Projection-type image display device

Abstract

To provide a projection type image display apparatus which has a cooling device whose space is saved.SOLUTION: A cooling device includes a first heat reception unit which has a rectangular opening on a center part. The first heat reception unit includes a channel part. An image display element includes a protrusion part which protrudes from the periphery of a reflection type image display part in a direction in which modulated light travels. The protrusion part has a front surface on a side on which light from a light source part is incident, a first side surface extending to the rear side from the outer end of the front surface and a first bottom surface extending to the outer side from the rear end of the first side surface. The protrusion part of the image display element is inserted to the opening of the first heat reception unit and the channel part of the first heat reception unit is brought into contact with the first side surface and first bottom surface of the protrusion part via a heat conductive member. The front surface of the channel part of the first heat reception unit is located so as to be convex on the same surface as the front surface of the protrusion part or in the direction in which the modulated light travels with respect to the front surface of the protrusion part.SELECTED DRAWING: Figure 10A

Description

Technical Field

[0006] ,

[0001] The present disclosure relates to a projection-type image display device using an image display element, and more particularly to a configuration of a cooling device for the image display element.

Background Art

[0002] Conventionally, a reflective image display section may be used as an image display element of a projection-type image display device. As an example of the reflective image display section, a DMD (Digital Mirror Device) can be mentioned. Since the DMD is composed of an inorganic material and has high reliability, it is also widely used in ultra-high brightness projection-type image display elements. However, in order to maintain the high reliability of a reflective image display section such as the DMD, it is necessary to achieve the temperature required in the image display element.

[0003] The cooling of the reflective image display section is mainly performed by connecting a heat dissipation means such as a heat sink or a liquid cooling device to the back surface. In addition, on the light incident side (front side) of the reflective image display section, there may also be a connection of a material with excellent thermal conductivity such as a copper plate or a heat pipe, or a liquid cooling device.

[0004] For example, Patent Documents 1 and 2 disclose a structure for cooling the DMD by flowing a refrigerant of air or liquid through the gap between the prism and the DMD.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, cooling the light incident side of the reflective image display unit could not achieve sufficient cooling performance because of the short distance to the optical element, such as a prism, located in front of the reflective image display unit. In the structure of Patent Document 1, dust inevitably adheres to the effective optical path area of ​​the image display unit, and the heat conduction efficiency is limited when using air as a coolant, thus limiting it to projection-type image display devices with low light output.

[0007] In the structure described in Patent Document 2, a piping tube for circulating a liquid coolant is placed between the image display unit and the prism, which is part of the projection optical system. By using a liquid instead of air as the coolant, cooling efficiency is improved. However, in order to increase the brightness of the projected image, it is necessary to increase the amount of light from the light source, and therefore it is necessary to improve the cooling efficiency of the image display unit.

[0008] The purpose of this disclosure is to provide a projection-type image display device equipped with a cooling device that improves cooling efficiency. [Means for solving the problem]

[0009] The projection-type image display device of this disclosure comprises a light source unit that emits light, an image display element having a reflective image display unit that modulates the light from the light source unit according to an external signal, a cooling device for cooling the image display element, and a projection lens unit that magnifies and projects an image generated by the light modulated by the image display element. The cooling device comprises a first heat receiving unit having a rectangular opening in the center, a pump that sends a liquid refrigerant to the first heat receiving unit, and a heat dissipation unit that dissipates the heat absorbed by the refrigerant. The first heat receiving unit comprises a first inlet pipe through which the refrigerant flows in from the pump, a first outlet pipe through which the refrigerant flows out, and a flow path section that forms an opening and connects the first inlet pipe and the first outlet pipe. The image display element has a projection on the side into which light from the light source unit is incident, which protrudes from the periphery of the reflective image display unit in the direction in which the modulated light propagates. The protruding portion has a front surface on the side into which light from the light source is incident, a first side surface extending rearward from the outer end of the front surface, and a first bottom surface extending outward from the rear end of the first side surface. The protruding portion of the image display element is inserted into the opening of the first heat receiving unit, and the flow channel portion of the first heat receiving unit is in contact with the first side surface and the first bottom surface of the protruding portion via a heat conductive member, and the front surface of the flow channel portion of the first heat receiving unit is positioned to be on the same plane as the front surface of the protruding portion or to be convex in the direction in which modulated light propagates from the front surface of the protruding portion. [Effects of the Invention]

[0010] The projection-type image display device described in this disclosure can be provided with a cooling device that improves cooling efficiency. [Brief explanation of the drawing]

[0011] [Figure 1] Configuration diagram of the projection-type image display device of Embodiment 1 [Figure 2] Peripheral configuration diagram of the prism unit in Embodiment 1 [Figure 3] Peripheral configuration diagram of the image display element in Embodiment 1 [Figure 4] Perspective view of the image display element of Embodiment 1 [Figure 5] Diagram showing the connection of the liquid cooling module of the cooling device in Embodiment 1. [Figure 6]Perspective view of the first heat receiving unit of Embodiment 1 [Figure 7A] Rear view of the first heat receiving unit of Embodiment 1 [Figure 7B] Side view of the first heat receiving unit of Embodiment 1 [Figure 7C] Front view of the first heat receiving unit of Embodiment 1 [Figure 8] View of the first heat receiving unit in the VIII direction in FIG. 7C [Figure 9] IX cross-sectional view of the first heat receiving unit in FIG. 7C [Figure 10A] Cross-sectional view of the image display element and the first heat receiving unit of Embodiment 1 [Figure 10B] Partial cross-sectional view of the protruding portion in FIG. 10A [Figure 11] Perspective view of the first heat receiving unit in a modification of Embodiment 1 [Figure 12] Configuration diagram of the projection type image display device of Embodiment 2 [Figure 13] Peripheral configuration diagram of the image display element of Embodiment 2 [Figure 14] Diagram showing the connection of the liquid cooling module of the cooling device in a modification [Figure 15] Front view of the first heat receiving unit as seen from the prism side in a modification [Figure 16] Front view of the first heat receiving unit as seen from the prism side in a modification

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, a more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and duplicate descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art. Note that the inventors provide the accompanying drawings and the following description for those skilled in the art to fully understand the present disclosure, and do not intend to limit the subject matter described in the claims thereby.

[0013] (Embodiment 1) Embodiment 1 will be described below with reference to Figures 1 to 5.

[0014] [1-1. Structure] [1-1-1. Overall Structure] Referring to Figure 1, the schematic configuration of the projection-type image display device of Embodiment 1 of this disclosure will be described. Figure 1 is a configuration diagram of the projection-type image display device of Embodiment 1 of this disclosure. For the convenience of the following explanation, Figure 1 will use the XY Cartesian coordinate system shown in the figure.

[0015] The projection-type image display device 100 comprises a light source unit 101, a light guide optical system LL, a prism unit 132, image display elements 138R, G, and B, a cooling device CL, and a projection lens unit 139. The light source unit 101 emits light, and the light guide optical system LL guides the light from the light source unit 101 to the image display elements 138R, G, and B via the prism unit 132. The prism unit 132 separates the light from the light source unit 101 into blue light, red light, and green light and guides them to the image display elements 138R, G, and B. The image display elements 138R, G, and B each modulate the separated light from the light source unit 101 according to an external signal. The cooling device CL cools the image display elements 138R, G, and B. The projection lens unit 139 magnifies and projects the image generated by the light modulated by the image display elements 138R, G, and B.

[0016] The light source unit 101 includes laser diode units 101a, 101b, mirrors 102, 104, lenses 103, 108, 110, diffusers 105, 115, condenser lenses 106, 116, 117, a dichroic mirror 107, and a rod integrator 111.

[0017] The system includes laser diode units 101a and 101b. Each laser diode unit 101a and 101b comprises multiple light sources, each light source having a pair of, for example, blue laser diodes and a collimating lens positioned on the emission side. This allows the light sources to emit laser light with reduced spread.

[0018] Light emitted from the laser diode unit 101a is incident on the mirror 102, which has a partial aperture. Of the light incident on the mirror 102, some is emitted in the +X direction through the partial aperture of the mirror 102, and the remaining light is reflected in the +Y direction by the reflector.

[0019] Light emitted from the laser diode unit 101b also enters the mirror 102. Similarly, upon entering the mirror 102, some of the light passes through the partial aperture of the mirror 102 and is emitted in the +Y direction, while the remaining light is reflected in the +X direction by the reflective section. The aperture shape of the mirror 102, which has a partial aperture, is designed such that the ratio of blue light traveling in the +Y direction to blue light traveling in the +X direction is higher for the light emitted from the laser diode units 101a and 101b.

[0020] Blue light emitted in the +X direction is focused by lens 103, reflected by mirror 104, then focused near diffuser plate 105 and diffused by diffuser plate 105. The diffused blue light enters condenser lens 106, becomes parallel light, and re-enters dichroic mirror 107. Dichroic mirror 107 has the characteristic of transmitting blue light and reflecting other colored light. Therefore, blue light incident on dichroic mirror 107 is transmitted through dichroic mirror 107. The transmitted blue light passes through lens 108, mirror 109, and lens 110 and is focused on the incident surface of rod integrator 111 which has a rectangular aperture.

[0021] Light that travels in the +Y direction through the mirror 102, which has a partial aperture, is focused by lenses 112 and 113, which form an afocal system with the mirror 114 in between, and incident on the diffuser plate 115. The blue laser light incident on the diffuser plate 115 is diffused here, then passes through the dichroic mirror 107 and incident on the condenser lenses 116 and 117. The blue light incident here is then incident on the phosphor section 119 of the phosphor wheel device 118.

[0022] The phosphor portion 119 is, for example, a ceramic phosphor, and a reflective layer (not shown) is formed on the surface opposite to the excitation light incident surface, which reflects light of the wavelength of fluorescence. The reflective layer is fixed to a spreader 121 with excellent thermal conductivity via an adhesive layer (omitted in the figure). The spreader 121 is a disc and is configured to be rotatable by a motor 122 located at its center.

[0023] Blue light incident on the phosphor section 119 is converted to yellow light upon contact with the phosphor section 119, reflected by the reflective layer 120 on the back, and emitted towards the condenser lens 117. The yellow light that has passed through the condenser lens 117 passes through the condenser lens 116 and is incident on the dichroic mirror 107. The yellow light is reflected here and, like the blue light, passes through lens 108, mirror 109, and lens 110, and is focused onto the incident surface of the rod integrator 111, which has a rectangular aperture. Inside the rod integrator 111, the blue light from the laser light source and the yellow light from the fluorescence are superimposed to generate white light.

[0024] Thus, the light source unit 101 may have a configuration other than the one described above, as long as it emits white light.

[0025] The light guide optical system LL comprises relay lenses 123, 124, a mirror 125, a field lens 126, and a total internal reflection prism 127.

[0026] Light emitted from the rod integrator 111 passes through relay lenses 123 and 124 and is reflected by the folding mirror 125. The totally reflected light passes through the field lens 126 and enters the totally reflected prism 127. The totally reflected prism 127 comprises a first prism 128 and a second prism 129, which are fixed together while maintaining a small gap (air gap) between them. Light incident on the totally reflected prism 127 is totally reflected by the side surface 130 of the first prism 128, then passes through the side surface 131 of the first prism 128 and enters the prism unit 132.

[0027] The prism unit 132 consists of a first prism 134 equipped with a blue-transmitting dichroic mirror surface 133 that reflects blue light, and a second prism 136 and a third prism 137 equipped with a green-transmitting dichroic mirror surface 135 that reflects red and blue light, all bonded together. However, an air gap is provided between the first prism 134 and the second prism 136 to utilize total internal reflection.

[0028] Image display elements 138R, 138G, and 138B are positioned opposite the end faces of the first prism 134, the second prism 136, and the third prism 137, respectively. The image display element 138 includes a reflective image display unit 138a (see Figure 2) in which multiple minute mirrors are arranged two-dimensionally. The tilt direction of each minute mirror is controlled in two directions in accordance with an external image signal. When an ON signal is received, the reflected light from the mirror returns to the prism unit 132 at an incident angle of 0 degrees, and when an OFF signal is received, it re-enters the prism unit 132 at a larger angle.

[0029] Image display element 138B is for blue light modulation, image display element 138R is for red light modulation, and image display element 138G is for green light modulation. Currently, these image display elements are used as DMDs (Direct Display Devices) in projection-type image display devices on the market.

[0030] In the image display elements 138R, 138G, and 138B, pixels in white display mode return to the prism unit 132, pass through the first prism 128 and second prism 129 of the total internal reflection prism 127, enter the projection lens unit 139, and reach the screen (not shown in the figure). In this way, color display is achieved.

[0031] [1-1-2. Structure of the main parts] Next, the configuration of the main parts will be explained with reference to Figure 2. Figure 2 is a diagram of the configuration around the prism unit 132. In Figure 2, the second heat receiving unit is omitted in order to clearly show the image display element 138R. Also, when describing the image display elements 138R, G, and B collectively, they will be referred to as the image display element 138. Furthermore, in the configuration around the image display element 138, the prism unit 132 side is considered the forward direction, and the opposite direction is considered the rear direction.

[0032] The image display element 138 receives and reflects strong light from the light source unit 101, but it also generates heat due to light being incident on and absorbed between the minute mirrors that constitute the reflective image display section 138a of the image display element 138, as well as for the operation of the image display element 138 itself. To ensure the reliability of the image display element 138, it is necessary to maintain it at a desired temperature. For this reason, as shown in Figure 3, a first heat receiving unit 141 and a second heat receiving unit 140 are provided.

[0033] The peripheral structure of the image display element 138 will be described with reference to Figure 3. Figure 3 is a peripheral configuration diagram of the image display element, showing the peripheral structure of image display elements R, G, and B, which correspond to one of the three image display elements 138R, G, and B, each corresponding to a single color light. The drive board 142 is connected to the control unit (not shown) and receives external signals from the control unit corresponding to the image content to be displayed. The drive board 142 and the image display element 138 are electrically connected via a socket 143.

[0034] The image display element 138 is supported by being sandwiched between fixing brackets 144 and 145. On the front side of the image display element 138, a mask substrate 146 that transmits effective light incident on the reflective image display unit 138a and an insulating substrate 147 are supported by a mask substrate support bracket 148, and the first heat receiving unit 141 is positioned between the image display element 138 and the insulating substrate 147. The mask substrate 146 absorbs stray light traveling through the first to third prisms 134, 136, and 137, respectively.

[0035] The second heat receiving unit 140 is capable of receiving the operating heat of the image display element 138 via conductive grease on the back surface of the image display element 138 using a compression spring (not shown). The first heat receiving unit 141 is thermally connected to the outer surface of the projection 138d that protrudes forward of the image display element 138 via a sheet-like heat conductive member 155 (see Figure 10A).

[0036] Next, refer to Figure 4. Figure 4 is a perspective view of the image display element. The image display element 138 has a rectangular cylindrical projection 138d that protrudes forward from the base 138c. The projection 138d has an opening 138e, and the front surface of the reflective image display unit 138a, which is located on the base 138c, is exposed through the opening 138e. The projection 138d has a rectangular shape when viewed from the front.

[0037] Next, refer to Figure 5. Figure 5 shows the connections of the liquid cooling module of the cooling device CL. The first heat receiving unit 141 includes a first inlet pipe 152 through which refrigerant flows into the first heat receiving unit 141, and a first outlet pipe 153 through which refrigerant flows out of the first heat receiving unit 141. The second heat receiving unit 140 includes a second inlet pipe 162 through which refrigerant flows into the second heat receiving unit 140, and a second outlet pipe 163 through which refrigerant flows out of the second heat receiving unit 140.

[0038] The second heat receiving unit 140 has a built-in pump 140a, and the refrigerant sent from the second heat receiving unit 140 flows into the first heat receiving unit 141 through the second outlet pipe 163, piping 191, and the first inlet pipe 152. The refrigerant that flows into the first heat receiving unit 141 absorbs heat from the front of the image display element 138 and its temperature rises. The refrigerant with the increased temperature flows out of the first heat receiving unit 141 and flows into the radiator 150, which acts as a heat dissipation unit, through the first outlet pipe 153 and piping 192. The refrigerant is cooled in the radiator 150, and the cooled refrigerant circulates back to the second heat receiving unit 140 through piping 193, the reserve tank 151, and piping 194.

[0039] Next, the configuration of the first heat receiving unit 141 will be described with reference to Figures 6 to 9. Figure 6 is a perspective view of the first heat receiving unit 141. Figure 7A is a rear view of the first heat receiving unit 141. Figure 7B is a side view of the first heat receiving unit 141. Figure 7C is a front view of the first heat receiving unit 141. Figure 8 is a view taken in the direction of arrow VIII in Figure 7C. Figure 9 is a cross-sectional view taken in the direction of IX in Figure 7C.

[0040] The refrigerant flowing in from the first inlet pipe 152 is connected to one of the four corners of the flow path section 154, or to its vicinity. The flow path section 154 is formed to conform to the shape of the front surface of the image display element 138. The flow path section 154 has, for example, an opening 179 that fits into the outer surface of the protrusion 138d of the image display element 138. The flow path section 154 branches in two directions from the connection point of the first inlet pipe 152, flows around the image display element 138, and rejoins to reach the first outlet pipe 153. The refrigerant Rg flowing out from the first outlet pipe 153 reaches the radiator 150 via piping.

[0041] The first inlet pipe 152 and the first outlet pipe 153 are connected so as to be located diagonally opposite each other at the four corners of the flow channel section 154. The first inlet pipe 152 is connected at a first joint 157 located at one corner of the flow channel section 154. The first outlet pipe 153 is connected at a second connection located at one corner of the flow channel section 154.

[0042] The flow path section 154 comprises a first pipe 173 and a second pipe 174 that branch off from the first joint 157. The first pipe 173 and the second pipe 174 merge at the second joint 161. The first pipe 173 and the second pipe 174 are the same length. That is, the distance in the flow path section 154 from the first inlet pipe 152 to the first outlet pipe 153 is the same, and the flow rate of the refrigerant Rg is distributed in a balanced manner. Here, the first pipe 173 and the second pipe 174 do not have to be exactly the same length, but may be approximately the same length. As described above, the image display element 138 and the flow path section 154 are thermally connected via a heat conductive member 155, so that heat from the front of the image display element 138 can be absorbed.

[0043] The first heat receiving unit 141 has an opening 179 in the center. The opening 179 is formed by the first pipe 173 and the second pipe 174. The opening 179 is one size larger than the tip shape of the protrusion 138d of the image display element 138, and is, for example, rectangular in shape.

[0044] In the first heat receiving unit 141, the two corners of the rectangular flow channel section 154 and the first inlet pipe 152 and the first outlet pipe 153 are each connected by a first joint. 157 and second joint 161 It is brazed via. The first inlet pipe 152 is made by bending a round pipe to form the first joint. 157 The first outflow pipe 153 is connected to the second joint. 161 Connected.

[0045] Furthermore, the flow channel section 154 (first inlet pipe 152, first outlet pipe 153) is constructed by brazing two thin metal plates 175 and 176 together, as shown in Figure 9. In this case, for example, the flow channel section 154 can be formed by assembling metal plates 175 and 176 made of clad material and passing them through a heating furnace. The flow channel section 154 is made of, for example, aluminum clad material.

[0046] As shown in Figures 10A and 10B, the protruding portion 138d of the image display element 138 has a stepped shape on its outer side. The protruding portion 138d comprises a front surface 138da, a first bottom surface 138db formed one step below (rearward), and a second bottom surface 138dc formed one step below (rearward) as a contact surface. The first bottom surface 138db is formed to be outward from the front surface 138da, and the second bottom surface 138dc is formed to be outward from the first bottom surface 138db. The front surface 138da and the first bottom surface 138db are connected by a first side surface 138dd which serves as a vertical wall.

[0047] The first side surface 138dd extends rearward from the outer end of the front surface 138da. The first bottom surface 138db extends outward from the rear end of the first side surface 138dd parallel to the front surface 138da. The second side surface 138de extends rearward from the outer end of the first bottom surface 138db. The second bottom surface 138dc extends outward from the rear end of the second side surface 138de parallel to the front surface 138da. The front surface 138da and the first side surface 138dd constitute the first stepped section 138df, and the second side surface 138de and the second bottom surface 138dc constitute the second stepped section 138dg.

[0048] The flow channel portion 154 of the first heat receiving unit 141 is in contact with the first side surface 138dd and the first bottom surface 138db of the protrusion 138d via the heat conductive member 155. As a result, even if stray light that could not be absorbed by the mask substrate 146 is irradiated onto the front surface of the protrusion 138d and the reflective image display portion 138a, the heat from the irradiation can be transferred to the flow channel portion 154 via the heat conductive member 155.

[0049] The front surface 175c of the flow channel portion 154 of the first heat receiving unit 141 is positioned on the same plane as the front surface 138da of the protrusion 138d or in front of the front surface 138da of the protrusion 138d, that is, convex in the direction in which the modulated light propagates. This ensures sufficient contact area with the first side surface 138dd even when a bend radius is required at the inner corner of the opening of the metal plate 175.

[0050] To simplify the processing of the upper and lower metal plates 175 and 176, a portion is formed on each of the metal plates 175 and 176 that faces the first side surface 138dd of the protruding portion 138d of the image display element 138, and these opposing portions are brazed to each other as first brazing surfaces 175a and 176a. In addition, portions are formed on each of the metal plates 175 and 176 in a direction perpendicular to the first side surface 138dd, extending outwards from the outer circumference of the flow channel portion 154, and these extending portions are brazed to each other as second brazing surfaces 175b and 176b.

[0051] The surface of the metal plate 175 opposite to the first brazed surface 175a constitutes the inner wall portion 181 of the flow channel portion 154. Therefore, the respective first brazed surfaces 175a and 176a of the two metal plates 175 and 176, which are brazed together, are parallel to the inner wall portion 181 that forms the opening 179.

[0052] In the flow channel section 154, a thinner thickness in the portion facing the first side surface 138dd can further reduce the thermal resistance between the image display element 138 and the refrigerant Rg. However, brazing can be performed more easily on the first brazing surfaces 175a and 176a facing the first side surface 138dd, respectively, to create the flow channel section 154.

[0053] Furthermore, as shown in Figure 8, the first joint 157 has an inclined surface 156 that intersects with the direction of refrigerant inflow in its internal structure, indicated by the dashed line. The refrigerant flowing from the first inflow pipe 152 through the reserve tank 151 to the first joint 157 collides with the inclined surface 156. As a result, even if air is mixed with the refrigerant, the collision causes the air to flow away as fine bubbles. In this way, air pockets are less likely to form in the first joint 157, and the refrigerant flows downstream without stagnation. Note that the inclined surface 156 is not limited to the first joint 157, but is only required to be placed at least before the refrigerant Rg reaches the flow path section 154 via the first inflow pipe 152.

[0054] By using a first joint 157 and a second joint 161 to connect the flow channel section 154 to the first inlet pipe 152 and the first outlet pipe 153, respectively, the components can be housed in the available space and connected to the flow channel section 154 without requiring small radius bends at the base of the first inlet pipe 152 and the first outlet pipe 153.

[0055] As shown in Figures 3 and 4, one side of the stepped flat portion of the protruding portion 138d of the image display element 138 is the second bottom surface 138dc, and the second bottom surface 138dc is in contact with the claw portion 159 of the fixing bracket 144. The first inlet pipe 152 and the first outlet pipe 153 extend between the prism unit 132, which is positioned opposite the image display element 138, and the image display element 138, and are connected to other cooling modules.

[0056] Since the first heat receiving unit 141 is positioned biased toward the fixing bracket 144 side of the space formed by the fixing bracket 144 and the prism unit 132, the first inlet pipe 152 and the first outlet pipe 153 can be positioned even in a narrow space by positioning them eccentrically toward the prism side of the flow path section 154 that contacts the image display element 138. This eccentricity can be achieved by bending the pipe as shown in the example in Figure 11, or by offsetting the inlet and outlet sides at the joint as shown in Figure 4.

[0057] A modified example of the first heat receiving unit 141 will be described with reference to Figure 11. Figure 11 is a perspective view showing a modified example of the first heat receiving unit 141. In Figure 11, if the first inlet pipe 152 and the first outlet pipe 153 can be bent at a 90-degree angle in the piping connection between the first inlet pipe 152, the first outlet pipe 153 and the flow path section 154, a similar effect can be obtained by providing a protrusion 160 at the base of the flow path section 154 so that the refrigerant flowing into the vertical wall section 164 collides with it. If the reserve tank 151 has the function of removing air mixed in with the refrigerant, the slope 156 and the vertical wall section 164 may be omitted in this respect. However, the presence of the slope 156 and the vertical wall section 164 is beneficial for balancing the flow rate of the refrigerant Rg when the flow path section 154 branches into two.

[0058] In Figure 9, the flow path section 154 is made of two sheet metal pieces, but it may also be made of sheet metal and machined parts. Making the flow path section 154 from two sheet metal pieces reduces processing costs.

[0059] In Embodiment 1, the second heat receiving unit 140 had a built-in pump 140a, but the pump 140a may be provided separately from the second heat receiving unit 140.

[0060] [1-2. Effects, etc.] As described above, the projection-type image display device 100 according to this embodiment includes a light source unit 101 that emits light, an image display element 138 that modulates the light from the light source unit 101 according to an external signal, a cooling device CL that cools the image display element 138, and a projection lens unit 139 that magnifies and projects the image generated by the light modulated by the image display element 138. The cooling device CL includes a first heat receiving unit 141 having a rectangular opening 179 in the center, a pump 140a that sends liquid refrigerant Rg to the first heat receiving unit 141, and a radiator 150 that dissipates the heat absorbed by the refrigerant Rg. The first heat receiving unit 141 includes a first inlet pipe 152 through which refrigerant Rg flows in from the pump 140a, a first outlet pipe 153 through which refrigerant Rg flows out, and a flow path section 154 that forms an opening 179 and connects the first inlet pipe 152 and the first outlet pipe 153. The image display element 138 has a projection 138d that protrudes from the periphery of the reflective image display element 138a in the direction in which the modulated light propagates, on the side into which light from the light source 101 is incident. The projection 138d has a front surface 138da on the side into which light from the light source 101 is incident, a first side surface 138dd extending rearward from the outer end of the front surface 138da, and a first bottom surface 138db extending outward from the rear end of the first side surface 138dd. The projection 138d of the image display element 138 is inserted into the opening 179 of the first heat receiving unit 141, and the flow channel 154 of the first heat receiving unit 141 is in contact with the first side surface 138dd and the first bottom surface 138db of the projection 138d via the heat conducting member 155. The front surface 175c of the flow channel portion 154 of the first heat receiving unit 141 is on the same plane as the front surface 138da of the protrusion 138d or is located in front of the front surface 138da of the protrusion 138d.

[0061] Since the flow channel portion 154 of the first heat receiving unit 141 contacts the first side surface 138dd and the first bottom surface 138db of the protrusion 138d of the image display element 138 via the heat conductive member 155, the light incident side of the image display element 138 can be efficiently cooled. Furthermore, the front surface 175c of the flow channel portion 154 of the first heat receiving unit 141 is on the same plane as the front surface 138da of the protrusion 138d or in front of the front surface 138da of the protrusion 138d, sufficient contact area with the first side surface 138dd can be secured even when a bending radius is required at the inner corner of the opening of the metal plate 175.

[0062] The flow path section 154 of the first heat receiving unit 141 has a first pipe 173 and a second pipe 174 that branch off from the first inlet pipe 152 and merge at the first outlet pipe 153. The first pipe 173 and the second pipe 174 form different sides of the rectangular opening 179 of the first heat receiving unit 141, and the first pipe 173 and the second pipe 174 are the same length. Because the first pipe 173 and the second pipe 174 are the same length, uniform cooling can be achieved along the opening 179 in the branched flow path section 154.

[0063] The first inlet pipe 152 and the first outlet pipe 153 of the first heat receiving unit 141 extend along the longitudinal direction of the surfaces of the prisms 134, 136, and 137 facing the image display element 138. This makes it possible to reduce the space required for the front cooling structure of the image display element 138.

[0064] The first heat receiving unit 141 has an inclined surface 156 that intersects with the inflow direction of the refrigerant Rg at least until the refrigerant Rg reaches the flow path section 154 via the first inlet pipe 152, and the refrigerant Rg collides with the intersecting inclined surface 156. As a result, even if the refrigerant Rg contains air, the air flows as fine bubbles, preventing the refrigerant Rg from becoming clogged.

[0065] The first inlet pipe 152 and the flow path section 154 of the first heat receiving unit 141 are connected via a first joint 171, or the first outlet pipe 153 and the flow path section 154 of the first heat receiving unit 141 are connected via a second joint 172.

[0066] The projection-type image display device 100 includes a second heat receiving unit 140 that receives the driving heat of the image display element 138. The first heat receiving unit 141 is positioned between the prism unit 132 and the image display element 138, and the image display element 138 is positioned between the first heat receiving unit 141 and the second heat receiving unit 140. The second heat receiving unit 140 includes a second inlet pipe 162 into which the refrigerant Rg flows, and a second outlet pipe 163 into which the refrigerant Rg flows out.

[0067] Since the image display element 138 is positioned between the first heat receiving unit 141 and the second heat receiving unit 140, and is cooled by both the first heat receiving unit 141 and the second heat receiving unit 140, both sides of the image display element 138 can be cooled, thereby improving cooling efficiency.

[0068] The second outlet pipe 163 of the second heat receiving unit 140 and the first inlet pipe 152 are connected in series so that the refrigerant Rg flowing out of the second outlet pipe 163 of the second heat receiving unit 140 reaches the first inlet pipe 152 of the first heat receiving unit 141. This allows for a space-saving cooling structure for the image display element 138.

[0069] The flow path portion 154 of the first heat receiving unit 141 is composed of two brazed metal plates 175 and 176, and the first brazed surfaces 175a and 176a, which are the joint surfaces of the two metal plates 175 and 176 that are brazed together, are parallel to the inner wall portion 181 of the flow path portion 154 that forms the opening 179.

[0070] The flow path portion 154 of the first heat receiving unit 141 is composed of two brazed metal plates 175 and 176. The second brazed surfaces 175b and 176b, which are the joint surfaces of the two metal plates 175 and 176 that are brazed together, are the portions of the metal plates 175 and 176 that extend from the outer circumference of the flow path portion 154 in a direction perpendicular to the inner wall portion 181 of the flow path portion 154 that forms the opening 179.

[0071] (Embodiment 2) The projection-type image display device 200 according to Embodiment 2 projects a full-color image with a different configuration from the projection-type image display device 100 according to Embodiment 1 described above. The projection-type image display device 200 according to Embodiment 2 of this disclosure will be described with reference to Figure 12. Figure 12 is a schematic diagram of the configuration of the projection-type image display device 200 according to Embodiment 2 of this disclosure. Except for the points described below, the configuration of the projection-type image display device 200 according to Embodiment 2 and the projection-type image display device 100 according to Embodiment 1 are common.

[0072] As shown in Figure 12, the projection-type image display device 200 according to Embodiment 2 consists of a light source unit 201 that generates light, an image generation unit 202 that converts light into image light, and a projection lens unit 203 that projects the image light onto, for example, a screen.

[0073] In the second embodiment, the light source unit 201 includes, for example, a light source lamp 204 which emits white diffused light, such as a high-pressure mercury lamp. The light source unit 201 also includes a plurality of optical elements that guide the light emitted from the light source lamp 204 to the image generation unit 202. These optical elements will be described along with the propagation of light.

[0074] The diffused light emitted from the light source lamp 204 is focused by the reflector 205 onto the incident surface of the rod integrator 206, which has a rectangular cross-section.

[0075] A color wheel 207 is positioned in front of the output surface of the rod integrator 206. The color wheel 207 includes a red transmission filter that transmits only red light contained in the white light from the light source lamp 204, a green transmission filter that transmits only green light, and a blue transmission filter that transmits only blue light. As the color wheel 207 is rotated by the motor 208, the red transmission filter, the green transmission filter, and the blue transmission filter are positioned in front of the output surface of the rod integrator 206 in sequence and repeatedly. As a result, red light, green light, and blue light are emitted from the color wheel 207 in sequence and repeatedly.

[0076] Light that has passed through the color wheel 207 enters the image generation unit 202 via lenses 209, 210, 211, mirror 212, and 213.

[0077] In the second embodiment, the image generation unit 202 includes a total reflection prism 214 and one image display element 223.

[0078] In Embodiment 2, the total internal reflection prism 214 comprises a first prism 215 and a second prism 216. The first prism 215 and the second prism 216 are prisms having a substantially triangular prism shape and are made of, for example, a glass material. An air gap 217 of several micrometers is formed between the first prism 215 and the second prism 216.

[0079] The first prism 215 includes a side surface 218 into which light Li from the light source unit 201 is incident, a side surface 219 that reflects the incident light Li, and a side surface 220 through which the reflected light Li is transmitted and which faces the image display element 223.

[0080] The second prism 216 has a side surface 221 that forms an air gap 217 by being parallel to and spaced apart from the side surface 219 of the first prism 215, and a side surface 222 that faces the projection lens unit 203. The side surface 219 of the first prism 215 and the side surface 221 of the second prism 216 are bonded to each other, for example, through an adhesive in the parts other than the light-transmitting portion, thereby forming the air gap 217.

[0081] The image display element 223 includes a DMD as a reflective image display unit. Light, namely red light, green light, and blue light, is incident on the image display element 223 sequentially and repeatedly from the light source unit 201 through the first prism 215 of the total reflection prism 214.

[0082] Furthermore, the reflected light from the image display element 223, i.e., the image light Lp, enters the total internal reflection prism 214, passes through its air gap 217 (internal total internal reflection surface), and is emitted from the side surface 222 of the second prism 216 to the projection lens unit 203. The image light is then projected onto the screen by the projection lens unit 203.

[0083] In Embodiment 2, as in Embodiment 1 described above, the first heat receiving unit 141A is provided around the front surface of the DMD of the image display element 223.

[0084] Figure 13 is a perspective view showing the peripheral structure of the image display element 223. As shown in Figure 13, the image generation unit 202 comprises a prism case 224, a packing 225, a light-shielding mask 226, a heat insulating material 227, a first heat receiving unit 141A, a drive board 142A, a socket 143A, an insulating sheet 231, and a retaining clip 232.

[0085] A total internal reflection prism 214 is enclosed within the prism case 224, which has a side surface 220 against which the image display element 223 is arranged without gaps via a packing 225, a light-shielding mask 226, and a heat insulating material 227. A first heat receiving unit 141A, similar to that in Embodiment 1, is connected to the DMD of the image display element 223 via a heat conductive member not shown in the figure. Meanwhile, the image display element 223 is arranged with a socket 143A, a drive board 142A, an insulating sheet 231, and a retaining clip 232, and the image display element 223 and the drive board 142A are electrically connected.

[0086] Although not shown in Figure 12, the second heat receiving unit 140 of Embodiment 1 is positioned on the back of the retaining clip 232, as shown in Figure 3.

[0087] Regarding the connection of the liquid cooling module, it can be connected in Embodiment 2 as shown in Figure 5, similar to Embodiment 1, and a pump for refrigerant circulation may be provided separately from the rear-side heat receiving unit.

[0088] The first heat receiving unit 141A has the same configuration as the first heat receiving unit 141 in Embodiment 1, as shown in Figures 4 and 10, and is capable of removing heat from the front of the image display element 223. In Embodiment 2, since there is no need to provide an image display element 223 for each color of light, the degree of freedom in the direction of the first inlet pipe 152 and the first outlet pipe 153 is high, and the need to align them in the same direction is reduced. This is optimized to suit the surrounding structure and is not a constraint on the basic structure.

[0089] This first heat receiving unit 141A is also constructed by brazing a first inlet pipe 152A and a first outlet pipe 153A, which are made by bending round pipes, to both ends of the flow channel section 154A. The flow channel section 154A is also formed by brazing two thin plates, one above the other, and the flow channel section 154A is optimized to match the dimensions of the image display element 223.

[0090] Here, the image display element 223 is sandwiched between the socket 143A and the prism case 224, and is designed so that the prism case 224 and the second bottom surface 138dc come into contact. In this case, the first heat receiving unit 141A is enclosed within the prism case 224, and the first inlet pipe 152 and the first outlet pipe 153 extend from its side. In this case, the first inlet pipe 152 and the first outlet pipe 153 only need to be in a position that does not interfere with the socket 143A, and unlike Embodiment 1, there are fewer constraints on the direction of light inlet and outlet for the flow path portion 154 of the first inlet pipe 152 and the first outlet pipe 153.

[0091] In Embodiment 2, even if the drawing direction and eccentric position of the first inlet pipe 152 and the first outlet pipe 153 are different, a protrusion is provided at the base to form a slope 156, and the effect of distributing the incoming refrigerant to two flow paths and expelling mixed air can be obtained in the same way by causing the incoming refrigerant to collide with it. In Embodiment 2, the flow path section 154 was made up of two metal plates, but it may also be made up of sheet metal and machined parts.

[0092] (Other embodiments) As described above, the above embodiments have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these embodiments and can be applied to embodiments that have been modified, replaced, added, or omitted. Furthermore, it is possible to create new embodiments by combining the components described in the above embodiments.

[0093] In Embodiment 1, the light source unit 101 generated white light from a blue laser using a laser diode unit 101a, but it is not limited to this. White light may be generated by combining light of each color from a red semiconductor laser, a blue semiconductor laser, and a green semiconductor laser, or a light source other than a laser, such as a lamp, may be used.

[0094] In Embodiment 1, the refrigerant Rg was flowed in series into the first heat receiving unit 141 and the second heat receiving unit 140, but this is not limited to this configuration. As shown in Figure 14, the first heat receiving unit 141 and the second heat receiving unit 140 may be configured so that the refrigerant Rg flows in parallel.

[0095] In embodiments 1 and 2, the projection-type image display device 100 includes a prism unit 132 in which a plurality of triangular or rectangular prism prisms 134, 136, and 137 are directly bonded to each other via an optical thin film, or fixed while maintaining an air gap, on the optical path between the image display element 138 and the projection lens unit 139. Here, as shown in Figure 15, the first inlet pipe 152 and the first outlet pipe 153 of the first heat receiving unit 141 may extend parallel to the surface of the flow channel 154 when viewed from the direction of light incident on the image display element 138, and may be connected to the flow channel 154 eccentrically (biased) toward the side where light is incident on the prism unit 132 with respect to the surface formed by the flow channel 154. Since the first inlet pipe 152 and the first outlet pipe 153 are connected to the flow channel section 154 eccentrically on the side where light is incident to the prism unit 132, the path of light incident to the prism unit 132 in the flow channel section 154 is shortened, and the cooling efficiency on the side where light is incident to the prism unit 132 can be increased.

[0096] Furthermore, as shown in Figure 16, the first inlet pipe 152 of the first heat receiving unit 141 may be connected to the flow channel 154 on the side of the prism unit 132 with high light density, and the first outlet pipe 153 may be connected to the flow channel 154 on the side of the prism unit 132 with low light density. Since the first inlet pipe 152 of the first heat receiving unit 141 is connected to the flow channel 154 on the side of the prism unit 132 with high light density, the refrigerant Rg can be introduced first to the side of the protruding portion 138d with a higher temperature, thereby improving cooling efficiency.

[0097] As described above, embodiments have been explained as examples of the technology in this disclosure. For this purpose, attached drawings and a detailed description have been provided. Therefore, among the components described in the attached drawings and detailed description, there may be not only components that are essential for solving the problem, but also components that are not essential for solving the problem, in order to illustrate the above technology. For this reason, the mere fact that these non-essential components are described in the attached drawings and detailed description should not be immediately assumed to be essential.

[0098] Furthermore, since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the claims or their equivalents.

[0099] (Summary of the embodiment) (1) The projection-type image display device of the present disclosure comprises a light source unit that emits light, an image display element having a reflective image display unit that modulates the light from the light source unit according to an external signal, a cooling device for cooling the image display element, and a projection lens unit that magnifies and projects an image generated by the light modulated by the image display element. The cooling device comprises a first heat receiving unit having a rectangular opening in the center, a pump that sends a liquid refrigerant to the first heat receiving unit, and a heat dissipation unit that dissipates the heat absorbed by the refrigerant. The first heat receiving unit comprises a first inlet pipe through which the refrigerant flows in from the pump, a first outlet pipe through which the refrigerant flows out, and a flow path section that forms an opening and connects the first inlet pipe and the first outlet pipe. The image display element has a projection on the side into which the light from the light source unit is incident, which protrudes from the periphery of the reflective image display unit in the direction in which the modulated light propagates. The protruding portion has a front surface on the side into which light from the light source is incident, a first side surface extending rearward from the outer end of the front surface, and a first bottom surface extending outward from the rear end of the first side surface. The protruding portion of the image display element is inserted into the opening of the first heat receiving unit, and the flow channel portion of the first heat receiving unit is in contact with the first side surface and the first bottom surface of the protruding portion via a heat conductive member. The front surface of the flow channel portion of the first heat receiving unit is on the same plane as the front surface of the protruding portion or is located in front of the front surface of the protruding portion.

[0100] In this way, the flow channel of the first heat receiving unit contacts the first side surface and the first bottom surface of the rectangular protrusion of the image display element via a heat conductive member, so that the light incident side of the image display element can be cooled efficiently. Furthermore, since the front surface of the flow channel of the first heat receiving unit is on the same plane as the front surface of the protrusion or positioned in front of the front surface of the protrusion, sufficient contact area with the first side surface 138dd can be secured even when a bend radius is required at the inner corner of the opening of the metal plate 175.

[0101] (2) In the projection-type image display device of (1), a prism unit is provided in which a plurality of triangular prisms or rectangular prisms are directly bonded to each other via an optical thin film or fixed while maintaining an air gap on the optical path between the image display element and the projection lens unit. The first inlet pipe and the first outlet pipe of the first heat receiving unit extend parallel to the surface of the flow channel when viewed from the direction of light incident on the reflective image display unit, and are connected to the flow channel eccentrically toward the side in which light is incident on the prism unit with respect to the surface formed by the flow channel.

[0102] (3) In the projection-type image display device of (1), the flow path of the first heat receiving unit has a first pipe and a second pipe that branch off from the first inlet pipe and merge at the first outlet pipe, the first pipe and the second pipe form different sides of the rectangular opening of the first heat receiving unit, and the first pipe and the second pipe are of the same length.

[0103] (4) In the projection-type image display device of (1) or (3), a prism unit is provided in which a plurality of triangular prisms or rectangular prisms are directly bonded to each other via an optical thin film or fixed while maintaining an air gap on the optical path between the image display element and the projection lens unit. The first inlet pipe of the first heat receiving unit is connected to the flow channel on the side of the prism unit with high light density, and the first outlet pipe is connected to the flow channel on the side of the prism unit with low light density.

[0104] (5) In the projection-type image display device of (2) or (4), the first inlet pipe and the first outlet pipe of the first heat receiving unit extend along the longitudinal direction of the prism facing the image display element.

[0105] (6) In any one of the projection-type image display devices described in (1) to (5), the plane parallel to the reflective image display section of the image display element is configured such that the direction in which the incident light enters the reflective image display section is on the opposite side from the direction in which the first inlet pipe and the first outlet pipe of the first heat receiving unit extend.

[0106] (7) In any one of the projection-type image display devices described in (1) to (6), the first heat receiving unit has a surface that intersects with respect to the direction of refrigerant inflow at least before the refrigerant reaches the flow path through the first inflow pipe, and the refrigerant collides with the intersecting surface.

[0107] (8) In any one of the projection-type image display devices described in (1) to (7), the first inlet pipe or first outlet pipe of the first heat receiving unit is connected to the flow path section via a joint.

[0108] (9) In any one of the projection-type image display devices described in (1) to (8), a second heat receiving unit is provided for receiving the driving heat of the image display element, and the first heat receiving unit is positioned between the prism unit and the image display element. The image display element is positioned between the first heat receiving unit and the second heat receiving unit. The second heat receiving unit includes a second inlet pipe for receiving a refrigerant and a second outlet pipe for discharging a refrigerant.

[0109] In the projection-type image display device of (10)(9), the second outlet pipe and the first inlet pipe are connected in series such that the refrigerant flowing out of the second outlet pipe of the second heat receiving unit reaches the first inlet pipe of the first heat receiving unit.

[0110] In the projection-type image display device of (11)(9), the first heat receiving unit and the second heat receiving unit are configured to receive the refrigerant in parallel.

[0111] (12) In any one of the projection-type image display devices described in (1) to (11), the flow path portion of the first heat receiving unit is composed of two brazed plate materials, and the brazed mating surfaces of the two plate materials are parallel to the inner wall portion that forms the opening.

[0112] (13) In any one of the projection-type image display devices described in (1) to (12), the flow path portion of the first heat receiving unit is composed of two brazed metal plates, and the brazed joint surfaces of the two plates are portions of the plates that extend from the outer circumference of the flow path portion in a direction perpendicular to the inner wall portion of the first heat receiving unit that forms the opening.

[0113] (14) In any one of the projection-type image display devices described in (1) to (13), the reflective image display unit is a digital mirror device.

[0114] (15) In any one of the projection-type image display devices described in (1) to (14), the flow path portion of the first heat receiving unit is made of aluminum-clad material. [Industrial applicability]

[0115] This disclosure is applicable to projection-type display devices that include an image display element having a reflective image display unit. [Explanation of Symbols]

[0116] 100, 200 Projection-type image display device 101, 201 Light source section 101a Laser Diode Unit 101b Laser Diode Unit 102, 104, 109, 114, 125, 212 Mirror 103, 108, 110, 112, 113, 209, 210, 211, 213 lenses 105, 115 Diffuser 106, 116, 117 Condenser lenses 107 Dichroic Mirror 111, 206 Rod Integrator 118 Phosphor Wheel Apparatus 119 Phosphor section 120 reflective layer 121 Spreader 122, 208 motors 123, 124 Relay Lens 126 Field Lens 127, 214 Total Internal Reflection Prism 128, 215 First Prism 129, 216 Second Prism 130, 131 Side of the first prism 132 Prism Unit 133 Blue Transmitting Dichroic Mirror Surface 134 The First Prism 135 Green Transmitting Dichroic Mirror Surface 136 The Second Prism 137 The Third Prism 138, 138R, 138G, 138B, 223 Image display elements 138a Reflective image display section 138c base 138d Protrusion 138dd First side view 138e aperture 139, 203 Projection lens unit 140, 140A Second heat receiving unit 140a pump 141, 141A First heat receiving unit 142, 142A drive board 143, 143A socket 144 Fixing bracket 145 Metal fittings 146 Mask substrate 147 Thermal insulation substrate 148 Mask substrate support bracket 149 Compression spring 150 Radiator 151 Reserve Tank 152, 152A 1st inflow pipe 153, 153A 1st outflow pipe 154, 154A flow path section 155 Heat conductive material 156 Slope 157 First joint 159 Nail area 160 Convex part 161 Second joint 162 2nd inflow pipe 163 Second Leak tube 1 73. First Piping 174 Second Piping 175 Metal plate 175a First brazing surface 176 Metal plate 176a First brazing surface 179 Opening 202 Image Generation Unit 205 Reflector 207 Color Wheel 217 Air Gap 218, 219, 220 Side of the first prism 221, 222 Side view of the second prism 224 Prism Case 223 Image display element 225 Packing 226 Light-blocking mask 227 Insulation 231 Insulating Sheet 232 Retaining clip LL light guiding optical system CL cooling device Rg refrigerant

Claims

1. A light source that emits light, An image display element having an image display unit that modulates light from the light source according to an external signal, A cooling device for cooling the image display element, A plate member supporting the image display element and having a first opening, The system includes a projection lens unit that projects an image generated by light modulated by the image display element, The plate member supports the image display element on the side opposite to the side of the plate member from which light from the light source is incident, and the side of the plate member from which light from the light source is incident is on the side of the image display element opposite to the side of the image display element from which light from the light source is incident. The cooling device, The first heat receiving unit comprises a second opening, The first heat receiving unit is, The first inlet pipe into which the refrigerant flows, The first outlet pipe through which the refrigerant flows out, It comprises a flow path section that forms the second opening and connects the first inlet pipe and the first outlet pipe, The second opening of the first heat receiving unit is positioned to surround the image display unit when viewed from the direction in which the modulated light propagates. At least a portion of the image display element is placed within the second opening of the flow channel of the first heat receiving unit. The surface of the first heat receiving unit on the side into which light from the light source is incident is on the same surface as the surface of the image display element on which light from the light source is incident, or is positioned so as to be more convex in the direction in which the modulated light propagates than the surface of the image display element on which light from the light source is incident. The first inlet pipe and the first outlet pipe of the first heat receiving unit extend along the side of the plate member on which light from the light source is incident, and the side of the first inlet pipe and the first outlet pipe opposite to the side on which light from the light source is incident is on the side of the plate member on which light from the light source is incident. Projection-type image display device.

2. A light source that emits light, An image display element having an image display unit that modulates light from the light source according to an external signal, A cooling device for cooling the image display element, A plate member supporting the image display element and having a first opening, The system includes a projection lens unit that projects an image generated by light modulated by the image display element, The plate member supports the image display element on the side opposite to the side of the plate member from which light from the light source is incident, and the side of the plate member from which light from the light source is incident is on the side of the image display element opposite to the side of the image display element from which light from the light source is incident. The cooling device, The first heat receiving unit comprises a second opening, The first heat receiving unit is, The first inlet pipe into which the refrigerant flows, The first outlet pipe through which the refrigerant flows out, It comprises a flow path section that forms the second opening and connects the first inlet pipe and the first outlet pipe, The image display element has a projection that protrudes from the periphery of the image display unit in the direction in which the modulated light propagates, on the side into which light from the light source unit is incident. The protruding portion has a front surface on the side into which light from the light source is incident, a first side surface extending rearward from the outer end of the front surface, a first bottom surface extending outward from the rear end of the first side surface, a second side surface extending rearward from the outer end of the first bottom surface, and a second bottom surface extending outward from the rear end of the second side surface. The protruding portion of the image display element is inserted into the opening of the first heat receiving unit. The flow path portion of the first heat receiving unit is positioned on the first bottom surface of the protruding portion. The front surface of the flow path portion of the first heat receiving unit is positioned on the same plane as the front surface of the protrusion or is convex in the direction in which the modulated light propagates, The first inlet pipe and the first outlet pipe of the first heat receiving unit extend along the side of the plate member on which light from the light source is incident, and the side of the first inlet pipe and the first outlet pipe opposite to the side on which light from the light source is incident is on the side of the plate member on which light from the light source is incident. Projection-type image display device.

3. At least a portion of the flow channel is disposed within the first opening of the plate member, The projection-type image display device according to claim 1 or 2.

4. The first inlet pipe and the first outlet pipe are arranged on the side of the flow path where light from the light source is incident, The first inlet pipe and the flow path section are connected via the first joint. The first outflow pipe and the flow path section are connected via a second joint. The projection-type image display device according to claim 3.

5. The direction of travel of the refrigerant flowing through the first inlet pipe is changed by the first joint from a direction along the surface of the plate member to a direction intersecting the surface of the plate member. The projection-type image display device according to claim 4.

6. The first heat receiving unit is equipped with a pump that supplies the refrigerant. A projection-type image display device according to any one of claims 1 to 5.

7. The flow path of the first heat receiving unit has a first pipe and a second pipe that branch off from the first joint and merge at the second joint, The first and second pipes form different sides of the rectangular opening of the first heat receiving unit. The first pipe and the second pipe are of the same length. The projection-type image display device according to claim 4.

8. A prism unit is provided in the optical path between the image display element and the projection lens unit. A projection-type image display device according to any one of claims 1 to 6.

9. The system includes a second heat receiving unit that receives the heat generated by the operation of the image display element, The first heat receiving unit is positioned between the prism unit and the image display element. The image display element is positioned between the first heat receiving unit and the second heat receiving unit. The second heat receiving unit is, A second inlet pipe through which the aforementioned refrigerant flows, The system comprises a second outlet pipe through which the refrigerant is discharged, The projection-type image display device according to claim 8.

10. The second outlet pipe and the first inlet pipe are connected in series such that the refrigerant flowing out of the second outlet pipe of the second heat receiving unit reaches the first inlet pipe of the first heat receiving unit. The projection-type image display device according to claim 9.

11. The first heat receiving unit and the second heat receiving unit are configured such that the refrigerant flows in in parallel. The projection-type image display device according to claim 9.

12. A light source that emits light, An image display element having an image display unit that modulates light from the light source according to an external signal, A cooling device for cooling the image display element, A plate member supporting the image display element and having a first opening, The system includes a projection lens unit that projects an image generated by light modulated by the image display element, The plate member supports the image display element on the side opposite to the side of the plate member from which light from the light source is incident, and the side of the plate member from which light from the light source is incident is on the side of the image display element opposite to the side of the image display element from which light from the light source is incident. The cooling device, The first heat receiving unit comprises a second opening, The first heat receiving unit is, The heat transfer portion that forms the second opening, It comprises a first pipe section extending from the heat transfer section to the heat dissipation section, The image display element has a projection that protrudes from the periphery of the image display unit in the direction in which the modulated light propagates, on the side into which light from the light source unit is incident. The protruding portion has a front surface on the side into which light from the light source is incident, a first side surface extending rearward from the outer end of the front surface, a first bottom surface extending outward from the rear end of the first side surface, a second side surface extending rearward from the outer end of the first bottom surface, and a second bottom surface extending outward from the rear end of the second side surface. The protruding portion of the image display element is inserted into the opening of the first heat receiving unit. The heat transfer portion of the first heat receiving unit is positioned on the first bottom surface of the protrusion, The front surface of the heat propagation portion of the first heat receiving unit is positioned on the same plane as the front surface of the protrusion or is convex in the direction in which the modulated light propagates compared to the front surface of the protrusion. The first tube portion of the first heat receiving unit extends along the side of the plate member on which light from the light source portion is incident, and the side of the first tube portion opposite to the side on which light from the light source portion is incident is on the side of the plate member on which light from the light source portion is incident. Projection-type image display device.

13. The side of the first tube opposite to the side into which light from the light source is incident is on the side of the heat propagation section that receives light from the light source, The projection-type image display device according to claim 12.

14. The heat transfer section of the first heat receiving unit has a first pipe and a second pipe that form different sides of the rectangular opening of the first heat receiving unit, The first pipe and the second pipe are of the same length. The projection-type image display device according to claim 13.

15. The image display unit is a digital mirror device. A projection-type image display device according to any one of claims 1 to 14.

Images