JP2014142466A - Projection device and control method of the same, program, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a focus unevenness in a projection surface to be generated when a projection device is tilted to a screen.SOLUTION: A projection device 100 has: projection means 171 for projecting an image onto a projection surface; adjustment means 170 for adjusting a focus position of a projection image; acquisition means 194 for acquiring a distance to the projection means from at least two positions spaced apart from each other by a predetermined distance of a periphery of the projection image; determination means 111 for determining whether or not the at least two positions are simultaneously focused from a difference between a maximum value of the distance and a minimum value thereof; and reduction means 140 for, when the at least two positions are not simultaneously focused, reducing the projection image on the basis of a distance acquired by the acquisition means.

Description

  The present invention relates to a projection apparatus.

  Conventionally, when installing a projector as a projection device, a user determines the position of the screen and the position of the projector in advance, and then the projection lens so that an optimal projection state can be obtained while viewing the image projected on the screen. The zoom and focus are adjusted. Also, if it becomes necessary to adjust the orientation of the projector and the lens shift amount, the zoom and focus of the projection lens must be adjusted again, and the same operation is repeated until the optimal projection state is obtained. It was complicated.

  For example, Japanese Patent Application Laid-Open No. 2004-268531 detects the accurate position information of the projector and the screen, and controls zoom, focus, and lens shift based on the detected position information. A technique for automatically obtaining a projected image has been proposed.

Japanese Patent No. 4090386

  The technique described in Patent Document 1 uses a projector and screen position information to automatically adjust a projection image. However, when the projector is tilted with respect to the screen, the out-of-focus portion generated by the focus distribution in the projection screen is not optimized over the entire projection screen. Therefore, as shown in FIG. 10, if there is a portion where the projection screen of the projector is not focused on the screen, it is necessary to individually adjust the zoom and focus so that the entire projection screen is focused.

  The present invention has been made in view of the above problems, and its object is to reduce the non-uniformity of focus in the projection screen that occurs when the projection apparatus is tilted with respect to the screen, and to optimize the focus position in the entire projection screen. It is to realize a technology that can be realized.

  In order to solve the above-described problems and achieve the object, a projection apparatus according to the present invention includes a projection unit that projects an image on a projection plane, an adjustment unit that adjusts a focus position of the projection image, and a predetermined periphery around the projection image. Acquisition means for acquiring the distance from the at least two positions separated by the distance to the projection means, and determination means for determining whether the at least two positions are in focus simultaneously from the difference between the maximum value and the minimum value of the distance And a reduction means for reducing the projection image based on the distance obtained by the acquisition means when the at least two positions are not in focus at the same time.

  According to the present invention, it is possible to reduce the non-uniformity of focus in the projection screen, which occurs when the projection apparatus is tilted with respect to the screen, and to optimize the focus position in the entire projection screen.

The block diagram which shows the apparatus structure of embodiment which concerns on this invention. 6 is a flowchart showing the basic operation of the projection apparatus of the present embodiment. The block diagram of an optical system control part. The block diagram of an image process part. The block diagram of an imaging part. 6 is a flowchart illustrating the operation of the projector according to the first embodiment. 10 is a flowchart showing the operation of the projector according to the second embodiment. 10 is a flowchart showing the operation of the projector according to the third embodiment. 10 is a flowchart showing the operation of the projector according to the fourth embodiment. The figure explaining the conventional subject.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. The embodiment described below is an example for realizing the present invention, and should be appropriately modified or changed according to the configuration and various conditions of the apparatus to which the present invention is applied. It is not limited to the embodiment. Moreover, you may comprise combining suitably one part of each embodiment mentioned later.

  Hereinafter, an embodiment in which the projection apparatus of the present invention is applied to, for example, a liquid crystal projector that projects a still image or a moving image will be described.

  <Apparatus Configuration> With reference to FIG. 1, an outline of the configuration and functions of a projection apparatus according to an embodiment of the present invention will be described.

  The liquid crystal projector according to the present embodiment (hereinafter referred to as a projector) controls the light transmittance of the liquid crystal element in accordance with an image to be displayed on the projection surface, and projects the light from the light source transmitted through the liquid crystal element onto the screen. Thus, the image is presented to the user.

  In FIG. 1, the projector 100 according to the present embodiment includes a CPU 110, a ROM 111, a RAM 112, an operation unit 113, an image input unit 130, and an image processing unit 140. The projector 100 also includes a liquid crystal control unit 150, liquid crystal elements 151R, 151G, and 151B, a light source control unit 160, a light source 161, a color separation unit 162, a color composition unit 163, an optical system control unit 170, and a projection optical system 171. Further, the projector 100 may include a recording / playback unit 191, a recording medium 192, a communication unit 193, an imaging unit 194, a display control unit 195, and a display unit 196.

  CPU 110 controls each operation block of projector 100. The ROM 111 stores a control program that describes the processing procedure of the CPU 110. The RAM 112 temporarily stores control programs and data as work memory. In addition, the CPU 110 temporarily stores the still image file and the moving image file read from the recording medium 192 by the recording / reproducing unit 191 and reproduces each still image and moving image using the program stored in the ROM 111. You can also Further, the CPU 110 can temporarily store the still image file and the moving image file received from the communication unit 193, and can reproduce each still image and moving image using the program stored in the ROM 111. In addition, the CPU 110 temporarily stores the image signal obtained by the imaging unit 194 in the RAM 112, generates a still image file or a moving image file using the program stored in the ROM 111, and records the still image file or moving image file on the recording medium 192. You can also.

  The operation unit 113 includes, for example, a switch, a dial, and a touch panel provided on the display unit 196. The operation unit 113 receives a user operation instruction and transmits an instruction signal to the CPU 110. For example, the operation unit 113 may be a signal reception unit (such as an infrared reception unit) that receives a signal from a remote controller (not shown) and transmits a predetermined instruction signal to the CPU 110 based on the received signal. Good. In addition, the CPU 110 receives control signals input from the operation unit 113 and the communication unit 193 and controls each operation block of the projector 100.

  The image input unit 130 receives a still image signal and a moving image signal from an external device. The image input unit 130 includes, for example, a composite terminal, an S video terminal, a D terminal, a component terminal, an analog RGB terminal, a DVI-I terminal, a DVI-D terminal, an HDMI (registered trademark) terminal, and the like. In addition, when receiving an analog still image signal or moving image signal, the image input unit 130 converts the received analog signal into a digital signal and transmits the digital signal to the image processing unit 140. Here, the external device may be any device such as a personal computer, a camera, a mobile phone, a smartphone, a hard disk recorder, or a game machine as long as it can output a still image signal or a moving image signal.

  As will be described in detail with reference to FIG. 4, the image processing unit 140 includes, for example, a microprocessor for image processing. To the liquid crystal control unit 150. Further, the image processing unit 140 does not need to be a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the image processing unit 140 by a program stored in the ROM 111. The image processing unit 140 can execute functions such as frame thinning processing, frame interpolation processing, resolution conversion processing, and distortion correction processing (keystone correction processing). In addition to the signal received from the image input unit 130, the image processing unit 140 can also perform the above-described change processing on the image or video reproduced by the CPU 110.

  The liquid crystal control unit 150 includes, for example, a control microprocessor, and is applied to the liquid crystal of the pixels of the liquid crystal elements 151R, 151G, and 151B of each liquid crystal panel based on the still image signal and the moving image signal processed by the image processing unit 140. The transmittance of the liquid crystal elements 151R, 151G, and 151B is adjusted by controlling the voltage to be applied. Note that the liquid crystal control unit 150 does not have to be a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the liquid crystal control unit 150 by a program stored in the ROM 111. For example, when a moving image signal is input to the image processing unit 140, the liquid crystal control unit 150 causes the liquid crystal control unit 150 to have a transmittance corresponding to an image every time one frame of image data is received from the image processing unit 140. The elements 151R, 151G, and 151B are controlled. The liquid crystal element 151 </ b> R is a liquid crystal element corresponding to red, and out of the light output from the light source 161, the light separated into red (R), green (G), and blue (B) by the color separation unit 162. Among them, the transmittance of red light is adjusted. The liquid crystal element 151 </ b> G is a liquid crystal element corresponding to green, and out of the light output from the light source 161, the light separated into red (R), green (G), and blue (B) by the color separation unit 162. Among them, the transmittance of green light is adjusted. The liquid crystal element 151 </ b> B is a liquid crystal element corresponding to blue, and of the light output from the light source 161, the light separated into red (R), green (G), and blue (B) by the color separation unit 162. Among them, the transmittance of blue light is adjusted.

  The light source control unit 160 includes, for example, a control microprocessor that controls on / off of the light source 161 and the amount of light. Note that the light source control unit 160 does not have to be a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the light source control unit 160 by a program stored in the ROM 111. The light source 161 is, for example, a halogen lamp, a xenon lamp, or a high-pressure mercury lamp, and outputs light for projecting an image or video on the screen 180. The color separation unit 162 includes, for example, a dichroic mirror and a prism, and separates light output from the light source 161 into red (R), green (G), and blue (B). In addition, when using LED etc. corresponding to each color as the light source 161, the color separation part 162 is unnecessary. The color composition unit 163 is composed of, for example, a dichroic mirror or a prism, and synthesizes red (R), green (G), and blue (B) light transmitted through the liquid crystal elements 151R, 151G, and 151B. Then, light obtained by combining the red (R), green (G), and blue (B) components by the color combining unit 163 is sent to the projection optical system 171. At this time, the liquid crystal elements 151 </ b> R, 151 </ b> G, and 151 </ b> B are controlled by the liquid crystal control unit 150 so as to have light transmittance corresponding to the image data input from the image processing unit 140. Therefore, when the light synthesized by the color synthesizing unit 163 is projected on the screen by the projection optical system 171, a still image or a moving image corresponding to the still image data or the moving image data input by the image processing unit 140 is displayed on the screen. Will be displayed.

  As will be described in detail with reference to FIG. 3, the optical system control unit 170 includes, for example, a control microprocessor, and controls the projection optical system 171. The optical system control unit 170 does not need to be a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the optical system control unit 170 by a program stored in the ROM 111. The projection optical system 171 projects the combined light output from the color combining unit 163 onto the screen. The projection optical system 171 includes a plurality of lenses and lens driving actuators. By driving the lenses with the actuators, the projection image can be enlarged, reduced, shifted, and focused.

  The recording / playback unit 191 plays back a still image file or a moving image file read from the recording medium 192, receives an image signal obtained by the imaging unit 194 from the CPU 110, and records it on the recording medium 192. Still image files and moving image files received from the communication unit 193 may be recorded on the recording medium 192. The recording / reproducing unit 191 includes, for example, an interface electrically connected to the recording medium 192 and a microprocessor for communicating with the recording medium 192. Note that the recording / reproducing unit 191 does not need to include a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the recording / reproducing unit 191 by a program stored in the ROM 111. The recording medium 192 can record still image files, moving image files, and other control data necessary for the projector according to the present embodiment. The recording medium 192 may be any type of recording medium such as a magnetic disk, an optical disk, or a semiconductor memory, and may be a detachable recording medium or a built-in recording medium.

  The communication unit 193 receives a control signal, an image signal, a still image file, a moving image file, and the like from an external device. For example, the communication unit 193 may be a wireless LAN, a wired LAN, USB, Bluetooth (registered trademark), or the like. The method is not particularly limited. Further, if the terminal of the image input unit 130 is, for example, an HDMI (registered trademark) terminal, CEC communication may be performed via the terminal. Here, the external device may be any device such as a personal computer, a camera, a mobile phone, a smartphone, a hard disk recorder, a game machine, and a remote controller as long as it can communicate with the projector 100.

  The imaging unit 194 is provided to capture a subject around the liquid crystal projector 100 and generate an image signal. The imaging unit 194 captures a still image or a movie projected via the projection optical system 171 (captures the screen direction). To do. Note that the imaging unit 194 is not limited to capturing the screen direction, and may capture the viewer side in the opposite direction to the screen, for example.

  The CPU 110 temporarily stores the image signal obtained by the imaging unit 194 in the RAM 112 and converts it into still image data or moving image data using a program stored in the ROM 111. In addition, the CPU 110 analyzes the converted still image data and moving image data, converts the data into in-focus data and luminance unevenness distribution data, and performs focus adjustment, lens aperture adjustment, and reduction processing by the optical system control unit 170 and the image processing unit 140. Color unevenness correction and the like are performed. Further, the CPU 110 converts the still image data or moving image data subjected to the above processing into a still image file or moving image file of a predetermined format and records it on the recording medium 192. The detailed configuration of the imaging unit 194 will be described later with reference to FIG.

  The display control unit 195 includes a display control microprocessor or the like, and controls the display unit 196 provided in the projector 100 to display an image such as an operation screen for operating the projector 100 or a switch icon. Note that the display controller 195 need not be a dedicated microprocessor. For example, the CPU 110 may execute the same processing as the display controller 195 by a program stored in the ROM 111. The display unit 196 displays an operation screen and a switch icon for operating the projector 100. The display unit 196 may be anything as long as it can display an image. For example, it may be a liquid crystal display, a CRT display, an organic EL display, or an LED display. Further, in order to post a specific button so that the user can recognize it, an LED or the like corresponding to each button may be made to emit light.

  Note that the image processing unit 140, the liquid crystal control unit 150, the light source control unit 160, the optical system control unit 170, the recording / playback unit 191, and the display control unit 195 according to the present embodiment perform processing similar to these operation blocks. There may be one or more possible microprocessors. Alternatively, for example, the CPU 110 may execute the same processing as that of each block by a program stored in the ROM 111.

  <Basic Operation> Next, the basic operation of the projector 100 of this embodiment will be described with reference to FIG. 1 and FIG.

  FIG. 2 is a flowchart showing the basic operation of the projector 100 of the present embodiment. 2 is realized by the CPU 110 developing the program stored in the ROM 111 in the work area of the RAM 112 and controlling each operation block. 2 starts when the user turns on the projector 100 with the operation unit 113 or the remote controller. When the user turns on the power of the projector 100 using the operation unit 113 or the remote controller, the CPU 110 starts supplying power from a power supply unit (not shown) to each unit of the projector 100 by a power supply control unit (not shown).

  Next, the CPU 110 determines the display mode selected by the operation of the operation unit 113 or the remote controller by the user (S210). One of the display modes of the projector 100 according to the present embodiment is an “input image display mode” for displaying still image data and moving image data input from the image input unit 130. In addition, one of the display modes of the projector 100 according to the present embodiment is a “file playback display mode” in which a still image file or a moving image file read from the recording medium 192 by the recording / playback unit 191 is displayed. In addition, one of the display modes of the projector 100 according to the present embodiment is a “file reception display mode” in which a still image file or a moving image file received from the communication unit 193 is displayed. In this embodiment, the case where the display mode is selected by the user will be described. However, the display mode at the time of turning on the power may be the display mode at the end of the previous time. These display modes may be set as the default display mode. In that case, the process of S210 can be omitted.

  Here, it is assumed that “input image display mode” is selected in S210.

  When the “input image display mode” is selected, the CPU 110 stands by until still image data or moving image data is input from the image input unit 130 (S220). If it is input (Yes in S220), the process proceeds to the projection process (S230).

  In S230, the CPU 110 causes the image processing unit 140 to change the number of pixels, the frame rate, the image shape, and the like of the still image data and the moving image data input by the image input unit 130, and performs processing for one processed screen. Is sent to the liquid crystal control unit 150. Then, the CPU 110 causes the liquid crystal control unit 150 to obtain a transmittance corresponding to the gradation level of each color component of red (R), green (G), and blue (B) of the received image data for one screen. The transmittance of the liquid crystal elements 151R, 151G, and 151B of each liquid crystal panel is controlled. Then, the CPU 110 controls the output of light from the light source 161 by the light source control unit 160. The color separation unit 162 separates the light output from the light source 161 into red (R), green (G), and blue (B), and separates each light into the liquid crystal elements 151R, 151G, and 151B of each liquid crystal panel. Supply. The amount of light of each color supplied to each liquid crystal element 151R, 151G, 151B is limited for each pixel of each liquid crystal element. The red (R), green (G), and blue (B) lights transmitted through the liquid crystal elements 151R, 151G, and 151B are supplied to the color synthesis unit 163 and synthesized again. The light synthesized by the color synthesis unit 163 is projected onto the screen 180 via the projection optical system 171.

  This projection processing is executed sequentially for each frame of image data while an image is being projected.

  At this time, when an operation instruction for the projection optical system 171 is input from the operation unit 113 by the user, the CPU 110 causes the optical system control unit 170 to change the focus of the projection image or change the magnification ratio of the optical system. The actuator of the projection optical system 171 is controlled so that it does.

  During execution of the projection processing, the CPU 110 determines whether or not an instruction to switch the display mode is input from the operation unit 113 by the user (S240). When an instruction to switch the display mode is input from the operation unit 113 (Yes in S240), the CPU 110 returns to S210 again and determines the display mode. At this time, the CPU 110 transmits a menu screen for selecting a display mode to the image processing unit 140 as OSD (On Screen Display) image data, and superimposes the OSD screen on the image being projected. The image processing unit 140 is controlled. The user selects a display mode while viewing the projected OSD screen.

  On the other hand, when the instruction for switching the display mode is not input from the operation unit 113 by the user during the projection processing (NO in S240), the CPU 110 determines whether or not the projection end instruction is input from the operation unit 113 by the user. Determination is made (S250). If an instruction to end projection is input from the operation unit 113 (YES in S250), the CPU 110 stops power supply to each operation block of the projector 100 and ends the projection process. On the other hand, when a projection end instruction is not input from the operation unit 113 (No in S250), the CPU 110 returns to S220, and thereafter, from S220 to S250 until a projection end instruction is input from the operation unit 113. Repeat the process.

  As described above, the projector 100 according to the present embodiment projects an image on the screen.

  In the “file playback display mode”, the CPU 110 causes the recording / playback unit 191 to read a file list of still image files and moving image files and thumbnail data of each file from the recording medium 192 and temporarily store them in the RAM 112. Then, based on the program stored in the ROM 111, the CPU 110 generates a character image based on the file list temporarily stored in the RAM 112 and image data based on the thumbnail data of each file, and transmits the image data to the image processing unit 140. . Then, the CPU 110 controls the image processing unit 140, the liquid crystal control unit 150, and the light source control unit 160 in the same manner as the normal projection processing (S230).

  Next, an instruction to select a character image or thumbnail corresponding to a still image file or a moving image file recorded on the recording medium 192 is input via the operation unit 113 on the projection screen. Then, the CPU 110 controls the recording / playback unit 191 to read the selected still image file or moving image file from the recording medium 192. Further, the CPU 110 temporarily stores the read still image file or moving image file in the RAM 112, and reproduces the still image or moving image based on the program stored in the ROM 111. Then, the CPU 110 sequentially transmits, for example, the reproduced still image data and moving image data to the image processing unit 140, and the image processing unit 140, the liquid crystal control unit 150, and the light source control unit 160, similarly to the normal projection processing (S230). To control.

  In the “file reception display mode”, the CPU 110 temporarily stores the still image file and the moving image file received by the communication unit 193 in the RAM 112, and stores the still image file and the moving image file based on the program stored in the ROM 111. Decode and play. Then, the CPU 110 sequentially transmits, for example, the reproduced still image data and moving image data to the image processing unit 140, and the image processing unit 140, the liquid crystal control unit 150, and the light source control unit 160, similarly to the normal projection processing (S230). To control.

  <Configuration of Optical System Control Unit> Next, the detailed configuration of the optical system control unit 170 of FIG. 1 will be described with reference to FIG.

  The focus control unit 301 adjusts the focus lens position according to an instruction from the CPU 110. The zoom control unit 302 adjusts the zoom lens position according to an instruction from the CPU 110. The lens aperture control unit 303 adjusts the aperture of the aperture according to an instruction from the CPU 110. The lens shift control unit 304 adjusts the lens shift position in accordance with an instruction from the CPU 110.

  The focus control unit 301, zoom control unit 302, lens aperture control unit 303, and lens shift control unit 304 notify the CPU 110 of the focus lens position, zoom lens position, aperture value, and lens shift position, respectively, and each information is stored in the RAM 112. Stored in

  Further, the optical system control unit 170 controls the projection optical system 171 in accordance with an instruction from the CPU 110.

  <Configuration of Image Processing Unit> Next, the detailed configuration of the image processing unit 140 of FIG. 1 will be described with reference to FIG.

  The image processing unit 140 performs image processing on the image data input from the outside by the image input unit 130. Specifically, the input processing unit 401 performs processing such as bit depth adjustment, level conversion, color space conversion, and frequency conversion on the image data in accordance with an instruction from the CPU 110, and sends the processed image data to the resolution conversion unit 402. The resolution conversion unit 402 converts the resolution of the image data subjected to the above processing in accordance with an instruction from the CPU 110 and sends the converted image data to the gradation conversion unit 403. The gradation conversion unit 403 performs gradation conversion processing such as gamma conversion, color conversion, and sharpness processing on the image data whose resolution has been converted based on an LUT stored in the RAM 112 in accordance with an instruction from the CPU 110. And sent to the image composition unit 404. The image composition unit 404 adds black image data to the resolution of the liquid crystal panel in accordance with the instruction from the CPU 110 to the image data subjected to the gradation conversion process, and sends the image data to the keystone correction unit 405. The trapezoidal correction unit 405 performs shape conversion on the image data having the resolution of the liquid crystal panel according to an instruction from the CPU 110 using a projective conversion matrix that is a parameter for shape conversion, and sends the image data to the panel correction unit 406. The panel correction unit 406 absorbs the characteristics of the liquid crystal panel with respect to the image data whose shape has been converted in accordance with an instruction from the CPU 110. Intensity unevenness correction is performed. The corrected image data is sent to the liquid crystal control unit 150, and the transmittance of the liquid crystal elements 151R, 151G, and 151B of each liquid crystal panel is controlled.

  <Configuration of Imaging Unit> Next, the detailed configuration of the imaging unit 194 in FIG. 1 will be described with reference to FIG.

  The imaging unit 194 includes a lens group 501 including a zoom lens and a focus lens that forms an optical image of a subject, an actuator 502 that drives the lens group 501, and an actuator control microprocessor 503 that controls the actuator 502. The imaging unit 194 also converts an object image formed by the lens group 501 into an electrical signal such as a CCD or CMOS image sensor 504, and an A / D that converts an image signal obtained by the image sensor 504 into a digital signal. A conversion unit 505 and an image processing microprocessor 506 are provided.

  A still image or a moving image projected via the projection optical system 171 is captured by the image sensor 504 through the lens group 501. The actuator control microprocessor 503 optimizes imaging conditions such as focus and zoom by controlling the actuator 502. An analog image signal captured by the image sensor 504 is converted into a digital signal by the A / D converter 505. The image processing microprocessor 506 analyzes the projection image data obtained by performing image processing on the digital signal, for example, by analyzing the edge portion of the projection image data to determine whether or not the edge portion of the projection image is in focus. Make a decision.

  [Embodiment 1] Next, the focus position setting process of Embodiment 1 will be described with reference to FIG. 6 is realized by the CPU 110 developing a program stored in the ROM 111 in the work area of the RAM 112 and controlling each operation block. 6 starts when the user turns on the projector 100 with the operation unit 113 or the remote controller. When the user turns on the power of the projector 100 using the operation unit 113 or the remote controller, the CPU 110 starts supplying power from a power supply unit (not shown) to each unit of the projector 100 by a power supply control unit (not shown).

  First, in S601, the CPU 110 determines whether the projector 100 is installed with an inclination with respect to the screen. When the image is tilted with respect to the screen, the CPU 110 performs trapezoid correction by the trapezoid correction unit 405 because the projected image on the screen is square but not rectangular. This trapezoidal correction may be performed automatically when the tilt of the projector 100 is detected by a sensor (not shown) and the tilt is detected, or may be performed manually while viewing the projected image.

  In step S <b> 602, the CPU 110 opens the aperture by the lens aperture controller 303 as an initial setting. As a result, the illuminance is highest.

  Next, in S603, the CPU 110 has a total of four points: a left and right intersection of the projection screen and the horizontal axis passing through the approximate center of the projection screen, and an upper and lower intersection of the projection screen and the vertical axis passing through the approximate center of the projection screen. Get distance data. As a specific method for acquiring the distance data, when the image processing microprocessor 506 of the imaging unit 194 determines that the focus is in focus, the encoding value of the focus position of the focus control unit 301 of the optical system control unit 170 is acquired. The value is stored in the RAM 112 as distance data. In the same manner, distance data is acquired sequentially for the four points. Further, the CPU 110 calculates an average value of the distance data of the four points and stores the value in the RAM 112 as a screen distance.

  Next, in S604, the CPU 110 extracts the maximum value and the minimum value from the distance data of the four points stored in the RAM 112, and stores (maximum value−minimum value) in the RAM 112 as a difference value of the distance data.

  In step S <b> 605, the CPU 110 reads out the focal length, the aperture value, the optical information of the diagonal length of the square of the display area on the liquid crystal panel, and the screen distance information from the RAM 112. The length of the diagonal diagonal of the display area on the liquid crystal panel means the length of the diagonal line of the active area on the liquid crystal panel according to the input signal. When the lengths of the two diagonal lines are different, the average value of the diagonal lines is set as the diagonal length of the square of the display area on the liquid crystal panel.

  Next, in S606, the CPU 110 performs calculations shown in the following formulas (1) to (4) using each information read in S605, and obtains the in-focus depth.

Depth of focus = Depth of focus in front + Depth of focus in rear (1)
Front focus depth = Allowable circle of confusion x Aperture value x Screen distance ² / (Focal distance ² + Allowable circle of confusion x Aperture value x Screen distance) (2)
Depth of focus = Allowable circle of confusion x Aperture value x Screen distance ² / (Focal distance ² -Allowable circle of confusion x Aperture value x Screen distance) (3)
Permissible circle of confusion = length of the diagonal of the display area on the liquid crystal panel / constant (constant is 1400) (4)
The in-focus depth in the above formulas (1) to (3) is a term corresponding to the depth of field in a camera or the like, and means a distance range in focus on the screen. Further, although the constant used for the permissible circle of confusion is 1400, it may be changed depending on the position of the user viewing the projection screen.

  In step S <b> 607, the CPU 110 compares the distance data difference value and the in-focus depth. If the distance data difference value is larger than the in-focus depth, the projection screen is reduced based on the relationship between the distance data difference value and the in-focus depth. The rate is calculated (S608). The reduction ratio is calculated by performing the calculation shown in the following formula (5).

Reduction ratio = focus depth distance / data difference value (5)
The in-focus depth of the above formula (5) corresponds to the depth of field of the camera or the like, and the constant used for the allowable circle of confusion can be changed.

  In step S <b> 609, the CPU 110 sets the reduction ratio calculated by the above equation (5) in the resolution conversion unit 402 of the image processing unit 140.

  Next, in S610, the CPU 110 sets the screen distance calculated in S603 in the focus control unit 301 of the optical system control unit 170, and returns to S603.

  On the other hand, if the distance data difference value is equal to or smaller than the in-focus depth in S607, the CPU 110 sets the screen distance calculated in S603 in the focus control unit 301 of the optical system control unit 170 and sets the focus position ( S611), this process is terminated.

  Note that the acquisition of distance data in S603 is not limited to the above four points (intersections between the projection screen and the horizontal axis and the vertical axis), but arbitrary points (first first) near one side of the projection image. And any two or more points separated by a predetermined distance such as an arbitrary point (second position) near the other side. It is also possible to select a point that is desired to be in focus. Further, the distance data is acquired using the encoded values of the imaging unit 194 and the focus control unit 301, but may be measured by a distance sensor or the like.

  In S604, the difference between the maximum value and the minimum value of the distance data of the four points is used as the distance data difference value. Instead of this value, the difference value of the distance data between the left end portion and the right end portion, the upper end portion, and the lower end The value obtained by multiplying the difference value of the distance data of the part by the aspect ratio (for example, × 4/3 in the case of 4: 3) may be compared, and the larger value may be used.

  In S607, the distance data difference value is compared with the in-focus depth, but some defocus is allowed, and the distance data difference value is compared with the in-focus depth multiplied by a constant. Also good.

  In S609, the resolution conversion unit 402 of the image processing unit 140 performs the electrical reduction process. However, the zoom control unit 302 of the optical system control unit 170 may perform the optical reduction process.

  When lens shift processing is performed by the lens shift control unit 304 of the optical system control unit 170, it is necessary to consider the lens shift amount in the setting of the focus position in S610 and S611.

  As described above, the projector according to the present embodiment has a focusing distance between any two points separated by a predetermined distance (for example, any point near one side of the projected image and any point near the other side). When these points are not in focus at the same time, the image is reduced. As a result, it is possible to reduce non-uniform focus within the projection screen that occurs when the projector is tilted with respect to the screen, and to optimize the focus position in the entire projection screen.

  In this embodiment, the liquid crystal projector has been described as an example. However, the present invention is not limited to the liquid crystal projector. The present invention can be applied to, for example, a DLP projector and other projection apparatuses as long as the apparatus projects onto a screen through a projection optical system such as a lens as in the present embodiment.

  [Embodiment 2] Next, a focus position setting process according to Embodiment 2 will be described with reference to FIG. Note that this embodiment is also an application example of a liquid crystal projector, and the apparatus configuration and basic operation are the same as those of the first embodiment, and thus description thereof is omitted. The configurations of the optical system control unit 170, the image processing unit 140, and the imaging unit 194 are the same as those in the first embodiment, and thus the description thereof is omitted.

  FIG. 7 is a flowchart showing the focus position setting process of the present embodiment. Note that the processing of S701 to S705 in FIG. 7 is the same as S601 to S605 described in FIG. 7 is realized by the CPU 110 developing a program stored in the ROM 111 in the work area of the RAM 112 and controlling each operation block. 7 starts when the user turns on the projector 100 with the operation unit 113 or the remote controller. When the user turns on the power of the projector 100 using the operation unit 113 or the remote controller, the CPU 110 starts supplying power from a power supply unit (not shown) to each unit of the projector 100 by a power supply control unit (not shown).

  In S706, using the information read out in S705, the CPU 110 calculates the aperture value by substituting the screen distance into the in-focus depth of the above formulas (1) to (4).

  In S707, the CPU 110 sets the aperture value calculated in S706 in the lens aperture controller 303 of the optical system controller 170 (S707).

  In step S708, the CPU 110 sets the screen distance calculated in step S703 in the focus control unit 301 of the optical system control unit 170. When the focus position is set, the process ends.

  In S706, the screen distance is substituted for the in-focus depth. However, a slight defocus is allowed, and a value obtained by multiplying the in-focus depth by a constant may be substituted for the screen distance.

  As described above, the projector according to the present embodiment acquires at least two in-focus distances separated by a predetermined distance, and performs an operation of narrowing the aperture when these points are not in focus at the same time. Yes. As a result, it is possible to reduce non-uniform focus within the projection screen that occurs when the projector is tilted with respect to the screen, and to optimize the focus position in the entire projection screen.

  [Third Embodiment] Next, a focus position setting process according to a third embodiment will be described with reference to FIG.

  The present embodiment is a combination of the first and second embodiments when there is a restriction on illuminance and the variable range of the aperture value is limited. After the aperture is adjusted, the image is reduced.

  Note that the apparatus configuration and basic operation of the liquid crystal projector of the present embodiment are the same as those of the first embodiment, and a description thereof will be omitted. The configurations of the optical system control unit 170, the image processing unit 140, and the imaging unit 194 are the same as those in the first embodiment, and thus the description thereof is omitted.

  FIG. 8 is a flowchart showing the focus position setting process of the present embodiment. 8 are the same as S601 to S605 and S610 described in FIG. 6, and S806, S812, and S813 are the same as S706 to S708 described in FIG. Therefore, a different process will be described. The operation of FIG. 8 is realized by the CPU 110 developing a program stored in the ROM 111 in the work area of the RAM 112 and controlling each operation block. 7 starts when the user turns on the projector 100 with the operation unit 113 or the remote controller. When the user turns on the power of the projector 100 using the operation unit 113 or the remote controller, the CPU 110 starts supplying power from a power supply unit (not shown) to each unit of the projector 100 by a power supply control unit (not shown).

  In S807, the CPU 110 compares the aperture value calculated in S806 with a limit value, and when the aperture value is smaller than the limit value, sets the aperture value to the limit value (S808).

  In S809, the CPU 110 calculates the reduction ratio of the projection screen by the above formulas (1) to (5) using the aperture value set in S808.

  In S810, the CPU 110 sets the reduction ratio obtained in S809 in the resolution conversion unit 402 of the image processing unit 140.

  If the aperture value is greater than or equal to the limit value in S807, the CPU 110 sets the aperture value calculated in S806 in the lens aperture controller 303 of the optical system controller 170 (S812).

  As described above, the projector according to the present embodiment acquires at least two in-focus distances separated by a predetermined distance, and when these points are not in focus at the same time, the operation for reducing the aperture and the image are reduced. Processing to reduce. As a result, it is possible to reduce non-uniform focus within the projection screen that occurs when the projector is tilted with respect to the screen, and to optimize the focus position in the entire projection screen.

  [Fourth Embodiment] Next, a focus position setting process according to a fourth embodiment will be described with reference to FIG.

  The present embodiment is a combination of the first and second embodiments when the reduction ratio is limited, and the aperture is adjusted after the image reduction processing.

  Note that the apparatus configuration and basic operation of the liquid crystal projector of the present embodiment are the same as those of the first embodiment, and a description thereof will be omitted. The configurations of the optical system control unit 170, the image processing unit 140, and the imaging unit 194 are the same as those in the first embodiment, and thus the description thereof is omitted.

  FIG. 9 is a flowchart showing the focus position setting process of the present embodiment. 9 are the same as S601 to S606 described in FIG. 6, and the processing of S908 and S912 is the same as S807 and S811 described in FIG. To do. 9 is realized by the CPU 110 developing the program stored in the ROM 111 in the work area of the RAM 112 and controlling each operation block. 9 starts when the user turns on the projector 100 with the operation unit 113 or the remote controller. When the user turns on the power of the projector 100 using the operation unit 113 or the remote controller, the CPU 110 starts supplying power from a power supply unit (not shown) to each unit of the projector 100 by a power supply control unit (not shown).

  In S907, the CPU 110 calculates the reduction ratio of the projection screen based on the in-focus depth calculated in S906, the distance data difference calculated in S904, and the above equation (5).

  In S908, the CPU 110 compares the reduction rate obtained in S907 with the limit value. If the reduction rate is smaller than the limit value, the limit value of the distance data difference obtained by the following equation (6) is set as the in-focus depth. The aperture value is substituted and the aperture value is calculated by the above formulas (1) to (4) (S909).

Distance data difference limit value = distance data difference x reduction rate limit value (6)
In S910, the CPU 110 sets the aperture value calculated in S909 in the lens aperture control unit 303 of the optical system control unit 170.

  In S911, the CPU 110 sets the larger value of the reduction ratio and the limit value obtained in S907 in the resolution conversion unit 402 of the image processing unit 140.

  As described above, the projector of this embodiment acquires at least two in-focus distances separated by a predetermined distance, and performs image reduction processing when these points are not in focus at the same time. After that, the aperture is reduced. As a result, it is possible to reduce non-uniform focus within the projection screen that occurs when the projector is tilted with respect to the screen, and to optimize the focus position in the entire projection screen.

  [Other Embodiments] The present invention is also realized by executing the following processing. That is, software (program) that realizes the functions of this embodiment is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, etc.) of the system or apparatus reads out and executes the program. It is processing to do.

Claims (15)

Projection means for projecting an image onto a projection plane;
Adjusting means for adjusting the focus position of the projected image;
Obtaining means for obtaining distances from the at least two positions separated by a predetermined distance around the projection image to the projection means;
Determining means for determining whether the at least two positions are simultaneously focused from a difference between the maximum value and the minimum value of the distance;
A projection apparatus comprising: a reduction unit that reduces the projection image based on a distance obtained by the acquisition unit when the at least two positions are not in focus at the same time.   The projection apparatus according to claim 1, wherein the reduction unit sets a reduction ratio of the projection image so that the at least two positions in the reduced image are simultaneously focused.   The projection apparatus according to claim 1, wherein the reduction unit sets a reduction ratio of the projection image based on a depth of focus of the projection unit. A correction means for correcting the shape of the projected image;
4. The projection according to claim 1, wherein the correction unit corrects the shape of the image, sets the reduction ratio by the reduction unit, and then adjusts the focus position by the adjustment unit. 5. apparatus. When the at least two positions are not in focus at the same time, the image forming apparatus further includes an aperture control unit that adjusts the aperture of the projection unit based on the distance obtained by the acquisition unit,
5. The projection apparatus according to claim 1, wherein the reduction unit sets a reduction ratio of the projection image using an aperture value of the aperture control unit. Projection means for projecting an image onto a projection plane;
Adjusting means for adjusting the focus position of the projected image;
Obtaining means for obtaining distances from the at least two positions separated by a predetermined distance around the projection image to the projection means;
Determining means for determining whether the at least two positions are simultaneously focused from a difference between the maximum value and the minimum value of the distance;
A projection apparatus comprising: a diaphragm control unit that adjusts a diaphragm of the projection unit based on a distance obtained by the acquisition unit when the at least two positions are not in focus at the same time.   The projection apparatus according to claim 6, wherein the aperture control unit sets the aperture value of the projection unit so that the at least two positions are simultaneously focused.   The projection apparatus according to claim 6, wherein the aperture control unit sets an aperture value of the projection unit based on a focus depth of the projection unit. A correction means for correcting the shape of the projected image;
9. The focus position is adjusted by the adjusting unit after the shape of the image is corrected by the correcting unit, the aperture value of the projecting unit is set by the aperture controlling unit, and the adjusting unit adjusts the focus position. The projection device according to item.   9. The projection apparatus according to claim 6, wherein after the aperture value of the projection unit is set by the aperture control unit, the focus position is adjusted by the adjustment unit. A reduction means for reducing the projection image based on the distance obtained by the acquisition means when the at least two positions are not in focus at the same time;
11. The projection apparatus according to claim 6, wherein the aperture control unit sets an aperture value of the projection unit using a reduction ratio of the reduction unit. A control method for a projection apparatus, comprising: a projection unit that projects an image onto a projection plane; and an adjustment unit that adjusts a focus position of the projection image,
An acquisition step of acquiring distances from at least two positions separated by a predetermined distance around the projection image to the projection unit;
A determination step of determining whether the at least two positions are in focus simultaneously from a difference between a maximum value and a minimum value of the distance;
And a setting step of setting a reduction ratio of the projection image based on the distance obtained by the acquisition step when the at least two positions are not in focus at the same time. A control method for a projection apparatus, comprising: a projection unit that projects an image onto a projection plane; and an adjustment unit that adjusts a focus position of the projection image,
An acquisition step of acquiring distances from at least two positions separated by a predetermined distance around the projection image to the projection unit;
A determination step of determining whether the at least two positions are in focus simultaneously from a difference between a maximum value and a minimum value of the distance;
And a setting step of setting an aperture value of the projection unit based on the distance obtained by the acquisition step when the at least two positions are not in focus at the same time.   The program which makes a computer function as each means of the projection apparatus of any one of Claim 1 thru | or 11.   A storage medium storing a program for causing a computer to function as each unit of the projection apparatus according to any one of claims 1 to 11.

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