JP2702868B2 - LCD projector - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector. 2. Description of the Related Art A liquid crystal projector uses a transmission type liquid crystal display panel to display an image, and enlarges and projects a display image of the liquid crystal display panel on a screen surface by a projection lens. It has the following configuration. FIG. 12 shows the principle of a liquid crystal projector. In the figure, reference numeral 1 denotes a projector case,
A projection lens 2 formed by combining a plurality of optical lenses is provided on the front surface of the case 1. [0004] Reference numeral 3 denotes a transmission type dot matrix liquid crystal display panel provided in the case 1, and 4 denotes a liquid crystal display panel 3.
The light source device 4 includes a light source lamp 5 and a reflector 6 that reflects illumination light from the light source lamp 5 toward the liquid crystal display panel 3. Has become. The illumination light from the light source device 4 enters the liquid crystal display panel 3, and the light transmitted through the liquid crystal display panel 3, that is, the display image of the liquid crystal display panel 3 is projected by a condenser lens (fresnel lens in the figure) 7. The light is condensed by the lens 2, expanded by the projection lens 2, and projected on a screen S disposed in front of the projector. This liquid crystal projector enlarges a display image of a liquid crystal display panel and projects it on a screen surface. According to this liquid crystal projector, a display image of a liquid crystal display panel having a small display screen is enlarged and viewed. be able to. However, in the above-mentioned liquid crystal projector, since the inside of the case 1 is heated by the heat radiated from the light source device 4 to its surroundings to heat the liquid crystal display panel 3, the liquid crystal projector As the temperature of the liquid crystal in the display panel 3 rises, the display contrast of the liquid crystal display panel 3 is reduced due to the influence, so that a clear image cannot be projected on the screen S, and the life of the liquid crystal in the liquid crystal display panel 3 is increased. Also had the problem of decreasing. The temperature rise in the case 1 can be suppressed to some extent by cooling the inside of the case 1 by ventilating the inside of the case 1. However, the high temperature generally used as the light source lamp 5 of the liquid crystal projector can be suppressed. Since a discharge lamp of high brightness generates considerable heat, in the case of a liquid crystal projector, both the light source and the liquid crystal display panel must be cooled. However, in the conventional liquid crystal projector, it is difficult to arrange a cooling fan due to its configuration, and therefore it is difficult to cool both the light source and the liquid crystal display panel properly. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to cool both a light source and a liquid crystal display panel well and to lower the contrast of the liquid crystal display panel due to an increase in temperature. An object of the present invention is to provide a liquid crystal projector capable of projecting a good image while preventing the occurrence of a cooling fan and of allowing a cooling fan to be arranged relatively freely. According to the present invention, there is provided a light source, a liquid crystal display panel, and a projection lens, wherein light from the light source is incident on the liquid crystal display panel and transmitted through the liquid crystal display panel. A liquid crystal projector that projects the light with the projection lens, wherein a display unit room in which the liquid crystal display panel is arranged in a projector case, and a light source room in which the light source is arranged.
And a light source box having a ventilation opening is disposed in the light source chamber, and a cooling fan for cooling the inside of the case is provided in the case.
One end of the heat wall is used as a baffle for distributing the air flow by the cooling fan to the display unit room side and the light source room side.
It is provided to extend near the light source chamber near the fan.
It is characterized in that it has constructed. According to the liquid crystal projector of the present invention, the air guide for guiding the air flow from the cooling fan to the display unit room and the light source room is provided.
Since it is provided at one end of the heat insulating wall and the light source is housed in a light source box having an open vent, the light source can be satisfactorily cooled despite being placed in a case for heat and damage prevention. Furthermore, by providing a wind guide extending toward the light source chamber near the fan, and configured so that more airflow flows to the display unit room side than when there is no wind guide ,
The liquid crystal display panel can be cooled well. Therefore, it is possible to project a good image while preventing a decrease in the contrast of the liquid crystal display panel due to a rise in temperature, and it is possible to design the arrangement of the cooling fan relatively freely. An embodiment of the present invention will be described below with reference to FIGS. First, the overall configuration of a liquid crystal projector will be described. In FIGS. 1 and 2, reference numeral 10 denotes a projector case.
A projection lens 20 having a plurality of lenses (not shown) arranged in a lens barrel is provided. In the case 10, a display device 30 is provided at a front portion thereof, and a light source device is provided at a rear portion thereof.
The light source device 50 and the display device 30 are provided between the light source device 50 and the display device 30. The light beam compressing Fresnel lens 21 that compresses the light beam of the illumination light from the light source device 50 to increase the luminance of the illumination light, and the light beam A luminous flux correcting Fresnel lens 22 that corrects illumination light passing through the compression Fresnel lens 21 into parallel light parallel to the optical axis O of the projector and causes the parallel light to enter the transmission type liquid crystal display panel 43 of the display device 30 is provided. . The front side of the display device 30 (projection lens 20)
On the side), there is provided a condensing Fresnel lens 23 for condensing the light transmitted through the liquid crystal display panel 43, that is, the display image of the liquid crystal display panel 43, on the projection lens 20. The light beam compressing Fresnel lens 21 is arranged close to the light source device 50, the light beam correcting Fresnel lens 22 is arranged close to the back surface of the display device 30, and the light collecting Fresnel lens 23
Is arranged close to the front surface of the display device 30. 3 to 5 show the display device 30. The display device 30 includes a display panel cooler 31 and a display unit 40 attached to one surface of the display panel cooler 31.
It consists of The display panel cooler 31 is provided in a thin box-shaped cooling container having a transparent area having a larger area than the display area 43a (see FIG. 6) of the liquid crystal display panel 43 on both sides. The cooling container comprises a frame 32 having an outer shape sufficiently larger than the liquid crystal display panel 43, and a transparent plate (a glass plate or an acrylic resin plate) 34 closing both sides of the frame 32. , 35. The frame 32 has a liquid crystal display panel on one surface thereof.
43, a display unit mounting plate 32a having a window 33 with a slightly larger area than the display area 43a is formed.
The transparent plate 35, which is sized to cover the outer surface of the frame 32, is adhered to the display unit mounting plate 32a and closes the other surface of the frame 32. Glued. Reference numeral 37 denotes a heat pipe inserted into the cooling container of the display panel cooler 30 so as to avoid a portion corresponding to the window 33. The heat pipe 37 has both ends on both sides of the cooler. Is inserted into the upper part of the cooling container in a state of protruding from the outside. This heat pipe 37 is provided with a display panel cooler.
The heat absorbed by the cooling liquid 36 in the heat pipe 37 is discharged to the outside of the cooler 31. The central portion of the heat pipe 37 inserted into the cooler is a heat absorbing portion a, and both ends of the heat pipe 37 projecting outside the cooler 31 The side portions are heat radiating portions b, b, and large area heat radiating fins 38, 38 in the shape of a vertically long strip are provided on the outer periphery of the heat radiating portions b, b. The above-mentioned heat pipe 37 is a pipe in which a volatile working fluid (heat transfer medium) is sealed in a metal pipe whose both ends are closed, and the working fluid in the heat pipe 37 is formed by capillary action over the entire inner surface thereof. As a result, an asbestos-like wick 37a is provided for guiding from the heat radiating portion b side to the heat absorbing portion a side. The working fluid transfers heat by reversible two-phase change of evaporation and condensation. As the working fluid, for example, a fluid having a high latent heat coefficient and excellent permeability, such as Freon, is used. I have. The working fluid is heated and evaporated by heat exchange with the cooling liquid 36 in the display panel cooler 31 in the heat absorbing portion a of the heat pipe 37, and evaporates as steam to rise inside the heat pipe 37. The working fluid that has been condensed and liquefied by heat radiation to the outside at the heat radiating part b of 37 is deprived of latent heat and is wicked.
It penetrates 37a and is again guided to the heat absorbing portion a by the capillary action. The heat pipe 37 guides the working fluid evaporated at the heat absorbing section a to the heat radiating sections b at both ends of the heat pipe, and liquefies the working fluid at the heat radiating sections b and permeates the wick 37a. In order to introduce the heat to the heat absorbing portion a again, the central portion is bent so as to be the lowest and both ends are inclined obliquely upward. On the other hand, the display unit 40 mounted on one surface of the display panel cooler 31 has liquid crystal display panels 43 on both surfaces.
The liquid crystal display panel 43 and its display drive circuit board 44 are housed in an ultra-thin case-shaped housing 41 provided with light-transmitting windows 42a and 42b corresponding to the above. The housing 41 has the following configuration. Has become. That is, in FIG. 6 to FIG.
b denotes a pair of metal cases forming the housing 41. The metal cases 41a and 41b have the light transmitting windows 42a and
42b is open. Of these translucent windows 42a and 42b,
The translucent window 42a on the side where the cooler is mounted is connected to the display panel cooler 31.
The size of the opening 42b on the opposite side is substantially the same as the size of the display area of the liquid crystal display panel 43. The display drive circuit board 44 has a light-transmitting window on the side of the cooler mounting surface of the housing 41 at the center thereof.
The circuit board 44 has a large number of display driving LEDs.
SI chips 45, 45 are provided so as to surround the opening 44a. These LSI chips 45, 45 are mounted on the circuit board 44 by soldering their respective electrodes to wiring (not shown) on the surface of the circuit board 44. The circuit board 44 is bonded and fixed to the inner surface of the metal case 41a on the side of the cooler mounting surface of the housing 41 with a double-sided adhesive sheet (not shown). On the other hand, the liquid crystal display panel 43 is a transmission type dot matrix liquid crystal display panel for displaying a television image.
A large number of display panel connection terminals (not shown) arranged and formed on the outer peripheral edge of
They are connected by 6, 46. Further, the liquid crystal display panel 43 is provided inside the housing 41 with light transmitting windows 42a on both sides thereof.
, 42b and are fixed to the inner surface of the housing 41 by a frame-shaped double-sided adhesive sheet (not shown). The display unit 40 has a liquid crystal display panel 43 in contact with a display unit mounting plate 32a of the display panel cooler 31 in contact with the display unit 40.
It is fixed to the mounting plate 32a by 7 and 47. Then, the display device 30 in which the display unit 40 is mounted on the display panel cooler 31 is used.
1 and 2 are arranged in the projector case 10 with the side facing the projection lens 20 and the cooler 31 facing the light source device 50.
A mounting plate 48 cut and raised in 41 is fixed to the inside of the case 10 by screwing it to the inner bottom surface of the projector case 10. In FIG. 2, reference numeral 49a denotes a linear circuit unit for processing a television wave received by an antenna unit and a tuner (not shown) provided in the projector case 10 and outputting an image signal; The image display control circuit unit is connected to the linear circuit unit 49a, and the display drive circuit board 44 in the display unit 40 is connected to the image display control circuit unit 49b by a connection cable (not shown). Next, the light source device 50 will be described. FIG.
11 show a light source device 50, in which 51 is a square box-shaped light source box made of a metal plate having a circular opening 51a formed on the front surface. The light source box 51 contains a light source lamp
52, and a reflector 53 for reflecting illumination light from the light source lamp 52 toward the display device 30 are provided. The reflector 53 is a parabolic mirror reflector that reflects illumination light from the light source lamp 52 as parallel light parallel to the optical axis of the reflector.
Is fixed to the inside of the light source box 51 by means of screws or the like with its opening surface facing the opening 51a on the front of the light source box. As the light source lamp 52, a high-voltage arc lamp such as a xenon lamp having a high emission luminance is used. The base of the high-voltage arc lamp 52 is inserted through the neck 53 of the reflector 53. The neck portion 53 is fixed by a ceramic adhesive 54 filled in the neck portion 53. 52a and 52b are terminal portions projecting from both ends of the high-voltage arc lamp 52. These terminal portions 52a and 52b are connected to power supply terminals provided on the outer surface of the light source box 51 by lead wires (not shown). ing. The direction of the arc generated between the electrodes of the high voltage arc lamp 52 is positioned diagonally above the light emitting portion 52a of the high voltage arc lamp 52 outside the neck portion 53 of the reflector 53. The permanent magnet 55 is provided at the tip of a magnet support member 55a made of a metal plate having a base inserted through the neck 53 of the reflector 53 and fixed by the ceramic adhesive 54. Fixed. Reference numeral 56 denotes a rectangular tube-shaped explosion-proof cylinder made of a metal plate attached to the front of the light source box 51 so as to protrude forward from the light source box 51. The front end has a transparent cover for covering the opening surface of the explosion-proof cylinder 56. Explosion-proof glass 57 is attached. The explosion-proof glass 57 is fitted to the front end of the explosion-proof
Are fixed by bending pieces 58 formed on both side surfaces of the sheet. When the high-voltage arc lamp 52 ruptures due to abnormal overheating, the explosion-proof cylinder 56 and the explosion-proof glass 57 are scattered by broken pieces (glass pieces) so that the device parts (Fresnel lenses 21 and 22) in the projector are scattered. , A display device, and a circuit section) are provided to prevent the explosion-proof glass 57 from being chemically strengthened, for example, about 5 mm thick blue glass. Further, on the lower surface of the light source box 51 and the explosion-proof cylinder 56, suction ports 59 and 60 are provided, and in the four corners on the front surface of the light source box 51, the inside of the light source box 51 and the explosion-proof cylinder 56 are provided.
Ventilation holes 6 that allow communication between the inside and outside of the reflector 53
1, 61 are provided, and exhaust holes 62, 62 are formed on the upper surface of the explosion-proof cylinder 56. The air inlets 59, 60, the air holes 61, 61 and the air outlets 62, 62 are provided for cooling the light source device 50, and are taken into the light source box 51 from the air inlet 59 on the lower surface thereof. The cooling air passes through the inside of the light source box 51 and cools the reflector 53 from the outer surface side, as shown by the arrow in FIG. The gas is discharged from the exhaust holes 62 on the upper surface of the cylinder.
Further, the cooling air taken into the explosion-proof cylinder 56 from the intake port 60 on the lower surface cools the reflector 53 and the explosion-proof glass 57 from the inner surface side, and is discharged from the exhaust holes 62, 62. The light source device 50 includes a projector case 10
A power supply unit 63 and a power supply cable are provided at the rear of the power supply unit as shown in FIGS.
Connected by 64. Note that this power cable 64
Is connected to the above-described power supply connection terminal provided on the outer surface of the light source box 51. The light source device 50 is completely replaced with the light source box 51 and the explosion-proof cylinder 56 when the high-voltage arc lamp 52 ruptures. Inside 10 is detachably fixed by means such as screwing. On the other hand, in FIGS. 1 and 2, reference numeral 70 denotes a heat insulating wall provided on the projector case 10. In the projector case 10, the display device 30 having the liquid crystal display panel 43 is disposed by the heat insulating wall 70. It is divided into a display unit room A and a light source room B in which the light source device 50 is arranged. The heat insulating wall 70 is provided near the display device 30 to partition the inside of the case 10 into the display device 30 side and the light source device 50 side, and extends from the upper end of the vertical wall portion to the vicinity of the light source device 50. The vertical wall has an opening 71 through which the illumination light from the light source device 50 passes. In the projector case 10, a lower partition wall 11a standing from the bottom of the case and an upper partition wall 11b hanging down from the upper surface of the case are provided close to the front of the display unit 40 of the display device 30. Is provided. The lower partition wall 11a has a frame shape which also serves as a support frame for the light-collecting Fresnel lens 23 disposed on the front side of the display device 30.
Is adhesively fixed to the lower partition wall 11a. Also,
The upper partition wall 11b has a lower end formed at a hanging height close to or in contact with the upper edge of the light-collecting Fresnel lens 23, and the upper partition wall 11b, the light-collecting Fresnel lens 23, and the lower partition wall 11a. Thus, a wind control wall 11 for flowing cooling air along the front surface of the display unit 40 is configured. On the lower surface of the projector case 10,
Intake portions 12a, 12b, and 12c are provided in the arrangement portion of the light source device 50, the portion between the light source device 50 and the display device 30, the arrangement portion of the display device 30, and the portion in front of the wind control wall 11, respectively. , 12d
The lower part of the wind control wall 11 (the lower partition wall 11a
(A portion below the light-collecting Fresnel lens 23) has a ventilation hole 13 for introducing air taken in from an intake hole 12d in front of the baffle wall 11 into an air passage between the baffle wall 11 and the display unit 40. Is provided. On the other hand, on the upper part of the projector case 10,
A blower fan 73 driven by a motor 72 is provided above the upper wall of the heat insulating wall 70, and exhaust holes 14, 14 are provided on the upper surface of the case in this portion. The blower fan 73 is provided with
a, 12b, 12c, and 12d are for sucking outside air into the projector case 10 as shown by an arrow in FIG. 1 to cool the inside of the projector. The cooling air taken in from the air inlet 12a is supplied to the light source chamber B The light source device 50 is cooled through the inside. The cooling air taken in from the air inlet 12b is guided to the light source room B by the wind guiding action of the heat insulating wall 70, passes between the light source device 50 and the display device 30, and the temperature in the case therebetween. Lens and luminous flux correction Fresnel lens
Cooling 22 and the cooling air taken in through the air inlet 12c
It is led to the display unit room A by the wind guiding action of the heat insulating wall 70,
The display device 30 is cooled from the outside, and the coolant in the display panel cooler 31 is exchanged by heat exchange with the heat pipe 37.
Cool 36. Further, the cooling air taken in through the air intake holes 12 d flows from the ventilation holes 13 provided below the
And the display unit 40, and cools the display unit 40 from the front side, and also cools the condenser Fresnel lens 23. The air that has cooled these parts is exhausted to the outside of the case 10 through the exhaust holes 14 and 14. In addition, the intake hole
The cooling air taken in from 12b passes through the space between the light source device 50 and the display device 30 and bypasses the top end and both sides of the heat insulating wall 70 to the outside of the case 10 through the exhaust holes 14 and 14. Exhausted. In FIGS. 1 and 2, reference numerals 15 and 16 denote air guide walls provided around the blower fan 73. The air guide wall 15 on the light source device 50 side extends along the width direction of the projector case 10. The air guide wall 16 on the display device 30 side is a semicircular wall. In the liquid crystal projector of this embodiment, the inside of the projector is air-cooled, and the light source device of the display device is used.
Since the heat insulating wall 70 is provided on the side facing 50, the light source device
The display device 30 can be prevented from being heated by the radiant heat from 50 to some extent. However, even in this case, the radiant heat from the light source device 50 leaks from the opening 71 of the heat insulating wall 70 and the periphery of the heat insulating wall 70 to the display device 30 side, and the display unit of the display device 30
The temperature of the liquid crystal display panel 43 provided in 40 is raised. Therefore, in the liquid crystal projector, the inside of the projector case 10 is divided by the heat insulating wall 70 into a display unit room A in which the display device 30 having the liquid crystal display panel 43 is arranged and a light source room B in which the light source device 50 is arranged. At the same time, by using the heat insulating wall 70 as a baffle for guiding the air flow from the cooling fan 73 to the display room A and the light source room B, the light source 50 and the display device The 30 liquid crystal display panels 43 are cooled. Therefore, according to the liquid crystal projector, the light source device 50 and the liquid crystal display panel 43 can be satisfactorily cooled by the airflow from the blower fan 73.
A good image can be projected while preventing a decrease in the contrast of the liquid crystal display panel 43 due to a rise in temperature, and the arrangement of the blower fan can be designed relatively freely. Further, in the above embodiment, the transparent cooling liquid 36 is filled in a container having a transparent portion having a larger area than the display area of the liquid crystal display panel 43 on both sides, and the cooling liquid is filled in the container.
A display unit 40 containing a liquid crystal display panel 43 and its display drive circuit board 44 is mounted on one surface of the display panel cooler 31 in which a heat pipe 37 for releasing the heat absorbed by 36 is inserted to the outside, and the display unit On the other surface side of 40, a Fresnel lens 23 for condensing light is provided in a portion facing the liquid crystal display panel 43, and a wind control wall 11 in which this portion is made transparent is provided in close proximity to the display unit 40, and this control is performed. Since the passage of the cooling air blown by the blower fan 73 is formed between the wind wall 11 and the display unit 40, the temperature rise of the liquid crystal display panel 43 can be more effectively suppressed. That is, the coolant 36 in the display panel cooler 31 convects in the cooler 31 while the heat pipes 37 and
In order to perform heat exchange with 37, the heat absorbed by the cooling liquid 36 is released to the outside by the heat pipes 37 and 37, so that the cooling effect of the display panel cooler 31 on the display unit 40 can always be kept high. In addition, this display panel cooler 31
A transparent cooling liquid 36 is filled in a container having a transparent portion having a larger area than the display area of the liquid crystal display panel 43 on both sides, and a portion of the wind control wall 11 facing the liquid crystal display panel 43 is also transparent. Therefore, light passing through the liquid crystal display panel 43 is not blocked by the display panel cooler 31 or the baffle wall 11. The cooling air flowing through the air passage between the display unit 40 and the wind control wall 11 flows at a high flow rate due to the narrow passage, so that the display unit 40 can be efficiently cooled by the cooling air. Therefore, the display panel in the display unit 40 is effectively cooled from both sides thereof. In the above embodiment, the liquid crystal display panel 43
Is housed in a housing 41 together with a display drive circuit board 44 to form a display unit 40, and the display unit 40 is mounted on a display panel cooler 31 to constitute the display device 30. Instead, the display panel cooler 31 may be attached alone. In the above embodiment, the liquid crystal display panel 43
The transparent portion of the wind control wall 11 provided in close proximity to the front surface of the wind control panel 11 and facing the liquid crystal display panel 43 is constituted by the light-collecting Fresnel lens 23. May be placed separately. In that case,
The portion of the liquid crystal display panel 43 facing the liquid crystal display panel 11 may be formed of a transparent plate such as a glass plate, or the entire wind control wall 11 may be formed of a transparent plate. According to the liquid crystal projector of the present invention, the air flow by the cooling fan is guided to the display unit room and the light source room.
Since the air body is provided at one end of the heat insulating wall and the light source is housed in a light source box having an open vent, the light source can be satisfactorily cooled despite being housed in a case to prevent heat and damage. Further, the air guide is provided to extend near the light source chamber near the fan, so that more air flows to the display unit chamber side than when there is no air guide, so that the liquid crystal display can be satisfactorily performed. Panel can be cooled. Therefore, it is possible to project a good image while preventing a decrease in the contrast of the liquid crystal display panel due to a rise in temperature, and it is possible to design the arrangement of the cooling fan relatively freely.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional front view of a liquid crystal projector according to one embodiment of the present invention. FIG. 2 is a partially cutaway plan view of the liquid crystal projector. FIG. 3 is a front view of the display device. FIG. 4 is a plan view of a display device. FIG. 5 is a vertical side view of the display device. FIG. 6 is a partially cutaway front view of the display unit. FIG. 7 is an enlarged sectional view taken along line VII-VII of FIG. 6; FIG. 8 is an enlarged sectional view taken along line VIII-VIII in FIG. 6; FIG. 9 is a vertical sectional front view of the light source device. FIG. 10 is a partially cutaway plan view of the light source device. FIG. 11 is a partially cut-away side view of the light source device. FIG. 12 is a diagram illustrating the principle of a conventional liquid crystal projector. [Description of Signs] 10 Projector case 20 Projection lens 30 Display device 31 Display panel cooler 43 Liquid crystal display panel 50 Light source device 70 Air guide (insulated wall) 73 Air blower A Display room B Light source room

Claims (1)

(57) [Claims] A light source, a liquid crystal display panel, and a projection lens,
A liquid crystal projector for projecting light from the light source into the liquid crystal display panel and projecting light transmitted through the liquid crystal display panel with the projection lens; and The light source room where the light source is located is separated by a heat insulating wall.
And a light source box having a ventilation opening is arranged in the light source chamber, and a cooling fan for cooling the inside of the case is provided in the case between the liquid crystal display panel and the light source. A wind guide for distributing an end of the heat insulating wall to the display section room side and the light source room side by the cooling fan.
And extended near the light source chamber near the fan.
Liquid crystal projector characterized by being configured as kicking.