JP2009016632A - Semiconductor laser drive device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser drive device which avoids early deterioration of a laser element by suppressing stray capacitance and inductance inherent in a wiring mechanism through to a plurality of laser elements from a drive element, and by suppressing excessive light emission because of overshoot of a laser beam. <P>SOLUTION: The drive elements 2 are mounted by dividing into a plurality of printed boards 1, and the drive elements 2 are arranged near semiconductor laser devices 3, respectively, and thereby lengths of the wiring mechanisms 5 from the drive elements 2 reaching the laser elements 4 are almost equal to each other. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor laser driving apparatus having a plurality of laser elements, for example, used in optical communication, a laser printer, and the like.

  FIG. 1 is a schematic configuration diagram of a conventional semiconductor laser driving apparatus in which switching of one laser element is performed by one driving element. The semiconductor laser driving device includes a driving element 2 mounted on a printed circuit board 1, a semiconductor laser device 3 on which a laser chip 6 having a laser element 4 is mounted, a conductor pattern and a connector on the printed circuit board 1, and the semiconductor laser. A wiring mechanism 5 for electrically connecting leads, wires, and the like in the apparatus 3 is provided.

  In this wiring mechanism 5, as described in Patent Document 1 and the like, a microstrip line is formed in a cable connecting the printed circuit board 1 and the semiconductor laser device 3, and the laser element 4 is modulated at high speed. In some cases, the impedance is maintained such that the characteristics of the light output are not deteriorated.

  On the other hand, in application to a laser printer or the like, a multi-beam scanning method using a plurality of laser beams is often employed with an increase in printing speed and printing dot density. In this multi-beam scanning method, as shown in FIGS. 2 and 4, a semiconductor laser device (for example, a semiconductor laser device 3A) on which a laser chip (for example, a laser chip 6A) having one laser element (for example, a laser element 4A) is mounted is used. In the case of using a plurality, and in the case of using one semiconductor laser array device 8 on which one laser array chip 7 formed with a plurality of laser elements 4A to 4C shown in FIG. There are cases where a plurality of laser array devices 8 are used.

JP-A-63-260465

  However, the following problems exist in the system in which switching of the plurality of laser elements shown in FIGS.

  For example, in the example shown in FIG. 2, there is a difference in length between the wiring mechanism 5A from the driving element 2A to the laser element 4A and the wiring mechanism 5B from the driving element 2B to the laser element 4B. A difference in the length of the wiring mechanisms 5A and 5B between the plurality of laser elements 4A and 4B is equivalent to a difference in stray capacitance and inductance inherent in the wiring mechanisms 5A and 5B. In application to the adopted laser printer or the like, a difference occurs in switching characteristics between scanning lines. As a result, there is a problem that vertical lines, diagonal lines, characters, outlines of solid portions, and the like cannot be printed sharply.

In the case of the example shown in FIG. 4, the wiring mechanisms 5A to 5D are provided between the plurality of laser elements 4A to 4D.
In addition to the difference in the length, the wiring mechanism 5 becomes longer depending on the laser element 4, and the stray capacitance and the inductance inherent in the wiring mechanism 5 increase, so that when the laser element 4 is switched, A phenomenon occurs in which the laser beam temporarily over-emits due to overshoot or the rise of the laser beam is delayed.

  For this reason, the light emitting end face of the laser element 4 is damaged and the laser element 4 deteriorates early, and the laser printer is suspended in application to a laser printer or the like, or the rising speed of the laser light is slow, so that the switching speed cannot be increased. However, there is a problem that it is difficult to increase the speed in application to a laser printer or the like.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a semiconductor laser driving apparatus capable of eliminating the above-described drawbacks of the prior art and suppressing stray capacitance and inductance inherent in a wiring mechanism from a driving element to a plurality of laser elements. It is in.

  In order to achieve the above object, according to a first means of the present invention, there is provided a semiconductor laser driving device that performs switching of a semiconductor laser device having a plurality of laser elements by a driving element. It is characterized by being approximately equal.

  A second means of the present invention is characterized in that, in the first means, a wiring mechanism from the drive element to the laser element is approximately equal in length between a plurality of laser elements.

  According to a third means of the present invention, in the first means, a wiring mechanism from the driving element to the laser element is approximately equal in length and equal in width between the plurality of laser elements.

  According to a fourth means of the present invention, in the first to third means, the plurality of driving elements are divided and mounted.

  The present invention is configured as described above, and can provide a semiconductor laser driving apparatus capable of suppressing stray capacitance and inductance inherent in a wiring mechanism extending from the driving element to a plurality of laser elements.

  According to the present invention, in a system in which a plurality of laser elements are switched by a drive element, the wiring mechanism from the drive element to the laser element is approximately equal in length between the plurality of laser elements. It is possible to make the switching characteristics equal.

  In addition, the drive element can be arranged in the vicinity of the semiconductor laser device by the configuration in which a plurality of printed circuit boards on which the drive element is mounted are dispersed. For this reason, it is easy to shorten the wiring mechanism from the driving element to the laser element, and it is possible to suppress stray capacitance and inductance inherent in the wiring mechanism from the driving element to the plurality of laser elements.

  Therefore, in application to a laser printer or the like, the modulation characteristics between scanning lines can be made equal, and vertical lines, diagonal lines, characters, outlines of solid portions, and the like can be printed sharply. is there. In addition, it is possible to avoid early deterioration of the laser element due to over-emission due to overshoot of the laser beam, shorten the rise time of the laser beam, avoid the stoppage of the laser printer operation, and increase the speed.

  Next, embodiments of the present invention will be described with reference to the drawings. 5 to 7 are schematic configuration diagrams of a semiconductor laser driving apparatus according to each embodiment of the present invention.

  In the embodiment shown in FIG. 5, the semiconductor laser devices 3A to 3D on which the laser chips 6A to 6D having the laser elements 4A to 4D are mounted are switched by the driving elements 2A to 2D mounted on the printed boards 1A to 1D. Yes. Further, a control board 9 having a function of dividing a video signal into four parts and transmitting the video signal to the drive elements 2A to 2D is provided.

  In this embodiment, since the driving elements 2A to 2D are divided and mounted on a plurality of printed boards 1A to 1D, the driving elements 2A to 2D can be disposed in the vicinity of the semiconductor laser devices 3A to 3D. .

  Therefore, the wiring mechanisms 5A to 5D extending from the driving elements 2A to 2D to the laser elements 4A to 4D can be made approximately equal in length, and the switching characteristics can be made equal among the laser elements 4A to 4D.

  Furthermore, the wiring mechanisms 5A to 5D extending from the driving elements 2A to 2D to the laser elements 4A to 4D can be shortened as compared with, for example, the conventional example shown in FIG. For this reason, it is possible to suppress stray capacitance and inductance inherent in the wiring mechanisms 5A to 5D extending from the drive elements 2A to 2D to the laser elements 4A to 4D.

  Therefore, in application to a laser printer or the like, the modulation characteristics between scanning lines can be made equal, and vertical lines, diagonal lines, characters, outlines of solid portions, and the like can be printed sharply. In addition, it is possible to avoid early deterioration of the laser element due to over-emission due to overshoot of the laser beam and to shorten the rise time of the laser beam, and it is possible to avoid stoppage of the laser printer and increase the speed.

  Further, although not shown in FIG. 5, the wiring mechanisms 5A to 5D extending from the driving elements 2A to 2D to the laser elements 4A to 4D are not only approximately equal in length but also approximately equal in width. The switching characteristics between the laser elements 4A to 4D can be made more equal.

  Further, it is sufficiently effective to extend the region where the wiring mechanisms 5A to 5D are approximately equal in length from the drive elements 2A to 2D to the leads of the semiconductor laser devices 3A to 3D.

  A configuration in which the semiconductor laser devices 3A to 3D are mounted on the printed boards 1A to 1D on which the driving elements 2A to 2D are mounted is also conceivable. In this case, since the wiring mechanisms 5A to 5D extending from the driving elements 2A to 2D to the laser elements 4A to 4D can be particularly shortened, stray capacitance and inductance inherent in the wiring mechanisms 5A to 5D are further suppressed. It is possible.

  In the embodiment shown in FIG. 6, the semiconductor laser devices 3A to 3D on which the laser chips 6A to 6D having the laser elements 4A to 4D are mounted are switched by the driving elements 2A to 2B mounted on the printed boards 1A to 1B. Yes. The driving element 2A drives the laser elements 4A to 4B, and the driving element 2B drives the laser elements 4C to 4D. A control board 9 having a function of dividing the video signal into four parts and transmitting the video signal to the driving elements 2A to 2B is provided.

  In this embodiment, since the driving elements 2A to 2B are divided and mounted on a plurality of printed boards 1A to 1B, the driving elements 2A to 2B can be arranged in the vicinity of the semiconductor laser devices 3A to 3D. .

  Therefore, the wiring mechanisms 5A to 5D extending from the driving elements 2A to 2B to the laser elements 4A to 4D can be made approximately equal in length, and the switching characteristics can be made equal among the laser elements 4A to 4D.

  Further, the wiring mechanisms 5A to 5D extending from the driving elements 2A to 2B to the laser elements 4A to 4D can be shortened as compared with, for example, the conventional example shown in FIG. For this reason, it is possible to suppress stray capacitance and inductance inherent in the wiring mechanisms 5A to 5D extending from the driving elements 2A to 2B to the laser elements 4A to 4D.

  Therefore, in application to a laser printer or the like, the modulation characteristics between scanning lines can be made equal, and vertical lines, diagonal lines, characters, outlines of solid portions, and the like can be printed sharply.

  In addition, it is possible to avoid early deterioration of the laser element due to over-emission due to overshoot of the laser beam, shorten the rise time of the laser beam, avoid the stoppage of the laser printer operation, and increase the speed.

  Further, although not shown in FIG. 5, the wiring mechanisms 5A to 5D extending from the driving elements 2A to 2B to the laser elements 4A to 4D are not only approximately equal in length but also configured to be approximately equal in width. The switching characteristics between the laser elements 4A to 4D can be made more equal.

  Further, it is sufficiently effective to extend the region where the wiring mechanisms 5A to 5D are approximately equal in length from the drive elements 2A to 2B to the leads of the semiconductor laser devices 3A to 3D.

  In the embodiment shown in FIG. 7, the semiconductor laser array device 8 on which the laser array chip 7 having the laser elements 4A to 4C is mounted is switched by the drive elements 2A to 2C mounted on the printed boards 1A to 1C. Further, a control board 9 having a function of appropriately dividing the video signal into three and transmitting it to the drive elements 2A to 2C is provided.

  In this embodiment, since the driving elements 2A to 2C are divided and mounted on the plurality of printed boards 1A to 1C, the driving elements 2A to 2C can be arranged in the vicinity of the semiconductor laser array device 8.

  Therefore, the wiring mechanisms 5A to 5C extending from the drive elements 2A to 2C to the laser elements 4A to 4C can be made approximately equal in length, and the switching characteristics can be made equal among the laser elements 4A to 4C.

  Further, the wiring mechanisms 5A to 5C extending from the driving elements 2A to 2C to the laser elements 4A to 4C can be shortened as compared with the conventional example shown in FIG. 3, for example. Therefore, it is possible to suppress stray capacitance and inductance inherent in the wiring mechanisms 5A to 5C extending from the driving elements 2A to 2C to the laser elements 4A to 4C.

  Therefore, in application to a laser printer or the like, the modulation characteristics between scanning lines can be made equal, and vertical lines, diagonal lines, characters, outlines of solid portions, and the like can be printed sharply. In addition, it is possible to avoid early deterioration of the laser element due to over-emission due to overshoot of the laser beam, shorten the rise time of the laser beam, avoid the stoppage of the laser printer operation, and increase the speed.

  Further, although not shown in FIG. 5, the wiring mechanisms 5A to 5C extending from the drive elements 2A to 2C to the laser elements 4A to 4C are not only approximately equal in length but also approximately equal in width. The switching characteristics between the laser elements 4A to 4C can be made more equal.

  Further, it is sufficiently effective to extend the region where the wiring mechanisms 5A to 5C are approximately equal in length from the drive elements 2A to 2C to the leads of the semiconductor laser array device 8.

  According to the present invention, in a system in which switching of a plurality of laser elements is performed by a driving element, the switching characteristics between the plurality of laser elements are made equal, and the wiring mechanism from the driving element to the laser element is shortened. It is possible to suppress stray capacitance and inductance inherent in the wiring mechanism extending from to the plurality of laser elements.

  Therefore, in application to a laser printer or the like, it can be used to realize printing of vertical lines, diagonal lines, characters, outlines of solid portions, etc. sharply by equalizing the modulation characteristics between scanning lines. Also, when laser beam overshooting avoids early deterioration of the laser element due to over-emission and shortens the rise time of the laser beam, so that the laser printer can be stopped and speeded up. Available to:

It is a schematic block diagram of the conventional semiconductor laser drive device. It is a schematic block diagram of the other conventional semiconductor laser drive device. It is a schematic block diagram of the other conventional semiconductor laser drive device. It is a schematic block diagram of the other conventional semiconductor laser drive device. It is a schematic block diagram of the semiconductor laser drive device concerning Example 1 of the present invention. It is a schematic block diagram of the semiconductor laser drive device which concerns on Example 2 of this invention. It is a schematic block diagram of the semiconductor laser drive device concerning Example 3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printed circuit board, 1A ... Printed circuit board, 1B ... Printed circuit board, 1C ... Printed circuit board, 1D ... Printed circuit board, 2 ... Drive element, 2A ... Drive element, 2C ... Drive element, 2D ... Drive element, 3 ... Semiconductor laser device, 3A ... Semiconductor laser device, 3B ... Semiconductor laser device, 3C ... Semiconductor laser device, 3D ... Semiconductor laser device, 4 ... Laser element, 4A ... Laser element, 4B ... Laser element, 4C ... Laser element, 4D ... laser element, 5 ... wiring mechanism, 5A ... wiring mechanism, 5B ... wiring mechanism, 5C ... wiring mechanism, 5D ... wiring mechanism, 6 ... laser chip, 6A ... laser chip, 6B ... laser chip, 6C ... laser chip, 6D ... Laser chip, 7 ... Laser array chip, 8 ... Laser array device, 9 ... Control board.

Claims (4)

  A semiconductor laser driving apparatus for performing switching of a semiconductor laser apparatus having a plurality of laser elements by a driving element, wherein the modulation characteristics of the laser elements are substantially equal among the plurality of laser elements.   2. The semiconductor laser driving device according to claim 1, wherein a wiring mechanism from the driving element to the laser element is approximately equal in length between a plurality of laser elements.   2. The semiconductor laser driving device according to claim 1, wherein a wiring mechanism from the driving element to the laser element is approximately equal in length and equal in width between a plurality of laser elements.   4. The semiconductor laser driving apparatus according to claim 1, wherein the plurality of driving elements are divided and mounted.

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