JP2008191361A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress temperature rise on the side of an image forming apparatus, and to efficiently cool the heat-generation of a polarizing plate. <P>SOLUTION: An outer case 1 stores the image forming apparatus 20, a projection lens 30, etc. inside. Further, an auxiliary polarizing plate 40 is detachably attached to the front surface of the outer case 1. The auxiliary polarizing plate 40 transmits the component light in a predetermined polarizing direction, of light after passing through the projection lens 30. The auxiliary polarizing plate 40 can suppress the temperature rise of exiting side polarizing plates 25i, 25j and 25k and liquid crystal panels 25a, 25b and 25c arranged in the vicinity of the exiting side polarizing plates 25i, 25j and 25k and further can suppress a deterioration in the exiting side polarizing plates. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projector that includes an image forming apparatus that forms an image by modulating light emitted from a light source, and projects an image formed by the image forming apparatus.

  As a conventional projector, there is known a projector in which polarizing plates are arranged on the incident side and the emitting side of a liquid crystal panel and a polarizing plate is arranged on the front surface of a lenticular lens for the purpose of improving the contrast of a projected image ( (See Patent Document 1). According to the present technology, image quality can be improved.

Another projector is known in which a polarizing plate is disposed on the incident side of a liquid crystal panel and a plurality of polarizing plates are disposed on the exit side of a cross dichroic prism (see Patent Document 2). According to the present technology, since the polarizing plate is disposed at a position away from the liquid crystal panel, an increase in the temperature of the liquid crystal panel due to heat generation of the polarizing plate can be suppressed.
JP 09-251149 A JP 2004-325807 A

However, the technique of Patent Document 1 has a problem in that since the polarizing plate is disposed on the front surface of the lenticular lens, the area of the polarizing plate increases and the cost increases. Further, in the technique of Patent Document 2, since a polarizing plate is arranged between the cross dichroic prism and the projection lens, the distance between the cross dichroic prism and the projection lens becomes large, which adversely affects the optical performance, There is a problem that the polarizing plate cannot be efficiently cooled.
The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a projector that can suppress the temperature increase on the image forming apparatus side and can efficiently cool the heat generated by the polarizing plate.

  In order to solve the above problems, a projector according to the present invention modulates light emitted from a light source to form an image, a projection lens that projects an image formed by the image forming apparatus, and an image A projector including a forming apparatus and an exterior case that houses a projection lens therein, and an auxiliary polarizing plate that is provided integrally with the exterior case on the emission side of the projection lens and transmits component light in a predetermined polarization direction Prepare.

  According to the projector, since the auxiliary polarizing plate is disposed on the emission side of the projection lens, it is possible to suppress a temperature rise that has conventionally occurred on the image forming apparatus side. The auxiliary polarizing plate is provided integrally with the exterior case on the emission side of the projection lens. For this reason, since a space can be ensured between the auxiliary polarizing plate and the projection lens, efficient cooling of heat generation due to absorption of component light other than the predetermined polarization direction described above can be realized. Further, the projection lens is not exposed in appearance. For this reason, contamination of the projection lens due to dust or the like can be prevented, and the design effect is improved. On the other hand, since component light in a predetermined polarization direction is transmitted by the auxiliary polarizing plate provided on the emission side of the projection lens, it is possible to reduce a decrease in contrast of the image. Therefore, the lifetime of the projector can be extended.

  Further, according to a specific aspect of the invention, in the projector, the image forming apparatus includes an illumination device including a light source, a liquid crystal panel that modulates a deflection direction of light from the illumination device, and a light source side of the liquid crystal panel. An incident-side polarizing plate disposed; and an output-side polarizing plate disposed on the projection lens side of the liquid crystal panel. According to this, the exit side polarizing plate and the auxiliary polarizing plate are disposed on the exit side of the liquid crystal panel, and component light other than the predetermined polarization direction can be blocked in stages by these deflecting plates.

  In still another aspect of the present invention, a part of the component light other than the predetermined polarization direction is absorbed by the output side polarizing plate, and the rest of the component light other than the predetermined polarization direction is absorbed by the auxiliary polarizing plate. The transmittances of the auxiliary polarizing plate and the output side polarizing plate are set so as to be substantially absorbed. According to this, the heat load resulting from the absorption of component light other than the predetermined polarization direction can be appropriately shared between the auxiliary polarizing plate and the output side polarizing plate. Therefore, the heat generation of the output side polarizing plate can be suppressed, and the temperature rise of the liquid crystal panel can be suppressed. In addition, it is possible to prevent the emission side polarizing plate from deteriorating.

  In yet another aspect of the present invention, the transmittance of the auxiliary polarizing plate and the output side polarizing plate with respect to the component light other than the predetermined polarization direction is the heat of the output side polarizing plate caused by absorption of the component light other than the predetermined polarization direction. The load is set to be smaller than the thermal load of the auxiliary polarizing plate. According to this, heat_generation | fever of an output side polarizing plate can be suppressed further.

  In yet another aspect of the present invention, the auxiliary polarizing plate is provided detachably with respect to the outer case. According to this, when the auxiliary polarizing plate is deteriorated, replacement work by the user for the purpose of contrast adjustment or the like can be easily performed.

  In yet another aspect of the present invention, a cooling mechanism is provided in which a duct through which cooling air flows is formed between the projection lens and the auxiliary polarizing plate, and a cooling fan is disposed on the cooling air flow path. According to this, since the cooling air can be circulated between the projection lens and the auxiliary polarizing plate, heat generation of the auxiliary polarizing plate due to light absorption can be efficiently prevented.

  In still another aspect of the present invention, a temperature sensor that detects the temperature around the auxiliary polarizing plate, and a fan drive control unit that controls driving of the cooling fan based on a temperature change around the auxiliary polarizing plate detected by the temperature sensor And further comprising. According to this, the cooling fan can be appropriately driven as necessary according to the temperature change around the auxiliary polarizing plate. Therefore, it becomes possible to more efficiently and reliably prevent the auxiliary polarizing plate from generating heat.

  Hereinafter, a projector according to an embodiment of the invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view for explaining the appearance of the projector according to the present embodiment. The projector 10 has a rectangular parallelepiped outer case 1. An auxiliary polarizing plate 40 described later is detachably attached to the front surface of the outer case 1, and an air inlet 3 for introducing outside air for cooling (cooling air) into the outer case 1 is provided. Further, on the rear surface of the exterior case 1, an exhaust port 5 for exhausting cooling air introduced from the intake port 3 and flowing through the interior of the exterior case 1, various input terminals (not shown), an AC inlet for supplying power, and the like Is provided as appropriate.

  FIG. 2 is a conceptual diagram illustrating the internal configuration of the projector 10. As shown in the figure, the exterior case 1 houses the image forming apparatus 20, the projection lens 30, the cooling mechanism 50, the temperature sensor 60, the circuit device 70, a power supply device (not shown), and the like. Further, as described above, the auxiliary polarizing plate 40 is detachably attached to the front surface of the outer case 1.

  The image forming apparatus 20 includes an illumination device 21 that generates light source light, a color separation optical system 23 that divides the light source light from the illumination device 21 into three colors of red, green, and blue, and each color emitted from the color separation optical system 23. A light modulation unit 25 illuminated by the illumination light and a cross dichroic prism 27 that synthesizes the image light of each color from the light modulation unit 25 are provided to form image light to be projected on the screen.

  The illumination device 21 includes a light source lamp 21a, a concave lens 21b, a pair of lens arrays 21d and 21e, a polarization conversion member 21g, and a superimposing lens 21i. Among these, the light source lamp 21a is composed of, for example, a high-pressure mercury lamp, and includes a concave mirror that collects the light source light and emits it forward. The concave lens 21b has a role of collimating the light source light from the light source lamp 21a, but may be omitted. The pair of lens arrays 21d and 21e is composed of a plurality of element lenses arranged in a matrix, and these element lenses divide the light source light from the light source lamp 21a that has passed through the concave lens 21b, and individually collect and diverge the light. The polarization conversion member 21g converts the light source light emitted from the lens array 21e into, for example, only the S-polarized component perpendicular to the paper surface of FIG. The superimposing lens 21i enables superimposing illumination on the light modulation devices of the respective colors provided in the light modulation unit 25 by appropriately converging the illumination light that has passed through the polarization conversion member 21g as a whole. That is, the illumination light that has passed through both the lens arrays 21d and 21e and the superimposing lens 21i passes through the color separation optical system 23 described in detail below, and passes through the liquid crystal panels 25a, 25b, and 25c of each color provided in the light modulation unit 25. Uniform overlapping illumination.

  The color separation optical system 23 includes first and second dichroic mirrors 23a and 23b, three field lenses 23f, 23g, and 23h that are correction optical systems, and reflection mirrors 23j, 23m, 23n, and 23o. Here, the first dichroic mirror 23a reflects, for example, red light and green light among the three colors of red, green, and blue and transmits blue light. The second dichroic mirror 23b reflects, for example, green light and transmits red light out of the incident red and green. In the color separation optical system 23, the substantially white light source light from the illumination device 21 is incident on the first dichroic mirror 23a after the optical path is bent by the reflection mirror 23j. The blue light that has passed through the first dichroic mirror 23a enters the field lens 23f through the reflection mirror 23m, for example, as S-polarized light. Further, the green light reflected by the first dichroic mirror 23a and further reflected by the second dichroic mirror 23b is incident on the field lens 23g as S-polarized light, for example. Further, the red light that has passed through the second dichroic mirror 23b remains as S-polarized light, for example, and enters the field lens 23h for adjusting the incident angle via the lenses LL1 and LL2 and the reflecting mirrors 23n and 23o. The lenses LL1 and LL2 and the field lens 23h constitute a relay optical system. This relay optical system has a function of transmitting the image of the first lens LL1 almost directly to the field lens 23h via the second lens LL2.

  The light modulation unit 25 includes three liquid crystal panels 25a, 25b, and 25c, and three sets of incident-side polarizing plates 25e, 25f, and 25g, and an output polarizing plate 25i that are disposed so as to sandwich the liquid crystal panels 25a, 25b, and 25c. 25j and 25k. Here, the liquid crystal panel 25a for blue light, and the pair of incident-side polarizing plates 25e and outgoing polarizing plates 25i sandwiching the liquid crystal panel 25a are for two-dimensionally modulating the luminance of the blue light of the illumination light based on image information. The liquid crystal light valve 25m for blue light is configured. Similarly, the green light liquid crystal panel 25b, the corresponding incident side polarizing plate 25f, and the output polarizing plate 25j constitute a green light liquid crystal light valve 25n, and the red light liquid crystal panel 25c and the incident side polarizing plate 25g. And the output polarizing plate 25k constitutes a liquid crystal light valve 25o for red light.

  Specifically, blue light branched by being reflected by the first dichroic mirror 23a of the color separation optical system 23 enters the blue light liquid crystal panel 25a via the field lens 23f. The green light branched by being reflected by the second dichroic mirror 23b of the color separation optical system 23 is incident on the green light liquid crystal panel 25b via the field lens 23g. The red light branched by passing through the second dichroic mirror 23b is incident on the red light liquid crystal panel 25c via the field lens 23h. The light of the three colors respectively incident on the liquid crystal panels 25a, 25b, and 25c is modulated according to the drive signal or image signal input as an electrical signal to the liquid crystal panels 25a, 25b, and 25c with respect to the polarization direction. . At that time, the polarization directions of the illumination light incident on the liquid crystal panels 25a, 25b, and 25c are accurately adjusted by the incident-side polarizing plates 25e, 25f, and 25g, and the output-side polarizing plates 25i, 25j, and 25k Component light in a predetermined polarization direction is extracted as image light from the modulated light emitted from the liquid crystal panels 25a, 25b, and 25c. In other words, the liquid crystal light valve 25m for blue light, the liquid crystal light valve 25n for green light, and the liquid crystal light valve 25o for red light each emit non-light-emitting light that modulates the spatial intensity distribution of incident illumination light. It functions as a modulation device. As will be described later, the transmittance of the output-side polarizing plates 25i, 25j, and 25k is set so as to absorb a part of component light other than a predetermined polarization direction (for example, P-polarized light horizontal to the paper surface of FIG. 2). Set.

  The cross dichroic prism 27 is a photosynthetic member, has a substantially square shape in plan view in which four right angle prisms are bonded together, and a pair of dielectric multilayer films that intersect in an X shape at the interface where the right angle prisms are bonded to each other. 27a and 27b are formed. One first dielectric multilayer film 27a reflects blue light, and the other second dielectric multilayer film 27b reflects red light. The cross dichroic prism 27 reflects the blue light from the liquid crystal panel 25a by the first dielectric multilayer film 27a and emits it to the right in the traveling direction, and the green light from the liquid crystal panel 25b to the first and second dielectric multilayer films 27a. , 27b, the red light from the liquid crystal panel 25c is reflected by the second dielectric multilayer film 27b and emitted to the left in the traveling direction.

  The projection lens 30 projects the color image light synthesized by the cross dichroic prism 27 on a screen (not shown) at a desired magnification via the auxiliary polarizing plate 40. That is, a color moving image or a color still image having a desired magnification corresponding to the drive signal or image signal input to each of the liquid crystal panels 25a, 25b, and 25c is projected on the screen.

  The auxiliary polarizing plate 40 transmits component light in a predetermined polarization direction (for example, P-polarized light horizontal to the paper surface of FIG. 2) out of the light that has passed through the projection lens 30, and component light other than the predetermined polarization direction (for example, FIG. 2). (S-polarized light perpendicular to the paper surface). Specifically, as described above, a part of the component light other than the predetermined polarization direction is absorbed by the exit-side polarizing plates 25i, 25j, and 25k, but the auxiliary polarizing plate 40 has the remaining other than the predetermined polarization direction. Absorbs component light. More specifically, the transmittance of the auxiliary polarizing plate 40 and the output side polarizing plates 25i, 25j, and 25k with respect to undesired polarized light is allowed to be generated by the output side polarizing plates 25i, 25j, and 25k due to light absorption. Set each so that it is kept at a certain level. Thereby, the heat load caused by the absorption of light is applied to the auxiliary polarizing plate and the outgoing side polarizing plates 25i, 25j, and 25k so that the heat generation of the outgoing side polarizing plates 25i, 25j, and 25k is maintained within an allowable range. Can be shared. Therefore, it is possible to suppress the temperature rise of the emission side polarizing plates 25i, 25j, 25k themselves and the liquid crystal panels 25a, 25b, 25c arranged in the vicinity of the emission side polarizing plates 25i, 25j, 25k. Further, it is possible to prevent deterioration of the output side polarizing plate. Therefore, the lifetime of the projector can be extended. On the other hand, since component light in a predetermined polarization direction is selectively transmitted by the auxiliary polarizing plate 40 provided on the emission side of the projection lens 30, it is possible to reduce a decrease in image contrast.

  Further, the auxiliary polarizing plate 40 is disposed in an opening formed at a position on the front side of the outer case 1 on the emission side of the projection lens 30. More specifically, the auxiliary polarizing plate 40 is detachably attached to the outer case 1 by a holding mechanism 41 such as a stopper, and the auxiliary polarizing plate 40 can be easily attached to and detached from the outer case 1. ing. Thus, the user can easily perform the replacement work when the auxiliary polarizing plate 40 is deteriorated or the replacement work of the auxiliary polarizing plate 40 for the purpose of contrast adjustment. Since the projection lens 30 is not exposed in appearance, contamination of the projection lens 30 due to dust or the like can be prevented, and the design effect is also improved.

  The cooling mechanism 50 includes a duct 53, a first cooling fan 55, and a second cooling fan 57. Among these, the duct 53 is surrounded by the space between the projection lens 30 and the auxiliary polarizing plate 40, that is, the flow path wall 51 and the front surface portion of the outer case 1. The flow path wall 51 has a role of partitioning the front duct 53 and the rear image forming apparatus 20 in the exterior case 1. The first cooling fan 55 is installed on the flow path wall 51 on the cooling air flow path AR described later. The second cooling fan 57 is disposed in the vicinity of the light source lamp 21a on the cooling air flow path AR. The cooling mechanism 50 circulates in the duct 53 from the intake port 3, passes through the image forming apparatus 20 side from the first cooling fan 55, and is a flow path of cooling air that is guided from the second cooling fan 57 to the exhaust port 5. AR is formed.

  When the first cooling fan 55 and the second cooling fan 57 are driven by a circuit device 70 described later, cooling air is introduced from the air inlet 3 and flows through the duct 53 to cool the auxiliary polarizing plate 40. . The cooling air that has cooled the auxiliary polarizing plate 40 passes through the first cooling fan 55 and is introduced to the image forming apparatus 20 side, cools each part constituting the image forming apparatus 20 side, and finally cools the light source lamp 21a. To do. The cooling air that has cooled the light source lamp 21 a is guided from the second cooling fan 57 to the exhaust port 5 and exhausted to the outside of the exterior case 1. According to this, since the cooling air introduced from the intake port 3 circulates in the duct 53 along the flow path wall 51, the heat generation of the auxiliary polarizing plate 40 can be efficiently cooled. As described above, the cooling air that circulates in the duct 53 and cools the auxiliary polarizing plate 40 passes through the image forming apparatus 20 side, so that the inside of the housing can also be cooled. Further, since the cooling air that has passed through the image forming apparatus 20 side is led to the exhaust port 5 and exhausted from the second cooling fan 57 disposed in the vicinity of the light source lamp 21a, the light source lamp 21a is also cooled. Can do. In addition to the cooling mechanism 50, a dedicated cooling system for cooling the liquid crystal light valves 25m, 25n, and 25o can be provided as a cooling device for the image forming apparatus 20.

  The temperature sensor 60 is disposed at an appropriate position around the auxiliary polarizing plate 40 and measures the temperature around the auxiliary polarizing plate 40.

  The circuit device 70 is composed of electronic components mounted on a printed circuit board, and comprehensively controls the operation of the projector 10 as a whole. The circuit device 70 is housed in a proper position in the outer case 1 and is indicated by a broken line in FIG.

FIG. 3 is a block diagram for explaining the configuration of the circuit device 70. The circuit device 70 includes an image processing unit 71 to which an external image signal such as a video signal is input, a light valve driving unit 73 that drives the liquid crystal light valves 25a, 25b, and 25c based on the output of the image processing unit 71, A cooling fan driving unit 75 that individually drives the first cooling fan 55 and the second cooling fan 57, a sensor driving unit 77 that drives the temperature sensor 60 to detect the temperature around the auxiliary polarizing plate 40, and the units 71 and 75. , 77 and the like.

  The image processing unit 71 includes an image correction circuit 71a that appropriately performs correction processing on the input external image signal. The image processing unit 71, that is, the image correction circuit 81 a performs various image processing such as color correction and distortion correction on the external image signal based on a command from the control unit 79.

  Based on the image signal after image processing input from the image processing unit 71, the light valve drive unit 73 includes a liquid crystal light valve 25m for blue light, a liquid crystal light valve 25n for green light, and a light valve 25o for red light. A drive signal for adjusting the display state is generated. As a result, image processing is performed in the liquid crystal panels 25a, 25b, and 25c, the incident side polarizing plates 25e, 25f, and 25g, and the liquid crystal light valves 25m, 25n, and 25o including the outgoing side polarizing plates 25i, 25j, and 25k. An image corresponding to the image signal output from the unit 71 can be formed.

  The cooling fan drive unit 75 generates drive signals for the first cooling fan 55 and the second cooling fan 57 based on a control signal input from the control unit 79. Specifically, the cooling fan drive unit 75 changes the rotation speeds of the first cooling fan 55 and the second cooling fan 57 according to a control signal input from the control unit 79, and thereby changes the first cooling fan 55 and the first cooling fan 55. 2 The cooling state of the cooling fan 57 is adjusted.

  The sensor driving unit 77 functions as a measuring device together with the temperature sensor 60. That is, the sensor driving unit 77 uses the temperature sensor 60 to detect the temperature around the auxiliary polarizing plate 40 in the projector 10 and outputs the detected value to the control unit 79.

  The control unit 79 includes a microcomputer or the like, and controls the cooling fan driving unit 75 according to a temperature change around the auxiliary polarizing plate 40 that is input from the sensor driving unit 77 as needed, as a process for realizing the present embodiment. Then, a process for driving the first cooling fan 55 and the second cooling fan 57 is performed. The control unit 79 has a built-in memory 70 a that holds various data necessary for the operation of the projector 10, and serves as a reference temperature for determining the cooling state of the first cooling fan 55 and the second cooling fan 57. Information is stored. The control unit 79 monitors the temperature change around the auxiliary polarizing plate 40 based on the detection value input from the sensor driving unit 77. Then, the cooling state of the first cooling fan 55 and the second cooling fan 57 is determined based on the reference temperature information stored in the memory 70a, and the cooling state is adjusted as necessary when the cooling state is not sufficient. A control signal for this is output to the cooling fan drive unit 75. According to this, since the 1st cooling fan 55 and the 2nd cooling fan 57 can be driven as needed, the heat_generation | fever of the auxiliary polarizing plate 40 can be prevented more efficiently. In addition, the noise level due to the driving of the first cooling fan 55 and the second cooling fan 57 can be reduced. Note that the temperature sensor 60 may not be provided, and the control unit 79 may always output the control signal to the cooling fan driving unit 75 to drive the first cooling fan 55 and the second cooling fan 57.

  The preferred embodiment to which the present invention is applied has been described above, but the following modifications are also possible. In other words, in the projector 10 of the above embodiment, the illumination device 21 is configured by the light source lamp 21a, the pair of lens arrays 21d and 21e, the polarization conversion member 21g, and the superimposing lens 21i, but the lens arrays 21d and 21e and the polarization conversion member. 21g and the like can be omitted, and the light source lamp 21a can be replaced with another light source such as an LED.

  Further, in the above embodiment, the color separation optical system 23 is used to perform color separation of illumination light, the light modulation unit 25 modulates each color, and then the cross dichroic prism 27 synthesizes each color image. However, the present invention can be similarly applied to a projector that omits the color separation optical system 23 and uses a single liquid crystal panel. Further, the liquid crystal panels 25a, 25b, and 25c are only transmissive examples, but the present invention can also be applied to projectors that employ reflective liquid crystal panels.

  In the above embodiment, only an example of a front type projector that projects from the direction of observing the screen has been described. However, the present invention can be applied to a rear type projector that projects from the side opposite to the direction of observing the screen. Is also applicable.

It is a perspective view explaining the external appearance of the projector which concerns on this embodiment. It is a conceptual diagram explaining the internal structure of a projector. It is a block diagram for demonstrating the structure of a circuit device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Projector 1 ... Exterior case 3 ... Intake port 5 ... Exhaust port 20 ... Image forming apparatus 21 ... Illumination device 23 ... Color separation optical system 25 ... Light modulation part 27 ... Cross dichroic prism 30 ... Projection lens 40 ... Auxiliary polarizing plate 50 ... Cooling mechanism 53 ... Duct 55 ... First cooling fan 57 ... Second cooling fan 60 ... Temperature sensor 70 ... Circuit device 71 ... Image processing unit 73 ... Light valve driving unit 75 ... Cooling fan driving unit 77 ... Sensor driving unit 79 ... Control unit

Claims (7)

An image forming apparatus that modulates light emitted from a light source to form an image, a projection lens that projects an image formed by the image forming apparatus, and an exterior case that houses the image forming apparatus and the projection lens therein A projector with
A projector provided with an auxiliary polarizing plate that is provided integrally with the exterior case on the emission side of the projection lens and transmits component light in a predetermined polarization direction out of the light that has passed through the projection lens.   The image forming apparatus includes an illumination device including the light source, a liquid crystal panel that modulates a deflection direction of light from the illumination device, an incident-side polarizing plate disposed on the light source side of the liquid crystal panel, and the liquid crystal panel The projector according to claim 1, further comprising: an exit-side polarizing plate disposed on the projection lens side.   A part of the component light other than the predetermined polarization direction is absorbed by the output-side polarizing plate, and the remainder of the component light other than the predetermined polarization direction is substantially absorbed by the auxiliary polarizing plate, The projector according to claim 2, wherein transmittances of the auxiliary polarizing plate and the output-side polarizing plate are respectively set.   The transmittance with respect to the component light other than the predetermined polarization direction of the auxiliary polarizing plate and the output side polarizing plate is the thermal load of the output side polarizing plate due to the absorption of the component light other than the predetermined polarization direction, The projector according to claim 3, wherein the projector is set to be smaller than a thermal load of the auxiliary polarizing plate.   The projector according to any one of claims 1 to 4, wherein the auxiliary polarizing plate is detachably provided to the exterior case.   The cooling mechanism in which a duct through which cooling air flows is formed between the projection lens and the auxiliary polarizing plate, and a cooling fan is disposed on the flow path of the cooling air. The projector according to any one of the above. A temperature sensor for detecting the temperature around the auxiliary polarizing plate;
Control means for controlling the driving of the cooling fan based on the temperature around the auxiliary polarizing plate detected by the temperature sensor;
The projector according to any one of claims 1 to 6, further comprising:

Images