JPH11160793A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce height dimension and to obtain cooling constitution effective to miniaturization and thinning by arranging a cooling fan on the side of a projection lens and guiding air sent from a cooling fan to a liquid crystal panel through a ventilating path. SOLUTION: The cooling fan 61 is arranged on the side of the projection lens 27, and the air sent from the fan 61 is guided to the liquid crystal panels 14, 18 and 21 through the ventilating path 65, so that the cooling constitution effective to miniaturization and thinning is obtained. Furthermore, by adopting a blower type sirocco fan as the fan 61, pressure loss caused by passage resistance is reduced to perform cooling with high efficiency. Then, the quantity and the speed of the air sent from the fan 61 to the liquid crystal panels 14, 18 and 21 are freely controlled so that the temperature rise of each liquid crystal panel may be kept minimum. Thus, the height dimension of the optical device such as a liquid crystal projector is restrained to the minimum and plane outside dimension is miniaturized to be equal to or under A4 file size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device such as a liquid crystal projector using a transmissive liquid crystal panel.
The present invention relates to a technique for cooling a liquid crystal panel.

[0002]

2. Description of the Related Art In a conventional optical device using a plurality of prisms, as shown in a side view of a projection lens of a liquid crystal projector and a liquid crystal panel portion shown in FIG. It is general that an axial flow type cooling fan 81 is arranged below 14, 18, and 21. In this case, the air from the fan is directly
The liquid crystal panels 14, 18, 21 can be easily cooled because the liquid crystal panels 14, 18, 21 (not shown) are used.

[0003]

In the conventional optical device shown in FIG. 2, the overall height of the device is determined by the projection lens 27 and the liquid crystal panels 14, 18, 21 shown in FIG.
The height L2 is added to the height of the portion. Further, at this time, a space (dead space) that is difficult to effectively use is generated below the projection lens 27, which is disadvantageous in reducing the height of the entire apparatus.

An object of the present invention is to provide an optical device which is reduced in height and is effective for downsizing the device.

[0005]

In order to achieve the above object, according to the present invention, as shown in FIG. 1, a cooling fan 61 is arranged on the side of the projection lens 27, and the air from the cooling fan 61 is blown. The liquid crystal panels 14, 18, 2 via the path 65
By adopting a configuration that leads to No. 1, a cooling configuration that is effective for downsizing and thinning is provided.

Further, in the present invention, the cooling fan 61 is a blower type sirocco fan so that pressure loss due to flow path resistance is reduced and cooling can be performed with high efficiency.

Further, in the present invention, the air flow from the cooling fan 61 can be freely controlled to the liquid crystal panels 14, 18, 21 so that the temperature rise of each liquid crystal panel is minimized. .

Further, according to the present invention, the air flow from the cooling fan 61 can be freely controlled to the liquid crystal panels 14, 18, 21 so that the temperature rise of each liquid crystal panel can be averaged. The air volume and the air velocity to the liquid crystal panel are such that the air volume and the air velocity to the G color light liquid crystal panel 18 are maximized, and the air volume and the air velocity to the R color light liquid crystal panel 14 are minimized.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a top view of the liquid crystal projector according to the first embodiment of the present invention.

Illumination light 2 from a discharge lamp 1 as a light source
Is incident on a dichroic mirror 10 via a polarization conversion element 6, a first lens array 7, a mirror 8 and a second lens array 9 via a lamp reflector 3, a lens 4 and a lens 5 of a parabolic mirror.

The dichroic mirror 10 has an R color light 11
Are transmitted, and the G and B color lights 12 are reflected. R color light 11
Is reflected by the mirror 13 and enters the R-color light liquid crystal panel 14. The G- and B-color lights 12 are incident on a dichroic mirror 15 that reflects G-color light and transmits B-color light.
Is reflected, and the B color light 17 is transmitted. The G color light 16 is incident on the liquid crystal panel 18 for G color light.

The B-color light 17 enters a B-color light liquid crystal panel 21 via a mirror 19 and a mirror 20.

The R transmitted light 22 from the liquid crystal panel 14, the G transmitted light 23 from the liquid crystal panel 18, and the B transmitted light 24 from the liquid crystal panel 21 are converted by the cross dichroic prism 2.
5, and the emitted light 26, which has been subjected to the color synthesis, is projected onto a screen (not shown) by the projection lens 27.

An exhaust fan 28 for cooling the light source is disposed near the discharge lamp 1 and the lamp reflector 3 so that the heat generated from the light source having a high temperature does not affect components other than the light source. Then, the hot air 30 is exhausted outside the housing 29 of the liquid crystal projector. In addition, a lamp power supply 31 is disposed near the discharge lamp 1.

In the present embodiment, a first dichroic mirror 10, a second dichroic mirror 15, a first mirror 13, a second mirror 19, and a third mirror 20 are used as color separation optical systems by a cross dichroic prism 25. A discharge lamp 1, a lamp reflector 3, a lens 4, a lens 5, a polarization conversion element 6, and an optical integrator, which are light sources for improving the efficiency of using illumination light from the light source and obtaining uniform illumination light while being provided in the surroundings. An illumination optical system including a first lens array 7, a mirror 8, and a second lens array 9 as means, and a lamp power supply 31 as a light source power supply
And a projection lens 27, a cross dichroic prism 25, a color separation optical system, an illumination optical system, and a lamp power supply 31 are arranged in this order.

The projection lens 27 is housed in the housing 29. The housing 29, that is, the external dimensions of the housing including the projections of the liquid crystal projector at the time of storage are substantially equal to or smaller than the A4 file size. The external dimensions of the embodiment are 307 mm in depth and 230 mm in width.

Note that the setting of the external dimensions is not limited to the present embodiment, and may be any size of approximately A4 file. As a result of investigating various A4 file sizes, the smallest size is 230 mm × 307 mm in the present embodiment, but a slightly larger size is 243 m.
mx 307mm, maximum size is 263mm x 3
18 mm. Therefore, in the present invention, the above three types of sizes are set as the A4 file size.

According to the liquid crystal projector having the configuration of the present embodiment, it is possible to obtain a liquid crystal projector having an outer dimension which can be used for a storage shelf or a carrying case which is widely used.

The smaller the size is, the more technically it is difficult to realize it. However, there is an effect that more and more widely used storage shelves and carrying cases can be used.

In this embodiment, the display screen size of the liquid crystal panel is set to 0.9 inch in order to realize the external dimensions. The projection lens 27 and the cross dichroic prism 25 can be reduced in size by using a liquid crystal panel as small as 0.9 inches as compared with the display screen size of the conventional liquid crystal panel of 1.3 inches. The optical system can also be made smaller.

In the present embodiment, in order to realize the A4 file size, the distance from the liquid crystal panel display surface to the tip of the projection lens is set to 135 mm. By setting this distance to 135 mm or less, the smallest A4 file size can be realized. For a larger A4 file size, it can be realized by setting this distance to 146 mm or less. This is because the A4 file size having a larger longitudinal dimension is 318 mm, the smaller one is 307 mm, and the difference is 11 mm.

In this embodiment, in order to realize an A4 file size, the cross dichroic prism 25 is provided as a color synthesizing optical system, and the plane size of the cross dichroic prism 25 is 32 mm × 32 mm.
If this dimension is set to 32 mm × 32 mm or less, the color separation optical system can be made more compact accordingly.

In this embodiment, a configuration example in which the depth dimension of the liquid crystal projector is larger than the width dimension has been described. However, the present invention is not limited to this, and a configuration in which the width dimension is larger than the depth dimension may be used.

In the figure, reference numeral 61 denotes the liquid crystal panels 14, 18,
A blower type sirocco fan is shown in the figure as a cooling fan for cooling the unit 21. 65 is a first air duct, 27 is a cooling heat sink, and 70 is a third air duct.

FIGS. 4 and 5 are detailed perspective views showing the cooling structure around the liquid crystal panels 14, 18, 21 and the projection lens 27 in the above embodiment. FIG. 4 is a perspective view from the direction of the illumination optical system, and FIG. 5 is a perspective view from the direction of the cooling fan 61. FIG. 6 is a detailed perspective view showing an air blowing structure of the cooling structure. Hereinafter, the cooling structure of the liquid crystal panel will be described with reference to FIGS.

The air discharged from the cooling fan 61 is guided below the liquid crystal panels 14, 18, 21 through the first air duct 65 as indicated by an arrow 111 in the figure. At this time, a first guide plate 123, a second guide plate 124, and a third guide plate 125 are arranged in the first air duct 65, and the air indicated by the arrow 111 is B
The configuration is such that the airflow 112 for the color light liquid crystal panel 14, the airflow 113 for the G color light liquid crystal panel 18, and the airflow 114 for the R color light liquid crystal panel 21 are divided and guided by each liquid crystal panel to cool each liquid crystal panel. . At this time, each guide plate 12
By appropriately arranging 3, 124, and 125, an arrangement is made such that the maximum amount or velocity of air is guided to the blast 113 for the liquid crystal panel 18 for G color light, which generally has the highest temperature rise. Liquid crystal panel 14 for B color light with high temperature rise
This is a configuration in which the temperature rise values of the respective liquid crystal panels can be substantially equalized by dividing the air into a blower 112 for the liquid crystal panel 21 and a blower 114 for the liquid crystal panel 21 for R color light whose temperature rise is not so high. That is, the cooling air passes through the air guide ports 91, 92, 93 (not shown) shown in FIG.
5, 116, 117 (not shown), the liquid crystal panels 14, 18, 21 are cooled.

Further, the cooling air passes through the second ventilation duct 101, is radiated by the cooling heat sink 27 provided on the inner and outer walls of the second ventilation duct 101, further passes through the third ventilation duct 70, and passes through the third ventilation duct 70. It is configured to pass through the four air ducts 71 and return to the cooling fan 61. At this time, the above-mentioned air ducts 65, 101, 70, 71 have a structure in which the liquid crystal panels 14, 18, 21 and the cooling fan 61 are sealed. Therefore, it is possible to prevent intrusion of dust from the outside and prevent a defect that dust adheres to the liquid crystal panel surface and dust is irradiated on the screen. In addition, the cooling structure described above does not need to be a closed structure in particular for the purpose of making the device thinner, and a countermeasure against dust can be made even if a dust-preventing glass is separately attached on the liquid crystal panel surface.

In the first embodiment, the air flow from the cooling fan 61 is divided by the guide plates 123, 124, and 125. However, the same applies to a structure in which the air is divided by three pipes or the like. The effect is obtained.

FIG. 7 is a top view of a liquid crystal projector according to a second embodiment of the present invention.

Illumination light 2 from a discharge lamp 1 as a light source
Is incident on a dichroic mirror 40 via a polarization conversion element 6, a first lens array 7, a mirror 8, and a second lens array 9 via a lamp reflector 3, a lens 4, and a lens 5 of a parabolic mirror.

The dichroic mirror 40 has an R color light 41
Is reflected, and the G and B color lights 42 are transmitted. R color light 41
Is reflected by the mirror 13 and enters the R-color light liquid crystal panel 14. The G- and B-color lights 42 are incident on the dichroic mirror 15 that reflects the G-color light and transmits the B-color light.
Is reflected, and the B color light 17 is transmitted. The G color light 16 is incident on the liquid crystal panel 18 for G color light.

The B-color light 17 enters the B-color light liquid crystal panel 21 via the mirrors 19 and 20.

The R transmitted light 22 from the liquid crystal panel 14, the G transmitted light 23 from the liquid crystal panel 18, and the B transmitted light 24 from the liquid crystal panel 21 are converted by the cross dichroic prism 2.
5, and the emitted light 26, which has been subjected to the color synthesis, is projected onto a screen (not shown) by the projection lens 27.

An exhaust fan 43 for cooling the light source is arranged near the discharge lamp 1 and the lamp reflector 3 so that the heat generated from the light source having a high temperature does not affect components other than the light source. Then, the hot air 45 is exhausted outside the housing 44 of the liquid crystal projector.

A lamp power supply 31 is disposed near the discharge lamp 1.

A first dichroic mirror 40, a second dichroic mirror 15, a first mirror 13, a second mirror 19, and a third mirror 20 are provided around the cross dichroic prism 25 as a color separation optical system. A discharge lamp 1, a lamp reflector 3, a lens 4, a lens 5, a lens 5, a polarization conversion element 6, and a light source for improving the utilization efficiency of illumination light from the light source and obtaining uniform illumination light.
An illumination optical system including a first lens array 7, a mirror 8, and a second lens array 9 as optical integrators, and a lamp power source 31 as a power source for a light source, a projection lens 27, a cross dichroic prism 25, The arrangement of the separation optical system, the illumination optical system, and the lamp power supply 31 are arranged in this order.

In the embodiment shown in FIG. 7, the cooling fan 61 is disposed on the side of the projection lens 27 as in the first embodiment.
This is the same as that shown in FIGS. At this time, since the cooling fan 61 is arranged near the lamp reflector 3 and is easily affected by heat, it is necessary to arrange the heat insulating plate 60 and the like. The same effect can be obtained.

As the configuration in which the projection lens 27 is housed in the housing 51, the housing 51, that is, the external dimensions of the housing 51 including the projections of the liquid crystal projector are substantially equal to or smaller than the A4 file size. The external dimensions of the embodiment are 230 mm in depth and 307 mm in width.

According to the present embodiment, as in the first embodiment, it is possible to obtain a liquid crystal projector having an outer dimension that can be used for a storage shelf or a carrying case that is widely used.

In this embodiment, the projection lens 27 is housed at the back of the housing 51, so that the distance from the liquid crystal panel display surface to the tip of the projection lens can be sufficiently increased. effective. In general, by increasing the distance, the degree of freedom in designing the projection lens is increased, and there is an effect that a projection lens with higher performance can be obtained.

In a configuration in which the width dimension is larger than the depth dimension, various layout changes are possible.

FIG. 8 is a top view of a liquid crystal projector according to a third embodiment of the present invention. The difference from the second embodiment is that the layout of the components such as the exhaust fan
1 in that the projection lens 27 is moved forward. In order to prevent the heat generated from the light source having a high temperature from affecting components other than the light source, an exhaust fan 50 for cooling the light source is arranged in the vicinity of the discharge lamp 1 and the lamp reflector 3 so as to be shifted laterally. The hot air 52 is exhausted outside the housing 51 of the liquid crystal projector.

In the case of the present embodiment, the cooling fan 61 is disposed on the side of the projection lens 27 opposite to the lamp reflector 3 so that the liquid crystal panel 14 is not affected by the heat from the lamp reflector 3. , 18,2
1 can be efficiently cooled. Also, at this time, the cooling structure of the liquid crystal panel has a configuration in which the left and right sides are reversed from the first and second embodiments, but the basic structure is the same. Further, the effect is the same even when a blower type fan is used as the exhaust fan 50 as shown by 50 'in the figure.

Further, according to the present embodiment, an empty space can be made behind the housing 51, the degree of freedom in the layout design of circuit components and the like is increased, and a higher performance and higher function circuit can be obtained. it can.

[0046]

As described above, according to the present invention,
The height of the optical device such as a liquid crystal projector can be minimized, and the outer diameter of the plane can be reduced to A4 file size or less. In particular, a fan can be arranged in a space-saving manner, and a plurality of liquid crystal panels can be cooled to a substantially uniform temperature with very high efficiency.

[Brief description of the drawings]

FIG. 1 is a side view around a liquid crystal panel of a liquid crystal projector according to a first embodiment of the present invention.

FIG. 2 is a side view around a liquid crystal panel of a conventional liquid crystal projector.

FIG. 3 is a top view of the liquid crystal projector according to the first embodiment of the present invention.

FIG. 4 is a perspective view of a cooling structure of the liquid crystal projector according to the first embodiment of the present invention.

FIG. 5 is a perspective view of a cooling structure of the liquid crystal projector according to the first embodiment of the present invention.

FIG. 6 is a lower detailed perspective view of a cooling structure of the liquid crystal projector according to the first embodiment of the present invention.

FIG. 7 is a top view of a liquid crystal projector according to a second embodiment of the present invention.

FIG. 8 is a top view of a liquid crystal projector according to a third embodiment of the present invention.

[Explanation of symbols]

1 ... discharge lamp, 2 ... illumination light, 3 ... lamp reflector,
4 lens, 5 lens, 6 polarization conversion element, 7 first
Lens array, 8 mirror, 9 second lens array, 1
0 ... dichroic mirror, 11 ... R color light, 12 ... G and B color light, 13 ... mirror, 14 ... liquid crystal panel, 15 ...
Dichroic mirror, 16 ... G color light, 17 ... B color light,
18 liquid crystal panel, 19 mirror, 20 mirror 21
... Liquid crystal panel, 22 ... R transmitted light, 23 ... G transmitted light, 24
... B transmitted light, 25 ... Cross dichroic prism, 2
6 ... Outgoing light, 27 ... Projection lens, 28 ... Exhaust fan, 2
9 ... housing, 30 ... hot air, 31 ... lamp power supply, 40 ... dichroic mirror, 41 ... R color light, 42 ... G and B color light, 43 ... exhaust fan, 44 ... housing, 45 ... hot air, 50
... exhaust fan, 51 ... housing, 52 ... hot air, 61 ... cooling fan, 65 ... first air duct, 101 ... second air duct, 70 ... third air duct, 71 ... fourth air duct, 123 ... first guide plate, 124 ... second guide plate, 1
25. Third guide plate.

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[Procedure amendment]

[Submission date] January 22, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04N 9/31 H04N 9/31 C (72) Inventor Nobuyuki Kaku 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Hitachi, Ltd. Multimedia Co., Ltd. Within the System Development Headquarters (72) Inventor Naohiro Ozawa 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Within the Multimedia System Development Headquarters Hitachi, Ltd. (72) Inventor Masahiko Yatsu 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Hitachi, Ltd. Multimedia System Development Division (72) Inventor Satoshi Ouchi 292, Yoshida-cho, Totsuka-ku, Yokohama, Kanagawa Prefecture Hitachi, Ltd. Multimedia System Development Division (72) Inventor Yasuo Otsuka Yokohama, Kanagawa 292 Yoshida-cho, Totsuka-ku, Ichiba Hitachi Multimedia Co., Ltd. Inside the System Development Headquarters (72) Inventor Takesuke Maruyama 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Hitachi Multimedia Systems Development Headquarters (72) Inventor Norihiro Onuma 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Hidetomo Yoshimura 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Pref. Hitachi Image Information Systems, Ltd.

Claims (19)

[Claims] 1. A liquid crystal display comprising: a first cooling circulation system having a closed ventilation passage including a liquid crystal panel; and a second cooling circulation system in an outer shell of the device for cooling the ventilation passage from outside. An optical device, wherein a panel is directly cooled by the first cooling circulation system and indirectly cooled by the second cooling circulation system. 2. The optical device according to claim 1, wherein said first cooling circulation system is provided with a dedicated cooling fan. 3. An optical apparatus for irradiating light to a plurality of liquid crystal panels and projecting the light from the liquid crystal panels onto a screen via a plurality of prisms and a projection lens, wherein a plurality of cooling devices for cooling the liquid crystal panels are provided. An optical device comprising a fan, wherein at least one of the cooling fans is arranged on a side of the projection lens. 4. An optical device for irradiating light to a plurality of liquid crystal panels and projecting the light from the liquid crystal panels onto a screen via a plurality of prisms and a projection lens, wherein a plurality of cooling devices for cooling the liquid crystal panels are provided. An optical device comprising a cooling fan, wherein at least one of the cooling fans is a sirocco fan. 5. The optical device according to claim 3, wherein at least one of the plurality of cooling fans is a dedicated cooling fan for cooling the liquid crystal panel. 6. A cooling air path to the liquid crystal panel,
The optical device according to claim 3, wherein the cooling air passage is configured to be divided into a plurality. 7. The optical device according to claim 6, wherein the plurality of divided cooling air passages are configured to increase a wind speed or an air flow to the liquid crystal panel for G color light (18). 8. The optical device according to claim 1, wherein the planar outer dimension is substantially equal to or less than the A4 file dimension. 9. The size of the A4 file is 263 mm × 31.
9. The optical device according to claim 8, which is 8 mm. 10. A first liquid crystal panel, a second liquid crystal panel, and a third liquid crystal panel, which are separated from light from a light source and color-separated.
A liquid crystal projector that combines colors of light emitted from a first liquid crystal panel, a second liquid crystal panel, and a third liquid crystal panel and projects on a screen with a projection lens, at least a plane including a projection of the liquid crystal projector when housed. Size is approximately A4
Claims 1 and 2, wherein the outer dimensions are smaller than the file size.
The optical device according to 3, 4, 5, 6 or 7. 11. The A4 file size is 263 mm ×
The optical device according to claim 10, wherein the length is 318 mm. 12. The A4 file size is 243 mm ×
The optical device according to claim 8, wherein the optical device is 307 mm. 13. The A4 file size is 230 mm ×
The optical device according to claim 8, wherein the optical device is 307 mm. 14. The optical device according to claim 8, wherein the display screen size of the liquid crystal panel is 0.9 inches or less. 15. The optical device according to claim 8, wherein the distance from the liquid crystal panel display surface to the tip of the projection lens is 146 mm or less. 16. The optical device according to claim 8, wherein the distance from the display surface of the liquid crystal panel to the tip of the projection lens is 135 mm or less. 17. The optical device according to claim 8, wherein a cross dichroic prism is provided as a color synthesizing optical system, and the cross dichroic prism has a planar dimension of 32 mm × 32 mm or less. 18. A color separation optical system comprising a first dichroic mirror, a second dichroic mirror, a first mirror, a second mirror, and a third mirror around a cross dichroic prism, and illumination from a light source. Includes an illumination optical system including a light source, a polarization conversion element, and an optical integrator means for improving light use efficiency and obtaining uniform illumination light, and a light source power supply, and a projection lens, a cross dichroic prism, and a color. The optical device according to claim 8, wherein the separation optical system, the illumination optical system, and the power supply for the light source are arranged in this order. 19. A color separation optical system comprising a first dichroic mirror, a second dichroic mirror, a first mirror, a second mirror, and a third mirror around a cross dichroic prism, and illumination from a light source. Includes an illumination optical system including a light source, a polarization conversion element, and an optical integrator means for improving light use efficiency and obtaining uniform illumination light, and a light source power supply, and a projection lens, a cross dichroic prism, and a color. The optical device according to claim 8, wherein an arrangement of separation optical systems, an illumination optical system, and a power source for a light source are arranged in this order.