JP2005301177A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the movement of a projector due to burglary or the like by a projector body itself. <P>SOLUTION: An angle detection means 14 detects angle data for automatic keystone correction of a projected image and is used also as a device for sensing the movement of the projector due to burglary. A movement decision means 15a decides the movement of the projector 10 on the basis of a change in the angle data detected by the angle detection means 14 and a threshold set by a threshold setting circuit 19. When the movement decision means 15a decides the movement, a light source 16a and a sound source 16b in a movement informing means 16 are driven to inform the periphery of the movement of the projector 10 due to burglary or the like. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projection apparatus, and more particularly, to a projection apparatus that is equipped with an automatic keystone correction function and realizes an antitheft function using the function.

  Conventionally, a projection apparatus is equipped with a function for correcting distortion of a projected image on a projection surface. Here, the signal processing circuit performs trapezoidal correction in the vertical and / or horizontal direction on the projected image itself, thereby correcting distortion on the projection plane.

  FIG. 7 is a diagram for explaining an example of a conventional trapezoidal correction process. FIG. 7A is a diagram showing an example of a state in which an image is projected from the projection apparatus onto the screen. FIG. An example of the image is shown in FIG. 4A, and the projection image after the keystone correction is shown in FIG. 4B. In FIG. 7, 10 is a projection device, 30 is a projection base on which the projection device is installed, and 40 is a screen for projecting an image.

  When the direction (optical axis) of the image projected from the projection apparatus 10 is not perpendicular to the projection surface of the screen 40, optical distortion occurs, so the image projected on the screen 40 is shown in FIG. ) Becomes a trapezoid like an image 41a. The trapezoidal distortion is reversely corrected by a signal processing circuit inside the projection apparatus 10, and as a result, a correct (close to rectangular) shape image as shown in an image 42 a in FIG. Reproduce on the projection surface. This function is called a keystone correction function.

  Keystone correction of a trapezoidal projection image has been performed based on visual observation by a user who has installed a projection apparatus and a screen. However, in recent projection apparatuses, a function of automatically correcting keystone correction in the vertical direction regardless of a user operation is being realized. Such a projection apparatus includes angle detection means for detecting the installation angle of the projection apparatus, and can automatically perform keystone correction according to the detection result of the angle detection means.

  For example, as shown in FIG. 7A, it is assumed that the projection apparatus 10 is arranged with an angle α with respect to the upper surface of the projection base 30 (the installation surface of the projection apparatus 10). At this time, it is assumed that the installation surface of the projection table 30 on which the projection apparatus 10 is installed and the projection surface of the screen 40 are vertical.

  Here, since the projection apparatus 10 is inclined at an angle α with respect to the upper surface of the projection table 30, the optical axis of the image projected onto the screen 40 is relative to the normal line n of the projection surface of the screen 40. Therefore, the angle α is shifted downward (negative direction). At this time, the image actually projected on the screen 40 is a trapezoidal image 41a having a long lower side as shown in FIG. 7B.

Next, the same problem is considered for the projection apparatus 10 provided with the angle detection means. The angle detection means in the projection apparatus 10 can detect that the projection apparatus 10 is inclined in the positive direction by the angle α with respect to the projection base 30, so that the optical axis is in the negative direction by the angle α with respect to the screen 40. We can infer that it is tilted. At this time, the projection apparatus 10 determines that the image actually projected on the screen 40 has a shape like the trapezoidal image 41a in FIG. 7B, and performs image conversion on the projected image. Then, the projection of the image 42b having a long upper side as shown in FIG. Then, by actually projecting this image 42b onto the screen 40, distortion of the image is compensated, and a projection image close to a rectangle (similar to the original image) as shown in the image 42a in FIG. 7C is obtained. Can do.
As the angle detection means, an acceleration sensor is often used, and a change in angle can be calculated by a change in gravitational acceleration or the like.

  In addition to the keystone correction function, communication with RS-232C or LAN is performed with respect to the projection apparatus 10 and a response is returned from the projection apparatus 10 to confirm that the apparatus “is present there” ( There is a system that performs polling processing, and a system that monitors the connector output between the computer and the projection apparatus 10 and confirms that the apparatus “is present there” by maintaining the connection state. If it does not exist there, that is, if there is no response from the projection device 10 or if the connection state is released, it will contact the administrator and sound an alarm as being “stolen”. Such a system is called an anti-theft system.

  FIG. 8 is a diagram for explaining a configuration example of the antitheft system of the projection apparatus, in which 50 is a PC and 51 is a LAN terminal. In general, a projection device anti-theft system includes devices such as a PC 50 and a LAN terminal 51 capable of RS-232C and LAN communication in addition to the projection device 10. The theft detection is performed by the PC 50.

Regarding the antitheft system as described above, for example, Patent Document 1 discloses an antitheft system for in-vehicle electronic devices. Here, a liquid crystal projector main body is illustrated as an in-vehicle electronic device, and the liquid crystal projector main body and an alarm control device are connected by a multicore cable. When the multicore cable is connected, the multicore cable carrying the theft detection signal is short-circuited in the liquid crystal projector main body. If someone cuts off the multi-core cable or removes the connector portion to take away the liquid crystal projector body, the multi-core cable is opened. This change is detected by an alarm control device, and a theft detection signal is supplied to the alarm device to prevent theft.
Japanese Patent Laid-Open No. 7-160955

  In the anti-theft system as shown in FIG. 8 described above, the mechanism itself for detecting the theft is not included in the projection apparatus 10, so that in addition to the projection apparatus 10 that is desired to prevent the theft, another apparatus for monitoring it. (PC50 etc.) is required.

  The projection apparatus 10 and the PC 50 are connected via RS-232C, LAN (Ethernet (R)), etc., and the theft is detected based on the presence or absence of a repeated communication response or the connection state is changed. Monitoring. For this reason, the connection of the communication path itself may be interrupted for some reason, or theft may be detected by mistake due to a communication failure. Know-how for preventing such erroneous detection is also required at the time of design, but often causes problems in the system evaluation and installation stage. This is because the device such as the PC 50 that detects theft prevention is provided by a vendor different from the projection device 10, and it is possible to perform both compatibility tests for the first time at the time of substantial installation. caused by.

  Similarly, in the anti-theft system as described in Patent Document 1 above, the mechanism itself for detecting the theft is not included in the liquid crystal projector, so in addition to the liquid crystal projector that wants to prevent the theft, it is necessary to monitor it. A separate system is required.

  The present invention has been made in view of the above-described circumstances, and is a projection device capable of detecting movement such as theft by the projector device main body without using a computer or the like that monitors connection by communication or the like. The purpose is to provide.

  Therefore, in order to solve the above-described problem, a first technical means is a projection apparatus having an angle detection means for detecting an installation angle of the projection apparatus, and the projection apparatus is moved using detection data detected by the angle detection means. It is characterized by having a movement judging means for judging that.

  The second technical means includes threshold setting means capable of setting a threshold for determining that the movement has been made according to the detection result of the angle detection means in the first technical means. Using the threshold value set in the means, the presence or absence of movement is determined from the detection result of the angle detection means.

  The third technical means is characterized in that in the second technical means, there is provided an operation input means capable of variably setting a threshold value set in the threshold value setting means.

  The fourth technical means includes movement notification means for notifying the outside that the movement determination means is outside when the movement determination means is determined to be movement in any one of the first to third technical means. It is characterized by.

  The fifth technical means includes control means for controlling the operation of the projection apparatus in any one of the first to fourth technical means, and the control means determines that the movement determination means is a movement. In addition, the projector is shifted to a prohibit mode in which the projection apparatus cannot be used.

  A sixth technical means is the fifth technical means, wherein the control means releases the prohibit mode in accordance with a predetermined input instruction.

  The seventh technical means is characterized by comprising an auxiliary power source for performing an operation when it is determined that the movement determination means is movement.

  The eighth technical means is the seventh technical means, when the power cut-off detecting means for detecting that the external power supply is cut off, and the power cut-off detecting means detecting the cut of the external power supply. And a power source switching means for supplying power from the auxiliary power source.

  The ninth technical means can switch between an operation state in which the operation based on the determination of the movement determination means and a non-operation state in which the operation is not executed in any one of the first to eighth technical means. It is characterized by.

  According to a tenth technical means, in any one of the first to ninth technical means, the movement judging means judges that the projection device has been stolen.

According to the present invention, since the movement due to theft or the like can be detected in the projector apparatus main body without using an external device such as a computer for monitoring the connection by communication or the like, it is reliable without incurring unnecessary costs. A movement prevention function such as theft can be realized.
Further, since the movement is detected by using the angle detection result of the angle detection means provided for the automatic keystone correction of the projection apparatus, a movement prevention function such as theft can be realized with a simple configuration.
In addition, since it is not necessary to use an external device as described above, it is possible to prevent the movement prevention function from being triggered when a communication failure occurs due to a cause such as the communication path with the external device being accidentally disconnected. be able to.

  FIG. 1 is a block diagram for explaining an embodiment of a projection apparatus according to the present invention. The projection apparatus 10 includes an image processing circuit 11, a display screen correction unit 12, and a video projection unit 13 provided in a normal projection apparatus 10, and an angle detection unit 14 for automatically performing keystone correction, Control means 15 for controlling the operation of the projection apparatus, movement determination means 15a for determining the presence or absence of movement due to theft or the like in the control means 15, movement notification means 16 for performing notification at the time of movement determination, main body key / remote control detector 17, non-volatile Memory 18, threshold setting circuit 19, built-in auxiliary power supply 20, normally used power supply circuit 21, voltage sensor 22, switch SW-1, and switch SW-2.

The video processing circuit 11 processes the input video signal and inputs the processed video signal to the display screen correction unit 12. The display screen correction unit 12 corrects the shape of the projected image on the projection surface according to the relative angle between the projection axis of the projection light detected by the angle detection unit 14 and the projection surface such as a screen. In other words, here, when the projection surface cannot be projected from the front (when the optical axis of the projection optical system and the projection surface are not perpendicular), the projection image shape that becomes a trapezoid as it is is corrected and distorted. The corrected video data for performing the projection without any image is output.
The video projection unit 13 modulates the light source light with a display device that displays video based on the video signal whose distortion has been corrected by the display screen correction unit 12 and the display video of the display device, and projects it onto a projection surface such as a screen (not shown). And a projection optical system for displaying a projected image.

The angle detection means 14 is composed of an acceleration sensor or the like, and is used not only for automatic keystone correction, which is the original application, but also as a device for sensing movement such as theft. The movement determination unit 15 a determines that the projection apparatus 10 has been moved based on the change in the angle data detected by the angle detection unit 14 and the threshold set by the threshold setting circuit 19. This threshold value setting circuit 19 functions as a threshold value setting means in which a threshold value for determining that the movement is more than necessary is set.
Further, by providing the switch SW-1 before and after the control means 15 or performing processing inside the microcomputer, the operation / non-operation of the movement prevention function such as theft can be switched. Thus, it is possible to switch between an operation state in which the operation based on the determination of the movement determination unit 5 is executed and a non-operation state in which the operation is not executed.

  FIG. 2 is a diagram for explaining a change in the angle detection amount due to movement such as theft. FIG. 2A shows a state where the projection apparatus 10 is installed on the projection table 30 at a normal installation angle. FIG. 2B shows a state where the projection apparatus 10 is moved from the state of FIG. Here, an angle formed between the projection apparatus 10 and the upper surface of the projection base 30 in the normal state shown in FIG. 2A is α, and the projection apparatus 10 and the projection base in the state shown in FIG. An angle formed with the upper surface of 30 is β (≠ α).

It is assumed that after the projection device 10 shifts to the movement prevention mode, a person who tries to steal the projection device 10 appears and touches the projection device 10. Then, the angle detection means 14 inside the apparatus detects that the angle of the projection apparatus 10 has changed. The angle variation in this case means that the horizontal installation angle of the projection apparatus 10 has not been changed, but that someone has moved the projection apparatus 10 in an attempt to remove it.
For example, when a person moves the projection apparatus 10 from the normal state shown in FIG. 2A to the state shown in FIG. 2B, the angle detection unit 14 obtains detection data corresponding to the angle change. Output.

  FIG. 3 is a diagram for explaining an example of the change in the angle amount data in the angle detection means. FIG. 3A shows the angle amount data in the projection device 10 in a normal state, and the angle is changed when the projection device 10 moves. FIG. 3B shows the angular amount data when changed. Here, the angle data with respect to the installation angle α of the projection apparatus 10 is α ′, the angle data with respect to the change angle β is β ′, and an example of angle data output along the time axis t is shown.

  If the position of the installed projection apparatus 10 is maintained without being touched by anyone, the angle amount data detected by the angle detection means 14 is constant angle data as shown in FIG. α ′ is output. On the other hand, when someone moves the projection apparatus 10 as described above, the change angle data β ′ is detected as shown in FIG. The movement determination means 15a determines that the projection apparatus 10 is about to be moved due to theft or the like by detecting the change in the angle amount data.

  At this time, the movement determination unit 15a determines whether or not the projection apparatus 10 is about to be moved based on a threshold value set in the threshold setting circuit 19 in advance. For example, when the threshold value set in the threshold value setting circuit 19 is 3 and the changing angle data is 3 ≦ angle change amount <10, ie, 3 ≦ | β ′ | − | α ′ | <10 Is determined to be a movement due to theft or the like, assuming that an abnormality equal to or greater than a threshold is detected in the data.

  On the other hand, for example, the threshold set in the threshold setting circuit 19 is 10, and the changing angle data is 3 ≦ angle change <10, that is, 3 ≦ | β ′ | − | α ′ | When <10, the movement determination unit 15a determines that there is no abnormality because the angle data has changed but is within a range that does not exceed the set threshold value.

  The threshold value of the change amount of the detection data for determining the movement is determined by inputting an operation signal to the threshold setting circuit 19 via the main body key / remote control detection unit 17 by operating an operation input unit (not shown). An arbitrary threshold value can be variably set in the setting circuit 19.

  When the determination result of the movement determination unit 15a is movement, the movement notification unit 16 causes the light source 16a built in the movement notification unit 16 to emit light according to the output signal from the movement determination unit 15a, or the movement notification unit 16 similarly. A sound is generated by a sound source 16b incorporated in the. As a result, it is possible to check the theft or the like, or to notify the administrator or the surrounding security personnel of the danger of the theft. The light source 16a and the sound source 16b included in the movement notification unit 16 may include both or only one of them. Further, other notification means such as communication means and display means for reporting to the outside can be provided as appropriate.

  Further, as one of operations at the time of movement due to theft or the like, when the movement determination unit 15a determines that the projection device 10 has been moved, the control unit 15 performs subsequent operations on the projection device 10 and projection of images. Shift to a mode that prohibits. In the prohibit mode, for example, when the projection apparatus 10 is turned on, a screen for prompting a password as shown in FIG. 4 is displayed on the display means of the projection apparatus 10 to prohibit the operation of the apparatus.

  The transition information to the prohibit mode as described above is stored in the non-volatile memory 18 in the projection apparatus 10 and cannot be used after being moved. In this way, if it is known that it cannot be used even if it is stolen, the urge to steal the projection device 10 is suppressed, and the theft of the projection device 10 can be prevented.

  Further, the return from the prohibit mode can be executed by operating an operation input means (not shown) and causing an operation signal to be input to the control means 15 via the main body key / remote control detector 17. For example, a specific main body key input preset by the administrator or a password preset by the administrator is entered to return from the prohibit mode.

FIG. 5 is a diagram for explaining a state when the projection apparatus 10 is fixed to the ceiling. FIG. 5A illustrates a state where the projection apparatus 10 is fixed to the ceiling at a normal installation angle. FIG. 5B shows a state where the projection apparatus 10 is moved from the state A) and the angle formed with the ceiling is changed.
The determination function of the movement when the projection apparatus 10 is installed on the projection base 30 as described above is the same even when the projection apparatus 10 is fixed to the ceiling 31 as shown in FIG. Can be realized. In this case, by replacing the relationship between the projection base 30 and the projection device 10 with the relationship between the ceiling 31 and the projection device 10, the projection device 10 can be operated in exactly the same manner.

  The projection apparatus 10 includes an auxiliary power source 20 shown in FIG. The auxiliary power supply 20 is built in the projection apparatus 10 in the form shown in FIG. In order to execute the operation during movement due to theft or the like as described above, it is essential that a current is supplied to the power source of the projection apparatus 10. When moving, first, if the power cable is disconnected, it is possible that subsequent operations during the movement will not work well. Therefore, the auxiliary power supply 20 is built in the projection apparatus 10 and a voltage sensor 22 that functions as a power-off detection means for detecting that the external power supply has been cut off is prepared, and the power supply from the power supply circuit 21 is cut off. It is possible to detect movements due to theft even after a long time.

  The auxiliary power source 20 can be realized by a fuel cell, a lithium battery, a nickel cadmium battery, a dry battery, or the like. Then, the voltage sensor 22 detects the voltage of the power supply circuit 21 to determine that the power supply has been cut off. When the power supply is cut off, the voltage sensor 22 outputs a switching signal, the switch SW-2 is switched, and the auxiliary power supply 20 supplies power, thereby enabling operation during movement. be able to. The switch SW-2 functions as power switching means for switching between external power supply and auxiliary power supply.

  Further, when a rechargeable lithium battery, a nickel cadmium battery, or the like is used as the auxiliary power source 20, the auxiliary power source 20 can be charged when the projection apparatus 10 is normally used. And when the projection apparatus 10 is moved, the operation at the time of movement can be rapidly performed by supplying electric power from the charged auxiliary power source 20.

  Further, even in the projection apparatus 10 that does not include a special auxiliary power supply, only a network-related block in the projection apparatus 10 that does not require much power can be used by using a large-capacity electrolytic capacitor or the like. Thus, the operation at the time of movement can be executed by the network. That is, a voltage sensor that senses that the power supply has been cut off is prepared, and when it is determined that the power supply has been cut off, the operation mode shifts to an operation mode in which power is temporarily supplied by an electrolytic capacitor or the like. This is because the projection device 10 is a device that handles a relatively large capacity power supply, so a large capacity capacitor is originally used to stabilize the large capacity power supply, which is impossible compared with other devices. It is possible to cope with it.

It is a block diagram for demonstrating one Embodiment of the projection apparatus by this invention. It is a figure for demonstrating the change of the angle detection amount by movement, such as theft. It is a figure for demonstrating an example of the change of the angle amount data in an angle detection means. It is a figure which shows an example of the display screen in the prohibition mode of a projection apparatus. It is a figure for demonstrating a state when a projection apparatus is fixed to a ceiling. It is a figure for demonstrating the auxiliary power supply of a projection apparatus. It is a figure for demonstrating the example of the conventional trapezoid correction process. It is a figure for demonstrating the structural example of the antitheft system of a projection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Projection apparatus, 11 ... Video processing circuit, 12 ... Display screen correction means, 13 ... Video projection means, 14 ... Angle detection means, 15 ... Control means, 15a ... Movement determination means, 16 ... Movement notification means, 16a ... Light source , 16b ... Sound source, 17 ... Main body key / remote control detector, 18 ... Non-volatile memory, 19 ... Threshold setting circuit, 20 ... Auxiliary power supply, 21 ... Power supply circuit, 22 ... Voltage sensor, 30 ... Projection stand, 31 ... Ceiling, 40 ... screen, 41a, 42a, 42b ... video, 50 ... PC, 51 ... LAN terminal.

Claims (10)

  A projection apparatus comprising angle detection means for detecting an installation angle of the projection apparatus, characterized by comprising movement determination means for determining that the projection apparatus has been moved using detection data detected by the angle detection means. Projection device.   It has a threshold setting means capable of setting a threshold for determining that the movement has been made according to the detection result of the angle detection means, and the theft movement fixing means uses the threshold set in the threshold setting means, The projection apparatus according to claim 1, wherein presence or absence of movement is determined from a detection result of the angle detection unit.   The projection apparatus according to claim 2, further comprising an operation input unit that can variably set a threshold set in the threshold setting unit.   The projection apparatus according to claim 1, further comprising a movement notification unit that notifies the outside of the movement when the movement determination unit determines that the movement is performed.   Control means for controlling the operation of the projection apparatus, wherein the control means shifts to a prohibit mode in which the projection apparatus cannot be used when it is determined that the movement determination means is movement. The projection apparatus according to claim 1.   6. The projection apparatus according to claim 5, wherein the control unit cancels the prohibit mode in accordance with a predetermined input instruction.   A projection apparatus comprising: an auxiliary power source for performing an operation when the movement determination means determines that the movement is a movement.   A power-off detection means for detecting that the external power supply has been cut off, and a power-switching means for supplying power from the auxiliary power supply when the power-off detection means detects the disconnection of the external power supply. The projection apparatus according to claim 7, further comprising:   The projection apparatus according to claim 1, wherein an operation state in which an operation based on the determination of the movement determination unit is executed and a non-operation state in which the operation is not executed can be switched.   The projection apparatus according to claim 1, wherein the movement determination unit determines that the projection apparatus has been stolen.

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