JP2008089720A - Projector and keystone distortion correction method for projector - Google Patents

Abstract

A projector and a method for correcting a trapezoidal distortion of a projector capable of automatically correcting a trapezoidal distortion at low cost.
A projector includes an adjustment leg configured to freely move back and forth, and changing a tilt state of the projector; a reflecting member provided on a surface intersecting a moving direction of the adjustment leg; and a light emitting device. , A light receiving device 92 that receives light emitted from the light emitting device 91 and reflected by the reflecting member 8 and outputs an electrical signal; a trapezoidal distortion correction indicating a relationship between the voltage signal and the trapezoidal distortion correction amount of the projected image; A storage unit 54 that stores amount information; a trapezoidal distortion correction unit 521 that calculates a trapezoidal distortion correction amount from the trapezoidal distortion correction amount information based on the voltage signal output from the light receiving device 92 and corrects the trapezoidal distortion of the projected image; Is provided. Since the keystone distortion correction amount is obtained using the light emitting device 91, the light receiving device 92, and the reflecting member 8, the keystone distortion correction processing can be realized automatically at a low cost.
[Selection] Figure 1

Description

  The present invention relates to a projector and a trapezoidal distortion correction method for the projector.

In the projector, trapezoidal distortion occurs in the projected image due to the inclination of the housing at the time of installation. Such trapezoidal distortion has been corrected by a user by operating a button, but in recent years, a method of automatically correcting it has also been adopted.
For example, there is a method in which a distance sensor for measuring the distance between the projector and the screen is incorporated in the projector, the tilt angle of the projector with respect to the screen is detected based on the output of the distance sensor, and the trapezoidal distortion is corrected according to the tilt angle. It is known (see, for example, Patent Document 1).
A method is also known in which an acceleration sensor is arranged in the projector to detect the tilt of the projector and correct the trapezoidal distortion of the projected image (see, for example, Patent Document 2).

JP 2000-122617 A JP 2003-283963 A

  However, these methods have a problem in that expensive parts such as a distance sensor and an acceleration sensor must be incorporated, resulting in an increase in cost. For this reason, particularly in projectors, it is difficult to incorporate into a low-priced popular machine in terms of cost, and the popular machine cannot automatically incorporate a trapezoidal distortion correction function (auto keystone function). was there.

  An object of the present invention is to provide a projector and a method for correcting a trapezoidal distortion of a projector that can automatically and automatically perform a trapezoidal distortion correction.

  The projector of the present invention is a projector that modulates and projects a luminous flux emitted from a light source according to image information, and is configured to be able to advance and retreat into and out of the exterior casing, and to adjust the tilt state of the projector; A reflecting member provided on a surface intersecting the advancing and retreating direction in the adjustment leg, a light emitting device that emits light toward the reflecting member, and light that is emitted from the light emitting device and reflected by the reflecting member is received. A light receiving device that outputs an electrical signal, a storage device that stores trapezoidal distortion correction amount information indicating a relationship between a voltage signal output from the light receiving device, and a trapezoidal distortion correction amount of a projected image, and the light receiving device. A trapezoidal distortion correction device for obtaining a trapezoidal distortion correction amount from the trapezoidal distortion correction amount information based on the output voltage signal, and correcting the trapezoidal distortion of the projected image using the trapezoidal distortion correction amount. And wherein the are.

According to the present invention, when the adjustment leg moves forward and backward, the reflecting member also moves, so that the distance between the reflecting member, the light emitting device, and the light receiving device also changes. As the distance changes, the amount of light emitted from the light emitting device, reflected by the reflecting member, and received by the light receiving device also changes, and the electrical signal output from the light receiving device also changes.
For this reason, the electrical signal output from the light receiving device changes in conjunction with the advance / retreat movement of the adjustment leg. Then, since the relationship between the advance / retreat amount of the adjustment leg, that is, the tilt state (angle) of the projector and the trapezoidal distortion correction amount of the projection image can be obtained in advance, the value of the voltage signal and the advance / retreat amount of the adjustment leg , The relationship between the value of the electric signal and the trapezoidal distortion correction amount can be grasped. Therefore, the trapezoidal distortion correction device projects the projection based on the value of the electrical signal output from the light receiving device by referring to the trapezoidal distortion correction amount information in which the relationship between the electrical signal value and the trapezoidal distortion correction amount is stored. The keystone distortion of the image can be automatically corrected.
Since the light-emitting device and the light-receiving device can be configured with parts that are less expensive than distance sensors and acceleration sensors such as light-emitting diodes and phototransistors, trapezoidal distortion correction can be performed automatically and inexpensively in a projector. For this reason, an auto keystone function can be installed even in a low-priced popular machine, adjustment work at the time of projector installation is reduced, and convenience can be improved.

  Further, since the reflecting member may be provided on the upper end surface of the adjusting leg portion, it is not necessary to perform special processing on the side surface of the adjusting leg portion. For this reason, the adjustment leg can use the existing member as it is, and the cost can be reduced as compared with the case where the special adjustment leg is used. In particular, the adjustment leg portion is often provided with a screw on the outer peripheral surface for fine adjustment, but the reflection member may be provided on the upper end surface of the adjustment leg portion. Even if it is, it can be applied and is highly versatile. Furthermore, since the reflecting member only needs to be provided on the upper end surface of the adjusting leg, the reflecting member is not exposed even when the adjusting leg protrudes to the outside of the exterior housing, and the design can be prevented from being reduced.

  The projector of the present invention is a projector that modulates and projects a luminous flux emitted from a light source according to image information, and is configured to be able to advance and retreat into and out of the exterior casing, and to adjust the tilt state of the projector; An interlocking device that displaces in conjunction with the advancing and retreating movement of the adjusting leg, a reflecting member provided on a surface that intersects the advancing and retracting movement direction in the interlocking device, and a light emitting device that irradiates light toward the reflecting member; A light receiving device that receives the light emitted from the light emitting device and reflected by the reflecting member and outputs an electrical signal, a trapezoid indicating the relationship between the voltage signal output from the light receiving device and the trapezoidal distortion correction amount of the projected image A trapezoidal distortion correction amount is obtained from the trapezoidal distortion correction amount information based on the storage device storing the distortion correction amount information and the voltage signal output from the light receiving device, and the trapezoidal distortion correction amount is used. Characterized in that it comprises a trapezoidal distortion correction apparatus for correcting trapezoidal distortion of the image morphism, the.

According to the present invention, when the interlocking device is displaced in conjunction with the advancement / retraction movement of the adjustment leg, the reflecting member also moves, so that the distance between the reflecting member, the light emitting device, and the light receiving device also changes. As the distance changes, the amount of light emitted from the light emitting device, reflected by the reflecting member, and received by the light receiving device also changes, and the electrical signal output from the light receiving device also changes.
For this reason, the electrical signal output from the light receiving device changes in conjunction with the advance / retreat movement of the adjustment leg. Then, since the relationship between the advance / retreat amount of the adjustment leg, that is, the tilt state (angle) of the projector and the trapezoidal distortion correction amount of the projection image can be obtained in advance, the value of the voltage signal and the advance / retreat amount of the adjustment leg , The relationship between the value of the electric signal and the trapezoidal distortion correction amount can be grasped. Therefore, the trapezoidal distortion correction device projects the projection based on the value of the electrical signal output from the light receiving device by referring to the trapezoidal distortion correction amount information in which the relationship between the electrical signal value and the trapezoidal distortion correction amount is stored. The keystone distortion of the image can be automatically corrected.
The light-emitting device and the light-receiving device can be configured with parts that are less expensive than distance sensors and acceleration sensors such as light-emitting diodes and phototransistors, and the interlocking device can also use inexpensive parts such as frames and springs. It is inexpensive and can automatically perform trapezoidal distortion correction. For this reason, an auto keystone function can be installed even in a low-priced popular machine, adjustment work at the time of projector installation is reduced, and convenience can be improved.

  Further, since the reflecting member may be provided on the interlocking member, it is not necessary to perform special processing or the like on the side surface of the adjustment leg. For this reason, the adjustment leg can use the existing member as it is, and the cost can be reduced as compared with the case where the special adjustment leg is used. In particular, the adjustment leg portion is often provided with a screw on the outer peripheral surface for fine adjustment, but the reflection member may be provided on the upper end surface of the adjustment leg portion. Even if it is, it can be applied and is highly versatile. Further, since the reflecting member may be provided on the interlocking member, the reflecting member is not exposed even when the adjustment leg protrudes outside the exterior casing, and the design can be prevented from being reduced.

  In the projector according to the aspect of the invention, the interlocking device is disposed inside the exterior housing and is guided in parallel with the advance / retreat direction of the adjustment leg, and is guided by the guide member. It is preferable that the reflective member is provided on a surface of the frame that is orthogonal to the moving direction of the frame.

  According to the present invention, when the adjustment leg part advances and retreats, the frame of the interlocking device is guided by the guide member to advance and retreat, and the reflection member provided on the frame also moves. As the reflecting member moves, the electrical signal value output from the light receiving device also changes. Therefore, the electrical signal value output from the light receiving device can detect the advance / retreat amount of the adjustment leg, that is, the tilt state of the projector, and correct the trapezoidal distortion. The amount can also be determined. Therefore, the keystone distortion correction of the projected image can be automatically performed.

In the projector according to the aspect of the invention, it is preferable that the interlock device includes an urging unit that makes the frame come into contact with an upper end portion of the adjustment leg portion.
Here, since the frame of the interlocking device only needs to be interlocked with the adjustment leg, for example, the adjustment leg and the frame may be connected with a connection pin or the like.
On the other hand, as in the present invention, when the frame is brought into contact with the upper end of the adjustment leg and is urged by the urging means, the frame can be interlocked with the adjustment leg with a very simple structure. Moreover, since it is not necessary to provide a special structure on the adjustment leg part side, it can be applied to an existing adjustment leg part, and is highly versatile and can reduce costs. Further, since the frame is brought into contact with the upper end portion of the adjustment leg by the urging means, even if the adjustment leg is caused by a screw or the like, the urging force of the urging means causes the Therefore, the value of the electric signal output from the light receiving device can be stabilized and the trapezoidal distortion correction process can be performed stably as compared with the case where the reflecting member is provided directly on the adjustment leg.

  A keystone distortion correction method for a projector according to the present invention is a method for correcting keystone distortion of a projector that modulates and projects a luminous flux emitted from a light source according to image information, and is configured to advance and retreat into and out of an exterior casing. An adjusting leg for changing the tilt state, a reflecting member provided on a surface intersecting the advancing / retreating movement direction in the adjusting leg, a light emitting device for irradiating light toward the reflecting member, and an irradiation from the light emitting device A light receiving device that receives light reflected by the reflecting member and outputs an electrical signal, a trapezoidal distortion correction device that corrects trapezoidal distortion of a projected image based on the electrical signal output from the light receiving device, and the light receiving device A trapezoidal distortion correction method for a projector, comprising: a storage device storing trapezoidal distortion correction amount information indicating a relationship between a voltage signal output from the keystone and a trapezoidal distortion correction amount of a projected image; Thus, a preparatory step for obtaining the keystone distortion correction amount information in advance and storing it in the storage device, and a trapezoid corresponding to an electric signal output from the light receiving device when the projector is installed by moving the adjustment leg forward and backward A trapezoidal distortion correction step of obtaining a distortion correction amount from the trapezoidal distortion correction amount information stored in the storage device and correcting the projected image with the trapezoidal distortion correction amount.

According to the present invention as described above, the same effects as the projector invention can be obtained. That is, when the adjustment leg (foot) moves back and forth, the trapezoidal distortion correction device refers to the trapezoidal distortion correction amount information, and based on the electrical signal output from the light receiving device, the trapezoidal distortion correction amount of the projected image The trapezoidal distortion of the projected image can be automatically corrected using this correction amount.
Since the light emitting device and the light receiving device are less expensive than the distance sensor and the acceleration sensor, the keystone distortion correction can be automatically performed at a low cost in the projector. For this reason, an auto keystone function can be installed even in a low-priced popular machine, adjustment work at the time of projector installation is reduced, and convenience can be improved.

  A keystone distortion correction method for a projector according to the present invention is a method for correcting keystone distortion of a projector that modulates and projects a luminous flux emitted from a light source according to image information, and is configured to advance and retreat into and out of an exterior casing. An adjustment leg that changes the tilt state, an interlocking device that displaces in conjunction with the advance and retreat movement of the adjustment leg, a reflection member that is provided on a surface that intersects the advancing and retreating direction of the interlocking device, and the reflection member A light emitting device that emits light toward the light source, a light receiving device that receives light emitted from the light emitting device and reflected by the reflecting member, and outputs an electrical signal; and a projection based on the electrical signal output from the light receiving device. A trapezoidal distortion correction device that corrects trapezoidal distortion of an image, trapezoidal distortion correction amount information indicating a relationship between a voltage signal output from the light receiving device and a trapezoidal distortion correction amount of a projection image is stored. A trapezoidal distortion correction method for a projector comprising a storage device, wherein a preparatory step of obtaining the keystone distortion correction amount information in advance and storing it in the storage device, and when the projector is installed by moving the adjustment leg forward and backward A trapezoidal distortion correction amount corresponding to the electrical signal output from the light receiving device is obtained from the trapezoidal distortion correction amount information stored in the storage device, and a trapezoidal distortion correction step of correcting the projected image with the trapezoidal distortion correction amount; It is characterized by providing.

According to the present invention as described above, the same effects as the projector invention can be obtained. That is, when the adjustment leg (foot) moves back and forth and the interlocking device is displaced, the trapezoidal distortion correction device refers to the trapezoidal distortion correction amount information and projects based on the electrical signal output from the light receiving device. The trapezoidal distortion correction amount of the image can be obtained, and the trapezoidal distortion of the projected image can be automatically corrected using this correction amount.
The interlocking device can be composed of inexpensive parts such as frames and springs, and the light emitting device and light receiving device are also cheaper than distance sensors and acceleration sensors. It can be performed. For this reason, an auto keystone function can be installed even in a low-priced popular machine, adjustment work at the time of projector installation is reduced, and convenience can be improved.
Further, since the interlocking device is provided, the adjustment leg can use the existing member as it is, and the cost can be reduced as compared with the case where the special adjustment leg is used.

[First embodiment]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings.
[Schematic configuration of projector]
FIG. 1 is a block diagram showing a schematic configuration of a projector 1 in the first embodiment.
The projector 1 modulates light emitted from a light source according to image information to form an optical image, and enlarges and projects the formed optical image on a screen.
As shown in FIG. 1, the projector 1 includes an operation unit 2 as a setting input unit, a power supply unit 3, an image forming unit 4, a control device 5, an adjustment leg unit 6, an interlocking device 7, a reflection device. The member 8, the light emitting device 91, and the light receiving device 92 are roughly configured.

The operation unit 2 includes a remote controller (not shown) and buttons and keys provided in the projector 1. The operation unit 2 recognizes an operation by the user and outputs a predetermined operation signal to the control device 5. As shown in FIG. 1, the operation unit 2 includes a trapezoidal distortion correction operation unit 21 and the like. In FIG. 1, an input unit that performs ON / OFF of the projector 1 in the operation unit 2, an input unit that performs volume adjustment, an input unit that performs image quality adjustment of the projection image, and an input that performs focus adjustment of the projection image The other input units such as the input unit and the input unit that performs zoom adjustment of the projection image are not shown.
The trapezoidal distortion correction operation unit 21 is an input button used when the user manually adjusts the trapezoidal distortion correction. The trapezoidal distortion correction operation unit 21 recognizes an input operation by the user and outputs a predetermined operation signal as a trapezoidal distortion correction amount to the control device 5.

  The power supply unit 3 supplies power supplied from the outside to each unit of the projector 1. Although not shown in the figure, for example, the power source unit 3 is a main power source that supplies power supplied from the outside to each unit of the projector 1 and a state in which the main power source is turned off by the operation of the operation unit 2 by the user (standby state). ), A sub power source that supplies power supplied from the outside only to the control device 5 of the projector 1 and the like.

  The image forming unit 4 forms an optical image and enlarges and projects it on a screen under the control of the control device 5. Although not shown, the image forming unit 4 includes a light source device including a light source lamp such as an ultrahigh pressure mercury lamp, a liquid crystal light valve as a light modulation device including a transmissive liquid crystal panel, a projection lens, and the like. It is a general one provided with a projection optical device and the like.

  As shown in FIGS. 2 and 3, the adjustment leg portion 6 is provided at the front center portion of the bottom surface portion of the projector 1. The adjustment leg 6 is configured to be able to move forward and backward in and out of the outer casing of the projector 1, and when the projector 1 is installed in a normal posture, the tip portion is grounded to a grounding surface such as a desk and moves forward and backward. 1 is changed in the vertical inclination state. As a result, the position of the projected image on the screen Sc moves up and down.

As shown in FIG. 4, the adjustment leg 6 includes a foot 61, a box 621 through which the foot 61 is inserted, and an operation lever 622. The foot 61 includes a shaft portion 611 formed in a substantially rod shape, and a cap 612 attached to the lower end of the shaft portion 611. A screw (not shown) is formed on the outer peripheral surface of the shaft portion 611.
The operation lever 622 can be manually operated in the vertical direction with respect to the box 621. When the operation lever 622 is disposed below, the operation lever 622 engages with the screw of the foot 61. The screw 61 is disengaged. For this reason, when the operation lever 622 is operated upward, the foot 61 can freely move up and down with respect to the box 621, the advancing / retreating position of the foot 61 can be largely changed, and so-called coarse adjustment can be performed. In the state where the operation lever 622 is returned downward, the advance / retreat position of the foot 61 can be finely adjusted by the action of the screw by rotating the foot 61 around the axis.

  The interlocking device 7 is provided in the housing of the projector 1 so as to be linearly movable along the shaft 75, which is disposed beside the foot 61 and along the forward / backward direction of the foot 61. A frame 76 and a coil spring 72 that urges the frame 76 to contact the upper end of the foot 61 are provided.

More specifically, the frame 76 includes a guide portion 761 inserted through the shaft 75 and a contact portion 762 that is formed continuously with the guide portion 761 and contacts the upper end of the foot 61. Yes. The upper surface of the contact portion 762 is formed in a direction orthogonal to the moving direction of the foot 61 and the frame 76.
The coil spring 72 is inserted into the shaft 75 and pressed against the upper end of the guide portion 761 to urge the frame 76 downward, that is, toward the foot 61.

  The reflection member 8 is configured by a reflection plate attached to the upper surface of the contact portion 762. As the reflector, a reflector made of various materials capable of reflecting light, such as a metal such as aluminum, glass, and synthetic resin can be used.

  The light emitting device 91 includes a light emitting diode (LED) that emits light such as visible light and infrared light.

The light receiving device 92 includes an illuminance sensor (light receiving element) such as a phototransistor or a photodiode.
Therefore, the light receiving device 92 receives the light emitted from the light emitting device 91 and reflected by the reflecting member 8, and outputs an electrical signal corresponding to the amount of the reflected light. Since the amount of reflected light varies depending on the distance between the light emitting device 91 and the light receiving device 92 and the reflecting member 8, the foot 61 and the frame 76 move forward and backward, and the reflecting member 8 moves relative to the light emitting device 91 and the light receiving device 92. The electric signal output from the light receiving device 92 also changes. For this reason, the position of the foot 61 can be indirectly detected by the electrical signal output from the light receiving device 92.
Here, the relationship between the value of the electric signal output from the light receiving device 92 and the position of the foot 61 is determined by measuring the value of the electric signal output from the light receiving device 92 while actually moving the foot 61. You only have to figure it out.

The control device 5 includes an arithmetic processing device such as a CPU (Central Processing Unit) and executes a predetermined program to control the power supply unit 3, the image forming unit 4, the light emitting device 91, the light receiving device 92, and the like. Then, the control device 5 controls the image forming unit 4 to form an image corresponding to the image signal input from the external device 10 or the like and project it on the screen.
As shown in FIG. 1, the control device 5 includes a signal input unit 51, a liquid crystal panel drive control unit 52 as a display control device, a frame memory 53, and a storage unit (storage device) 54.

The signal input unit 51 inputs image signals and the like output from various external devices, converts them into image signals that can be processed by the liquid crystal panel drive control unit 52, and outputs them. The image signal (digital image signal) output from the signal input unit 51 is temporarily recorded in the frame memory 53 as image data for each frame, for example.
The liquid crystal panel drive control unit 52 appropriately reads the image data output from the signal input unit 51 and sequentially stored in the frame memory 53, performs a predetermined process on the read image data, and corresponds to the processed image A drive signal as image information to be output is output to the liquid crystal light valve of the image forming unit 4 to form a predetermined optical image. Examples of the predetermined processing in the liquid crystal panel drive control unit 52 include image size adjustment processing such as enlargement / reduction, trapezoidal distortion correction processing, image quality adjustment processing, and gamma correction processing. Note that image size adjustment processing such as enlargement / reduction, image quality adjustment processing, and gamma correction processing are well-known techniques, and thus will not be described in detail. Only trapezoidal distortion correction processing will be described below. As shown in FIG. 1, the liquid crystal panel drive control unit 52 includes a trapezoidal distortion correction unit (trapezoidal distortion correction device) 521 and a panel drive unit 522.

  The trapezoidal distortion correction unit 521 refers to trapezoidal distortion correction amount information (to be described later) stored in the storage unit 54, and trapezoidal distortion correction corresponding to the value (voltage value, current value, etc.) of the electric signal output from the light receiving device 92. Find the amount. Then, the trapezoidal distortion correction unit 521 performs a trapezoidal distortion correction process for a projected image that occurs when the projector 1 performs a tilt projection on the image data read from the frame memory 53 based on the calculated trapezoidal distortion correction amount. carry out. In the trapezoidal distortion correction process, for example, a digital process is performed in which the number of pixels in the scanning line is changed in units of a predetermined scanning line or the time axis is changed.

  The panel drive unit 522 outputs drive signals corresponding to the image data and black image data output from the trapezoidal distortion correction unit 521 to the liquid crystal light valve. The liquid crystal light valve forms an optical image that has been subjected to the trapezoidal distortion correction process in accordance with the drive signal.

  The trapezoidal distortion correction process is automatically performed by the trapezoidal distortion correction unit 521. However, when the user operates the trapezoidal distortion correction operation unit 21 in addition to the trapezoidal distortion correction process, the trapezoidal distortion correction process is performed. The trapezoidal distortion correction unit 521 performs the correction process by adjusting the trapezoidal distortion correction amount according to the operation amount.

As shown in FIG. 1, the storage unit 54 includes a trapezoidal distortion correction amount information storage unit 541. The trapezoidal distortion correction amount information storage unit 541 includes the advance / retreat position of the foot 61 of the adjustment leg 6 that is indirectly detected by the value of the electrical signal output from the light receiving device 92 and the value of the electrical signal (advance / retreat position). In this case, the keystone distortion correction amount information associated with the keystone distortion correction amount for correcting the keystone distortion of the projected image is stored.
This trapezoidal distortion correction amount information may be stored in, for example, a lookup table format or a function format.

[Keystone distortion correction method for projectors]
Next, the trapezoidal distortion correction method for the projector 1 described above will be described.
(Preparation process)
The keystone distortion correction amount information storage unit 541 of the projector 1 stores keystone distortion correction amount information in advance. Normally, when the projector 1 is manufactured, the relationship between the tilt angle of the projector and the trapezoidal distortion amount is inspected, and the relationship between the value of the electrical signal of the light receiving device 92 corresponding to the position of the foot 61 and the trapezoidal distortion correction amount is obtained. This information is stored in the trapezoidal distortion correction amount information storage unit 541.

(Keystone distortion correction process)
When setting to use the projector 1, the user operates the operation lever 622 to advance and retract the foot 61 by coarse movement, and rotates the cap 612 of the foot 61 to perform fine movement adjustment.
When the foot 61 of the adjusting leg 6 is advanced and retracted, the frame 76 of the interlocking device 7 moves in conjunction with it.
As a result, the distance between the light emitting device 91, the light receiving device 92, and the reflecting member 8 changes, so that the amount of light emitted from the light emitting device 91 and reflected by the reflecting member 8 and received by the light receiving device 92 also changes. The value of the electrical signal output from the light receiving device 92 varies.

The trapezoidal distortion correction unit 521 of the liquid crystal panel drive control unit 52 refers to the value of the electric signal output from the light receiving device 92 and the trapezoidal distortion correction amount information stored in the trapezoidal distortion correction amount information storage unit 541, and A trapezoidal distortion correction amount corresponding to the electric signal value is obtained.
Then, the trapezoidal distortion correction unit 521 performs the above-described trapezoidal distortion correction process according to the obtained trapezoidal distortion correction amount.

FIG. 5 is a diagram illustrating a specific example of the trapezoidal distortion correction process by the trapezoidal distortion correction unit 521.
For example, as shown in FIGS. 2 and 3, when vertical tilt projection is performed with the projector 1 tilted to project an image upward, the optical axis of the light projected from the projector 1 Is inclined with respect to the normal direction of the screen Sc plane, and as shown in FIG. 5A, the upper width of the projected image 100 projected on the screen Sc is wide and the lower width is narrow. At this time, the trapezoidal distortion correction unit 521 makes the projection image 100 a projection image 100 ′ without distortion according to the trapezoidal distortion correction amount obtained based on the value of the electric signal output from the light receiving device 92. The trapezoidal distortion correction process is performed on the image data read from the frame memory 53. In the trapezoidal distortion correction process, as shown in FIG. 5B, the upper width of the formation region 421 that forms the optical image on the liquid crystal light valve by predistorting in the opposite direction to the distortion state of the projected image 100 is set. Longitudinal distortion correction is performed to form a correction formation region 422 that is narrow and wide on the lower side. In addition, the trapezoidal distortion correction unit 521 masks the formation area 421 by putting the area 423 excluding the correction formation area 422 into a blanking state. As a result, the trapezoidal distortion is corrected, and a projection image without distortion is projected onto the screen Sc.

The first embodiment having such a configuration has the following effects.
(1) Interlocking device 7 interlocked with the advance / retreat movement of the adjusting leg 6, a reflecting member 8 that moves together with the interlocking device 7, a light emitting device 91 that changes the distance from the reflecting member 8 as the interlocking device 7 moves, Since the device 92 is provided, the advance / retreat amount of the adjusting leg 6, that is, the tilt angle of the projector 1 can be detected by the value of the electric signal output from the light receiving device 92. Then, the trapezoidal distortion correction unit 521 can perform the trapezoidal distortion correction process with the trapezoidal distortion correction amount obtained according to the value of the electric signal with reference to the trapezoidal distortion correction amount information storage unit 541.
Therefore, it is not necessary to provide a distance sensor or an acceleration sensor as in the prior art, and the light emitting device 91, the light receiving device 92, and the reflecting member 8 are used which are cheaper than these sensors, and the interlocking device 7 is also the frame 76. In addition, since the auto keystone operation can be realized with a simple configuration, the cost can be reduced, and the auto keystone function can be mounted even in a low-priced popular machine.

(2) The reflective member 8 is not directly attached to the foot 61, but is attached to the interlocking device 7, and there is no need to provide a special configuration for the foot 61. Therefore, the adjustment leg 6 can use an existing member as it is, Therefore, it can be provided at a lower cost. Furthermore, since it is not necessary to perform special processing etc. on the foot 61, even when the foot 61 protrudes outside the exterior housing, the design is not deteriorated and the design can be improved.
Further, since the contact portion 762 of the interlocking device 7 can be formed with a larger area than the upper end surface of the shaft portion 611, the reflecting member 8 attached to the contact portion 762 can also have a relatively large area, The light from the light emitting device 91 can be reliably reflected and received by the light receiving device 92.

(3) Since the frame 76 is moved forward and backward in the same direction as the foot 61, it can be disposed close to the adjustment leg 6, and the projector 1 can be easily assembled into the exterior housing.
Furthermore, since the movement amount of the foot 61 and the frame 76 is the same, if the movement amount of the frame 76 and the fluctuation amount of the electric signal value output from the light receiving device 92 are measured, the movement amount of the foot 61 is directly measured. Since the relationship is with the fluctuation amount of the electric signal value, the relationship between the electric signal value and the trapezoidal distortion correction amount can be easily obtained.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
The projector 1 of the second embodiment is different from the first embodiment in that the interlocking device 7 is not provided and the reflecting member 8 is directly attached to the foot 61, and the other configurations are the same. For this reason, in the following description, the same structure and the same member as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted or simplified.

That is, in the second embodiment, the reflecting member 8 is attached to the upper end surface of the shaft portion 611 of the foot 61. The light receiving device 92 is arranged at a position where it can receive the reflected light irradiated from the light emitting device 91 and reflected by the reflecting member 8.
Also in such 2nd Embodiment, if the foot 61 of the adjustment leg part 6 is moved forward and backward, the reflection member 8 will move. For this reason, since the distance between the reflecting member 8 and the light emitting device 91 and the light receiving device 92 changes, the value of the electric signal output from the light receiving device 92 also fluctuates. Corresponding value. Accordingly, as in the first embodiment, the trapezoidal distortion correction unit 521 obtains the trapezoidal distortion correction amount according to the electric signal value from the trapezoidal distortion correction amount information storage unit 541, and executes the trapezoidal distortion correction process with this correction amount. To do.

In the second embodiment as described above, the same operational effects as (1) of the first embodiment can be obtained.
(4) Furthermore, since the interlocking device 7 is not provided and the reflecting member 8 is directly attached to the foot 61, the number of parts can be reduced and the cost can be further reduced.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above embodiment, the trapezoidal distortion correction amount information storage unit 541 of the storage unit 54 stores the keystone distortion correction amount information in advance when the projector 1 is manufactured. It may be configured to input or correct by operating.
For example, depending on the use environment of the user, a generally assumed state in which the screen Sc is inclined with respect to the vertical direction, or the part where the projector 1 is installed is slightly inclined with respect to the horizontal direction. And may be different. The trapezoidal distortion correction amount information stored at the time of manufacture of the projector 1 is set in a general usage environment, that is, a condition in which the screen Sc is arranged vertically and the projector 1 is installed on a horizontal plane. In other words, even if the advance / retreat position of the foot 61 is grasped by the value of the electric signal output from the light receiving device 92 and the trapezoidal distortion correction processing is performed with the trapezoidal distortion correction amount corresponding to the value, the correction may be insufficient. There is.
In such a case, the user manually operates the keystone distortion correction operation unit 21 to correct the keystone distortion. Therefore, at this time, the trapezoidal distortion correction unit 521 stores the correction amount manually performed in the trapezoidal distortion correction amount information storage unit 541 so that the trapezoidal distortion correction amount with respect to the value of the electric signal can be corrected from the next time. You may keep it. According to such a configuration, there is an advantage that a trapezoidal distortion correction process according to the usage status of each user can be performed, and correction with higher accuracy can be automatically performed after manual adjustment.

The interlocking device 7 is not limited to the one provided with the frame 76 and the coil spring 72. For example, an interlocking device in which the frame is connected to the foot with a connecting pin may be used.
The position where the reflecting member 8 is installed is not limited to the above-described embodiments. In the foot or the interlocking device, the reflecting member 8 is moved in conjunction with the movement of the foot 61, and the light emitting device 91 and the light receiving device 92 are associated with the movement. It may be installed at a position where the distance of fluctuates. That is, the reflecting member 8 should just be provided in the surface which cross | intersects with respect to the moving direction of the foot 61 or the interlocking device 7 at least. At this time, it is preferably provided on a surface orthogonal to the moving direction, but not necessarily a surface orthogonal to the moving direction, and may be provided on a surface inclined with respect to the moving direction. In short, the reflecting member 8 may be installed at a position where the distance between the light emitting device 91 and the light receiving device 92 varies and the light from the light emitting device 91 can be reflected and received by the light receiving device 92.
In each of the above embodiments, the projector 1 uses a liquid crystal light valve as the light modulation device. However, a light modulation device other than liquid crystal, such as a device using a micromirror, may be used.

Although the best configuration for carrying out the present invention has been disclosed in the above description, the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but it is not intended to depart from the technical concept and scope of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations.
Therefore, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

  Since the projector of the present invention can automatically and inexpensively correct the trapezoidal distortion of the image projected on the screen, it is useful as a low-priced projector for use in presentations and home theaters.

1 is a block diagram showing a schematic configuration of a projector according to a first embodiment. The side view which shows typically the projection state of the projector in the said embodiment. The perspective view which shows typically the projection state of the projector in the said embodiment. The perspective view which shows the structure of the adjustment leg part in the said embodiment, a reflection member, a light-emitting device, and a light-receiving device. The figure which shows the specific example of the trapezoid distortion correction process in the said embodiment. The figure which shows schematic structure of the adjustment leg part in 2nd Embodiment, a reflection member, a light-emitting device, and a light-receiving device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector, 2 ... Operation part, 3 ... Power supply part, 4 ... Image formation part, 5 ... Control apparatus, 6 ... Adjustment leg part, 7 ... Interlocking apparatus, 8 ... Reflective member, 21 ... Trapezoid distortion correction operation part, 51 Signal input unit 52 Liquid crystal panel drive control unit 53 Frame memory 54 Memory unit 61 Foot 62 Foot button 72 Coil spring 75 Shaft 76 Frame 91 Light emitting device 92 ... Light receiving device, 521... Trapezoidal distortion correction unit, 522... Panel drive unit, 541.

Claims (6)

A projector that modulates and projects a luminous flux emitted from a light source according to image information,
An adjustment leg that is configured to be movable back and forth inside and outside the exterior housing, and changes the tilt state of the projector;
A reflective member provided on a surface intersecting the advancing and retreating movement direction in the adjustment leg,
A light emitting device that emits light toward the reflecting member;
A light receiving device that receives light emitted from the light emitting device and reflected by the reflecting member and outputs an electrical signal; and
A storage device storing trapezoidal distortion correction amount information indicating a relationship between the voltage signal output from the light receiving device and the trapezoidal distortion correction amount of the projection image;
A trapezoidal distortion correction device that calculates a trapezoidal distortion correction amount from the trapezoidal distortion correction amount information based on the voltage signal output from the light receiving device, and corrects the trapezoidal distortion of the projected image using the trapezoidal distortion correction amount. A projector characterized by that. A projector that modulates and projects a luminous flux emitted from a light source according to image information,
An adjustment leg that is configured to be movable back and forth inside and outside the exterior housing, and changes the tilt state of the projector;
An interlocking device that displaces in conjunction with the forward and backward movement of the adjustment leg,
A reflective member provided on a surface intersecting the advancing and retreating movement direction in the interlocking device;
A light emitting device that emits light toward the reflecting member;
A light receiving device that receives light emitted from the light emitting device and reflected by the reflecting member and outputs an electrical signal; and
A storage device storing trapezoidal distortion correction amount information indicating a relationship between the voltage signal output from the light receiving device and the trapezoidal distortion correction amount of the projection image;
A trapezoidal distortion correction device that calculates a trapezoidal distortion correction amount from the trapezoidal distortion correction amount information based on the voltage signal output from the light receiving device, and corrects the trapezoidal distortion of the projected image using the trapezoidal distortion correction amount. A projector characterized by that. The projector according to claim 2,
The interlock device is
A guide member disposed inside the exterior housing and disposed parallel to the advancing and retreating direction of the adjustment leg,
A frame that is guided by the guide member and is moved in conjunction with advancement and retraction of the adjustment leg,
The projector according to claim 1, wherein the reflecting member is provided on a surface of the frame orthogonal to a moving direction of the frame. The projector according to claim 3, wherein
The interlocking device includes a biasing means for bringing the frame into contact with an upper end portion of an adjustment leg portion. A trapezoidal distortion correction method for a projector that modulates and projects a luminous flux emitted from a light source according to image information,
An adjustment leg that is configured to be movable back and forth inside and outside the exterior housing, and changes the tilt state of the projector;
A reflective member provided on a surface intersecting the advancing and retreating movement direction in the adjustment leg,
A light emitting device that emits light toward the reflecting member;
A light receiving device that receives light emitted from the light emitting device and reflected by the reflecting member and outputs an electrical signal; and
A trapezoidal distortion correction device that corrects the trapezoidal distortion of the projected image based on the electrical signal output from the light receiving device;
A storage device storing trapezoidal distortion correction amount information indicating a relationship between the voltage signal output from the light receiving device and the trapezoidal distortion correction amount of the projection image;
A keystone distortion correction method for a projector equipped with
A preparatory step of obtaining the keystone distortion correction amount information in advance and storing it in the storage device;
The trapezoidal distortion correction amount corresponding to the electrical signal output from the light receiving device when the projector is installed with the adjustment leg moved forward and backward is obtained from the trapezoidal distortion correction amount information stored in the storage device, and the trapezoidal distortion correction is performed. A trapezoidal distortion correction process for correcting the projected image by the amount,
A keystone distortion correction method for a projector, comprising: A trapezoidal distortion correction method for a projector that modulates and projects a luminous flux emitted from a light source according to image information,
An adjustment leg that is configured to be movable back and forth inside and outside the exterior housing, and changes the tilt state of the projector;
An interlocking device that displaces in conjunction with the forward and backward movement of the adjustment leg,
A reflective member provided on a surface intersecting the advancing and retreating movement direction in the interlocking device;
A light emitting device that emits light toward the reflecting member;
A light receiving device that receives light emitted from the light emitting device and reflected by the reflecting member and outputs an electrical signal; and
A trapezoidal distortion correction device that corrects the trapezoidal distortion of the projected image based on the electrical signal output from the light receiving device;
A storage device storing trapezoidal distortion correction amount information indicating a relationship between the voltage signal output from the light receiving device and the trapezoidal distortion correction amount of the projection image;
A keystone distortion correction method for a projector equipped with
A preparatory step of obtaining the keystone distortion correction amount information in advance and storing it in the storage device;
The trapezoidal distortion correction amount corresponding to the electrical signal output from the light receiving device when the projector is installed with the adjustment leg moved forward and backward is obtained from the trapezoidal distortion correction amount information stored in the storage device, and the trapezoidal distortion correction is performed. A trapezoidal distortion correction process for correcting the projected image by the amount,
A keystone distortion correction method for a projector, comprising:

Images