• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    PURPOSE: A laser scanning unit is provided for enhancing a scanning speed of a laser diode without increasing a revolution of a polygon mirror. CONSTITUTION: First and second laser diodes(200, 201) scan a laser beam used as a light source in accordance with a video signal of an input image. First and second collimator lenses(202, 203) change each lease beam from the first and second laser diodes(200, 201) to a parallel beam with respect to an optical axis. First and second cylinder lenses(204, 205) change the parallel beam from the first and second collimator lenses(202, 203) to a horizontal linear beam with respect to a sub-scanning direction. A polygon mirror(206) moves the horizontal linear beam from the first and second cylinder lenses(204, 205) at a constant speed and scan the same. A reflection mirror(208) reflects the laser beam outputted from the second laser diode(201) and refracted by the polygon mirror(206).
    公开号:KR20000060134A
    申请号:KR1019990008212
    申请日:1999-03-12
    公开日:2000-10-16
    发明作者:정수종
    申请人:윤종용；삼성전자 주식회사；
    IPC主号:
    专利说明:

    Laser Scanning Unit {LASER SCANNING UNIT}
    The present invention relates to a laser scanning unit, and more particularly, by installing a plurality of laser diodes (Laser Diode) for emitting light according to the video data input from the laser scanning unit by dividing one line of the photosensitive drum, The present invention relates to a laser scanning unit capable of improving the scanning speed of a laser diode at a constant rotation speed.
    In general, a laser printer is an apparatus for reproducing an image image by imaging a laser beam emitted from a laser diode by a video signal on a photosensitive drum and transferring a latent image formed on the photosensitive drum to a medium such as paper.
    The configuration of a conventional laser scanning unit that generates a laser beam in the laser printer and forms an image on a photosensitive drum will be described with reference to FIG. 1.
    1 is a perspective view showing a conventional laser scanning unit.
    As shown in the figure, a laser diode 100 for emitting a laser beam used as a light source in accordance with a video signal of the input image; A collimator lens 101 for making the laser beam emitted from the laser diode 100 into parallel light with respect to the optical axis; A cylinder lens 102 for making parallel light through the collimator lens 101 into linear light in a horizontal direction with respect to the sub-scanning direction; A polygon mirror 103 for scanning by moving the linear light in the horizontal direction through the cylinder lens 102 at an isotropic speed; A polygon mirror driving motor 104 which rotates the polygon mirror 103 at an isotropic speed; An f Lens 105 having a constant negative refractive index with respect to the optical axis and polarizing light at an isoline velocity through the polygon mirror 103 in the main scanning direction and correcting spherical aberration to focus on the scanning surface; an imaging reflection mirror 106 for vertically reflecting the laser beam through the fθ lens 105 to form an image on the surface of the photosensitive drum 107, which is an imaging plane; a horizontal synchronous mirror 108 for reflecting the laser beam through the fθ lens 105 in a horizontal direction; The optical sensor 109 is configured to receive the laser beam reflected from the horizontal synchronous mirror 108 and to synchronize the laser beam.
    The fθ lens 105 may include a spherical aberration correcting spherical lens 105a that focuses and polarizes a laser beam refracted at an isoline speed in the polygon mirror 103; And a toric lens 105b that polarizes the spherical aberration-corrected laser beam through the spherical lens 105a in the main scanning direction with a constant refractive index.
    In order to improve the recording speed in such a conventional laser scanning unit, the speed at which the laser beam is refracted for each of the rotating polygon mirrors, that is, the polygon mirrors 103, can be increased, thereby increasing the scanning speed. .
    For example, assuming that the rotation speed of the polygon mirror 103 is 10,000 rpm (Revolution Per Minute) in 8PPM (Pulse Phase Modulation), the polygon mirror 103 is rotated at 20,000 rpm to use the laser scanning unit at 16 PPM. You have to.
    Therefore, in order to use the laser scanning unit in a high resolution, high speed printer, a high speed polygon motor driving motor 104 which speeds up the rotation speed of the polygon mirror 103 is required. In order to increase the rotation speed of the polygon mirror 103 to increase the speed, an air bearing or a magnetic bearing should be used. Such a device has a problem that its price is very expensive.
    That is, in the conventional laser scanning unit, in order to quickly rotate the polygon mirror in order to improve the recording speed, the price of the device increases, and a problem arises in that noise and vibration increase due to the fast driving of the polygon mirror driving motor. do.
    Accordingly, the present invention is to solve such a problem, an object of the present invention by using a plurality of laser diodes to be performed by dividing the scanning of one line, to improve the scanning speed while maintaining the speed of the motor as it is A laser scanning unit can be provided.
    1 is a perspective view showing a conventional laser scanning unit,
    2 is a perspective view of a laser scanning unit according to the present invention;
    Features of the present invention for achieving the above object are a collimator lens for advancing a laser beam emitted according to an input video signal to parallel light, a cylinder lens for advancing parallel light to a linear light in a horizontal direction, and a horizontal direction A laser scanning unit comprising a polygon mirror that moves a linear light at an isotropic speed to form an image point on a photosensitive drum through an imaging lens, wherein the laser beam emits a laser beam on opposite mirror surfaces among various mirror surfaces of the polygon mirror. When the video data is input from the first and second laser diodes and the video controller, the laser diode controller divides the data corresponding to one line of the video data and transmits the signals according to the divided video data to the first and second laser diodes, respectively. And a polygon mirror emitted from the second laser diode The standing refractive laser beam lies in comprising a reflecting mirror for reflecting.
    Preferably, the first laser diode receives a video signal from the beginning to the middle of the divided video data, and the second laser diode receives a video signal from the last to the middle of the divided video data.
    Preferably, the reflecting mirror is concave.
    Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, in adding reference numerals to the elements of each drawing, it should be noted that the same elements are denoted by the same reference numerals as much as possible even if they are displayed on different drawings. In addition, in the following description there are shown a number of specific details, such as components of the specific circuit, which are provided only to help a more general understanding of the present invention that the present invention may be practiced without these specific details. It is self-evident to those of ordinary knowledge in Esau. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.
    And, there may be a plurality of embodiments of the present invention, hereinafter will be described in detail for the preferred embodiment. Through this preferred embodiment, it is possible to better understand the objects, features and advantages of the present invention.
    2 is a perspective view showing a laser scanning unit according to the present invention.
    According to an embodiment of the invention, the first and second laser diodes (200, 201) for emitting a laser beam used as a light source in accordance with the video signal of the input image; First and second collimator lenses 202 and 203 for making respective laser beams emitted from the first and second laser diodes 200 and 201 into parallel light with respect to the optical axis; First and second cylinder lenses 204 and 205 for making parallel light through the first and second collimator lenses 202 and 203 into linear light in a horizontal direction with respect to the sub-scan direction; A polygon mirror 206 for scanning by moving the linear light in the horizontal direction through the first and second cylinder lenses 204 and 205 at an isotropic speed; A polygon mirror driving motor 207 for rotating the polygon mirror 206 at an isotropic speed; A reflector 208 which reflects the laser beam emitted from the second laser diode 201 and refracted by the polygon mirror 206; An fθ lens 209 having a constant negative refractive index with respect to the optical axis and polarizing light at an isoline velocity through the polygon mirror 206 in the main scanning direction and correcting spherical aberration to focus on the scanning surface; an imaging reflecting mirror 210 which vertically reflects a laser beam through the fθ lens 209 and forms an image on a surface of the photosensitive drum 211 as an imaging surface in a point shape; a horizontal synchronous mirror 211 for reflecting the laser beam through the fθ lens 209 in a horizontal direction; The optical sensor 212 is configured to receive the laser beam reflected from the horizontal synchronous mirror 211 and to synchronize the laser beam.
    Here, the polygon mirror 206 uses only one mirror surface among six mirror surfaces to refract the laser beam emitted from the first laser diode 200. Accordingly, the second laser diode 201 is installed at a position where the emitted laser beam can be refracted in the unused mirror surface among the six mirror surfaces of the polygon mirror 206, that is, the position opposite to the first laser diode 200. It is preferable to be.
    In addition, the reflector 208 reflects the laser beam emitted from the second laser diode 201 and reflected by the polygon mirror 206 to be imaged on the photosensitive drum 211 through the f Lens 209. In this case, the position where the laser beam emitted from the first laser diode 200 is refracted is closer to the photosensitive drum 211 than the position where the laser beam emitted from the second laser diode 201 is reflected by the reflector 208. The angle of view of the laser beam reflected by 208 and formed on the photosensitive drum 211 ( ) Is the angle of view of the laser beam emitted from the first laser diode 200 and refracted by the polygon mirror 206. Must be less than). Therefore, the reflector 208 is an angle of view of the laser beam emitted from the second laser diode 201 ( It is preferable that it is a concave reflector in order to reduce).
    The laser diode controller 300 controls the time of turning on the first and second laser diodes 200 and 201 according to the input video data. That is, when the video data is input, one line of data scanned by the photosensitive drum 211 is divided and transmitted to the first and second laser diodes 200 and 201, respectively.
    The operation of the present invention configured as described above will be described in detail with reference to FIG. 2.
    When the video data is input from the video controller (not shown), the laser diode controller 300 divides the video data corresponding to one line formed in the photosensitive drum 211 and divides the first laser diode from the first start data to the intermediate data. 200 is transmitted to the second laser diode 201 from the last end data to the intermediate data at the same time.
    The first laser diode 200 is turned on according to the input video signal and emits a laser beam. Through the first collimator lens 202, the laser beam changes parallel light with respect to the optical axis, and the parallel light is connected to the first cylinder lens ( At 204, the light is changed into linear light in the horizontal direction with respect to the sub-scan direction. The laser beam made of linear light is refracted at one surface a of six surfaces of the polygon mirror 206 to be incident on the fθ lens 209, and the laser beam incident on the fθ lens 209 is polarized in the main scanning direction. And correct the spherical aberration and focus on the scanning plane. The laser beam through the fθ lens 209 is vertically reflected by the imaging reflective mirror 210 to form an electrostatic latent image at the initial starting position of the surface of the photosensitive drum 211, which is an imaging plane, and rotation of the polygon mirror 206. As a result, the laser beam sequentially forms an electrostatic latent image while moving from the start position of the photosensitive drum 211 to an intermediate position.
    On the other hand, the second laser diode 201 is turned on in accordance with the input video signal and emits a laser beam, the laser beam changes parallel light with respect to the optical axis through the second collimator lens 203, parallel light is the second cylinder The lens 205 is changed into linear light in the horizontal direction with respect to the sub-scanning direction. The laser beam made of linear light is refracted at one surface b of six surfaces of the polygon mirror 206 and incident on the reflector 208. The reflector 208 reflects the incident laser beam, and the laser beam reflected by the reflector 208 is incident on the fθ lens 209, and the laser beam incident on the fθ lens 209 is polarized in the main scanning direction and spherical Correct the aberration to focus on the scanning plane. The laser beam through the fθ lens 209 is vertically reflected by the imaging reflective mirror 210 to form an electrostatic latent image at the last end position of the surface of the photosensitive drum 211 which is the imaging surface, and rotation of the polygon mirror 206. As a result, the laser beam sequentially moves from the end position to the intermediate position of the photosensitive drum 211 to form an electrostatic latent image.
    Since the laser beam is emitted from the first and second laser diodes 200 and 201 by dividing the input video data of one line, the time for forming the electrostatic latent image on the photosensitive drum 211 is reduced by half. That is, using the polygon mirror 206 which rotates at the speed of the same polygon mirror driving motor 207, it is possible to obtain twice the scanning speed.
    As described above, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.
    As described above, according to the laser scanning unit according to the present invention, since the electrostatic latent image is formed on the photosensitive drum using a plurality of laser diodes, the scanning speed of the laser diode can be improved without increasing the rotation speed of the polygon mirror. There is an advantage to that.
    权利要求:
    Claims (3)
    [1" claim-type="Currently amended] A collimator lens configured to advance the laser beam emitted according to the input video signal into parallel light; A cylinder lens for advancing the parallel light into linear light in a horizontal direction; In the laser scanning unit consisting of a polygon mirror for moving the horizontal linear light at an isotropic speed to scan the image to form a point on the photosensitive drum through the imaging lens,
    First and second laser diodes which emit the laser beam on mirror surfaces facing each other among various mirror surfaces of the polygon mirror;
    A laser diode controller which divides data corresponding to one line of the video data and transmits a signal according to the divided video data to the first and second laser diodes, respectively, when video data is input from a video controller;
    And a reflector reflecting the laser beam emitted from the second laser diode and refracted by the polygon mirror.
    [2" claim-type="Currently amended] The display device of claim 1, wherein a first to middle video signal of the divided video data is input to the first laser diode, and a last to middle video signal of the divided video data is input to the second laser diode. Laser scanning unit, characterized in that.
    [3" claim-type="Currently amended] The laser scanning unit of claim 1, wherein the reflector is concave.
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    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1999-03-12|Application filed by 윤종용, 삼성전자 주식회사
    1999-03-12|Priority to KR1019990008212A
    2000-10-16|Publication of KR20000060134A
    优先权:
    申请号 | 申请日 | 专利标题
    KR1019990008212A|KR20000060134A|1999-03-12|1999-03-12|Laser scanning unit|
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