JP2005181726A - Projector apparatus and method for adjusting projected image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector apparatus capable of displaying an image over the display area of a screen with a simple configuration. <P>SOLUTION: The projector apparatus comprises a light receiving sensor 21 for receiving reflected light and outputting an electric signal corresponding to received light quantity, an operation part 22 for applying operation to an output from the light receiving sensor 21 and outputting sensor data and a control circuit 3 for controlling display by using the sensor data so that an image pattern is displayed over the display area of the screen. The control circuit 3 performs control for matching the end part 13 of the image pattern with the end part 11 of the screen 1 by comparing the position of a sensor which receives reflected light from the end part 11 of the screen 1 with the position of a sensor which receives reflected light from the end part 13 of the image pattern. Thereby an image can be displayed over the display area of the screen 1 with the simple configuration. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a projector device, and more particularly to a projector device having a function of displaying an image in a full screen display area (hereinafter referred to as an auto zoom function) and a projected image adjustment method in the projector device.

  A projector apparatus having an auto zoom function is disclosed in Patent Document 1. The projector device disclosed in Patent Document 1 includes an active distance measuring device that measures the distance from the projector device to the screen. The light emitting element of the distance measuring device is moved up, down, left, and right, and a signal is input to the light receiving element. Investigating changes in level. Since the reflectance of the projection light changes greatly between the screen and the screen, the edge of the screen can be detected. When the screen edge is detected, the screen size is calculated from the amount of movement of the light emitting element and the focal length information of the projection lens, and auto-zoom is performed based on the screen size.

JP-A-6-27431

  However, the drive mechanism for moving the light emitting element is a mechanism that is not originally required for the projector apparatus, and there is a problem that the apparatus configuration becomes large and the apparatus becomes expensive.

  Further, the size of the screen must be calculated from the movement amount of the light emitting element and the focal length information of the projection lens, and unnecessary calculation processing occurs.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a projector device and a projection image adjustment method capable of realizing an auto zoom function with a simple configuration.

  In order to achieve the above object, the projector apparatus according to claim 1 includes an image projecting unit that enlarges and displays an image on a screen, and a sensor data output unit that includes a sensor having a plurality of pixels and outputs sensor data according to the amount of received light. And the pixel that has received the reflected light at the edge of the screen and the pixel that has received the reflected light at the edge of the image projected on the screen. And a control means for controlling the image projection means so as to match with the end portion.

  According to the first aspect of the present invention, the pixel of the sensor that receives the reflected light at the edge of the screen is compared with the pixel of the sensor that receives the reflected light at the edge of the image projected on the screen. The image projecting means is controlled so that is aligned with the edge of the screen. Therefore, an image can be displayed in the entire display area of the screen with a simple configuration. In addition, since it is not necessary to calculate the screen size, the calculation process can be omitted.

  According to a second aspect of the present invention, in the projector device according to the first aspect, the control means selects sensor data to be compared with a predetermined threshold value from the central portion toward the end portion of the sensor. By detecting sensor data that exceeds the threshold value, the pixel that has received reflected light at the edge of the screen or the pattern image is detected.

  According to the second aspect of the present invention, the comparison between the predetermined threshold value and the sensor data is performed from the center to the end of the sensor. Since the central part of the sensor receives reflected light from the screen or image, particularly reflected light corresponding to white, the sensor data value is substantially constant, and the sensor data at the screen edge and the image edge are judged. Becomes easier.

  According to a third aspect of the present invention, in the projector device according to the first or second aspect, when the control means determines that the end of the image is outside the end of the screen, the image The image projecting means is driven in a direction to reduce the image, the image is stored in the screen, and the end of the image is aligned with the end of the screen while enlarging the image.

  According to the third aspect of the present invention, when it is determined that the edge of the image is outside the edge of the screen, the image is reduced and stored in the screen, and the edge of the image is enlarged while the image is enlarged. Aligned with the edge. Since the value of sensor data outside the screen changes depending on the arrangement state of the screen, it is difficult to match the screen and the edge of the image in the direction of reducing the image. Therefore, the size of the image can be accurately adjusted to the screen size by reducing the size of the image so that the image is projected smaller than the screen and adjusting the image to the screen edge while enlarging the image.

  A projector device according to a fourth aspect is the projector device according to any one of the first to third aspects, wherein an edge of a white image is black in the image.

  In the invention described in claim 4, the image is an image in which the edge of the white image is black. Accordingly, since the sensor data value can be different between the white image and the black image at the end, it is easy to determine the end of the image.

  A projector device according to a fifth aspect is the projector device according to any one of the first to fourth aspects, wherein an end portion of the screen is formed in black.

  In the invention described in claim 5, the end of the screen is formed in black. Accordingly, since the sensor data value can be different between the display area and the edge of the screen, it is easy to determine the edge of the screen.

  The projected image adjustment method according to claim 6, wherein a reflected light of the screen is received by a sensor having a plurality of pixels, and a sensor data output step of outputting sensor data corresponding to the amount of reflected light, and a sensor from the sensor Based on the data, a screen end position specifying step for specifying the pixel that has received reflected light from the screen end portion, an image projecting step for projecting an image on the screen, and reflected light on the screen of the image by the sensor. A second sensor data output step for receiving sensor light and outputting sensor data corresponding to the amount of reflected light; and the pixel that has received reflected light at the edge of the image projected on the screen by sensor data from the sensor. The image edge specifying step for specifying, the pixel receiving the reflected light at the screen edge, and the reflected light at the edge of the image projected on the screen By comparing the pixel that has received, it is characterized by having an image adjustment step of bringing the end portion of the screen end of the image.

  The invention according to claim 6 compares the pixel of the sensor that has received the reflected light at the edge of the screen with the pixel of the sensor that has received the reflected light at the edge of the image projected on the screen. Is aligned with the edge of the screen. Therefore, an image can be displayed in the entire display area of the screen by a simple procedure. In addition, since it is not necessary to calculate the screen size, the calculation process can be omitted.

  The projection image adjustment method according to claim 7 is the projection image adjustment method according to claim 6, wherein sensor data to be compared with a predetermined threshold value is selected from the center to the end of the sensor, By detecting sensor data that exceeds a threshold value, the pixel that has received reflected light at the edge of the screen or the pattern image is detected.

  According to the seventh aspect of the present invention, the comparison between the predetermined threshold value and the sensor data is performed from the center to the end of the sensor. Since the central part of the sensor receives reflected light from the screen or image, particularly reflected light corresponding to white, the sensor data value is substantially constant, and the sensor data at the screen edge and the image edge are judged. Becomes easier.

  The projection image adjustment method according to claim 8 is the projection image adjustment method according to claim 6 or 7, wherein the image adjustment step is performed when the edge of the image is outside the edge of the screen. The image is reduced and stored in the screen, and the edge of the image is aligned with the edge of the screen while enlarging the image.

  According to the eighth aspect of the present invention, when it is determined that the edge of the image is outside the edge of the screen, the image is reduced and stored in the screen. Aligned with the edge. Since the value of sensor data outside the screen changes depending on the arrangement state of the screen, it is difficult to match the screen and the edge of the image in the direction of reducing the image. Therefore, the size of the image can be accurately adjusted to the screen size by reducing the size of the image so that the image is projected smaller than the screen and adjusting the image to the screen edge while enlarging the image.

  The present invention can display an image over the entire display area of a screen with a projector device having a simple configuration.

  The best embodiment of the present invention will be described with reference to the accompanying drawings.

  First, the configuration of the projector apparatus according to the present embodiment will be described with reference to FIG. As shown in FIG. 1, the projector device 2 of the present embodiment receives the reflected light of the image projected on the screen 1 by the projection lens optical system 8 and determines the contrast value for determining the focal position of the projected image. An automatic focus detection device 20 that calculates the distance, a first passive distance measuring device 30 that measures the distance from the projector device 2 to the screen 1 at a plurality of points in the left-right direction (horizontal direction) of the screen 1, and the projector device 2 An image is input from a second passive distance measuring device 40 that measures the distance to the screen 1 at a plurality of points in the vertical direction (vertical direction) of the screen 1 and a device such as a personal computer (not shown) to output image information. The projection image generation unit 5, the display drive unit 6 that outputs an image to the projection lens optical system 8, and the image output by the display drive unit 6 are screened. An optical system drive unit 7 comprising a projection lens optical system 8 that projects onto the screen 1 and a stepping motor that moves the projection lens optical system 8 along the optical axis in order to change the focal length of the projection lens optical system 8 And a memory unit 4 that stores data and commands necessary for the configuration of the projector device 2, and a control circuit 3 that controls these units.

  As shown in FIG. 1, the automatic focus detection device 20 receives a reflected light of an image projected on the screen 1 by the projection lens optical system 8 and calculates an electric signal output from the light receiving sensor 21. And a calculation unit 22 that calculates sensor data corresponding to the amount of received light and image contrast. In this embodiment, a CCD line sensor is applied as the light receiving sensor 21.

  The calculation unit 22 of the automatic focus detection apparatus 20 will be described with reference to FIG. As shown in FIG. 2, the calculation unit 22 includes a high-pass filter (hereinafter also referred to as HPF) 221 that extracts a high-frequency component from the electrical signal input from the light receiving sensor 21, and the amplitude of the luminance signal that is only the high-frequency component. A detector 222 that performs detection, an A / D converter 223 that converts the detection output of the detector 222 into digital sensor data, and digital sensor data output from the A / D converter 223 And an integrator 224 for integrating. Sensor data is output from the A / D converter 223, and contrast data of the image signal shown in FIG. 3 is output from the integrator 224.

  As shown in FIG. 3, the contrast appearing in the high-frequency component of the image signal has a characteristic that the contrast becomes maximum at the in-focus position and decreases as the position deviates from the in-focus position. Using this characteristic, the position (focus position) of the projection lens optical system 8 when an image photographed by the projection lens optical system 8 forms an image on the screen 1 is obtained (hereinafter, this method is hill-climbed and autofocused). Called).

  FIG. 4 is a diagram showing a configuration of projector device 2 shown in FIG. 1 as viewed from the front. A projection lens is provided in front of the projector device 2. The projection lens is included in a projection lens optical system (which may include a condenser lens) 8, and an image is projected onto the screen 1 through the projection lens.

  As shown in FIG. 4, the first passive distance measuring device 30 includes a pair of lenses 31 a and 31 b that are spaced apart by a base line length a in the horizontal direction on the plane that forms the front of the projector device 2. An imaging unit 31 is provided. Similarly, the second passive distance measuring device 40 includes a pair of lenses 41a and 41b that are spaced apart by a base line length b in the vertical direction on the plane that forms the front of the projector device 2 as shown in FIG. It has an imaging unit 41 provided. In this embodiment, as shown in FIG. 4, the direction parallel to the base line length a of the imaging unit 31 is referred to as the first reference direction of the projector device 2. A direction parallel to the base line length b of the imaging unit 41 is referred to as a second reference direction of the projector device 2.

  A pair of line sensors 31c and 31d separated by a base line length c are provided below the pair of lenses 31a and 31b separated by a base line length a. Similarly, a pair of line sensors 41c and 41d separated by a base line length d are provided below the pair of lenses 41a and 41b separated by a base line length b. As shown in FIG. 5A, the distance between the lenses 31a and 31b that are spaced apart by the baseline length a is longer than the distance between the line sensors 31c and 31d that are spaced apart by the baseline length c. It has become. Although not shown, the distance between the lenses 41a and 41b that are similarly spaced apart by the baseline length b is longer than the distance between the line sensors 41c and 41d that are spaced apart by the baseline length d. It has become. Therefore, as shown in FIG. 5B, the optical axes of the pair of lenses are arranged so as to be located outside the optical axes of the pair of line sensors. With this configuration, it is possible to widen the light receiving range of the passive distance measuring device as shown in FIG. Note that the lens indicated by the dotted line in FIG. 5A is a lens disposed at the normal position, and the light receiving range of this lens is indicated by the dotted line. A lens indicated by a solid line is a lens position in the present embodiment, and a light receivable range of the lens is indicated by a one-dot chain line.

  The configuration of the imaging unit 31 will be described with reference to FIG. A line sensor 31c is disposed below the lens 31a that receives light incident from the outside and spaced apart by the focal length f, and a line sensor 31d is disposed below the sensor 31b and spaced apart by the focal length f. ing. These line sensors 31c and 31d are composed of a pair of line CCDs having a plurality of photodetecting elements arranged in a straight line or other line type image pickup elements. The configuration of the line sensors 31c and 31d will be described later in detail for convenience of explanation. For the image formed on the line sensors 31c and 31d via the lenses 31a and 31b, the imaging unit 31 serially outputs an electrical signal corresponding to the light amount of the image via an output unit (not shown). As with the imaging unit 31, the imaging unit 41 is also separated from the lenses 41a and 41b by a focal length f and line sensors 41c and 41d are arranged, respectively.

  The calculation unit 32 calculates a correlation value while sequentially shifting at least one of the pair of image signals output from the line sensors 31c and 31d over a predetermined shift range. Similarly, the calculation unit 42 calculates a correlation value while sequentially shifting at least one of the pair of image signals output from the line sensors 41c and 41d over a predetermined shift range, and calculates the correlation value. Based on this, the distance to the screen 1 is calculated.

  The control circuit 3 calculates the tilt angle θ1 (see FIG. 7A) of the screen 1 with respect to the first reference direction (horizontal direction) of the projector device 2 based on the distance measurement calculation result of the first passive distance measuring device 30. . Similarly, the inclination angle θ2 of the screen 1 with respect to the second reference direction (vertical direction) of the projector device 2 (see FIG. 7B) is calculated based on the distance measurement calculation result of the second passive distance measuring device 40.

  The projection image generation unit 5 receives image data output from an image data output unit such as an external personal computer, converts the input image data into display data, and outputs the display data to the display drive unit 6.

  The display driving unit 6 functions as an image distortion correction unit, and includes a condenser lens optical system including a condenser lens (not shown) based on the tilt angles with respect to the first reference direction and the second reference direction calculated by the control circuit 3. 8 is adjusted to correct the trapezoidal distortion of the projected image. The display driving unit 6 functions as an autofocus unit that automatically adjusts the focus of a projection lens (not shown). The projection lens optical system 8 projects predetermined image light on the screen 1.

  Next, the operation principle of the first passive distance measuring device (external light triangular distance measuring method) 30 will be described with reference to FIG. FIG. 6 is a diagram showing how the first passive distance measuring device 30 measures the distance to the screen 1. The operation principle of the second passive distance measuring device 40 is the same as that of the first passive distance measuring device 30, and thus the description thereof is omitted.

  6A, a pair of lenses 31a and 31b are arranged apart from each other by a predetermined baseline length a extending in the horizontal direction on a plane constituting the front surface of the projector device 2. A pair of line sensors 31c and 31d that are spaced apart from the pair of lenses 31a and 31b by their focal lengths f and extend in the direction of the baseline length a are disposed below the plane that forms the front surface of the projector device 2. Yes. The optical axes of the lenses 31a and 31b are arranged so as to be located outside the optical axes of the pair of line sensors 31c and 31d. With this configuration, it is possible to widen the light receiving range of the passive distance measuring device as shown in FIG. On these line sensors 31c and 31d, an image T at a certain position on the screen 1 for distance measurement (ranging) is formed via the corresponding lenses 31a and 31b. In FIG. 6A, the measurement position T on the screen 1 is imaged on the line sensors 31c and 31d through the optical paths A and B in different directions and through the respective lenses 31a and 31b. .

  Assuming that the measurement position T exists at an infinite position, the measurement position T is located on the line sensors 31c and 31d at the focal length f from the pair of lenses 31a and 31b, and the optical axes 31ax of the lenses 31a and 31b. And 31bx are imaged at reference positions 31cx and 31dx. Here, when the measurement position T approaches from the infinity position along the direction A on the optical axis 31ax of the lens 31a and reaches the position LC in FIG. 4A, that is, the distance LC from the lens 31a to the screen 1, the measurement position is reached. Although T is imaged on the reference position 31cx on the line sensor 31c, it is imaged on the line sensor 31d at a position shifted by a phase difference (deviation amount) α from the reference position 31dx by the lens 31b. Is done.

  At this time, the distance LC from the principle of triangulation to the measurement position T is obtained by LC = af / α. Here, the base line length a and the focal length f are known values known in advance, and the distance LC can be measured by detecting the phase difference (shift amount) α from the reference position 31dx on the line sensor 31d. That is, the distance to the screen 1 can be detected. This is the operating principle of a passive line sensor distance measuring device for external light triangulation. The detection of the phase difference (deviation amount) α and the calculation of LC = af / α are executed by the calculation unit 32 shown in FIG.

  Detection of the phase difference (shift amount) α from the reference position 31dx of the line sensor 31d is performed by detecting the partial image data group iLm extracted from the pair of image data signal sequences IL and IR output from the pair of line sensors 31c and 31d, respectively. iRn is detected by the calculation unit 32 performing a correlation calculation.

  An outline of the correlation calculation will be described. As shown in FIG. 6 (B), the correlation calculation is performed by using the line sensors 31c and 31d as the line sensors 31c and 31d. This is a calculation that is detected while relatively shifting. In FIG. 6B, the position of the partial image data group iLm from one line sensor 31c is fixed to the reference position 31cx and used as the reference portion. The partial image data group iRn from the other line sensor 31d is shifted one pixel at a time as a reference portion, and the partial image data group iRn having the highest degree of coincidence with the reference portion is searched. The interval between the position on the line sensor 31d that generates the partial image data group iRn having the highest degree of coincidence and the reference position 31dx of the line sensor 31d is the phase difference (deviation amount) α.

  Since each of the line sensors 31c and 31d is composed of a pair of line CCDs in which a predetermined number of photodetecting elements (pixels) are arranged on a straight line having a predetermined length, the phase difference (shift amount) α is the partial image data. It can be easily obtained from the pixel position and pixel pitch in the image data signal sequence IR of the group iRn. In this way, the distance LC to the measurement position T in the same direction A as the optical axis 31ax of the lens 31a can be measured by detecting the phase difference (deviation amount) α.

  Next, the configuration of the line sensor will be described with reference to FIG. FIG. 8 shows the configuration of a line sensor when a pair of line sensors 31c and 31d detect distances in a plurality of directions. As shown in FIG. 8, by dividing the line sensors 31c and 31d into a plurality and setting a plurality of reference positions according to the distance measuring direction, the distance in a plurality of directions can be detected by one distance measuring device. That is, when distance measurement in a plurality of directions is performed by the pair of line sensors 31c and 31d, a plurality of distance measurement directions (R (right), C (center in this example) are included in the line sensor 31c as shown in FIG. ), L (left)), a plurality of distance measurement calculation areas (31cR, 31cC, 31cL) corresponding to a plurality of reference positions are provided. Similarly, a plurality of ranging calculation areas (31dR, 31dC, 31dL) corresponding to a plurality of reference positions based on a plurality of ranging directions (R, C, L) are provided in the line sensor 31d. Then, the amount of deviation from the reference position can be obtained by using partial video data in a pair of distance measurement calculation areas (31cR and 31dR, 31cC and 31dC, 31cL and 31dL) corresponding to the distance measurement direction.

  The projector device 2 of this embodiment has an auto zoom function for projecting an image over the entire display area of the screen 1. The operation procedure for realizing this function will be described with reference to the flowchart shown in FIG. First, in a state where an image is not projected on the screen 1, the position of the end of the screen 1 is detected and stored using the output of the light receiving sensor 21 (step S1). The electric signal output from the light receiving sensor 21 of the automatic focus detection apparatus 20 shown in FIG. Since the light receiving sensor 21 receives the reflected light from the screen 1, an electrical signal corresponding to the amount of reflected light from the screen 1 is output from each sensor of the light receiving sensor 21. As shown in FIG. 10A, the screen 1 includes a display area 10 for displaying an image and an end portion 11 formed in black over a predetermined width. For this reason, there is a difference in the amount of reflected light between the display area (white) 10 and the end (black) 11 of the screen 1, so that a considerable difference also occurs in the corresponding sensor data. By comparing the value of the sensor data with the threshold value, the end 11 of the screen 1 can be detected. Specifically, the comparison between the sensor data and the threshold value is performed from the center of the screen toward the edge, and the pixel whose sensor data first exceeds the threshold value (hereinafter, this pixel is referred to as pixel S) is the screen. It becomes a boundary between the display area 10 and the end 11. The sensor data used for detecting the screen edge may use any one of the sensor outputs of the line sensors 31c, 31d, 41c, and 41d, or a pair of line sensors 31c. The sensor output of 31d or the line sensors 41c and 41d may be used. In addition, when any one of the line sensors 31c, 31d, 41c, and 41d is used for detecting the screen end, only one end of the screen 1 in the horizontal direction or the vertical direction is detected by one line sensor. And the case where both ends are detected. For this reason, when detecting the edge of the screen using one line sensor, it is preferable to start the comparison with the threshold value from the output of the pixel located at the center of the line sensor.

  Next, autofocus processing for performing focusing so that the projected image is focused on the screen 1 (step S2), and trapezoidal distortion correction processing for correcting trapezoidal distortion caused by the positional relationship between the projector device 2 and the screen 1 (step S3). ) Etc., but the detailed procedure will be described later. It should be noted that the autofocus process and the trapezoidal distortion correction process are performed before the projection image adjustment process for aligning the edge part 13 of the image pattern with the edge part 11 of the screen, so that the edge part 13 of the image pattern is moved to the screen. It can be adjusted to the end portion 11 with high accuracy. That is, the accuracy of the auto zoom function can be improved. Further, during the screen edge detection process (step S1), the image pattern is not projected from the projector device 2 onto the screen 1, so that the light source included in the projection lens optical system 8 is not turned on. Therefore, by performing the screen edge detection process before the autofocus process and the trapezoidal distortion correction process, it is possible to save the trouble of switching the light source ON / OFF.

  Next, an image pattern for auto-zoom is projected onto the screen 1 to perform projection image adjustment processing (step S4). First, an image pattern for auto-zoom is projected onto the screen 1 to extract sensor data, and the position of the end of the image pattern is detected. The image pattern for auto zooming includes a white image region 12 and a black end portion 13. FIG. 10B shows a state in which an image pattern is projected on the screen 1. The image pattern may be projected on the screen 1 so that the center of the image pattern and the center of the screen 1 substantially coincide. If the center of the image pattern is greatly deviated from the center of the screen 1, there is a possibility that the image protrudes from the screen 1 even if the adjustment processing of the projected image is performed, or that the image is not projected to the full screen. The sensor data output from the light receiving sensor 21 and calculated and output by the calculation unit 22 includes the reflected light of the screen 1 and the reflected light of the image pattern, and compares the sensor data with a predetermined threshold value. By doing so, the end 11 of the screen and the end 13 of the image pattern can be detected. That is, the sensor data is compared with the threshold value from the center of the screen toward the edge, and a pixel in which the sensor data first exceeds the threshold value (hereinafter, this pixel is referred to as pixel P) is detected. If this pixel is at the same position as the pixel S detected in step S1, it can be determined that this is the boundary between the display area 10 and the end 11 of the screen 1. Further, when the position of the detected pixel P is different from the position of the pixel S (when closer to the screen center than the pixel S), this is the boundary between the image region 12 and the end portion 13 of the image pattern. As in the case of detecting the screen edge 11, the line sensor used for detecting the image pattern edge 13 uses any one of the line sensors 31c, 31d, 41c, and 41d. Alternatively, a pair of line sensors 31c and 31d or line sensors 41c and 41d may be used. Moreover, when one line sensor is used for the detection of the image pattern edge part 13, the case where the one end part of the target object is detected, and the case where the both end parts are detected are considered. For this reason, when detecting an edge using one line sensor, it is good to start the comparison with the threshold value from the output of the sensor located at the center of the line sensor.

  When the position of the pixel P is different from the position of the pixel S, that is, when the end 13 of the image pattern is detected, the image pattern is projected smaller than the screen size as shown in FIG. Therefore, the projection lens optical system 8 is driven so as to enlarge the image pattern (hereinafter, the drive of the projection lens optical system 8 in the direction of enlarging the image pattern is referred to as wide driving). For example, when a step motor is used as the lens driving means, one step is driven to the wide side, the sensor data at this position is taken out, and the screen edge 11 (position of the pixel S) and the image pattern edge 13 (pixel P Position). Thereafter, this process is repeated until the edge 13 of the image pattern and the edge 11 of the screen 1 coincide, that is, the position of the pixel P where the sensor data first exceeds the threshold value is the pixel S of the screen edge 11. Repeat until they match.

  Further, when the position of the pixel P is the same as the position of the pixel S, that is, when the screen edge 11 is detected, the image pattern is projected larger than the screen size as shown in FIG. Therefore, the projection lens optical system 8 is driven so as to reduce the image pattern (hereinafter, the driving of the projection lens optical system 8 in the direction of reducing the image pattern is referred to as tele-side driving), as shown in FIG. Thus, the image pattern is projected to be smaller than the screen size. For example, the projection lens optical system 8 is driven one step toward the tele side, sensor data at this position is taken out, and the screen end 11 and the image pattern end 13 are detected. This process is repeated until the image pattern end 13 is closer to the center than the screen end 11, that is, until the position of the pixel P is closer to the center than the position of the pixel S detected previously. Thereafter, wide side driving is performed to match the end 13 of the image pattern with the end 11 of the screen. Since the sensor data value outside the screen changes depending on the arrangement state of the screen 1, it is difficult to match the screen 1 and the edge of the image pattern in the direction of reducing the image pattern. Therefore, in this embodiment, the image pattern is reduced to a state in which the image pattern is projected smaller than the screen size, and the image pattern is adjusted to the screen edge 11 while enlarging the image pattern.

  Thus, the present embodiment compares the pixel of the sensor that has received the reflected light from the screen end 11 with the pixel of the sensor that has received the reflected light from the end 13 of the image pattern projected onto the screen 1. The edge 13 of the image pattern is aligned with the edge 11 of the screen 1. Accordingly, it is possible to display an image over the entire display area of the screen with a projector device having a simple configuration. In addition, since it is not necessary to calculate the screen size, the calculation process can be omitted.

  Further, the comparison between the predetermined threshold value and the sensor data is performed from the center of the screen 1 toward the end, that is, from the center of the line sensor toward the end. Since the central part of the line sensor receives reflected light of the screen 1 or the image pattern, particularly reflected light corresponding to white, the value of the sensor data is substantially constant. Therefore, it becomes easy to determine the sensor data of the screen end 11 and the image pattern end 13 from the difference between the sensor data of white and black, and the end can be reliably detected. Further, since it is possible to easily and reliably detect the end 11 of the screen and the end 13 of the image pattern, the projection lens optical system 8 may be driven from the current position to the tele side, or driven to the wide side. It is possible to easily determine whether it should be done.

  In the projector apparatus, since the aspect ratio of the projected image is constant, if the process of aligning the edge of the image pattern and the edge of the screen is performed in either the horizontal direction or the vertical direction, the other is inevitable. Will be matched.

  In this embodiment, the end 11 of the screen is black. However, if there is a black object (for example, a wall) behind the screen 1, the end 11 of the screen is sufficiently detected even if the entire screen 1 is white. can do.

  Next, a detailed procedure of each process described above will be described with reference to a flowchart. First, the details of the screen edge detection process (step S1 shown in FIG. 9) will be described with reference to the flowchart shown in FIG. In a state where the image is not projected onto the screen 1, the electric signal output from the light receiving sensor 21 is calculated by the calculating unit 22 to extract sensor data (step S10). Since the light receiving sensor 21 receives the reflected light of the screen 1, sensor data corresponding to the amount of reflected light of the screen 1 is output by performing calculation on the output of each sensor. As described above, the line sensor used to detect the screen end 11 may use any one of the line sensors 31c, 31d, 41c, and 41d, or a pair of lines. Sensors 31c and 31d or line sensors 41c and 41d may be used.

  The control circuit 3 compares the sensor data output from the calculation unit 22 with the threshold value from the center of the screen toward the end 11 (step S11). The comparison target is gradually moved to the sensor data on the screen end 11 side for the first time with comparison with the threshold value from the sensor data in the center of the screen. When sensor data larger than the threshold value is detected (step S11 / YES), the pixel number of the sensor data is stored (in the following description, this pixel number is S) (step S12). If all the pixels are compared with the threshold value and sensor data larger than the threshold value cannot be detected (step S13 / YES), an error is displayed on the display unit (not shown) of the projector device 2. Display is performed (step S14). Alternatively, an error display may be displayed and the screen edge detection process may be performed again. In the case where edge detection is performed using one line sensor, comparison with a threshold value may be started from the output of the sensor located at the center of the line sensor.

  Next, the operation procedure of autofocus (step S2 shown in FIG. 9) will be described with reference to the flowchart shown in FIG. Although hill-climbing autofocus is described here, autofocus is not limited to hill-climbing autofocus, and other methods can be applied. In the following, an example in which the projection lens optical system 8 is driven using a step motor will be described. However, other motors such as a DC motor may be used. In this case, the drive amount of the projection lens optical system 8 is controlled by the energization time of the DC motor. First, the projection lens optical system 8 is driven to the initial position by the optical system driving unit 7, and the area of the memory unit 4 for storing the measurement result is initialized (step S20). Information to be initialized includes a contrast value (cont) calculated by the automatic focus detection device 20, a contrast value (Max_cont) having the maximum value among the calculated contrast values, and from the initial position to the Max_cont position. Information on the number of steps.

  Next, an image pattern for autofocus suitable for automatic focus adjustment stored in advance in the projector device 2 is projected onto the screen 1 by the projection lens optical system 8 (step S21).

  Next, as shown in FIG. 3, the projection lens optical system 8 is moved from the initial position at a constant speed by the optical system driving unit 7 such as a stepping motor (start of feeding). The initial position is the position of the projection lens optical system 8 at which the position (focus position) where the image projected by the projection lens optical system 8 is focused is infinite. At the same time, the light receiving sensor 21 receives the reflected light of the image pattern projected on the screen 1 (step S22). The light receiving sensor 21 outputs an electrical signal corresponding to the amount of reflected light received to the subsequent calculation unit 22 (step S23). The electric signal from the light receiving sensor 21 is subjected to filter processing, A / D conversion processing, integration processing, and the like by the calculation unit 22 (step S24), and an image contrast value (cont) is calculated (step S25). The calculated contrast value (cont) is output to the control circuit 3.

  The control circuit 3 determines whether or not the contrast value (cont) calculated by the calculation unit 22 is larger than the maximum contrast value (Max_cont). The maximum contrast value (Max_cont) is the maximum value among the contrast values obtained before the calculated contrast value. If the calculated contrast value (cont) is larger than the maximum contrast value (Max_cont) (step S26 / YES), the contrast value (cont) is replaced as the maximum contrast value (Max_cont), and the number of steps up to this position (initial value) (When the position is counted as 0) is registered in the memory unit 4 (step S27). If the calculated contrast value is smaller than the maximum contrast value (Max_cont) (step S26 / NO), processing for this contrast value is performed. Exit.

  Next, the control circuit 3 checks whether or not the number of steps for driving the stepping motor has reached a preset number of steps (step S28). Since the number of steps for driving the projection lens optical system 8 from the initial position to the nearest position is determined in advance, it is determined whether or not the current number of driving steps has reached the number of steps up to this nearest position. If not reached (step S28 / NO), the contrast value is calculated from the electrical signal corresponding to the amount of reflected light output from the light receiving sensor 21, and the procedure of comparing with the maximum contrast value (Max_cont) is repeated. The nearest position is a position of the projection lens optical system 8 at which the projection lens optical system 8 can focus on a position closest to the projector device 2.

  When the current number of driving steps reaches the number of steps up to the nearest position (step S28 / YES), the measurement of the contrast value is terminated, and control is performed to move the projection lens optical system 8 to the detected Max_cont position. (Step S29). Through such a procedure, the projected image can be focused on the screen.

  Next, the procedure of trapezoidal distortion correction (step S3 shown in FIG. 9) will be described with reference to the flowchart shown in FIG. First, an image pattern for phase difference detection is projected on the screen 1 by the projection lens optical system 8 (step S30). An image pattern of white and black vertical stripes is used as the phase difference detection image so that the phase difference can be easily detected by the first passive distance measuring device 30 and the second passive distance measuring device 40. The reflected light of the phase detection image projected on the screen 1 is received by the first passive distance measuring device 30 and the second passive distance measuring device 40, and the projector device 2 reaches the plurality of measurement positions on the screen 1. The distance is measured (step S31). Reflected light of the phase difference detection image is received by the line sensors 31c, 31d, 41c, and 41d, and deviations (phase differences) from the reference positions of the line sensors are detected by the calculation units 32 and 42, respectively. The distance to the object (measurement position on the screen 1) is measured. The calculation unit 32 performs a correlation calculation on the partial image data groups extracted from the pair of image data signal sequences output from the line sensors 31c and 31d, and detects the shift amount. Similarly, the calculation unit 42 performs a correlation calculation on the image data output from the line sensors 41c and 41d, and detects a deviation amount. The distance measurement data measured by the first passive distance measuring device 30 and the second passive distance measuring device 40 is transmitted to the control circuit 3.

Next, angle calculation is performed using distance measurement data (step S32). The angle calculation will be described by taking as an example a method of calculating the tilt angle θ1 (see FIG. 7) of the screen 1 with respect to the first reference direction from the distance measurement data of the first passive distance measuring device 30. As shown in FIG. 14, the inclination angle of the screen 1 with respect to the first reference direction (the horizontal direction of the projector device 2) of the first passive distance measuring device 30 is θ1, and the distance calculation calculation area 31cC is set for the distance measurement position 1A. The distance calculation result is L1, the distance calculation result for the distance measurement position 1B using the distance calculation area 31cR is L2, the distance between the distance measurement position 1A and the optical axis L is L1 ′, When the distance between the ranging position 1B and the optical axis L is L2 ′, the inclination angle θ1 is
tan θ1 = (L2−L1) / (L1 ′ + L2 ′)
Is required.

  Here, L1: L1 ′ = f: P (1a−k) holds due to the similarity of the triangles. When this is expanded, L1 '= PL1 (1a-k) / f. Here, 1a is the pixel number corresponding to the contrast centroid position of the distance measurement position 1A imaged in the distance calculation calculation area 31cL, k is the pixel number of the line sensor corresponding to the optical axis, P is the pixel pitch of the line sensor, f Is the focal length. Similarly, L2 'can be expressed by L2' = PL2 (1b-k) / f. Here, 1b is a pixel number corresponding to the contrast gravity center position of the distance measurement position 1B imaged in the distance measurement calculation area 31cR. P and f are constants obtained at the design stage or the like, and these values are stored in the control circuit 3 in advance. In addition, since the method for obtaining the contrast center-of-gravity position is a known technique (see, for example, JP-A-8-75985), the description thereof is omitted in this embodiment. A similar method can be applied to a method of calculating the inclination angle θ2 of the screen 1 with respect to the second reference direction based on the distance measurement data of the second passive distance measuring device 40.

  When the inclination angles θ1 and θ2 are obtained, the control circuit 3 outputs the obtained inclination angles θ1 and θ2 to the display driving unit 6. The display driver 6 adjusts the projection lens optical system 8 including the condenser lens based on the horizontal and vertical tilt angles calculated by the control circuit 3 to correct the trapezoidal distortion of the projected image (step S33). In addition, based on the horizontal and vertical tilt angles calculated by the control circuit 3 in the projection image generation unit 5, display data of an image having a trapezoidal distortion opposite to the projection image is generated (keystone correction), and the trapezoid of the projection image is generated. You may make it correct | amend distortion electrically.

  Next, a detailed operation procedure of the projection image adjustment process (step S4 shown in FIG. 9) will be described with reference to the flowchart shown in FIG. First, an image pattern for auto zoom is projected onto the screen 1 (step S40). The image pattern for auto zooming includes a white image region 12 and a black end portion 13. An image pattern projected on the screen 1 is shown in FIG. The image pattern may be projected on the screen 1 so that the center of the image pattern and the center of the screen 1 substantially coincide. The light reflected by the screen 1 is received by the light receiving sensor 21 of the automatic focus detection device 20. An electrical signal corresponding to the amount of reflected light is sent from the light receiving sensor 21 to the calculation unit 22. The arithmetic unit 22 extracts a high frequency component from the input electric signal by the high-pass filter 221, performs amplitude detection by the detector 222, and outputs sensor data obtained by A / D converting the output of the detector 222 to the control circuit 3. (Step S41). As described above, the line sensor used for detecting the end portion may use any one of the line sensors 31c, 31d, 41c, and 41d, or a pair of line sensors 31c. 31d or line sensors 41c and 41d may be used.

  The sensor data calculated and extracted by the calculation unit 22 includes the reflected light of the screen 1 and the reflected light of the image pattern. By comparing the sensor data with the threshold value, the sensor data is compared with the edge 11 of the screen. The edge 13 of the image pattern can be detected. The control circuit 3 compares the sensor data with the threshold value from the center of the screen toward the edge, and detects a pixel whose sensor data first exceeds the threshold value (hereinafter, this pixel is referred to as a pixel P). . The pixel number of the pixel P is stored in the memory unit 4. In addition, even if the sensor data and the threshold value are compared in the direction from the center to the end of the screen, if sensor data having a value larger than the threshold value cannot be found in all pixels (step S46). / YES), an error is displayed on a display unit (not shown) (step S47). Further, after displaying the error display, the image pattern may be projected again on the screen 1 to perform the projected image adjustment processing. Further, in the case where edge detection is performed using one line sensor, comparison with a threshold value may be started from the output of the sensor located at the center of the line sensor.

  When the pixel P whose sensor data value first exceeds the threshold value is detected (step S42 / YES), the control circuit 3 compares the pixel P with the pixel S detected in the screen edge detection process (step S44). . If the pixel number of the pixel P is the same as the pixel number of the pixel S (step S44 / YES), it can be determined that this is the boundary between the display area 10 and the end 11 of the screen 1 (that is, the image The end of the pattern is outside the screen shown in FIG. 10C). Further, when the pixel number of the detected pixel P is different from the pixel number of the pixel S (that is, when the position of the pixel P is closer to the center of the screen than the position of the pixel S) (step S44 / NO), this is projected. It can be determined that this is the boundary between the image region 12 and the end 13 of the image pattern.

  When the pixel numbers of the pixel P and the pixel S do not match (step S44 / NO), as shown in FIG. 10B, the pixel P is closer to the center than the pixel S (the end of the image pattern). 13 is located on the inner side of the screen end 11), the projection lens optical system 8 is driven to the wide side to align the pixel P with the pixel S (the image pattern end 13 is the screen end 11). (Step S45). If the pixel numbers of the pixel P and the pixel S match (step 44 / YES), the projected image pattern is projected larger than the screen size as shown in FIG. Therefore, the image pattern is reduced (step S48) so that the pixel P can be detected inside the pixel S at the screen end 11. Thereafter, wide-side driving is performed to enlarge the image pattern and align the pixel P with the pixel S (step S49).

  Next, a detailed procedure of the wide side driving process (step S45 and step S49 in FIG. 15) will be described with reference to the flowchart shown in FIG. First, the projection lens optical system 8 is driven one step to the wide side (step S50). The image pattern is projected onto the screen 1 at this position, and the reflected light from the screen 1 is received by the light receiving sensor 21. The calculation unit 22 calculates the output of the light receiving sensor 21 and outputs sensor data (step S51). The control circuit 3 compares the sensor data with the threshold value from the center of the screen toward the screen edge (step S52). For the first time, comparison is made with the threshold value from the sensor data at the center of the screen. When sensor data larger than the threshold value is detected (step S52 / YES), the pixel number of the sensor data is stored (in the following description, this pixel number is P) (step S53). Note that, even if the sensor data and the threshold value are compared in the direction from the center to the edge of the screen, if sensor data having a value larger than the threshold value cannot be found in all pixels (step S55). / YES), an error is displayed on a display unit (not shown) (step S56).

  When the pixel P whose sensor data value first exceeds the threshold value is detected (step S52 / YES), the control circuit 3 compares the pixel P with the pixel S detected in the screen edge detection process (step S1). (Step S54). When the pixel number of the pixel P and the pixel number of the pixel S match (step S54 / YES), the end 13 of the projected image pattern can be matched with the end 11 of the screen, and thus this processing is finished. To do. If the pixel number of the pixel P does not match the pixel number of the pixel S, the processing from step S50 to step S53 described above is repeated to match the pixel number of the pixel P and the pixel number of the pixel S. Let

  Next, the detailed procedure of the tele-side drive process (step S48 in FIG. 15) will be described with reference to the flowchart shown in FIG. First, the projection lens optical system 8 is driven one step to the tele side (step S60). The image pattern is projected onto the screen 1 at this position, and the reflected light from the screen 1 is received by the light receiving sensor 21. The calculation unit 22 calculates the output of the light receiving sensor 21 and outputs sensor data (step S61). The control circuit 3 compares the sensor data with the threshold value from the screen center toward the screen edge (step S62). For the first time, comparison is made with the threshold value from the sensor data at the center of the screen, and the comparison target is gradually changed to the sensor data at the screen end 11 side. When sensor data larger than the threshold value is detected (step S62 / YES), the pixel number of the sensor data is stored (in the following description, this pixel number is P) (step S63). If sensor data and threshold values are compared in the direction from the center of the screen to the edge, sensor data having a value larger than the threshold value cannot be found in all pixels (step S65 / YES), an error is displayed on a display unit (not shown) (step S66).

  When the pixel P whose sensor data value first exceeds the threshold value is detected (step S62 / YES), the control circuit 3 compares the pixel P with the pixel S detected in the screen edge detection process (step 1). (Step S64). If the pixel number of the pixel P and the pixel number of the pixel S match (step S64 / YES), the projected image pattern is still projected larger than the screen size, so the above-described steps S60 to S63 are performed. The above processes are repeated so that the pixel number of the pixel P does not match the pixel number of the pixel S. If the pixel number of the pixel P and the pixel number of the pixel S do not match (step S64 / NO), it is determined that the end 13 of the projected image pattern is inside the end 11 of the screen. be able to. Therefore, the above-described wide side driving process is performed to enlarge and display the image pattern, and the end 13 of the image pattern is aligned with the end 11 of the screen 1.

  The above-described embodiment is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

2 is a diagram showing a configuration of a projector device 2. FIG. 2 is a block diagram showing a configuration of an automatic focus detection device 20. FIG. It is a figure for demonstrating hill-climbing autofocus. It is a figure which shows the structure which looked at the projector apparatus from the front. It is a figure for demonstrating the positional relationship of lens 31a, 31b, 41a, 41b and line sensor 31c, 31d, 41c, 41d. It is the figure which showed a mode that a screen distance-measures with a passive ranging device. (A) is a figure for demonstrating the inclination angle with respect to the horizontal direction of the screen 1, (B) is a figure for demonstrating the inclination angle with respect to the vertical direction of the screen 1. FIG. It is a figure which shows the structure of a line sensor. It is a flowchart which shows the procedure of an auto zoom process. It is a figure which shows the sensor data taken out from the output of the light receiving sensor 21, (A) shows the sensor data when the reflected light of the screen 1 is received, (B) shows that an image pattern is projected smaller than a screen size. (C) is a diagram showing the sensor data when the image pattern is projected larger than the screen size. It is a flowchart which shows the detailed procedure of a screen edge part detection process. It is a flowchart which shows the detailed procedure of an autofocus. It is a flowchart which shows the detailed procedure of trapezoid distortion correction. It is a figure for demonstrating the calculation method of an inclination angle. It is a flowchart which shows the detailed procedure of a projection image adjustment process. It is a flowchart which shows the detailed procedure of a wide side drive process. It is a flowchart which shows the detailed procedure of a tele side drive process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Screen 2 Projector apparatus 3 Control circuit 4 Memory part 5 Projection image generation part 6 Display drive part 7 Optical system drive part 8 Projection lens optical system 20 Automatic focus detection apparatus 21 Light receiving sensor 22 Calculation part 30 1st passive ranging device 31 Imaging Unit 31a, 31b Lens 31c, 31d Line sensor 32 Calculation unit 40 Second passive distance measuring device 41 Imaging unit 41a, 41b Lens 41c, 41d Line sensor 42 Calculation unit 221 HPF
222 Detector 223 A / D converter 224 Integrator

Claims (8)

Image projection means for enlarging and displaying an image on a screen;
Sensor data output means comprising a sensor having a plurality of pixels and outputting sensor data according to the amount of received light;
The pixel receiving the reflected light at the screen edge is compared with the pixel receiving the reflected light at the edge of the image projected on the screen, and the edge of the image is compared with the edge of the screen. Control means for controlling the image projection means so as to match the projector. The control means selects sensor data to be compared with a predetermined threshold value from the central part toward the end part of the sensor, and first detects the sensor data exceeding the threshold value, whereby the screen or The projector device according to claim 1, wherein the position of a sensor that receives reflected light at an edge of the image is detected. When the control means determines that the edge of the image is outside the edge of the screen, the control means drives the image projection means in a direction to reduce the image, and the image is transferred to the inside of the screen. The projector apparatus according to claim 1, wherein an end portion of the image is aligned with an end portion of the screen while enlarging the image. 4. The projector device according to claim 1, wherein an edge of the white image is black in the image. 5. The projector device according to claim 1, wherein an end portion of the screen is formed in black. A first sensor data output step of receiving reflected light of the screen by a sensor having a plurality of pixels and outputting sensor data corresponding to the amount of reflected light;
A screen end position specifying step for specifying the pixel that has received the reflected light from the screen end by sensor data from the sensor;
An image projecting step of projecting an image on the screen;
A second sensor data output step of receiving reflected light on the screen of the image by the sensor and outputting sensor data according to the amount of reflected light;
An image edge specifying step for specifying the pixel that has received the reflected light at the edge of the image projected on the screen, based on sensor data from the sensor;
The pixel that has received the reflected light at the edge of the screen is compared with the pixel that has received the reflected light at the edge of the image projected on the screen, and the edge of the image is used as the edge of the screen. A projection image adjustment method comprising: an image adjustment step for matching. By selecting sensor data to be compared with a predetermined threshold value from the center to the edge of the sensor, and detecting the sensor data exceeding the threshold first, the edge of the screen or the image The projection image adjustment method according to claim 6, wherein the pixel that receives the reflected light is detected. In the image adjustment step, when the edge of the image is outside the edge of the screen, the image is reduced and stored in the screen, and the edge of the image is enlarged while enlarging the image. The projection image adjustment method according to claim 6, wherein the projection image adjustment method is adjusted to an end portion of the screen.

Images