JP2007121382A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve resolution while keeping a desired plotting condition. <P>SOLUTION: A light source part 10 is composed of semiconductor substrates 12 to 14 of red, green and blue. Surface emitting laser elements 15 to 17 of corresponding colors are provided on the respective semiconductor substrates 12 to 14. The respective semiconductor substrates 12 to 14 are so laminated that the positions of the laser elements 15 to 17 are displaced from each other and notches are formed at the parts of the optical paths of the respective laser elements 15 to 17. The respective laser elements 15 to 17 are aligned in a subscanning direction when vied from front and simultaneously output laser beams of the respective colors for 3 lines. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus that forms an image by scanning with a laser beam.

There is known a projector that displays an image by irradiating a screen with laser light and scanning the laser light (see, for example, Patent Document 1). In the projector device described in Patent Document 1, a laser light source unit provided for each color for outputting red, green, and blue laser light is provided, and laser light output from each is passed through an optical modulator. A dichroic mirror is used to form one laser beam, and this laser light is two-dimensionally scanned and irradiated onto a screen to draw a color image.
Japanese Patent Laid-Open No. 2001-264661

  By the way, when the resolution of the image to be drawn is made high, the scanning distance by the laser beam becomes long, and if the scanning is completed within a certain drawing time, the moving speed of the laser beam is not increased. In other words, there is a problem that the luminance of the image to be drawn is lowered and the image quality is deteriorated. On the other hand, in the case where the drawing time is lengthened and the moving speed of the laser light is not so high, the effect of visual afterimage is reduced and is not recognized as one completed image, resulting in a preferable image quality. Not.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of improving image quality.

  In order to achieve the above object, in the image forming apparatus according to claim 1, a plurality of surface-emitting type semiconductor laser elements that emit laser light perpendicular to the substrate surface are arranged side by side on the substrate, and a plurality of lines are provided. And a scanning unit that deflects each laser beam from the light source unit and scans at least perpendicular to the direction in which the laser beams are arranged.

  According to a second aspect of the present invention, the light source unit has a plurality of surface emitting semiconductor laser elements of different colors, and the surface emitting semiconductor laser elements of each color are arranged in a line. According to a third aspect of the present invention, the light source unit is provided with a plurality of surface emitting semiconductor laser elements of different colors for each line.

  5. The image forming apparatus according to claim 4, wherein the light source unit includes a substrate for each color on which the surface emitting semiconductor laser elements of the same color are formed, and the substrates of each color are overlapped in the laser light output direction. The portion on the optical path of the laser beam from the surface emitting semiconductor laser element provided on the colored substrate is cut out. In the image forming apparatus according to the fifth aspect, each of the substrates of each color has a comb-teeth shape in which a portion corresponding to the surface emitting semiconductor laser element of the substrate of the other color is cut out. According to another aspect of the image forming apparatus of the present invention, the light source unit outputs red, green, and blue laser beams to form a color image. According to another aspect of the image forming apparatus of the present invention, the scanning unit performs sub-scanning in the direction in which the laser beams are arranged together with main scanning orthogonal to the direction in which the laser beams are arranged.

  The image forming apparatus according to claim 8 is provided with a plurality of microlenses arranged on the respective front surfaces of the respective surface emitting semiconductor laser elements. In the image forming apparatus according to claim 9, The lens array plate provided integrally is arranged on the front surface of the semiconductor substrate.

  According to the image forming apparatus of the present invention, since a plurality of lines of laser light are simultaneously irradiated from a plurality of surface-emitting type semiconductor laser elements provided on a semiconductor substrate, and a plurality of lines are drawn at the same time. A resolution image can be drawn. In addition, since the lasers of different colors are emitted in a state of being alternately arranged by superimposing the substrates for each color on which the surface emitting semiconductor laser elements of the same color are formed in the laser light output direction, the color image can be generated with a simple configuration. Can draw.

  A projector apparatus as an image forming apparatus embodying the present invention is shown in FIG. The projector device 2 irradiates the screen 4 with laser light from the opening 3a provided in the housing 3, and scans the irradiated laser light in the main scanning direction (arrow M direction) and the sub-scanning direction (arrow S direction). As a result, a color image is drawn in the display area 5 on the screen 4. In the housing 3, a light source unit 6, a sub-scanning device 7 and a main scanning device 8 constituting scanning means, and a circuit unit 9 comprising various circuits for controlling and driving them are provided. For convenience of explanation, in FIG. 1, the projector device 2 is drawn larger than the screen 4.

  The light source unit 6 outputs laser light for a plurality of lines, in this example, laser light for three lines. In order to display a color image, laser light for one line is laser light of three colors of red, green, and blue, and the light source unit 6 outputs nine laser lights in total for each of the three colors. The direction in which the laser beams are arranged is a sub-scanning direction orthogonal to the main scanning direction in which one line extends.

  Each laser beam from the light source unit 6 enters the sub-scanning device 7. The sub-scanning device 6 is for deflecting each laser beam in the sub-scanning direction and performing sub-scanning, and moves the irradiation position of the laser beam in the sub-scanning direction by three lines for each main scanning. The movement in the sub-scanning direction is performed when the main scanning position is outside the display area 5 where the laser beam is turned off.

  The main scanning device 8 performs main scanning by deflecting each laser beam deflected by the sub-scanning mirror device 7 in the main scanning direction, and reflects each incident laser beam toward the screen 4. The drive mechanism 8b is composed of a DC motor or the like for swinging the main scanning mirror 8a at high speed. By swinging the main scanning mirror 8a by the driving mechanism 8b, the irradiation position of each laser beam moves in the main scanning direction. In this example, display for 6 lines is performed by reciprocating the irradiation position of each laser beam in the main scanning direction.

  FIG. 2 shows the light source unit 10 and the lens array plate 11 incorporated in the light source unit 6. Moreover, the state which decomposed | disassembled the light source part 10 is shown in FIG. The light source unit 10 includes semiconductor substrates 12 to 14 for red, green, and blue stacked in the laser beam output direction, and a lens array plate 11 is assembled on the front surface thereof.

  The light source unit 10 outputs nine laser beams LR1, LG1, LB1, LR2, LG2,... LB3 of red, green, blue, red, green,. Nine laser beams LR1, LG1, LB1, LR2, LG2,... LB3 are laser beams for three lines, and three laser beams arranged in the order of red, green, and blue are one line. The laser beams LR1, LG1, and LB1, the laser beams LR2, LG2, and LB2 and the laser beams LR3, LG3, and LB3 are each for one line.

  A semiconductor substrate 12 for red, a semiconductor substrate 13 for green, and a semiconductor substrate 14 for blue are stacked in order toward the rear, and laser light of a corresponding color is provided on each of the semiconductor substrates 12 to 14 for each color. Are arranged so as to be arranged in a line at a predetermined pitch along the sub-scanning direction when viewed from the front. Each of the laser elements 15, 16, and 17 is a surface emitting laser semiconductor element that outputs the laser light in a direction perpendicular to the surface of the semiconductor substrate, in which the direction of light resonance is perpendicular to the surface of the semiconductor substrate It outputs ahead (arrow A direction) from the end.

  The red semiconductor substrate 12 has a comb-like shape in which three protrusions 12a and notches 12b are alternately formed at a predetermined pitch along the sub-scanning direction, and one red is provided for each protrusion 12a. A laser element 15 for outputting the laser beam is provided. The notch 12b is located on the front side without blocking the laser beams LG1 to LG3 from the laser element 16 of the green semiconductor substrate 13 and the laser beams LB1 to LB3 from the laser element 17 of the blue semiconductor substrate 14. The green and blue semiconductor substrates 13 and 14 are formed so as to cut out portions overlapping with the protruding portions 13a and 14a.

  Similar to the red semiconductor substrate 12, the green semiconductor substrate 13 has a comb-teeth shape in which protrusions 13a and notches 13b are alternately formed at a predetermined pitch. One green is formed on each protrusion 13a. A laser element 16 for outputting the laser beam is provided. Each protruding portion 13 a is shifted by one protruding portion in the sub-scanning direction with respect to each protruding portion 12 a so as not to overlap with the protruding portion 12 a of the red semiconductor substrate 12, and is output from the laser element 16. The laser beams LG1 to LG3 are output forward through the notch 12b of the semiconductor substrate 12 for red. The notch 13b provided in the green semiconductor substrate 13 is provided to pass the laser beams LB1 to LB3 from the laser elements 17 of the blue semiconductor substrate 14 disposed behind without blocking. The blue semiconductor substrate 14 is formed so as to cut out a portion that overlaps each protrusion 14a.

  The blue semiconductor substrate 14 is also the same as the red and green semiconductor substrates 12 and 13 and has a comb-like shape in which the protruding portions 14a and the cutouts 14b are alternately formed, one for each protruding portion 14a. Laser elements 17a to 17c for outputting blue laser light are provided, and each protruding portion 14a is arranged in the sub-scanning direction so as not to overlap the protruding portions 12a and 13a of the semiconductor substrates 12 and 13 for red and green. It is provided to be shifted.

  In this example, the semiconductor substrates 12 to 14 are stacked in the order of red, green, and blue toward the rear, but the order can be arbitrarily determined. Further, each of the semiconductor substrates 12 to 14 has a comb-teeth shape, but when the semiconductor substrates 12 to 14 are stacked, the laser light from the laser element provided on the semiconductor substrate on the rear side of the semiconductor substrate on the front side is emitted. Any shape may be used as long as it can be prevented from blocking, and a cutout may be formed at least in a portion on the optical path of a laser beam from a laser element provided on a substrate of another color. For this reason, for example, it is not necessary to form the notch 14b in the blue semiconductor substrate 14 at the backmost position, and the blue semiconductor substrate 14 at the back of the green semiconductor substrate 13 in the middle is not required. It is only necessary to form a notch that allows the laser beam from to pass through. Further, the shape of the notch may be any shape as long as the laser beam from the laser element can pass through, and may be an opening instead of the notch.

  Normally, only surface emitting laser elements of the same color can be arranged on the same semiconductor substrate. However, in the present invention, a plurality of surface emitting laser elements of different colors are arranged for each color as described above. By arranging the semiconductor substrates of the respective colors in the laser light output direction by arranging them on the respective semiconductor substrates, it is possible to output laser lights having different colors in a line.

  The laser elements 15 to 17 are arranged so that laser elements of the same color are spaced by one line in the sub-scanning direction, but laser elements of the same line are arranged at intervals of one line. Alternatively, it may be arranged at intervals smaller than that. In this case, the semiconductor substrates 12 to 14 may be stacked while being relatively shifted. In this example, the case of three lines has been described. However, for example, 40 laser elements may be provided for each color, and laser light for 40 lines may be output.

  The lens array plate 11 is assembled to the front surface of the light source unit 10. The lens array plate 11 is formed with collimating microlenses 11a at respective positions where each laser beam passes, and each microlens 11a appropriately applies incident laser beams LR1 to LR3, LG1 to LG3, and LB1 to LB3. It is converted into a parallel light beam with a large diameter and output.

  Since the microlenses 11a are arranged at positions close to the laser elements 15 to 17 to collimate the respective laser beams, the laser elements 15 to 17 of the respective colors of the light source unit 10 configured as described above are output directions of the laser beams. There is no particular problem even if it is around. Note that the microlenses 11a can be moved back and forth and arranged stepwise depending on the front and back of the laser element. Further, the power of the micro lens 11a may be increased or decreased according to the distance between the laser elements 15 to 17 of each color and the micro lens 11a and the wavelength of the laser light.

  FIG. 4 shows the sub-scanning device 7 used in this example. As the sub-scanning device 7, an electromagnetically driven optical scanner formed as a micro device called a so-called MEMS (Micro Electro Mechanical System) in which functional elements are formed on one substrate using a semiconductor process technology is used. In the sub-scanning device 7, a mirror 22 is arranged inside a rectangular frame 21. The mirror 22 is connected to the frame 21 by a pair of torsion bars 23 provided at both ends thereof, and is swingable in a direction about the torsion bar 23 as an axis. A drive coil 24 is provided on the periphery of the mirror 22. A pair of magnets 25 that provide a magnetic field in a direction orthogonal to the torsion bar 23 are disposed outside the frame 21. When a current is passed through the drive coil 24 placed in the magnetic field generated by the pair of magnets 25, a Lorentz force that rotates the mirror 22 is generated, and the mirror 22 rotates to a position that matches the restoring force of the torsion bar 23. The direction and amount of rotation of the mirror 22 are determined by the direction and magnitude of the current flowing through the drive coil 24.

  The sub-scanning device 7 configured as described above is arranged such that the direction of the rotation axis of the mirror 22 is orthogonal to the sub-scanning direction (the direction in which the laser beams are arranged), and every time one main scanning is completed, The mirror 22 is rotated by a certain amount, and the laser beam irradiation position is moved by three lines in the sub-scanning direction, and is controlled so that it returns to a predetermined expected position every time main scanning for one screen is completed. To do.

  In this example, sub-scanning is performed using an electromagnetically driven optical scanner, but an electromagnetically driven optical scanner can also be used in the main scanning direction. Also, main scanning and sub-scanning can be performed using one electromagnetically driven optical scanner capable of swinging the mirror in the biaxial direction. Also, other scanning devices such as a polygon mirror can be used.

  FIG. 5 shows an electrical configuration of the projector device 2. The controller 31 controls each part of the projector device 2. In the image memory 32, image data for one frame of red, green, and blue of a still image to be displayed when a still image is displayed is input and written from an external computer or the like. The image data written in the image memory 32 is repeatedly read when displaying an image.

  In addition, when displaying a moving image, a video signal is input to the A / D converter 33 from the outside. The A / D converter 33 converts the input video signal into red, green, and blue image data and sends the image data to the scan converter 34. The image data written to the image memory 32 and the image data output from the A / D converter 33 are 8-bit data and can represent 256 gradations.

  The scan converter 34 is for absorbing the difference between the input video signal and the scanning speed of the image display by the projector device 2, and controls the memory that requires a memory capacity for a plurality of frames and the input / output of each memory. Consists of a memory controller and the like, while image data for one frame is read from the memory a plurality of times, the image data of the next frame is recorded in another memory, and after this recording is completed, the memory is switched and one frame worth is recorded. Are read from the memory.

  The selector 35 selects one of the image memory 32 and the scan converter 34, and sends image data from the selected side to the γ correction unit 36. Selection by the selector 35 is controlled by the controller 31 in accordance with an operation of an operation unit (not shown).

  The γ correction unit 36 performs correction to appropriately reproduce the gradation of the input image. For example, the image data generated in accordance with the gamma characteristic of a display such as a CRT has a specific gamma characteristic. Gamma correction is performed by the projector device 2 so as to obtain an appropriate gradation expression. The γ correction unit 36 has an LUT (look-up table) 36a that stores in advance γ-corrected corrected image data corresponding to input image data in association with each value of image data. Then, gamma correction is performed by taking out the corresponding corrected image data from the LUT 36a and outputting it.

  The corrected image data output from the γ correction unit 36 is sent to the buffer memory unit 37. The buffer memory unit 37 is composed of nine line memories provided so as to correspond to the nine laser elements. Each line memory has a capacity for storing one color of corrected image data for one line. By writing one line of corrected image data for one line to be displayed by the laser element corresponding to each line memory, three lines of corrected image data to be displayed simultaneously in one main scan are written in the buffer memory unit 37. Is written. The buffer memory unit 37 simultaneously reads out the corrected image data for three lines and sequentially outputs them. The contents of the buffer memory unit 37 are updated to the corrected image data for the next three lines every time display for three lines by one main scan is completed. Note that the direction in which the corrected image data is read from each line memory corresponds to the moving direction of the laser beam during main scanning, and the reading direction is alternately switched.

  The D / A converter 38 includes nine D / A converters provided corresponding to the respective line memories of the buffer memory unit 37, and each D / A converter includes a corresponding line memory. The corrected image data input in synchronization with the main scanning during the main scanning period is converted into a signal level obtained by linearly converting the value and output. As a result, the corrected image data of three colors for three lines stored in the line memory unit 37 are converted into analog modulation signals, respectively.

  The laser drive circuit 39 drives each laser element 15, 16, 17 of the light source unit 10 based on the corresponding modulation signal. The laser drive circuit 39 operates in an ACC (Auto Current Control) mode in which, for example, a drive current corresponding to a modulation signal flows through the laser element, and directly modulates each laser beam.

  The light source unit 6 is provided with a cooler 41 composed of, for example, a Peltier element and a heat sink, and the temperature of the light source unit 10 is kept constant by operating the cooler 41 under the control of the temperature control circuit 42. It is supposed to be kept. As a result, the intensity of the laser light output from each of the laser elements 15 to 17 corresponds to the drive current.

  The scanning control circuit 44 controls driving of the sub-scanning device 7 and the main scanning device 8. The scanning position detection unit 45 receives a detection light reflected from the main scanning mirror 8a when the irradiation position of the laser light reaches the edge of the display area 5 and a light projecting unit that irradiates the main scanning mirror 8a with detection light. And a timing signal when the detection light is received by the light receiving unit. This timing signal is sent to the controller 31 and is used for sub-scanning timing by the sub-scanning mirror device 7 and timing control for turning on / off the laser elements 15 to 17 during main scanning.

  FIG. 6 shows a laser light irradiation state. In FIG. 6, the positions irradiated with the red laser beams LR1 to LR3 are denoted by reference numerals R1 to R3, the positions irradiated with the green laser beams LG1 to LG3 are denoted by reference numerals G1 to G3, and the blue laser beams LB1 to LB1 are irradiated. The positions where LB3 is irradiated are indicated by symbols B1 to B3. The screen 4 is irradiated with three lines of laser light of three colors for one line in a line with red, green, blue, red, green,..., Blue along the sub-scanning direction.

  For example, when “N” is 1, 2, 3,..., When the red laser beam LR1, the green laser beam LG1, and the blue laser beam B1 are irradiated to display the Nth line. The laser beams LR2, LG2, and LB2 of each color are irradiated to display the (N + 1) th line, and the laser beams LR3, LG3, and LB3 of each color are irradiated to display the (N + 1) th line. Although the irradiation positions of the laser beams of the respective colors in one line are not overlapped, since these positions are close to each other, it is visually recognized as a color line obtained by combining the three colors.

  FIG. 7 shows the scanning state of the laser beam. In FIG. 7, the irradiation positions LA of the laser beams LR1 to LR3, LG1 to LG3, and LB1 to LB3 are shown. The irradiation position LA moves from one outer side of the display area 5 to the other outer side by one main scanning. This movement is performed by the main scanning device 8 as described above. During this one main scan, based on the timing signal, a lighting period in which the laser element is turned on only when the irradiation position LA is in the display area 5, and a light-out period in which the laser element is turned off when outside the display area 5. It is controlled to become.

  When the irradiation position LA reaches the outside of the display area 5 during one main scanning, that is, when the extinction period is reached, the irradiation position LA is moved by three lines in the sub-scanning direction. This movement in the sub-scanning direction is performed by a sub-scanning mirror. After the movement for the three lines, the irradiation position LA moves in the direction opposite to the movement during the previous main scanning, and the next main scanning is performed. In this way, three lines are displayed in one main scan, and a sub-scan is performed for each main scan, thereby rendering a color image on the entire surface of the display area 5.

  Next, the operation of the above configuration will be described. For example, when displaying a still image, image data of an image to be displayed is input to the projector device 2 from an external computer or the like and written into the image memory 32. After this writing is completed, the image memory 32 is selected by the selector 35 by operating the operation unit.

  After the selection of the selector 35 is completed, for example, red image data of the first line is sequentially read from the image memory 32 and sent to the γ correction unit 36. The γ correction unit 36 extracts, from the LUT 36a, red corrected image data corresponding to the value of the input image data for sequentially input image data. As a result, the image data is converted to gamma-corrected corrected image data and output. Then, each of the red corrected image data from the γ correction unit 36 is written in one line memory of the buffer memory unit 37.

  In this way, when each red corrected image data of the first line is written into the line memory, the green image data of the first line is subsequently read out sequentially from the image memory 32 and is the same as the red image data. Then, the image data is converted into corrected image data that has been gamma corrected by the γ correction unit 36 and sent to the buffer memory unit 37. The green corrected image data of the first line is written in a line memory different from the line memory in which the red corrected image data is written.

  When each of the green corrected image data of the first line is written into the line memory, the blue image data of the first line is sequentially read out from the image memory 32 and converted into corrected image data in the same procedure. The red, green corrected image data is written in a line memory different from the line memory in which the corrected image data is written.

  After the corrected image data of the three colors for the first line is written in the buffer memory unit 37 as described above, the image data for the second line is sequentially read from the image memory 32 for each color, It is converted into corrected image data by the same procedure and written in the buffer memory unit 37. At this time, the corrected image data of the second line is written for each color in a line memory different from the first line. Similarly, after writing the corrected image data of the second line, the image data of each color of the third line is sequentially read out from the image memory 32, converted into corrected image data, and written into the buffer memory unit 37. It is.

  As described above, when each of the corrected image data of the first to third lines is written in the buffer memory unit 37, the main scanning by the main operation device 8 is started, and the irradiation position of each laser beam is from the outside of the display area 5. When the edge is reached, a timing signal is input from the scanning position detector 45 to the controller 31. Then, in response to an instruction from the controller 31, the laser elements 15 to 17 are turned on by the laser driving unit 39, and the corrected image data of each color of the first to third lines is sequentially read from the buffer memory 37, and D / Each of the modulation signals is converted into a modulation signal by the A conversion unit 38 and input to the laser drive circuit 39. Thereby, each of the laser beams output from the laser elements 15 to 17 is modulated by the modulation signal, and their irradiation positions are moved in the main scanning direction.

  At this time, the laser beams LR1, LG1, and LB1 are driven based on the modulation signals generated from the corrected image data of the first line of the corresponding color, respectively. Further, the laser beams LR2, LG2, and LB2 are based on the modulation signals generated from the corrected image data of the second line of the corresponding color, respectively, and the laser beams LR3, LG3, and LB3 are the third of the corresponding color, respectively. Modulation is performed based on a modulation signal generated from the corrected image data of the line. Therefore, the first to third lines are displayed by the first main scanning.

  When the irradiation position of the laser beam reaches the edge of the display area 5 on the side opposite to the scanning start side in the first main scanning, each laser element 15 to 17 is turned off in response to the timing signal generated at that time. . Further, a sub-scanning instruction is given from the controller 31 to the sub-scanning device 7 via the scanning control circuit 44. As a result, the rotation amount in one direction of the mirror 22 of the sub-scanning device 7 is increased by a certain amount, and the irradiation position of the laser beam is moved by three lines in the sub-scanning direction.

  Further, while the laser elements 15 to 17 are extinguished and the extinction period is set, the image data of the fourth to sixth lines are read from the image memory 32, and the same as in the case of the first to third lines. Then, it is converted into corrected image data through the selector 35 and the γ correction unit 36 and written into the buffer memory unit 37.

When the main scanning of the laser beam is turned back and the irradiation position reaches the edge of the display area 5 again, the laser elements 15 to 17 are turned on by the laser driving unit 39 and the colors of the fourth to sixth lines are corrected. Image data is sequentially read from the buffer memory 37, converted into modulated signals by the D / A converter 38, and input to the laser drive circuit 39. At this time, the corrected image data in the buffer memory unit 37 is read in the direction opposite to the first to third lines. As a result, the second main scanning is performed while the laser beams output from the laser elements 15 to 17 are modulated by the modulation signals of the fourth to sixth lines.

  When the irradiation position of the laser beam reaches the edge of the display area 5 on the opposite side in the second main scanning, the laser elements 15 to 17 are turned off and the mirror 22 of the sub-scanning device 7 is in one direction. The rotation amount is further increased by a certain amount, and the irradiation position of the laser beam is moved by 3 lines in the sub-scanning direction. Further, during the turn-off period, the image data of the seventh to ninth lines are read out, and the corrected image data is written in the buffer memory unit 37 and read out when the display area 5 is reached. Each laser beam is modulated by the modulation signal created from them, and the seventh to ninth lines are displayed. Thereafter, display up to the last line is performed in the same manner.

  When the display of the final line is completed, the sub-scanning device 8 is returned so that the laser beam is at the irradiation position of the first to third lines, and then the display from the first to the last line is performed in the same procedure as described above. Is done and it is repeated. The observer can recognize the image displayed with the laser beam in this way as one image by the afterimage phenomenon.

  In the case of a moving image, the image data sent out from the scan converter 34 periodically changes in accordance with the periodic change of the frame. Therefore, the image (frame) displayed by the laser beam is periodically changed. Switched and displayed as a video.

  A still image is displayed on the screen 4 as described above. However, since main scanning is performed three lines at a time, even if the moving speed of the laser beam, that is, the main scanning speed is reduced, the necessary number of lines is displayed. Since it can be described, the main scanning speed can be slowed down and brightly displayed. In addition, since more lines can be displayed within the same time, high resolution can be achieved. These effects can be obtained at the same time.

  In the above embodiment, the case where a color image is displayed has been described. However, the present invention can also be used when displaying an image in a single color. When displaying an image in a single color, a plurality of laser elements of one color are used. They can be arranged in a line on the same semiconductor substrate. In the above-described embodiment, an example of a projector device has been described. However, the projector device can be used for various devices as long as it forms an image by scanning laser light. For example, the present invention can also be used for a printer device that irradiates photographic paper with laser light.

It is a perspective view which shows the outline of the projector apparatus which implemented this invention. It is a perspective view which shows a light source part. It is a disassembled perspective view which decomposes | disassembles and shows each semiconductor substrate of a light source part. It is a perspective view which shows an example of a subscanning device. It is a block diagram which shows the electrical structure of a projector apparatus. It is explanatory drawing which shows the irradiation state of each laser beam. It is explanatory drawing which shows the scanning state of each laser beam.

Explanation of symbols

2 projector device 6 light source unit 7 sub-scanning device 8 main scanning device 10 light source unit 11a microlens 12-14 semiconductor substrate 15-16 laser element

Claims (9)

In an image forming apparatus that forms an image by irradiating a laser beam,
A plurality of surface emitting semiconductor laser elements that emit laser light perpendicular to the substrate surface are arranged in a line on the substrate, and a light source unit that outputs laser light for a plurality of lines;
An image forming apparatus comprising: a scanning unit that deflects each laser beam from the light source unit and performs scanning at least perpendicular to a direction in which the laser beams are arranged.   The image forming apparatus according to claim 1, wherein the light source unit includes surface emitting semiconductor laser elements of a plurality of colors having different colors, and the surface emitting semiconductor laser elements of each color are arranged in a line. .   The image forming apparatus according to claim 2, wherein the light source unit includes a plurality of surface emitting semiconductor laser elements having different colors for each line.   The light source unit has a substrate for each color on which surface emitting semiconductor laser elements of the same color are formed, and the substrates for each color are overlapped in the laser light output direction and provided on at least other color substrates. 4. The image forming apparatus according to claim 2, wherein a portion on the optical path of the laser beam from the surface emitting semiconductor laser element is cut out.   5. The image forming apparatus according to claim 4, wherein each of the substrates of the respective colors has a comb-teeth shape in which portions corresponding to the surface emitting semiconductor laser elements of the substrates of the other colors are cut out.   6. The image forming apparatus according to claim 2, wherein the light source unit outputs red, green, and blue laser beams to form a color image.   6. The image forming apparatus according to claim 1, wherein the scanning unit performs sub-scanning in the direction in which the laser beams are arranged together with main scanning orthogonal to the direction in which the laser beams are arranged.   8. The image forming apparatus according to claim 1, further comprising a plurality of microlenses arranged on the front surface of each of the surface emitting semiconductor laser elements.   9. The image forming apparatus according to claim 8, wherein a lens array plate in which the microlenses are integrally provided is disposed on the front surface of the semiconductor substrate.

Images