JPH10253908A - Optical deflection scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assemble a drive board to a laser holder without using a screw. SOLUTION: The laser holder 2 is provided with a feeding hole feeding a semiconductor laser 1, a pair of abutment members 2d, a pair of engagement pawls 5 and a positioning pin projecting from one side of a pair of abutment members 2d, and the abutment surfaces of both abutment members 2d are abutted on the rear surface of the drive board 3, and the positioning pin 2c is engaged with a positioning hole 3b on the drive substrate 3, and the engagement pawls 5 are engaged elastically with long holes 3c, and the drive board 3 is assembled to the laser holder 2. Trouble due to a joining tool when a screw is tightened is evaded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light deflection scanning device used for an image forming apparatus such as a laser beam printer and a laser facsimile.

[0002]

2. Description of the Related Art A light deflection scanning device used in an image forming apparatus such as a laser beam printer or a laser facsimile is
Light beams such as a laser beam are reflected by a rotating polygon mirror that rotates at a high speed to perform deflection scanning. The scanning light obtained in this way is formed on a photoreceptor on a rotating drum to form an electrostatic latent image. Next, the electrostatic latent image on the photoreceptor is visualized as a toner image by a developing device, transferred to a recording medium such as recording paper, sent to a fixing device, and printed by heating and fixing the toner on the recording medium ( Print) is performed.

A light source that generates a light beam such as a laser beam is assembled as a light source unit integrated with a collimator lens or the like on a side wall of an optical box that houses a rotating polygon mirror or an imaging lens system.

FIG. 6 shows a light source unit E ₀ of an optical deflection scanning device according to a conventional example, which is a semiconductor laser 1.
A laser holder 102 having a semiconductor laser press-fitting hole for press-fitting the semiconductor laser 101, a drive substrate 103 on which a laser drive circuit for driving the semiconductor laser 101 is mounted, and a collimator lens unit 104 containing a collimator lens and a diaphragm are provided. The laser holder 102 has a plate-like portion 102a formed at the center of the semiconductor laser press-fitting hole, and a semiconductor laser 1
The collimator lens unit 104 is fitted to the cylindrical portion 102b of the laser holder 102 and fixed by a method such as bonding. .

The driving substrate 103 has a through hole 103a for penetrating a plurality of lead pins 101a of the semiconductor laser 101, a positioning hole 103b for engaging a positioning pin 102c projecting from a plate-like portion 102a of the laser holder 102, and a driving substrate 103. Hole 1 through which a pair of screws 105 for screwing 103 to laser holder 102 pass
03c. The plate-like portion 102a of the laser holder 102 has three abutting members 102d for abutting the drive substrate 103, and the positioning pin 102c protrudes from one abutting surface of the three abutting members. A screw hole 102e is formed in each of the two contact members 102d. Screws 105 for screwing the drive substrate 103 to the laser holder 102 are provided in the screw holes 10 of each contact member 102d.
2e.

[0006]

However, according to the above-mentioned prior art, since the driving substrate is screwed to the laser holder of the light source unit as described above, the process of assembling the driving substrate is difficult. In addition, it is necessary to use a fastening tool to tighten screws screwed into the screw holes of the laser holder through the respective holes of the drive board. Therefore, a clearance space for rotating the fastening tool (the hatched area in FIG. 6). (Shown) on the surface of the drive board. Since this space requires an area at least about twice the size of the head of the screw, the effective area of the drive board for forming a circuit pattern or the like is reduced by that much, and the circuit design is reduced. There is an unsolved problem that it becomes a big constraint and it becomes difficult to reduce the size of the driving substrate.

In addition, when a screw is tightened, static electricity is applied to the fastening tool close to the semiconductor laser, so that the optical performance of the semiconductor laser is deteriorated and the semiconductor laser is broken. . In particular, even if the optical performance immediately after the optical deflection scanning device is completed as a product is satisfactory, the above-mentioned trouble due to static electricity becomes apparent over time, and the image quality significantly deteriorates during the operation of the optical deflection scanning device. And may lead to important matters.

The present invention has been made in view of the above-mentioned unresolved problems of the prior art, and does not require a screw for assembling a driving board to a light source unit. Therefore, it is an object of the present invention to provide a small and high-performance optical deflection scanning device capable of avoiding troubles such as an increase in the size of a driving substrate and a loss of optical performance due to generation of static electricity in a semiconductor laser.

[0009]

In order to achieve the above object, an optical deflection scanning apparatus according to the present invention comprises: a semiconductor laser for generating a light beam toward a scanning optical system having a rotary polygon mirror; A laser holder for holding, and a driving substrate on which a laser driving circuit for driving the semiconductor laser is mounted, wherein the laser holder has locking means for elastically locking to a predetermined portion of the driving substrate, Thus, the drive substrate and the laser holder are integrally coupled.

It is preferable that the locking means of the laser holder has a pair of locking members separated from each other, and a holding portion for holding the semiconductor laser is provided on a straight line connecting these members.

The locking means of the laser holder has at least three locking members separated from each other, and a holding portion for holding the semiconductor laser is disposed inside a polygon formed by connecting these members. You may.

[0012]

When the driving board is screwed to the laser holder holding the semiconductor laser, a clearance space is required so that the fastening tool does not interfere with the circuit components of the driving board during the work of fastening the screws. In addition, the size of the driving substrate increases. Further, static electricity may be generated in the semiconductor laser by the fastening tool, and the optical performance of the semiconductor laser may be impaired. Therefore, a locking means is provided in the laser holder, and the locking means is elastically locked in a cavity or a notch of the semiconductor laser, whereby the semiconductor laser and the laser holder are integrally connected without using screws.

Since a screw fastening tool is not required, a space for the fastening tool is not required, and the drive board can be reduced in size.

Further, the above-mentioned trouble caused by static electricity generated when the fastening tool is brought close to the semiconductor laser can be avoided.

As a result, a compact and high-performance optical deflection scanning device can be realized.

The locking means of the laser holder has a pair of locking members separated from each other, and a holding portion for holding the semiconductor laser is disposed on a straight line connecting them, or the locking means of the laser holder. If the means has at least three locking members separated from each other, and a holding portion for holding the semiconductor laser is disposed inside a polygon formed by connecting them,
It is also possible to avoid troubles such as a force applied to a lead pin of a semiconductor laser when a cable or the like is connected to or disconnected from a connector of a drive board.

[0017]

Embodiments of the present invention will be described with reference to the drawings.

[0018] Figure 1 shows a light source unit E ₁ of the optical deflection scanning apparatus according to an embodiment, which includes a semiconductor laser 1
A laser holder 2 having a press-fit hole serving as a semiconductor laser holding unit for press-fitting the semiconductor laser 1, a drive substrate 3 on which a laser drive circuit for driving the semiconductor laser 1 is mounted, and a collimator lens unit 4 having a collimator lens and a diaphragm built therein. The laser holder 2 includes a plate-like portion 2a formed at the center of the press-fit hole, and a cylindrical portion 2b extending along the optical axis of a laser beam as a light beam generated from the semiconductor laser 1. The lens unit 4 is fitted to the cylindrical portion 2b of the laser holder 2 and fixed by a method such as bonding.

The drive board 3 has through holes 3a through which the plurality of lead pins 1a of the semiconductor laser 1 respectively pass, and positioning pins 2 projecting from the plate-like portion 2a of the laser holder 2.
c has a positioning hole 3b for engagement.

The plate-like portion 2a of the laser holder 2 is integrally formed of a plastic material, and has a pair of locking claws (locking means) 5 which are a pair of locking members protruding from opposite side edges thereof. It has a contact member 2d. Both contact members 2d
Each has a contact surface that comes into contact with the back surface of the drive substrate 3, and the above-described positioning pin 2 c further projects from the contact surface of the one contact member 2 d to form a positioning hole of the drive substrate 3. 3b.

Each of the locking claws 5 is elastically locked in a long hole 3c, which is a space provided in the drive board 3, and fixes the drive board 3 to the laser holder 2 by so-called patching. The semiconductor laser 1 is disposed such that the press-fit hole of the semiconductor laser 1 is located on a straight line connecting both the locking claws 5. This is because, when the driving substrate 3 is fixed to the laser holder 2 by the above-mentioned patching, the center of the driving substrate 3 through the lead pins 1a of the semiconductor laser 1 is most stably fixed between the locking claws 5. However, this is to prevent the force acting on the drive board 3 from being applied to the connector of the drive board 3 when connecting or disconnecting a cable or the like to the lead pins 1a of the semiconductor laser 1.

[0022] Next, steps of assembling the optical box 50 (see FIG. 5) to process and later assembling the light source unit E _1. First, the semiconductor laser 1 is press-fitted into a press-fitting hole of a laser holder 2 made of plastic, and is fixed.
b, and each lead pin 1a of the semiconductor laser 1 is soldered to the surface of the drive substrate 3 through the through hole 3a of the drive substrate 3. At this time, each contact member 2 of the laser holder 2
d, the back surface of the drive board 3 is brought into contact with the
By patching into the long hole 3c, the laser holder 2
Is fixed to the drive substrate 3.

Next, the collimator lens unit 4 is put on the cylindrical portion 2b of the laser holder 2 to
Is emitted, and the collimator lens unit 4 is moved forward and backward along the optical axis to perform focusing so that the laser light of the semiconductor laser 1 becomes parallel light, and then the collimator lens unit 4 is moved to the cylindrical portion 2 b of the laser holder 2. Glue. By assembling the light source unit E ₁ that completed the assembly on the side wall of the optical box 50 performs its focus with a cylindrical lens C ₁ disposed is moved in the optical axis direction between the rotating polygon mirror 51 which will be described later, At that position, the cylindrical lens C
₁ is bonded to the optical box 50. Thus, the assembly of the light source portion of the light deflection scanning device is completed.

According to the present embodiment, the step of screwing the drive substrate is unnecessary in assembling the light source unit. Therefore, it is necessary to provide an escape space on the drive substrate for a fastening tool used for screwing. Since there is no drive board, the effective area of the drive substrate can be small, and the miniaturization of the device can be greatly promoted.

Further, since there is no trouble such as performance degradation due to generation of static electricity when a fastening tool or the like is brought close to the semiconductor laser, a high-performance and highly reliable optical deflection scanning device can be realized.

Further, there is an added advantage that a force for pulling a cable or the like into and out of the connector of the drive board fixed to the laser holder can be effectively prevented from being applied to the lead pins of the semiconductor laser.

[0027] Figure 2 shows a first variant E _2. this is,
Positioning pins 22c are projected from both abutting members 22d of the laser holder 22 so as to be engaged with a pair of positioning holes 23b provided in the driving substrate 23, and the laser in a plane orthogonal to the optical axis is formed. There is an advantage that the relative positioning between the holder 22 and the driving substrate 23 can be performed more stably.

[0028] Figure 3 shows a second modification E _3. this is,
Three locking claws 35 project from the opposite side edge of the laser holder 32. When the three locking claws 35 are respectively locked in the elongated holes 33b of the driving substrate 33, the driving substrate 33 can be fixed to the laser holder 32 in an extremely stable state. Three contact members 32d are provided on the laser holder 32, and the positioning pins are omitted. In this case, a through-hole 33a for penetrating each lead pin 1a of the semiconductor laser 1 is provided inside a triangle which is a polygon connecting the three long holes 33b.

[0029] Figure 4 shows a third modification E ₄ of. this is,
A pair of cutouts 43 c are provided on the opposite side edge of the drive board 43, and the locking portions 45 a of the locking claws 45 of the laser holder 42 are provided.
Are arranged so as to face inward toward the center of the laser holder 42, and each locking claw 45 is locked to each notch 43 c from outside the opposite side edge of the drive board 43. It is. Since only the notch 43c is required to be formed at the side edge of the drive board 43 instead of the long hole, there is an added advantage that the processing cost is low and the effective surface of the drive board 43 can be widened.

[0030] FIG. 5 shows the entire light beam scanner, which, as described above, the light source unit E ₁ for generating a light beam (luminous flux) such as laser beam, the rotating polygon mirror of the laser beam a cylindrical lens C ₁ to linearly focused on the reflecting surface 51a of 51, rotating the light beam polygon mirror 51
The scanning optical system has a scanning optical system that performs deflection scanning by the rotation of the lens and forms an image on a photoconductor 53 on a rotating drum via an imaging lens system 52. The imaging lens system 52 includes a spherical lens 52a, a toric lens 52b, and the like, and has a so-called fθ function of correcting a scanning speed and the like of a point image formed on the photoconductor 53.

When the rotating polygon mirror 51 is rotated by the motor, its reflecting surface 51a rotates around the axis of the rotating polygon mirror 51 at a constant speed. As described above, the angle between the optical path of the light beam generated from the light source unit E ₁ and collected by the cylindrical lens C ₁ and the normal to the reflection surface 51 a of the rotary polygon mirror 51, that is, the light beam with respect to the reflection surface 51 a Changes with time with the rotation of the rotary polygon mirror 51, and similarly the reflection angle also changes. Therefore, the point image formed by condensing the light beam on the photoreceptor 53 is shifted in the axial direction (main direction) of the rotating drum. (Scan direction).

The imaging lens system 52 focuses the light beam reflected by the rotary polygon mirror 51 on the photosensitive member 53 into a point image having a predetermined spot shape, and scans the point image in the main scanning direction. Is designed to keep the speed constant.

The point image formed on the photoreceptor 53 is formed as an electrostatic latent image by the main scanning by the rotation of the rotary polygon mirror 51 and the sub-scanning by the rotation of the photoreceptor 53 around the axis of the rotating drum. To form

A corona discharge device for uniformly charging the surface of the photoconductor 53 is provided around the photoconductor 53, and an electrostatic latent image formed on the surface of the photoconductor 53 is visualized as a toner image. developing apparatus, the toner image transferring corona discharger for transferring the recording paper (both not shown) are arranged such, recording information by light beams generated from the light source unit E ₁ is printed on a recording paper or the like You.

The detection mirror 54 reflects the light beam on the upstream side in the main scanning direction from the optical path of the light beam incident on the write start position of the recording information on the surface of the photoreceptor 53, and receives a light receiving element 55 having a photodiode or the like. To the light receiving surface of The light receiving element 55 outputs a scanning start signal for detecting a scanning start position (write start position) when the light receiving surface is irradiated with the light beam.

The semiconductor laser 1 of the light source unit E ₁ generates a light beam corresponding to a signal given from a processing circuit for processing information from a host computer. The signal given to the semiconductor laser 1 corresponds to information to be written to the photoconductor 53, and the processing circuit converts information corresponding to one scanning line, which is a locus formed by a point image formed on the surface of the photoconductor 53. The signal represented is given to the semiconductor laser 1 as one unit. This information signal is transmitted in synchronization with a scanning start signal given from the light receiving element 55.

The rotating polygon mirror 51 and the imaging lens system 52
Are housed in the optical box 50, and the light source unit E _{1 and the} like are attached to the side wall of the optical box 50. After the rotating polygon mirror 51, the imaging lens system 52, and the like are assembled in the optical box 50, a lid (not shown) is attached to the upper opening of the optical box 50.

[0038]

Since the present invention is configured as described above, the following effects can be obtained.

A screw for assembling the drive substrate to the light source unit is not required, and the drive substrate becomes large due to a fastening tool used for fastening the screws, or static electricity is generated in the semiconductor laser and optical performance is impaired. And other troubles can be avoided.

Thus, a compact and high-performance optical deflection scanning device can be realized. By mounting such a light deflection scanning device, it is possible to greatly contribute to downsizing and high performance of the image forming apparatus.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an exploded light source unit of a light deflection scanning device according to an embodiment.

FIG. 2 is an exploded perspective view showing a light source unit according to a first modification in an exploded manner.

FIG. 3 is an exploded perspective view showing an exploded light source unit according to a second modified example.

FIG. 4 is an exploded perspective view showing an exploded light source unit according to a third modification.

FIG. 5 is a diagram illustrating the entire light deflection scanning device.

FIG. 6 is an exploded perspective view showing an exploded light source unit according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor laser 1a Lead pin 2,22,32,42 Laser holder 2d, 22d, 32d Contact member 3,23,33,43 Driving board 3b, 23b, 33b Positioning hole 3c Long hole 5,35,45 Locking claw 43c Notch 50 Optical box 51 Rotating polygon mirror

Claims (4)

[Claims] 1. A semiconductor laser for generating a light beam toward a scanning optical system having a rotary polygon mirror, a laser holder for holding the semiconductor laser, and a drive substrate on which a laser drive circuit for driving the semiconductor laser is mounted. Wherein the laser holder has locking means for elastically locking to a predetermined portion of the drive substrate, whereby the drive substrate and the laser holder are integrally coupled. Optical deflection scanning device. 2. The optical deflection scanning device according to claim 1, wherein the locking means of the laser holder is configured to lock in a vacant space or a notch of the driving substrate. 3. The laser holder locking means has a pair of locking members spaced apart from each other, and a holding portion for holding the semiconductor laser is disposed on a straight line connecting the locking members. An optical deflection scanning device according to claim 1. 4. The laser holder locking means has at least three locking members separated from each other, and a holding portion for holding the semiconductor laser is disposed inside a polygon formed by connecting these members. The light deflection scanning device according to claim 1, wherein