JP2003344949A - Exhaust duct for projection type display device and the projection type display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-noise and high-safety projection type display device characterized in that noise of an exhaust fan is small and no fragment scatters directly to outside when a light source is broken. <P>SOLUTION: The exhaust duct 3 for the projection type display device 100 equipped with the exhaust fan 504 has its entrance 1 coupled with the exhaust fan 504 and its exit 2 coupled with an exhaust port provided to the projection type display device, and also has at least one curved part so that exhausted air flowing in from the entrance 1 reaches the exhaust port while changing its flowing direction. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust duct for a projection display device and a projection display device.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional general projection type display device 5.
The outer shape of 00 is shown. In the figure, 501 is a projection lens, 502 is an operation panel, and 510 is a projection light beam. FIG. 6 shows the internal structure of the projection display device 500. In the figure, 520 is a power supply unit, 522 is an electronic circuit board, 525 is a light source unit, 523 is an optical system, 524 is a light valve, 519 is a light combining prism. The projection display apparatus 500 further includes a cooling fan 521 that takes in cooling air inside, an exhaust fan 504 that discharges the inside air to the outside, and the like. The air taken in by the exhaust fan 504 passes through the exhaust duct 505 and goes out through the exhaust port 506.

When the power switch provided on the operation panel 502 is pressed, the light source in the light source unit 525 is turned on, and the light emitted from the light source is transmitted through the optical system 523 to the light valve 5.
Illuminate 24. The images formed by the plurality of light valves 524 are combined by the light combining prism 519 and enlarged and projected as a projection light beam 510 from the projection lens 501 onto a screen or the like (not shown) to display an image. Further, at this time, the cooling fan 521, the exhaust fan 504, and the like operate to cool the inside of the apparatus.

[0004]

The exhaust duct 505 connected to the exhaust fan 504 has a smooth shape so that the exhaust gas does not flow back into the inside of the device and the pressure loss is as small as possible. The inside of the device is prevented from becoming hot by efficiently guiding the air in the device, which has risen, to the outside. However, on the other hand, there is a problem that the noise of the exhaust fan 504 leaks to the outside with almost no attenuation in the exhaust duct, and the noise during use of the device is large. Further, when the light source bursts for some reason, the fragments pass through the exhaust duct and can be scattered to the outside at high speed.

The present invention has been made in view of the above problems, and an object thereof is to reduce noise during use of a projection display device. Another object of the present invention is to prevent the fragments from scattering to the outside at high speed even if the light source bursts.

[0006]

[Means for Solving the Problems] In order to achieve the above object,
According to the invention of claim 1, an exhaust duct for a projection display device comprising an exhaust fan, wherein an inlet of the exhaust duct is connected to the exhaust fan, and an outlet of the exhaust duct is provided in the projection display device. At least 1 so that the exhaust gas flowing from the inlet reaches the exhaust port while changing its traveling direction.
An exhaust duct for a projection display device is obtained which has two curved portions.

According to a second aspect of the invention, in the first aspect of the invention, the traveling direction of the exhaust gas flowing from the inlet changes by 90 degrees or more before reaching the exhaust port.

A third aspect of the invention is characterized in that, in the first or second aspect of the invention, a part or all of the inner wall is covered with a sound absorbing material.

The invention according to claim 4 is the same as claims 1 to 3.
In the invention described in any one of the above items, a rectifying member is provided in order to prevent separation of air from the inner wall.

According to the invention of claim 5, claim 1
By providing the exhaust duct according to any one of items 1 to 4, a projection display device with low noise and high safety can be obtained.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. FIG. 1 shows the internal structure of a projection display device 100 according to the present invention. In the figure, the same or corresponding elements as those shown in FIG. 6 are designated by the same reference numerals. That is, 501 is a projection lens, 5
Reference numeral 04 is an exhaust fan, 521 is a cooling fan, 520 is a power supply unit, 525 is a light source unit, 523 is an optical system, 5
Reference numeral 24 is a light valve, and 519 is a light combining prism.

Reference numeral 3 denotes an exhaust duct for the projection type display device according to the present invention. The exhaust duct 3 is an exhaust fan 504.
And a duct outlet 1 connected to an exhaust port (not shown). The shape of the exhaust duct 3 is enlarged and shown in FIG.

When the projection display device is in use, the exhaust fan 50
Exhaust from 4 flows into exhaust duct 3 from duct inlet 1 and is discharged to the outside from duct outlet 2. As shown in FIG. 2, since the exhaust duct 3 has the substantially U-shaped curved portion 6,
The exhaust gas that has entered through the duct inlet 1 is bent 90 degrees or more at the curved portion 6 and exits through the duct outlet 2.

The noise of the projection display device is mainly due to the noise of the exhaust fan that leaks to the outside through the exhaust duct. In the above embodiment, however, the exhaust duct 3 has the curved portion 6, so A part of the entered sound is reflected by the bending portion 6 and returns. Further, the amount of sound attenuation on the inner wall of the exhaust duct 3 is large, and the duct length between the exhaust fan and the exhaust port may be long. It is significantly lower than that.

In the projection display device of the first embodiment, when the light source 5 bursts for some reason, some of the fragments pass through the exhaust duct 3 and go out.
However, most of the fragments that have jumped into the exhaust duct 3 collide with the inner wall of the curved portion 6 of the exhaust duct 3, and the kinetic energy of the fragments is greatly reduced. Furthermore, since the distance between the exhaust fan and the exhaust port is long, the kinetic energy lost by the time the fragments reach the exhaust port is large, and most of the fragments that have jumped into the exhaust duct 3 fall without reaching the exhaust port. Then stay in the exhaust duct. Also, even if it goes out from the exhaust port, the kinetic energy is greatly reduced, so the high speed immediately after the burst cannot be maintained, and it should go out at a low speed almost equal to the speed of the exhaust flow from the exhaust port. become.

As described above, in the first embodiment, a duct having a substantially U-shaped curved portion is used as the exhaust duct connecting the exhaust fan and the exhaust port, and the sound entering the exhaust duct is curved. Since the noise is reflected or attenuated by, the noise of the exhaust fan leaking outside through the exhaust duct is greatly reduced. Further, by using the exhaust duct as described above, when the light source bursts for some reason, most of the fragments are contained in the exhaust duct, and even if it goes out, its scattering speed is equal to the exhaust flow. It will be almost the same. Therefore, according to the first embodiment, a low noise and high safety projection display device can be obtained.

Embodiment 2. Another embodiment of an exhaust duct used in the projection display device of the present invention is shown in FIG. 3 as a second embodiment. Note that, in FIG. 3, elements corresponding to the elements shown in FIG. 2 are denoted by the same reference numerals. That is, 3 is an exhaust duct, 1 is a duct inlet, and 2 is a duct outlet. The exhaust duct according to the second embodiment differs from the exhaust duct according to the first embodiment in that the sound absorbing material 7 is attached to a part or all of the inner wall.

In the second embodiment, the sound absorbing material absorbs the sound entering the exhaust duct, so that a larger noise reduction effect than in the first embodiment can be obtained. Since the other points are the same as those of the first embodiment, detailed description thereof will be omitted.

Third Embodiment Next, still another embodiment of the exhaust duct used in the projection display device of the present invention will be described as a third embodiment. Also in FIG. 4, elements corresponding to the elements shown in FIG. 2 are denoted by the same reference numerals. That is, 3 is an exhaust duct, 1 is a duct inlet, and 2 is a duct outlet.
The exhaust duct of the third embodiment differs from the exhaust duct of the first embodiment in that a rectifying member 8 is provided inside.

In the third embodiment, the flow regulating member 8 suppresses the separation of air from the side wall of the exhaust duct 3. Therefore, the decrease in exhaust efficiency due to the provision of the curved portion 6 can be minimized. Other points are Embodiment 1
Since it is the same as, the detailed description will be omitted. A sound absorbing material may be attached to the inner wall of the exhaust duct, and in this case, the noise reduction effect is improved as in the case of the second embodiment.

[0021]

According to the invention described in claims 1 and 2,
An exhaust duct that has a curved portion is used as the exhaust duct that connects the exhaust fan and the exhaust port, and the sound that enters the exhaust duct is reflected or attenuated at the curved portion, so the exhaust fan leaks to the outside through the exhaust duct. The noise is greatly reduced.

According to the third aspect of the invention, since the sound absorbing material absorbs the sound entering the exhaust duct, a greater noise reduction effect can be obtained.

According to the invention as set forth in claim 4, since air separation from the side wall of the exhaust duct is suppressed by the rectifying member, a decrease in exhaust efficiency due to the curved portion provided in the exhaust duct is minimized. It can be limited.

According to the fifth aspect of the present invention, it is possible to obtain a low noise and high safety projection display device in which the noise of the exhaust fan is small and the fragments are not scattered to the outside when the light source is ruptured. .

[Brief description of drawings]

FIG. 1 is a diagram showing a structure of a projection display device according to a first embodiment of the present invention.

FIG. 2 is an external view of an exhaust duct used in the projection display device according to the first embodiment.

FIG. 3 is a view showing another form of the exhaust duct according to the present invention.

FIG. 4 is a view showing still another form of the exhaust duct according to the present invention.

FIG. 5 is an external view of a conventional projection display device.

FIG. 6 is an explanatory diagram of an internal structure of a conventional projection display device.

[Explanation of symbols]

1 duct inlet, 2 duct outlet, 3 exhaust duct, 5 light source, 6 curved portion, 7 sound absorbing material, 8 rectifying member, 100,500 projection display device, 501
Projection lens, 502 Operation panel, 504 Exhaust fan, 510 Projection luminous flux, 519 Photosynthesis prism, 520 Power supply unit, 521 Cooling fan,
522 electronic circuit board, 523 optical system, 524
Light valve, 525 light source unit.

Claims (5)

[Claims] 1. An exhaust duct for a projection display device having an exhaust fan, wherein an inlet of the exhaust duct is connected to the exhaust fan, and an outlet of the exhaust duct is provided in the projection display device. An exhaust duct for a projection display device, wherein the exhaust duct has at least one curved portion so that exhaust gas flowing from the inlet reaches the exhaust port while changing its traveling direction. 2. The exhaust duct for a projection display device according to claim 1, wherein the traveling direction of the exhaust gas flowing from the inlet changes by 90 degrees or more before reaching the exhaust port. 3. The exhaust duct for a projection display device according to claim 1, wherein a part or all of the inner wall is covered with a sound absorbing material. 4. The exhaust duct for a projection display device according to claim 1, further comprising a rectifying member for preventing air from being separated from the inner wall. 5. A projection display device comprising the exhaust duct according to claim 1. Description: