JP2012013746A - Image forming device - Google Patents

Abstract

To provide an image forming apparatus that draws all image data without thinning out image data even when an optical scanner whose drawing time changes for each image is used.
An image forming apparatus includes a light emitting unit that emits a laser beam LL, and a main scanning and a sub-scanning of the laser beam LL emitted from the light emitting unit 3, thereby drawing a region S11 on a screen S. And a laser beam on the drawing area S11 when each image is displayed based on the shape and size of the image displayed on the drawing area S11 on the drawing area S11. The drive control unit 5 controls the drawing of the next image data after changing the scanning range of LL and drawing one image data.
[Selection] Figure 1

Description

  The present invention relates to an image forming apparatus.

For example, an optical scanning projector is widely known as an image forming apparatus that displays an image on a surface such as a screen (see, for example, Patent Document 1).
The optical scanning projector of Patent Document 1 includes a light source that emits laser light of a desired color at a desired timing, and a polarization unit that two-dimensionally scans the laser light emitted from the light source. Further, the polarization means has a first optical scanner that scans the laser beam in the horizontal direction and a second optical scanner that scans in the vertical direction. Each of these two optical scanners has a mirror that reflects the laser beam, and is configured to scan the laser beam by rotating the mirror around a predetermined axis. Such an optical scanning projector is configured to display a desired image on a screen by scanning two-dimensionally by scanning a laser beam with a first optical scanner and then scanning with a second optical scanner. Has been.

The optical scanning projector disclosed in Patent Document 1 is a value in which the amplitudes of the first optical scanner and the second optical scanner are set for any image regardless of the size of the image displayed on the screen. Drive to keep on. Therefore, for example, the horizontal width of an image displayed on the screen (hereinafter also referred to as “display image”) is much smaller than the amplitude of the first optical scanner, or the vertical width is the amplitude of the second optical scanner. Even if it is much smaller than that, the first optical scanner and the second optical scanner must be rotated with a large amplitude with respect to the display image.
In the first optical scanner and the second optical scanner of Patent Document 1, when a small image is drawn, the drawing time is not changed even though it can be drawn in a short time, so that one image is displayed. This time may be longer than necessary.

  Therefore, it is conceivable to use the optical scanner of Patent Document 1 to change the drawing time for each image, that is, to drive while changing the refresh rate (rate for drawing one image). On the other hand, usually, on the host side that transmits image data to the projector, an image is transmitted to the optical scanner at a fixed frame frequency (vertical synchronization frequency). In this case, if it takes a time longer than the frame period to draw a large image, the next image data may not be drawn, that is, the image data may be thinned out.

JP 2007-199251 A

  An object of the present invention is to provide an image forming apparatus that draws all image data without thinning out image data even when an optical scanner whose drawing time changes for each image is used. .

Such an object is achieved by the present invention described below.
An image forming apparatus according to the present invention includes a light source, an optical scanner that scans light from the light source into a drawing area, an image data input unit that captures a plurality of continuous image data, and the size of each of the plurality of image data. An image size detection unit that detects each image, an image data storage unit that sequentially stores the plurality of image data, and image data that transmits the plurality of image data to the optical scanner in the order stored in the image data storage unit A transmission control unit that controls the driving of the optical scanner, and changes the operation of the optical scanner in accordance with the size of each image of the plurality of image data. After drawing one image data of the plurality of image data, the next image data of the one image data is drawn.
As a result, even when image data having a large image size is input, the image data is temporarily stored in the image data storage unit and sequentially drawn by the optical scanner, so that the image is thinned out. All images can be drawn.

In the image forming apparatus described above, the operation time of the optical scanner is lengthened as the size of each of the plurality of image data increases.
Accordingly, it is possible to reliably draw image data having a large image size without increasing the operation speed of the optical scanner.

In the image forming apparatus described above, the optical scanner performs main scanning of light from the light source in a first direction and sub-scanning in a second direction orthogonal to the first direction, thereby performing the drawing. Scanning the light two-dimensionally in the region, fixing or changing the amplitude of the scanner in the first direction, changing the amplitude of the scanner in the second direction, and drawing the image of the image data Features.
Thereby, the size of the image drawn by the optical scanner in the first direction for main scanning and the second direction for sub-scanning can be changed.

In the image forming apparatus described above, the drive control unit may set the main scanning amplitude on the drawing area to be equal to the maximum width in the first direction of the image range to be drawn in the drawing area. The driving of the optical scanner is controlled.
As a result, main scanning with an amplitude larger than necessary can be prevented, so that an image can be efficiently drawn by the optical scanner.

In the image forming apparatus described above, the drive control unit may set the amplitude of the sub-scan on the drawing area to be equal to the maximum width in the second direction of the image range drawn in the drawing area. The driving of the optical scanner is controlled.
As a result, sub-scanning with a large amplitude can be prevented, so that an image can be efficiently drawn by the optical scanner.

In the image forming apparatus of the present invention, a light source, an optical scanner that scans light from the light source into a drawing area, an image data input unit that captures a plurality of continuous image data, and a size of each of the plurality of image data An image size detection unit that detects each image, an image data storage unit that sequentially stores the plurality of image data, and an image that transmits the plurality of image data to the optical scanner in the order stored in the image data storage unit A data transmission unit; and a drive control unit that controls driving of the optical scanner, and a first drawing mode for operating the optical scanner so as to draw the plurality of image data at a constant cycle; As the image size of each of the plurality of image data increases, the operation time of the optical scanner is lengthened to switch to the second drawing mode that changes the drawing cycle. Possible and characterized by.
As a result, even if a mode that allows moving images to be formed at an accurate speed and image data having a large image size are input, the image data is temporarily stored in the image data storage unit and sequentially drawn by the optical scanner. Therefore, the mode in which all the images are drawn can be switched without thinning out the images.

1 is a configuration diagram illustrating a first embodiment of an image forming apparatus of the present invention. FIG. 2 is a partial cross-sectional perspective view of an optical scanner provided in the image forming apparatus shown in FIG. 1. FIG. 3 is a cross-sectional view illustrating driving of the optical scanner shown in FIG. 2. It is a block diagram which shows the drive control part, optical scanning part, and light source unit which are shown in FIG. FIG. 4 is a plan view for explaining an optical scanning operation of the image forming apparatus shown in FIG. 1. FIG. 2 is a diagram for explaining a drawing timing operation of the image forming apparatus shown in FIG. 1. FIG. 2 is a diagram for explaining a drawing positional relationship of the image forming apparatus illustrated in FIG. 1. FIG. 6 is a diagram for explaining a second drawing timing operation of the image forming apparatus shown in FIG. 1.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an image forming apparatus of the invention will be described with reference to the accompanying drawings.

<First Embodiment>
1 is a configuration diagram illustrating a first embodiment of an image forming apparatus according to the present invention, FIG. 2 is a partial cross-sectional perspective view of an optical scanner included in the image forming apparatus illustrated in FIG. 1, and FIG. 3 is a diagram illustrating the light illustrated in FIG. FIG. 4 is a block diagram illustrating a drive control unit, an optical scanning unit, and a light source unit illustrated in FIG. 1, and FIG. 5 illustrates an optical scanning operation of the image forming apparatus illustrated in FIG. FIG. 6 is a diagram for explaining the drawing timing operation of the image forming apparatus shown in FIG. 1, and FIG. 7 is a diagram for explaining the positional relationship of drawing of the image forming apparatus shown in FIG. FIG. 8 is a diagram for explaining the second drawing timing operation of the image forming apparatus shown in FIG. In the following, for convenience of explanation, the upper side of the figure is referred to as “upper”, the lower side is referred to as “lower”, the right side is referred to as “right”, and the left side is referred to as “left”.

  An optical scanning projector (image forming apparatus) 1 shown in FIG. 1 displays still images such as photographs, illustrations, commercials, promotional videos, and moving images in a drawing area S11 formed on a display surface S1 of a screen S, for example. It is a device to display. The optical scanning projector 1 includes a light source unit (light emitting unit) 3 that emits laser light (light), an optical scanning unit 4 that scans laser light emitted from the light source unit 3 with respect to the drawing region S11, and light. And a drive control unit 5 that controls driving of the scanning unit 4. Hereinafter, each of these components will be sequentially described in detail.

(Light source unit)
The light source unit 3 includes laser light sources 31r, 31g, and 31b for the respective colors, collimator lenses 32r, 32g, and 32b and dichroic mirrors 33r, 33g, and 33b provided corresponding to the laser light sources 31r, 31g, and 31b for the respective colors, It has.
As shown in FIG. 4, the laser light sources 31r, 31g, and 31b for the respective colors have drive circuits 310r, 310g, and 310b, a red light source 320r, a green light source 320g, and a blue light source 320b, 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 a drive signal transmitted from a light source modulation unit 54 (to be described later) of the drive control unit 5, and are collimator lenses 32r that are collimating optical elements. The beams are collimated by 32g and 32b to form a thin beam.

The dichroic mirrors 33r, 33g, and 33b 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 to 1 Two laser beams LL are emitted.
A collimator mirror can be used in place of the collimator lenses 32r, 32g, and 32b. 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 31r, 31g, and 31b of the respective colors, the collimator lenses 32r, 32g, and 32b can be omitted. Further, the laser light sources 31r, 31g, and 31b can be replaced with light sources such as light emitting diodes that generate similar light beams.

  Further, the order of the laser light sources 31r, 31g, and 31b, the collimator lenses 32r, 32g, and 32b and the dichroic mirrors 33r, 33g, and 33b in FIG. 1 is merely an example, and the combination of the colors (red indicates the laser light source 31r). , Collimator lens 32r, dichroic mirror 33r, green for laser light source 31g, collimator lens 32g, dichroic mirror 33g, blue for laser light source 31b, collimator lens 32b, dichroic mirror 33b) Can be set freely. For example, a combination of blue, red, and green is also possible in the order closer to the optical scanning unit 4.

(Optical scanning unit)
The optical scanning unit 4 scans the laser light LL emitted from the light source unit 3 in the horizontal direction (first direction) with respect to the drawing region S11 (horizontal scanning: main scanning) and is slower than the scanning speed in the horizontal direction. The scanning is performed two-dimensionally by scanning in the vertical direction (second direction) at the scanning speed (vertical scanning: sub-scanning).
The optical scanning unit 4 detects the angle (behavior) of the optical scanner 41 that scans the laser light LL emitted from the light source unit 3 in the horizontal direction with respect to the drawing region S11 and a movable plate 411a (to be described later) of the optical scanner 41. An angle detection unit (behavior detection unit) 43, an optical scanner 42 that scans the laser light LL emitted from the light source unit 3 in a vertical direction with respect to the drawing region S11, and an angle (described later) of the movable plate 421a of the optical scanner 42 Angle detecting means (behavior detecting means) 44 for detecting (behavior).

  Hereinafter, the configuration of the optical scanners 41 and 42 will be described. Since the optical scanners 41 and 42 have the same configuration, the optical scanner 41 will be described below as a representative, and the optical scanner 42 will be described. Omitted.

  As shown in FIG. 2, the optical scanner 41 is a so-called one-degree-of-freedom vibration system, and includes a base 411, a counter substrate 413 provided to face the lower surface of the base 411, a base 411, a counter substrate 413, and the like. And a spacer member 412 provided therebetween.

  The base 411 includes a movable plate 411a, a support portion 411b that rotatably supports the movable plate 411a, and a pair of connecting portions 411c and 411d that connect the movable plate 411a and the support portion 411b.

  The movable plate 411a has a substantially rectangular shape in plan view. On the upper surface of the movable plate 411a, a light reflecting portion (mirror) 411e having light reflectivity is provided. The surface (upper surface) of the light reflecting portion 411e constitutes a reflecting surface that reflects light. The light reflecting portion 411e is made of a metal film such as Al or Ni, for example. A permanent magnet 414 is provided on the lower surface of the movable plate 411a.

  The support portion 411b is provided so as to surround the outer periphery of the movable plate 411a in a plan view of the movable plate 411a. That is, the support part 411b has a frame shape, and the movable plate 411a is located inside thereof.

The connecting portion 411c connects the movable plate 411a and the support portion 411b on the left side of the movable plate 411a, and the connecting portion 411d connects the movable plate 411a and the support portion 411b on the right side of the movable plate 411a. Yes.
Each of the connecting portions 411c and 411d has a longitudinal shape. Further, each of the connecting portions 411c and 411d can be elastically deformed. The pair of connecting portions 411c and 411d are provided coaxially with each other, and the movable plate 411a rotates with respect to the support portion 411b around this axis (hereinafter referred to as “rotation center axis J1”). Move.

  Such a base 411 is made of, for example, silicon as a main material, and a movable plate 411a, a support portion 411b, and connection portions 411c and 411d 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 optical scanner 41 can be downsized.

The spacer member 412 has a frame shape, and its upper surface is joined to the lower surface of the base 411. The spacer member 412 is substantially equal to the shape of the support portion 411b in the plan view of the movable plate 411a. Such a spacer member 412 is made of, for example, various glasses, various ceramics, silicon, SiO ₂ or the like.
The method for joining the spacer member 412 and the base 411 is not particularly limited. For example, the spacer member 412 may be joined via another member such as an adhesive, or anodic joining may be performed depending on the constituent material of the spacer member 412. It may be used.

Similar to the spacer member 412, the counter substrate 413 is made of, for example, various kinds of glass, silicon, SiO ₂ or the like. A coil 415 is provided on the upper surface of the counter substrate 413 and on a portion facing the movable plate 411a.

The permanent magnet 414 has a plate bar shape and is provided along the lower surface of the movable plate 411a. Such a permanent magnet 414 is magnetized (magnetized) in a direction orthogonal to the rotation center axis J1 in a plan view of the movable plate 411a. That is, the permanent magnet 414 is provided such that a line segment connecting both poles (S pole and N pole) is orthogonal to the rotation center axis J1.
The permanent magnet 414 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 415 is provided so as to surround the outer periphery of the permanent magnet 414 in the plan view of the movable plate 411a.

  Further, as shown in FIG. 3, the optical scanner 41 includes a voltage applying unit 416 that applies a voltage to the coil 415. The voltage application unit 416 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 416, the coil 415, and the permanent magnet 414 constitute a driving unit 417 that rotates the movable plate 411a.

  A predetermined voltage is applied to the coil 415 from the voltage applying unit 416 under the control of the drive control unit 5, and a predetermined current flows. For example, when an alternating voltage is applied from the voltage application unit 416 to the coil 415 under the control of the drive control unit 5, a current flows accordingly, a magnetic field in the thickness direction of the movable plate 411a is generated, and the direction of the magnetic field Switches periodically. That is, the state A in which the vicinity of the upper side of the coil 415 is the S pole and the vicinity of the lower side is the N pole, and the state B in which the vicinity of the upper side of the coil 415 is the N pole and the vicinity of the lower side is alternately switched.

  In the state A, as shown in FIG. 3A, the right side of the permanent magnet 414 is displaced upward by the repulsive force with the magnetic field generated by energizing the coil 415, and the left side of the permanent magnet 414 is the magnetic field. Displaces downward due to the suction force. Thereby, the movable plate 411a is rotated counterclockwise and tilted. On the contrary, in the state B, as shown in FIG. 3B, the right side of the permanent magnet 414 is displaced downward and the left side of the permanent magnet 414 is displaced upward. Thereby, the movable plate 411a rotates clockwise and tilts. By alternately repeating the state A and the state B, the movable plate 411a rotates around the rotation center axis J1 while twisting and deforming the connecting portions 411c and 411d.

  Further, the current flowing can be adjusted by adjusting the voltage applied from the voltage applying unit 416 to the coil 415 under the control of the drive control unit 5, whereby the movable plate 411 a (the reflection surface of the light reflection unit 411 e). The swing angle (amplitude) about the rotation center axis J1 can be adjusted.

  The configuration of such an optical scanner 41 is not particularly limited as long as the movable plate 411a can be rotated. For example, the drive system is replaced with electromagnetic drive using a coil 415 and a permanent magnet 414. For example, piezoelectric driving using a piezoelectric element or electrostatic driving using electrostatic attraction may be used.

  As shown in FIG. 1, the optical scanners 41 and 42 having the above-described configuration are provided so that the rotation center axes J1 and J2 are orthogonal to each other. By providing the optical scanners 41 and 42 in this manner, the laser light LL emitted from the light source unit 3 can be two-dimensionally scanned with respect to the drawing region S11. Thereby, a two-dimensional image can be drawn in the drawing area S11 with a relatively simple configuration.

  More specifically, the laser beam LL emitted from the light source unit 3 is reflected by the reflecting surface of the light reflecting unit 411e of the light scanner 41, and then reflected by the reflecting surface of the light reflecting unit 421e of the light scanner 42, The image is projected onto the drawing area S11 of the screen S. The laser beam LL emitted from the light source unit 3 is rotated by rotating the light reflecting portion 411e of the optical scanner 41 and rotating the light reflecting portion 421e of the optical scanner 42 at an angular velocity slower than the angular velocity (speed). Is scanned in the horizontal direction with respect to the drawing region S11 and in the vertical direction at a scanning speed slower than the scanning speed in the horizontal direction. As a result, the laser beam LL emitted from the light source unit 3 is two-dimensionally scanned with respect to the drawing area S11, and an image is drawn in the drawing area S11.

Here, in order to rotate the light reflecting portion 421e of the light scanner 42 at an angular velocity slower than the angular velocity of the light reflecting portion 411e of the light scanner 41, for example, the light scanner 41 is set to resonance driving using resonance, and the optical scanner is used. 42 is preferably a non-resonant drive that does not utilize resonance.
The laser beam LL emitted from the light source unit 3 may be reflected first by the light reflecting portion 421e of the light scanner 42 and then reflected by the light reflecting portion 411e of the light scanner 41. That is, it may be configured such that vertical scanning is performed first and then horizontal scanning is performed.

  Next, the angle detection unit 43 that detects the angle of the movable plate 411a of the optical scanner 41 will be described. Note that the angle detection unit 44 that detects the angle of the movable plate 421a of the optical scanner 42 has the same configuration as the angle detection unit 43, and thus description thereof is omitted.

  As shown in FIG. 2, the angle detection means 43 includes a piezoelectric element 431 provided on the connection part 411 c of the optical scanner 41, an electromotive force detection part 432 that detects an electromotive force generated from the piezoelectric element 431, and an electromotive force. And an angle detector 433 for obtaining the angle of the movable plate 411a based on the detection result of the detector 432.

  The piezoelectric element 431 is deformed along with the torsional deformation of the connecting portion 411c as the movable plate 411a rotates. When the piezoelectric element 431 is deformed from a natural state to which no external force is applied, the piezoelectric element 431 has a property of generating an electromotive force having a magnitude corresponding to the amount of deformation. Therefore, the angle detection unit 433 obtains the degree of twist of the connecting part 411c based on the magnitude of the electromotive force detected by the electromotive force detection part 432, and further obtains the angle of the movable plate 411a from the degree of twist. . In addition, the angle detection unit 433 obtains a deflection angle around the rotation center axis J1 of the movable plate 411a. A signal including information on the angle and deflection angle of the movable plate 411 a is transmitted from the angle detection unit 433 to the drive control unit 5.

  Note that the angle of the movable plate 411a to be detected may be set to an angle based on any state of the optical scanner 41 (the angle is 0 °). For example, the initial state of the optical scanner 41 (coil 415 can be set to an angle when the reference (angle is 0 °).

  Further, the detection of the angle of the movable plate 411a may be performed in real time (continuously) or may be performed intermittently. Further, the angle detection unit 43 is not limited to the one using the piezoelectric element as in the present embodiment as long as the angle of the movable plate 411a can be detected. For example, a light receiving element such as a photodiode and a laser light emitting unit that emits laser light toward the light receiving element are configured such that the laser light is blocked by the movable plate 411a when the movable plate 411a reaches a predetermined angle. The angle of the movable plate 411a may be detected by installing and detecting the timing at which the laser beam is blocked by the light receiving element.

(Drive control unit)
Next, the drive control unit 5 will be described.
The drive control unit 5 changes the horizontal amplitude of the laser light LL on the drawing area S11 according to the maximum horizontal width of the image displayed in the drawing area S11, and the vertical direction of the image displayed in the drawing area S11. Control is performed to change the vertical amplitude of the laser light LL on the drawing region S11 in accordance with the maximum width of the direction. This will be specifically described below.

  For example, when a predetermined image is drawn in the drawing area S11 by the optical scanning projector 1 as shown in FIGS. 5A, 5B, and 5C, the drive control unit 5 is in the light emitting state. The angle of the movable plate 411a of the optical scanner 41 is controlled so that the horizontal amplitude of the laser light LL is equal to the maximum horizontal width of the image displayed in the drawing region S11. At the same time, the drive control unit 5 makes the vertical amplitude of the laser light LL in the light emission state equal to the maximum width in the vertical direction of the image displayed in the drawing region S11, and on the screen S (drawing region S11). The angle of the movable plate 421a of the optical scanner 42 is controlled so that the vertical interval of the laser beam LL does not change.

  By performing such control by the drive control unit 5, the rotation angle of the movable plates 411 a and 421 a of the optical scanners 41 and 42 can be set to the minimum angle necessary for drawing an image. Therefore, power consumption of the optical scanning projector 1 can be reduced without consuming a large amount of power. In addition, since the number of horizontal scans is reduced and the time required to display one image (one frame) can be shortened, the number of images that can be drawn per unit time is increased. As a result, even if the output of the laser beam LL is lowered, an image having the same brightness as the conventional one can be displayed in the drawing area S11. From this viewpoint as well, power saving of the optical scanning projector 1 can be achieved. it can. Further, if the number of images that can be drawn per unit time increases, an image with smoother motion can be displayed particularly when a moving image or the like is displayed.

  Note that when two images having the same maximum horizontal width and different maximum vertical widths are compared, an image having a larger maximum vertical width takes longer to draw.

Hereinafter, the configuration of the drive control unit 5 for realizing the above-described control will be described.
The video data storage unit 51 temporarily stores video data input from an external device such as a computer.

  The image size detection unit 58 detects the maximum horizontal width and the maximum vertical width when an image corresponding to the video data stored in the video data storage unit 51 is displayed in the drawing area S11. This more reliably changes the horizontal amplitude of the laser beam LL on the drawing area S11 in accordance with the maximum horizontal width of the image displayed in the drawing area S11, and the image displayed in the drawing area S11. The vertical amplitude of the laser beam LL on the drawing region S11 can be changed according to the maximum width in the vertical direction.

  A method for detecting the maximum width in each direction is not particularly limited. For example, the video data stored in the video data storage unit 51 includes at least information on whether to irradiate the laser beam LL with respect to each part (virtually set pixel) on the drawing region S11. ing. From this information, the leftmost pixel and the rightmost pixel among the pixels to be irradiated with the laser light LL are obtained, and correspond to the center of these two pixels and vibration (rotation of the movable plate 411a). By calculating the horizontal distance between each pixel and selecting the pixel with the larger distance, the maximum horizontal width of the image represented in the drawing area S11 can be obtained. Similarly, from the video data, the pixel located on the lowermost side and the pixel located on the uppermost side among the pixels irradiated with the laser light LL are obtained, and the vertical distance between these two pixels is calculated. The maximum width in the vertical direction of the image displayed in the drawing area S11 can be obtained.

  Further, when the video data stored in the video data storage unit 51 includes data relating to the maximum horizontal width and the maximum vertical width displayed in the drawing area S11 in advance, this data is used. Can do. As described above, if the video data includes data relating to the maximum width in advance, the image size detection unit 58 does not have to obtain the maximum width in the two directions of the image by the method described above. Therefore, an image can be displayed more smoothly in the drawing area S11.

  The drawing timing generation unit 53 generates drawing timing information and drawing line information, respectively. The drawing timing information includes drawing timing information and the like. Further, the drawing line information includes information on the vertical position (angle of the movable plate 421a) of the drawing line L for drawing. Note that the position of any part of the drawing line L may be set as the position in the vertical direction of the drawing line L, 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 53, the video data calculation unit 52 reads the video data corresponding to the pixel to be drawn from the video data storage unit 51, performs various correction calculations, and the like. The luminance data of each color is sent to the light source modulator 54.

  The light source modulation unit 54 modulates each light source 320r, 320g, 320b via each drive circuit 310r, 310g, 310b based on the luminance data of each color input from the video data calculation unit 52. That is, the light sources 320r, 320g, and 320b are turned on / off, the output is adjusted (increased / decreased), and the like.

  The calibration curve storage unit 57 stores the vertical position (drawing line) of the laser beam LL to be scanned in the drawing region S11 in the light emission state, where the fluctuation width of the laser beam LL is constant along the vertical direction. A calibration curve such as a table or an arithmetic expression (function) indicating the relationship between the vertical position of L) and the deflection angle of the movable plate 411a is stored (stored). When drawing an image, using the calibration curve, the maximum horizontal width of the image detected by the image size detection unit 58, and data relating to the positions of the two pixels located at both ends, the drawing area S11 is used. Based on the position in the vertical direction on the drawing area S11 of the laser beam LL to be scanned, a target value of the deflection angle is obtained. The calibration curve can be obtained by calculation and is stored in advance in the calibration curve storage unit 57.

(Optical scanning projector)
Next, the operation of the optical scanning projector 1 when drawing an image on the drawing area S11 of the screen S will be described.
First, video data is input to the optical scanning projector 1. The input video data is temporarily stored in the video data storage unit 51, and an image is drawn using the video data read from the video data storage unit 51.
In this case, drawing of the image may be started after all of the video data is stored in the video data storage unit 51, and after part of the video data is stored in the video data storage unit 51, Drawing may be started, and the video data storage unit 51 may store the video data that follows the drawing of the image.

When drawing an image after a part of the video data is stored in the video data storage unit 51, first, video data of at least one frame, preferably two frames or more (for example, two frames). Is stored in the video data storage unit 51, and then image drawing is started.
This is because the raster scan module draws an image by performing horizontal scanning in each of the forward and backward passes of the vertical scan (hereinafter also simply referred to as “reciprocating drawing in the vertical direction”), and as described later, the vertical scan Since the image data read-out order from the video data storage unit 51 is reversed between when the image is drawn on the forward path and when the image is drawn on the return path of the vertical scan, the image is drawn on the return path of the vertical scan. 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 51 in order to read the video data from the opposite side when starting.

The image size detection unit 58 detects the maximum horizontal width and the maximum vertical width when an image corresponding to the video data stored in the video data storage unit 51 is displayed in the drawing area S11.
The drawing timing generation unit 53 generates drawing timing information and drawing line information. The drawing timing information is sent to the video data calculation unit 52, and the drawing line information is sent to the deflection angle calculation unit 55.

Based on the drawing timing information input from the drawing timing generation unit 53, the video data calculation unit 52 reads the video data corresponding to the pixel to be drawn from the video data storage unit 51, performs various correction calculations, and the like. The luminance data of each color is sent to the light source modulator 54.
The light source modulation unit 54 modulates each light source 320r, 320g, 320b via each drive circuit 310r, 310g, 310b based on the luminance data of each color input from the video data calculation unit 52. That is, on / off of each light source 320r, 320g, 320b, adjustment (increase / decrease) of output, etc. are performed.

  The angle detection means 43 on the optical scanner 41 side detects the angle and the deflection angle of the movable plate 411a, and draws information on the angle and the deflection angle (angle information of the movable plate 411a) and a drawing timing generation unit 53 and a deflection angle calculation unit. To 55. Further, the angle detector 44 on the optical scanner 42 side detects the angle of the movable plate 421 a and sends information on the angle (angle information of the movable plate 421 a) to the angle instruction unit 56.

  When the drawing of the current drawing line L is completed and information on the deflection angle of the movable plate 411a is input from the angle detection unit 43, the drawing timing generation unit 53 synchronizes with the angle indication unit 56 and then Target angle information indicating the target angle of the movable plate 421a when the laser beam LL is irradiated to the drawing start point of the drawing line L for drawing is sent. The target angle of the movable plate 421a is set so that the vertical interval between adjacent drawing start points is constant. In addition, the target angle of the movable plate 421a is set to be equal to the maximum width in the vertical direction of the image when the image is displayed in the drawing area S11 detected by the image size detection unit 58. The angle instruction unit 56 compares the angle of the movable plate 421a detected by the angle detection unit 44 with the target angle of the movable plate 421a, performs correction so that the difference becomes zero, and drives the optical scanner 42. Drive data is sent to the means 427.

  The drive unit 427 drives the optical scanner 42 based on the drive data (applies a voltage to the coil). Thereby, when the laser beam LL is irradiated to the drawing start point, the angle of the movable plate 421a becomes the target angle.

  In the present embodiment, in each drawing line L, the angular velocity of the movable plate 421a may be constant from the drawing start point to the drawing end point, and the vertical scanning speed of the laser light LL may be constant. The angular velocity of 421a may be gradually changed, and the scanning speed of the laser beam LL in the vertical direction may be gradually changed.

  In addition, the drawing timing generation unit 53 sends drawing line information, that is, information on the position in the vertical direction of the drawing line L to be drawn next, to the deflection angle calculation unit 55.

  The deflection angle calculation unit 55 uses the information read from the calibration curve storage unit 57 (target value of the deflection angle of the movable plate 411 a corresponding to each drawing line L), and is input next from the drawing timing generation unit 53. Based on the information on the vertical position of the drawing line L for drawing, the target deflection angle of the movable plate 411a in the drawing line L for drawing next is obtained. Then, based on the information on the swing angle of the movable plate 411a input from the angle detection means 43 and the target swing angle of the movable plate 411a, the optical scanner 41 is set so that the swing angle of the movable plate 411a becomes the target swing angle. Drive data is sent to the drive means 417.

  Based on the driving data, the driving unit 417 applies an effective voltage having the same frequency as the resonance frequency of the optical scanner 41 to the coil 415 to cause a current to flow to generate a predetermined magnetic field. By changing the phase difference between and the drive waveform, energy is supplied to the optical scanner 41, or conversely, energy is taken from the optical scanner 41. As a result, the swing angle of the movable plate 411a that is in resonance motion becomes the target swing angle. In this way, based on the information (detection result) of the deflection angle of the movable plate 411a detected by the angle detection means 43 and the target deflection angle (target value), the deflection angle of the movable plate 411a becomes the target deflection angle. While adjusting the deflection angle of the movable plate 411a, the laser beam LL is sequentially scanned on the necessary portions on each drawing line L in the drawing region S11 to draw an image.

  In addition, the drawing timing generation unit 53 manages whether a frame to be drawn is an odd frame (odd number frame) or an even frame (even number frame), so that the movable plate 421a The rotation direction (movement direction) and the reading order of the video data from the video data storage unit 51 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 in the drawing area S11 in the odd frame and the even frame. In other words, the laser beam LL is scanned so that each drawing line L in the odd frame matches each drawing line L in the even frame.

  Specifically, for example, drawing is started from the upper left for the first frame (odd-numbered frame) and drawn to the lower right in a zigzag manner, and the movable plate is drawn for the second frame (even-numbered frame). Contrary to the first frame (odd-numbered frame), the rotation direction of 421a is drawn from the lower right to the upper left. 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 in the drawing area S11 in the odd-numbered frame and the even-numbered frame.

Next, as a specific example, the operation of the optical scanning projector 1 when displaying a moving image formed by continuously displaying six images will be described.
As shown in FIG. 6, the video data storage unit 51 includes six memories, that is, a first memory 511, a second memory 512, a third memory 513, a fourth memory 514, a fifth memory 515, and a first memory 515. 6 memories 516. These six memories 511 to 516 store six images in the order in which they are displayed. That is, first, image data of an image displayed first (hereinafter referred to as “first image data”) is stored in the first memory 511, and then image data of an image displayed second (hereinafter referred to as “first image data”). “Second image data”) is stored in the second memory 512, and then the image data of the third image displayed (hereinafter referred to as “third image data”) is stored in the third memory 513 in the same manner. In addition, the video data of the image displayed for the fourth time (hereinafter referred to as “fourth image data”) is stored in the fourth memory 514 for the video data of the image displayed for the fifth time (hereinafter referred to as “fifth image data”). ) Is stored in the fifth memory 515 in sequence, and the image data of the sixth image (hereinafter referred to as “sixth image data”) is sequentially stored in the sixth memory 516. Note that the input rate of such video data to the video data storage unit 51 is set at, for example, 10 Hz by the host that transmits the image data.

  When the input of the first image data to the first memory 511 is completed, the drive control unit 5 takes out the first image data from the first memory 511 and performs the first operation corresponding to the first image data as described above. The image is drawn in the drawing area S11. If the maximum width of the first image in the vertical and horizontal directions is relatively small and the image can be drawn on the drawing area S11 in a short time, the drawing rate is 14 Hz (ie 1/14). ).

  Next, the drive control unit 5 takes out the second image data from the second memory 512 in which the second image data that is the next image data of the first image data is stored, and has finished drawing the first image data. Later, drawing of the second image corresponding to the second image data is started. If the maximum width in the vertical direction and horizontal direction of the image is larger than that of the first image data, the second image data that is the second video data to be displayed takes longer than the drawing time of the first image data. Drawing. It is assumed that this drawing rate is 11 Hz (that is, it takes 1/11 second).

  Next, the drive control unit 5 takes out the third image data from the third memory 513 in which the third image data that is the next image data of the second image data is stored, and has finished drawing the second image data. Later, drawing of the third image corresponding to the third image data is started. If the maximum width in the vertical direction and horizontal direction of the image is larger than the second image data, the third image data, which is the video data displayed third, takes a longer time than the drawing time of the second image data. Drawing. It is assumed that this drawing rate is 9 Hz (that is, it takes 1/9 seconds).

  Next, the drive control unit 5 extracts the fourth image data from the fourth memory 514 in which the fourth image data that is the next image data of the third image data is stored, and has finished drawing the third image data. Later, drawing of the fourth image corresponding to the fourth image data is started. If the maximum width in the vertical direction and horizontal direction of the image is smaller than that of the third image data, the fourth image data that is the fourth video data displayed takes a shorter time than the drawing time of the third image data. Drawing. It is assumed that this drawing rate is 14 Hz (that is, it takes 1/14 seconds).

  Next, the drive control unit 5 takes out the fifth image data from the fifth memory 515 in which the fifth image data that is the next image data of the fourth image data is stored, and has finished drawing the fourth image data. Later, drawing of the fifth image corresponding to the fifth image data is started. For example, the fifth image data, which is the fifth image data to be displayed, takes a longer time than the drawing time of the fourth image data when the maximum vertical and horizontal widths of the image are larger than the fourth image data. Drawing. It is assumed that this drawing rate is 11 Hz (that is, it takes 1/11 second).

  Next, the drive control unit 5 takes out the sixth image data from the sixth memory 516 in which the sixth image data that is the next image data of the fifth image data is stored, and finishes drawing the fifth image data. Later, drawing of the sixth image corresponding to the sixth image data is started. If the maximum width in the vertical direction and horizontal direction of the image is larger than that of the fifth image data, the sixth image data that is the image data displayed sixth is longer than the drawing time of the fifth image data. Drawing. Also, if the maximum width in the vertical and horizontal directions of the sixth image data, which is the image data displayed sixth, is smaller than the fifth image data, it is shorter than the drawing time of the fifth image data. Drawing takes time.

  As described above, in the optical scanning projector 1 of the present embodiment, the optical scanners 41 and 42 are driven by changing the refresh rate (the rate at which one image is drawn), but the image stored in the video data storage unit is displayed. Since the images are drawn in order, the image data is not thinned out.

  In the example described above, the configuration in which the video data storage unit 51 includes six memories has been described. However, the number of memories is not particularly limited as long as the above-described operation is possible. In the above-described example, a moving image formed by six images has been described. However, a moving image formed by seven or more images may be used. In this case, the seventh and subsequent images are overwritten in order from the first memory 511.

  In the optical scanning projector 1 according to the present embodiment, the refresh rate is changed for each frame of a moving image, so that there is a problem that it becomes faster or slower than the actual speed. However, this is an extremely effective technique for applications that require drawing without thinning out all image data. This case will be described with reference to FIG.

FIG. 7 is an explanatory diagram illustrating a projector used in an application that draws an evacuation direction on a wall or a floor with an arrow, for example, in an evacuation guidance signage at the time of a fire, and a drawing position thereof.
When the image data shown in FIGS. 5A, 5 </ b> B, and 5 </ b> C are repeatedly transmitted to the optical scanning projector 1 in order, the drawing time varies depending on the size of the image data. Is as described with reference to FIG.
For example, when the optical scanning projector 1 draws an image at 10 Hz that is a clock frequency at which image data is transmitted, the drawing rate of the third image is 9 Hz, and the fourth image (the next image after the third image) In this case, the same image of the first image) cannot be drawn and is thinned out. Then, there may be a case where the person in the drawing range of the first image cannot see the image and the evacuation guidance cannot be performed smoothly.

  Further, in the advertisement signage, there may be an application that displays a message one character at a time by a projector, particularly an application that displays a certain character extremely large in order to attract people's attention. In such a case, it is meaningful to display the characters reliably one by one, and there may be a case where a correct message cannot be transmitted if even one character is thinned out.

  The optical scanning projector 1 according to the present embodiment is characterized in that when a plurality of image data is continuously received, the next image data is drawn after drawing one image data. In this specification, the drawing mode is referred to as a signage mode. On the other hand, the same optical scanning projector 1 may be used to draw content with a constant image size, such as a movie. In this case, each image may be drawn in synchronization with the frame frequency on the image data transmission side, as in the conventional case. This drawing timing is shown in FIG. In this specification, a mode in which each image is drawn in synchronization with the frame frequency as shown in FIG. 8 is called a movie mode.

  If the optical scanning projector 1 is provided with means for switching between the signage mode and the movie mode described above, it is convenient for the purpose.

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

  Further, in the present embodiment, the mode of drawing an image in the drawing area S11 formed on the display surface of the screen S has been described. However, the present invention is not limited to this. For example, an image is drawn directly on a wall surface, a floor surface, or the like. Also good.

  In this embodiment, the optical scanning unit 4 includes a pair of optical scanners 41 and 42. However, the present invention is not limited to this as long as the laser beam can be scanned. For example, the optical scanner, the galvanometer mirror, May be used. In this case, the galvanometer mirror is preferably used for vertical scanning.

  In the present embodiment, the laser beam LL is reciprocally scanned in the vertical direction. However, the present invention is not limited to this, and the laser beam may be scanned in only one direction in the vertical direction.

  In the present embodiment, the three dichroic mirrors 33r, 33g, and 33b are used to combine the red laser light RR, the green laser light GG, and the blue laser light BB to produce one laser light (light) LL. Although it is emitted, it may be coupled using a dichroic prism or the like.

  In the above-described embodiment, the light source unit 3 includes a laser light source 31r that emits a red laser, a laser light source 31b that emits a blue laser, and a laser light source 31g that emits a green laser. However, the present invention is not limited to this. For example, a laser light source that emits a red laser, a laser light source that emits a blue laser, and a laser light source that emits an ultraviolet laser may be provided. In this case, the screen includes a phosphor that generates green fluorescence when irradiated with an ultraviolet laser. Thereby, a full-color image can be displayed in the drawing area.

  DESCRIPTION OF SYMBOLS 1 ... Optical scanning projector, 3 ... Light source unit, 31r, 31g, 31b ... Laser light source, 310r, 310g, 310b ... Drive circuit, 320r, 320g, 320b ... Light source, 32r, 32g, 32b ... Collimator lens, 33r, 33g, 33b ... Dichroic mirror, 4 ... Optical scanning unit, 41, 42 ... Optical scanner, 411 ... Substrate, 411a, 421a ... Movable plate, 411b ... Supporting unit, 411c, 411d ... Connecting unit, 411e, 421e ... Light reflecting unit 412 ... Spacer member, 413 ... Counter substrate, 414 ... Permanent magnet, 415 ... Coil, 416 ... Voltage application means, 417 ... Drive means, 427 ... Drive means, 43 ... Angle detection means, 431 ... Piezoelectric element, 432 ... Origin Power detection unit, 433 ... angle detection unit, 44 ... angle detection means, 5 ... drive control unit, 51 ... projection Data storage unit, 511 ... first memory, 512 ... second memory, 513 ... third memory, 514 ... fourth memory, 515 ... fifth memory, 516 ... sixth memory, 52 ... video data Calculation unit 53 ... Drawing timing generation unit, 54 ... Light source modulation unit, 55 ... Deflection angle calculation unit, 56 ... Angle instruction unit, 57 ... Calibration curve storage unit, 58 ... Image size detection unit, S ... Screen, S1 ... Display Surface, S11: drawing region, L: drawing line, LL: laser beam.

Claims (6)

A light source;
An optical scanner that scans light from the light source into a drawing area;
An image data input section for capturing a plurality of continuous image data;
An image size detector for detecting the size of each of the plurality of image data for each image;
An image data storage unit for sequentially storing the plurality of image data;
An image data transmission unit for transmitting the plurality of image data to the optical scanner in the order stored in the image data storage unit;
A drive control unit for controlling the drive of the optical scanner,
The operation of the optical scanner is changed according to the size of each image of the plurality of image data, and after the optical scanner finishes drawing one image data of the plurality of image data, the one image data An image forming apparatus for drawing next image data.   The image forming apparatus according to claim 1, wherein an operation time of the optical scanner is lengthened as an image size of each of the plurality of image data is increased.   The optical scanner scans light two-dimensionally in the drawing area by performing main scanning in the first direction with light from the light source and sub-scanning in a second direction orthogonal to the first direction. 3. The image of the image data is drawn by fixing or changing the amplitude of the scanner in the first direction and changing the amplitude of the scanner in the second direction. The image forming apparatus described.   The drive control unit controls the driving of the optical scanner so that the amplitude of the main scanning on the drawing area is equal to the maximum width in the first direction of the image range drawn in the drawing area. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The drive control unit controls driving of the optical scanner so that an amplitude of the sub-scan on the drawing area is equal to a maximum width in the second direction of an image range drawn in the drawing area. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. A light source;
An optical scanner that scans light from the light source into a drawing area;
An image data input section for capturing a plurality of continuous image data;
An image size detector for detecting the size of each of the plurality of image data for each image;
An image data storage unit for sequentially storing the plurality of image data;
An image data transmission unit for transmitting the plurality of image data to the optical scanner in the order stored in the image data storage unit;
A drive control unit for controlling the drive of the optical scanner,
A first drawing mode for operating the optical scanner to draw the plurality of image data at a constant period;
As the size of each image of the plurality of image data increases, the second drawing mode for changing the drawing cycle by extending the operation time of the optical scanner;
Can be switched.

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