JP5038043B2 - Image projection device - Google Patents

Description

  The present invention relates to an image projection apparatus (projector) that projects an image formed on an image display element (liquid crystal panel, light guide, etc.) on an irradiated surface by a projection optical system.

  Conventionally, various image projection apparatuses (liquid crystal projectors) that enlarge and project an image of an image display element (liquid crystal panel, light valve) onto a screen by a projection optical system have been proposed as apparatuses for observing an enlarged projection image.

  In this liquid crystal projector, if dust or dirt adheres to the surface of the liquid crystal panel, these are enlarged and projected together with the projected image, which causes the image quality of the projected image to deteriorate.

  For this reason, a space formed by the liquid crystal panel and an optical element (for example, a λ / 4 wavelength plate) adjacent to the liquid crystal panel is surrounded by a dustproof cover or a rubber sheet so that dust or dirt does not adhere to the surface of the liquid crystal panel. It is a sealed space. Liquid crystal projectors using such a dustproof structure are known (Patent Documents 1 and 2).

  In the liquid crystal projector, the liquid crystal panel is illuminated with a light beam from the light source means. The temperature of the liquid crystal panel may rise due to heat from the light source means or light incident from the light source means, and the performance of the liquid crystal panel may deteriorate.

  In order to reduce the temperature rise of the liquid crystal panel at this time, in Patent Document 2, the back surface of the liquid crystal panel (light valve) is connected to a cooling member via a heat conductive material.

And it discloses disclosing the liquid crystal panel from the back via a heat conductive material by applying cooling air to the heat dissipating fins provided on the cooling member.
Japanese Patent Laid-Open No. 11-305676 JP 2004-20603 A

  In a liquid crystal projector, a liquid crystal panel is illuminated with a light beam from a light source means (lamp). In recent years, high-power light source means for obtaining bright projection images have been used.

  For this reason, there is a problem that the temperature of the sealed space formed by the liquid crystal panel and the optical member adjacent to the liquid crystal panel is increased, and the performance of the liquid crystal panel and the optical member adjacent thereto is deteriorated.

  For example, an organic film retardation plate or a polarizing element may be used as an optical member adjacent to the liquid crystal panel.

  In this case, when the temperature of these optical members increases, the optical performance decreases. As a result, there is a problem that the contrast of the projected image is greatly reduced.

  On the other hand, the space formed between the liquid crystal panel and the optical member disposed adjacent to the liquid crystal panel needs to be sealed to have a dustproof structure.

  For this reason, conventionally, in order to obtain a dustproof effect and a cooling effect, a cooling member is provided on the back surface (surface opposite to the light incident side) of the liquid crystal display element, and cooling air is applied to the cooling member to indirectly In other words, a method of cooling the liquid crystal display element has been used.

  However, this method provides a dustproof effect, but cooling is not always sufficient.

  The present invention can reduce the temperature rise in the space formed by the image display element and the optical member arranged adjacent to the image display element while preventing dust, and the contrast of the projected image is good. It is an object to provide an image projection apparatus.

Image projection apparatus of the present invention includes an image display element for forming an image, a light source means for emitting light, an illumination optical system for illuminating the image display element with light from the light source means, formed in the image display device A projection optical system that projects an image to be projected onto a projection surface, an optical element is disposed adjacent to the image display element, and a part of a holding member that holds the optical element is , the image display element and surrounds a portion of the space formed between said optical element, said holding member includes: the space, vents connecting the external space outside thereof is formed The vent hole is characterized by having a shape having one or more bent portions or a curved shape .
In addition, the image projection apparatus of the present invention includes an image display element that forms an image, a light source means that emits light, an illumination optical system that illuminates the image display element with light from the light source means, and the image display element A projection optical system for projecting the image formed on the projection surface, an optical element is disposed adjacent to the image display element, and one of the holding members for holding the optical element The portion surrounds a part of a space formed between the image display element and the optical element, and the holding member is formed with a vent hole that connects the space and an external space outside the space. The vent hole is formed in a direction perpendicular to and parallel to the surface normal of the image display element, and these are communicated with each other.

  ADVANTAGE OF THE INVENTION According to this invention, the temperature rise in the space formed with an image display element and the optical member arrange | positioned adjacent to an image display element can be reduced, aiming at dust prevention, and the contrast of a projection image Therefore, it is possible to obtain an image projection apparatus having a good quality.

  Embodiments of an image projection apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

An image projection apparatus of the present invention includes an image display element (liquid crystal panel, light guide) that forms an image, a light source unit that emits light, an illumination optical system that illuminates the image display element with light from the light source unit, and an image and a projection optical system for projecting the image formed on the display element onto a projection surface.

  FIG. 1 shows a schematic diagram of a main part of a first embodiment of an image projection apparatus (projection display apparatus) according to the present invention.

  In FIG. 1, 1 is a light source means (lamp), 2 is a lamp holder for holding the lamp 1, 3 is an explosion-proof glass disposed in front of the lamp 1 (light emission side), and 4 is a glass retainer for the explosion-proof glass 3. .

  α denotes an illumination optical system that makes light from the lamp 1 incident on the liquid crystal display element (image forming element) side for image display. Reference numeral β denotes a color separation / synthesis optical system including image display elements (light valves) for three colors R (red), G (green), and B (blue) that receive light emitted from the illumination optical system α.

  Reference numeral 5 denotes a projection lens barrel that emits light emitted from the color separation / synthesis optical system β and projects an image onto a screen (projected surface) (not shown). The projection lens barrel 5 houses a projection lens optical system (projection optical system) described later. Reference numeral 6 denotes an optical box that houses the lamp 1, the illumination optical system α, and the color separation / synthesis optical system β and to which the projection lens barrel 5 is fixed.

  The optical box 6 is formed with a lamp case member as a lamp peripheral member surrounding the periphery of the lamp 1.

  Reference numeral 7 denotes an optical box lid that covers the optical box 6 with the illumination optical system α and the color separation / synthesis optical system β housed therein. 8 is a power source, and 9 is a power filter. Reference numeral 10 denotes a ballast power source for uniting with the power source 8 to light the lamp 1. Reference numeral 11 denotes a circuit board for driving the light bulb and sending a lighting command for the lamp 1 with power from the power source 8. 12 (12A, 12B) is a cooling fan for an optical system for cooling an optical element (member) such as a light valve in the color separation / synthesis optical system β by sucking air from an air inlet 21a of an exterior cabinet 21 described later. (Member cooling fan) (cooling fan A / cooling fan B).

  Reference numeral 13 denotes an RGB duct (fan duct) for sending wind from the cooling fan 12 to an optical element such as a light valve in the color separation / synthesis optical system β.

  Reference numeral 14 denotes a cooling fan for a light source lamp (lamp cooling fan) for sending blowing air to the lamp 1 to cool the lamp 1.

  Reference numeral 15 denotes a lamp duct for sending the cooling air to the lamp 1 while holding the lamp cooling fan 14. Reference numeral 16 denotes a lamp duct for holding the cooling fan 14 together with the lamp duct 15 to construct a duct.

  17 is a power supply for simultaneously cooling the power supply 8 and the ballast power supply 10 by sucking air from an air inlet 21b provided in an exterior cabinet (exterior case) 21 to be described later to circulate air in the power supply 8 and the ballast power supply 10. This is a cooling fan (exhaust fan in the housing).

  Reference numeral 18 denotes an exhaust fan (lamp exhaust fan). The exhaust fan 18 discharges the wind from the cooling fan 14 after passing through the lamp 1.

  The lamp exhaust fan 18 and the exhaust fan 17 in the housing are composed of axial fans that can obtain a large air volume.

  Reference numeral 19 denotes a lamp exhaust louver, and reference numeral 20 denotes a lamp exhaust louver, which has a light shielding function so that light from the lamp 1 does not leak outside the apparatus.

  21 is an exterior cabinet for housing the optical box 6 and the like (lower part of the exterior case), and 22 is an exterior cabinet lid for covering the exterior cabinet 21 with the optical box 6 and the like (upper part of the exterior case). is there.

  Reference numeral 23 denotes a side plate, and 24 denotes a side plate. The exterior cabinet 21 has the above-described intake ports 21a and 21b, and the side plate 24 has an exhaust port.

  Reference numeral 25 denotes an interface board on which connectors for receiving various signals are mounted. Reference numeral 26 denotes an interface reinforcing plate attached to the inside of the side plate 23.

  Reference numeral 27 denotes a lamp exhaust box for guiding the exhaust heat from the lamp 1 to the exhaust fan 18 so as not to dissipate the exhaust air inside the apparatus, and holds the lamp exhaust louver 19 and the lamp exhaust louver 20.

  Reference numeral 28 denotes a lamp lid. The lamp cover 28 is detachably provided on the bottom surface of the exterior cabinet 21 and is fixed by screws (not shown). Reference numeral 29 denotes a set adjustment leg. The set adjustment leg 29 is fixed to the exterior cabinet 21, and the height of the leg portion 29a can be adjusted. The tilt angle of the apparatus main body can be adjusted by adjusting the height of the leg 29a.

  Reference numeral 30 denotes an RGB intake plate for holding a filter (not shown) attached to the outside of the intake port 21a of the exterior cabinet 21.

  Reference numeral 31 denotes a prism base that holds the color separation / synthesis optical system β. Reference numeral 32 denotes a box side cover having a duct-shaped portion for guiding cooling air from the cooling fan 12A and the cooling fan 12B in order to cool each optical element and light valve constituting the color separation / synthesis optical system β.

  Reference numeral 33 denotes an RGB duct for forming a duct by being combined with the box side cover 32.

  Reference numeral 34 denotes an RGB board (driving circuit board) connected to the circuit board 11 and connected to the FPC from the light valve, which is disposed in the color separation / synthesis optical system β. Reference numeral 35 denotes an RGB substrate cover for preventing electrical noise from entering the RGB substrate 34.

  2A and 2B are a plan view and a side view of the optical configuration of the projection type image display apparatus of FIG.

  2A and 2B show a projection type equipped with a light valve (reflection type liquid crystal display element) composed of the lamp 1, the illumination optical system α, the color separation / synthesis optical system β, and the projection lens 5 described above. 2 shows an optical configuration of an image display device.

  2A and 2B, the same members as those shown in FIG. 1 are denoted by the same reference numerals.

  In FIG. 2B, reference numeral 41 denotes an arc tube that emits white light in a continuous spectrum. A reflector 42 condenses light from the arc tube 41 in a predetermined direction. A lamp (light source means) 1 is formed by the arc tube 41 and the reflector 42.

  Reference numeral 43a denotes a first cylinder array composed of a lens array having a refractive power in the horizontal direction (horizontal direction in the traveling direction of light from the lamp 1 (the vertical direction in FIG. 2B)) in the YZ plane.

  Reference numeral 43b denotes a second cylinder array having lens arrays corresponding to the individual lenses of the first cylinder array 43a. 44 is an ultraviolet absorption filter. A polarization conversion element 45 aligns non-polarized light with predetermined polarized light.

  A front compressor 46 is constituted by a cylindrical lens having refractive power in the vertical direction (Y direction). Reference numeral 47 denotes a total reflection mirror for converting the optical axis by 88 degrees. Reference numeral 43c denotes a third cylinder array formed of a lens array having a refractive power in the vertical direction (the vertical direction in the traveling direction of light from the lamp 1 (the vertical direction in FIG. 2B)).

  43d is a fourth cylinder array having lens arrays corresponding to the individual lenses of the third cylinder array 43c.

  Reference numeral 50 denotes a color filter for transmitting color light in a specific wavelength region in order to adjust the color coordinates to a certain value. Reference numeral 48 denotes a condenser lens. Reference numeral 49 denotes a rear compressor composed of a cylindrical lens having a refractive power in the vertical direction.

  Each of the above members constitutes one element of the illumination optical system α.

  2A, reference numeral 58 denotes a dichroic mirror that reflects light in the wavelength region of blue light (B) and red light (R) and transmits light in the wavelength region of green light (G). Reference numeral 59 denotes a G-use incident side polarizing plate in which a polarizing element is attached to a transparent substrate, and transmits only P-polarized light. Reference numeral 60 denotes a first polarization beam splitter that transmits P-polarized light and reflects S-polarized light, and has a polarization separation surface.

  61R, 61G, and 61B reflect the incident light and modulate the image, the red reflective liquid crystal display element (light valve), the green reflective liquid crystal display element (light valve), and the blue reflective liquid crystal display. It is an element (light valve).

  62R, 62G, and 62B are a quarter wavelength plate for red, a quarter wavelength plate for green, and a quarter wavelength plate for blue, respectively. A trimming filter 64a returns orange light to the lamp 1 side in order to increase the color purity of R. 64b is an incident-side polarizing plate for R and B light in which a polarizing element is bonded to a transparent substrate, and transmits only P-polarized light. 65 is a color selective phase difference plate that converts the polarization direction of the R light by 90 degrees and does not convert the polarization direction of the B light. Reference numeral 66 denotes a second polarization beam splitter that transmits P-polarized light and reflects S-polarized light, and has a polarization separation surface.

  Reference numeral 68B denotes an exit side polarizing plate (polarizing element) for B, which rectifies only the S-polarized light of B. 68G is an exit side polarizing plate for G that transmits only S-polarized light. Reference numeral 69 denotes a dichroic prism that transmits RB light and reflects G light.

  Each member from the dichroic mirror 58 to the dichroic prism 69 constitutes the color separation / synthesis optical system β.

Here, if the definitions of P-polarized light and S-polarized light are clarified, the polarization conversion element 45 converts P-polarized light into S-polarized light. The P-polarized light and S-polarized light defined here are described with reference to the polarization conversion element 45. Yes.

  On the other hand, since the light incident on the dichroic mirror 58 is considered based on the polarization beam splitters 60 and 66, P-polarized light is incident. Although the light emitted from the polarization conversion element 45 is S-polarized light, the same S-polarized light is defined as light that enters the dichroic mirror as P-polarized light in this embodiment.

  Next, the optical action will be described.

  Light emitted from the arc tube 41 is collected in a predetermined direction by the reflector 42. The reflector 42 has a paraboloid shape, and light from the focal position of the paraboloid becomes a light beam parallel to the symmetry axis of the paraboloid.

  However, since the light source from the arc tube 41 is not an ideal point light source but has a finite size, the condensed light flux contains many light components that are not parallel to the symmetry axis of the paraboloid. Yes.

  These light beams are incident on the first cylinder array 43a. The light beam incident on the first cylinder array 43a is divided into a plurality of light beams corresponding to the respective cylinder lenses and condensed (a plurality of belt-shaped light beams in the vertical direction), and the second cylinder is passed through the ultraviolet absorption filter 44. The light enters the array 43b. Then, a plurality of light beams (a plurality of belt-shaped light beams in the vertical direction) are formed in the vicinity of the polarization conversion element 45 through the second cylinder array 43b.

  The polarization conversion element 45 includes a polarization separation surface, a reflection surface, and a half-wave plate, and a plurality of light beams are incident on the polarization separation surface corresponding to the column, and are reflected by the transmitted P-polarized component light. The light is divided into polarized light components. The reflected light of the S polarization component is reflected by the reflecting surface and is emitted in the same direction as the P polarization component.

  On the other hand, the transmitted P-polarized light component is transmitted through the half-wave plate, converted into the same polarized light component as the S-polarized light component, and emitted as light having the same polarization direction.

  A plurality of light beams that have undergone polarization conversion (a plurality of light beams in a strip shape in the vertical direction) are emitted from the polarization conversion element 45 and then reflected by a reflection mirror 47 via the front compressor 46, and are reflected by a third cylinder array. 43c. The light beam incident on the third cylinder array 43c is divided and condensed into a plurality of light beams corresponding to the respective cylinder lenses (a plurality of belt-shaped light beams in the horizontal direction). Then, after passing through the color filter 50 and the fourth cylinder array 43d, a plurality of light beams (a plurality of light beams in a strip shape in the horizontal direction) are formed, and reach the condenser lens 48 and the rear compressor 49.

  Here, due to the optical action of the front compressor 46, the condenser lens 48, and the rear compressor 49, a rectangular uniform illumination area is formed by overlapping the rectangular images of the plurality of light beams. Reflective liquid crystal display elements 61R, 61G, and 61B, which will be described later, are arranged in this illumination area.

  Next, the light converted to S-polarized light by the polarization conversion element 45 enters the dichroic mirror 58.

  The dichroic mirror 58 reflects light of B (wavelength 430 nm to 495 nm) and R (wavelength 590 nm to 650 nm) and transmits light of G (wavelength 505 nm to 580 nm).

  Next, the G optical path will be described.

  The G light transmitted through the dichroic mirror 58 enters the incident side polarizing plate 59. The G light is still P-polarized light after being decomposed by the dichroic mirror 58 (S-polarized light in the case of 45 polarization conversion element standard).

  The G light exits from the incident-side polarizing plate 59, then enters the first polarizing beam splitter 60 as P-polarized light, passes through the polarization separation surface, and enters the G reflective liquid crystal display element 61G. And so on. In the reflective liquid crystal display element 61G for G, the G light is image-modulated and reflected.

  The P-polarized component of the image-modulated G reflected light is transmitted again through the polarization separation surface of the first polarization beam splitter 60, returned to the light source side, and removed from the projection light. On the other hand, the S-polarized component of the image-modulated G reflected light is reflected by the polarization separation surface of the first polarization beam splitter 60 and travels toward the dichroic prism 69 as projection light.

  At this time, in a state in which all the polarization components are converted to P-polarized light (in a state where black is displayed), ¼ provided between the first polarizing beam splitter 60 and the reflective liquid crystal display element 61G for G. The slow axis of the wave plate 62G is adjusted in a predetermined direction.

  Thereby, it is possible to suppress the influence of the disturbance of the polarization state generated in the first polarization beam splitter 60 and the G-type reflective liquid crystal display element 61G.

  The G light emitted from the first polarizing beam splitter 60 enters the dichroic prism 69 as S-polarized light, and the G light is reflected by the dichroic film surface of the dichroic prism 69 and reaches the projection lens 70.

  On the other hand, the R and B lights reflected from the dichroic mirror 58 enter the incident side polarizing plate 64a.

The R and B lights are still P-polarized light after being decomposed by the dichroic mirror 58. The light of R and B, after being cut orange light trimming filter 64a, and exit through entry elevation side polarization plate 64b, is incident upon the color selective phase plate 65.

  The color-selective phase difference plate 65 has an action of rotating the polarization direction of only R light by 90 degrees, whereby the R light becomes S-polarized light and the B light becomes P-polarized light. Is incident on. The R light incident on the second polarization beam splitter 66 as S-polarized light is reflected by the polarization separation surface of the second polarization beam splitter 66 and reaches the R reflective liquid crystal display element 61R.

  The B light incident on the second polarization beam splitter 66 as P-polarized light passes through the polarization separation surface of the second polarization beam splitter 66 and reaches the B-use reflective liquid crystal display element 61B.

  The R light incident on the R reflective liquid crystal display element 61R is image-modulated and reflected. The S-polarized light component of the image-modulated R reflected light is reflected again by the polarization separation surface of the second polarization beam splitter 66, returned to the light source side, and removed from the projection light.

  On the other hand, the P-polarized component of the image-modulated reflected R light passes through the polarization separation surface of the second polarization beam splitter 66 and travels toward the dichroic prism 69 as projection light.

  The B light incident on the B reflective liquid crystal display element 61B is image-modulated and reflected. The P-polarized component of the image-modulated B reflected light is again transmitted through the polarization separation surface of the second polarization beam splitter 66, returned to the light source 1, and removed from the projection light.

  On the other hand, the S-polarized component of the image-modulated B reflected light is reflected by the polarization separation surface of the second polarization beam splitter 66 and travels toward the dichroic prism 69 as projection light.

  At this time, by adjusting the slow axes of the quarter-wave plates 62R and 62B provided between the second polarizing beam splitter 66 and the reflective liquid crystal display elements 61R and 61B for R and B, G As in the case of, the black display of R and B can be adjusted.

  In this way, the B light out of the R and B projection lights emitted from the second polarization beam splitter 66, which is combined into one light beam, is detected by the exit-side polarizing plate 68B and enters the dichroic prism 69.

  Further, the R light is transmitted through the polarizing plate 68B as it is as the P-polarized light and enters the dichroic prism 69.

  Incidentally, the B projection light is generated by passing through the second polarizing beam splitter 66, the B-use reflective liquid crystal display element 61B, and the quarter-wave plate 62B by being analyzed by the exit-side polarizing plate 68B. The light is cut from invalid components.

  The R (P-polarized) and B (S-polarized) projection light incident on the dichroic prism 69 passes through the dichroic film surface of the dichroic prism 69 and is reflected by the dichroic film surface described above. It is combined with the light and reaches the projection lens 5.

  Then, the combined R, G, B projection light is enlarged and projected onto a projection surface such as a screen by the projection lens 5.

  Since the optical path described above is for the case where the reflective liquid crystal display element displays white, the optical path for the case where the reflective liquid crystal display element displays black will be described below.

  First, the G optical path will be described.

  The P-polarized light of the G light that has passed through the dichroic mirror 58 enters the incident-side polarizing plate 59, and then enters the first polarizing beam splitter 60 and is transmitted through the polarization separation surface. It reaches the element 61G.

  However, since the reflective liquid crystal display element 61G displays black, the G light is reflected without being image-modulated.

  Accordingly, since the G light remains P-polarized light after being reflected by the reflective liquid crystal display element 61G, it is transmitted again through the polarization separation surface of the first polarization beam splitter 60 and transmitted through the incident-side polarizing plate 59. Then, it is returned to the light source side and removed from the projection light.

  Next, the R and B optical paths will be described.

  P-polarized light of R and B light reflected from the dichroic mirror 58 is incident on the incident-side polarizing plate 64b. Then, the R and B lights are emitted from the incident side polarizing plate 64 b and then enter the color selective phase difference plate 65.

  The color-selective phase difference plate 65 has an action of rotating the polarization direction of only R light by 90 degrees, whereby the R light becomes S-polarized light and the B light becomes P-polarized light. Is incident on.

  The R light incident on the second polarization beam splitter 66 as S-polarized light is reflected by the polarization separation surface of the second polarization beam splitter 66 and reaches the R reflective liquid crystal display element 61R.

  The B light incident on the second polarization beam splitter 66 as P-polarized light passes through the polarization separation surface of the second polarization beam splitter 66 and reaches the B-use reflective liquid crystal display element 61B. Here, since the R reflective liquid crystal display element 61R displays black, the R light incident on the R reflective liquid crystal display element 61R is reflected without being image-modulated.

  Therefore, even after being reflected by the reflective liquid crystal display element 61R for R, the R light remains as S-polarized light, and is reflected again by the polarization separation surface of the second polarizing beam splitter 66, and is incident on the incident side polarizing plate. Since it passes through 64b and returns to the light source 1 side and is removed from the projection light, black display is obtained.

  On the other hand, the P-polarized B light incident on the B reflective liquid crystal display element 61B is reflected without being image-modulated because the B reflective liquid crystal display element 61B displays black.

  Therefore, even after being reflected by the reflective liquid crystal display element 61B for B, the B light remains as P-polarized light, so that it is again transmitted through the polarization separation surface of the second polarization beam splitter 66, and the color selective position. The phase difference plate 65 converts the light into P polarized light.

  Thereafter, the light passes through the incident-side polarizing plate 64b, is returned to the light source side, and is removed from the projection light.

  The above is the optical configuration in the projection type image display apparatus using the reflective liquid crystal display element (reflective liquid crystal panel).

  Note that a transmissive liquid crystal display element may be used instead of the reflective liquid crystal display element.

  Next, the cooling structure of the liquid crystal display element (light valve), which is a feature of this embodiment, will be described with reference to FIGS.

  FIG. 3 is a perspective view of an essential part of the prism unit.

  In FIG. 3, reference numeral 31 denotes a prism base that holds the color separation / synthesis optical system β. Reference numeral 70 (70R, 70G, 70B) denotes a heat sink for holding the reflective liquid crystal display element and for radiating heat from the liquid crystal display element to the outside. Reference numeral 73 denotes a quarter-wave plate holder that holds the quarter-wave plate 62.

  Reference numerals 70R, 70G, and 70B (70) denote heat sinks that hold the reflective liquid crystal display elements 61R, 61G, and 61B for R light, G light, and B light, respectively. Similarly, 73R, 73G, and 73B (73) are quarter wave plate holders for holding the quarter wave plates 62R, 62G, and 62B for R light, G light, and B light.

  In FIG. 3, the relative positional relationship of the reflective liquid crystal display element for RGB light is shown.

  FIG. 4 is an explanatory diagram of a liquid crystal display element unit 61b including a liquid crystal display element 61 and members disposed in the vicinity thereof.

  FIG. 5 is a perspective view of a main part of a liquid crystal display element unit (image display element unit) 61b.

  FIG. 6 is an explanatory diagram of a part of FIG. FIG. 7 is a cross-sectional view of the main part of FIG.

  FIG. 4 shows the structure from the heat sink 70 for heat radiation to the quarter-wave plate holder 73, which is a configuration common to the reflection type liquid crystal display elements for R, G, and B color lights.

  In FIG. 4, 71 is a panel mask. Reference numeral 72 denotes a rubber shield for preventing dust from adhering to the light incident / exit surface of the reflective liquid crystal display element 61.

  The liquid crystal display element 61 is injected and disposed between the substrate and the glass substrate on which the conductor film is formed. 61 a is a flexible substrate connected to the liquid crystal display element 61.

  In FIG. 5, the state from the heat sink 70 to the panel mask 71 and the rubber shield 72 is arranged at the design position and laminated.

  In this state, the heat sink 70 surrounds the back surface of the reflective liquid crystal display element 61. The side surface of the reflective liquid crystal display element 61 is surrounded by a panel mask 71. A quarter-wave plate 62 is positioned adjacent to the upper surface (light incident side) of the reflective liquid crystal display element 61 as an optical component. The quarter wavelength plate 62 is surrounded by a quarter wavelength plate holder (λ / 4 plate holder) 73, and the remaining gap is surrounded by a rubber shield 72.

  In this configuration, the space formed by the liquid crystal display element and the quarter-wave plate 62 provided on the light incident side is constructed in a substantially sealed space to obtain high dustproof performance.

  When light from the light source means (lamp) enters the liquid crystal panel, it is also referred to as a space 81 (hereinafter referred to as “light incident side space of the liquid crystal display element”) formed by the λ / 4 wavelength plate on the light incident side of the liquid crystal display element. ) The temperature inside increases.

  If parts having high heat resistance are used for each optical element, there is no problem of temperature rise in the space on the light incident side of the liquid crystal display element. However, the liquid crystal in the reflective liquid crystal display element, the liquid crystal rubbing film, and the quarter-wave plate 62 are organic materials made of a polycarbonate material. For this reason, it is easily affected by heat, and the optical performance may be deteriorated by raising the temperature.

Therefore, in this embodiment, a plurality of ventilation holes (for heat radiation) are formed in a part of the holding member 73 (1/4 wavelength plate holder 73) that holds the optical element (1/4 wavelength plate) 62 adjacent to the liquid crystal display element 61. Groove-shaped portion ) 73a is formed.

  By forming the plurality of ventilation holes 73a, the space 81 on the light incident side of the liquid crystal display element 61 and the external space 82 are communicated with each other, and the temperature rise in the space 81 is reduced.

  FIG. 6 shows an outline of the quarter-wave plate holder 73. 6 and 7, the Z axis is the optical axis direction (the surface normal direction of the liquid crystal display element 61). The X axis and Y axis are perpendicular to the Z axis (in-plane direction of the liquid crystal display element 61). 73a is a ventilation hole (groove shape part).

In this embodiment, the quarter-wave plate holder 73 is provided with a plurality of ventilation holes 73a. When this portion of the groove opening side rubber shield 72 comes into contact, the groove-opening surface of the groove-shaped portion 73a is blocked, the groove inside the quarter-wave plate holder 73 remains, and the groove-shaped cross section is fine. It becomes a pore (ventilation hole).

  The space 81 formed between the reflective liquid crystal display element 61 and the quarter-wave plate 62 communicates with the outside through the plurality of ventilation holes 73a. Thereby, ventilation with the outside is attained. As a result, the high-temperature air inside the light incident side space of the liquid crystal display element is replaced with the external cold air, and the heat in the light incident side space 81 of the liquid crystal display element 61 is transferred to the external space 82. Dissipate heat.

  Reference numeral 83 denotes an air vent that communicates with the external space 82.

  In the present embodiment and each of the following embodiments, the fine ventilation holes 73a are preferably formed in a shape having a bent portion or a curved shape or a curved shape.

  The fine ventilation holes 73a may have a straight line shape, but it is necessary to maintain the dustproof performance as much as possible, so that one or more bends or curves (curves) are drawn. This prevents intrusion of dust.

  When the size of the dust that becomes a problem attached to the image display element 61 is 50 μm, it is desirable that the cross-sectional diameter of the groove-shaped portion is 50 μm or less.

  In this embodiment, since it is desired to increase the ventilation heat dissipation efficiency, the groove-shaped section has a larger sectional diameter (50 μm to 100 μm) and is provided with a bent portion.

  This increases the cross-sectional diameter of the groove-shaped portion, so that the dust cannot easily enter due to the resistance caused by bending even though the air volume is increased.

  In the present embodiment, the ventilation hole 73a has two bent shapes or curved shapes when viewed from the light incident side. This prevents dust from entering much even if the diameter of the vent hole is set to a relatively large pore cross-sectional diameter.

  This is because the air flow resistance is generated by the bends and curves formed by the ventilation holes 73a to reduce the wind speed and weaken the force for sucking dust.

  Further, the space 81 formed between the image display element 61 and the optical element (¼ wavelength plate) is communicated with the external space 82 only by the ventilation hole 73a.

  Thereby, the dustproof effect in the space 81 is enhanced.

  In the present embodiment, the ventilation holes 73 a are formed in a direction orthogonal to the surface normal of the image display element 61.

  In this embodiment and each embodiment described later, a cooling means for sending cooling air to the λ / 4 wavelength plate holder (holding member) 73 is disposed.

  At this time, the ventilation holes 73a are provided around the quarter-wave plate holder 73 in a region where the cooling air does not hit.

  Specifically, as shown in FIG. 6, the ventilation holes 73 a are provided on three sides of the four sides of the quarter-wave plate holder 73, but are not provided on the remaining one side.

  This is because one side where the ventilation hole 73a is not provided is at a position where cooling air from a cooling means (not shown) is blown.

  This prevents dust from being forced into the ventilation hole 73a at a position where the wind speed is high. The remaining three sides are sides in a direction orthogonal to the flow of the cooling air, or are disposed on the discharge side even in the direction of the cooling air flow, so that dust is forced into the ventilation holes 73a. It is possible to greatly reduce the possibility of being lost.

In this embodiment, as shown in FIG. 7, a part of the space 81 formed between the image display element 61 and the quarter wavelength plate 62 is covered with a rubber sheet 72 made of a fluorine-based rubber material.

  The quarter-wave plate 62 is rotated and adjusted around the optical axis in order to ensure the contrast of the image displayed on the liquid crystal display element 61.

  For this reason, the quarter-wave plate holder 73 rotates. In this case, since it is in contact with the rubber shield 72, a frictional resistance is generated during rotational sliding. As a result, the thin and soft rubber shield 72 may be deformed to be turned over or warped, leaving a gap that allows dust to enter.

In this embodiment, to suppress the frictional force by using a fluorine-based rubber rubber seal de 7 2, thereby preventing curling and warping.

  As described above, by providing the ventilation hole 73a in a part of the quarter-wave plate holder 73, the dustproof performance is maintained while improving the heat dissipation by performing natural convection ventilation.

  In this embodiment, by selecting the rubber shield 72 with less friction, turning and warping are prevented, and generation of a dust intrusion path due to work is suppressed.

  FIG. 8 is a schematic view of a main part of a liquid crystal display element unit 61b according to the second embodiment of the present invention.

  FIG. 9 is a cross-sectional view of the main part of FIG. 8 and 9, the same members as those shown in FIGS. 6 and 7 are denoted by the same reference numerals. The same applies to the following drawings.

  In the first embodiment shown in FIGS. 6 and 7, the ventilation holes 73 a are provided on the surface of the quarter-wave plate holder 73 that makes contact with the rubber shield 72, and the fine holes are formed by making contact with the rubber shield 72. It was.

On the other hand, in the present embodiment, the groove-shaped portion 73 a is provided on a part of the quarter-wave plate holder 73 on the contact surface 62 a side with the quarter-wave plate 62. Since it is in contact with both the flat surface and the end surface of the quarter-wave plate 62, a groove 73c orthogonal to the optical axis (the surface normal direction of the image display element 61) and a groove 73d parallel to the optical axis are connected to each other. Ventilation holes 73a that expand in dimension are formed.

  Reference numeral 84 denotes a vent hole at the end face of the quarter-wave plate 62.

  In the present embodiment, the air holes 73a are formed in a direction orthogonal to and parallel to the surface normal of the image display element 61, and these communicate with each other. As a result, the same effect as in the first embodiment is obtained.

  FIG. 10 is a schematic diagram of a main part of a liquid crystal display element unit 61b according to Embodiment 3 of the present invention. 11 is a cross-sectional view of the main part of FIG.

  In the first and second embodiments, the space on the light incident side of the liquid crystal display element and the outside communicate with each other through the grooves facing each other, and both air flows in and out.

  Outside air flows from one ventilation hole and reaches the center, and the inside air heated in the center is discharged from another ventilation hole. On the other hand, in Example 3, one connected ventilation hole 73a is connected to the outside by two ventilation openings 83 and 84. As a result, the wind flows in from the ventilation hole at one end and flows out from the ventilation hole at the other end. Although ventilation is not performed directly from the central part, the temperature difference in the peripheral part of the central part is eliminated and saturation is achieved, so that the same effect as in the first embodiment can be obtained by ventilating only from the peripheral part.

  FIG. 12 is a schematic view of the essential portions of a liquid crystal display element unit 61b according to Embodiment 4 of the present invention. 13 is a cross-sectional view of the main part of FIG. The ventilation hole 73 a of this embodiment is interrupted in the middle of the quarter-wave plate holder 73, but instead is connected to a through hole 73 b to the back surface of the quarter-wave plate holder 73. Thereby, the internal space 81 and the external space 82 are ventilated.

  Although the shape of the ventilation hole 73a of a present Example differs from Examples 1-3, the frequency | count of bending is the same as Example 1. FIG. As a result, the same effect as in Example 1 is obtained.

  As described above, in the image projection apparatus of each embodiment, the ventilation hole 73b is provided in the quarter wavelength plate holder 73 that holds the quarter wavelength plate 62 disposed adjacent to the light incident side of the image display element 61. Yes. A part of the quarter wave plate holder 73 surrounds a part of a space 81 formed between the image display element 61 and the quarter wave plate 62. The ventilation hole 73b is configured to connect the space 81 and the outer space 82 outside thereof.

In each embodiment, by adopting the configuration as described above, it is possible to improve heat dissipation while maintaining the dustproof performance of the liquid crystal display element unit 61b. For this reason, since a retardation plate or a polarizing element made of a high-performance organic film can be used adjacent to the liquid crystal display element, a projector capable of obtaining a higher contrast image can be provided.

  This is because the deflection element made of an organic film such as polycarbonate has a smaller phase resistance wavelength range and less leakage light during black display than the deflection element made of inorganic material such as quartz with high heat resistance. It is. Moreover, since the temperature rise can be suppressed even in the high luminance model, a high contrast image can be obtained.

  In particular, the liquid crystal display element and the optical elements in the periphery thereof are easily affected by heat, which also affects the durability. On the other hand, in each Example, since heat dissipation can be improved, a highly durable product can be provided.

  In each embodiment, the case where the optical element is arranged on the light incident side of the image display element has been described. However, the same applies to the case where the optical element is arranged on the light emitting side of the image display element. By providing, the effect of the present invention can be obtained.

1 is an exploded perspective view of an image projection apparatus equipped with a reflective liquid crystal display element of the present invention. Optical configuration diagram of an image projection apparatus equipped with a reflective liquid crystal display element of the present invention The perspective view which shows the prism unit which concerns on this invention. The exploded view which shows the main components of the liquid crystal display unit which concerns on this invention. Explanatory drawing which shows the form of the unit of the liquid crystal display element which concerns on this invention. FIG. 3 is a component shape diagram showing characteristics of the liquid crystal display unit according to the present invention. Cross-sectional view of the main part of FIG. FIG. 6 is a component shape diagram showing characteristics of a unit of a liquid crystal display element according to Example 2 of the invention. Cross-sectional view of the main part of FIG. FIG. 7 is a component shape diagram showing characteristics of a unit of a liquid crystal display element according to Example 3 of the invention. Cross-sectional view of the main part of FIG. FIG. 10 is a component shape diagram showing characteristics of a unit of a liquid crystal display element according to Example 4 of the invention. 13 is a cross-sectional view of the main part of FIG.

Explanation of symbols

1 is a light source lamp, 2 is a lamp holder, 3 is explosion-proof glass, 4 is a glass holder, 5 is a projection lens, 6 is an optical box, 7 is an optical box lid, 8 is a power supply, 9 is a power filter, 10 is a ballast power supply, 11 is a circuit board, 12A and 12B are optical cooling fans A and B, 13 is an RGB duct A, 14 is a lamp cooling fan (blowing fan), 15 is a lamp duct A, 16 is a lamp duct B, and 17 is a cooling fan for power supply. , 18 is an exhaust fan, 19 is a lamp exhaust louver A, 20 is a lamp exhaust louver B, 21 is an exterior cabinet, 22 is an exterior cabinet lid (exterior case), 23 is a side plate A, 24 is a side plate B, 25 is an interface board, 26 is an interface reinforcing plate, 27 is an exhaust box, 28 is a lamp lid, 29 is a set adjustment leg, 30 is an exterior cabinet, 31 Prism base, 32 is a box side cover, 33 is an RGB duct B, 34 is an RGB substrate, 35 RGB substrate cover, 41 is a lamp arc tube (light source), 42 is a reflector, 43a is a first cylinder array, 43b is a second Cylinder array, 43c is the third cylinder array, 43d is the fourth cylinder array, 44 is the ultraviolet absorption filter, 45 is the polarization conversion element, 46 is the front compressor, 47 is the total reflection mirror, 48 is the condenser mirror, 49 is the rear Compressor, 50, color filter, 58, dichroic mirror, 59, G incident side polarizing plate, 60, first polarizing beam splitter, 61, reflective liquid crystal display element, 62, 1/4 wavelength plate, 64a, trimming filter , 64b is an incident side polarizing plate for RB, 65 color selective phase difference plate, 6 is a second polarizing beam splitter, 68B is a B output side polarizing plate, 68G is a G output side polarizing plate, 69 is a dichroic prism, 70 is a heat sink, 71 is a panel mask, 72 is a rubber shield, 73 is 1 / 4 wavelength plate holder.

Claims (6)

An image display element for forming an image;
Light source means for emitting light;
An illumination optical system for illuminating the image display element with light from the light source means;
A projection optical system for projecting the image formed by the image display device onto a projection surface,
In an image projection apparatus having
The image display device are arranged optical elements adjacent to, a portion of the holding member for holding the optical element, surrounds a portion of the space formed between said image display element and the optical element and de, the holding member includes: the space, and the ventilation hole is formed for connecting the outer space of the outer,
The image projection device according to claim 1, wherein the ventilation hole is formed in a shape having a bent portion or a curved shape at least once . An image display element for forming an image;
  Light source means for emitting light;
  An illumination optical system for illuminating the image display element with light from the light source means;
  A projection optical system that projects an image formed by the image display element onto a projection surface;
In an image projection apparatus having
  An optical element is disposed adjacent to the image display element, and a part of the holding member that holds the optical element surrounds a part of a space formed between the image display element and the optical element. And the holding member is formed with a vent hole connecting the space and the external space outside the space.
  The ventilation holes are formed in a direction perpendicular to and parallel to the surface normal of the image display element,
An image projection apparatus characterized by being communicated.   The image projection apparatus according to claim 1 or 2, wherein a space formed between the image display element and the optical element is communicated with an external space only by the ventilation hole. The image projection apparatus according to claim 1, wherein the ventilation hole is formed in a direction orthogonal to a surface normal of the image display element. The image display element and the part of the space formed between the optical element of any one of claims 1 to 4, characterized in that it is covered with a rubber sheet made of rubber material of the fluorinated Image projection device. A cooling means for sending cooling air to said holding member, a periphery of the holding member, according to claim 1 to 5, characterized in that the ventilation holes in the area in which the cooling air is not exposed is provided The image projection apparatus of any one item | term.