JP2003021865A - Liquid crystal projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dust or the like from infiltrating into a liquid crystal projector when the projector is not used without using a dust-proof cover. SOLUTION: This liquid crystal projector (1) has a 1st housing (2) having an illumination optical system and vents (12a and 12b) for cooling the illumination optical system, and a 2nd housing (4) whose one side is turnably coupled with one side of the 1st housing. When the liquid crystal projector is housed, the surface of the 1st housing provided with the vents is covered with one surface of the 2nd housing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector, and more particularly, to a liquid crystal projector having a first housing having a vent and a second housing, and the second housing is provided on the first housing during storage. The present invention relates to a liquid crystal projector configured to cover the formed ventilation hole.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 9-133967 discloses a liquid crystal projector having a fan for cooling a lamp house and a vent for the fan on the front surface of a single housing. Further, Japanese Patent Laid-Open No. 11-354963 describes a liquid crystal projector in which a sirocco fan for cooling an LCD or the like is provided in a lower part of a single housing, and an exhaust port for the sirocco fan is provided on a front surface of the housing. Has been done.
Further, Japanese Patent Laid-Open No. 2000-124651 discloses a liquid crystal projector in which an axial fan is attached to a side portion of a single housing, and a ventilation hole for the axial fan is provided on a side surface of the housing. There is.

[0003]

Since the cooling of the illumination optical system of the liquid crystal projector is indispensable for the normal operation of the liquid crystal projector, it is necessary to provide a cooling vent hole from the inside of the liquid crystal projector housing to the outside air. become. However, if a ventilation hole for cooling is provided on the front surface of the housing as in the liquid crystal projector described in Japanese Patent Laid-Open No. 9-133967, dust or the like may enter the housing from the outside even when the liquid crystal projector is not used. There is a problem of invading.
In particular, if the product is left without the dustproof cover for a long time when not in use, dust will accumulate on the louver part of the ventilation port, and if you use it again without cleaning it, the efficiency of air supply and exhaust will deteriorate and the temperature inside the equipment will rise. This may shorten the life of the liquid crystal projector, and may cause smoke or fire.

Further, when the ventilation hole is provided on the bottom surface of the liquid crystal projector as in the liquid crystal projector disclosed in Japanese Patent Laid-Open No. 11-354963, the invasion of dust can be prevented to some extent. However, in general, a louver such as a wire mesh or a lattice is attached to the vent to prevent foreign matter from entering from the outside, and this louver is unavoidably weakened in structure. Therefore, when the liquid crystal projector is accidentally dropped during transportation, the louver portion provided on the bottom surface is likely to be damaged, and the housing body may be damaged from the louver portion that is structurally weak. Furthermore, a ventilation port is provided in the side portion of JP-A-2000-12.
The liquid crystal projector described in Japanese Patent No. 4651 also has the same problem as the above-described conventional liquid crystal projector. In addition to this problem, when a ventilation port is provided on the side surface of the liquid crystal projector casing and a ventilation fan for supplying and exhausting air is provided at the ventilation port, the wind and noise of the ventilation fan may affect the liquid crystal projector. There is a problem that the projected image may reach the viewer who is viewing the projected image on the side.

Therefore, an object of the present invention is to prevent dust and the like from entering the inside of the liquid crystal projector when not in use, without using a separate dustproof cover. Also,
An object of the present invention is to provide a liquid crystal projector in which the louver portion of the vent hole and the housing are less likely to be damaged even when dropped when not in use. Further, the present invention provides
Even when a ventilation fan for supplying and exhausting air is provided in the ventilation port, it is an object to prevent the wind and noise of the ventilation fan from interfering with the viewer who is viewing the projected image of the liquid crystal projector.

[0006]

In order to solve the above-mentioned problems, a liquid crystal projector according to the present invention includes a first housing having an illumination optical system and a vent for cooling the same, and one side. , And a second housing rotatably connected to one side of the first housing, and when the liquid crystal projector is housed, the surface of the first housing provided with the vent is the first. It is characterized by being covered by one surface of two housings.

With this structure, when the liquid crystal projector is not used, the surface of the first housing on which the ventilation hole is provided and one surface of the second housing face each other, and the ventilation hole is on the second housing. Covered by one side of the body. In addition, when the liquid crystal projector is used, the second housing is rotated and the ventilation hole of the first housing is exposed to the outside air.

With this structure, when the liquid crystal projector is stored, it is possible to prevent dust from entering through the ventilation hole and protect the structurally weak ventilation hole portion, and the ventilation hole must be exposed to the outside air during use. It is possible to secure proper ventilation. Further, the liquid crystal projector of the present invention further has a blower fan for supplying or exhausting air from the vent, and the vent is provided on the same surface as the projection lens attached to the first housing. good. With this configuration, it is possible to improve the cooling efficiency of the ventilation port and prevent the air flow of the blower fan and the noise of the fan from directly reaching the viewer of the image projected by the liquid crystal projector.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing the liquid crystal projector 1 according to the embodiment of the present invention when it is stored, and FIG. 2 is a perspective view showing the liquid crystal projector 1 when it is used.

A liquid crystal projector 1 according to an embodiment of the present invention includes a first housing 2 containing an illumination optical system (not shown), a projection lens 10, a power source (not shown), and an electronic device such as an image processing circuit. It is configured by a second housing 4 having a built-in circuit (not shown), and the first and second housings are rotatably connected by a hinge component 6. This hinge part 6
Includes the liquid crystal projector 1 and the front surface 2b of the first housing and the second
From the storage state shown in FIG. 1 in which the front surface 4b of the housing faces each other, the upper surface 2a of the first housing and the upper surface 4a of the second housing face each other and the first housing is supported on the second housing. It is configured so that it can be transformed into the usage state shown in FIG. A plurality of operation switches 8 are provided on the outer side surface of the first housing. Further, the projection lens 10 and the vent holes 12a and 12b for cooling the illumination optical system and the like are provided on the front surface 2 of the first housing.
It is provided in b. As shown in FIG. 2, the surface provided with the vent hole 12 is exposed to the outside air only during use. Also,
The ventilation ports 12a and 12b are provided with lattice-shaped louvers so as to prevent foreign matter from entering from the outside and ensure ventilation.

FIG. 3 is a sectional view showing the inside of the first and second casings. As shown in the figure, the first housing 2 contains an illumination optical system 14, a power supply 16 for the illumination optical system, and a projection lens 10. The second housing 4 also contains an electronic circuit board 56 on which an image processing circuit and the like are mounted, and a DC power supply 58 for operating the circuits of the electronic circuit board 56. The illumination optical system 14 includes a light source 18, a light pipe 20, a first condenser lens 22, and a second condenser lens 23.
A first dichroic mirror 24, a second dichroic mirror 26, and a mirror 28, which constitute a color separation optical system.
30 and 32, and transmission type liquid crystal plates 34 and 3 which are modulation optical systems.
6 and 38, and a dichroic prism 40 that is a combining optical system. Each of these optical elements includes the first to sixth optical elements.
It is arranged in each of the light tunnels 42, 44, 46, 48, 50 and 52. Preferably, these light tunnels have a sectional shape corresponding to the shape of the light to be emitted from the projection lens 10. That is, in the case of emitting light having a cross-sectional shape with an aspect ratio of 4: 3, it is preferable that the cross-sectional shape of the light tunnel be a substantially rectangular shape and the aspect ratio of the rectangle be 4: 3.

The first light tunnel 42 is constructed so as to communicate with the light pipe 20, receives the light beam emitted from the light source 18 and passing through the light pipe 20. At the entrance of the first light tunnel 42, the condenser lens 22
Is installed. The second light tunnel 44 communicates with the first light tunnel 42, and extends at a right angle to the first light tunnel 42 from the side of the tip of the first light tunnel 42 beyond the condenser lens 22. The first dichroic mirror 24 has a first light tunnel 42 at a branch point between the first light tunnel 42 and the second light tunnel 42.
It is mounted at an angle of 45 ° with respect to. The dichroic mirror 24 is configured to reflect red light, direct it to the second light tunnel 44, and transmit light of other colors.

The third light tunnel 46 communicates with the first light tunnel 42, and is perpendicular to the first light tunnel 42 from the side closer to the tip than the second light tunnel 44.
It extends parallel to the second light tunnel 44. The second dichroic mirror 26 is attached at a branch point between the first light tunnel 42 and the third light tunnel 46 at an angle of 45 ° with respect to the first light tunnel 42. The second dichroic mirror 26 is configured to reflect green light, direct the green light to the third light tunnel 46, and transmit light of another color (blue light).

The fourth light tunnel 48 communicates with the first light tunnel 42 and extends from the tip of the first light tunnel 42 at right angles to the first light tunnel 42 and parallel to the third light tunnel 46. . Mirror 28
It is attached to the tip of the first light tunnel 42 at an angle of 45 ° with respect to the first light tunnel 42.
The mirror 28 is configured to direct incident light to the fourth light tunnel 48.

The fifth light tunnel 50 communicates with the second light tunnel 44 and extends parallel to the first light tunnel 42 from the tip of the second light tunnel 44 toward the tip of the third light tunnel 46. The mirror 30 is attached to the tip of the second light tunnel 44 and the second light tunnel 4
It is attached at an angle of 45 ° with respect to 4, and guides the red light reflected by the dichroic mirror 24 toward the fifth light tunnel 50.

Similarly, the sixth light tunnel 52 has a fourth
Communicating with the light tunnel 48, the fourth light tunnel 48
From the tip of the first light tunnel 42 toward the tip of the third light tunnel 46. Mirror 3
2 is attached to the tip of the fourth light tunnel 48 at an angle of 45 ° with respect to the fourth light tunnel 48,
The blue light reflected by the mirror 28 is guided toward the sixth light tunnel 52.

The liquid crystal plate 34 for modulating the red light is the fifth
A liquid crystal plate 36 for modulating green light is provided at the tip of the light tunnel 50, and a liquid crystal plate 38 for modulating blue light is provided at the tip of the third light tunnel 46 and a sixth light tunnel 52.
It is attached to the tip of each. A substantially cubic dichroic prism 40 is attached at the confluence of the third, fifth, and sixth light tunnels, and the dichroic prism 40 has a reflecting surface provided in the direction of the diagonal line thereof for reflecting only red light. 40r and a reflecting surface 4 provided in a direction orthogonal to the reflecting surface 40r and reflecting only blue light.
0b are provided. As a result, the dichroic prism 40 enters the fifth light tunnel 50 and receives the red light that is modulated by the liquid crystal plate 34, the third light tunnel 46 that receives the green light that is modulated by the liquid crystal plate 36, and the sixth light. It is configured to combine the incident blue light that is incident from the light tunnel 52 and is modulated by the liquid crystal plate 38, respectively. The light combined by the dichroic prism 40 is configured to be projected from the projection lens 10.

FIG. 4 is an enlarged sectional view showing the attachment of the first dichroic mirror 24 to the first light tunnel 42. In this embodiment, each light pipe is provided with a groove 54 which is a component holding portion formed with a predetermined dimensional accuracy. As shown in FIG. 4, each dichroic mirror or mirror is fitted into the groove 54 to be fixed to each light pipe.

FIG. 5 shows each of the light tunnels 46, 50, 5
2 is a cut perspective view showing how the liquid crystal plates 34, 36, 38 and the dichroic prism 40 are attached. As shown in FIG. 5, a holding component 60 receives and holds the dichroic prism 40 therein. The liquid crystal plate 34 is the fifth
It is sandwiched between the light tunnel 50 and the holding component 60. Similarly, the liquid crystal plate 36 is sandwiched between the third light tunnel 46 and the holding component 60, and the liquid crystal plate 38 is sandwiched between the sixth light tunnel 52 and the holding component 60.

FIG. 6 is a perspective view showing the holding component 60. The holding component 60 has a substantially hexahedral frame structure, and has a prism receiving hole 62 for receiving the dichroic prism 40 inside and three liquid crystal plate holding recesses 64 for holding the liquid crystal plates respectively. There is. The prism receiving hole 62 is formed with a predetermined dimensional accuracy so that the dichroic prism 40 can be received and held without backlash. The liquid crystal plate holding recesses 64 are formed on three of the four side surfaces of the holding component 60, respectively. Each liquid crystal plate holding recess 64 has a liquid crystal plate contact surface 66,
And an outer peripheral surface 68. The liquid crystal plate received in the liquid crystal plate holding recess 64 is held in a state where the outer edge of the plate surface is in contact with the liquid crystal plate contact surface 66 and the side surface is in contact with the outer peripheral surface 68. The liquid crystal plate contact surface 66 is formed by the dichroic prism 40.
The liquid crystal plate is formed with a required dimensional accuracy so that the liquid crystal plate can be held in parallel with the incident surface at a predetermined distance.

The dichroic prism 40 holds the holding component 6
0, and each liquid crystal plate is pressed against the liquid crystal plate contact surface 66 in the liquid crystal holding concave portion 64 by each light tunnel, so that each liquid crystal plate is moved to the dichroic prism 40 by a predetermined distance. Positioned with precision.

FIG. 7 is a side sectional view of the first housing 2. As shown in FIG. 7, the light source 18 includes a lamp 70, a lamp reflector 72 that reflects the light of the lamp and directs the light to the first light tunnel, and an explosion-proof cover that covers the opening of the lamp reflector 72. And glass 74.

Axial fan 7 for cooling the illumination optical system
6 is provided on the back surface of the lamp reflector 72. The air introduced into the housing 2 by the axial fan 76 is
A duct 82 for directing to the light tunnel 42 is provided on the front surface of the lamp reflector 72. Further, an annular fin 84 is provided on the inner surface of the duct 82 so as to direct a part of the air flowing into the duct 82 from the rear surface to the front surface of the lamp reflector 72 toward the explosion-proof glass 74. Further, a fan 78 for discharging the air sucked into the housing 2 by the axial fan 76.
Is provided below the dichroic prism 40.
In order to dissipate heat from each light tunnel to the housing 2, heat conductive sheets 80 of various thickness are attached to the light tunnel. The heat conductive sheet 80 is made of a material having a high heat conductivity, and is provided so as to be in direct contact with both the light tunnel and the first housing 2.

Next, the operation of the liquid crystal projector 1 according to the embodiment of the present invention will be described. When the liquid crystal projector 1 is used, the first housing 2 is rotated to transform the liquid crystal projector 1 from the housed state shown in FIG. 1 to the used state shown in FIG. In the use state, since the second housing 4 is supported on the first housing 2, the second housing 4 functions as a leg of the liquid crystal projector 1. Further, in the housed state, the projection lens 10 is covered by the second housing 4, so the second housing 4 functions as a lens cap for protecting the projection lens 10. Similarly, the second housing 4 also functions as a protective cover that protects the vent hole 12 in the stored state and prevents intrusion of dust and the like from the vent hole 12, and in the used state, the vent hole 12 is outside air. Exposed to.

After the liquid crystal projector 1 is transformed into a use state, the operation switch 8 is operated to operate the liquid crystal projector 1.
Then, the projection lens 10 is projected from the first housing 2 as shown in FIG. Then, the lamp 70 of the light source 18 is turned on by the operation switch 8.

The light emitted from the lamp 70 enters the light pipe 20 directly or after being reflected by the lamp reflector 72. The light passing through the light pipe 20 passes through the first condenser lens 22 mounted in the first light tunnel 42, and then the first dichroic mirror 24.
Incident on. The wavelength component of the red light of the light that has entered the first dichroic mirror 24 is reflected by the first dichroic mirror 24 and is directed into the second light tunnel 44. The red light that has passed through the second light tunnel 44 is reflected by the mirror 30 attached to the tip of the second light tunnel 44. The light reflected by the mirror 30 enters the fifth light tunnel 50 extending from the tip of the second light tunnel 44 at a right angle to the second light tunnel 44, and the liquid crystal plate 34 attached to the tip of the fifth light tunnel 50. Incident on.

On the other hand, the wavelength components other than the red light in the light incident on the first dichroic mirror 24 are transmitted through the first dichroic mirror 24 and are incident on the second dichroic mirror 26. The wavelength component of the green light in the light incident on the second dichroic mirror 26 is reflected by the second dichroic mirror 26, is directed into the third light tunnel 46, and is attached to the tip of the third light tunnel 46. It is incident on the liquid crystal plate 36.

Of the light incident on the second dichroic mirror 26, blue light having a wavelength component other than green light passes through the second dichroic mirror 26 and enters the mirror 28. This blue light is reflected by the mirror 28 and directed into the fourth light tunnel 48,
The light passes through the second condenser lens 23 mounted in the fourth light tunnel 48. The blue light transmitted through the second condenser lens 23 is reflected by the mirror 32 attached to the tip of the fourth light tunnel 48. Mirror 32
The light reflected by the light enters the sixth light tunnel 52 extending from the tip of the fourth light tunnel 48 at a right angle to the fourth light tunnel 48, and the sixth light tunnel 52.
Enters the liquid crystal plate 38 attached to the tip of the.

The red light incident on the liquid crystal plate 34 is reflected by the liquid crystal plate 3.
It is modulated by 4 and enters the dichroic prism 40. The reflecting surface 40r provided in the dichroic prism 40 reflects red light and reflects it on the projection lens 10
Send to. Similarly, the green light that has entered the liquid crystal plate 36 is modulated by the liquid crystal plate 36 and enters the dichroic prism 40. The green light passes through the reflecting surfaces 40r and 40b provided in the dichroic prism 40 and enters the projection lens 10. The blue light that has entered the liquid crystal plate 38 is modulated by the liquid crystal plate 38 and enters the dichroic prism 40. The reflecting surface 40 b provided in the dichroic prism 40 reflects blue light and directs it to the projection lens 10. This allows
The lights modulated by the liquid crystal plates 34, 36, 38 are combined by the dichroic prism 40, enter the projection lens 10, and form an image on a screen (not shown).

Next, the cooling action on the illumination optical system will be described. The axial fan 76 sucks air from the outside of the first housing 2 through the ventilation port 12a and causes the air to flow from the rear side to the front side of the lamp reflector 72. Since the axial fan 76 is mounted directly behind the lamp reflector 72, a uniform air flow is generated around the lamp reflector 72 by the axial fan 76. The air flowing along the back surface of the lamp reflector 72 enters a duct 82 provided in front of the lamp reflector 72. A part of the air that has entered the duct 82 is deflected by the fins 84 provided in the duct 82 to form a vortex. The air flow caused by the vortex cools the peripheral portion of the lamp reflector 72.

On the other hand, a part of the air flowing into the duct 82 flows between the inner wall and the outer wall of the first light tunnel 42. The air flowing between the inner wall and the outer wall of the first light tunnel 42 flows between the inner wall and the outer wall of the second to sixth light tunnels, which are in communication with each other, and the air flows into the third, fifth and sixth walls.
Eject from the tip of the light tunnel. The air jetted from the tip of each light tunnel cools the liquid crystal plates 34, 36, 38 attached to the tip of each light tunnel. The air that has cooled each liquid crystal plate is supplied to the dichroic prism 40.
Is discharged to the outside of the first housing through the ventilation port 12b by the fan 78 provided below the.

The heat of each light tunnel is transmitted to the heat conducting sheet 80 attached to the light tunnel, and further to the first casing 2 which is in contact with the heat conducting sheet 80, and is then transmitted to the first casing 2. Emitted from the outside.

According to this embodiment, the liquid crystal projector 1
In the housed state, since the ventilation holes 12a and 12b are covered by the second housing 4, it is possible to prevent intrusion of dust and the like. Further, in the stored state, the ventilation holes 12a, 12
Since b is hidden between the first housing 2 and the second housing 4, even if the liquid crystal projector 1 is accidentally dropped, the louver and the like of the vent hole 12 are not damaged. . Further, according to the present embodiment, since the ventilation hole 12 is provided on the front surface of the liquid crystal projector in which the viewer who views the projected image of the liquid crystal projector does not sit, the ventilation hole 12 is provided.
The wind from the air and the noise of the blower fan leaking from the ventilation port 12 do not reach the viewer directly and do not interfere with the viewing.

Although the preferred embodiments of the present invention have been described above, various modifications may be made to the disclosed embodiments within the scope of the technical matters described in the claims without departing from the scope or spirit of the present invention. Can be changed. In particular, the number of housings may be two or more, and
The first housing and the second housing may be connected by a component other than the hinge component.

[0035]

According to the present invention, it is possible to prevent dust and the like from entering the inside of the liquid crystal projector when not in use, without using a separate dustproof cover. Further, according to the present invention, it is possible to obtain a liquid crystal projector in which the louver portion of the vent hole and the housing are not easily damaged even when dropped when not in use. Further, according to the present invention, even when a ventilation fan for supplying and exhausting air is provided in the ventilation port, the wind and noise of the ventilation fan,
It does not hinder the viewer who is viewing the projected image of the liquid crystal projector.

[Brief description of drawings]

FIG. 1 is a perspective view of a liquid crystal projector according to an embodiment of the present invention in a stored state.

FIG. 2 is a perspective view of a liquid crystal projector according to an embodiment of the present invention in a use state.

FIG. 3 is a cross-sectional top view of a liquid crystal projector according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view showing how a dichroic mirror is attached to a light tunnel.

FIG. 5 is a cut perspective view showing a mounting state of each liquid crystal plate to a dichroic prism.

FIG. 6 is a perspective view of a holding component for holding each liquid crystal plate.

FIG. 7 is a side sectional view showing a structure of a light source and a duct.

[Explanation of symbols]

1 LCD projector 2 First case 4 second housing 6 Hinge parts 8 operation switch 10 Projection lens 12 vents 14 Illumination optical system 16 Illumination optical system power supply 18 light source 20 light pipes 22 First Condenser Lens 23 Second condenser lens 24 First Dichroic Mirror 26 Second Dichroic Mirror 28 mirror 30 mirror 32 mirror 34 LCD plate 36 LCD plate 38 LCD plate 40 dichroic prism 42 First Light Tunnel 44 Second Light Tunnel 46 Third Light Tunnel 48 Fourth Light Tunnel 50th Light Tunnel 52 6th Light Tunnel 54 groove 56 electronic circuit board 58 DC power supply 60 holding parts 62 Prism receiving hole 64 LCD plate holding recess 66 Liquid crystal plate contact surface 68 outer peripheral surface 70 lamp 72 lamp reflector 74 Explosion-proof glass 76 axial fan 78 fans 80 Thermal conductive sheet 82 duct 84 fins

Claims (2)

[Claims] 1. A liquid crystal projector, comprising: a first casing having an illumination optical system and a vent for cooling the illumination optical system; and one side with respect to one side of the first casing. A second housing that is rotatably connected, and when the liquid crystal projector is housed, the surface of the first housing provided with the ventilation hole is covered by one surface of the second housing. A liquid crystal projector characterized by the above. 2. A blower fan for supplying or exhausting air from the vent, the vent being provided on the same surface as the projection lens attached to the first housing. The liquid crystal projector according to claim 1, wherein: