JPH10235928A - Optical scanner and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect shift of a scanning light in the subscanning direction and to grasp the correction amount thereof instantaneously by counting the time required for the scanning light to pass through a light receiving element while setting the scanning light incoming side of the light receiving element normal to the advancing direction of the scanning light and inclining the outgoing side. SOLUTION: Shift of an aligner in the subscanning direction is detected by light receiving elements 74Y-74K also serving as horizontal sync signal detectors. The scanning light incoming side of the light receiving elements 74Y-74K is set normal to the optical scanning direction, as shown by an arrow, so that the scanning light can be received constantly regardless of the subscanning direction. Outgoing side of the light receiving elements 74Y-74K is inclined against the optical scanning direction. When a light beam is shifted in the subscanning direction, the time between the start and the end of receiving light is shifted and the shift of light beam can be determined by detecting the time shift.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applicable to a color printer, a color digital copying machine, etc., and forms an image for each color component on a plurality of photoreceptors and superimposes the color image on a recording medium. The present invention relates to an optical scanning device and an image forming apparatus to be formed.

[0002]

2. Description of the Related Art Conventionally, there is a method of forming four images per rotation on a photosensitive belt or a transfer belt (hereinafter referred to as a tandem system). In this case, a developing machine for forming an image is used in parallel. Four scanning beams are required, and four scanning light beams are required to be exposed on the photosensitive member of the developing machine at the same time.

In the tandem system, there is a tandem system in which a single exposure device simultaneously generates four scanning light beams to form latent images on four photosensitive members simultaneously and independently, thereby forming a full-color image. By arranging four independent exposure devices and controlling them independently, the size of the device can be significantly reduced as compared with a device that forms a full-color image.

According to the present invention, in the case of an exposure apparatus which simultaneously generates four scanning beams from one exposure apparatus, four light sources are required, and it is necessary to supply independent image data.

The light beam emitted from the light source is shaped by a condenser lens or a collimator lens, guided to a rotating polygon mirror, scanned by being reflected by the rotating polygon mirror, and then scanned by the fθ lens. At a constant speed and guided to the photoconductor. At this time, an optical signal is detected once per rotation of the rotating polygon mirror, and an image is written out at a certain timing based on the signal, and an image having an aligned image writing position is obtained.

At this time, since data is sent independently from the four light sources, separate image writing signals are detected for each of the four light sources, the time from signal detection to image writing is adjusted, and writing of the four light beams is performed. The positions need to be aligned (positioning in the main scanning direction, which is the axial direction of the photoconductor).

[0007] In addition, the deviation in the sub-scanning direction orthogonal to the main scanning direction also occurs due to various factors such as the deviation of the optical axis of the laser due to the temperature change and the eccentricity of the photosensitive drum. The shift in the sub-scanning direction has been corrected by reading the shift amount appearing as an image, shifting the laser emission timing, shifting the laser scanning position, or the like. These deviations occur more or less, and their correction is indispensable for obtaining a good image.

[0008]

Conventionally, means for detecting the positional deviation of the scanning light in the sub-scanning direction includes paper, a transfer belt,
Alternatively, the image on the photosensitive member is read and detected by the reading means. Here, the shift amount to be read is a total shift amount including all shift amounts such as a shift amount of the laser beam and a shift amount of the photoconductor.

[0009] Ultimately, the deviation must be corrected, but it is advantageous to grasp the deviation of each element in correcting the deviation. For example, when the exposure position and the transfer position of the photoconductor drum are at a position of 180 °, the exposure light beam is exposed while being tilted by 1 ° in the sub-scanning direction, and when there is no tilt shift in the photoconductor rotation axis, the image becomes 1 ° It is drawn inclined.

On the other hand, there is no deviation in the exposure light beam,
If the rotation axis of the photoconductor is shifted by 1 °, the image is drawn at 2 °. However, in the related art, it is not possible to grasp the shift amount of each element, and in the case of correction, it is necessary to converge the shift amount by performing several corrections. There was much to do and was uneconomical.

Conventionally, when detecting an image writing signal, due to the optical arrangement, a plurality of light beams are respectively detected at different places or detected by individual light receivers.

For this reason, the writing position changes depending on the positional accuracy between the light receivers and the displacement of the light receivers, and it is necessary to correct the displacement. In addition, since there is no reference surface for positioning in the case of the light receiving device, the position adjustment at the time of assembling has been troublesome.

The present invention has been made in view of the above circumstances,
The amount of shift in the sub-scanning direction of the scanning light emitted from the light source and scanned can be calculated. Also, a plurality of light receiving elements can be arranged without generating a positional shift with each other. It is an object of the present invention to provide an optical scanning device and an image forming apparatus which can be positioned at a predetermined position.

[0014]

In order to solve the above-mentioned problems, the present invention has a plurality of light sources for emitting light, and a light source for reflecting light emitted from the plurality of light sources. Scanning means for scanning, and a plurality of light receiving elements that receive and receive light scanned by the scanning means from one side perpendicular to the scanning direction, and emit light from the other side inclined with respect to the scanning direction, Control means for causing the plurality of light sources to emit light in accordance with image information by receiving light receiving signals of the plurality of light receiving elements; and a plurality of image information lights emitted from the plurality of light sources and scanned by the scanning means. And an optical system for guiding to the scanned portion.

According to a fourth aspect of the present invention, there are provided a plurality of light sources for emitting light, scanning means for reflecting and emitting light emitted from the plurality of light sources, respectively, and light for scanning by the scanning means. A plurality of light receiving elements that receive light by being incident from one side perpendicular to the scanning direction and emit light from the other side that is inclined with respect to the scanning direction; a holding member that integrally holds the plurality of light receiving elements; Control means for causing the plurality of light sources to emit light in accordance with image information by receiving a light receiving signal of the light receiving element, and a plurality of image information lights emitted from the plurality of light sources and scanned by the scanning means. An optical system for guiding to the scanning unit.

According to a fifth aspect of the present invention, there are provided a plurality of light sources for emitting light, scanning means for reflecting and emitting light emitted from the plurality of light sources, respectively, and light for scanning by the scanning means. A plurality of light receiving elements that receive light by being incident from one side perpendicular to the scanning direction and emit light from the other side that is inclined with respect to the scanning direction; a holding member that integrally holds the plurality of light receiving elements; Formed on the member,
A reference surface for positioning the holding member at a predetermined position by being brought into contact with the mounting portion, and a light corresponding to image information is emitted to the plurality of light sources by receiving light receiving signals of the plurality of light receiving elements. And an optical system for guiding image information light emitted from the plurality of light sources and scanned by the scanning means to a plurality of scanned portions.

According to a ninth aspect of the present invention, there are provided a plurality of light sources which emit light, scanning means for reflecting and emitting light emitted from the plurality of light sources, respectively, and light which is scanned by the scanning means. A plurality of light receiving elements that are incident and received from one side perpendicular to the scanning direction, and are emitted from the other side inclined with respect to the scanning direction, and receive the light receiving signals of the plurality of light receiving elements, thereby receiving the plurality of light receiving elements. Control means for causing a light source to emit light according to image information; an optical system for emitting image information light emitted from the plurality of light sources and scanned by the scanning means in a plurality of directions; A plurality of image carriers for receiving the applied light to form an electrostatic latent image; a plurality of developing means for developing the latent images formed on the plurality of image carriers; and a visual image developed by the developing means To Comprising a transfer means for transferring the Utsushizai.

According to a tenth aspect of the present invention, there are provided a plurality of light sources for emitting light, scanning means for reflecting and emitting light emitted from the plurality of light sources, respectively, and light for scanning by the scanning means. A plurality of light receiving elements that receive light by being incident from one side perpendicular to the scanning direction and emit light from the other side that is inclined with respect to the scanning direction; a holding member that integrally holds the plurality of light receiving elements; Control means for causing the plurality of light sources to emit light in accordance with image information by receiving a light receiving signal of the light receiving element, and image information light emitted from the plurality of light sources and scanned by the scanning means in a plurality of directions. , A plurality of image carriers for receiving light guided in a plurality of directions by the optical system to form an electrostatic latent image, and a plurality of developing devices for developing the latent images formed on the plurality of image carriers. Present Comprising means, a transfer means for transferring the visible image developed on the transfer material by these developing means.

According to the eleventh aspect, there are provided a plurality of light sources for emitting light, scanning means for reflecting and emitting light emitted from the plurality of light sources, respectively, and light for scanning by the scanning means. A plurality of light receiving elements that receive light by being incident from one side perpendicular to the scanning direction and emit light from the other side that is inclined with respect to the scanning direction; a holding member that integrally holds the plurality of light receiving elements; A reference surface for positioning the holding member at a predetermined position by being formed on the member and being brought into contact with the mounted portion, and receiving light receiving signals of the plurality of light receiving elements, the plurality of light sources provide image information. Control means for emitting corresponding light; an optical system for emitting image information light emitted from the plurality of light sources and scanned by the scanning means; and a light receiving means for receiving light guided in a plurality of directions by the optical system. A plurality of image carriers for forming an electrostatic latent image by developing the latent images formed on the plurality of image carriers; And a transfer means for transferring the image to the printer.

According to the present invention, one side of the light receiving element on which the scanning light is incident is perpendicular to the traveling direction of the scanning light, and the other side of the scanning light is inclined, so that the scanning light passes through the light receiving element. , The amount of deviation of the scanning light in the sub-scanning direction can be detected.

Further, by holding the plurality of light receiving elements integrally by the holding member, it is possible to prevent the occurrence of displacement between the light receiving elements. Further, by providing a reference surface for positioning on the holding member of the light receiving element, the positional relationship of the light receiving element with respect to the scanning light can be accurately and quickly determined.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in FIGS. FIG. 1 is a sectional view schematically showing an internal structure of a digital copying apparatus (hereinafter, referred to as a copying apparatus) 1.

The copying apparatus 1 includes a scanner unit 2 for reading a document image and a printer unit 4 for forming an image on a recording medium as a material to be transferred based on image data.
An ADF 6 is set above the scanner unit 2. The ADF 6 is attached to the document table 81 of the scanner unit 2 so as to be openable and closable, and holds an object to be read, i.
The document D is fed one by one toward the platen 81 and functions as a document holder for bringing the document D placed on the platen 81 into close contact with the platen.

The printer unit 4 performs image separation for each color component based on a well-known subtractive color mixing method, that is, a yellow image.
(Hereinafter referred to as Y), magenta (hereinafter referred to as M), cyan (hereinafter referred to as C), and black (hereinafter referred to as K)
The first to fourth image forming units 10Y, 10M, 10C, and 10K that form the four color images respectively.
These image forming units 10Y, 10M, 10C, 10K
Are composed of independent cartridge type units, and each unit is detachably formed from the copying apparatus main body 1A.

Each of the image forming units 10Y, 10M, 10C, 1
Below 0K, a transport mechanism 20 as a transport unit including a transport belt 21 that transports the image of each color formed by each of the image forming units 10Y to 10K in the direction of arrow a in the figure is provided. The transport belt 21 includes a driving roller 24 rotated by a belt motor (not shown) and the driving roller 2.
4 and a driven roller 26 which is separated by a predetermined distance from the driven roller 26, is stretched, and runs endlessly at a constant speed in the direction of arrow a. Each image forming unit 10Y, 10M, 10C, 10K
Are arranged in series along the transport direction of the transport belt 21.

Each of the image forming units 10Y, 10M, 10C, 1
0K includes photoconductor drums 11Y, 11M, 11C, and 11K as image carriers whose outer peripheral surfaces are rotatable in the same direction at positions in contact with the conveyor belt 21. Each photoconductor drum 11Y, 11M, 11C, 11
K is a photoconductor drum 11Y, 11M, 11C, 11K.
Is connected to a drum motor (not shown) for rotating the motor at a predetermined peripheral speed.

Each of the photosensitive drums 11Y, 11M,
The axes of 11C and 11K are arranged so as to be orthogonal to the direction in which the image is conveyed by the conveyor belt 21, and the axes of the photosensitive drums are arranged at equal intervals. In the following description, each of the photosensitive drums 11Y, 11M, 11C,
The main scanning direction is defined as the axial direction of the photosensitive drum 11K.
The direction in which Y, 11M, 11C, and 11K are rotated, that is, the transport direction of the transport belt 21 is defined as a sub-scanning direction.

Each of the photosensitive drums 11Y, 11M, 11C,
Around 11K, charging rollers 12Y, 12M, 12C and 12K as charging means extending in the main scanning direction, developing devices 13Y, 13M and 13C as developing means similarly extending in the main scanning direction, 13K, transfer devices 14Y and 14M as transfer means similarly extended in the main scanning direction,
14C, 14K, and cleaning devices 15Y, 15M, 15C, 15K similarly extended in the main scanning direction.
Respectively correspond to the photosensitive drums 11Y, 11M,
They are arranged in order along the rotation directions of 11C and 11K. The transfer devices 14Y, 14M, 14C, 14K
Are the corresponding photosensitive drums 11Y, 11M, 11C, 1
It is disposed at a position where the conveyor belt 21 is held between 1K and the inside of the conveyor belt 21. Exposure points by an exposure device described later are respectively set to the charging roller 12.
Y, 12M, 12C, 12K and developing devices 13Y, 13
M, 13C, 13K, and the photosensitive drums 11Y, 1
It is formed on the outer peripheral surface of 1M, 11C, 11K.

Below the transport mechanism 20, each image forming unit 1
A paper cassette 30 containing a plurality of recording papers P as a recording medium for transferring images formed by 0Y, 10M, 10C, and 10K is arranged.

At one end of the paper cassette 30 and on the side close to the driven roller 26, there is disposed a pickup roller 32 for taking out the recording paper P stored in the paper cassette 30 one by one from the top. . The paper cassette 3 is located between the pickup roller 32 and the driven roller 26.
0 and the image forming unit 10Y
A registration roller 34 for aligning the leading end of the Y toner image formed on the photosensitive drum 11Y is disposed. Incidentally, the toner images (M, C, K) formed on the other photosensitive drums 11M, 11C, 11K are supplied to respective transfer positions in accordance with the transport timing of the recording paper P transported on the transport belt 21. You.

Registration roller 34 and first image forming section 1
0Y, near the driven roller 26, substantially on the outer periphery of the driven roller 26 with the conveyance belt 21 interposed therebetween, the recording paper P conveyed at a predetermined timing via the registration roller 34. A suction roller 36 for providing a predetermined electrostatic suction force is disposed. Note that the axis of the suction roller 36 and the axis of the driven roller 26 are arranged parallel to each other.

An image pattern formed on the transport belt 21 is detected at one end of the transport belt 21 and near the drive roller 24, substantially on the outer periphery of the drive roller 24 with the transport belt 21 interposed therebetween. Sensor 38 for
Are arranged at a predetermined distance from the drive roller 24. The registration sensor 38 is configured by a transmission type or reflection type optical sensor.

A belt cleaner 40 is disposed on the transport belt 21 on the outer periphery of the drive roller 24 and downstream of the registration sensor 38 to remove toner adhered to the transport belt 21 or paper residue of the recording paper P. ing.

In the direction in which the recording paper P conveyed via the conveyance belt 21 is detached from the drive roller 24 and further conveyed, the toner transferred to the recording paper P by heating the recording paper P to a predetermined temperature. A fixing device 50 that fuses the image and fixes the toner image on the recording paper P is provided.

A supply port 4a for manually feeding recording paper P is formed on a side surface of the copying apparatus main body 1A located on the right side of the printer section 4, and a paper feed tray 42 is provided in the supply port 4a. . The recording paper P fed through the supply port 4a is guided to a registration roller 34, and the image forming unit 10
Y to 10K. On the side of the copying apparatus main body 1A located on the left side of the printer section 4, a paper output tray 44 for receiving the recording paper P discharged via the fixing device 50 is provided.

The exposing device 60 for forming an electrostatic latent image which is color-separated on the outer peripheral surface of each photosensitive drum is provided with image data (Y, M) for each color component which is color-separated by an image processing unit described later. , C, and K), and has semiconductor lasers 70Y, 70M, 70C, and 70K (shown in FIG. 2) for each color, the emission of which is controlled based on the respective colors.

Each of the semiconductor laser devices 70Y, 70M, 70
Laser beams y, m, c, k emitted from C, 70K
(Shown in FIG. 2) and each laser beam y, m, while rotating at a predetermined rotation speed.
A polygon mirror 61 is provided as a single scanning unit that deflects each of the laser beams y, m, c, and k in the main scanning direction by simultaneously reflecting c and k on the same reflection surface.

The four laser beams y, m, c and k guided to the polygon mirror 61 are incident at different angles in the sub-scanning direction, and the four laser beams y, m and c are reflected on the reflecting surface.
c and k are reflected at positions shifted in the sub-scanning direction.

The polygon mirror 61 has eight reflecting surfaces arranged adjacent to each other. In this embodiment, the laser beams y, m, c, and k are deflected by using the respective reflecting surfaces of the polygon mirror 61, and the laser beams are linearly formed on the photosensitive drum 11 in the axial direction, that is, in the main scanning direction. Scan. The polygon mirror 61 is rotated at a predetermined rotation speed by a polygon motor 61a provided below the polygon mirror 61.

In the direction in which the laser beam is reflected by the polygon mirror 61, each of the reflected laser beams is corrected, and a predetermined image forming position, that is, exposure on each of the corresponding photosensitive drums 11Y, 11M, 11C, and 11K is performed. First to third lenses 62, 63, 64 for forming an image at a position
Is provided.

Third lens 64 and each photosensitive drum 11
Between Y, 11M, 11C, and 11K, laser beams y, m, c, for each color that have passed through the third lens 64.
k is bent toward the exposure position of each of the photosensitive drums 11Y, 11M, 11C, and 11K.
(Y, M, C, K) and first folding mirror 6
The second and third mirrors 66 (Y, M, C) and 67 (Y, M, and C) for further bending the laser beams y, m, c, and k bent by 5Y, 65M, and 65C.
C) is arranged. The black laser beam k is returned by the first return mirror 65K, and then guided to the photosensitive drum 11K without passing through another mirror.

The scanner unit 2 for reading an image of a document is disposed above the ADF 6 which is in a closed state.
Is set on the document table 81 made of transparent glass. Below the document table 81, an exposure lamp 82 for illuminating the document D placed on the document table 81, a reflector 84 for condensing light from the exposure lamp 82 on the document D, and reflected light from the document D A first mirror 86 and the like, which are bent leftward in the figure, are provided.

The exposure lamp 82 and the reflector 8
4 and the first mirror 86 are fixed to the first carriage 88. The first carriage 88 is connected to a pulse motor (not shown) via a toothed belt or the like (not shown), and is driven in parallel by the driving force of the pulse motor to move along the document table 81.

In the left side of the drawing with respect to the first carriage 88, that is, in the direction in which the reflected light reflected by the first mirror 86 is guided, a document table is driven via a driving mechanism (not shown) such as a toothed belt and a DC motor. A second carriage 90 movably provided in parallel with 81 is provided. The second carriage 90 has a second mirror 92 for bending the reflected light from the document D guided by the first mirror 86 downward, and a third mirror for bending the reflected light from the second mirror 92 rightward in the figure. 94 are arranged at right angles to each other. The second carriage 90 is driven by the first carriage 88, and is 1 /
The document is moved in parallel along the document table 81 at a speed of 2.

An image forming lens 96 for forming an image of the reflected light from the second carriage 90 at a predetermined magnification is arranged in a plane including the optical axis of the light turned back through the second carriage 90. In a plane substantially perpendicular to the optical axis of the light that has passed through the imaging lens 96, a CC that converts the reflected light given converging properties by the imaging lens 96 into an electric signal, that is, image data
A D image sensor 98 is provided.

When the light from the exposure lamp 82 is condensed on the original D on the original plate 81 by the reflector 84 by the scanner unit 2 having the above-described configuration, the reflected light from the original D is reflected by the first mirror 86, The light is incident on the CCD image sensor 98 via the second mirror 92, the third mirror 94, and the imaging lens 96, and the information of the original image is converted into image data as an electric signal. CCD image sensor 98
Are connected to the image processing unit 99. The image processing unit includes an image memory for temporarily storing image data supplied from the CCD image sensor 98. The image processing unit creates image data for each color component based on the image data stored in the image memory.

FIG. 2 shows a light beam receiving portion 73 provided in the exposure device 60 for determining an image writing position. As shown in FIG. 4, the light receiving section 73 includes a plurality of light receiving elements 74Y, 74M. 74C, 74K and these light receiving elements 74Y, 74M. A holding plate 75 as a holding member for holding the 74C and 74K integrally.

The light receiving elements 74Y, 74M. 74C, 74K
Is a scanning start light beam which is arranged at the condensing portion of the four laser beams y, m, c, and k, is scanned on the fθ lens 62 by the polygon mirror 61, and passes through positions deviated from the return mirrors 65Y to 65K. Laser beams y, m,
c and k are respectively received.

As shown in FIG. 3, the light receiving section 73 is connected to the control section 45 via a signal path 46,
Y, 74M. When the laser beams 74C and 74K receive the laser beams y, m, c, and k as the scanning start light beams, the light receiving signals (writing signals) are sent to the control unit 45.

Upon receiving the light receiving signal, the control section 45 gives a light emission command to the semiconductor lasers 70Y to 70K after a predetermined time has elapsed, and emits laser beams y, m, c, and k according to the image information. I have. Conventionally, the scanning of the laser beams y, m, c, and k causes the photosensitive drums 11Y to 11Y to 11
The image written on K is read by the reading means 47, and the shift amount of the writing position of the image in the main scanning direction is detected. The control unit 4 according to the shift amount of the writing start position
5 corrects the time from the reception of the write-out signal to the start of writing the image, corrects the shift amount, and corrects the color shift with respect to the image writing position in the main scanning direction.

As a cause of the color shift in the main scanning direction of the image, a shift between the individual light receiving elements 74Y to 74K corresponding to each color can be considered. However, in this embodiment, since the four light receiving elements 74Y to 74K are integrally held by the holding plate 75, no shift occurs between the light receiving elements 74Y to 74K, and the position relative to the image writing position in the main scanning direction is not generated. Color shift can be avoided.

At the time of writing the image, the image written by the four light beams y, m, c, and k may be shifted in the sub-scanning direction (the traveling direction of the sheet). Although there are various causes for this, the semiconductor laser 7
Factors that the light beams y, m, c, and k are shifted in the sub-scanning direction due to a temperature rise of 0Y to 70K,
Factors such as deviation due to eccentricity and inclination of the rotation axis of Y to 11K are considered. In such a case, the image appears as a phenomenon that the image is shifted in parallel to the sub-scanning direction or the image is inclined in the sub-scanning direction. This can be corrected by adjusting the angles of the folding mirrors 65Y to 65K.

However, the correction amount varies depending on whether the photosensitive drums 11Y to 11K are displaced, the exposure light beam is displaced, or the displacement is compounded. Explaining with an example, the photosensitive drums 11Y to 11Y
In the case where the exposure position and the transfer position of K are at the position of 180 °, the exposure light beam is exposed while being inclined by 1 ° in the sub-scanning direction,
If the rotation axis of the photoconductor does not deviate, 1 °
It is drawn inclined.

On the other hand, when the exposure light beam has no inclination shift and the rotation axis of the photosensitive member is inclined by 1 °, the image is drawn inclined by 2 °. As described above, it is advantageous to grasp the deviation amounts of various factors in order to accurately perform the correction.

Of course, it is also possible to control to reduce the amount of deviation by finely dividing the steps from the images drawn on the photosensitive drums 11Y to 11K without grasping the amount of deviation of various factors. To converge, toner is consumed for a long time.

Therefore, in this embodiment, as a means for detecting the amount of deviation in the sub-scanning direction of the exposure apparatus, the amount of deviation in the sub-scanning direction is detected by light receiving elements 74Y to 74K which also serve as horizontal synchronization signal detectors. .

One side of the light receiving elements 74Y to 74K where the scanning light is incident is perpendicular to the light scanning direction indicated by the arrow in FIG. 4, so that the scanning light is kept constant irrespective of the shift in the sub-scanning direction. To receive light.

The other side of the light receiving elements 74Y to 74K from which the scanning light is emitted is inclined with respect to the light scanning direction. Therefore, when the light beam shifts in the sub-scanning direction, a time shift occurs from the start to the end of light reception, and the shift amount can be calculated by detecting the time.

FIG. 5 shows a second embodiment of the light receiving element. In this embodiment, the light receiving elements 101Y, 101M, 1
The inclination of the other side from which the scanning light of 01C and 101K is emitted is formed stepwise.

According to this shape, the scanning lights 70y to 70k
Can be detected as a digital signal when the light passes through the light receiving elements 101Y to 101K, and is an advantageous means depending on an algorithm for processing.

FIG. 6 shows a third embodiment of the light receiving element. In this embodiment, the light receiving elements 102Y to 102K are configured in a wedge shape. With this shape, the same effect as described above can be obtained.

At the time of assembling and adjusting the optical receiver 73, the scanning light beams 70y to 70k are applied to the light receiving elements 74Y to 74K (101).
Y-101K, 102Y-102K) in the sub-scanning direction.

This is because the scanning light beams 70y to 70y
When 0k is shifted, the scanning light beams 70y to 70k are shifted to one of the light receiving elements 74Y to 74K (101Y).
〜１０101K, 102Y〜１０102K) and no signal can be detected.

Conventionally, the shape of the light receiving element has generally been a rectangular shape long in the sub-scanning direction. However, with this shape,
In order to arrange the scanning light beam so as to cross the center of the light receiving element, precise adjustment is required and much time is required.

In this embodiment, the light receiving elements 74Y to 74Y to 7
In order to incline the other side from which the scanning light of 4K (101Y to 101K, 102Y to 102K) is emitted, the light receiving element 10
The time to pass the center between 1Y and 101K can be calculated in advance.

Therefore, the light receiving elements 74Y to 74K (1
01Y to 101K, 102Y to 102K), the scanning light passes through the scanning light 70y to 70k.
k is the light receiving elements 74Y to 74K (101Y to 101K, 1
02Y to 102K) is very easy to adjust.

Conventionally, there is no reference for positioning between the light receiving element and the holding member, and much time is required for adjustment. Therefore, in the present invention, as shown in FIGS. 7 to 9, by providing a reference surface for positioning on the holding member, positioning on another member to which the light receiving unit is attached is facilitated.

The holding member 105 shown in FIG. 7 has a positioning reference surface 10 on its side surface along a direction orthogonal to the scanning light beam.
6,106 are formed. According to this embodiment,
By bringing the reference surfaces 106 and 106 into contact with the mounting portion, the positioning can be accurately performed in the main scanning direction, and the timing of receiving the horizontal synchronization signal becomes accurate.

The holding member 108 shown in FIG. 8 has reference surfaces 109, 109 formed on the lower surface thereof in parallel with the scanning light beam.
According to this embodiment, the light receiving elements 74Y to 74K can be accurately positioned in the sub-scanning direction, and can be mounted with a sufficient margin for displacement in the sub-scanning direction.

FIG. 9 shows a fourth embodiment of the holding member. In this embodiment, positioning reference surfaces 112, 112, 113, 113 along the main scanning direction and the sub-scanning direction are provided on the side surface and the lower surface of the holding member 111.

In this embodiment, the light receiving elements 74Y to 74Y to 7
4K can be accurately positioned in the main scanning direction and the sub-scanning direction, and both effects can be obtained. Further, in the present invention, when the light receiving element is mounted on another component, the reference surface is strongly pressed against the other reference surface with an elastic material and fixed, so that the fixing can be performed with high accuracy and stability.

[0072]

As described above, according to the present invention, one side of the light receiving element where the scanning light is incident is perpendicular to the traveling direction of the scanning light, and the other side which emits the scanning light is inclined. By counting the time that the light passes through the light receiving element, the amount of deviation of the scanning light in the sub-scanning direction can be detected.

Therefore, the amount of correction when the scanning light is shifted in the sub-scanning direction can be instantaneously grasped, and the position of the scanning light can be properly corrected, and a good image without color shift can be easily provided. .

Further, the time required for the scanning light to pass through the center of the light receiving element can be calculated, and the assembling adjustment of the light receiving element can be easily performed so that the scanning light scans the center of the light receiving element. Furthermore, light reception for generating an image writing signal and detection of the amount of positional deviation in the sub-scanning direction can be performed by the same light receiving element, so that the number of parts can be reduced and the light receiving element can be mounted. Requires less space. Therefore, the whole shape can be reduced in size, and a cheaper product can be supplied.

Further, since the plurality of light receiving elements are integrally held by the holding member, no displacement occurs between the light receiving elements. Therefore, the image writing position (main scanning direction) of each light beam can be accurately calculated and aligned, and a pure displacement amount of the scanning light in the sub scanning direction can be detected.

Further, since the positioning reference surface is provided on the holding member of the light receiving element, the positional relationship of the light receiving element with respect to the scanning light can be accurately and quickly determined, and the accurate beam position can be detected.

[Brief description of the drawings]

FIG. 1 is an internal configuration diagram showing a digital copying apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an exposure apparatus.

FIG. 3 is a block diagram showing a control system for image writing.

FIG. 4 is a front view showing an optical receiver.

FIG. 5 is a front view showing a second embodiment of the optical receiver.

FIG. 6 is a front view showing a third embodiment of the optical receiver.

FIG. 7 is a perspective view showing a first embodiment of the holding member.

FIG. 8 is a perspective view showing a second embodiment of the holding member.

FIG. 9 is a perspective view showing a third embodiment of the holding member.

[Explanation of symbols]

 70Y-70K semiconductor laser (light source) 61 polygon mirror (scanning means) 74Y-74K light receiving element 45 control means 65Y-65K optical system 75 holding member 106, 108, 112, 113 reference plane 11Y-11K ... Photosensitive drum (image carrier) 13Y to 13K ... Developing device (developing means) 14Y to 14K ... Transfer device (transfer means)

Claims (11)

[Claims] 1. A plurality of light sources for emitting light, scanning means for reflecting and emitting light emitted from the plurality of light sources, respectively, and scanning light by the scanning means perpendicular to the scanning direction. A plurality of light receiving elements that receive light from one side and receive light, and emit light from the other side inclined with respect to the scanning direction, by receiving light receiving signals of these plurality of light receiving elements,
Control means for causing the plurality of light sources to emit light in accordance with image information; and an optical system for guiding image information light emitted from the plurality of light sources and scanned by the scanning means to a plurality of scanned portions. An optical scanning device, comprising: 2. The optical scanning device according to claim 1, wherein the other side of the light receiving element from which scanning light is emitted is linearly inclined. 3. The optical scanning device according to claim 1, wherein the other side of the light receiving element from which the scanning light is emitted is inclined stepwise. 4. A plurality of light sources for emitting light, scanning means for reflecting and emitting light emitted from the plurality of light sources, respectively, and light scanning by the scanning means perpendicular to the scanning direction. A plurality of light receiving elements that receive light from one side and receive light, and emit light from the other side inclined with respect to the scanning direction; a holding member that integrally holds the plurality of light receiving elements; and a light receiving signal of the plurality of light receiving elements Receiving means for causing the plurality of light sources to emit light corresponding to image information; and an optical system for guiding image information light emitted from the plurality of light sources and scanned by the scanning means to a plurality of scanned portions. An optical scanning device, comprising: 5. A plurality of light sources for emitting light, scanning means for reflecting and scanning light emitted from the plurality of light sources, respectively, and light scanned by the scanning means perpendicular to the scanning direction. A plurality of light receiving elements that receive light from one side and receive light, and emit light from the other side inclined with respect to the scanning direction; a holding member that integrally holds the plurality of light receiving elements; A reference surface for positioning the holding member at a predetermined position by being brought into contact with a mounting portion; and receiving light receiving signals of the plurality of light receiving elements, causing the plurality of light sources to emit light according to image information. An optical scanning device, comprising: a control unit; and an optical system that guides image information light emitted from the plurality of light sources and scanned by the scanning unit to a plurality of scanned parts. 6. The optical scanning device according to claim 5, wherein a reference surface of said holding member is provided perpendicular to a scanning direction of light. 7. The optical scanning device according to claim 5, wherein a reference surface of said holding member is provided in parallel with a scanning direction of light. 8. The reference surface of the holding member comprises a first reference surface portion perpendicular to the light scanning direction and a second reference surface portion parallel to the light scanning direction. The optical scanning device according to claim 1. 9. A plurality of light sources for emitting light, scanning means for reflecting and emitting light emitted from the plurality of light sources, respectively, and scanning light which is scanned by the scanning means in a direction perpendicular to the scanning direction. A plurality of light receiving elements that receive light from one side and receive light, and emit light from the other side inclined with respect to the scanning direction, by receiving light receiving signals of these plurality of light receiving elements,
Control means for causing the plurality of light sources to emit light according to image information; an optical system which emits light from the plurality of light sources and guides image information light scanned by the scanning means in a plurality of directions; A plurality of image carriers for receiving the light guided in the direction to form an electrostatic latent image; a plurality of developing units for developing the latent images formed on the plurality of image carriers; And a transfer unit for transferring the developed image to a transfer material. 10. A plurality of light sources for emitting light, scanning means for reflecting and emitting light emitted from the plurality of light sources, respectively, and light scanned by the scanning means perpendicular to the scanning direction. A plurality of light receiving elements that receive light from one side and receive light, and emit light from the other side inclined with respect to the scanning direction; a holding member that integrally holds the plurality of light receiving elements; and a light receiving signal of the plurality of light receiving elements Control means for causing the plurality of light sources to emit light in accordance with image information, and an optical system which emits light from the plurality of light sources and guides image information light scanned by the scanning means in a plurality of directions, A plurality of image carriers for receiving light guided in a plurality of directions by the optical system to form an electrostatic latent image; a plurality of developing means for developing latent images formed on the plurality of image carriers; An image forming apparatus characterized by comprising a transfer means for transferring the visible image developed on the transfer material by the image unit. 11. A plurality of light sources for emitting light, scanning means for reflecting and emitting light emitted from the plurality of light sources, respectively, and scanning light which is perpendicular to the scanning direction by the scanning means. A plurality of light receiving elements that receive light from one side and receive light, and emit light from the other side inclined with respect to the scanning direction; a holding member that integrally holds the plurality of light receiving elements; A reference surface for positioning the holding member at a predetermined position by being brought into contact with a mounting portion; and receiving light receiving signals of the plurality of light receiving elements, causing the plurality of light sources to emit light according to image information. A control unit; an optical system that emits light from the plurality of light sources and guides image information light scanned by the scanning unit to a plurality of light sources; and receives light guided in a plurality of directions by the optical system to form an electrostatic latent image. A plurality of image carriers to be formed; a plurality of developing units for developing latent images formed on the plurality of image carriers; a transfer unit for transferring a visible image developed by these developing units to a material to be transferred; An image forming apparatus comprising: