JP2005331585A - Projector having device for measuring distance and tilt angle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector, having a distance and tilt angle measuring device for measuring the tilt angle of a projection surface with respect to the projection optical axis of the projector, and the distance to the projection surface, in order to correct the distortions of a video. <P>SOLUTION: The projector is constituted so that reflected light from the bright lines 71 and 72 of a test pattern projected in predetermined shape in a predetermined direction at a predetermined angle to the right and the left of the projection surface 70 may pass through an imaging lens 51 provided separately in the horizontal direction of a projection lens 21 and made incident on an optical position detection element 53 as the incident points 41 and 42 of the bright lines respectively. The space between the incident points becomes a fixed value, regardless of the distance when the projection surface 70 is perpendicular to the projection optical axis 27, and the entire incident position is moved correlated with the distance, and the space becomes larger or smaller than the fixed value, according to the tilt direction and the angle of the projection surface 70, whereby the tilt angle of the projection surface 70 to the projection optical axis of a projection device is calculated from the position information on the incident points and outputted as the tilt information. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projector, and more particularly to a projector having a distance tilt angle measuring device for calculating a distance to a projection surface of a projector to be used and a tilt angle between a projection optical axis of the projection device and a projection surface.

  With the rapid development of liquid crystal technology and DLP (registered trademark) (digital light processing) technology, the size and performance of projectors have increased, and the use of projectors for video projection has expanded. It is also attracting attention as a large-sized display device that can replace this.

  However, unlike a display-type television, a projector has a problem that a video image is distorted due to the relative relationship between the projection optical axis of the projector and the projection surface because the video screen is a screen or a wall. Patent Document 1 has a liquid crystal projector installation angle detection means and a distance detection means for detecting the distance between the liquid crystal projector and the projection target, and the angle of the liquid crystal display unit is adjusted by the angle calculated from both detection results. Is disclosed (see Patent Document 1). In this case, it is necessary to mechanically adjust the angle of the liquid crystal display unit. In Patent Document 2, the light spot of a laser pointer capable of angle control is projected onto a curved screen. On the other hand, a point image for measurement is generated, projected from the projector onto the screen, and photographed with a camera. Measure the position of the image and move the point image. When the two points coincide, replace the pixel coordinates on the frame memory of the point image with the coordinates on the input image of the light point and set in the coordinate conversion parameter memory. A distortion correction method is disclosed (see Patent Document 2). In this case, it is necessary to control the angle of the laser pointer, and the structure becomes complicated.

On the other hand, a technique for projecting an image without distortion on a screen by converting the coordinates of the frame memory of the projector according to the vertical and horizontal inclinations of the screen with respect to the projection optical axis of the projector has been put into practical use. For this reason, in order to measure the vertical tilt that is likely to cause distortion, the vertical tilt of the projector is detected by the gravity sensor on the premise that the screen is installed vertically, and distortion correction corresponding to the tilt is performed. Projectors have already been disclosed and sold (see Patent Document 3).
JP-A-9-281597 Japanese Patent Application Laid-Open No. 2001-169211 JP 2003-5278 A

  However, the method described in Patent Document 3 is based on the premise that the screen is installed vertically, and when the screen is not installed vertically or is inclined in the horizontal direction with respect to the projection optical axis of the projector. There is a problem that accurate distortion correction cannot be performed. There is also a liquid crystal projector having a tilt angle measuring device that can accurately measure the vertical and horizontal tilt angles of the screen with respect to the projection optical axis of the liquid crystal projector using a digital camera having a laser pointer and an image sensor for image distortion correction. It has been studied and is very good as a means for accurately obtaining the angle of the projector with respect to the screen, but the cost is high because a digital camera is used for the component device. In addition, with the generalization of projectors, there is an increasing demand for automatic adjustment of the focus of the projection lens.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a distance tilt angle measuring device that can measure the horizontal and vertical tilt angles of a projection surface with respect to the projection optical axis of a projector and the distance to the projection surface at a low cost for image distortion correction. It is to provide a projector.

The projector having the distance inclination angle measuring device of the present invention,
A projection device capable of projecting test pattern light for generating a first bright line and a second bright line parallel to predetermined positions on both sides of the projection surface from a projection lens; and a test pattern generation unit for controlling the test pattern light; A distance inclination angle measuring device, and an image control unit that corrects the distortion of the image projected on the projection surface based on the inclination angle between the projection optical axis of the projection device and the projection surface and projects the image from the projection device. . The distance inclination angle measuring device detects an incident position of an imaging lens disposed at a predetermined interval in a predetermined direction from a projection lens, and a reflected light from a bright line transmitted through the imaging lens, and outputs it as positional information. An optical position detecting element, a position of reflected light that has passed through the imaging lens from the first bright line and entered the optical position detecting element, and an optical position detecting element that has passed through the imaging lens from the second bright line. The tilt angle of the projection surface is calculated based on the interval with the position of the incident reflected light, the distance to the projection surface is calculated based on the incident position information of each reflected light, and the distance to the image control unit is calculated as the distance tilt angle information. A light receiving position analysis distance inclination angle calculation unit for outputting.

  The light receiving position analysis distance inclination angle calculation unit transmits the first bright line and the second bright line that are formed in parallel to the predetermined positions on both sides on the projection surface and is incident on the optical position detection element through the imaging lens. The distance to the bright line is calculated from the information on the incident position of the light, and when the projection surface is perpendicular to the projection optical axis of the projection lens, the distance between both incident positions that is constant regardless of the distance is used as a reference value. When the interval is equal to the reference value, the inclination angle of the projection surface is set to 0. When the interval is smaller than the reference value, the projection surface on the projection lens side with respect to the imaging lens is inclined away, and when it is larger than the reference value, the projection lens Assuming that the projection surface on the imaging lens side is tilted away from the projection lens, the tilt angle of the projection surface may be calculated based on the ratio between the interval between the two incident positions and the reference value and output as tilt information.

  The imaging lens is provided separately in the horizontal direction of the projection lens, and the optical position detection element is provided in the horizontal direction at a position where reflected light of bright lines formed separately on the projection surface incident from the imaging lens is input in the horizontal direction. The light receiving position analysis distance inclination angle calculation unit provided may calculate the horizontal inclination of the projection surface from the input position information of the reflected light of the optical position detection element, and further, the inclination angle with respect to the direction of gravity The image control unit may correct the distortion of the image projected on the projection surface based on the horizontal inclination and the vertical inclination and project the image from the projection device.

  The imaging lens is provided apart in the vertical direction of the projection lens, and the optical position detection element is perpendicular to the position where the reflected light of the bright line formed on the projection surface incident from the imaging lens is vertically separated. The light receiving position analysis distance inclination angle calculation unit provided may calculate the vertical inclination of the projection surface from the input position information of the reflected light of the optical position detection element.

  In another aspect, the first bright line and the second bright line in the vertical direction are generated at predetermined positions on the left and right sides away from the intersection of the projection optical axes of the projection surface, respectively, and at the intersection of the projection optical axes than the left and right bright lines. A projection device that can project a test pattern light that generates a long center bright line from the projection lens, a test pattern generation unit that controls the test pattern light, a distance inclination angle measurement device, and a projection optical axis of the projection device And an image control unit that corrects distortion of the image projected on the projection surface based on the inclination angle between the projection surface and the projection surface, and causes the projection device to project the image. The distance inclination angle measuring device detects an incident position of an imaging lens disposed at a predetermined interval in the horizontal direction from the projection lens and a reflected light from a bright line transmitted through the imaging lens, and outputs it as position information. An optical position detection element capable of two-dimensional measurement that detects a positional shift in the horizontal direction of the upper and lower ends of the reflected light of the central bright line and outputs it as position information; The horizontal tilt angle of the projection plane is calculated from the distance between the position of the reflected light incident on the optical position detection element and the position of the reflected light transmitted through the imaging lens from the second emission line and incident on the optical position detection element. Then, the distance to the projection surface is calculated from the incident position information of each reflected light, and the vertical inclination angle of the projection surface is calculated from the horizontal position shift values of the upper and lower ends of the reflected light of the central bright line. And distance tilt angle And a light receiving position analysis distance inclination angle calculator for outputting the image control unit as information.

  The optical position detection element may be a PSD, a CCD sensor, or a CMOS sensor, and the imaging lens may be an optical lens or an air lens (pinhole).

  The present invention projects a test pattern light that generates a predetermined bright line from a projection lens to a predetermined position on a projection surface, passes through an imaging lens arranged in the horizontal direction of the projection lens, and enters the optical position detection element. Since the distance from the incident position of the reflected light to the bright line is calculated, and the inclination angle between the projection optical axis of the projection device and the projection surface is calculated from the interval between the incident positions of the reflected light of the two bright lines projected apart, Easily calculate the horizontal and / or vertical tilt angles between the projection optical axis and the projection surface of the projection device, and correct the image projected on the projection surface by moving the display unit to the pixel of the image. There is an effect that it can be corrected to the state.

  Moreover, since the distance to the test pattern projected on the projection surface can be calculated, there is an effect that the focal length of the projection lens can be automatically adjusted.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic block diagram of a projector having a distance tilt angle measuring apparatus according to the first embodiment of the present invention, and FIG. 2 has a distance tilt angle measuring apparatus according to the first embodiment of the present invention. FIGS. 3A and 3B are schematic diagrams of a projector, FIG. 3A is a front view, FIG. 3B is a side view, FIG. 3C is a top view, and FIG. 3 shows a state of reflected light of test pattern light projected from the projection device onto the projection surface. FIG. 4 is a schematic diagram for explaining a method of obtaining the distance between the test pattern on the screen and the projector based on the incident point position of the reflected light of the bright line on the optical position detection element in FIG. FIG. 5 is an explanatory diagram, FIG. 5 is a schematic diagram showing a projected test pattern and the incident position of reflected light of the test pattern on the optical position detection device, and (a) is a schematic diagram of the test pattern projected from the projection lens. , (B) is a screen Schematic diagram showing the incident position of the reflected light of the test pattern when the projection optical axis is perpendicular to the screen, (c) is the reflected light of the test pattern when the screen is inclined in the horizontal direction with respect to the projection optical axis. FIG. 6 is a schematic diagram illustrating an incident position, and FIG. 6 is a schematic diagram for explaining a method of obtaining the distance between the bright line on the projection surface and the projector based on the incident point position of the reflected light of the bright line on the optical position detection element in FIG. FIG.

  The projector 10 includes a projection device 20 having a projection lens 21 and a display unit 22, an image control unit 23 that controls the image of the display unit 22, a distance inclination angle measurement device 30, and a central processing unit that controls the overall operation. 60. The distortion of the image on the projection surface 70 is corrected by controlling the output image of the display unit 22 according to the inclination angle calculated by the distance inclination angle measurement device 30. Image distortion correction is automatically performed by the central processing unit 60 in a predetermined procedure. When the focus of the projection lens 21 is automatically adjusted based on the distance information obtained by the distance tilt angle measurement device 30, the projection device 20 includes the focus adjustment unit 26.

  The projection device 20 has a test pattern light output function capable of projecting the predetermined test pattern formed by the test pattern generation unit 55 from the projection lens 21 onto the projection surface 70 at a predetermined direction and angle at a predetermined time. The distance inclination angle measuring device 30 includes an imaging lens 51 provided on the front surface of the projector 10 at a predetermined interval in the horizontal direction from the projection lens 21 and a bright line of a test pattern from the projection surface 70 passing through the imaging lens 51. An optical position detecting element 53 provided in the projector 10 in the horizontal direction so as to receive the reflected light and output the position information of the light receiving point, a light receiving position analysis distance inclination angle calculating section 54, and an image control section. 23 is a test pattern generator for causing a predetermined test pattern light to be projected from the projection lens 21 onto the projection surface 70 at a predetermined direction and angle at a predetermined time. And a 5. Here, the test pattern is two vertical lines projected from the projection lens 21 at the same left and right angles, and two bright lines are drawn on the left and right sides of the projection surface 70.

  The light receiving position analysis distance inclination angle calculation unit 54 reflects the reflected lights 33 and 34 from the vertical bright lines 71 and 72 drawn by the test pattern projected to the left and right in the horizontal direction on the projection surface 70 acquired by the optical position detection element 53. From the incident position information, the distance between the bright lines 71 and 72 of the test pattern on the projection surface 70 and the projector 10 and the horizontal inclination angle of the projection surface 70 are calculated and output to the image control unit 23. The distance is calculated by a table prepared in advance from the incident position information of each of the reflected lights 33 and 34 from the bright lines 71 and 72, and the horizontal inclination angle is prepared in advance from the interval between the incident positions of the reflected lights 33 and 34. It can be calculated by a table. Further, the distance from the projector 10 to the two bright lines 71 and 72 on the left and right sides on the projection surface 70 is determined from the incident position on each optical position detection element 53 and the projection optical axis 27 passing through the center of the imaging lens 51. Can be calculated as a function using the distance between the line parallel to the optical position detection element 53 and the intersection of the optical position detection element 53 as a variable, and the obtained distances to the respective bright lines 71 and 72 and the projection of the test pattern light. The horizontal inclination angle between the plane perpendicular to the projection optical axis 27 and the projection plane 70 can also be calculated from the interval between the two bright lines 71 and 72 obtained from the angle.

  The image control unit 23 controls the output video of the display unit 22 based on the tilt angle so as to correct the distortion. Here, the horizontal direction refers to the horizontal direction when the projector 10 is installed in a normal use state.

  The present invention can be applied regardless of whether the projector 10 is a liquid crystal projector or a DLP (registered trademark) (digital light processing) type projector, and the display unit 22 in the case of a liquid crystal projector is a liquid crystal display unit. The display unit 22 includes a DMD (digital micromirror device) display unit, a color wheel, and a light source.

  Next, a method for calculating the distance and the tilt angle in the projector having the distance tilt angle measuring apparatus according to the first embodiment of the present invention will be described.

  As shown in FIG. 2, the imaging lens 51 is provided on the front surface of the projector 10 at a predetermined interval in the horizontal direction from the projection lens 21. The optical position detection element 53 is provided in the horizontal direction inside the housing of the projector 10 so as to receive the reflected lights 33 and 34 from the projection surface 70 of the test pattern lights 31 and 32 that pass through the imaging lens 51. ing.

  During the distance tilt angle measurement operation, as shown in FIG. 3, predetermined test pattern lights 31 and 32 from the projection lens 21 are controlled in a predetermined direction, angle, and predetermined by control of the test pattern generation unit 55 and the image control unit 23. Is projected onto the projection surface 70 at the timing of. The shape of the test pattern is schematically shown in FIG. In FIG. 3, the projection surface 70 is described as being disposed perpendicular to the projection optical axis 27, and the test pattern lights 31 and 32 are vertical first bright lines 71 separated in the horizontal direction on the projection surface 70. The bright line reflected light 33, 34 is transmitted through the imaging lens 51, and two bright line incident points 41, 42 are formed on the optical position detection element 53. The Here, two incident points 41 and 42 are displayed, but since the optical position detection element 53 can acquire only one incident light position at the same time, this is displayed in combination with two position acquisition operations. It is a schematic diagram.

  First, this operation will be described in detail with respect to the first bright line 71. At the first time, the first test pattern light 31 is projected from the projection lens 21 toward the projection surface 70, and the vertical first bright line 71 is obtained. Formed on the projection surface 70. The first bright line 71 is a vertical line formed at a position away from the intersection of the projection optical axis 27 and the projection surface 70 of the projection apparatus 20 in the horizontal direction. The reflected light 33 from the first bright line 71 enters the imaging lens 51 and enters the optical position detection element 53 as the incident point 41 of the first bright line. Since there is only one incident point, the position of the first incident point 41 of the first bright line 71 is acquired and stored in the light receiving position analysis distance inclination angle calculation unit 54.

  At the second time, the second test pattern light 32 is projected from the projection lens 21 toward the projection surface 70, and a vertical second bright line 72 is formed on the projection surface 70. The reflected light 34 from the second bright line 72 enters the imaging lens 51 and enters the optical position detection element 53 as the incident point 42 of the second bright line 72. Since there is one incident point, the position 42 of the incident point of the second bright line 72 is acquired and stored in the light receiving position analysis distance inclination angle calculation unit 54.

  Next, a method for acquiring the distance between the projector 10 and the bright lines 71 and 72 and the inclination angle of the projection surface 70 will be described. For the sake of explanation, FIG. 4 shows only the positions and intervals of the main points in FIG. 3 and shows a state in which the test pattern is projected on two projection surfaces 70a and 70b that are separated from each other. . When test pattern light is projected onto the projection surface 70a perpendicular to the projection optical axis 27, bright lines are formed on CR1 and CL1, and the reflected light is incident on DR1 and DL1 of the optical position detection element 53. DR1 and DL1 are separated from the intersection O between the optical position detection element 53 and a line parallel to the projection optical axis 27 passing through the center point A of the imaging lens 51, respectively. When test pattern light is projected onto the projection surface 70b perpendicular to the projection optical axis 27 farther than the projection surface 70a, bright lines are formed at CR2 and CL2, and the reflected light enters the DR2 and DL2 of the optical position detection element 53. DR2 and DL2 are separated from the intersection O between the optical position detection element 53 and a line parallel to the projection optical axis 27 passing through the center point A of the imaging lens 51, respectively.

As described above, when the test pattern light is projected onto the projection surface 70 perpendicular to the projection optical axis 27, the incident position of the reflected light of the right bright line moves so as to approach the center point O as the projection surface 70 moves away. The incident position of the reflected light of the left bright line moves away from the center point O. This is because the center A of the imaging lens 51 is to the left of the center B of the projection lens 21. Here, the right triangle A-CR1-E1 is similar to the right triangle A-DR1-O.
(C1 + d) / L1 = f1 / e, and substituting c1 = L1 × tan α,
f1 = e × tan α + e × d / L1.

The right triangle A-CL1-E1 is similar to the right triangle A-DL1-O,
(C1-d) / L1 = f2 / e, and substituting c1 = L1 × tan α,
f2 = e × tan α−e × d / L1.

  Therefore, f1 + f2 = 2 × e × tan α, and it can be seen that it is independent of the distance L1 to the projection surface 70.

Similarly, when the incident position of the reflected light from the projection surface 70b is obtained,
g1 = e × tan α + e × d / L2
g2 = e × tan α−e × d / L2, and g1 + g2 = 2 × e × tan α.

  As described above, when the test pattern light is projected onto the projection surface 70 perpendicular to the projection optical axis 27, the first bright line incident point 41 and the second bright line incident point regardless of the distance to the projection surface 70. Since the distance 42 is the same, the projection plane 70 is perpendicular to the projection optical axis 27 if the distance between the incident point 41 of the first bright line and the incident point 42 of the second bright line is the value. On the other hand, when the distance to the projection surface 70 increases, the two incident points 41 and 42 move to the left in FIGS. 3 and 4. Therefore, if a table is created in advance, the position to the projection surface 70 depends on the position of each incident point. Can get the distance.

  When the projection surface is inclined, for example, the position of the left bright line remains at the position CL1 in FIG. 4, and the right bright line moves to the position CR2 in FIG. In this case, the incident point 42 of the second bright line remains DL1 and the incident point 41 of the first bright line moves from DR1 to DR2 on the right side, and the incident point 41 of the first bright line and the incident of the second bright line The interval between the points 42 is narrowed. (B) and (c) of FIG. 5 show the state. On the contrary, when the position of the right bright line remains at the position CR1 in FIG. 4 and the left bright line moves to the position CL2 in FIG. While the incident point 41 remains DR1, the incident point 42 of the second bright line moves from DL1 to the right DL2, and the distance between the incident point 41 of the first bright line and the incident point 42 of the second bright line is increased. That is, when the projection plane is parallel, the right side is inclined when it is narrower than the reference interval, and when the projection plane is wider than the reference interval, the left side is inclined so that it is narrowed or widened. Correlates with the tilt angle. If it becomes narrower, it is inclined in the direction away from the right side, and if a table of correlation between the incident point position and the distance is provided in advance, the distance to the second bright line is obtained at the position of the incident point 42 of the second bright line. In addition, if a table of correlation between the ratio between the interval between the two incident points and the reference interval and the tilt angle is provided in advance, the tilt angle can be obtained from the interval between the two incident points. For example, when the distance is larger than the reference interval, the left side is inclined in a direction away from the left side, and the distance to the first emission line can be obtained at the position of the incident point 41 of the first emission line. The inclination angle can be obtained from the correlation with

  The vertical distance between the projector 10 and the bright lines 71 and 72 on the projection surface 70 can also be calculated. FIG. 6 is a schematic partial enlarged view for explaining a method of obtaining the distance between the bright lines 71 and 72 on the projection surface 70 and the projector 10 based on the incident point position of the bright line of the test pattern on the optical position detecting element 53. A description will be given with reference to an example in which the plane perpendicular to the projection optical axis 27 and the projection plane 70 are inclined. The center point of the imaging lens 51 is A, the center point of the projection lens 21 is B, the position of the first bright line 71 is CR2, and the plane perpendicular to the projection optical axis 27 including the first bright line 71 and the projection optical axis 27 The intersection is D, the intersection of the axis extending parallel to the projection optical axis 27 from the center point A of the imaging lens 51 and the plane perpendicular to the projection optical axis 27 including the first emission line 71 is E, and the reflected light of the first emission line 33, the incident point 41 to the optical position detecting element 53 is DR2, the intersection of the optical position detecting element 53 and the axis extending parallel to the projection optical axis 27 from the center point A of the imaging lens 51 is O, and the first bright line 71. The position of the line of intersection between the plane parallel to the projection optical axis 27 including and the plane perpendicular to the projection optical axis 27 including the imaging lens 51 is FR2, and the plane perpendicular to the projection optical axis 27 including the center of the imaging lens 51 The distance from one bright line 71, that is, the length of the line segment CR2-FR2, is L2, and the line segment The length of R2-O is g1, the distance between the imaging lens 51 and the optical position detection element 53, that is, the length of the line segment A-O is e, the length of the line segment CR2-D is c2, and the imaging lens 51 and The distance from the projection lens 21, that is, the length of the line segment AB and the line segment DE is d, and the projection angles of the first test pattern light 31 and the second test pattern light 32 are α.

Right triangle A-CR2-E and right triangle A-DR2-0 are similar,
(L2 × tan α + d) / g1 = L2 / e
The distance L2 between the surface perpendicular to the projection optical axis 27 including the center of the imaging lens 51 and the first bright line 71 is
L2 = e × d / (g1-e × tan α)
It becomes. Here, since e, d, and α are known, L2 can be calculated if g1, that is, the position of the reflected light from the bright line in the optical position detecting element 53 is known.

Similarly, the distance to the second bright line 72 can be calculated. However, in this case, + d becomes -d,
L1 = e × d / (e × tan α−f2)
Since e, d, and α are already known, L1 can be calculated if the position of the reflected light from the bright line in the optical position detecting element 53 is known.

  If each distance can be calculated, since the projection angle α is known, the distances c2 and c1 on the plane perpendicular to the projection optical axis 27 between the first bright line 71 and the second bright line 72 can be calculated. The inclination angle can be calculated by a trigonometric function from the difference in distance to both emission lines (L2−L1) and the distance between both emission lines (c1 + c2).

  When the average distance between the projector 10 and the projection surface 70 is calculated by the light receiving position analysis distance inclination angle calculation unit 54 as an average value of the distances obtained from the positions of the two incident points, and automatic focus adjustment is performed. The focus adjustment unit 26 can be controlled by this average distance.

  The projection surface 70 is often a vertical surface when a wall or a screen is used, and the projector 10 is installed horizontally, between the projection optical axis 27 of the projection device 20 and a vertical line on the projection surface 70. When the tilt angle formed in the above is close to 90 °, there is not much distortion in the vertical image, so there is no problem even if the distortion adjustment is performed only with the tilt angle in the horizontal direction obtained by the above method. .

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a schematic block diagram of a projector having the distance tilt angle measuring apparatus according to the second embodiment of the present invention.

  In the first embodiment, the distortion is adjusted only by the horizontal inclination angle. In the second embodiment, a vertical inclination sensor is further provided, and the distortion using the inclination angle between the horizontal direction and the vertical direction is provided. Make adjustments. In the second embodiment, the distance inclination angle measuring device 30 is an inclination sensor (G sensor) using an acceleration detection element that is also used for centering a machine, and the inclination angle with respect to the direction of gravity. Since the configuration and the operation are the same as those of the first embodiment except that the vertical direction inclination sensor 56 that precisely measures and outputs numerical data is provided, the same components are denoted by the same reference numerals and the same parts are designated by the same reference numerals. Description is omitted.

  The vertical inclination angle detected by the vertical inclination sensor 56 is input to the light reception position analysis distance inclination angle calculation unit 54, and the light reception position analysis distance inclination angle calculation unit 54 receives the light reception position information measured by the optical position detection device 53. The horizontal inclination angle is calculated by the above and output to the image control unit 23 together with the vertical inclination angle detected by the vertical inclination sensor 56. The image control unit 23 takes into account the horizontal and vertical inclinations. To generate LSI control parameters.

  FIG. 8 is a schematic flowchart showing a process of correcting the output image of the display unit 22 from the incident position of the reflected light of the optical position detection element 53 and the measurement result of the vertical direction tilt sensor in the second embodiment.

  The light receiving position analysis distance inclination angle calculation unit 54 sets the first bright line position and the second bright line position at predetermined positions in the horizontal direction of the projection surface (step S11), and projects a test pattern at the first bright line position. Then, the position of the first incident point of the optical position detection element 53 is acquired (step S12), the distance from the first incident point position to the first bright line is calculated (step S13), and the second bright line is obtained. A test pattern is projected onto the position to obtain the position of the second incident point of the optical position detection element 53 (step S14), and the distance from the second incident point position to the second bright line is calculated (step S15). ), The horizontal inclination angle between the optical axis of the projection apparatus and the projection surface is calculated based on the distance to the first emission line and the distance to the second emission line (step S16). Further, the vertical inclination angle is acquired from the vertical inclination sensor 56 (step S17).

  In response to the generated horizontal and vertical inclination angles, the image control unit 23 generates LSI control parameters (step S21), and controls the projector image processing LSI (step S22), thereby correcting the input video 24. As a result, the output image 25 is displayed on the display unit 22. When the output video 25 is projected onto the projection surface 70, it becomes a video similar to the input video 24.

  Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 9 is a schematic diagram of a projector having a distance tilt angle measuring apparatus according to a third embodiment of the present invention, where (a) is a front view, (b) is a side view, and (c) is a top view. In the first embodiment, the imaging lens 51 is provided apart from the projection lens 21 in the horizontal direction, and the optical position detection element 53 is arranged in the horizontal direction. In the third embodiment, the imaging lens 151 is provided. Are provided apart from each other in the vertical direction of the projection lens 121, and the optical position detection element 153 is provided in the vertical direction, and the inclination angle of the projection surface 170 in the vertical direction is calculated. Since only the measurement direction is changed by 90 ° and other configurations and functions are the same as those in the first embodiment, the description thereof is omitted.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 10 shows a projector having a distance / tilt angle measuring apparatus according to the fourth embodiment of the present invention, in which the vertical bright line projected on the center of the projection plane extends from the incident position of the optical position detection element in the vertical direction of the projection plane. It is explanatory drawing of the method of acquiring inclination, (a) is a schematic diagram of the test pattern projected from a projection lens, (b) is incident of the reflected light of a test pattern in case a projection optical axis is perpendicular | vertical with respect to a projection surface. FIG. 6C is a schematic diagram showing the incident position of the reflected light of the test pattern when the projection surface is inclined in the direction perpendicular to the projection optical axis.

  In the fourth embodiment, in addition to the test patterns projected to the left and right of the first embodiment, a long vertical test pattern is projected at the center, and two optical position detection elements are used. Since it is the same as that of the first embodiment except that an optical position detection element capable of measuring dimensions is used, the description of the same configuration and function is omitted. The incident position of the reflected light of the test pattern when the projection optical axis is perpendicular to the projection surface is perpendicular to the projected test pattern as shown in FIG. 10B, but the projection surface is at the projection optical axis. On the other hand, the reflected light of the bright line when tilted in the vertical direction is incident in a tilted state as shown in FIG. Since the projection lens and the imaging lens are separated in the horizontal direction, the portion where the bright line is separated moves closer to the projection lens than the portion where the bright line is close. FIG. 10C shows a state in which the optical position detection device is viewed from the incident side in a state where the upper part of the inclined surface is inclined in a direction away from the upper surface. By using an optical position detection element capable of two-dimensional measurement, the horizontal difference between the upper end 243a and the lower end 243b of the incident position 243 of the central bright line can be obtained. And the inclination angle in the vertical direction can be calculated from a table in which the inclination angle is associated. Generation of LSI control parameters in step 21 shown in FIG. 8 and control of the projector image processing LSI in step S22 can be performed based on the horizontal inclination angle and the vertical inclination angle described in the first embodiment.

  The imaging lens described so far is not limited to an optical lens, but may be an air lens using a pinhole. The optical position detection element may be a CCD (charge coupled device), a CMOS (complementary metal oxide semiconductor) sensor, or a PSD (position detection photodiode).

It is a typical block block diagram of the projector which has the distance inclination angle measuring apparatus of the 1st Embodiment of this invention. It is a schematic diagram of the projector which has the distance inclination angle measuring apparatus of the 1st Embodiment of this invention. (A) is a front view. (B) is a side view. (C) is a top view. It is a schematic diagram which shows the state of the reflected light of the test pattern light projected on the projection surface from the projection apparatus. FIG. 4 is a schematic explanatory diagram for explaining a method for obtaining a distance between a test pattern on a screen and a projector based on an incident point position of reflected light of a bright line on the optical position detection element in FIG. 3. It is a schematic diagram which shows a projection test pattern and the incident position of the reflected light of the test pattern to an optical position detection apparatus. (A) is a schematic diagram of the test pattern projected from a projection lens. (B) is a schematic diagram which shows the incident position of the reflected light of a test pattern in case a projection optical axis is perpendicular | vertical with respect to a projection surface. (C) is a schematic diagram which shows the incident position of the reflected light of a test pattern in case a projection surface inclines in a horizontal direction with respect to a projection optical axis. FIG. 4 is a schematic partial enlarged view for explaining a method of obtaining a distance between a bright line on a projection surface and a projector based on an incident point position of reflected light of the bright line on the optical position detection element in FIG. 3. It is a typical block block diagram of the projector which has the distance inclination-angle measuring apparatus of the 2nd Embodiment of this invention. It is a typical flowchart which shows the process which corrects the output image of a display part from the incident position of the reflected light of an optical position detection element, and the measurement result of a vertical direction inclination sensor. It is a schematic diagram of the projector which has the distance inclination-angle measuring apparatus of the 3rd Embodiment of this invention. (A) is a front view. (B) is a side view. (C) is a top view. The vertical inclination of the projection plane is obtained from the incident position of the optical position detection element of the vertical bright line projected on the center of the projection plane by the projector having the distance inclination angle measuring device of the fourth embodiment of the present invention. It is explanatory drawing of the method to do. (A) is a schematic diagram of the test pattern projected from a projection lens. (B) is a schematic diagram which shows the incident position of the reflected light of a test pattern in case a projection optical axis is perpendicular | vertical with respect to a projection surface. (C) is a schematic diagram which shows the incident position of the reflected light of a test pattern in case a projection surface inclines in the orthogonal | vertical direction with respect to a projection optical axis.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 110 Projector 20 Projection apparatus 21, 121 Projection lens 22 Display part 23 Image control part 24 Input image 25 Output image 26 Focus adjustment part 27 Projection optical axis 30 Distance inclination-angle measurement apparatus 31 1st test pattern light 32 2nd Test pattern light 33 Reflected light of first bright line 34 Reflected light of second bright line 41 Incident point of first bright line 42 Incident point of second bright line 51, 151 Imaging lens 53, 153 Optical position detecting element 54 Position analysis distance inclination angle calculation part 55 Test pattern generation part 56 Vertical direction inclination sensor 60 Central processing unit 70 Projection surface 71 First bright line 72 Second bright line 241 First bright line incident position 242 Second bright line incident position 243 Incident position of bright line in the center 243a Upper end 243b Lower end S11-S17, S21, S22 Step

Claims (11)

A projection device capable of projecting test pattern light for generating first and second bright lines parallel to predetermined positions on both sides of the projection surface from a projection lens, and a test pattern generation unit for controlling the test pattern light A distance inclination angle measuring device, and an image control unit that corrects distortion of an image projected on the projection surface based on an inclination angle between a projection optical axis of the projection device and the projection surface, and causes the projection device to project the image distortion And
The distance inclination angle measuring device is:
An imaging lens disposed at a predetermined interval in a predetermined direction from the projection lens;
An optical position detection element that detects an incident position of reflected light from the bright line that has passed through the imaging lens and outputs it as position information;
The position of the reflected light that has passed through the imaging lens from the first emission line and entered the optical position detection element, and the reflected light that has passed through the imaging lens from the second emission line and entered the optical position detection element An inclination angle of the projection surface is calculated based on the distance from the position of the reflected light, and a distance to the projection surface is calculated based on the position information, and output to the image control unit as distance inclination angle information. A projector having a distance tilt angle measuring device, the light receiving position analysis distance tilt angle calculating section.   The light receiving position analysis distance inclination angle calculation unit transmits the imaging lens from the first bright line and the second bright line formed in parallel to predetermined positions on both sides on the projection surface, and transmits the optical position detection element. The distance to the bright line is calculated from the information on the incident position of the reflected light incident on the projection line, and when the projection surface is perpendicular to the projection optical axis of the projection lens, the distance between the two incident positions is constant regardless of the distance. When the interval between the two incident positions is the same as the reference value, the inclination angle of the projection surface is set to 0. When the interval is smaller than the reference value, the projection surface on the projection lens side with respect to the imaging lens is inclined in the direction away from it. If it is larger than a reference value, the projection surface on the imaging lens side with respect to the projection lens is inclined in a direction away from the projection lens, and the inclination angle of the projection surface is set based on the ratio between the interval between both incident positions and the reference value. Calculate And outputs as the tilt information, a projector having a distance inclination angle measuring device according to claim 1.   The imaging lens is provided separately in the horizontal direction of the projection lens, and the optical position detection element inputs reflected light of bright lines formed in the horizontal direction on the projection surface incident from the imaging lens. The horizontal position is provided at a position, and the light receiving position analysis distance inclination angle calculation unit calculates the horizontal inclination of the projection surface from input position information of reflected light of the optical position detection element. A projector having the distance inclination angle measuring device according to claim 2.   And a vertical inclination sensor for measuring an inclination angle with respect to a direction of gravity, wherein the image control unit corrects distortion of an image projected on the projection plane based on a horizontal inclination and a vertical inclination. The projector which has a distance inclination-angle measuring apparatus of Claim 3 made to project from a projection apparatus.   The imaging lens is provided apart in the vertical direction of the projection lens, and the optical position detection element receives reflected light of bright lines formed in the vertical direction on the projection surface incident from the imaging lens. The light receiving position analysis distance inclination angle calculation unit calculates an inclination in the vertical direction of the projection surface from input position information of reflected light of the optical position detection element. A projector having the distance inclination angle measuring device according to claim 2. First vertical emission lines and second emission lines are generated at predetermined left and right positions away from the intersection of the projection optical axes of the projection surface, respectively, and the vertical direction longer than the left and right emission lines is formed at the intersection of the projection optical axes. A projection device capable of projecting a test pattern light for generating a central bright line from a projection lens, a test pattern generation unit for controlling the test pattern light, a distance inclination angle measuring device, a projection optical axis of the projection device, and the An image control unit that corrects distortion of an image projected on the projection surface based on an inclination angle with the projection surface and projects the image from the projection device;
The distance inclination angle measuring device is:
An imaging lens disposed at a predetermined interval in the horizontal direction from the projection lens;
The incident position of the reflected light from the bright line transmitted through the imaging lens is detected and output as position information, and the positional deviation in the horizontal direction of the upper and lower ends of the reflected light of the central bright line is detected as position information. An optical position detection element capable of two-dimensional measurement to output;
The position of reflected light that has passed through the imaging lens from the first emission line and entered the optical position detection element, and the reflected light that has passed through the imaging lens from the second emission line and entered the optical position detection element The horizontal tilt angle of the projection surface is calculated from the distance to the position of the projection surface, the distance to the projection surface is calculated from the incident position information of each reflected light, and the upper and lower ends of the reflected light of the central bright line are calculated. Distance tilt angle measurement, comprising: a light receiving position analysis distance tilt angle calculation unit that calculates a tilt angle in the vertical direction of the projection plane from a position shift value in the horizontal direction and outputs the tilt angle information to the image control unit as distance tilt angle information A projector having a device.   The projector which has a distance inclination-angle measuring apparatus of any one of Claims 1-6 whose said optical position detection element is PSD (position detection photodiode).   The projector having a distance tilt angle measuring device according to any one of claims 1 to 6, wherein the optical position detection element is a CCD (charge coupled device) sensor.   The projector having a distance inclination angle measuring device according to any one of claims 1 to 6, wherein the optical position detection element is a CMOS (complementary metal oxide semiconductor) sensor.   The projector which has a distance inclination angle measuring device of any one of Claims 1-9 whose said imaging lens is an optical lens.   The projector which has a distance inclination angle measuring device of any one of Claims 1-9 whose said imaging lens is an air lens (pinhole).

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