Projection display device

Abstract

The projection display device has a light source part and an optical system unit which processes light from the light source part and emits the light to the outside. The optical system unit has a housing member. A transparent member is installed on the housing member at an exit opening part which is provided at a position of emitted light. The transparent member is maintained at a holding temperature which is 1°C or more higher than the inner wall temperature of the housing member after the light source is turned off. The holding time of the holding temperature of the glass cover is 30 minutes or more after the light source is turned off.

Description

Technical Field

[0001] This disclosure relates to projection display devices. Background Technology

[0002] Patent Document 1 discloses a projection-type display device in which a transparent member is mounted on a housing member that houses multiple optical system components for properly processing light from a light source unit. This transparent member blocks the emission opening formed at the location where white light is emitted.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2011 / 148498 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, the sealing materials, thermal greases, and other grease-based organic substances used inside the outer casing, the metal plates inside the outer casing, the release agents adhering during die casting, and the grease-based organic substances adhering during processing all adhere to the metal plates and die castings inside the outer casing. As the light source unit's temperature rises when the light source is turned on, the grease-based organic substances vaporize and float inside the optical system unit. Furthermore, when the light source is turned off, the floating gas liquefies, making it prone to adhering to the transparent components that come into contact with the air outside the optical system unit and experience rapid temperature drops. Therefore, the adhesion of gas to the transparent components causes blurring, potentially reducing the projector's optical performance due to decreased transmittance. Thus, in optical system units containing impurities such as grease-based organic substances, it is necessary to suppress the adhesion of impurities to the transparent components.

[0008] The present invention was made in view of the above circumstances, and its object is to provide a projection display device that, in an optical system unit containing impurities, can suppress the adhesion of impurities to a transparent component and suppress the reduction of optical performance.

[0009] Methods for solving problems

[0010] The first aspect of the present invention provides a projection-type display device comprising: a light source unit; and an optical system unit that processes light from the light source unit and emits it to the outside. The optical system unit has a housing member, on which a transparent member is mounted at an emission opening. The emission opening is located at the position where the light is emitted. The transparent member is maintained at a holding temperature that is at least 1°C higher than the temperature of the inner wall of the housing member after the light source is turned off.

[0011] Invention Effects

[0012] According to the present invention, in an optical system unit containing impurities, it is possible to suppress the adhesion of impurities to transparent components and suppress the reduction of optical performance. Attached Figure Description

[0013] Figure 1 This is a perspective view showing the appearance of the projector according to the first embodiment of the present invention.

[0014] Figure 2 Viewed from the oblique rear Figure 1 A 3D image of the projector showing the state of the casing with the top cover removed.

[0015] Figure 3 It means Figure 2 A three-dimensional view of the light source device in the image.

[0016] Figure 4 It means in Figure 3 A three-dimensional view of the glass cover after it has been disassembled.

[0017] Figure 5 yes Figure 2 A horizontal sectional view of the light source device in the image.

[0018] Figure 6 It means Figure 5 Enlarged view of the main parts of the glass cover in its installed state.

[0019] Figure 7 Is Figure 6 A simplified horizontal sectional view of the outer casing component with the glass cover installed.

[0020] Figure 8A It is a diagram illustrating the function of the optical system units, and a cross-sectional view showing the state when the light source is not lit.

[0021] Figure 8B It is a diagram illustrating the function of the optical system units, and a cross-sectional view showing the state when the light source is lit.

[0022] Figure 8C It is a diagram illustrating the function of the optical system units, and a cross-sectional view showing the state when the light source is off.

[0023] Figure 9 This is a perspective view showing the appearance of the light source device according to the second embodiment of the present invention.

[0024] Figure 10 It means in Figure 9 A three-dimensional view of the glass cover after it has been disassembled.

[0025] Figure 11 It means Figure 9 A horizontal sectional view of the main part of the glass cover in its installed state.

[0026] Figure 12 Is Figure 11 A simplified horizontal sectional view of the outer casing component with the glass cover installed.

[0027] Figure 13 This is a simplified horizontal cross-sectional view of the outer shell component provided with adsorbent material according to the third embodiment of the present invention.

[0028] Figure 14 The results of the embodiment are a graph showing the relationship between time elapsed after extinguishing and temperature difference.

[0029] Figure 15 The results of the embodiment are a graph showing the relationship between time elapsed after extinguishing and temperature difference.

[0030] Figure 16 The results of the measurement in the example are a graph showing the relationship between glass thickness and temperature difference. Detailed Implementation

[0031] (First Implementation)

[0032] The following is for reference Figure 1 Figure 8 illustrates one embodiment of the present invention.

[0033] like Figures 1-3 As shown, the projector 1 (projection type display device) of this embodiment is a device that projects image light (image) onto a display surface such as a screen. The projector 1 includes a light source device 3, an image light forming device 4, a projection device 5, a housing 11, a fan 12, and an air duct 13.

[0034] The image light forming apparatus 4 generates image light based on the light output from the light source device 3, which will be described later. Although not shown, the image light forming apparatus 4 includes light modulation elements such as a DMD (Digital Micromirror Device), a liquid crystal panel, and electronic components for controlling the light modulation elements.

[0035] The projection device 5 amplifies the image light output from the image light forming device 4 and projects it onto a display surface such as a screen.

[0036] The housing 11 houses the light source device 3, the image light forming device 4, the projection device 5, the air supply fan 12, and the air duct 13. The housing 11 has: a base plate 14, which houses the light source device 3, the image light forming device 4, the projection device 5, the air supply fan 12, and the air duct 13; and an upper cover 15, which covers the light source device 3, the image light forming device 4, the projection device 5, the air supply fan 12, and the air duct 13 from above.

[0037] The light source device 3, the air supply fan 12, and the air duct 13 constitute a cooling structure for cooling the light source section 10 of the light source device 3.

[0038] like Figures 3-5 As shown, the light source device 3 includes a light source unit 10, a heat dissipation unit 20, and an optical system unit 30.

[0039] like Figure 5 As shown, the light source unit 10 emits light. The light source device 3 of this embodiment has multiple (e.g., four) light source units 10. Each light source unit 10 has a substrate 16 and a light-emitting element 17 mounted on the substrate 16. The light-emitting element 17 can be, for example, an LED (Light Emitting Diode), but in this embodiment it is a laser diode. Furthermore, the type of light-emitting element 17 is not limited. The light-emitting element 17 of this embodiment emits laser light in the blue wavelength region. That is, the light source unit 10 of this embodiment is a laser substrate. The number of light-emitting elements 17 provided in the light source unit 10 is, for example, two, but is not limited to this.

[0040] The heat dissipation unit 20 is used to cool the light source unit 10 and has a heat dissipation plate 21 and a plurality of heat dissipation fins 22.

[0041] The heat sink portion 21 is formed as a plate having a mounting surface 21a and a back surface 21b facing the side opposite to the mounting surface 21a. The mounting surface 21a and the back surface 21b are formed to be substantially flat and substantially parallel to each other.

[0042] like Figure 5 As shown, the aforementioned light source portion 10 is mounted on the mounting surface 21a. Specifically, a substrate 16 of the light source portion 10 is disposed overlapping the mounting surface 21a. The substrate 16 may be in direct contact with the mounting surface 21a, but, for example, a thermally conductive grease, which is an oil-based organic material, is placed between the substrate 16 and the mounting surface 21a to improve heat transfer from the substrate 16 to the heat dissipation portion 20. The heat dissipation plate portion 21 is made of a material with high electrical conductivity, such as copper.

[0043] With the light source 10 placed on the mounting surface 21a, the light generated in the light-emitting element 17 of the light source 10 is mainly directed away from the mounting surface 21a (in Figure 5 (Centering towards the bottom of the paper). In Figure 5 In the diagram, arrows LD1 and LD2 indicate the direction of light travel emitted from the light source 10.

[0044] like Figure 5 and Figure 6As shown, the optical system unit 30 is disposed on the mounting surface 21a side of the heat sink portion 21 on which the light source portion 10 is disposed. The optical system unit 30 processes the light (blue light) from the light source portion 10 appropriately and emits white light into the image light forming apparatus 4. The optical system unit 30 has a plurality of optical system components 31 for appropriately processing the light from the light source portion 10, and a housing member 32 for housing these optical system components 31.

[0045] The optical system component 31 includes a reflecting mirror 31A, a condenser lens 31B, a diffuser plate 31C, a dichroic mirror 31D, etc. Figure 5 In the diagram, arrows LD1 and LD2 indicate the direction of light travel emitted from the light source 10. The condenser lens 31B, for example, focuses the light from the light source 10.

[0046] like Figures 5-7 As shown, the housing member 32 of the optical system unit 30 has an opening edge that allows light emitted from the light source unit 10 to enter the interior of the housing member 32. By having the opening edge of the housing member 32 in close contact with the area surrounding the light source unit 10 in the mounting surface 21a, the housing member 32 can cover the light source unit 10. As a result, dust on the outside of the housing member 32 can be suppressed or prevented from reaching the light source unit 10.

[0047] The outer shell component 32 is made of die-cast aluminum and is formed into a roughly rectangular box shape.

[0048] like Figures 3-5 As shown, the outer casing member 32 has an upper wall 321, a lower wall 322, a pair of side walls 323 and 324 extending along the length direction, a first end wall 325 on the heat dissipation portion 20 side of the pair of side walls 323 and 324, and a second end wall 326 on the side opposite to the heat dissipation portion 20 side in the length direction. The internal space 32A surrounded by the aforementioned walls (upper wall 321, lower wall 322, side walls 323 and 324, first end wall 325, and second end wall 326) of the outer casing member 32 is sealed to the outside. Therefore, as described above, the internal space 32A blocks external air and dust. The outer surface of the outer casing member 32 is provided in a state of contact with air (external air E).

[0049] Here, the internal space 32A of the outer casing 32 contains grease-based organic matter that adheres to the inner wall 32c when the light source of the light source 10 is turned off and floats when the light source is turned on. Figure 8AThe grease-based organic compound G refers to impurities such as sealing materials, thermally conductive greases (such as conductive greases between the light source section 10 and the heat dissipation section 20) used in the internal space 32A of the outer casing member 32, the metal plate inside the outer casing member, the release agent adhering during die casting, and impurities adhering during processing. At low temperatures (e.g., below 55°C), the grease-based organic compound G adheres to the metal plate inside the outer casing member 32 and the die casting, while at high temperatures (e.g., above 55°C), it floats inside the outer casing member 32.

[0050] An emission opening 32a is provided on the side wall 323 of the outer casing member 32 at the position where the light is emitted. The emission opening 32a is generally rectangular in shape when viewed from a direction perpendicular to the opening surface. A glass cover 6 equipped with a transparent member 60 is installed on the emission opening 32a. Here, the transparent member 60 is composed of a pair of glass covers 60A and 60B (described later) and a heat insulation layer 64 formed between these glass covers 60A and 60B. Specifically, the glass cover 6 blocks the emission opening 32a from the outside of the outer casing member 32, and is configured to fit tightly against the opening edge of the emission opening 32a without gap.

[0051] like Figures 4-6 As shown, the glass cover 6 includes: a pair of plate-shaped glass covers 60A and 60B (glass components) arranged at intervals between each other; a glass support 61 that holds the pair of glass covers 60A and 60B parallel to each other at a certain interval; a retaining frame 62 that is fixed to the periphery of the exit opening 32a of the outer shell component 32; and a pressing metal plate 63 that clamps and holds the pair of glass covers 60A and 60B, on which the glass support 61 is clamped, between the metal plate 63 and the retaining frame 62.

[0052] The transparent member 60 has an outer glass cover 60A and an inner glass cover 60B. The pair of glass covers 60A and 60B are transparent members with low thermal conductivity and transparency compared to components such as metal plates and die-cast aluminum parts, and are formed of the same shape and thickness. However, the outer glass cover 60A and the inner glass cover 60B may have different thicknesses. The pair of glass covers 60A and 60B are each formed into a rectangular shape that is larger than the exit opening 32a when viewed from above. The thickness of the pair of glass covers 60A and 60B is, for example, about 1 mm to 2 mm.

[0053] like Figure 4As shown, the glass holder 61 is frame-shaped and sandwiched between a pair of glass covers 60A and 60B. The glass holder 61 has retaining recesses 61a and 61b on its front and rear sides to hold the outer peripheries of the glass covers 60A and 60B as a whole. The second retaining recess 61b on the side of the glass holder 61 facing the exit opening 32a holds the outer periphery 60a of the inner glass cover 60B. The first retaining recess 61a on the side of the glass holder 61 facing away from the exit opening 32a holds the outer periphery 60a of the outer glass cover 60A.

[0054] By installing a pair of glass covers 60A and 60B on the glass holder 61, a heat insulation layer 64 is formed, which is surrounded and sealed by the pair of glass covers 60A and 60B and the glass holder 61 and contains gas (air).

[0055] The outer periphery of the glass holder 61 is provided with a first engaging hole 611 that engages with the outer shell component 32 and a first engaging protrusion 612 that engages with the pressing metal plate 63.

[0056] The retaining frame 62 is formed in a frame shape with the same size as the glass holder 61. One fixing surface 62a of the retaining frame 62 is in liquid-tight contact with the periphery of the ejection opening 32a, and a third retaining recess 62b is formed on the other surface to retain the outer periphery 60a of the inner glass cover 60B. A second engaging protrusion 621 that engages with the first engaging hole 611 of the glass holder 61 and a second engaging hole 622 that engages with the outer shell member 32 and the pressing metal plate 63 are provided on the outer periphery of the retaining frame 62.

[0057] The pressing metal plate 63 is frame-shaped. A fourth retaining recess 63a is formed on the surface of the pressing metal plate 63 facing the outer casing member 32 to retain the outer periphery 60a of the outer glass cover 60A. A third engaging hole 631 is provided on the outer periphery of the pressing metal plate 63 to engage with the first engaging protrusion 612 of the glass bracket 61, and a passage... Figure 3 The screw 64 shown is inserted through the second engaging hole 622 of the retaining frame 62 and engages with the third engaging hole 632 of the outer surface of the housing member 32. Additionally, the pressing metal plate 63 has pressing surfaces 630 at its upper and lower edges. The pressing surfaces 630 extend along the upper and lower edges and abut against and press against the outer surface of the housing member 32 while the pressing metal plate 63 is fixed to the housing member 32.

[0058] like Figure 6 and Figure 7As shown, the glass cover 6 is positioned such that the outer glass surface 60b of the outer glass cover 60A is in contact with the external air E. The transparent member 60 held by the glass cover 6 is configured such that, after the light source of the light source unit 10 is extinguished, it maintains a holding temperature at least 1°C higher than the inner wall temperature of the inner wall 32c of the outer casing member 32. More precisely, the temperature of the inner glass surface 60i of the inner glass cover 60B (the side opposite to the outer glass cover 60A) is maintained at a temperature at least 1°C higher than the inner wall temperature of the inner wall 32c of the outer casing member 32. The holding temperature of the inner glass surface 60i of the inner glass cover 60B (a temperature difference of at least 1°C between the inner glass surface 60i and the inner wall temperature of the outer casing member 32 after the light source is extinguished) is maintained for at least 30 minutes after the light source is extinguished.

[0059] In the projector 1 of this embodiment, there is a light source unit 10 and an optical system unit 30 that processes the light from the light source unit 10 and emits it to the outside. The optical system unit 30 has a shell member 32 that contains an oily organic compound G as an impurity inside. Therefore, as Figure 8A As shown, when the light source 10 is not lit, the grease-based organic matter G adheres to the inner wall 32c of the outer casing member 32 and the metal plate inside the outer casing member 32 that forms the retaining structure of the optical system component 31.

[0060] Moreover, such as Figure 8B As shown, when the light source unit 10 is lit, the temperature of the internal space 32A of the outer casing member 32 rises, and the grease-based organic matter G adhering to the inner wall 32c of the outer casing member 32 vaporizes and floats, becoming floating gas G1. Furthermore, as... Figure 8C As shown, when the light source 10 is extinguished, the temperature of the internal space 32A of the outer casing 32 decreases. Therefore, similar to when the light source is not lit, the floating gas G1 re-attaches to the inner wall 32c of the outer casing 32. At this time, since the outer side of the outer casing 32 is in contact with the external air E, the grease-based organic matter G adheres to the contact portion with the external air E, the part with high thermal conductivity and rapid temperature decrease, namely the inner wall 32c of the outer casing 32 made of aluminum die casting, and the metal plate that forms the retaining structure of the optical system components 31. Furthermore, the optical system components 31, such as lenses, disposed in the internal space 32A of the outer casing 32 are not in contact with the external air E, so their temperature decreases slowly. Therefore, after the light source is extinguished, it is difficult for the floating gas G1 to re-attach to these optical system components 31.

[0061] Furthermore, in the projector 1 of this embodiment, a transparent member 60 is installed on the housing member 32 at the emission opening 32a located at the position of the emitted light. Moreover, the transparent member 60 is a glass member, and the inner surface 60i of the inner glass cover 60B is maintained at a holding temperature that is at least 1°C higher than the inner wall temperature of the housing member 32 after the light source is turned off.

[0062] Therefore, after the light source is turned off, the transparent member 60 installed in the emission opening 32a of the housing member 32 maintains a temperature difference of more than 1°C with the inner wall temperature of the housing member 32. This reduces heat dissipation from the transparent member 60 to the external air E flowing outside the housing member 32, thus maintaining the inner wall temperature (temperature of the inner surface 60i of the glass) of the inner glass cover 60B of the transparent member 60 at a predetermined time. Based on this structure, the floating gas G1 that floats when the light source is lit can actively adhere to the inner wall 32c of the housing member 32, the metal plate disposed in the internal space 32A of the housing member 32, and other parts, suppressing its adhesion to the inner glass cover 60B of the transparent member 60 and suppressing the reduction of optical performance.

[0063] Furthermore, in the projector 1 of this embodiment, the temperature of the inner glass surface 60i of the inner glass cover 60B is maintained for at least 30 minutes after the light source is turned off. In this case, the inner glass surface 60i of the inner glass cover 60B can maintain a temperature at least 1°C higher than the inner wall temperature of the outer casing member 32 after the light source is turned off for a long period of 30 minutes or more. Therefore, the internal space 32A and the inner wall 32c of the outer casing member 32 reach the liquefaction temperature of the floating gas G1 earlier than the transparent member 60, which allows the floating gas G1 floating when the light source is turned on to adhere more reliably to the inner wall 32c of the outer casing member 32, the metal plate provided in the internal space 32A of the outer casing member 32, and other parts.

[0064] Furthermore, in the projector 1 of this embodiment, the transparent member 60 has a pair of plate-shaped glass covers 60A and 60B arranged at intervals from each other, and a heat insulation layer 64 disposed between the pair of glass covers 60A and 60B. Thus, the transparent member 60 becomes a structure with improved heat preservation effect due to the heat insulation layer 64, effectively reducing heat loss from the transparent member 60 to the external air E flowing outside the outer shell member 32, and maintaining the inner wall temperature of the transparent member 60 at a predetermined time. In this embodiment, the heat insulation layer 64 is air, but is not limited to air; it can also be other gases or solids, or even a vacuum.

[0065] (Second Implementation)

[0066] like Figures 9-12As shown, the projector 1A (projection type display device) of the second embodiment has a structure in which a glass cover 7 having a transparent member 70 made of thick plate glass 71 is installed on the emission opening 32a of the housing member 32. That is, the glass cover 7 blocks the emission opening 32a from the outside of the housing member 32 and is arranged in a state of tight contact with the periphery of the emission opening 32a without gap.

[0067] The glass cover 7 includes a thick glass plate 71 (glass component), a retaining frame 72 fixed to the periphery of the emission opening 32a of the outer shell component 32, and a pressing metal plate 73 that clamps and retains the thick glass plate 71 between itself and the retaining frame 72.

[0068] The thick glass 71 is a transparent component with low thermal conductivity and high transparency compared to components such as metal plates and die-cast aluminum parts. The thick glass 71 has a stepped shape with a protrusion 711 protruding to one side. When viewed from above, the protrusion 711 of the thick glass 71 forms a rectangular shape substantially the same as the emission opening 32a. The protrusion 711 fits into the inner side of the emission opening 32a of the housing member 32. That is, the thick glass 71 is configured to have a thickness on the side closer to the inner space 32A than the outer surface of the housing member 32. Furthermore, the planar shape of the protrusion 711 can also be smaller than the opening shape of the emission opening 32a.

[0069] The outer periphery (flange 712) of the outer glass surface 71a side of the thick glass plate 71 is held and retained by the retaining frame 72 and the pressing metal plate 73.

[0070] As described later, the thickness of the thick glass 71 is preferably 3 mm or more in order to maintain the holding temperature of the transparent member 70 at or above 1°C. Furthermore, from a manufacturing and cost perspective, the upper limit of the thickness of the thick glass 71 is, for example, around 10 mm.

[0071] The retaining frame 72 is frame-shaped. One fixing surface 72a of the retaining frame 72 is in liquid-tight contact with the periphery of the ejection opening 32a, and a first retaining recess 72b for retaining the flange portion 712 of the thick glass plate 71 is formed on the other surface. A engaging protrusion 721 for engaging with the pressing metal plate 73 and a first engaging hole 722 for engaging with the outer casing member 32 are provided on the outer periphery of the retaining frame 72.

[0072] The pressing metal plate 73 is frame-shaped. A second retaining recess 73a is formed on the surface of the pressing metal plate 73 facing the housing member 32, for retaining the flange portion 712 of the thick glass plate 71. A second engaging hole 731 is provided on the outer periphery of the pressing metal plate 73 to engage with the engaging protrusion 721 of the retaining frame 72, and a passage... Figure 9The screw 74 shown is inserted through the first engagement hole 722 of the retaining frame 72 and engages with the third engagement hole 732 of the outer surface of the housing member 32.

[0073] The glass cover 7 is positioned such that the outer surface 71a of the thick glass plate 71 is in contact with the external air E. The transparent member 70 held by the glass cover 7 is configured to maintain a temperature at least 1°C higher than the inner wall temperature of the inner wall 32c of the outer casing member 32 after the light source of the light source unit 10 is extinguished. More precisely, the temperature of the inner surface 71b of the thick glass plate 71 is maintained at a temperature at least 1°C higher than the inner wall temperature of the inner wall 32c of the outer casing member 32. The maintenance time of the maintenance temperature of the inner surface 71b of the thick glass plate 71 (a temperature difference of at least 1°C between the inner surface and the inner wall temperature of the outer casing member 32 after the light source is extinguished) is at least 30 minutes after the light source is extinguished.

[0074] In the projector 1A of the second embodiment, the same effect as in the first embodiment is achieved. Specifically, by maintaining the transparent member 70, mounted on the emission opening 32a of the housing member 32, at a temperature difference of 1°C or higher with the inner wall of the housing member 32 after the light source is turned off, heat dissipation from the transparent member 70 to the external air E flowing outside the housing member 32 is reduced, thus maintaining the inner wall temperature (temperature of the inner glass surface 71b) of the transparent member 70 for a specified time. Based on this structure, the floating gas G1 that floats when the light source is lit can actively adhere to the inner wall 32c of the housing member 32, the metal plate disposed in the internal space 32A of the housing member 32, and other parts, suppressing its adhesion to the inner glass surface 71b of the transparent member 70 and suppressing the reduction in optical performance.

[0075] (Third Implementation)

[0076] Figure 13 The projector 1B (projection-type display device) of the third embodiment shown has a structure in which an adsorbent material 8 is provided in the internal space 32A. This adsorbent material 8 can adsorb oily organic matter G (impurities) floating inside the outer casing member 32. In the third embodiment, a thin glass plate 35 is installed from the outside of the outer casing member 32 through the emission opening 32a. The thin glass plate 35 has a thickness of about 1 mm to 2 mm, for example, and is a glass member with a thickness smaller than that of the transparent members 60 and 70 of the first and second embodiments described above.

[0077] The adsorbent material 8 is, for example, activated carbon, which is capable of adsorbing oily organic compounds G. As the adsorbent material 8, it is preferable to use a material that does not vaporize and re-float once the adsorbed oily organic compounds G are adsorbed. The position of the adsorbent material 8 in the internal space 32A of the outer shell member 32 is not particularly limited as long as it is inside the outer shell member 32, but it is preferable to be near the exit opening 32a.

[0078] In the projector 1B of the third embodiment, when the light source is turned on and after the light source is turned off, the adsorbent material 8 actively adsorbs the oily organic matter G (floating gas G1) floating in the internal space 32A of the outer casing member 32, thereby reducing the amount of oily organic matter G floating in the internal space 32A of the outer casing member 32. Therefore, the adhesion of oily organic matter G to the thin glass 35 can be suppressed, and the reduction in optical performance can be suppressed.

[0079] Furthermore, the adsorbent material 8 of the third embodiment can further exert the above-mentioned effects by being disposed within the outer shell member 32 using the transparent members 60 and 70 of the first and second embodiments described above.

[0080] Next, embodiments will be described to demonstrate the effectiveness of the projection display device described in the above embodiments.

[0081] (Example)

[0082] In this embodiment, the projector 1 described above (refer to...) is used. Figures 1-12 The temperature difference between the glass and the inner wall of the outer shell components caused by the difference in the thickness of the glass in the glass cover was measured, and the temperature difference caused by the thickness of the glass and the heat preservation effect were verified.

[0083] As shown in Table 1, the test subjects were used in four different cases (cases 1 to 4) with varying glass thicknesses. Case 1 is a comparative example using a thin sheet of glass with a thickness of 1.1 mm. Case 2 is an example using a thick sheet of glass with a thickness of 3.3 mm bonded to a thin sheet of glass with a thickness of 1.1 mm, resulting in a total glass thickness of 4.4 mm, corresponding to the structure of the second embodiment described above. Case 3 is an example using a thick sheet of glass with a thickness of 1.1 mm bonded to a thin sheet of glass with a thickness of 6.6 mm, resulting in a total glass thickness of 7.7 mm, corresponding to the structure of the second embodiment described above. Case 4 is an example where two thin sheets of glass with a thickness of 1.1 mm are spaced apart by a spacer, corresponding to the structure of the first embodiment described above.

[0084] [Table 1]

[0085]

[0086] The measurements were taken in cases 1-4, at intervals after the light source was extinguished (0 minutes, 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 10 minutes, 20 minutes, 30 minutes), measuring the temperature (°C) at the center of the inner side of the glass (CG) (outer shell component side) and the temperature (°C) of the inner wall of the outer shell component (EG), and calculating the temperature difference (°C). Since the temperature at the center of the inner side of the glass is higher than the temperature of the inner wall of the outer shell component, the temperature difference represents how many degrees higher the temperature at the center of the inner side of the glass is relative to the inner wall of the outer shell component. In cases 1-4, it was evaluated whether the temperature difference could be guaranteed to be greater than 1°C after 30 minutes and 5 minutes after the extinguishing time. Here, the temperature difference of 1°C used as the evaluation benchmark is based on the condition that if a temperature difference of 1°C exists, impurities (oil-based organic matter) will adhere to the inner wall of the lower-temperature outer shell component.

[0087] In addition, in each of cases 1 to 4, the adhesion status of impurities (oil-based organic matter) to the glass surface is confirmed by visual inspection.

[0088] Figures 14-16 The results of the measurements in the examples are shown. Figure 14 and Figure 15 It is a graph showing cases 1 to 4, with the horizontal axis representing the time (minutes) elapsed after the extinguishing process and the vertical axis representing the temperature difference (°C). Figure 14 This is a graph showing the time elapsed up to 30 minutes after the power is turned off. Figure 15 This is a graph showing the time elapsed up to 5 minutes after the screen went out. Figure 16 It is a graph showing the measurement results of cases 1 to 3 after 30 minutes when the horizontal axis is set to glass thickness (mm) and the vertical axis is set to temperature difference (°C).

[0089] As shown in Table 1, Figure 14 and Figure 15 As shown, in all cases 1-4, the temperature difference decreased with the elapsed time after the glass was extinguished. In case 1, it was confirmed that although the temperature difference could be maintained at more than 1°C until 4 minutes after the glass was extinguished, it became 0.5°C after 5 minutes, and the temperature difference between the center of the inner side of the glass and the inner wall of the outer casing component decreased to less than 1°C. Furthermore, in case 1, it was confirmed that grease-based organic matter was adhering to the glass surface.

[0090] On the other hand, in cases 2, 3, and 4, it is evident that even 30 minutes after the maximum elapsed time (the time of the measured extinction) the temperature difference can be sufficiently ensured to be above 1°C, and even 5 minutes after extinction the temperature difference can be above 2°C. As in cases 2 and 3, in thick glass, the greater the thickness, the greater the temperature difference even at the same time after extinction. Furthermore, in case 4, the temperature difference is greater than the 4.4 mm thick glass in case 2. Moreover, in cases 2, 3, and 4, it is not visually identifiable that grease-like organic matter adheres to the glass surface.

[0091] Moreover, by Figure 16 It is known that the temperature difference increases proportionally with the glass thickness. Therefore, it can be confirmed that by making the glass thickness 3mm or more, a temperature difference of 1°C or more can be ensured.

[0092] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments and can be appropriately modified without departing from its spirit.

[0093] In this invention, for example, the temperature of the transparent member is maintained at 1°C or more for at least 30 minutes after the light source is turned off, but the maintenance time is not limited to 30 minutes or more.

[0094] In the first embodiment, the transparent member installed on the exit opening of the outer casing is a structure in which a heat insulation layer 64 is provided between a pair of glass covers 60A and 60B, and in the second embodiment, a structure in which a thick glass plate 71 is provided. However, the transparent members 60 and 70 are not limited to these structures, and other transparent members of different shapes and forms can also be used.

[0095] In the second embodiment described above, the protrusion 711 of the stepped thick glass plate 71 is fitted into the emission opening 32a of the housing member 32, and is configured to have a thickness on the side closer to the inner space 32A than the outer surface of the housing member 32, but is not limited to such a shape of thick glass plate. For example, it is also possible to arrange a thick glass plate of a certain thickness only on the outer side of the housing member 32 across the entire surface.

[0096] Label Explanation

[0097] 1. 1A, 1B Projectors (projection-type display devices)

[0098] 3. Light source device

[0099] 6, 7 Glass Cover

[0100] 10. Light Source Section

[0101] 20 Heat dissipation section

[0102] 30 Optical System Units

[0103] 31 Optical System Components

[0104] 32. Shell components

[0105] 32A Interior Space

[0106] 32a Ejection opening

[0107] 60 and 70 transparent components

[0108] 60A Outer glass cover (glass component)

[0109] 60B Inner glass cover (glass component)

[0110] 61 Glass support

[0111] 62, 72 retaining frame

[0112] Press metal plates 63, 73

[0113] 64 Insulation layer

[0114] 71 Thick Plate Glass

[0115] E. Outside air

[0116] G. Oily organic compounds (impurities)

Claims

1. A projection-type display device, characterized in that, The projection display device includes: Light source section; and The optical system unit processes the light from the light source and emits it to the outside. The optical system unit has a housing component. A transparent component is mounted on the outer casing member at the emission opening, the emission opening being positioned where the light is emitted. The transparent component maintains a holding temperature that is at least 1°C higher than the inner wall temperature of the outer shell component after the light source is turned off.

2. The projection display device according to claim 1, characterized in that, The transparent component maintains its temperature for at least 30 minutes after the light source is turned off.

3. The projection display device according to claim 1, characterized in that, The transparent component has: A pair of plate-like glass components, arranged spaced apart from each other; and A heat insulation layer is disposed between the pair of glass components.

4. The projection display device according to claim 1, characterized in that, The transparent component is a thick sheet of glass.

5. The projection display device according to claim 4, characterized in that, The thickness of the thick glass plate is 3mm or more.

6. The projection display device according to claim 4, characterized in that, The thick glass is configured to have a thickness on the inner space side of the outer surface of the housing member.

7. The projection display device according to claim 1, characterized in that, The light source unit has a laser diode.

Images