Projection device and control method for projection device

Abstract

To reduce a scan frequency.SOLUTION: The projection device of the present invention includes: a light emission display panel in which a plurality of pixels having a light emission element are arranged in a matrix; a scan mirror for reflecting an image light emitted from the light emission display panel to a scan target surface and two-dimensionally scanning the reflected image light in the scan target surface; and a projection optical system for guiding the image light from the light emission display panel to the scan mirror.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a projection device and a control method for a projection device. [Background technology]

[0002] Patent Document 1 listed below discloses a projection display device that projects an image using a laser array and a scanner arranged in a line. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-169988 Summary of the Invention [Problem to be solved by the invention]

[0004] Because the scanner's scan angle and scan frequency are inversely proportional, increasing the scan angle to display a larger screen results in a lower scan frequency. This means the image frame rate will be lower. Furthermore, as the vertical size of the image (Y-axis direction) increases, the vertical size of the scanner also increases, and the optical system also becomes larger. For example, to display a 4K image, approximately 2,000 pixels are required vertically. In that case, even if the vertical pixel size is 2 μm, a panel with a vertical size of 4 mm is required, and as the panel size increases, the scanner size also increases. [Means for solving the problem]

[0005] In order to solve the above problem, one embodiment of the projection device of the present invention comprises a light-emitting display panel in which a plurality of pixels each having a light-emitting element is arranged in a matrix, a scanning mirror that reflects image light emitted from the light-emitting display panel toward a scanned surface and scans the reflected image light two-dimensionally on the scanned surface, and a projection optical system that guides the image light from the light-emitting display panel to the scanning mirror.

[0006] One embodiment of the present invention provides a method for controlling a projection device that includes a light-emitting display panel in which a plurality of pixels having light-emitting elements are arranged in a matrix, a scanning mirror, and a projection optical system that guides image light from the light-emitting display panel to the scanning mirror, wherein the scanning mirror reflects the image light emitted from the light-emitting display panel toward a surface to be scanned, and scans the reflected image light two-dimensionally across the surface to be scanned. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram schematically illustrating an overall view of a projection device according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram schematically illustrating a configuration of a main part of a projection device. [Figure 3] FIG. 1 is a schematic diagram illustrating the overall configuration of a light-emitting display panel provided in a projection device. [Figure 4] 2 is an equivalent circuit diagram showing an example of a circuit configuration of each pixel provided in a light-emitting display panel. FIG. [Figure 5] FIG. 1 is a diagram illustrating an example of the mechanical structure of a MEMS scanner having a scanning mirror. [Figure 6] 10 is a diagram schematically illustrating the relationship between the rotation angle θ of the scanning mirror around the Y axis and the position of the scanning point on the surface to be scanned. FIG. [Figure 7] 10 is a diagram schematically illustrating the relationship between the rotation angle φ of the scanning mirror about the X axis and the position of the scanning point on the surface to be scanned. FIG. [Figure 8] 3 is a diagram showing a scannable area that can be scanned by a scanning mirror within the in-plane area of the surface to be scanned; FIG. [Figure 9] FIG. 2 is a diagram showing an example of a scanning path set within a scannable area of a surface to be scanned. [Figure 10] FIG. 10 is a diagram illustrating an example of an input image. [Figure 11] 10 is a timing chart showing the temporal correspondence between the X-direction position of a scanning point and the amount of light emitted by a light-emitting display panel in a step scanning mode. [Figure 12] 10A and 10B are diagrams showing how child images are sequentially formed on the scanned surface as the scanning point passes through each image display point set on the scanning path in step scanning mode. [Figure 13] FIG. 10 is a first explanatory diagram regarding an overlap area provided in a child image. [Figure 14] FIG. 2 is a second explanatory diagram regarding the overlap area provided in the child image. [Figure 15] FIG. 10 is a third explanatory diagram regarding the overlap area provided in the child image. [Figure 16] FIG. 4 is a fourth explanatory diagram regarding an overlap area provided in a child image. [Figure 17] 10A and 10B are diagrams showing how child images are sequentially formed on the scanned surface as the scanning point passes through each image display point set on the scanning path in the constant scanning mode. [Figure 18] 10 is a timing chart showing the temporal correspondence between the X-direction position of the scanning point, the main scanning rotation angle θ of the scanning mirror 4, and the amount of light emitted by the light-emitting display panel in the constant scanning mode. [Figure 19] FIG. 1 is a diagram schematically illustrating an example of the mechanical structure of a MEMS scanner that can mechanically realize operation in a step-scanning mode. [Figure 20] 10 is a diagram showing a schematic view of a scanning mirror periodically rotating during a period in which a rotary frame is constantly rotating; FIG. [Figure 21] 10 is a timing chart showing the temporal correspondence between a mirror rotation angle θ1, a frame rotation angle θ2, and a main scanning rotation angle θ. [Figure 22]FIG. 10 is a diagram schematically illustrating a combination of a scanning mirror and a polygon mirror that can mechanically realize a step scanning mode operation. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings below, the dimensions of the components may be shown on different scales to make them easier to see.

[0009] Fig. 1 is a diagram schematically illustrating an overall view of a projection device 1 according to this embodiment. As shown in Fig. 1, the projection device 1 according to this embodiment is a projection display device that includes a light-emitting display panel 2, a projection optical system 3, and a scanning mirror 4, and projects image light L toward a scanned surface 200 and two-dimensionally scans the scanned surface 200 with the image light L, thereby displaying an image on the scanned surface 200. The scanned surface 200 is the surface of an object onto which the image light L is projected. The scanned surface 200 may be the surface of a projector screen, or may be a wall surface, etc.

[0010] In each drawing, an XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system where appropriate. The Z-axis direction is a direction perpendicular to the scanned surface 200. The XY plane, which includes the mutually perpendicular X-axis and Y-axis directions, is a plane parallel to the scanned surface 200. In the following description, the direction parallel to the X-axis direction may be referred to as the "horizontal direction," and the direction parallel to the Y-axis direction may be referred to as the "vertical direction." Furthermore, within the horizontal direction, the positive side (+X side) may be referred to as the "right side," and the negative side (-X side) may be referred to as the "left side." Furthermore, within the vertical direction, the positive side (+Y side) may be referred to as the "upper side," and the negative side (-Y side) may be referred to as the "lower side." Note that the terms horizontal, vertical, right, left, top, and bottom are simply names used to describe the relative positional relationships of each part, and the actual positional relationships may be other than those indicated by these names.

[0011] Fig. 2 is a diagram schematically illustrating the configuration of the main parts of the projection device 1 according to this embodiment. As shown in Fig. 2, the projection device 1 according to this embodiment includes a light-emitting display panel 2, a projection optical system 3, a scanning mirror 4, an fθ lens 5, and a controller 6 (controller).

[0012] The light-emitting display panel 2 is a light-emitting display panel in which a plurality of pixels, each having a light-emitting element, is arranged in a matrix. As an example, the light-emitting display panel 2 in this embodiment is a self-luminous electro-optical device such as an OLED (Organic Light Emitting Diode) panel, a μLED (Micro Light Emitting Diode) panel, or an LD (Laser Diode) panel. A self-luminous electro-optical device is a device that generates light by itself using externally applied electrical energy, without requiring a light source such as a backlight.

[0013] As will be described in detail later, the light-emitting display panel 2 has a plurality of pixels arranged in a matrix. The number of pixels in the vertical direction (row direction) of the light-emitting display panel 2 is m, and the number of pixels in the horizontal direction (column direction) of the light-emitting display panel 2 is n. m and n are integers equal to or greater than 2. As an example, in this embodiment, the number of pixels m in the vertical direction of the light-emitting display panel 2 is 200, and the number of pixels n in the horizontal direction of the light-emitting display panel 2 is 200.

[0014] Each pixel of the light-emitting display panel 2 has a plurality of light-emitting elements that emit visible light of different colors. As an example, each pixel in this embodiment has a total of four light-emitting elements: one red light-emitting element that emits red light, one green light-emitting element that emits green light, and two blue light-emitting elements that emit blue light. The light emission brightness of the four light-emitting elements of each pixel is controlled by the controller 6, thereby displaying a color image on the light-emitting display panel 2. The light-emitting display panel 2 emits image light L, which represents an image to be displayed on the light-emitting display panel 2, to the projection optical system 3. The image light L includes visible light (colored light) emitted from the four light-emitting elements provided in each pixel of the light-emitting display panel 2.

[0015] FIG. 3 is a schematic diagram showing the overall configuration of the light-emitting display panel 2. As shown in FIG. 3, a pixel region 12 and a non-pixel region 13 are provided on a substrate 14 of the light-emitting display panel 2. The non-pixel region 13 includes a peripheral region 15 and a mounting region 16. The pixel region 12 is a rectangular region in which m×n pixels 11 are arranged in a matrix. The pixel region 12 is provided with m scanning lines 31 extending in the horizontal direction, m control lines 32 extending in the horizontal direction corresponding to each scanning line 31, and n data lines 33 extending in the vertical direction. As described above, in this embodiment, m and n are 200. The pixel 11 has a circuit configuration as shown in FIG. 4. The circuit configuration of the pixel 11 will be described later.

[0016] The peripheral region 15 is a rectangular frame-shaped region surrounding the pixel region 12. Three drive circuits 35 are provided in the peripheral region 15. The three drive circuits 35 are circuits that drive each pixel 11 in the pixel region 12. The drive circuits 35 include two scanning line drive circuits 36 and a data line drive circuit 37. The mounting region 16 is provided on the opposite side of the peripheral region 15 from the pixel region 12, i.e., outside the peripheral region 15. A plurality of mounting terminals 39 are provided in the mounting region 16. Various signals necessary for driving each pixel 11, such as control signals and power supply potentials, are supplied from the controller 6 to the mounting terminals 39 via a flexible cable (not shown).

[0017] 4 is an equivalent circuit diagram showing an example of the circuit configuration of each pixel 11. Since the circuit configuration of each pixel 11 is the same, the following description will take as an example the circuit configuration of the pixel 11 located in the i-th row and j-th column. Note that "i" is a symbol that generally indicates the number of the row in which the pixel 11 is arranged and is an integer greater than or equal to 1 and less than or equal to m. "j" is a symbol that generally indicates the number of the column in which the pixel 11 is arranged and is an integer greater than or equal to 1 and less than or equal to n.

[0018] In this embodiment, since four light-emitting elements are provided in each pixel 11, multiple data lines 33 are normally required for one pixel 11. However, for the sake of simplicity, the following description will representatively describe a circuit configuration for driving one of the four light-emitting elements provided in each pixel 11.

[0019] 4, the pixel 11 includes a selection transistor 51, a drive transistor 52, a light-emitting control transistor 53, a light-emitting element 54, and a storage capacitor 55. In this embodiment, the selection transistor 51, the drive transistor 52, and the light-emitting control transistor 53 are each a P-channel MOS-FET.

[0020] The gate electrode of the selection transistor 51 is electrically connected to the i-th row scanning line 31. The other of the source / drain regions of the selection transistor 51 is electrically connected to the j-th column data line 33. One of the source / drain regions of the selection transistor 51 is electrically connected to the gate electrode of the drive transistor 52 and one electrode of the storage capacitor 55. The back gate of the selection transistor 51 is electrically connected to a power supply wiring 61 to which a power supply potential is applied.

[0021] The gate electrode of the drive transistor 52 is electrically connected to one of the source / drain regions of the selection transistor 51 and one electrode of the storage capacitor 55. One of the source / drain regions of the drive transistor 52 is electrically connected to a power supply wiring 61. The other of the source / drain regions of the drive transistor 52 is electrically connected to one of the source / drain regions of the light-emitting control transistor 53. The back gate of the drive transistor 52 is electrically connected to the power supply wiring 61.

[0022] The gate electrode of the light-emitting control transistor 53 is electrically connected to the control line 32 of the i-th row. One of the source / drain regions of the light-emitting control transistor 53 is electrically connected to the other of the source / drain regions of the drive transistor 52. The other of the source / drain regions of the light-emitting control transistor 53 is electrically connected to the anode of the light-emitting element 54. The back gate of the light-emitting control transistor 53 is electrically connected to the power supply wiring 61.

[0023] The light-emitting element 54 is a light-emitting element that emits visible light having a predetermined color. The light-emitting element 54 has a configuration in which a light-emitting layer is sandwiched between an anode and a cathode, and is, for example, an OLED, μLED, or LD. The anode of the light-emitting element 54 is electrically connected to the other of the source / drain regions of the light-emitting control transistor 53. The cathode of the light-emitting element 54 is electrically connected to a common wiring 62 to which a common potential is applied.

[0024] The storage capacitor 55 is a capacitor for holding the gate potential of the drive transistor 52. One electrode of the storage capacitor 55 is electrically connected to one of the source / drain regions of the selection transistor 51 and the gate electrode of the drive transistor 52. The other electrode of the storage capacitor 55 is electrically connected to the power supply wiring 61. Note that the storage capacitor 55 may be a capacitance parasitic on the gate electrode of the drive transistor 52, or a capacitance formed by sandwiching an insulating layer between different conductive layers on the substrate 14.

[0025] In the pixel circuit configured as described above, when the scanning signal GWR(i) supplied to the scanning line 31 of the i-th row is at a high level, the selection transistor 51 is in an off state. On the other hand, when the scanning signal GWR(i) is at a low level, the selection transistor 51 is in an on state. When the selection transistor 51 is in an on state, a charging current flows to the storage capacitor 55 in accordance with the potential difference Vd between the potential of the data line 33 and the potential of the power supply line 61, and the storage capacitor 55 is charged until the inter-electrode voltage of the storage capacitor 55 reaches the potential difference Vd.

[0026] The current flowing between the other source / drain region and one of the source / drain regions of the driving transistor 52 depends on the gate potential of the driving transistor 52. The gate potential of the driving transistor 52 is equal to the voltage held by the storage capacitor 55, i.e., the inter-electrode voltage of the storage capacitor 55. Therefore, a current having a current value according to the voltage held by the storage capacitor 55 flows between the other source / drain region and one of the source / drain regions of the driving transistor 52. Hereinafter, the current flowing between the other source / drain region and one of the source / drain regions of the driving transistor 52 is referred to as the "driving current."

[0027] When the control signal GEL(i) supplied to the control line 32 of the i-th row is at a high level, the light-emitting control transistor 53 is in an off state. When the light-emitting control transistor 53 is in an off state, the anode of the light-emitting element 54 is electrically disconnected from the other of the source / drain regions of the drive transistor 52, and therefore no drive current flows to the light-emitting element 54 via the drive transistor 52. In other words, when the light-emitting control transistor 53 is in an off state, the light-emitting element 54 does not emit light.

[0028] On the other hand, when the control signal GEL(i) is at a low level, the light-emission control transistor 53 is turned on. When the light-emission control transistor 53 is on, the anode of the light-emitting element 54 is electrically connected to the other of the source and drain regions of the drive transistor 52 via the light-emission control transistor 53, and therefore a drive current having a current value corresponding to the voltage held by the storage capacitor 55 flows to the light-emitting element 54 via the drive transistor 52. In other words, when the light-emission control transistor 53 is on, the light-emitting element 54 emits light at a luminance corresponding to the drive current. The luminance of the light-emitting element 54 changes depending on the value of the drive current, i.e., the voltage held by the storage capacitor 55.

[0029] The controller 6 controls the level inversion timing of the scanning signal GWR(i), the level inversion timing of the control signal GEL(i), the potential of the data line 33, and the like, thereby controlling the light emission brightness and light emission period of the light emitting element 54 provided in each pixel 11, and as a result, image light L representing a predetermined image is emitted from the light emitting display panel 2. The image light L includes visible light (colored light) emitted from the light emitting element 54 provided in each pixel 11 of the light emitting display panel 2.

[0030] Returning to FIG. 2, the following explanation will be continued. The projection optical system 3 is composed of multiple optical elements such as lenses, and is an optical system that guides image light L from the light-emitting display panel 2 to the scanning mirror 4. The projection optical system 3 enlarges and projects the image light L emitted from the light-emitting display panel 2 onto the scanning mirror 4. The scanning mirror 4 reflects the image light L emitted from the light-emitting display panel 2 toward the scanned surface 200, and two-dimensionally scans the scanned surface 200 with the reflected image light L. The fθ lens 5 forms an image of the image light L reflected by the scanning mirror 4 on the scanned surface 200. The scanning mirror 4 is located at the pupil position of the projection optical system 3. This allows the size of the scanning mirror 4 to be reduced. The scanning mirror 4 is also located at the entrance pupil position of the fθ lens 5.

[0031] 1 and 2, the scanning mirror 4 in this embodiment is a mirror of a MEMS (Micro Electro Mechanical Systems) scanner 40. FIG. 5 is a diagram schematically showing an example of the mechanical structure of the MEMS scanner 40 having the scanning mirror 4. In FIG. 5, the diagram on the left is a plan view of the MEMS scanner 40, and the diagram on the right is a cross-sectional view of the MEMS scanner 40 taken along the line AA. In addition to the scanning mirror 4, the MEMS scanner 40 has a pair of torsion bars 41, a mirror support member 42, a base plate 43, and a vertical scanning shaft 44.

[0032] As shown in FIG. 5 , the scan mirror 4 is a rectangular plate member having a mirror surface on its surface. The scan mirror 4 is supported by a pair of torsion bars 41 inside a frame-shaped mirror support member 42 so as to be rotatable around the Y-axis. The mirror support member 42 is fixed to the surface of a base plate 43, which is a rectangular plate member, and has a predetermined height in the Z-axis direction from the surface of the base plate 43. In other words, the scan mirror 4 is located at a predetermined height from the surface of the base plate 43. A vertical scanning shaft 44 extending in the X-axis direction is adhered to the back surface of the base plate 43. The base plate 43 is supported by the vertical scanning shaft 44 so as to be rotatable around the X-axis.

[0033] 5, in the MEMS scanner 40, a coil is provided along the outer periphery of the scanning mirror 4, and a magnet is provided to surround the scanning mirror 4. A driving current is supplied from the controller 6 to the coil, causing the scanning mirror 4 to rotate around the Y axis. In other words, the rotation angle of the scanning mirror 4 around the Y axis is controlled by the controller 6.

[0034] Furthermore, the vertical scanning shaft 44 rotates by controlling a motor (not shown) that rotates the vertical scanning shaft 44 by the controller 6. When the vertical scanning shaft 44 rotates, the base plate 43 rotates around the X axis, and as a result, the scanning mirror 4 also rotates around the X axis. In other words, the rotation angle of the scanning mirror 4 around the X axis is controlled by the controller 6.

[0035] 6 is a diagram schematically showing the relationship between the rotation angle θ of the scanning mirror 4 about the Y-axis and the incident position P of the central light ray Lc on the scanned surface 200. As shown in FIG. 6, the axis perpendicularly connecting the center of the scanning mirror 4 and the scanned surface 200 is defined as the reference axis AX, and the intersection of the reference axis AX and the scanned surface 200 is defined as the origin position P0. The reference axis AX coincides with the optical axis of the fθ lens 5. Furthermore, of the light rays contained in the image light L, the light ray that is incident on the center of the scanning mirror 4 parallel to the X-axis direction is defined as the central light ray Lc.

[0036] When the tilt angle of the scan mirror 4 with respect to the X-axis direction is 45°, the central ray Lc reflected by the scan mirror 4 passes along the reference axis AX and is incident on the origin position P0. This state in which the tilt angle of the scan mirror 4 with respect to the X-axis direction is 45°, i.e., the state in which the central ray Lc reflected by the scan mirror 4 passes along the reference axis AX and is incident on the origin position P0, is referred to as the "reference state."

[0037] As shown in FIG. 6 , when the scanning mirror 4 rotates clockwise around the Y axis by a rotation angle θ from the reference state, the central ray Lc reflected by the scanning mirror 4 is incident at position P, a distance x (= f × θ) away from the origin position P0 toward the right (+X side) in the X axis direction. When the scanning mirror 4 rotates clockwise around the Y axis by a maximum rotation angle θmax from the reference state, the central ray Lc reflected by the scanning mirror 4 is incident at position P1, a distance x (= f × θmax) away from the origin position P0 toward the right (+X side) in the X axis direction. When the scanning mirror 4 rotates counterclockwise around the Y axis by a maximum rotation angle −θmax from the reference state, the central ray Lc reflected by the scanning mirror 4 is incident at position P2, a distance x (= −f × θmax) away from the origin position P0 toward the left (-X side) in the X axis direction. Note that f is the focal length of the fθ lens 5.

[0038] As described above, the distance x between the incident position P of the central light ray Lc in the X-axis direction and the origin position P0 is proportional to the rotation angle θ of the scanning mirror 4 about the Y-axis due to the optical characteristics of the fθ lens 5. In other words, the movement speed of the incident position P of the central light ray Lc in the X-axis direction is proportional to the rotation speed of the scanning mirror 4 about the Y-axis. In this way, the incident position P of the central light ray Lc in the X-axis direction moves between positions P1 and P2 in accordance with the rotational motion of the scanning mirror 4 about the Y-axis.

[0039] 7 is a diagram schematically showing the relationship between the rotation angle φ of the scanning mirror 4 about the X axis and the incident position P of the central light ray Lc on the scanned surface 200. As shown in Fig. 7, when the scanning mirror 4 rotates clockwise around the X axis by the rotation angle φ from the reference state, the central light ray Lc reflected by the scanning mirror 4 is incident at a position P that is a distance y (= f × φ) away from the origin position P0 toward the upper side (+Y side) in the Y axis direction. When the scanning mirror 4 rotates clockwise around the X axis by the maximum rotation angle φmax from the reference state, the central light ray Lc reflected by the scanning mirror 4 is incident at a position P3 that is a distance y (= f × φmax) away from the origin position P0 toward the upper side (+Y side) in the Y axis direction. When the scanning mirror 4 rotates counterclockwise around the X-axis by the maximum rotation angle -φmax from the reference state, the central light ray Lc reflected by the scanning mirror 4 is incident on a position P4 that is a distance y (=-f×φmax) away from the origin position P0 toward the lower side (-Y side) in the Y-axis direction.

[0040] As described above, the distance y between the incident position P of the central light ray Lc in the Y-axis direction and the origin position P0 is proportional to the rotation angle φ of the scanning mirror 4 about the X-axis due to the optical characteristics of the fθ lens 5. In other words, the movement speed of the incident position P of the central light ray Lc in the Y-axis direction is proportional to the rotation speed of the scanning mirror 4 about the X-axis. In this way, the incident position P of the central light ray Lc in the Y-axis direction moves between positions P3 and P4 in accordance with the rotational motion of the scanning mirror 4 about the X-axis.

[0041] To summarize the explanations regarding FIGS. 6 and 7, as shown in FIG. 8, within the in-plane area of the scanned surface 200, a rectangular area 210 having a length of 2f·θmax in the X-axis direction and a length of 2f·φmax in the Y-axis direction, centered at the origin position P0, is the area that can be scanned by the scanning mirror 4. Hereinafter, this rectangular area 210 will be referred to as the "scannable area." The incident position P of the central light beam Lc moves within the scannable area 210 in accordance with the rotational motion of the scanning mirror 4 about the Y-axis and the X-axis. In the following explanation, the incident position P of the central light beam Lc that moves within the scannable area 210 in accordance with the rotational motion of the scanning mirror 4 as described above will be referred to as the "scanning point." In the following explanation, the rotation angle θ of the scanning mirror 4 about the Y-axis will sometimes be referred to as the "main-scanning rotation angle," and the rotation angle φ of the scanning mirror 4 about the X-axis will sometimes be referred to as the "sub-scanning rotation angle."

[0042] In this embodiment, the number of pixels m in the vertical direction of the light-emitting display panel 2 is 200, and the number of pixels n in the horizontal direction of the light-emitting display panel 2 is 200. Therefore, when the image light L emitted from the light-emitting display panel 2 is reflected by the scanning mirror 4 toward the scanned surface 200, the image light L is projected onto an area of the in-plane area of the scanned surface 200, having a length corresponding to 200 pixels in the X-axis direction and a length corresponding to 200 pixels in the Y-axis direction, with the scanning point P as the center (see FIG. 1 ). In this way, by projecting the image light L onto the area centered on the scanning point P, an image having a size of 200 pixels x 200 pixels is formed on the scanned surface 200, with the scanning point P as the center.

[0043] The controller 6 controls the light-emitting display panel 2 and the scanning mirror 4. Specifically, the controller 6 controls the rotational motion of the scanning mirror 4 so that the scanning point P moves on a predetermined scanning path SR on the scanned surface 200, and controls the light-emitting display panel 2 so that the image light L is emitted when the scanning point P reaches each of a plurality of image display points set on the scanning path SR.

[0044] 9 is a diagram showing an example of a scanning path SR set within the scannable area 210 of the scanned surface 200. The scanning path SR is a path along which the scanning point P passes through image display points P10, P11, P12, P13, P14, P15, P16, P17, P18, P19, P20, and P21 in this order. The image display points P10, P11, P12, and P13 are arranged in this order in a line from left to right in the X-axis direction, and are arranged at intervals equivalent to 200 pixels in the X-axis direction.

[0045] Image display points P14, P15, P16, and P17 are arranged in this order in a line from right to left in the X-axis direction, and are arranged at intervals equivalent to 200 pixels in the X-axis direction. The point group including image display points P14, P15, P16, and P17 is arranged at a position equivalent to 200 pixels below the point group including image display points P10, P11, P12, and P13 in the Y-axis direction.

[0046] Image display points P18, P19, P20, and P21 are arranged in this order in a line from left to right in the X-axis direction, and are arranged at intervals equivalent to 200 pixels in the X-axis direction. The point group including image display points P18, P19, P20, and P21 is arranged at a position equivalent to 200 pixels below the point group including image display points P14, P15, P16, and P17 in the Y-axis direction.

[0047] The controller 6 controls the rotational movement of the scanning mirror 4 so that the scanning point P moves at a constant speed through the section between two adjacent image display points on the scanning path SR set as described above and stops for a predetermined time at the image display point it reaches, and controls the light-emitting display panel 2 so that image light L is emitted within the predetermined time that the scanning point P is stopped at the image display point. Furthermore, the controller 6 divides the input image 100 into a plurality of child images, and controls the light-emitting display panel 2 so that, when the scanning point P reaches each of the plurality of image display points set on the scanning path SR, image light L representing the child image corresponding to the image display point it reaches is emitted. In the following description, the mode in which the controller 6 cooperatively controls the scanning mirror 4 and the light-emitting display panel 2 as described above is referred to as the "step scanning mode." The operation of the controller 6 in the step scanning mode will be described in detail below.

[0048] FIG. 10 is a diagram showing an example of an input image 100, showing images of several types of vegetables. The input image 100 is an image to be displayed on the scanned surface 200 during one frame period. The controller 6 acquires the input image 100 to be displayed on the scanned surface 200 during one frame period based on a video signal input from outside the projection device 1. After acquiring the input image 100 from the video signal, the controller 6 divides the input image 100 into 12 child images 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, and 121, as shown in FIG.

[0049] Child image 110 is a child image corresponding to image display point P10. Child image 111 is a child image corresponding to image display point P11. Child image 112 is a child image corresponding to image display point P12. Child image 113 is a child image corresponding to image display point P13. Child image 114 is a child image corresponding to image display point P14. Child image 115 is a child image corresponding to image display point P15. Child image 116 is a child image corresponding to image display point P16. Child image 117 is a child image corresponding to image display point P17. Child image 118 is a child image corresponding to image display point P18. Child image 119 is a child image corresponding to image display point P19. Child image 120 is a child image corresponding to image display point P20. Child image 121 is a child image corresponding to image display point P21. The controller 6 performs compression or decompression processing on each child image as necessary so that the size of each child image becomes 200 pixels x 200 pixels.

[0050] After dividing the input image 100 into 12 child images, the controller 6 feedback-controls the main-scanning rotation angle θ and the sub-scanning rotation angle φ of the scanning mirror 4 so that the scanning point P moves to the first image display point P10 on the scanning path SR. Then, when the scanning point P reaches the image display point P10, the controller 6 controls the scanning mirror 4 so that the scanning point P stops at the image display point P10 for a predetermined time, and controls the light-emitting display panel 2 so that the image light L representing the child image 110 corresponding to the image display point P10 is emitted during the predetermined time that the scanning point P is stopped at the image display point P10.

[0051] FIG. 11 is a timing chart showing the temporal correspondence between the position of scanning point P in the X-axis direction and the amount of light emitted by the light-emitting display panel 2 in the step scanning mode. In FIG. 11, the position of scanning point P in the X-axis direction is expressed as the number of pixels from image display point P10. As shown in FIG. 11, when scanning point P reaches image display point P10 at time t0, scanning point P stops at image display point P10 until time t1 arrives. The time from time t0 to time t1 is a predetermined time. During the predetermined time from time t0 to time t1, image light L representing a sub-image 110 corresponding to image display point P10 is emitted from the light-emitting display panel 2. As a result, as shown in FIG. 12, a sub-image 110 having a size of 200 pixels by 200 pixels and centered on image display point P10 is formed on the scanned surface 200 during the predetermined time from time t0 to time t1.

[0052] When a predetermined time has elapsed with scanning point P stopped at image display point P10, controller 6 turns off light-emitting display panel 2, and then feedback-controls main-scanning rotation angle θ of scanning mirror 4 so that scanning point P moves at a constant speed along scan path SR between image display point P10 and the next image display point P11. As shown in Fig. 11 , when a predetermined time has elapsed with scanning point P stopped at image display point P10 and time t1 arrives, scanning point P moves at high speed and at a constant speed along the X-axis direction from image display point P10 to the next image display point P11. While scanning point P moves from image display point P10 to the next image display point P11, the amount of light emitted by light-emitting display panel 2 is zero.

[0053] When the scanning point P reaches the image display point P11, the controller 6 controls the scanning mirror 4 so that the scanning point P stops at the image display point P11 for a predetermined time, and also controls the light-emitting display panel 2 so that image light L representing the child image 111 corresponding to the image display point P11 is emitted during the predetermined time that the scanning point P is stopped at the image display point P11.

[0054] 11, when scanning point P reaches image display point P11 at time t2, scanning point P stops at image display point P11 until time t3 arrives. The period from time t2 to time t3 is a predetermined period. Furthermore, during the predetermined period from time t2 to time t3, image light L representing a sub-image 111 corresponding to image display point P11 is emitted from the light-emitting display panel 2. As a result, as shown in FIG. 12, during the predetermined period from time t2 to time t3, a sub-image 111 having a size of 200 pixels by 200 pixels and centered on image display point P11 is formed on the scanned surface 200.

[0055] When a predetermined time has elapsed with scanning point P stopped at image display point P11, controller 6 turns off light-emitting display panel 2, and then feedback-controls main-scanning rotation angle θ of scanning mirror 4 so that scanning point P moves at a constant speed along scan path SR between image display point P11 and the next image display point P12. As shown in Fig. 11 , when a predetermined time has elapsed with scanning point P stopped at image display point P11 and time t3 arrives, scanning point P moves at high speed and at a constant speed along the X-axis direction from image display point P11 to the next image display point P12. While scanning point P moves from image display point P11 to the next image display point P12, the amount of light emitted by light-emitting display panel 2 is zero.

[0056] When the scanning point P reaches the image display point P12, the controller 6 controls the scanning mirror 4 so that the scanning point P stops at the image display point P12 for a predetermined time, and also controls the light-emitting display panel 2 so that image light L representing the child image 112 corresponding to the image display point P12 is emitted within the predetermined time that the scanning point P is stopped at the image display point P12.

[0057] 11, when scanning point P reaches image display point P12 at time t4, scanning point P stops at image display point P12 until time t5 arrives. The period from time t4 to time t5 is a predetermined period. During the predetermined period from time t4 to time t5, image light L representing a sub-image 112 corresponding to image display point P12 is emitted from the light-emitting display panel 2. As a result, as shown in FIG. 12, during the predetermined period from time t4 to time t5, a sub-image 112 having a size of 200 pixels by 200 pixels and centered on image display point P12 is formed on the scanned surface 200.

[0058] When a predetermined time has elapsed with scanning point P stopped at image display point P12, controller 6 turns off light-emitting display panel 2, and then feedback-controls main-scanning rotation angle θ of scanning mirror 4 so that scanning point P moves at a constant speed along scan path SR between image display point P12 and next image display point P13. As shown in Fig. 11 , when a predetermined time has elapsed with scanning point P stopped at image display point P12 and time t5 arrives, scanning point P moves at high speed and at a constant speed along the X-axis direction from image display point P12 to next image display point P13. While scanning point P moves from image display point P12 to next image display point P13, the amount of light emitted by light-emitting display panel 2 is zero.

[0059] When the scanning point P reaches the image display point P13, the controller 6 controls the scanning mirror 4 so that the scanning point P stops at the image display point P13 for a predetermined time, and also controls the light-emitting display panel 2 so that the image light L representing the child image 113 corresponding to the image display point P13 is emitted within the predetermined time that the scanning point P is stopped at the image display point P13.

[0060] 11, when scanning point P reaches image display point P13 at time t6, scanning point P stops at image display point P13 until time t7 arrives. The time from time t6 to time t7 is a predetermined time. Furthermore, during the predetermined time from time t6 to time t7, image light L representing a sub-image 113 corresponding to image display point P13 is emitted from the light-emitting display panel 2. As a result, as shown in FIG. 12, during the predetermined time from time t6 to time t7, a sub-image 113 having a size of 200 pixels by 200 pixels and centered on image display point P13 is formed on the scanned surface 200.

[0061] When a predetermined time has elapsed with scanning point P stopped at image display point P13, controller 6 turns off light-emitting display panel 2, and then feedback-controls sub-scanning rotation angle φ of scanning mirror 4 so that scanning point P moves at a constant speed along scanning path SR between image display point P13 and the next image display point P14. When scanning point P reaches image display point P14, controller 6 controls scanning mirror 4 so that scanning point P stops at image display point P14 for a predetermined time, and controls light-emitting display panel 2 so that image light L representing child image 114 corresponding to image display point P14 is emitted during the predetermined time that scanning point P is stopped at image display point P14. As a result, as shown in FIG. 12 , child image 114 having a size of 200 pixels by 200 pixels and centered at image display point P14 is formed on scanned surface 200 during the predetermined time that scanning point P is stopped at image display point P14.

[0062] When a predetermined time has elapsed with scanning point P stopped at image display point P14, controller 6 turns off light-emitting display panel 2, and then feedback-controls main-scan rotation angle θ of scanning mirror 4 so that scanning point P moves at a constant speed along scanning path SR between image display point P14 and the next image display point P15. When scanning point P reaches image display point P15, controller 6 controls scanning mirror 4 so that scanning point P stops at image display point P15 for a predetermined time, and controls light-emitting display panel 2 so that image light L representing child image 115 corresponding to image display point P15 is emitted during the predetermined time that scanning point P is stopped at image display point P15. As a result, as shown in FIG. 12 , child image 115 having a size of 200 pixels by 200 pixels and centered on image display point P15 is formed on scanned surface 200 during the predetermined time that scanning point P is stopped at image display point P15.

[0063] When a predetermined time has elapsed with scanning point P stopped at image display point P15, controller 6 turns off light-emitting display panel 2, and then feedback-controls main-scan rotation angle θ of scanning mirror 4 so that scanning point P moves at a constant speed along scanning path SR between image display point P15 and the next image display point P16. When scanning point P reaches image display point P16, controller 6 controls scanning mirror 4 so that scanning point P stops at image display point P16 for a predetermined time, and controls light-emitting display panel 2 so that image light L representing child image 116 corresponding to image display point P16 is emitted during the predetermined time that scanning point P is stopped at image display point P16. As a result, as shown in FIG. 12 , child image 116 having a size of 200 pixels by 200 pixels and centered on image display point P16 is formed on scanned surface 200 during the predetermined time that scanning point P is stopped at image display point P16.

[0064] When a predetermined time has elapsed with scanning point P stopped at image display point P16, controller 6 turns off light-emitting display panel 2, and then feedback-controls main-scan rotation angle θ of scanning mirror 4 so that scanning point P moves at a constant speed along scanning path SR between image display point P16 and the next image display point P17. When scanning point P reaches image display point P17, controller 6 controls scanning mirror 4 so that scanning point P stops at image display point P17 for a predetermined time, and controls light-emitting display panel 2 so that image light L representing child image 117 corresponding to image display point P17 is emitted during the predetermined time that scanning point P is stopped at image display point P17. As a result, as shown in FIG. 12 , child image 117 having a size of 200 pixels by 200 pixels and centered on image display point P17 is formed on scanned surface 200 during the predetermined time that scanning point P is stopped at image display point P17.

[0065] When a predetermined time has elapsed with scanning point P stopped at image display point P17, controller 6 turns off light-emitting display panel 2, and then feedback-controls sub-scanning rotation angle φ of scanning mirror 4 so that scanning point P moves at a constant speed along scanning path SR between image display point P17 and the next image display point P18. When scanning point P reaches image display point P18, controller 6 controls scanning mirror 4 so that scanning point P stops at image display point P18 for a predetermined time, and controls light-emitting display panel 2 so that image light L representing child image 118 corresponding to image display point P18 is emitted during the predetermined time that scanning point P is stopped at image display point P18. As a result, as shown in FIG. 12 , child image 118 having a size of 200 pixels by 200 pixels and centered on image display point P18 is formed on scanned surface 200 during the predetermined time that scanning point P is stopped at image display point P18.

[0066] When a predetermined time has elapsed with scanning point P stopped at image display point P18, controller 6 turns off light-emitting display panel 2, and then feedback-controls main-scan rotation angle θ of scanning mirror 4 so that scanning point P moves at a constant speed along scanning path SR between image display point P18 and the next image display point P19. When scanning point P reaches image display point P19, controller 6 controls scanning mirror 4 so that scanning point P stops at image display point P19 for a predetermined time, and controls light-emitting display panel 2 so that image light L representing child image 119 corresponding to image display point P19 is emitted during the predetermined time that scanning point P is stopped at image display point P19. As a result, as shown in FIG. 12 , child image 119 having a size of 200 pixels by 200 pixels and centered on image display point P19 is formed on scanned surface 200 during the predetermined time that scanning point P is stopped at image display point P19.

[0067] When a predetermined time has elapsed with scanning point P stopped at image display point P19, controller 6 turns off light-emitting display panel 2, and then feedback-controls main-scan rotation angle θ of scanning mirror 4 so that scanning point P moves at a constant speed along scanning path SR between image display point P19 and the next image display point P20. When scanning point P reaches image display point P20, controller 6 controls scanning mirror 4 so that scanning point P stops at image display point P20 for a predetermined time, and controls light-emitting display panel 2 so that image light L representing child image 120 corresponding to image display point P20 is emitted during the predetermined time that scanning point P is stopped at image display point P20. As a result, as shown in FIG. 12 , child image 120 having a size of 200 pixels by 200 pixels and centered at image display point P20 is formed on scanned surface 200 during the predetermined time that scanning point P is stopped at image display point P20.

[0068] When a predetermined time has elapsed with scanning point P stopped at image display point P20, controller 6 turns off light-emitting display panel 2, and then feedback-controls main-scan rotation angle θ of scanning mirror 4 so that scanning point P moves at a constant speed along scanning path SR between image display point P20 and the next image display point P21. When scanning point P reaches image display point P21, controller 6 controls scanning mirror 4 so that scanning point P stops at image display point P21 for a predetermined time, and controls light-emitting display panel 2 so that image light L representing child image 121 corresponding to image display point P21 is emitted during the predetermined time that scanning point P is stopped at image display point P21. As a result, as shown in FIG. 12 , child image 121 having a size of 200 pixels × 200 pixels and centered at image display point P21 is formed on scanned surface 200 during the predetermined time that scanning point P is stopped at image display point P21.

[0069] As described above, the above operations are performed every time the scanning point P reaches each of the 12 image display points set on the scanning path SR, and ultimately an image that is visually recognized by the user as the same image as the input image 100 is displayed on the scanned surface 200. The above-described series of operations is performed within the period of one frame.

[0070] 13, due to the accuracy of the feedback control of the scanning mirror 4, for example, the center of the child image 111 adjacent to the right of the child image 110 may become a point P11' that is shifted a distance d to the right from the image display point P11 set on the scanning path SR. In this case, a gap having a width d occurs between the adjacent child images 110 and 111. In this way, the gap that occurs between a pair of adjacent child images may be visually recognized by the user as an image defect such as a bright line or a dark line.

[0071] Therefore, when dividing input image 100 into a plurality of sub-images, controller 6 divides input image 100 so that a pair of adjacent sub-images have overlapping regions where they overlap each other. Focusing on a pair of adjacent sub-images 110 and 111, for example, as shown in FIG. 14 , input image 100 is divided so that sub-image 110 has overlapping region 110a and sub-image 111 has overlapping region 111a. The widths of overlapping regions 110a and 111a are preferably set to a value equal to the maximum value of displacement d between image display points. For example, if the maximum value of displacement d between image display points is a length equivalent to five pixels, the widths of overlapping regions 110a and 111a are also set to a length equivalent to five pixels (see FIG. 14 ).

[0072] 15 , when the center of the child image 111 adjacent to the right of the child image 110 on the scanned surface 200 coincides with the image display point P11 set on the scanning path SR, the overlapping region 110a of the child image 110 and the overlapping region 111a of the child image 111 completely overlap. In this case, the boundary between the child images 110 and 111 is connected without any image misalignment, and the image is visually recognized by the user as being equivalent to the input image 100.

[0073] 15, even if the center of the child image 111 adjacent to the right of the child image 110 is at point P11', which is shifted by five pixels to the right from the image display point P11 set on the scanning path SR, no gap will occur between the child images 110 and 111. In this case, image misalignment occurs near the boundary between the overlapping area 110a of the child image 110 and the overlapping area 111a of the child image 111, but it is not so large that it is visible to the user. In this way, by providing an overlapping area where a pair of adjacent child images among the plurality of child images overlap each other, it is possible to prevent gaps from occurring between the pair of adjacent child images.

[0074] When the overlapping area 110a of the child image 110 and the overlapping area 111a of the child image 111 partially or entirely overlap, the brightness of the overlapping area doubles. Such a partial increase in brightness may be visually recognized by a user as brightness variation. Therefore, in this embodiment, as shown in FIG. 16 , the brightness of the child image 110 is set so that the brightness gradually decreases from the boundary between the overlapping area 110a and other areas toward the edge of the overlapping area 110a. Similarly, the brightness of the child image 111 is set so that the brightness gradually decreases from the boundary between the overlapping area 111a and other areas toward the edge of the overlapping area 111a. This leveling out the brightness of the overlapping area prevents the brightness from being visually recognized by a user as brightness variation, even when the overlapping area 110a of the child image 110 partially or entirely overlaps with the overlapping area 111a of the child image 111.

[0075] In the above explanation of the overlapping areas, attention has been focused on the horizontally adjacent child images 110 and 111, but it goes without saying that it is preferable to provide overlapping areas for all pairs of adjacent child images. For example, an overlapping area may also be provided for the vertically adjacent child images 110 and 117. For example, in the case of child image 116, an overlapping area may also be provided for each of the child images 111, 115, 117, and 119 that are adjacent to each other in the vertical and horizontal directions.

[0076] In addition to the step scanning mode described above, the controller 6 can also coordinately control the scanning mirror 4 and the light-emitting display panel 2 in a constant scanning mode. In the constant scanning mode, the controller 6 controls the rotational motion of the scanning mirror 4 so that the scanning point P moves on the scanning path SR at a constant speed, and controls the light-emitting display panel 2 so that, when the scanning point P reaches each of a plurality of image display points set on the scanning path SR, the image light L representing the child image corresponding to the image display point is emitted. The operation of the controller 6 in the constant scanning mode will be described in detail below.

[0077] 17, the scanning path SR in the constant scanning mode is a path in which the scanning point P passes through image display points P10, P11, P12, P13, P14, P15, P16, P17, P18, P19, P20, and P21 in this order. The scanning path SR in the constant scanning mode differs from that in the step scanning mode in that it zigzags in a sinusoidal manner. Therefore, as the scanning point P moves along the scanning path SR, the position of the image display point gradually decreases.

[0078] When the controller 6 acquires an input image 100 from a video signal, it divides the input image 100 into 12 sub-images 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, and 121. As shown in Fig. 17, after dividing the input image 100 into the 12 sub-images, the controller 6 feedback-controls the main-scanning rotation angle θ and the sub-scanning rotation angle φ of the scanning mirror 4 so that the scanning point P moves to the start point Ps of the scanning path SR. After the scanning point P reaches the start point, the controller 6 rotates the scanning mirror 4 at a uniform speed so that the scanning point P moves along the scanning path SR at a uniform speed.

[0079] Then, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P10, the image light L representing the child image 110 corresponding to the image display point P10 is emitted. As a result, at the timing when the scanning point P reaches the image display point P10, the image light L representing the child image 110 corresponding to the image display point P10 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the child image 110 having a size of 200 pixels x 200 pixels and centered at the image display point P10 is formed on the scanned surface 200 for only a very short time.

[0080] Next, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P11, the image light L representing the child image 111 corresponding to the image display point P11 is emitted. As a result, at the timing when the scanning point P reaches the image display point P11, the image light L representing the child image 111 corresponding to the image display point P11 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the child image 111 having a size of 200 pixels x 200 pixels and centered at the image display point P11 is formed on the scanned surface 200 for only a very short time.

[0081] Next, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P12, the image light L representing the child image 112 corresponding to the image display point P12 is emitted. As a result, at the timing when the scanning point P reaches the image display point P12, the image light L representing the child image 112 corresponding to the image display point P12 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the child image 112 having a size of 200 pixels x 200 pixels and centered at the image display point P12 is formed on the scanned surface 200 for only a very short time.

[0082] Next, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P13, the image light L representing the child image 113 corresponding to the image display point P13 is emitted. As a result, at the timing when the scanning point P reaches the image display point P13, the image light L representing the child image 113 corresponding to the image display point P13 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the child image 113 having a size of 200 pixels x 200 pixels and centered on the image display point P13 is formed on the scanned surface 200 for only a very short time.

[0083] Next, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P14, the image light L representing the sub-image 114 corresponding to the image display point P14 is emitted. As a result, at the timing when the scanning point P reaches the image display point P14, the image light L representing the sub-image 114 corresponding to the image display point P14 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the sub-image 114 having a size of 200 pixels x 200 pixels and centered on the image display point P14 is formed on the scanned surface 200 for only a very short time.

[0084] Next, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P15, the image light L representing the child image 115 corresponding to the image display point P15 is emitted. As a result, at the timing when the scanning point P reaches the image display point P15, the image light L representing the child image 115 corresponding to the image display point P15 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the child image 115 having a size of 200 pixels x 200 pixels and centered on the image display point P15 is formed on the scanned surface 200 for only a very short time.

[0085] Next, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P16, the image light L representing the sub-image 116 corresponding to the image display point P16 is emitted. As a result, at the timing when the scanning point P reaches the image display point P16, the image light L representing the sub-image 116 corresponding to the image display point P16 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the sub-image 116 having a size of 200 pixels x 200 pixels and centered at the image display point P16 is formed on the scanned surface 200 for only a very short time.

[0086] Next, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P17, the image light L representing the sub-image 117 corresponding to the image display point P17 is emitted. As a result, at the timing when the scanning point P reaches the image display point P17, the image light L representing the sub-image 117 corresponding to the image display point P17 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the sub-image 117 having a size of 200 pixels x 200 pixels and centered on the image display point P17 is formed on the scanned surface 200 for only a very short time.

[0087] Next, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P18, the image light L representing the sub-image 118 corresponding to the image display point P18 is emitted. As a result, at the timing when the scanning point P reaches the image display point P18, the image light L representing the sub-image 118 corresponding to the image display point P18 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the sub-image 118 having a size of 200 pixels x 200 pixels and centered on the image display point P18 is formed on the scanned surface 200 for only a very short time.

[0088] Next, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P19, the image light L representing the child image 119 corresponding to the image display point P19 is emitted. As a result, at the timing when the scanning point P reaches the image display point P19, the image light L representing the child image 119 corresponding to the image display point P19 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the child image 119 having a size of 200 pixels x 200 pixels and centered on the image display point P19 is formed on the scanned surface 200 for only a very short time.

[0089] Next, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P20, the image light L representing the child image 120 corresponding to the image display point P20 is emitted. As a result, at the timing when the scanning point P reaches the image display point P20, the image light L representing the child image 120 corresponding to the image display point P20 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the child image 120 having a size of 200 pixels x 200 pixels and centered at the image display point P20 is formed on the scanned surface 200 for only a very short time.

[0090] Finally, the controller 6 controls the light-emitting display panel 2 so that, when the scanning point P reaches the image display point P21, the image light L representing the child image 121 corresponding to the image display point P21 is emitted. As a result, at the timing when the scanning point P reaches the image display point P21, the image light L representing the child image 121 corresponding to the image display point P21 is instantaneously emitted from the light-emitting display panel 2. As a result, as shown in Fig. 17 , the child image 121 having a size of 200 pixels x 200 pixels and centered at the image display point P21 is formed on the scanned surface 200 for only a very short time.

[0091] As described above, the above operation is performed each time the scanning point P reaches each of the 12 image display points set on the scanning path SR, and the image finally viewed by the user is displayed on the scanned surface 200. However, as shown in FIG. 17 , in the constant scanning mode, as the scanning point P advances along the scanning path SR, the position of the image display point gradually decreases, and therefore, as the scanning point P advances along the scanning path SR, the child images formed at each image display point also gradually decrease. Therefore, the image finally displayed on the scanned surface 200 may be perceived by the user as an image different from the input image 100. Therefore, in the constant scanning mode, image processing of each child image is performed taking the above image misalignment into consideration. Note that, even in the constant scanning mode, an overlap area is provided in each child image.

[0092] FIG. 18 is a diagram showing the correspondence relationship between the X-direction position of the scanning point P, the main-scanning rotation angle θ of the scanning mirror 4, and the light-emission amount of the light-emitting display panel 2 in the constant scanning mode. In FIG. 18, the position of the scanning point P in the section from the start point Ps to the image display point P13 is expressed as the number of pixels from the start point Ps. As shown in FIG. 18, in the constant scanning mode, when the scanning point P reaches each of the image display points P10, P11, P12, and P13, the light-emitting display panel 2 must be momentarily illuminated with a very high light-emission amount. Compared with the step scanning mode, the constant scanning mode requires the light-emitting display panel 2 to be illuminated with a light-emission amount several hundred times greater (see FIG. 11). Furthermore, compared with the case where an image is displayed using the conventional point scanning method, the constant scanning mode requires the light-emitting display panel 2 to be illuminated with a light-emission amount approximately equal to the number of pixels (see FIG. 18). Therefore, in the constant scanning mode, the light-emitting display panel 2 must be driven at high speed, and high-output light-emitting elements 54 are required.

[0093] As described above, in the projection device 1 of this embodiment, the image light L emitted from the light-emitting display panel 2 having 200 × 200 pixels is reflected by the scanning mirror 4 onto the scanned surface 200 and scanned two-dimensionally, thereby displaying an image on the scanned surface 200 that is visually recognized by the user as the same image as the input image 100. According to this embodiment, when displaying, for example, a 4k image, the number of horizontal scans (i.e., horizontal scan frequency) can be reduced to 1 / 200 compared to the conventional point scan method. Furthermore, for example, if the number of vertical pixels of the light-emitting display panel 2 is increased, the horizontal scan frequency can be reduced in inverse proportion thereto.

[0094] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0095] For example, the step scanning mode operation may be mechanically realized by using a MEMS scanner 70 shown in Fig. 19. In Fig. 19, the left side is a plan view of the MEMS scanner 70, and the right side is a cross-sectional view of the MEMS scanner 70 taken along the line B-B. In addition to the scanning mirror 4, the MEMS scanner 70 has a pair of first torsion bars 71, a rotary frame 72, a pair of second torsion bars 73, a mirror support member 74, a base plate 75, and a vertical scanning shaft 76.

[0096] As shown in FIG. 19 , the scan mirror 4 is supported by a pair of first torsion bars 71 inside a rotating frame 72, which is a frame-shaped plate member, so as to be rotatable about the Y-axis. The rotating frame 72 is supported by a pair of second torsion bars 73 inside a frame-shaped mirror support member 74 so as to be rotatable about the Y-axis. The mirror support member 74 is fixed to the surface of a base plate 75, which is a rectangular plate member, and has a predetermined height in the Z-axis direction from the surface of the base plate 75. In other words, the scan mirror 4 and the rotating frame 72 are located at a predetermined height from the surface of the base plate 75. A vertical scanning shaft 76 extending in the X-axis direction is adhered to the back surface of the base plate 75. The base plate 75 is supported by the vertical scanning shaft 76 so as to be rotatable about the X-axis.

[0097] 19, in the MEMS scanner 70, coils are provided along the outer peripheries of the scanning mirror 4 and the rotating frame 72, and magnets are provided to surround the scanning mirror 4 and the rotating frame 72. When a driving current is supplied to each coil from the controller 6, the scanning mirror 4 and the rotating frame 72 rotate around the Y axis. In other words, the controller 6 controls the rotation angles of the scanning mirror 4 and the rotating frame 72 around the Y axis.

[0098] In the following description, the rotation angle of the scanning mirror 4 about the Y axis relative to the rotating frame 72 will be referred to as the "mirror rotation angle θ1," and the rotation angle of the rotating frame 72 about the Y axis relative to the base plate 75 will be referred to as the "frame rotation angle θ2." As will be described later, the rotation angle θ of the scanning mirror 4 about the Y axis relative to the base plate 75 (main scanning rotation angle θ) is the sum of the mirror rotation angle θ1 and the frame rotation angle θ2. The mirror rotation angle θ1 changes by a relatively small deflection angle of about ±5 degrees. The frame rotation angle θ2 changes by a relatively large deflection angle of about ±50 degrees.

[0099] Furthermore, the vertical scanning shaft 76 rotates by controlling a motor (not shown) that rotates the vertical scanning shaft 76 by the controller 6. When the vertical scanning shaft 76 rotates, the base plate 75 rotates around the X axis, and as a result, the scanning mirror 4 also rotates around the X axis. In other words, the rotation angle of the scanning mirror 4 around the X axis (sub-scanning rotation angle φ) is controlled by the controller 6.

[0100] Fig. 20 is a diagram showing a schematic diagram of the periodic rotation of the scanning mirror 4 while the rotating frame 72 is constantly rotating. Fig. 21 is a timing chart showing the temporal correspondence between the mirror rotation angle θ1, the frame rotation angle θ2, and the main scanning rotation angle θ. Fig. 20 shows the states of the scanning mirror 4 and the rotating frame 72 at times ta, tb, tc, td, te, and tf shown in Fig. 21.

[0101] 20 and 21, at time ta, the rotating frame 72 has rotated 5 degrees counterclockwise relative to the base plate 75, and the scanning mirror 4 has rotated 5 degrees clockwise relative to the rotating frame 72. At time ta, the mirror rotation angle θ1 is 5 degrees and the frame rotation angle θ2 is −5 degrees, so the main scanning rotation angle θ, which is the sum of the mirror rotation angle θ1 and the frame rotation angle θ2, is 0 degrees.

[0102] From this state at time ta, the rotating frame 72 rotates clockwise relative to the base plate 75, and the scanning mirror 4 rotates counterclockwise relative to the rotating frame 72 by the same angle, reaching the state at time tb. In the state at time tb, the rotating frame 72 is parallel to the base plate 75, and the scanning mirror 4 is also parallel to the rotating frame 72. In this state at time tb, the mirror rotation angle θ1 and the frame rotation angle θ2 are both 0 degrees, and therefore the main scanning rotation angle θ, which is the sum of the mirror rotation angle θ1 and the frame rotation angle θ2, also becomes 0 degrees.

[0103] From this state at time tb, the rotating frame 72 rotates clockwise relative to the base plate 75, and the scanning mirror 4 rotates counterclockwise relative to the rotating frame 72 by the same angle, reaching the state at time tc. At time tc, the rotating frame 72 has rotated 5 degrees clockwise relative to the base plate 75, and the scanning mirror 4 has rotated 5 degrees counterclockwise relative to the rotating frame 72. At time tc, the mirror rotation angle θ1 is -5 degrees and the frame rotation angle θ2 is 5 degrees, so the main scanning rotation angle θ, which is the sum of the mirror rotation angle θ1 and the frame rotation angle θ2, is 0 degrees. In this manner, during the period from time ta to time tc, the scanning mirror 4 and the rotary frame 72 rotate in opposite directions at the same angle, so the main scanning rotation angle θ is maintained at 0 degrees.

[0104] From the state at time tc, the rotating frame 72 rotates 5 degrees clockwise relative to the base plate 75, and the scanning mirror 4 rotates 5 degrees clockwise relative to the rotating frame 72, reaching the state at time td. In this state at time td, the mirror rotation angle θ1 and the frame rotation angle θ2 are each 5 degrees, so the main scanning rotation angle θ, which is the sum of the mirror rotation angle θ1 and the frame rotation angle θ2, is 10 degrees. Therefore, in the very short period of time from time tc to time td, the emission direction of the reflected light by the scanning mirror 4 instantaneously rotates 20 degrees.

[0105] At time te, the rotating frame 72 has rotated clockwise to 10 degrees relative to the base plate 75, and the scanning mirror 4 has rotated counterclockwise to 0 degrees relative to the rotating frame 72. At time te, the mirror rotation angle θ1 is 0 degrees and the frame rotation angle θ2 is 10 degrees, so the main scanning rotation angle θ, which is the sum of the mirror rotation angle θ1 and the frame rotation angle θ2, is 10 degrees.

[0106] At time tf, the rotating frame 72 has rotated clockwise to 15 degrees relative to the base plate 75, and the scanning mirror 4 has rotated counterclockwise to -5 degrees relative to the rotating frame 72. In this state at time tf, the mirror rotation angle θ1 is -5 degrees and the frame rotation angle θ2 is 15 degrees, so the main scanning rotation angle θ, which is the sum of the mirror rotation angle θ1 and the frame rotation angle θ2, is 10 degrees. In this way, during the period from time td to time tf, the scanning mirror 4 and the rotating frame 72 rotate in opposite directions by the same angle, so the main scanning rotation angle θ is maintained at 10 degrees. By repeating the above-described operation from time ta to time tf, it is possible to realize the operation in the step scanning mode mechanically.

[0107] 22, for example, the step scanning mode operation may be realized mechanically by combining the scanning mirror 4 and the polygon mirror 7. The image light L incident on the scanning mirror 4 is reflected by the scanning mirror 4 toward one of a plurality of mirror surfaces provided on the outer periphery of the polygon mirror 7. The image light L incident on the mirror surface of the polygon mirror 7 from the scanning mirror 4 is reflected by the mirror surface of the polygon mirror 7 toward the scanned surface 200.

[0108] By rotating the scanning mirror 4 and the polygon mirror 7 clockwise, the angle between the mirror surface of the polygon mirror 7 and the mirror surface of the scanning mirror 4 is maintained constant while the scanning mirror 4 and the polygon mirror 7 rotate, and therefore the emission direction of the image light L does not change. In Fig. 22, states A, B, and C indicate states in which the image light L is reflected by the mirror surface 7a of the polygon mirror 7, and states D, E, and F indicate states in which the image light L is reflected by the mirror surface 7b of the polygon mirror 7.

[0109] As the polygon mirror 7 rotates, the mirror surfaces 7a and 7b of the polygon mirror 7 are periodically tilted. While the mirror surfaces 7a and 7b of the polygon mirror 7 are periodically tilted, the emission direction of the image light L does not change. Furthermore, since the scanning mirror 4 is also turning while the polygon mirror 7 is rotating, the emission direction of the image light L changes in a stepwise manner. By repeating the above-described operations from state A to state F, it is possible to mechanically realize the operation in the step scanning mode.

[0110] A projection device according to an aspect of the present invention may have the following configuration. A projection device according to one embodiment of the present invention includes a light-emitting display panel having a plurality of pixels, each having a light-emitting element, arranged in a matrix; a scanning mirror that reflects image light emitted from the light-emitting display panel toward a surface to be scanned and scans the reflected image light two-dimensionally on the surface to be scanned; and a projection optical system that guides the image light from the light-emitting display panel to the scanning mirror.

[0111] A projection device according to one embodiment of the present invention includes a control unit that controls the light-emitting display panel and the scanning mirror, and the control unit controls the rotational movement of the scanning mirror so that a scanning point moves along a predetermined scanning path on the scanned surface, and may control the light-emitting display panel so that the image light is emitted when the scanning point reaches each of a plurality of image display points set on the scanning path.

[0112] In one embodiment of the projection device of the present invention, the control unit may control the rotational movement of the scanning mirror so that the scanning point moves at a constant speed through the section between two adjacent image display points and stops for a predetermined time at the image display point it reaches, and control the light-emitting display panel so that the image light is emitted within the predetermined time that the scanning point is stopped at the image display point.

[0113] In one aspect of the projection device of the present invention, the control unit may control the rotational motion of the scanning mirror so that the scanning point moves along the scanning path at a constant speed, and control the light-emitting display panel so that the image light is emitted when the scanning point reaches each of the multiple image display points set on the scanning path.

[0114] In one aspect of the projection device of the present invention, the control unit may divide an input image into a plurality of child images, and control the light-emitting display panel so that, when the scanning point reaches each of a plurality of image display points set on the scanning path, the image light representing the child image corresponding to the image display point that has been reached is emitted.

[0115] In the projection device according to one aspect of the present invention, a pair of adjacent child images among the plurality of child images may have overlapping regions where they overlap each other.

[0116] In the projection device according to one aspect of the present invention, the brightness of the child image may gradually decrease from the boundary between the overlap region and the other region toward the edge of the overlap region.

[0117] The projection device according to the aspect of the present invention may further include an fθ lens that forms an image of the image light reflected by the scanning mirror on the surface to be scanned.

[0118] A method for controlling a projection device according to an aspect of the present invention may have the following configuration. A control method for a projection device according to one embodiment of the present invention is a control method for a projection device comprising a light-emitting display panel in which a plurality of pixels each having a light-emitting element is arranged in a matrix, a scanning mirror, and a projection optical system that guides image light from the light-emitting display panel to the scanning mirror, wherein the scanning mirror reflects the image light emitted from the light-emitting display panel toward a surface to be scanned and scans the reflected image light two-dimensionally on the surface to be scanned.

[0119] A control method for a projection device according to one aspect of the present invention may include a step of controlling the rotational movement of the scanning mirror so that a scanning point moves along a predetermined scanning path on the scanned surface, and a step of controlling the light-emitting display panel so that the image light is emitted when the scanning point reaches each of a plurality of image display points set on the scanning path. [Explanation of symbols]

[0120] 1...Projection device, 2...Light-emitting display panel, 3...Projection optical system, 4...Scanning mirror, 5...fθ lens, 6...Controller (control unit), 11...Pixel, 54...Light-emitting element, 200...Scanned surface, L...Image light

Claims

1. a light-emitting display panel in which a plurality of pixels each having a light-emitting element is arranged in a matrix; The image light emitted from the light-emitting display panel is reflected toward the surface to be scanned, and the reflected a scanning mirror that scans the image light two-dimensionally on the scanned surface; a projection optical system that guides the image light from the light-emitting display panel to the scanning mirror; Equipped with a control unit for controlling the light-emitting display panel and the scanning mirror; the control unit controls the rotational movement of the scanning mirror so that a scanning point moves on a predetermined scanning path on the scanned surface, and controls the light-emitting display panel so that the image light is emitted when the scanning point reaches each of a plurality of image display points set on the scanning path; the control unit divides an input image into a plurality of child images, and controls the light-emitting display panel so that, when the scanning point reaches each of the plurality of image display points set on the scanning path, the image light representing the child image corresponding to the image display point that the scanning point reaches is emitted; a pair of adjacent child images among the plurality of child images has an overlapping region where the child images overlap each other; A projection device, wherein the brightness of the child image gradually decreases from the boundary between the overlap region and another region toward the edge of the overlap region.

2. the control unit controls the rotational movement of the scanning mirror so that the scanning point moves at a uniform speed through a section between two adjacent image display points and stops for a predetermined time at the image display point that the scanning point reaches, and controls the light-emitting display panel so that the image light is emitted within the predetermined time that the scanning point stops at the image display point. The projection device according to claim 1 .

3. the control unit controls the rotational motion of the scanning mirror so that the scanning point moves on the scanning path at a uniform speed, and controls the light-emitting display panel so that the image light is emitted when the scanning point reaches each of the plurality of image display points set on the scanning path. The projection device according to claim 1 .

4. an fθ lens that forms an image of the image light reflected by the scanning mirror on the surface to be scanned; The projection device according to claim 1 .

5. A control method for a projection device including a light-emitting display panel in which a plurality of pixels each having a light-emitting element is arranged in a matrix, a scanning mirror, and a projection optical system that guides image light from the light-emitting display panel to the scanning mirror, the method comprising: the scanning mirror reflects the image light emitted from the light-emitting display panel toward a surface to be scanned, and two-dimensionally scans the surface to be scanned with the reflected image light; controlling the rotational movement of the scanning mirror so that the scanning point moves along a predetermined scanning path on the scanned surface; controlling the light-emitting display panel so that the image light is emitted when the scanning point reaches each of a plurality of image display points set on the scanning path; and In the step of controlling the light-emitting display panel, an input image is divided into a plurality of child images, and when the scanning point reaches each of the plurality of image display points set on the scanning path, the light-emitting display panel is controlled so as to emit the image light representing the child image corresponding to the image display point that the scanning point reaches; a pair of adjacent child images among the plurality of child images has an overlapping region where the child images overlap each other; In the child image, the brightness is gradually decreased from the boundary between the overlap region and another region toward the edge of the overlap region. A method for controlling a projection device.

Images