JP2011166647A - Projector and image projection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector that enhances the workability of adjustment of trapezoidal correction using a simple structure with the increase in cost suppressed, and to provide an image projection method by the projector. <P>SOLUTION: A controller 11, which is a correction-amount controller, reduces the amount of trapezoidal correction by a trapezoidal correction unit to zero, when the controller 11 determines that the projector foot is being put away. Resultantly, it is avoidable that the amount of trapezoidal correction is maintained to a large value, even though the foot is put away and a projection state changes a lot; and the number of operations for changing the amount of trapezoidal correction to an appropriate value can be reduced so that the adjustment work for the amount of trapezoidal correction can be made efficient. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a projector capable of projecting a trapezoidally corrected image and an image projection method using the projector.

  In order to reduce image distortion due to oblique projection, a projector that corrects trapezoidal distortion of a displayed image by forming an image in a part of the image display area of the image forming panel is known. In this case, the trapezoidal distortion correction amount, that is, the trapezoidal correction amount is saved when the operation is stopped, and this trapezoidal correction amount is read out at the next start-up to perform the previous keystone correction. In such a projector, it is convenient if the projection position of the projector before stopping is substantially the same when it is next started, but the projector's posture has changed significantly until the next start. In this case, the number of operations for making the trapezoid correction amount appropriate at the time of subsequent activation increases, and the operation tends to become troublesome. In order to improve the function of the above-described manual adjustment type projector, there is a type in which the installation angle of the projector is detected and keystone correction is automatically performed according to the installation angle (see Patent Document 1).

JP 2003-283963 A

  However, the projector as disclosed in Patent Document 1 requires an installation angle detection device such as an angle sensor, which complicates the device and increases the cost.

  SUMMARY An advantage of some aspects of the invention is that it provides a projector that can improve the workability of adjustment of trapezoidal correction with a simple structure that suppresses an increase in cost, and an image projection method using the projector.

  In order to solve the above problems, a projector according to the present invention accommodates a main body including a video projection unit that projects an image, a trapezoid correction unit that performs a keystone correction process on an image projected on the video projection unit, and a video projection unit. A housing, a foot supporting the housing in an inclined state by protruding from the housing, a foot position detecting unit for detecting at least that the foot is in a storage position with the smallest protruding amount, and a foot position detecting unit And a correction amount control unit that performs control to suppress trapezoidal correction by the trapezoidal correction unit when it is detected that the foot is in the storage position.

  According to the above projector, when it is determined that the foot is in the retracted state, the correction amount control unit suppresses the trapezoidal correction by the trapezoidal correction unit. Nevertheless, it is possible to prevent the trapezoid correction amount from being kept large, and to reduce the number of operations for making the trapezoid correction amount appropriate, thereby making the adjustment process of the trapezoid correction amount efficient.

  In a specific aspect of the present invention, the correction amount control unit reduces the trapezoid correction amount by the trapezoid correction unit when it is detected that the foot is in the storage position upon activation. Generally, when starting up, it is often impossible to use the previous keystone correction process as it is, so at least when the foot is in the storage position, the keystone correction amount can be reduced to speed up the adjustment process of the keystone correction amount. be able to.

  In another aspect of the present invention, the foot position detection unit continues detection until a predetermined time elapses from the start of image projection, and the correction amount control unit finalizes the detection result by the foot position detection unit when the predetermined time elapses. It is characterized by accepting as a result. In this case, for example, even when the user temporarily puts and removes the foot immediately after starting the projector, the trapezoidal correction amount can be set according to the final foot state.

  According to still another aspect of the present invention, the correction amount control unit makes the trapezoid correction amount by the trapezoid correction unit zero when the foot position detection unit detects that the foot is in the storage position. In this case, it can be interpreted that the projector is installed in a different environment from before, and the keystone correction amount adjustment operation can be speeded up by once releasing the keystone correction process.

  In still another aspect of the present invention, the image processing apparatus further includes a storage unit that stores a trapezoidal correction amount immediately before the stop of image projection, and the correction amount control unit is detected by the foot position detection unit when the foot is not in the storage position. In this case, the keystone correction amount by the keystone correction unit is adjusted based on the keystone correction amount stored in the storage unit. In this case, by applying the trapezoid correction amount immediately before the stop of image projection stored in the storage unit, the number of operations for making the trapezoid correction amount appropriate is reduced, and the adjustment work of the trapezoid correction amount is made efficient. can do.

  In yet another aspect of the present invention, when the correction amount control unit detects that the foot is in the storage position by the foot position detection unit, the trapezoid correction amount by the trapezoid correction unit is set to zero or a predetermined reference value. It is characterized by being changed in stages. In this case, since the process of returning to zero or a predetermined reference value without using the trapezoidal correction amount corresponding to the previous state can be visually understood, the user can clearly grasp the state of the projector.

  In still another aspect of the present invention, the storage unit stores the detection result of the foot position detection unit in correspondence with the trapezoidal correction amount immediately before stopping the image projection, and the correction amount control unit includes the foot position detection unit. A trapezoidal correction amount corresponding to the detection result is displayed on the video projection unit, and whether or not the keystone correction processing amount is maintained can be selected. In this case, when the user's intention is different from the determination result in the correction amount control unit, the user can prioritize his intention.

  In still another aspect of the present invention, the foot position detection unit includes a first detection unit that detects that the foot is in a first position where the protruding amount is larger than the storage position, and the foot is more than the first position. A second detection unit that detects that the protrusion is located at the second position where the protrusion amount is large, and the correction amount control unit corrects the keystone when the first detection unit determines that the foot is at the first position. The trapezoidal correction amount when the foot is determined to be in the second position by the second detector is larger than the amount. In this case, the trapezoidal correction amount adjustment work can be made efficient by changing the correction amount according to the position of the foot.

  An image projection method according to the present invention protrudes from a video projection unit that projects an image, a trapezoid correction unit that performs a keystone correction process on an image projected on the video projection unit, and a housing that houses a main body including the video projection unit. An image projection method by a projector having a foot that supports the housing in an inclined state, and a foot position detection step for detecting that the foot is in a storage position with the smallest protrusion amount, and a foot position detection A correction amount control step for performing control to suppress trapezoidal correction when it is detected that the foot is in the storage position by the step.

  According to the above image projection method, when it is determined that the foot is stored, the keystone correction by the trapezoid correction unit can be suppressed in the correction amount control step, so that the foot is stored and projected. It can be avoided that the keystone correction amount is kept large despite the fact that the state has changed greatly, and the number of operations to make the keystone correction amount appropriate is reduced, and the keystone correction amount adjustment work is made efficient. can do.

It is a block diagram which shows the structure of the projector of 1st Embodiment. It is a figure which illustrates the key element which comprises a key operation part. It is a figure which shows the external appearance of a projector. (A)-(C) are figures which show the structure of the foot of a projector. It is a figure explaining the flow of the process performed with the projector of 1st Embodiment. It is a figure explaining the flow of the process performed with the projector of a modification. (A), (B) is a figure shown about the screen display in the process of the projector of a modification. It is a block diagram which shows the structure of the projector of 2nd Embodiment. (A), (B) is a figure which shows the structure of the foot in the projector of 2nd Embodiment. It is a figure explaining the flow of the process performed with the projector of 2nd Embodiment. It is a figure explaining the flow of the process performed with the projector of 2nd Embodiment. It is a figure explaining the flow of the process performed with another projector.

[First Embodiment]
Hereinafter, a projector according to a first embodiment of the invention will be described with reference to FIGS.

[A. Projector structure)
As shown in FIG. 1, the projector 10 includes a control unit 11, a storage unit 12, a key input processing unit 13, an input selection unit 14, an image processing unit 15, and a video projection unit 17 as a main body 10 a. , A communication unit 18, a foot position detection unit 19, and a power supply unit 22.

  The control unit 11 controls the overall operation of the projector 10. That is, the control unit 11 is communicably connected to the storage unit 12, the key input processing unit 13, the input selection unit 14, the image processing unit 15, the communication unit 18, the foot position detection unit 19, the power supply unit 22, and the like. Information is taken from these parts, or control signals are sent to these parts to control the operation state. The control unit 11 includes a foot position reading unit 11a, a correction amount reading unit 11b, a correction amount determination unit 11c, a correction amount storage control unit 11d, and the like as functions particularly related to trapezoidal correction, and for keystone correction processing in image projection. Functions as a correction amount control unit. Details of these functions will be described later.

  The storage unit 12 includes a ROM 12a, a RAM 12b, a nonvolatile memory 12c, and the like, and holds programs, data, and the like necessary for operating the projector 10. In particular, the nonvolatile memory 12c is composed of an EEPROM or the like, and data stored in the nonvolatile memory 12c so as to be rewritable includes, for example, information on keystone correction performed by the keystone correction unit 15a of the image processing unit 15, specifically Includes a keystone correction amount and the like during the previous operation. In addition, the storage unit 12 also holds image data corresponding to a projection image to be projected on the video projection unit 17. The image data includes a menu screen for changing input signals and operation modes, a dialog screen for inputting user instructions, and the like. In addition to the image data that the projector 10 has from the beginning, the image data or the image signal captured from the outside via the communication unit 18, the input selection unit 14, and the like are added to the storage unit 12 in an appropriate file format. Can be saved.

  The key input processing unit 13 is an input unit for inputting a user instruction, and includes a key operation unit 28 including a set of operation keys. The key input processing unit 13 can be accompanied by a display as a UI. A remote control light receiving unit 25 is provided along with the key input processing unit 13 so that a command signal can be received remotely from the remote control 26 by radio.

  As illustrated in FIG. 2, the key operation unit 28 includes a power button 28a, an input switching button 28b, a menu button 28c, an escape button 28d, four triangular buttons 29a, 29b, 29c, 29d, and a confirmation button. A button 29e, two trapezoid correction buttons 29f and 29g, a zoom button 29h, and the like are provided in an appropriate arrangement as a set of operation keys. These buttons 28a, 28b, 28c, 28d, 29a, 29b, 29c, 29d, 29e, 29f, 29g, 29h, that is, a set of operation keys can be provided not only on the key operation unit 28 but also on the remote control 26. . Of the two trapezoidal correction buttons 29f and 29g constituting the key operation unit 28, the first trapezoidal correction button 29f is for increasing the reduction on the upper side. This is used to suppress a phenomenon in which an image is relatively enlarged on the upper side when image projection is performed above the optical axis. The second trapezoidal correction button 29g is for strengthening the reduction on the lower side. For example, when the projector 10 is in an upright state and an image is projected below the optical axis of the projection lens, It is used to suppress the phenomenon that the image is relatively enlarged on the lower side.

  Returning to FIG. 1, the input selection unit 14 is connected to the connector 41. A plurality of image output devices (not shown) such as a computer, a disk player and the like can be connected to the connector 41 at the same time. The input selection unit 14 operates under the control of the control unit 11, receives an input signal (that is, an image signal) from any one of a plurality of image output devices connected to the connector 41, and sends it to the image processing unit 15. Output.

  The image processing unit 15 performs various correction processes including gradation correction, color correction, keystone correction, and magnification correction on an image signal or image data input from the outside via the input selection unit 14 or the communication unit 18. Can do. These gradation correction, color correction, trapezoidal correction, magnification correction, and the like can be changed under the control of the control unit 11, and the user uses the key input processing unit 13 to change the contents of the image processing unit 15. The image processing state can be switched, and settings such as gradation correction, color correction, keystone correction, and magnification correction can be adjusted as appropriate. In particular, the image processing unit 15 can form an image only on a part of the liquid crystal panel (trapezoidal region) of the video projection unit 17 by performing coordinate conversion or the like on the image corresponding to the input signal by the trapezoid correction unit 15a. As a result, the trapezoidal distortion of the image projected on the screen can be corrected. The degree of the keystone correction, that is, the keystone correction amount can be increased or decreased by operating the keystone correction buttons 29f and 29g of the key operation unit 28 as described above, and a substantially rectangular image can be projected on the screen. It becomes possible. In addition, the image processing unit 15 can generate an image signal for displaying a menu screen and other information including character information extracted from the storage unit 12 based on a command from the control unit 11.

  The video projection unit 17 includes a liquid crystal panel drive unit 17 a that drives the liquid crystal panels for each color of RGB based on the image signal after image processing output from the image processing unit 15. Although a specific description is omitted, the video projection unit 17 includes, as an optical system, for example, an illumination device, a liquid crystal panel for each color, a combining prism, a projection lens, and the like, and a liquid crystal light valve for each color including a liquid crystal panel. A color image is displayed on a screen (not shown) by synthesizing and projecting the light transmitted through. Note that the optical system of the video projection unit 17 is not limited to the liquid crystal system, but can use various systems such as a digital micromirror device system, an LCOS system, a GLV system, and a CRT system.

  The communication unit 18 is an interface circuit that enables communication. The communication unit 18 can be, for example, a wireless interface circuit that enables communication in an ad hoc mode of a wireless LAN.

  The foot position detector 19 is a sensor that detects the protruding state of the foot 60 (see FIG. 3 and the like) that supports the projector 10 so as to be tilted, that is, the state and position of the foot 60. The foot position detection unit 19 operates under the control of the control unit 11 and detects, for example, whether or not the foot 60 is in the retracted state based on the detection signal of the pressing switch 50 attached around the foot 60. Details of the foot 60 and the pressing switch 50 will be described later.

  The power supply unit 22 operates under the control of the control unit 11 and supplies power to each unit of the projector 10.

  As shown in FIG. 3, in the projector 10, each element of the apparatus main body including the video projection unit 17 is accommodated in a case unit SC that is a housing. The projector 10 adjusts the attitude of the projector 10 by adjusting a foot 60 that can be taken in and out at a bottom BP on the lower side (−Y side) of the case part SC and a protruding amount of the foot 60 that is partially built in the case part SC. The protrusion amount adjusting device 24 that enables the above is attached.

  4A is an enlarged plan sectional view conceptually illustrating the structure of the protrusion amount adjusting device 24, and FIGS. 4B and 4C are enlarged side sectional views of the protrusion amount adjusting device 24. is there.

  The foot 60 includes a grounding part 81a supported by an installation surface PS that is an upper surface of a desk, a floor, and the like, and a bolt part 81b extending from the grounding part 81a toward the inside of the bottom part BP of the case part SC.

  The protrusion amount adjusting device 24 includes a holding portion 82 that holds the foot 60 and a release button 83. The holding portion 82 is fixed to the bottom portion BP, and includes a pair of split nut portions 82a that are screwed with the bolt portions 81b, and a support portion 82b that supports both the split nut portions 82a so as to be openable and closable. The pair of split nut portions 82a is provided with a member (not shown) such as a spring that urges the split nut portions 82a so as to close the tip sides close to each other. The release button 83 is pivotally supported by a hole CA formed in the side part SP of the case part SC, and can be pushed between extension parts 82c extending to the outside of the support part 82b of the split nut part 82a. The hole CB formed in the bottom part BP of the case part SC is larger than the outer shape of the bolt part 81b, and the bolt part 81b can be freely moved in the axial direction.

  The operation of the foot 60 and the protrusion amount adjusting device 24 will be described. By rotating the grounding portion 81a of the foot 60, the bolt portion 81b is sandwiched and rotated between the pair of split nut portions 82a, and moves up and down in the Y direction. . That is, the foot 60 finely moves in the Y direction by rotation. Thereby, the foot 60 can be taken in and out of the case part SC, and the protrusion amount of the grounding part 81a can be adjusted. That is, as shown in FIG. 4B, when the protrusion amount of the grounding portion 81a is increased, the bottom portion BP of the case portion SC is separated from the installation surface PS, and the projector 10 is inclined to increase toward the front which is the projection side. It becomes a state. On the other hand, when the protrusion amount of the grounding portion 81a is decreased, the bottom portion BP is close to the installation surface PS, and the projector 10 is in a nearly horizontal state. In particular, as shown in FIG. 4C, when the foot 60 is at the position (storage position) where the projection amount is the smallest, the projector 10 is parallel to the installation surface PS, that is, in a horizontal state.

  When the user pushes the release button 83 into the side portion SP, the pair of split nut portions 82a of the holding portion 82 are separated from each other, and the screwing between the foot 60 and the holding portion 82 is released. Thereby, the bolt part 81b can freely move in the Y direction, and the grounding part 81a of the foot 60 can be largely taken in and out of the case part SC. When the user releases the release button 83, the foot 60 and the holding portion 82 are screwed again, so that the foot 60 is returned to a state of being slightly moved in the Y direction by the rotation.

  Further, as shown in FIG. 4B, the push switch 50 is disposed above the foot 60 (+ Y side) inside the case portion SC. The pressing switch 50 includes a switch base part 50a provided on a plate part BB extending horizontally inward from the side part SP, and a button 50b provided so as to protrude from the switch base part 50a. The button 50b is always urged downward by a spring (not shown) incorporated in the switch base 50a, and can be pushed upward. As shown in FIG. 4C, when the foot 60 is housed, that is, when the protruding amount of the foot 60 is minimized, the button 50b of the push switch 50 is pressed upward by the upper end portion 60a of the bolt 81b. At this time, the push switch 50 is turned on. On the other hand, as shown in FIG. 4B, when the foot 60 is protruded to some extent, the button 50b returns to the state of protruding downward by the spring bias, and the push switch 50 is turned off. . The foot position detection unit 19 in FIG. 1 determines whether or not the foot 60 is in the storage position at which the foot 60 is most stored or is in a protruding state protruding from the storage position by detecting the on / off state of the push switch 50. Is detected.

[B. Projector operation)
Hereinafter, an example of a projection operation by the projector 10 will be described with reference to FIG. When the instruction signal detected by the key input processing unit 13 requests activation, the control unit 11 of the projector 10 starts processing described below. Specifically, when the projection operation of the projector 10 is in a stopped state, when the user presses the power button 28a of the key operation unit 28, display processing for projecting an image is started.

  First, the control unit 11 starts the startup process of the projector 10. That is, a sequence for lighting the lamp of the video projection unit 17 is executed, and the image processing unit 15 is appropriately operated to cause the video projection unit 17 to start preparation for image projection and the like (step S11).

  And the control part 11 reads the state of the foot 60 from the foot position detection part 19 as the foot position reading part 11a (step S12). Specifically, as shown in FIGS. 4B and 4C, the foot position detection unit 19 detects whether the pressing switch 50 is on or off, and receives the detection result as a signal. At this time, the foot position detection unit 19 continues to detect the foot state, that is, the position for a certain period of time, considering that the user changes the state of the foot 60 by moving the foot 60 in and out at startup (steps S12 and S13). ) After a certain period of time, the control unit 11 accepts the information assuming that the final state of the foot 60 has been determined (step S14). If it is determined in step S14 that the push switch 50 is on, that is, the foot 60 is in the storage position and is in the storage state (step S14: Y), it is interpreted that the projector 10 has been installed in a different environment. The keystone correction process can be speeded up by once canceling the trapezoidal correction process. Therefore, the control unit 11 outputs an instruction to the image processing unit 15 as the correction amount determination unit 11c, and performs a process for canceling or resetting the trapezoid correction process by the trapezoid correction unit 15a. In this case, the control unit 11 controls the trapezoidal correction unit 15a of the image processing unit 15 to read out the previous trapezoidal correction amount that is the previous trapezoidal correction amount for the keystone correction process (step S15). This front trapezoidal correction amount is a trapezoidal correction amount in the projection operation performed before the current projection operation, and in this case, corresponds to the trapezoidal correction amount immediately before the projector 10 is stopped. The control unit 11 once maintains the trapezoid correction amount by the trapezoid correction unit 15a at the previous trapezoid correction amount (step S16), and then decreases the trapezoid correction amount by the trapezoid correction unit 15a by one step for a predetermined time toward zero. (Step S17). The control unit 11 checks the trapezoidal correction amount as a result of reduction in step S17, and determines whether or not the reduced keystone correction amount has reached the target value of zero (step S18).

  When the keystone correction amount has not reached the target value of zero (step S18: N), the control unit 11 instructs the user to stop the correction amount reduction using the key operation unit 28 provided in the key input processing unit 13. If there is no stop instruction to reduce the correction amount (step S19: N), the process returns to step S17 to reduce the trapezoid correction amount by the trapezoid correction unit 15a to zero again and decrease by one step. Let With such an operation, the trapezoidal correction amount can be decreased stepwise toward zero.

  On the other hand, when the trapezoidal correction amount reaches zero of the target value (step S18: Y) or when the user gives an instruction to stop the correction amount reduction (step S19: Y), the control unit 11 performs the trapezoidal correction processing amount. The change process is terminated. As described above, when the control unit 11 determines that the foot 60 is in the storage position, the control unit 11 performs control to reduce the correction amount toward the target value of zero, that is, suppress trapezoidal correction.

  On the other hand, if it is determined in step S14 that the push switch 50 is off, that is, the foot 60 is not in the storage position (step S14: N), the control unit 11 serves as the correction amount reading unit 11b in the storage unit 12. The front keystone correction amount is read from the nonvolatile memory 12c (step S20). When the foot 60 is not in the stowed position, it is highly likely that the projection is performed in a state that is the same as or similar to the previous trapezoidal correction state. Therefore, the control unit 11 outputs an instruction to the image processing unit 15 as the correction amount determination unit 11c, and causes the keystone correction unit 15a to perform the keystone correction process with the front keystone correction amount (step S21).

  Even after the trapezoidal correction process as described above, until the end of projection, the control unit 11 accepts an operation of the keystone correction buttons 29f and 29g of the key input processing unit 13 by the user. The control unit 11 determines whether or not the keystone correction amount by the keystone correction unit 15a is changed by operating the keystone correction buttons 29f and 29g (step S22), and when the keystone correction amount is changed (step S22: Y). The keystone correction amount is stored in the nonvolatile memory 12c as the correction amount storage control unit 11d that performs the keystone correction process with the new trapezoid correction amount after the change (step S23).

  On the other hand, when the keystone correction amount has not changed (step S22: N), the control unit 11 checks the operation of the power button 28a of the key input processing unit 13 and determines whether or not there is an instruction to end projection from the user. To do. When there is no instruction to end projection from the user, the control unit 11 returns to step S22 and executes the processes of steps S22 to S24. On the other hand, when there is an instruction to end projection from the user, the control unit 11 stores the current signal processing state in the nonvolatile memory 12c of the storage unit 12 to stop the operation of the image processing unit 15, and the video projection unit 17 The lamp driving operation is stopped and the lamp is turned off (step S25).

  As is apparent from the above description, according to the projector 10 of the present embodiment, when the control unit 11 determines that the foot 60 is stored, the control unit 11 that is a correction amount control unit. However, the keystone correction amount by the keystone correction unit is reduced to zero. That is, the control unit 11 performs control to suppress trapezoidal correction. As a result, it is possible to avoid that the keystone correction amount is kept large despite the fact that the foot 60 is stored and the projection state is greatly changed, and the keystone correction is performed by reducing the number of operations for making the keystone correction amount appropriate. The amount adjustment work can be made efficient. If it is determined that the foot 60 is not in the retracted position and is in the protruding state, the control unit 11 can apply a front trapezoidal correction amount that is a trapezoidal correction amount immediately before the stop of projection.

  Hereinafter, modifications of the projection operation by the projector 10 will be described. FIG. 6 is a flowchart for explaining this modification. Note that the projector of the present modification is the same as the projector 10 shown in FIG.

  Also in the case of this modification, as in the case described with reference to FIG. 5, the control unit 11 first detects the position of the foot 60 from the foot position detection unit 19 (steps S111 to S113). Here, in the present modification, the information about the position of the foot 60 at this time is also stored in the nonvolatile memory 12c of the storage unit 12 corresponding to the front trapezoidal correction amount. That is, the ON / OFF state of the corresponding press switch 50 when the front trapezoidal correction amount is stored is stored. If it is determined in step S30 that the current state of the foot 60 and the state of the foot 60 corresponding to the storage of the front trapezoidal correction amount do not match (step S30: N), the control unit 11 performs FIG. As shown in FIG. 4, a display operation for selecting whether to cancel or reset the trapezoid correction process by the trapezoid correction unit 15a to perform the process without the initial keystone correction is performed via the image processing unit 15. The projection unit 17 is caused to perform the process (step S31). When the user selects the selection button D1 or the selection button D2 by operating the triangular buttons 29d or 29c of the key operation unit 28 and presses the confirmation button 29e, the displayed “Yes” or “No” is displayed. 11 performs processing accordingly. That is, when the selection button D1 indicating that there is no initial trapezoid correction is selected and confirmed (step S31: Y), the control unit 11 cancels or resets the trapezoid correction processing by the trapezoid correction unit 15a (step S31). S32) A trapezoidal correction process is performed to make the keystone correction amount zero (step S33). In step S31, when the selection button D2 indicating that the initial trapezoid correction is not performed, that is, the state based on the previous trapezoid correction amount is selected and confirmed (step S31: N), the control unit 11 is non-volatile. The keystone correction amount is read from the memory 12c (step S35), and the keystone correction process is performed with the keystone correction amount (step S33).

  On the other hand, if it is determined in step S30 that the current state of the foot 60 and the state of the foot 60 corresponding to the storage of the front trapezoidal correction amount are the same (step S30: Y), the control unit 11 performs FIG. ), The video projection unit 17 is caused to perform a display operation to the effect that the keystone correction unit 15a performs the keystone correction process with the front keystone correction amount via the image processing unit 15 (step S34). When the user presses the selection button D1 indicating that the keystone correction processing is performed with the front keystone correction amount (step S34: Y), the control unit 11 reads the front keystone correction amount from the nonvolatile memory 12c (step S34). S35), a keystone correction process is performed with the front keystone correction amount (step S33). In step S25, when the selection button D2 indicating that the keystone correction process is not performed with the previous keystone correction amount is pressed (step S31: N), the control unit 11 cancels or resets the keystone correction process by the keystone correction unit 15a. (Step S32) A trapezoidal correction process for setting the keystone correction amount to zero is performed (step S33).

  After the trapezoid correction process in step S33, the control unit 11 determines whether or not the keystone correction amount by the keystone correction unit 15a is changed by a user key input (step S122), and the keystone correction amount is appropriately stored in the nonvolatile memory. 12c (step S123), and this operation is repeated until the user gives an instruction to end projection (step S124). When there is an instruction to end projection from the user, the control unit 11 stores the current signal processing state in the nonvolatile memory 12c of the storage unit 12 to stop the operation of the image processing unit 15, and the lamp of the video projection unit 17 The driving operation is stopped and the lamp is turned off (step S125). In this modification, in step S23, in addition to the trapezoidal correction amount, information on the position of the foot 60 at this time, that is, information on whether the push switch 50 is on or off is stored in the nonvolatile memory 12c. Stored together.

  As described above, in this modification, in steps S31 and S34, the control unit 11 causes the video projection unit 17 to display the correction amount of the keystone correction determined from the detection result of the foot position detection unit 19, and the correction amount. The user can select whether or not to maintain. Thereby, when a user's intention and the judgment result in the control part 11 differ, the user can give priority to his intention.

  In step S30, if the position of the foot 60 corresponding to the previous trapezoidal correction amount and the current position of the foot 60 coincide with each other corresponding to the state without the trapezoidal correction, which process should be performed? It is also possible to omit the display operation for making the selection, and proceed to step S33 to perform the trapezoid correction process in which the initial trapezoid correction is not performed.

[Second Embodiment]
Hereinafter, a projector according to a second embodiment of the invention will be described with reference to FIGS. 8, 9 </ b> A, 9 </ b> B, and the like. The projector according to the present embodiment is a modification of the projector 10 according to the first embodiment shown in FIG. 1 and the like, and those that are not particularly described are the same as those of the first embodiment.

  As shown in FIG. 8, the projector 110 according to the present embodiment includes, as its main body 10a, a control unit 11, a storage unit 12, a key input processing unit 13, an input selection unit 14, an image processing unit 15, and the like. A video projection unit 17, a communication unit 18, a foot position detection unit 119, and a power supply unit 22 are provided. The foot position detection unit 119 includes a first detection unit 119a and a second detection unit 119b, and detects the protruding state of the foot 60 in two stages based on the detection signal of the push switch 350 (FIG. 9A, etc.). reference).

  As shown in FIGS. 9A and 9B, the press switch 350 of the projector 110 according to the present embodiment includes a first press switch 150 and a second press switch 250. The first push switch 150 has the same structure as the push switch 50 shown in FIG. 4 and the like, and includes a first switch base portion 150a and a first switch base portion 150b. The second push switch 250 includes a second switch base part 250a provided on a plate part CC extending vertically inward from the bottom part BP, and a second button 250b provided so as to protrude from the switch base part 250a. Like the first button 150b, the second button 250b is always urged laterally by a spring (not shown) incorporated in the second push switch 250, and is pushed sideways against the urging force. It is possible.

  The plate part CC extends along the bolt part 81 b, and the second switch base part 250 a is installed at a substantially intermediate position between the first pressing switch 150 and the holding part 82. More specifically, the foot 60 is in the maximum protruding state when the stopper ST provided adjacent to the upper end portion 60a contacts the holding portion 82, and the second switch base portion 250a has the maximum protruding state. The second button 250b is installed at a position intermediate between the position of the upper end 60a in the state and the position of the upper end 60a in the stored state. The 2nd button 250b has the smooth convex top part TP, and the top part TP is located on the course of the bolt part 81b. As a result, for example, as shown in FIG. 9A, when the bolt portion 81b is raised by the distance T1 from the housed state and the distance from the installation surface PS to the bottom portion BP becomes the distance D1, the second pressure switch 250 The button 250b is pushed and pushed sideways (-Z direction) by the side surface portion 60b of the bolt 81b, and at this time, the second push switch 250 is turned on. At this time, the first pressing switch 150 is in an OFF state. Here, when the foot 60 is in such a state, it is assumed that the foot 60 is in the first position. Further, as shown in FIG. 9B, the foot 60 is further lowered, that is, protruded from the case shown in FIG. 9A, and the bolt part 81b is raised by the distance T2 from the stored state, and the bottom part from the installation surface PS. When the distance to the BP is the distance D2, the second button 250b protrudes to the side (+ Z side) by the bias of the spring, and the second push switch 250 is turned off. At this time, the first pressing switch 150 is also in an OFF state. Here, when the foot 60 is in such a state, it is assumed that the foot 60 is in the second position where the protruding amount is larger than the first position. Of the foot position detection unit 119 of FIG. 8, the first detection unit 119a detects that the foot 60 is at the first position shown in FIG. That is, it is detected that the first push switch 150 is off and the second push switch 250 is on. The second detection unit 119b detects that the foot 60 is at the second position shown in FIG. That is, it is detected that both the first and second pressing switches 150 and 250 are in the off state. If both the first and second pressing switches 50 and 150 are in the on state, detection is not performed in any of the first and second detection units 119a and 119b, and the foot position detection unit 119 has the foot 60 in the storage position. Is detected. In FIG. 8, is the foot position detection unit 119 located at the storage position, the first position that is an intermediate position protruding to some extent, or the second position that is a position protruding largely? The detection result is transmitted to the control unit 11.

  Hereinafter, the projection operation by the projector according to the present embodiment will be described with reference to FIG. First, the control unit 11 detects the position of the foot 60 from the foot position detection unit 19 (steps S211 to S213), and when it is determined that the foot 60 is in the storage position (step S214: Y), it is shown in FIG. As described above, the control unit 11 outputs an instruction to the image processing unit 15 as the correction amount determination unit 11c, and cancels or resets the trapezoid correction processing by the trapezoid correction unit 15a (step S232). That is, the keystone correction by the image processing unit 15 is reset, the keystone correction amount becomes zero, and the keystone correction process is performed (step S233).

  On the other hand, when it is determined in step S214 in FIG. 10 that the first push switch 150 is off, that is, the foot 60 is not in the storage position (step S214: N), the control unit 11 reads the correction amount reading unit 11b. The information about the position of the foot 60 at the time of the front trapezoidal correction amount is read from the nonvolatile memory 12c of the storage unit 12 (step S50), and the information about the current position of the foot 60 is read (step S51). That is, the on / off states of the first and second press switches 150 and 250 at the time of the front trapezoidal correction amount and the current time are read out. Next, as shown in FIG. 11, the control unit 11 compares the positions of both feet 60 read in steps S50 and S51, that is, whether the difference between the positions of both feet 60 is within an allowable range. Judgment is made (step S52). In step S52, if the difference in the position of the foot 60 between step S50 and step S51 is within an allowable range (step S52: Y), projection may be performed in a state that is equal to or similar to the previous trapezoidal correction state. Therefore, it is thought that the correction work is quicker if the previous trapezoid correction state is maintained. Therefore, the control unit 11 reads the front keystone correction amount (step S53), and causes the keystone correction process to be performed with the front keystone correction amount (step S233). Here, as an example of the determination method within the allowable range in step S52, the determination is made based on whether or not the position of the foot 60 (specifically, the first position or the second position) matches. To do. In other words, when the on / off states of the first and second pressing switches 150 and 250 at the front trapezoidal correction amount and the current state all match, the difference in the position of the foot 60 is within an allowable range. Judgment is made (step S52: Y). If they do not match, it is judged that the difference in the position of the foot 60 is not within the allowable range (step S52: N).

  If it is determined in step S52 that the difference in the position of the foot 60 is not within the allowable range (step S52: N), the control unit 11 reads the current position of the foot 60 again (step S54). Is determined to be in the first position (step S54: (1)), a first correction amount that is a predetermined medium correction amount is read from the nonvolatile memory 12c (step S54). A trapezoidal correction process is performed with the correction amount (step S233). On the other hand, if it is determined in step S54 that the foot 60 is in the second position (step S53: (2)), the second correction amount having a correction amount larger than the first correction amount is read from the nonvolatile memory 12c. (Step S55), the keystone correction process is performed with the second correction amount (Step S233).

  After the trapezoid correction process in step S233, the control unit 11 determines whether or not the keystone correction amount by the keystone correction unit 15a has been changed by the user's key input (step S222), and the keystone correction amount is appropriately stored in the nonvolatile memory. 12c (step S223), and this operation is repeated until the user gives an instruction to end projection (step S224). When there is an instruction to end projection from the user, the control unit 11 stores the current signal processing state in the nonvolatile memory 12c of the storage unit 12 to stop the operation of the image processing unit 15, and the lamp of the video projection unit 17 The driving operation is stopped and the lamp is turned off (step S225). In the present embodiment, in step S223, in addition to the trapezoidal correction amount, information on the position of the foot 60 at this time, that is, the foot 60 is stored in the storage position, the first position, and the second position as appropriate. Information on where the location is is also stored.

[Other modifications]
Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments, and can be implemented in various modes without departing from the gist thereof. Such modifications are also possible.

  In the above embodiment, when it is determined that the foot 60 is stored, the control unit 11 reduces the trapezoid correction amount by the trapezoid correction unit to zero, but does not set the trapezoid correction amount to zero. It is also possible to set a predetermined value in consideration of the use environment and the like.

  Moreover, although the position detection of the foot 60 is performed by the pressing switch, the position detection can be performed by various things other than the pressing switch such as a proximity sensor. Further, by appropriately determining the position where the push switch is turned on, for example, not only when the foot 60 is in the fully retracted position but also in the retracted position if it is within a certain range from the fully retracted position. It can also be judged.

  Moreover, in the said 2nd Embodiment, although the one press switch 150 is used on the board part CC for the position detection of the foot 60, in order to increase the number of steps of the position detection of the foot 60 further, on the board part CC. It is also possible to increase the number of push switches installed in the. It is also possible to accurately detect the position of the foot 60 (for example, the distance from the button 50 to the upper end 60a) using a potentiometer or the like. In this case, as shown in the flowchart of FIG. 12, when it is determined in step S314 that the foot 60 is not in the retracted position (step S314: N), the control unit 11 corrects the front keystone accurately measured by the potentiometer. The position of the foot 60 in the amount and the current position of the foot 60 are read out (steps S60 and S61), and the trapezoidal correction amount can be determined based on whether or not the difference between the two distances is within an allowable value ( Step S62). That is, if the difference between the distances is within the allowable value, the previous keystone correction amount is read (step S63), and if not, the keystone correction process is canceled or reset (step S332), and the keystone correction process is performed. (Step S333). Other processes (steps S311 to S313, S322 to S325) are the same as those in the first embodiment. In this case, an allowable value needs to be determined in advance (for example, set within ± several mm) and stored in the storage unit 12.

  Further, in the above embodiment, the upper keystone correction and the lower keystone correction can be performed by the trapezoid correction unit 15a of the image processing unit 15. However, the keystone correction can also be performed on the left and right by the trapezoid correction unit 15a. . In this case, not only the upper and lower keystone corrections but also the left and right keystone corrections are determined to have allowable values, and it is determined that the amount of front keystone correction exceeds a predetermined allowable value after startup or after signal processing changes. In this case, the trapezoid correction amount by the trapezoid correction unit 15a can be set to zero.

  Further, in the above-described embodiment, for example, rewritable data such as information relating to the keystone correction performed by the keystone correction unit 15a of the image processing unit 15 is stored in the nonvolatile memory 12c. Data storage is not necessarily stored in a non-volatile memory. For example, when the power is turned on, the data can be stored in the RAM 12b of the storage unit, and the data can be stored by a volatile memory with a backup power source for storing the data.

  Moreover, although the projector 10 which projects using a lamp as a light source was illustrated in the said embodiment, it can apply also to the projector which projects using a LED light source, a laser light source, etc. as a light source.

  DESCRIPTION OF SYMBOLS 10,110 ... Projector, 11 ... Control part (correction amount control part), 11a ... Foot position reading part, 11b ... Correction amount reading part, 11c ... Correction amount determination part, 11d ... Correction amount storage control part, 12 ... Storage part 12c ... Nonvolatile memory, 13 ... Key input processing unit, 14 ... Input selection unit, 15 ... Image processing unit, 15a ... Trapezoid correction unit, 17 ... Video projection unit, 17a ... Liquid crystal panel drive unit, 18 ... Communication unit, 19, 119 ... foot position detection unit, 119a ... first detection unit, 119b ... second detection unit, 24 ... projection amount adjusting device, 28 ... key operation unit, 28a ... power button, 28b ... input switching button, 28c ... menu 29f, 29g ... keystone correction button, 29h ... zoom button, 41 ... connector, 50 ... push switch, 60 ... foot, SC Housing (case section)

Claims (9)

A video projection unit for projecting an image;
A trapezoid correction unit that performs a keystone correction process on the image projected on the video projection unit;
A housing for housing a main body including the video projection unit;
A foot that supports the housing in an inclined state by protruding from the housing;
A foot position detector that detects at least that the foot is in the storage position with the smallest protrusion amount;
A correction amount control unit that performs control to suppress keystone correction by the keystone correction unit when the foot position detection unit detects that the foot is in the storage position;
A projector comprising:   The projector according to claim 1, wherein the correction amount control unit reduces a trapezoid correction amount by the trapezoid correction unit when it is detected that the foot is in the storage position at the time of activation.   The foot position detection unit continues detection until a predetermined time elapses from the start of image projection, and the correction amount control unit accepts a detection result by the foot position detection unit when the predetermined time elapses as a final result. The projector according to claim 2, characterized in that:   The correction amount control unit causes the trapezoid correction amount by the trapezoid correction unit to be zero when the foot position detection unit detects that the foot is in the storage position. The projector according to any one of Items 3 to 3. A storage unit for storing a keystone correction amount immediately before the stop of image projection;
The correction amount control unit determines the trapezoid correction amount by the trapezoid correction unit based on the trapezoid correction amount stored in the storage unit when the foot position detection unit detects that the foot is not in the storage position. The projector according to any one of claims 1 to 4, wherein the projector is adjusted.   The correction amount control unit changes the trapezoid correction amount by the trapezoid correction unit stepwise toward zero or a predetermined reference value when the foot position detection unit detects that the foot is in the storage position. The projector according to claim 5, wherein: The storage unit stores the detection result of the foot position detection unit corresponding to the trapezoidal correction amount immediately before the stop of image projection,
The correction amount control unit causes the video projection unit to display the trapezoid correction amount corresponding to the detection result by the foot position detection unit, and enables selection of whether or not to maintain the trapezoid correction amount. The projector according to claim 5. The foot position detector includes a first detector that detects that the foot is in a first position having a larger protruding amount than the storage position, and a second that has a larger protruding amount than the first position. And a second detection unit that detects being at the position of 2,
The correction amount control unit is configured such that the foot is in the second position by the second detection unit as compared to the trapezoidal correction amount when the foot is determined to be in the first position by the first detection unit. The projector according to any one of claims 1 to 7, wherein a trapezoidal correction amount is increased when it is determined. A video projection unit that projects an image, a trapezoid correction unit that performs a keystone correction process on an image that is projected on the video projection unit, and an inclination of the case by protruding from a case that houses a main body including the video projection unit An image projection method using a projector having a foot to support in a state in which
A foot position detection step for detecting that the foot is in the storage position with the smallest protrusion amount;
A correction amount control step for performing control for suppressing keystone correction when the foot position detection step detects that the foot is in the storage position; and
An image projection method comprising:

Images