JP5010202B2 - Projector and projection image adjustment method - Google Patents

Description

  The present invention relates to a projector, and more particularly to a projector that projects an image using a structure such as a wall instead of a screen.

  A projector equipped with a projection lens including a lens shift mechanism and a zoom mechanism is provided (see Patent Document 1). The lens shift mechanism is a mechanism that shifts the projection lens in a direction perpendicular to the optical axis. The zoom mechanism is a mechanism that adjusts the angle of view of the projection lens by moving the zoom lens constituting the projection lens in the optical axis direction. In this type of projector, the position and size of a projected image can be adjusted as appropriate using a lens shift mechanism and a zoom mechanism.

In addition to the above, there has also been proposed a projector that detects the edge of the screen and matches the size of the projected image with the size of the screen (see Patent Document 2). The screen is provided with a black region frame along its edge, and the black region frame is a region (white region) on which an image is projected. The edge of the screen can be detected by detecting the black area using the difference in reflectance between the white area and the black area.
JP 2005-121689 A JP 2005-181726 A

  However, the projector described in Patent Document 1 has the following problems.

  When an image is projected using a wall instead of a screen, a part of the projected image may be applied to the ceiling or other wall depending on the installation condition of the projector. FIG. 15 shows a state where a part of the projection image is applied to the ceiling.

  Referring to FIG. 15, the projector 500 is disposed on the desk 405 so as to project an image on a wall 402 positioned in front. In this example, since a part of the projection image 501 projected by the projector 500 is on the ceiling 401, it is difficult to see the projection image. In such a case, the user usually needs to re-install the projector 500 or manually perform an operation of adjusting the position and size of the projected image using a lens shift mechanism or a zoom mechanism. Such re-installation and adjustment operations are very troublesome for the user.

  In the projector described in Patent Document 2, since the edge of the screen is detected and the size of the projected image is adjusted according to the size of the screen, it is possible to prevent the image from being projected outside the screen. it can. However, since this adjustment requires the use of a special screen, it is difficult to apply to a form using walls instead of the screen. In addition, depending on how the projector is installed, part of the projected image may be blocked by the edge of the desk on which the projector is installed, and the entire image may not be projected on the screen.

  Note that Patent Document 2 describes that a screen having a white area as a whole is used, and an edge of the screen is detected by using a difference in reflectance between the screen and a structure behind the screen (for example, a wall). Has been. However, in this case as well, it is difficult to apply to a form in which a wall is used instead of a screen. For example, it is difficult to detect a wall boundary using a difference in reflectance between a wall on which an image is projected and a wall adjacent to the left and right.

  The object of the present invention is to solve the above problems and automatically project the position and size of a projected image so that the projected image does not cover other structures when the image is projected onto a structure such as a wall. It is to provide a projector that can be adjusted automatically.

In order to achieve the above object, the present invention provides a projector having a projection lens capable of adjusting an angle of view, the lens shift control unit for shifting the projection lens in a direction intersecting the optical axis thereof, and the projection lens. A zoom control unit that adjusts the angle of view, and a measurement target within a predetermined angle range greater than the maximum angle of view of the projection lens for each of the first direction and the second direction that intersects the first direction. And a control unit that adjusts the position and size of the image projected on the structure by the projection lens through the lens shift control unit and the zoom control unit, the movable distance sensor, in accordance with the control by the control unit, for each of said first and second directions, cut measurement angle within the predetermined angular range stepwise Ete was measured, the control unit is configured for each of the first and second directions to obtain the distance data including distance information in each of the angle supplied from the moving distance sensors, said first direction In the distance data, the first image capable of projecting the image on the structure with respect to the first direction based on the angle with the maximum distance and the angle with the maximum distance next to the angle . An angle range is acquired, and the image is obtained with respect to the second direction based on the angle with the maximum distance and the angle with the maximum distance next to the angle in the distance data in the second direction. A second angle range that can be projected onto the structure is acquired, and a first angle that is an intermediate value of the first angle range and a second angle that is an intermediate value of the second angle range adjusting the position of the image based on bets And, to adjust the size of the image based on the first and second angular range, characterized in that.

In the projector of the present invention, the size of the projection image is automatically adjusted based on the first and second angle ranges, and the position of the projection image is automatically adjusted based on the first and second angles. Thus, the image is projected within a projectable range with reference to the center position on the target wall. Therefore, a part of the projection image does not cover the ceiling, the left and right walls, the edge of the desk, or the like. Also, there is no need for the user to make such adjustments manually.

  According to the present invention, since a part of the projection image does not cover the ceiling, the left and right walls, the edge of the desk, etc., it is possible to provide a good image display.

  In addition, since the adjustment of the position and size of the projected image is automatically performed, the troublesome manual adjustment can be eliminated.

  Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a main part of a projector according to an embodiment of the present invention. Referring to FIG. 1, the projector includes a movable distance sensor 1, a distance sensor control unit 2, a memory 3, a CPU 4, a focus control unit 5, a vertical lens shift control unit 6, a horizontal lens shift control unit 7, a zoom control unit 8, It has a dedicated switch 9, a power switch 10, and an acceleration sensor 11.

  In addition to the above-described configuration, the projector can display a video processing circuit, a liquid crystal panel and a driving circuit for forming an image based on a video signal supplied from an external video signal source, and an image formed by the liquid crystal panel. An optical system including a projection lens for projecting toward a structure such as a screen or a wall is included. Here, a screen or a structure (such as a wall) on which an image is projected is referred to as an image projecting member.

  The power switch 10 is a switch for turning on / off the power of the projector. The dedicated switch 9 is a switch for causing the projector to perform a predetermined operation. The dedicated switch 9 and the power switch 10 are disposed on a projector main body or a remote controller for operating the projector. Here, for example, when an image is projected onto a wall (target wall), the projected image is applied to the boundary between the target wall and another wall, or between the target wall and the ceiling or floor. This refers to an operation of adjusting the position and size of the projected image so as not to be hung, and adjusting the focus as necessary after the adjustment. Hereinafter, the process accompanying this operation is referred to as a projected image adjustment process.

  The movable distance sensor 1 is provided on the side of the projector where the projection lens is disposed, and measures the distance from the sensor to the measurement target. The movable distance sensor 1 can adjust the angle in the two-axis directions of the X axis and the Y axis. The distance sensor control unit 2 controls driving of a motor that rotates the X axis and the Y axis of the movable distance sensor 1. The output of the movable distance sensor 1 is supplied to the CPU 4.

  The projection lens includes a focus adjustment mechanism, a lens shift mechanism, and a zoom mechanism. The focus adjustment mechanism adjusts the focus by moving the focus lens back and forth along the optical axis. The lens shift mechanism has both a first direction (longitudinal direction) intersecting the optical axis and a second direction (lateral direction) intersecting the optical axis and intersecting the first direction (vertical direction). Is provided with a mechanism for moving the projection lens, and by this mechanism, the position of the image projected on the image projection member is adjusted by moving the projection lens in the first or second direction or both directions. The zoom mechanism adjusts the angle of view of the projection lens by moving the zoom lens back and forth along the optical axis.

  The focus control unit 5 controls driving of a motor for moving the focus lens in the optical axis direction. The vertical lens shift control unit 6 controls driving of a motor for moving the projection lens in the vertical direction in the lens shift mechanism. The lateral lens shift control unit 7 controls driving of a motor for moving the projection lens in the lateral direction in the lens shift mechanism. The zoom control unit 8 controls driving of a motor for moving the zoom lens in the optical axis direction.

  The acceleration sensor 11 detects acceleration applied to the projector. As the acceleration sensor 11, for example, a uniaxial acceleration sensor or a multiaxial acceleration sensor can be used. The output of the acceleration sensor 11 is supplied to the CPU 4.

  The CPU 4 controls the operation of the entire projector and executes processing (including projection image adjustment processing) based on programs and data stored in the memory 3. The CPU 4 can detect the projection angle adjustment work of the projector based on the output of the acceleration sensor 11 and determine the end timing of the work. The CPU 4 executes the projection image adjustment process triggered by the timing when the dedicated switch 9 or the power switch 10 is turned on or the work end timing based on the output of the acceleration sensor 11. The projected image adjustment process by the CPU 4 includes a boundary detection process for controlling the distance sensor control unit 2 to change the angle of the movable distance sensor 1 and detecting a boundary based on the output of the movable distance sensor 1, and a vertical lens. Projection position adjustment processing for adjusting the projection position by controlling the shift control unit 6 and the lateral lens shift control unit 7, projection screen size adjustment processing for adjusting the projection screen size by controlling the zoom control unit 8, and a focus control unit 5 and a focus adjustment process for adjusting the focus.

  Next, the operation of the projector of this embodiment will be specifically described.

  First, the configuration and operation of the movable distance sensor 1 will be briefly described. In FIG. 2, the structure of the movable part of the movable distance sensor 1 is shown. Referring to FIG. 2, the movable distance sensor 1 includes an X-axis rotation shaft 202 and a Y-axis rotation shaft 203 that intersect with each other, and a distance sensor unit 201 supported by these shafts. Each of the X-axis rotating shaft 202 and the Y-axis rotating shaft 203 is rotated around the respective axes by a motor (not shown). By rotating the X-axis rotation shaft 202, the angle of the distance sensor unit 201 in the arrow A direction can be adjusted (X-axis rotation). By rotating the Y-axis rotation shaft 203, the angle of the distance sensor unit 201 in the arrow B direction can be adjusted (Y-axis rotation). The distance sensor control unit 2 controls driving of a motor that rotates each of the X-axis rotating shaft 202 and the Y-axis rotating shaft 203.

  FIG. 3 shows the configuration of the distance sensor unit 201 of the movable distance sensor 1. Referring to FIG. 3, the distance sensor unit 201 is an optical distance sensor, and a main part thereof includes a light emitter 204, an image receiving device 205, and lenses 206 and 207.

  The light emitter 204 is a light source for projection represented by a semiconductor laser or LED. The light from the light emitter 204 is emitted in the direction of the image projection member through the lens 206. The image receiving device 205 is a device in which light receiving elements are arranged in an array, such as a CMOS sensor or PSD (Position Sensitive Detector). Of the light from the light emitter 204, the light reflected by the image projecting member enters the image receiving device 205 through the lens 207. The image receiving device 205 may be any device as long as it can receive the reflected light from the image projecting member.

  Hereinafter, the principle of distance measurement by the movable distance sensor 1 will be briefly described with reference to FIG. Here, the case where the distance from the movable distance sensor 1 to the screens 208 and 209 is measured will be described as an example.

  When measuring the distance of the screen 208, light from the light emitter 204 is irradiated onto the screen 208 through the lens 206, and reflected light from the screen 208 is incident on the image receiving device 205 through the lens 207. In this case, light from the screen 208 is received at a point A on the image receiving device 305.

  On the other hand, when measuring the distance of the screen 209 positioned behind the screen 208, light from the light emitter 204 is irradiated onto the screen 209 through the lens 206, and reflected light from the screen 209 passes through the lens 207. Is incident on. In this case, light from the screen 209 is received at a point B on the image receiving device 305. The light receiving point B is closer to the center of the image receiving device 305 than the light receiving point A.

  The farther the screen that is the object of measurement is, the closer the light receiving point on the light receiving device 205 is to the center of the light receiving unit. That is, the amount of movement of the light receiving point on the light receiving device 205 corresponds to a change in the distance to the measurement target. Therefore, if the relationship between the three parameters of the output of the movable distance sensor 1, the position of the light receiving point on the light receiving device 205, and the distance to the measurement object is obtained in advance, the movable distance sensor 1 is determined according to the relationship. The distance from the output to the object to be measured can be obtained.

  In addition, since there is a correlation in the relationship between the above parameters, it can be calculated by an approximate expression. Specifically, it can be obtained by the following approximate expression.

In here, a and b are parameters that vary depending on the characteristics such as the characteristics and the lens 207 of the light receiving device 205. The information related to the above relationship or Expression 1 is stored in the memory 3 in advance, and the CPU 4 obtains the distance from the output of the movable distance sensor 1 to the measurement object using the information.

  Next, the lens shift mechanism will be briefly described. FIG. 4 schematically shows a shift state of the projection lens in the vertical direction (vertical direction) when the projection lens portion of the projector is viewed from the side surface side. In FIG. 4, the arrow A indicates the upward shift of the projection lens 12, and the arrow B indicates the downward shift of the projection lens 12.

  The dichroic prism 13 synthesizes image light from R, B, and G liquid crystal panels (not shown). The RGB image light synthesized by the dichroic prism 13 is projected by the projection lens 12. It is projected onto the member. The projection lens 12 can be moved in the directions of arrows A and B by a motor (not shown).

  When the projection lens 12 is not shifted, the projection direction of the image light from the dichroic prism 13 is the projection direction a0. When the projection lens 12 is shifted in the direction of arrow A (upward), the projection direction of the image light is the projection direction a1. The projection direction a1 is upward compared to the projection direction a0. When the projection lens 12 is shifted in the direction of arrow B (downward), the projection direction of the image light is the projection direction a2. The projection direction a2 is downward compared to the projection direction a0. When the projection lens 12 is shifted in this way, the position of the image projected on the image projection member is also shifted according to the shift amount.

  FIG. 5 schematically shows the shift range of the projected image by the lens shift mechanism. The projector 400 is a projector having the lens shift mechanism shown in FIG. In FIG. 5, an arrow C indicates a shift range of the projected image by the lens shift mechanism. The projection direction a11 indicates the projection direction at the limit value of the upward lens shift, and the projection direction a21 indicates the projection direction at the limit value of the downward lens shift. The shift range (arrow C) of the projected image is given by the distance between the center (center line B) of the image projected in the projection direction a11 and the center (center line A) of the image projected in the projection direction a21. .

  Next, the projection image adjustment processing by the CPU 4 that is a feature of the projector according to the present embodiment will be specifically described. FIG. 6 shows one procedure of the projection image adjustment process. Hereinafter, the operation of the CPU 4 will be described with reference to FIGS.

  When the operator depresses the dedicated switch 9 or the power switch or adjusts the angle of the projector, the CPU 4 is triggered by the operation to acquire distance data (step 100), calculate the center position and size (step 101), Projection image adjustment processing including alignment (step 102), size adjustment (step 103), and focus adjustment (step 104) of the projection image is executed. The specific execution procedure is described below.

(1) Distance data acquisition:
The CPU 4 is movable through the distance sensor control unit 2 within a predetermined angle range larger than the maximum field angle of the projection lens in each of the vertical direction (X direction in FIG. 2) and the horizontal direction (Y direction in FIG. 2). The distance sensor 1 changes the angle stepwise, and at each angle, the distance data from the output of the movable distance sensor 1 to the object to be measured is stored in the memory 3 according to the aforementioned parameter relationship or approximate expression. To get. The measurement object is all structures positioned within a predetermined angle range.

  If the width for changing the angle of the movable distance sensor 1 is reduced, the distance measurement accuracy increases. However, since the amount of distance data to be acquired becomes enormous, it is necessary to use a memory 3 having a large capacity. Cost increases. On the contrary, if the width for changing the angle of the movable distance sensor 1 is increased, the memory 3 having a small capacity can be used, so that the cost can be suppressed, but the distance measurement accuracy is lowered. It is desirable to determine the angle change width in consideration of measurement accuracy and cost.

(2) Calculation of center position and size:
Based on the distance data obtained in step 100, the CPU 4 calculates the center position and size of the image to be projected, and determines whether to give priority to the vertical direction or the horizontal direction of the projected image.

(2a) Center position in the vertical direction (X direction in FIG. 2) and projectable range (size):
FIG. 7 schematically shows the measurement range of the movable distance sensor 1 in the vertical direction. The projector 400 has the configuration shown in FIG. In FIG. 7, the shaded area indicates the image projection range, and the arc-shaped arrow A indicates the measurement range in the vertical direction of the movable distance sensor 1 provided in the projector 400.

  The projector 400 is installed on the desk 405 so that an image is projected onto the wall 402 on the front. FIG. 7 shows a state in which the projector 400 is viewed from the side, and the upper part of the projection image 406 covers a part of the ceiling 401. The measurement range A of the movable distance sensor 1 is a range including the projection range of the projection image 406, and the entire area in the vertical direction of the wall 402 on which the image is to be projected, and the floor 403 and the ceiling 401 adjacent to the wall 402. And part of.

  FIG. 8 shows distance data measured in the measurement range A by changing the angle of the movable distance sensor 1 stepwise. In FIG. 8, the vertical axis indicates the distance to the measurement object, and the horizontal axis indicates the angle in the vertical direction of the movable distance sensor 1. The distance data at each angle when the angle of the movable distance sensor 1 is changed stepwise in the angle range of 70 ° to −70 ° is plotted.

  When the angles are 60 ° and −10 °, peaks P1 and P2 are obtained. The peak P1 corresponds to the boundary between the wall 402 and the ceiling 401 shown in FIG. The peak P2 corresponds to the edge of the desk 405 (the edge limits the projection range at the lower end of the projected image 406). When the angle of the movable distance sensor 1 gradually decreases from 60 °, the distance data also gradually decreases from the peak P1, and becomes minimum at the point a1. After the point a1, the distance data gradually increases and reaches the peak P2. At the point a1, the distance between the projector 400 and the wall 402 is the shortest. A range of peaks P1 to P2 (angle of 60 ° to −10 °) is a range b1 (projectable size) in which an image can be projected in the vertical direction. When the angle of the peak P1 is φa and the angle of the peak P2 is φb, the center C of the vertical projection position can be calculated by the following equation.

Contact name in the state shown in FIG. 7, the most points a1 is close at the longitudinal projection position of the center C and the wall 402 do not necessarily agree.

(2b) Center position in the left-right direction (Y direction in FIG. 2) and projectable range (size):
FIG. 9 schematically shows the measurement range of the movable distance sensor 1 in the left-right direction. The state shown in FIG. 9 is the state shown in FIG. 7 as viewed from the upper surface side of the projector. In FIG. 9, an arc-shaped arrow B indicates a measurement range in the left-right direction of the movable distance sensor 1 provided in the projector 400. The left and right portions of the projection image 406 are respectively applied to parts of the left and right walls 404a and 404b. The measurement range B of the movable distance sensor 1 is a range including the projection range of the projection image 406, and includes the entire region of the wall 402 in the left-right direction and part of the left and right walls 404a, 404b.

  FIG. 10 shows distance data measured in the measurement range B by changing the angle of the movable distance sensor 1 stepwise. In FIG. 10, the vertical axis indicates the distance to the measurement object, and the horizontal axis indicates the angle in the left-right direction of the movable distance sensor 1. The angle of the movable distance sensor 1 is changed stepwise in the angle range of 70 ° to −70 °, and the distance data at each angle is plotted.

When the angles are 40 ° and −40 °, peaks P3 and P4 are obtained, respectively. The peak P3 corresponds to the boundary between the wall 402 and the wall 404b, and the peak P4 corresponds to the boundary between the wall 402 and the wall 404a. When the angle of the movable distance sensor 1 gradually decreases from 40 °, the distance data also gradually decreases from the peak P3 and becomes the minimum at the point a2. After the point a2, the distance data gradually increases and reaches the peak P4. At the point a2, the distance between the projector 400 and the wall 402 is the shortest. In the range of peak P3～P4 (angle 4 0 ° ~- 4 0 range °) which can image projection in the lateral direction ranges b2 (projection can size).

  The center C of the lateral projection position can be calculated by using the above-described formula 2 and setting the angle of the peak P3 to φa and the angle of the peak P4 to φb. In the example shown in FIG. 9, projection images are applied to the left and right walls 404a and 404b by substantially the same width, and the center C of the lateral projection position is zero. In this case, the center of the lateral projection position and the point a2 closest to the wall 402 coincide. When the widths of the projection images on the left and right walls are different, the center of the horizontal projection position and the closest point a2 of the wall 402 do not necessarily match.

(3) Projection image alignment:
The CPU 4 adjusts the position of the projected image by lens shift based on the projection position center and the projectable size b1 in the vertical direction and the center of the projection position and the projectable size b2 in the horizontal direction acquired in step 101. Position adjustment in the vertical direction is performed through the vertical lens shift control unit 6, and position adjustment in the horizontal direction is performed through the horizontal lens shift control unit 7. In the position adjustment using the distance data shown in FIG. 8, the projection lens is moved in the vertical direction so that the center of the projected image (center lines A and B in FIG. 5) is the projection position center (25 °) in the vertical direction. Shifted. In the position adjustment using the distance data shown in FIG. 10, the center of the projection position with respect to the left-right direction is 0 °, and thus no lens shift is performed. When the widths of the projection images on the left and right walls are different, the projection lens is shifted in the left-right direction so that the center of the projection image is the center of the acquired projection position. The alignment may be performed first in either the vertical direction or the horizontal direction.

(4) Size adjustment:
The CPU 4 adjusts the size of the projected image whose center position has been adjusted by zoom adjustment through the zoom control unit 8. In the size adjustment, first, it is determined which of the vertical direction (vertical direction) and the horizontal direction (horizontal direction) is given priority. The reason for determining the priority direction will be described below.

  FIG. 11 is a schematic diagram of a projected image when size adjustment is performed with priority in the vertical direction with respect to an image that needs size adjustment with priority in the horizontal direction. In this case, both ends of the projection image 406 are applied to the left and right walls 404a and 404b. FIG. 12 is a schematic diagram of a projected image when size adjustment is performed with priority in the horizontal direction with respect to an image that needs to be size adjustment with priority in the vertical direction. In this case, the upper end of the projection image 406 covers the ceiling 401. In order to prevent the projection image from projecting to the left and right walls and the ceiling, it is necessary to determine which of the horizontal direction and the vertical direction is prioritized when performing size adjustment.

  In the priority direction determination process, the CPU 4 uses lens characteristic information regarding the degree of zoom, the size of the image, and the projection distance (distance from the projection lens to the image projection member) stored in advance in the memory 3. FIG. 13 is a schematic diagram for explaining lens characteristic information in the vertical direction. In FIG. 13, what is indicated by a broken line with a narrow interval indicates a wide-time projection image, and what is indicated by a broken line with a wide interval indicates a tele-time projection image. At the wide time, the size of the projected image increases at a constant rate according to the projection distance. Similarly, the size of the projected image increases at a constant rate according to the projection distance even during tele. The memory 3 stores, as lens characteristic information in the vertical direction, a relationship regarding three parameters such as the zoom degree (magnification), the size of the projected image, and the projection distance.

  Although not shown in FIG. 13, also in the left-right direction, the size of the wide-time projection image and the tele-time projection image increases at a constant rate according to the projection distance. The memory 3 stores, as lens characteristic information in the left-right direction, a relationship regarding three parameters such as the degree of zoom (magnification), the size of the projected image, and the projection distance.

  The CPU 4 uses the lens characteristic information about the vertical direction and the horizontal direction stored in advance in the memory 3 and the projection distance obtained from the distance information acquired from the movable distance sensor 1 in the vertical direction and the horizontal direction of the projection image. Calculate the size. Next, the CPU 4 compares the calculated sizes in the vertical direction and the horizontal direction with the sizes of the images corresponding to the projectable sizes b1 and b2 acquired in step 101. Then, from the comparison result, it is determined whether or not the image protrudes in each of the vertical direction and the horizontal direction. In this determination, it is considered that the size of the projected image differs in the vertical direction and the horizontal direction depending on the aspect ratio (4: 3, 16: 9, etc.) of the projected image.

  If the image protrudes in either the vertical direction or the horizontal direction, the CPU 4 adjusts the image size by giving priority to the direction in which the protrusion occurs. If neither the vertical direction nor the horizontal direction protrudes, the image size is not adjusted (in this case, only the position is adjusted). When protrusions occur in both the vertical direction and the horizontal direction, priority is given to a preset direction or a direction with a large amount of protrusion.

  The distance data from the movable distance sensor 1 includes sensor angle information and distance information, and the CPU 4 calculates the projection size according to the following expression 3 based on these information.

In here, theta is the angle range of possible projection in the preferential direction (b2 in b1 and 10 of FIG. 8).

  For example, when the distance data shown in FIG. 8 is acquired in step 100 and the size adjustment is performed with priority in the vertical direction, the projection size is calculated as follows. Since the projectable size b1 is in the angle range of 60 ° to −10 °, the angle θ is set to 70 °. Further, since the center alignment is performed in step 102, the projection center distance is the distance at the point a1. By substituting these angles θ (= 70 °) and the projection center distance into the above equation 3, the projection size in the vertical direction is calculated. Then, the CPU 4 executes zoom processing through the zoom control unit 8 so that the size of the projected image in the vertical direction becomes the calculated projection size.

  When the distance data shown in FIG. 10 is acquired in step 100 and size adjustment is performed with priority in the left-right direction, the projection size is calculated as follows. Since the projectable size b2 is in the angle range of 40 ° to −40 °, the angle θ is set to 80 °. In step 102, since the center is adjusted, the projection center distance is the distance at the point a2. The projection size in the left-right direction is calculated by substituting these angles θ (= 80 °) and the projection center distance into Equation 3 above. Then, the CPU 4 executes zoom processing through the zoom control unit 8 so that the size of the projected image in the left-right direction becomes the calculated projection size.

  In addition, the calculation process using Formula 3 has a high load on the CPU 4. In order to reduce the load on the CPU 4, for example, the step width for changing the angle of the movable distance sensor 1 is set to 5 °, and the relationship between the distance and the projection size at each angle is obtained in advance, and the obtained relationship (table information ) May be stored in the memory 3. In this case, the CPU 4 acquires the projection size according to the table information stored in the memory 3.

  Further, the sizes of the minimum projection image (television projection image) and the maximum projection image (wide projection image), which are the parameters of the lens characteristic information described above, vary depending on the projector model. For this reason, it is necessary to acquire lens characteristic information for each projector model.

(5) Focus adjustment:
The CPU 4 adjusts the focus of the image whose projection size has been adjusted in step 103 through the focus control unit 5. Since the projection center position is known by the vertical lens shift and the horizontal lens shift, and the distance to the projection center position has already been acquired, the CPU 4 controls the focus adjustment by the focus control unit 5 based on the information. To do.

  FIG. 14 shows the state of the projected image after focus adjustment. In the state of FIG. 14, the projected image 406 is projected on the wall 402 without a part of the image being applied to the ceiling 401, the left and right walls 404 a and 404 b, and the edge of the desk 405.

  Note that when the zoom rate is changed, there is a case where the focus needs to be readjusted, and there is a case where the focus does not need to be readjusted even when the zoom rate is changed. In the former case, the processing shown in FIG. 6 can be applied as it is. In the latter case, the processing shown in FIG. 6 can be applied by replacing the processing of step 103 and step 104.

  According to the projector of the present embodiment described above, when an image is projected onto the wall 402 as a structure, the entire wall 402 and other structures (ceiling 401, left and right walls 404a, 404b, floor 403, desk 405, etc.) are partly located. These walls 402 and other structures are measurement objects whose distances should be measured by a movable distance sensor.

  The distance measurement by the movable distance sensor 1 is performed in each of the vertical direction and the horizontal direction. Here, the vertical direction is a direction that traverses the projection image in the vertical direction (vertical direction), and the left-right direction is a direction that traverses the projection image in the horizontal direction (horizontal direction). In the movable distance sensor 1, the angle is switched stepwise within a predetermined angle range in the vertical direction, and the distance to the measurement object is measured at each angle. Similarly, in the left-right direction, the angle is switched stepwise within a predetermined angle range, and the distance to the measurement object is measured at each angle. In measuring the distance at each angle, the boundary between the wall 402 and another structure appears as a peak value of the distance data. That is, in the vertical direction, the boundary between the wall 402 and the ceiling 401 and the edge of the desk 405 (or the boundary between the wall 402 and the floor 403) appear as peak values of the distance data, and in the horizontal direction, the wall 402 and the left and right walls The boundary between 404a and 404b appears as a peak value of the distance data. Therefore, based on these peak values, a first angle range that can project an image on the wall 402 in the up-down direction and a second angle range that can project an image on the wall 402 in the left-right direction are calculated. Can do. The size of the projection image is adjusted based on the first and second angle ranges thus calculated.

  In the measurement of the distance at each angle, the center position of the wall 402 appears as the minimum value of the distance data in the first angle range in the vertical direction, and the distance in the second angle range in the left-right direction. Appears as the minimum value of the data. Therefore, based on these minimum values, the first and second angles indicating the center position of the wall 402 in the vertical and horizontal directions can be calculated. The position of the projection image is adjusted based on the first and second angles calculated in this way.

  In the projector of this embodiment, the size of the projection image is automatically adjusted based on the first and second angle ranges, and the position of the projection image is automatically adjusted based on the first and second angles. Thus, the image is projected within a projectable range with reference to the center position on the wall 402. Therefore, a part of the projection image does not cover the ceiling, the left and right walls, the edge of the desk, or the like. Also, there is no need for the user to make such adjustments manually. Therefore, a good image display can be provided, and the troublesome manual adjustment can be eliminated.

  The projector described above is an example of the present invention, and the configuration and operation thereof can be changed as appropriate without departing from the spirit of the invention.

  The present invention can be applied to all projectors in which an image is projected onto a structure such as a wall by a projection lens.

1 is a block diagram illustrating a configuration of a main part of a projector that is an embodiment of the present invention. FIG. It is a schematic diagram for demonstrating the structure of the movable part of the movable distance sensor shown in FIG. It is a schematic diagram for demonstrating the structure of the distance sensor part shown in FIG. It is a schematic diagram for demonstrating the lens shift mechanism of a projection lens. It is a schematic diagram for demonstrating the shift range of the projection image by a lens shift mechanism. It is a flowchart which shows the procedure of the projection image adjustment process performed in the projector shown in FIG. It is a schematic diagram which shows the measurement range in the up-down direction of the movable distance sensor shown in FIG. It is a figure which shows the distance data at the time of measuring by changing the angle of a movable distance sensor in steps in the up-down direction measurement range shown in FIG. It is a schematic diagram which shows the measurement range in the left-right direction of the movable distance sensor shown in FIG. It is a figure which shows the distance data at the time of measuring by changing the angle of a movable distance sensor in steps in the measurement range of the left-right direction shown in FIG. It is a schematic diagram of a projected image when size adjustment is performed with priority in the vertical direction with respect to an image that needs to be size adjustment with priority in the horizontal direction. It is a schematic diagram of a projection image when size adjustment is performed with priority in the horizontal direction with respect to an image that needs to be size adjustment with priority in the vertical direction. It is a schematic diagram for demonstrating the lens characteristic information in an up-down direction. It is a schematic diagram which shows the state of the projection image of the projector shown in FIG. It is a schematic diagram which shows an example of the display state of the image projected with the general projector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Movable distance sensor 2 Distance sensor control part 3 Memory 4 CPU
DESCRIPTION OF SYMBOLS 5 Focus control part 6 Vertical lens shift control part 7 Horizontal lens shift control part 8 Zoom control part 9 Dedicated switch 10 Power switch 11 Acceleration sensor

Claims (9)

A projector having a projection lens capable of adjusting the angle of view,
A lens shift controller that shifts the projection lens in a direction intersecting the optical axis;
A zoom control unit for adjusting the angle of view of the projection lens;
A movable distance sensor capable of measuring a distance to a measurement object within a predetermined angle range larger than a maximum field angle of the projection lens for each of a first direction and a second direction intersecting the first direction; ,
A control unit that adjusts the position and size of the image projected on the structure by the projection lens through the lens shift control unit and the zoom control unit, and
The movable distance sensor performs measurement by gradually switching the measurement angle within the predetermined angle range for each of the first and second directions in accordance with control by the control unit,
The controller is
Obtaining distance data including distance information at each angle supplied from the movable distance sensor for each of the first and second directions ;
The image is projected onto the structure with respect to the first direction on the basis of an angle at which the distance is maximum and an angle at which the distance is maximum next to the angle in the distance data in the first direction. get the first angle range as possible,
The image is projected onto the structure with respect to the second direction based on the angle with the maximum distance and the angle with the maximum distance next to the angle in the distance data in the second direction. get the second angular extent possible
Adjusting the position of the image based on the second angle is an intermediate value of the first angle and the second angle range is an intermediate value of the first angle range, the first and second A projector, wherein the size of the image is adjusted based on an angle range of 2.   In one of the first and second directions, the control unit adjusts the size of the image in preference to the direction when a part of the image is projected onto another structure. The projector according to claim 1.   The control unit sets in advance one of the first and second directions when a part of the image is projected onto another structure in each of the first and second directions. The projector according to claim 1, wherein the size of the image is adjusted with priority on a direction.   In the first and second directions, when the part of the image is projected onto another structure in the first and second directions, the control unit includes the other structure out of the first and second directions. The projector according to claim 1, wherein the size of the image is adjusted with priority given to a larger width of the image portion projected onto the body. As the zoom lens characteristic information constituting the projection lens, the zoom lens, the projection distance, and a memory in which the relationship between the projection image sizes is stored in advance,
The control unit refers to the characteristic information stored in the memory and is projected onto the structure based on the distance information at the first and second angles supplied from the movable distance sensor. The size of the projected image is calculated, the size of the projected image is compared with the size of the images in the first and second directions obtained from the first and second angle ranges, and based on the comparison result 5. The projector according to claim 2, wherein the projection in the first and second directions is determined to protrude from the other structure. 6. A focus control unit that adjusts the focus of the projection image by moving a focus lens constituting the projection lens;
The control unit adjusts the focus of the image after adjusting the position and size based on the distance information at the first and second angles supplied from the movable distance sensor through the focus control unit. performed, the projector according to any one of claims 1 to 5.   An acceleration sensor for detecting an acceleration applied to the projector;
  The control unit detects an end timing of an adjustment operation of a projection angle of the projector based on an output of the acceleration sensor, and adjusts the position and size of the image at the end timing. The projector according to any one of the above.   A power switch for turning on and off the projector;
  The projector according to claim 1, wherein the control unit adjusts a position and a size of the image at a timing when the power switch is turned on. A projection image adjustment method for a projector having a projection lens capable of adjusting the angle of view,
For each of the first direction and the second direction that intersects the first direction, the angle of the distance sensor is switched stepwise within a predetermined angle range that is larger than the maximum angle of view of the projection lens, until the object to be measured Measuring the distance of
For each of the first and second directions, distance data including distance information at each angle acquired by the distance sensor is acquired, and an angle at which the distance is maximum in the distance data in the first direction is obtained. Based on the angle having the maximum distance after the angle, a first angle range capable of projecting an image on the structure is obtained with respect to the first direction, and the distance data in the second direction is obtained. Obtaining a second range of angles capable of projecting the image on the structure with respect to the second direction based on an angle at which the distance is maximum and an angle at which the distance is maximum next to the angle. Steps,
Based on a first angle that is an intermediate value in the first angle range and a second angle that is an intermediate value in the second angle range , the projection lens is set in a direction intersecting the optical axis. Shifting and adjusting the position of the projected image projected onto the structure;
Before SL based on the first and second angle range, the adjusting the angle of the projection lens, and a step of adjusting the size of the projection image projected onto the structure, the projection image adjustment method.

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