JP2011087130A - Image projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image projector which can perform distortion correction of a projected image while suppressing increase of burdens to an electric circuit and a deflection optical element. <P>SOLUTION: The image projector 10 is provided with: a projection optical system 20 which forms a scanning area 13 on a projection surface 11; and a control mechanism 30 which drives and controls the deflection optical element 25 and a light source 21 based on image data 14. The control mechanism 30 corrects the image data 14 using a conversion equation for correction stored in a storage (36) so as to change an emission amount from the light source 21 to a scanning position by the deflection optical element 25 so as to correct distortion by an influence of optical characteristics in the projection optical system 20 and distortion by an influence of a projected optical axis angle θp to be formed by a reference optical axis Lb and the normal direction N of the projection surface 11 in the projection optical system 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image projection apparatus that projects an image on a projection surface such as a screen, and more particularly to an image projection apparatus that can correct distortion of a projection image formed on the projection surface.

  2. Description of the Related Art Conventionally, image projection apparatuses (projectors) that form illumination images on a projection plane by using illumination light emitted from a light source on a projection plane have been proposed and have become widespread. In such an image projection apparatus, a laser projector using a laser beam having excellent monochromaticity and directivity as illumination light has been proposed in order to make it easy to obtain an image with good color reproducibility.

  In this laser projector, for example, laser light from a laser light source is two-dimensionally deflected by a deflecting optical element, so that a two-dimensional optical scan is performed on the projection surface with spots imaged by the projection optical system. It is considered to form a two-dimensional projection image on the projection surface by the afterimage effect. As this deflection optical element, for example, a MEMS device manufactured using a polygon mirror, a galvano mirror, a MEMS (Micro Electro Mechanical Systems) technology (micro mechanical system), or the like is used.

  Here, in such a laser projector, the light from the light source (converged light) is scanned two-dimensionally, that is, the projection angle (relative to the projection plane) depending on the position in the projection image formed on the projection plane. Therefore, the projection image to be formed has various distortions due to the difference in the angle formed by the traveling direction of the laser beam and the optical characteristics of the projection optical system.

  Therefore, the amplitude of the scanning mirror as the deflection optical element is changed in accordance with the position of the scanning line in the sub-scanning direction so that the lengths of the scanning lines (scan lines) seen on the projection surface are equal to each other. As described above, a laser projector that adjusts a drive signal to the deflection optical element by a feedback signal is considered (for example, see Patent Document 1).

  However, in the laser projector described above, the drive signal to the deflecting optical element is adjusted by the feedback signal, so that the burden on the electric circuit increases as the processing amount increases, and the position of the scanning line in the sub-scanning direction Accordingly, since the amplitude of the scanning mirror as the deflection optical element is changed, the burden on the scanning mirror increases as the amplitude operation becomes complicated.

  The present invention has been made in view of the above problems, and provides an image projection apparatus capable of correcting distortion of a projection image while suppressing an increase in the burden on an electric circuit and a deflection optical element. It is aimed.

  In order to solve the above-described problem, the invention according to claim 1 forms a spot on the projection plane by forming an image of the light emitted from the light source, and two-dimensionally scans the projection plane with the spot. A projection optical system that forms a scanning region on the projection surface by deflecting the emitted light with a deflecting optical element, and an image for forming a projection image on the projection surface by optical scanning with the projection optical system. A control mechanism for driving and controlling the deflection optical element and the light source based on the data, the control mechanism in the projection image, distortion due to the influence of optical characteristics in the projection optical system, and in the projection optical system In order to correct the distortion caused by the influence of the angle of the projection optical axis formed by the reference optical axis and the normal direction of the projection surface, the amount of light emitted from the light source with respect to the scanning position by the deflection optical element is changed. Part And correcting the image data by using a paid the correction conversion expression.

The invention according to claim 2 is the image projection apparatus according to claim 1, wherein the control mechanism sets the coordinates of each pixel in the image data to (x, y) and an image based on the image data. An image indicated by the image data inside the scanning area on the projection plane according to a projection optical axis angle formed by a reference optical axis set in the projection optical system and a normal direction of the projection plane; The coordinates of the pixel-corresponding portion in the scanning region in the state of being adapted to the image forming region set to the same shape is (x ′, y ′), and each coefficient d (d _{x1 to} d _x6 and d the _{y1 to d y9)} as a coefficient which varies in accordance with only the change of the projection optical axis angle, using the following formula as the correction conversion expression and sets the coefficients d corresponding to the projection optical axis angle Complement the image data Characterized in that it.

^{_{x'= (d x1 y 2 +}} d x2 y + d x3) x + (d x4 y 2 + d x5 y + d x6)
y ′ = (d _y1 x ² + d _y2 x + d _y3 ) y ² + (d _y4 x ² + d _y5 x + d _y6 ) y
+ (D _y7 x ² + d _y8 x + d _y9 )
The invention according to claim 3 is the image projection apparatus according to claim 1 or 2, further comprising a housing that houses at least the projection optical system, and an inclination of the housing with respect to a plane to be projected. And the control mechanism sets the projection optical axis angle based on a detection result from the tilt detection means.

  The invention according to claim 4 is the image projection apparatus according to claim 1 or 2, further comprising a first housing that houses at least the projection optical system, and an inclination relative to the first housing. A second casing that is connected to the first casing in a changeable manner and is placed on a plane to be projected, and tilt detection that detects the tilt of the first casing with respect to the second casing And the control mechanism sets the projection optical axis angle based on a detection result from the tilt detection means.

  The invention according to claim 5 is the image projection apparatus according to claim 2, wherein each of the coefficients d of a plurality of combinations is stored in the storage unit, and the control mechanism determines the projection optical axis angle. The projection optical axis angle obtained by setting the correction conversion formula corresponding to the obtained projection optical axis angle by reading out each coefficient corresponding to the obtained projection optical axis angle from the storage unit. When each coefficient corresponding to is not stored in the storage unit, the coefficient corresponding to the projection angle closest to the calculated projection optical axis angle is read from the storage unit and the correction conversion formula is set. The correction amount of distortion due to the influence of the projection optical axis angle is adjusted according to the input adjustment signal.

  According to the image projection apparatus of the present invention, the deterioration of the projected image is suppressed by changing the amount of light emitted from the light source for driving the deflection optical element, that is, by changing the light emission timing of the light source for driving the deflection optical element. Therefore, it is possible to correct the distortion of the projection image on the projection surface while suppressing an increase in the burden on the electric circuit in the control mechanism.

  In addition, since the deterioration of the projection image is suppressed by changing the light emission timing of the light source with respect to the driving of the deflection optical element, the amplitude operation of the deflection optical element can be made constant. The distortion of the projected image on the projection plane can be corrected while suppressing an increase in the burden on the projection surface.

  Further, since the image data is corrected using the correction conversion formula stored in the storage unit, the correction table for each pixel data under the condition of the corresponding projection optical axis angle is stored in the storage unit. The capacity of the storage unit can be extremely small, which is extremely useful from the viewpoint of miniaturization.

In addition to the configuration described above, the control mechanism sets the coordinates of each pixel in the image data to (x, y), and displays an image based on the image data with the reference optical axis set in the projection optical system and the A state in which the image forming region is set to the same shape as the image indicated by the image data inside the scanning region on the projection surface according to the projection optical axis angle formed by the normal direction of the projection surface. (X ′, y ′) and the coefficients d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) are only changes in the projection optical axis angle. When the coefficient d corresponding to the projection optical axis angle is set as a coefficient that changes in accordance with the correction and the image data is corrected using the following formula as the correction conversion formula, the corresponding projection light Shaft angle Under the conditions of, it is possible to correct both the distortion due to the influence of the distortion and the projection optical axis angle due to the influence of the optical characteristics in the projection optical system.

^{_{x'= (d x1 y 2 +}} d x2 y + d x3) x + (d x4 y 2 + d x5 y + d x6)
y ′ = (d _y1 x ² + d _y2 x + d _y3 ) y ² + (d _y4 x ² + d _y5 x + d _y6 ) y
+ (D _y7 x ² + d _y8 x + d _y9 )
In addition to the above-described configuration, the control mechanism further includes a housing that houses at least the projection optical system, and an inclination detection unit that detects an inclination of the housing with respect to a plane to be projected. If the projection optical axis angle is set based on the detection result from the detection means, the case, that is, the case where the projection optical system accommodated therein is installed inclined with respect to the plane to be projected. Even in this case, it is possible to appropriately correct the distortion of the projected image on the plane (projection plane) to be projected.

  In addition to the above-described configuration, at least a first housing that accommodates the projection optical system, and a plane that is connected to the first housing so that the inclination with respect to the first housing can be changed and is a projection target And a tilt detecting means for detecting the tilt of the first casing with respect to the second casing, and the control mechanism detects from the tilt detecting means. If the projection optical axis angle is set on the basis of the result, the second casing regardless of the inclination of the first casing in which the projection optical system is accommodated in the foldable terminal with respect to the second casing. It is possible to appropriately correct the distortion of the projected image on the same plane (projection plane) as the plane on which is mounted.

  In addition to the above-described configuration, each of the coefficients d of a plurality of combinations is stored in the storage unit, and the control mechanism obtains the projection optical axis angle and corresponds to the obtained projection optical axis angle. The correction conversion formula corresponding to the obtained projection optical axis angle is set by reading the coefficient from the storage unit, and each coefficient corresponding to the obtained projection optical axis angle is not stored in the storage unit In this case, each coefficient corresponding to the projection angle closest to the obtained projection optical axis angle is read from the storage unit, the correction conversion formula is set, and the projection optical axis angle is set according to the input adjustment signal. If the amount of distortion correction due to the influence of the adjustment is adjusted, the number of combinations of coefficients d stored in the storage unit can be limited, so that the capacity of the storage unit can be reduced. The size of the (equipment (terminal) for mounting it) image projection apparatus can be made easy Te. At this time, although the number of combinations of each coefficient d stored in the storage unit is limited, it is possible to adjust the correction amount of distortion due to the influence of the projection optical axis angle according to the input adjustment signal. Therefore, a projection image having no distortion based on the image data can be formed on the projection target surface.

1 is an explanatory diagram schematically showing a configuration of an image projection apparatus 10 according to Embodiment 1 of the present invention. FIG. 3 is a diagram schematically showing a configuration of a deflection optical element 25. FIG. It is explanatory drawing which shows typically a mode that the image projection apparatus 10 forms the projection image 12 on the projection surface 11 by front projection. It is explanatory drawing which shows typically the projection image 12 (without distortion correction) which the image projector 10 forms on the projection surface 11 by front projection. It is explanatory drawing similar to FIG. 3 which shows a mode that the image projection apparatus 10 forms the projection image 12 on the projection surface 11 by diagonal projection. FIG. 5 is an explanatory view similar to FIG. 4 schematically showing a projection image 12 (without distortion correction) formed on the projection surface 11 by the oblique projection. It is explanatory drawing for demonstrating the mode of correction | amendment of the projection image 12 in the control mechanism 30, (a) shows typically the relationship of each pixel data G (t) in the image which the image data 14 shows, (b). (C) schematically shows the relationship between the pixel corresponding positions P (t) corresponding to the pixel data G (t) in the projection image 12 formed on the projection surface 11 by oblique projection without any correction, and Is a pixel-corresponding portion P () corresponding to each pixel data G (t) in the corrected projection image 12 formed on the image forming region 15 set inward of the scanning region 13 in the oblique projection similar to (b). The relationship t) is schematically shown. It is explanatory drawing which shows typically the positional relationship of the scanning area | region 13 seen on the projection surface 11 in the oblique projection, and the projection image 12 after correction | amendment. 3 is a block diagram illustrating a configuration of a control mechanism 30 of the image projection apparatus 10. FIG. It is explanatory drawing which shows the projection image 12 with respect to the image data 14 which has not performed any correction | amendment, in order to demonstrate the concept of the conversion formula (1) for correction | amendment, and the calculation method of each coefficient d. In order to explain the concept of the correction conversion equation (1) and the calculation method of each coefficient d, it is an explanatory diagram showing an image forming region 15 set in the projection image 12 for the image data 14 that has not been subjected to any correction. is there. It is explanatory drawing for demonstrating the concept of the conversion formula (1) for correction | amendment, and the calculation method of each coefficient d, (a) represents image data 14 notionally in xy coordinate system, (b) is the image data. 14 conceptually represents the projected image 12 formed on the projection surface 11 without any correction and the image forming region 15 set inward thereof in the XY coordinate system, and FIG. Virtual image data 16 based on each pixel size drawn in the region 15 is conceptually represented in the xy coordinate system, and (d) conceptually represents virtual xy coordinates set on the XY coordinates. It is explanatory drawing which shows an example of a mode that a projection image is formed by diagonal projection using the mobile telephone 40 carrying the image projector. FIG. 10 is an explanatory diagram schematically illustrating an example of a reference posture for forming a projection image by oblique projection using a mobile phone 402 on which an image projection apparatus according to a second embodiment is mounted. It is explanatory drawing which shows typically the state in which the opening attitude | position in the mobile telephone 402 changed from the reference | standard attitude | position. It is explanatory drawing which shows typically an example which forms a projection image in the projection target which is not the same plane as the mounting surface 43 using the mobile telephone 402. FIG. It is explanatory drawing which shows the state which the projection optical axis angle with respect to the mounting surface 43 made into a projection object changed by mounting the mobile telephone 403 on the convex part 46 on the mounting surface 43. FIG. FIG. 10 is an explanatory view schematically showing a state in which a mobile phone 404 is placed on a placement surface 43 and a projection image is formed on the plane with the placement surface 43 as a projection target.

  Embodiments of an image projection apparatus according to the present invention will be described below with reference to the drawings.

  FIG. 1 is an explanatory diagram schematically showing a configuration of an image projection apparatus 10 according to the first embodiment of the present invention. FIG. 2 is a diagram schematically showing the configuration of the deflection optical element 25. FIG. 3 is an explanatory diagram schematically showing how the image projection apparatus 10 forms the projection image 12 on the projection surface 11 by front projection, and FIG. 4 shows the image projection apparatus 10 on the projection surface 11 by front projection. It is explanatory drawing which shows typically the projection image 12 (without distortion correction) formed in this. FIG. 5 is an explanatory view similar to FIG. 3 schematically showing how the image projection apparatus 10 forms the projection image 12 on the projection surface 11 by oblique projection. FIG. 6 is an oblique projection of the image projection apparatus 10. FIG. 5 is an explanatory view similar to FIG. 4 schematically showing a projection image 12 (without distortion correction) formed on the projection surface 11 by the above. FIG. 7 is an explanatory diagram for explaining the correction of the projected image 12 in the control mechanism 30, and (a) schematically shows the relationship between the pixel data G (t) in the image indicated by the image data 14. , (B) schematically shows the relationship between the pixel corresponding positions P (t) corresponding to the pixel data G (t) in the projection image 12 formed on the projection surface 11 by oblique projection without any correction. , (C) is each pixel corresponding to each pixel data G (t) in the corrected projection image 12 formed on the image forming area 15 set inside the scanning area 13 in the oblique projection similar to (b). The relationship of the corresponding location P (t) is schematically shown. FIG. 8 is an explanatory diagram schematically showing the positional relationship between the scanning region 13 viewed on the projection plane 11 and the corrected projection image 12 in oblique projection. FIG. 9 is a block diagram illustrating a configuration of the control mechanism 30 of the image projection apparatus 10. FIG. 10 is an explanatory diagram showing the projection image 12 for the image data 14 that has not been subjected to any correction in order to explain the concept of the correction conversion equation (1) and the calculation method of each coefficient d. FIG. 11 shows an image forming area 15 set in the projection image 12 for the image data 14 not subjected to any correction in order to explain the concept of the correction conversion formula (1) and the calculation method of each coefficient d. It is explanatory drawing shown. FIG. 12 is an explanatory diagram for explaining the concept of the correction conversion equation (1) and the calculation method of each coefficient d. (A) conceptually represents the image data 14 in the xy coordinate system, and (b). (C) conceptually represents the projected image 12 formed on the projection surface 11 without any correction of the image data 14 and the image forming area 15 set inward thereof in the XY coordinate system, Represents conceptually virtual image data 16 based on each pixel size drawn in the image forming area 15 in the xy coordinate system, and (d) conceptually represents virtual xy coordinates set on the XY coordinates. ing. FIG. 13 is an explanatory diagram showing an example of a state in which a projection image is formed by oblique projection using the mobile phone 40 equipped with the image projection device 10. Note that FIG. 12 shows the concept of the projection image 12, the image data 14, the image forming region 15, the virtual image data 16, and the like for easy understanding, and does not necessarily match the actual relationship.

  In the first embodiment, the image projection apparatus 10 includes a projection optical system 20 and a control mechanism 30 as shown in FIG. This image projection apparatus 10 (projection optical system 20) forms a projection image 12 (see FIGS. 4, 6, 7, etc.) on a projection surface 11 of a screen Sc as a projection target. The projection optical system 20 is mainly composed of a light source 21, a collimating lens 22, a mirror 23, an imaging lens 24, a deflection optical element 25, and a magnifying lens 26.

  In the first embodiment, the light source 21 is configured as a monochromatic light source, and a semiconductor laser is used. As will be described later, the light source 21 is driven and controlled together with the deflection optical element 25 by the control mechanism 30 (the light source 21 controls the blinking operation).

  The collimating lens 22 has positive power and converts divergent light emitted from a semiconductor laser as the light source 21 into parallel light (hereinafter also referred to as a light beam R). The imaging lens 24 has positive power, condenses the emitted light (light ray R) from the light source 21 that has been collimated by the collimator lens 22 and reflected by the mirror 23, and converts it into convergent light. That is, the collimating lens 22 and the imaging lens 24 set the divergence angle of the emitted light so that the spot S having a predetermined size is formed on the screen Sc (projection surface 11) based on the emitted light from the light source 21. It has a function of converting into an angle that converges.

  The deflecting optical element 25 scans outgoing light (light ray R), which is converged by the imaging lens 24, in a two-dimensionally orthogonal direction, that is, in a first scanning direction and a second scanning direction orthogonal thereto. In order to achieve this, it is deflected in the first scanning direction and the second scanning direction. The first scanning direction and the second scanning direction are included in the projection surface 11 as a projection target (in this example, the screen Sc). In the example of FIG. 1, a direction orthogonal to the drawing (see arrow X) and It is the extending direction of the screen Sc (see arrow Y) on the drawing.

  As shown in FIG. 2, the deflecting optical element 25 includes a rectangular outer frame portion 25a, a rectangular inner frame portion 25b provided inside the rectangular outer frame portion 25a, and a rectangular shape provided therein. The movable mirror portion 25c is generally configured. The movable mirror portion 25c forms a mirror surface that reflects the light beam R (emitted light), and is rotatably supported by the inner frame portion 25b via a pair of holding shafts 25d. The inner frame portion 25b is rotatably supported by the outer frame portion 25a via a pair of holding shafts 25e extending in a direction orthogonal to the pair of holding shafts 25d. Accordingly, for example, the movable mirror portion 25c is rotated in the horizontal direction with the pair of holding shafts 25d as the support shafts, and the inner frame portion 25b is rotated in the vertical direction with the pair of holding shafts 25e as the support shafts. . One rotation direction is the first scanning direction, and the other rotation direction is the second scanning direction.

  Such a deflection optical element 25 can be composed of a known MEMS mirror, and a silicon crystal is used as the material thereof. For example, in this type of MEMS mirror, the movable mirror portion 25c and the inner frame portion 25b are formed at a position lifted by an etching technique from the bottom substrate of the silicon crystal substrate.

  In this MEMS mirror, although not shown, an electrode divided into left and right is formed on the bottom substrate on the lower side of the movable mirror portion 25c, and a voltage is applied between the electrode of the movable mirror portion 25c and the electrode on the bottom substrate. As a result, an electrostatic force acts between the two electrodes, and the movable mirror portion 25c is inclined in a direction in which the pair of holding shafts 25d are twisted.

  In the MEMS mirror, although not shown, an electrode divided into upper and lower portions is formed on the bottom substrate on the lower side of the inner frame portion 25b, and a voltage is applied between the electrode on the inner frame portion 25b and the electrode on the bottom substrate. By applying the electrostatic force, an electrostatic force acts between both electrodes, and the inner frame portion 25b is inclined in a direction in which the pair of holding shafts 25e are twisted.

  The movable mirror portion 25c may be formed with a magnetic body on the back surface and tilted by a magnetic force generated from a coil formed on the bottom substrate, and the deformation force of the piezoelectric element (piezo element) is used as a driving force. It may be tilted and is not limited to the first embodiment.

  In order to deflect the light ray R (beam) at high speed using such a MEMS mirror, it is necessary to drive the movable mirror portion 25c near the resonance point. For this reason, the deflection angle, that is, the tilt angle of the movable mirror portion 25c is changed in a sine wave shape with respect to time. Since the movable mirror portion 25c has a small size of about 1 mm square and a small rotational moment, the primary resonance frequency in the twist direction can be increased by the thickness and width (design) of the pair of holding shafts 25d. A high primary resonance frequency can be easily obtained around the axis 25d (horizontal direction). In this example, rotation around the holding shaft 25d, that is, horizontal scanning is defined as a high-speed scanning direction (main scanning direction), and rotation around the holding shaft 25e, ie, vertical scanning is defined as a sub-scanning direction.

  Here, according to a normal driving method, it is difficult to increase the amplitude of the movable mirror portion 25c. In addition, the driving of the movable mirror portion 25c is not stable due to non-uniform driving force, air resistance, and the like. However, according to this MEMS mirror, the movable mirror 25c is driven in the vicinity of the primary resonance frequency, so that the amplitude is large enough to scan the area of the predetermined size on the screen Sc over the entire surface. And stable driving can be realized.

  Light rays R (beams) that have been converged by the imaging lens 24 by the deflecting optical element 25 constituted by the MEMS mirror are two-dimensionally orthogonal to each other, that is, in the first scanning direction (in this example, as shown in FIG. 1 is a direction orthogonal to the drawing as viewed at 1 and a direction corresponding to the X-axis direction on the projection plane 11, and a second scanning direction orthogonal to the first scanning direction (in this example, as viewed in FIG. 1. The spot S is scanned in a direction along the screen Sc and a direction corresponding to the Y-axis direction on the projection plane 11), and the spot S moves in a region having a predetermined size on the projection plane 11. Hereinafter, a region having a predetermined size scanned by the spot S on the projection surface 11 is referred to as a scanning region 13 (see FIGS. 4, 6, 7, etc.).

  In the first embodiment, the first deflecting element and the second deflecting element are integrally formed. However, the first deflecting element and the second deflecting element may be formed separately. As a mechanism for forming the first deflecting element and the second deflecting element separately, for example, a structure using two MEMSs that are single-axis rotating elements or a plane mirror attached to the output shaft of a stepping motor, A configuration in which the plane mirror is rotationally driven at a constant angular velocity is conceivable.

  Here, the traveling direction of the light beam R deflected by the deflection optical element 25 (the light beam R reflected by the movable mirror unit 25c) when the movable mirror portion 25c of the deflection optical element 25 is at the amplitude center position is defined as the reference optical axis. Let Lb be the angle of the traveling direction of the light beam R deflected by the deflecting optical element 25 with respect to the reference optical axis Lb, and let it be the deflection angle θ, and the light beam R emitted from the magnifying lens 26 (projection optical system 20 or image projection device 10). An angle with respect to the reference optical axis Lb is defined as a scanning angle α. The reference optical axis Lb only needs to be set as the optical axis reference position in the projection optical system 20 (the optical axis of each optical element), and the movable mirror portion 25c of the deflecting optical element 25 is positioned at the amplitude center position. It is not necessary to coincide with the traveling direction of the light beam R deflected by the deflection optical element 25.

  The magnifying lens 26 converts the deflection angle θ of the light beam R deflected by the deflection optical element 25 into a larger scanning angle α, and the optical setting of the imaging lens 24 and the movement of the deflection optical element 25 are performed. Considering the size and amplitude of the mirror portion 25c, the design and arrangement are optimal. The magnifying lens 26 cooperates with the deflecting optical element 25 to image the light ray R converted into convergent light by the imaging lens 24 on the projection surface 11 of the screen Sc (less than a predetermined size). A spot S having a small diameter).

  The light source 21 and the deflection optical element 25 in the projection optical system 20 are driven and controlled by the control mechanism 30. As shown in FIG. 1, the control mechanism 30 includes a deflection optical element drive control unit 31 that is a deflection angle control circuit, a light emission amount control unit 32 that is a light source control circuit, and an image processing unit 33 that is an image processing circuit. I have. Image data 14 is input to the control mechanism 30. The image data 14 represents a rectangular image (see FIG. 7A), and the first scanning direction is the x direction and the second scanning direction orthogonal to the y direction is the coordinate (x , Y) has a plurality of pixel data G (x, y) indicating output values (intensity of monochromatic light since it is monochromatic in the first embodiment). In the first embodiment, each pixel data G (x, y) is data of x coordinate value in the image data 14, data of y coordinate value in the image data 14, and output (intensity) at the coordinates (x, y). Output value data indicating.

  In the control mechanism 30, the deflection optical element drive control unit 31 drives and controls the deflection optical element 25, and the light emission amount control unit 32 controls the light source based on the image data 14 (each pixel data G (x, y)) and the mirror position signal Mp. 21 is driven and controlled. The deflection optical element drive control unit 31 drives and controls the deflection optical element 25 by transmitting a rotation control signal Wc, and the light emission amount control unit 32 controls driving of the light source 21 by transmitting a light emission amount control signal Lc. To do.

  The mirror position signal Mp is a signal indicating the displacement position of the movable mirror portion 25c to be rotated. In the example shown in FIG. 1, the mirror position signal Mp is a signal output from the deflection optical element 25 itself according to the displacement of the movable mirror portion 25c. Here, as a signal output from the deflection optical element 25 itself, if the deflection optical element 25 uses an electromagnetic actuator as a driving force, the mirror position signal Mp is obtained by monitoring the counter electromotive force due to mirror rotation. Obtainable. If the deflection optical element 25 uses a piezo actuator as a driving force, the mirror position signal Mp can be obtained by monitoring the counter electromotive force generated in the piezo. In addition to this, the mirror position signal Mp is not shown, but a light receiving element for synchronization detection is installed at an appropriate position capable of receiving the light beam R (emitted light) deflected (reflected) by the movable mirror portion 25c. The signal from the light receiving element can also be obtained in association with the installation position, that is, the displacement position of the movable mirror portion 25c. Further, although not shown, electrodes are provided at the displacement portion (movable mirror portion 25c in this example) and a desired position that maintains a predetermined position regardless of the displacement, and the capacitance that changes according to the displacement of the displacement portion is provided. It may be configured to detect and use the capacitance in association with the displacement position of the displacement unit, or to use a drive control signal from the deflection optical element drive control unit 31. In the first embodiment, the light emission amount control unit 32 drives and controls the light source 21 so as to match the drive control of the deflection optical element 25 by the deflection optical element drive control unit 31.

  In the control mechanism 30, the horizontal (x) direction in the image data 14 is the X axis as the first scanning direction when viewed on the projection surface 11 on which the emitted light (ray R) reflected by the movable mirror unit 25c is imaged. Corresponding to the direction and the horizontal (y) direction in the image data 14 corresponds to the Y-axis direction as the second scanning direction when viewed on the projection plane 11, that is, the coordinates (x, y) in the image data 14. The deflection optical element drive control unit 31 and the light emission amount control unit 32 operate so as to correspond to the coordinates (X, Y) in the scanning region 13 on the projection surface 11. For example, in the image data 14, when the i th pixel in the horizontal (x) direction and the j th pixel in the vertical (y) direction are projected onto the screen Sc, the first scan (X ) Direction and the j-th position in the second scanning (Y) direction, when the rotation posture (inclination to be formed) for forming the spot S is reached, that is, the scanning position on the projection surface 11 is (i , J) When the pixel corresponding position (i, j) corresponding to the pixel position is reached, the light amount R (emitted light) based on the pixel data G (i, j) of the pixel is output to the light source 21. A projection image 12 is formed by transmitting a light emission amount control signal Lc to the effect to the light source 21. When a deflecting optical element that can be driven non-resonant, such as a stepping motor, is used, the screen corresponding to the (i, j) th pixel position in synchronization with the light emission amount control signal Lc. An image can be formed by the deflection optical element drive control unit 31 outputting a drive control signal to the deflection optical element so that a spot S is formed at a pixel corresponding location (i, j) on Sc. .

  In the image projection apparatus 10 according to the present invention, instead of changing the amplitude of the deflection optical element 25, that is, correcting the scanning area as in the prior art, the light emission timing of the light source 21 with respect to the rotation of the deflection optical element 25 is adjusted. By correcting, deterioration of the projected image is suppressed. That is, in the image projection device 10, the image processing unit 33 of the control mechanism 30 uses the image data 14 (each pixel data G (x, y)) input to the control mechanism 30 in the scanning region 13 with distortion. The light emission amount control unit is appropriately corrected so as to be appropriately formed as a projection image on the projection surface 11 of the screen Sc, and based on the corrected image data 14 (each pixel data G ′ (x ′, y ′)). 32 controls driving of the light source 21 (flashing control). The image processing unit 33 executes a distortion correction method described later by executing a program stored in a memory 36 described later. The correction in the image processing unit 33 is basically performed on the optical characteristics in the projection optical system 20 (for example, the optical characteristics of the collimating lens 22, the imaging lens 24, and the magnifying lens 26, the scanning speed characteristics in the deflecting optical element 25, etc.). This is to prevent deterioration of the projection image 12 formed on the projection surface 11 of the screen Sc with respect to the image data 14 caused by the cause.

  The deterioration of the projection image 12 is as follows. In the image projection apparatus 10, the projection optical axis angle θp formed by the reference optical axis Lb and the normal direction N of the projection plane 11, that is, the reference optical axis Lb and the normal direction N of the projection plane 11 is 0. Assume that a two-dimensional projection image 12 formed on the projection surface 11 based on image data 14 without any correction by a certain front projection (see FIG. 3) is in the state shown in FIG. In the projection image 12 of FIG. 4, since the image data 14 that has not been subjected to any correction is formed on the projection surface 11 by front projection, the optical characteristics (for example, the collimating lens 22 and the connection result) in the projection optical system 20 are obtained. The scanning region 13 is distorted due to the optical characteristics of the image lens 24 and the magnifying lens 26, the scanning speed characteristics of the deflecting optical element 25, etc., thereby causing deterioration (distortion). A two-dimensional projection image is projected onto the projection surface 11 based on the image data 14 without any correction by oblique projection with the projection optical axis angle θp having a value other than 0 (see FIG. 5). When 12 is formed, as shown in FIG. 6, a large distortion occurs as compared with the projection image 12 (see FIG. 4) of front projection. In the scanning region 13, in the case of oblique projection, it is considered that the trapezoidal distortion due to the projection optical axis angle θp is added to the deterioration in the front projection due to the optical characteristics (see FIG. 4). . Thus, in the image projection apparatus 10, the scanning region 13 on the projection surface 11 is deformed according to the projection optical axis angle θp.

  The projection image 12 is distorted in accordance with the distortion of the scanning region 13 as follows. For example, in the oblique projection similar to FIGS. 5 and 6, the image data 14 shown in FIG. 7A (each pixel data G (t) (t indicates a number viewed in the scanning order)) is corrected. When the two-dimensional projection image 12 is formed on the projection surface 11 without performing the above, since the large distortion occurs in the shape of the scanning region 13 as shown in FIG. 7B, each pixel data G (t) Since each pixel corresponding position P (t) corresponding to the above is distorted following the shape of the scanning region 13, the projection image 12 is distorted following the shape of the scanning region 13. Here, to form the two-dimensional projection image 12 on the projection plane 11 without any correction of the image data 14 shown in FIG. 7A, the coordinate (x in each pixel data G (x, y)) , Y) as they are as coordinates (X, Y) of the scanning region 13 (x = X, y = Y), and the output value (light quantity) of each pixel data G (x, y) is projected onto the scanning region 13. Thus, it means that a two-dimensional projection image 12 is formed on the projection surface 11.

  In order to prevent such deterioration of the projection image 12, the image projection apparatus 10 according to the present invention basically performs correction in consideration of the influence of the projection optical axis angle θp while taking into consideration the optical characteristics of the projection optical system 20. The image data 14 (each pixel data G (x, y)) is corrected using the conversion formula (1). More specifically, in the image projection apparatus 10, as shown in FIG. 8, the scanning region 13 on the projection surface 11 corresponding to the projection optical axis angle θp set to execute image projection (FIG. 8 shows FIG. 6). The image forming area 15 having the same shape (rectangular shape) as that of the rectangular image indicated by the image data 14 is set inward, and the deflection optical element 25 is rotated ( The light emission amount control unit 32 drives and controls the light source 21 so as to form a spot S having a light amount corresponding to the image data 14 on the projection surface 11 only when the scanning position by driving is positioned on the image forming area 15. As described above, the image data 14 is corrected. Thereby, on the projection surface 11, a projection image corresponding to the image data 14 is formed only on the rectangular image forming area 15 in the scanning area 13, so that the projection image has a rectangular shape without distortion. Image. Such correction is performed in the image processing unit 33 of the control mechanism 30.

  As shown in FIG. 9, the image processing unit 33 includes a correction calculation part 34, a write conversion part 35, and a memory 36. The memory 36 stores image data 14 and the like (each pixel data G (x, y), correction conversion formula (1), its coefficient d, and each pixel data G ′ (x ′, y ′) after correction described later. Etc.), and the correction calculation part 34 can store and read data as appropriate.

  The write conversion part 35 is the pixel data G (x, y) as the image data 14, that is, the data of the x coordinate value in the image data 14, the data of the y coordinate value in the image data 14, and the coordinates (x, y When the output value data indicating the output (intensity) is input, the x coordinate value data and the y coordinate value data as the two-dimensional coordinate values are converted into a one-dimensional data together with the output value data. The data is stored (saved) in the memory 36 (x coordinate value data, y coordinate value data, and output value data associated with each other as one-dimensional data).

  The correction calculation portion 34 uses the following correction conversion equation (1) to convert the coordinates (x, y) in the image data 14 (each pixel data G (x, y)) stored in the memory 36 into a scanning region. The image data 14 stored in the memory 36 is corrected by converting it to the coordinates (X, Y) at 13.

  As shown in FIG. 8, the correction conversion formula (1) is equal to the image indicated by the image data 14 inside the scanning region 13 on the projection surface 11 corresponding to the set projection optical axis angle θp. An image forming area 15 having a shape (rectangular shape in this example) is set, and a projection image based on the image data 14 (each pixel data G (x, y)) is formed on the image forming area 15. Each pixel (x, y) of the image data 14 in the area 15 indicates which coordinate (X, Y) in the scanning area 13 corresponds to. For this reason, the image forming area 15 has a similar relationship with the image indicated by the image data 14. The image forming area 15 circumscribes the scanning area 13 in the first embodiment. Further, the coordinates (x ′, y ′) after the conversion are the scanning area 13 for each pixel data G (x, y) of the image in a state where the image based on the image data 14 is adapted to the image forming area 15. The pixel corresponding location (x ′, y ′) (each pixel corresponding location P ′ (t) (see FIG. 7C)) is shown.

^{_{x'= (d x1 y 2 +}} d x2 y + d x3) x + (d x4 y 2 + d x5 y + d x6)
y ′ = (d _y1 x ² + d _y2 x + d _y3 ) y ² + (d _y4 x ² + d _y5 x + d _y6 ) y
+ (D _y7 x ² + d _y8 x + d _y9 )
(1)
Here, each coefficient d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) is a coefficient that changes according to the projection optical axis angle θp. That is, the correction conversion equation (1) is basically a conversion equation for correcting distortion due to the influence of the optical characteristics in the projection optical system 20, and each coefficient d is changed in accordance with the projection optical axis angle θp. Thus, this is a conversion equation for correcting distortion due to the influence of the projection optical axis angle θp. In other words, each coefficient d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) is a coefficient that changes only in accordance with the change in the projection optical axis angle θp, and under the condition of the corresponding projection optical axis angle θp. The correction conversion equation (1) is set to be a conversion equation that corrects both distortion caused by the optical characteristics of the projection optical system 20 and distortion caused by the projection optical axis angle θp.

As an example of each coefficient d, each coefficient d (0) (combination of coefficients d (0)) in the case of front projection where the projection optical axis angle θp is 0 degrees and the projection optical axis angle θp is 53.38 degrees. Each coefficient d (53.38) (combination of coefficients d (53.38)) in the case of oblique projection is shown below.
In the case of front projection (projection optical axis angle θp is 0 degree), the value of each coefficient d d _x1 (0): 3.03 × 10 ⁻⁷
d _x2 (0): 3.33 × 10 ⁻⁶
d _x3 (0): 8.5 × 10 ⁻¹
d _x4 (0): −1.1 × 10 ⁻⁴
d _x5 (0): −2.1 × 10 ⁻³
d _x6 (0): 2.48
d _y1 (0): 1.96 × 10 ⁻¹⁰
d _y2 (0): −1.47 × 10 ⁻⁷
d _y3 (0): 1.0 × 10 ⁻⁴
d _y4 (0): 1.0029 × 10 ⁻⁶
d _y5 (0): −7.5 × 10 ⁻⁴
d _y6 (0): 8.1 × 10 ⁻¹
d _y7 (0): _−1.0 × 10 ⁻³
d _y8 (0): 7.7 × 10 ⁻¹
d _y9 (0): −138.54

In the case of oblique projection (projection optical axis angle θp is 53.38 degrees), the value of each coefficient d d _x1 (53.38): 5.4 × 10 ⁻⁷
d _x2 (53.38): −1.1 × 10 ⁻³
d _x3 (53.38): 9.7 × 10 ⁻¹
d _x4 (53.38): -4.0 × 10 ^-4
d _x5 (53.38): 7.9 × 10 ⁻¹
d _x6 (53.38): -386.83
d _y1 (53.38): −8.58 × 10 ⁻¹⁰
d _y2 (53.38): 1.26 × 10 ⁻⁶
d _y3 (53.38): −7.4 × 10 ⁻⁴
d _y4 (53.38): 1.6 × 10 ⁻⁶
d _y5 (53.38): -2.3 × 10 ⁻³
d _y6 (53.38): 1.64
d _y7 (53.38): _−7.9 × 10 ⁻⁴
d _y8 (53.38): 1.16
_dy9 (53.38): -385.19

In the image projection apparatus 10 (control mechanism 30), the projection image 12 is corrected as follows.

  First, in the image processing unit 33 of the control mechanism 30, the write conversion unit 35 stores (saves) each pixel data G (x, y) of the input image data 14 in the memory 36.

  Next, in the image processing unit 33, the correction calculation part 34 sets a reference for the actual projection plane 11 (when image projection is performed) in order to set each coefficient d of the correction conversion equation (1) used for the correction calculation. Data relating to the projection optical axis angle θp made by the optical axis Lb (hereinafter referred to as projection angle data Dd) is acquired. As a method for obtaining the projection angle data Dd, the image projection device 10 may be input from the outside, or a value set in the image projection device 10 itself may be used. You may use the value according to the usage condition in the projection apparatus 10. FIG.

  Next, the correction calculation section 34 uses the correction conversion formula (1) described above for each coordinate (x, y) in each pixel data G (x, y) of the image data 14 stored in the memory 36. The coordinates are converted into coordinates (x ′, y ′) represented by the coordinates (X, Y) of the scanning region 13. Further, the correction calculation portion 34 converts the data of the coordinates (x ′, y ′) in the scanning area 13 after the conversion (after correction) into the data of the output value in the coordinates (x, y) data before the conversion. The corrected pixel data G ′ (x ′, y ′) is generated together with the corrected pixel data G ′ (x ′, y ′) and stored in the memory 36. At this time, the corrected pixel data G ′ (x ′, y ′) may include coordinate (x, y) data before conversion.

  Next, based on the synchronization detection mirror position signal Mp output from the deflection optical element 25, the light emission amount control unit 32 of the control mechanism 30 scans the scanning region 13 in the scanning region 13 by the rotation of the deflection optical element 25 ( Data of coordinates (X, Y)) is acquired, and conversion equal to the acquired scanning position coordinates (X, Y) among the corrected pixel data G ′ (x ′, y ′) stored in the memory 36 It is determined whether or not there is data having later coordinate (x ′, y ′) data.

  When there is corrected pixel data G ′ (x ′, y ′) having converted coordinate (x ′, y ′) data equal to the scanning position coordinates (X, Y), the light emission amount control unit 32 performs mirroring. A light emission quantity control signal Lc for outputting the output light (light ray R) of the output value (light quantity) of the corresponding corrected pixel data G ′ (x ′, y ′) in synchronization with the position signal Mp to the light source 21. It transmits to the light source 21, and the said light source 21 is drive-controlled.

  In addition, the light emission amount control unit 32 has no corrected pixel data G ′ (x ′, y ′) having converted coordinate (x ′, y ′) data equal to the scanning position coordinates (X, Y). The emitted light amount control signal Lc is not transmitted to the light source 21. For this reason, the emitted light (light ray R) is not output from the light source 21.

  As a result, the light source 21 outputs divergent light having a light amount based on the corrected pixel data G ′ (x ′, y ′) toward the collimator lens 22, and the collimator lens 22 converts the divergent light into parallel light. Then, the parallel light is reflected by the mirror 23 and travels toward the imaging lens 24, and the imaging lens 24 converts the parallel light into convergent light, which converges toward the deflecting optical element 25.

  The convergent light forms a spot S at the coordinates (x ′, y ′) in the scanning region 13 on the projection surface 11 of the screen Sc, that is, the deflecting optical element 25 brought into an appropriate state by the deflecting optical element drive control unit 31. Reflected by the movable mirror portion 25c having such an angle, the horizontal direction and the vertical direction are deflected toward the magnifying lens 26. The deflected convergent light is converted into a scanning angle α by the deflection angle θ converted by the magnifying lens 26 and guided to the screen Sc as a projection target in the traveling direction of the scanning angle α. As a result, a light spot S based on the corrected pixel data G ′ (x ′, y ′) is formed at the coordinates (x ′, y ′) in the scanning region 13 on the projection surface 11 of the screen Sc.

  By performing the above-described series of operations until the scanning position coordinates (X, Y) that change due to the rotation of the deflecting optical element 25 reach the entire scanning region 13, as shown in FIG. On the projection surface 11, a projection image 12 having no distortion based on the image data 14 is formed in the image forming area 15 of the scanning area 13. At this time, the spot S by the light source 21 is not formed in an area other than the image forming area 15 in the scanning area 13, and no projection image is formed.

  Next, the concept of the correction conversion equation (1) and the calculation method of each coefficient d will be described. In the following description, it is assumed that the image data 14 has a pixel resolution (number of pixels) of (640 × 480) according to the VGA (Video Graphics Array) standard.

  In this example, as shown in FIG. 10, since the image data 14 is composed of 640 × 480 pixel data G, the projection image 12 formed without any correction on the image data 14 is also 640. It is composed of × 480 pixel data G. As described above, the projection image 12 has a shape that follows the distortion of the scanning region 13 caused by the optical characteristics of the projection optical system 20 and the projection optical axis angle θp.

  In the distortion correction method according to the present invention, as described above, the image data 14 is stored inside the scanning area 13 on the projection surface 11 corresponding to the distorted scanning area 13, that is, the set projection optical axis angle θp. An image forming area 15 having the same shape as the image shown (rectangular in this example) is set, and a projection image based on the image data 14 (each pixel data G (x, y)) is formed on the image forming area 15 (See FIG. 11). In this image forming area 15, in order to ensure the screen resolution set as the image data 14, it is necessary to provide the number of drawing points equal to the number of pixel data G (640 × 480) of the image data 14.

  Specifically, the image data 14 conceptually represented in the xy coordinate system is a rectangle abcd in FIG. 12A, and the image data 14 is formed on the projection surface 11 without any correction. Assume that the projected image 12 conceptually represented in the XY coordinate system is a distorted square a′b′c′d ′ in FIG. Here, as described above, since the projection image 12 is formed along the distorted scanning region 13, the image formation region 15 is set in the projection image 12 (FIG. 12 ( b)). When each pixel size drawn in the image forming area 15 is set as a reference (an area obtained by dividing the image forming area 15 corresponding to each pixel data G of the image data 14 is set as a reference), a distorted square a′b In order to form the projection image 12 represented by 'c'd', as shown in FIG. 12C, a larger number of input coordinates than the image data 14 composed of 640 × 480 pixel data. Virtual image data 16 (rectangle a ″ b ″ c ″ d ″) composed of (scanning position information by the deflection optical element 25) is required. The virtual image data 16 is conceptually represented by a rectangle a ″ b ″ c ″ d ″ in the xy coordinate system, and the distorted quadrangle a′b ′ conceptually represented by the projection image 12 in the XY coordinate system. When the correspondence relationship with c′d ′ is obtained, it indicates which arbitrary coordinate (x, y) in the virtual image data 16 corresponds to which coordinate (X, Y) in the projection image 12. Therefore, this correspondence is a correction conversion formula. This correspondence is obtained as follows, for example.

  First, the shape of the scanning region 13 on the projection surface 11 corresponding to the set projection optical axis angle θp is calculated by optical simulation (see the rectangle a′b′c′d ′ in FIG. 12B).

  Next, an image forming area 15 is set in the scanning area 13 (see FIG. 12B), and virtual image data 16 (see FIG. 12C) corresponding to the scanning area 13 with the image forming area 15 as a reference. Square a ″ b ″ c ″ d ″). In the first embodiment, the scanning area 13 and the virtual image data 16 are a ″ (1, 1), b ″ (when the front projection is performed (projection optical axis angle θp is 0 degree). 750, 1), c ″ (1, 700), d ″ (750, 700), the scanning region 13 is a ′ (−54, −482), b ′ (698, −482), c ′ (4, −149), d ′ (640, −149), and when the projection optical axis angle θp is 53.38 degrees, the virtual image data 16 is a ″ (1, 1), b ″ ( 1463, 1), c ″ (1, 1077), d ″ (1463, 1077), the scanning region 13 is a ′ (23, 559), b ′ (617, 559), c ′ ( -412, -502) and d '(1052, -502). The coordinates of the scanning area 13 and the virtual image data 16 are values corresponding to an example of each coefficient d described above.

  Next, as shown in FIG. 12C, a plurality of scanning lines (reference numerals l1 ′ and l2 ′) in the scanning region 13 corresponding to a plurality of scanning lines (refer to reference numerals l1, l2 and l3) in the virtual image data 16. , L3 ′ reference) is obtained. In each of these mathematical formulas, if an arbitrary coordinate in the XY coordinate system is (x ′, y ′), x ′ is a function having x as a variable. In order to make such a plurality of mathematical expressions (the mathematical expressions of the scanning lines l1 ′, l2 ′, and l3 ′) as one mathematical expression, the coefficients of the mathematical expressions are collectively used as a function relating to y. Similarly, y ′ is a function having y as a variable, and the coefficients of each mathematical expression are combined into one mathematical expression as a function relating to x. As a result, the correspondence (correction conversion equation (1)) indicating which arbitrary coordinate (x, y) in the virtual image data 16 corresponds to which coordinate (X, Y) in the projection image 12 is obtained. Can be sought.

In this correspondence relationship (conversion formula), since the relationship is established regardless of the coordinates (x, y) in the virtual image data 16, each coordinate of the image forming area 15 is ((x = 1 to 1). 640) and (y = 1 to 480)), the virtual xy coordinates are set on the XY coordinates (see FIG. 12D), and each coefficient d (d _x1 ) is adapted to the virtual xy coordinates. ˜d _x6 and dy ₁ ˜d _y9 ), each pixel (x, y) of the image data 14 in the image forming area 15 corresponds to any coordinate (X, Y) in the scanning area 13. It is possible to calculate the correction conversion formula (1) and each coefficient d that indicate whether or not there is.

  In the image projection apparatus 10 (control mechanism 30) according to the present invention, the deterioration of the projected image is suppressed by changing the light emission timing of the light source 21 with respect to the rotation of the deflection optical element 25. Distortion correction of the projection image 12 on the projection surface 11 can be performed while suppressing an increase in the burden on the electric circuit. This is because, in the configuration in which the amplitude of the deflecting optical element 25 is changed so as to correct the scanning region as in the prior art, a feedback circuit for driving control of the deflecting optical element 25 is required, and the processing amount in the circuit including them is increased. This increases the burden on the electric circuit.

  In the image projection apparatus 10 (control mechanism 30), since the deterioration of the projected image is suppressed by changing the light emission timing of the light source 21 with respect to the rotation of the deflection optical element 25, the amplitude operation of the deflection optical element 25 is performed. Therefore, the distortion of the projection image 12 on the projection surface 11 can be corrected while suppressing an increase in the burden on the deflection optical element 25.

  Further, in the image projection device 10 (control mechanism 30), the coordinates (x, y) in the image data 14 (each pixel data G (x, y)) are converted into the scanning region 13 using the correction conversion formula (1). Since the image data 14 stored in the memory 36 is corrected by converting to the coordinates (X, Y) at, the optical characteristics of the projection optical system 20 under the condition of the corresponding projection optical axis angle θp are corrected. Both distortion due to influence and distortion due to the influence of the projection optical axis angle θp can be corrected.

  Since the image projection apparatus 10 (control mechanism 30) corrects the image data 14 (each pixel data G (x, y)) using the correction conversion formula (1) stored in the memory 36, the corresponding projection is performed. Compared with storing the correction table of each pixel data in the condition of the optical axis angle θp in the memory 36, the capacity of the memory 36 can be extremely reduced, which is extremely useful from the viewpoint of miniaturization.

  In the image projection apparatus 10, by using the magnifying lens 26, a large scanning angle can be obtained even if the deflection angle in the deflection optical element 25 is small, and the object to be projected at a close distance (screen Sc in this example). A large projection image can be formed, and the simple configuration is extremely useful from the viewpoint of miniaturization. At this time, the use of the magnifying lens 26 may cause distortion in the scanning region 13 on the projection surface 11 easily. However, as described above, the control mechanism 30 includes projection optics including the magnifying lens 26. Since both the distortion due to the influence of the optical characteristics in the system 20 and the distortion due to the influence of the projection optical axis angle θp can be corrected, there is no problem. Therefore, for example, as shown in FIG. 13, the image projection device 10 is incorporated in a lid 41 including a display screen (not shown) of the mobile phone 40, and a telephone main body 42 including a key operation part (not shown). On the other hand, in the open state in which the lid 41 is orthogonal, a projection image can be formed on the same plane as the placement surface 43 on which the telephone main body 42 is placed (the same plane is used as a projection target). At this time, in the mobile phone 40, since the size of the mobile phone 40 and the mounting position of the image projection apparatus 10 there are set in advance, when the image projection function (projector function) is used. By determining the aspect of the mobile phone 40 and the projection target for the placement position, the distance from the emission position of the image projection apparatus 10 (the magnifying lens 26 in the first embodiment) to the projection target and their positional relationship are determined as predetermined. In addition, the projection optical axis angle θp formed by the reference optical axis Lb and the normal direction N of the projection surface 11 can be set to a predetermined value. Therefore, an optical setting in the projection optical system 20 and a correction conversion formula (1) corresponding to the optical setting and the projection optical axis angle θp are determined in advance, and distortion correction is performed on the mounting surface 43. The projected image can be formed.

  Therefore, the image projection apparatus 10 according to the present invention can correct the distortion of the projected image while suppressing an increase in the burden on the electric circuit and the deflection optical element.

  Next, an image projection apparatus 102 according to Embodiment 2 of the present invention will be described. The second embodiment is an example in which the distortion of the projected image is corrected in consideration of the inclination from the reference posture in the image projection apparatus 102. Since the basic configuration of the image projecting apparatus 102 (and the mobile phone 402) of the second embodiment is the same as that of the image projecting apparatus 10 and the mobile phone 40 of the first embodiment, the same components are the same. Reference numerals are assigned and detailed description thereof is omitted. FIG. 14 is an explanatory diagram schematically illustrating an example of a reference posture for forming a projected image by oblique projection using the mobile phone 402 equipped with the image projection apparatus 102 according to the second embodiment. FIG. 15 is an explanatory diagram schematically showing a state where the opening posture of the mobile phone 402 is changed from the reference posture. FIG. 16 is an explanatory diagram schematically illustrating an example of forming a projection image on a projection target that is not flush with the placement surface 43 using the mobile phone 402.

  In the mobile phone 402, the image projection device 102 and the gravitational acceleration sensor 44 are provided on a lid 412 (first housing) provided with a display screen (not shown). In this cellular phone 402, the same plane as the mounting surface 43 extending in a substantially horizontal direction on which the telephone main body 422 (second housing) including a key operation portion (not shown) is mounted is set as a projection target. Therefore, the open state in which the lid 412 is orthogonal to the telephone main body 422 is set as a reference posture in an image projection function for forming a projection image using the image projection device 102.

  The gravitational acceleration sensor 44 detects the inclination of the lid 412, that is, the image projection apparatus 102 itself provided there. That is, in the mobile phone 402, it is assumed that the telephone body 422 is mounted on the mounting surface 43 extending in a substantially horizontal direction, and therefore the gravitational acceleration sensor 44 is connected to the telephone body 422 with respect to the lid 412. The inclination is detected. In the second embodiment, the gravitational acceleration sensor 44 detects an inclination angle θi (see FIG. 15) with respect to a reference posture in the image projection apparatus 102 (lid portion 412), and uses the inclination angle θi as a projection angle with respect to the projection optical axis angle θp. Data Dd is output to the correction calculation part 34.

The correction calculation part 34 obtains the projection optical axis angle θp based on the input projection angle data Dd, and calculates the coefficients d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) corresponding to the projection optical axis angle θp. The correction conversion equation (1) corresponding to the projection optical axis angle θp is set by reading from the memory 36. In the correction calculation part 34, the image data 14 (each pixel data G (x, y)) is corrected using the set correction conversion formula (1). Since this correction method is the same as that of the first embodiment, detailed description thereof is omitted.

  Here, correction of the projected image in the mobile phone 402 will be described below. In the mobile phone 402 according to the second embodiment, as described above, when the same plane as the placement surface 43 on which the phone main body 422 is placed is a projection target, the reference posture in the image projection function is relative to the phone main body 422. Thus, the lid portion 412 is in an open state orthogonal to each other. For this reason, in the cellular phone 402, the gravity acceleration sensor 44 is in the state of being placed on the placement surface 43 extending in a substantially horizontal direction, and the gravitational acceleration sensor 44 is the image projection device 102 with respect to the normal direction of the placement surface 43. Is detected as the inclination angle θi.

  Further, in the mobile phone 402, the emission direction from the image projection device 102, that is, the direction of the reference optical axis Lb with respect to the lid portion 412 is determined in advance from the optical setting in the image projection device 102 and the mounting posture in the lid portion 412. Yes. Here, an angle formed by the extending direction of the lid 412 and the direction of the reference optical axis Lb is set as an emission setting angle θs. Further, the projection optical axis angle (the reference optical axis Lb is relative to the normal direction N of the mounting surface 43) when the projection target is the same plane as the mounting surface 43 on which the telephone body 422 is mounted in the reference posture. The angle to be made is θp1. Here, in the mobile phone 402, the projection optical axis angle θp1 in the reference posture (see FIG. 14) is determined in advance from the size of the mobile phone 402 and the mounting position and posture of the image projection apparatus 102 there. For this reason, in the second embodiment, the projection optical axis angle θp1 is stored in the memory 36 of the control mechanism 30 in advance.

  In the cellular phone 402, when an image projection function for forming a projection image is activated by an operation on a key operation portion (not shown) provided on the telephone body 422, the gravitational acceleration sensor 44 is tilted at an inclination angle θi. , And projection angle data Dd corresponding to the detected angle is output to the correction calculation portion 34. In the case of the reference posture shown in FIG. 14, the gravitational acceleration sensor 44 generates the projection angle data Dd indicating that the inclination angle θi is 90, that is, the image projection device 102 (lid portion 412) is not inclined from the reference posture. . Further, the gravitational acceleration sensor 44 generates projection angle data Dd indicating the detected inclination angle θi in a state where it is inclined from the reference posture shown in FIG. The projection optical axis angle in this inclined state is assumed to be θp2.

  In the correction calculation part 34, when the projection angle data Dd is input, the projection optical axis angle θp2 is calculated based on the detection result of the gravitational acceleration sensor 44. The projection optical axis angle θp2 can be calculated from the predetermined projection optical axis angle θp1 since the emission setting angle θs is constant. Specifically, in the case of Example 2, since θp2 = θp1 + (90−θi), the projection optical axis angle θp2 can be calculated.

Thereafter, in the correction calculation part 34, the respective coefficients d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) corresponding to the calculated projection optical axis angle θp2 are read from the memory 36 and corrected according to the projection optical axis angle θp2. The conversion formula (1) is set. Then, the correction calculation part 34 corrects the image data 14 (each pixel data G (x, y)) using the correction conversion formula (1) corresponding to the projection optical axis angle θp2. Therefore, the mobile phone 402 can form a projection image without distortion (corrected for distortion) based on the image data 14 on the placement surface 43 that is the projection target.

  Since the basic configuration of the image projection apparatus 102 according to the second embodiment is the same as that of the image projection apparatus 10 according to the first embodiment, the same effects as those of the image projection apparatus 10 can be obtained.

  Further, since the basic configuration of the mobile phone 402 of the second embodiment is the same as that of the mobile phone 40 of the first embodiment, the same effects as the mobile phone 40 can be obtained.

  In addition, in the mobile phone 402 according to the second embodiment, even when the lid portion 412 is in an opened state at an arbitrary angle with respect to the phone main body 422 instead of the preset reference posture, Since a projection image without distortion based on the image data 14 can be formed, usability can be improved, and the degree of freedom of the size of the projection image on the mounting surface 43 can be increased.

  In the second embodiment, the gravitational acceleration sensor 44 is provided on the lid portion 412. However, if the inclination from the reference posture in the image projecting apparatus 102 can be detected, for example, the image projecting apparatus 102 is used. The configuration may be incorporated in (for example, an electric circuit constituting the same), and is not limited to the second embodiment.

  Further, in the second embodiment, an example in which the same plane as the placement surface 43 on which the telephone main body 422 is placed is projected, but, for example, as shown in FIG. However, the wall surface 45 facing the mobile phone 402 (image projection apparatus 102) may be a projection target, and is not limited to the second embodiment. Even when the wall surface 45 is a projection target, if the emission setting angle θs is constant and a reference posture when the wall surface 45 is a projection target is set, the normal direction of the wall surface 45 in the reference posture Since the projection optical axis angle (θp) with respect to N is determined in advance and the inclination angle θi from the reference posture can be detected by the gravitational acceleration sensor 44, the image data 14 is displayed on the wall surface 45 as in the second embodiment. It is possible to form a projection image without distortion based on the above.

  Furthermore, in the second embodiment, the gravitational acceleration sensor 44 is used as the tilt detection means. However, if the tilt from the reference posture in the image projection apparatus 102 (lid portion 412) is detected, for example, the telephone main body 422 is used. A mechanism (such as a rotary encoder) for detecting the degree of inclination of the lid portion 412 with respect to may be used, and is not limited to the second embodiment.

  In the second embodiment, an example in which the image projection apparatus 102 is mounted on the mobile phone 402 is shown. However, the first projection optical system is housed in the second casing placed on the plane to be projected. Is detected, the projection optical axis angle is obtained based on the detection result, a correction conversion equation (1) corresponding to the projection optical axis angle is set, and the set correction conversion equation (1) The image data 14 (each pixel data G (x, y)) may be corrected using the above, and is not limited to the second embodiment.

  Next, an image projection apparatus 103 according to Embodiment 3 of the present invention will be described. The third embodiment is an example different from the second embodiment in which the distortion of the projected image is corrected in consideration of the inclination from the reference posture in the image projection apparatus 103. Since the basic configuration of the image projecting apparatus 103 (and the mobile phone 403) of the third embodiment is the same as that of the image projecting apparatus 10 and the mobile phone 40 of the first embodiment, the same components are the same. Reference numerals are assigned and detailed description thereof is omitted. FIG. 17 is an explanatory diagram showing a state in which the projection optical axis angle with respect to the placement surface 43 to be projected changes as the mobile phone 403 is placed on the convex portion 46 on the placement surface 43.

  In the mobile phone 403, a gravitational acceleration sensor 443 is provided in a telephone body 423 (at least a housing for accommodating a projection optical system) including a key operation portion (not shown). In this cellular phone 403, on the assumption that a plane parallel to the horizontal plane is a projection target, the image projection device 103 is in an open state in which the lid portion 413 provided with the image projection device 103 is orthogonal to the phone main body 423. Is set as a reference posture in an image projecting function for forming a projected image.

  As shown in FIG. 17, the gravitational acceleration sensor 443 detects the inclination (inclination angle θi ′) of the telephone body 423, that is, the mobile phone 403 with respect to the plane to be projected, and uses the inclination angle θi ′ as the projection optical axis angle θp. Is output to the correction calculation portion 34 as projection angle data Dd. Since the gravitational acceleration sensor 443 presupposes that a plane parallel to the horizontal plane is a projection target in the third embodiment, the inclination of the telephone body 423 (mobile phone 403) with respect to the horizontal plane is detected as an inclination angle θi ′. To do.

The correction calculation part 34 obtains the projection optical axis angle θp based on the input projection angle data Dd, and calculates the coefficients d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) corresponding to the projection optical axis angle θp. The correction conversion equation (1) corresponding to the projection optical axis angle θp is set by reading from the memory 36. In the correction calculation part 34, the image data 14 (each pixel data G (x, y)) is corrected using the set correction conversion formula (1). Since this correction method is the same as that of the first embodiment, detailed description thereof is omitted.

  Here, correction of the projected image in the mobile phone 403 will be described below. In the mobile phone 403 according to the third embodiment, as described above, the reference posture in the image projection function is an open state in which the lid 413 is orthogonal to the phone main body 423, and a plane parallel to the horizontal plane is the projection target. Yes. For this reason, in the cellular phone 403, as shown in FIG. 17, when the mobile phone 403 is placed on the convex portion 46 on the placement surface 43 extending in the substantially horizontal direction, the gravitational acceleration sensor 443 extends in the horizontal direction. The inclination of the telephone body 423 with respect to the placement surface 43 to be detected is detected as the inclination angle θi ′.

  Further, in the mobile phone 403, the emission direction from the image projection device 103, that is, the direction of the reference optical axis Lb relative to the lid 413 is determined in advance from the optical setting in the image projection device 103 and the mounting posture in the lid 413. Yes. Here, an angle formed by the extending direction of the lid 413 and the direction of the reference optical axis Lb is set as an emission setting angle θs. In addition, when the telephone body 423 of the reference posture is placed on the placement surface 43 and the same plane as the placement surface 43 is the projection target, the projection optical axis angle (in the normal direction N of the placement surface 43) The angle formed by the reference optical axis Lb is θp1 (see FIG. 14). Here, in the mobile phone 403, the projection optical axis angle θp1 in the reference posture (see FIG. 14) is determined in advance based on the size of the mobile phone 403, the mounting position and posture of the image projection device 103 therein, and the like. For this reason, in the third embodiment, the projection optical axis angle θp1 is stored in the memory 36 of the control mechanism 30 in advance.

  In this cellular phone 403, when an image projection function for forming a projection image is activated by an operation on a key operation portion (not shown) provided on the telephone body 423, the gravitational acceleration sensor 443 is tilted at an inclination angle θi. ′ Is detected, and projection angle data Dd corresponding to it is output to the correction calculation section 34. As shown in FIG. 17, the gravitational acceleration sensor 443 is placed on the convex portion 46 on the placement surface 43 extending in the substantially horizontal direction, and the telephone body with respect to the placement surface 43 (horizontal plane). The inclination angle θi ′ formed by the extending direction of the portion 423 is detected. A projection optical axis angle in a state where the telephone body 423 is placed on the convex portion 46 on the placement surface 43 is defined as θp3.

  When the projection angle data Dd is input, the correction calculation portion 34 calculates the projection optical axis angle θp3 based on the detection result of the gravitational acceleration sensor 443. The projection optical axis angle θp3 can be calculated from the predetermined projection optical axis angle θp1 since the emission setting angle θs is constant. Specifically, in the case of Example 3, θp3 = θp1 + θi ′, and the projection optical axis angle θp3 can be calculated.

Thereafter, in the correction calculation part 34, the respective coefficients d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) corresponding to the calculated projection optical axis angle θp3 are read from the memory 36 and corrected according to the projection optical axis angle θp3. The conversion formula (1) is set. Then, the correction calculation part 34 corrects the image data 14 (each pixel data G (x, y)) using the correction conversion equation (1) corresponding to the projection optical axis angle θp3. For this reason, in the mobile phone 403, even if the telephone body 423 is placed on the convex portion 46 on the placement surface 43 that extends in the horizontal direction as the projection target, In addition, it is possible to form a projection image without distortion (corrected for distortion) based on the image data 14. That is, even when the projector is placed with an inclination with respect to the projection target surface, there is no distortion based on the image data 14 on the projection target surface (distortion correction has been performed). ) A projection image can be formed.

  Since the basic configuration of the image projector 103 according to the third embodiment is the same as that of the image projector 10 according to the first embodiment, the same effects as those of the image projector 10 can be obtained.

  Further, since the basic configuration of the mobile phone 403 according to the third embodiment is the same as that of the mobile phone 40 according to the first embodiment, the same effects as those of the mobile phone 40 can be obtained.

  In addition, in the mobile phone 403 according to the third embodiment, even if the telephone body 423 is not placed on the same plane as the projection target surface, distortion based on the image data 14 is generated on the projection target surface. Therefore, the usability can be improved and the degree of freedom of the size of the projected image on the mounting surface 43 can be increased.

  In the third embodiment, the gravitational acceleration sensor 443 serving as the inclination detecting unit is provided in the telephone main body 423. However, any lid that can detect the inclination of the telephone main body 423 relative to the projection target can be used. The configuration may be incorporated in the unit 413 or the image projection apparatus 103 (for example, an electric circuit constituting the unit), and is not limited to the third embodiment.

  In the third embodiment, an example in which the same plane as the placement surface 43 on which the telephone body 423 is placed is used as a projection target. However, as in the second embodiment, for example, while extending in the vertical direction, A wall surface (not shown) that faces the mobile phone 403 (image projection apparatus 103) may be a projection target, and is not limited to the third embodiment. Even when this wall surface is the projection target, if the emission setting angle θs is constant and the reference posture when the vertical surface is the projection target is set, the normal line of the wall surface (45) in the reference posture is set. Since the projection optical axis angle (θp) with respect to the direction N is determined in advance and the inclination angle θi ′ from the vertical plane can be detected by the gravitational acceleration sensor 443, the image data 14 is displayed on the wall surface as in the third embodiment. It is possible to form a projection image without distortion based on the above.

  Further, in the third embodiment, the example in which the image projection apparatus 103 is mounted on the mobile phone 403 is shown. However, the tilt with respect to the projection target in the mounted device (the casing on which the projection optical system is mounted) is detected, A projection optical axis angle is obtained based on the detection result, a correction conversion equation (1) corresponding to the projection optical axis angle is set, and image data 14 (each pixel is set using the correction conversion equation (1) thus set. Any data that corrects data G (x, y)) may be used, and the present invention is not limited to the third embodiment.

Next, an image projection apparatus 104 according to Embodiment 4 of the present invention will be described. The fourth embodiment is an example in which the number of combinations of the coefficients d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) stored in the memory 36 is limited. Since the basic configuration of the image projecting device 104 (and the mobile phone 404) of the fourth embodiment is the same as that of the image projecting device 10 (and the mobile phone 40) of the first embodiment described above, the image projecting device 104 (and the mobile phone 404) has the same configuration. Are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 18 is an explanatory view schematically showing a state in which the mobile phone 404 is placed on the placement surface 43 and a projection image is formed on the plane with the placement surface 43 as a projection target. It is.

In the mobile phone 404, the number of combinations of the coefficients d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) stored in advance in the memory 36 (see FIG. 9) of the control mechanism 30 is limited. , Three combinations (each coefficient d (20), each coefficient d (40), each coefficient d (60)) corresponding to the case where the projection optical axis angle θp is 20 degrees, 40 degrees, and 60 degrees are stored. ing.

  Further, in the mobile phone 404, a distortion adjustment button 42b is set in a key operation portion 42a provided in the phone main body 42. The distortion adjustment button 42b is for adjusting the correction amount of distortion due to the influence of the projection optical axis angle θp in the projection image formed on the projection target (mounting surface 43). When the distortion adjustment button 42b is operated, an adjustment signal corresponding to the operation is transmitted to the correction calculation portion 34 (see FIG. 9) of the control mechanism 30.

In the correction calculation part 34, the projection optical axis angle θp is obtained based on the input projection angle data Dd, and the coefficients d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) corresponding to the projection optical axis angle θp. Is read from the memory 36 as in the first embodiment. The generation method of the projection angle data Dd may be the same as that in the second and third embodiments, for example.

  However, in the fourth embodiment, since only the three combinations of coefficients d corresponding to the three projection optical axis angles are stored in the memory 36, each coefficient corresponding to the calculated projection optical axis angle θp is stored. If there is no d, the correction calculation section 34 reads out each coefficient d corresponding to the projection optical axis angle closest to the calculated projection optical axis angle θp from the memory 36, and a correction conversion formula corresponding to the projection optical axis angle. Set (1). In the correction calculation part 34, the image data 14 (each pixel data G (x, y)) is corrected using the set correction conversion formula (1). Since this correction method is the same as that of the first embodiment, detailed description thereof is omitted.

In addition, when an adjustment signal corresponding to an operation on the distortion adjustment button 42b is input to the correction calculation part 34, the correction amount of distortion due to the influence of the projection optical axis angle θp is adjusted according to the operation amount. In the adjustment of the correction amount, in the fourth embodiment, each coefficient d read from the memory 36 is continuously changed according to the operation amount to the distortion adjustment button 42b, and the changed coefficient d ′ is used. Then, the correction conversion equation (1) is reset, and the image data 14 (each pixel data G (x, y)) is corrected using the newly set correction conversion equation (1). Here, as a method of continuously changing each read coefficient d according to the operation amount to the distortion adjustment button 42b, for example, distortion is performed for each coefficient (d _{x1 to} d _x6 and d _{y1 to} d _y9 ). It is conceivable to previously set a change mode with respect to the operation on the adjustment button 42b and a change amount with respect to the operation amount. In the fourth embodiment, distortion adjustment is performed between the coefficients d of the two combinations that are adjacent to each other when the coefficients d of the three combinations stored in the memory 36 are viewed at the corresponding projection optical axis angles. Each coefficient d is changed by linearly changing it according to the operation amount to the button 42b.

  In the cellular phone 404 according to the fourth embodiment, when there is no coefficient d corresponding to the calculated projection optical axis angle θp, the set correction conversion equation (1) does not completely correspond to the calculated projection optical axis angle θp. Therefore, as shown in FIG. 18, a projection image 12a whose distortion is not completely corrected is formed on the projection target (mounting surface 43).

  In this case, since the mobile phone 404 can adjust the correction amount of distortion due to the influence of the projection optical axis angle θp by operating the distortion adjustment button 42b of the key operation part 42a of the telephone body 42, the projection target (mounting) By appropriately operating the distortion adjustment button 42b while viewing the projection image 12a formed on the placement surface 43), the projection image 12a can be changed to a projection image 12b without distortion.

  Since the basic configuration of the image projecting apparatus 104 according to the fourth embodiment is the same as that of the image projecting apparatus 10 according to the first embodiment, the same effects as those of the image projecting apparatus 10 can be obtained.

  In addition, since the basic configuration of the mobile phone 404 of the fourth embodiment is the same as that of the mobile phone 40 of the first embodiment, the same effects as the mobile phone 40 can be obtained.

In addition, in the mobile phone 404 of the fourth embodiment, the number of combinations of the coefficients d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) stored in the memory 36 is limited (three in the fourth embodiment). Therefore, the capacity of the memory 36 can be reduced, and as a result, the image projection device 104 (mobile phone 404) can be easily downsized.

Furthermore, in the mobile phone 404 of the fourth embodiment, although the number of combinations of the coefficients d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) stored in the memory 36 is limited, the key of the telephone body 42 is not limited. Since it is possible to adjust the correction amount of distortion due to the influence of the projection optical axis angle θp by operating the distortion adjustment button 42b of the operation portion 42a, the distortion based on the image data 14 on the projection target surface It is possible to form a projection image without any image.

  As described above, the present invention has been described in detail based on the respective embodiments. However, the present invention is not limited to these specific configurations, and design changes that do not depart from the spirit of the present invention are included in the technical scope of the present invention.

  In each of the above-described embodiments, the main scanning direction is also resonantly driven. However, instead of creating an image by raster scanning, necessary pixels on the entire image surface are obtained by overlapping spot trajectories (Lissajous) by biaxial scanning. As an image forming method (for example, an image forming method described in Japanese Patent Publication No. 2005-526289), the sub-scanning direction may also be resonance driven. By using this method, both the main scanning direction and the sub-scanning direction can be resonantly driven, so that even with a small amount of energy, a large amplitude can be obtained in the main scanning direction and the sub-scanning direction. Projection is possible. Even in this case, in order to change the light emission timing of the light source 21 with respect to the rotation of the deflection optical element 25, the image processing unit 33 uses the coordinates (in the image data 14 (each pixel data G (x, y)) ( x, y) is converted into coordinates (X, Y) in the scanning region 13 using the correction conversion formula (1), whereby each pixel data G (x, y) is converted into pixel data G ′ (x If the configuration is such that the spot S is formed on the basis of the corrected pixel data G ′ (x ′, y ′), the same effect as in the above-described embodiments can be obtained. it can.

  In each of the above embodiments, the image projection device is mounted on the lid of the mobile phone. For example, the projection optical system in the image projection device is mounted on the lid of the mobile phone, and the control mechanism is mounted on the lid. May be provided as appropriate in the unit and / or the telephone body, and is not limited to the above-described embodiments.

  Further, in each of the above-described embodiments, the scanning region 13 is formed on the projection surface 11 by deflecting the monochromatic laser light emitted from the light source 21 by the deflecting optical element 25 in the image projection apparatus (10 or the like). The projection image 12 is formed on the projection surface 11 (scanning region 13). The projection surface 11 (scanning) is configured such that the light source emits light rays R of a plurality of colors (for example, three colors of RGB). A color projection image may be formed on the region 13), and is not limited to the above-described embodiments.

  In each of the above-described embodiments, the image processing unit 33 is formed by the correction calculation portion 34, the write conversion portion 35, and the memory 36, but the input image data 14 (each pixel data G (x, y)) ) Is appropriately corrected so that it can be appropriately formed as a projection image on the projection surface 11 of the screen Sc while using the distorted scanning region 13, more specifically, the projection light set to execute the image projection An image forming area 15 having the same shape (rectangular shape) as the rectangular image indicated by the image data 14 is set inward of the scanning area 13 on the projection surface 11 corresponding to the axial angle θp, and the deflection optical element 25 Only when the scanning position by rotation (driving) is positioned on the image forming area 15, the light emission amount control unit 32 controls the light source 21 to form a spot S having a light amount corresponding to the image data 14 on the projection surface 11. Drive system As to, it corrects the image data 14 may be any, but is not limited to the embodiments described above.

DESCRIPTION OF SYMBOLS 10, 102, 103, 104 Image projection apparatus 11 Projection surface 12 Projection image 13 Scanning area 14 Image data 15 Image formation area 20 Projection optical system 21 Light source 25 Deflection optical element 30 Control mechanism 36 Memory 40 (401 as a memory | storage part) , 402, 403, 404 Mobile phone 41, 412, 413 Cover portion (as a housing or first housing) 42, 422, 423 Phone body portion (as a second housing) 43, 443 Mounting surface 44 Gravity acceleration sensor (as tilt detection means) 45 Wall surface (as projection target) d coefficient Lb Reference optical axis S Spot Sc Screen (as projection target) θp Projection optical axis angle

Special table 2008-547054 gazette

Claims (5)

The projection is performed by deflecting the emitted light with a deflecting optical element so that the emitted light from the light source is imaged to form a spot on the projection surface and the spot is two-dimensionally scanned on the projection surface. A projection optical system that forms a scanning region on the surface;
A control mechanism for driving and controlling the deflection optical element and the light source based on image data in order to form a projection image on the projection surface by optical scanning with the projection optical system,
In the projection image, the control mechanism is distorted due to an influence of an optical characteristic in the projection optical system and a distortion due to an influence of a projection optical axis angle formed by a reference optical axis in the projection optical system and a normal direction of the projection plane. The image data is corrected using a correction conversion formula stored in a storage unit so as to change the amount of light emitted from the light source with respect to the scanning position by the deflecting optical element. Image projection device. The control mechanism has coordinates of each pixel in the image data as (x, y), and an image based on the image data, a reference optical axis set in the projection optical system, and a normal direction of the projection plane The scanning region of each pixel in a state adapted to an image forming region set in the same shape as the image indicated by the image data inside the scanning region on the projection surface according to the projection optical axis angle (X ′, y ′) and the coefficients d (d _{x1 to} d _x6 and d _{y1 to} d _y9 ) are coefficients that change only in accordance with the change in the projection optical axis angle. ,
The image projection apparatus according to claim 1, wherein the coefficient d corresponding to the projection optical axis angle is set and the image data is corrected using the following equation as the correction conversion equation.
^{_{x'= (d x1 y 2 +}} d x2 y + d x3) x + (d x4 y 2 + d x5 y + d x6)
y ′ = (d _y1 x ² + d _y2 x + d _y3 ) y ² + (d _y4 x ² + d _y5 x + d _y6 ) y
+ (D _y7 x ² + d _y8 x + d _y9 ) The image projector according to claim 1 or 2,
Furthermore, a housing that houses at least the projection optical system, and an inclination detection unit that detects an inclination of the housing with respect to a plane to be projected,
The image projection apparatus, wherein the control mechanism sets the projection optical axis angle based on a detection result from the tilt detection means. The image projector according to claim 1 or 2,
Furthermore, a first housing that houses at least the projection optical system, and a second housing that is connected to the first housing so as to be changeable in inclination with respect to the first housing and is placed on a plane to be projected. And a tilt detection means for detecting the tilt of the first housing with respect to the second housing,
The image projection apparatus, wherein the control mechanism sets the projection optical axis angle based on a detection result from the tilt detection means. The storage unit stores a plurality of combinations of the coefficients d,
The control mechanism obtains the projection optical axis angle and reads the coefficients corresponding to the obtained projection optical axis angle from the storage unit to thereby obtain the correction conversion formula corresponding to the obtained projection optical axis angle. Set
When each coefficient corresponding to the obtained projection optical axis angle is not stored in the storage unit, the coefficient corresponding to the projection angle closest to the obtained projection optical axis angle is read from the storage unit and corrected. The image projection apparatus according to claim 2, wherein a conversion equation is set, and a correction amount of distortion due to the influence of the projection optical axis angle is adjusted in accordance with an input adjustment signal.