JP2021167860A - Projection type display device - Google Patents

Abstract

To provide a projection type display device that can prevent a deterioration in image quality even when vibrations with different frequencies are output from vibration sources, such as a plurality of fans.SOLUTION: A projection type display device (500) has a first vibration source (54), first holding members (21) that hold the first vibration source, a second vibration source (55), and second holding members (22) that hold the second vibration source. The first holding members and the second holding members are different in spring constant from each other.SELECTED DRAWING: Figure 4

Description

The present invention relates to a projection type display device that reduces deterioration of a projected image due to vibration.

Conventionally, a projection type display device such as a projector that magnifies and projects an image on a screen or the like using an optical system is known. A fan is generally used for cooling in the projection type display device. When the fan is driven, vibration occurs due to eccentricity due to the tolerance of the rotating part and the like. If the vibration generated by driving the fan is transmitted to the optical element of the optical system, image quality deterioration such as vibration of the image may occur. Patent Document 1 discloses a configuration in which an elastic member is arranged between a fan and a holding member that holds the fan, and the vibration of the fan is suppressed from being transmitted to the holding member.

Further, when a plurality of fans are provided, if the vibration of one fan resonates with the vibration of the other fans, the vibration of one fan is amplified. When the amplified vibration is transmitted to the optical element, the projected image quality may be deteriorated due to the displacement of the optical element. Patent Document 2 discloses a configuration in which a plurality of fans are fixed to a base member via holding members, and each holding member is connected to a portion other than the portion fixed to the base member by a connecting damper. .. According to such a configuration, it is possible to suppress the transmission of vibration between a plurality of fans.

Japanese Patent No. 6264017 Japanese Patent No. 5936156

Since there are a plurality of cooling targets in the projection type display device, a configuration using a plurality of fans is common. Further, in the projection type display device, the rotation speed of the corresponding cooling fan may be determined while checking the temperature of the cooling target. Depending on the temperature of each of the plurality of cooling targets, the target temperature of each of the plurality of cooling targets, and the respective characteristics of the corresponding cooling fans, the rotation speeds of the plurality of cooling fans may deviate by about 100 rpm. A deviation of the rotation speed of about 100 rpm is a deviation of about 2 Hz as a vibration. Since the vibration of about 2 Hz is easily recognized by humans, when such vibration is transmitted to the optical element, the vibration of the image is noticeable.

With the configuration disclosed in Patent Document 1, the vibration of a single fan can be suppressed, but the vibration caused by the deviation of the rotation speeds of a plurality of fans cannot be suppressed. In the configuration disclosed in Patent Document 2, vibration transmitted between a plurality of fans can be suppressed, but a beat (vibration) of several Hz caused by a deviation in the frequency of vibration of the plurality of fans is transmitted to the optical element. Cannot be suppressed. resulting in,
Therefore, an object of the present invention is to provide a projection type display device capable of suppressing deterioration of image quality even when vibrations having different frequencies are output from vibration sources such as a plurality of fans.

The projection type display device as one aspect of the present invention comprises a first vibration source, a first holding member for holding the first vibration source, a second vibration source, and the second vibration source. It has a second holding member for holding, and the spring constants of the first holding member and the second holding member are different from each other.

Other objects and features of the present invention will be described in the following embodiments.

According to the present invention, it is possible to provide a projection type display device capable of suppressing deterioration of image quality even when vibrations having different frequencies are output from vibration sources such as a plurality of fans.

It is an external perspective view of the projector in this embodiment. It is an optical block diagram of the optical box of the projector in this embodiment. It is explanatory drawing of the flow of the cooling air inside the projector in this embodiment. It is an exploded view of the holding structure of a fan in this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, the outline of the projector (projection type display device) 500 according to the present embodiment will be described with reference to FIG. FIG. 1 is an external perspective view of the projector 500. A projection lens 100 is mounted on the front surface of the projector 500. An optical box 300 (see FIG. 2) containing a light source, a color separation / synthesis unit, an illumination optical system, and a light modulation element such as a liquid crystal panel is housed in the housing of the projector 500.

Next, with reference to FIG. 2, the optical configuration of the optical box 300 in the housing of the projector 500 will be described. FIG. 2 is an optical configuration diagram of the optical box 300. The optical box 300 includes a light source optical system 310, an illumination optical system 320, a color separation synthetic optical system 330, and the like. The light source optical system 310 includes a plurality of LDs (laser diodes) 311b, 311r as a light source, a compression optical system, a condensing optical system including a phosphor unit, and the like. The phosphor unit has a phosphor wheel 312 including a phosphor that is irradiated with excitation light from a plurality of LD311b and 311r. The illumination optical system 320 includes a fly-eye lens, a polarization conversion element, a condenser lens, and the like. The color separation / synthesis optical system 330 includes a reflective liquid crystal display element 331R, 331G, 331B, a dichroic mirror, a polarization beam splitter, a color selectivity retardation plate, and the like. The light from the light source is synthesized as an image by the color separation synthesis optical system 330, and is magnified and projected onto a projected surface such as a screen by the projection lens 100.

Next, the flow of the cooling air inside the projector 500 will be described with reference to FIG. FIG. 3 is a configuration diagram of the projector 500 excluding the upper portion of the housing and an explanatory diagram of the flow of cooling air inside the projector 500. In FIG. 3, the projector 500 has a housing 10 in which the optical box 300 is arranged. The housing 10 has an intake port 10A for taking in outside air and an exhaust port 10B for exhausting internal air. The intake port 10A is arranged on the housing surface 10C on which the projection lens 100 is arranged. A light source heat sink 2 and a phosphor heat sink 4 are arranged in the vicinity of the intake port 10A. The light source heat sink 2 and the LD311b and LD311r arranged in the optical box 300 are configured to transfer heat, and the heat generated by the LD311b and 311r is transmitted to the light source heat sink 2 and dissipated. Further, the phosphor heat sink 4 and the phosphor unit in the condensing optical system are configured to transfer heat, and the heat generated by the phosphor unit is transmitted to the phosphor heat sink 4 and dissipated.

In the projector 500 of the present embodiment, the light source cooling fan 51 is arranged on the intake side of the light source heat sink 2, and the light source cooling fan 52 is arranged on the exhaust side of the light source heat sink 2. As described above, the projector 500 constitutes a duct structure (not shown) in which a radiator (light source heat sink 2) is arranged between the fan 51 and the fan 52.

Further, in the projector 500, a fan 53 for cooling the phosphor is arranged on the intake side of the phosphor heat sink 4. With such a configuration, the cooling air can be accurately introduced into the phosphor heat sink 4, and the cooling performance of the phosphor unit can be improved.

Further, in the projector 500, exhaust fans 54, 55, and 56 are arranged in the vicinity of the exhaust port 10B in the housing 10. With such a configuration, it is possible to suppress the temperature rise in the housing 10 and reduce the ventilation resistance in the housing 10. As a result, it is possible to suppress the temperature rise of the LD311b, LD311r and the phosphor unit, and improve the cooling performance.

Next, with reference to FIG. 4, the holding structure of the exhaust fans 54, 55, 56 will be described. FIG. 4 is an exploded view of the holding structure of the exhaust fans 54, 55, 56. 20A is a fan holder (upper fan holder), and 20B is a fan holder (lower fan holder). 21, 22 and 23 are holding members. The holding members 21, 22, and 23 are each composed of damping materials having different spring constants (Young's modulus). In the present embodiment, the spring constant (Young's modulus) of the holding member 21 is twice the spring constant (Young's modulus) of the holding member 22. Further, the spring constant (Young's modulus) of the holding member 22 is twice the spring constant (Young's modulus) of the holding member 23. The fans 54, 55, and 56 are sandwiched between the fan holders 20A and 20B via the holding members 21, 22, and 23, respectively, and are unitized and attached to the housing 10.

In the above configuration, the fan 54 is driven at 3400 rpm, the fan 55 is driven at 3300 rpm, and the fan 56 is driven at 3200 rpm. At this time, the vibrations input to the holding members 21, 22, and 23 are 56.7 Hz, 55 Hz, and 53.3 Hz, respectively. Since the spring constants of the holding members 21, 22 and 23 are different from each other, the frequencies of vibration output from the holding members 21, 22 and 23 are 50 Hz, 30 Hz and 15 Hz, respectively. The difference in vibration frequency is 20 Hz and 15 Hz, and even when the output vibration is combined, there is no beat. Further, the amplitude of the output vibration is attenuated by the holding members 21, 22, and 23. As a result, even if the combined vibration is transmitted to the optical elements of the projection lens 100 and the optical box 300, the image quality does not deteriorate.

As described above, in the present embodiment, the projection type display device (projector 500) has a first vibration source, a first holding member for holding the first vibration source, a second vibration source, and a second vibration source. It has a second holding member that holds the vibration source of the above. Further, the spring constants of the first holding member and the second holding member are different from each other. The first vibration source and the second vibration source are, for example, fans 54 and 55, and the first holding member and the second holding member are, for example, holding members 21 and 22. However, the present embodiment is not limited to this, and any two fans of the fans 51 to 56 of the present embodiment may be used as the first vibration source and the second vibration source, respectively. Further, the first vibration source and the second vibration source are not limited to the fan, respectively, and other vibration sources such as the phosphor wheel 312 may be used as the first vibration source or the second vibration source. ..

Further, in the present embodiment, when the first vibration source vibrates at the first frequency, the first holding member vibrates at the third frequency due to the vibration of the first vibration source, and the second vibration source becomes the second vibration source. When vibrating at the second frequency, the second holding member vibrates at the fourth frequency due to the vibration of the second vibration source. At this time, preferably, the absolute value of the difference between the third frequency and the fourth frequency is larger than the absolute value of the difference between the first frequency and the second frequency. More preferably, the absolute value of the difference between the first frequency and the second frequency is 10 Hz or less.

Preferably, the first holding member and the second holding member each include a damping material (eg, a rubber member). Also, preferably, the materials of the first holding member and the second holding member are different from each other. Further, preferably, the thicknesses (thicknesses) of the first holding member and the second holding member are different from each other. Further, preferably, the attachment positions of the first holding member and the second holding member to the first vibration source and the second vibration source, respectively, are different from each other.

Preferably, the first vibration source is a first fan for cooling (one of fans 51-56), and the second vibration source is a second fan for cooling (another one of fans 51-56). One). The first fan can be driven at the first rotation speed, and the second fan can be driven at a second rotation speed different from the first rotation speed. More preferably, the first fan and the second fan are driven at the same rotation speed when the same voltage is applied.

In the present embodiment, with respect to vibrations having a deviation of several Hz generated from a plurality of fans (vibration sources), the plurality of damped vibrations output from the holding member are elastic bodies provided for each fan and having different spring constants. Therefore, each has a deviation of several tens of Hz. As described above, since each of the plurality of damped vibrations has a deviation of several tens of Hz, the combined vibration does not have a beat of several Hz. In addition, the elastic body attenuates the amplitude of the input vibration. As a result, even when the combined vibration is transmitted to the optical element, deterioration of the image due to the positional deviation of the optical element can be suppressed. Therefore, according to the present embodiment, a projection type display device capable of suppressing deterioration of image quality even when vibrations having different frequencies (vibrations deviated by several Hz) are output from vibration sources such as a plurality of fans. Can be provided.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and modifications can be made within the scope of the gist thereof.

For example, the rotation speed of each fan and the difference in the rotation speed of each fan can be changed. Moreover, you may change the position and the number of each holding member. Further, the spring constant may be changed by changing the thickness of each holding member. Further, although the exhaust fans 54, 55, and 56 have been described as a plurality of vibration sources in the present embodiment, they can be applied to other fans and other vibration sources such as the phosphor wheel 312.

21 Holding member (first holding member)
22 Holding member (second holding member)
54 fan (first vibration source)
55 fan (second vibration source)
500 projector (projection type display device)

Claims (10)

The first vibration source and
The first holding member that holds the first vibration source and
The second source of vibration and
It has a second holding member that holds the second vibration source, and has.
A projection type display device characterized in that the spring constants of the first holding member and the second holding member are different from each other. When the first vibration source vibrates at the first frequency, the first holding member vibrates at the third frequency due to the vibration of the first vibration source.
When the second vibration source vibrates at the second frequency, the second holding member vibrates at the fourth frequency due to the vibration of the second vibration source.
The first aspect of claim 1, wherein the absolute value of the difference between the third frequency and the fourth frequency is larger than the absolute value of the difference between the first frequency and the second frequency. Projection type display device. The projection type display device according to claim 2, wherein the absolute value of the difference between the first frequency and the second frequency is 10 Hz or less. The projection type display device according to any one of claims 1 to 3, wherein the first holding member and the second holding member each include a vibration damping material. The projection type display device according to any one of claims 1 to 4, wherein the materials of the first holding member and the second holding member are different from each other. The projection type display device according to any one of claims 1 to 4, wherein the thicknesses of the first holding member and the second holding member are different from each other. Any of claims 1 to 4, wherein the positions of the first holding member and the second holding member attached to the first vibration source and the second vibration source, respectively, are different from each other. The projection type display device according to item 1. The first vibration source is a first fan for cooling.
The second vibration source is a second fan for cooling.
The first fan can be driven at the first rotation speed and can be driven.
The projection type display device according to any one of claims 1 to 7, wherein the second fan can be driven at a second rotation speed different from the first rotation speed. The projection type display device according to claim 8, wherein the first fan and the second fan are driven at the same rotation speed when the same voltage is applied. The projection type display device according to any one of claims 1 to 7, wherein the first vibration source or the second vibration source is a phosphor wheel.

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