c to the light combining prism 21 in this way, the rigidity of the image combining unit 20 can be increased, the shape change due to temperature change is small, and distortion caused by thermal expansion of components Deformation and stress can be avoided, stable holding accuracy can be ensured, and positional deviation due to temperature change of the synthesized light can be reduced.

  In the above description, as the image forming unit 1, the incident illumination light is incident on the optical path separation element 2, and the illumination light incident on the optical path separation element 2 is transmitted and incident on the reflective light modulation element 3. The illumination light incident at 3 is optically modulated in units of pixels in accordance with the image signal, the modulated image light is reflected and incident on the optical path separation element 2, and the image light is reflected by the optical path separation element 2 to transmit the light. 4 shows the case where the light is transmitted through, but the incident illumination light is incident on the translucent member 4 as in the image forming unit 1A shown in the front view of FIG. 12A and the side view of FIG. Then, the illumination light incident on the translucent member 4 is transmitted and incident on the optical path separation element 2, and the illumination light is reflected on the optical path separation element 2 and incident on the reflective light modulation element 3. 3, the illumination light incident in 3 is optically modulated in units of pixels in accordance with the image signal, and the modulated image light is Incident on the light path separation element 2 shines, the optical path division element 2 may be emitted through the image light.

  Then, as shown in FIG. 13, three sets of image forming units 1Aa, 1Ab, and 1Ac are arranged facing the three incident surfaces of the light combining prism 21 to form an image combining unit 20a, and each image forming unit 1Aa Even if the illumination light of different wavelength bands, for example, green (G) color, blue (B) color and red (R) color, is incident on and modulated in 1 Ac, and the light-modulated image light is combined by the light combining prism 21 good.

  Next, an image projection apparatus using the image composition unit 20 having the image forming units 1a to 1c will be described. As shown in the schematic configuration diagram of FIG. 14, the image projection apparatus 30 includes a light source 31, a lens 32, dichroic mirrors 33 a and 33 b, a mirror 34, an image composition unit 20, a projection lens 35, and a screen 36.

  When an image is projected onto the screen 36 by the image display device 30, the illumination light emitted from the light source 31 is separated into red, blue and green light by the dichroic mirrors 33a and 33b via the lens 31, and separated. The light of each color is incident on the image composition unit 20, the incident light of each color is modulated by the image forming units 1a to 1c, the modulated image light of each color is reflected and synthesized by the light synthesis prism 21, and the synthesized image light Is projected onto the screen 36 by the projection lens 35 to display an image. When this image is displayed, the image composition unit 20 emits synthesized light with a small positional shift even if there is a temperature change, so that a high-quality image can be displayed stably.

It is a block diagram of the image forming unit of this invention. FIG. 6 is a configuration diagram of a second image forming unit. FIG. 6 is a configuration diagram of a third image forming unit. It is a block diagram of the 4th image forming unit. FIG. 10 is a configuration diagram of a fifth image forming unit. It is a block diagram of a 6th image forming unit. FIG. 10 is a configuration diagram of a seventh image forming unit. It is a block diagram of the 8th image forming unit. It is a block diagram of the image composition unit of this invention. It is a block diagram of the 2nd image composition unit. FIG. 3 is a configuration diagram illustrating a state in which an image forming unit and an image composition unit are connected. It is a block diagram of the 9th image forming unit. It is a block diagram of the image composition unit using the ninth image forming unit. It is a block diagram of the image projection apparatus of this invention. It is a perspective view which shows the structure of the conventional optical apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Image formation unit, 2; Optical path separation element, 3; Reflection type light modulation element,
4; translucent member; 5; support member; 6; first intermediate support member;
7; second intermediate support member, 8; sealing member, 9; polarizer, 10; translucent prism member,
11: Glass plate, 12: Phase modulation element, image projection device, 31: Light source,
32; Lens, 33; Dichroic mirror, 34; Mirror 35; Projection lens,
36; screen.

Claims (15)

A reflective light modulation element having an image forming unit that modulates or deflects light in pixel units according to an image signal;
An optical path separation element that transmits illumination light of a predetermined wavelength band, enters the reflection type light modulation element, and reflects the image light modulated and reflected by the reflection type light modulation element;
A translucent member that transmits and emits image light reflected by the optical path separation element;
A pair of support members formed in a triangular prism shape having two apex angles of 45 degrees,
Both ends of the optical path separation element are fixed to the inclined surfaces of the pair of support members, both ends of the reflective light modulation element are fixed to one orthogonal surface of the pair of support members, and the other surface An image forming unit, wherein both ends of the translucent member are fixed to each other. A reflective light modulation element having an image forming unit that modulates or deflects light in pixel units according to an image signal;
A translucent member that transmits illumination light in a predetermined wavelength band;
An optical path separating element that reflects the illumination light transmitted through the translucent member and enters the reflective light modulation element, and transmits the image light modulated and reflected by the reflective light modulation element;
A pair of support members formed in a triangular prism shape having two apex angles of 45 degrees,
Both ends of the optical path separation element are fixed to the inclined surfaces of the pair of support members, both ends of the reflective light modulation element are fixed to one orthogonal surface of the pair of support members, and the other surface An image forming unit, wherein both ends of the translucent member are fixed to each other.   3. The image forming unit according to claim 1, wherein the support member is formed of optical glass or a ceramic or a low expansion alloy having a linear expansion coefficient substantially the same as that of optical glass.   4. The device according to claim 1, wherein any one, two, or all of the reflective light modulation element, the optical path separation element, and the translucent member are fixed to the pair of support members via an intermediate support member. The image forming unit described in 1.   The image forming unit according to claim 4, wherein the intermediate support member that supports the optical path separation element is formed in a frame shape.   The image forming unit according to claim 1, wherein an internal space surrounded by the reflective light modulation element, the optical path separation element, the translucent member, and the pair of support members is sealed.   The image forming unit according to claim 6, wherein an inner space surrounded and sealed by the reflective light modulation element, the optical path separation element, the translucent member, and the pair of support members is filled with a translucent liquid.   The image forming unit according to claim 1, wherein a polarizer is disposed on a light incident surface side or an output surface of the translucent member. A reflective light modulation element having an image forming unit that modulates or deflects light in pixel units according to an image signal;
An optical path separation element that transmits illumination light of a predetermined wavelength band, enters the reflection type light modulation element, and reflects the image light modulated and reflected by the reflection type light modulation element;
A translucent prism member formed in a triangular prism shape having two apex angles of 45 degrees, and
The optical path separating element is fixed to the inclined surface of the translucent prism member, and both end portions of the reflective light modulation element are fixed to one orthogonal surface of the translucent prism member. unit.   The image forming unit according to claim 9, wherein a polarizer is disposed on an emission surface side of the translucent prism member. A reflective light modulation element having an image forming unit that modulates or deflects light in pixel units according to an image signal;
An optical path separation element that reflects illumination light of a predetermined wavelength band and enters the reflection-type light modulation element, and transmits image light that is modulated and reflected by the reflection-type light modulation element;
A translucent prism member formed in a triangular prism shape having two apex angles of 45 degrees, and
The optical path separating element is fixed to the inclined surface of the translucent prism member, and both end portions of the reflective light modulation element are fixed to one orthogonal surface of the translucent prism member. unit.   The image forming unit according to claim 11, wherein a polarizer is disposed on an incident surface side of the translucent prism member. It has at least two sets of image forming units according to any one of claims 1 to 12 and a light combining prism,
The at least two sets of image forming units each receive illumination light of different wavelength bands, light-modulate the incident illumination light, and emit image light,
The image synthesizing unit, wherein the light synthesizing prism synthesizes and emits image lights emitted from the image forming units.   The image synthesizing unit according to claim 13, wherein the image forming unit and the light synthesizing prism are connected by a fixing member.   The image composition unit according to claim 13 or 14, wherein the illumination light emitted from the light source is separated into light of different wavelength bands, and the separated light of each color is incident on the image composition unit. An image projection apparatus characterized by modulating incident light of each color, combining and emitting the modulated light of each color, and displaying an image on a projection surface.

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