JP2002244213A - Projector and cooling control method for projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector which is very silent and a cooling control method for the projector without any entry of dust in an unused state while securing cooling efficiency. SOLUTION: This projector 1 is equipped with an air cooling control structure including an air discharge opening 160 consisting of a slit 160A, an air discharge opening cover 112 which is arranged opposite to the air discharge opening 160 and has the same number of cover slits 112A formed in the same shape and at the same height positions as the slits 160A, an air discharge cover driving part 113 which moves the air discharge cover 112 to the right and left, and an air discharge cover position adjusting means which adjusts the driving of the air discharge cover driving part 113 according to the detected temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a projector and a method for controlling cooling of the projector.

[0002]

2. Description of the Related Art In recent years, the environment in which a projector is used has been expanding, and the projector is used not only for in-company meetings and presentations at business trips, but also for CAD / CAM.
By taking in and projecting / CAE data, it is used for technical review meetings in research and development departments, various seminars and workshops, school classes for audiovisual education, and even at home. . It is also used to project medical images and data such as CT scans and MRIs, to use in examining treatment methods, to provide medical guidance, and to effectively produce exhibitions and events where many people gather. In this way, today, when projectors are used in all environments, the specifications and functions required of the projectors are also various, and lightweight and compact models pursuing portability,
There are high-brightness models and high-resolution models that pursue image quality, and high-performance models that enable connection with various digital devices and mobile tools.

As such a projector, for example, an optical system that modulates a light beam emitted from a light source and forms a projection image by enlarging and projecting the image in accordance with image information by a light modulator, and houses the optical system There is known a configuration including an external case that performs the operation. Of the components constituting such an optical system, various optical elements such as a light modulator and a polarization conversion element are relatively weak to heat, and it is important how to efficiently cool them. . For this reason, an air intake / exhaust port is formed in an exterior case that houses the optical system, and a fan is arranged inside the external case, thereby cooling the inside of the projector.

[0004]

However, since the air intake and exhaust ports are always open, dust enters the projector when not in use, and adheres to the optical elements such as the light modulation device, thereby deteriorating the image quality. there is a possibility. Also, since the intake and exhaust ports are always open, noise such as fan operating noise and wind noise leaks to the outside as it is, which makes it particularly difficult to use in quiet conference rooms and at home. is there.

An object of the present invention is to secure cooling efficiency and
An object of the present invention is to provide a projector that is quiet and does not allow dust to enter when not in use, and a cooling control method for the projector.

[0006]

SUMMARY OF THE INVENTION A projector according to the present invention comprises: an optical system for modulating a light beam emitted from a light source in accordance with image information by a light modulator, and performing enlarged projection to form a projected image; A projector for accommodating the optical system and the fan, wherein the exterior case has an air inlet for sucking cooling air therein, and the cooling air from the inside. An exhaust port for discharging is formed, and an opening area adjusting mechanism for adjusting an opening area of the intake port and / or the exhaust port is provided.

[0007] In this invention, since the opening area of at least one of the intake port and the exhaust port is configured to be adjustable, the intake amount or the discharge amount of the cooling air can be adjusted. For this reason, for example, if the opening area adjusting mechanism is set so as to increase the opening area of the intake port or the exhaust port with an increase in the internal temperature, without increasing the rotation speed of the fan,
The cooling air intake or discharge can be adjusted. That is,
An optimum opening area that can ensure a sufficient cooling effect can be selected according to various conditions such as the internal temperature. Therefore, while ensuring a sufficient cooling effect, the opening area of the intake port or the exhaust port can be minimized, and noise such as the operating noise of the fan leaking to the outside is minimized, and quietness is reduced. Can be secured.

Further, as a structure for adjusting the opening area,
For example, a louver is provided at the exhaust port or the intake port, a configuration in which the opening area is adjusted by changing the angle of the louver, or an exhaust port is formed in a slit shape, and a slit having a shape corresponding to the exhaust port is provided. Cover facing the exhaust port,
By moving the cover and changing the degree of overlap between the exhaust port and the slit, various configurations such as a configuration for adjusting the opening area can be adopted. In such a case, a large component or the like is not necessary again. Also, portability can be secured.

The present invention includes the case where the opening area is zero, that is, the case where the intake port or the exhaust port is not open at all and is closed, which is also included in the present invention. By setting the opening area adjusting mechanism as described above, it is possible to prevent dust from entering the inside by closing the intake port or the exhaust port when not in use. The opening area adjusting mechanism may be configured to be adjusted by a user, but is preferably configured to be adjusted automatically. With this configuration, it is not necessary for the user to adjust the opening area by himself, so that the burden on the user can be reduced.

The projector according to the present invention includes a temperature detecting element for detecting a temperature of a plurality of optical elements including the light modulation device, and the opening area adjusting mechanism operates based on the temperature detected by the temperature detecting element. Preferably, the opening area is adjusted. According to this structure, the temperature detecting unit detects the temperatures of the plurality of optical elements.
By monitoring the temperature of an optical element that is easily affected by temperature, such as a light modulator, and setting an opening area adjustment mechanism to adjust the opening area, it is possible to more reliably prevent the temperature of the optical element from rising. The performance of the projector can be sufficiently ensured. Since the light modulator is particularly weak against heat,
It is preferable to dispose a temperature detecting element near the light modulation device. In this case, the performance of the projector can be more reliably ensured.

The projector according to the present invention includes an illumination optical system for illuminating the image forming area of the light modulation device substantially uniformly, and the temperature detecting element detects temperatures of the illumination optical system and the light modulation device. It is preferable that the opening area adjustment mechanism adjusts the opening area based on the higher temperature of the illumination optical system and the light modulation device. According to such a configuration, since the aperture area is adjusted according to the higher temperature of the illumination optical system and the light modulation device, the temperature rise of the optical element can be prevented more reliably, and the performance of the projector can be sufficiently improved. Can be secured.

It is preferable that the opening area adjusting mechanism adjusts an opening area of the exhaust port. In general projectors, the opening area of the exhaust port can be adjusted in this way, considering that the exhaust port is not provided with various dustproof means such as an air filter in order to secure the discharge amount of cooling air. Therefore, if the opening area adjusting mechanism is set so as to close the exhaust port when not in use, it is possible to prevent dust and the like from entering the inside of the projector, and to reliably ensure the performance of the projector.

According to the projector of the present invention, the light beam emitted from the light source is modulated by the light modulator according to the image information.
An optical system that forms a projection image by enlarging and projecting, a fan for flowing air, and a projector including an outer case that houses the optical system and the fan,
The exterior case has an intake port for taking in cooling air therein and an exhaust port for discharging this cooling air from the inside. An opening area adjustment mechanism for adjusting the opening area of the mouth is provided. With this configuration, the same function and effect as the above-described invention can be obtained. Further, as such a start operation, various operations such as an input operation of a power switch and an operation of removing a lens cover for protecting a lens constituting an optical system can be adopted, and these operations can be used by any user. Since the necessary operation is performed beforehand, the required opening area is not forgotten, so that the opening area can be ensured and the cooling effect can be sufficiently ensured. Note that the present invention can be modified in a manner corresponding to the technology described above. In that case, the same effect as described above can be secured.

Preferably, in the optical system, an optical path from the light source to the light modulation device is provided in a substantially U-shaped plane. With this configuration, the size of the optical system can be reduced, and the size of the projector itself can be reduced, and portability can be improved, as compared with the case where the projector is provided in a plane linear shape.

A cooling control method for a projector according to the present invention is a method for controlling cooling of a projector according to any one of the above, wherein a temperature detecting procedure for detecting a temperature of the optical system, A temperature determination procedure for determining whether or not the temperature detected by the temperature detection means exceeds a predetermined temperature; and, if the detected temperature exceeds the predetermined temperature, whether the opening area is the maximum. An opening area determining step of determining whether the detected temperature exceeds the predetermined temperature, and if the opening area is not the maximum, an opening area adjusting step of adjusting the opening area; and A fan rotation speed increasing step of increasing the rotation speed of the fan when the area is maximum.

The predetermined temperature indicates a permissible limit temperature when the projector is used as specified. When the temperature is equal to or lower than the predetermined temperature, the opening area may be set to a size as an initial setting when the projector is started. The case where the opening area is the maximum indicates a case where the opening area becomes the maximum (maximum value) within the preset fluctuation range. Therefore, the case where the opening area is not the maximum indicates the case where the opening area is equal to or more than the minimum value of the variation range and less than the maximum value.

According to the present invention, a step of increasing the number of rotations of the fan is provided, so that the temperature of the optical system rises above a predetermined temperature,
And in the case where the opening area cannot be increased because the opening area is maximized, and even in an emergency where the temperature of the optical system is further increased, by increasing the rotation speed of the fan,
The optical system can be sufficiently cooled, and the performance of the projector can be secured. In other words, in the normal state where the opening area is not the maximum, by adjusting the opening area by the opening area adjustment procedure, the cooling effect, the quietness, the portability, etc. can be ensured as described above, and the temperature is further increased. Even in an emergency, a sufficient cooling effect can be ensured by increasing the rotation speed of the fan.

The fans according to the present invention include, for example, axial fans and sirocco fans having different structures,
There are intake and exhaust fans with different functions,
The fan may be a combination of any structure and function.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIG. First Embodiment <1> Overall Configuration of Apparatus FIGS. 1 and 2 are schematic perspective views of a projector 1 according to the present embodiment. FIG.
Is a perspective view as viewed from the lower surface side. The projector 1 separates a light beam emitted from a light source device as a light source into three primary colors of red (R), green (G), and blue (B), and passes these color light beams through a liquid crystal panel constituting an optical modulation device. In this type, the light is modulated in accordance with image information, and modulated light fluxes of the respective colors are combined by a cross dichroic prism and enlarged and displayed on a projection surface via a projection lens 6. Each component is housed inside the outer case 2, and the projection lens 6 is provided so as to be able to protrude from the outer case 2 as needed by its zoom mechanism.

<2> Structure of Outer Case The outer case 2 is basically composed of an upper case 3 that covers the upper surface of the device, a lower case 4 that forms the bottom surface of the device, and a front case 5 that covers the front portion. The upper case 3 and the lower case 4 are made of magnesium die-cast, and the front case 5 is made of resin.

An intake port 240 covered with a resin intake port cover 241 is provided on the upper right side of the upper case 3 (right side when viewed from the front). This inlet cover 24
1, a slit-shaped opening 241A for introducing air taken in from the outside as cooling air into the apparatus is formed, and an air filter 242 (FIG. 8) is provided inside the air inlet cover 241. I have. By attaching and detaching the intake port cover 241 from the upper surface side of the upper case 3, the internal air filter 242 can be replaced.

On the upper surface of the upper case 3,
A large number of communication holes 251 for the speaker 250 (FIG. 7) are formed on the front side of the intake port cover 241. An operation panel 60 for adjusting the image quality and the like of the projector 1 is provided beside the communication hole 251. These intake port cover 241, communication hole 251 and operation panel 60
As shown in FIGS. 7 and 8, a portion provided with a swelling portion 3 in which a part of the upper case 3 swells upward.
A in the internal space formed by the bulging portion 3A, the air filter 242 and the speaker 25
0, a circuit board 61 for the operation panel 60 and the like are accommodated.

In FIG. 2, a lamp replacement cover 27 for replacing the light source lamp unit 8 (FIGS. 3 and 4) housed therein is provided on the bottom surface of the lower case 4. A foot 31 is provided at the front corner of the bottom of the lower case 4.
R, 31L are provided, and a foot 31C is provided in the center on the rear side.
Is provided. The feet 31R and 31L are configured to move in the protruding direction by rotating a dial portion or operating the levers 32R and 32L, and change the height or inclination of the display screen by adjusting the amount of movement. It is possible.

In FIG. 1, a light receiving section 70 for receiving an optical signal from a remote controller (not shown) is provided on a right side of the front surface of the front case 5 as viewed from the front. At an approximate center of the front case 5, an exhaust port 160 for discharging air inside the apparatus is provided. On the side and back of the exterior case 2 near the intake port 240,
An AC inlet 50 for connection to an external power supply and various input / output terminal groups 51 are arranged.

<3> Internal Structure of the Device FIGS. 3 to 8 show the internal structure of the projector 1. 3 is a schematic perspective view showing the inside of the apparatus, FIG. 4 is a perspective view showing the optical system, FIGS. 5 and 6 are perspective views showing the inside of the optical system, and FIGS. 7 and 8 are vertical sectional views of the projector 1. In these figures, a light source lamp unit 8, a power supply unit 9 as a power supply, an optical unit 10, a driver board 11 (FIG. 8), a main board 1
2, an AV board 13 and the like are arranged. In the present embodiment, the light source lamp unit 8 and the optical unit 1
9 and the projection lens 6 described above, as shown in FIG. 9, a planar U-shaped optical system according to the present invention is configured, and the boards 11, 12, and 13 configure a control system.

The power supply unit 9 includes a projection lens 6 of the optical system.
A first power supply block 9A disposed on the side of the side, a second power supply block 9B disposed in the central opening 14 of the flat U-shaped optical system, that is, between the projection lens 6 and the light source lamp unit 8. And a third power supply block 9C arranged on the side of the optical system on the light source lamp unit 8 side. The first power supply block 9A is connected to the AC inlet 5.
0, and distributes and supplies power from an external power supply obtained through the AC inlet 50 to the second power supply block 9B and the third power supply block 9C. The second power supply block 9B transforms the power obtained from the first power supply block 9A and supplies it to the main board 12, which mainly forms a control unit. The exhaust port 160 of the second power supply block 9B
On the side, an auxiliary exhaust fan 15 driven by electric power from the second power supply block 9B is attached. Further, an auxiliary exhaust fan 15 and a main exhaust fan 1 described later are used.
An exhaust port cover driving device 111 that is driven by electric power from the second power supply 9B is attached to the exhaust port 160 side (front side) of No. 6. The third power supply block 9C transforms the power obtained from the first power supply block 9A and supplies it to a light source device 183 (FIG. 9) as a light source in the light source lamp unit 8. That is, the third power supply block 9C is larger than the first and second power supply blocks 9A and 9B because the third power supply block 9C needs to supply power to the light source device 183 having the largest power consumption.
It is provided in a size extending across the projector 1.

The first to third power supply blocks 9A to 9A
9C is fixed to the lower case 4 with screws or the like prior to the projection lens 6 and the optical unit 10. The first
The power supply block 9A may supply power only to the second power supply block 9B, and the third power supply block 9C may receive power from the second power supply block 9B. The light source lamp unit 8 constitutes a light source part of the projector 1, and as shown in FIG.
The light source device 183 includes the light source device 183 and the concave mirror 182, and a lamp housing 184 that accommodates the light source device 183. Note that the lamp housing 184 includes a use presence / absence determination unit 2 for determining whether the light source lamp 181 is used.
60 are provided.

In the lamp housing 184, the light source lamp unit 8, which is a light source device, is covered by an accommodating portion 9021 integral with an upper light guide 901 constituting a light guide 900 described later. It is configured so that it can be opened and removed. A main exhaust fan 16 larger than the auxiliary exhaust fan 15 is disposed at a position corresponding to the exhaust port 160 in front of the housing portion 9021. The main exhaust fan 16 is also the second
It is driven by power from the power supply block 9B.

The optical unit 10 is a unit for optically processing a light beam emitted from the light source lamp unit 8 to form an optical image corresponding to image information, and includes a light guide 900. This light guide 900 is composed of an upper light guide 901 made of resin and made in a box shape, and a lower light guide 902 made of magnesium and made in a lid shape, and has an illumination optical system 923 and a color light separation optical system inside. 9
24, a light modulator 925, a relay optical system 927, and a cross dichroic prism 910 are housed therein. The lower light guide 902 is provided with a vertical head plate 903 to which the projection lens 6 is fixed. Light modulator 925 and cross dichroic prism 91
The optical elements of the optical unit 10 other than 0 are configured to be held between the upper and lower light guides 901 and 902. The upper light guide 901 and the lower light guide 902 are integrated and fixed to the lower case 4 side.

The cross dichroic prism 910 is
It is arranged on the opposite side of the projection lens 6 with the head plate 903 interposed therebetween, and is fixed on the lower light guide 902 via a support member. Each of the liquid crystal panels 925R, 925G, and 925B constituting the light modulation device 925 is disposed to face three side surfaces of the cross dichroic prism 910, and is bonded and fixed to a surface of the cross dichroic prism 910 via a fixing member. Each liquid crystal panel 925
The positional relationship between R, 925G, and 925B is such that the liquid crystal panel 925B and the liquid crystal panel 925R are provided at positions facing each other with the cross dichroic prism 910 interposed therebetween.
The liquid crystal panel 925G is a cross dichroic prism 9
The lens 10 is provided at a position facing the projection lens 6 with the film 10 interposed therebetween. And, these liquid crystal panels 925R, 925
G and 925B are cross dichroic prisms 910
And is cooled by cooling air from the intake fan 17 provided corresponding to the above-described intake port 240. At this time, electric power for driving the intake fan 17 is supplied from the main board 12 via the driver board 11.

The driver board 11 includes the liquid crystal panels 925R, 925G, and 925 of the light modulator 925 described above.
B, and is disposed above the optical unit 10. The main board 12 is provided with a control circuit for controlling the entire projector 1.
It stands upright behind the optical unit 10. Therefore, the main board 12 and the driver board 11 are arranged at right angles to each other and are electrically connected via the connector. The main board 12 includes a lamp information detection circuit board 2 for detecting information from the use presence / absence determination unit 260.
30 are connected via a cable. The AV board 13 is a circuit board provided with the above-described input / output terminal group 51, and is provided upright between the optical unit 10 and the main board 12, and is electrically connected to the main board 12.

In the above internal structure, the intake fan 1
The cooling air sucked in 7 cools the light modulator 925, and then cools the boards 11, 12, 13 by the rotation of the exhaust fans 15, 16 while cooling the boards 11, 12, 13.
Guided to the side. The cooling air flows into the light source lamp unit 8 together with new cooling air from the suction port 4A (FIG. 2) provided on the bottom surface of the lower case 4 to cool the internal light source device 183. In addition, a part of the cooling air flows on the second power supply block 9B side, and another part flows on the third power supply block 9C side to cool the respective parts. After this,
The cooling air is supplied to the exhaust port 16 by the exhaust fans 15 and 16.
Air is exhausted from 0 to the front side of the projector 1.

<4> Structure of Optical System Next, an optical unit 10 as an optical system according to the present invention will be described in detail with reference to FIGS. The optical unit 10 includes an illumination optical system 923 housed in the upper light guide 901, a color light separation optical system 924,
It comprises a relay optical system 927, a cross dichroic prism 910 fixed to the lower light guide 902, and the projection lens 6 fixed to the head plate 903 of the lower light guide 902.

The illumination optical system 923 is an integrator illumination optical system for almost uniformly illuminating the image forming areas of the three liquid crystal panels 925R, 925G, and 925B of the light modulation device 925, and includes a light source device 183 and a first light source device 183. , A second lens array 922, a reflection mirror 931 and a superimposing lens 932. These lens arrays 921 and 922, the superimposing lens 932, and the reflection mirror 931 are arranged in a state of being supported by the rising portion of the upper light guide 901, and are fixed by the clip 7 as a falling-off prevention member. Even if the light guide 901 is inverted from the state shown in FIG. 3, it does not fall off. The light source device 183 forming the illumination optical system 923 includes a light source lamp 181 as a radiation light source that emits a radial light beam, and the concave mirror 1 that emits a radiation light emitted from the light source lamp 181 as a substantially parallel light beam.
82. As the light source lamp 181, a halogen lamp, a metal halide lamp, or a high-pressure mercury lamp is often used. As the concave mirror 182, it is preferable to use a parabolic mirror or an elliptical mirror.

The first lens array 921 has a configuration in which small lenses 9211 having a substantially rectangular outline are arranged in a matrix of M rows and N columns. Each small lens 9211
Divides a parallel light beam incident from a light source into a plurality of (ie, M × N) partial light beams, and forms an image of each of the partial light beams near the second lens array 922. Each small lens 92
The contour shape of the eleventh liquid crystal panel 925R, 925G,
925B is set to be substantially similar to the shape of the image forming area. For example, if the aspect ratio (the ratio between the horizontal and vertical dimensions) of the image forming area of the liquid crystal panel is 4: 3, the aspect ratio of each small lens is also set to 4: 3.

The second lens array 922 also corresponds to the small lens 9211 of the first lens array 921.
It has a configuration in which small lenses 9221 are arranged in a matrix of M rows and N columns. The second lens array 922 has a function of aligning the central axes (principal rays) of the respective partial luminous fluxes emitted from the first lens array 921 so as to be perpendicularly incident on the incident surface of the superimposing lens 932. Here, the superimposing lens 932 converts the plurality of partial luminous fluxes into three liquid crystal panels 92.
It has a function of superimposing on 5R, 925G, and 925B. In addition, as shown in FIG. 5, the second lens array 922 is arranged at an angle of 90 degrees with respect to the first lens array 921 with the reflection mirror 931 interposed therebetween.

The reflecting mirror 931 converts the light beam emitted from the first lens array 921 into a second lens array 922.
This is not necessarily required depending on the configuration of the illumination optical system. For example, it is unnecessary if the first lens array 921 and the light source are provided in parallel with the second lens array 922. Color light separation optical system 924
Is provided with two dichroic mirrors 941 and 942 as optical components according to the present invention, and a reflection mirror 943, and emits light emitted from the superimposing lens 932 of the illumination optical system 923 into three colors of red, green, and blue. Has a function of separating the light into two colors. Each of the mirrors 941, 942, 943 is supported by the rising portion of the upper light guide 901 as described above, and is fixed to the upper light guide 901 by the clip 7.

The relay optical system 927 includes an entrance side lens 95.
4. Relay lens 973 and reflection mirrors 971, 9
72, and these reflection mirrors 971, 972
Is also fixed to the upper light guide 901 by the clip 7. Liquid crystal panels 925R and 92 of the light modulation device 925
5G and 925B use, for example, a polysilicon TFT as a switching element. Each liquid crystal panel 9
25R, 925G, and 925B are upper light guides 901
Of the cross dichroic prism 910 in a state of being arranged corresponding to the concave portion 904 (FIG. 5) provided on the outer periphery of the upper light guide 901 and facing three side surfaces of the cross dichroic prism 910. Is fixed to the surface to be bonded via a fixing member. Each of the liquid crystal panels 925R, 925G, and 925B has an incident-side polarizing plate 960R, 960G, and 960B on the light incident / exit surface side, and an output-side polarizing plate 961R, 961G, and 961 on the light exit surface side.
B are arranged respectively.

The cross dichroic prism 910 is
It has a function of forming a color image by combining three color lights, and is fixed to the upper surface of the lower light guide 902 by a fixing screw. In the cross dichroic prism 910, a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a substantially X shape along the interface of the four right-angle prisms. Three color lights are synthesized by the body multilayer film. The projection lens 6 is the projector 1
Is the heaviest optical component among them, and is connected to the lower light guide 90 via a flange 62 provided on the base end side.
The second head plate 903 is fixed with screws or the like.

The optical unit 10 configured as described above
Is assembled as follows. First, a box-shaped upper light guide 901 is placed with its opening side facing upward, and the illumination optical system 9 is placed in the upper light guide 901.
23, color light separation optical system 924, and relay optical system 92
The optical components (reflection mirrors, various lenses, etc.) constituting the components 7 and the like are arranged, and these optical components are fixed to the upper light guide 901 by the clips 7.

On the other hand, in the lid-like lower light guide 902, the liquid crystal panels 925R, 925G,
The cross dichroic prism 910 to which 5B is fixed is fixed, and the projection lens 6 is fixed to the head plate 903. Next, the upper light guide 9 on which each optical component is mounted
01, and it is attached and fixed so as to cover the lower light guide 902. Finally, the light guide 900 thus completed is fixed to the lower case 4 with screws or the like.

The liquid crystal panels 925R, 925G, 9
25B, the lower light guide 902 on which the cross dichroic prism 910 and the projection lens 6 are mounted is fixed to the lower case 4 first, and then the upper light guide 901 on which each optical component is mounted is inverted. Then, the lower light guide 902 is mounted so as to cover the lower light guide 902. Thereafter, the upper light guide 901 is screwed or the like.
May be fixed to the lower case 4. Further, only the lower light guide 902 is screwed to the lower case 4 first, and the liquid crystal panels 925R, 925
G, 925B and cross dichroic prism 91
0, or fix the projection lens 6, and then hold the upper light guide 901 on which each optical component is mounted, turn it over, and attach it so as to cover the lower light guide 902. Thereby, the upper light guide 901 may be fixed to the lower case 4.

In the present embodiment, the fixing of the cross dichroic prism 910 and the projection lens 6 to the lower light guide 902 and the fixing of the upper and lower light guides 901 and 902 to the lower case 4 are performed by screws. Such fixing may be performed by another appropriate fixing method such as bonding or fitting.

<5> Function of Optical System In the optical unit 10 shown in FIG.
The substantially parallel luminous flux emitted from is divided into a plurality of partial luminous fluxes by first and second lens arrays 921 and 922 constituting an integrator optical system (illumination optical system 923). Each small lens 9211 of the first lens array 921
Are partially superimposed on the image forming areas of the liquid crystal panels 925R, 925G, and 925B by the superimposing lens 932. As a result, each liquid crystal panel 9
25R, 925G, and 925B are illuminated with illumination light having a substantially uniform in-plane distribution.

At this time, the first dichroic mirror 941 of the color light separation optical system 924 reflects the red light component of the light beam emitted from the illumination optical system 923, and transmits the blue light component and the green light component. The red light reflected by the first dichroic mirror 941 is reflected by the reflection mirror 943, passes through the field lens 951, and reaches the liquid crystal panel 925R for red. This field lens 951 converts each partial light beam emitted from the second lens array 922 into a light beam parallel to its central axis (principal ray). The same applies to the field lenses 952 and 953 provided in front of the other liquid crystal panels 925G and 925B.

Of the blue light and the green light transmitted through the first dichroic mirror 941, the green light is reflected by the second dichroic mirror 942 and reaches the liquid crystal panel 925G for green through the field lens 952.
On the other hand, the blue light passes through the second dichroic mirror 942, passes through the relay optical system 927, and further reaches the liquid crystal panel 925B for blue light through the field lens 953. The reason why the relay optical system 927 is used for blue light is that the optical path length of the blue light is longer than the optical path length of the other color lights, thereby preventing a decrease in light use efficiency due to light diffusion or the like. That's why. That is, the partial light beam incident on the incident side lens 954 is directly used as the field lens 953.
It is to tell.

The red, green, and blue light components are transmitted to a liquid crystal panel 925.
R, 925G, and 925B are incident on the incident-side polarizers 960R, 960G, and 960B, and are converted into only specific polarized light. Thereafter, each polarized light is applied to each liquid crystal panel 925.
R, 925G and 925B are modulated according to the image information given thereto, and output-side polarizing plates 961R as modulated light.
The light is emitted to 961G and 961B. Then, in the output-side polarizing plates 961R, 961G, and 961B, only specific polarized light of the modulated light is transmitted and output to the cross dichroic prism 910. The emitted polarized lights of the respective color lights are combined by the cross dichroic prism 910 to be combined light, and emitted in the direction of the projection lens 6. This combined light is projected as a color image on a projection surface such as a projection screen by the projection lens 6.

<6> Cooling Control Structure and Control Method Thereof A cooling control structure for controlling the cooling of the projector 1 will be described with reference to FIG. FIG. 10 is a block diagram illustrating a cooling control structure of projector 1. The cooling control structure 101 is, as shown in FIG.
Exhaust port 160, exhaust port cover driving device 111,
It comprises a fan driving device 121, a temperature detecting element 102, and a control unit 103.

The intake port 240 is formed on the upper right side of the upper case 3 as described above, and cooling air is introduced from the outside. The exhaust port 160 is provided substantially at the center of the front case 5 as described above, and has a shape in which a plurality of rectangular slits 160A that are long in the up-down direction are arranged at equal heights at equal intervals. These slits 160A
The cooling air is exhausted from the inside of the device via.

The exhaust port cover drive device 111 is disposed between the exhaust port 160 and the auxiliary exhaust fan 15 and the main exhaust fan 16 as shown in FIGS.
An exhaust port cover 112 and an exhaust port cover driving unit 113 are provided. The exhaust port cover 112 is a rectangular plate-like member in which the same number of cover slits 112A as the slits 160A of the exhaust port 160 are formed, and the slit 160A and the cover slit 112A have the same height position. They are arranged to face each other. A rack 114 is formed at the lower edge of the exhaust port cover 112. On the other hand, although not shown, the upper edge of the exhaust port cover 112 is configured to engage with a rail-shaped hook formed on the upper part of the front case 5, and the exhaust port cover 112 extends along the hook. , Which are slidable in the left-right direction.

The exhaust port cover drive unit 113 includes a pinion 115 meshing with the rack 114 and a pinion 11
And a drive motor 116 for rotating the motor 5. Therefore, the pinion 115 is driven by the drive motor 116.
Rotates, and the exhaust port cover 112 can move in the left-right direction. Therefore, since the overlapping area between the slits 160A and 112A changes, the opening area of the exhaust port 160 can be adjusted. The drive motor 116 receives a signal from the exhaust port cover position adjusting means 105 described later,
The position of the exhaust port cover 112 can be changed. Note that the movable range of the exhaust port cover 112 includes a fully open position where the cover slit 112A and the slit 160A of the exhaust port 160 completely overlap and the opening area of the exhaust port 160 is maximized, and the slits 160A and 112A. It is between the closed position in which the positions are completely shifted from each other and the opening area is zero.

More specifically, as shown in FIG. 12, the exhaust port cover 112 moves in the left-right direction.
When the exhaust port cover 112 is at the position (A) in FIG. 12, the opening area of the exhaust port 160 is equal to the width of L1 in the figure due to the overlap between the slits 160A and 112A. Note that the position of the exhaust port cover 112 at this time is an initial position at the time of startup. In addition, when it is located at the position (B) in FIG.
2A are completely overlapped with each other, and the opening area thereof has the width of L2 in the figure, and the opening area is the maximum. The position of the exhaust port cover 112 at this time is the fully open position. Further, when it is at the position (C) in FIG. 12, the slit 160A and the cover slit 112A are completely displaced and have no opening area. The position of the exhaust port cover 112 at this time is the closing position.

The fan drive unit 121 includes a fan drive unit 122 composed of a motor and the like, the intake fan 17, and the exhaust fans 15, 16, and operates the fan drive unit 122 to operate the intake fan 17, the exhaust fan 15, and the exhaust fan 15. 16 is rotated at a predetermined rotation speed. At this time, the intake fan 17 always rotates at a predetermined rotation speed, but the exhaust fans 15, 16
A signal from a fan rotation speed adjusting means 106 described later is input to adjust the rotation speed. In addition,
As with the exhaust fans 15 and 16, the intake fan 17 may be configured such that its rotation can be adjusted by a signal from the fan rotation speed adjusting unit 106.

The temperature detecting element 102 is composed of a temperature sensor. Although not shown, the temperature detecting element 102 is disposed in two places, that is, in the vicinity of the light modulator 925 having various optical elements and in the vicinity of the illumination optical system 923. And illumination optical system 923
Near temperature is detected.

The control section 103 constitutes the main board 12 and includes a storage section 104 such as a memory, an exhaust port cover position adjustment section 105 as an opening area adjustment mechanism, and a fan speed adjustment section 106. Is done.

The storage means 104 stores each of the temperature detecting elements 102
Corresponding to the temperature detected in the step (a), the position information of the exhaust port cover 112 and the rotation speed information of the exhaust fans 15 and 16 are provided. The exhaust port cover position adjusting unit 105 receives the temperature detected by the temperature detecting element 102, compares the temperature with the position information for each temperature stored in the storage unit 104, and determines the temperature. Then, the position information of the exhaust port cover 112 is output. The fan rotation speed adjusting means 106 receives a signal from the exhaust port cover position adjusting means 105 that the position of the exhaust port cover 112 is at the fully open position (FIG. 12B), and detects the temperature detected by the temperature detecting element 102. If the temperature exceeds the limit temperature, the detected temperature at this time is input, and this temperature is compared with the rotation speed information for each temperature stored in the storage unit 104 to determine the temperature. The rotation speed information of the exhaust fans 15 and 16 is output.

Next, a cooling control method will be described with reference to FIG. FIG. 13 is a flowchart showing a procedure for controlling the cooling inside the projector. When the power switch is turned on and the projector 1 is energized via the AC inlet 50, the cooling control starts.

First, the exhaust port cover drive unit 113 is operated, and the exhaust port cover 112 has the maximum opening area from the closing position ((C) in FIG. 12) where the opening area is completely closed. The exhaust port cover position adjusting means 105 confirms the moving distance from the closed position to the fully opened position (step S1). Next, the fan drive unit 122 operates to rotate the intake fan 17 and the exhaust fans 15, 16 at a predetermined speed (step S2). Then, the exhaust port cover position adjusting means 105
After confirming the moving distance from the closed position to the fully open position, the exhaust port cover 112 is returned from the fully open position to the closed position again, and further moved therefrom by a predetermined moving distance to the initial position (FIG. 12). (A)) (procedure S
3: Opening area adjustment procedure).

Specifically, for example, if one stage is set in advance from the closed position as the origin to the initial position and four stages are set from the closed position to the fully opened position, the exhaust is actually performed from the closed position to the fully opened position. By moving the mouth cover 112 and recognizing the total moving distance at that time, the moving distance for one step can be recognized. Therefore, the initial position can be set by moving a distance of one step from the closing position. At this time, it may be set so as to return to the initial position by returning three steps from the fully open position.

Next, the temperature detecting element 102 detects the temperature of each part (procedure S4: temperature detecting procedure). Then, the exhaust port cover position adjusting means 105 determines whether or not the detected temperature is higher than a predetermined temperature (step S5:
Temperature determination procedure). When the detected temperature is equal to or lower than the predetermined temperature, the exhaust port cover 112 is kept at the initial position, and the temperature detection state is maintained as it is. On the other hand, if the detected temperature is higher than the predetermined temperature, the procedure proceeds to the next procedure (procedure S6: procedure for determining the opening area).

Subsequently, the exhaust port cover position adjusting means 105
Determines whether the exhaust port cover 112 is at the fully open position (step S6: opening area determination procedure). When the exhaust port cover 112 is in the fully open position, the following procedure (procedure S
7: increasing the number of rotations of the fan), and if it is not at the fully open position, proceed to a procedure of adjusting the position of the exhaust port cover for adjusting the position of the exhaust port cover 112 (procedure S3: procedure of adjusting the opening area).

The exhaust port cover position adjusting means 105 adjusts the position of the exhaust port cover 112 based on the temperature detected by the temperature detecting element 102 and based on the position information stored in the storage means 104 ( Procedure S3: opening area adjustment procedure). Specifically, as the detected temperature rises,
That is, it moves in the direction in which the opening area increases, and when the detected temperature decreases, it moves in the front right direction, that is, in the direction in which the opening area decreases. As described above, the opening area adjustment procedure including the movement to the initial position at the time of startup is performed. Thus, the opening area of the exhaust port 160 is controlled.

On the other hand, when the temperature detected by the temperature detecting element 102 exceeds a predetermined temperature and the exhaust port cover 112 is at the fully open position, the fan rotation speed adjusting means 106 activates the fan driving section 122. Then, the rotation speed of the exhaust fans 15, 16 is increased (procedure S7: fan rotation speed increasing procedure). When the rotation speeds of the exhaust fans 15 and 16 increase and the detected temperature decreases and the exhaust port cover 112 is not at the fully open position, the rotation speeds of the exhaust fans 15 and 16 are returned to the predetermined rotation speed again. It is. In this way, the rotation speeds of the exhaust fans 15, 16 are controlled. Through the above procedure, the cooling of the projector 1 is controlled.

When the power switch is turned off after the use of the projector 1, the exhaust port cover 112 moves to the above-described closing position to close the opening area, and stops the exhaust port cover driving unit 113. The intake fan 17 and the exhaust fans 15 and 16 are turned off at the same time as the power switch is turned off.
The positive drive by the fan drive unit 122 is stopped to reduce the number of revolutions, and the number of revolutions is reduced to a value that does not cause an overload due to the sudden stop of the fans 15, 16, 17, and then the fan drive unit 122 is stopped. . It takes about 30 seconds from when the power switch is turned off to when the fan drive unit 122 stops, and the power supply to the projector 1 is terminated after such a stop of the fan drive unit 122.

<7> Effects of the First Embodiment The first embodiment as described above has the following effects. (1) Since the opening area of the exhaust port 160 is configured to be adjustable, the discharge amount of the cooling air can be adjusted.

(2) Since the opening area of the exhaust port 160 is automatically adjusted by the exhaust port cover position adjusting means 105, it is not necessary for the user to adjust the opening area by himself / herself, so that the burden on the user can be reduced. .

(3) The exhaust port cover position adjusting means 105
Based on the temperature detected by the temperature detection element 102, the opening area of the exhaust port 160 can be adjusted by moving the exhaust port cover 112, so that an optimal opening area that can ensure a sufficient cooling effect can be selected. For this reason, while ensuring a sufficient cooling effect, the opening area of the exhaust port 160 can be minimized, and each of the fans 15,
Operation noises of 16, 17 can be minimized, and quietness can be ensured.

(4) The exhaust port cover position adjusting means 105 is
Sufficient portability is secured because the exhaust port cover 112 having the cover slit 112A is moved to the left and right, facing the slit 160A of the exhaust port 160, so that a particularly large arrangement space and a large member are not required. it can.

(5) When the projector 1 is not used, since the opening area of the exhaust port 160 is closed, dust and the like can be prevented from entering the inside of the projector 1 and the performance of the projector 1 can be ensured. .

(6) Since the fan rotation speed adjusting means 106 is provided, the detected temperature rises above a predetermined temperature, and the exhaust port cover 112 is in the fully open position. Even at times, the exhaust fan 15,
By increasing the number of rotations of 16, a sufficient cooling effect can be secured, and the performance of the projector 1 can be secured.

(7) Light modulator 925 and illumination optical system 9
23, the temperature detecting element 102 for detecting the temperature at two locations is provided, so that the position of the exhaust port cover 112 is adjusted based on the higher temperature of the light modulator 925 and the illumination optical system 923. By doing so, the temperature rise can be prevented more reliably, and the performance of the projector 1 can be sufficiently ensured. Moreover, since the temperature detecting element 102 is arranged near the light modulator 925 that is particularly vulnerable to heat, the performance of the projector 1 can be more reliably ensured.

[Second Embodiment] A second embodiment according to the present invention will be described with reference to FIG. FIG. 14 is a schematic external view of a projector 301 according to the second embodiment of the invention. The same or equivalent components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted or simplified.
The projector 301 according to the second embodiment of the present invention has various internal components such as various optical systems and a cooling control structure in substantially the same manner as the projector 1 according to the first embodiment. Are different.

The outer case 302 as an external structure includes an upper case 3, a lower case 4, and a front case 305, as in the first embodiment. The front case 305 includes a front case main body 306 and a lens cover 307 disposed on the front side of the front case main body 306. The outer case 302 is formed in a box shape by the upper case 3, the lower case 4, and the front case main body 306 as in the first embodiment.

As in the first embodiment, the front case body 306 is provided with an exhaust port 308 for discharging air from the inside of the apparatus at substantially the center of the front surface. The exhaust port 308 has a rectangular slit 308 long in the left-right direction.
A is a plurality of A's arranged at equal intervals at the same width position, and cooling air is discharged from the inside of the apparatus through these slits 308A.

The lens cover 307 has a scalloped plate-like cross section, and is provided with cover slits 307A having the same shape and the same number as the slits 308A on the right side when viewed from the front. The lens cover 307 is movable in the front left and right directions by a predetermined slide structure as shown by an arrow 309 in the figure. At this time, when the lens cover 307 is located on the right side when viewed from the front with respect to the front case body 306 as shown in FIG. It functions so as to close the exhaust port 308. Therefore, when the projector 301 is not used, it is set to this position. On the other hand, when the lens cover 307 is located on the left side of the front case body 306 as viewed from the front as shown in FIG.
8A and the cover slit 307A completely overlap, so that the exhaust port 308 functions to be completely opened. Therefore, when the projector 301 is used,
It is set to this position. Therefore, the activation operation according to the claims refers to an operation of moving the lens cover 307 from the right side to the left side when viewed from the front with respect to the front case main body 306.

On the other hand, the internal structure is substantially the same as that of the first embodiment as described above, but in the first embodiment, the exhaust port cover 112 of the exhaust port cover driving device 111 is moved in the left-right direction. Although the configuration in which the opening area of the exhaust port 160 is adjusted is adopted, in the present embodiment, although not shown, a configuration in which the opening area of the exhaust port 308 is adjusted by moving the exhaust port cover 112 in the vertical direction is employed. It is different in that it is. Therefore, the exhaust port cover driving device 111 (not shown) is disposed between the exhaust port 308 and the exhaust fans 15 and 16 and has a cover slit 112B corresponding to the slit 160B in the left-right direction, as in the first embodiment. Exhaust port cover 112 and exhaust port cover drive unit 113
And The other internal configuration, external configuration, and cooling control method are the same as those in the first embodiment, and thus description thereof will be omitted.

The procedure for using the projector 301 will be described below. First, when turning on a power switch (not shown), the user moves the lens cover 307 with his / her hand from right to left as viewed from the front, and moves the projection lens 6.
And the exhaust port 308 is opened.
When the power switch is turned on, the inside of the projector 301 is cooled according to the flow chart shown in FIG. 13, as in the first embodiment. When the power of the projector 301 has been turned off after use, the lens cover 307 is moved from left to right as viewed from the front to cover the projection lens 6 and close the exhaust port 308. Thus, the projector 301 is used.

<8> Effects of the Second Embodiment In the above-described second embodiment, the effects of the first embodiment are obtained.
The following effects can be obtained in addition to the effects (1) to (7). (8) Since the lens cover 307 can be moved in the left-right direction when viewed from the front, the position of the lens cover 307 can be selected according to each scene such as during use or non-use.

(9) When the lens cover 307 is moved rightward when viewed from the front, the projection lens 6 and the exhaust port 3
08, so that the projection lens 6 can be protected from external impact in this case,
The exhaust port 308 can be completely closed to prevent dust from entering the inside. Therefore, when the projector 301 is not used, it is preferable to set the lens cover 307 to the right position.

(10) When the lens cover 307 is moved to the left as viewed from the front, the projection lens 6 is exposed and the exhaust port 308 is opened. In this case, the projection lens 6 Can be exposed to the outside to prepare for the projection state, and the exhaust port 308 can be opened to prepare the exhaust state. Therefore, when using the projector 301, it is preferable to set the lens cover 307 to the leftward position.

(11) Since the exhaust port 308 is opened by moving the lens cover 307, these operations are necessary for any user before use. Without forgetting to secure the area, the opening area can be reliably secured and the cooling effect can be sufficiently exhibited.

<9> Modifications of Embodiments of the Present Invention The present invention is not limited to the above-described embodiments, but includes modifications and improvements as long as the object of the present invention can be achieved. Included. For example, in the first embodiment, as the opening area adjusting mechanism, the exhaust port cover 112 having the cover slit 112A is moved with respect to the slit 160A of the exhaust port 160, and the cover slit 1 is moved.
The opening area can be adjusted according to the degree of overlap between the slit 12A and the slit 160A. In the second embodiment, as the opening area adjusting mechanism, the exhaust port cover 112 having a cover slit 112B for the slit 308A of the exhaust port 308.
To move the cover slit 112B and the slit 30
Although the opening area can be adjusted depending on the degree of overlap with 8A, the present invention is not limited to such a configuration, and a configuration in which louvers whose angles can be adjusted via hinges are provided at the ends of the exhaust ports 160 and 308, and the A configuration may be used in which a blade that rotates around the center of the ports 160 and 308 as a rotation axis is provided to adjust the opening area. In short, it suffices if the opening area can be adjusted.

In each of the above embodiments, the exhaust port 16
Although the opening area of only 0, 308 was adjustable,
The invention is not limited thereto, and the opening area of the intake port 240 may be configured to be adjustable, and the exhaust ports 160 and 308 and the intake port 240 may be adjusted.
Both opening areas may be adjustable. In this case, the intake port 240 may be provided with various opening area adjustment mechanisms having the same configuration as the exhaust ports 160 and 308.

In each of the above embodiments, the exhaust port cover 112 having the rack 114 engaged with the pinion 115 is moved by the rotation of the pinion 115 by the exhaust port cover driving unit 113. However, the present invention is not limited to this. Instead, for example, by using an urging means such as a spring,
The exhaust port cover 112 may be moved by the expansion and contraction of the urging means. In short, the exhaust port cover 1
It suffices if 12 is configured to be movable.

In each of the above embodiments, the intake port 240
Also, the same configuration as the exhaust port cover position adjusting means 105,
For example, when the intake port cover position adjusting means is provided,
The following configuration may be used. In other words, the exhaust port cover position adjusting means 105 adjusts the position of the exhaust port cover 112 according to the temperature detected by the temperature detecting element 102 arranged near the illumination optical system 923, while the intake port cover position adjusting means Adjusts the position of the air inlet cover according to the temperature detected by the temperature detecting element 102 disposed near the light modulation device 925. Furthermore, fan rotation speed adjusting means 1
06 adjusts the rotation speed of each of the exhaust fans 15 and 16 or the intake fan 17 based on each temperature detection element 102. With this configuration, each of the temperature detection elements 10 provided near the illumination optical system 923 and the light modulation device 925 can be used.
2 based on the respective temperatures detected at the intake port 240 or the exhaust port 1 near these temperature detecting elements 102.
Since the opening area of 60 is adjusted, it is possible to efficiently cool the light modulator 925 and the illumination optical system 923 that require rapid cooling at high temperature, and the cooling efficiency can be further improved.

In the second embodiment, the lens cover 30
Although the exhaust port 308 is opened by moving the hand 7 manually, the present invention is not limited to this, and the lens cover 307 may be automatically moved at the same time as the power switch is turned on. . In this way, the burden on the user can be reduced. At this time, the lens cover 307 may be configured such that, for example, the opening area of the exhaust port 308 is adjusted by the blade rotating about the center of the exhaust port 308 as a rotation axis as described above.

In each of the above embodiments, the light modulation device 925
Is composed of three liquid crystal panels 925R, 925G, and 925B, but is not limited thereto, and may be composed of one or two liquid crystal panels. In each of the above embodiments, the liquid crystal panel is used as the light modulation device. However, the invention may be applied to a projector using a plasma element or a device using a micromirror as the light modulation device.

Further, the liquid crystal panels 925R, 925G, and 925B in each of the above embodiments are of a type in which light fluxes R, G, and B are transmitted and modulated, but are not limited thereto.
The present invention may be applied to a projector including a reflection-type light modulation device that modulates and emits incident light while reflecting the same. Further, the prism is not limited to the cross dichroic prism in which two types of color selection surfaces are formed along the bonding surface of the four triangular prisms as in the above embodiments,
The color selection surface may be one type of dichroic prism or a polarization beam splitter. Further, a dichroic prism in which two types of color selection surfaces are formed along the interface of three prisms having different shapes may be used. Others
The prism may be such that a light-selecting surface is arranged in a substantially hexahedral light-transmitting box and the liquid is filled therein.

[0089]

The projector according to the present invention is configured such that the opening area of at least one of the intake port and the exhaust port can be adjusted, so that the intake or exhaust of the cooling air can be adjusted. Therefore, an optimal opening area that can ensure a sufficient cooling effect can be selected according to various conditions such as the internal temperature. That is, while ensuring a sufficient cooling effect, the opening area of the intake port or the exhaust port can be minimized, so that noise leaking to the outside can be minimized and quietness can be ensured. Furthermore, if the opening area adjusting mechanism is set so that the opening area of the exhaust port or the intake port becomes zero, the ingress of the exhaust port or the exhaust port is closed when not in use, thereby preventing dust from entering the inside.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a projector according to a first embodiment of the invention when viewed from the top.

FIG. 2 is an external perspective view of the projector according to the embodiment as viewed from a lower surface side.

FIG. 3 is a perspective view showing an internal structure of the projector in the embodiment.

FIG. 4 is a perspective view showing an optical system of the projector according to the embodiment.

FIG. 5 is a perspective view showing a structure of an optical system in the embodiment.

FIG. 6 is another perspective view showing the structure of the optical system in the embodiment.

FIG. 7 is a sectional view taken along the line VII-VII of FIG. 1 and is a vertical sectional view of the projector.

8 is a sectional view taken along line VIII-VIII in FIG. 7, and is another vertical sectional view of the projector.

FIG. 9 is a schematic diagram for explaining functions of an optical system in the embodiment.

FIG. 10 is a block diagram showing a cooling control structure in the embodiment.

FIG. 11 is a schematic diagram showing an exhaust port cover driving device in the embodiment.

FIG. 12 is a schematic diagram showing an opening area of an exhaust port in the embodiment.

FIG. 13 is a flowchart showing a procedure for controlling cooling inside the projector in the embodiment.

FIG. 14 is a schematic external view of a projector according to a second embodiment of the invention.

[Explanation of symbols]

Reference Signs List 1,301 Projector 2,302 Outer case 5,305 Front case 15 Auxiliary exhaust fan 16 Main exhaust fan 17 Intake fan 101 Cooling control structure 102 Temperature detection element 103 Control unit 104 Storage unit 105 Exhaust port cover position as opening area adjusting mechanism Adjusting means 106 Fan rotation speed adjusting means 111 Exhaust port cover drive unit 112 Exhaust port cover 112A, 112B, 307A Cover slit 113 Exhaust port cover drive unit 114 Rack 115 Pinion 116 Drive motor 121 Fan drive unit 122 Fan drive unit 160, 308 Exhaust Mouth 160A, 112A, 308A Slit 240 Inlet 307 Lens cover 923 Illumination optical system 924 Color light separation optical system 925 Light modulator 925R, 925G, 925B Liquid crystal panel 927 Relay optics

Claims (7)

[Claims] An optical system that modulates a light flux emitted from a light source according to image information by a light modulator, and performs enlarged projection to form a projected image; a fan for flowing air;
An outer case that houses the optical system and the fan;
The exterior case is provided with an air inlet for taking in cooling air therein and an air outlet for discharging this cooling air from the inside, and these air inlets and / or A projector comprising an opening area adjusting mechanism for adjusting an opening area of an exhaust port. 2. The projector according to claim 1, further comprising a temperature detection element for detecting a temperature of a plurality of optical elements including the light modulation device, wherein the opening area adjustment mechanism is detected by the temperature detection element. A projector, wherein the opening area is adjusted based on a temperature. 3. The projector according to claim 2, further comprising: an illumination optical system for illuminating an image forming area of the light modulation device substantially uniformly, wherein the temperature detecting element includes the illumination optical system and the light modulation device. A projector configured to detect a temperature of the device, wherein the aperture area adjustment mechanism adjusts the aperture area based on a higher temperature of the illumination optical system and the light modulation device. . 4. The projector according to claim 1, wherein the opening area adjustment mechanism adjusts an opening area of the exhaust port. 5. An optical system for modulating a light beam emitted from a light source in accordance with image information by a light modulator and enlarging and projecting to form a projected image; and a fan for flowing air.
An outer case that houses the optical system and the fan;
In the projector, the exterior case is formed with an intake port for taking in cooling air inside, and an exhaust port for discharging this cooling air from inside, and A projector provided with an opening area adjustment mechanism for adjusting an opening area of an intake port and / or an exhaust port of the projector. 6. The projector according to claim 1, wherein an optical path from the light source to the light modulation device is provided in a substantially U-shape in the optical system. projector. 7. A method for controlling cooling of a projector according to claim 1, wherein the temperature of the optical system is detected by a temperature detecting step. A temperature determination procedure for determining whether or not the temperature detected at the temperature exceeds a predetermined temperature; and, when the detected temperature exceeds the predetermined temperature,
An opening area determining step of determining whether the opening area is the maximum; and adjusting the opening area when the detected temperature exceeds the predetermined temperature and the opening area is not the maximum. A cooling control method for a projector, comprising: an opening area adjustment procedure; and a fan rotation speed increasing step of increasing a rotation number of the fan when the opening area is the maximum.