JPH10244707A - Optical deflection scan apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust an angle of a beam array by setting a small substrate to a driving substrate and rotating the substrate together with a semiconductor laser. SOLUTION: Each lead pin 1a of a semiconductor laser 1 generating a plurality of laser beams is soldered to a small substrate 15, and electrically connected to a laser-driving circuit on a driving substrate 14 via the small substrate 15. When the semiconductor laser 1 is rotated to adjust an angle of a beam array and adjust a distance of beams, it is not necessary to rotate the driving substrate 14 of a large area, where by a spare space is eliminated. An installation space for an optical deflection scan apparatus can be accordingly reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-beam type optical 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 In recent years, in an image forming apparatus such as a laser beam printer or a laser facsimile, in order to increase a recording speed, an optical deflection scanning apparatus of a multi-beam writing method for simultaneously writing a plurality of lines using a plurality of laser beams or the like. Was developed.

In this method, a plurality of laser beams separated from each other are simultaneously scanned. As shown in FIG. 8, for example, three laser beams are generated from a semiconductor laser 101, and these are collimated by a collimator lens 102, respectively. After being formed, the light is irradiated on the reflection surface 105 a of the rotary polygon mirror 105 through the cylindrical lens 104, and is imaged on the photosensitive member of the rotary drum 107 through the imaging lens system 106.

[0004] The three laser beams enter the reflecting surface 105a of the rotating polygon mirror 105 while being separated in a direction along the rotation axis of the rotating polygon mirror 105 (hereinafter, referred to as "Z-axis direction"). Is scanned in the main scanning direction (Y-axis direction) perpendicular to the direction, and the electrostatic latent image is formed on the photoconductor by the main scanning in the Y-axis direction by the rotation of the rotating polygon mirror 105 and the sub-scanning in the Z-axis direction by the rotation of the rotating drum 107. Form.

[0005] The cylindrical lens 104 condenses each laser beam linearly on the reflection surface 105 a of the rotary polygon mirror 105. This has a function of preventing the point image formed on the photoconductor from being distorted due to the tilting of the rotary polygon mirror 105 as described above. Further, the imaging lens system 10
6 is a spherical lens 106a and a toric lens 106b
These have the function of preventing the distortion of the point image on the photoreceptor similarly to the cylindrical lens 104,
It has a so-called Fθ function for correcting the point image so that it is scanned at a constant speed in the main scanning direction on the photoconductor.

The three laser beams are respectively
Detection mirror 1 at the end of the main scanning plane (XY plane) in the Y-axis direction
08, the optical sensor 1 is separated below the main scanning surface.
09, converted into a write start signal, and transmitted to the semiconductor laser 101. Upon receiving the write start signal, the semiconductor laser 101 starts write modulation of each laser beam.

By adjusting the timing of the write modulation of each laser beam in this manner, the write start (write) position of the electrostatic latent image on each line formed on the photosensitive member is controlled.

The semiconductor laser 101 is a multi-beam laser that emits a plurality of laser beams simultaneously as described above. As shown in FIG. 7, the semiconductor laser 101 is integrated with a collimator lens 102 via a driving substrate 114 and a laser holder 112. as the light source unit E ₀ which is coupled to the optical box 110
On the side wall of the vehicle.

The light source unit E ₀ presses the semiconductor laser 101 into the center hole 111 a of the base 111, and attaches the lens barrel 113 holding the collimator lens 102 to the laser holder 112 together with the base 111 by a method such as bonding or screwing. It is stuck. Before screwing the base 111 to the laser holder 112, the base 111 is rotated around its central axis while emitting the semiconductor laser 101, and the arrangement direction of the emission points of the plurality of laser beams of the semiconductor laser 101 ( The angle of the laser array is adjusted, and the beam interval is adjusted so that the interval between the writing lines on the photoconductor matches the designed value.

[0010]

However, according to the above prior art, as described above, when the light source unit is assembled to the optical box, the base is rotated while emitting a semiconductor laser which is a multi-beam laser. so,
A step of finally adjusting the beam interval between the plurality of laser beams is required. At this time, the driving substrate screwed to the base also rotates to the same angle. As described above, since the drive substrate is also rotated to the same angle as the semiconductor laser,
An escape space for rotating the drive board having a large area must be secured around the light source unit.

As a result, inconveniences such as an increase in the size of the optical box and an increase in the space required for mounting the optical box in the image forming apparatus are caused, which is a major obstacle in reducing the size of the image forming apparatus.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned unresolved problems of the prior art, and has a small size capable of adjusting a beam interval of a multi-beam laser or the like without rotating a driving substrate. It is an object of the present invention to provide a high-performance light deflection scanning device.

[0013]

In order to achieve the above object, an optical deflection scanning apparatus according to the present invention has a light emitting source for generating a light beam toward a scanning optical system having a rotating polygon mirror, and holds the light emitting source. Holding means, a small board coupled to the electrical connection means of the light emitting source, and a driving board mounted with a driving circuit for driving the light emitting source, the driving circuit of the driving board,
It is electrically connected to the light emitting source through the small substrate.

[0014] Instead of the small substrate, a flexible cable coupled to the electric connection means of the light emitting source may be provided.

[0015]

In a multi-beam type optical deflection scanning device or the like configured to simultaneously write a plurality of lines by using a light emitting source that generates a plurality of light beams such as a multi-beam laser, an assembling process of a light source unit includes: It is necessary to adjust a so-called laser array that adjusts the interval between light beams by rotating the light emitting source while emitting light.

At this time, if the driving substrate having a large area is also rotated to the same angle as the light emitting source, a sufficient clearance space is required so that the driving substrate does not interfere with components around the light source unit. Become. Therefore, if the small board is connected to the electrical connection means such as the lead pins of the light emitting source, and only the small board is rotated to the rotation position of the light emitting source and then assembled to the driving board, the driving board having a large area can be rotated. The above-described adjustment of the laser array and the like can be performed without performing the above operation.

Since there is no need to provide an escape space for rotating the drive substrate, it is possible to greatly contribute to miniaturization of the optical box and saving of the installation space of the optical deflection scanning device in the image forming apparatus.

[0018]

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

FIG. 1 shows an optical deflection scanning device according to a first embodiment, which generates _two laser beams P ₁ and P ₂ from a semiconductor laser 1 as a light emitting source. After being collimated by the collimator lens 2, the light passes through the stop 3 and the cylindrical lens 4, and the reflecting surface 5 of the rotary polygon mirror 5 which forms a scanning optical system together therewith.
a through the imaging lens system 6 to form an image on the photosensitive member on the rotating drum 7.

The two laser beams P ₁ and P ₂ are incident on the reflecting surface 5a of the rotary polygon mirror 5 while being separated from each other in the direction along the rotation axis of the rotary polygon mirror 5 (Z-axis direction). Is scanned in the main scanning direction (Y-axis direction) perpendicular to the direction, and the electrostatic latent image is formed on the photoconductor by the main scanning in the Y-axis direction by the rotation of the rotary polygon mirror 5 and the sub-scanning in the Z-axis direction by the rotation of the rotating drum 7. Form.

Note that the cylindrical lens 4 condenses each of the laser beams P ₁ and P ₂ linearly on the reflection surface 5 a of the rotary polygon mirror 5. This has the function of preventing the point image formed on the photosensitive member from being distorted due to the tilting of the rotary polygon mirror 5 as described above, and the image forming lens system 6 includes a spherical lens 6a. And a toric lens 6b.
Like the cylindrical lens 4, it has a function of preventing a point image on the photoconductor from being distorted, and a function of correcting the point image so that the point image is scanned at a constant speed in the main scanning direction on the photoconductor.

The two laser beams P ₁ and P ₂ are separated below the main scanning plane by the detection mirror 8 at the end of the main scanning plane (XY plane) in the Y-axis direction, and traverse the main scanning plane. The light is introduced into the optical sensor 9 on the opposite side, converted into a write start signal, and transmitted to the semiconductor laser 1. Upon receiving the write start signal, the semiconductor laser 1 starts write modulation of both laser beams P ₁ and P ₂ .

By adjusting the timing of the write modulation of the laser beams P ₁ and P _{2 in} this manner, the write start (write) position of the electrostatic latent image formed on the photosensitive member is controlled.

The semiconductor laser 1 is a multi-beam laser that emits a plurality of laser beams simultaneously as described above. As shown in FIG. 2, a collimator lens is provided via a driving substrate 14 and a laser holder 12 as holding means. assembled on the side wall of an optical box 10 as 2 and the light source unit E ₁ which are integrally connected.

The light source unit E ₁ includes a base 11 into which the semiconductor laser 1 is pressed into a center hole 11 a, and a laser holder 12.
And a lens barrel 13 holding the collimator lens 2, and the semiconductor laser 1 is a multi-beam laser having two light emitting points as described above. The base 11 and the lens barrel 13 are fixed to the laser holder 12 by a known method such as screwing or bonding. The plurality of lead pins 1a, which are the electrical connection means of the semiconductor laser 1, pass through the through hole 14a of the drive substrate 14 and are drawn out to the surface on the opposite side of the small substrate 15 to form the connection pattern 15a of the small substrate 15 (see FIG. 5). Soldered.

The drive substrate 14 has mounted thereon a laser drive circuit or the like which is a drive circuit for causing the semiconductor laser 1 to emit light, and is fixed to the laser holder 12 by screws 16. After the drive substrate 14 is fixed in this way, the laser holder 12 is fixed to the side wall of the optical box 10 using screws 17 as shown in FIG.

[0027] In assembling the light source unit E ₁ is
By rotating the base 11 to which the semiconductor laser 1 is fixed, the arrangement direction of the laser array of the semiconductor laser 1 is adjusted, and the beam interval ΔP of _two laser beams P ₁ and P ₂ generated from the semiconductor laser 1 is adjusted. 4) on the rotating drum 7 to match the design values.
Each lead pin 1a of the semiconductor laser 1 is drawn out to the surface of the small substrate 15 through the through hole 14a, and soldered to the connection pattern 15a of the small substrate 15. Then, the small substrate 15
Is connected to the connection pattern 14b of the drive substrate 14 by soldering. Thus, the semiconductor laser 1 is electrically connected to the laser drive circuit on the drive substrate 14. Next, the entire assembly process source unit E _1.

First, the lens barrel 13 holding the collimator lens 2 is fitted to the cylindrical portion of the laser holder 12, and before the base 11 into which the semiconductor laser 1 is press-fitted is fixed to the laser holder 12, A known laser emitting jig is connected to the lead pin 1a, and the base 11 is rotated around the axis O while the semiconductor laser 1 emits light, to adjust the beam interval ΔP as described above.

Subsequently, the optical axis is aligned by moving the base 11 in a direction perpendicular to the axis O. Then, the base 11 is screwed to the laser holder 12, and the lens barrel 13 is moved in the axial direction. After the focus is adjusted by moving the collimator lens 2, the lens barrel 13 is fixed to the laser holder 12 by a known method such as bonding.

Next, the drive substrate 14 is screwed to the laser holder 12 with screws 16, and each lead pin 1 a of the semiconductor laser 1 is pulled out to the surface of the small substrate 15 and soldered to the connection pattern 15 a.

The connecting member 15b of the small substrate 15 is
Then, the laser holder 12 is screwed to the optical box 10 with screws 17. The optical box 10 has a protruding pin 10 a (see FIG. 3), and by engaging this with a positioning hole 12 a of the laser holder 12, the rotational position deviation until the laser holder 12 is screwed to the optical box 10 is eliminated. prevent.

The connection pattern 14b of the drive substrate 14
It is needless to say that the dimension of (1) needs to be large enough to maintain the state of overlapping with the connecting member 15b even when the small substrate 15 is relatively rotated to adjust the beam interval ΔP as described above. No.

According to this embodiment, since the small substrate for connecting the lead pins of the semiconductor laser is separate from the drive substrate, when the semiconductor laser is rotated for adjusting the beam interval, only the small substrate and the base are used. May be rotated to the rotation position of the semiconductor laser. Therefore, unlike the case where the drive substrate is rotated in the adjustment process of the laser array, there is no need for a clearance space in the optical box or its surroundings, and it is greatly reduced in size of the optical deflection scanning apparatus and the image forming apparatus equipped with the same. Can contribute.

It should be noted that a known flexible cable may be provided instead of the small board and connected to the connection pattern of the drive board in a state where the flexible cable is loosened.

[0035] Figure 6 shows a light source unit E ₂ of the optical deflection scanning apparatus according to the second embodiment. This is provided by providing a long hole 22b in the laser holder 22 and screwing the laser holder 22 to the optical box 20 with a screw 27 passing therethrough.
The optical box 20 is provided with a boss 20b having a screw hole, and the drive board 24 is directly fixed to the optical box 20 by screws 26 screwed into the boss 20b. Base 21,
For the lens barrel 23, the small substrate 25, etc., the base 1 of the first embodiment
1, the description is omitted because it is the same as the lens barrel 13, the small substrate 15, and the like.

Adjustment of the beam interval as in the first embodiment,
After aligning the optical axis and adjusting the focus, before the laser holder 22 is screwed to the optical box 10, the laser holder 22 can be rotated around the axis O to adjust the beam interval again. . Even after adjusting the beam interval by rotating the base 21 holding the semiconductor laser 1 with respect to the laser holder 22 as in the first embodiment, assembling the lens system of the optical deflection scanning device and the rotating polygon mirror. Since errors often occur in the beam interval due to errors, inclinations, and the like, it is desirable to correct the beam interval again.
Therefore, the rotation position of the laser holder 22 is adjusted immediately before screwing the laser holder 22 to the optical box 20, and the beam interval is corrected. After strictly adjusting the beam interval in this way, the small substrate 25 is
Then, the drive board 24 is screwed to the optical box 20. This makes it possible to realize a multi-beam type light deflection scanning device with higher performance. Other points are 1st
This is the same as the embodiment.

[0037]

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

Since the laser array can be adjusted without rotating the driving substrate, a clearance space for rotating the driving substrate can be omitted, the optical box of the optical deflection scanning device can be reduced in size, and image formation can be performed. This greatly contributes to a reduction in the installation space of the light deflection scanning device in the apparatus.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a light deflection scanning device according to a first embodiment.

FIG. 2 is a partial schematic cross-sectional view showing only the light source unit of FIG.

FIG. 3 is a perspective view showing a laser holder of the apparatus shown in FIG. 2;

FIG. 4 is a diagram illustrating a method for adjusting a beam interval.

FIG. 5 is a perspective view showing a semiconductor laser, a driving substrate, and a small substrate of the device of FIG. 2;

FIG. 6 is an exploded perspective view showing a light source unit according to a second embodiment in an exploded state.

FIG. 7 is a partial schematic cross-sectional view showing a light source unit of a light deflection scanning device according to a conventional example.

8 shows the entire light deflection scanning device of FIG. 7;

[Description of Signs] 1 Semiconductor laser 1a Lead pin 2 Collimator lens 4 Cylindrical lens 5 Rotating polygon mirror 10,20 Optical box 11,21 Base 12,22 Laser holder 13,23 Lens tube 14,24 Driving board 15,25 Small board 16, 17, 26, 27 screws

Claims (6)

[Claims] A light source for generating a light beam toward a scanning optical system having a rotary polygon mirror; holding means for holding the light source; a small substrate coupled to an electrical connection means for the light source; An optical deflection scanning device, comprising: a driving substrate on which a driving circuit for driving a light source is mounted, wherein the driving circuit of the driving substrate is electrically connected to the light emitting source via the small substrate. 2. The light deflection scanning device according to claim 1, wherein the light emitting source is a multi-beam laser that generates a plurality of light beams. 3. The light deflection scanning device according to claim 1, wherein a collimator lens for collimating the light beam is coupled to the holding means. 4. The light deflection scanning device according to claim 1, wherein the driving substrate is coupled to the holding means. 5. The optical board as claimed in claim 1, wherein the driving substrate and the holding means are individually assembled to the optical box.
The light deflection scanning device according to claim 1. 6. The light deflection scanning device according to claim 1, wherein a flexible cable connected to an electric connection means of the light emitting source is provided instead of the small substrate.