JP2012189675A - Display device, and method for detecting movement of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to detect movement of a display device by a method of increasing the number of components of the display device as little as possible.SOLUTION: A projector (display device) 10 includes: a cooling fan 31 for cooling an object to be cooled; a revolving speed detector 183 for detecting a revolving speed of the cooling fan 31; and a movement detector 124 for detecting movement of the display device 10 based on a change of the revolving speed of the cooling fan 31 detected by the revolving speed detector 183.

Description

  The present invention relates to a display device including a cooling fan and a method for detecting movement of the display device.

  2. Description of the Related Art Conventionally, display devices such as projectors are known that have a function of detecting movement of a display device body for theft prevention or image correction (see, for example, Patent Document 1). Patent Document 1 discloses a technique for detecting the movement of a projector using an acceleration sensor or a vibration sensor.

JP 2006-133401 A

However, when an acceleration sensor, a vibration sensor, or the like that detects movement is provided in the display device body as in the device described in Patent Document 1, there is a problem due to an increase in the number of parts and a complicated configuration of the display device. Concerned.
An object of the present invention is to solve the above-described problems of the prior art and to detect movement of the display device by a method that does not increase the number of parts of the display device as much as possible.

In order to achieve the above object, the present invention provides a display device comprising: a cooling fan that cools an object to be cooled; a rotation speed detection unit that detects a rotation speed of the cooling fan; and the rotation speed detection unit. And a movement detecting means for detecting the movement of the display device based on the detected change in the number of rotations of the cooling fan.
According to the present invention, it is possible to detect the movement of the display device main body without increasing the number of components based on the change in the rotation speed of the cooling fan included in the main body of the display device.

The display device may further include a fan control unit that changes a rotation speed of the cooling fan according to a cooling state of the cooling target, and the movement detection unit is detected by the rotation number detection unit. The movement of the display device is detected based on the change in the rotation speed of the cooling fan and the change in the rotation speed of the cooling fan by the fan control means.
According to the present invention, in order to perform efficient cooling or reliable cooling, the number of rotations of the cooling fan is changed in accordance with the object to be cooled by the cooling fan or the cooling state of the space to be cooled. However, the movement of the display device body can be accurately detected based on the number of rotations of the cooling fan.

According to the present invention, the display device is a projector having a plurality of fans including a light source and a cooling fan for cooling the light source.
According to the present invention, in a projector having a plurality of fans, it is possible to efficiently and reliably move the projector without increasing the number of parts by using the number of rotations of the cooling fan provided for cooling the light source and the like of the projector. Can be detected.

According to the present invention, in the display device, when the movement detecting unit detects movement of the display device, the correcting unit corrects trapezoidal distortion by deforming an image displayed in the display area of the display device. It is provided with.
According to the present invention, since the movement of the display device that is a projector is detected and trapezoidal distortion correction is performed, when the display device moves after the first correction and the projection environment changes, the change in the projection environment changes. It is possible to project an image in a good state promptly.

In the display device according to the aspect of the invention, the movement detection unit may detect the start or end of movement of the display device based on a change in the number of rotations of the cooling fan, and the correction unit may The keystone distortion correction is performed when the movement of the apparatus is started or when the movement is finished.
According to the present invention, since the keystone distortion correction is performed by detecting the start or end of movement of the display device main body, which is a projector, quickly responding to changes in the projection state accompanying the movement of the display device main body, Keystone distortion can be corrected.

In order to achieve the above object, the present invention provides a movement detection method for a display device including a cooling fan, wherein the number of rotations of the cooling fan is detected by detecting the number of rotations of the cooling fan. The movement of the display device is detected on the basis of the change.
By executing the movement detection method of the present invention, it is possible to detect the movement of the display device main body without increasing the number of components based on the change in the number of rotations of the cooling fan included in the display device main body.

  According to the present invention, it is possible to detect the movement of the display device main body without increasing the number of components based on the change in the rotation speed of the cooling fan included in the main body of the display device.

1 is a schematic plan view of a projector according to an embodiment to which the invention is applied. It is a block diagram which shows the structure of a projector. It is a flowchart which shows operation | movement of a projector. It is a schematic diagram which shows the arrangement | positioning state of the fan in the housing | casing of a projector.

Hereinafter, an embodiment to which the present invention is applied will be described with reference to the drawings.
FIG. 1 is a plan view illustrating a schematic configuration of a projector 10 as a display device according to the embodiment. The projector (display device) 10 is provided with a screen SC as a projection surface. The projector 10 receives an image signal from a video source (not shown) stored in a built-in storage device or an external image supply device (not shown) such as a personal computer or various video players. The projector 10 modulates the light emitted from the built-in light source 141 (FIG. 2) based on the input image signal, projects the modulated light toward the screen SC, and displays an image (hereinafter referred to as “projected image”). Display as. The image input to the projector 10 may be either a moving image (video) or a still image, and the projector 10 can project a video on the screen SC or continue to project a still image on the screen SC. In the present embodiment, a case where a video is projected based on a video signal input from the outside will be described as an example. The screen SC corresponds to a display area for the projector 10 to display an image. When the projector 10 projects an image on a projection surface (for example, a wall surface) other than the screen SC, this projection surface corresponds to a display area.

  As shown in FIG. 1, the projector 10 includes an illumination optical system 140 having a light source 141 in a housing 11 serving as a display device body, and a liquid crystal that is a light modulation device that modulates light emitted from the illumination optical system 140. The image projection unit 21 includes a panel 130 (130R, 130G, and 130B) and a projection optical system 150 that projects the modulated light modulated by the liquid crystal panel 130 onto the screen SC. Here, the light source 141 included in the illumination optical system 140 of the present embodiment is a light emitting unit such as a xenon lamp, an ultra-high pressure mercury lamp, or an LED (Light Emitting Diode), or the light emitted from the light emitting unit to the liquid crystal panel 130 side. It has a leading reflector and an auxiliary reflector. The illumination optical system 140 includes a first lens array 321, a second lens array 322, a polarization conversion element 323, a superimposing lens 324, and a light control element 325 on a path that guides light emitted from the light source 141 to the liquid crystal panel 130. Various optical components such as dichroic mirrors 331 and 332, reflection mirrors 333, 342, and 344 are provided. The first lens array 321 and the second lens array 322 have a plurality of lens elements arranged in an array. The first lens array 321 divides the light emitted from the light source 141 into a plurality of parts by each lens element. Each lens element of the first lens array 321 condenses light emitted from the light source 141 in the vicinity of the lens elements of the second lens array 322. Each lens element of the second lens array 322 corresponds to the lens element of the first lens array 321. The second lens array 322 has a function of superimposing the images of the lens elements of the first lens array 321 on the liquid crystal panel 130 together with the superimposing lens 324. The polarization conversion element 323 converts light from the second lens array 322 into predetermined linearly polarized light. The light control element 325 reduces the amount of light incident on the liquid crystal panel 130 out of the light emitted from the light source 141. The dichroic mirrors 331 and 332 separate the light emitted from the light source 141 into R, G, and B components. The reflection mirrors 333, 342, and 344 guide the separated light to the liquid crystal panels 130R and 130B.

The liquid crystal panel 130 is composed of a transmissive liquid crystal panel in which a plurality of pixels are arranged in a matrix. The liquid crystal panel 130 is driven by a light modulator driving unit 132 described later, and changes the light transmittance of each pixel, thereby changing the illumination optical system 140. From the light (indicated by symbol L in FIG. 1).
The projector 10 according to the present embodiment is a 3LCD projector, and the liquid crystal panel 130 includes three liquid crystal panels 130R, 130G, and 130B corresponding to three colors of R, G, and B. The projection optical system 150 includes a lens group for enhancing the optical characteristics of the projection light, polarizing plates 351 and 353, and a cross dichroic prism 354. In addition, the projection optical system 150 includes a zoom lens 152 (FIG. 2) that performs enlargement / reduction of an image projected onto the screen SC and adjustment of the focus.

  With this configuration, the projector 10 separates the light emitted from the illumination optical system 140 into light of three colors R, G, and B, transmits the light to the liquid crystal panels 130R, 130G, and 130B, and combines them with the cross dichroic prism 354. To generate a color image. The configuration of the image projection unit 21 is not limited to the configuration illustrated in FIG. 1, for example, a scheme using a single liquid crystal panel and a color wheel, a scheme using three digital mirror devices (DMD), and a single sheet. You may comprise by the system etc. which combined the digital mirror device and the color wheel. Here, when only one liquid crystal panel or DMD is used as the light modulation device, a member corresponding to a combining optical system such as a cross dichroic prism is unnecessary. In addition to the liquid crystal panel and the DMD, any configuration that can modulate the light emitted from the light source 141 can be used without any problem.

  In the housing 11, together with the image projection unit 21, a power supply unit 22 that supplies power to each unit of the projector 10, a circuit board 33 on which an image processing system circuit to be described later is mounted, and a cooling fan 31 are arranged. The The cooling fan 31 is a fan that takes in outside air and blows it into the housing 11 to cool a cooling target including the power supply unit 22 and the image projection unit 21 (particularly, the light source 141). The cooling target is a target such as the power supply unit 22 and the image projection unit 21 cooled by the cooling fan, or a cooling target space inside the housing 11. On the side surface of the housing 11, the cooling fan 31 sucks cooling air (outside air) into the housing, and after cooling the power supply unit 22 and the image projection unit 21, the cooling air is exhausted outside the housing 11. An exhaust port 16 is formed. In the configuration shown in FIG. 1, only one cooling fan 31 is shown. However, a cooling fan that cools a semiconductor device provided on the circuit board 33, a cooling fan that cools the power supply unit 22, and the like. Of course, it is also possible to have a configuration in which the housing 11 includes a plurality of cooling fans.

FIG. 2 is a block diagram illustrating a functional configuration of the projector 10.
The projector 10 is roughly divided into an optical system that forms an optical image and an image processing system that electrically processes a video signal. This optical system is the image projection unit 21 described above.
The projector 10 drives the zoom lens 152 of the projection optical system 150 to adjust the zoom level, the zoom adjustment motor 156, the focus adjustment motor 157 for adjusting the focus, the zoom adjustment motor 156, and the focus adjustment. A lens driving unit 155 that controls the motor 157 is provided.

  On the other hand, the image processing system is configured around a CPU 120 and a video processor 134 that control the entire projector 10 in an integrated manner, and includes an A / D conversion unit 110, a light modulation device driving unit 132, a lens driving unit 155, A RAM 160, a ROM 170, a fan driving unit 180, a remote control unit 190, a remote control 191, an operation unit 195, and the like are provided. These elements constituting the image processing system are connected to each other via a bus 102.

The A / D conversion unit 110 is a device that performs A / D conversion on an analog input signal input from the above-described external image supply apparatus via the cable 200, and outputs the converted digital signal to the video processor 134. . The video processor 134 performs image processing for adjusting the display state of an image, such as brightness, contrast, color density, hue, and projected image shape, on the digital signal input from the A / D conversion unit 110. After that, the processed video signal is output to the light modulator driving unit 132. The light modulator driving unit 132 drives the liquid crystal panel 130 based on the video signal input from the video processor 134. As a result, a video corresponding to the video signal input to the A / D conversion unit 110 is formed on the liquid crystal panel 130, and this image is formed as a projection image on the screen SC via the projection optical system 150. The image processing performed by the video processor 134 includes, for example, correction of brightness, contrast, hue, and the like, and keystone distortion correction (keystone correction).
When performing trapezoidal distortion correction, the video processor 134 functions as the trapezoidal distortion correction unit 136 (correction unit) shown in FIG. The trapezoidal distortion correction unit 136 detects a trapezoidal distortion caused by the influence of the relative angle of the projector 10 main body with respect to the screen SC in the projected image projected on the screen SC, and draws the image on the liquid crystal panel 130 to correct the trapezoidal distortion. Deform the image. For example, when the projector 10 includes an imaging unit that captures the screen SC, the trapezoidal distortion is detected by capturing a projection image (or an image for correcting trapezoidal distortion) projected on the screen SC by the imaging unit. Then, the outer shape of the projection image is detected from the photographed image data, and the distortion state of the projection image is detected. Then, the trapezoidal distortion correction unit 136 automatically performs keystone correction when the detected trapezoidal distortion is greater than or equal to a predetermined distortion. The trapezoidal distortion correction unit 136 processes the video signal output to the light modulation device driving unit 132 and causes the liquid crystal panel 130 to draw a corrected image.
Note that the trapezoidal distortion correction unit 136 distorts an image drawn on the liquid crystal panel 130 into a trapezoid according to an operation via the remote controller 191 or the operation unit 195 when the projector 10 does not include an imaging unit, for example. The keystone correction may be performed.

  The CPU 120 executes a control program stored in the ROM 170 to control each unit of the projector 10, and for example, controls the video processor 134 to perform the above-described image processing. In addition, the CPU 120 includes a fan control unit 123 and a movement detection unit 124, and controls the cooling fan 31 and detects the movement of the projector 10. The fan control unit 123 and the movement detection unit 124 are realized by the CPU 120 executing a specific program stored in advance in the ROM 170.

The cooling fan 31 includes a fan motor 181 and a fan 182 attached to the rotation shaft of the fan motor 181, and the fan motor 181 is connected to the fan drive unit 180. The fan drive unit 180 supplies a drive current to the fan motor 181 based on a control signal input from the CPU 120 by the function of the fan control unit 123 and controls rotation / stop of the fan motor 181. The fan drive unit 180 includes a rotation number detection unit 183 that detects the rotation number of the cooling fan 31, and the rotation number (rotation speed) detected by the rotation number detection unit 183 is output to the CPU 120.
The fan control unit 123 detects the cooling state of the image projection unit 21 based on an input from a temperature sensor (not shown), and increases the number of rotations of the cooling fan 31 when it is necessary to increase the cooling capacity. If the cooling capacity is sufficient, control is performed to reduce the rotational speed of the cooling fan 31. The fan drive unit 180 changes the rotation speed of the cooling fan 31 based on the control signal input from the fan control unit 123. The rotation speed of the cooling fan 31 is changed by changing the voltage applied to the fan motor 181 or the duty ratio of PWM (Pulse Width Modulation). In this control, since the rotation speed of the cooling fan 31 detected by the rotation speed detection unit 183 is fed back to the CPU 120, the fan control unit 123 rotates the rotation speed of the cooling fan 31 fed back from the rotation speed detection unit 183. The load of the fan motor 181 is controlled from the cooling state of the image projection unit 21.

The temperature sensor used by the fan control unit 123 to control the cooling fan 31 detects the temperature of the image projection unit 21. More specifically, the temperature sensor detects the temperature of the light source 141, It is a temperature sensor that detects the temperature of the liquid crystal panel 130 or the vicinity thereof. In addition to these sensors, a temperature sensor that detects the temperature of the power supply unit 22, a temperature sensor that detects the surface temperature of the semiconductor device mounted on the circuit board 33, and the like are arranged, and the detection values of these sensors are input to the CPU 120. It is good also as a structure to be. Of the components of the projector 10, the power supply unit 22, the circuit board 33, the light source 141, and the like can be heat sources that generate a particularly large amount of heat. Therefore, it is efficient to arrange temperature sensors in locations where these temperatures can be detected.
In this case, the fan control unit 123 of the CPU 120 controls the number of rotations of the cooling fan 31 based on the detection values of the plurality of temperature sensors. When the projector 10 includes a plurality of cooling fans, each cooling fan is controlled. The number of rotations is controlled individually.

The projector 10 has a function of detecting the movement of the projector 10 based on a change in the number of rotations of the cooling fan 31 by the movement detection unit 124.
When the projector 10 starts to move, an inertial force acts on the cooling fan 31 inside the projector 10. This inertial force includes Coriolis force due to the rotation of the earth. In addition, since gravity acts naturally on the cooling fan 31, changing the direction of the cooling fan 31 with respect to the direction of gravity changes the direction of gravity acting on the cooling fan 31. When the magnitude and direction of the force acting on the cooling fan 31 change in this way, the force acting on the cooling fan 31 varies, so the rotational speed of the cooling fan 31 changes. That is, when the projector 10 moves or when the direction of the cooling fan 31 with respect to the ground surface (or the ground axis) changes, the rotational speed of the cooling fan 31 changes.

  The movement detection unit 124 detects the number of rotations of the cooling fan 31 detected by the rotation number detection unit 183 in a predetermined cycle, temporarily stores the detected number of rotations in the RAM 160, and compares it with the number of rotations detected in the past. The change in the rotational speed is calculated by statistical processing. In the simplest example, there is a method of calculating the difference between the average value of the number of rotations detected in the past several times and the latest number of rotations. The movement detection unit 124 determines whether the change in the rotation speed of the cooling fan 31 exceeds a preset reference value or a reference value dynamically calculated by a preset method. It is detected that the casing 11 has moved (including displacement and rotation).

  As described above, the rotation speed of the cooling fan 31 can be adjusted by the fan control unit 123 based on the temperature detected by a temperature sensor (not shown). When calculating the change in the rotational speed of the cooling fan 31, the movement detection unit 124 executes a statistical process that excludes the fluctuation due to the control of the fan control unit 123 from the actual fluctuation in the rotational speed of the cooling fan 31. To do. Thereby, the movement of the projector 10 can be detected more accurately.

The CPU 120 can execute various operations when the movement detection unit 124 detects the movement of the projector 10.
For example, when the projector 10 moves, it may be necessary to redo the keystone correction for an image on the screen SC that has been subjected to the keystone correction before the projector 10 moves. Therefore, when the movement of the projector 10 is detected by the action of the movement detection unit 124, the CPU 120 controls the video processor 134 to perform keystone correction of the image input from the A / D conversion unit 110 and perform a keystone distortion correction unit. 136 is executed. When the keystone correction is manually performed based on an input operation via the remote controller 191 or the operation unit 195, the CPU 120 uses the function of the trapezoidal distortion correction unit 136 included in the video processor 134 to display the keystone correction image on the liquid crystal panel. The operation mode is changed to an operation mode in which the keystone correction is executed. Further, when the movement of the projector 10 is detected by the action of the movement detection unit 124, the CPU 120 may perform focus adjustment by driving the focus adjustment motor 157. In order to perform the focus adjustment, the zoom ratio of the zoom lens 152 is necessary, and this zoom ratio may be calculated from the driving amount of the zoom lens 152 by the zoom adjustment motor 156, for example.

  Further, the movement detection unit 124, when the change in the rotation speed of the cooling fan 31 continues for a predetermined time or more, the duration, the magnitude of the change amount of the rotation speed of the cooling fan 31, the change in the change amount, etc. Thus, it can be easily determined whether the movement amount of the casing 11 of the projector 10 is large or small. Therefore, when the CPU 120 determines that the movement amount of the projector 10 is large by the function of the movement detection unit 124, the alarm sound is output by a built-in audio output circuit (not shown) in order to prevent the projector 10 from being taken away. May be. In this case, the CPU 120 may lock the operation so that the image cannot be projected. That is, the CPU 120 controls the video processor 134 so as not to output a video signal to the light modulation device driving unit 132. Furthermore, a special screen for pointing out the possibility of taking away and guiding the input of the password for unlocking may be displayed on the screen SC. In this case, since a safety device (not shown) such as an audio output circuit is activated based on fluctuations in the number of rotations of the cooling fan 31 as in the case where a sensor such as an acceleration sensor is newly provided, theft damage can be suppressed. Can be expected.

The RAM 160 forms a work area for temporarily storing programs executed by the CPU 120 and data. Note that the video processor 134 includes a work area necessary for executing each process, such as an image display state adjustment process performed by itself, as a built-in RAM.
The ROM 170 stores a control program executed by the CPU 120 to realize each processing unit described above, data related to the program, and the like.

The remote control control unit 190 receives a radio signal transmitted from the remote control 191 outside the projector 10. The remote controller 191 includes an operation element (not shown) operated by a user, and transmits an operation signal corresponding to an operation on the operation element as an infrared signal or a wireless signal using a radio wave of a predetermined frequency. The remote control unit 190 includes a light receiving unit (not shown) that receives an infrared signal and a receiving circuit (not shown) that receives a radio signal. The remote control unit 190 receives a signal transmitted from the remote control 191, analyzes it, and operates by a user. Is generated and output to the CPU 120.
The operation unit 195 includes an operation element (not shown), and outputs an operation signal corresponding to an operation on the operation element to the CPU 120. As this operation element, there is a switch for instructing power ON / OFF.

Next, the operation of the projector 10 will be described.
FIG. 3 is a flowchart showing the operation of the projector 10.
As shown in FIG. 3, when the power supply of the projector 10 is turned on (step S1), the CPU 120 initializes each unit of the projector 10 (step S2). Next, the CPU 120 starts the rotation of the cooling fan 31 by the function of the fan control unit 123 and also starts the control of the rotation speed of the cooling fan 31 based on the detected value of the temperature sensor (not shown) (step S3). ). In addition, the CPU 120 starts acquiring the rotation speed of the cooling fan 31 detected by the rotation speed detection unit 183, sequentially stores the acquired rotation speed in the RAM 160, and detects movement based on the stored rotation speed value. Is started (step S4).

  The CPU 120 determines whether or not the movement of the projector 10 has been detected based on the change in the rotational speed of the cooling fan 31 (step S5), and performs the operation while the movement of the projector 10 is not detected (step S5: No). If the movement of the projector 10 is detected (step S5: Yes), it is determined whether the projector 10 has stopped (step S6). The CPU 120 waits while the movement of the projector 10 continues (step S6; No), and detects that the projector 10 has stopped due to a phenomenon such as fluctuations in the rotational speed due to the movement of the projector 10 converge (step S6). : Yes), the video processor 134 is controlled, and the trapezoidal distortion correction unit 136 shifts to a state where keystone processing can be started (step S7).

  In order to detect the movement of the projector 10 more sensitively, a plurality of cooling fans 31a, 31b, and 31c having different installation angles with respect to the direction of gravity are provided inside the projector 10 as shown in FIG. It can also be set as the structure to arrange. In this case, a configuration may be adopted in which the movement of the projector 10 is detected based on fluctuations in the rotational speed of the cooling fan having the largest moment of inertia among the plurality of cooling fans 31a, 31b, 31c. Alternatively, when there is a cooling fan that rotates at a constant speed, regardless of the servo mechanism among the cooling fans 31a, 31b, and 31c, the rotation of the cooling fan that rotates at a constant speed A configuration may be adopted in which the movement of the projector 10 is detected based on the variation in the number. Moreover, the structure which detects the movement of the projector 10 from the installation angle of several cooling fan 31a, 31b, 31c and the fluctuation | variation of the rotation speed of each cooling fan 31a, 31b, 31c may be sufficient. According to such a configuration, when a change in the action of Coriolis force or gravity due to the movement of the projector 10 occurs, the rotation speed of any one of the cooling fans 31a, 31b, and 31c varies particularly greatly due to the change. It is possible. Further, when the fan control unit 123 adjusts the rotation speed of each cooling fan 31a, 31b, 31c based on the temperature detected by a temperature sensor (not shown), all the cooling fans 31a, 31b, 31c It is not often the case that the rotational speed is adjusted uniformly. For this reason, it is also possible to select a cooling fan suitable for detecting the movement of the projector 10 and detect the movement of the projector 10 based on the rotation speed of the selected fan. Accordingly, the movement of the projector 10 can be detected more sensitively and accurately than in the case where the number of rotations of one cooling fan 31 is monitored.

  As described above, according to the embodiment to which the present invention is applied, the projector 10 detects the rotational speed of the cooling fan 31 and the cooling fan detected by the rotational speed detector 183. Since the movement detecting unit 124 that detects the movement of the projector 10 based on the change in the number of rotations 31 is provided, the number of components is increased based on the change in the number of rotations of the cooling fan 31 included in the casing 11 of the projector 10. The movement of the projector 10 can be detected without any problem. In this configuration, it is not necessary to provide hardware such as an acceleration sensor or a vibration sensor for detecting the movement of the projector 10, so that the system can be simplified and contribution to cost reduction can be expected.

  Further, the CPU 120 of the projector 10 determines the number of rotations of the cooling fan 31 in an object to be cooled by the cooling fan 31 such as the light source 141, the power supply unit 22, and the circuit board 33, or in a cooling target space of the cooling fan 31. A fan control unit 123 that changes a cooling target such as an internal space of a certain housing 11 according to the cooling state is provided, and the movement detection unit 124 detects a change in the rotation speed of the cooling fan 31 detected by the rotation speed detection unit 183. The movement of the projector 10 is detected based on the change in the rotational speed of the cooling fan 31 by the fan control unit 123. That is, the movement of the projector 10 is detected by excluding or canceling the fluctuation in the rotational speed of the cooling fan 31 based on the control of the fan control unit 123 from the change in the rotational speed of the cooling fan 31. For this reason, even when the rotation speed of the cooling fan 31 is changed in order to perform efficient cooling or reliable cooling, the projector 10 is accurately moved based on the rotation speed of the cooling fan 31. It can be detected.

  Further, by applying the present invention to the projector 10 having the illumination optical system 140 including the light source 141 and the cooling fan 31 that cools the light source 141, a cooling fan necessary for cooling the light source 141 by the projector 10 is used. 31 can be used to detect the movement of the projector 10 without increasing the number of parts. Further, the projector 10 needs to detect the movement of the projector 10 in order to execute the keystone correction or to activate a safety device for theft prevention. However, the rotation speed of the cooling fan 31 varies. Therefore, the movement of the projector 10 can be detected, and the system can be simplified as compared with the case where the movement of the projector 10 is detected using an acceleration sensor or a vibration sensor to detect the movement.

  Further, when the movement detection unit 124 detects the movement of the projector 10, the trapezoidal distortion correction unit 136 performs the trapezoidal distortion correction. Therefore, after the projector 10 performs the first correction, the projector 10 moves and the projection environment changes. In this case, the image can be projected in a good state in response to the change in the projection environment.

  The movement detection unit 124 detects the start or end of the movement of the projector 10 based on the change in the number of rotations of the cooling fan 31, and the trapezoidal distortion correction unit 136 detects when the movement of the projector 10 is started or When the movement is completed, trapezoidal distortion correction is performed. Thereby, based on the change in the number of rotations of the cooling fan 31 included in the casing 11 of the projector 10, the start of movement of the projector 10 or the end of movement is detected without increasing the number of components, and the trapezoidal distortion correction is performed. It can be carried out. Therefore, trapezoidal distortion correction can be performed in response to a change in the projection state accompanying the movement of the main body of the projector 10. Further, it is not necessary to provide hardware such as an acceleration sensor or a vibration sensor for detecting the movement of the projector 10, and it can be expected to contribute to simplification of the system and cost reduction.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to this. In the present embodiment, the cooling fan 31 is configured to be a cooling fan provided in the projector 10, but is not limited thereto, and may be a cooling fan provided in, for example, a notebook personal computer, A configuration may be used in which the movement of the notebook personal computer is detected based on the change in the number of rotations of the cooling fan and used for safety improvement such as theft prevention.

  In addition, embodiment mentioned above does not limit this invention, It is also possible to apply this invention as an aspect different from the said embodiment. For example, the display device of the present invention is not limited to a projector that projects an image on the screen SC, but is displayed on a liquid crystal monitor or liquid crystal television that displays an image / image on a liquid crystal display panel, or on a PDP (plasma display panel). Monitor device or television receiver for displaying the image, self-light emission of the monitor device or television receiver for displaying an image / image on an organic EL display panel called OLED (Organic light-emitting diode), OEL (Organic Electro-Luminescence), etc. Various display devices such as a type display device are also included in the image display device of the present invention. Note that in a direct-view display device such as a liquid crystal television, a screen for displaying an image corresponds to a display area.

In addition, the projector 10 is configured to cool each part in the housing 11 by the single cooling fan 31, but a plurality of cooling fans 31 may be provided as described above, and a plurality of cooling fans having different sizes may be provided. It is also possible to use a fan. Furthermore, the cooling fan 31 is not necessarily arranged in contact with the object to be cooled or the space to be cooled. For example, fluid cooling that cools each part in the housing 11 by circulating a heat medium such as cooling water. A circuit may be arranged in the housing 11, a cooling fan may be provided in a heat radiating part that radiates heat from the fluid cooling circuit, and the movement of the projector 10 may be detected based on a change in the number of rotations of the cooling fan. . Furthermore, the fan control unit 123 and the movement detection unit 124 included in the CPU 120 may be provided separately from the CPU 120.
Further, the control program stored in the ROM 170 in the above-described embodiment may be downloaded from another device connected to the projector 10 via a communication network and executed, or the control program may be stored on a portable recording medium. It is good also as a structure which records and reads said each program from this recording medium, and performs it.

  In addition, each functional unit of the projector 10 illustrated in FIG. 2 indicates a functional configuration, and a specific mounting form is not particularly limited. That is, it is not always necessary to install hardware corresponding to each functional unit individually, and it is of course possible to implement a function of a plurality of functional units by one processor executing a program. In addition, in the above embodiment, a part of the function realized by software may be realized by hardware, or a part of the function realized by hardware may be realized by software. In addition, the specific detailed configuration of the projector 10 can be arbitrarily changed without departing from the gist of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Projector (display device), 11 ... Housing | casing (main body), 15 ... Intake port, 16 ... Exhaust port, 21 ... Image projection part, 22 ... Power supply part, 31 ... Cooling fan, 33 ... Circuit board, 102 ... Bus, 110 ... D conversion unit, 120 ... CPU, 123 ... fan control unit (fan control means), 124 ... movement detection unit (movement detection means), 130 ... liquid crystal panel, 134 ... video processor, 136 ... trapezoidal distortion correction (Correction means), 140 ... illumination optical system, 141 ... light source, 150 ... projection optical system, 160 ... RAM, 170 ... ROM, 180 ... fan drive unit, 181 ... fan motor, 182 ... fan, 183 ... rotation number detection Part (rotational speed detection means), SC ... screen.

Claims (6)

A display device,
A cooling fan for cooling the object to be cooled;
A rotational speed detecting means for detecting the rotational speed of the cooling fan;
A movement detection means for detecting movement of the display device based on a change in the rotation speed of the cooling fan detected by the rotation speed detection means;
A display device comprising: Fan control means for changing the number of rotations of the cooling fan according to the cooling state of the cooling target;
The movement detecting means detects the movement of the display device based on a change in the number of rotations of the cooling fan detected by the rotation number detection means and a change in the number of rotations of the cooling fan by the fan control means. The display device according to claim 1, wherein the display device is detected.   The display device according to claim 1, wherein the display device includes a plurality of cooling fans including a light source and the cooling fan that cools the light source.   4. A correction means for correcting trapezoidal distortion by deforming an image displayed in a display area of the display device when the movement detection means detects a movement of the display device. The display device described. The movement detection means detects the start or end of movement of the display device based on a change in the number of rotations of the cooling fan,
The display device according to claim 4, wherein the correction unit performs trapezoidal distortion correction when the movement of the display device is started or when the movement is finished. A method for detecting movement of a display device including a cooling fan,
Detecting the number of rotations of the cooling fan;
A movement detection method for a display device, wherein the movement of the display device is detected based on the detected change in the rotational speed of the cooling fan.

Images