JPH11242176A - Scanning optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanning optical device which prevents penetration of dust from fitting parts and contact surfaces to an optical box of a light source unit, a scan lens, a deflecting means, etc., to keep output images having a high image quality for a long time. SOLUTION: The light source unit or the deflecting means has a cylindrical fitting part 8, and the fitting part is fitted to a fitting hole 10 opened in the side wall or the bottom surface of the optical box, and a projecting or recessed part provided in the periphery of the fitting part of the light source unit or the deflecting means is inserted to a recessed or projecting part provided in the periphery of the fitting hole of the optical box. Or a scan lens means has a contact part to the optical box, and an elastic member is arranged around the contact part. Or the scan lens means has a contact part to the optical box, and a projecting or recessed part provided in the periphery of the contact part is inserted to a recessed or projecting part provided in the periphery of the contact part of the optical box with which the contact part of the scan lens means is brought into contact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning optical device for writing an image used in a laser printer, a digital copying machine or the like.

[0002]

2. Description of the Related Art Conventionally, a scanning optical device used for image recording has a configuration as shown in FIG. In the figure, 1
Reference numeral 01 denotes a laser unit that emits a laser beam, and the laser beam emitted from the laser unit is a cylindrical lens 102.
Thus, a line image is formed on the rotating polygon mirror 103. The rotating polygon mirror 103 is rotated by a scanner motor 103a, the laser beam is deflected, and is scanned and imaged on a photosensitive member (not shown) via a scanning lens 104 and a folding mirror 105. Further, a part of the deflected laser beam is bent by the sensor mirror 106 and the optical sensor 107
Is reached, and is used for writing start position detection. Each of the above components is housed in the optical box 108. The optical box 108 is entirely covered with a lid (not shown).

[0003] Here, when the rotating polygon mirror 103 rotates, the surrounding air is also agitated, and air enters and exits the optical box. At the same time, dust and toner around the optical box 108 are sucked, and the dust adheres to the rotary polygon mirror 103 and the scanning lens 104. If the rotation speed of the scanner motor 103a is increased in order to increase the output speed of an image, the degree of adhesion is accelerated and the amount of light becomes uneven, which is a serious problem. Conventionally, as a countermeasure,
Configurations such as 0 have been used. That is, the elastic members 109 are arranged above and below the scanning lens to fill the gap, and the above-described lid 11 is closed.
0, the periphery of the rotary polygon mirror is simply sealed to prevent dust from entering, and the rotary polygon mirror 103 and the scanning lens 104 are prevented from entering.
Is to be protected from dirt.

[0004]

However, the above conventional example has the following disadvantages. That is, a gap of several tens of μm is formed at a fitting portion between the optical box and the scanner motor, the laser unit, or the like. In addition, the contact surfaces of these and the scanning lens, etc. are also required
m gap is created. Therefore, when the scanner motor operates at a high speed, dust enters through these gaps and contaminates the rotating polygon mirror and the scanning lens. If the rotary polygon mirror or the scanning lens becomes dirty, the reflectance and the transmittance of the laser beam are reduced only in that portion, resulting in a problem that the density unevenness occurs in the output image.

Therefore, the present invention solves the above-mentioned problems of the prior art, and prevents entry of dust from a fitting portion with an optical box, such as a light source unit, a scanning lens, and a deflecting means, and a contact surface, thereby preventing a long time. It is an object of the present invention to provide a scanning optical device capable of maintaining a high quality output image.

[0006]

In order to solve the above-mentioned problems, the present invention is characterized in that the scanning optical device is constructed as follows. That is, the scanning optical device of the present invention is a light source unit that converts a laser light beam emitted from a laser light source into a substantially parallel light beam, a deflecting unit that deflects the laser light beam, and scans the deflected laser light beam on a photosensitive member. In a scanning optical device having a scanning lens unit for forming an image and an optical box including the laser light source, the deflecting unit, the scanning lens unit, and the like, the light source unit has a cylindrical fitting portion, Is fitted in a fitting hole opened in the side wall of the optical box, and a convex or concave portion provided around the fitting portion of the light source unit is provided around the fitting hole of the optical box. The light source unit has a cylindrical fitting portion, and the fitting portion fits into a fitting hole opened in a side wall of the optical box. And that an elastic member is arranged around the fitting portion. It is set to. Further, the scanning optical device of the present invention is a light source unit that converts a laser beam emitted from a laser light source into a substantially parallel beam, a deflecting unit that deflects the laser beam, and scans the deflected laser beam onto a photoconductor. In a scanning optical device having a scanning lens unit for forming an image and an optical box including the laser light source, the deflecting unit, the scanning lens unit, and the like, the scanning lens unit has a contact portion with the optical box. A convex or concave portion provided around the portion is inserted into a concave or convex portion provided around the contact portion of the optical box with which the contact portion contacts, or the scanning is performed. The lens means has a contact portion to the optical box, and an elastic member is arranged around the contact portion. Further, the scanning optical device of the present invention is a light source unit that converts a laser beam emitted from a laser light source into a substantially parallel beam, a deflecting unit that deflects the laser beam, and scans the deflected laser beam onto a photoconductor. In a scanning optical device having a scanning lens unit for forming an image and an optical box including the laser light source, the deflecting unit, the scanning lens unit, and the like, the deflecting unit has a cylindrical fitting portion, Is fitted in a fitting hole opened in the bottom surface of the optical box, and a convex or concave portion provided around the fitting portion of the deflecting means is provided around the fitting hole of the optical box. The deflecting means has a cylindrical fitting portion, and the fitting portion fits into a fitting hole opened in the bottom surface of the optical box. And an elastic member is arranged around the fitting portion.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, according to the present invention, the convex or concave portion provided around the fitting portion of the light source unit is provided with the concave or convex portion provided around the fitting hole of the optical box. By being configured to be inserted into the part, dust from the gap is stopped on the way by the so-called labyrinth effect in the light source unit and the optical box, the dust enters the inside of the optical box, and adheres to the rotating polygon mirror and the scanning lens Can be prevented,
It is possible to provide a high-quality recorded image for a long time. Further, according to the present invention, by arranging an elastic member in the vicinity of a fitting portion of the light source unit to the optical box, and by configuring so as to be sealed, dust trying to enter the inside of the optical box is stopped by the elastic member, Adhesion to a rotating polygon mirror or a scanning lens can be prevented, and a high-quality recorded image can be provided for a long period of time. . Further, the present invention is configured such that the convex or concave portion provided around the contact portion is inserted into the concave or convex portion provided around the contact portion of the optical box with which the contact portion comes into contact. By doing so, the so-called labyrinth effect prevents the dust from the gap from being stopped on the way by the scanning lens means and the optical box, and prevents the dust from entering the inside of the optical box and adhering to the rotating polygon mirror and the scanning lens. Thus, it is possible to provide a high-quality recorded image for a long period of time. Further, according to the present invention, the elastic member is arranged near the contact portion of the scanning lens unit to the optical box and is configured to be sealed, so that dust entering the inside of the optical box is stopped by the elastic member. Thus, it is possible to prevent adhesion to a rotating polygon mirror or a scanning lens, and it is possible to provide a high-quality recorded image for a long period of time. Also, the present invention
The deflecting means has a cylindrical fitting part, the fitting part is fitted in a fitting hole opened in the bottom surface of the optical box, and a convex provided around the fitting part of the deflecting means. Or, by configuring the concave portion to be inserted into a concave or convex portion provided around the fitting hole of the optical box, dust from the gap is interposed in the deflecting means and the optical box due to a so-called labyrinth effect. , And can be prevented from entering the inside of the optical box and adhering to the rotating polygon mirror or the scanning lens, and a high-quality recorded image can be provided for a long period of time. Also, the present invention
An elastic member is arranged near the fitting portion of the deflecting means to the optical box,
By configuring so as to be sealed, dust trying to enter the inside of the optical box is stopped by the elastic member,
Adhesion to a rotating polygon mirror or a scanning lens can be prevented, and a high-quality recorded image can be provided for a long period of time.

[0008]

Embodiments of the present invention will be described below. [Embodiment 1] FIG. 1 is a cross-sectional view best illustrating Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a semiconductor laser which emits a laser beam, and 2 denotes a semiconductor laser mounted by a known technique such as press fitting. A laser holder 3, a collimator lens for converting the laser beam into a parallel beam or a prescribed convergent beam, 4 an aperture stop, 5 a lens barrel on which the collimator lens 3 and an aperture stop 4 are attached, and 6 A laser unit 1 to 6; a scanning lens 7 (not shown);
This is an optical box to which a scanner motor and the like are attached. In the above configuration, the laser holder 2 has a cylindrical fitting portion 8 and a circumferential projection 9 on the outside thereof.
A fitting hole 10 into which the fitting portion 8 is inserted;
Are provided, respectively. FIG. 2 shows a state where the laser unit 6 is assembled to the optical box 7. In the same figure, a laser unit 6 includes an optical box 7.
Is fixed by a known technique such as a screw (not shown).

Here, a gap 12 of several tens μm is opened between the fitting portion 8 or the projection 9 of the laser unit 6 and the fitting hole 10 or the concave portion 11 of the optical box 7. However, the gap 12 has a so-called labyrinth structure as shown in FIG. Therefore, dust sucked from the outside to the inside of the optical box 7 (from left to right in FIG. 2) by the rotation of the scanner motor is stopped in the middle of the gap 12, and does not enter the inside of the optical box. Therefore, the rotating polygon mirror and the lens system can be protected from dirt, and a high-quality output image can be provided for a long time. In this embodiment, the protruding portion is provided on the laser unit,
Although the recess is provided in the optical box, the protrusion may be provided in the optical box and the recess may be provided in the laser unit. Further, a plurality of protrusions 9 and recesses 11 may be provided to further enhance the labyrinth effect.

[Embodiment 2] FIG. 3 is a drawing that best illustrates the features of Embodiment 2 of the present invention. In FIG. 3, reference numeral 13 denotes a groove provided outside the fitting portion 8 of the laser holder 2;
An elastic member 14 is inserted into the groove 13. Other configurations are the same as those in the first embodiment, and a description thereof will not be repeated. In the above configuration, the thickness of the elastic member 14 is
When the laser unit 6 is assembled to the optical box 7, the elastic member is compressed, and the gap 15 between the laser holder 2 and the optical box 7 is closed as shown in FIG.

By using the above configuration, the first embodiment
Similarly to the above, it is possible to prevent dust from entering the inside of the optical box, protect the rotary polygon mirror and the scanning lens from dirt, and provide a high-quality output image for a long period of time. In this embodiment, the groove is provided in the laser holder 2, but a groove may be provided in the optical box 7 side and the elastic member 14 may be inserted therein. The elastic member 14 may be any material such as a so-called malt plane, rubber, adhesive, or the like, as long as it can close the gap. This is the same for the elastic members used in other embodiments described below.

[Embodiment 3] FIG. 5 is a drawing that best illustrates the features of Embodiment 3 of the present invention. In FIG. 5, reference numeral 15 denotes a rotary polygon mirror for deflecting a laser beam emitted from a laser unit 6; Reference numeral 16 denotes a scanner motor for driving the rotary polygon mirror 15 for rotation, 17 a cylindrical lens for forming a laser beam emitted from the laser unit 6 into a line image on the reflection surface of the rotary polygon mirror 15, and 18 a rotary lens. Polygon mirror 15
A scanning lens for scanning and imaging the laser beam deflected by the laser beam on a photosensitive drum (not shown);
A mirror that guides the laser beam emitted from the laser beam onto a photosensitive drum (not shown); 20 is a lens base that projects from the optical box 7 to mount the scanning lens 15; 21 is a seating surface provided on the scanning lens 18; Is provided on the lens base 20, and a lens abutment against which the seating surface 21 abuts, 23
Are a plurality of projections provided on both sides of the seating surface 21;
Numerals 4 are provided on both sides of the lens abutment 22, and are the same number of recesses as the number of projections.

In the above configuration, the scanning lens 18 is fixed to the lens mount 19 by a known technique such as a leaf spring (not shown). In this state, the projections 23 are
4, the gap 25 between the scanning lens 18 and the lens mount 19 has a so-called labyrinth structure in which irregularities are combined. Therefore, the rotation of the rotary polygon mirror 15 causes the gap 2
The dust entering from the position 5 and adhering to the rotary polygon mirror 15 and the scanning lens 18 is stopped in the middle of the gap 25 and does not enter the scanner motor 15 side. Therefore, the rotary polygon mirror and the lens system can be protected from dirt, and a high-quality output image can be provided for a long time. FIG. 5 shows the abutting surface of the scanning lens 18 in the direction perpendicular to the scanning plane. However, the labyrinth structure according to the present embodiment is used in the abutting direction perpendicular to this, that is, in the direction orthogonal to the paper surface of FIG. May be used, or both may be used in combination.

[Embodiment 4] FIG. 6 is a drawing that best illustrates Embodiment 4 of the present invention. In FIG. 6, reference numeral 26 denotes an elastic member, 27 denotes a lens base, and the elastic member 26 is inserted. Groove. Example 3 for other configurations
Therefore, the description is omitted. The elastic member 26 protrudes by several mm from the lens abutment 22 when inserted into the groove 27. Here, when the scanning lens 18 is fixed by a known technique such as a leaf spring (not shown), the elastic member 26 is compressed and closes the gap between the scanning lens 18 and the lens mount 20.

By using the above configuration, the scanning lens 18
Accuracy (flatness) of the seating portion 21 and lens abutment 22
Dust trying to enter from a gap of several tens of μm caused by an error is prevented by the elastic member 26 and does not adhere to the rotating polygon mirror 15 or the scanning lens 18. Therefore, the rotary polygon mirror and the lens system can be protected from dirt, and a high-quality output image can be provided for a long time.
Although FIG. 6 shows the abutting surface of the scanning lens 18 in the direction perpendicular to the scanning plane, the structure of the present embodiment is applied to the abutting direction perpendicular to the scanning plane, that is, the direction orthogonal to the paper surface of FIG. They may be used, or both may be used in combination.

[Embodiment 5] Fig. 7 is a drawing that best illustrates Embodiment 5 of the present invention. In Fig. 7, reference numeral 28 denotes a motor fitting portion provided on the scanner motor 16, and 29 denotes an optical box. A motor fitting hole into which the motor fitting portion 28 is fitted, 30 is a motor seating surface, 31 is a circumferential groove provided on the bottom surface of the scanner motor 16, and 32 is provided on the optical box 7. A convex circumferential protrusion 33 corresponding to the groove 31 is a screw for fixing the scanner motor 16 to the optical box 7. In the above configuration, when the scanner motor 16 is fixed to the optical box 7 with the screw 33, the gap between the scanner motor 16 and the optical box 7 has a labyrinth structure due to the circumferential groove 31 and the circumferential protrusion 32. For this reason, dust that tries to enter the optical box from the fitting gap between the motor fitting portion 28 and the motor fitting hole 29 is stopped by the labyrinth structure, and adheres to the rotating polygon mirror 15 and the scanning lens 18. Nothing to do.

Therefore, the rotary polygon mirror and the lens system can be protected from dirt, and a high-quality output image can be provided for a long period of time. At the same time, since the lower portion of the scanner motor 16 is exposed to the outside of the optical box 7 and dust prevention measures can be taken, it is possible to suppress the temperature rise inside the optical box 7 due to the rotation of the motor. In this embodiment, the groove is provided on the scanner motor and the convex is provided on the optical box. However, conversely, the convex may be provided on the scanner motor and the groove may be provided on the optical box.
A plurality of circumferential grooves 31 and circumferential protrusions 32 may be provided to further enhance the labyrinth effect.

[Embodiment 6] FIG. 8 is a drawing that best illustrates Embodiment 6 of the present invention. In FIG. 8, a circumferential concave portion provided on the bottom surface of a scanner motor 16 and a ring-shaped elastic member 35 are shown. It is. The other configuration is the same as that of the fifth embodiment, and the description is omitted. In the above configuration, when the ring-shaped elastic member 35 is inserted into the circumferential concave portion 34, it protrudes several mm from the motor seating surface 30. When the scanner motor 16 is attached to the optical box 7 in this state, the ring-shaped elastic member 35 is compressed, and the scanner motor 16 and the optical box 7 are compressed.
Close the gap. For this reason, dust entering the optical box through the fitting gap between the motor fitting portion 28 and the motor fitting hole 29 is stopped by the ring-shaped elastic member 35 and adheres to the rotating polygon mirror 15 and the scanning lens 18. Nothing to do.

Therefore, the rotary polygon mirror and the lens system can be protected from dirt, and a high-quality output image can be provided for a long period of time. At the same time, since the lower portion of the scanner motor 16 is exposed to the outside of the optical box 7 and dust prevention measures can be taken, the temperature rise inside the optical box 7 due to the rotation of the motor can be suppressed. Vibration caused by the rotation of is absorbed by the ring-shaped elastic member 34, and the scanning optical device in which the vibration is suppressed can be provided. In this embodiment, the concave portion is provided on the bottom of the scanner motor and the ring-shaped elastic member is attached, but the concave portion may be provided on the optical box 7. In addition, the ring-shaped elastic member 35 is not limited to a ring shape, but any shape may be used as long as it can prevent dust entering from the fitting gap.

[0020]

As described above, according to the present invention,
A few tens of μm caused by a fitting gap between the light source unit or the scanning means and the optical box, or a surface accuracy error of the seating surface of the scanning lens means.
Prevents dust from entering the optical box through the gap, and adheres to the rotating polygon mirror or scanning lens for a long time.
High quality output images can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a scanning optical device according to a first embodiment of the invention.

FIG. 2 is a cross-sectional view illustrating a scanning optical device according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a scanning optical device according to a second embodiment of the present invention.

FIG. 4 is a sectional view illustrating a scanning optical device according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a scanning optical device according to a third embodiment of the present invention.

FIG. 6 is a diagram illustrating a scanning optical device according to a fourth embodiment of the present invention.

FIG. 7 is a diagram illustrating a scanning optical device according to a fifth embodiment of the present invention.

FIG. 8 is a diagram illustrating a scanning optical device according to a sixth embodiment of the invention.

FIG. 9 is a diagram illustrating a conventional scanning optical device.

FIG. 10 is a diagram illustrating a conventional dust-proof measure.

[Explanation of symbols]

 2: Laser holder 6: Laser unit 7: Optical box 8: Fitting part 9: Projection part 10: Fitting hole 11: Concave part 12: Gap 13: Groove part 14: Elastic member 15: Rotating polygon mirror 16: Scanner motor 18: Scanning lens 20: Lens base 21: Seating surface 22: Lens abutment 23: Projection 24: Concave 25: Gap 26: Elastic member 27: Groove 28: Motor fitting portion 29: Motor fitting hole 31: Circumferential groove 32 : Circumferential convex part 33: screw 34: circumferential concave part 35: ring-shaped elastic member 101: laser unit 102: cylindrical lens 103: rotating polygon mirror 103 a: scanner motor 104: scanning lens 105: folding mirror 106: sensor mirror 107: light sensor 108: Optical box 109: Elastic member 110: Lid

Claims (6)

[Claims] 1. A light source unit for converting a laser beam emitted from a laser light source into a substantially parallel beam, a deflecting means for deflecting the laser beam, and a scanning lens for scanning and imaging the deflected laser beam on a photosensitive member. Means and an optical box including the laser light source, the deflecting means, the scanning lens means, and the like, wherein the light source unit has a cylindrical fitting portion, and the fitting portion is formed of the optical box. The convex or concave portion provided around the fitting portion of the light source unit is fitted in the fitting hole opened in the side wall, and the concave or convex portion provided around the fitting hole of the optical box. A scanning optical device, wherein the scanning optical device is inserted into a scanning optical device. 2. A light source unit for converting a laser beam emitted from a laser light source into a substantially parallel beam, a deflecting means for deflecting the laser beam, and a scanning lens for scanning and imaging the deflected laser beam on a photosensitive member. Means and an optical box including the laser light source, the deflecting means, the scanning lens means, and the like, wherein the light source unit has a cylindrical fitting portion, and the fitting portion is formed of the optical box. A scanning optical device which is fitted in a fitting hole opened in a side wall, and an elastic member is arranged around the fitting portion. 3. A light source unit for converting a laser beam emitted from a laser light source into a substantially parallel beam, a deflecting means for deflecting the laser beam, and a scanning lens for scanning and imaging the deflected laser beam on a photosensitive member. A scanning optical device including a laser unit, a laser light source, a deflecting unit, a scanning lens unit and the like, wherein the scanning lens unit has a contact portion with the optical box and is provided around the contact portion. The scanning optical device, wherein the provided convex or concave portion is inserted into a concave or convex portion provided around a contact portion of the optical box with which the contact portion contacts. 4. A light source unit for converting a laser beam emitted from a laser light source into a substantially parallel beam, a deflecting means for deflecting the laser beam, and a scanning lens for scanning and imaging the deflected laser beam on a photosensitive member. A scanning optical device having a laser light source, a deflecting device, a scanning lens device and the like, wherein the scanning lens device has a contact portion with the optical box, and has elasticity around the contact portion. A scanning optical device comprising a member. 5. A light source unit for converting a laser beam emitted from a laser light source into a substantially parallel beam, a deflecting means for deflecting the laser beam, and a scanning lens for scanning and imaging the deflected laser beam on a photosensitive member. Means, and an optical box including the laser light source, the deflecting means, the scanning lens means, and the like, wherein the deflecting means has a cylindrical fitting portion, and the fitting portion is provided on the optical box. The convex or concave portion provided around the fitting portion of the deflecting means is fitted in the fitting hole opened in the bottom surface, and the concave or convex portion provided around the fitting hole of the optical box. A scanning optical device, wherein the scanning optical device is inserted into a scanning optical device. 6. A light source unit for converting a laser beam emitted from a laser light source into a substantially parallel beam, a deflecting means for deflecting the laser beam, and a scanning lens for scanning and imaging the deflected laser beam on a photosensitive member. Means, and an optical box including the laser light source, the deflecting means, the scanning lens means, and the like, wherein the deflecting means has a cylindrical fitting portion, and the fitting portion is provided on the optical box. A scanning optical device, wherein the scanning optical device is fitted in a fitting hole opened in a bottom surface, and an elastic member is arranged around the fitting portion.