JP2015179161A - projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector capable of accommodating rapid temperature changes in a housing.SOLUTION: A projector 1 comprises: an exterior housing 2 having an air intake port 12 for introducing ambient air; air intake ducts 10G and 10RB being connected to the air intake port 12 and guiding the ambient air introduced from the air intake port 12 to an optical modulation device 52; cooling fans 91G and 91RB being disposed in each of the air intake ducts 10G and 10RB and sending the ambient air introduced from the air intake port 12 to the optical modulation device 52; a dustproof filter 14 being disposed in the air intake port 12 and removing dust contained in the ambient air introduced from the air intake port 12; at least one temperature sensor 8 being disposed in the vicinity of the optical modulation device 52 and detecting a temperature of the optical modulation device 52; a control section 15 for controlling rotation drive of the cooling fans 91G and 91RB in response to results of detection by the temperature sensor 8; and output means 16 for outputting information on the dustproof filter 14 based on the results of detection by the temperature sensor 8 to a user.

Description

  The present invention relates to a projector.

  The projector is provided with a cooling fan in order to suppress a temperature rise inside the housing, and is configured to take in outside air from an air inlet provided in the exterior housing. A dustproof filter is disposed at the intake port in order to suppress entry of dust mixed in outside air. If dust accumulates in the dustproof filter over time, it is difficult to take in air and cooling efficiency is reduced. Therefore, it is necessary to periodically perform maintenance work such as filter replacement.

  However, high-intensity projectors, among other projectors, are often installed at event venues such as outdoors or on the ceiling of large auditoriums, and it is often difficult to perform maintenance work such as filter replacement. When the dustproof filter is clogged by using the projector for a long time, outside air containing dust (air not passing through the dustproof filter) enters the housing from the gaps of the housing. If dust or the like adheres to the image forming unit mounted inside the housing, the high image quality cannot be maintained and the image quality is deteriorated. Therefore, in high-brightness projectors, it is important to ensure at least dustproof performance for the image forming unit.

  As a dust-proof measure for the image forming unit, for example, a dust-proof structure in which the cooling flow path is substantially sealed has been proposed in order to prevent outside air from flowing in from places other than the dust-proof filter. However, when the dust filter is clogged, the cooling air for cooling the image forming unit is reduced. As a result, the temperature of the image forming unit rapidly increases, causing a problem that the image forming unit and the optical components constituting the image forming unit are damaged.

  In a high-intensity projector using such a dustproof structure, a method for appropriately cooling an image forming unit using a plurality of temperature sensors is disclosed (for example, Patent Documents 1 and 2).

JP 2009-047824 A JP 2001-355937 A

  In the conventional configuration, the temperature in the casing is managed by performing cooling control based on the detection result from the temperature sensor. However, in Patent Document 1, for example, when an intake filter attached to a duct suction unit that guides cooling air to the image forming unit is blocked, the image forming unit and an optical component constituting the image forming unit respond to a sudden temperature change. There are no considerations for it.

  SUMMARY An advantage of some aspects of the invention is that it provides a projector that can cope with a rapid temperature change of an image forming unit and optical components constituting the image forming unit. .

  A projector that is one embodiment of the present invention includes an illumination optical system that irradiates light, a light modulation device that modulates the light, a projection optical system that projects light modulated by the light modulation device onto a projection surface, An exterior housing having an intake port for introducing outside air; an intake duct connected to the intake port for guiding the outside air introduced from the intake port to the object to be cooled; and the outside air introduced from the intake port. An intake fan that blows air to an object to be cooled; a dust-proof filter that is provided at the air inlet and removes dust contained in the outside air introduced from the air inlet; and the object to be cooled that is disposed in the vicinity of the object to be cooled At least one temperature sensor for detecting the temperature of the air, a control unit for controlling rotational driving of the intake fan according to a detection result by the temperature sensor, and the detection result by the temperature sensor Characterized in that it comprises an output means for outputting information about the dust filter towards the user, a.

  According to this, since the temperature sensor is disposed in the vicinity of the object to be cooled, the temperature of the object to be cooled can be directly detected. Therefore, when the cooling air is reduced due to clogging of the dustproof filter and the temperature of the object to be cooled is increased, information on the dustproof filter can be output to the user based on the detection result by the temperature sensor. In this way, it is possible to instantly respond to the temperature change of the object to be cooled, and to avoid the damage of the object to be cooled accompanying the temperature rise.

  The projector according to one aspect of the present invention may have a configuration in which the object to be cooled and the temperature sensor are arranged in the intake duct.

  In the present invention, an object to be cooled and a temperature sensor are arranged in an intake duct connected to an intake port provided with a dustproof filter. For this reason, it has the structure which prevented the inflow of air other than the external air which passed the dustproof filter into the cooling flow path formed of an intake duct. Thereby, a cooling target object can be cooled with the cooling air which does not contain dust etc. As a result, no dust adheres to the object to be cooled, so that the image does not deteriorate and a high-quality image can be displayed.

  A projector that is one embodiment of the present invention includes an illumination optical system that irradiates light, a light modulation device that modulates the light, a projection optical system that projects light modulated by the light modulation device onto a projection surface, It is good also as a structure by which the said temperature sensor is arrange | positioned at the light-incidence side of the said light modulation apparatus which is the said cooling target object.

  According to this, an accurate temperature of the light modulation device can be detected by arranging the temperature sensor on the light incident side of the light modulation device that is hardly influenced by the input video signal.

  The projector according to one embodiment of the present invention may have a configuration in which the temperature sensor is disposed between the light modulation device and the incident-side polarizing plate.

  According to this, a more accurate temperature of the light modulation device can be detected by arranging the temperature sensor between the light modulation device and the incident side polarizing plate.

  The projector according to one embodiment of the present invention may have a configuration in which the temperature sensor is disposed on the downstream side of the cooling channel.

  According to this, by disposing the temperature sensor on the downstream side of the cooling flow path constituted by the intake duct, it is possible to detect the temperature of the place where the cooling air is hardly hit and is most difficult to be cooled.

  The projector according to one embodiment of the present invention may be configured such that the temperature sensor is disposed on a light incident side of the light modulation device that emits at least green light.

  According to this, since the temperature sensor is provided on the light incident side of the light modulation device that emits green light with high energy, the number of temperature sensors can be reduced.

  In the projector according to one aspect of the present invention, the control unit detects the temperature sensor even when the specified time has expired after the detection result of the temperature sensor is output to the user by the output unit. When the temperature is higher than a preset threshold temperature, the power may be turned off or shut down.

  According to this, when the user is not aware of the warning, it is possible to prevent the temperature of the light modulation device from further rising, and to reliably avoid damage to the light modulation device due to the temperature rise.

  In the projector according to one aspect of the present invention, the threshold temperature is a threshold value of a temperature that increases due to clogging of the dustproof filter, and a threshold value of the temperature that increases due to a luminance variation of the light modulation device. It is good also as a structure set to higher temperature.

  According to this, it can be determined that the temperature rise of the light modulation device is caused by the dustproof filter.

  The projector according to one aspect of the present invention includes the first intake duct and the second intake duct that are respectively connected to the intake port, and emits green light into the first intake duct. The light modulation device may be arranged, and the light modulation device that emits red light and the light modulation device that emits blue light may be arranged in the second intake duct.

  According to this, by arranging the light modulation device that emits green light and the light modulation device that emits red and blue light respectively in different ducts, the light modulation device for green having the highest energy can be obtained. The number of rotations of the cooling fan can be increased compared to other drives. Thereby, the green light modulation device can be efficiently cooled.

FIG. 2 is a schematic diagram illustrating a schematic configuration of a projector according to an embodiment. The perspective view of an optical apparatus. The top view which shows the structure of a cooling device typically. FIG. 6 is a diagram schematically illustrating a cooling structure corresponding to each color electro-optical device, where (A) is a diagram schematically illustrating a cooling structure corresponding to a green electro-optical device, and (B) is red and blue. FIG. 6 is a diagram schematically showing a cooling structure corresponding to the electro-optical device. Sectional drawing of an optical apparatus and a cooling device. The top view which shows schematic structure of the projector of 2nd Embodiment.

Hereinafter, a projector according to the present invention will be described with reference to the drawings.
The projector according to the present embodiment modulates the light beam emitted from the light source in accordance with image information and projects the enlarged light on a screen or the like. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[First Embodiment]
FIG. 1 is a schematic diagram illustrating a schematic configuration of a projector according to the present embodiment. FIG. 2 is a perspective view of the optical device. FIG. 3 is a plan view showing the configuration of the cooling device in detail. 4A and 4B are diagrams schematically showing a cooling structure corresponding to the electro-optical device of each color, in which FIG. 4A is a diagram schematically showing a cooling structure corresponding to the green electro-optical device, and FIG. FIG. 2 is a diagram schematically showing a cooling structure corresponding to red and blue electro-optical devices. FIG. 5 is a cross-sectional view of the optical device and the cooling device.

  As shown in FIG. 1, the projector 1 includes an exterior casing 2 constituting an exterior, a control unit 15, an optical unit 3 having a light source device (illumination optical system) 31, and a cooling device 9. Although illustration is omitted, a power supply device for supplying power to the light source device 31 and the control unit 15 is further arranged inside the exterior housing 2.

  Although the detailed description is omitted, the exterior housing 2 has an upper case constituting the upper portion, a lower case constituting the lower portion, and the like, which are fixed by screws or the like. The exterior housing 2 is provided with an intake port 12 for taking in outside air, an exhaust port 13 for exhausting warm air inside the exterior housing 2 to the outside, and the like. A dustproof filter 14 is disposed at the air inlet 12 and is configured to suppress intrusion of dust mixed in outside air into the exterior housing 2.

  The control unit 15 includes a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and the like, and functions as a computer. The control unit 15 controls the operation of the projector 1, for example, projects an image. The control related to the control and the drive of the cooling fan provided in the cooling device 9 are performed. The control unit 15 of the present embodiment includes a temperature control circuit 17 described later.

  The optical unit 3 optically processes and projects the light beam emitted from the light source device 31 under the control of the control unit 15. As shown in FIG. 1, in addition to the light source device 31, the optical unit 3 includes an integrator illumination optical system 32, a color separation optical system 33, a relay optical system 34, an optical device 4, a projection lens (projection optical system) 36, and these. The optical component casing 38 is disposed at a predetermined position on the optical path.

  For example, as shown in FIG. 1, the optical unit 3 is formed in a substantially L shape in plan view, and the light source device 31 is detachably disposed at one end, and the projection lens 36 is disposed at the other end. In the following, for convenience of explanation, the direction in which the light beam is emitted from the light source device 31 is the + X direction, the direction in which the light beam is emitted from the projection lens 36 is the + Y direction (front side), and the projector 1 is placed on a desk or the like. The upper direction in the stationary posture is described as the + Z direction (upper side).

  The light source device 31 includes a discharge-type light source 311 including a super high pressure mercury lamp, a metal hydrolamp, a reflector 312 and the like. The light source device 31 emits the light beam emitted from the light source 311 toward the integrator illumination optical system 32 by aligning the emission direction by the reflector 312.

  The integrator illumination optical system 32 includes a first lens array 321, a second lens array 322, a polarization conversion element 323, and a superimposing lens 324.

  The first lens array 321 is an optical member that divides the light beam emitted from the light source device 31 into a plurality of partial light beams, and is matrixed in a plane substantially orthogonal to the optical axis L of the light beam emitted from the light source device 31. A plurality of small lenses arranged in a shape.

  The second lens array 322 has substantially the same configuration as the first lens array 321, and superimposes the partial light beam emitted from the first lens array 321 on the surface of the light modulation device described later together with the superimposing lens 324. .

  The polarization conversion element 323 has a function of providing random light emitted from the second lens array 322 to approximately one type of polarized light that can be used in the light modulation device.

  The color separation optical system 33 includes two dichroic mirrors 331 and 332 and a reflection mirror 333, and a light beam emitted from the integrator illumination optical system 32 is converted into red light (hereinafter referred to as “R light”) and green light (hereinafter referred to as “G light”). Light) and blue light (hereinafter referred to as “B light”).

  The relay optical system 34 includes an incident side lens 341, a relay lens 343, and reflection mirrors 342 and 344, and has a function of guiding the R light separated by the color separation optical system 33 to a liquid crystal panel for R light. The optical unit 3 has a configuration in which the relay optical system 34 guides the R light. However, the configuration is not limited thereto, and may be configured to guide the B light, for example.

  As shown in FIGS. 1 and 2, the optical device 4 includes an electro-optical device 5 provided for each color light of R light, G light, and B light (an electro-optical device for R light is used for 5R and G light). The electro-optical device is 5G, the electro-optical device for B light is 5B), and a cross dichroic prism 41 and a support member 6 for fixing the cross dichroic prism 41 are provided as a color synthesis optical device. The optical device 4 modulates each color light separated by the color separation optical system 33 according to image information, and synthesizes each modulated color light.

  Each electro-optical device 5 includes an incident side polarizing plate 51, a light modulation device (cooling target) 52 (light modulation device 52R for R light, light modulation device 52G for G light, and light modulation device 52B for B light shown in FIG. A light modulation device 52B), an exit-side polarizing plate 54, and the device storage portion 7 and holding members 81 and 82 shown in FIG.

  The incident-side polarizing plate 51 is an optical element disposed on the upstream side of the optical path of the light modulation device 52, and transmits polarized light aligned by the polarization conversion element 323 out of each color light separated by the color separation optical system 33. Then, polarized light different from the polarized light is absorbed and emitted to the light modulation device 52.

  Although not shown in detail, the light modulation device 52 includes a liquid crystal panel in which liquid crystal is sealed and sealed in a pair of transparent glass substrates, and has a rectangular pixel region in which minute pixels are formed in a matrix. Yes. The light modulation device 52 has an outer periphery held by a panel frame 52F (FIG. 2), and is connected to the control unit 15 via a flexible substrate 52P (FIG. 2). The light modulation device 52 controls the alignment state of the liquid crystal according to the drive signal input from the control unit 15 and modulates the incident color light according to the image information.

  The exit-side polarizing plate 54 is an optical element disposed on the rear side of the optical path of the light modulation device 52. The exit-side polarizing plate 54 has substantially the same function as the incident-side polarizing plate 51, transmits polarized light in a certain direction among the color light modulated by the light modulation device 52, and transmits polarized light different from the polarized light. Absorbed and emitted to the cross dichroic prism 41.

The device storage section 7 stores the incident side polarizing plate 51, the light modulation device 52, and the emission side polarizing plate 54, and is formed in a cylindrical shape with the incident side polarizing plate 51 and the emission side polarizing plate 54.
The device storage portion 7 is formed in a rectangular parallelepiped shape and is hollow inside so that the incident side polarizing plate 51, the light modulation device 52, and the emission side polarizing plate 54 are stored, and air can flow in the vertical direction (Z direction). Is formed.
The holding member 81 is attached to the apparatus housing portion 7 with the incident-side polarizing plate 51 bonded and fixed thereto. The holding member 82 is attached to the apparatus housing 7 with the emission-side polarizing plate 54 bonded and fixed thereto.

  The cross dichroic prism 41 has a substantially square shape in plan view in which four right-angle prisms are bonded to each other, and as shown in FIG. 2, the three light beam incident sides on which the electro-optical devices 5R, 5G, and 5B are arranged to face each other. It has an end face 41A.

  In the cross dichroic prism 41, two dielectric multilayer films are formed at the interface where right-angle prisms are bonded together. In the cross dichroic prism 41, the dielectric multilayer film reflects the color light emitted from the electro-optical devices 5R and 5B, transmits the color light emitted from the electro-optical device 5G, and synthesizes each color light.

As shown in FIG. 2, the support member 6 is disposed below the cross dichroic prism 41 and supports the cross dichroic prism 41. The above-described device housing portion 7 housing the incident-side polarizing plate 51, the light modulation device 52, and the exit-side polarizing plate 54 is fixed to the support member 6 after the position is adjusted with respect to the cross dichroic prism 41.
The projection lens 36 is configured as a combined lens in which a plurality of lenses are combined, and enlarges and projects the light combined by the cross dichroic prism 41 shown in FIG. 1 onto a screen (projected surface) SC.

As shown in FIGS. 1 and 3, the cooling device 9 includes cooling fans (intake fans) 91G and 91RB configured by sirocco fans, and an intake duct 10 (first intake duct 10G and second intake duct 10RB). And.
The first intake duct 10G is formed so as to guide the cooling air sent from the cooling fan 91G to the electro-optical device 5G.
The second intake duct 10RB is formed so as to guide the cooling air sent from the cooling fan 91RB to the electro-optical devices 5R and 5B.

  The cooling device 9 guides the cooling air sent from the cooling fans 91G, 91RB to the electro-optical devices 5R, 5G, 5B by the first intake duct 10G and the second intake duct 10RB, and the light modulation devices 52R, 52G, 52B. The incident side polarizing plate 51 and the exit side polarizing plate 54 are cooled.

(Configuration of cooling device)
Here, the configuration of the cooling device 9 will be described.
As shown in FIGS. 1 to 3, the exterior housing 2 is provided with an intake port 12 for introducing outside air into the interior. In the present embodiment, two intake ducts 10 (first 1 intake duct 10G and second intake duct 10RB) are connected. A dustproof filter 14 is detachably provided inside the air inlet 12. Thereby, it is possible to replace or clean the dustproof filter 14 during maintenance.

  As shown in FIG. 1, the dustproof filter 14 includes a filter main body 42 and a filter frame 43. The filter body 42 is a member that has air permeability and removes dust contained in the air introduced from the air inlet 12 and is formed in a rectangular shape in plan view. The filter frame 43 is made of synthetic resin, and is formed in a rectangular frame shape in plan view so as to hold the outer periphery of the filter body 42.

  As shown in FIG. 2, the first intake duct 10G and the second intake duct 10RB are formed in a rectangular parallelepiped shape as a whole, and as shown in FIG. 3, the cylinders in which the openings 101 provided at both ends communicate with each other. It is formed in a shape.

  In the present embodiment, two intake ducts 10 are connected to one intake port 12, but an intake port 12 corresponding to each intake duct 10 may be provided. In that case, the dustproof filters 14 and 14 are individually provided for the intake ports 12 and 12, respectively.

As shown in FIGS. 4A and 5, the first intake duct 10G includes a first duct portion 10A, a second duct portion 10B, and a third duct portion 10C (device storage portion 7). One end portion 10a side is connected to the air inlet 12, and the other end portion 10b side holds an electro-optical device 5G including a light modulation device 52 that is a cooling target.
The first intake duct 10G of the present embodiment includes a device storage portion 7G that holds the electro-optical device 5G as a third duct portion 10C.

  The cooling fan 91G is disposed in the end portion 10a (first duct portion 10A) on the intake port 12 side of the first intake duct 10G, and the cooling air introduced from the intake port 12 is electro-optical device 5G (light modulation device 52G). ).

As shown in FIGS. 4B and 5, the second intake duct 10 </ b> RB has a shape in which the end portion 10 b side opposite to the end portion 10 a connected to the intake port 12 is branched into two. The first duct portion 10A, the pair of second duct portions 10B, and the pair of third duct portions 10C (device storage portion 7) are configured.
The second intake duct 10RB of the present embodiment includes a device storage portion 7R that holds the electro-optical device 5R as one third duct portion 10C, and the device storage portion 7B that holds the electro-optical device 5B as the other third. It is provided as a duct portion 10C.

  The cooling fan 91RB is disposed in the end portion 10a (first duct portion 10A) of the second intake duct 10RB on the intake port 12 side, and the cooling air introduced from the intake port 12 is supplied to each of the electro-optical devices 5R and 5B. It blows toward.

  The first duct portion 10A in the first intake duct 10G and the second intake duct 10RB is made of synthetic resin and is disposed below the optical component casing 38 shown in FIG.

  The second duct portion 10B in the first intake duct 10G and the second intake duct 10RB is a flexible member that deforms in accordance with the adjustment of the shape and position of the device storage portion 7 constituting the third duct portion 10C. (For example, a thermoplastic elastomer). As shown in FIG. 5, the third duct portion 10 </ b> C (device storage portion 7) is fixed in a posture in which the end portion side is inserted into the second duct portion 10 </ b> B. Therefore, the flexible second duct portion 10B is in close contact with the exterior of the device storage portion 7G (the end portion of the third duct portion 10C), and there is no gap between them. Similarly, no gap is formed between each second duct portion 10B and the device storage portions 7R and 7B in the second intake duct 10RB.

  In the present embodiment, the circumferential direction of the cooling channel K is sealed over the longitudinal direction, and air other than outside air that has passed through the dust-proof filter 14 does not flow into the cooling channel K.

  In the first intake duct 10G and the second intake duct 10RB of the present embodiment, a third duct portion 10C that is a part of the duct is configured by the device storage portion 7. That is, the first intake duct 10G and the second intake duct 10RB are configured to hold the electro-optical devices 5R, 5G, and 5B, and the cooling flow path of the first intake duct 10G and the second intake duct 10RB. Electro-optical devices 5R, 5G, and 5B exist on K (in the internal space).

  The cooling air sent from the cooling fans 91G and 91RB sequentially flows in the first duct portion 10A and the second duct portion 10B of the first intake duct 10G, and then in the device storage portion 7 which is the third duct portion 10C. The inside flows from the lower side (−Z direction) to the upper side (+ Z direction). The cooling air flowing in the device housing portion 7 (third duct portion 10C) is incident on the light exit side end surface of the incident side polarizing plate 51, on the light incident side end surface and on the light exit side end surface of the light modulation device 52G, and on the exit side polarizing plate 54. These optical components are cooled by flowing along the end surface of the light beam incident side of the light.

  Further, the cooling flow path K of the first intake duct 10G and the second intake duct 10RB, that is, the flow path extending from the opening 101 on the cooling fan 91G side to the opening 101 on the apparatus housing 7 side is formed in a tubular shape. As a result, the cooling air sent from the cooling fan 91G tends to be turbulent, and the above-described optical component is efficiently cooled.

  It should be noted that the first intake duct 10G and the second intake duct 10RB (first duct portion 10A) in the present embodiment include the exterior casings of the cooling fans 91G and 91RB, respectively.

  The cooling device 9 of the present embodiment includes a plurality of temperature sensors 8 that detect individual temperatures of the light modulation devices 52 (52R, 52G, and 52B) that are objects to be cooled.

  The temperature sensor 8 is disposed in the vicinity of each of the light modulation devices 52R, 52G, and 52B in the first intake duct 10G and the second intake duct 10RB. Since the temperature (heat generation amount) on the light emission side of the light modulation devices 52R, 52G, and 52B varies depending on the type of image, the temperature sensor 8 is less affected by the input video signal. 52B is arranged on the light incident side.

  Specifically, between the light modulation device 52R and the incident side polarizing plate 51, between the light modulation device 52G and the incident side polarizing plate 51, between the light modulation device 52B and the incident side polarizing plate 51, The temperature sensors 8 are respectively arranged on the downstream side of the cooling channel K (on the projection lens 36 side).

  In addition, the temperature sensor 8 should just be arrange | positioned in the space between each light modulation apparatus 52R, 52G, 52B and the incident side polarizing plate 51. FIG. However, by arranging the light modulators 52R, 52G, 52B and the incident side polarizing plate 51 on the downstream side of the cooling channel K in particular, the light modulators are difficult to receive the cooling air and are not easily cooled. It becomes possible to more accurately detect the temperatures of the ends of 52R, 52G, and 52B (ends to which the flexible substrate 52P is connected). For this reason, the temperature sensor 8 is preferably disposed in the space between each of the light modulation devices 52R, 52G, and 52B and the incident-side polarizing plate 51 and on the downstream side of the cooling channel K.

  In the present embodiment, a thermistor is used as the temperature sensor 8.

  The temperature sensor 8 is connected to the temperature control circuit 17 in the control unit 15 (not shown). The temperature control circuit 17 detects the temperature of the light modulators 52R, 52G, and 52B by each temperature sensor 8, and when each detected temperature is higher than a preset threshold temperature, the output means 16 (FIG. Alert the user via 1). In this embodiment, as information based on the detection result by the temperature sensor 8, a warning regarding the dust filter 14 (warning such as replacement or cleaning of the dust filter 14) is output to the user. This warning prompts the user to replace the dust filter 14 or perform maintenance work for cleaning. If the temperature detected by the temperature sensor 8 falls below the threshold temperature between the time when the warning is issued and the time when the specified time expires, the temperature control circuit 17 ends the warning.

  On the other hand, if the temperature detected by the temperature sensor 8 is higher than the threshold temperature even after a specified time has elapsed after the warning, the temperature control circuit 17 performs drive control to increase the rotation speed of each of the cooling fans 91G and 91RB. . The warning to the user is continued during this operation. After that, when the temperature detected by the temperature sensor 8 is higher than the threshold temperature even after a specified time has elapsed, that is, when the user does not perform maintenance work on the dust filter 14, the temperature control circuit 17 is It is determined that the warning is not noticed, and the projector 1 is turned off or shut down.

  The threshold temperature is a temperature threshold that rises due to clogging of the dust filter 14, and is set to a temperature that is higher than the temperature threshold that rises due to luminance variations of the light modulators 52R, 52G, and 52B. ing. Accordingly, the temperature control circuit 17 performs the above-described control only when the temperature increase of the light modulators 52R, 52G, and 52B is a temperature increase related to the clogging of the dustproof filter 14, as distinguished from the temperature increase caused by the luminance variation. .

  As described above, in the projector 1 according to the present embodiment, the light modulation device 52G and the temperature sensor 8 are disposed in the internal space of the first intake duct 10G, and light is transmitted in the internal space of the second intake duct 10RB. Modulators 52R and 52B and a plurality of temperature sensors 8 are arranged. The connecting portions of the three duct portions (the first duct portion 10A, the second duct portion 10B, and the third duct portion 10C) constituting the first intake duct 10G and the second intake duct 10RB are in close contact with each other. In addition, there is no place where outside air flows into each of the intake ducts 10G and 10RB from other than the opening 101 on the intake port 12 side. That is, by adopting a dust-proof configuration that prevents the inflow of air other than the air that has passed through the dust-proof filter 14, cooling air that does not contain dust, dust, or the like flows in the cooling channel K formed by the intake ducts 10G and 10RB. Will do. As a result, it is possible to prevent the image quality from deteriorating due to foreign matters such as dust or dirt adhering to the light modulation devices 52R, 52G, and 52B.

  However, in the case of the above-described configuration, when the dust filter 14 is clogged, the amount of outside air sucked into the first intake duct 10G and the second intake duct 10RB is remarkably reduced, and the temperature of the light modulation device 52 is rapidly increased. There is a risk of rising.

  In order to prevent this, in this embodiment, the temperature sensor 8 is disposed between the light modulation device 52 and the incident-side polarizing plate 51 to directly detect the temperature of the light modulation device 52, and the temperature of the light modulation device 52. A configuration that can respond to changes instantly.

  As described above, first, when the temperature detected by the light modulation device 52 by the temperature sensor 8 exceeds the threshold temperature, a warning is given to inform the user that the dustproof filter 14 is clogged. Even during the warning period, the rotational speed of the cooling fans 91G and 91RB is increased so that the temperature of the light modulation device 52 does not further increase. If the user is not aware of the warning, the optical modulation device is prevented from being damaged by forcibly terminating the device.

As described above, in the projector 1 according to the present embodiment, when the dustproof filter 14 is blocked due to clogging or the like, the light modulation device 52 and the light modulation device 52 and the light modulation device 52 are instantaneously responded to the rapid temperature rise of the light modulation device 52. It has a structure that can prevent damage to the optical components.
Therefore, it is possible to provide a highly reliable projector 1 while enabling high-quality image projection.

  In the present embodiment, the light modulation device 52G that emits green light and the light modulation devices 52R and 52B that emit red and blue light, respectively, are arranged in different intake ducts 10G and 10RB, thereby providing energy. The number of rotations of the cooling fan 91G with respect to the green light modulation device 52G having the highest value can be increased as compared with driving of the other cooling fans 91RB. As a result, the green light modulation device 52G, which is likely to be hot, can be efficiently cooled.

[Second Embodiment]
Next, a projector according to a second embodiment of the invention will be described.
FIG. 6 is a plan view illustrating a schematic configuration of the projector according to the second embodiment.
The basic configuration of the projector of this embodiment shown below is substantially the same as that of the above embodiment, but differs in the number of temperature sensors installed. Therefore, in the following description, the temperature sensor will be described in detail, and description of common parts will be omitted. Moreover, in each drawing used for description, the same code | symbol shall be attached | subjected to the same component as FIGS.

As shown in FIG. 6, in the projector according to the present embodiment, the temperature sensor 8 is disposed only in the first intake duct 10G.
Of the three light modulation devices 52R, 52G, and 52B, the light modulation device 52G has the highest energy. Therefore, the temperature sensor 8 may be arranged at least between the light modulation device 52G and the incident-side polarizing plate 51 facing the light modulation device 52G. As a result, the number of temperature sensors 8 can be reduced, and cooling control based on the detected temperature is facilitated.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

  The cooling device 9 of each embodiment described above is configured to prevent the inflow of outside air other than the air that has passed through the dust filter 14, but may be a projector that does not have such a dust protection structure.

The cooling device 9 of each embodiment described above includes the intake ducts 10G, 10RB including the plurality of duct portions 10A, 10B, 10C. However, the plurality of duct portions 10A, 10B, 10C are integrally formed. Also good.
In the above-described embodiment, the second duct portion 10B is made of a flexible member. However, the connection of the duct portions 10A, 10B, and 10C is prevented so that outside air does not flow into the intake ducts 10G and 10RB. If the portion can be sealed, it may be made of a synthetic resin material.

  Although the cooling device 9 of each embodiment described above includes two cooling fans 91G and 91RB, the number of cooling fans is not limited to two and may be one or three or more. The cooling fan is not limited to a sirocco fan but may be an axial fan or a combination of a sirocco fan and an axial fan.

In the embodiment, three light modulation devices 52 are provided, but the number is not limited to three, and may be one, two, or four or more.
Further, although the light modulation device 52 of the above-described embodiment is configured to include a transmissive liquid crystal panel, a reflection type liquid crystal panel may be used.

  The light source 311 is not limited to a discharge lamp, and may be a solid light source such as a lamp of another type or a light emitting diode.

  DESCRIPTION OF SYMBOLS 1 ... Projector, 2 ... Exterior housing, 8 ... Temperature sensor, K ... Cooling flow path, 10G (10) ... 1st intake duct, 10RB (10) ... 2nd intake duct, 12 ... Intake port, 14 ... Dust-proof filter, 15 ... control unit, 16 ... output means, 17 ... temperature control circuit, 31 ... light source device (illumination optical system), 36 ... projection lens (projection optical system), 51 ... incident side polarizing plate, 52, 52B, 52G, 52R ... Light modulator, 52 ... Light modulator (cooling object), 91G ... Cooling fan (intake fan), SC ... Screen (projected surface)

Claims (9)

An illumination optical system that emits light;
A light modulation device for modulating the light;
A projection optical system that projects light modulated by the light modulation device onto a projection surface;
An exterior housing having an air inlet for introducing outside air;
An intake duct that is connected to the intake port and guides the outside air introduced from the intake port to the object to be cooled;
An intake fan that blows the outside air introduced from the intake port to an object to be cooled;
A dust-proof filter that is provided in the air inlet and removes dust contained in the outside air introduced from the air inlet;
At least one temperature sensor disposed in the vicinity of the cooling object and detecting the temperature of the cooling object;
A control unit for controlling the rotational drive of the intake fan according to the detection result by the temperature sensor;
An output means for outputting information related to the dustproof filter based on a detection result by the temperature sensor to a user.   The projector according to claim 1, wherein the object to be cooled and the temperature sensor are arranged in the intake duct.   The projector according to claim 1, wherein the temperature sensor is disposed on a light incident side of the light modulation device that is the cooling target.   The projector according to any one of claims 1 to 3, wherein the temperature sensor is disposed between the light modulation device and an incident-side polarizing plate.   The projector according to claim 1, wherein the temperature sensor is disposed on the downstream side of the cooling flow path.   The projector according to claim 1, wherein the temperature sensor is disposed on a light incident side of the light modulation device that emits at least green light.   After the control unit outputs the detection result of the temperature sensor to the user by the output unit, the detection temperature of the temperature sensor is set in advance even when the specified time expires. The projector according to any one of claims 1 to 6, wherein the projector is turned off or shut down when it is higher.   The threshold temperature is a threshold value of a temperature that rises due to clogging of the dustproof filter, and is set to a temperature that is higher than a threshold value of a temperature that rises due to luminance variation of the light modulation device. Item 8. The projector according to Item 7. The first intake duct and the second intake duct connected to the intake port respectively,
The light modulation device for emitting green light is disposed in the first intake duct,
The projector according to claim 1, wherein the light modulation device that emits red light and the light modulation device that emits blue light are arranged in the second intake duct.

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