JP2010230730A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, preventing trapezoidal distortion of an image without a sudden change in deviation angle around the central axis of rotation of a reflecting surface scanning in a first direction, while heightening time numerical aperture. <P>SOLUTION: This image forming apparatus 1 includes: a light emitting part configured to scan light on a projection surface 21 to thereby draw an image; an optical scanning part 5 having at least one reflecting surface and scanning the light on the projection surface 21 in a first direction and in a second direction; and an adjusting means for adjusting the deviation angle of the reflecting surface scanning in the first direction. The scanning in the second direction is performed in an outgoing path and a return path, and in each of scanning in the second direction in the outgoing path and return path, respectively, the scanning in the first direction is performed to draw an image. In scanning in the first direction, the adjusting means adjusts the deviation angle so that the deviation width in the first direction of the light on the projection surface 21 in the light emitting state of emitting light from the light emitting part is equal along the second direction as compared with the case where adjustment is not performed by the adjusting means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus.

Scan projectors of the two-mirror type (for example, a type that draws with two mirrors, a horizontal scanning mirror using resonance and a vertical scanning mirror such as a galvano mirror), emit light emitted from the light emitting unit to the projection surface. In addition to scanning in the horizontal direction (horizontal scanning: main scanning) and scanning in the vertical direction (vertical scanning: sub-scanning) at a scanning speed slower than the horizontal scanning speed, the projection surface An image (video) is drawn on top. The deflection angle (amplitude) about the rotation center axis of the horizontal scanning mirror is constant.
In such a scan projector, when drawing an image on the projection surface, distortion caused by the optical path difference to the projection surface, for example, in the horizontal direction (upper and lower sides of the image drawn on the projection surface) Since distortion called “trapezoidal distortion” having different lengths in the horizontal direction occurs, correction is necessary.

  By the way, as shown in FIG. 14, the light locus on the projection surface 21 when the light is two-dimensionally scanned on the projection surface in the light emission state where the light is emitted from the light emitting portion of the scan projector 300. Among the plurality of drawing lines (scanning lines) 141, the left side portion of the left drawing limit line and the right side portion of the right drawing limit line each have a low angular velocity (speed) of the horizontal scanning mirror, and drawing is performed. Not suitable for. For this reason, an area between the left drawing limit line and the right drawing limit line on the projection surface 21 is used as a drawable area 143 in which an image can be drawn, and the image is stored in the drawable area 143. A drawing area 142, which is a drawing area, is set. That is, the drawable area 143 is divided into a drawing area 142 that is an area where an image is drawn and a non-drawing area that is an area where an image is not drawn. The drawing area 142 is located at the center of the drawable area 143 and is set to form a rectangle (including a square). The right and left portions of the drawing area 142 are non-drawing areas.

  In order to prevent (correct) the trapezoidal distortion, normally, as described above, the rectangular drawing area 142 is set on the projection surface 21, and the light emitted from the light emitting portion is projected into the drawing area 142 ( The driving of the light emitting part is controlled so that the light is irradiated. That is, within the drawing area 142, every time corresponding to one pixel on the projection surface 21 according to the angle of the vertical scanning mirror and the angle of the horizontal scanning mirror (this time also depends on the drawing position, so the mirror angle In general, the light source is modulated and the image is corrected and displayed (pixel density correction).

  However, when viewed from the horizontal direction, the larger the angle (angle) formed by the optical axis of the light emitted from the scan projector 300 toward the projection surface 21 and the projection surface, the greater the distortion correction is required. . For example, as shown in FIG. 15, when projecting an image from the oblique direction in the vertical direction on the projection surface 21, the position farther from the scan projector 300 in the vertical direction is the horizontal direction of one drawing line 141. The length (the horizontal fluctuation width of the light on the projection surface in the light emitting state where light is emitted from the light emitting portion) is increased, thereby increasing the non-drawing area and the time aperture ratio (image drawing). The ratio of the period during which the light source is performed is reduced, the luminance per pixel is lowered, and the light source needs to be modulated at high speed.

As means for solving the above-described problem, a technique has been proposed in which the deflection angle (amplitude) about the rotation center axis of the horizontal scanning mirror is made variable and gradually changed (see, for example, Patent Document 1).
That is, as shown in FIG. 16, in the scan projector 300 of Patent Document 1, when scanning light onto the projection surface 21, the vertical position on the projection surface 21 where the light is scanned is from the scan projector 300. The farther away, the smaller the deflection angle of the horizontal scanning mirror is, and the trapezoidal distortion of the image is prevented.

Further, the scan projector 300 of Patent Document 1 performs one-side drawing for drawing an image only in the forward path (one side) of vertical scanning.
Further, since the operating frequency of the horizontal scanning mirror is high, an energy-efficient resonant drive type (using resonance) is usually used as the horizontal scanning mirror.

  However, since the scan projector 300 of Patent Document 1 performs one-sided drawing, as shown in FIG. 17, during the vertical blanking period, the deflection angle of the horizontal scanning mirror is from the maximum value to the minimum value (or minimum). Although it is necessary to change it abruptly (from the value to the maximum value), it is very difficult to change the deflection angle of the horizontal scanning mirror using resonance particularly rapidly and reliably.

In order to solve this problem, for example, the vertical blanking period may be lengthened. However, if the vertical blanking period is lengthened without changing the time of one frame, the period for drawing an image is shortened. In order to maintain the vertical resolution, it is necessary to increase the operating frequency of the horizontal scanning mirror, which makes it difficult to design the horizontal scanning mirror.
In addition, since the image is not drawn in the vertical blanking period, there is a problem that if the vertical blanking period is long, the time aperture ratio is lowered and the luminance per pixel is lowered.

JP 2007-199251 A

  An object of the present invention is to prevent trapezoidal distortion of an image without increasing a deflection angle around the rotation central axis of a reflecting surface that scans in a first direction while increasing a time aperture ratio. An object of the present invention is to provide an image forming apparatus capable of performing the above.

Such an object is achieved by the present invention described below.
The image forming apparatus of the present invention is configured to draw an image by scanning light on a projection surface,
A light emitting portion for emitting light;
Reflecting the light emitted from the light emitting part and having at least one reflecting surface rotatably provided, the light emitted from the light emitting part is directed to the projection surface in a first direction. An optical scanning unit that scans two-dimensionally by scanning in a second direction orthogonal to the first direction at a scanning speed slower than the scanning speed in the first direction;
Adjusting means for adjusting a swing angle about the rotation center axis of the reflecting surface that scans in the first direction;
Scanning in the second direction is performed in each of the forward path and the backward path, and scanning is performed in the first direction in each of the forward path and the backward path of the scanning in the second direction, and an image is drawn.
When performing the scanning in the first direction, the adjusting means is configured so that a fluctuation width in the first direction of light on the projection surface in a light emitting state in which light is emitted from the light emitting portion is the adjusting means. Compared to the case where the adjustment according to (1) is not performed, the deflection angle is adjusted so as to be aligned along the second direction.

This prevents trapezoidal distortion of the image without increasing the deflection angle (amplitude) about the rotation central axis of the reflecting surface that scans in the first direction while increasing the time aperture ratio. Can do.
That is, the adjusting means has a second direction in which the fluctuation width in the first direction of the light on the projection surface in the light emitting state in which light is emitted from the light emitting portion is not adjusted by the adjusting means. The deflection angle of the reflecting surface that scans in the first direction is adjusted so that the non-drawing area can be reduced, so that the trapezoidal distortion of the image can be reduced while increasing the time aperture ratio. Can be prevented.

  In each of the forward and backward scans in the second direction, the first direction scan is performed and an image is drawn. Therefore, when switching from the forward pass to the return pass in the second direction scan, or from the return pass to the forward pass When switching, it is not necessary to change the deflection angle of the reflecting surface that scans in the first direction abruptly, so that the deflection angle of the reflecting surface that scans in the first direction can be adjusted easily and reliably. it can.

  Further, since the image is drawn by performing the scanning in the first direction in each of the forward path and the backward path in the second direction, there is no blanking period in the second direction. The ratio of the display period can be reduced. Accordingly, when the image is drawn by performing scanning in the first direction only in the scanning path in the second direction and when the angular velocity (speed) of the reflecting surface scanned in the first direction is the same, only the traveling path is provided. As compared with the case of drawing an image, the number of frames (frame number) per unit time can be increased, and thereby, it is possible to easily cope with a fast movement in a moving image. In other words, when the image is drawn by scanning in the first direction only in the forward path of the second direction and when the number of frames per unit time is the same, the image is drawn only in the forward path As compared with the above, it is possible to reduce the angular velocity of the reflecting surface that scans in the first direction, thereby stably drawing an image.

In the image forming apparatus according to the aspect of the invention, the adjusting unit may be configured such that, in the light emitting state, the fluctuation width of the light on the projection surface in the first direction is constant along the second direction. It is preferable that the deflection angle is adjusted.
Thereby, the width | variety of a non-drawing area | region can be made smaller and, thereby, a time aperture ratio can be made higher.

In the image forming apparatus according to the aspect of the invention, the adjustment unit stores a calibration curve that stores a calibration curve indicating a relationship between a position of the light scanned on the projection plane in the second direction on the projection plane and the deflection angle. Having storage means;
It is preferable that the calibration curve is used to obtain a target value of the deflection angle based on a position in the second direction on the projection plane of light scanned on the projection plane.
Thereby, the trapezoid distortion of an image can be prevented easily and reliably.

The image forming apparatus of the present invention includes an angle detection unit that detects an angle of the reflection surface that scans in the first direction,
It is preferable that the adjustment unit is configured to adjust the deflection angle so that the deflection angle becomes the target value based on the detection result of the angle detection unit and the target value.
Thereby, the trapezoid distortion of an image can be prevented easily and reliably.

In the image forming apparatus according to the aspect of the invention, it is preferable that the optical scanning unit is configured to scan light on the same line of the projection plane in the forward path and the backward path of the scanning in the second direction.
As a result, it is possible to more reliably draw an image in each of the forward and backward scans in the second direction.
The image forming apparatus of the present invention has video data storage means for storing video data used when drawing an image,
The order of reading out the video data from the video data storage means is reversed between when the image is drawn in the forward path of the scanning in the second direction and when the image is drawn in the backward path of the scanning in the second direction. It is preferable that it is comprised so that it may become.
As a result, it is possible to more reliably draw an image in each of the forward and backward scans in the second direction.

In the image forming apparatus according to the aspect of the invention, the optical scanning unit is rotatably provided and has a movable plate having a reflecting surface that scans in the first direction, and a support unit that rotatably supports the movable plate. An actuator comprising: a connecting portion for connecting the movable plate and the support portion; and a driving means for rotating the movable plate;
It is preferable to include a galvanometer mirror having a reflecting surface that scans in the second direction.
As a result, the trapezoidal distortion of the image can be prevented without increasing the deflection angle about the rotation central axis of the reflecting surface that scans in the first direction, while increasing the time aperture ratio more reliably. be able to.
The image forming apparatus of the present invention preferably includes a screen having the projection surface.
Thereby, the visibility of an image improves.

1 is a diagram illustrating a first embodiment of an image forming apparatus of the present invention. FIG. 2 is a schematic perspective view showing an actuator of the image forming apparatus shown in FIG. 1. FIG. 2 is a schematic cross-sectional view showing driving of an actuator of the image forming apparatus shown in FIG. 1. It is a figure which shows the galvanometer mirror of the image forming apparatus shown in FIG. FIG. 2 is a block diagram illustrating an operation control unit, an optical scanning unit, and a light source unit of the image forming apparatus illustrated in FIG. 1. FIG. 2 is a diagram for explaining the operation of the image forming apparatus shown in FIG. 1 (a is a side view, and b is a front view). 2 is a graph showing a deflection angle (change in deflection angle with time) of a movable plate of an actuator during operation of the image forming apparatus shown in FIG. 1. 2 is a graph showing a mirror angle (change in angle with time) of a galvanometer mirror during operation of the image forming apparatus shown in FIG. 1. FIG. 2 is a diagram showing a modification of the image forming apparatus shown in FIG. 1 and its operation (a is a side view, and b is a front view). It is a typical top view showing an actuator with which an image drawing device concerning a 2nd embodiment of the present invention is provided. It is the BB sectional view taken on the line in FIG. It is a block diagram which shows the voltage application means of the drive means with which the actuator shown in FIG. 10 is provided. It is a figure which shows an example of the voltage which generate | occur | produces in the 1st voltage generation part shown in FIG. 12, and a 2nd voltage generation part. It is a figure for demonstrating operation | movement of the conventional scan projector (a is a side view, b is a front view). It is a figure for demonstrating operation | movement of the conventional scan projector (a is a side view, b is a front view). It is a figure for demonstrating operation | movement of the conventional scan projector (a is a side view, b is a front view). It is a graph which shows the deflection angle (change with time of a deflection angle) of the mirror for horizontal scanning during operation | movement of the conventional scanning projector shown in FIG. FIG. 10 is a diagram for explaining the operation of the image forming apparatus according to the second embodiment of the present invention (a is a side view, and b is a front view).

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an image forming apparatus of the invention will be described with reference to the accompanying drawings. In the present embodiment, the first direction is typically described as “horizontal direction” and the second direction as “vertical direction”.
<First Embodiment>
First, a first embodiment of the image forming apparatus of the present invention will be described.

1 is a diagram illustrating a first embodiment of an image forming apparatus according to the present invention, FIG. 2 is a schematic perspective view illustrating an actuator of the image forming apparatus illustrated in FIG. 1, and FIG. 3 is an image forming apparatus illustrated in FIG. FIG. 4 is a diagram showing a galvano mirror of the image forming apparatus shown in FIG. 1, and FIG. 5 is an operation control unit, an optical scanning unit, and a light source of the image forming apparatus shown in FIG. It is a block diagram which shows a unit. 6 is a view for explaining the operation of the image forming apparatus shown in FIG. 1, FIG. 6 (a) is a side view, and FIG. 6 (b) is a front view. 7 is a graph showing the deflection angle of the movable plate of the actuator during operation of the image forming apparatus shown in FIG. 1 (change over time in the deflection angle), and FIG. 8 is during operation of the image forming apparatus shown in FIG. It is a graph which shows the angle (change with time of an angle) of the mirror of this galvanometer mirror. FIG. 9 is a diagram showing a modification of the image forming apparatus shown in FIG. 1 and its operation. FIG. 9A is a side view, and FIG. 9B is a front view. Hereinafter, for convenience of explanation, the upper side in FIGS. 2, 3, 6, and 9 is referred to as “upper”, the lower side as “lower”, the right side as “right”, and the left side as “left”.
As shown in FIG. 1, an image forming apparatus 1 includes a screen (object) 2 and an image forming apparatus main body 3 that scans light on the screen 2 to form (draw) (project) an image (video). Have. Hereinafter, these will be sequentially described.

The surface of the screen 2 on the image forming apparatus main body 3 side constitutes an optical scanning surface on which light is scanned by the image forming apparatus main body 3, that is, a projection surface 21. A predetermined image such as a still image or a moving image is drawn on the projection surface 21 by scanning light with the image forming apparatus main body 3. By using such a screen 2, the visibility of the image is improved.
The constituent material of the screen 2 is not particularly limited, and for example, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyamide, acrylic resin, ABS resin, fluorine resin, epoxy resin, silicone resin, or these are mainly used. Copolymers, blends, polymer alloys and the like can be mentioned, and one or more of these can be used in combination.

Next, the image forming apparatus main body 3 will be described.
As shown in FIG. 1, the image forming apparatus main body 3 includes a light source unit (light emitting unit) 4 that emits light, a light scanning unit 5 that scans light emitted from the light source unit 4 with respect to the projection surface 21, and It has an operation control device (control means) 8 for controlling the operation (drive) of the light source unit 4 and the optical scanning unit 5.

As shown in FIG. 1, the light source unit 4 includes laser light sources 41r, 41g, 41b for each color, collimator lenses 42r, 42g, 42b and dichroic mirrors provided corresponding to the laser light sources 41r, 41g, 41b for each color. 43r, 43g, 43b.
As shown in FIG. 5, each color laser light source 41r, 41g, 41b has drive circuits 410r, 410g, 410b, a red light source 420r, a green light source 420g, and a blue light source 420b, respectively. As shown in FIG. 1, red, green, and blue laser beams RR, GG, and BB are emitted. The laser beams RR, GG, and BB are emitted in a modulated state corresponding to drive signals transmitted from a light source modulation unit 84 (to be described later) of the operation control device 8, and collimator lenses 42r that are collimating optical elements, The beams are collimated by 42g and 42b to form a thin beam.

The dichroic mirrors 43r, 43g, and 43b have characteristics of reflecting the red laser beam RR, the green laser beam GG, and the blue laser beam BB, respectively, and combine the laser beams RR, GG, and BB of the respective colors into one laser beam. (Light) LL is emitted.
A collimator mirror can be used in place of the collimator lenses 42r, 42g, and 42b. In this case as well, a narrow beam of parallel light beams can be formed. Further, when parallel light beams are emitted from the laser light sources 41r, 41g, and 41b of the respective colors, the collimator lenses 42r, 42g, and 42b can be omitted. Further, the laser light sources 41r, 41g, and 41b can be replaced with light sources such as light emitting diodes that generate similar light beams. In addition, the order of the laser light sources 41r, 41g, 41b, the collimator lenses 42r, 42g, 42b, and the dichroic mirrors 43r, 43g, 43b in FIG. , Collimator lens 42r, dichroic mirror 43r, green is laser light source 41g, collimator lens 42g, dichroic mirror 43g, blue is laser light source 41b, collimator lens 42b, dichroic mirror 43b) and the order is freely set it can. For example, a combination of blue, red, and green is also possible in the order closer to the optical scanning unit 5.

Next, the optical scanning unit 5 will be described.
The optical scanning unit 5 scans the laser light LL emitted from the light source unit 4 in the horizontal direction (first direction) with respect to the projection surface 21 (horizontal scanning: main scanning) and is slower than the horizontal scanning speed. Two-dimensional scanning is performed by scanning (vertical scanning: sub-scanning) in the vertical direction (second direction orthogonal to the first direction) at the scanning speed. The optical scanning unit 5 includes an actuator (first direction scanning unit) 51 that is a horizontal scanning mirror that scans the projection surface 21 with the laser light LL emitted from the light source unit 4 in the horizontal direction, and an actuator 51 described later. The angle detection means (behavior detection means) 52 for detecting the angle (behavior) of the movable plate 511a (reflection surface of the light reflecting portion 511e), and the laser light LL emitted from the light source unit 4 in the direction perpendicular to the projection plane 21 Angle detection means (behavior) for detecting the angle (behavior) of a galvano mirror (second direction scanning unit) 12 that is a vertical scanning mirror that scans the galvano mirror and a later-described mirror 121 (reflection surface of the mirror 121) of the galvano mirror 12 Detection means) 13.

As shown in FIG. 2, the actuator 51 is a so-called resonance driven type (using resonance), and is a so-called one-degree-of-freedom vibration system, and faces the base 511 and the lower surface of the base 511. And a spacer member 512 provided between the base body 511 and the counter substrate 513.
The base 511 includes a movable plate 511a, a support portion 511b that rotatably supports the movable plate 511a, and a pair of connecting portions 511c and 511d that connect the movable plate 511a and the support portion 511b.

  The movable plate 511a has a substantially rectangular shape in plan view. A light reflecting portion (mirror) 511e having light reflectivity is provided on the upper surface of the movable plate 511a. The surface (upper surface) of the light reflecting portion 511e constitutes a reflecting surface (first reflecting surface) that reflects light. The light reflecting portion 511e is made of a metal film such as Al or Ni, for example. A permanent magnet 514 is provided on the lower surface of the movable plate 511a.

The support portion 511b is provided so as to surround the outer periphery of the movable plate 511a in a plan view of the movable plate 511a. That is, the support portion 511b has a frame shape, and the movable plate 511a is located inside thereof.
The connecting portion 511c connects the movable plate 511a and the support portion 511b on the left side of the movable plate 511a, and the connecting portion 511d connects the movable plate 511a and the support portion 511b on the right side of the movable plate 511a. Yes.

Each of the connecting portions 511c and 511d has a longitudinal shape. Further, each of the connecting portions 511c and 511d can be elastically deformed. The pair of connecting portions 511c and 511d are provided coaxially with each other, and the movable plate 511a supports the shaft (hereinafter referred to as “rotation center axis J”) as a center (rotation center). It rotates with respect to the part 511b.
Such a substrate 511 is made of, for example, silicon as a main material, and a movable plate 511a, a support portion 511b, and connection portions 511c and 511d are integrally formed. As described above, by using silicon as a main material, it is possible to realize excellent rotation characteristics and to exhibit excellent durability. Further, fine processing (processing) is possible, and the actuator 51 can be downsized.

The spacer member 512 has a frame shape, and its upper surface is joined to the lower surface of the base 511. The spacer member 512 is substantially equal to the shape of the support portion 511b in the plan view of the movable plate 511a. Such a spacer member 512 is made of, for example, various glasses, various ceramics, silicon, SiO ₂ or the like.
The method for joining the spacer member 512 and the substrate 511 is not particularly limited. For example, the spacer member 512 may be joined via another member such as an adhesive, or anodic bonding may be used depending on the constituent material of the spacer member 512. May be used.

Similar to the spacer member 512, the counter substrate 513 is made of, for example, various types of glass, silicon, SiO ₂ or the like. A coil 515 is provided on the upper surface of the counter substrate 513 and on a portion facing the movable plate 511a.
The permanent magnet 514 has a plate bar shape and is provided along the lower surface of the movable plate 511a. Such a permanent magnet 514 is magnetized (magnetized) in a direction orthogonal to the rotation center axis (first rotation center axis) J in a plan view of the movable plate 511a. That is, the permanent magnet 514 is provided so that a line segment connecting both poles (S pole and N pole) is orthogonal to the rotation center axis J. As shown in FIG. 3, in the present embodiment, the left side of the rotation center axis J is an N pole, and the right side is an S pole.
The permanent magnet 514 is not particularly limited, and for example, a neodymium magnet, a ferrite magnet, a samarium cobalt magnet, an alnico magnet, or the like can be used.
The coil 515 is provided so as to surround the outer periphery of the permanent magnet 514 in a plan view of the movable plate 511a.

  In addition, the actuator 51 includes voltage application means (drive circuit) 516 that applies a voltage to the coil 515. The voltage application unit 516 is configured to be able to adjust (change) each condition such as the voltage value and frequency of the voltage to be applied. The voltage applying unit 516, the coil 515, the permanent magnet 514, and the like constitute a driving unit 517 that rotates the movable plate 511a.

A predetermined voltage is applied to the coil 515 from the voltage applying unit 516 under the control of the operation control device 8, and a predetermined current flows.
For example, when an alternating voltage is applied from the voltage application unit 516 to the coil 515 under the control of the operation control device 8, a current flows accordingly, and a magnetic field in the thickness direction of the movable plate 511a (up and down direction in FIG. 3) is generated. And the direction of the magnetic field is periodically switched. That is, a state A in which the vicinity of the upper side of the coil 515 is the S pole and the vicinity of the lower side is an N pole, and a state B in which the vicinity of the upper side of the coil 515 is the N pole and the vicinity of the lower side is an S pole are alternately switched.

In the state A, as shown in FIG. 3A, the right side of the permanent magnet 514 is displaced upward by a repulsive force with the magnetic field generated by energizing the coil 515, and the left side of the permanent magnet 514 is the magnetic field. It is displaced downward by the suction force. Thereby, the movable plate 511a rotates counterclockwise and tilts.
On the contrary, in the state B, as shown in FIG. 3B, the right side of the permanent magnet 514 is displaced downward and the left side of the permanent magnet 514 is displaced upward. As a result, the movable plate 511a rotates clockwise and tilts.

By alternately repeating the state A and the state B, the movable plate 511a rotates (vibrates) around the rotation center axis J while twisting and deforming the connecting portions 511c and 511d.
Also, the current applied can be adjusted by adjusting the voltage applied from the voltage application means 516 to the coil 515 under the control of the operation control device 8, whereby the movable plate 511 a (the reflecting surface of the light reflecting portion 511 e). The swing angle (amplitude) about the rotation center axis J) can be adjusted. Therefore, the voltage application means 516 and the operation control device 8 constitute the main part of the adjustment means that adjusts the deflection angle about the rotation center axis J of the movable plate 511a. In the present embodiment, this adjustment means adjusts the deflection angle according to the angle of a mirror 121 (reflecting surface of the mirror 121) described later of the galvanometer mirror 12. The deflection angle is a maximum angle when the movable plate 511a rotates clockwise (predetermined direction) and a maximum angle when the movable plate 511a subsequently rotates counterclockwise (opposite direction). It is a difference.
The configuration of the actuator 51 is not particularly limited as long as the movable plate 511a can be rotated. For example, the driving method is replaced with electromagnetic driving using the coil 515 and the permanent magnet 514. For example, piezoelectric driving using a piezoelectric element or electrostatic driving using electrostatic attraction may be used.

  As shown in FIG. 4, the galvanometer mirror 12 has a reflection surface (second reflection surface) that reflects light on the surface, and rotates about a rotation center axis (second rotation center axis) Ja. A mirror 121 provided in a possible manner, and a drive unit 124 having a motor (drive source) 122 for rotating the mirror 121 and a drive circuit 123 for the motor 122 are provided. In the galvano mirror 12, the motor 122 repeats forward rotation and reverse rotation alternately by the drive circuit 123, whereby the mirror 121 rotates (vibrates) around the rotation center axis Ja.

  As shown in FIG. 1, the actuator 51 and the galvanometer mirror 12 are provided so that their rotation center axes J and Ja are orthogonal to each other. By providing the actuator 51 and the galvanometer mirror 12 in this manner, the laser light LL emitted from the light source unit 4 can be scanned two-dimensionally (in two directions orthogonal to each other) on the projection plane 21. Thereby, a two-dimensional image can be drawn on the projection surface 21 with a relatively simple configuration.

The light emitted from the light source unit 4 is reflected by the reflecting surface of the light reflecting portion 511e of the actuator 51, then reflected by the reflecting surface of the mirror 121 of the galvanometer mirror 12, and projected (irradiated) on the projection surface 21 of the screen 2. The Then, while rotating the light reflecting portion 511e (simultaneously) and rotating the mirror 121 at an angular velocity slower than the angular velocity (speed), the laser light LL emitted from the light source unit 4 is directed to the projection surface 21. In addition to being scanned in the horizontal direction (simultaneously), it is scanned in the vertical direction at a scanning speed slower than the horizontal scanning speed. Thereby, the laser beam LL emitted from the light source unit 4 is scanned two-dimensionally with respect to the projection surface 21, and an image is drawn on the projection surface 21.
The light emitted from the light source unit 4 may be first reflected by the reflecting surface of the mirror 121 of the galvano mirror 12 and then reflected by the reflecting surface of the light reflecting portion 511e of the actuator 51. . That is, it may be configured such that the vertical scanning is performed first and then the horizontal scanning is performed.

Next, the angle detection means 52 for detecting the angle of the movable plate 511a (the reflection surface of the light reflecting portion 511e) of the actuator 51 will be described.
As shown in FIG. 2, the angle detection means 52 includes a piezoelectric element 521 provided on the connecting portion 511 c of the actuator 51, an electromotive force detection unit 522 that detects an electromotive force generated from the piezoelectric element 521, and an electromotive force detection. And an angle detection unit (behavior detection unit) 523 that obtains (detects) an angle (behavior) of the movable plate 511a based on the detection result of the unit 522.

  When the connecting portion 511c is torsionally deformed as the movable plate 511a rotates, the piezoelectric element 521 is deformed accordingly. When the piezoelectric element 521 is deformed from a natural state to which no external force is applied, the piezoelectric element 521 has a property of generating an electromotive force having a magnitude corresponding to the deformation amount. Therefore, the angle detection unit 523 includes the electromotive force detection unit 522. The degree of twist of the connecting portion 511c is obtained on the basis of the magnitude of the electromotive force detected in Step 1, and the angle (rotation angle) of the movable plate 511a (the reflection surface of the light reflecting portion 511e) is determined from the degree of twist. Ask. In addition, the angle detection unit 523 obtains a deflection angle around the rotation center axis J of the movable plate 511a. A signal including information on the angle and deflection angle of the movable plate 511 a is transmitted from the angle detection unit 523 to the operation control device 8.

Note that the angle of the movable plate 511a to be detected may be set to an angle based on any state of the actuator 51 (the angle is 0 °). For example, the initial state of the actuator 51 (coil 515). The angle when the voltage is not applied to the reference (angle 0 °) can be set.
Further, the detection of the angle of the movable plate 511a may be performed in real time (continuously) or intermittently. Needless to say, the angle detection means 52 is not limited to the one using the piezoelectric element as in the present embodiment as long as the angle of the movable plate 511a can be detected.

Next, the angle detection means 13 for detecting the angle of the mirror 121 (the reflecting surface of the mirror 121) of the galvanometer mirror 12 will be described.
As shown in FIG. 4, the angle detection means 13 receives an encoder 131 provided in the galvano mirror 12 and a signal sent from the encoder 131, and the angle (behavior) of the mirror 121 based on information included in the signal. And an angle detection unit (behavior detection unit) 132 for (detecting).

  When the mirror 121 is rotated by the operation of the driving unit 124, a signal is transmitted from the encoder 131 to the angle detection unit 132 accordingly. The angle detection unit 132 obtains the angle (rotation angle) of the mirror 121 based on information included in the signal transmitted from the encoder 131. A signal including information on the angle of the mirror 121 is transmitted from the angle detection unit 132 to the operation control device 8.

The angle of the mirror 121 to be detected may be set to an angle when any state of the galvano mirror 12 is used as a reference (angle is 0 °).
The angle of the mirror 121 may be detected in real time (continuously) or intermittently. Needless to say, the angle detection means 13 is not limited to the one using the encoder as in the present embodiment as long as the angle of the mirror 121 can be detected.

Next, the operation control device 8 will be described.
As shown in FIG. 5, the operation control device 8 includes a video data storage unit (video data storage unit) 81 that stores video data (image data) used when drawing an image, a video data calculation unit 82, A drawing timing generation unit 83, a light source modulation unit (light modulation unit) 84, a deflection angle calculation unit (amplitude calculation unit) 85, an angle instruction unit 86, and a calibration curve storage unit (a calibration curve storage unit) that stores a calibration curve 87).

  The image forming apparatus 1 performs scanning in the vertical direction (second direction) (hereinafter, also simply referred to as “vertical scanning”) in each of the forward path and the backward path, and in the horizontal direction ( An image is drawn by performing scanning in the first direction (hereinafter also simply referred to as “horizontal scanning”) in each of the forward path and the backward path, and laser light (light) LL is emitted from the light source unit 4 when performing horizontal scanning. The horizontal deflection width of the laser beam LL on the projection surface 21 (hereinafter also simply referred to as “the deflection width of the laser beam (light) LL”) in the light emission state (hereinafter also simply referred to as “light emission state”). However, compared with the case where the adjustment (adjustment by the adjusting means) of the deflection angle (hereinafter, also simply referred to as “the deflection angle of the movable plate 511a”) around the rotation center axis J of the movable plate 511a is not performed. To align along It is configured to adjust the swing angle of the movable plate 511a. In particular, it is preferable that the deflection angle of the movable plate 511a is adjusted so that the deflection width of the laser beam LL is constant along the vertical direction in the light emission state. As a result, it is possible to prevent the trapezoidal distortion of the image while increasing the time aperture ratio. In the present embodiment, a description will be given of a case where the deflection width is typically adjusted to be constant along the vertical direction.

  The deflection width is the position of the laser beam LL on the projection surface 21 when the movable plate 511a is rotated clockwise (predetermined direction) to the maximum angle in the light emitting state, and subsequently the movable plate. The horizontal distance (interval) from the position of the laser beam LL on the projection plane 21 when 511a is rotated counterclockwise (in the opposite direction) to the maximum angle, that is, as shown in FIG. When the laser beam LL is two-dimensionally scanned on the projection surface 21 in the light emitting state, the horizontal direction of each of a plurality of drawing lines (scanning lines) 141 that are the locus of the laser beam LL on the projection surface 21 Is the length of

  As shown in FIG. 6, the plurality of drawing lines 141 are arranged in a zigzag manner. Of each drawing line 141, the left end portion and the right end portion each have a small angular velocity (speed) of the mirror 121 and are not suitable for drawing. Therefore, except for the left end portion and the right end portion, A drawing area that is an area for drawing an image is set. The drawing area is set so as to form a rectangle (including a square), for example.

  When the swing angle of the movable plate 511a is constant, the swing width of the laser light LL in the light emission state changes according to the angle of the mirror 121, and the vertical direction on the projection surface 21 on which the laser light LL light is scanned. Is longer as the position (the position in the vertical direction of the drawing line 141) is farther from the image forming apparatus main body 3. Therefore, in this image forming apparatus 1, the deflection angle of the movable plate 511 a is adjusted according to the angle of the mirror 121. In other words, the deflection angle of the movable plate 511a is reduced as the vertical position (the vertical position of the drawing line 141) on the projection surface 21 scanned with the laser light LL is farther from the image forming apparatus main body 3. The fluctuation width of the laser beam LL in the light emission state is made constant along the vertical direction.

  The calibration curve storage unit 87 stores the vertical position (drawing line) of the laser beam LL on the projection plane 21 that scans the projection plane 21 where the fluctuation width of the laser beam LL is constant along the vertical direction in the light emission state. A calibration curve such as a table or an arithmetic expression (function) showing the relationship between the position of the movable plate 511a and the deflection angle of the movable plate 511a is stored (stored). When drawing an image, the calibration curve is used to determine the target value (target deflection angle) of the deflection angle based on the vertical position on the projection plane 21 of the laser light LL that scans the projection plane 21. The calibration curve can be obtained by calculation and is stored in advance in the calibration curve storage unit 87.

  In the image forming apparatus 1, in the drawing area 142, the vertical spacing between adjacent drawing lines 141 is constant for each odd-numbered drawing line 141 from the upper side. With respect to the drawing lines 141, it is preferable to adjust the angle and angular velocity of the mirror 121 so that the vertical spacing between adjacent drawing lines 141 is constant. Thereby, the distortion of the image in the vertical direction can be prevented.

  In the present embodiment, for example, at the left end and the right end of the drawing area 142 at the start of drawing of each drawing line 141, the vertical spacing between adjacent drawing lines 141 is constant. The angle of the mirror 121 is adjusted, and the angular velocity of the mirror 121 is set to a predetermined value. That is, for each drawing line 141, the angle of the mirror 121 is adjusted so that the vertical interval between adjacent drawing start points is constant, and the angular velocity of the mirror 121 is set to a constant value for each drawing line 141. . The angular velocity of the mirror 121 is set to be smaller as the vertical position of the drawing line 141 is farther from the image forming apparatus body 3. Thereby, it is possible to prevent distortion of the image in the vertical direction with relatively simple control.

Next, the operation (action) of the image forming apparatus 1 when an image is drawn on the projection surface 21 of the screen 2 will be described.
First, video data is input to the image forming apparatus main body 3. The input video data is temporarily stored in the video data storage unit 81, read from the video data storage unit 81, and an image is drawn using the video data. In this case, the drawing of the image may be started after all of the video data is stored in the video data storage unit 81, and after a part of the video data is stored in the video data storage unit 81, Drawing may be started, and the subsequent video data may be stored in the video data storage unit 81 in parallel with the drawing of the image.

  When drawing of an image is started after a part of the video data is stored in the video data storage unit 81, video data for at least one frame, preferably two frames or more (for example, two frames) is first used. Is stored in the video data storage unit 81, and then image drawing is started. This is because the image forming apparatus 1 draws an image by performing horizontal scanning in each of the forward and backward passes of the vertical scanning (hereinafter, also simply referred to as “reciprocating drawing in the vertical direction”), as will be described later. The drawing order of the video data from the video data storage unit 81 is reversed between when the image is drawn in the scanning forward path and when the image is drawn in the vertical scanning backward path, so that the image drawing is performed in the vertical scanning backward path. This is because at least one frame of video data used for drawing an image on the return path needs to be stored in the video data storage unit 81 in order to read the video data from the opposite side when starting the video.

The drawing timing generation unit 83 generates drawing timing information and drawing line information, respectively. The drawing timing information is sent to the video data calculation unit 82, and the drawing line information is sent to the deflection angle calculation unit 85.
The drawing timing information includes drawing timing information and the like. Further, the drawing line information includes information on the position (angle of the mirror 121) in the vertical direction of the drawing line 141 on which drawing is performed. Note that the position of any part of the drawing line 141 may be set as the vertical position of the drawing line 141, and examples include the left end, the right end, and the center.

Based on the drawing timing information input from the drawing timing generation unit 83, the video data calculation unit 82 reads the video data corresponding to the pixel to be drawn from the video data storage unit 81, performs various correction calculations, and the like. The luminance data of each color is sent to the light source modulator 84.
The light source modulation unit 84 modulates the light sources 420r, 420g, and 420b via the drive circuits 410r, 410g, and 410b based on the luminance data of each color input from the video data calculation unit 82. That is, the light sources 420r, 420g, and 420b are turned on / off, the output is adjusted (increased / decreased), and the like.

  The angle detection means 52 on the actuator 51 side detects the angle and swing angle of the movable plate 511a, and uses the angle and swing angle information (angle information of the movable plate 511a) as the drawing timing generation unit 83 of the operation control device 8 and This is sent to the deflection angle calculation unit 85. Further, the angle detection means 13 on the galvano mirror 12 side detects the angle of the mirror 121 and sends the angle information (angle information of the mirror 121) to the angle instruction unit 86 of the operation control device 8.

  When the drawing of the current drawing line 141 is completed and the information on the deflection angle of the movable plate 511a is input from the angle detection unit 52, the drawing timing generation unit 83 synchronizes with the angle indication unit 86 and then Target angle information (angle instruction) indicating the target angle of the mirror 121 when the laser beam LL is irradiated to the drawing start point of the drawing line 141 for drawing is sent. The target angle of the mirror 121 is set so that the vertical interval between adjacent drawing start points is constant. The angle instruction unit 86 compares the angle of the mirror 121 detected by the angle detection unit 13 with the target angle of the mirror 121, performs correction so that the difference is zero, and drives the galvano mirror 12 Drive data is sent to 124.

The driving unit 124 drives the motor 122 based on the driving data. Accordingly, when the drawing start point is irradiated with the laser beam LL, the angle of the mirror 121 becomes the target angle.
In this embodiment, in each drawing line 141, the angular velocity of the mirror 121 may be constant from the drawing start point to the drawing end point, and the vertical scanning speed of the laser beam LL may be constant. The angular velocity may be gradually changed, and the scanning speed in the vertical direction of the laser beam LL may be gradually changed.

Further, the drawing timing generation unit 83 sends drawing line information, that is, information on the position of the drawing line 141 in the vertical direction to be drawn next, to the deflection angle calculation unit 85.
The deflection angle calculation unit 85 uses the calibration curve read from the calibration curve storage unit 87, and based on the vertical position information of the drawing line 141 to be drawn next input from the drawing timing generation unit 83. Next, the target deflection angle of the movable plate 511a in the drawing line 141 for drawing is obtained. Then, based on the information on the swing angle of the movable plate 511a input from the angle detection means 52 and the target swing angle of the movable plate 511a, the actuator 51 so that the swing angle of the movable plate 511a becomes the target swing angle. The driving data is sent to the driving means 517.

  Based on the driving data, the driving means 517 applies an effective voltage having the same frequency as the resonance frequency of the actuator 51 to the coil 515 to cause a current to flow, generates a predetermined magnetic field, and determines the magnitude of the effective current and the actuator 51. By changing the phase difference from the drive waveform, energy is supplied to the actuator 51, and conversely, energy is taken away from the actuator 51. As a result, the deflection angle of the movable plate 511a that is in resonance is the target deflection angle. In this way, based on the information (detection result) of the deflection angle of the movable plate 511a detected by the angle detection means 52 and the target deflection angle (target value), the deflection angle of the movable plate 511a is the target deflection angle. The laser beam LL is sequentially scanned on each drawing line 141 in the drawing area 142 while adjusting the deflection angle of the movable plate 511a so as to draw an image.

  In addition, the drawing timing generation unit 83 manages whether a frame to be drawn is an odd frame (odd number frame) or an even number frame (even number frame). The moving direction (moving direction) and the reading order of the video data from the video data storage unit 81 are determined. That is, the video data reading order is reversed between when an image is drawn in an odd frame (vertical scanning forward path) and when an image is drawn in an even frame (vertical scanning backward path).

Further, the laser beam LL is scanned on the same line on the projection surface 21 in the odd frame and the even frame. That is, the laser beam LL is scanned so that each drawing line 141 of the odd frame matches each drawing line 141 of the even frame.
Specifically, for example, as shown in FIG. 6, for the first frame (odd-numbered frame), the drawing starts from the upper left, draws to the lower right zigzag, and the second frame (even-numbered frame) For the frame), the rotation direction of the mirror 121 is reversed, and drawing is performed from the lower right to the upper left in the opposite direction. Thereafter, similarly, the odd-numbered frame is drawn from the upper left to the lower right, and the even-numbered frame is drawn from the lower right to the upper left.

In this embodiment, the vertical scanning forward path is an odd frame and the vertical scanning backward path is an even frame. However, the present invention is not limited to this, and the vertical scanning backward path is an odd frame. The scanning forward path may be an even frame.
In the present embodiment, the drawing start position for the first frame is at the upper left, but is not limited thereto, and may be, for example, the upper right, the lower left, the lower right, or the like.
Further, the laser beam LL may be scanned on different lines on the projection surface 21 in the odd-numbered frame and the even-numbered frame.

Here, the change with time of the deflection angle of the movable plate 511a and the change with time of the angle of the mirror 121 during the drawing of the image are as follows.
In horizontal scanning, as shown in FIG. 7, the deflection angle of the movable plate 511a gradually increases from the minimum deflection angle, reaches the maximum deflection angle, gradually decreases, reaches the minimum deflection angle, and then again. The operation is gradually increased, and thereafter the operation is repeated in the same manner.

As described above, in this image forming apparatus 1, the swing angle of the movable plate 511a does not change abruptly. Therefore, the swing angle of the movable plate 511a of the actuator 51 configured to operate by using resonance is easily and reliably adjusted. be able to.
In the vertical scanning, as shown in FIG. 8, the display period (drawing period) in which an image is drawn in an odd frame (vertical scanning forward path) and the image in an even frame (vertical scanning backward path). A non-display period (non-drawing period) in which an image is not drawn is provided between a display period in which drawing is performed. In this display period, each timing such as a timing for starting drawing of the next frame can be adjusted.

Since the image is drawn both in the forward and backward passes of the scanning in the vertical direction, that is, when the mirror 121 is rotated in a predetermined direction and when it is rotated in the opposite direction, the conventional method is used. A vertical blanking period becomes unnecessary, and the non-display period can be shortened. Thereby, a time aperture ratio (ratio of the period which draws an image) can be made high.
In other words, the vertical non-display period in one frame can be shortened by reciprocatingly drawing, thereby increasing the vertical time aperture ratio and drawing an image by performing horizontal scanning only in the forward path of vertical scanning. When the angular velocity (velocity) of the movable plate 511a is the same as the case, the number of frames (frame number) per unit time can be increased compared to the case where an image is drawn only on the forward path. It can easily cope with movement. In other words, when the image is drawn by performing horizontal scanning only in the forward path of the vertical scanning and when the number of frames per unit time is the same, the angular velocity of the movable plate 511a is larger than when the image is drawn only in the forward path. Can be made smaller, whereby an image can be stably drawn. In the above case, when the angular velocity of the movable plate 511a is not changed, drawing with higher vertical resolution is possible.
Here, in practice, for example, the inertia (moment of inertia) of the movable plate 511a of the actuator 51 is large, and the movable plate 511a may not instantaneously follow. In such a case, for example, the drive current of the actuator 51 may be set to zero, or the actuator 51 may be driven in reverse phase (braking).

As described above, according to the image forming apparatus 1, it is possible to prevent the trapezoidal distortion of the image without increasing the deflection angle of the movable plate 511a while increasing the time aperture ratio.
In addition, since the image is drawn by performing horizontal scanning in each of the forward and backward passes of vertical scanning, the swing angle of the mirror 121 is abruptly changed when switching from the forward pass to the return pass in vertical scanning or when switching from the return pass to the return pass. This eliminates the need to change, and thus the swing angle of the mirror 121 can be adjusted easily and reliably.

Next, a modified example will be described based on FIG.
In the image forming apparatus 1 shown in FIG. 9, the fluctuation width of the laser light LL is not constant along the vertical direction in the light emission state, but the fluctuation width of the laser light LL in the light emission state is that of the movable plate 511a. Compared to the case where the deflection angle is not adjusted, the deflection angle of the movable plate 511a is adjusted so as to be aligned along the vertical direction. As a result, the width on the upper side of the drawable area 143 where the image can be drawn decreases, the shape of the drawable area 143 approaches a rectangle (including a square), and the non-drawn area can be reduced.

In the image forming apparatus 1, a rectangular drawing area 142 is set on the projection surface 21, that is, in the drawable area 143, and the laser light LL emitted from the light source unit 4 is projected (irradiated) into the drawing area 142. Thus, the drive of the light source unit 4 is controlled. Thereby, the trapezoid distortion of an image can be prevented.
If the inertia of the movable plate 511a of the actuator 51 is relatively large, the fluctuation width of the laser light LL in the light emitting state may not be constant along the vertical direction. As described above, the deflection of the movable plate 511a is more uniform in the vertical direction than the case where the deflection angle of the movable plate 511a is not adjusted, in the light emission state. By adjusting the angle, the time aperture ratio can be increased.

<Second Embodiment>
Next, a second embodiment of the image forming apparatus of the present invention will be described.
10 is a schematic plan view showing an actuator provided in the image drawing apparatus according to the second embodiment of the present invention, FIG. 11 is a sectional view taken along line BB in FIG. 10, and FIG. 12 is an actuator shown in FIG. FIG. 13 is a block diagram showing the voltage application means of the drive means provided in FIG. 13, FIG. 13 is a diagram showing an example of the voltage generated in the first voltage generator and the second voltage generator shown in FIG. 12, and FIG. It is a figure for demonstrating the operation | movement in the odd-numbered frame of the image drawing apparatus which concerns on 2nd Embodiment, Fig.18 (a) is a side view, FIG.18 (b) is a front view. In the following, for convenience of explanation, the front side of the page in FIG. 10 is referred to as “up”, the back side of the page is referred to as “down”, the right side is referred to as “right”, and the left side is referred to as “left”. The upper side, the lower side is called “lower”, the right side is called “right”, and the left side is called “left”.

Hereinafter, the image display apparatus according to the second embodiment will be described focusing on the differences from the first embodiment described above, and description of similar matters will be omitted.
The image forming apparatus according to the second embodiment is different from the first embodiment except that the configuration of the actuator provided in the optical scanning unit is different and that the trajectory of scanning (horizontal scanning) in the first direction on the projection surface 21 is not a straight line. It is almost the same as the form.

The optical scanning unit 5 has one actuator 53 of a so-called two-degree-of-freedom vibration system.
The actuator 53 includes a base 54 having a first vibration system 54 a, a second vibration system 54 b, and a support portion 54 c as shown in FIG. 10, a counter substrate 56 arranged to face the base 54, and a base 54. A spacer member 55 provided between the substrate 56, a permanent magnet 57, and a coil 58 are provided.

The first vibration system 54a includes a frame-shaped drive unit 541a provided inside the frame-shaped support unit 54c, and a pair of first connection units 542a that support the drive unit 541a on the support unit 54c. 543a.
The second vibration system 54b includes a movable plate 541b provided inside the drive unit 541a, and a pair of second coupling portions 542b and 543b that support the movable plate 541b on both sides of the drive unit 541a. Yes.

The drive unit 541a has an annular shape in a plan view of FIG. The shape of the drive unit 541a is not particularly limited as long as it has a frame shape. For example, the drive unit 541a may have a quadrangular ring shape in a plan view of FIG. A permanent magnet 57 is joined to the lower surface of the driving unit 541a.
Each of the first connecting portions 542a and 543a has a longitudinal shape and can be elastically deformed. The first connecting portions 542a and 543a connect the driving portion 541a and the supporting portion 54c so that the driving portion 541a can be rotated with respect to the supporting portion 54c, respectively. Such first connecting portions 542a and 543a are provided coaxially with each other, and the drive portion 541a is connected to the support portion 54c around this axis (hereinafter referred to as “rotation center axis J1”). And is configured to rotate.

The first connecting portion 542a is provided with a piezoelectric element 521 for detecting the angle (rotation angle around the rotation center axis J1) (behavior) of the movable plate 541b.
The movable plate 541b has a circular shape in plan view of FIG. However, the shape of the movable plate 541b is not particularly limited as long as the movable plate 541b can be formed inside the drive unit 541a. For example, the shape of the movable plate 541b may be an elliptical shape or a rectangular shape in a plan view of FIG. It may be done. A light reflecting portion 544b having light reflectivity is formed on the upper surface of the movable plate 541b.

Each of the second connecting portions 542b and 543b has a longitudinal shape and can be elastically deformed. The second connecting portions 542b and 543b connect the movable plate 541b and the drive portion 541a so that the movable plate 541b can be rotated with respect to the drive portion 541a, respectively. Such second connecting portions 542b and 543b are provided coaxially with each other, and the movable plate 541b is located with respect to the drive portion 541a around this axis (hereinafter referred to as “rotation center axis J2”). It is configured to rotate.
The second connecting portion 542b is provided with a piezoelectric element 521 for detecting the angle (rotation angle around the rotation center axis J2) (behavior) of the movable plate 541b.

As shown in FIG. 10, the rotation center axis J1 and the rotation center axis J2 are orthogonal to each other. Further, the centers of the drive unit 541a and the movable plate 541b are respectively located on the intersections of the rotation center axis J1 and the rotation center axis J2 in the plan view of FIG. Hereinafter, for convenience of explanation, an intersection of the rotation center axis J1 and the rotation center axis J2 is also referred to as an “intersection point G”.
As shown in FIG. 11, the base 54 as described above is bonded to the counter substrate 56 via the spacer member 55. A coil 58 that generates a magnetic field acting on the permanent magnet 57 is provided on the upper surface of the counter substrate 56.

In the plan view of FIG. 10, the permanent magnet 57 passes through the intersection point G and is inclined with respect to each of the rotation center axis J1 and the rotation center axis J2 (hereinafter, this line segment is referred to as “line segment”). M ”).
Such a permanent magnet 57 has an S pole on one side in the longitudinal direction with respect to the intersection point G and an N pole on the other side. In FIG. 11, the left side of the permanent magnet 57 in the longitudinal direction is the S pole and the right side is the N pole.

In the plan view of FIG. 10, the inclination angle θ of the line segment M with respect to the rotation center axis X is preferably 30 to 60 degrees, more preferably 40 to 50 degrees, and approximately 45 degrees. Is more preferable. By providing the permanent magnet 57 in this way, the movable plate 541b can be smoothly rotated around the rotation center axis J1 and the rotation center axis J2. In the present embodiment, the line segment M is inclined by about 45 degrees with respect to each of the rotation center axis X and the rotation center axis Y.
Further, as shown in FIG. 11, a concave portion 57 a is formed on the upper surface of the permanent magnet 57. The recess 57a is an escape portion for preventing contact between the permanent magnet 57 and the movable plate 541b. By forming such a recess 57a, it is possible to prevent the movable plate 541b from coming into contact with the permanent magnet 57 when the movable plate 541b rotates around the rotation center axis J2.

The coil 58 is formed so as to surround the outer periphery of the drive unit 541a in the plan view of FIG. Thereby, when the actuator 53 is driven, the contact between the drive unit 541a and the coil 58 can be reliably prevented. As a result, the distance between the coil 58 and the permanent magnet 57 can be made relatively short, and the magnetic field generated from the coil 58 can be applied to the permanent magnet 57 efficiently.
The coil 58 is electrically connected to the voltage application means 59, and when a voltage is applied to the coil 58 by the voltage application means 59, the respective axes of the rotation center axis J1 and the rotation center axis J2 from the coil 58. A magnetic field is generated in the axial direction perpendicular to.

  As shown in FIG. 12, the voltage applying means 59 includes a first voltage generator 591 that generates a first voltage V1 for rotating the movable plate 541b about the rotation center axis J1, and a movable plate 541b. A second voltage generator 592 for generating a second voltage V2 for rotating around the rotation center axis J2, and the first voltage V1 and the second voltage V2 are superimposed, and the voltage is applied to the coil 58. And a voltage superimposing portion 593 applied to the.

Similarly to FIG. 8 of the first embodiment, the first voltage generator 591 has a first voltage V1 (vertical scanning) that periodically changes at a period T1 that is twice the frame frequency, as shown in FIG. Voltage).
The first voltage V1 has a waveform like a triangular wave. Therefore, the actuator 53 can perform vertical reciprocating scanning (sub scanning) of light effectively. Note that the waveform of the first voltage V1 is not limited to this. Here, the frequency (1 / T1) of the first voltage V1 is not particularly limited as long as it is a frequency suitable for vertical scanning, but is preferably 15 to 40 Hz (about 30 Hz).
In the present embodiment, the frequency of the first voltage V1 is different from the torsional resonance frequency of the first vibration system 54a configured by the drive unit 541a and the pair of first coupling portions 542a and 543a. Has been adjusted.

On the other hand, as shown in FIG. 13B, the second voltage generator 592 generates a second voltage V2 (horizontal scanning voltage) that periodically changes at a period T2 different from the period T1. .
The second voltage V2 has a waveform like a sine wave. Therefore, the actuator 53 can perform main scanning of light effectively. Note that the waveform of the second voltage V2 is not limited to this.

  The frequency of the second voltage V2 is not particularly limited as long as it is higher than the frequency of the first voltage V1 and is suitable for horizontal scanning, but is preferably 10 to 40 kHz. As described above, the frequency of the second voltage V2 is set to 10 to 40 kHz, and the frequency of the first voltage V1 is set to about 30 Hz as described above, so that the movable plate 541b can be moved at a frequency suitable for drawing on the screen. It can be rotated around the rotation center axis J1 and the rotation center axis J2. However, if the movable plate 541b can be rotated around the rotation center axis J1 and the rotation center axis J2, the combination of the frequency of the first voltage V1 and the frequency of the second voltage V2 can be obtained. There is no particular limitation.

In the present embodiment, the frequency of the second voltage V2 is adjusted to be equal to the torsional resonance frequency of the second vibration system 54b configured by the movable plate 541b and the pair of second coupling portions 542b and 543b. Has been. Thereby, the rotation angle around the rotation center axis J2 of the movable plate 541b can be increased.
When the resonance frequency of the first vibration system 54a is f ₁ [Hz] and the resonance frequency of the second vibration system 54b is f ₂ [Hz], f ₁ and f ₂ are f ₂ > f. ₁ is preferably satisfied, and more preferably f ₂ ≧ 10f ₁ is satisfied. As a result, the movable plate 541b is rotated more smoothly around the rotation center axis J1 at the frequency of the first voltage V1 and at the frequency of the second voltage V2 around the rotation center axis J2. Can do.

The first voltage generator 591 and the second voltage generator 592 are each connected to the operation control device 8 and are driven based on a signal from the operation control device 8. A voltage superimposing unit 593 is connected to the first voltage generating unit 591 and the second voltage generating unit 592.
The voltage superimposing unit 593 includes an adder 593 a for applying a voltage to the coil 58. The adder 593a receives the first voltage V1 from the first voltage generator 591 and receives the second voltage V2 from the second voltage generator 592 so that these voltages are superimposed and applied to the coil 58. It has become.

The actuator 53 configured as described above is driven as follows.
For example, the first voltage V1 as shown in FIG. 13A and the voltage V2 as shown in FIG. 13B are superimposed by the voltage superimposing unit 593, and the superimposed voltage is applied to the coil 58 ( This superimposed voltage is also referred to as “voltage V3”.
Then, by the voltage corresponding to the first voltage V1 in the voltage V3, the magnetic pole which tries to attract the south pole side of the permanent magnet 57 to the coil 58 and separate the north pole side from the coil 58, and permanent The magnetic pole 57 is alternately switched to the magnetic field to be attracted to the coil 58 while the south pole side of the magnet 57 is to be separated from the coil 58. As a result, the drive unit 541a rotates around the rotation center axis J1 at the frequency of the first voltage V1 together with the movable plate 541b while twisting and deforming the first coupling portions 542a and 543a.

  The frequency of the first voltage V1 is set to be extremely lower than the frequency of the second voltage V2, and the resonance frequency of the first vibration system 54a is the resonance frequency of the second vibration system 54b. Designed lower than. Therefore, the first vibration system 54a is easier to vibrate than the second vibration system 54b, and the movable plate 541b is rotated around the rotation center axis J2 by the first voltage V1. Can be prevented.

On the other hand, a magnetic field that attempts to attract the south pole side of the permanent magnet 57 to the coil 58 and separates the north pole side from the coil 58 by a voltage corresponding to the second voltage V2 in the voltage V3, The magnetic pole 57 is alternately switched to the magnetic field to be attracted to the coil 58 while the south pole side of the magnet 57 is to be separated from the coil 58. As a result, the movable plate 541b rotates around the rotation center axis J2 at the frequency of the second voltage V2 while twisting and deforming the second connecting portions 542b and 543b.
Since the frequency of the second voltage V2 is equal to the torsional resonance frequency of the second vibration system 54b, the movable plate 541b is predominantly rotated around the rotation center axis J2 by the second voltage V2. Can do. Therefore, it is possible to prevent the movable plate 541b from rotating around the rotation center axis J1 by the second voltage V2.

  According to the actuator 53 as described above, laser light (light) can be scanned two-dimensionally with one actuator, and space saving of the optical scanning unit 5 can be achieved. Further, for example, when an actuator and a galvanometer mirror are used as in the first embodiment, the relative positional relationship between the actuator and the galvanometer mirror must be set with high accuracy. Therefore, manufacturing can be facilitated.

Further, in the present embodiment, unlike FIG. 6 of the first embodiment, the laser light LL is projected on the projection surface 21 in the light emission state in which the laser light (light) LL is emitted from the light source unit 4 as shown in FIG. A plurality of drawing lines (scanning lines) 141 that are trajectories of the laser beam LL on the projection surface 21 when two-dimensionally scanning are arranged in a zigzag manner and distorted.
Further, since the scanning line is distorted, the video data calculation unit 82 reads out from the video data storage unit 81 while calculating data corresponding to pixel data to be drawn on the line to be scanned from now on, and the drawing timing generation unit 83. After performing various correction calculations based on the drawing timing information input from, luminance data of each color is sent to the light source modulator 84.
Regarding processing other than the above, the same processing as in the first embodiment is performed.
Also by such 2nd Embodiment, the effect similar to 1st Embodiment can be exhibited.

The image forming apparatus of the present invention has been described based on the illustrated embodiment. However, the present invention is not limited to this, and the configuration of each unit is replaced with an arbitrary configuration having the same function. can do. In addition, any other component may be added to the present invention.
Further, the present invention may be a combination of any two or more configurations (features) of the above embodiments.

In the above-described embodiment, the image forming apparatus that draws an image on the screen has been described. However, the present invention is not limited to this. For example, the image forming apparatus may draw an image on a wall or the like. The transmitted / diffused light may be viewed from the opposite side using a light diffusing plate or the like.
In the present invention, the screen may not be included as a component.
Further, in the first embodiment, as the optical scanning unit, an actuator that is driven by resonance and a galvanometer mirror are used. However, the present invention is not limited to this, and for example, an actuator that is driven by resonance. Two may be used.

In the present embodiment, the first direction is the “horizontal direction” and the second direction is the “vertical direction”. However, the present invention is not limited to this. For example, the first direction is the “vertical direction”. The second direction may be the “horizontal direction”.
In the embodiment, the dichroic mirrors 43r, 43g, and 43b are used to combine the red laser light RR, the green laser light GG, and the blue laser light BB to emit one laser light (light) LL. Alternatively, they may be combined using a dichroic prism or the like.

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 2 ... Screen 21 ... Projection surface 3 ... Image forming apparatus main body 4 ... Light source unit (light emission part) 41r, 41g, 41b ... Laser light source 410r, 410g, 410b ... Drive circuit 42r, 42g, 42b ... Collimator lens 420r, 420g, 420b ... Light source 43r, 43g, 43b ... Dichroic mirror 5 ... Optical scanning part 51 ... Actuator 511 ... Base 511a ... Movable plate 511b ... Support 511c, 511d, connecting portion 511e, light reflecting portion 512, spacer member 513, counter substrate 514, permanent magnet 515, coil 516, voltage applying means 517, driving means 52, angle detecting means 521 …… Piezoelectric element 522 …… Electromotive force detector 523 …… Angle detection Knowledge part 53 …… Actuator 54 …… Substrate 54a …… First vibration system 541a …… Drive part 542a, 543a …… First connection part 54b …… Second vibration system 541b …… Moving plate 542b, 543b ... ... second connecting portion 544b ... light reflecting portion 54c ... supporting portion 55 ... spacer member 56 ... counter substrate 57 ... permanent magnet 57a ... concave 58 ... coil 59 ... voltage applying means 591 ... first 1 voltage generator 592 ... 2nd voltage generator 593 ... voltage superposition unit 593a ... adder 300 ... scan projector 8 ... operation control device 81 ... video data storage unit 82 ... video data calculation unit 83 …… Drawing timing generation unit 84 …… Light source modulation unit 85 …… Deflection angle calculation unit 86 …… Angle instruction unit 87 …… Calibration curve storage unit 12 …… Rubano mirror 121 …… mirror 122 …… motor 123 …… drive circuit 124 …… drive means 13 …… angle detection means 131 …… encoder 132 …… angle detection unit 141 …… drawing line 142 …… drawing area 143 …… drawable Area LL, RR, GG, BB ... Laser beam J, Ja, J1, J2 ... Rotation center axis

Claims (8)

The projection surface is configured to draw an image by scanning light,
A light emitting portion for emitting light;
Reflecting the light emitted from the light emitting part and having at least one reflecting surface rotatably provided, the light emitted from the light emitting part is directed to the projection surface in a first direction. An optical scanning unit that scans two-dimensionally by scanning in a second direction orthogonal to the first direction at a scanning speed slower than the scanning speed in the first direction;
Adjusting means for adjusting a swing angle about the rotation center axis of the reflecting surface that scans in the first direction;
Scanning in the second direction is performed in each of the forward path and the backward path, and scanning is performed in the first direction in each of the forward path and the backward path of the scanning in the second direction, and an image is drawn.
When performing the scanning in the first direction, the adjusting means is configured so that a fluctuation width in the first direction of light on the projection surface in a light emitting state in which light is emitted from the light emitting portion is the adjusting means. The image forming apparatus is configured to adjust the deflection angle so as to be aligned along the second direction as compared with the case where the adjustment according to (1) is not performed.   The adjusting means is configured to adjust the deflection angle so that a deflection width in the first direction of light on the projection surface in the light emitting state is constant along the second direction. The image forming apparatus according to claim 1. The adjustment means includes a calibration curve storage means for storing a calibration curve indicating a relationship between a position of the second direction of the light scanned on the projection plane in the projection plane and the deflection angle;
3. The target value of the deflection angle is obtained based on a position in the second direction on the projection plane of light scanned on the projection plane using the calibration curve. Image forming apparatus. Angle detecting means for detecting the angle of the reflecting surface that scans in the first direction;
The said adjustment means is comprised so that the said deflection angle may be adjusted so that the said deflection angle may become the said target value based on the detection result of the said angle detection means, and the said target value. Image forming apparatus.   5. The image according to claim 1, wherein the optical scanning unit is configured to scan light on the same line of the projection plane in the forward path and the backward path of the scanning in the second direction. Forming equipment. Having video data storage means for storing video data used when drawing an image;
The order of reading out the video data from the video data storage means is reversed between when the image is drawn in the forward path of the scanning in the second direction and when the image is drawn in the backward path of the scanning in the second direction. The image forming apparatus according to claim 1, wherein the image forming apparatus is configured as described above. The optical scanning unit is rotatably provided and has a movable plate having a reflecting surface that scans in the first direction, a support unit that rotatably supports the movable plate, the movable plate, and the support unit. And an actuator comprising a connecting portion for connecting the movable plate and a driving means for rotating the movable plate,
The image forming apparatus according to claim 1, further comprising a galvanometer mirror having a reflecting surface that scans in the second direction.   The image forming apparatus according to claim 1, further comprising a screen having the projection surface.

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