JP2000330056A - Scanning optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scanning optical device in which the mounting height and inclination of an optical lens mounted on an optical lens mounting base can be adjusted finely by reworking. SOLUTION: This scanning optical device is provided with a resin casing supporting an optical lens 6, a female screw section 52 which is inserted into the resin casing, and a male screw section 20 which is inserted into the female screw section 52 from the direction opposite to the inserting direction of the female screw section 52 into the resin casing. The protruded amount of the lens 6 is adjusted by bringing the front end section of the male screw section 20 into contact with the lens 6 by protruding the section 20 from the female screw section 52.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a scanning optical device used as an image exposing means in an image forming apparatus and for optically scanning a light beam on an image carrier.

[0002]

2. Description of the Related Art In an image forming apparatus such as a laser printer, as a means for writing an image, a laser beam enters a high-speed rotating polygon mirror of a deflector based on read information and scans reflected light. The image is recorded by projecting the image on the photoconductor surface of the image carrier. FIG. 12 is a perspective view showing an embodiment of a scanning optical device using a deflector of a polygon mirror.

In the drawing, reference numeral 2 denotes a laser light source for emitting laser light, 3 denotes a collimator lens of a beam shaping optical system,
3a is a first cylindrical lens, 4 is a polygon mirror, 5 is an fθ lens, 6 is a second cylindrical lens,
9a is a mirror, 9b is a cover glass, and 100 is an image carrier. Reference numeral 7 denotes a reflection mirror for detecting synchronization, and reference numeral 8 denotes a photodetector for detecting synchronization.

The beam light emitted from the laser light source 2 is converted into parallel light by a collimator lens 3 and enters a mirror surface of a polygon mirror 4 rotating at a constant speed and a high speed through a first cylindrical lens 3a. This reflected light passes through the fθ lens 5 and the second cylindrical lens 6
(a) A (main) scan is performed at a predetermined spot diameter on the peripheral surface of the rotating drum-shaped or belt-shaped image carrier 100 via the cover glass 9b. In addition, a (sub) scan is performed in accordance with the rotational movement of the image carrier 100, and image exposure of an image is performed on the peripheral surface of the image carrier 100. The main scanning direction of the scanning optical device is finely adjusted by an adjustment mechanism, and synchronization detection for each line is performed by entering the photodetector 8 via the reflection mirror 7 before the start of scanning.

The main components of such a scanning optical device are fixed on a plate-shaped or a plate-shaped optical lens mounting base having a rising portion around the scanning optical system. Is mounted on a predetermined position of the image forming apparatus to perform image exposure. Further, a plurality of scanning optical devices are mounted around the image carrier to perform image exposure, and a multicolor toner image is superimposed on the image carrier to form a color image.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a scanning optical device which solves the following problems.

In the scanning optical device shown in FIG.
The reflected light from the mirror surface of the polygon mirror 4 needs to pass through optical lenses such as the fθ lens 5 and the second cylindrical lens 6 and be irradiated as scanning light at an appropriate position on the image carrier 100. When a color image is formed by superimposing images of a plurality of colors on the image carrier 100, the image is recognized as an image shift.

[0008] Therefore, it is necessary to finely adjust the installation height and inclination of the optical lens installed on the optical lens installation table so as to be at an appropriate irradiation position, and an adjustment mechanism has been desired. Recently, rework of each component installed in the scanning optical device has been desired, and it has been demanded that the above-mentioned adjustment mechanism has a structure that can be easily separated from the scanning optical device.

A first object of the present invention is to provide a scanning optical device having an adjustment mechanism which enables rework and enables fine adjustment of the position of an optical lens.

In the scanning optical device shown in FIG.
If the positions of the optical lenses such as the fθ lens 5 and the second cylindrical lens 6 are shifted, the positional deviation of the scanning light scanned on the image carrier 100 will be recognized as an image deviation. In order to prevent a positional shift due to a change over time, the optical lens is firmly fixed directly to the optical lens mounting base with an adhesive or the like.

However, from the viewpoint of rework,
If the optical lens is fixed to the optical lens mounting base with an adhesive or the like, it is not easy to remove the optical lens, and it is impossible to rework the optical lens.

A second object of the present invention is to provide a scanning optical apparatus which facilitates fixing an optical lens to an optical lens installation table, and enables rework by removing the optical lens.

In the scanning optical device shown in FIG.
The photodetector 8 for detecting the scanning reference position of the light beam that has been deflected and scanned is provided in the scanning optical device so that the light beam that has passed through the fθ lens 5 is condensed at a detection position serving as the scanning reference of the photodetector 8 The scanning position of the light beam on the surface of the image carrier is determined by detecting the collected light beam.

However, if the light beam passing through the fθ lens 5 is focused on the photodetector 8 of the synchronous detection means without passing through any lens, the arrangement of the photodetector 8 is restricted, and the scanning optical device is controlled. There is a possibility that the size of the scanning optical device becomes large due to the restriction of the layout of the scanning optical device.

A third object of the present invention is to provide a scanning optical device which has a degree of freedom in the installation position of the photodetector 8 of the scanning optical device and which has a simplified layout.

[0016]

A first object of the present invention is to provide at least a light source, a deflector for deflecting a light beam generated from the light source in the main scanning direction, and forming an image of the light beam after passing through the deflector. What is claimed is: 1. A scanning optical apparatus comprising: an optical lens that scans and forms an image on a carrier; a resin casing that supports the optical lens; a female screw portion inserted into the resin casing; A male screw part that is inserted into the female screw part and projects its tip from the female screw part, in a direction opposite to the direction in which the screw part is inserted, and has a tip part of the male screw part A scanning optical device (the invention of claim 1), wherein the installation height and inclination of the optical lens are adjusted by contacting the optical lens and adjusting the amount of protrusion of the tip of the male screw portion. Achieved.

The second object is to provide at least a light source,
A scanning optical device comprising: a deflector that deflects a light beam generated from the light source in a main scanning direction; and an optical lens that scans and forms an image of the light beam after passing through the deflector on an image carrier. Disposing a positioning boss on the optical lens, disposing a positioning hole into which the positioning boss is inserted in a resin casing for fixedly supporting the optical lens, inserting the positioning boss into the positioning hole, and then positioning the positioning boss. A boss is abutted against the edge of the positioning hole, and a stopper member for fixing the position of the optical lens is abutted against the positioning boss,
This is achieved by a scanning optical device (the invention of claim 4), wherein the optical lens is positioned on the resin casing by fixing the stopper member.

The third object is to provide at least a light source,
A deflector that deflects the light beam generated from the light source in the main scanning direction, an optical lens that scans and forms the light beam after passing through the deflector on the image carrier, and scans the light beam that has been deflected and scanned. A synchronous detecting means for detecting a reference position, wherein a condensing lens is disposed between the optical lens and the synchronous detecting means, and a converging position in the main scanning direction by the optical lens. The converging lens is arranged so that the light beam and the synchronization detecting means are in a conjugate relationship with each other.

[0019]

1 to 3 are explanatory views showing an embodiment of a scanning optical apparatus according to the present invention. FIG. 1 is a plan view, FIG. 2 is a front view, and FIG. 3 is a bottom view.

As shown in FIG. 1, a laser light source 2, a collimator lens 3, and a first cylindrical lens 3a for emitting a laser beam in a horizontal direction are provided on an upright wall portion 11 of a resin casing 1, which is an optical lens installation table. Attached,
On the bottom plate portion 12 of the resin casing 1, a polygon mirror 4 as a deflector for oscillating the laser light emitted from the laser light source 2 and passing through the collimator lens 3 in the main scanning direction is provided rotatably about a vertical axis. I have. Further, on the bottom plate portion 12 of the resin casing 1, the fθ lens 5 on which the laser light reflected by the polygon mirror 4 is incident, and the laser light passing through the fθ lens 5 are formed on the image carrier which is the surface to be scanned. A second cylindrical lens 6 as an image lens is attached.

According to the first and second aspects of the present invention, the height and inclination of the optical lens of the fθ lens 5 or the second cylindrical lens 6 can be finely adjusted on the bottom plate 12 in such a manner that the work can be reworked. A technique for fixing the finely adjusted optical lens on the bottom plate 12 in a reworkable manner will be described later in detail.

Adjustment screws 13 and 14 are provided at the mounting portion of the fθ lens 5 on the bottom plate portion 12 of the resin casing 1 so that the tips contact the lower surfaces of both ends of the fθ lens 5 in order to adjust the installation height and inclination. An adjusting screw 15 is provided on the lower surface of the intermediate portion, the tip of which is in contact with the adjusting screw 15. And adjusting screw 13,1
The fθ lens 5 can be adjusted
The height and inclination of the installation are adjusted.

The bottom plate portion 12 is provided with projections 16 and 17 which come into contact with the incident side surface of the fθ lens 5. An engagement projection 51 for fixing, which will be described in detail later, is provided on the lower surface of the intermediate portion of the fθ lens 5, and the fθ lens 5 that has been engaged with the engagement projection 51 is fixed to the bottom plate portion 12. There is a stopper 19 attached separately from the engaging hole 18, and the fθ lens 5 has projections 16, 1 on both sides.
7 is fixed to the bottom plate 12 in a state where it is in contact with the side wall of the engaging hole 18 by the stopper 19 in a state where the installation height and the inclination are adjusted by the adjusting screws 13, 14 and 15. .

As shown in FIGS. 4 and 5, the second cylindrical lens 6 has a collar portion 61 at the upper portion and a collar portion 62 at the lower portion, and an effective lens portion 63 is provided therebetween.
Base portions 65 and 66 are formed on the lower surfaces of both ends of the flange portion 62, respectively, and a base portion 67 is also formed on the lower surface of the intermediate portion of the flange portion 62. An engaging projection 68 projecting downward is formed on the base 67.

The mounting portion of the second cylindrical lens 6 on the bottom plate portion 12 of the resin casing 1 has a base 65, which will be described later with reference to FIG.
Adjusting screws 20 and 21 whose tips contact the lower surface of 66;
An adjusting screw 22 having a tip abutting on the lower surface of the base 67 is provided, and the installation height and inclination of the second cylindrical lens 6 are adjusted by adjusting the amount of protrusion of the adjusting screws 20, 21 and 22. That is, the vertical movement (sub-scanning direction) of the second cylindrical lens 6 and the vertical tilting (rotation about an axis parallel to the main scanning direction) can be performed.

The bottom plate 12 engages with the projections 23 and 24 which come into contact with the side surfaces of both ends of the second cylindrical lens 6, which will be described later with reference to FIG. There is a stopper 26 attached separately from an engagement hole 25 for fixing the cylindrical lens 6. The second cylindrical lens 6 abuts the incident side surface on the projections 23, 24, and the adjustment screws 20, 2.
With the installation height and the inclination adjusted by 1 and 22, the stopper plate 26 is fixed to the bottom plate 12 in a state of contacting the side wall of the engagement hole 25 by the stopper 26.

The front wall 40 of the base 1 which is located in front of the second cylindrical lens 6 and faces the surface to be scanned,
As shown in FIG. 2, a slit 41 for emitting laser light having passed through the second cylindrical lens 6 is formed, and a frame 42 is formed so as to surround the slit 41. A transparent cover 43 is adhered to the inside of the frame 42 so as to cover the slit 41.

In the vicinity of the end of the second cylindrical lens 6, a reflection mirror 7 is arranged.
The laser light incident through the fθ lens 5 is reflected toward the photodetector 8 attached to the vertical wall 11. The light detector 8 is for detecting that the laser beam has reached a predetermined beam position, and a condensing lens 81 described later is provided in the middle of the optical path,
The output of the photodetector 8 is used for synchronizing the main scanning.

The scanning by the laser beam in this embodiment is as follows.
It is exactly the same as the conventional device. That is, the laser light emitted in the horizontal direction from the laser light source 2 is collimated by the collimator lens 3, shaped by a slit (not shown), then incident on the polygon mirror 4, and reflected by the polygon mirror 4. The light passes through the fθ lens 5 and enters the second cylindrical lens 6. Further, the laser light that has passed through the second cylindrical lens 6 reaches the surface to be scanned through the slit 41.

Here, since the polygon mirror 4 is rotating, the beam spot on the surface to be scanned moves in the main scanning direction, and exposure according to the modulation by the laser light source 2 is performed. Further, since the scanned surface is moving in the sub-scanning direction, the scanned surface is two-dimensionally exposed. The exposure start timing on each scanning line is determined based on the photodetector 8.

(Embodiment 1) The invention according to claims 1 to 3 The present invention relates to an adjusting screw section (book) for adjusting the installation height and inclination of an optical lens (fθ lens 5 or second cylindrical lens 6 in this embodiment). In the embodiment, the adjusting screws 13 and 1 are used.
4, 15, or the adjusting screws 20, 21, 22), and the adjusting screws 13, 14, 15 are also adjusted screws 20, 2,
1 and 22 have similar configurations, the adjustment screw 20 for adjusting the position of the second cylindrical lens 6 will be described.

FIG. 6A shows a cross-sectional view, and FIG.
A female screw part 52 made of metal is inserted from the inside into the bottom plate part 12 of the resin casing 1 facing the base part 65 of the cylindrical lens 6. The female screw part 52 is screwed into the female screw part 52 in the opposite direction to the inserted female screw part 52, that is, from the outside of the bottom plate part 12, and its tip protrudes from the female screw part 52 to the base part 65 of the second cylindrical lens 6. The adjusting screw 20 that comes into contact is inserted.

The bottom plate 12 has an adjustment screw 20 that has been adjusted once.
An adjustment screw guide 27 for guiding the cylindrical head of the adjustment screw 20 is provided so as to protrude outward from the bottom plate 12 in order to prevent the deflection of the adjustment screw 20. Further, a compression spring 28 is provided between the female screw portion 52 and the adjusting screw 20 so as to absorb play in the screw fitting portion. The inner surface of the adjusting screw guide 27 and the adjusting screw 2
6 so that no run-out occurs between the outer circumference of the head of FIG.
As shown in the external view of the main part of (b), a part of the adjusting screw guide 27 is separated from the peripheral wall and elastically presses the head of the adjusting screw 20 against the opposing peripheral wall with elasticity.
By providing a, the deflection of the adjusting screw 20 can be further reduced.

If an ultraviolet curing adhesive is applied to the boundary between the female screw portion 52 and the adjusting screw 20 in advance, the adjusting screw 2
Immediately after the positioning adjustment of 0, 21 and 22 is performed by irradiating and fixing the ultraviolet rays, the second cylindrical lens 6 can maintain the adjusted installation height and inclination which are not deviated by vibration and aging. The same effect can be obtained by applying a screw lock adhesive to the screw portion of the adjustment screw 20 in advance.

Since the adjusting screw 20 is inserted into the female screw part 52 from the opposite direction, the female screw part 52, which is a metal member, and the adjusting screw 20 are made by hitting the head of the adjusting screw 20 with a hammer or the like. Since both can be separated from the resin casing 1, rework can be easily performed.

(Embodiment 2) Inventions of Claims 4 to 7 The present invention provides an optical lens in which the position-adjusted optical lens (in this embodiment, the fθ lens 5 or the second cylindrical lens 6) can be reworked. Since the fixing method is similar to that of the fθ lens 5 and the second cylindrical lens 6, the second cylindrical lens 6 whose position has been adjusted is fixed to the bottom plate portion of the resin casing 1. A fixing method for fixing the fixing member 12 will be described.

FIG. 7 is an explanatory view showing a method of fixing the second cylindrical lens 6, wherein FIG. 7A is a plan view and FIG.
7 is a side sectional view, and FIGS. 7C and 7D are main part views showing another example.

An engaging projection 68 projecting downward is provided near the center of the lower flange 62 forming the lower surface of the second cylindrical lens 6 and fixed to the resin casing 1. On the other hand, on the upper surface of the bottom plate portion 12 of the resin casing 1, an engagement hole portion 25 into which the engagement protrusion 68 is inserted and engaged is provided. When attaching the second cylindrical lens 6 to the resin casing 1, the second cylindrical lens 6 is abutted on the polygon mirror side in the optical axis direction by the projections 23 and 24, and the adjustment screws 20, 21 and 22 are adjusted. After that, it is fixed as follows.

The bottom plate portion 12 is provided with a stopper portion 26 which separately contacts the engagement protrusion 68 and fixes the second cylindrical lens 6 at the adjustment position. On the other hand, the engagement protrusion 6
8 is provided on the side surface facing the stopper portion 26 of FIG.
Are provided. Industrial resin or metal material is used for the stopper 26,
The side surface that comes into contact with the engagement protrusion 68 has a shape that matches the uneven shape of the protrusion side surface.

The restriction on the image plane side of the second cylindrical lens 6 in the optical axis direction, that is, the direction opposite to the abutting direction of the projections 23 and 24 is performed by friction at the concave / convex portion. If the attachment of the stopper portion 26 as shown in the plan view of the main part is inclined with respect to the optical axis direction, it is possible to prevent the second cylindrical lens 6 from moving toward the image plane side in the optical axis direction. is there.

FIG. 7D is a side sectional view showing another example of the main part, in which a soft elastic member such as a rubber material or a sponge material is used as the stopper portion 26. In this case, by pressing the stopper portion 26, the contact surface does not need to match the uneven shape of the side surface of the engagement protrusion 68, and the stopper portion 26
By pressing, the contact surface can be stably contacted in a shape conforming to the uneven shape of the engagement protrusion 68. Further, the rubber material or the like has a high friction coefficient, and is effective in preventing the second cylindrical lens 6 from coming off on the image plane side in the optical axis direction.

In the embodiment shown in FIG. 7, when the second cylindrical lens 6 is to be fixed more firmly in the optical axis direction,
An adhesive is applied to the contact surface of the concave / convex shape portion, and the stopper portion 26
And the second cylindrical lens 6 are fixed. In this case, if the stopper portion 26 is made of the same material as the second cylindrical lens 6, there is no problem in recyclability even if bonding is performed. In this case, the stopper 26
Is different from the material of the second cylindrical lens 6,
By releasing the fixing of the stopper 26 to the bottom plate 12, the bonded stopper 26 and the second cylindrical lens 6 can be separated from the lens mount, and the operation of removing the stopper 26 from the second cylindrical lens 6 can also be performed. It will be easier. Further, by removing the stopper portion 26 and the second cylindrical lens 6 from the lens mount, the lens mount can be recycled.

(Embodiment 3) The invention according to claims 8 to 11 The present invention relates to the arrangement of synchronous detection means for detecting the scanning reference position of a light beam that has been deflected and scanned. A condensing lens is arranged between an optical lens that scans and forms the beam on the image carrier and the synchronization detecting means, so that the condensing position in the main scanning direction by the optical lens and the synchronization detecting means have a conjugate relationship. It is characterized in that a condenser lens is arranged. Here, the condensing position in the main scanning direction by the optical lens is a position corresponding to the optical path length from the optical lens to the image carrier of the light beam for performing image exposure on the optical path for synchronization detection.

FIG. 8 is an explanatory diagram showing an optical path portion for synchronization detection in FIG. The light beam reflected by the polygon mirror 4 passes through the fθ lens 5 to become a light beam for performing main scanning on the image carrier at a constant speed. The light beam at the head of the light beam is detected by the photodetector 8. The light is received and the scanning reference position is detected. In the present embodiment, the light beam for detection is reflected by the reflection mirror 7, passes through the condenser lens 81, and is condensed on the photodetector 8. Here, F indicates the focusing position of the detection light beam that has passed through the fθ lens 5, and the focusing lens 81 is arranged in a conjugate relationship with the focusing position and the light receiving surface of the photodetector 8.

Here, the condenser lens 8 is desirably a cylindrical lens having the same function as the second cylindrical lens 6 and having a function of condensing light in the main scanning direction or the sub-scanning direction. Further, a condensing lens having both functions of condensing light in the main scanning direction and condensing light in the sub-scanning direction may be used.

In the scanning optical device shown in FIG.
The scanning light that has passed through the lens 5 is condensed by the second cylindrical lens 6 to perform main scanning on the image carrier, and the reflection mirror 7 is composed of two lenses, the fθ lens 5 and the second cylindrical lens 6. Is arranged between the optical lenses and the light beam is guided to the photodetector 8 through the condenser lens 81. However, the present invention is not limited to this, and the scanning with three or more optical lenses is provided. Even in the optical device, a reflection mirror is arranged between any one of the optical lenses, and the light beam for scanning reference position detection reflected by the reflection mirror is guided to the synchronization detection means via the condenser lens. This is also included in the present invention.

In the present invention, by arranging the condenser lens as described above, the synchronous detection position can be freely set, and a compact scanning optical device having a free layout is provided. It became a thing.

(Example of Application to Image Forming Apparatus) The scanning optical device fixedly supported by the resin casing of the present invention is attached to the image forming apparatus and performs image exposure on the image carrier. In an image forming apparatus described in the following application example, four scanning optical devices are arranged in the sub-scanning direction, and color images are formed by toners of four colors of Y, M, C, and K.

In the configuration diagram of FIG. 9, the belt-shaped image carrier 100 is fed in a clockwise direction (direction of an arrow) while being wound around rollers 101 to 103. In the vicinity of the image carrier 100, scanning optical devices 111 to 114 are arranged in the sub-scanning direction so as to face the image carrier 100. Each of the scanning optical devices 111 to 114 has the same configuration as that shown in FIG. 1, and includes a light source, a collimator lens into which a light beam generated from the light source is incident, and a light beam after passing through the collimator lens. And a deflector for deflecting the light beam in the main scanning direction, and an imaging lens for forming an image of the light beam after passing through the deflector on the surface to be scanned of the image carrier.

Here, the scanning optical device 111 forms a latent image for Y (yellow) using laser light, and the scanning optical device 112 forms a latent image for M (magenta) using laser light. The scanning optical device 113 forms a latent image for C (cyan) using laser light, and the scanning optical device 114 forms a latent image for K (black) using laser light.

Adjacent ones of the scanning optical devices 111 to 114 are connected after positioning. This connection is performed using a connection member. Specifically, as shown in FIG. 10, the connecting member 200 is detachably fixed to each of the scanning optical devices 111 to 114 using a plurality of screws 201 on both sides, and then, as shown in FIG. One adjacent scanning optical device is positioned in a floating state with respect to the other scanning optical device, and the upper and lower end surfaces of the connecting members 200 of the adjacent scanning optical devices are fixed using an ultraviolet curing adhesive or the like.

In this embodiment, a scanning optical device 114 is used in which scanning optical devices 113 to 111 are sequentially stacked. The connecting member 200 and the screw 20
Reference numeral 1 is unnecessary in the scanning optical apparatus of the present invention, but is also shown in FIGS. 1 to 3 in order to facilitate understanding of the connection structure of the scanning exposure apparatus.

Referring again to FIG. 9, each scanning optical device 11
In the preceding stages of 1, 112, 113, and 114, charging units 121, 122, 123, and 124 for providing Y, M, C, and K charges to the image carrier 100 are provided, respectively. , 112, 113, 114,
Each of the scanning optical devices 111, 112, 113, 1
Developing devices 131, 132, 133, and 134 for developing the latent image formed at 14 using Y, M, C, and K developers.
Is provided.

The transfer paper 142 in the paper supply unit 141 is carried out by a paper supply roller 143, and is fed to the transfer unit 151 by a pair of conveyance rollers 144 and a timing roller 145. The transfer unit 151 includes a transfer pole 152 for transferring the toner image on the image carrier 100 to the transfer paper 142 by corona discharge, and a separation pole 153 for separating the transfer paper 142 from the image carrier 100 by AC discharge.

The fixing unit 161 includes a heat roller 162 and a pressure roller 163, and fuses a toner image to the transfer paper 142. The transfer paper 142 after the fixing is discharged to a discharge tray by a transport unit 171 at the subsequent stage. The toner remaining on the image carrier 100 after the transfer is scraped off by the cleaning unit 191.
It is stored in the collection box 192.

In this embodiment, the scanning optical device 11 for each color of Y, M, C, and K is provided around the image carrier 100.
1 to 114 and developing devices 131 to 134 are arranged in the sub-scanning direction for each color, and the electrostatic latent images of the respective colors are placed on the respective scanning optical devices 111 to 114 so as to exactly overlap the toner images of other colors. Is formed and developed by the developing devices 131 to 134. That is, the scanning optical device 111 and the developing device 131
After forming the Y toner image by using the scanning optical device 112 and the developing device 132, an M toner image is formed by superimposing the Y toner image on the Y toner image, and the scanning optical device 113 and the developing device 133 A color toner image is completed by forming a C toner image by using the scanning optical device 114 and the developing device 134 so that the K toner image is overlaid.
The image is transferred to the transfer paper 142 by the transfer unit 151.

When using different scanning optical devices for each color as described above, it is necessary for each scanning optical device to form a latent image so that the latent images are accurately overlapped in order to avoid deterioration in image quality. In other words, each scanning optical device 111-
Making the scanning lines drawn by the scanning optical devices 111 to 114 overlap so that the scanning lines drawn by the scanning optical devices 111 to 114 overlap with each other (first condition) (second condition). Condition) is required.

In this embodiment, the scanning optical devices 111 to 11
4, since the scanning optical devices shown in FIGS. 1 to 3 are used, it is easy to adjust each of the scanning optical devices 111 to 114 so as to draw a scanning line with uniform characteristics. Can be cleared. In particular, each of the scanning optical devices 111 to 1
If the optical components such as the second cylindrical lens in 14 are identical in shape and material in design and obtained from the same production lot, the characteristics of the optical components alone will be uniform, and Since it is only necessary to perform pure positioning adjustment of the optical components, it becomes easier to cause each of the scanning optical devices 111 to 114 to draw a scanning line with uniform characteristics.

On the other hand, in the present embodiment, in order to satisfy the second condition, the individual adjustments of the scanning optical devices 111 to 114 are completed, and the connecting member 200 is removed by using a plurality of screws 201 on both sides. With respect to the scanning optical devices 111 to 114 fixed as possible, one adjacent scanning optical device is positioned in a state of being floated with respect to the other scanning optical device, and the upper and lower end faces of the connecting members 200 of the adjacent scanning optical devices. Are fixed using an ultraviolet curing adhesive or the like.

As adjustment jigs, Y, M, and
Assuming four parallel ideal scanning lines corresponding to each color of C and K, a plurality of sensors are arranged on each scanning line. Each sensor can detect how much the actual beam deviates from the ideal scanning line.

The adjustment work is performed as follows. First, a beam is generated in the scanning optical device 114, and the scanning optical device 114 is positioned (attached to the adjustment jig) so that the actual scanning line by this scanning overlaps with the ideal scanning line for K.

Next, the scanning optical device 113 is supported in a state of being floated with respect to the scanning optical device 114,
3, a beam is generated, and the actual scanning line at this time is positioned so as to overlap the ideal scanning line for C, and the upper and lower end surfaces of the connecting members 200 of the scanning optical devices 114 and 113 are coated with an ultraviolet curable adhesive. Use and fix.

Further, the scanning optical device 112 is supported in a floating state with respect to the scanning optical device 113,
2, the actual scanning line at this time is positioned so as to overlap the ideal scanning line for M, and the upper and lower end surfaces of the connecting members 200 of the scanning optical devices 113 and 112 are coated with an ultraviolet curable adhesive. Use and fix.

Finally, the scanning optical device 111 is supported in a floating state with respect to the scanning optical device 112, and similarly, the actual scanning line is positioned so as to overlap the ideal scanning line for Y, and the scanning optical device 112 is similarly positioned. , 111 connecting member 20
The upper and lower end surfaces of the zeros are fixed using an ultraviolet curable adhesive.

Incidentally, as a cause of the relative displacement between the adjacent scanning optical devices, there are, for example, the following.

Up-down direction (sub-scanning direction) with respect to the surface to be scanned The scanning line also shifts up-down direction.

Shift in the left-right direction (main scanning direction) with respect to the surface to be scanned The scanning line also shifts in the left-right direction.

Shift in the direction perpendicular to the surface to be scanned The length of the scanning line increases or decreases (the lateral magnification changes).

The scanning line tilted about a horizontal axis perpendicular to the surface to be scanned tilts up and down.

The pixel density (interval) on the rotation scanning line about a vertical axis parallel to the surface to be scanned is increased at one end and narrowed at the other end.

The above detections can be performed by arranging three sensors on an ideal scanning line. For example, if three sensors for detecting the positions of the beam spots at the beginning, end, and center of the scanning line actually drawn by the scanning optical device are arranged, the deviation of the position is the position of each beam spot at the beginning and end. Can be easily detected, and the deviation can be detected depending on whether the center beam spot is closer to the start or end.

In this embodiment, the scanning optical device to be positioned is supported by an arm of an assembling robot in a state of being lifted from an adjacent scanning optical device, and positioning is adjusted. Can also be moved easily. Therefore, the displacement can be easily reduced based on the outputs of the plurality of sensors. The degree to which the accuracy of the positioning adjustment is increased depends on the image quality required for the image forming apparatus.

In the experiment of the present inventor, the displacement of the latent image of each color of Y, M, C, and K formed on the surface to be scanned was 200 μm.
In the following, it was confirmed that if the thickness is desirably 120 μm or less, it can be recognized as an image having no uncomfortable feeling.

The connection of the scanning optical devices can be performed while a plurality of scanning optical devices are mounted on the image forming apparatus. However, in reality, the plurality of scanning optical devices are connected in advance, and
The operation becomes much simpler when the connected scanning optical device is mounted on the image forming apparatus.

[0075]

According to the first to third aspects of the present invention, there is provided a scanning optical apparatus capable of performing fine adjustment of the height and inclination of the installation while the optical lens installed on the optical lens installation table can be reworked. Will be provided.

According to the present invention, the optical lens set on the optical lens setting table can be easily fixed in an adjusted state, and the optical lens can be detached to enable rework. A device has been provided.

In the case of the eighth to eleventh aspects, the degree of freedom is given to the installation position of the synchronous detection means (photodetector) for detecting the scanning reference position of the light beam deflected and scanned, so that the layout becomes easy and the size is reduced. Is provided.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a scanning optical device of the present invention.

FIG. 2 is a front view showing an embodiment of the scanning optical device of the present invention.

FIG. 3 is a bottom view showing an embodiment of the scanning optical device of the present invention.

FIG. 4 is a front view of a second cylindrical lens.

FIG. 5 is a plan view of a second cylindrical lens.

FIG. 6 is an explanatory diagram illustrating an adjustment method according to the first embodiment.

FIG. 7 is an explanatory diagram showing a fixing method according to the second embodiment.

FIG. 8 is an explanatory diagram showing an optical path portion according to the third embodiment.

FIG. 9 is a configuration diagram of an image forming apparatus.

FIG. 10 is a perspective view showing an attachment structure of a connecting member.

FIG. 11 is a configuration diagram showing a connected state of the scanning optical devices.

FIG. 12 is a perspective view illustrating an outline of a scanning optical device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin casing 2 Laser light source 3 Collimator lens 4 Polygon mirror 5 fθ lens 6 Second cylindrical lens 7 Reflection mirror 8 Photodetector 9a Mirror 9b Cover glass 11 Upright wall section 12 Bottom plate section 13, 14, 15, 20, 21, 22 Adjustment Screw 16, 17, 23, 24 Projection 18, 25 Engagement hole 19, 26 Stopper 51, 68 Engagement protrusion 52 Female thread 81 Condenser lens

Claims (11)

[Claims] At least a light source, a deflector that deflects a light beam generated from the light source in a main scanning direction, and an optical lens that scans and forms an image beam on the image carrier after passing through the deflector A scanning optical device having a resin casing that supports the optical lens, a female screw portion inserted into the resin casing, and a direction opposite to the direction in which the female screw portion is inserted into the resin casing. And a male screw part inserted into the female screw part and projecting a distal end thereof from the female screw part, and the distal end of the male screw part is brought into contact with the optical lens, and the male screw part is provided. A scanning optical apparatus, wherein an installation height and an inclination of the optical lens are adjusted by adjusting a protruding amount of a tip portion of the optical lens. 2. The scanning optical device according to claim 1, wherein a peripheral wall surrounding the male screw portion is formed around the male screw portion in the resin casing. 3. The scanning according to claim 2, wherein a head of the male screw portion is pressed against the peripheral wall, and a fall prevention member for preventing the male screw portion from falling is formed in the resin casing. Optical device. 4. At least a light source, a deflector for deflecting a light beam generated from the light source in the main scanning direction, and an optical lens for scanning and forming an image on the image carrier after passing through the deflector. A positioning boss is provided on the optical lens, and a positioning hole for inserting the positioning boss is provided in a resin casing which fixedly supports the optical lens, and the positioning boss is provided. After being inserted into the positioning hole, the positioning lens is abutted against the edge of the positioning hole, a stopper member for fixing the position of the optical lens is abutted against the positioning boss, and the stopper member is fixed to fix the optical lens. A scanning optical device, wherein the scanning optical device is positioned on the resin casing. 5. A part of the positioning boss is concave or convex, and a part of the stopper member has a shape conforming to the concave or convex shape, and each of the positioning boss and the stopper member has an irregular shape. By matching the stopper member to the positioning boss so that
The scanning optical device according to claim 4, wherein the optical lens is positioned on the resin casing. 6. One of the positioning boss and the stopper member has a concave or convex shape, and one of the positioning boss and the stopper member is formed of a member having a soft hardness. The scanning optical device according to claim 4, wherein the optical lens is positioned on the resin casing such that the optical lens is fixed by the stopper member. 7. The scanning optical device according to claim 4, wherein the optical lens and the stopper member are fixed with an adhesive. 8. At least a light source, a deflector for deflecting a light beam generated from the light source in the main scanning direction, and an optical lens for scanning and forming an image on the image carrier after passing through the deflector. And a synchronization detection unit that detects a scanning reference position of the light beam that has been deflected and scanned.A scanning optical device, comprising: a condenser lens disposed between the optical lens and the synchronization detection unit; A scanning optical device, wherein the condensing lens is arranged such that a condensing position of the optical lens in the main scanning direction in the main scanning direction and the synchronization detecting means are in a conjugate relationship. 9. The scanning optical device according to claim 8, wherein the condenser lens is a cylindrical lens that condenses the light beam in the main scanning direction. 10. The scanning optical device according to claim 9, wherein the condenser lens is a cylindrical lens that condenses the light beam in a sub-scanning direction. 11. The apparatus according to claim 8, wherein a plurality of said optical lenses are arranged, a reflection mirror is arranged between said plurality of optical lenses, and a light beam is guided to said synchronization detecting means.
The scanning optical device according to claim 10.