JP2009276543A - Light source apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source apparatus which is made compact and in which the position of a collimator lens is easily adjustable. <P>SOLUTION: The light source apparatus 1 is used for an optical scanner. A laser diode 2 emits a beam B. A mirror 5 bends the optical path of the beam B. The collimator lens 7 is held in a barrel 38 and condenses the beam B passing through the mirror 5. A base 30 holds the mirror 5 and the barrel 38. A circuit substrate 32 is extended in parallel to the beam B passing through the mirror 5, and is connected to a laser diode 2. An open part is provided on the base 30, the open part which penetrates through the barrel 38 and is directed to the advancing direction of the beam B which the laser diode 2 emits. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light source device, and more particularly to a light source device used in an optical scanning device.

  FIG. 7 is a configuration diagram of a conventional light source device 100. The light source device 100 includes a laser diode 102, a circuit board 104, a holding table 108, and a collimator lens 112. In the light source device 100, the beam emitted from the laser diode 102 is directly incident on the collimator lens 112 and converted into parallel light.

  By the way, the light source device 100 has a problem that the device becomes large. More specifically, as shown in FIG. 7, the circuit board 104 is mounted perpendicular to the beam emitted by the laser diode 102. In addition, since the holding table 108 holds the laser diode 102 and the collimator lens 112, it has a longitudinal direction in the optical axis direction of the beam. Therefore, the circuit board 104 and the holding table 108 are L-shaped, and a useless space is generated on the holding table 108. That is, the light source device 100 has been increased in size.

  As a configuration for solving such a problem, for example, a light beam scanning optical device described in Patent Document 1 can be cited. FIG. 8 is a configuration diagram of the light beam scanning optical apparatus 200 described in Patent Document 1. In FIG. In FIG. 8, for easy understanding, the light beam scanning optical device described in Patent Document 1 is simplified.

  In the light beam scanning optical apparatus 200, the light beam emitted from the laser diode 102 facing downward is reflected in the horizontal direction by the mirror 110 and converted into parallel light by the collimator lens 112. The circuit board 104 can be horizontally arranged by bending the optical path of the light beam in this way. As a result, the circuit board 104 and the holding table 108 are not arranged in an L shape, and useless space on the holding table 108 is eliminated.

  However, the light beam scanning optical apparatus 200 has a problem that the workability of the position adjustment of the collimator lens 112 is poor. More specifically, in the light beam scanning optical apparatus 200, the position of the collimator lens 112 is adjusted by moving the holder 114 of the collimator lens 112 on the holding table 108 in the direction of the arrow. Therefore, the assembler of the light beam scanning optical apparatus 200 touches and moves the holder 114 from above.

However, as shown in FIG. 8, in the light beam scanning optical apparatus 200, the circuit board 104 is provided so as to cover the holding table 108. Therefore, it is difficult for the assembler to touch and move the holder 114 from above with the circuit board 104 attached.
Japanese Patent Laid-Open No. 11-218698

  SUMMARY OF THE INVENTION An object of the present invention is to provide a light source device that can reduce the size of the device and can easily adjust the position of a collimator lens.

  A light source device according to an aspect of the present invention is a light source device used in an optical scanning device, and is held by a light source that emits a beam, an optical path conversion unit that bends an optical path of the beam, a first holder, and A collimator lens that condenses the beam that has passed through the optical path changing means, a second holder that holds the optical path changing means and the first holder, and a parallel extension of the beam that has passed through the optical path changing means. And a circuit board to which the light source is connected. The second holder communicates with the first holder and faces the traveling direction of the beam emitted by the light source. An opening is provided in the space.

  In the light source device, the second holder is provided with an opening that communicates with the first holder and that is open to face the traveling direction of the beam emitted by the light source. Accordingly, even if the circuit board covers the second holder, the assembler can touch the first holder through the opening without removing the circuit board. Therefore, even if the circuit board is provided so as to cover the second holder in order to reduce the size of the light source device, the assembler can easily adjust the position of the collimator lens.

  Embodiments of a light source device according to the present invention will be described below with reference to the accompanying drawings.

(Outline of optical scanning device)
First, an outline of an optical scanning device to which a light source device according to the present invention is applied will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an outline of an optical scanning device. In FIG. 1, the optical scanning device generally includes a light source device 1, a cylindrical lens 11, a polygon mirror 12, three fθ lenses 13, 14 and 15, a cylindrical lens 16, and a plane mirror 17.

  The light source device 1 includes a laser diode 2 as a light source that emits a beam B, a mirror 5 that bends the optical path of the beam B, and a collimator lens 7 as a condensing unit. The beam B radiated from the laser diode 2 is reflected by the mirror 5, the optical path is bent by 90 degrees, and further collected by the collimator lens 7 into parallel light (or convergent light).

  The beam B that has passed through the collimator lens 7 reaches the polygon mirror 12 via the cylindrical lens 11. The cylindrical lens 11 condenses the beam B in the form of a long line in the main scanning direction near the reflecting surface of the polygon mirror 12. The polygon mirror 12 is rotationally driven at a constant angular velocity in the direction of arrow a. The beam B is deflected and scanned at an equal angular velocity on each reflecting surface based on the rotation of the polygon mirror 12, passes through the fθ lenses 13, 14, 15 and the cylindrical lens 16, and is reflected downward by the plane mirror 17. Thereafter, the beam B forms an image on the photosensitive drum 25 and scans in the arrow b direction.

  The fθ lenses 13, 14, and 15 have a function of correcting the main scanning speed on the photosensitive drum 25 at a constant speed (distortion aberration correction) for the beam B deflected at a constant angular speed by the polygon mirror 12. Similar to the cylindrical lens 11, the cylindrical lens 16 has power only in the sub-scanning direction, and the two cylindrical lenses 11 and 16 cooperate to correct the surface tilt error of the polygon mirror 12.

  The photosensitive drum 25 is driven to rotate at a constant speed in the direction of arrow c, and is subjected to main scanning in the direction of arrow b by the polygon mirror 12 and the fθ lenses 13, 14, and 15, and sub scanning in the direction of arrow c of the photosensitive drum 25. An image (electrostatic latent image) is written on the photosensitive drum 25.

(Configuration of light source device)
Next, the structure of the light source device 1 will be described with reference to the drawings. 2 to 4 are configuration diagrams of the light source device 1. More specifically, FIG. 2A is a front view of the light source device 1, and FIG. 2B is a side view of the light source device 1. FIG. 3 is a top view of the light source device 1, and FIG. 4 is a bottom view of the light source device 1. In the following description, the x-axis direction is a direction parallel to the optical axis of the beam B reflected by the mirror 5, the y-axis direction is a direction orthogonal to the x-axis direction on the horizontal plane, and the z-axis direction. Means a direction parallel to the optical axis of the beam B emitted by the laser diode 2.

  The light source device 1 includes a laser diode 2, a mirror 5, a collimator lens 7, a base base 30, a circuit board 32, a light source holder 34, male screws 36 a and 36 b, a lens barrel 38, and a leaf spring 40. Since the laser diode 2, the mirror 5, and the collimator lens 7 have already been described, further description is omitted.

  The circuit board 32 is a circuit for driving the laser diode 2 to which the laser diode 2 is electrically connected. The circuit board 32 is disposed so as to be perpendicular to the optical axis of the beam B emitted from the laser diode 2 (that is, parallel to the xy plane). Further, as shown in FIG. 3, holes hc, hd, and he for attaching the light source holder 34 are formed in the circuit board 32.

  The light source holder 34 is a holder for holding the laser diode 2 and is manufactured by bending a metal plate. The light source holder 34 is attached to the circuit board 32 so as to be parallel to the circuit board 32. More specifically, the light source holder 34 has attachment portions 34c, 34d, and 34e formed by being bent perpendicularly to the xy plane. The light source holder 34 has the mounting portions 34c, 34d, 34e inserted into holes hc, hd, he formed in the circuit board 32, so that the circuit board 32 is parallel to the circuit board 32. Is attached. As a result, the optical axis of the beam B emitted from the laser diode 2 is perpendicular to the light source holder 34.

  As shown in FIGS. 2 to 4, the light source holder 34 has attachment portions 34 a and 34 b that project in both the positive and negative directions in the y-axis direction. The mounting portions 34a and 34b are formed with holes for allowing the male screws 36a and 36b to pass therethrough.

  The lens barrel 38 is a holder that holds the collimator lens 7 and has a cylindrical shape.

  The base table 30 is a holder that holds the mirror 5, the light source holder 34, and the lens barrel 38. For example, the base table 30 is a table manufactured by a casting method. As shown in FIG. 2B, the base 30 has mounting arm portions 30a and 30b that extend in the z-axis direction and bend and extend in the x-axis direction at the tip thereof. . Attachment portions 34a and 34b of the light source holder 34 are fixed to the attachment arm portions 30a and 30b via male screws 36a and 36b, respectively. More specifically, the mounting arm portions 30a and 30b are formed with female screws extending in the z-axis direction and to which the male screws 36a and 36b are screwed. Then, the mounting portions 34a and 34b of the light source holder 34 are disposed on the lower side in the z-axis direction of the mounting arm portions 30a and 30b, and the male screws 36a and 36b are inserted into the female screws from the lower side in the z-axis direction. Thereby, the light source holder 34 is fixed on the base table 30, and the laser diode 2 and the circuit board 32 are also fixed on the base table 30. As a result, the circuit board 32 extends in the x-axis direction on the base table 30 as shown in FIG. 2B, and covers the base table 30 as shown in FIGS. Become.

  Further, in the base table 30, as shown in FIG. 2B, a mirror 5 is attached to the lower side of the laser diode 2 in the z-axis direction. In FIG. 2B, the mirror 5 needs to reflect the beam B incident from the upper side in the z-axis direction in the x-axis direction, so that the base 5 is rotated 45 degrees from the xy plane around the y-axis. It is attached to the base 30.

  The lens barrel 38 is attached to the base 30 on the left side in the x-axis direction with respect to the mirror 5 as shown in FIG. More specifically, as shown in FIG. 4, the base table 30 is formed with a mounting groove 30 c that extends in the x-axis direction and faces the negative direction side in the z-axis direction. As shown in FIG. 2A, the lens barrel 38 is attached to the base 30 so that the circuit board 32 side (that is, the upper side in the z-axis direction) contacts the attachment groove 30c. The leaf spring 40 has one end attached to the base table 30 and the other end contacting the lens barrel 38, thereby pressing the lens barrel 38 against the attachment groove 30c.

  Further, as shown in FIG. 4, the base table 30 communicates with the lens barrel 38 and faces the traveling direction of the beam B emitted from the laser diode 2 (that is, the negative direction side in the z-axis direction). A vacant opening O is formed. In the present embodiment, as shown in FIG. 4, the lens barrel 38 is viewed in a plan view in a direction opposite to the traveling direction of the beam B emitted from the laser diode 2 (that is, the positive direction side in the z-axis direction). The lens barrel 38 is exposed from the base 30 through the opening O. Thereby, the assembler of the light source device 1 moves the lens barrel 38 along the mounting groove 30c in the direction parallel to the beam B that has passed through the mirror 5 (that is, the x-axis direction) through the opening O. Position adjustment. In addition, the assembler attaches the lens barrel 38 to the base through the opening O from the direction opposite to the traveling direction of the beam B emitted by the laser diode 2 (that is, the negative direction side in the z-axis direction). Attach to the base 30.

(effect)
According to the light source device 1, as shown in FIGS. 2 to 4, even when the circuit board 32 and the lens barrel 38 overlap when viewed in plan from the normal direction (z-axis direction) of the circuit board 32. As described below, the assembler can easily adjust the position of the lens barrel 38.

  More specifically, in the light source device 1, the circuit board 32 is provided on the upper surface side of the base table 30, and the opening O is provided on the lower surface of the base table 30. Thereby, even if the circuit board 32 covers the base table 30, the lens barrel 38 is exposed from the inside of the base table 30 to the outside. As a result, the assembler can touch the lens barrel 38 through the opening O without removing the circuit board 32. Therefore, even if the circuit board 32 is provided so as to cover the base table 30 in order to reduce the size of the light source device 1, the assembler can easily adjust the position of the lens barrel 38.

(Other embodiments)
The light source device according to the embodiment of the present invention is not limited to the light source device 1. Therefore, the light source device 1 can be appropriately changed within the scope of the gist thereof. FIG. 5 is a configuration diagram of a light source device 1a according to another embodiment. Fig.5 (a) is a front view of the light source device 1a, and FIG.5 (b) is a side view of the light source device 1a.

  In the light source device 1 shown in FIG. 2, the mounting portions 34a and 34b are disposed on the lower side in the z-axis direction of the mounting arm portions 30a and 30b, and the male screws 36a and 36b are mounted from the lower side in the z-axis direction. On the other hand, in the light source device 1a shown in FIG. 5, the mounting portions 34a and 34b are disposed on the upper side in the z-axis direction of the mounting arm portions 30a and 30b, and the male screws 36a and 36b are mounted from the lower side in the z-axis direction. Yes. Since the other structure of the light source device 1a is the same as the other structure of the light source device 1, description is abbreviate | omitted. Even in the light source device 1 a having such a configuration, the assembler can easily adjust the position of the lens barrel 38.

  FIG. 6 is a configuration diagram of a light source device 1b according to another embodiment. FIG. 6A is a bottom view of the light source device 1b, and FIG. 6B is a front view of the light source device 1b.

  In the light source device 1 shown in FIG. 2, the lens barrel 38 is exposed to the outside from the base table 30 through the opening O. However, the lens barrel 38 does not necessarily have to be exposed to the outside from the base table 30. For example, as shown in FIG. 6, when the leaf spring 40 is large, the lens barrel 38 may be completely covered by the leaf spring 40 when viewed from the negative direction in the z-axis direction. Even in such a case, if the opening O communicates with the lens barrel 38, the assembler inserts the tweezers P into the opening O and sandwiches the lens barrel 38 as shown in FIG. Position adjustment can be performed.

  The laser diode 2 may be a multi-beam type laser diode that can emit a plurality of beams B simultaneously.

It is the block diagram which showed the outline | summary of the optical scanning device. It is a block diagram of the light source device which concerns on one Embodiment of this invention. It is a block diagram of the light source device which concerns on one Embodiment of this invention. It is a block diagram of the light source device which concerns on one Embodiment of this invention. It is a block diagram of the light source device which concerns on other embodiment. It is a block diagram of the light source device which concerns on other embodiment. It is a block diagram of the conventional light source device. 1 is a configuration diagram of a light beam scanning optical device described in Patent Document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a, 1b Light source device 2 Laser diode 5 Mirror 7 Collimator lens 11 Cylindrical lens 30 Base stand 30a, 30b Mounting arm part 30c Mounting groove 32 Circuit board 34 Light source holder 34a-34e Mounting part 36a, 36b Male screw 38 Lens barrel

Claims (6)

In the light source device used in the optical scanning device,
A light source that emits a beam;
An optical path changing means for bending the optical path of the beam;
A collimator lens that is held in the first holder and collects the beam that has passed through the optical path changing means;
A second holder for holding the optical path changing means and the first holder;
A circuit board extending in parallel with the beam that has passed through the optical path changing means, and to which the light source is connected;
With
The second holder is provided with an opening that communicates with the first holder and that is open to face the traveling direction of the beam emitted by the light source.
An optical device characterized by the above. The first holder is exposed from the opening when viewed in plan in a direction opposite to the traveling direction of the beam emitted from the light source;
The light source device according to claim 1. The first holder is in contact with the second holder on the circuit board side;
The light source device according to claim 1, wherein: The first holder is attached to the second holder from a direction opposite to the traveling direction of the beam emitted by the light source;
The light source device according to any one of claims 1 to 3, wherein: The first holder can be adjusted in position in a direction parallel to the beam that has passed through the optical path changing means;
The light source device according to any one of claims 1 to 4, wherein: The first holder is provided at a position overlapping the circuit board when viewed from the normal direction of the circuit board;
The light source device according to claim 1, wherein:

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