JP2013083690A - Projection type image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projection type image display device capable of projecting a horizontally long image and a vertically long image without reducing resolution.SOLUTION: The projection type image display device includes: an image projection unit 8 for projecting an image; a movable part 6 for supporting the image projection unit switchably between a horizontally long image projection attitude and a vertically long image projection attitude; and a correction optical system 10 having a function of deflecting, in a predetermined direction, projection light of the image projected by the image projection unit and a function of correcting trapezoidal distortion caused by the deflection. The image from the image projection unit taking one of the horizontally long image projection attitude and the vertically long image projection attitude is projected through the correction optical system.

Description

  The present invention relates to a projection type image display apparatus.

  In recent years, a projection-type image display device capable of switching between a horizontally long image and a vertically long image has been known (see, for example, Patent Document 1). In such a projection-type image display device, when a landscape image is projected horizontally and then a portrait image is projected vertically, the center position of the portrait image is shifted from the center position of the landscape image. . Therefore, the shape of the image displayed on the display panel is changed so that the vertically long image becomes rectangular by image processing in order to correct the trapezoidal distortion caused by moving the device manually and aligning the center position. I am letting.

Japanese Patent No. 4616092

  However, since the projection type image display apparatus described above corrects trapezoidal distortion by changing the shape of the projected image, there is a problem that pixels that are not used on the display panel are generated and the resolution of a part of the projected image is reduced. was there.

  An object of the present invention is to provide a projection type image display apparatus that projects a horizontally long image and a vertically long image without reducing the resolution.

  The projection type image display device of the present invention is projected by an image projection unit that projects an image, a movable unit that supports the image projection unit so as to be switchable to a horizontally long image projection posture or a vertically long image projection posture, and the image projection unit. And a correction optical system having a function of deflecting projection light of an image in a predetermined direction and a function of correcting trapezoidal distortion caused by the deflection, and the posture of either one of the horizontally long image projection posture and the vertically long image projection posture The image from the image projection unit is projected through the correction optical system.

  According to the projection type image display apparatus of the present invention, it is possible to provide a projection type image display apparatus that projects a horizontally long image and a vertically long image without reducing the resolution.

It is a perspective view which shows the landscape image projection attitude | position in the projection type image display apparatus which concerns on embodiment. It is a perspective view which shows the vertical image projection attitude | position in the projection type image display apparatus which concerns on embodiment. It is a perspective view which shows the projection image projected on the screen from the projection type image display apparatus which concerns on embodiment. It is a front view which shows the projection image projected on the screen from the projection type image display apparatus which concerns on embodiment. It is a schematic sectional drawing which shows the image projection unit which concerns on embodiment. It is a schematic sectional drawing which shows the correction | amendment optical system which concerns on embodiment. It is a block diagram of the projection type image display device concerning an embodiment. It is a flowchart which shows the projection process of the projection image which concerns on embodiment. It is a figure which shows the modification of the correction | amendment optical system which concerns on embodiment.

  The projection type image display apparatus according to the present embodiment will be described below with reference to the drawings. FIG. 1 is a perspective view showing a landscape image projection posture in the projection type image display apparatus according to the embodiment. FIG. 2 is a perspective view showing a portrait image projection posture in the projection type image display apparatus according to the embodiment. The projection type image display device 2 includes a gantry 4, a movable unit 6, an image projection unit 8, and a correction optical system storage unit 10.

  The movable part 6 has a plate shape, and the image projection unit 8 is attached to one surface. One edge of the movable portion 6 is rotatably attached to a hinge mechanism 7 fixed to the gantry 4. Thereby, the image projection unit 8 can be set to the landscape image projection posture shown in FIG. 1 or the portrait image projection posture shown in FIG.

  The image projection unit 8 includes an image memory unit that stores image data of a projection image, a light source, an image display unit that displays a projection image, a projection lens 8a, and the like. The image projection unit 8 also includes an operation unit including operation keys for inputting instructions such as projection start and projection end of the projection light, and is based on image data stored in the image memory unit in accordance with the instruction input by the operation unit. Projection light is projected through the projection lens 8a. Note that the image projection unit 8 can be detached from the gantry 4 and the movable portion 6 and used alone.

  The correction optical system storage unit 10 is installed on a support column erected on the gantry 4. When the image projection unit 8 is in the vertically long image projection posture, the projection lens 8 a faces the correction optical system storage unit 10. Thereby, the projection light projected from the projection lens 8 a is projected through the correction optical system in the correction optical system storage unit 10. Here, the correction optical system includes an optical system that deflects the projection light projected from the image projection unit 8 and an optical system that corrects trapezoidal distortion of the projection image caused by the deflection of the projection light. An optical system that corrects aberrations of various optical systems other than trapezoidal distortion may also be included.

  FIG. 3 is a perspective view showing a projection image projected on the screen from the projection type image display apparatus according to the embodiment, and FIG. 4 shows a projection image projected on the screen from the projection type image display apparatus according to the embodiment. FIG. Here, FIG. 3 shows a state in which a projection image is projected from the projection type image display device 2 onto a screen (not shown) located at a projection distance L.

  In FIG. 3, a horizontal image projected in the horizontal image projection posture from the projection type image display device 2 is indicated by a solid line. The horizontal image has a vertical length V and a horizontal length H. Yes. This horizontally long image is indicated by a solid rectangle PQRS in FIG. Further, in FIG. 3, a vertically long image projected from the projection type image display device 2 in the vertically long image projection posture via the correction optical system is indicated by a two-dot chain line. A vertically long image through this correction optical system is indicated by a two-dot chain line rectangle P′Q′R ′S ′ in FIG.

  Further, in FIG. 3, a vertically long image when projected from the projection type image display apparatus 2 in the vertically long image projection posture without passing through the correction optical system is indicated by a broken line. A vertically long image projected without passing through the correction optical system is indicated by a broken-line rectangle P "Q" R "S" in FIG.

  In FIG. 3, the detailed shape of the gantry 4 in the projection type image display device 2 and the vertically long image projection posture of the image projection unit 8 are not shown. Further, the positional deviation of the optical axis of the projection lens 8a due to the switching between the vertical image projection posture and the horizontal image projection posture on the gantry 4 is relatively small compared to the length from the projection type image display device 2 to the screen. Therefore, it will be described as being ignored.

  A point C shown in FIGS. 3 and 4 is an intersection of the optical axis of the projection lens 8a and the screen when a horizontally long image is projected, and is located at the center of the lower side in the horizontally long image. Here, the vertically long image projected without passing through the correction optical system is projected on the screen at a position rotated 90 degrees counterclockwise around the optical axis, that is, around the point C with respect to the horizontally long image. Half is projected onto P "Q" R "S" below the lower side RS of the landscape image.

  A point C ′ shown in FIGS. 3 and 4 is an intersection of the optical axis of the projection lens 8a and the screen when a vertically long image is projected through the correction optical system, and is located on the screen at the upper right of the point C. To do. By moving the position of the intersection between the optical axis and the screen in this way, the lower side P ′S ′ of the vertically long image projected via the correction optical system can be positioned on the same straight line as the lower side RS of the horizontally long image. it can. In addition, by moving the position of the intersection of the optical axis and the screen, the position of the vertical center line of the vertically long image projected through the correction optical system substantially matches the position of the vertical center line of the horizontally long image. Can be made.

  Here, FIG. 5 is a schematic sectional view showing the image projection unit according to the embodiment. The image projection unit 8 has an image display element 8b for displaying a projected image. The image display element 8b is arranged so that the upper end portion is located on a line passing through the optical axis of the projection lens 8a. Thereby, the vertically long image and the horizontally long image projected by the image projection unit 8 have a configuration in which the optical axis of the projection lens 8a is located at the edge, that is, the offset of the optical axis is 100%. The image display element 8b is configured in a rectangular shape with an aspect ratio of 4: 3 or 16: 9, and the vertical direction in FIG. 5 is the short direction of the image display element 8b.

  Next, the configuration of the correction optical system stored in the correction optical system storage unit 10 will be described with reference to FIG. FIG. 6 shows the correction optical system storage section 10 cut along a plane passing through a point O indicating the emission position of the projection light of the projection type image display device 2 shown in FIG. 3 and a triangle OCC ′ composed of the points C and C ′. It is sectional drawing.

  The correction optical system includes a first reflecting mirror 20, a correction lens 22, and a second reflecting mirror 24. The first reflecting mirror 20 is disposed at an inclination of 45 degrees with respect to the optical axis of the projection lens 8a in order to deflect and reflect the incident projection light by 90 degrees. The correction lens 22 is a lens having a free curved surface for correcting trapezoidal distortion generated in a projected image and projecting a vertically long image in a normal shape such as a rectangular shape on a screen.

  The second reflecting mirror 24 projects projection light in a direction tilted clockwise by an angle α with respect to the direction of the point C ′ on the screen, that is, the direction of the optical axis of the projection lens 8a of the image projection unit 8 shown in FIG. It is a mirror that deflects. Therefore, the second reflecting mirror 24 is installed in a state tilted by 45 degrees + (1/2) α degrees with respect to the optical axis of the projection lens 8 a bent by the first reflecting mirror 22.

  Here, the angle α for deflecting the projection light in the direction of the point C ′ on the screen will be described. The angle α is the angle of the vertex O of the triangle OCC ′ in FIG. 3, and when the projection lens 8a is a fixed focus lens, it has a constant value regardless of the projection distance.

  The angle α when the aspect ratio of the image display element 8b is 4: 3 is calculated as follows. In FIG. 4, the relationship between the horizontal length H and the vertical length V of the horizontally long image is H: V = 4: 3 from the aspect ratio. Since CS ′: C ′S ′ = 1.5: 2, ２C′CS ′ = arctan (C ′S ′ / CS ′) = arctan (2 / 1.5) = 53.13 °. .

Since CC ′ = (2 ² +1.5 ² ) ^0.5 × (H / 4) = 0.625H, in the triangle OCC ′ in FIG. 3, α = arctan (CC ′ / L) = arctan (0 .625 × (H / L)). Here, when the projection ratio (projection distance L: width H of the landscape image) is 2: 1, α = 17.35 °.

  FIG. 7 is a block diagram of the projection type image display apparatus according to the embodiment. In FIG. 7, the projection type image display apparatus 2 includes a control unit 30 that controls the entire apparatus. A vertical / horizontal switching drive unit 32, a vertical / horizontal state detection unit 34, an image memory unit 36, an image data detection unit 38, and an image processing unit 40 are connected to the control unit 30.

  The vertical / horizontal switching drive unit 32 is a drive mechanism such as a motor attached to the gantry 4 and operates the movable unit 6 in accordance with an instruction from the control unit 30 to change the posture of the image projection unit 8 to a horizontal image projection posture or a vertical image projection. Switch to posture.

  The vertical / horizontal state detection unit 34 is a detection switch, a sensor, or the like mounted on the gantry 4 and detects whether the image projection unit 8 is in the vertical image projection posture or the horizontal image projection posture.

  Note that an interface cable is provided between the image projection unit 8 and the gantry 4 in order to make an electrical connection between the vertical / horizontal switching drive unit 32 and the vertical / horizontal state detection unit 34 mounted on the gantry 4 and the control unit 30. Or direct connection using a connector. The vertical / horizontal state detection unit 34 may be a gravity sensor (acceleration sensor) mounted on the image projection unit 8 instead of the detection switch or sensor mounted on the gantry 4.

  The image memory unit 36 stores image data of a projection image projected by the image projection unit 8, vertical / horizontal position information indicating the correct projection direction of the projection image associated with the image data, and the like. Vertical / horizontal position information indicates that the projection image is a landscape image, that is, “horizontal position” indicating that the horizontal orientation is the correct projection orientation, and the projection image is rotated 90 degrees counterclockwise on the screen from the horizontal orientation. "Vertical position / counterclockwise 90 degree rotation" indicating that the vertical direction is the correct projection direction, and the vertical direction obtained by rotating the projected image 90 degrees clockwise on the screen from the horizontal state is the correct projection direction There are three types of “vertical position / clockwise 90 degree rotation”.

  In the present embodiment, as shown in FIGS. 1 and 2, the image projection unit 8 has a horizontally long image projection posture when the direction from the back side of the projection type image display device 2 toward the screen is used as a reference. By rotating 90 degrees counterclockwise, a vertically long image projection posture is obtained. Therefore, the projected image of “vertical position / counterclockwise 90 degree rotation” is an image projected in the correct projection direction in the portrait image projection posture. On the other hand, the projection image of “vertical position / 90 ° clockwise rotation” is an image projected upside down in the portrait orientation.

  The image data detection unit 38 detects vertical / horizontal position information associated with the image data. The image processing unit 40 has a function of converting the image data read from the image memory unit 36 into a format that can be reproduced by the projection type image display device 2. The image processing unit 40 also has a function of rotating a projection image based on image data as necessary. Therefore, when projecting a projection image based on the image data of “vertical position / clockwise 90 degree rotation” in the portrait image projection posture, the image processing unit 40 rotates the projection image 180 degrees and corrects it to the correct orientation.

  Here, the image data stored in the image memory unit 36 is used, but image data stored in the memory of an external computer may be used instead of the image memory unit 36. In that case, an external computer and the projection type image display apparatus 2 are connected via an interface cable or a connector.

  Here, the projection processing of the projected image will be described using the flowchart of FIG. First, when the user performs an operation for projecting an image using an operation unit (not shown) of the projection type image display device 2, image data in the image memory unit 36 is input to the control unit 30 (step S1). Then, when the control unit 30 recognizes that the image projection unit 8 is in the landscape image projection posture based on the detection result by the portrait and landscape state detection unit 34, the control unit 30 proceeds to the next step S3 and recognizes that the image projection unit 8 is in the portrait image projection posture. If so, the process proceeds to step S8 (step S2).

  When the control unit 30 recognizes that the image projection unit 8 is in the horizontal image projection posture (step S2, Yes), the vertical / horizontal position information is determined based on the detection result of the vertical / horizontal position information of the image data by the image data detection unit 38. It is determined whether or not the “horizontal position”, that is, the projection image based on the image data is a horizontally long image (step S3). When the control unit 30 determines that the projection image is a horizontally long image (Yes at Step S3), the image projection unit 8 projects a projection image based on the image data onto a screen (not shown), and ends the projection process (Step S4).

  In addition, when the vertical / horizontal position information is “vertical position / counterclockwise 90 degree rotation” or “vertical position / clockwise 90 degree rotation” in step S3, the control unit 30 determines that the projection image is a portrait image ( In step S3, No), the movable unit 6 is driven by the vertical / horizontal switching drive unit 32 to switch the image projection unit 8 from the horizontal image projection posture to the vertical image projection posture (step S5).

  The control unit 30 determines whether the vertical / horizontal position information of the image data is “vertical position / clockwise 90 degree rotation” (step S6). When determining that the vertical / horizontal position information is “vertical position / counterclockwise 90 degree rotation” (step S6, No), the control unit 30 causes the image projection unit 8 to project a projection image based on the image data, and ends the projection process. (Step S4).

  When the control unit 30 determines that the vertical / horizontal position information is “vertical position / 90 ° clockwise rotation” (Yes in step S6), the image processing unit 40 performs image processing for rotating the projection image based on the image data by 180 °. (Step S7). And the control part 30 projects the projection image based on image data by the image projection unit 8, and complete | finishes a projection process (step S4).

  When the control unit 30 recognizes that the image projection unit 8 is in the vertically long image projection posture (step S2, No), the vertical and horizontal position information is determined based on the detection result of the vertical and horizontal position information of the image data by the image data detection unit 38. It is determined whether or not the “horizontal position”, that is, the projection image based on the image data is a horizontally long image (step S8).

  When determining that the projection image is a landscape image (Yes in step S8), the control unit 30 drives the movable unit 6 by the portrait / landscape switching drive unit 32 to switch the image projection unit 8 from the portrait image projection posture to the landscape image projection posture ( Step S9). Then, the control unit 30 causes the image projection unit 8 to project a projection image based on the image data, and ends the projection process (step S4).

  The control unit 30 determines that the vertical / horizontal position information is “vertical position / counterclockwise 90 degree rotation” or “vertical position / clockwise 90 degree rotation” and the projected image is a portrait image in step S8 (step S8). No), it is determined whether the vertical / horizontal position information of the image data is “vertical position / 90 ° clockwise rotation” (step S10).

  When the control unit 30 determines that the vertical / horizontal position information is “vertical position / counterclockwise 90 degree rotation” (step S10, No), the control unit 30 causes the image projection unit 8 to project a projection image based on the image data. Then, the projection process is terminated (step S4).

  Further, when the control unit 30 determines that the vertical / horizontal position information is “vertical position / clockwise 90 degree rotation” (step S10, Yes), the image processing unit 40 rotates the projection image based on the image data by 180 degrees. Is performed (step S11). And the control part 30 projects the projection image based on image data by the image projection unit 8, and complete | finishes a projection process (step S4).

  In this way, switching of the orientation of the image projection unit 8 by the portrait / landscape switching drive unit 32 so that the projection image is projected in the correct orientation based on the orientation of the image projection unit 8 and the correct projection orientation of the projection image, Control of each unit such as rotation of the projection image by the image processing unit 40 is automatically performed.

  According to this embodiment, by providing the correction optical system, it is possible to project a horizontally long image and a vertically long image in a normal shape without reducing the resolution. Also, through the correction optical system, the position of the lower side of the portrait image is aligned with the position of the lower side of the landscape image, and the position of the vertical center line of the portrait image is almost the same as the position of the vertical center line of the landscape image. Therefore, it is possible to save the trouble of manually aligning the projected image when the posture of the image projection unit is switched.

  In the present embodiment, the vertical / horizontal position information associated with the image data may be information that the user has written on the image data as the correct orientation of the projected image by operating the operation unit. When using an image photographed by a camera, information indicating the correct orientation of an image written at the time of photographing by an electronic camera may be used.

  FIG. 9 shows a modification of the correction optical system according to the embodiment, and is a cross-sectional view of the correction optical system storage unit 10 taken along a plane passing through the triangle OCC ′ in FIG. As shown in FIG. 9, the correction optical system includes a prism 44 and a correction lens 46 that corrects trapezoidal distortion. Therefore, the projection light emitted through the projection lens 8a is incident on the prism 44 inside the correction optical system storage unit 42 and is deflected by the deviation angle α. Further, the light passes through the correction lens 46 and is emitted to the outside. Even with the correction optical system having such a configuration, the deflection of the projection light and the correction of the trapezoidal distortion can be performed in the same manner as the correction optical system of the above-described embodiment.

  In the present embodiment, the correction lens is configured as a single lens. However, the present invention is not limited to this, and a configuration including a plurality of lenses and lens groups is desirable. In addition, it is desirable to use a free-form surface lens for the correction lens or a plurality of lenses and lens groups instead of the correction lens. Instead of the correction lens, a trapezoidal distortion may be corrected by applying a mirror having a free-form surface or a prism having an entrance surface or an exit surface having a free-form surface.

  In the present embodiment, the projection lens 8a is configured as a single convex lens. However, the present invention is not limited to this, and a configuration including a plurality of lenses and lens groups is desirable.

  In this embodiment, the projection lens 8a and the image display element 8b are arranged so that the offset of the optical axis is 100%. However, the present invention is not limited to this arrangement, and the offset is 100% or more. An arrangement with the following settings may be used.

  In the present embodiment, the vertical image is projected so that the vertical center line and the lower side of the vertical image coincide with the vertical center line and the lower side of the horizontal image, but the present invention is not limited to this. For example, the vertically long image may be projected so that the horizontal and vertical center lines of the vertically long image coincide with the horizontal and vertical center lines of the horizontally long image.

  Further, in the present embodiment, the projection light is deflected by the correction optical system at the time of the portrait image projection posture, but the present invention is not limited to this, and the optical axis of the projection lens 8a is projected when the portrait image is projected. However, the optical mechanism for deflecting the projection light from the correction optical system may be removed by taking the hinge mechanism 7 of the movable portion 6 at an appropriate position so that the point C ′ passes on the screen.

  DESCRIPTION OF SYMBOLS 2 ... Projection type image display apparatus, 4 ... Stand, 6 ... Movable part, 8 ... Image projection unit, 10 ... Correction optical system storage part.

Claims (7)

An image projection unit for projecting an image;
A movable part that supports the image projection unit so as to be switchable to a horizontally long image projection posture or a vertically long image projection posture;
A correction optical system having a function of deflecting projection light of an image projected by the image projection unit in a predetermined direction and a function of correcting trapezoidal distortion caused by the deflection;
A projection-type image display apparatus that projects an image from the image projection unit in any one of the landscape orientation and the orientation of the portrait image projection via the correction optical system.   The correction optical system is configured so that the position of the center line in the vertical direction of the image projected in the horizontally long image projection posture substantially matches the position of the center line in the vertical direction of the image projected in the vertically long image projection posture. The projection image display apparatus according to claim 1, wherein the projection light from the image projection unit is deflected.   The correction optical system deflects the projection light from the image projection unit so that the lower side of the image projected in the horizontal image projection posture and the lower side of the image projected in the vertical image projection posture substantially coincide with each other. The projection type image display device according to claim 2, wherein   The correction optical system substantially matches the position of the horizontal center line of the image projected in the landscape image projection posture with the position of the horizontal center line of the image projected in the portrait image projection posture. 3. The projection type image display device according to claim 2, wherein the projection light from the image projection unit is deflected.   The projection type image display device according to any one of claims 1 to 4, wherein the correction optical system includes a free-form surface for correcting trapezoidal distortion. A drive unit that drives the movable unit and switches the posture of the image projection unit;
A portrait and landscape state detection unit that detects whether the image projection unit is the portrait image projection posture or the landscape image projection posture;
6. The posture of the image projection unit is switched by the drive unit according to a correct orientation of the image and the posture of the image projection unit detected by the vertical / horizontal state detection unit. The projection-type image display device according to any one of the above. An image processing unit that rotates the direction of the projected image;
The projection type image display according to claim 6, wherein when projecting an image in the portrait orientation, the image processing unit rotates the image by 180 degrees based on the correct orientation of the image. apparatus.

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