JPH03180813A - Optical scanner - Google Patents

Abstract

PURPOSE:To obtain the compact optical scanning device which is easily adjustable and has high accuracy by arranging a light source and a lens fixed in a cylindrical frame, and providing a reflecting mirror which has a single reflecting surface rotatably. CONSTITUTION:An optical scanning unit 30 is constituted by arranging the semiconductor laser 27 and collimator lens 28 fixedly in the cylindrical support frame 42 and arranging the rotary reflecting mirror 29 which has the single reflecting surface so that the mirror can be rotated by a driving motor 48. Thus, only the reflecting means is driven and rotated, so the device is made compact and unitized and its handling is made extremely easy. Further, the respective elements are only arranged concentrically in the single cylindrical frame 42, so centering and position adjustment are extremely easy and an optical scan with high accuracy is made.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical scanning device that can be suitably used as an optical scanning unit in an electrophotographic image recording apparatus.

Conventional technology An optical scanning device in an electrophotographic image recording apparatus usually uses a rotating polygon mirror, as disclosed in Japanese Patent Application Laid-open No. 55-129313, etc., and its rotation axis is The mirror is configured to irradiate a laser beam from a vertical direction, and as the rotating polygon mirror rotates, the laser beam is sequentially reflected from each reflective surface on the outer periphery of the rotating polygon mirror for optical scanning.

However, rotating polygon mirrors require a constant reflection state for each reflecting surface, which requires high-precision processing and is expensive, and it is also necessary to place a laser light source, collimator lens, etc. on the side of the rotating polygon mirror. This poses a problem in that it cannot be constructed compactly and that each optical element must be positioned with high accuracy in three axial directions, and that position adjustment requires a great deal of effort.

On the other hand, for example, in Japanese Patent Application Laid-open No. 61-239211, a cylinder body that can be rotated around a central axis is provided, and a light source, a collimator lens, etc. are arranged so that the axis of the cylinder body and the optical axis coincide. An optical scanning device has been proposed that includes a built-in optical system and a reflecting means having a reflecting surface inclined with respect to the optical axis.

According to this optical scanning device, the light source, collimator lens, and reflecting means need only be arranged on one optical axis, and the light is reflected at one point using a single reflecting surface, which is compared to the case where a rotating polygon mirror is used. It is possible to have a compact configuration, enable highly accurate optical scanning, and furthermore, position adjustment is easy.

Problems to be Solved by the Invention However, even in the optical scanning device disclosed in the above-mentioned publication, since the cylindrical body containing the light source, collimator lens, reflection means, etc. is rotatably driven, the rotational drive means does not require torque. A large motor is required and the drive configuration is complicated, - it is difficult to miniaturize the layer, and since the entire cylindrical body is rotated, it is difficult to increase the rotation accuracy, making it difficult to increase the precision of optical scanning. There was a problem.

SUMMARY OF THE INVENTION In view of the above conventional problems, it is an object of the present invention to provide an optical scanning device that is compact, easy to adjust, and capable of highly accurate optical scanning.

Means for Solving the Problems In order to achieve the above object, the present invention includes a light source, a lens arranged to coincide with the optical axis of the light source, and a reflection surface having a reflective surface on the optical axis and inclined with respect to the optical axis. The light source and the lens are fixedly disposed within a cylindrical support frame, and the reflecting means is disposed within the cylindrical support frame so as to be rotatable around the same axis as the optical axis.

Effects According to the above structure of the present invention, the light source, the lens, and the rotatable reflection means are arranged within the cylindrical support frame, and only the reflection means is rotationally driven, so that the structure can be made compact. It is easy to handle as it can be made into a unit, and since each element can be arranged concentrically within a single cylindrical support frame, centering and positioning are extremely easy and highly accurate optical scanning is possible. It is possible.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to FIGS. 1 to 7.

First, the overall schematic structure of the image recording device will be explained with reference to FIGS. 6 and 7. Reference numeral 1 denotes the main body of the image recording device, and the front side, which is inclined forward and backward, has a lower end that can be opened and closed around a pivot shaft 2a. A pivotally supported main body cover 2 is provided, and an operating section 3 is provided at the front portion of the upper surface of the main body 1. The main body 1 includes a paper feed section 4, a process section 5, an optical section 6, a fixing section 7, a control section 8, and the like.

In the paper feed section 4, as shown in FIG. 7, a paper tray 9 is installed on the upper surface of the main body 1 in an inclined position diagonally upward, and the paper is fed diagonally downward along the front surface of the main body 1. A pickup roller 11, a feed roller 12, a paper sensor 13, a registration roller 14, etc. are arranged so that a path is formed.

The process section 5 includes a process unit 15, a developing unit 16, a toner bottle 17, and the like. The process unit 15 includes a photoconductor drum 18, a charging section 19 disposed below the photoconductor drum 18, a transfer section 20 disposed above the photoconductor drum 18 with the paper passing path 10 in between,
It is composed of a cleaning section 21 arranged between a paper passage path 10 and a charging section 19. The cleaning section 21 includes a cleaning blade 22 that comes into contact with the photosensitive drum 18 and removes residual toner, and a waste toner box 23.

The developing unit 16 is disposed facing the photosensitive drum 18 from the charging section 19 to the transfer section 20 in the rotational direction of the photosensitive drum 18, and is located below the paper feeding section 4. This developing unit 16 includes a developing roller 24,
First and second stirring screws 25 and 26 are built in and configured to replenish the second stirring screw 26 with toner from the toner bottle 17. This toner bottle 17 is detachably attached to the developing unit 16.

The optical section 6 includes a semiconductor laser 27 and a collimator lens 28.
A light scanning unit 30 using a rotating reflecting mirror 29 and a reflecting mirror 31 are arranged in a case 32. The light output toward the rear is reflected diagonally forward and upward by a reflecting mirror 31, and the photosensitive drum is exposed between the charging section 19 and the developing unit 16.

The fixing section 7 includes a heat roller 33, a pressure roller 34, a separating claw 35, and the like, and continuously heats and presses the paper sent out from the process section 5, melts the toner, and fixes the toner on the paper. Further, the paper on which fixing has been completed is discharged onto a paper discharge tray 38 by a paper discharge roller 36 via a static elimination brush 37.

The control unit 8 uses a microcomputer or the like, and integrally controls the paper feed unit 4, process unit 5, optical unit 6, etc. based on commands from the operation unit 3 or commands from an external device (not shown). The image information entered manually is recorded on paper.

Next, the configuration of the optical scanning unit 30 in the image recording apparatus having the overall configuration as described above will be explained in detail based on FIG. 1.

The optical scanning unit 30 is arranged inside a case 32 of the optical section 6. A mounting base 41 formed by bulging the bottom wall inward is provided in a portion of the case 32 where the optical scanning unit 30 is placed, and a cylindrical support frame 42 is installed on the mounting base 41 . A semiconductor laser 27 is mounted on the upper end of this cylindrical support frame 42.
The collimator lens 28 is fitted into a mounting hole 44 having a step 45 formed on the inner periphery of the middle part in the vertical direction, and the support flange 46 on the lower inner periphery is fixed.
A substrate 47 on which a drive morph 48 such as a flat motor is installed is fixed, and a rotating reflector 29 is attached to the output shaft of the drive motor 48 so that the reflecting surface 29a has an inclination angle of 45 degrees with respect to its axis. has been done. And semiconductor laser 2
The mounting plate 43 and the substrate 47 are positioned so that the optical axes of the collimator lens 7 and the axis of the drive motor 48 are concentric, and appropriate positioning means (not shown) such as positioning pins are provided for this purpose. It is being Further, an fθ lens 49 is disposed on the peripheral wall of the cylindrical support frame 42 at a position on a horizontal plane passing through the intersection of the optical axis and the reflective surface 29a.

Next, the action will be explained.

In the above configuration, when a command and image data are input to the control unit 8, the optical unit 6 scans the photosensitive drum 18 with a laser beam, the paper feed unit 4 supplies paper to the process unit 5, and the process unit 5 In the electrophotographic process, the toner image is continuously fixed on the paper by the fixing unit 7, and an image is recorded on the paper.

In this image forming apparatus, a paper feed section 4 is provided at the top of the main body 1, and a conveyance path 10 for paper passing through the processing section 5 and the fixing section 7 is formed diagonally downward along the front surface of the main body 1. Therefore, the installation area of the apparatus can be reduced compared to an apparatus in which the paper passing path 10 is formed horizontally.

Also, if a paper jam occurs during image recording,
Since most of the paper passing path IO is exposed by opening the main body cover 2, appropriate measures can be easily taken.

When replenishing toner, all you need to do is remove the paper tray 9 and replace the toner bottle 17, which eliminates the need for the expensive developing unit 16.
toner bottle 17 can be effectively used up to its service life limit regardless of the capacity of the toner bottle 17. Also, toner bottle 17
Since it can be easily replaced, its capacity can be reduced and the device can be configured more compactly.

The process unit 15 includes a photoreceptor drum 18, a charging section 1
9. Since the transfer section 20 and the cleaning section 21 are integrated, the process unit 15 can be efficiently operated by designing the capacity of the waste toner box 23 of the cleaning section 21 according to the service life limit of the photoreceptor drum 18. can be used. Also, this waste toner box 23
serves to insulate the optical scanning unit 30 from the heat of the fixing section 7. Further, the process unit 15 can be taken out upward and replaced by opening the main body cover 2, and maintainability is extremely high.

In the optical scanning unit 30, a semiconductor laser 27 and a collimator lens 2 are provided in a cylindrical support frame 42.
8, the rotary reflecting mirror 29, and its drive motor 48, it can be constructed compactly, and since it is unitized, assembly, replacement, and maintenance can be easily performed. or,
Since each of the above-mentioned optical elements need only be arranged concentrically within a single cylindrical support frame 42, their centering and position adjustment can be performed extremely easily and with high precision, resulting in highly accurate optical scanning. is possible. Furthermore, since the cylindrical support frame 42 covers all parts except for the parts necessary for outputting light, it is difficult for dust and the like to adhere to it, and it is also difficult to be affected by external light.

Furthermore, since the entire optical section 6 is integrated into a unit, assembly and maintenance management are easier.

Next, a second embodiment of the present invention will be described with reference to FIG. This embodiment has a semiconductor laser 27 and a collimator lens 28.
A diaphragm 51 is disposed between the two.

According to this embodiment, the rotating reflector 29 blocks scattered light just before the collimator lens 28 and transmits highly accurate and stable light.
The quality of the image can be improved.

In the third embodiment shown in FIG. 3, a slit-shaped scanning opening 52 is formed in the peripheral wall of a cylindrical support frame 42.
The influence of dust and external light can be reduced. In this embodiment, the fθ lens is separately provided between the optical scanning unit 1-30 and the reflecting mirror 31.

Next, a fourth embodiment shown in FIG. 4 will be described. In this embodiment, instead of directly mounting the rotating reflector 29 on the output shaft of the drive motor 48, the rotating reflector 29 is rotatably supported by the cylindrical support frame 42 via a bearing 53. The arranged drive motor 54 and the rotary reflecting mirror 29 are connected by a flexible shaft joint 55.

According to this embodiment, since the rotation accuracy of the rotary reflecting mirror 29 is defined only by the bearing 53, the rotation accuracy can be further increased, the accuracy of optical scanning can be increased, and the image quality can be further improved.

Next, a fifth embodiment shown in FIG. 5 will be described. In this embodiment, the collimator lens 28 is not supported by the cylindrical support frame 42 alone, but is attached as a unit with the semiconductor laser 27. That is, the mounting cylinder 56 is mounted in the mounting hole 43a formed in the mounting plate 43 positioned and mounted on the upper end of the cylindrical support frame 42, and the semiconductor laser 27 is held in the upper part of the mounting cylinder 56, and the semiconductor laser 27 is held in the lower part. A collimator lens 28 held by a tube 57 and a fixing ring 58 which also serves as an aperture is attached coaxially. Further, a drive motor 48 is mounted on a substrate 59 positioned and attached to the lower end of the cylindrical support frame 42, and the drive motor 48 is inserted into a fitting hole 59a formed in the substrate 59.
The fitting portion 48a protruding from the lower surface of the holder is fitted into the fitting portion 48a for positioning.

Furthermore, the fθ lens 49 includes a retaining ring 60 and a fixing ring 6.
1 to the cylindrical support frame 42.

According to this embodiment, the semiconductor laser 27 and the collimator lens 28 can be centered in advance, making alignment during assembly easier.

Effects of the Invention According to the present invention, a light source, a lens, and a rotatable reflection means are arranged within a cylindrical support frame, and only the reflection means are driven simultaneously, so that a compact structure can be achieved. It is easy to handle as it can be made into a unit, and since each element only needs to be arranged concentrically within a single cylindrical support frame, centering and positioning are extremely easy, allowing for high-precision optical Scanning is possible, and since it is covered with a cylindrical support frame, it exhibits great effects such as being less likely to attract dust and being less affected by external light.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of an optical scanning device according to an embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of main parts of an optical scanning device according to a second embodiment of the present invention, and FIG. FIG. 4 is a vertical cross-sectional view of the optical scanning device according to the fourth embodiment of the present invention, and FIG. 5 is a vertical cross-sectional view of the optical scanning device according to the fifth embodiment of the present invention. , FIG. 6 is a longitudinal sectional side view showing the overall configuration of an image recording device to which the optical scanning device of the first embodiment of the present invention is applied, and FIG.
The figure is a perspective view of the same external appearance. 27-...-... Semiconductor laser 8 29 0 2 Collimator lens Rotating reflecting mirror Optical scanning unit Cylindrical support frame

Claims (1)

[Scope of Claims] A light source, a lens arranged to match the optical axis of the light source, and a reflecting means having a reflective surface on the optical axis and inclined with respect to the optical axis, the light source and the lens being arranged in a cylinder. An optical scanning device, characterized in that the reflecting means is fixedly disposed within a cylindrical support frame, and is rotatably disposed within the cylindrical support frame about the same axis as an optical axis.