JP2004245987A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of reducing noise although it can be used widely in a variety of use environments. <P>SOLUTION: A projector 1 is made to control voltage applied to a fan 15 for internal cooling according to the temperature inside the projector 1 and can switch a plurality of cooling modes wherein the voltage applied to the fan 15 is different even when the temperature in the projector 1 is the same. The cooling modes are switched according to use environments to make driving control over the fan matching the use environments possible, and consequently, noise is reduced. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a projector.
[0002]
[Prior art]
The projector is provided with a high-luminance lamp as a light source, and air cooling has been conventionally performed by a cooling fan in order to suppress an increase in internal temperature due to the lamp. In recent years, a projector has been proposed which controls the driving of a cooling fan in order to effectively perform the air cooling. For example, a plurality of temperature sensors for detecting the temperature inside the projector are provided, and each of the temperature sensors is provided. There is a liquid crystal projector that controls the drive of a fan based on the temperature detected by the projector (for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 2002-258238
[Problems to be solved by the invention]
In recent years, projectors have been used in various usage environments. For example, it has come to be used in high altitudes where the atmospheric pressure is low. At high altitudes, the air pressure is low and the air density is low, so if the fan is operated at the same speed as when used in low altitude, the same cooling effect as when using in low altitude is not obtained, and the temperature inside the projector will decrease. Will rise. Therefore, as in the above-described prior art, in a projector that does not particularly distinguish between use environments such as a lowland and a highland, and simply controls driving of a fan based on a temperature detected by each temperature sensor, it is necessary in a certain use environment. Even if a good cooling effect is obtained, a sufficient cooling effect cannot be obtained in another use environment, and there may be a problem that the internal temperature rises and the projector shuts down.
[0005]
In order to solve this problem, it is possible to cope with the problem by setting the rotation speed of the fan to a high value in advance in accordance with a use environment requiring a high cooling capacity. However, if the rotation speed of the fan is determined according to the usage environment requiring such high cooling capacity, the fan will operate at an unnecessarily high rotation speed when used in other usage environments. This results in an increase in noise.
[0006]
The present invention has been made in view of such a point, and an object of the present invention is to provide a projector that can be widely used in various use environments and that can reduce noise.
[0007]
[Means for Solving the Problems]
The projector according to the present invention is a projector that controls an applied voltage supplied to a fan for internal cooling in accordance with a temperature inside the projector. A plurality of different cooling modes can be switched.
[0008]
Further, the projector according to the present invention is a projector that controls an applied voltage to be supplied to a fan for cooling the inside of the projector in accordance with the temperature inside the projector, and supplies the voltage to the fan even when the temperature inside the projector is the same. A plurality of cooling modes having different applied voltages, a cooling mode setting unit for setting any one of the cooling modes, a temperature detection unit for detecting a temperature inside the projector, a fan driving unit for driving a fan, and a cooling mode The control unit controls the fan drive unit based on the cooling mode set in the setting unit and the temperature detected by the temperature detection unit.
[0009]
With the configuration as described above, the cooling mode can be switched according to the use environment, and thus, the drive control of the fan according to the use environment can be performed. Therefore, it is possible to obtain a projector that can be widely used in various use environments, can prevent the fan from being driven at an unnecessarily high rotational speed that does not match the use environment, and can reduce noise. .
[0010]
Further, the projector according to the present invention has a control table storage unit for storing, for each cooling mode, a control table in which a relationship between a temperature inside the projector and an applied voltage applied to the fan when the temperature is detected is set. The control unit selects a corresponding control table from the control table storage unit based on the cooling mode set in the cooling mode setting unit, and based on the selected control table and the temperature detected by the temperature detection unit. Thus, an applied voltage to be applied to the fan is determined, and the fan drive unit is controlled so as to apply the applied voltage to the fan. As described above, the applied voltage to be supplied to the fan is determined based on the control table and the detected temperature selected according to the cooling mode, so that the process of the control unit when determining the applied voltage is simplified. Can be.
[0011]
Further, the projector according to the present invention is provided with a selection switch for selecting any one of a plurality of cooling modes on the projector main body, and the cooling mode can be switched by the selection switch. As described above, the switching of the cooling mode can be selected by the selection switch. By operating the selection switch, the user can appropriately switch the cooling mode according to the usage environment.
[0012]
Further, the projector according to the present invention displays a menu screen on which any one of a plurality of cooling modes can be selected, and can switch the cooling mode from the menu screen. As described above, the switching selection of the cooling mode is possible from the menu screen, and the user can appropriately switch the cooling mode on the menu screen according to the usage environment.
[0013]
Further, in the projector according to the present invention, the plurality of cooling modes are provided according to a use environment in which the projector is installed, and a low altitude mode set when the projector is used in a low altitude with a high atmospheric pressure. And a high altitude mode which is set when the projector is used at a high altitude where the atmospheric pressure is low. As a result, it is possible to switch the cooling mode between the case of using at low altitude and the case of using at high altitude, and to execute the drive control of the fan according to the use environment.
[0014]
In the projector according to the present invention, the plurality of cooling modes are provided according to the use environment in which the projector is installed, and are set when the projector is installed on a desk or floor and used. There are two types of modes: a ceiling mode and a ceiling mode set when the projector is used in a ceiling-suspended state. This makes it possible to switch the cooling mode between the case where the fan is installed on a desk or a floor and the case where the fan is used in a suspended state, and to control the drive of the fan according to the usage environment.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First, prior to the description of the features of the present invention, the internal configuration of the projector will be described.
[0016]
FIG. 1 is an external perspective view of a projector according to an embodiment of the present invention as viewed from the front side. FIG. 2 is an external perspective view of the projector according to the embodiment of the present invention as viewed from the rear side. The outer case 2 of the projector 1 of this example has a rectangular parallelepiped shape. The outer case 2 basically includes an upper case 3, a lower case 4, and a front case 5 which defines the front of the apparatus. The front end portion of the projection lens unit 6 projects from the center of the front case 5. An operation panel 70 for inputting various control information and data to the projector 1 is provided on the upper surface of the upper case 3. A selection switch 71 for selecting any one of a plurality of cooling modes described below is provided on the rear surface of the outer case 2.
[0017]
FIG. 3 is a diagram showing the arrangement of each component in the exterior case of the projector. As shown in this figure, a power supply unit 7 is disposed at the rear end side inside the outer case 2. A light source lamp unit 8 and an optical unit 9 are arranged at a position adjacent to the front side of the apparatus. Further, at the center of the front side of the optical unit 9, the base end side of the projection lens unit 6 is located.
[0018]
On the other hand, on one side of the optical unit 9, an interface board 11 on which an input / output interface circuit is mounted is arranged in the front-rear direction of the apparatus, and in parallel with this, a video board 12 on which a video signal processing circuit is mounted is provided. Are located. Further, a control board 13 for controlling the drive of the apparatus is disposed above the light source lamp unit 8 and the optical unit 9, and speakers 14R and 14L are disposed at the left and right corners on the front end side of the apparatus.
[0019]
Further, in the outer case 2, a plurality of fans 15 (15A, 15B, 15C) for cooling the inside of the projector are arranged. Specifically, intake fans 15A and 15B are arranged above and below the optical unit 9. An exhaust fan 15 </ b> C is disposed on the side of the apparatus, which is the back side of the light source lamp unit 8.
[0020]
Among these fans 15, the fan 15B mainly functions as a cooling fan for the liquid crystal panels 40R, 40G, and 40B described later. Note that the fan 15A can be used for cooling the liquid crystal panels 40R, 40G, and 40B.
[0021]
Hereinafter, the configurations of the optical unit 9 and the optical system will be described with reference to FIG.
[0022]
FIG. 4A is a diagram illustrating a portion of the optical unit. As shown in this figure, the optical unit 9 has a configuration in which optical elements other than the prism unit 20 constituting the color synthesizing means are held between upper and lower light guides 901 and 902 from above and below. ing. The upper light guide 901 and the lower light guide 902 are fixed to the upper case 3 and the lower case 4 by fixing screws, respectively. These upper and lower light guides 901 and 902 are similarly fixed to the prism unit 20 side by fixing screws.
[0023]
The prism unit 20 is fixed to the back surface of a thick head plate 30, which is a die-cast plate, with fixing screws. On the front surface of the head plate 30, the base end side of a projection lens unit 6 as a projection means is fixed by fixing screws. Therefore, in the present example, the prism unit 20 and the projection lens unit 6 are fixed so as to be integrated with the head plate 30 interposed therebetween.
[0024]
FIG. 4B is a diagram illustrating a schematic configuration of an optical system incorporated in the projector. The optical system of this example includes a lamp 805 as a light source, a uniform illumination optical system 923 having integrator lenses 921 and 922, which are uniform illumination optical elements, and a light beam W emitted from the illumination optical system 923, which emits red and green light. , A color separation optical system 924 that separates each color light beam R, G, and B, three liquid crystal panels 40R, 40G, and 40B as electro-optical devices that modulate each color light beam, and the modulated color light beam. It is composed of a prism combining body 22 as a color combining optical system, and a projection lens unit 6 for enlarging and projecting the combined luminous flux on a projection surface. In addition, it has a relay optical system 927 for guiding the blue light flux B among the respective color light fluxes separated by the color separation optical system 924 to the corresponding liquid crystal panel 40B.
[0025]
The uniform illumination optical system 923 further includes a reflection mirror 931 so that the optical axis 1a of the light emitted from the lamp 805 is bent at a right angle toward the front of the device. With the mirror 931 interposed therebetween, the integrator lenses 921 and 922 are arranged to be orthogonal to the front and rear.
[0026]
The color separation optical system 924 includes a blue-green reflecting dichroic mirror 941, a green reflecting dichroic mirror 942, and a reflecting mirror 943. First, in the blue-green reflecting dichroic mirror 941, the blue light beam B and the green light beam G included in the light beam W that has passed through the uniform illumination optical system 923 are reflected at a right angle, and the green reflecting dichroic mirror 942 side. Head for. The red light flux R passes through the mirror 941, is reflected at a right angle by the rear reflection mirror 943, and is emitted from the emission section 944 of the red light flux toward the color combining optical system. Next, in the green reflection dichroic mirror 942, only the green light flux G of the blue and green light fluxes B and G reflected by the mirror 941 is reflected at a right angle, and the green light flux output portion 945 of the color combining optical system. Emitted to the side. The blue light flux B that has passed through the mirror 942 is emitted from the emission part 946 of the blue light flux toward the relay optical system 927. In this example, the distances from the light emitting portion of the uniform illumination optical element to the light emitting portions 944, 945, 946 of the respective color light beams in the color separation optical system 924 are all set to be substantially equal.
[0027]
Condensing lenses 951 and 952 are arranged on the emission sides of the emission units 944 and 945 of the red light beam and the green light beam of the color separation optical system 924, respectively. Therefore, the red light beam and the green light beam emitted from each emission unit are incident on these condenser lenses 951 and 952 and are parallelized.
[0028]
The parallelized red and green luminous fluxes R and G are polarized by the polarizing plates 60R and 60G, and then incident on the liquid crystal panels 40R and 40G, where they are modulated, and image information corresponding to each color light is added. You. That is, switching of these liquid crystal panels 40R and 40G is controlled by an image signal corresponding to image information by a driving unit (not shown), and thereby, each color light passing therethrough is modulated. As such a driving unit, a known unit can be used as it is.
[0029]
On the other hand, the blue luminous flux B passes through the relay optical system 927, and after being polarized by the polarizing plate 60B, is led to the corresponding liquid crystal panel 40B, where the light is similarly modulated according to image information. Will be applied. Incidentally, as the liquid crystal panels 40R, 40G, 40B of the present embodiment, for example, those using a polysilicon TFT as a switching element can be used.
[0030]
The relay optical system 927 includes a condenser lens 974, an incident-side reflection mirror 971, an exit-side reflection mirror 972, an intermediate lens 973 disposed between these mirrors, and a condenser lens 953 disposed in front of the liquid crystal panel 40B. Consists of The length of the optical path of each color light beam, that is, the distance from the lamp 805 to each liquid crystal panel, is the longest for the blue light beam B, and therefore, the light amount loss of this light beam is the largest. However, by interposing the relay optical system 927, the light amount loss can be suppressed.
[0031]
Each color light beam modulated through each of the liquid crystal panels 40R, 40G, and 40B is incident on the polarizing plates 61R, 61G, and 61B, and the light transmitted therethrough is incident on the prism composite 22, where they are combined. In this example, a color combining optical system is configured using a prism combining body 22 composed of a dichroic prism. The synthesized color image is enlarged and projected on the projection surface 10 at a predetermined position via the projection lens unit 6.
[0032]
Hereinafter, features of the present invention will be described with reference to the drawings.
Here, the outline of the projector of the present invention will be briefly described. The projector of the present invention controls the applied voltage to be supplied to the internal cooling fan provided inside the projector in accordance with the temperature inside the projector. A plurality of cooling modes with different applied voltages to be supplied can be switched according to the use environment (for example, a low altitude with a high atmospheric pressure or a high altitude with a low atmospheric pressure). In other words, a plurality of cooling modes are prepared in advance in accordance with the usage environment in which the projector is installed, and the cooling mode is appropriately switched and used by the user, so that the drive control of the fan according to the usage environment is performed. Is made. As a result, the fan is driven so as to perform necessary and sufficient cooling without overcooling or insufficient cooling of the inside of the projector, increasing the noise by driving the fan at an excessive number of revolutions, or causing unintended shutdown. It enables prevention.
[0033]
FIG. 5 is a block diagram showing an electrical configuration of a main part of the projector according to the embodiment of the present invention.
[0034]
The projector 1 includes an I / O unit 72 that outputs signals from the operation panel 70 and the selection switch 71 to a control unit 75 described below, and a temperature that detects a temperature inside the projector 1 and outputs the detected temperature to the control unit 75 described below. The detection unit 73 is provided. In addition, a control table storage unit 74 that stores a control table described below for each cooling mode is provided. Further, a control unit 75 including a microcomputer for performing various control operations based on signals from the operation panel 70, the selection switch 71, and the temperature detection unit 73 and controlling the entire projector 1 is provided.
[0035]
The projector 1 also includes a lamp driving unit 76 that drives the lamp 805 in the light source lamp unit 8 (see FIG. 3) and a fan driving unit 77 that drives the fan 15 for cooling the inside of the projector 1.
[0036]
Further, a projection display control unit 78 that supplies video signals input from the outside to the liquid crystal panels 40R, 40G, and 40B and controls various operations of the liquid crystal panels 40R, 40G, and 40B according to control signals from the control unit 75 is provided. Have.
[0037]
Hereinafter, details of each unit will be described.
The selection switch 71 allows the user to arbitrarily select one of the plurality of cooling modes, as described above. In this example, there are two types of cooling modes, a low altitude mode set when the projector 1 is used in a low altitude where the air pressure is high, and a high altitude mode set when the projector 1 is used in a high altitude where the air pressure is low. Can be selected.
[0038]
The control table storage unit 74 is a unit that stores a control table used by the control unit 75 when determining the applied voltage to be supplied to the fan 15. The control table for the low altitude mode and the high altitude mode are prepared in advance, and both of them are stored in the control table storage unit 74. The control table sets the relationship between the temperature inside the projector 1 and the applied voltage applied to the fan 15 when the temperature is detected, and an example is shown in the following figure.
[0039]
FIG. 6 is a diagram illustrating an example of two control tables for the lowland mode and the highland mode stored in the control table storage unit. Note that (a) is for the low altitude mode and (b) is for the high altitude mode, and the applied voltages VaL, VbL, VcL, and VdL are each lower than the applied voltages VaH, VbH, VcH, and VdH.
In each control table, an applied voltage optimized for cooling efficiency and noise reduction is set in advance for each temperature based on the use environment in which the control table is used. For this reason, as shown in FIG. 6, the applied voltage supplied to the fan 15 is different between the low altitude mode and the high altitude mode even if the temperature inside the projector 1 is the same. That is, at high altitudes, as described above, it is necessary to increase the cooling efficiency as compared to when using at low altitudes. Therefore, the applied voltage is set higher than at low altitudes, and the fan 15 is operated at a high rotation speed. Has become. On the other hand, at low altitude, the applied voltage is set low, and the fan 15 is operated at a low rotation speed, since the cooling efficiency is lower than that at high altitude. Further, the voltage applied to the control table is optimized not only in terms of cooling efficiency but also in terms of noise reduction as described above, and is set so that the fan 15 is driven at a necessary and sufficient number of revolutions in each mode. I have.
[0040]
The fan 15 refers to three fans 15A, 15B, and 15C as shown in FIG. 3, but each fan uses the same low altitude mode control table and high altitude mode control table. The operation may be performed, or a separate low altitude mode control table and high altitude mode control table may be used. In this example, it is assumed that all of the fans 15A, 15B, and 15C use the same control table shown in FIG.
[0041]
The control unit 75 has a cooling mode setting unit 75a. A selection signal from the selection switch 71 is input to the cooling mode setting section 75a, and one of the lowland mode and the highland mode is set based on the selection signal. The control unit 75 selects a corresponding control table from the control table storage unit 74 based on the setting mode set in the cooling mode setting unit 75a, and compares the selected control table with the temperature detected by the temperature detection unit 73. The applied voltage to be applied to the fan 15 is determined based on this. Then, a control signal is output to the fan drive unit 77 so as to supply the determined applied voltage to the fan 15. The control unit 75 performs various setting operations and operation control of each unit based on a signal from an operation panel 70 provided in the projector 1 main body.
[0042]
The lamp driving unit 76 is a power supply circuit for supplying driving power to the lamp 805, and transforms the power supplied from the outside and supplies it to the lamp 805. In the lamp driving section 76, the control section 75 controls the amount of electric power supplied to the lamp 805, whereby the output luminance of the lamp 805 is adjusted.
The fan driving unit 77 is configured by a motor or the like, and supplies power to the fan 15. The fan driving unit 77 supplies an applied voltage to the fan 15 according to a control signal from the control unit 75.
[0043]
The projection display control unit 78 reads, for example, an image displayed on a personal computer or the like or a video signal stored in advance therein, and supplies it to the corresponding liquid crystal panels 40R, 40G, and 40B as RGB signals. Further, processing such as controlling the liquid crystal panels 40R, 40G, and 40B to project and display a menu screen for performing various settings for image display in accordance with an instruction from the control unit 75 is also performed.
[0044]
Hereinafter, the operation of the present embodiment will be described. FIG. 7 is a flowchart showing the flow of the operation of the present embodiment.
After turning on the power of the projector 1, the control unit 75 accesses the cooling mode setting unit 75a to read the current cooling mode (S1). The temperature detecting section 73 detects the temperature inside the projector 1 while the power of the projector 1 is turned on, and the control section 75 reads the temperature detected by the temperature detecting section 73 (S2). Then, the control unit 75 selects a control table corresponding to the current cooling mode from the control table storage unit 74, and determines an applied voltage to be applied to the fan 15 based on the selected control table and the temperature detected by the temperature detection unit 73. It is determined (S3).
[0045]
Then, a control signal for supplying the determined applied voltage to the fan 15 is output to the fan driving unit 77 (S3). As a result, the fan drive unit 77 supplies the applied voltage determined by the control unit 75 to the fan 15. The above operation is repeatedly performed at predetermined time intervals, and drive control of the fan 15 according to the cooling mode and the detected temperature at that time is realized.
[0046]
Hereinafter, a specific example will be described. Here, the following description will be made assuming that the control table shown in FIG. 6 is used.
When the cooling mode read at a certain read timing is the high altitude mode and the detected temperature is read as Ta, the applied voltage is determined as VaH. Then, the applied voltage VaH is supplied to the fan 15. Thereafter, while the selection switch 71 is set to the high altitude mode, the applied voltage determined based on the high altitude mode control table and the detected temperature is supplied to the fan 15. When the selection switch 71 is switched to the low altitude mode, the cooling mode is read out to the low altitude mode at the cooling mode read timing performed after the switching timing, and the detected temperature is set to Tb in the process of step S2. When read, the applied voltage is determined as VbL. Then, the applied voltage VbL is supplied to the fan 15.
[0047]
As described above, according to the present embodiment, the cooling mode can be switched in accordance with the use environment, and the drive control of the fan 15 according to the use environment is performed. It is possible to obtain the projector 1 which can be used in a wide range, but in which the driving of the fan 15 at a rotational speed higher than necessary as in the related art is prevented and noise can be reduced. Further, it is possible to solve the problem that the internal temperature rises and shuts down due to the driving of the fan that does not match the usage environment as in the related art.
[0048]
In this embodiment, an example in which the lowland mode and the highland mode are prepared and switched according to the usage environment has been described.However, the present invention is not limited to this. A desktop mode for performing the operation and a ceiling mode for suspending the apparatus from a ceiling or the like may be prepared. When the projector 1 is used in a suspended state from the ceiling, the projector 1 is used in a state of being installed upside down when used on a desktop while being suspended. For this reason, the flow of the cooling air by the fan 15 may be different from that when the desktop is used, and the cooling efficiency may be changed. Therefore, by preparing the desktop mode and the ceiling hanging mode, and switching and using the control table of each mode according to the use environment, it is possible to implement the drive control of the fan 15 suitable for the use environment. .
[0049]
The number of cooling modes is not limited to two, and may be three or more. In short, the present invention may be configured so that a plurality of cooling modes in which the temperature applied to the fan 15 is different even when the temperature inside the projector 1 is the same are prepared in advance and the cooling mode can be switched according to the use environment. The contents of the actual use environment in which the cooling mode can be switched and the number of the cooling modes are not particularly limited.
[0050]
Further, in the present embodiment, the cooling mode can be switched by the selection switch 71. However, the menu screen is displayed using the operation panel 70 provided on the projector 1 main body, and the cooling mode can be switched from the menu screen. You may do it.
[0051]
FIG. 8 is a diagram illustrating an example of the menu screen.
The menu screen 100 is a screen projected and displayed by pressing a menu button 80 of the operation panel 70. In addition to a cooling mode selection area 101 for a user to select a desired cooling mode, a menu in which various settings can be made. Selection area. The cooling mode selection area 101 shown in FIG. 8 shows an example in which either the High mode or the Normal mode can be selected. The selection operation can be made by operating the direction buttons 81a and 81b (see FIGS. 1 and 2) of the operation panel 70. The mode selected here is set in the cooling mode setting section 75a, and the drive control of the fan 15 according to the set mode is performed.
[0052]
The selection of the cooling mode is not limited to the manual operation as described above, and may be performed automatically. For example, when selecting either the low altitude mode or the high altitude mode, a configuration may be adopted in which a sensor for detecting the atmospheric pressure is provided, and the sensor is automatically selected according to the detected atmospheric pressure.
[0053]
In the above embodiment, the case where the present invention is applied to a projector using a transmissive liquid crystal panel has been described as an example. However, the present invention can also be applied to a projector using a reflective liquid crystal panel. It is possible. Here, “transmission type” means that the liquid crystal panel transmits light, and “reflection type” means that the liquid crystal panel reflects light.
[0054]
Further, in the above embodiment, a liquid crystal panel is used as a light modulation element for modulating light from a lamp. However, the present invention is not limited to a liquid crystal panel. For example, a device using a micromirror, a CCD (Charge Coupled Device) May be used, and the present invention can be applied to a projector including these.
[0055]
Further, as the projection type projector, there are a front projection type projector which performs projection from a direction in which a projected image is observed, and a rear projection type projector which performs projection from a side opposite to a direction in which a projected image is observed. Can be applied to any of them.
[0056]
Further, in the above embodiment, the case where the present invention is applied to a so-called three-panel type projector using three liquid crystal panels is described as an example. However, the present invention is not limited to this, and for example, two or four liquid crystal panels are used. The present invention can be applied to a two-plate or four-plate projector.
[Brief description of the drawings]
FIG. 1 is an external perspective view of a projector according to the invention as viewed from the front side.
FIG. 2 is an external perspective view of the projector according to the invention as viewed from the rear side.
FIG. 3 is a diagram showing an arrangement of each component in the exterior case of FIG. 1;
FIG. 4A is a diagram illustrating a part of an optical lens unit and a projection lens unit taken out and shown, and FIG. 4B is a schematic configuration diagram of an optical system.
FIG. 5 is a block diagram showing an electrical configuration of a main part of one embodiment of the present invention.
FIG. 6 is a diagram showing an example of a control table.
FIG. 7 is a flowchart showing the operation of the present embodiment.
FIG. 8 is a diagram showing an example of a menu screen.
[Explanation of symbols]
Reference Signs List 1 projector, 15 (15A, 15B, 15C) fan, 40B liquid crystal panel, 40R, 40G, 40B liquid crystal panel, 71 selection switch, 73 temperature detection unit, 74 control table storage unit, 75a cooling mode setting unit, 77 fan drive unit , 78 Projection display control unit, 80 menu buttons, 100 menu screen, 805 lamp

Claims (7)

A projector configured to control an applied voltage supplied to a fan for internal cooling according to a temperature inside the projector,
A projector characterized in that a plurality of cooling modes in which the applied voltage to be supplied to the fan is different even when the temperature inside the projector is the same can be switched. A projector configured to control an applied voltage to be supplied to a fan for cooling the inside of the projector according to a temperature inside the projector,
A cooling mode setting unit that has a plurality of cooling modes in which the applied voltage supplied to the fan is different even when the temperature inside the projector is the same, and sets one of the cooling modes;
A temperature detector for detecting the temperature inside the projector,
A fan driving unit that drives the fan;
A projector comprising: a control unit that controls the fan drive unit based on a cooling mode set in the cooling mode setting unit and a temperature detected by the temperature detection unit. A control table storage unit that stores a control table in which a relationship between the temperature inside the projector and an applied voltage to be applied to the fan when the temperature is detected is set for each of the cooling modes, and the control unit includes: A corresponding control table is selected from the control table storage unit based on the cooling mode set in the cooling mode setting unit, and is applied to the fan based on the selected control table and the temperature detected by the temperature detection unit. 3. The projector according to claim 2, wherein an applied voltage to be applied is determined, and the fan drive unit is controlled so as to apply the applied voltage to the fan. 4. The projector according to claim 1, wherein a selection switch for selecting one of the plurality of cooling modes is provided on the projector body, and the cooling mode can be switched by the selection switch. 5. 4. The cooling screen according to claim 1, wherein a menu screen for selecting any one of the plurality of cooling modes is displayed, and the cooling mode can be switched from the menu screen. Projector. The plurality of cooling modes are provided according to the use environment in which the projector is installed. The projector according to any one of claims 1 to 5, wherein the projector has two types of modes, a high altitude mode and a high altitude mode, which are set at the time of the operation. The plurality of cooling modes are provided according to the use environment in which the projector is installed, and are used in a desktop mode set when the projector is installed and used on a desk or a floor, and used in a ceiling-mounted state. The projector according to any one of claims 1 to 5, wherein the projector has two types of modes, a ceiling hanging mode set at the time.

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