JPH1155600A - Radiator of projective television device using liquid crystal element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To circulate enough outside air internally regardless of an installation place and to maintain the temperature of a device in a constant temperature by providing an intake fan that is placed on the bottom inside a housing and 1st and 2nd inlets which are arranged at different planes of the housing and draw outside air. SOLUTION: An intake fan 18 is arranged just under of a liquid crystal element 12 in a housing 11. A 1st inlet 19 is provided on the bottom 11c of the housing 11 near the fan 18 and a 2nd inlet 20 is provided on the front plane 11a of the housing 11. Also, an outside air guiding path 21 that connects the inlets 19 and 20 is provided. Also, an exhaust air fan 22 and an air outlet 23 are provided on the rear 11b of the housing 11. The rotation of the fan 18 introduces outside air from either of the inlets 19 and 20 inside the housing 11. Both sides of the element 12 is cooled by the outside air which is drawn from the inlets 19 and 20 by the fan 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection television apparatus using a liquid crystal element for projecting and displaying television images, and more particularly to an apparatus for efficiently radiating heat applied to a liquid crystal element.

[0002]

2. Description of the Related Art Projection television devices have been widely used as devices for simultaneously viewing television images or images created by computer devices on a large screen and by a large number of people.

In this projection television apparatus, a signal-processed image is displayed on a cathode ray tube or a liquid crystal element, and is enlarged and projected on a screen using optical means.

A projection television apparatus using a CRT generally employs a system using three CRTs for reproducing and displaying each of three primary colors of a television signal. However, since three CRTs are used, the projection television apparatus is used. The shape is large,
The weight is heavy and the installation is poor.

On the other hand, liquid crystal elements have come to be used in projection television equipment due to the improvement in definition of an image reproduced and displayed and an increase in screen size. By using this liquid crystal element, the size and weight of the projection television device can be reduced, the projection television device can be used in any place such as at home, and the installation location can be easily moved and handled.

The configuration of a projection television apparatus using this liquid crystal element will be described with reference to FIG. FIG. 2A is a cross-sectional perspective view in which a liquid crystal element 32 is disposed inside a housing 31. A light source 33, a reflector 34, and an optical filter 35 are disposed behind the liquid crystal element 32, and an optical lens group 36 is disposed in front of the liquid crystal element 32.

A predetermined video signal is input to the liquid crystal element 32 from a video signal processing circuit (not shown), and a video is displayed. The light source 33 uses a metal halide lamp, and is mounted in a reflector 34 having a semicircular parabolic light reflecting surface. The light emitted from the light source 33 is reflected by the reflector 34 and is projected on the liquid crystal element 32 via the optical filter 35.
The light projected from the light source 33 removes unnecessary light such as ultraviolet light and infrared light, and projects the light transmitted through the optical filter 35 that transmits only visible light to the liquid crystal element 32. The light transmitted through the liquid crystal element 32 is
Is converted into the image light displayed on the screen. The optical lens group 36 enlarges the image light transmitted through the liquid crystal element 32 and projects it on a screen (not shown). That is,
The light emitted from the light source 33 enlarges and projects the image light displayed on the liquid crystal element 32 onto a screen along a path indicated by solid lines 37 and 37 'in the drawing.

Although not shown, between the liquid crystal element 32 and the optical filter 35, there is a fly for adjusting a light beam projected on the liquid crystal element 32 to a screen shape of the liquid crystal element 32 and converting it into parallel light. An eye and a Fresnel lens are arranged. Further, between the liquid crystal element 32 and the optical lens group 36, a Fresnel lens or the like that prevents diffusion of transmitted image light from the liquid crystal element 32 is disposed.

The optical lens group 36 includes a lens for enlarging transmitted image light, an objective lens for adjusting the focus of an image displayed on a screen, and the like.

In the liquid crystal projection television apparatus having the above-described configuration, the light projected from the light source
In transmitting the light 2, unnecessary light which adversely affects the liquid crystal material in the optical liquid crystal element 32 or causes a temperature rise is removed by the optical filter 35. In order to secure a predetermined brightness of the projected image screen, it is necessary to secure a predetermined amount of light quantity projected from the light source 33 onto the liquid crystal element 32, that is, light transmission quantity of the liquid crystal element 32. For this reason, even if unnecessary light is removed from the light projected on the liquid crystal element 32 by the color filter 35 and only the visible light is projected, the visible light impinging on the liquid crystal element 32 generates heat and the light is not used for a long time. In addition, unstable operation and deterioration of the liquid crystal material occur. Further, heat is also generated from a video signal processing circuit that is housed in the housing 31 and supplies a video signal to the liquid crystal element 32, and the temperature of the generated heat causes unstable operation and deterioration of the liquid crystal element 32.

In order to stably operate and reduce the deterioration of the liquid crystal element 32, an air inlet 38 is provided on the front surface 31a of the housing 31 for releasing heat generated in the housing 31. The intake fan 3 is provided inside the housing 31 of the opening 38.
The outside air is taken in from the intake port 38 and supplied into the housing 31 by the rotation of the intake fan 39. On the other hand, an exhaust port 4 is provided on the back surface 31b of the housing 31.
0, and an exhaust fan 41 is disposed inside the casing 31 of the exhaust port 40. The rotation of the exhaust fan 41 causes the liquid crystal element 32 and the video signal processing circuit and the like inside the casing 31 to rotate. The exhausted heat is exhausted to the outside air. That is, the outside air sucked from the intake port 38 is supplied into the housing 31, and the heat generated in the housing 31 is exhausted from the exhaust port 40, so that the temperature inside the housing 31 always approximates the outside air temperature. It keeps the value to prevent unnecessary temperature rise.

However, when the intake port 38 is provided on the front surface 31a of the housing 31, it is provided below the position where the optical lens group 36 is disposed from the viewpoint of design of the liquid crystal projection television apparatus. Therefore, the outside air sucked from the intake port 38 is exhausted from the exhaust port 40 through a path indicated by a dotted line 42 in the drawing. That is, the main part of the outside air sucked from the air inlet 38 passes through the lower side of the liquid crystal element 32 and flows out to the air outlet 40. On the other hand, a part of the outside air taken in from the intake port 38 is guided to the upper end of the liquid crystal element 32 by the liquid crystal element 32, and the heat of the liquid crystal element 32 flows out to the exhaust port 40. The amount of outside air flowing to the upper end of the liquid crystal element 32 is small, and
The outside surface, that is, the surface of the liquid crystal element 32 on the exhaust port 40 side, is in a state where almost no outside air flows. Therefore, there is a problem that the liquid crystal element 32 cannot sufficiently dissipate heat.

The intake port 38 and the intake fan 39
Almost the same problem remains when is disposed on the side surface of the housing 31.

On the other hand, as shown in FIG. 2B, the bottom surface 31c of the housing 31 immediately below the liquid crystal element 32 disposed inside the housing 31 in order to allow the outside air to sufficiently flow through the liquid crystal element 32.
It is also practiced to dispose an intake port 38 'and an intake fan 39' at the same time.

In FIG. 2B, the same parts as those in FIG. 2A are denoted by the same reference numerals, and the detailed description thereof will be omitted.

As a result, the outside air sucked from the suction port 38 'forcibly flows on both sides of the liquid crystal element 32 as shown by a dotted line 42' in FIG. Since the exhaust gas is exhausted from the exhaust port 40, the heat generated by the liquid crystal element 32 is forcibly exhausted, and is maintained at substantially the same temperature as the outside air temperature.

However, as shown in FIG.
A suction port 38 'and a suction fan 3 are provided on the bottom 31c of the housing 31.
When the 9 ′ is arranged, as a place where the housing 31 is installed, for example, when the carpet 43 is arranged and installed on a long carpet 43, the carpet of the carpet 43 closes the intake port 38 ′, Even if the outside air is forcibly sucked by the suction fan 39 ', sufficient outside air flowing on both sides of the liquid crystal element 32 cannot be sucked. Also, when the housing 31 is similarly disposed and installed on a thin sheet of paper or resin, the sheet is sucked by the air inlet 38 ′ to close the air inlet 38 ′, and sufficient air is taken in. Can not.

Further, when the apparatus is placed on an installation without obstruction that blocks the intake port 38 'of the housing 31, dust and ash on the installation object may be connected to the intake port 38' during long use. Is attached, and the outside air intake amount is reduced, so that there is a problem that sufficient heat radiation of the liquid crystal element 32 cannot be performed.

An intake port 38 'is provided on the bottom surface 31c of the housing 31.
And an intake fan 39 ′ for closing the intake port 38 ′ and preventing adhesion of dust and ash.
In addition to making the case supporting legs 44 attached to the bottom surface 31c of the first unit large, the use of the liquid crystal element 32 impairs the reduction in size and weight, which is a feature of the projection television device.

[0020]

As described above, in order to keep the temperature inside the housing of a conventional projection television device using a liquid crystal element equal to the outside air temperature, the outside air is forcibly sucked into the housing. In addition, when exhausting the outside air inside the housing, if the air inlet is provided on the front or side of the housing, the heat generated outside air in the housing cannot be efficiently exhausted. There is a problem that the air intake port is blocked and sufficient external air cannot be sucked in depending on the condition of the installation location of the body.

According to the present invention, sufficient outside air can be circulated inside the projection television device without impairing the size and weight of the projection television device using the liquid crystal element and regardless of the condition of the installation location of the projection television device. Therefore, it is an object of the present invention to provide a heat radiating device that keeps the temperature of the device constant.

[0022]

A housing has a liquid crystal element for reproducing at least a video signal in a housing, a light source for projecting the liquid crystal element, and an optical lens group for enlarging and projecting the image light transmitted through the liquid crystal element. In a liquid crystal projection television device, an intake fan installed on a bottom surface in the housing near the position where the liquid crystal element is installed, an outside air introduction path for introducing outside air to the intake fan, and a connection to the outside air introduction path. And a first and a second, which are provided on different surfaces of the housing and take in outside air.
And an exhaust fan and an exhaust port installed on the back surface of the housing.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an oblique sectional view showing an embodiment of a heat radiating device for a projection television device using a liquid crystal element according to the present invention.

A liquid crystal element 12 is disposed inside the housing 11, a light source 13, a reflector 14 and an optical filter 15 are disposed behind the liquid crystal element 12, and a liquid crystal element 12 is disposed in front of the liquid crystal element 12. An optical lens group 16 is arranged.

A predetermined video signal is input to the liquid crystal element 12 from a video signal processing circuit (not shown), and a video is displayed. The light source 13 uses a metal halide lamp, and is mounted in a reflector 14 having a semicircular parabolic light reflecting surface. Light emitted from the light source 13 is reflected by the reflector 14 and is projected on the liquid crystal element 12 via the optical filter 15.
Light emitted from the light source 13 is filtered by an optical filter 15 to remove unnecessary light, and only visible light is transmitted to the liquid crystal element 12 and projected. The light transmitted through the liquid crystal element 12 is converted into image light displayed on the liquid crystal element 12. The optical lens group 16 enlarges the image light transmitted through the liquid crystal element 12 and projects it on a screen (not shown). That is, the light emitted from the light source 13 enlarges and projects the image light displayed on the liquid crystal element 12 onto the screen along the path indicated by the solid lines 17 and 17 'in the drawing.

Although not shown, between the liquid crystal element 12 and the optical filter 15, a fly-eye and a fly-eye for converting the light beam from the light source 13 into the screen shape of the liquid crystal element 12 and converting it into parallel light are provided. Fresnel lens etc. are arranged,
Further, between the liquid crystal element 12 and the optical lens group 16, a Fresnel lens or the like for preventing diffusion of transmitted image light from the liquid crystal element 12 is arranged.

The optical lens group 36 includes a lens for enlarging transmitted image light, an objective lens for adjusting the focus of an image displayed on a screen, and the like.

Further, the liquid crystal element 1 is provided in the housing 11.
2, an intake fan 18 is arranged, a first intake port 19 is provided on a bottom surface 11 c of the housing 11 near the intake fan 18, and a second intake port is provided on a front surface 11 a of the housing 11. 20 and the first and second intake ports 19, 2
An outside air introduction path 21 that connects 0 is provided. Also,
An exhaust fan 22 and an exhaust port 23 are provided on the back surface 11b of the housing 11.

The outside air introduction passage 21 is supplied to the outside air from the second intake port 20 by the intake fan 18 by the housing 1.
1 is an introduction path to be introduced into the inside of the apparatus. On the other hand, the first
The intake port 19 is an opening that is connected to the outside air introduction passage 21 and allows outside air to be introduced into the housing 11 by the intake fan 18.

That is, by the rotation of the intake fan 18, outside air is introduced into the housing 11 from both the first and second intake ports 19 and 20.

The outside air introduced into the housing 11 by the intake fan 18 flows from the lower side of the liquid crystal element 12 to the upper side along both sides as shown by a dotted line 24 in the figure. At this time, the heat generated in the liquid crystal element 12 is absorbed by the outside air and flows to the inside of the upper surface of the housing 11, and the heat generated by the exhaust fan 22 provided on the back surface of the housing 11 is supplied to the exhaust port 23. Guided and released into the open air. That is,
The first and second intake ports 19 and 20 are used to supply the intake fan 1
The outside air taken in at 8 cools both side surfaces of the liquid crystal element 12, and the outside air whose temperature is raised by the heat generated at the liquid crystal element 12 is forcibly moved from the exhaust port 23 by the exhaust fan 22 to the housing. 11 is exhausted to the outside. Further, heat generated in a video signal processing circuit (not shown) and the like is exhausted from the exhaust port 23 together with the flow of the outside air taken in from the intake ports 19 and 20. Thereby,
The liquid crystal element 12 and the video signal processing circuit can always be maintained at substantially the same temperature as the outside air.
Can be stably maintained and the degradation of the liquid crystal material can be eliminated.

When the projection television device using the liquid crystal element configured as described above is installed in a place using a carpet with long hairs, the first air inlet 19 may be closed by a carpet. Is a second air inlet 20 provided in front of the housing 11.
Since there is nothing to be blocked, the liquid crystal element 1 is forcibly forced by the intake fan 18 through the outside air introduction passage 21.
2 allows the outside air to flow.

Further, dust ash adheres to each of the air inlets 19 and 20 due to dust and ash at the place where the casing 11 is installed, but is provided on the bottom surface 11c of the casing 11 closest to the dust and ash at the place where the casing 11 is installed. Although the adhesion to the first intake port 19 is remarkable and early, the second intake port 2 provided on the front of the housing 11
0 is low in the adhesion rate due to being away from the dust,
The heat inside the housing 11 can be sufficiently exhausted by the outside air sucked from the second air inlet 20.

As described above, the liquid crystal projection television device according to the present invention is connected by a single outside air introduction path in the housing, and the first and second intake air provided on two different surfaces of the housing. The outside air taken out of the mouth is taken into the housing by a single intake fan, and the outside air is circulated upward from below the liquid crystal element installed inside the housing, and the outside air in the housing is exhausted. With the configuration in which the air is exhausted from the fan and the exhaust port, the inside of the housing is always kept at substantially the same temperature as the outside air temperature, and in particular, the operation of the liquid crystal element can be stabilized and the liquid crystal material can be prevented from being deteriorated. Furthermore, the liquid crystal projection television can be freely installed without affecting the installation conditions of the installation location.

The intake fan 18 and the exhaust fan 22 are fans having an electric motor, and when supplying operation power when using a liquid crystal projection television,
It is obvious that the driving power is supplied to the intake and exhaust fans 18 and 22 at the same time.

The second air inlet 20 is provided in the housing 11
It is apparent that the same effect can be obtained even if it is provided on the side surface of the housing 11.

[0037]

According to the present invention, the installation location can be selected without impairing the size and weight reduction which is a characteristic of the liquid crystal projection television equipment, and without considering the installation location of the equipment. During use, the inside of the device is constantly maintained at substantially the same temperature as the outside air, and has the effect of maintaining stable operation of various operating elements in the device and preventing deterioration.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view showing an embodiment of a heat radiating device for a projection television device using a liquid crystal element according to the present invention.

FIG. 2 is a cross-sectional perspective view showing a conventional heat dissipation device of a projection television device using a liquid crystal element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Housing | casing, 12 ... Liquid crystal element, 13 ... Light source, 14 ... Reflector, 15 ... Optical filter, 16 ... Optical lens group, 1
8 ... intake fan, 19 ... first intake port, 20 ... second intake port, 21 ... outside air introduction path, 22 ... exhaust fan, 23
…exhaust port.

Claims (3)

[Claims] 1. A liquid crystal having at least a liquid crystal element for reproducing a video signal, a light source for projecting light to the liquid crystal element, and an optical lens group for enlarging and projecting image light transmitted through the liquid crystal element in a housing. In the projection television device, an intake fan installed on a bottom surface in the housing near the position where the liquid crystal element is installed, an outside air introduction path for introducing outside air to the intake fan, and a connection to the outside air introduction path. And first and second air intake ports provided on the bottom surface of the housing and other different surfaces for sucking outside air, and an exhaust fan and an air outlet installed on the back surface of the housing. A heat dissipation device for projection television equipment using a liquid crystal element. 2. A first air inlet, which is connected to the outside air introduction passage and inhales outside air, is provided on a bottom surface of the housing, and a second air inlet is provided on either a side surface or a front surface of the housing. A heat radiating device for projection television equipment using the liquid crystal element according to claim 1. 3. A liquid crystal device according to claim 1, wherein outside air taken from said first and second intake ports is taken into said housing by a single intake fan. Radiator for projection television equipment.