JP2009258505A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of achieving improvement of cooling efficiency for an optical element disposed on an optical path of light emitted from a light source. <P>SOLUTION: The projector is equipped with a cooling device 5 for cooling a liquid crystal panel 451G disposed on the optical path of the light emitted from the light source. The cooling device 5 is equipped with a vortex pump 51 having discharge pressure of about 4.75 kPa, and a nozzle 52 jetting cooling air discharged from the vortex pump 51 to the liquid crystal panel 451G. By such constitution, speed of the cooling air near the liquid display panel 451G is increased sufficiently, and temperature of the liquid crystal panel 451G can be lowered even in a saturation area. Therefore, the cooling efficiency for the liquid crystal panel 451G can be improved, and consequently the life of the projector can be prolonged. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a projector.

Conventionally, a projector that modulates light emitted from a light source according to image information to form image light and projects the formed image light is known (see, for example, Patent Document 1).
The projector described in Patent Document 1 includes a cooling device that cools an optical element such as a liquid crystal panel and a polarizing plate disposed on an optical path of light emitted from a light source. This cooling device includes a sirocco fan (low static pressure blower), and cools the optical element by circulating the cooling air discharged from the sirocco fan along the light incident side end face and the light emission side end face of the optical element. ing.

JP 2003-121931 A

Here, when the surface area of the optical element is constant, the temperature of the optical element can be reduced as the velocity of the circulating cooling air increases. However, when the wind speed reaches a certain level, the saturation region is reached and it becomes difficult to reduce the temperature of the optical element.
For this reason, in order to further reduce the temperature of the optical element even in the saturation region, it is necessary to significantly increase the speed of the circulating cooling air. However, like the cooling device described in Patent Document 1, a sirocco fan or the like However, in the cooling device using the low static pressure blower, there is a problem that the speed of the cooling air cannot be sufficiently increased. Even if the discharge pressure of the sirocco fan is increased by applying a high voltage or the like, the pressure of the cooling air is lost in the flow path that guides the discharged cooling air to the optical element. There is a problem that it is difficult to raise.

  The objective of this invention is providing the projector which can improve the cooling efficiency of the optical element arrange | positioned on the optical path of the light inject | emitted from the light source.

  The projector of the present invention is a projector that modulates light emitted from a light source according to image information to form image light, and projects the formed image light on an optical path of the light emitted from the light source. A cooling device for cooling the optical element disposed, the cooling device directing the high static pressure blower having a discharge pressure of 4.5 kPa or more and the cooling air discharged from the high static pressure blower toward the optical element. And a nozzle for jetting.

  According to such a configuration, since the cooling device includes the high static pressure blower having a discharge pressure of 4.5 kPa or more and the nozzle, it is possible to sufficiently increase the wind speed of the cooling air, and in the saturation region, the optical speed can be increased. The temperature of the element can be reduced. Therefore, it is possible to improve the cooling efficiency of the optical element, and to extend the life of the projector.

  In the present invention, the cooling device includes a low static pressure blower having a discharge pressure of less than 4.5 kPa, and the low static pressure blower is provided on at least one of a light incident side end surface and a light emission side end surface of the optical element. The high static pressure blower is disposed so as to discharge cooling air along the nozzle, and the nozzle is in the direction of 0 ° to 90 ° with respect to the discharge direction of the cooling air discharged from the low static pressure blower. It is preferable to arrange so as to eject the cooling air discharged from.

According to such a configuration, since the optical element is cooled by the cooling air discharged from the high static pressure blower and the cooling air discharged from the low static pressure blower, the cooling efficiency of the optical element is further improved. be able to.
Here, when the jet direction of the cooling air by the nozzle is larger than 90 ° with respect to the discharge direction of the cooling air by the low static pressure blower, the direction is opposite to the discharge direction of the cooling air by the low static pressure blower. The wind speeds of the cooling air discharged from the high static pressure blower and the low static pressure blower are reduced. Therefore, it is preferable that the discharge direction of the cooling air by the nozzle is 0 ° to 90 ° with respect to the discharge direction of the cooling air by the low static pressure blower.
In addition, when the discharge direction of the cooling air by the nozzle is larger than 0 ° with respect to the discharge direction of the cooling air by the low static pressure blower, the cooling air discharged from the high static pressure blower and the low static pressure blower is Turbulence occurs near the optical element. Therefore, the cooling efficiency of the optical element can be further increased.

  In the present invention, it is preferable that the injection port of the nozzle is formed in a substantially circular shape and is set so that the cooling air velocity in the vicinity of the optical element is maximized.

Here, when the inner diameter of the nozzle injection port is small, the nozzle injection port is closed and the cooling air velocity is reduced. Moreover, when the internal diameter of the nozzle injection port is large, the wind speed of the cooling air discharged from the high static pressure blower cannot be sufficiently increased.
On the other hand, in the present invention, since the inner diameter of the injection port is set so that the wind speed of the cooling air in the vicinity of the optical element is maximized, the air speed of the cooling air can be sufficiently increased. The cooling efficiency of the element can be further improved.

  In the present invention, it is preferable that the distance between the optical element and the nozzle outlet is set so that the cooling air velocity in the vicinity of the optical element is maximized.

Here, when the distance between the optical element and the nozzle outlet is small, the optical element closes the nozzle outlet and the cooling wind speed decreases. When the distance between the optical element and the nozzle injection port is large, the cooling air pressure is lost in the flow path from the nozzle injection port to the optical element, so that the cooling air velocity decreases.
On the other hand, in the present invention, the distance between the optical element and the nozzle outlet is set so that the cooling air speed in the vicinity of the optical element is maximized. The temperature can be sufficiently increased, and the cooling efficiency of the optical element can be further improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[Configuration of projector]
FIG. 1 is a schematic diagram showing a schematic configuration of a projector 1 according to an embodiment of the present invention.
The projector 1 modulates light emitted from a light source according to image information to form a color image (image light), and enlarges and projects this color image on a projection surface (not shown) such as a screen. As shown in FIG. 1, the projector 1 includes a substantially rectangular parallelepiped outer casing 2, a projection lens 3, an optical device 4, a cooling device 5 (not shown in FIG. 1), and the like. The cooling device 5 will be described in detail later.
Although not shown in FIG. 1, a power supply device that supplies power to each component in the projector 1 and a control that controls each component in the projector 1 are provided in the exterior casing 2. Devices etc. are arranged.
The projection lens 3 is configured as a combined lens in which a plurality of lenses are combined, and enlarges and projects a color image formed by the optical device 4 described later.

The optical device 4 forms a color image corresponding to the image information by optically processing the light emitted from the light source under the control of the control device described above. The optical device 4 includes a light source device 41, an illumination optical device 42, a color separation optical device 43, a relay optical device 44, an optical device 45, and illumination light in which these optical components 41 to 45 are set inside. And an optical component casing 46 disposed at a predetermined position with respect to the axis A.
The light source device 41 includes a light source lamp 411 that emits light and a reflector 412 that aligns the emission direction of the light emitted from the light source lamp 411. Then, the light whose emission direction is aligned by the reflector 412 is emitted toward the illumination optical device 42.

  The illumination optical device 42 includes a first lens array 421, a second lens array 422, a polarization conversion element 423, and a superimposing lens 424. The light emitted from the light source device 41 is divided into a plurality of partial lights by the first lens array 421 and forms an image in the vicinity of the second lens array 422. Each partial light emitted from the second lens array 422 is incident so that its central axis (principal ray) is perpendicular to the incident surface of the polarization conversion element 423, and approximately one type of linearly polarized light is incident on the polarization conversion element 423. As injected. A plurality of partial lights emitted from the polarization conversion element 423 as linearly polarized light and passed through the superimposing lens 424 are superimposed on three liquid crystal panels 451 described later of the optical device 45.

The color separation optical device 43 includes two dichroic mirrors 431 and 432, and a reflection mirror 433, and has a function of separating a plurality of partial lights emitted from the illumination optical device 42 into three color lights of red, green, and blue. Have.
The relay optical device 44 includes an incident side lens 441, a relay lens 443, and reflection mirrors 442 and 444, and color light separated by the color separation optical device 43, for example, red light, which will be described later on the optical device 45. The liquid crystal panel 451R has a function of leading to the liquid crystal panel 451R.

  The optical device 45 modulates incident light according to image information to form a color image. The optical device 45 includes three liquid crystal panels 451 (the liquid crystal panel on the red light side is 451R, the liquid crystal panel on the green light side is 451G, and the liquid crystal panel on the blue light side is 451B), and an optical path upstream of each liquid crystal panel 451. An incident-side polarizing plate 452 disposed on the side, an exit-side polarizing plate 453 disposed on the rear side of the optical path of each liquid crystal panel 451, and a cross dichroic prism 454. Of these members 451 to 454, each liquid crystal panel 451, each exit-side polarizing plate 453, and cross dichroic prism 454 are integrated to form an optical device body 45A (see FIG. 2).

Each incident-side polarizing plate 452 transmits only light having a polarization direction substantially the same as the polarization direction aligned by the polarization conversion element 423 and absorbs other light. A polarizing film is formed on the translucent substrate. It is affixed and configured.
Each liquid crystal panel 451 has a configuration in which a liquid crystal, which is an electro-optical material, is hermetically sealed between a pair of transparent glass substrates, and the alignment state of the liquid crystal is controlled by a drive signal from the above-described control device, so that the incident side The polarization direction of light emitted from the polarizing plate 452 is modulated.
Each exit-side polarizing plate 453 has substantially the same function as the incident-side polarizing plate 452, transmits light having a certain polarization direction among light modulated by the liquid crystal panel 451, and absorbs other light. To do.

  The cross dichroic prism 454 combines the color lights emitted from the emission-side polarizing plates 453 to form a color image. The cross dichroic prism 454 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and two dielectric multilayer films are formed at the interface where the right-angle prisms are bonded together. These dielectric multilayer films transmit color light emitted from the liquid crystal panel 451G and transmitted through the emission side polarizing plate 453, and reflect each color light emitted from the liquid crystal panels 451R and 451B and transmitted through the emission side polarizing plate 453. In this way, the color lights are combined to form a color image. The color image formed by the cross dichroic prism 454 is enlarged and projected by the projection lens 3 described above.

[Configuration of cooling device]
FIG. 2 is a diagram illustrating a schematic configuration of a part of the cooling device 5 that cools the optical device main body 45A and the liquid crystal panel 451G on the green light side.
The cooling device 5 cools each component inside the projector 1. In the present embodiment, only a part of the cooling device 5 for cooling the liquid crystal panel 451G (optical element) will be described, and description of other parts will be omitted.
As shown in FIG. 2, the cooling device 5 connects the vortex pump 51, the nozzle 52 that jets the cooling air discharged from the vortex pump 51 toward the liquid crystal panel 451 </ b> G, the vortex pump 51, and the nozzle 52. A tube 53, a sirocco fan 54, and a duct 55 for guiding cooling air discharged from the sirocco fan 54 to the liquid crystal panel 451G are provided.

FIG. 3 is a diagram showing the relationship between the static pressure in the vortex pump 51 and the air volume. FIG. 4 is a diagram showing the relationship between the static pressure in the sirocco fan 54 and the air volume. 3 and 4 are graphs in which the vertical axis represents static pressure and the horizontal axis represents air volume. In FIG. 3, the unit of the vertical axis is kPa and the unit of the horizontal axis is L / min, whereas in FIG. 4, the unit of the vertical axis is Pa and the unit of the horizontal axis is m ³ / min. Yes.
In the present embodiment, as shown in FIG. 3, a vortex pump 51 having a discharge pressure of about 4.75 kPa (static pressure when the air volume is 0) is employed. Further, as shown in FIG. 4, a sirocco fan 54 having a discharge pressure of about 110 Pa is employed.

As shown in FIG. 2, the eddy current pump 51 as a high static pressure blower includes a substantially rectangular parallelepiped case 511, and the case 511 has an intake port 511 </ b> A and an exhaust port 511 </ b> B. And one end of the tube 53 is connected to the exhaust port 511B.
The eddy current pump 51 has a general configuration and is not illustrated in detail, but includes a pump unit housed in the case 511 and a motor that drives the pump unit.
The pump unit includes a disk member formed in a disk shape, and an impeller that is formed in a disk shape having the same diameter as the disk member and is provided to face the disk member. The disk member is formed with a semicircular groove having a semicircular cross section that guides the air introduced from the intake port 511A to the exhaust port 511B. Further, the impeller is formed with a semicircular groove having a semicircular cross section at a position facing the groove of the disk member, and the impeller groove has a plurality of blades extending along the diameter direction. Is formed. Then, by disposing the disk member and the impeller so as to face each other in a non-contact manner, a flow path having a substantially circular cross section is formed by the disk member and the groove of the impeller.

The rotation shaft of the motor is inserted through a disk member and a through hole formed at the center of the impeller, and is fixed to the impeller. Further, the disk member is fixed to the case 511.
Then, when the impeller is rotated with respect to the disk member by rotating the rotating shaft of the motor, the air introduced from the intake port 511A is accelerated and boosted in the flow path by the rotation of the impeller, and from the exhaust port 511B. Discharged.

The nozzle 52 is a nozzle formed in a conical shape penetrating in the height direction, and a base end portion corresponding to the bottom surface of the cone is connected to the other end of the tube 53. Therefore, the cooling air discharged from the vortex pump 51 is injected from the injection port 52A (tip portion) of the nozzle 52 formed in a substantially circular shape. The inner diameter of the injection port 52A is set to 0.8 mm. The ejection port 52A is disposed at a position where the distance from the light incident side end surface 451A of the liquid crystal panel 451G is about 10 mm.
Further, the nozzle 52 is disposed so as to eject the cooling air discharged from the vortex pump 51 at an angle of about 30 ° from the lower side in FIG. 2 toward the light incident side end surface 451A of the liquid crystal panel 451G.

FIG. 5 is a diagram showing the relationship between the cooling air velocity in the vicinity of the liquid crystal panel 451G and the inner diameter of the injection port 52A. FIG. 5 is a graph in which the vertical axis represents the wind speed (m / s) and the horizontal axis represents the inner diameter (mm).
When the inner diameter of the injection port 52A is smaller than 0.6 mm, the wind speed in the vicinity of the liquid crystal panel 451G decreases as the inner diameter decreases, as shown in FIG. This is because when the inner diameter of the injection port 52A is reduced, the injection port 52A is closed and the wind speed is reduced.
Further, when the inner diameter of the ejection port 52A is larger than 1 mm, the wind speed in the vicinity of the liquid crystal panel 451G decreases as the inner diameter increases. This is because the nozzle outlet is too wide.
On the other hand, when the inner diameter of the injection port 52A is 0.6 mm to 1 mm, the wind speed in the vicinity of the liquid crystal panel 451G is 30 m / s or more. In particular, when the inner diameter of the injection port 52A is 0.8 mm (indicated by an arrow in FIG. 5), the wind speed in the vicinity of the liquid crystal panel 451G is about 32 m / s and is maximum. In the present embodiment, since the inner diameter of the injection port 52A is set to 0.8 mm, the air velocity of the cooling air in the vicinity of the liquid crystal panel 451G is set to be maximum.

FIG. 6 is a diagram illustrating the relationship between the cooling air velocity in the vicinity of the liquid crystal panel 451G and the distance between the liquid crystal panel 451G and the ejection port 52A. FIG. 6 is a graph in which the vertical axis represents wind speed (m / s) and the horizontal axis represents distance (mm).
When the distance between the liquid crystal panel 451G and the ejection port 52A is smaller than 5 mm, the wind speed in the vicinity of the liquid crystal panel 451G decreases as the distance decreases, as shown in FIG. This is because the liquid crystal panel 451G has a shape that closes the injection port 52A, and the wind speed decreases.
When the distance between the liquid crystal panel 451G and the ejection port 52A is greater than 30 mm, the wind speed in the vicinity of the liquid crystal panel 451G decreases as the distance increases. This is because the pressure of the cooling air is lost in the flow path from the injection port 52A to the liquid crystal panel 451G.
On the other hand, when the distance between the liquid crystal panel 451G and the injection port 52A is 5 mm to 30 mm, the wind speed in the vicinity of the liquid crystal panel 451G is 30 m / s or more and is substantially constant. In the present embodiment, since the distance between the liquid crystal panel 451G and the ejection port 52A is set to about 10 mm, the cooling air velocity in the vicinity of the liquid crystal panel 451G is set to be maximum.

The sirocco fan 54 is a fan that sucks air from the rotation axis direction and discharges the sucked air in the rotation tangential direction, and one end of a duct 55 having a substantially L-shaped cross section is connected to the discharge port 54A. Has been.
The duct 55 guides the cooling air discharged from the sirocco fan 54 to the liquid crystal panel 451G. More specifically, the other end of the duct 55 is cooled along the light incident side end surface 451A and the light emission side end surface (not shown) of the liquid crystal panel 451G from the lower side to the upper side in FIG. It arrange | positions so that a wind may be discharged.
That is, in the present embodiment, the low static pressure blower is configured by the sirocco fan 54 and the duct 55, and the nozzle 52 is about 30 ° with respect to the discharge direction of the cooling air discharged from the low static pressure blower. It arrange | positions so that the cooling air discharged from the vortex pump 51 may be injected toward a direction.

FIG. 7 is a diagram showing a theoretical value of the relationship between the temperature rise amount of the liquid crystal panel 451G when the projector 1 is in operation and the cooling air velocity in the vicinity of the liquid crystal panel 451G. FIG. 7 is a graph in which the vertical axis represents the temperature rise (° C.) and the horizontal axis represents the wind speed (mm).
When the projector 1 is activated, the liquid crystal panel 451G generates heat when light emitted from the light source lamp 411 enters, and is cooled as cooling air discharged from the vortex pump 51 and the sirocco fan 54 circulates. . At this time, as shown in FIG. 7, the theoretical value of the temperature rise amount of the liquid crystal panel 451G decreases as the wind speed of the cooling air rises, and reaches the saturation region when reaching a certain wind speed.

FIG. 8 is a diagram showing the relationship between the temperature rise amount of the liquid crystal panel 451G during the operation of the projector 1 and the operating states of the vortex pump 51 and the sirocco fan 54. FIG. 8 is a graph in which the vertical axis represents the temperature rise (° C.) and the horizontal axis represents the operating state of the vortex pump 51 and the sirocco fan 54.
Of the two adjacent bar graphs, the left bar graph indicates that the drive voltage of the sirocco fan 54 is 4V, 5V, 9V, and 13V, respectively, and the temperature rise of the liquid crystal panel 451G when the vortex pump 51 is not operated. The bar graph on the right side shows the amount of temperature rise of the liquid crystal panel 451G when the drive voltage of the sirocco fan 54 is 4 V, 5 V, 9 V, and 13 V, respectively, and the vortex pump 51 is operated.

For example, when the driving voltage of the sirocco fan 54 is 4 V and the eddy current pump 51 is not operated, the temperature rise amount of the liquid crystal panel 451G is about 39 ° C. as shown in FIG. In this case, if the wind speed of the cooling air in the vicinity of the liquid crystal panel 451G is superimposed on the theoretical value shown in FIG. 7, the wind speed S1 is obtained.
Further, for example, when the driving voltage of the sirocco fan 54 is set to 13 V and the eddy current pump 51 is not operated, the temperature rise amount of the liquid crystal panel 451G is about 21 ° C. as shown in FIG. In this case, if the wind speed of the cooling air in the vicinity of the liquid crystal panel 451G is superimposed on the theoretical value shown in FIG. 7, the wind speed S2 is obtained.

Here, as shown in FIG. 7, the temperature rise amount of the liquid crystal panel 451 </ b> G is less likely to decrease when it exceeds the wind speed S <b> 2 and reaches the saturation region.
Therefore, for example, if the drive voltage of the sirocco fan 54 is set to 13 V and the eddy current pump 51 is operated, the temperature rise amount of the liquid crystal panel 451G is about 16 ° C. as shown in FIG. Note that the wind speed S3 is obtained by superimposing the wind speed of the cooling air in the vicinity of the liquid crystal panel 451G in this case on the theoretical value shown in FIG.
As described above, by setting the eddy current pump 51 in an operating state, the temperature rise amount of the liquid crystal panel 451G can be reduced even in the saturation region.

According to this embodiment, there are the following effects.
(1) Since the cooling device includes the vortex pump 51 having a discharge pressure of 4.5 kPa or more and the nozzle 52, the cooling air speed can be sufficiently increased, and the temperature of the liquid crystal panel 451G can be increased even in the saturation region. Can be reduced. Accordingly, it is possible to improve the cooling efficiency of the liquid crystal panel 451G, and thus to extend the life of the projector 1.
(2) Since the liquid crystal panel 451G is cooled by the cooling air discharged from the vortex pump 51 and the cooling air discharged from the sirocco fan 54, the cooling efficiency of the liquid crystal panel 451G can be further improved.

(3) The nozzle 52 is disposed so as to inject the cooling air discharged from the vortex pump 51 in a direction that is approximately 30 ° with respect to the cooling air discharge direction by the sirocco fan 54. The direction in which the cooling air is ejected by 52 is forward with respect to the direction in which the sirocco fan 54 ejects the cooling air. Therefore, the wind speeds of the cooling air discharged from the vortex pump 51 and the sirocco fan 54 do not decrease each other.
(4) Since the discharge direction of the cooling air from the nozzle 52 is larger than 0 ° with respect to the discharge direction of the cooling air from the sirocco fan 54, the cooling air discharged from the vortex pump 51 and the sirocco fan 54 is liquid crystal panel 451G. It becomes a turbulent flow in the vicinity. Therefore, the cooling efficiency of the liquid crystal panel 451G can be further increased.

(5) The injection port 52A of the nozzle 52 is formed in a substantially circular shape, and the inner diameter of the injection port 52A is set so that the cooling air velocity in the vicinity of the liquid crystal panel 451G is maximized. The wind speed of the discharged cooling air can be sufficiently increased, and the cooling efficiency of the liquid crystal panel 451G can be further improved.
(6) The distance between the liquid crystal panel 451G and the injection port 52A of the nozzle 52 is set so that the wind speed of the cooling air in the vicinity of the liquid crystal panel 451G is maximized. The speed of the cooling air can be sufficiently increased, and the cooling efficiency of the liquid crystal panel 451G can be further improved.

[Modification of Embodiment]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
In the embodiment, the vortex pump 51 having a discharge pressure of about 4.75 kPa is employed as the high static pressure blower. On the other hand, you may employ | adopt the scavenging pump etc. which have a larger discharge pressure than the discharge pressure of the vortex pump 51 as a high static pressure air blower. In short, the high static pressure blower only needs to have a discharge pressure of 4.5 kPa or more.

FIG. 9 is a diagram showing the relationship between the static pressure and the air volume in the vortex pump 51 and the diaphragm-type scavenging pump. In FIG. 9, a graph showing the relationship between the static pressure in the vortex pump 51 and the air volume is G1, and a graph showing the relationship between the static pressure in the scavenging pump and the air volume is G2.
This diaphragm-type scavenging pump is a scavenging pump having a discharge pressure of 90 kPa or more, and has a higher discharge pressure than the vortex pump 51 in the first embodiment, as shown in FIG. Even when such a scavenging pump is employed as a high static pressure blower, the same effects as those of the first embodiment can be obtained.

However, such a diaphragm-type scavenging pump compresses air introduced from the intake port by reciprocating the diaphragm and discharges it from the exhaust port. Since the contact area of the movable part is large, the vortex pump Although the discharge pressure is higher than 51, there is a problem that the life is short, and consequently the life of the cooling device is shortened.
On the other hand, the eddy current pump 51 in the above-described embodiment is disposed in a state where the disk member, which is a movable part, and the impeller are opposed to each other in a non-contact manner, and thus has a lifetime compared to a diaphragm scavenging pump. Therefore, the service life of the cooling device can be extended.

  In the said embodiment, although the cooling device 5 was provided with the sirocco fan 54 and the duct 55 as a low static pressure air blower, the low static pressure air blower does not need to be provided. However, when the surface area of the optical element is large, it is preferable to use a low static pressure blower capable of cooling the entire optical element in combination with a high static pressure blower as in the present embodiment.

In the said embodiment, the nozzle 52 was arrange | positioned so that the cooling air discharged from the eddy current pump 51 might be injected toward the direction which becomes about 30 degrees with respect to the discharge direction of the cooling air by a low static pressure air blower. However, what is necessary is just the direction used as 0 degree-90 degrees. For example, the nozzle may be disposed so as to inject cooling air discharged from the high static pressure blower toward a direction of 0 ° with respect to the discharge direction of the cooling air by the low static pressure blower. However, in this case, since the cooling air discharged from the high static pressure blower and the low static pressure blower cannot obtain an effect of turbulent flow in the vicinity of the optical element, the configuration in this embodiment is preferable.
The nozzle may be arranged to inject cooling air discharged from the high static pressure blower toward a direction larger than 90 ° with respect to the cooling air discharge direction by the low static pressure blower. Since the cooling air injection direction by the nozzle is opposite to the cooling air discharge direction by the low static pressure blower, the wind speeds of the cooling air discharged from the high static pressure blower and the low static pressure blower are reduced. The configuration of the present invention is preferable.

In the above-described embodiment, the injection port 52A of the nozzle 52 is formed in a substantially circular shape, and the inner diameter of the injection port 52A is set to 0.8 mm, but may be set to 0.6 mm to 1 mm. However, when the inner diameter of the injection port 52A is 0.8 mm, the wind speed in the vicinity of the liquid crystal panel 451G is about 32 m / s and becomes the maximum, so the configuration in this embodiment is preferable. In short, the inner diameter of the ejection port 52A may be set so that the cooling air velocity near the liquid crystal panel 451G is maximized.
In addition, the injection port of the nozzle may be formed in shapes other than circular. Moreover, although the internal diameter of an injection port may be set to internal diameters other than 0.6 mm-1 mm, since the wind speed in the optical element vicinity falls, the structure of this invention is preferable.

In the above-described embodiment, the ejection port 52A is disposed at a position where the distance from the light incident side end surface 451A of the liquid crystal panel 451G is about 10 mm, but may be disposed at a position where the distance is 5 mm to 30 mm. . In short, it suffices if the cooling air velocity in the vicinity of the liquid crystal panel 451G is set to be maximum.
In addition, although a jet nozzle may be arrange | positioned in the position where the distance between optical elements becomes other than 5 mm-30 mm, since the wind speed in the optical element vicinity falls, the structure of this invention is preferable.

In the embodiment, the liquid crystal panel 451G is cooled by the cooling device 5 including the vortex pump 51. However, for example, the incident side polarizing plate 452, the emission side polarizing plate 453, and the like may be cooled.
In the embodiment, the projector 1 includes the three liquid crystal panels 451. However, the projector 1 may be configured as a projector including two light modulation devices or a projector including four or more liquid crystal panels.
In the above-described embodiment, the liquid crystal panel 451 employs a configuration in which the liquid crystal, which is an electro-optical material, is sealed in a pair of transparent glass substrates and transmits incident light. A liquid crystal panel configured as described above, or a DMD (Digital Micromirror Device) (trademark of Texas Instruments, Inc.) may be employed.

  The present invention can improve cooling efficiency and extend the life of the projector. Therefore, the present invention can be suitably used for projectors used for presentations and home theaters.

1 is a schematic diagram showing a schematic configuration of a projector according to an embodiment of the invention. The figure which shows schematic structure of a part of cooling device which cools the optical apparatus main body in the said embodiment, and the liquid crystal panel by the side of green light. The figure which shows the relationship between the static pressure in the vortex pump in the said embodiment, and an air volume. The figure which shows the relationship between the static pressure in the sirocco fan in the said embodiment, and an airflow. The figure which shows the relationship between the wind speed of the cooling wind in the liquid crystal panel vicinity in the said embodiment, and the internal diameter of an injection nozzle. The figure which shows the relationship between the wind speed of the cooling wind in the liquid crystal panel vicinity in the said embodiment, and the distance between a liquid crystal panel and a jet nozzle. The figure which shows the theoretical value of the relationship between the temperature rise amount of the liquid crystal panel at the time of the operation | movement of the projector in the said embodiment, and the wind speed of the cooling wind in the liquid crystal panel vicinity. The figure which shows the relationship between the temperature rise amount of the liquid crystal panel at the time of operation | movement of the projector in the said embodiment, and the operating state of a vortex pump and a sirocco fan. The figure which shows the relationship between the static pressure in an eddy current pump and a diaphragm type scavenging pump, and an air volume.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector, 5 ... Cooling device, 51 ... Eddy current pump (high static pressure blower), 52 ... Nozzle, 52A ... Injection port, 54 ... Sirocco fan (low static pressure blower), 55 ... Duct (low static pressure blower), 451A: Light incident side end surface, 451G: Liquid crystal panel (optical element).

Claims (4)

A projector that modulates light emitted from a light source according to image information to form image light, and projects the formed image light,
A cooling device for cooling an optical element disposed on an optical path of light emitted from the light source;
The cooling device is
A high static pressure blower having a discharge pressure of 4.5 kPa or more;
A projector comprising: a nozzle that jets cooling air discharged from the high static pressure blower toward the optical element. The projector according to claim 1, wherein
The cooling device is
Equipped with a low static pressure blower with a discharge pressure of less than 4.5 kPa,
The low static pressure blower is
Arranged to discharge cooling air along at least one of the light incident side end surface and the light emission side end surface of the optical element;
The nozzle is
The cooling air discharged from the high static pressure blower is jetted toward the direction of 0 ° to 90 ° with respect to the discharge direction of the cooling air discharged from the low static pressure blower. Characteristic projector. In the projector according to claim 1 or 2,
The injection port of the nozzle is formed in a substantially circular shape,
The projector is characterized in that an inner diameter of the ejection port is set so that a cooling air velocity in the vicinity of the optical element is maximized. The projector according to any one of claims 1 to 3,
The projector is characterized in that the distance between the optical element and the nozzle outlet is set so that the cooling air velocity in the vicinity of the optical element is maximized.

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