JP2003140076A - Optical scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical scanner which is free from deviation of an irradiation position caused by unexpected movement of an already adjusted adjustment pin. SOLUTION: Columnar projections 62 and 64 extended downward beyond the front end of an adjustment pin 32a project from a bottom face 60a of an optical box 60. That is, the projections 62 and 64 project from the bottom face 60a of the optical box 60 downward beyond the adjustment pin 32a. The projections 62 and 64 are integrally formed in the optical box 60.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a scanning optical device incorporated in an image forming apparatus such as a laser beam printer or a digital copying machine which scans a laser beam to form an image.

[0003]

[Prior art]

Conventionally, a digital image forming apparatus has been widely known. This image forming apparatus usually incorporates a scanning optical device for writing light carrying image information on an image carrier such as a photosensitive drum. The scanning optical device will be described with reference to FIGS.

FIG. 5 is a plan view showing a scanning optical device. FIG. 6 is a partially cutaway view taken along a plane that includes the optical axis of the fθ lens of the scanning optical device of FIG. 5 and is orthogonal to the deflection surface.

The scanning optical device 10 includes a plurality of devices for irradiating an image bearing member such as the photosensitive drum 2 with light carrying image information, and an optical box (scanner body) 30 having the plurality of devices built therein. Is equipped with. As multiple devices,
A semiconductor laser device 12 that emits a laser beam (light flux) carrying image information, a collimator lens 14 that converts the light flux emitted by the semiconductor laser device 12 into a parallel light flux, and a cylindrical light beam that condenses the parallel light flux that has passed through the collimator lens 14 into a linear shape. Examples include the lens 16 and the like.

In addition to the above, as the above-mentioned equipment, a rotary polygon mirror 18 having a deflecting / reflecting surface 18a for reflecting and deflecting the light flux passing through the cylindrical lens 16, a motor 20 for rotating the rotary polygon mirror 18, etc. Is mentioned. Further, the Fθ lens 22 that condenses the light beam reflected by the deflecting / reflecting surface 18a so that the light beam forms a spot on the photosensitive drum 2 is also mentioned as the above-mentioned device. The Fθ lens 22 is designed so that the scanning speed of the spots described above is kept constant. In order to obtain such characteristics, the Fθ lens 22 has a spherical lens 22.
It is composed of a and a toric lens 22b. Further, the light flux condensed by the Fθ lens 22 is transferred to the photosensitive drum 2
The reflecting mirror 24 that reflects toward is also one of the above devices.

The optical box 30 has an opening 26 through which the light beam reflected by the reflecting mirror 24 passes. Therefore,
The light beam deflected and reflected by the deflection reflection surface 18a is the Fθ lens 2
2. The photosensitive drum 2 is irradiated with light passing through the opening 26 via the reflecting mirror 24.

As the rotary polygon mirror 18 rotates, the photosensitive drum 2 performs main scanning with a light beam. On the other hand, the sub-scan is performed by rotating the photosensitive drum 2 around the axis of the cylinder (in the circumferential direction). In this way, an electrostatic latent image is formed on the photosensitive drum 2. Around the photosensitive drum 2, a developing device (not shown) for visualizing the electrostatic latent image formed on the photosensitive drum 2 into a toner image (developed image), or a toner image on a recording paper. A transfer roller (not shown) for transferring to a recording medium such as the above is arranged, and by these functions, image information corresponding to the laser beam (light flux) emitted by the semiconductor laser device 12 is formed on the recording medium.

By the way, the laser light emitted from the semiconductor laser device 12 is applied to a predetermined position (regular position) of the photosensitive drum 2, so that an image corresponding to the image information carried by the laser light is formed on the photosensitive drum 2. It is formed as an electrostatic latent image. In order to irradiate the regular position of the photosensitive drum 2 with the laser light emitted from the semiconductor laser device 12 in this way, the optical box 30 is provided with the adjusting foot 32 for adjusting the irradiation position. The adjusting foot 32 is moved by a dedicated adjusting tool (not shown) so that the laser beam is applied to the regular position of the photosensitive drum 2.

The adjusting foot 32 is provided with an adjusting pin 32a extending in the direction of the rotation axis of the rotary polygon mirror 18. The adjustment pin 32a projects (projects) below the bottom surface 30a of the optical box 30. When adjusting the irradiation position, the adjusting foot 32 is moved in the horizontal direction to adjust the irradiation position, and then the adjusting foot 32 is adjusted by the screw 32b.
Is fixed to the optical box 30. After this adjustment, the optical box 30 is positioned on the body frame of the image forming apparatus by the adjusting pin 32a of the adjusting foot 32. Positioned optical box 30
Is fixed to the body frame of the image forming apparatus with screws 34.

[Problems to be Solved by the Invention]

However, the scanning optical device 10 having the above structure
Then, the adjustment pin 3 of the adjustment foot 32 is more than the bottom surface of the optical box 30.
Since 2a is protruding, the following problems occur.

As described above, when adjusting the irradiation position, the adjustment foot 32 is moved in the horizontal direction to adjust the irradiation position, and then the adjustment foot 32 is moved by the screw 32b.
Fixed at 0. The optical box 30 whose irradiation position is adjusted in this manner is placed and stored in a predetermined storage rack or storage box. When the optical box 30 is placed on a predetermined storage shelf or storage box, the adjustment pin 32a of the adjustment foot 32 is protruding more than the bottom surface 30a of the optical box 30, so that the tip (lower end) of the adjustment pin 32a is stored on the storage shelf or storage. It will come into contact with the box.

Since the optical box 30 is supported by the adjusting pin 32a, if this state continues for a long time, the optical box 30
Depending on the weight of the adjustment foot 32, a load is applied to the adjustment foot 32 and the fixing screw 32b is loosened, and the adjustment foot 32 may move and be displaced. In addition, after adjusting the irradiation position, depending on the situation of the storage work in which the optical box 30 is stored in a predetermined place, the adjustment foot 3
2 may be shocked. In this case, the impact may cause the screw 32b to loosen and the adjusting foot 32 to move. In this way, when the adjustment foot 32 is displaced, the adjusted irradiation position is displaced. As a result, the laser light is transferred to the photosensitive drum 2.
Since the shifted electrostatic latent image is formed on the photosensitive drum 2 without irradiating it to the regular position, the image formed on the recording medium also shifts. In view of the above circumstances, it is an object of the present invention to provide a scanning optical device in which an adjusted adjustment pin does not move carelessly and the irradiation position does not shift.

[Means for Solving the Problems]

A scanning optical device of the present invention for achieving the above object comprises a device for irradiating an image carrier incorporated in a predetermined image forming apparatus main body with light carrying image information.
An optical box containing these devices and an adjustment pin protruding downward from the bottom surface of the optical box and fixed to the optical box are provided so that the light irradiates a predetermined position of the image carrier. A scanning optical device incorporated in the predetermined image forming apparatus main body after the adjustment pin is moved and fixed to the optical box, (1) comprises a protrusion protruding below the adjustment pin from the bottom surface of the optical box. It is characterized by that.

Here, (2) the device has a rotating polygon mirror for deflecting the bundle of light, and (3) the adjusting pin causes the light flux deflected by the rotating polygon mirror to change with time. The position at which the light irradiates the image carrier may be adjusted by moving the optical box in a direction perpendicular to and parallel to the deflection surface formed by the light flux surface to be formed.

(4) The protrusions may be three or more protrusions protruding from the bottom surface of the optical box by the same length.

Further, (5) the protrusion may house the tip of a screw for fixing the device to the optical box.

Furthermore, (6) the protrusion may guide the adjusting pin to a predetermined position of the image forming apparatus main body.

Furthermore, (7) the main body of the image forming apparatus may have a positioning hole formed at the predetermined position for determining a position where the adjusting pin is inserted and the optical box is fixed. Good.

Furthermore, (8) the main body of the image forming apparatus is formed with a hole into which the protrusion is inserted, and (9) the protrusion is thinner than the inner diameter of the hole at its tip. It may have an inclined portion.

Furthermore, (10) the main body of the image forming apparatus may be formed with a hole into which the protrusion is inserted, the inner diameter of the upper portion of which is larger than the outer diameter of the protrusion.

DETAILED DESCRIPTION OF THE INVENTION

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

FIG. 1 is a side view showing a part of the scanning optical device in a cutaway manner. 2 shows the scanning optical device of FIG.
It is the front view seen from the direction. FIG. 3 is a perspective view of the scanning optical device of FIG. 1 viewed from the direction of arrow B. FIG. 4 is an explanatory view showing the bottom surface of the optical box and the main body of the image forming apparatus. In these figures, the same components as those shown in FIGS. 5 and 6 are designated by the same reference numerals.

The scanning optical device 50 includes the photosensitive drum 2 (see FIG. 6).
A plurality of devices for irradiating an image bearing member with light carrying image information, and an optical box (scanner body) 60 in which the plurality of devices are incorporated. The plurality of devices include a semiconductor laser device 12 that emits a laser beam (light flux) carrying image information, and a collimator lens 14 that converts the light flux emitted by the semiconductor laser device 12 into a parallel light flux (see FIG. 1).
And a cylindrical lens 16 (see FIG. 1) that condenses the parallel light flux that has passed through the collimator lens 14 into a linear shape.

The optical box 60 is provided with adjusting feet 32 for adjusting the irradiation position in order to irradiate the regular position of the photosensitive drum 2 with the laser light emitted from the semiconductor laser device 12. The adjusting foot 32 is moved by a dedicated adjusting tool (not shown) so that the laser beam is applied to the regular position of the photosensitive drum 2. After adjusting the irradiation position as described later, the screw 32b is tightened to fix the adjusting foot 32 to the optical box 60.

The adjusting foot 32 is provided with an adjusting pin 32a extending in the direction of the rotation axis of the rotary polygon mirror 18 (see FIG. 1). The adjustment pin 32a is provided on the bottom surface 60a of the optical box 60.
It protrudes more downward (protrudes). From the bottom surface 60a of the optical box 60, columnar protrusions 62 and 64 extending below the tip of the adjustment pin 32a are projected. That is, the protrusions 62 and 64 are the bottom surface 60 of the optical box 60.
It projects below a from the adjustment pin 32a.

The above-mentioned projections 62 and 64 are formed integrally with the optical box 60. Therefore, in forming the protrusions 62 and 64, no additional parts or members are required, and therefore the cost does not increase. Also, the protrusions 62,
In order to stably support the scanning optical device 50, three or more 64 are formed at appropriate positions with respect to the center of gravity thereof (three shown in FIG. 3). Further, the protrusions 62, 64
Have the same length and their tips are located in one plane. Therefore, when the optical box 60 is placed on a predetermined installation surface,
The optical box 60 can be placed horizontally with respect to this installation surface.

The protrusion 64 has a larger outer diameter than the protrusion 62, and a space is formed inside the protrusion 64. Inside the protrusion 64, the tip of a screw 70 for fixing the motor 20 to the optical box 60 is housed. Therefore, the tip of the screw 70 is protected by the protrusion 64,
Since the tip portion is not inadvertently impacted, the position of the motor 20 cannot be displaced.

When adjusting the irradiation position described above, the adjustment foot 32 is moved in the horizontal direction to adjust the irradiation position, and then the adjustment foot 32 is fixed to the optical box 60 by the screw 32b. After this adjustment, the scanning optical device 50 is placed and stored in a predetermined storage rack or storage box. When the scanning optical device 50 is placed on a predetermined storage rack or storage box, the protrusions 62 and 64 project beyond the adjustment pin 32a of the adjustment foot 32, so that the tips (lower ends) of the protrusions 62 and 64 are stored on the storage rack. It will come into contact with the storage box. Therefore, the protrusions 62 and 64 support the scanning optical device 50, and the adjustment pin 32a does not contact the storage shelf. Therefore, no load is applied to the adjusting foot 32, and the screw 32b does not loosen. Screw 32b
Does not come loose, so adjustment foot 32 cannot come off. As a result, the adjusted irradiation position does not shift. Therefore, when the scanning optical device 50 is attached to the main body of the image forming apparatus, the laser light irradiates the regular position of the photosensitive drum 2 (see FIG. 2),
Since the electrostatic latent image is formed at the regular position on the photosensitive drum 2, a high quality image can be formed on the recording medium.

The procedure for attaching the scanning optical device 50 to the image forming apparatus main body (fixing the optical box 60 to the image forming apparatus main body) will now be described.

Here, the optical box 60 has, instead of the above-mentioned protrusion 62, a protrusion 66 in which an inclined portion 66a that becomes thinner toward the tip (lower end) is formed, as shown in FIG. In addition, the frame 100 of the image forming apparatus main body,
A hole 100b into which the protrusion 66 is inserted is formed. The inclined portion 66a is thinner than the inner diameter of the hole 100b. Further, the frame 100 of the image forming apparatus main body is
A positioning hole 100a into which the adjustment pin 32a is inserted is formed. The adjustment pin 32 is inserted into the positioning hole 100a.
By inserting a, the position where the optical box 60 is fixed is determined. The positioning hole 100a is an example of the predetermined position according to the present invention.

When the scanning optical device 50 is attached to the frame 100 of the image forming apparatus main body, the optical box 60 is brought close to the frame 100 while keeping it substantially parallel. In this case, since the protrusions 64 and 66 protrude below the adjustment pin 32a, first, the tips of the protrusions 64 and 66 are in the hole 1
00b. In this case, as described above, the hole 1
Since the inclined portion 66a is thinner than the inner diameter of 00b, the protrusion 66 can be easily inserted into the hole 100b.

About half of the protrusions 64 and 66 are holes 100b.
When the adjustment pin 32a is inserted into the positioning hole 1
It begins to be plugged into 00a. Therefore, the protrusions 64, 66
Guides the adjusting pin 32a to the positioning hole 100a. In this way, the optical box 60 is moved to the frame 100 of the image forming apparatus main body by the adjusting pin 32a of the adjusting foot 32.
To position. Positioned optical box 60 has screws 34
It is fixed to the frame 100 of the image forming apparatus main body (see FIG. 5).

The protrusion 62 is used in place of the protrusion 66, and the inner diameter of the upper portion thereof is changed to the protrusion 62 instead of the hole 100b.
A hole larger than the outer diameter of the frame 100 may be formed in the frame 100. Even in this case, the protrusion 62 can be easily inserted into this hole. For this reason, the adjustment pin 32a is attached to the positioning hole 100a.
Can be easily guided to.

【The invention's effect】

As described above, according to the scanning optical device of the present invention, since the protrusion projects below the adjusting pin, it is possible to adjust the irradiation position or place the optical box on the workbench. However, the adjustment pin is not loaded. Therefore, the adjusted adjustment pin does not inadvertently move and the irradiation position does not shift.

Here, the device has a rotating polygon mirror for deflecting the bundle of light, and the adjusting pin is
The position where the light irradiates the image carrier is adjusted by moving the optical box in a direction that is perpendicular to and parallel to a deflection surface that is a light flux surface formed by the light flux deflected by the rotating polygon mirror over time. In this case, since the optical box does not inadvertently move in the direction perpendicular to and parallel to the deflecting surface, the irradiation position does not shift more reliably.

Further, when the protrusions are three or more protruding from the bottom surface of the optical box by the same length, the optical box can be placed in parallel on a predetermined mounting surface.

Further, in the case where the protrusion accommodates the tip of the screw for fixing the device to the optical box, the tip of the screw is accommodated in the protrusion. Will not be inadvertently shocked. Therefore, the position of the device built in the optical box does not shift.

Furthermore, when the protrusions guide the adjusting pin to a predetermined position of the image forming apparatus main body, the adjusting pin can be easily positioned at the predetermined position.

Further, in the image forming apparatus main body, when the adjusting pin is inserted and the positioning hole for determining the position where the optical box is fixed is formed at the predetermined position, the adjusting pin is provided. Since the position where the optical box is fixed is determined by inserting the optical box into the positioning hole, the optical box can be easily placed at a predetermined position.

Furthermore, the main body of the image forming apparatus is formed with a hole into which the protrusion is inserted, and the protrusion has an inclined portion thinner than the inner diameter of the hole at the tip thereof. In the case of one, since an inclined portion thinner than the inner diameter of the hole is formed at the tip of the protrusion, the protrusion can be easily inserted into the hole, and the adjustment pin can be guided to the predetermined position more easily. .

Further, in the case where the projection is inserted into the main body of the image forming apparatus, a hole having an inner diameter larger than the outer diameter of the projection is formed,
Since the inner diameter of the upper portion of the hole is larger than the outer diameter of the protrusion, the protrusion can be easily inserted into the hole, and the adjustment pin can be more easily guided to the predetermined position.

[Brief description of drawings]

FIG. 1 is a side view showing a scanning optical device according to an embodiment of the present invention with a part thereof broken away.

FIG. 2 is a front view of the scanning optical device of FIG. 1 viewed from the direction of arrow A.

3 is a perspective view of the scanning optical device of FIG. 1 viewed from a direction of an arrow B. FIG.

FIG. 4 is an explanatory diagram showing a bottom surface of an optical box and an image forming apparatus main body.

FIG. 5 is a plan view showing a conventional scanning optical device.

6 is a partially cutaway view of the scanning optical device of FIG. 5, taken along a plane that includes the optical axis of the fθ lens and is orthogonal to the deflection surface.

[Explanation of symbols]

32 adjustment feet 32a Adjustment pin 32b screw 50 Scanning optical device 60 optical box 60a bottom 62, 64, 66 protrusions 66a inclined part 70 screws 100 Image forming apparatus frame 100a Positioning hole

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C362 BA04 DA02                 2H045 DA04 DA41                 5C051 AA02 CA07 DB02 DB22 DB24                       DB30 DC02 DC04 DC05 DC07                       DE21 FA01                 5C072 AA03 BA13 HA02 HA09 HA13                       HA20 HB08 XA01 XA05

Claims (8)

[Claims] 1. A device for irradiating an image carrier, which is incorporated in a predetermined image forming apparatus main body, with light carrying image information, an optical box containing these devices, and a bottom surface of the optical box. Also protrudes downward and is fixed to the optical box, and moves the adjusting pin so that the light irradiates a predetermined position of the image carrier, and fixes the optical box to the predetermined image formation. A scanning optical device incorporated in a main body of the device, comprising a protrusion protruding downward from the bottom surface of the optical box below the adjustment pin. 2. The device has a rotary polygon mirror for deflecting the bundle of light, and the adjustment pin has a deflection surface formed by a light flux surface formed by a light flux deflected by the rotary polygon mirror over time. The scanning optical device according to claim 1, wherein the position at which the light irradiates the image carrier is adjusted by moving the optical box in a direction perpendicular to and parallel to the surface. 3. The scanning optical device according to claim 1, wherein the protrusions are three or more and protrude from the bottom surface of the optical box by the same length. 4. The scanning optical device according to claim 1, wherein the protrusion accommodates a tip end portion of a screw that fixes the device to the optical box. 5. The scanning according to claim 1, wherein the protrusion guides the adjustment pin to a predetermined position of the image forming apparatus main body. Optical device. 6. The main body of the image forming apparatus is characterized in that a positioning hole for determining a position where the adjustment box is inserted and the optical box is fixed is formed at the predetermined position. Item 5. The scanning optical device according to Item 5. 7. The main body of the image forming apparatus is formed with a hole into which the protrusion is inserted, and the protrusion is formed with an inclined portion thinner than an inner diameter of the hole at a tip end portion thereof. 7. The scanning optical device according to claim 5, wherein: 8. The image forming apparatus main body is formed with a hole into which the protrusion is inserted, the inner diameter of the upper portion of which is larger than the outer diameter of the protrusion. 6. The scanning optical device according to item 6.