JP2001343708A - Cooling mechanism for back projection type display apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling mechanism for a back projection type display apparatus, constituted to surely cool a projection block, regardless of the installed state of a device body by cooling the projection block through a flow passage (duct) and to prevent the deterioration of image quality, by preventing the adhesion of dust to the rear surface of a screen and the front surface of a projection lens. SOLUTION: The back projection type display apparatus is constituted with a separate chamber, including the projection block section separately from a space including the front surface of the projection lens, in correspondent to the transmission-type screen within a cabinet of the device body. An aperture for air intake and/or exhaust is disposed on the front surface side of the apparatus body alongside the transmission type screen, in order to cool the parts constituting the projection block section and the duct shape section communicating between this aperture and the separate chamber is disposed within the cabinet, by which the flow passage for the air for cooling is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling mechanism inside a cabinet of a main body of a rear projection display device.

[0002]

2. Description of the Related Art Conventionally, in a rear projection type display apparatus comprising a projection block having an image source and a projection lens, and a transmission type screen for forming an image enlarged and projected by the projection lens, the image is obtained. In order to prevent parts and the like constituting the generation source from becoming high in temperature, the cooling means has been devised.

[0003] For example, an opening for air intake and exhaust is provided at the back of the display or the like, and outside air is introduced into the cabinet of the apparatus main body using natural suction or a fan to cool the projection block. Cooling devices are known. FIG. 10 is a plan view showing an outline of a cooling mechanism of the conventional rear projection type display device.
FIG. 11 is a side view of FIG. 10.

In FIGS. 10 and 11, reference numeral 70 denotes a cabinet of the apparatus main body, 71 denotes an opening for cooling installed in the cabinet 70, 72 denotes a fan, 73 denotes a projection block, 74 denotes a projection block mounting member, and 75 denotes a projection block mounting member. A transmission screen 76 is a screen fixing frame. An opening 71 is provided at the back of the cabinet, and a fan 72 sucks or exhausts air from the cabinet. It is needless to say that the projection block 5 may be cooled by omitting the fan 72 and introducing external air into the apparatus main body by natural suction.

[0005]

However, an air intake / exhaust opening is provided at the back of the display device or the like,
In the means for cooling the projection block, in order to perform sufficient cooling, it is necessary to secure a sufficient space or flow path for intake and exhaust around the opening when the apparatus main body is installed. In particular, in a liquid crystal projector system in which a light valve such as a liquid crystal panel is used as an image source and light from the light source is transmitted or reflected by the light valve and an image is displayed on a transmissive screen, the projection lamp and light of the light source are used. The temperature of the valves and various optical parts is likely to be high, and therefore, it is important to secure a sufficient space or flow path for intake and exhaust around the openings.

However, the rear projection type display device is
Due to its large screen size, it is often used in public facilities and commercial facilities, etc.There are many installation forms embedded in the wall or integrated with other equipment, etc. In such a case, a space for cooling and a flow path for intake and exhaust are not sufficiently secured around the opening in many cases.

In a multi-screen type in which a plurality of rear-projection display devices are arranged and an image is displayed as a collective screen, a plurality of projection blocks requiring cooling exist in close proximity to each other. It is more difficult to secure a sufficient space and a flow path for intake and exhaust, which can cope with each cooling of the projection block.

Therefore, even in the above-mentioned installation state, in order to surely cool the projection block, an opening for cooling is installed on the front surface of the device main body of the rear projection type display device, and the air intake and / or exhaust air is exhausted. Means for doing so are also conceivable. However, assuming a structure in which the inside of the transmissive screen and the inside of the cabinet of the apparatus main body pass through as a flow path for intake and / or exhaust from an opening provided on the front surface, a filter for preventing dust is provided in the opening. Even if it is installed, external dust smaller than the filter opening diameter will enter the inside of the cabinet and pass through the inner space corresponding to the screen.

However, since the screen is usually made of a material such as acrylic, it is easy for static electricity to be charged, so that dust that has entered through the opening adheres to the inside of the screen and the displayed image is not displayed. It degrades the luminance and the like, and causes a decrease in performance. Similarly, in the case where the flow path of the intake air and / or the exhaust air from the opening passes through the space on the surface of the projection lens, dust adheres to the lens surface, and as described above, the performance is deteriorated. Contributes.

Further, in the rear projection type display device, when it is necessary to clean the inside of the screen and the lens surface in the cabinet, if the work for removing the frame holding the screen is not carried out, the access to the cleaning place is prevented. In addition, the screen itself is often large, so it is not easy to remove the frame. For this reason, frequent cleaning is not performed, and even if the image deteriorates due to dirt, there is a tendency that the image is left as it is.

The present invention has been made based on the above circumstances, and has as its object to partition the inside of the cabinet of the apparatus main body including the inside of the screen and the surface of the projection lens, and make the space on the side of the projection block a separate room. A flow path of intake air and / or exhaust air from a cooling opening installed in the front of the main body is communicated with this separate chamber, and cooling of the projection block is performed through this flow path (duct). Cooling of the rear projection display device, which reliably cools the projection block regardless of the installation state of the main body, prevents dust from adhering to the back of the screen and the surface of the projection lens, and prevents deterioration of image quality To provide a mechanism.

[0012]

According to the present invention, there is provided a projection block having an image source and a projection lens, and a transmission screen for forming an image enlarged and projected by the projection lens. In a rear projection display device comprising: a separate room including the projection block portion separated from a space including a projection lens surface corresponding to the transmission screen, a separate room including the projection block portion is configured in a cabinet of the device main body, and the projection is performed. In order to cool the components constituting the block portion, an opening for intake and / or exhaust is provided on the front side of the apparatus body, beside the transmission screen, and the opening and the separate chamber are connected to each other. It is characterized in that a duct-shaped portion communicating between them is provided in the cabinet to serve as a flow path of cooling air.

In this case, as an embodiment of the present invention, the structural member constituting the cabinet of the apparatus main body is used as a part of the duct-shaped portion, and the opening from the separate room including the projection block is opened. The duct-shaped part to
It is formed beside the space including the projection lens surface corresponding to the transmissive screen, and further, corresponding to the separate room, the cabinet is equipped with a fan for intake or / and exhaust. preferable.

[0014]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows an embodiment of a cooling mechanism for a rear-projection display device according to the present invention, in which a schematic configuration of a rear-projection display device using a transmissive liquid crystal panel as an image generation source is disclosed. ing. FIG. 2 is a plan view of FIG.
Is a side view of the same.

1, 2 and 3, an image is enlarged and projected on a screen 2 composed of a lenticular sheet 3 and a Fresnel lens 4 from a projection block 5 having an image source and a projection lens. Is made. The projection block 5 is fixed to a housing (cabinet) 1 of the apparatus main body via an attachment member 6.

The screen 2 is fixed to the front of the housing 1 by a screen fixing frame 7. Further, openings 11 and 12 as cooling air introduction ports for cooling the projection block 5 are provided on the sides of the screen 2 and the screen fixing frame 7 at the front of the housing. I have.

The interior of the casing 1 is separated by a partition plate 20 from a space 24 containing the projection block 5 as a separate room from a space 24 containing the projection lens surface facing the screen 2 and the device inside. . The structural members 21 and 22 constituting the housing 1 have a cross-sectional shape 23 shown in FIG. 4 and are connected to the openings 11 and 12 installed on the side of the front part of the apparatus main body. Further, in a space 25 including the projection block 5, an intake fan 13 and an exhaust fan 14 t are attached to a structural member 21 constituting the housing 1.

As a result, a flow path is formed from the opening 11 provided on the front surface of the apparatus main body, through the cross section of the structural member 21, for intake by the intake fan 13. Similarly, a flow path for exhausting air from the opening 12 is formed by the exhaust fan 14 through the cross section of the structural member 22. Also,
The projection block is opened by the intake fan
1 and is passed through the duct-shaped portion of the structural member 21 and cooled by the introduced air. Then, the heated air passes through the duct-shaped portion of the structural member 22 by the exhaust fan 14 and is discharged from the opening 12.

In the above configuration, the air introduced from the outside for cooling the projection block is separated by the partition plate 20 into the space 24 including the inside of the screen unit 2 and the projection lens surface including the projection block 5. Since it is separated from the separate room consisting of the space 25, it does not enter this space 24. As a result, even if an opening is provided on the front surface of the apparatus main body and the projection block is cooled, it is possible to prevent external dust from entering and adhering to the inside of the screen apparatus and the lens surface. It should be noted that the same configuration can be used when another display device such as a CRT is used as the image generation source of the projection block 5.

FIG. 4 shows a schematic configuration of a projection block 5 having an image source and a projection lens.
Reference numeral 31 denotes a projection lens, and 32 denotes a housing for holding and fixing optical components. A drive circuit 33 for driving the liquid crystal panel is fixed to an upper part of the housing. Reference numeral 34 denotes a lamp power supply circuit for driving the light source. FIG. 5 is a schematic plan view showing the configuration of the optical system of the projection block.

In FIG. 3, reference numeral 35 denotes a light source, 36 denotes a dichroic mirror that transmits only the blue component of white light, and reflects other components, and 37 denotes a dichroic mirror.
The dichroic mirrors 38, 39, and 40 that reflect only the green component in the light excluding the blue component transmitted through 6 and transmit the remaining red component, are total reflection mirrors.

Reference numeral 41 denotes a red liquid crystal panel for displaying an image corresponding to red, 42 denotes a green liquid crystal panel similarly corresponding to green, and 43 denotes a blue liquid crystal panel corresponding to blue. Reference numeral 44 denotes a dichroic prism, which combines the lights separated by the dichroic mirrors 36 and 37 and incident on the liquid crystal panels 41, 42 and 43.

Next, the operation of the projection block 5 will be described. A light source 35 such as a metal halide lamp emits white light by a lamp power supply circuit 34. The irradiated white light enters the dichroic mirror 36 and transmits only the blue component light. The transmitted blue component light is incident on the total reflection mirror 38, is reflected by the mirror 38, and is incident on the blue liquid crystal panel 43. Light other than the blue component transmitted by the dichroic mirror 36 is reflected and enters the dichroic mirror 37.

The dichroic mirror 37 reflects only the green component, and the reflected green component light enters the green liquid crystal panel 42. Further, the illumination light from the lamp that reflects the green component by the dichroic mirror 37 and becomes only the red component is reflected by the total reflection mirrors 39 and 40 and enters the red liquid crystal panel 41. Then, each liquid crystal panel 38,
The images displayed on 39 and 40 are synthesized by the dichroic prism 44 and enlarged and projected on the screen 2 by the projection lens 31.

Further, as shown in FIG. 7, the duct-shaped portion in the housing 1 includes structural components 62 and 63 constituting the housing 1.
Like the cross-sectional shape 60, it is also possible to form a duct-shaped portion together with the duct structural member 61. This makes it possible to simplify the structure by reducing the number of parts of the duct structure and reduce the space required for installing the duct. In addition,
If necessary to cool the projection block, install only the air inlet on the front side of the main unit, and perform only air intake from the front side of the main unit, or install only the exhaust port on the front side of the main unit. Alternatively, only the exhaust can be performed from the front side of the apparatus main body. In addition, the intake fan and the exhaust fan installed in the housing 1 are also installed according to the necessity of cooling the projection block. However, it is possible to select a configuration in which only a natural intake and a natural exhaust are used without using a fan. It is possible.

As shown in FIGS. 8 and 9, the space inside the housing 1 on the side of the projection block 5 is a separate room, and
A space including the inside of the screen 2 and the surface of the projection lens 31 is formed by forming a flow path of cooling air passing through a duct-shaped portion from a vent (opening) in the front part of the apparatus body. In the same manner as in the above-described embodiment, even when the projection block is cooled, entry of external dust is prevented, and dust adheres to the inside of the screen device and the lens surface due to static electricity and the like. It is possible to avoid.

[0027]

The present invention has been described above. By installing a duct in the cabinet of the apparatus main body, the projection block is formed by passing through the above-mentioned duct from the opening provided on the front side of the apparatus. Intake air for cooling or /
In addition, the exhaust can be performed directly from the front side of the apparatus, and the space including the projection block to be cooled is separated as a separate room from the space including the rear side of the screen (inside the apparatus) and the surface of the projection lens. By blocking the space on the screen side from the flow of air with the outside of the device, it is possible to prevent dust from outside the device from entering the space.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a cooling mechanism of a rear projection display device showing an embodiment of the present invention.

FIG. 2 is also a plan view.

FIG. 3 is also a side view.

FIG. 4 is a perspective view schematically showing a projection block.

FIG. 5 is a schematic view showing an arrangement of optical components in a projection block.

FIG. 6 is a schematic diagram showing a cabinet structure of the apparatus main body in FIG.

FIG. 7 is a schematic view of a cabinet structure showing a modification of the present invention.

FIG. 8 is a plan view showing a cooling mechanism of the rear projection display device.

FIG. 9 is a side view showing the cooling mechanism.

FIG. 10 is a plan view showing a cooling mechanism of a conventional rear projection display device.

FIG. 11 is a side view showing the cooling mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Housing (cabinet) 2 Screen 3 Fresnel sheet 4 Lenticular lens 5 Projection block 6 Attachment member 7 Screen fixing frame 11 Opening 12 Opening 13 Intake fan 14 Exhaust fan 20 Partition plate 21 Structural member 22 Structural member 23 Structural member 23 Sectional shape 24 Screen Space including the inside of the device and the surface of the projection lens 25 Space including the projection block 31 Projection lens 32 Housing 33 Drive circuit 34 Lamp power supply circuit 35 Projection lamp 36 Dichroic mirror 37 Dichroic mirror 38 Total reflection mirror 39 Total reflection mirror 40 Total reflection mirror Reference Signs List 41 Liquid crystal panel for red 42 Liquid crystal panel for green 43 Liquid crystal panel for blue 44 Dichroic prism 50 Space including screen device inside and projection lens surface 51 Partition member 60 Cross-sectional shape 1 ductwork member 62 structural member 63 structural member 70 cabinet 71 opening 72 fan 73 projecting block 74 projected block mounting member 75 Screen 76 Screen fixed frame

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/74 H04N 5/74 F (72) Inventor Hiroto Yasumura 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Shigehiro Kadota 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Minoru Noji 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F term (reference) 2H088 EA14 EA15 HA05 MA20 5C058 AB03 BA35 EA01 EA43 EA52 5G435 AA11 AA12 BB12 BB17 CC12 DD02 DD05 DD07 EE02 GG01 GG04 GG05 GG06 GG08 GG44 GG46 LL15

Claims (4)

[Claims] 1. A rear projection display device comprising: a projection block section having an image source and a projection lens; and a transmission screen for forming an image enlarged and projected by the projection lens. Separate from the space including the projection lens surface corresponding to the above, separate room including the projection block portion is configured in the cabinet of the apparatus body, and the transmission type to cool the components constituting the projection block portion An opening for intake and / or exhaust is provided on the side of the screen and on the front side of the apparatus body, and a duct-shaped portion communicating between the opening and the separate room is provided in the cabinet. A cooling mechanism for a rear projection display device, wherein the cooling mechanism is a cooling air flow path. 2. The cooling mechanism for a rear projection display device according to claim 1, wherein a structural member constituting a cabinet of the device body is used as a part of the duct-shaped portion. 3. A duct-shaped portion from a separate room including the projection block to the opening is formed beside a space including a projection lens surface corresponding to the transmissive screen. 3. The cooling mechanism for a rear projection display device according to 1 or 2. 4. The rear projection according to claim 1, wherein the cabinet is provided with a fan for intake and / or exhaust corresponding to the separate room. Cooling mechanism for portable display devices.