JP2009251542A - Projector and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of comparing the size of a projected image after trapezoidal distortion correction with the side of a projected image before correction, and its control method. <P>SOLUTION: The projector includes an image signal processing part 32 for generating an image signal for an projected image on the basis of an input image signal, an optical modulation part for modulating a luminous flux emitted from a light source 11 on the basis of the image signal generated by the image signal processing part 32, a projection optical system 13 for enlarging and projecting the luminous flux modulated by the optical modulation part, and a trapezoidal distortion correction part 321 for generating a correction frame image signal equivalent to the profile of an image when the trapezoidal distortion of the projected image is corrected on the basis of a given correction amount. The image signal processing part 32 generates a synthetic image signal obtained by synthesizing the image signal with the correction frame image signal. The trapezoidal distortion correction part 321 corrects the image signal so that after the image based on the synthetic image signal is projected, the profile of the image based on the image signal matches the correction frame image on the basis of the correction frame image signal. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a projector for correcting image distortion and a control method therefor.

  As a conventional technique, for example, Patent Document 1 discloses a projector that corrects trapezoidal distortion of a tilted image, an operation detection unit that detects a user operation necessary to project an image, and installation of the projector. A projector including an angle detection unit that detects an angle and an image correction unit that corrects the trapezoidal distortion according to the installation angle when the user operation is detected has been proposed (for example, claims). 1).

JP 2001-228537 A

Conventionally, when correcting trapezoidal distortion (hereinafter referred to as “trapezoidal distortion”) caused by the inclination of the normal of the projection surface of the screen and the optical axis of the projection light, the image signal is deformed (corrected) and projected. The trapezoidal distortion of the projected image is corrected by adopting a trapezoidal shape opposite to the projected image.
In such trapezoidal distortion correction, as the correction amount increases, the upper base (lower base) and height of the trapezoid shape become shorter, the area of the projected image based on the image signal decreases, and the resolution decreases. Become.

  However, since the conventional projector does not retain the projection image before correction (hereinafter also referred to as “original image”) after correcting the trapezoidal distortion, the projection image is compared with the original image before and after correction. There was a problem that it was impossible to compare how much it was reduced.

  The present invention has been made to solve such a problem, and provides a projector capable of comparing the size of a projected image after correction of trapezoidal distortion with the size of a projected image before correction, and a control method thereof. With the goal.

A projector according to the present invention modulates a light beam emitted from a light source based on an image signal processing unit that generates an image signal for a projected image based on an input image signal, and an image signal generated by the image signal processing unit. Corresponding to the contour of the image when the trapezoidal distortion of the projected image is corrected based on the given correction amount, and the optical modulation unit that performs the projection of the light beam modulated by the light modulation unit. A trapezoidal distortion correction unit that generates a correction frame image signal, the image signal processing unit generates a combined image signal obtained by combining the image signal and the correction frame image signal, and the trapezoidal distortion correction unit After the image based on the composite image signal is projected, the image signal is corrected so that the contour of the image based on the image signal matches the correction frame image based on the correction frame image signal.
In the present invention, after projecting an image based on a composite image signal obtained by synthesizing the image signal and the correction frame image signal, the image signal is adjusted so that the contour of the image based on the image signal matches the correction frame image based on the correction frame image signal. Therefore, the size of the projected image after the trapezoidal distortion correction can be compared with the size of the projected image before the correction.

When a projector according to the present invention receives an operation signal input unit for inputting an operation signal corresponding to the operation content and an operation signal for correcting trapezoidal distortion from the operation signal input unit, the correction according to the operation signal And a control unit that outputs the amount to the trapezoidal distortion correction unit.
In the present invention, since the correction amount according to the operation signal is output to the trapezoidal distortion correction unit, the size of the projected image after the keystone distortion correction by the user's operation is compared with the size of the projected image before the correction. be able to.

The projector according to the present invention includes an angle detection unit that detects an inclination angle of the projection optical axis with respect to a horizontal direction, and a control unit that outputs a correction amount according to the inclination angle detected by the angle detection unit to the trapezoidal distortion correction unit. Is further provided.
In the present invention, since the correction amount corresponding to the tilt angle detected by the angle detection unit is output to the trapezoidal distortion correction unit, the size of the projected image after the trapezoidal distortion correction is performed according to the tilt angle, and the projection before correction The size of the image can be compared.

The projector according to the present invention outputs, to the trapezoidal distortion correction unit, an imaging unit that captures the projected image, and a correction amount for correcting the trapezoidal distortion of the projected image based on the image captured by the imaging unit. And a control unit.
In the present invention, since the correction amount based on the captured image is output to the trapezoidal distortion correction unit, the size of the projection image after the trapezoidal distortion correction according to the trapezoidal distortion of the captured projection image, and the pre-correction The size of the projected image can be compared.

In the projector according to the present invention, the control unit projects an image based on the composite image signal, and causes the trapezoidal distortion correction unit to correct the image signal after a predetermined time has elapsed.
In the present invention, an image based on the composite image signal is projected, and the image signal is corrected after a predetermined time has elapsed. Therefore, the user can determine the size of the projected image after the keystone correction is performed for a predetermined time and the projection before the correction. The size of the image can be compared.

In the projector according to the aspect of the invention, when the control unit receives a predetermined operation signal from the operation signal input unit after the image based on the composite image signal is projected, the image signal is transmitted to the trapezoidal distortion correction unit. Correction is performed.
In the present invention, when an image based on the composite image signal is projected and a predetermined operation is performed, the image signal is corrected. Therefore, the user can determine the size of the projected image after the keystone correction and the size before the correction. After comparing the size of the projected image, the image signal can be corrected by a predetermined operation.

In the projector according to the aspect of the invention, the image signal processing unit stops the generation of the composite image signal after the trapezoidal distortion correction unit corrects the image signal, and extracts the correction frame image from the projection image. Is to be deleted.
In the present invention, the correction frame image can be deleted from the projected image after correcting the image signal.

A projector control method according to the present invention is a projector control method for generating an image signal for a projection image based on an input image signal, and projecting an image by modulating light from a light source based on the image signal. Obtaining a correction amount; generating a correction frame image signal corresponding to an outline of an image when correcting the trapezoidal distortion of the projection image based on the correction amount; and the image signal and the correction frame A step of generating a composite image signal obtained by combining the image signal, a step of projecting an image based on the composite image signal, and a contour of the image based on the image signal so as to match the correction frame image based on the correction frame image signal, And correcting the image signal.
In the present invention, after projecting an image based on a composite image signal obtained by synthesizing the image signal and the correction frame image signal, the image signal is adjusted so that the contour of the image based on the image signal matches the correction frame image based on the correction frame image signal. Therefore, the size of the projected image after the trapezoidal distortion correction can be compared with the size of the projected image before the correction.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing the configuration of the projector according to the first embodiment, and FIG. 2 is a diagram showing the configuration of the operation panel according to the first embodiment. As shown in the figure, the projector 1 includes a light source 11, liquid crystal light valves 12 R, 12 G, and 12 B (hereinafter, simply referred to as “liquid crystal light valve 12” if not distinguished), and a projection optical system 13. A liquid crystal light valve drive unit 14, a control unit 20, an image input unit 31, an image signal processing unit 32, a frame memory 33, an operation panel 41, a remote control light receiving unit 42, and an operation signal input unit 43. And a storage unit 44. The image signal processing unit 32 includes an OSD (On-Screen Display) processing unit 320 and a trapezoidal distortion correction unit 321. Further, the operation panel 41 has trapezoidal distortion correction keys 410-1 and 410-2.
The projector 1 projects image light corresponding to an input image signal supplied from the external connection device 2 and enlarges and projects the image light onto a projection target (hereinafter referred to as “screen SC”) such as a screen, a white wall, or a whiteboard. Is.

  The control unit 20 is connected to the light source 11, the image input unit 31, the image signal processing unit 32, the operation signal input unit 43, and the storage unit 44, and comprehensively controls the operation of the projector 1. The control unit 20 is configured by a microprocessor or the like, executes a control program stored in the storage unit 44, etc., calculates various data input from each unit connected to the control unit 20, and outputs the calculation results. Output to each section. Further, when an operation signal for correcting the trapezoidal distortion is received from the operation signal input unit 43 by an operation described later, a correction amount corresponding to the operation signal is output to the trapezoidal distortion correction unit 321. The control unit 20 controls the light source 11 via a light source driving unit (not shown).

  The image input unit 31 includes one or a plurality of connection terminals that are connected to the external connection device 2, and takes in one or a plurality of input image signals input from the external connection device 2, for example, when it is an analog image signal Performs processing such as conversion into a digital image signal and outputs the digital image signal to the image signal processing unit 32. Note that the connection terminals included in the image input unit 31 include, for example, an RGB terminal, a BNC terminal, an S terminal, a video terminal, a DVI terminal, and the like, and are connected to a personal computer, various video devices, a DVD playback device, and the like.

  The image signal processing unit 32 is configured by a signal processing circuit such as a microprocessor (for example, DSP), for example, and performs various processes by executing a control program stored in a storage unit incorporated therein. A frame memory 33 is connected to the image signal processing unit 32, and an input image signal from the image input unit 31 is stored in the frame memory 33 for each frame (one image screen) and stored in the frame memory 33. For the projected image by performing various signal processing such as resolution conversion processing for adjusting the resolution of the image signal to the resolution of the liquid crystal light valve 12. The image signal is generated.

  The OSD processing unit 320 of the image signal processing unit 32 is a menu image for performing characters and symbols representing various states of the projector 1 and image quality adjustment in accordance with a control command from the control unit 20, a correction frame image 100 described later, and the like. The OSD image signal is synthesized with the frame image signal to generate a synthesized image signal. Specifically, the control unit 20 reads various menu image data from, for example, the storage unit 44 and supplies the menu image data to the image signal processing unit 32. The image signal processing unit 32 generates an OSD image signal based on the menu image data, for example, and this OSD The image signal is combined with the frame image signal. If OSD processing is not performed, the frame image signal is output as it is. When the menu image is displayed by the OSD process, the user sets or adjusts the function of each unit of the projector 1 according to the menu image.

  The trapezoidal distortion correction unit 321 of the image signal processing unit 32 corrects the input image signal in order to correct the trapezoidal distortion that occurs when the projector 1 is projected (tilted projection) with the projector 1 tilted with respect to the screen SC. The corrected image signal is output to the liquid crystal light valve driving unit 14. Further, a correction frame image signal corresponding to the contour of the image when the trapezoidal distortion of the projected image is corrected is generated based on the correction amount given from the control unit 20 by an operation described later. The processing of the trapezoidal distortion correction unit 321 will be further described later.

  The liquid crystal light valve drive unit 14 drives the liquid crystal light valves 12R, 12G, and 12B according to the input image signal. In the liquid crystal light valves 12R, 12G, and 12B, a plurality of pixels (not shown) are formed in a matrix, and the light source 11 is adjusted by adjusting the transmittance of each pixel by the liquid crystal light valve driving unit 14. R (red), G (green), and B (blue) light emitted from the color light separation optical system (not shown) and separated by the color light separation optical system (not shown) by the corresponding liquid crystal light valves 12R, 12G, and 12B. Modulate. The image lights emitted from the liquid crystal light valves 12R, 12G, and 12B are combined by a combining optical system such as a cross dichroic prism (not shown), and enlarged and projected on the screen SC by the projection optical system 13.

  The operation panel 41 is provided in the main body of the projector 1, and as shown in FIG. 2, trapezoidal distortion correction keys 410-1 and 410-2 for performing operations in accordance with the correction direction of the trapezoidal distortion (hereinafter, not distinguished). Is simply referred to as “trapezoidal distortion correction key 410”), a power key, an input switching key for performing an input image switching operation, a menu key, a selection key for performing an item selection operation by moving the cursor up and down, left and right, etc. Various switches for changing the state of the projector 1 and the like are provided, and an operation signal corresponding to a key operation by the user is input to the operation signal input unit 43.

  A remote controller (hereinafter referred to as “remote controller RC”) is provided outside the projector 1 and has various switches similar to the operation panel 41 and numeric keys from 0 to 9 according to the key operation by the user. Send an operation signal. An operation signal from the remote controller RC is input to the operation signal input unit 43 via the remote control light receiving unit 42.

  The operation signal input unit 43 receives an operation signal from the operation panel 41 or the remote control light receiving unit 42 and inputs an operation signal corresponding to the operation content to the control unit 20.

  The storage unit 44 stores a control program executed by the control unit 20, OSD information for generating an OSD image such as a correction frame image 100 and a menu image, and stores various setting values of the projector 1. Further, correction amount information corresponding to the operation is stored by an operation described later.

  With the configuration as described above, the projector 1 receives an input image signal from the external device 2 to the image input unit 31, converts the input image signal by the image signal processing unit 32, and generates an image signal for a projected image. . The generated image signal is input to the liquid crystal light valve driving unit 14, and the liquid crystal light valve driving unit 14 drives the liquid crystal light valve 12 in accordance with the input image signal. The liquid crystal light valve 12 modulates the light of the light source 11 and emits image light by adjusting the transmittance of each pixel by the liquid crystal light valve driving unit 14. The image light (hereinafter also referred to as “projection light”) is projected onto the screen SC via the projection optical system 13.

  By the way, when displaying an image on the projection surface of the screen SC, if the optical axis (center axis) of the projection light emitted from the projector 1 and the normal line of the projection surface of the screen SC do not coincide with each other, An image displayed on the projection surface is distorted into a substantially trapezoidal shape. In other words, when the projector 1 tilts and projects an image, the projected image is distorted into a substantially trapezoidal shape. This is because the distance until the light emitted from the projector 1 reaches the screen SC is different at each point in the projected image.

  Such image distortion (trapezoidal distortion) is corrected by adjusting an image signal supplied to the liquid crystal light valve 12. Thereby, the distortion of the image projected on the screen SC can be corrected. Such trapezoidal distortion correction will be described next.

  FIG. 3 is an explanatory diagram for explaining the keystone distortion correction of the projector. FIG. 3 shows a state where the projection image displayed on the screen SC is enlarged toward the upper side and distorted into a trapezoidal shape when tilting upward. FIG. 3A is a diagram for explaining a state before correction, and FIG. 3B is a diagram for explaining a state after correction. FIGS. 3A-1 and 3B-1 are diagrams showing image signals (frame images) input to the liquid crystal light valve 12, and FIGS. 3A-2 and 3B-2. These are figures which show the projection image projected on the screen SC.

  As shown in FIG. 3A-1, when the trapezoidal distortion correction unit 321 does not adjust the image signal, the image 12a is formed on the liquid crystal light valves 12R, 12G, and 12B. At this time, as shown in FIG. 3A-2, a substantially trapezoidal projection image G1 swelled upward is displayed on the screen SC.

  Therefore, as shown in FIG. 3B-1, the trapezoidal distortion correction unit 321 adjusts the image signal to form an image forming region 12b for forming an image (projected image G2) based on the image signal. It is defined in the pixel region 12a. In other words, the image forming area 12b has a trapezoidal shape opposite to the projection image G1 so that the trapezoidal distortion is offset and the projected image G2 is displayed on the screen SC in a regular shape, and outside the image forming area 12b. By correcting the image signal so that the transmittance of each pixel included in the region 12c is minimized, the projected image G2 is displayed on the screen SC in a regular shape as shown in FIG. .

  As described above, the trapezoidal distortion correction unit 321 adjusts the image signal to correct the distortion of the image displayed on the screen SC.

However, after projecting the projection image G2 corrected for trapezoidal distortion as described above, the projection image G1 before correction (hereinafter also referred to as “original image”) does not remain, so before and after correction, It is impossible to compare how much the projected image is reduced with respect to the original image. For this reason, the user cannot know a guideline for determining whether to perform the trapezoidal distortion correction process or to adjust the installation state of the projector 1 when the corrected image becomes too small and the resolution is lowered.
Therefore, in the present embodiment, the correction frame image 100 is generated at a position corresponding to the contour portion of the image based on the corrected image signal, displayed on the screen SC, and then matched with the correction frame image 100. The image signal is corrected. Details of such an operation will be described below with reference to FIGS.

  FIG. 4 is a flowchart showing the trapezoidal distortion correction operation according to the first embodiment, and FIG. 5 is a diagram showing a projected image at the time of trapezoidal distortion correction according to the first embodiment. 5A is a diagram showing a projected image before trapezoidal distortion correction, and FIGS. 5B and 5C are diagrams showing a projected image obtained by synthesizing a correction frame image, and FIG. () Is a diagram showing a projected image after trapezoidal distortion correction.

  As shown in FIG. 5A, when correcting the trapezoidal distortion of the projection image G1 projected on the screen SC, the user presses the keystone distortion correction key 410 corresponding to the correction direction of the operation panel 41. When the keystone distortion correction key 410 is pressed, the operation signal input unit 43 receives an operation signal corresponding to the key input and outputs the operation signal to the control unit 20. The control unit 20 detects an operation of the keystone distortion correction key 410 based on the input operation signal (S101), and outputs a correction amount corresponding to the operation to the keystone distortion correction unit 321. This correction amount is, for example, a correction direction corresponding to the key input of the trapezoidal distortion correction key 410-1 or 410-2, and outputs a predetermined correction amount preset for one-step operation. In addition, the control unit 20 stores the correction amount in the storage unit 44.

Based on the input correction amount, the trapezoidal distortion correction unit 321 generates a correction frame image signal corresponding to the contour of the image when correcting the trapezoidal distortion of the projected image. The image signal processing unit 32 outputs a composite image signal obtained by combining the input image signal input from the image input unit 31 and the correction frame image signal generated by the trapezoidal distortion correction unit 321 by the OSD processing unit 320.
The synthesized composite image signal is projected onto the screen SC via the projection optical system 13 by the liquid crystal light valve 12 driven by the liquid crystal light valve driving unit 14, and as shown in FIG. The correction frame image 100 based on the correction frame image signal is displayed on the projection image G1 based on the signal (S102).

  Here, the correction frame image 100 is displayed as a dotted line along the contour of the image when the trapezoidal distortion is corrected, and a predetermined hue is used as the display color. The correction frame image 100 is not limited to this, and any image that specifies the contour of the corrected image may be used, and any image can be used. Alternatively, the correction frame image 100 may be displayed blinking by displaying the correction frame image 100 at a predetermined time interval.

  Next, after starting the timer (S103), the control unit 20 determines whether or not the keystone distortion correction key 410 has been operated, and whether or not an operation key other than the keystone distortion correction key 410 has been operated (S104). , S105). Then, it is determined whether or not a predetermined time has elapsed since the timer start (S106).

  Note that the determination in step S105 is not limited to whether or not an operation key other than the trapezoidal distortion correction key 410 has been operated, and it may be determined whether or not a predetermined operation key has been operated.

  When the trapezoidal distortion correction key 410 is operated before the predetermined time has elapsed from the start of the timer (S104), the process returns to step S102, and the control unit 20 outputs a correction amount corresponding to the operation to the trapezoidal distortion correction unit 321. The trapezoidal distortion correction unit 321 again generates a correction frame image signal based on the input correction amount. In other words, a correction frame image signal corresponding to the contour of the image when the trapezoidal distortion of the projected image is corrected with the correction amount obtained by adding the correction amount by the operation to the correction amount stored in the previous step S102 is generated. If the correction direction of the correction amount corresponding to the operation is different from the correction direction in the previous step S102, the correction amount obtained by subtracting the correction amount by the operation from the correction amount stored in the previous step S102. A correction frame image signal is generated.

  Similarly, the image signal processing unit 32 outputs a composite image signal obtained by combining the input image signal and the correction frame image signal, and the correction frame image 100 based on the correction frame image signal is displayed on the projection image G1 based on the input image signal. Is displayed. As a result, as shown in FIG. 5C, the correction frame image 100 further corrected by the operation of the trapezoidal distortion correction key 410 is displayed.

  On the other hand, when an operation key other than the trapezoidal distortion correction key 410 is operated before the predetermined time elapses from the timer start (S105), or when a predetermined time elapses after the timer start (S106), the control unit 20 uses the image signal. The trapezoidal distortion correction unit 321 corrects the image signal so that the contour of the projection image G1 matches the correction frame image 100 based on the correction frame image signal (S107). This correction can be performed so that the contour of the projected image G1 matches the correction frame image 100 by correcting the image signal using the correction amount when the correction frame image signal is finally generated.

  Next, the image signal processing unit 32 stops the generation of the composite image signal by the OSD processing unit 320 and outputs the corrected image signal as it is, as shown in FIG. The corrected projected image G2 from which 100 is deleted is projected (S108).

  As described above, in the first embodiment, on the projected image G1 based on the input image signal, the contour of the image when the trapezoidal distortion of the projected image is corrected by the correction amount according to the operation of the trapezoidal distortion correction key 410 is used. Since the corresponding correction frame image 100 is displayed, the size of the projection image G2 after the trapezoidal distortion correction can be compared with the size of the projection image G1 before the correction.

  Further, by comparing the size of the projection image G2 after the keystone correction and the size of the projection image G1 before the correction, the user can convert the projection image G2 after the correction into the projection image G1 (original image) before the correction. You can see the guideline for changing the installation position when it is too small.

  Further, after the correction frame image 100 is displayed, when an operation key other than the keystone distortion correction key 410 is operated or when a predetermined time has elapsed, the image signal is corrected, so that the user can correct the keystone distortion for a predetermined time. The size of the subsequent projection image G2 can be compared with the size of the projection image G1 before correction. Further, the user can correct the image signal by a predetermined operation.

  Further, since the image signal is corrected so that the contour of the projected image G1 based on the image signal matches the correction frame image 100 based on the correction frame image signal, the image signal is corrected by the correction amount corresponding to the operation of the trapezoidal distortion correction key 410. Correction can be performed.

  In addition, since the correction frame image 100 is deleted from the projected image after the image signal is corrected, an image based on the input image signal can be projected after the trapezoidal distortion correction is performed.

  In the first embodiment, the operation when the keystone distortion correction is performed by operating the keystone distortion correction key 410 of the operation panel 41 has been described. However, the present invention is not limited to this, and the keystone distortion correction key is provided on the remote controller RC. In addition, trapezoidal distortion correction may be performed by operating the remote controller RC.

Embodiment 2. FIG.
In the first embodiment, the keystone distortion is corrected by operating the keystone distortion correction key 410. However, in the second embodiment, the tilt angle of the projection optical axis of the projector 1 with respect to the horizontal direction is detected, and this tilt angle is set. A mode of correcting the trapezoidal distortion based on the corresponding correction amount will be described. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 6 is a block diagram showing the configuration of the projector according to the second embodiment, and FIG. 7 is a diagram showing the configuration of the operation panel according to the second embodiment. As shown in the figure, the projector 1 according to the second embodiment includes an angle detection unit 45 that detects an inclination angle of the projection optical axis with respect to the horizontal direction in addition to the configuration of the first embodiment. Further, the operation panel 41 according to the second embodiment includes an automatic correction key 411 in addition to the configuration of the first embodiment.

The angle detection unit 45 is connected to the control unit 20 and outputs the detected inclination angle to the control unit 20. The angle detection unit 45 detects the installation angle of the projector 1 using an acceleration sensor, for example, and outputs the detected tilt angle information to the control unit 20.
Further, the storage unit 44 of the second embodiment stores correction amount information (table) for trapezoidal distortion correction according to the tilt angle of the projection optical axis with respect to the horizontal direction.

With the configuration as described above, the projector 1 according to the second embodiment corrects the correction described in the first embodiment described above in the automatic correction processing for correcting the trapezoidal distortion according to the tilt angle detected by the angle detection unit 45. The frame image 100 is displayed.
Details of such an operation will be described below with reference to FIG.

FIG. 8 is a flowchart showing the trapezoidal distortion correction operation according to the second embodiment.
When the user presses the automatic correction key 411 of the operation panel 41, the operation signal input unit 43 receives an operation signal corresponding to the key input and inputs this operation signal to the control unit 20. The control unit 20 detects the operation of the automatic correction key 411 based on the input operation signal and starts the automatic correction process (S201).
Next, the control unit 20 acquires the tilt angle information detected by the angle detection unit 45, and outputs a correction amount corresponding to the tilt angle to the trapezoidal distortion correction unit 321 (S202). For example, the correction amount can be obtained by acquiring, from the storage unit 44, information related to a correction amount set in advance for each inclination angle. The generation of the correction amount is not limited to this, and may be obtained by other methods such as calculation for the inclination angle.

Similar to the operation of the first embodiment, the trapezoidal distortion correction unit 321 generates a correction frame image signal corresponding to the contour of the image when correcting the trapezoidal distortion of the projected image based on the input correction amount. To do. The image signal processing unit 32 outputs a composite image signal obtained by combining the input image signal input from the image input unit 31 and the correction frame image signal generated by the trapezoidal distortion correction unit 321 by the OSD processing unit 320.
The synthesized composite image signal is projected onto the screen SC via the projection optical system 13 by the liquid crystal light valve 12 driven by the liquid crystal light valve driving unit 14.
As a result, the correction frame image 100 corresponding to the contour of the projected image that is finally corrected by the automatic correction is displayed (S203).

  Next, after starting the timer (S204), the control unit 20 determines whether or not the automatic correction key 411 has been operated and whether or not a predetermined time has elapsed since the timer was started (S205, S206).

  When the automatic correction key 411 is operated before a predetermined time elapses from the timer start or when a predetermined time elapses after the timer start (S205, S206), the control unit 20 displays the outline of the projection image G1 based on the image signal as a correction frame. The trapezoidal distortion correction unit 321 corrects the image signal so as to match the correction frame image 100 based on the image signal (S207).

  Next, the image signal processing unit 32 stops the generation of the composite image signal by the OSD processing unit 320 and outputs the corrected image signal as it is, thereby correcting the projected image after the correction frame image 100 is deleted. G2 is projected (S208).

  As described above, in the second embodiment, an image when the trapezoidal distortion of the projection image is corrected on the projection image G1 based on the input image signal by the correction amount corresponding to the inclination angle detected by the angle detection unit 45 is displayed. Since the correction frame image 100 corresponding to the contour is displayed, the size of the projection image G2 after the trapezoidal distortion correction can be compared with the size of the projection image G1 before the correction.

  Further, by comparing the size of the projection image G2 corrected by the automatic correction process with the size of the projection image G1 before correction, the user can determine that the projection image G2 after correction is the projection image G1 before correction (original You can see the guide to change the installation position when it is too small compared to the image.

  Further, after the correction frame image 100 is displayed, when the automatic correction key 411 is operated again or when a predetermined time has elapsed, the image signal is corrected, so that the user can perform projection after correcting the keystone distortion for a predetermined time. The size of the image G2 can be compared with the size of the projection image G1 before correction. The user can also correct the image signal by operating the automatic correction key 411.

  Further, since the image signal is corrected so that the contour of the projection image G1 based on the image signal matches the correction frame image 100 based on the correction frame image signal, the image signal is corrected by the correction amount corresponding to the inclination angle detected by the angle detection unit 45. Can be corrected.

  In addition, since the correction frame image 100 is deleted from the projected image after the image signal is corrected, an image based on the input image signal can be projected after the trapezoidal distortion correction is performed.

  Further, by performing the automatic correction process with the correction amount corresponding to the tilt angle detected by the angle detection unit 45, it is not necessary to perform a correction operation using the trapezoidal distortion correction key 410, and the operability can be improved.

Embodiment 3 FIG.
In the second embodiment, the case where the trapezoidal distortion is corrected based on the correction amount according to the tilt angle has been described. However, in the third embodiment, the trapezoidal distortion of the projected image is corrected based on the captured projection image. The form to perform is demonstrated. The same parts as those in the second embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 9 is a block diagram showing a configuration of the projector according to the third embodiment. As shown in the figure, the projector 1 according to the third embodiment includes a CCD camera 46 that is an imaging unit that captures a projected image, instead of the angle detection unit 45 of the second embodiment. The operation panel 41 and other configurations are the same as those in the second embodiment.

  The CCD camera 46 is provided on the same side as the projection lens of the projection optical system 13 and captures an image projected on the screen SC. The control unit 20 generates a correction amount for correcting the trapezoidal distortion of the projected image from the image captured by the CCD camera 46 and outputs the correction amount to the trapezoidal distortion correction unit 321. Note that the imaging means of the present invention is not limited to a CCD camera, and for example, a CMOS sensor, an RGB sensor, or the like may be used.

Next, the operation of the third embodiment will be described focusing on the differences from the second embodiment.
As in the second embodiment, when the user presses the automatic correction key 411 on the operation panel 41, the control unit 20 starts the automatic correction process.
The CCD camera 46 captures an image projected on the screen SC and outputs the captured information to the control unit 20. Here, the imaging information is information obtained by digitizing, for example, the luminance value for each pixel of the CCD camera 46.

  The control unit 20 detects a projected image from imaging information captured by the CCD camera 46, and generates a correction amount for correcting the trapezoidal distortion of the projected image. For this correction amount, for example, the four corners of the projected image are detected from the luminance information of the captured image, and the shape of the trapezoidal distortion is obtained from the coordinates of the four corners. Then, the correction amount can be obtained by calculating a trapezoid shape in the opposite direction that cancels out the trapezoidal distortion. The generation of the correction amount is not limited to this. For example, the correction amount may be obtained by another method such as obtaining a trapezoidal distortion shape of a projected image by projecting a test pattern and capturing the pattern.

  Thereafter, after the correction frame image 100 is displayed on the projection image G1 based on the correction amount calculated by the control unit 20 by the same operation (S203 to S208) as in the second embodiment described above, The image signal is corrected to match.

  As described above, in the third embodiment, the same effect as in the second embodiment described above can be obtained.

  In the first to third embodiments, the case where the correction direction of the trapezoidal distortion correction is the vertical direction has been described. Alternatively, any trapezoidal distortion correction such as correcting the four corner vertices of the projected image to an arbitrary position may be used.

  In the first to third embodiments, the case where the image signal processing unit 32 includes the trapezoidal distortion correction unit 321 and the image signal input to the image signal processing unit 32 is corrected for trapezoidal distortion has been described. Not limited to this, a trapezoidal distortion correction unit 321 is provided at the subsequent stage of the image signal processing unit 32, and the trapezoidal distortion correction processing is performed when the image signal output from the image signal processing unit 32 is input to the liquid crystal light valve driving unit 14. You may make it do.

  In the first to third embodiments, the liquid crystal light valve 12 is used to modulate the light emitted from the light source 11, but the present invention is not limited to this, and other spatial light modulators may be used. For example, a DMD (Digital Micromirror Device) that projects an image by controlling the tilt of a mirror with a small area spread on a semiconductor substrate based on an image signal may be used. DMD is a registered trademark of Texas Instruments Incorporated.

1 is a block diagram illustrating a configuration of a projector according to a first embodiment. 3 is a diagram showing a configuration of an operation panel according to Embodiment 1. FIG. It is explanatory drawing explaining the keystone distortion correction of a projector. 3 is a flowchart showing an operation of keystone distortion correction according to the first embodiment. 6 is a diagram showing a projected image at the time of trapezoidal distortion correction according to Embodiment 1. FIG. FIG. 6 is a block diagram showing a configuration of a projector according to a second embodiment. 6 is a diagram showing a configuration of an operation panel according to Embodiment 2. FIG. 10 is a flowchart showing an operation of trapezoidal distortion correction according to the second embodiment. FIG. 10 is a block diagram illustrating a configuration of a projector according to a third embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Projector, 2 External connection apparatus, 11 Light source, 12R Liquid crystal light valve, 12G Liquid crystal light valve, 12B Liquid crystal light valve, 13 Projection optical system, 14 Liquid crystal light valve drive part, 20 Control part, 31 Image input part, 32 Image signal Processing unit, 33 frame memory, 41 operation panel, 42 remote control light receiving unit, 43 operation signal input unit, 44 storage unit, 45 angle detection unit, 46 CCD camera, 100 correction frame image, 320 OSD processing unit, 321 trapezoidal distortion correction unit , 410 Keystone correction key, 411 Auto correction key, RC remote control, SC screen.

Claims (8)

An image signal processing unit that generates an image signal for a projection image based on an input image signal;
A light modulation unit that modulates a light beam emitted from a light source based on the image signal generated by the image signal processing unit;
A projection optical system for enlarging and projecting the light beam modulated by the light modulation unit;
A trapezoidal distortion correction unit that generates a correction frame image signal corresponding to the contour of the image when correcting the trapezoidal distortion of the projected image based on a given correction amount;
The image signal processing unit generates a combined image signal by combining the image signal and the correction frame image signal,
The trapezoidal distortion correction unit corrects the image signal so that an image contour based on the image signal matches a correction frame image based on the correction frame image signal after an image based on the composite image signal is projected. Projector. An operation signal input unit for inputting an operation signal according to the operation content;
2. The apparatus according to claim 1, further comprising: a control unit that, when receiving an operation signal for correcting trapezoidal distortion from the operation signal input unit, outputs a correction amount corresponding to the operation signal to the trapezoidal distortion correction unit. The projector described. An angle detector that detects an inclination angle of the projection optical axis with respect to the horizontal direction;
The projector according to claim 1, further comprising a control unit that outputs a correction amount corresponding to the tilt angle detected by the angle detection unit to the trapezoidal distortion correction unit. Imaging means for capturing the projected image;
The control unit according to claim 1, further comprising: a control unit that outputs a correction amount for correcting trapezoidal distortion of the projected image to the trapezoidal distortion correcting unit based on an image captured by the imaging unit. projector. The controller is
The projector according to claim 2, wherein an image based on the composite image signal is projected, and the trapezoidal distortion correction unit corrects the image signal after a predetermined time has elapsed. The controller is
3. The trapezoidal distortion correction unit corrects the image signal when a predetermined operation signal is received from the operation signal input unit after an image based on the composite image signal is projected. The projector described.   The image signal processing unit, after the trapezoidal distortion correction unit corrects the image signal, stops generating the composite image signal and deletes the correction frame image from the projection image. Item 7. The projector according to any one of Items 1 to 6. A method for controlling a projector that generates an image signal for a projection image based on an input image signal, modulates light from a light source based on the image signal, and projects an image.
Obtaining a correction amount;
Generating a correction frame image signal corresponding to the contour of the image when correcting the trapezoidal distortion of the projected image based on the correction amount;
Generating a composite image signal obtained by combining the image signal and the correction frame image signal;
Projecting an image from the composite image signal;
And a step of correcting the image signal so that an outline of the image based on the image signal matches a correction frame image based on the correction frame image signal.

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