JP5744566B2 - Image projection device - Google Patents

Description

  The present invention relates to an image projection apparatus such as a liquid crystal projector, and more particularly to an image projection apparatus having a lens shift function.

  Patent Document 1 discloses a projector that detects the position of a lens shift mechanism with a variable resistor and limits the movable range of the lens shift mechanism based on the output. Patent Document 2 discloses a lens exchange type projection lens support device that regulates a moving range of a mount base on which a lens barrel is detachably mounted based on a lens identification signal representing a type of a projection lens.

JP 2005-173460 A JP 2001-145047 A

  Conventionally, since the size (dimension) of the area of the image display element is not taken into consideration, the image light formed by the image display element due to the lens shift is difficult to correctly pass through the projection lens. As a result, there is a risk that unacceptable distortion, chromatic aberration, image loss, and the like may occur in the projected image.

  Therefore, an object of the present invention is to provide an image projection apparatus capable of projecting a high-quality projection image.

  An image projection apparatus according to the present invention is an image projection apparatus capable of projecting light from an image display element onto a projection surface as a projection image via a projection lens of an interchangeable lens unit. A lens shift mechanism for shifting the image display element, an input means for inputting a shift direction and shift amount by the lens shift mechanism, a first storage means for storing the size of the display area of the image display element, and the image display element An effective image display that is a region in which the projection lens has a higher evaluation value than a predetermined evaluation value by communicating with the lens unit and a first acquisition unit that acquires a center position of the region A second acquisition means for acquiring a region; the shift direction and the shift amount input to the input means; and the image display element stored in the first storage means. Based on the size of the display area, the center position of the area of the image display element acquired by the first acquisition means, and the effective image display area acquired by the second acquisition means. Control means for controlling the shift by the lens shift mechanism so that the entire area falls within the range of the effective image display area.

  ADVANTAGE OF THE INVENTION According to this invention, the image projection apparatus which can project a high quality projection image can be provided.

It is a block diagram of a projector (image projection apparatus) equipped with the interchangeable lens of the present invention. Example 1 It is a schematic diagram which shows the relationship between an effective image display area and panel size. It is a flowchart for demonstrating operation | movement of the control part shown in FIG. It is a block diagram of a projector (image projection apparatus) equipped with the interchangeable lens of the present invention. (Example 2) It is a block diagram of a projector (image projection apparatus) equipped with the interchangeable lens of the present invention. (Example 3)

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a block diagram of a projector 200A to which the lens unit 100A of Example 1 is attached. The projector 200A is an image projection apparatus that projects light (that is, an image) modulated by an image display element such as a liquid crystal panel in accordance with an input image signal onto a projection surface such as a screen as a projection image via a projection lens. .

  The lens unit 100A is detachably attached to the projector 200A, and includes a projection lens (exchange lens) 102, a lens microcomputer 104, and a memory 106. The projection lens 102 forms a projection image from the light from the image display element. The lens microcomputer 104 is a microcomputer provided in the lens unit 100 </ b> A, is configured to be able to communicate with the control unit 210, and can notify the control unit 210 of information in the memory 106 and other information. The memory 106 stores an effective image display area (described later) of the lens unit 100A.

  The projector 200A (projector main body) includes a control unit 210, a lens shift mechanism 220, an operation unit 230, a video signal input unit 232, an image processing unit 234, a lamp 236, a panel 238, a panel drive unit 240, and a display unit 242.

  The control unit 210 is a control unit configured to control each unit of the apparatus in accordance with an input from the operation unit 230 and to be communicable with the lens microcomputer 104 and is configured from a microcomputer. The control unit 210 includes a panel size storage unit 212 and a shift movable determination unit 214.

  The panel size storage unit 212 is a first storage unit that stores the size (dimension) of the area (panel area) of the panel 238. Since the panel area is usually rectangular, the panel size (for example, diagonal length), the panel aspect ratio, and the panel resolution (number of pixels) need only be stored in the panel size storage unit 212. However, the present invention is not limited to this, and information on the panel area and the length of one side may be used. Further, the data may be data based on the panel size stored in the first storage unit, and does not have to exactly match the panel size. For example, data with a margin for the actual panel size may be stored as the panel size according to the specifications to be obtained, or conversely, the data is stored as a size smaller than the actual panel size. May be.

  The shift movable determination unit 214 functions as a first acquisition unit that acquires the size of the region (panel region) of the panel 238 from the panel size storage unit 212.

  Further, the shift movable determination unit 214 obtains the size of the effective image display area from the memory 106 in the above-described plane perpendicular to the optical axis of the projection lens 102 by the control unit 210 communicating with the lens microcomputer 104. It also functions as a means.

  Note that the first acquisition unit and the second acquisition unit may be separate members from the shift movable determination unit 214. Further, the size of the panel area and the size of the effective image display area may be data necessary for calculating the respective shapes and dimensions.

  Further, the shift movable determination unit 214 acquires the current center position of the panel area (or a position associated therewith) from the shift amount detection unit 222 described later. Further, the shift movable determination unit 214 obtains information on the direction to be shifted and the shift amount from the operation unit 230.

  The shift movable determination unit 214 determines whether or not the effective image display area can be shifted by determining whether or not the entire panel area after the shift is within the effective image display area based on the information. To do. If the shift is possible, the shift drive unit 224 of the lens shift mechanism 220 is controlled to perform the shift drive, and if the shift is impossible, the shift drive is not performed.

  Here, the effective image display area is an area through which the reflected light (or transmitted light) from the panel 238 can pass through the projection lens 102 without being vignetted when the above-described plane is considered. The light that has passed through the effective image display area forms a projected image with a predetermined quality guaranteed. The effective image display area is similar to the image circle of the lens, and its shape is preferably approximate to the shape of the image circle of the lens. In other words, the effective image display area is an area (size, coordinate) in which a projection image (projection image) having an evaluation value higher than a predetermined evaluation value can be projected (displayed). Here, the predetermined evaluation value is, for example, a value obtained by evaluating distortion, chromatic aberration, missing image, etc. of the projected image, and a higher evaluation value has a higher image quality of the projected image and a lower evaluation value. If the image quality of the projected image is low, it is the minimum acceptable evaluation value.

  2A to 2C are schematic diagrams showing the relationship between the effective image display area and the panel size in the plane described above. This plane is a plane perpendicular to the optical axis at an arbitrary position on the optical axis of the projection lens 102. This position is the position of the exit surface of the projection lens 102 in this embodiment, but is not limited to this position.

  For example, the effective image display area 301 has an ellipse (circle) shown in FIG. 2A, a polygon shown in FIG. 2B, and a quadrangle shown in FIG. A panel region 302 indicated by a broken line when the shift is 0% is a region where the center of the panel 238 coincides with the optical axis of the projection lens and light from the panel 238 passes through. When the shift is performed a plurality of times, such as when the installation environment of the image projection apparatus changes, the panel area 302 indicated by the dotted line at the time of 0% shift is the current panel area (immediately before the shift is about to be performed).

  A panel region 303 indicated by a long broken line after the shift is a region through which light from the shifted panel 238 passes. 2A to 2C, the shift amounts are different. The lens shift is realized by changing the positional relationship between the panel 238 and the projection lens (lens unit 100A).

  If a part of the panel area 303 after the shift comes out of the effective image display area 301, the projected image is not correctly projected, and an unacceptable distortion, chromatic aberration, missing image, etc. occur or deviate from the allowable depth. . For this reason, it is necessary to move the panel area within the effective image display area.

  The lens shift mechanism 220 moves the projection position by moving the projection lens (lens unit 100A) in a direction perpendicular to the optical axis. Lens shift is effective as a method for correcting trapezoidal distortion of a projected image that occurs when an image is projected from the image projection apparatus onto the projection surface from obliquely below or obliquely from the side. The shift direction is not limited to the direction perpendicular to the optical axis, and may be an oblique direction as long as it has a component perpendicular to the optical axis.

  The lens shift mechanism 220 includes a shift amount detection unit 222 and a shift drive unit 224.

  The shift amount detection unit 222 provides information on the center position of the current panel area by detecting the movement amount of the effective image display area 301.

  The shift driving unit 224 shifts the projection lens 102 in a direction (vertical direction and horizontal direction) orthogonal to the optical axis, and is configured by an actuator such as a motor. In this embodiment, a motor (a DC motor, a stepping motor, a vibration motor, or the like) is used as an actuator.

  The operation unit 230 includes a switch, a dial, a button, a remote control light receiving unit, and the like (not shown) that accept various operations including a lens shift operation from the user. The operation unit 230 functions as an input unit that inputs a direction and a shift amount to be shifted by the lens shift mechanism 220.

  The video signal input unit 232 receives a single video signal or a plurality of video signals.

  The image processing unit 234 performs various image processing and synchronization timing change on the video signal from the video signal input unit 232, and outputs the processed video signal to the panel driving unit 240.

  The lamp 236 is a light source for projection light. Light emitted from the lamp 236 reaches the panel 238 through color separation, PS conversion, and the like.

  The panel 238 receives a timing signal and a video signal from the panel driving unit 240 and forms a light reflection pattern (or transmission pattern). The panel 238 includes a liquid crystal panel that modulates light from the lamp 236 in accordance with an input image signal from the video signal input unit 232 and an image display element (light modulation element) such as a DMD (digital micromirror device). .

  The panel drive unit 240 drives the panel 238 based on the output from the image processing unit 234 and generates D / A conversion and drive pulses.

  The display unit 242 displays that when the shift movable determination unit 214 determines that the lens cannot be shifted, or when the actual shift amount is smaller than the input shift amount.

  FIG. 3 is a flowchart for explaining the operation of the control unit 210, and “S” is an abbreviation of a step. FIG. 3 is embodied as a computer-executable computer program.

  When the user performs a lens shift operation on the operation unit 230, the control unit 210 obtains the direction and shift amount to be shifted from the operation unit 230 (S402). The control unit 210 according to the present embodiment detects the direction in which the center of the panel area 302 at the time of shift 0% (the origin in FIG. 2) is about to move by the shift. However, the reference position only needs to be associated with the panel area 302 before the shift, and is not necessarily limited to the center position.

  Next, the control unit 210 determines whether the center of the panel area is close to the center of the effective image display area 301 by shifting the projection lens in the direction in which the projection lens is to be shifted (S404). It is determined whether or not shift driving is possible by shifting in the direction in which the projection lens is to be shifted. If the passing through the effective image display area (the center of the image passing area) is in the direction approaching the center of the effective image display area 301 (“Yes” in S404), the shift movable determination unit 214 of the control unit 210 is shifted. Determine that it is possible. Then, the shift movable determination unit 214 moves the projection lens via the shift drive unit 224 of the lens shift mechanism 220 (S410).

  If the direction to be shifted is a direction away from the center of the effective image display area 301 (“No” in S <b> 404), the control unit 210 causes the entire area of the panel area 303 after the shift to be within the effective image display area 301. It is determined whether or not there is (S406).

  Hereinafter, the details of S406 will be described assuming that the four coordinate points of the panel region 303 after the shift are Pn = (Pxn, Pyn), where n = 1, 2, 3, and 4.

  As shown in FIG. 2A, when the effective image display area 301 is defined by an ellipse (or circle), the entire area of the shifted panel area 303 is the effective image if the following expression holds for all n. It will be within the range of the display area 301.

  However, (Sx, Sy) is the amount of deviation from the optical axis center (0, 0) of the effective image display area 301, and (Rx, Ry) is the radius of the effective image display area 301 in the X axis direction and the Y direction. Radius.

  Next, when An = (Ax, Ay), the Z component of the outer product composed of three points A1, A2, and A3 is defined as follows.

  As shown in FIG. 2B, when the effective image display area 301 is defined by a polygon, the entire area of the panel area 303 after the shift is displayed as an effective image if the following expression holds for all i and n. It falls within the range of the area 301. Each vertex of the polygon showing the effective image display area 301 is defined by Qm = (Qxm, Qym) (1 ≦ m ≦ k). It is assumed that the vertices are arranged in order clockwise (clockwise).

  As shown in FIG. 2C, when the effective image display area 301 is defined by a rectangle, each vertex of the rectangle indicating the effective image display area 301 is defined by Qm = (Qxm, Qym) (m = 1, 2, 3, 4). However, it is assumed that the vertices are arranged in order clockwise (clockwise), Q1 indicates the upper left coordinate, and Q3 indicates the lower right coordinate. At this time, considering the shifted panel region 303 that satisfies the following equation:

If the following equation is satisfied for all n, the entire area of the panel area 303 after the shift is within the range of the effective image display area 301.

  If the entire area of the panel area 303 is within the effective image display area 301 (“Yes” in S406), the process proceeds to S408.

  On the other hand, if a part of the panel area 303 falls outside the range of the effective image display area 301 (“No” in S406), the shift movable determination unit 214 determines whether or not the shift amount can be reduced (S407). . That is, the shift movable determination unit 214 determines whether the entire area of the panel area 303 after the shift is within the range of the effective image display area 301 if the shift amount is smaller than the shift amount input to the operation unit 230. To do.

  If the shift movable determination unit 214 determines that the entire area of the panel area 303 after the shift is within the range of the effective image display area 301 if the shift amount is smaller than the shift amount input to the operation unit 230 (S407). "Yes") The process proceeds to S408. In step S <b> 408, the lens shift mechanism shifts the projection lens to a position where the entire area of the panel area 303 does not go out of the effective image display area 301.

  On the other hand, if the shift movable determination unit 214 determines that the shifted panel area 303 is at the marginal position of the effective image display area 301 and can no longer be shifted (“No” in S407), the lens shift is not performed and the process is performed. finish.

  The display unit 242 displays that the actual shift amount is smaller than the input shift amount, or that it is no longer possible to shift in the same direction, or both. The display may be a gauge that shows the shift direction, the shift amount, and how much can be shifted, or may be a character or the like. Even if the projection lens cannot be shifted by the shift amount input by the user, the degree of freedom of installation can be increased as much as possible by shifting the projection lens in the direction desired by the user as much as possible by the processing according to the above flow. it can. In addition, as another effect, the user can obtain the maximum shift amount that can be shifted by indicating the shift amount.

  As described above, according to the present embodiment, since the control unit 210 performs lens shift in consideration of the size of the panel area, the panel area 303 after the shift is within the range of the effective image display area 301 and the quality of the projected image is ensured. can do.

  FIG. 4 is a block diagram of a projector (image projection apparatus) 200B according to the second embodiment. The projector 200B according to the second embodiment includes a memory 250 corresponding to the memory 106 in the projector. The memory 250 functions as a second storage unit that stores information on a plurality of sets of types of projection lenses and corresponding effective image display areas.

  The control unit 210 acquires identification information that defines the type of the projection lens 102 by communicating with the lens microcomputer 104 of the lens unit 100B (for this reason, the lens unit 100B stores a memory (not shown) that stores the identification information of the projection lens 102. Have). Then, the control unit 210 acquires an effective image display area corresponding to the identification information from the memory 250, and uses it to determine the shift amount of the panel area. The memory 250 may be configured as a rewritable or additionally writable nonvolatile memory. By having a memory in the lens unit 100B, versatility can be improved. For example, the projector body can have a minimum amount of information, and even when the number of lens units that can be attached to the projector increases later, the projection lens is shifted using information from the lens units. Can do.

  Also in the present embodiment, since the control unit 210 performs lens shift in consideration of the size of the panel area, the shifted panel area 303 is within the effective image display area 301 and the quality of the projected image can be ensured. it can.

  FIG. 5 is a block diagram of a projector (image projection apparatus) 200C according to the third embodiment. In the third embodiment, the lens shift mechanism 220 is provided as the lens shift mechanism 108 inside the lens unit 100C. The shift amount detection unit 222 and the shift drive unit 224 are provided as a shift amount detection unit 108a and a shift drive unit 108b, respectively.

  Also in the present embodiment, since the control unit 210 performs lens shift in consideration of the size of the panel area, the shifted panel area 303 is within the effective image display area 301 and the quality of the projected image can be ensured. it can.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these Examples, A various deformation | transformation and change are possible within the range of the summary.

  The image projection apparatus can be applied to a projector application.

100A to 100C Lens unit 102 Projection lens 108, 220 Lens shift mechanism 200A to 200C Image projection device 230 Operation unit (input means)
238 Panel (image display element)
210 Control unit (control means)
212 Panel size storage unit (first storage means)
214 Shift movable determination unit (first acquisition means, second acquisition means)

Claims (6)

In an image projection apparatus capable of projecting light from an image display element as a projection image on a projection surface via a projection lens of a replaceable lens unit,
A lens shift mechanism for shifting the projection lens with respect to the optical axis;
An input means for inputting a shift direction and a shift amount by the lens shift mechanism;
First storage means for storing a size of a display area of the image display element;
First acquisition means for acquiring a center position of a region of the image display element;
A second acquisition means for acquiring an effective image display area that is an area in which the projection lens can display a projection image having an evaluation value higher than a predetermined evaluation value by communicating with the lens unit;
The shift direction and the shift amount input to the input means, the size of the display area of the image display element stored in the first storage means, the center of the area of the image display element acquired by the first acquisition means Based on the position and the effective image display area acquired by the second acquisition means, the lens shift mechanism causes the entire display area of the image display element after the shift to fall within the effective image display area. Control means for controlling the shift;
An image projection apparatus comprising:   The image projection apparatus according to claim 1, wherein the second acquisition unit acquires information on a size of the effective image display area from the lens unit. A second storage means for storing information of a plurality of sets of types of the projection lens and an effective image display area corresponding to the projection lens;
The second acquisition unit acquires identification information defining the type of the projection lens acquired from the lens unit, and acquires an effective image display area corresponding to the identification information from the second storage unit. The image projection apparatus according to claim 1. A projection lens and a lens unit having a lens shift mechanism for shifting the projection lens with respect to the optical axis are interchangeably mounted, and light from the image display element is projected as a projection image onto the projection surface via the projection lens. In an image projection apparatus capable of
An input means for inputting a shift direction and a shift amount by the lens shift mechanism;
First storage means for storing a size of a display area of the image display element;
First acquisition means for acquiring a center position of a region of the image display element;
A second acquisition means for acquiring an effective image display area that is an area in which the projection lens can display a projection image having an evaluation value higher than a predetermined evaluation value by communicating with the lens unit;
The shift direction and the shift amount input to the input means, the size of the display area of the image display element stored in the first storage means, and the center position of the area of the image display element acquired by the first acquisition means Based on the effective image display area acquired by the second acquisition means, the shift by the lens shift mechanism is performed so that the entire area of the display area of the image display element after the shift is within the range of the effective image display area. Control means for controlling
An image projection apparatus comprising: The control means, the shift directions are entered from said input means, said image display device region center direction if approaching the center of the effective image display area of the shift driving by prior Symbol lens shift mechanism The image projection device according to claim 1, wherein the image projection device is determined to be possible . Claims actual shift amount from the shift amount input to said input means is small, or can not be shifted in the shift direction is input to the input means, characterized by further comprising display means for displaying that image projection apparatus according to any one of claims 5 to claim 1.