JP2006154527A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector which can be automatically set to the projection mode most suitable for appreciation in accordance with a use and an environment for use. <P>SOLUTION: The projector for reproducing inputted image signals and audio signals is provided with; an illumination optical system having a light source including a lamp 29 and a fan 33 for cooling the light source; and a switching means 35 for switching the operation control of the illumination optical system in accordance with classifications of the audio signals. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector, and more particularly to a projector having a fan that cools a light source that generates heat during image projection.

  Conventionally, with respect to projectors such as liquid crystal projectors, proposals have been made to take measures against temperature rise when the temperature rise around the light source exceeds a specified value.

  For example, in Patent Document 1, when a temperature in a projector rises abnormally, a user performs a protective operation to lower the temperature by reducing the light amount of a lamp light source or increasing the number of rotations of a cooling fan. Techniques that can be performed in selected modes are disclosed. According to the technique disclosed in Patent Document 1, when the temperature measured by the temperature sensor exceeds a specified value, the cooling power of the cooling device is increased (by increasing the number of rotations of the fan) to suppress the temperature rise. When it is not desired to raise the noise caused by the fan, the user can arbitrarily select a mode in which the rotation speed of the fan is kept as it is or lower, and the lamp light quantity is reduced to suppress the temperature rise.

  Further, regarding a technique for switching the operation mode, there has been proposed a technique capable of improving usability and operability by automatically specifying the operation mode of the apparatus main body and limiting the operation.

For example, in Patent Document 2, when an accessory is connected to the camera body to improve the function, the operation mode of the camera body is automatically defined according to the type of accessory to be connected, and the operation of the camera body is limited. Thus, a technique for improving operability is disclosed. According to the technique disclosed in Patent Document 2, it is possible to reduce power consumption by automatically controlling ON / OFF of a monitor power supply of a connected monitor.
JP 2003-15224 A JP-A-6-343137

  However, in the technique disclosed in Patent Document 1, it is necessary for the user to set the mode himself, so it can be said that it takes time and effort for the user.

  The technique disclosed in Patent Document 2 switches the operation mode according to the connection accessory, but is not a technique for finely controlling the relationship between audio and video by the switching.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a projector that automatically sets a projection mode that is optimal for viewing according to a use application and a use environment.

  In order to achieve the above object, a projector according to a first aspect of the present invention is an illumination optical system having a light source including a lamp and a fan for cooling the light source in a projector that reproduces an input image signal and audio signal. And switching means for switching operation control of the illumination optical system in accordance with the types of the image signal and the audio signal.

  In order to achieve the above object, a projector according to a second aspect of the present invention is a projector that reproduces an input image signal, an illumination optical system that includes a light source including a lamp and a fan that cools the light source, and And switching means for switching operation control of the illumination optical system in accordance with the type of image signal.

  ADVANTAGE OF THE INVENTION According to this invention, the projector which sets automatically the projection mode optimal for viewing according to a use application and a use environment can be provided.

  Hereinafter, a projector according to an embodiment of the invention will be described with reference to the drawings.

  FIG. 1 shows the configuration of a projector according to an embodiment of the present invention. Hereinafter, the configuration of a projector according to an embodiment of the present invention will be described with reference to FIG.

  The sound and image source 2 is connected as a device for inputting sound and image signals to be reproduced by the projector 1 according to the present embodiment. Examples of the sound and image source 2 include information devices such as personal computers, audio visual devices (hereinafter referred to as AV devices) such as DVD players and video recorders, and image devices such as digital cameras. Can be mentioned. That is, a sound signal and an image signal are input to the projector 1 from the sound and image source 2 through the sound input circuit 3 and the image input circuit 5. As the audio signal and the image signal, for example, an image signal and an audio signal such as a movie, a photograph, or a presentation are assumed, but other audio signals and image signals may be used.

  The voice input circuit 3 is an interface circuit for voice input. The audio signal is input from the audio and image source 2 to the audio input circuit 3, further amplified by the audio reproduction amplifier circuit 7, and reproduced by the speaker 9. Similarly, the image input circuit 5 is an image signal input interface circuit. In the image input circuit 5, analog or various digital video signals, such as RGB signals or video signals input from the sound and the image source 2, are converted into digital image signals having a predetermined number of pixels of resolution. , Input to the image forming circuit 10.

  An arithmetic control circuit unit (CPU) 11 composed of a microcontroller or the like is provided as a means for serving as a switching means and for controlling various operation controls of the projector 1 (details will be described later for convenience of explanation). . Further, a switch 11 a is connected to the arithmetic control circuit unit (CPU) 11. The operation state of the switch 11a by the user is determined by the arithmetic control circuit unit (CPU) 11, and operation control according to the operation state is performed by the arithmetic control circuit unit (CPU) 11. Further, the arithmetic control circuit unit (CPU) 11 can determine whether or not an audio signal is input to the projector 1 via the audio input circuit 3.

  A remote controller (not shown) is used as the operating means for the projector 1 other than the switch 11a. Therefore, a remote control sensor 13 is provided as means for detecting an operation by a user of the remote control (not shown). The operation state of the remote control (not shown) by the user detected by the remote control sensor 13 is determined by the arithmetic control circuit unit (CPU) 11, and control according to the determination result is performed by the arithmetic control circuit unit (CPU) 11. Is done. The remote control sensor 13 can perform operations such as adjusting the volume of reproduced sound.

  The image forming circuit 10 controls the operation of the image forming element 19 that can control the brightness of each pixel and the color wheel that rotates the color wheel 17 under the control of the arithmetic control circuit unit (CPU) 11. Controls the operation of the drive motor 21. That is, the arithmetic control circuit unit (CPU) 11 controls the image forming element 19 by determining the rotational position of the color wheel 17 (color of the color filter) from the control state of the color wheel driving motor 21. The light emitted from the light source is colored by the color wheel 17 and then enters the image forming element 19 through the mirror 23.

  Further, as shown in FIG. 2, the color wheel 17 is composed of RGB (red, green, blue) color filters and white (W) filters, and is a member that rotates at high speed. The color wheel 17 irradiates the image forming element 19 with red light when the light passes through the R filter, green light when it passes through the G filter, and blue light when it passes through the B filter. be able to. The white (W) filter is used to enhance the brightness.

  For example, an LCD (Liquid Crystal Display) or DMD (Digital Mirror Device) is used as the image forming element 19. In the present embodiment, a reflective DMD (digital mirror device) is used as the image forming element 19. A DMD (digital mirror device) will be described below with reference to FIG.

  FIG. 3 is a diagram schematically showing an enlarged part of the DMD. The DMD is an element having a structure in which minute mirrors for resolution (hereinafter referred to as pixel mirrors) are physically arranged on a device and tilted by, for example, +10 degrees or −10 degrees by electrostatic attraction. Then, with one being an ON position and the other being an OFF position, a switching operation with light such as 0 or 1 is given depending on how light is reflected at this ON position or OFF position. That is, the pixel mirror is configured so that the direction of the light beam incident from the light source can be directed to the direction of the projection lens at the ON position, or can be deflected in a different direction from the projection lens at the OFF position. These pixel mirrors are individually controlled according to display data by a circuit for pixel control. The brightness can be controlled by controlling the frequency of tilt control of the individual micromirrors constituting each pixel. That is, a pixel that has reflected light to the projection lens many times within a certain period of time becomes brighter, and conversely, a pixel whose number of reflections has been reduced becomes darker.

  In the present embodiment, the case where the image is guided to the projection lens 25 and the case where the image is not guided are controlled by the above-described operation principle of DMD, and the brightness of each pixel forming the image is switched. At this time, light of each primary color of RGB is emitted from the color wheel 17, so that the lightness and darkness of each pixel becomes the magnitude of the mixing ratio of each primary color, and as a result is projected as a color projection image 27. . For this purpose, of course, it is necessary to synchronize the control of the rotational position of the color wheel 17 (color of the color filter) and the control of the image forming element 19 which is a DMD.

  As shown in FIG. 2, a lamp 29 is used as the light source of the projector 1. The voltage applied to the lamp 29 can be switched under the control of the light quantity control circuit 31. The light emitted from the lamp 29 is reflected by a reflector 29a provided around the lamp 29, and is then made uniform by a light guide 29b (not shown in FIG. 1) so as to enter the color wheel 17. ing.

  Since the lamp 29 generates heat as well as strong light, a fan 33 is provided as a cooling mechanism. The fan life is stabilized by air cooling by the fan 33. The fan 33 is controlled by a fan control circuit 35.

  The light amount control circuit 31 controls the light amount of the lamp 29 under the control of the arithmetic control circuit unit (CPU) 11. Similarly, the fan control circuit 35 receives the control of the arithmetic control circuit unit (CPU) 11 and controls the rotational speed of the fan 33.

  Incidentally, in the projector 1, the amount of heat generated by the lamp 29 naturally changes as the light amount of the lamp 29 changes. For example, when the light amount of the lamp 29 is decreased, the heat generation amount of the lamp 29 is also decreased. Therefore, when the light quantity of the lamp 29 is decreased, the rotational speed of the fan 33 may be decreased in conjunction with the decrease, whereby the noise generated by the fan 33 can be reduced.

  In the present embodiment, the following two types of modes are employed as the projection mode of the projector 1.

  First, the first projection mode is a mode in which the noise generated by the fan 33 can be used without much concern, in other words, a mode in which no inconvenience occurs even if the rotational speed of the fan 33 is increased for cooling. It is. Further, the second projection mode is a mode in a situation where noise caused by the fan 33 is inconvenient, that is, a situation where noise caused by the fan 33 should be reduced.

  A typical scene in which the above-described two types of projection modes are used is shown in FIGS. Hereinafter, the above-described two types of projection modes will be described with reference to FIG.

  FIG. 4A shows a business scene in which a presentation is performed using the projector 1. Specifically, a color projection image 27 of a material such as a graph created by the personal computer 39 is copied on a wall surface, and the user 41 is giving a presentation. In such a situation, it is necessary to project so that all the participants in the presentation can see the color projection image 27 by the projector 1. Therefore, it can be said that it is necessary to increase the amount of light projected during image projection. In addition, since it is conceivable that the participants of the presentation take notes, it may be necessary to brighten the environment around the projector 1. In such a presentation, there are many scenes that display figures and graphs as reproduced images, and it is not necessary to worry about the hue so much, but rather the brightness is important as described above.

  On the other hand, regarding the sound, it can be said that the noise caused by the fan 33 does not cause much inconvenience in the above situation shown in FIG. That is, the rotational speed of the fan 33 for cooling can be increased without worrying about generated noise. Therefore, the light quantity of the lamp 29 as the light source is increased to increase the projected light quantity, and the cooling effect is increased by increasing the number of revolutions of the fan 33 in order to cool the heat generation of the lamp 29 that has increased accordingly. In order to secure a sufficient amount of light, the white filter of the color wheel 17 is used.

  In the present embodiment, the above-described projection mode used in the usage situation as shown in FIG. 4A is referred to as a first projection mode. Note that the first projection mode will be described in more detail in the operation description to be described later using the flowchart shown in FIG.

  On the other hand, FIG. 4B shows a situation where the projector 1 is used as a home theater. Here, a portable DVD player 43 is connected to the projector 1 as the sound and image source 2. In such a situation, it is necessary to prevent the noise generated by the fan 33 from disturbing the sound reproduced by the speaker 9.

  When the projector 1 is used like a home theater as described above, it is expected that the projection is often performed from a short distance to some extent as shown in FIG. Therefore, compared with the situation in FIG. 4A described above, there are many scenes in which the amount of projection light may be small. Moreover, the brightness of the room in which the projector 1 is used can be adjusted as desired to some extent by closing the curtain or turning off the light. In this way, if the room in which the projector 1 is used is darkened, it is possible to reproduce an image having a color tone that can be fully appreciated even when the light amount of the lamp 29 is reduced. That is, by reducing the light amount of the lamp 29, the amount of heat generated by the lamp 29 can be reduced, and thereby the rotational speed of the fan 33 can be reduced. In this way, noise generated by the fan 33 is reduced by reducing the rotational speed of the fan 33. Further, the use of the white filter of the color wheel 17 is suppressed in order to improve color reproduction. That is, as shown in FIG. 4B, in a situation where the projector 1 is used like a home theater, the color tone of the reproduced image is an important factor. Therefore, it is preferable that the white (W) filter of the color wheel 17 is not used much and an image is reproduced with only RGB (red, green and blue) color filters as much as possible. That is, when the color wheel 17 is at the rotation position of the white filter, the DMD that is the image forming element 19 is set to the OFF position. Note that the use of a special screen that emphasizes brightness so that the projection can be sufficiently enjoyed even if the projection light quantity is reduced, the projection light quantity of the lamp 29 can be further reduced.

  The above-described projection mode used in the usage situation as shown in FIG. 4B is referred to as a second projection mode in this embodiment. In the description of the operation using the flowchart shown in FIG. 5, the second projection mode will be described in more detail.

  Hereinafter, reproduction control using the above-described two types of projection modes in the projector according to the present embodiment will be described with reference to the flowchart of FIG. Note that, for convenience of the configuration of the flowchart and the description, the second projection mode will be described first.

  First, in S <b> 1, the arithmetic control circuit unit (CPU) 11 determines whether or not there is an input audio signal to the projector 1. If it is determined that there is an input audio signal, the Y branch is made and the process proceeds to S10. S10 is a step of determining the magnitude of the volume change of the reproduced sound based on the input sound signal. This determination is made by the arithmetic control circuit unit (CPU) 11 based on the output signal of the voice input circuit 3. Note that the voice input circuit 3 itself may determine the magnitude of the volume change. Here, when it is determined that the volume change of the sound is large, it can be said that the input sound signal is a case where reproduction that emphasizes subtle nuances such as music and movie speech should be performed. If it is determined in S10 that the volume change is small, the process branches to S3. Note that the steps to be followed after S3 will be described later for convenience of explanation. On the other hand, when it is determined in S10 that the volume change is large, the process branches to Y and branches to S11.

  S11 is a step of determining whether or not the volume setting of the speaker 9 is set to the maximum value. This determination is made by the arithmetic control circuit unit (CPU) 11. Here, when it is determined that the volume setting of the speaker 9 is set to the maximum value, it is considered that the projector according to the present embodiment is used in an environment in which it is very difficult to hear sound. If it is determined in S11 that the volume is set to the maximum value, the Y branch is made and the process proceeds to S14. The steps from S14 to S16 are steps for executing the second projection mode described above.

  First, in S <b> 14, the arithmetic control circuit unit (CPU) 11 controls the light amount control circuit 31, so that the light amount control circuit 31 decreases the light amount of the lamp 29. Note that the amount of heat generated by the lamp 29 also decreases as the light amount of the lamp 29 decreases. Then, even if the rotational speed of the fan 33 which is a cooling means of the lamp 29 is decreased, no inconvenience occurs. Therefore, in S15, the noise caused by the fan 33 is reduced by reducing the rotational speed of the fan 33. Operation control of the fan 33 is performed by the fan control circuit 35 under the control of the arithmetic control circuit unit (CPU) 11.

  The subsequent S16 is a step of improving the color reproducibility of the reproduced image. In this step, the color reproducibility of the reproduced image is improved by reducing the use frequency of the white (W) filter of the color wheel 17. In this step, the above-described operation control is performed by the image forming circuit 10 controlling the DMD which is the image forming element 19 under the control of the arithmetic control circuit unit (CPU) 11.

  As described above, the operation control executed in steps S14 to S16 is the second projection mode in the projector according to the present embodiment. In the second projection mode, since the operation control for reducing the noise of the fan 33 is performed, it is possible to reproduce the sound so that the sound can be heard to a subtle nuance. Further, by suppressing the frequency of use of the white (W) filter of the color wheel 17, the color reproducibility of the reproduced image is improved. In addition, as a case where the second projection mode shown in the operation control of S14 to S16 described above is adopted (when reaching S14), there are other cases as follows.

  First, in S11 described above, it is determined that the volume setting is not the maximum value, and N branches and proceeds to S12. S12 is a step of determining whether or not short-distance projection is being performed. This determination is performed by the arithmetic control circuit unit (CPU) 11 with reference to the focus position detection unit 46. Here, if it is determined that the projection distance is short, it can be said that a sufficiently clear image can be reproduced even if the lamp light quantity is small. In addition, an energy saving effect is achieved by reducing the lamp light quantity. That is, there is no problem even if the light quantity of the lamp 29 is reduced. Therefore, when it is determined that the projection is a short-distance projection, the Y-branch is advanced to S14, and the second projection mode is adopted. After S14, steps S14 to S16 are followed as described above.

  If it is determined in S12 that the projection is not a short-distance projection, the process branches to N13 after branching N. S13 is a step of determining the brightness of the environment in which the projector is used. In the brightness determination performed in S13, the remote control sensor 13 detects light, and the calculation control circuit unit (CPU) 11 determines from the detection result. If the projected image is not erased by the light in the environment where the projector is used, it can be said that the amount of projection light may be reduced. Therefore, if it is determined that the light in the projector usage environment does not hinder the image projection, it is considered that the light amount of the lamp 29 may be reduced. Thereafter, the steps S14 to S16 described above, which is the second projection mode, are followed.

  On the other hand, when it is determined in S13 that the environment is a brightness environment that hinders image projection, the process branches to Y3 and proceeds to S3. Note that the steps to be followed after S3 will be described later for convenience of explanation.

  In the second projection mode described above, a decrease in the rotational speed of the fan 33 and a decrease in the light amount of the lamp 29 are linked. This is because there is a concern that the cooling effect on the lamp 29 is reduced and the amount of heat generated by the lamp 29 is increased as the rotational speed of the fan 33 decreases. However, it is not necessary to always link the two. For example, when the temperature of the lamp 29 exceeds a predetermined value, the light amount is decreased, or the light amount is not changed for a predetermined time after the rotation speed of the fan 33 is decreased. And may be gradually lowered with time. In this way, the brightness of the screen suddenly becomes dark with the mode change, and the viewer does not feel uncomfortable.

  In the foregoing, the operation control part specific to the second projection mode of the projector according to the present embodiment has been mainly described. Hereinafter, an operation control part specific to the first projection mode of the projector according to the present embodiment will be mainly described.

  If it is determined in S1 that there is no input audio signal, the process branches to S2 after branching N. S2 is a step of determining whether or not the input image signal is an input signal from an AV device. This determination is performed by the arithmetic control circuit unit (CPU) 11 via the image input circuit 5. Here, when it is determined that the input image signal is a signal from an AV device, in order to select the second projection mode in which projection is performed with emphasis on the color reproducibility of the reproduced image, a Y branch is performed. Proceed to S11. Thereafter, the steps from S11 described above are followed.

  On the other hand, if it is determined in S2 that the input image signal is not a signal from an AV device, the process branches to S3 after branching N times.

  Note that the determination of whether or not the input image signal is from the AV device in S2 is, for example, whether or not the input image signal is a moving image because the image signal input from the AV device is mainly a moving image. By making such a determination, the determination in S2 can be performed. Of course, the determination in S2 may be made by referring to a physical contact means such as a terminal.

  S3 is a step of determining whether or not the projection by the projector according to the present embodiment is a short-distance projection. This determination is performed by the arithmetic control circuit unit (CPU) 11 from the detection result of the focus position detection unit 46, as in the short distance projection determination in S12 described above. Here, if it is determined that the projection is a short-distance projection, it can be said that a sufficiently clear image can be reproduced even if the light amount of the lamp 29 is reduced. Moreover, the energy saving effect by reducing the light quantity of the lamp | ramp 29 also arises. Therefore, if it is determined that the projection is a short distance projection, the process branches to Y and proceeds to S14, and the operation control step in the second projection mode is followed.

  If it is determined in S3 that the projection is not a short distance projection, the process branches to N4 after branching N. Thereafter, steps S4 to S6 are steps for executing the first projection mode.

  First, S4 is a step of increasing the light quantity of the lamp 29. Here, the light amount control circuit 31 increases the light amount of the lamp 29 under the control of the arithmetic control circuit unit (CPU) 11.

  In S5, the rotational speed of the fan 33, which is a cooling means, is increased due to the amount of heat generated by the lamp 29 that has increased due to the increase in the amount of light in S4. The operation control in this step is performed by the fan control circuit 35 under the control of the arithmetic control circuit unit (CPU) 11.

  In S6, the brightness of the reproduced image is improved by utilizing the white (W) filter of the color wheel 17. As described above, this is achieved by the image forming circuit 10 controlling the DMD that is the image forming element 19 under the control of the arithmetic control circuit unit (CPU) 11.

  As described above, the operation control executed in steps S4 to S6 is the first projection mode in the projector according to the present embodiment. In the first projection mode, the light quantity of the lamp 29 is increased, and the number of rotations of the fan 33 is increased in order to cool the heat generation of the lamp 29 that increases accordingly. Further, the brightness of the reproduced image is improved by utilizing the white segment of the color wheel 17. Therefore, the first projection mode does not require reproduction that emphasizes the subtle nuances of reproduced sound and images, such as when listening to music and movies, but rather the brightness of the reproduced image so that it can be clearly seen by many people. Used in scenes where is important. That is, the first projection mode is a projection mode that is used for a scene in which the sharpness of the reproduced image is important without worrying about fan noise.

  As described above, after the first projection mode or the second projection mode is set in S6 or S16, the process proceeds to S20. S20 is a step of performing image reproduction and sound reproduction under the control of the arithmetic control circuit unit (CPU) 11.

  The subsequent S21 is a step in which the arithmetic control circuit unit (CPU) 11 determines whether or not a projection end operation is performed by the user, and performs control according to the determination result. If it is determined that the projection end operation has not been performed, the process branches to S1 after branching N. On the other hand, if it is determined that the projection end operation has been performed, the process branches to Y and proceeds to S22.

  In S22, the lamp 29 is turned off and the color wheel driving motor 21 is stopped under the control of the arithmetic control circuit unit (CPU) 11. Further, in step S23, the fan 33 is stopped under the control of the arithmetic control circuit unit (CPU) 11, and a series of projection operations is ended.

  As described above, according to one embodiment of the present invention, it is possible to provide a projector in which a projection mode that is optimal for viewing is automatically selected according to the intended use and usage environment of the projector.

  Specifically, for example, when a projector is used in a business presentation, there is no need for reproduction that emphasizes the subtle nuances of reproduced audio and images, such as when listening to music and movies, rather many In a situation where the brightness of the reproduced image that is clearly visible to humans is regarded as important, the projector 33 performs projection by controlling the brightness of the reproduced image without worrying about the noise caused by the fan 33. That is, the first projection mode is used.

  On the other hand, for example, when a projector is used for watching a movie or music, sound reproduction that emphasizes color reproducibility and subtle nuance of the reproduced image is required. Along with this, the number of rotations of the fan 33 is also reduced to reduce noise caused by the fan 33. Furthermore, by reducing the frequency of use of the white (W) filter of the color wheel 17, the color reproducibility of the reproduced image is also improved. That is, the second projection mode is used. In the second projection mode, an energy saving effect is also obtained by reducing the light amount of the lamp.

  Although one embodiment of the present invention has been described above, the present invention can be modified in various ways without departing from the gist of the present invention other than the above-described embodiment.

  For example, it goes without saying that the present invention can be applied to an image reproducing device in which current consumption changes depending on brightness and heat dissipation by a fan is necessary. Of course, the present invention is not limited to lamps, and the present invention is also effective for heat dissipation of image processing circuit ICs, etc., which have recently been highly integrated.

  In S2, it is determined whether or not the input is from an AV device based on whether it is a moving image or not, but in the case of determining by physical contact means such as a terminal, a digital camera that outputs not only the AV device but also a still image It is possible to determine whether or not an image device such as the above is connected. When the image device is connected, it is possible to set the second projection mode giving priority to color reproducibility.

1 is a diagram showing a configuration of a projector according to an embodiment of the present invention. It is a figure showing the lamp | ramp and the color wheel periphery part in the projector which concerns on one Embodiment of this invention. It is the figure which expanded and represented typically a part of DMD (Digital Mirror Device). It is a figure showing the typical situation where two types of projection methods of a projector concerning one embodiment of the present invention are used. 5 is a flowchart showing operation control of the projector according to an embodiment of the present invention.

Explanation of symbols

    DESCRIPTION OF SYMBOLS 1 ... Projector, 2 ... Image source, 3 ... Audio | voice input circuit, 5 ... Image input circuit, 7 ... Sound reproduction amplifier circuit, 9 ... Speaker, 10 ... Image formation circuit, 11 ... Operation control circuit part, 11a ... Switch, DESCRIPTION OF SYMBOLS 13 ... Remote control sensor, 17 ... Color wheel, 19 ... Image forming element, 21 ... Motor for color wheel drive, 23 ... Mirror, 25 ... Projection lens, 29 ... Lamp, 29a ... Reflector, 29b ... Light guide, 31 ... Light quantity Control circuit 33 ... Fan 35 ... Fan control circuit 37 ... Projector 39 ... Personal computer 40 ... Projected image 41 ... User 43 ... DVD player 46 ... Focus position detection unit

Claims (12)

In a projector that reproduces input image signals and audio signals,
An illumination optical system having a light source including a lamp and a fan for cooling the light source;
Switching means for switching operation control of the illumination optical system according to the type of the image signal and the audio signal;
A projector comprising:   The projector according to claim 1, wherein the switching unit determines whether or not the audio signal is input, and performs control to switch the operation of the illumination optical system according to the determination result.   The projector according to claim 2, wherein the switching unit reduces the rotational speed of the fan when it is determined that the audio signal is input.   The switching means determines whether or not the image signal is an input signal from an audiovisual device, and performs control for switching the operation of the illumination optical system according to a result of the determination. The projector described.   The projector according to claim 4, wherein the switching unit reduces the rotational speed of the fan when it is determined that the image signal is an input signal from an audiovisual device. The projector further includes a sensor unit that determines a distance of image projection by the projector,
The projector according to claim 1, wherein the switching unit performs control to switch the operation of the illumination optical system in accordance with a projection distance determined by the sensor unit.   The said switching means reduces the light quantity which the said light source projects, and reduces the rotation speed of the said fan, when it determines with the said projection distance being shorter than predetermined distance. Projector. The projector further includes a sensor unit that determines brightness around the projector,
The projector according to claim 1, wherein the switching unit performs control to switch the operation of the illumination optical system in accordance with brightness around the projector determined by the sensor unit.   The switching means reduces the amount of light projected by the light source and reduces the rotational speed of the fan when it is determined that the brightness around the projector is darker than a predetermined brightness. The projector according to claim 8. In a projector that reproduces an input image signal,
An illumination optical system having a light source including a lamp and a fan for cooling the light source;
Switching means for switching the operation control of the illumination optical system according to the type of the image signal;
A projector comprising:   11. The control unit according to claim 10, wherein the switching unit determines whether or not the image signal is an input signal from an audiovisual device, and performs control to switch the operation of the illumination optical system according to a result of the determination. The projector described.   The switching means reduces the amount of light projected by the light source and reduces the rotation speed of the fan when it is determined that the image signal is an input signal from an audiovisual device. The projector according to claim 11.

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