JPH02130542A - image projection device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> The disclosed technology is for enlarging and projecting a color image formed on a liquid crystal panel onto a wall screen, etc. in the passenger compartment of an aircraft or vehicle, in an office, or in a school. It belongs to the technical field of the structure of compact type image projection devices.

Summary of the gist> The invention of this application is based on a method in which a light source such as a halogen lamp is provided near one side of the inside of a box-shaped casing made of a predetermined heat insulating material such as resin or metal. A projection lens is provided on the other side of the screen, a condensing lens is provided on the light source side between the light source and the projection lens, and a projection original image unit such as a liquid crystal panel is provided on the projection lens side. This invention relates to an image projection device that is equipped with a predetermined cooling device to prevent a temperature rise caused by the light source inside the casing, and in particular, the casing is formed in a sealed manner to the outside of the system, and A heat absorber is provided, and a heat radiator is provided on the outside of the casing, and a heat transfer body such as a heat pipe is connected in series between the heat absorber and the heat radiator, and the mechanical part is connected to the heat absorber. This invention relates to an image projecting device that is cooled to prevent temperature rise, and also prevents dust from the outside from adhering to the optical system mechanism inside the casing, so that the device functions are always maintained as designed.

<Prior art> As is well known, the dramatic improvements in civil society and industrial society due to science and technology are extremely remarkable, and in particular, information technology is extremely important, and improvements in televisions, computers, word processors, etc. The so-called 0-A technology is given a remarkable amount of attention, and the research and development of this photoelectric technology is becoming more and more popular, and it is even a matter of time before we enter the so-called high-tech era.

As the information society progresses, information display technology using cathode ray tubes, such as televisions, is becoming more and more popular in a wide range of fields, from comfortable citizens' lives to schools, research institutes, companies, and factories. It has even entered the realm of three-dimensional image transmission technology, going beyond information transmission by 3D technology, and more sophisticated and dense information transmission is becoming possible.

Since the cathode ray tube has only a limited display area, various types of information processing devices using cathode ray tube displays, which have been the mainstream until now, have a so-called face-to-face type device mechanism, and the information processing The number of processors is one, or at most three, and it is extremely difficult for an unspecified number of researchers, administrative staff, etc. to process the information, and a so-called video projector method is also required to enlarge and project the data onto a screen. Although a method has been devised, the brightness is insufficient, color shift is unavoidable due to overlapping projection, and since it uses a heavy device, it requires not only installation but also maintenance and inspection. There was also the inconvenience that maintenance etc. were extremely cumbersome.

In place of this, with the rapid development of liquid crystal panels through research and development, information transmission processing devices such as extremely compact LCD televisions began to contribute to the larger technology of cathode ray tubes, while the other micron technology contributed to the development of LCD panels. A processing technology has been developed that uses the light transmittance of the panel to enlarge and project an image formed by an electronic drive device on the liquid crystal panel onto the screen to simultaneously transmit a large amount of information to an unspecified number of viewers. On the one hand, there is a tendency for the development to become polarized with the so-called high-definition television system and high-brightness television system of cathode ray tube televisions.

The method of enlarging and projecting a color image or a color stereoscopic image onto a screen by utilizing the light transmittance of such a liquid crystal panel is not only the method of enlarging and projecting a color image formed on a liquid crystal panel by an electronic drive device. Feedback has been fed back to enlarged projection technologies such as slide projectors and color movies, and new reuse has been attempted, and excellent research and development has been carried out, making it useful not only for educational purposes but also for transmitting confidential information and administrative information processing. It is beginning to make a major contribution.

In such color image projection technology, etc., the precision technology, compact technology, etc. that have been accumulated so far have been fully utilized, but on the other hand, new obstacles have also started to arise. It's coming.

In other words, in such an image projection device, various electronic devices and optical system mechanisms are installed densely in a predetermined casing, and a light source such as a halogen lamp for projection is installed. There is little space for gas flow, and heat tends to accumulate.For example, there is a risk that the temperature of the liquid crystal panel will change due to temperature rise, or that the total reflection mirror or dichroic mirror may become distorted.Therefore, various cooling devices are used to deal with this problem. It is becoming more and more developed.

That is, in the liquid crystal color image projection device 1 that has been developed so far and is hung from the ceiling of a vehicle or installed on a tabletop, as shown in FIG. 4, a predetermined resin or metal casing is used. A total reflection mirror 3 and a condensing lens 4 are installed on one side of the 2, a light source 5 such as a halogen lamp is interposed between them, and a projection lens 6 is installed on the other side facing a screen (not shown). A liquid crystal panel 8 having a Fresnel lens 7 as a condensing lens is provided between the projection lens 6 and the condensing lens 4, and a predetermined color image is formed by an electronic driving device 9. The light is enlarged and projected onto the screen via the projection lens 6, and as a countermeasure against heating and temperature rise caused by the light source 5 in the casing 2, the condenser lens 4 and Fresnel lens 7 are passively used. A heat ray absorption filter 10 is interposed between the liquid crystal panel 8
In order to prevent functional deterioration due to temperature rise in the casing 2, we also proactively installed an air exhaust port 11 near the base of the casing 2 and an air intake port 12 on the side opposite to the electronic drive device 9 at the bottom. By rotating the exhaust fan 13 provided on the side of the exhaust port 4,
Outside air is taken in through the air intake port 12, circulated within the casing 2, and then exhausted through the air exhaust port 11 to achieve forced cooling through air cooling, thereby preventing the temperature of the optical system, electronic circuits, etc. from rising, and preventing functional deterioration. I was wearing it.

<Problem to be solved by the invention> Therefore, in order to improve the cooling performance of the cooling fan 13, etc., the inlet 1
Measures to lower the temperature by using a specified gas cooling device attached to the casing 2 to reliably prevent a rise in temperature inside the casing 2 and maintain its initial function have not yet achieved good results. However, the air intake port 12 and
Since circulation of outside air inside and outside of the casing 2 through the exhaust port 11 is unavoidable, the inside of the casing 2 may be filled with smoke from cigarettes in a sealed room or air containing a lot of dust from the outside air. In order to pass through, these cigarette smoke and dust adhere to halogen lamps, condensing lenses, projection lenses, and most importantly, LCD panels and heat absorption filters, impeding light transmission. There is a risk that the sharpness of the image may be reduced, resulting in the inconvenience that the designed function cannot be fully demonstrated.

To deal with this, it is possible to disassemble and inspect the device at a predetermined timing and clean the predetermined parts, but this work is extremely cumbersome due to the narrow mechanical section. In particular, in the case of a device attached to the ceiling of a vehicle, installation and removal are extremely time-consuming, making it difficult to reassemble accurately, and furthermore, the mechanical parts of the optical system may be damaged by wiping, etc. In addition, skill is required to operate the joints of each mechanical part, misalignment of the optical axis, etc. must be avoided, and there is a risk of moisture, mold, etc. for,
A negative point was that it was not possible to open the facility frequently for inspection.

<Object of the Invention> The object of the invention of this application is to provide an atmospheric forcing device for projecting images, etc., formed on a liquid crystal panel based on the highly developed photoelectric technology based on the above-mentioned prior art onto a screen. The problem of cooling through circulation was considered a technical issue to be solved, and while trying to make the photoelectric device and electronic drive device inside the casing more compact, and making full use of the advantages of integrated technology, we also tried to make the light source etc. In addition, it reliably prevents heating and temperature rise caused by air pollution, and also prevents the occurrence of misalignment and scratches on mechanical equipment parts, and ensures that the initial design function can be fully utilized. The purpose is to provide an excellent image projection device that will benefit the public.

<Means/effects for solving the problem> In order to solve the above-mentioned problem, the structure of the invention of this application, which is summarized in the above-mentioned claims, is intended to solve the above-mentioned problem. An image projection device set on a desk in a classroom, etc., enlarges and projects an image from a projection original unit installed in the casing of the image projection device onto a screen installed on a wall in front of the device. When doing so, a light source such as a halogen lamp installed near one side of the casing is turned on, and the light is transmitted to an image original unit such as a liquid crystal panel through a condensing lens installed between the projection lens and the projection lens. , the projection lens is used to project an enlarged image onto the screen, and during this time the temperature inside the casing rises over time due to heat generated by the light source, causing undesirable quality or To avoid any possibility of distortion etc.
Forming the casing in a closed manner with respect to the outside of the casing,
A heat absorber made of copper coated with a black material is set inside the casing to absorb heat, and the heat is transferred from the heat absorber to a heat transfer body such as a heat pipe extending outside the casing. The heat radiator is led out of the casing and is supplied to a large heat radiating area outside the casing, and the heat radiator is forcedly cooled by a heat radiating fan, etc., thereby preventing the heating temperature inside the casing from rising, and preventing the optical system from heating up. The mechanical parts and electronic circuits of the optical system are not affected, and the functions as originally designed are reliably maintained.The sealed casing prevents dust and moisture from entering from outside the casing, and the optical system It does not adhere to the mechanical parts or electronic circuits, and by sealing dry gas in the casing in advance, it always prevents dew condensation from occurring on the optical system mechanical parts and electronic circuits due to temperature changes. Technical measures have been taken to maintain constant functionality, eliminate the need for maintenance, inspection, and maintenance, improve durability, and make full use of the advantages of a compact image projection device.

<Example> Next, an example of the invention of this application will be described below based on FIGS. 1 to 3.

Note that the same parts as in FIG. 4 will be explained using the same reference numerals.

In the embodiment shown in FIG. 1, 1' is an image projection device that forms the center of the gist of the invention of this application. In a compact type mode, which is set in a predetermined location such as a school research facility to enlarge and project a predetermined color image onto a wall screen (not shown), a heat-insulating type casing 2' made of a predetermined material and approximately rectangular in side view is required. On the front side of the interior, there is provided a heat absorbing bracket 15 made of copper that is U-shaped in side view and whose inner surface is coated with black paint, and a concave mirror type total reflection mirror 3 is formed near the front of the bracket 15. A light source 5 such as a halogen lamp is interposed between the condenser lens 4 in front of the condenser lens 4 to form a heat absorber that absorbs heat generated by the light source 5.

In addition, a projection lens 6 is installed in front of the casing 2' near a screen (not shown) in the same manner as in the conventional system, and inside the casing 2' in front of the projection lens 6, there is a dryer which has been sealed in the casing 2' in advance. Fan 1 for forced air circulation
3' has been set up.

And on the condenser lens 4 side inside the casing 2',
A heat ray absorption filter 10 and a color liquid crystal panel 8 as an original image unit with a Fresnel lens γ in front are set to transmit light from a light source 5, and an electronic drive device is displayed on a screen (not shown) through a lens 6. The color image formed by 9 can be enlarged and projected.

A porous heat radiator 17 made of a predetermined metal is provided on the outside of the base of the casing 2', and a fan 13' for promoting heat radiation is provided below the heat radiator 17. A heat pipe 18 as a heat transfer body is connected between the body 15 and the heat absorber 15 to transfer heat generated by the light source 5 etc.
The heat is conducted from there to the heat radiating body 17 to radiate the heat and cool it.

In the above configuration, the cooling fan 13' and the circulation fan 131 are operated to form a predetermined color image based on a TV program or video on the liquid crystal panel 8 as an original image unit by the electronic drive device 9, and the halogen lamp 5 as a light source is activated.
When the light source 5 is turned on, the light from the light source 5 is subjected to a condensing action by the condensing lens 4, passes through the heat ray filter 15, passes through the Fresnel lens 7, picks up an image on the liquid crystal panel 8, and passes through the projection lens 6 to the front (not shown). project the enlarged image onto the screen.

During this time, as mentioned earlier, the heat generated by the light source 5 increases over time.
The inside of the casing 2' is heated due to the temperature increase of the liquid crystal panel 8, etc., or the heat from the light from the condenser lens 4 is absorbed by the heat absorption filter 12, and the heat generated from the light source 5 is absorbed by the heat absorption filter 12. Absorbed by the absorber 15 and transferred to the heat pipe 18
The heat is transferred to the heat sink 17 via the cooling fan 13'.
The forced cooling is performed by the air blown by the casing 2', thereby preventing the temperature inside the casing 2' from rising.

Then, the dry air sealed in advance in the casing 2' is circulated within the casing 2' by a circulation fan 13', and is absorbed by the heat absorber 15 and sent through the heat pipe 18 to the heat radiator 17. The heat is radiated and cooled, and therefore the temperature of the mechanical parts of each optical system and the electronic drive device 9 inside the casing 2' is prevented from rising, and functional deterioration, deterioration, and distortion due to temperature rise are prevented. 2', it is possible to completely prevent inconveniences such as the adhesion of dust and cigarettes, or the occurrence of scratches or deviation of the optical axis due to cleaning operations to remove them, and always. The original design assembly remains functional and accurate color image magnification projection onto the screen is maintained.

Of course, the dry air previously sealed in the casing 2' does not cause any effects such as dew condensation on the mechanical parts of the optical system and the electronic drive unit @9 due to temperature changes.

Next, in the embodiment shown in FIG. 2, guichroic mirrors 20 and 20' are used to pass and reflect colors for the liquid crystal panel 8'8'8' as an original image unit.
, 20', 20', and a total reflection mirror 19.
19. 19 are arranged so as to follow a predetermined optical path, a condenser lens 4 is arranged on the light source 5 side, a projection lens 6 is arranged on the front side,
A heat absorber 15' made of black copper and having a total reflection mirror 3 is arranged behind the halogen lamp 5 as a light source, and a metal net 1 of a multi-mesh heat radiator is provided at the rear of the casing 2'.
A copper wire bundle 18' is connected between the casing 7' and the heat absorber 15' to serve as a heat transfer body, and a pre-sealed dry air circulation fan 13' is disposed inside the casing 2'. However, its substantial operation and effect are the same as those of the above-mentioned embodiment.

Further, in the embodiment shown in FIG. 3, although a circulation fan 13' for sealed dry air is provided at the inner bottom of the casing 2', an air exhaust port 1 provided at the top of the light source 5 is provided.
A tube body 181 serving as a heat transfer body is disposed between the casing 1' and an air intake port 12' provided at the bottom of the liquid crystal panel 8 in a sealed state from outside the system. A heat exchange type cooling device 17' is interposed as a heat radiator in the middle of the casing 2'.
The inside and outside of the casing 2' are shut off, and the inside of the casing 2' is sealed to prevent moisture, dust, etc. from entering the casing 2'.
', the inside of the casing 2' is forcibly cooled in the process of passing through the cooling device 17', which serves as a heat radiator, to prevent temperature rise and ensure that the mechanical parts of each optical system and the electronic drive unit 9 function as designed. This is a mode in which the present invention can be maintained at a high temperature, and the operation and effect are substantially the same as those of the above-mentioned embodiments.

It should be noted that the embodiments of the invention of this application are of course not limited to the above-mentioned embodiments, and the original image unit may be of a slide projector type or a movie film. Various aspects can be adopted for the heat transfer body, such as using other mechanisms.

<Effects of the Invention> As described above, according to the invention of this application, the ceiling of an aircraft or Shinkansen vehicle, the inner ceiling of a car, or a laboratory,
A heating element used when an image formed on an original image unit such as a liquid crystal panel set in a compact image projection device set on a desk in a room in a company factory, school, etc. is enlarged and projected onto a screen via a light source lens. Because heating and temperature rise inside the casing caused by light sources such as halogen lamps can be avoided by heat dissipation and cooling in the internal and external circulation paths, thermal effects on mechanical parts such as liquid crystal panels and electronic drive devices whose heat resistance is not favorable are avoided. The excellent effect is that the image projection function as designed is maintained.

In addition, there is no need to frequently open the casing and perform maintenance and inspections on the optical system, electronic drive mechanism, etc., which simplifies the work, prevents scratches on these mechanisms, and prevents optical axis misalignment, etc. It has the excellent effect of preventing this and maintaining a constant function in a stable manner.

Furthermore, by sealing dry air in the casing, there is an effect that dew condensation does not occur and adhesion due to intrusion of dust from the outside can be avoided.

Furthermore, since the contents of the set, such as hanging it from the ceiling, do not need to be changed, there is an effect that the optimum set state can be maintained.

In this way, almost no maintenance is required, and therefore initial assembly is free, and durability is also improved.

In addition, since a heat dissipation body can be installed outside the casing via a heat transfer body in contrast to the heat absorption body installed inside the casing, the casing is not only reliably cooled but also has a degree of freedom in design and is easy to assemble. It has the effect of being easy to use,
There is also the advantage that the mechanism part within the casing can be made more compact.

[Brief explanation of the drawing]

1 to 3 are detailed explanatory diagrams of the invention of this application, in which FIG. 1 is a schematic sectional view of one embodiment, FIGS. 2 and 3 are schematic sectional views of other embodiments, and FIG. 4 is a schematic sectional view of another embodiment. 1 is a cross-sectional view of an image projection device based on the prior art; FIG. 17... Cooling device, 15... Heat absorber, 1'... Image projection device,

Claims (5)

[Claims] (1) In an image projection device in which a light source is provided on one side of a casing, a projection lens is provided on the other side, a projection original image unit is interposed between the two, and a cooling device is attached to the casing, The casing is formed in a sealed manner to the outside of the system, a heat absorbing body is provided inside the casing, a heat radiating body is provided outside the casing, and a heat transfer body is connected between the two. Characteristic image projection device. (2) The image projection device according to claim 1, wherein dry gas is sealed within the casing. (3) The image projection device according to claim 1, wherein the heat transfer body is a heat conductive metal body. (4) The image projection device according to claim 1, wherein the heat transfer body is a sealed gas circulation pipe. (5) The image projection apparatus according to claim 1, wherein the projection original image unit is a liquid crystal panel.