JP2008193280A - Projector, electronic equipment, control unit of projector, and control method of projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector for projecting an image, wherein a keystone distortion is corrected and the image is projected in a desired size. <P>SOLUTION: The projector is provided with: a liquid crystal light bulb 32 for demodulating light emitted by a light source 31 by the pixel; a liquid crystal light bulb driving part 3 for changing a demodulation state in each pixel of the liquid crystal light bulb 32; a zoom control unit 26 for projecting light demodulated by the liquid crystal light bulb 32 onto a projection surface by set zoom ratio; and a keystone distortion correction part 23 for correcting the keystone distortion on the projection surface according to a set prescribed correction condition. When a size of an image to be projected onto the projection surface is designated by operation of a remote controller 3 or a control panel 13, a combination of the zoom ratio and the correction condition by the keystone distortion correction part 23 is obtained by a control unit 11 on the basis of the designated size. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a projector that projects an image on a projection surface, an electronic device including the projector, a projector control device, and a projector control method.

When projecting an image or image on a screen with a projector such as a projection display device,
If the light source of the projector and the projection surface of the screen do not face each other, the image is distorted into a trapezoid. Conventionally, a projector that corrects the trapezoidal distortion of the image (so-called trapezoidal distortion) is known (see, for example, Patent Document 1). This projector adjusts the zoom rate after correcting the trapezoidal distortion, and compensates for the reduction in image size accompanying the correction of the trapezoidal distortion.
Some conventional projectors detect a trapezoidal distortion by photographing a projected image and correct the trapezoidal distortion (see, for example, Patent Document 2).
JP 2001-249401 A JP 2006-201494 A

However, when correcting the trapezoidal distortion and adjusting the zoom ratio as in the projector disclosed in Patent Document 1, if the zoom ratio is changed after correcting the trapezoidal distortion, the keystone distortion is caused again. there were.
Further, a projector as disclosed in Patent Document 2 corrects a trapezoidal distortion when a trapezoidal distortion is caused by adjusting a zoom ratio or the like, so that a keystone distortion is always corrected last. For this reason, even if the image size becomes a desired size by adjusting the zoom ratio, there is a problem that the image size is changed by the subsequent trapezoidal distortion correction.
Accordingly, an object of the present invention is to make it possible to correct a trapezoidal distortion and project an image with a desired size in a projector that projects an image.

[Mode 1] In order to solve the above-described problem, a projector according to mode 1 includes a light modulation unit that includes a plurality of pixels and modulates light from a light source in units of pixels, and the light based on input image data. A modulation control means for changing a modulation state in each of the pixels of the modulation means; a zoom control means for projecting the light modulated by the light modulation means on a projection plane at a set zoom rate; and a predetermined correction set According to the conditions, the modulation control means changes the modulation state in each pixel of the light modulation means, thereby correcting the trapezoid distortion correction means for correcting the keystone distortion on the projection plane, and the image projected on the projection plane. A designating unit for designating a size, and an operation for obtaining a combination of the zoom ratio and the correction condition based on the size designated by the designating unit. Calculation means; and a control means for setting the zoom ratio obtained by the computing means in the zoom control means and setting the correction condition obtained by the computing means in the trapezoidal distortion correcting means. It is characterized by that.
According to this configuration, when the projector that projects the light modulated by the light modulation unit at the designated zoom rate and corrects the trapezoidal distortion on the projection surface is designated as the image size on the projection surface, the designated size is obtained. In order to project an image, a combination of the zoom rate and the trapezoidal distortion correction condition is obtained, and the zoom rate is controlled according to this combination and the trapezoidal distortion correction is performed. Here, since the zoom rate and the correction conditions for correcting the trapezoidal distortion are obtained as a combination, the problem as in the case of individually adjusting the zoom rate and correcting the trapezoidal distortion is completely eliminated. In other words, correcting the trapezoidal distortion after adjusting the zoom factor does not change the size of the projected image, or adjusting the zoom factor after correcting the keystone distortion does not cause the keystone distortion again. The keystone distortion can be corrected and an image can be projected at a size specified by the user.

[Mode 2] In the projector according to mode 2, in the projector according to mode 1, the specifying means can specify the position of the image on the projection plane together with the size of the image projected on the projection plane, and the calculation The means obtains a combination of the zoom ratio and the correction condition based on the designated size and position when the position of the image is designated together with the size of the image by the designation means. .
In this case, it is possible to designate the position of the image on the projection plane together with the size of the image by the designation means, and the projector obtains a combination of the zoom ratio and the correction condition based on the designated size and position. For this reason, it is possible to easily adjust the projected image size and the projected position as desired without causing problems such as the case where the zoom ratio, the trapezoidal distortion correction, and the adjustment of the projected position are individually performed.

[Mode 3] The projector according to mode 3 includes the storage unit that stores a plurality of sizes of the image projected on the projection plane in the projector according to mode 1 or 2, and the designation unit stores the plurality of sizes stored in the storage unit. The size of the image is designated by selecting one of the image sizes.
In this case, the zoom ratio adjustment and the trapezoidal distortion correction are performed simply by the user selecting a desired size from the sizes of the plurality of images stored in the storage means by the designation means. An image with no trapezoidal distortion can be projected.

[Mode 4] The projector according to mode 4 is the projector according to any one of modes 1 to 3, wherein the projector detects tilt between the optical axis of the light modulated by the light modulation unit and the projection plane, and the projection. Distance detecting means for detecting a distance to the surface, and the computing means is the size of the image specified by the specifying means, the inclination detected by the inclination detecting means,
A combination of the zoom ratio and the correction condition is obtained based on the distance detected by the distance detection means.
In this case, in addition to the size of the image specified by the specifying means, the zoom ratio and the correction condition are determined based on the inclination of the optical axis of the light modulated by the light modulating means and the projection plane, and the distance from the projection plane. Therefore, the keystone distortion can be corrected, and the calculation for obtaining the zoom rate can be executed efficiently and at high speed.

[Mode 5] The projector according to mode 5 is the projector according to any one of modes 1 to 4, wherein the calculation unit calculates, as the correction condition, a parameter for designating an outer shape of an image projected on the projection plane, The trapezoidal distortion correction means determines the display shape of the image data input to the modulation control means according to the parameter calculated by the calculation means, controls the modulation control means, and each pixel of the light modulation means To form an image of the display shape.
In this case, correction of trapezoidal distortion is controlled using a parameter that specifies the display shape of the image projected onto the projection plane, that is, the shape of the image formed by the light modulated by the light modulation means. There is an advantage that the processing according to can be executed efficiently and at high speed.

[Mode 6] In order to solve the above problem, an electronic apparatus according to mode 6 includes the projector according to any one of modes 1 to 5.
According to this electronic apparatus, operations and effects equivalent to those of the projectors according to modes 1 to 5 can be obtained.

[Mode 7] In order to solve the above-described problem, a projector control apparatus according to mode 7 is based on light modulation means in which a plurality of pixels are arranged and modulates light from a light source in units of pixels, and input image data. A modulation control unit that changes a modulation state in each pixel of the light modulation unit, a zoom control unit that projects light modulated by the light modulation unit on a projection plane at a set zoom rate, and A control device for a projector, comprising: a trapezoidal distortion correcting unit that corrects a trapezoidal distortion in the projection plane by changing a modulation state in each of the pixels of the light modulating unit by the modulation control unit according to a predetermined correction condition. A designating unit for designating a size of an image projected on the projection surface, and a size designated by the designating unit, An arithmetic means for obtaining a combination of the zoom ratio and the correction condition, and setting the zoom ratio obtained by the arithmetic means in the zoom control means, and setting the correction condition obtained by the arithmetic means to the trapezoid distortion Control means for setting the correction means.
According to this configuration, when the image size on the projection plane is specified by controlling the projector that projects the light modulated by the light modulation means at the specified zoom ratio and corrects the trapezoidal distortion on the projection plane. A combination of the zoom ratio and the correction condition is obtained so that an image is projected with the determined size, and the zoom ratio is controlled according to this combination and trapezoidal distortion correction is performed. For this reason, since the zoom ratio and the correction condition are obtained as a combination, it is possible to completely eliminate problems such as when adjusting the zoom ratio and correcting the trapezoidal distortion individually, correcting the trapezoidal distortion, and An image can be projected at a size specified by the user.

[Mode 8] In order to solve the above problem, a projector control method according to mode 8 is based on light modulation means in which a plurality of pixels are arranged and modulates light from a light source in units of pixels, and input image data. A modulation control unit that changes a modulation state in each pixel of the light modulation unit, a zoom control unit that projects light modulated by the light modulation unit on a projection plane at a set zoom rate, and A control method for a projector, comprising: a trapezoidal distortion correcting unit that corrects a trapezoidal distortion in the projection plane by changing a modulation state in each of the pixels of the light modulating unit by the modulation control unit according to a predetermined correction condition. And, based on the designation step for designating the size of the image projected on the projection surface, and the size designated by the designation step, A calculation step for obtaining a combination of the zoom rate and the correction condition; setting the zoom rate obtained by the calculation step in the zoom control means; and setting the correction condition obtained by the calculation step to the trapezoidal distortion. And a control step for setting the correction means.
According to this method, operations and effects equivalent to those of the control device for the projector according to mode 7 can be obtained.

Embodiments to which the present invention is applied will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a projector system 1 according to the present embodiment.
The projector system 1 includes an image supply device 2 that outputs an image signal, and a projector 10 that projects an image based on the image signal output from the image supply device 2. The image projected by the projector system 1 may be either a still image or a moving image, and the image described below includes both a still image and a moving image.

The projector 10 includes a control unit 11 that controls each unit of the projector 10, and the control unit 11 implements various functions of the projector 10 by reading and executing a control program stored in the storage unit 12. Here, the control unit 11 constitutes the projector 10 itself, but may be regarded as functioning as a control device of the projector 10.
The projector 10 includes an operation panel 13 having operation elements such as switches and buttons operated by a user, and an operation signal processing unit 14 that generates an operation signal according to an operation on the operation panel 13 and outputs the operation signal to the control unit 11. ing. The operation signal processing unit 14 has a function of receiving a radio signal transmitted from the remote controller 3 operated by the user and detecting an operation on the remote controller 3, and generates and controls an operation signal corresponding to the operation of the remote controller 3. To the unit 11.

The storage unit 12 stores a control program executed by the control unit 11 and various setting values related to the operation of the projector 10. Examples of various setting values stored in the storage unit 12 include information indicating the size and position of an image projected by the projector 10.
FIG. 2 is a diagram schematically showing a configuration of a projection condition table 12A as an example of information stored in the storage unit 12. As shown in FIG.
The projection condition table 12A shown in FIG. 2 stores projection condition information that associates information indicating the size of a projected image with information indicating the position of the image for each type of image. FIG.
In this example, the projection condition table 12A stores projection condition information for three types of images. For example, in the projection condition information corresponding to a movie, the image size (display size) is 80 inches diagonal, and the image position is (X, Y) = (960, 540).
Here, the position of the image is represented as a relative position using an XY orthogonal coordinate system that is virtually provided on the projection surface of the screen 4 (FIG. 3) on which the projector 10 projects an image, as will be described later. . This XY orthogonal coordinate system is developed along the projection plane with the center of the screen 4 as the origin O, and extends in the horizontal direction of the projection plane, that is, in the long side direction, and in the vertical direction of the projection plane, that is, in the short side direction. It consists of the Y axis. The position of the image in the projection condition table 12A is the position coordinate of the upper right corner of the image in the XY rectangular coordinate system.

In the projection condition table 12A, in the projection condition information corresponding to news, the image size is 40 inches diagonal, the image position is (X, Y) = (430, 322),
In the projection condition information corresponding to home video, the image size is 67 inches diagonal, and the image position is (X, Y) = (720, 540).
The projection condition table 12A is used so that the user can specify the size and position of the image with a simple operation. That is, the user can easily specify the image size and position for the projector 10 by selecting one of the plurality of pieces of projection condition information included in the projection condition table 12A. Also, as shown in FIG. 2, the projection condition table 12A may include an image aspect ratio so that the user can select projection condition information. Further, for the same purpose, the projection condition table 12A may include information indicating the image signal format (1080i, 1080p, 540p, etc.) together with the image type.
Here, the position of the image is not limited to the coordinate position on the projection surface of the screen 4, and may be determined as a relative position based on the vertical size Sx and the horizontal size Sy of the image. For example, a position moved upward from the reference position by ¼ of the vertical size Sy is represented as + Sy / 4, and a position moved from the reference position by ¼ of the horizontal size Sx to the right is represented as + Sx / 4. Good.
The storage unit 12 in the present embodiment stores an image size S0 (for example, 60 inches) and an image position (X0, Y0) = (± 0, ± 0) as initial values. According to this initial value, an image having a size of S0 inches is displayed at the center of the projection surface of the screen 4.

As shown in FIG. 1, the projector 10 includes an image processing unit including an image signal processing unit 21, an OSD processing unit 22, and a trapezoidal distortion correction unit 23 that process an image signal according to the control of the control unit 11.
Further, the projector 10 includes a light source 31 including a light emitter, a liquid crystal light valve 32 as a light modulation unit that modulates light emitted from the light source 31, and light transmitted through the liquid crystal light valve 32 on the screen 4 (FIG. 3). And an optical system including a projection lens 33 that projects toward the screen. Further, the projector 10 drives the liquid crystal light valve 32 as a modulation control means, the focus control unit 25 that drives the projection lens 33 to adjust the focus, and the projection lens 33 drives the zoom. An optical drive unit including a zoom control unit 26 as zoom control means for performing adjustment is provided.
Furthermore, the projector 10 includes an installation angle detection unit 27 that detects the installation angle of the projector 10 and a sensor unit that includes a distance measurement unit 28.

The image signal processing unit 21 performs various processes such as A / D conversion processing of the image signal input from the image supply device 2 and resolution conversion processing for adjusting the resolution of the image signal to the resolution of the liquid crystal light valve 32 according to the control of the control unit 11. Processing is performed to generate digital image data, which is output to the OSD processing unit 22.
The OSD processing unit 22 receives characters and symbols representing the operating state of the projector 10 or an OSD (On Screen Display) image such as a menu image when performing image quality adjustment or the like as image data input from the image signal processing unit 21. Is generated and output to the trapezoidal distortion correction unit 23.
A trapezoidal distortion correcting unit 23 as a trapezoidal distortion correcting unit
Corrects distortion (hereinafter referred to as trapezoidal distortion) that occurs when projection is performed in a tilted state (tilting projection). Specifically, in order to display the composite image data input from the trapezoidal distortion correction unit 23 on the liquid crystal light valve 32 in a shape that compensates for the trapezoidal distortion, the display shape of the composite image data is changed. Then, the trapezoidal distortion correction unit 23 outputs the processed composite image data to the liquid crystal light valve driving unit 24.
The liquid crystal light valve drive unit 24 displays an image on the transmissive liquid crystal panel of the liquid crystal light valve 32 based on the composite image data input from the trapezoidal distortion correction unit 23.

The focus control unit 25 performs focus adjustment by operating a focus mechanism (not shown) of the projection lens 33 according to the control of the control unit 11. Specifically, the focus state is adjusted by moving the focus lens constituting the projection lens 33 in the optical axis direction. The focus control unit 25 can also detect a focus adjustment amount, that is, a focus lens movement amount (focus amount). In this case, the focus control unit 25 outputs the detected focus amount to the control unit 11. The focus amount is detected by a rotating cam mechanism that moves the focus lens in the optical axis direction (
This can be realized by using a detection mechanism such as a rotary encoder or a potentiometer that detects a rotation amount (not shown). Alternatively, the focus amount may be detected based on the number of steps of a stepping motor that is a drive source of the focus mechanism.

Further, the zoom control unit 26 operates a zoom mechanism (not shown) included in the projection lens 33 according to the control of the control unit 11 and moves the zoom lens along the optical axis, so that an enlargement / reduction magnification (during projection) ( Hereinafter, the zoom ratio is changed), and an image is projected at the zoom ratio designated by the control unit 11. The zoom control unit 26 also functions as a zoom amount detection unit that detects the focal length, that is, the movement amount (zoom amount) of the zoom lens, and outputs the detected zoom amount to the control unit 11. As a method for detecting the zoom amount, as with the method for detecting the focus amount, a detection mechanism such as a rotary encoder or a potentiometer that detects the rotation amount of a rotating cam mechanism (not shown) for moving the zoom lens in the optical axis direction. This can be realized by using. Alternatively, the focus amount may be detected based on the number of steps of a stepping motor that is a drive source of the zoom mechanism.

The projector 10 according to the present embodiment automatically changes the focus amount and the zoom amount by manually adjusting the focus amount and the zoom amount by the user operating the operation elements provided on the operation panel 13 and the remote controller 3. Auto focus function and auto zoom function are provided.
The autofocus function is to automatically change the focus amount according to the distance to the screen 4 so that the projected image is in an optimal focus state (in-focus state). When this autofocus function is executed, the control unit 11 controls the focus control unit 25 based on the projection distance measured by the distance measurement unit 28 to change the focus amount.
On the other hand, the auto zoom function is a function for changing the zoom ratio in order to project an image in a size specified by the user. When the auto zoom function is executed, the control unit 11 calculates a zoom amount necessary for projecting an image with a size specified by the operation of the remote controller 3 or the operation panel 13, and the calculated zoom amount is used as the zoom control unit 26. And the projection lens 33 is driven.

The installation angle detection unit 27 detects the installation angle of the projector 10, that is, the tilt angle by a method of detecting an angle difference between the installation surface of the projector 10 and the direction of gravity using, for example, an acceleration sensor or a gyro sensor. The tilt angle is equal to the size of the angle formed by the optical axis of the light projected by the projector 10 and the plane perpendicular to the screen 4, and the optical axis of the light of the projector 10 is calculated from the size of the tilt angle. The angle formed by the projection surface of the screen 4 can be obtained. In other words, the installation angle detection unit 27 functions as an inclination detection unit, and indirectly detects the inclination of the optical axis of the light projected by the projector 10 with respect to the projection surface of the screen 4 by detecting the installation angle of the projector 10. To detect. This is not limited to the case where the projector 10 is installed on a horizontal plane and the projection surface of the screen 4 is installed in the vertical direction. If the angle between the installation surface of the projector 10 and the screen 4 is known, the screen 4 is in any case.
The inclination of the optical axis of the light projected by the projector 10 with respect to the projection plane can be detected.
The distance measuring unit 28 as a distance detecting unit measures the distance from the reference position of the projector 10, that is, the projection lens 33 or the liquid crystal light valve 32 to the projection surface of the screen 4, and outputs the measured result to the control unit 11. . As a method for the distance measuring unit 28 to measure the distance, an infrared method in which infrared or ultrasonic waves are emitted to the screen 4, reflected light or reflected sound waves are detected, and the detected intensity and reflection time are measured to measure the distance. Alternatively, an ultrasonic method can be used.

The light source 31 includes lamps such as a high pressure mercury lamp and an ultra high pressure mercury lamp, and other light emitters.
The liquid crystal light valve 32 is configured by a transmissive liquid crystal panel in which a plurality of pixels are arranged in a matrix. The liquid crystal light valve 32 is driven by the liquid crystal light valve driving unit 24 and forms an image by changing the light transmittance of each pixel arranged in a matrix.
Here, when the projector 10 is configured as a 3LCD projector, R,
Three liquid crystal light valves 32 corresponding to the three colors G and B, a prism for distributing and condensing light from the light source 31, and the like are disposed. In this embodiment, for convenience of understanding, a configuration including one liquid crystal light valve 32 will be described as an example only.
The projection lens 33 is configured by combining a lens group including one or a plurality of lenses.
It has a configuration capable of executing focus adjustment by being driven by the focus control unit 25. The projection lens 33 is driven by the zoom control unit 26 and the liquid crystal light valve 3.
2 has a configuration capable of enlarging or reducing the light transmitted through 2.
The optical system of the projector 10 includes a light source 31, a liquid crystal light valve 32, and a projection lens 33, a lens array for adjusting light distribution, a polarization adjusting element for adjusting polarization, a mirror,
Although it is good also as a structure containing a prism, dustproof glass, etc., illustration and description are abbreviate | omitted here.

Next, an operation when the projector 10 projects an image will be described.
FIG. 3 is a diagram showing the relationship between the installation state of the projector 10 and the projection state on the screen 4. FIG. 3 shows an example in which the projector 10 is installed on a horizontal plane. FIG. 3 (A)
Shows the state of the pixels in the liquid crystal light valve 32, FIG. 3B shows the positional relationship between the projector 10 and the screen 4, and FIG. 3C shows the projection state on the screen 4.
4 is a diagram showing the relationship between the installation state of the projector 10 and the trapezoidal distortion of the image projected on the screen 4, and FIG. 5 is a diagram showing an example of the trapezoidal distortion correction. 4A and FIG.
(A) shows the state of the pixel in the liquid crystal light valve 32, and FIG. 4 (B) and FIG. 5 (B).
Indicates the positional relationship between the projector 10 and the screen 4, and FIGS. 4C and 5C show the projection state on the screen 4.
The grid pattern indicated by the broken line in FIGS. 3 to 5 is the maximum pixel area 32A, which is the maximum area where the image of the liquid crystal light valve 32 can be formed, and the area where the image is actually formed by transmitting light. Lines supplementarily added to indicate the correspondence between a certain image forming area 32B, the maximum projection area 4A that is the maximum area that can be projected onto the screen 4, and the image projection area 4B that is the area where the image is actually projected. It does not mean that such a lattice-like pattern is actually formed or displayed.

The state shown in FIG. 3 corresponds to, for example, the case where the projector 10 is installed on a horizontal plane and the screen 4 is arranged along the vertical direction. In this example, the optical axis 10L of the projector 10 is perpendicular to the projection surface of the screen 4 as shown in FIG. In other words, the optical axis 10L and the normal line of the projection surface of the screen 4 are parallel.
For this reason, as shown in FIG. 3A, a rectangular image forming area 32B is arranged in the maximum pixel area 32A in which pixels are arranged in the liquid crystal light valve 32, and this image forming area 32 is arranged.
The image displayed in B is projected onto the regular maximum projection area 4A. Here, the regular shape is generally a rectangle having an aspect ratio Sx: Sy of 4: 3 or 16: 9.

On the other hand, in the example shown in FIG. 4, the projector 10 is at an angle θ (
≠ 0) and the optical axis 10L is obliquely upward. Thus, the optical axis 10
Projecting in a state where L is obliquely upward is referred to as “tilting projection”, and the angle θ is referred to as “tilting angle”. When the projection surface of the screen 4 is vertical, the tilt angle θ is equal to the angle formed by the projection surface of the screen 4 and the virtual plane 6 perpendicular to the optical axis 10L.
In the state shown in FIG. 4, the maximum projection area 4A on which the rectangular image forming area 32B is projected is distorted into a trapezoid as shown in FIG. This distortion is so-called trapezoidal distortion, and the magnitude of the distortion increases with the tilt angle θ.
Therefore, when the keystone distortion is corrected by the projector 10, the image forming area 32B deformed in the liquid crystal light valve 32 is used as shown in FIG. 5A, and the keystone distortion in the maximum projection area 4A is canceled. The image forming area 32B in FIG. 5A has a trapezoidal shape with a short upper side and a long lower side so as to compensate for distortion (the upper side is long and the lower side is short) of the maximum projection area 4A. The composite image data is deformed by the trapezoidal distortion correction unit 23 (FIG. 1) so as to be adapted to the image forming area 32B, displayed on the image forming area 32B, and projected by the light of the light source 31.
), A rectangular image having the same aspect ratio as that of the original composite image data is projected. Here, the ratio of the upper side to the lower side of the image forming area 32B (the length of the upper side / the length of the lower side) is approximately the ratio of the upper side to the lower side of the maximum projection area 4A (the length of the upper side / the length of the lower side). Reciprocal.
When this trapezoidal distortion correction is performed, an image projection area 4B having a regular shape can be projected on the screen 4, but on the other hand, only a part of the maximum pixel area 32A can be used in the image formation area 32B. The image size to be obtained is smaller than the maximum projection area 4A. Obviously, the image projection area 4B is smaller than the maximum projection area 4A. For this reason, when trapezoidal distortion correction is executed, the image is reduced if the zoom rate remains constant. In FIG. 5C, the maximum projection area 4A is shown with hatching for reference, but this hatched part corresponds to a non-transmission part of the maximum pixel area 32A and is actually visually recognized. Never happen.

FIG. 6 is a schematic diagram showing a three-dimensional positional relationship between the projector 10 and the screen 4.
FIG. 6 illustrates a state in which the projector 10 is installed at the tilt angle θ and the screen 4 is a vertical plane, and an XYZ orthogonal coordinate system having the optical axis 10L as the Z axis is virtually set. ing.
In this coordinate system, the intersection point between the optical axis 10L and the projection surface of the screen 4 is defined as an origin O. The XY plane is a plane perpendicular to the optical axis 10 </ b> L and passing through the origin O, and this plane is defined as a virtual plane 6. The X axis of the virtual plane 6 extends in the horizontal direction through the origin O, and the screen 4 and the virtual plane 6 intersect at this X axis. The Y axis passes through the origin O and the tilt angle θ with respect to the projection surface of the screen 4
It is just a tilted straight line. A Y ′ axis extending in the vertical direction is disposed on the projection surface of the screen 4, and the angle formed by the Y axis and the Y ′ axis is equal to the tilt angle θ. The normal line of the projection surface of the screen 4 is taken as the Z ′ axis.
Here, the virtual plane 6 is substantially parallel to the maximum pixel area 32A of the liquid crystal light valve 32, and an image forming area 32B constituted by a part or all of the maximum pixel area 32A is projected onto the virtual plane 6 as an image. . The image of the maximum pixel area 32A in the virtual plane 6 is the screen 4
Can be regarded as equivalent (equivalent) to the maximum projection area 4A.

When the trapezoidal image forming area 32B is provided in the maximum pixel area 32A of the liquid crystal light valve 32 at the time of correcting the keystone distortion of the projector 10, the maximum projection area 4A on the screen 4 corresponds to the maximum pixel area 32A, and image formation is performed. The area 32B corresponds to the image projection area 4B. At this time, the area excluding the image forming area 32B in the maximum pixel area 32A is not substantially visually recognized because the light transmittance of the pixels of the liquid crystal light valve 32 is minimum.
If an arbitrary point K (x, y) on the outer periphery of the image forming area 32B is projected onto a point K ′ (x ′, y ′) on the outer periphery of the image projection area 4B, the geometry shown in FIG. The following formulas (1) and (2) are derived from the scientific relationship.
tan α = x / f
= (X ′ / d) / (1+ (y ′ / d) × sin θ) (1)
tan β = y / f
= (Y ′ / d) × cos θ / (1+ (y ′ / d) × sin θ) (2)
Where α is the angle of view of point K in the X-axis direction, β is the angle of view of point K in the Y-axis direction, f is the focal length of the zoom lens, and d is the projection distance (projector 10 and XYZ coordinate system). Distance from the center O), θ
Indicates the projection angle (tilt angle).

In the above formulas (1) and (2), the projection angle θ can be detected by the installation angle detection unit 27, and the projection distance d can be measured by the distance measurement unit 28. For this reason, screen 4
By substituting the above coordinates (x ′, y ′) into these equations, the field angle α and the field angle β in the X-axis direction and the Y-axis direction can be obtained, respectively.
In the example of FIG. 6, the image projection area 4B is a rectangle having an aspect ratio of 4: 3, and the image projection area 4
On the outer periphery of B, the upper right vertex from the projector 10 toward the screen 4 is the vertex A ′, the lower right vertex is the vertex B ′, the lower left vertex is the vertex C ′, and the upper left vertex is the vertex D ′. Vertex A
The angle of view of X ′ in the X axis direction is α1, the angle of view of the X axis direction of the vertex B ′ is α2, the angle of view of the vertex C ′ in the X axis direction is α3, and the angle of view of the vertex D ′ in the X axis direction is α4. The angle of view of the vertex A ′ in the Y-axis direction is β1, the angle of view of the vertex B ′ in the Y-axis direction is β2, the angle of view of the vertex C ′ in the Y-axis direction is β3, and the angle of view of the vertex D ′ in the Y-axis direction is β4. And

Substituting the coordinates (x ′, y ′) of the four vertices A ′, B ′, C ′, D ′ into the expressions (1) and (2), respectively, the vertices A ′, B ′, C ′, D The angle of view α in the X-axis direction and the angle of view β in the Y-axis direction can be obtained. Thereby, t at each vertex A ′, B ′, C ′, D ′
The ratio between anα and tanβ is the ratio between the x coordinate and the y coordinate of the image forming area 32B.
Further, the coordinates of the vertex A ′ are (x1, y1), the coordinates of the vertex B ′ are (x2, y2), and the vertex C ′.
If the coordinates of (x3, y3) and the coordinates of the vertex D ′ are (x4, y4), the following relationships (3) and (4) hold.
tan α1: tan α2: tan α3: tan α4 = x1: x2: x3: x4 (3)
tan β1: tan β2: tan β3: tan β4 = y1: y2: y3: y4 (4)

Further, by arranging at least two points out of the four vertices A, B, C, and D of the image forming area 32B so as to be in contact with the outer periphery of the maximum pixel area 32A, 4 in the image forming area 32B is obtained.
The coordinates of the point can be obtained.
Here, in the liquid crystal light valve 32, it is desirable to use the largest possible part of the maximum pixel area 32A as the image forming area 32B. This is the image forming area 32B.
This is because the more pixels that are included in the pixel, the less waste of the pixels and the better the image quality. Accordingly, when obtaining the coordinates of the four points of the image forming area 32B, the image forming area 32B is set to the maximum size that can be inscribed in the maximum pixel area 32A. Four vertices A, B, and B of the image forming area 32B
It is preferable that at least two, preferably all of C and D, be arranged so as to be in contact with the outer periphery of the maximum pixel region 32A. After the position of the image forming area 32B is determined as described above, the zoom ratio of the projection lens 33 may be adjusted in order to adjust the size of the image projection area 4B to the size designated by the user.
Then, the coordinates of one of the vertices A, B, C, and D on the image forming area 32B and the vertices A ′, B ′, C ′, and D ′ (for example, on the image projection area 4B corresponding to the vertex) (for example, , The coordinates of the vertex A ′) corresponding to the vertex A are substituted into the equations (1) and (2), respectively, to determine the focal length f of the projection lens 33 and further the zoom ratio of the projection lens 33. it can.

The control unit 11 outputs the coordinates (x, y) of the four points of the image forming region 32B to the trapezoidal distortion correcting unit 23, and processes the composite image data so as to conform to the image forming region 32B, thereby reducing the trapezoidal distortion. to correct. Further, the control unit 11 outputs the focal length f obtained by the above calculation to the zoom control unit 26 and drives the zoom mechanism of the projection lens 33. Thereby, it is possible to project a projected image with a desired size and position.

7, 8 and 9 are diagrams showing examples of correspondence between the display state of the liquid crystal light valve and the projected image, respectively. Specifically, the coordinates (x ′, y ′) of the four vertices A ′, B ′, C ′, D ′ of the image projection area 4B and the four vertices A ′, B ′, C ′, D ′ Correspondingly, equation (1)
And the relationship with the coordinates of the image forming area 32B obtained by the equation (2).
FIG. 7A shows a case where a regular image having an aspect ratio of 4: 3 is projected around the origin O on the screen 4, and FIG. FIG. 9A shows a state where a projection image of the same size is shifted by δ vertically upward. FIGS. 7B, 8B, and 9B show the state in which the image forming region 32B is arranged based on the coordinates calculated based on the above equations (1) and (2), respectively. Show.
In FIGS. 7 to 9, the portions other than the image projection region 4B in the maximum projection region 4A,
The portions other than the image forming region 32B in the maximum pixel region 32A are shown with hatching, but these portions are not actually visually recognized. Also, the broken lines in the figure are supplementary lines so that the center of the maximum projection area 4A, the maximum pixel area 32A, etc. can be easily understood, and such a broken line or grid pattern is actually formed, or It does not mean that it is displayed.

In order to project the rectangular image projection area 4B shown in FIG. 7A, it is necessary to arrange the trapezoidal image forming area 32B as shown in FIG. 7B. Since the image projection area 4B is a horizontally long rectangle, when the image forming area 32B is arranged as large as possible in the maximum pixel area 32A, both side ends of the image forming area 32B are in contact with the outer periphery of the maximum pixel area 32A.
In this state, when it is desired to move the image projection area 4B downward as shown in FIG. 8A, the image forming area 32B can be moved downward within the maximum pixel area 32A as shown in FIG. 8B. That's fine. As shown in FIG. 9A, when it is desired to move the image projection area 4B upward from the position shown in FIG. 7A, the image forming area 32B is moved to the maximum pixel area 32A as shown in FIG. 9B. What is necessary is just to move upward within.

FIGS. 10 and 11 are diagrams showing examples of correspondence between the display state of the liquid crystal light valve and the projected image, respectively, and show examples of shifting (changing the position) in the horizontal direction.
10A shows a state in which a projection image of the same size is shifted by δ in the horizontal left direction from the state shown in FIG. 7A. FIG. 11A shows a projection image of the same size in the horizontal right direction. This is a state shifted by δ. FIG. 10B and FIG. 11B respectively show the above formulas (1) and (
A state in which the image forming region 32B is arranged based on the coordinates calculated based on 2) is shown.
As shown in FIG. 10A, when it is desired to move the image projection area 4B leftward from the position shown in FIG. 7A, the image forming area 32B can be moved leftward in the maximum pixel area 32A. That's fine. However, as shown in FIG. 7B, the horizontal width of the image forming area 32B is equal to the horizontal width of the maximum pixel area 32A. For this reason, as shown in FIG.
It is necessary to reduce 2B and position the image forming area 32B to the left of the maximum pixel area 32A. In this case, if the zoom rate is not changed, the size of the image projection area 4B is reduced as the image forming area 32B is reduced. Therefore, the projector 10 changes the zoom rate by the zoom control unit 26 to compensate for the reduction of the image forming area 32B. This
The image projection area 4B can be projected with the same size as in FIG.
Similarly, when it is desired to move the image projection area 4B to the right from the position shown in FIG. 7A as shown in FIG. 11A, the image forming area 32B is changed as shown in FIG. The zoom control unit 26 changes the zoom ratio so as to reduce the position of the image forming area 32B to the right of the maximum pixel area 32A and to compensate for the reduction of the image forming area 32B. Accordingly, the image projection area 4B can be projected with a size that is not different from that in FIG.

FIG. 12 is a flowchart showing the operation of the projector 10 and shows the operation when an image is projected on the screen 4. In executing this operation, the control unit 11 functions as a calculation unit and a control unit.
Prior to this operation, the user can operate the operation panel 1 while the projector 10 is operable.
3 or the remote controller 3 is operated to specify the image size (step S11). In step S11, the operation panel 13 and the remote controller 3 function as designation means. The size specified here is the size of the image projected on the screen 4. In step S11, the above-described initial values (size S0, position ± 0, ± 0) may be automatically read.
The user may input and specify an arbitrary size, or the projection condition table 12A (FIG. 2).
) May be displayed on the screen 4 and the user may specify a desired projection condition from a plurality of displayed projection conditions, and the display position of the image on the screen 4 may be specified together with the image size. May be.
Then, the control unit 11 temporarily stores the designated image size in the storage unit 12.

Subsequently, the control unit 11 controls the installation angle detection unit 27 to detect the installation angle of the main body of the projector 10, that is, the tilt angle of the optical axis 10 </ b> L (Step S <b> 12). The distance d to the projection surface of the screen 4 is measured and detected (step S13). Here, the control unit 11 calculates a focus adjustment value corresponding to the distance d and controls the focus control unit 25 to drive the focus mechanism (not shown) of the projection lens 33 to perform focus adjustment (step). S14).

Next, the control unit 11 acquires the designated image size from the storage unit 12 (step S1).
5) Further, the display position of the image projection area 4B on the screen 4 is acquired (step S).
16). The size of the image projection area 4B acquired here is the latest size stored in the storage unit 12 among the image size specified in step S11, the initial value, and the image specified in step S21 described later. . Further, the display position of the image projection area 4B is set at step S.
11 is the latest position stored in the storage unit 12 among the position specified in 11, the initial value, or the position specified in step S <b> 20 described later.
Then, the control unit 11 calculates the coordinates of the vertex of the image forming region 32B in the maximum pixel region 32A and the zoom rate by performing the calculations shown in the above formulas (1) and (2), for example (step S17).
The control unit 11 outputs and sets the calculated zoom rate to the zoom control unit 26 (step S1).
8) The projection lens 33 is driven by the zoom control unit 26 in accordance with the zoom rate.
Further, the control unit 11 arranges the image forming region 32B based on the calculated coordinates of the vertex of the image forming region 32B, and the trapezoidal distortion correcting unit 2 so as to conform to the image forming region 32B.
The trapezoidal distortion correction of the composite image data is performed by 3 (step S19).
By the operation up to step S19, the liquid crystal light valve 32 displays an image in the newly provided image forming area 32B, and the image projection area 4B is projected on the screen 4 at the designated position and size. .

Here, the control unit 11 determines whether or not an instruction to change the display position of the image has been given by operating the operation panel 13 or the remote controller 3 (step S20).
The instructed position is acquired and temporarily stored in the storage unit 12, and the process returns to step S16.
On the other hand, when there is no instruction to change the position (step S20; No), the control unit 11 determines whether or not an instruction to change the image size is given (step S21). The acquired image size is acquired and temporarily stored in the storage unit 12, and the process returns to step S15.
If no change in the image size is instructed (step S21; No), the control unit 11 displays the image while continuing the processing of steps S20 to S21 until an instruction to end the display is given (step S22). If there is an instruction to end the display (step S22; Yes)
), This process is terminated.

As described above, according to the projector system 1 according to the embodiment to which the present invention is applied, the light from the light source 31 is modulated by the liquid crystal light valve 32 and projected from the projection lens 33 onto the projection surface of the screen 4. When the image size on the projection plane is designated by the control unit 11, a combination of the zoom ratio and the coordinates of the vertex of the image forming area 32B is obtained so as to match the designated image size, and based on this combination, The projection lens 33 is driven by the zoom control unit 26, and the keystone distortion is corrected by adjusting the shape of the image forming region 32B by deforming the image data by the trapezoidal distortion correction unit 23. Here, since the zoom rate and the coordinates of the image forming area 32B are calculated as one-to-one correspondence, problems such as when zoom rate adjustment and trapezoidal distortion correction are performed individually are completely eliminated. The In other words, correcting the trapezoidal distortion after adjusting the zoom ratio will change the size of the projected image,
By adjusting the zoom rate after correcting the keystone distortion, the keystone distortion is not caused again, and the keystone distortion can be corrected and an image can be projected at a size specified by the user.

In the projector 10, it is possible to specify the position of the image on the projection plane as well as the size of the image on the projection plane of the screen 4, and the control unit 11 can zoom in based on the specified size and position. And the coordinates of the vertices of the image forming area 32B. For this reason, it is possible to project an image on the screen 4 with a desired image size and position without causing problems as in the case of performing zoom ratio correction, trapezoidal distortion correction, and projection position adjustment individually.
Furthermore, by operating the operation panel 13 or the remote controller 3, the image size and the like can be specified by selecting a desired projection condition from the projection conditions included in the projection condition table 12A stored in the storage unit 12. An image having a desired size and no trapezoidal distortion can be projected.

Further, the projector 10 can correct the trapezoidal distortion based on the installation angle detected by the installation angle detection unit 27 and the distance measured by the distance measurement unit 28, and can efficiently perform the calculation for obtaining the zoom rate at high speed. . Furthermore, since the control unit 11 obtains the coordinates of the apex of the image forming area 32B and controls the trapezoidal distortion correction unit 23, there is an advantage that the processing relating to the correction of the trapezoidal distortion can be executed efficiently and at high speed.

As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to this. For example, in the above embodiment, the size of the displayable area of the screen 4 is stored in the storage unit 12 in advance, and the screen 4 is operated by operating the remote control 3 or the operation panel 13.
When a size exceeding the displayable area is designated, guidance for the user may be output. In this embodiment, the case where the maximum pixel area 32A of the liquid crystal light valve 32 is a horizontally long rectangle has been described. However, the shape of the maximum pixel area 32A is arbitrary, for example, at a position in the vertical direction of the image forming area 32B. In order to give a degree of freedom, it may be a vertically long rectangle. In the rule embodiment, the configuration in which the optical axis 10L of the projector 10 coincides with the center of the maximum pixel region 32A is shown and described. However, the maximum pixel region 32A can be moved relative to the optical axis 10L. Good.

Moreover, although the said embodiment demonstrated the case where the pixel was arrange | positioned at the liquid crystal light valve 32 at the matrix form, it is good also as a structure which has arrange | positioned the pixel at honeycomb shape. Furthermore, in the above embodiment, the configuration using the liquid crystal light valve 32 provided with the transmissive liquid crystal display panel has been described. However, the present invention is not limited to this, and for example, the reflective liquid crystal display panel is replaced with the liquid crystal light valve 32. Alternatively, instead of the liquid crystal light valve 32, a digital mirror device (DMD (registered trademark)) or the like may be used. The pixel arrangement in the reflective liquid crystal panel and the digital mirror device may be a matrix or a honeycomb.
In addition, in the above-described embodiment, an example in which an image is projected toward the screen 4 installed outside the projector 10 has been described. However, for example, a so-called rear projection display device is arranged in the same housing as the projector 10. For the transmissive screen 4 provided,
It is good also as a structure which projects an image. In addition to the rear projection display device, the projector 10 can be applied to an electronic apparatus having a function of projecting an image. Furthermore, it is of course possible to configure the image supply device 2 and the projector 10 in the same housing.

In the above description, the case where the control program for realizing the function of the projector 10 is stored in the storage unit 12 has been described.
Semiconductor recording media such as ROM, magnetic storage type recording media such as FD and HD, CD, CDV, LD,
It is possible to record on an optical reading type recording medium such as a DVD, or a magnetic recording type / optical reading type recording medium such as an MO. This recording medium is an electronic, magnetic, optical or other reading method. Regardless, any recording medium can be used as long as it can be read by a computer. Then, the control program recorded on these recording media is stored in the control unit 1.
1, by providing a network interface as a communication interface in the projector 10 and downloading and executing a control program from the network interface via the network.
It is good also as a structure which implement | achieves the function mentioned above. Further, the image supply device 2 may be provided with a network interface, and image data may be downloaded from the network interface via the network and output to the projector 10, and other specific configurations may also be included in the gist of the present invention. Of course, it can be changed arbitrarily within a range not impairing the above.

It is a block diagram which shows the structure of the projector system which concerns on embodiment. It is a figure which shows the structural example of the projection condition table memorize | stored in a memory | storage part. It is a figure which shows the relationship between the installation state of a projector, and a projection state. It is a figure which shows the relationship between the installation state of a projector, and trapezoid distortion. It is a figure which shows the example of the display state of a liquid crystal light valve, and trapezoid distortion correction. It is a schematic diagram which shows the three-dimensional positional relationship of a projector and a screen. It is a figure which shows the example of a response | compatibility with the display state of a liquid crystal light valve, and a projection image. It is a figure which shows the example of a response | compatibility with the display state of a liquid crystal light valve, and a projection image. It is a figure which shows the example of a response | compatibility with the display state of a liquid crystal light valve, and a projection image. It is a figure which shows the example of a response | compatibility with the display state of a liquid crystal light valve, and a projection image. It is a figure which shows the example of a response | compatibility with the display state of a liquid crystal light valve, and a projection image. 3 is a flowchart showing the operation of the projector 10.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Projector system, 2 ... Image supply apparatus, 3 ... Remote control (designating means), 4 ... Screen, 4A ... Maximum projection area, 4B ... Image projection area, 10 ... Projector, 11 ... Control part (Calculation means, Control means, Projector control device), 12 storage unit, 12A projection condition table, 13 operation panel (designating means), 14 operation signal processing unit, 21 image signal processing unit, 22 OSD processing unit, 23 keystone distortion Correction unit (trapezoidal distortion correction unit), 24 ... Liquid crystal light valve driving unit (modulation control unit), 25 ... Focus control unit, 26 ... Zoom control unit (zoom control unit), 27 ... Installation angle detection unit (tilt detection unit) , 28 ... Distance measuring unit (distance detecting means),
31 ... Light source, 32 ... Liquid crystal light valve (light modulation means), 32A ... Maximum pixel area, 32B ...
Image forming area, 33... Projection lens.

Claims (8)

A plurality of pixels, light modulation means for modulating light from a light source in units of pixels;
Modulation control means for changing a modulation state in each pixel of the light modulation means based on input image data; and
Zoom control means for projecting light modulated by the light modulation means on a projection surface at a set zoom rate;
Trapezoidal distortion correction means for correcting trapezoidal distortion in the projection plane by changing the modulation state in each pixel of the light modulation means by the modulation control means in accordance with a set predetermined correction condition;
Designation means for designating a size of an image projected on the projection plane;
An arithmetic means for obtaining a combination of the zoom ratio and the correction condition based on the size designated by the designation means;
Control means for setting the zoom ratio obtained by the computing means in the zoom control means and setting the correction condition obtained by the computing means in the trapezoidal distortion correcting means;
A projector comprising: The designation means can designate the position of the image on the projection plane together with the size of the image projected on the projection plane,
The calculation means, when the position of the image is designated together with the size of the image by the designation means, to obtain a combination of the zoom ratio and the correction condition based on the designated size and position;
The projector according to claim 1. Storage means for storing a plurality of image sizes projected on the projection plane;
The designation means designates the size of the image by selecting one of the sizes of the plurality of images stored in the storage means;
The projector according to claim 1 or 2. An inclination detecting means for detecting an inclination between the optical axis of the light modulated by the light modulating means and the projection plane;
A distance detecting means for detecting a distance from the projection plane;
The computing means is based on the size of the image designated by the designation means, the inclination detected by the inclination detection means, and the distance detected by the distance detection means, and the zoom ratio and the correction condition. Seeking a combination of
The projector according to any one of claims 1 to 3. The calculation means calculates a parameter for designating an outer shape of an image projected on the projection plane as the correction condition,
The trapezoidal distortion correction means determines the display shape of image data input to the modulation control means according to the parameter calculated by the calculation means, controls the modulation control means, and each of the light modulation means Forming an image of the display shape with pixels;
The projector according to claim 1, wherein:   An electronic apparatus comprising the projector according to claim 1. A plurality of pixels, light modulation means for modulating light from a light source in units of pixels;
Modulation control means for changing a modulation state in each pixel of the light modulation means based on input image data; and
Zoom control means for projecting light modulated by the light modulation means on a projection surface at a set zoom rate;
A projector comprising: a trapezoidal distortion correcting unit configured to correct a trapezoidal distortion in the projection plane by changing a modulation state in each of the pixels of the light modulating unit by the modulation control unit according to a predetermined correction condition set; A control device of
Designation means for designating a size of an image projected on the projection plane;
An arithmetic means for obtaining a combination of the zoom ratio and the correction condition based on the size designated by the designation means;
Control means for setting the zoom ratio obtained by the computing means in the zoom control means and setting the correction condition obtained by the computing means in the trapezoidal distortion correcting means;
A projector control apparatus comprising: A plurality of pixels, light modulation means for modulating light from a light source in units of pixels;
Modulation control means for changing a modulation state in each pixel of the light modulation means based on input image data; and
Zoom control means for projecting light modulated by the light modulation means on a projection surface at a set zoom rate;
A projector comprising: a trapezoidal distortion correcting unit configured to correct a trapezoidal distortion in the projection plane by changing a modulation state in each of the pixels of the light modulating unit by the modulation control unit according to a predetermined correction condition set; Control method,
A designation step for designating a size of an image projected on the projection plane;
An operation step for obtaining a combination of the zoom ratio and the correction condition based on the size specified by the specifying step;
A control step of setting the zoom ratio determined by the calculation step in the zoom control unit, and setting the correction condition determined by the calculation step in the trapezoidal distortion correction unit;
A projector control method characterized by comprising:

Images