JP4796383B2 - Optical characteristic measuring apparatus for scanning optical system, scanning optical system unit, and image forming apparatus - Google Patents

Description

  The present invention relates to a scanning optical system optical property measuring apparatus, a scanning optical system unit, and an image forming apparatus for measuring a beam main / sub position, a beam profile, and a beam position interval between scanning stations in a scanning optical system unit for writing or reading. About.

  2. Description of the Related Art In various image forming apparatuses such as laser printers and digital copying machines, scanning optical systems that focus a laser beam as a light spot on a surface to be scanned and scan the surface to be scanned are generally widely known. In particular, in recent years, “higher density and multi-beam” scanning by a scanning optical system is intended, and “higher accuracy” is required for the scanning position by the light spot.

  Such a light spot moves on the surface to be scanned and scans the surface to be scanned. The ideal moving direction of the light spot on the surface to be scanned is called the main scanning direction, and is orthogonal to the main scanning direction. It is well known that the direction to do is called the sub-scanning direction. Further, the trajectory of the light spot is called a “main scanning line”. The “scanned surface” referred to here is a virtual plane, and is essentially a photosensitive surface in a photoconductive photoreceptor.

  Ideally, the main scanning line is an accurate straight line, but actually, the main scanning line does not become an exact straight line due to various factors, and a slight curve occurs. In addition, when the laser beam is deflected by a rotating polygon mirror, the main scanning line due to the deflection of each deflecting reflecting surface of the rotating polygon mirror may fluctuate by a small distance in the sub-scanning direction due to the effect of so-called “surface tilt”. Can be considered. Such “curvature” and “minor distance fluctuation in the sub-scanning direction” of the main scanning line need to be within a predetermined allowable range. However, when the scanning density is increased or when scanning is performed with multiple beams. The tolerance of is quite narrow.

  Normally, when actually assembling the scanning optical system or after it is assembled, the bending of the main scanning line and the fluctuation in the sub-scanning direction as described above are adjusted, or whether these are within the allowable range as designed. To do. Therefore, it becomes necessary to measure the scanning position in the sub-scanning direction at a desired main scanning position on the surface to be scanned.

  In the case of a color image, in the case of the tandem method in which writing is performed by optical scanning from different stations for each color, the deviation of the beam position interval between the stations becomes the color deviation (position deviation) in the sub-scanning direction. Therefore, it is necessary to accurately adjust the beam position interval between the stations.

  Further, since the scanning lines of each station have different bends and inclinations, the beam position interval between the stations varies depending on the image height. Accordingly, it is necessary to accurately measure the beam position interval between stations in order to reduce the color shift in the sub-scanning direction over the entire scanning range by adjusting the difference to be small.

As an apparatus for measuring the scanning position in the sub-scanning direction at a desired main scanning position on the surface to be scanned, for example, the invention disclosed in Patent Document 1 is known. Patent Document 1 discloses an invention relating to a measuring apparatus that moves one CCD camera to a desired main scanning position by a moving stage and measures the scanning position in the sub-scanning direction.
JP 2000-039573 A

  By the way, the purpose of measuring the scanning position in the sub-scanning direction is to obtain the scanning line curve and inclination from the sub-scanning position over the entire image height. Although it is possible to measure the scanning position on a single scanned surface with a conventional measuring apparatus, it is possible to accurately determine the beam position interval between stations of, for example, a tandem scanning optical system having a plurality of stations. It was not possible to measure.

  In view of such problems, the present invention provides an optical characteristic measuring apparatus and a scanning optical system unit for a scanning optical system capable of accurately measuring a beam position interval between stations having a plurality of stations as in the tandem method. It is another object of the present invention to provide an image forming apparatus.

In order to achieve the above object, the invention according to claim 1 is directed to a scanning position of a scanning optical system of an optical unit including a scanning optical system that has a light source, a polygon mirror, and a folding mirror and scans an image plane. An optical characteristic measuring apparatus for measuring a light intensity pattern, in which a light receiving portion that receives a light beam emitted from an optical unit, and a direction perpendicular to a main scanning direction of a scanning optical system and a rotation axis of a polygon mirror is a sub-scanning direction And the distance between the light beams that are farthest in the sub-scanning direction among the light beams emitted from the optical unit is the sub-scanning width of the scanning optical system, and the scanning width of the scanning optical system in the main scanning direction is the main scanning width. A moving means that can move the light receiving portion to an arbitrary position in a plane that is equal to or larger than the sub-scanning width and the main scanning width, the moving means is configured by combining a plurality of stages, and holds the light receiving portion, And, The holding portion at both ends of the stage which is movable in the sub-scanning direction of the scanning optical system, characterized by having a sliding member supporting the stage.

According to a second aspect of the present invention, there is provided an optical unit that includes a scanning optical system that has a light source, a polygon mirror, and a folding mirror, and that scans an image plane. A characteristic measuring device, a light receiving unit that receives a light beam emitted from the optical unit , and a direction perpendicular to the main scanning direction of the scanning optical system and the rotation axis of the polygon mirror is a sub-scanning direction, and is emitted from the optical unit. The distance between the light beams that are farthest in the sub-scanning direction is the sub-scanning width of the scanning optical system, and the scanning width of the scanning optical system in the main scanning direction is the main scanning width. And a moving means that can move at least in the sub-scanning direction within a plane that is equal to or larger than the main scanning width. direction At both ends of the movable and the said stage has a sliding member supporting the stage, the light receiving unit is characterized in that it is provided a plurality in the main scanning direction of the stage.

  According to a third aspect of the present invention, in the optical characteristic measuring apparatus for a scanning optical system according to the first or second aspect, the light receiving unit is arranged in a direction perpendicular to a moving plane by the moving unit. .

According to a fourth aspect of the present invention, in the optical characteristic measuring apparatus for a scanning optical system according to the first or second aspect, the light receiving unit moves in the width direction of the scanning optical system and an arbitrary main scanning direction. in the position, the position in the sub-scanning direction of the light beam emitted from the optical unit after the movement and position in the sub-scanning direction of the light beam emitted from the optical unit in the previous movement, the position of the light beam emitted from the optical unit An interval is calculated.

  According to a fifth aspect of the present invention, in the optical characteristic measuring apparatus for a scanning optical system according to the first or second aspect, an ideal moving plane that connects the image plane position of the scanning optical system at an arbitrary position of the light receiving unit. The first measuring means for measuring in advance the difference between the position of the light receiving unit on the top and the position of the light receiving unit on the actual moving plane is corrected, and the difference is corrected based on the measurement result of the first measuring means. It is characterized by doing.

  According to a sixth aspect of the present invention, in the optical characteristic measuring apparatus for a scanning optical system according to the first or second aspect, an ideal moving plane connecting the image plane positions of the scanning optical system at an arbitrary position of the light receiving unit. Based on the measurement result of the second measuring unit, the second measuring unit has a difference between the position of the light receiving unit on the top and the position of the light receiving unit on the actual moving plane while measuring the optical characteristics. The difference is corrected.

A seventh aspect of the present invention is the optical characteristic measuring apparatus for a scanning optical system according to the first or second aspect, wherein the difference in thermal expansion coefficient between the stage and the sliding member is 2.2 × 10 ⁻⁶ or less. It is composed of a material characterized by Rukoto.

According to an eighth aspect of the present invention, in the optical characteristic measuring apparatus for a scanning optical system according to the first or second aspect , the power source and the signal line of the light receiving unit are connected to locations other than the surface facing the light receiving unit. It is characterized by that.

According to a ninth aspect of the present invention, the scanning is detachable from the image forming apparatus and is measurable with respect to the optical characteristic measuring device of the scanning optical system according to any one of the first to eighth aspects. wherein the optical system unit der Rukoto.

A tenth aspect of the present invention is an image forming apparatus having the scanning optical system unit according to the ninth aspect.

  As described above, according to the optical characteristic measuring apparatus, the scanning optical system unit, and the image forming apparatus of the scanning optical system of the present invention, it is possible to accurately measure the beam position interval between stations having a plurality of stations.

Hereinafter, an optical characteristic measuring apparatus, a scanning optical system unit, and an image forming apparatus of a scanning optical system according to the present embodiment will be described with reference to the drawings. In addition, this embodiment is not limited to what is described below, A various change is possible in the range which does not deviate from the meaning.
FIG. 1 is a block diagram showing the configuration of the optical characteristic measuring apparatus of this embodiment.

  As shown in FIG. 1, the optical characteristic measuring apparatus of this embodiment includes a scanning optical system unit 1, a light receiving unit 2, an X stage 3a, and a Y stage 3b. A semiconductor laser (Laser Diode: LD) serving as a light source is installed in the scanning optical system unit 1 that performs writing or reading. The laser beam emitted from the semiconductor laser is focused on the mirror surface of the polygon mirror by a collimator lens and a cylindrical lens. The laser beam focused on the polygon mirror is reflected by the mirror surface, passes through the fθ lens, forms an image as a light spot on the surface to be scanned (image surface), and is scanned in the main scanning direction.

  As shown in FIGS. 7 and 11, the color scanning optical system unit has four stations corresponding to each color of cyan (C), M (magenta), yellow (Y), and black (K). A laser beam is emitted from each station. The laser beam scanned in this way is irradiated to the light receiving unit 2 of the optical specific measuring device arranged on the trajectory of the light spot on the surface to be scanned.

  As the light receiving unit 2, for example, a line CCD or an area CCD that can identify the position of the irradiated light spot is used. By providing the X stage 3a and the Y stage 3b, the light receiving unit 2 can be moved to an arbitrary position within a plane larger than the main scanning width and the station interval. The light receiving unit 2 is installed in a direction substantially perpendicular to the plane in the moving direction so that the light spot can be irradiated.

  FIG. 9 is a diagram showing the output intensity when the line CCD of this embodiment is irradiated with a laser beam. As shown in FIG. 9, the position of the light spot in the sub-scanning direction can be determined by obtaining the position of the center of gravity of the output intensity.

  FIG. 10 is a diagram showing the output intensity when the area CCD of this embodiment is irradiated with a laser beam. In FIG. 10, by obtaining the barycentric position of the output intensity, the position of the light spot in the main scanning direction and the sub scanning direction can be determined. In this case, it is necessary to control the pulse lighting at an arbitrary position.

  As described above, according to the optical characteristic measuring apparatus of the present embodiment, the light receiving unit can freely move in a plane that is not less than the main scanning width and not less than the station interval. Therefore, it is possible to measure the beam position interval between the stations over the entire region in the main scanning direction of the optical scanning optical system.

Next, another configuration example in the optical characteristic measuring apparatus of the present embodiment will be shown.
FIG. 2 is a diagram illustrating a case where a plurality of light receiving units are installed so as to extend over the entire region in the main scanning direction using a fixing member.

  As shown in FIG. 2, the plurality of light receiving portions 2 are held by fixing members 4 provided in the entire region in the main scanning direction. As each light receiving portion, a device capable of specifying the position of the irradiated light spot, such as the above-described line CCD or area CCD, is used. By providing the X stage 3a, the light receiving unit 2 can be moved to any position within a plane in a range larger than the station interval.

  In this type of optical characteristic measuring apparatus, it is naturally not necessary to move the light receiving unit 2 in the main scanning direction. Therefore, the time required for measurement can be dramatically shortened. Furthermore, since the positions of the light spots at a plurality of main scanning positions can be determined within the same scanning, it is possible to perform highly accurate measurement.

  Although not shown here, the light receiving unit 2 does not reach the entire region in the main scanning direction even in an optical characteristic measuring apparatus provided with a plurality of light receiving units using the fixing member 4 as described in FIG. In this case, as shown in FIG. 1, the light receiving unit 2 may be moved beyond the main scanning width by using the X stage 3a and the Y stage 3b.

  As described above, according to the optical characteristic measuring apparatus of the present embodiment, the fixing member provided with the plurality of light receiving portions can move in the plane that is equal to or greater than the station interval over the entire region in the main scanning direction. Therefore, it is possible to measure the beam position interval between stations in the entire main scanning area of the scanning optical system.

  Next, FIG. 3 is a diagram illustrating the principle of calculating the laser beam position interval between the stations.

  First, the position in the sub-scanning direction of the light spot of the m-th station is measured at a certain main scanning position. In the present embodiment, measurement is performed at the position of the light receiving unit 2a before movement. Next, the X stage 3a is accurately moved by a certain distance. Then, the position of the light receiving unit 2b after the movement, that is, the position in the sub-scanning direction in the light spot of the nth station is measured.

  At this time, the movement amount of the X stage 3a is moved by an accurate distance by driving the stepping motor, or the movement amount of the X stage 3a is accurately obtained by a linear scale. It is desirable to determine the amount accurately.

  The difference in the sub-scanning direction position of each light spot at the position at the m-th station and the position at the n-th station is added to the movement amount of the X stage 3a thus obtained. Thereby, the position interval of the laser beam between the stations can be accurately calculated.

Next, correction for stage deflection in the optical characteristic measurement apparatus of the present embodiment will be described.
FIG. 4 is a diagram schematically illustrating an example of a state in which the X stage 3a is bent.

  As shown in FIG. 4, when the stage configuration is a combination of the X stage 3a and the Y stage 3b, the long stage (X stage 3a in this figure) that is on the upper side in the direction of gravity is supported only at the center. Has been. Therefore, the X stage 3a is bent as the light receiving unit 2 moves.

  The amount of deflection at this time cannot be unconditionally defined because it varies depending on the rigidity and length of the X stage 3a main body, the weight of the light receiving unit 2, and the like. Further, the amount of bending also varies depending on the stop position of the light receiving unit 2. If the measurement is performed in a state where the X stage 3a is bent, an accurate measurement of the beam position interval cannot be performed, and some correction for the bending is required.

  Since the deflection amount is reproducible, the deflection amount can be measured in advance at the stop position of the light receiving unit 2. Further, since the amount of deflection is approximately several tens to several hundreds of micrometers, the displacement direction can be regarded as only the Z direction as shown in FIG.

  Therefore, in the present embodiment, the Z stage 3 c is installed between the long stage (X stage 3 a) and the light receiving unit 2. Then, the Z stage 3c is driven by the amount of bending that is bent at the stop position of the light receiving unit 2. In this way, the light receiving unit 2 can always be positioned on the optical scanning plane, and an accurate measurement result can be obtained.

  FIG. 5 is a diagram schematically showing another example of correction for bending of the X stage 3a.

  As shown in FIG. 5, the entire optical property measuring apparatus of the present embodiment is installed on a fixed base 5 having good smoothness such as a surface plate. Therefore, the amount of deflection of the stage can be obtained by measuring the distance from the fixed base 5 using the displacement meter 6 installed in the vicinity of the light receiving unit 2.

In the case of a contact-type displacement meter such as a dial gauge or a differential transformer, the displacement meter 6 comes into contact with the stage when passing through the lower stage (Y stage 3b in this figure). It becomes an obstacle because it becomes. Therefore, it is desirable to use a non-contact type displacement meter such as a laser type.
The deflection amount obtained by the displacement meter 6 is corrected by the Z stage 3c.

Furthermore, it is also possible to prevent the occurrence of the bending itself with respect to the correction for the bending of the stage of the optical characteristic measuring apparatus of the present embodiment.
FIG. 6 shows a diagram for preventing the stage from being bent in the optical characteristic measuring apparatus according to the present embodiment.

  In FIG. 6, the fall-preventing sliding member 7 is placed between the upper stage (X stage 3 a in this figure), the vicinity of both ends in the longitudinal direction, and the fixed base 5 of the entire optical property measuring apparatus. Prepare. In the present embodiment, a front-side falling prevention sliding member 7a and a rear-side falling prevention sliding member 7b are provided. By installing this falling prevention sliding member 7, the occurrence of bending itself is prevented.

  The fall-preventing sliding member 7 is installed on the fixed base 5 so that the height thereof exactly matches the distance between the bottom surface of the X stage 3 a and the top surface of the fixed base 5. The sliding surface with the X stage 3a is smooth so as not to be a stage moving load. Further, a lubricant such as grease may be applied to reduce the load of moving the stage.

Further, when there is a temperature change, there is a possibility that the distance from the stage bottom surface to the fixed table top surface and the height of the sliding member may vary depending on the respective materials. Therefore, materials having substantially the same thermal expansion coefficient are used as the base material of the stage and the material of the sliding member. For example, if the height of the sliding member 7 for preventing fall is set to 75 mm, the difference in thermal expansion coefficient is 2.2 × 10 ^{−6 in} order to suppress the temperature variation at 30 ° C. to the range of 5 μm. .

  In general, aluminum is used as a base material used for the stage. Therefore, when such a stage is used, the fall-preventing sliding member 7 may be made of aluminum. Needless to say, the material used for each stage and the fall-preventing sliding member 7 may be other than aluminum.

  FIG. 8 is a diagram showing the arrangement of the power supply and signal lines from the light receiving unit 2 in the optical characteristic measuring apparatus according to the present embodiment.

  In the case of a CCD camera used in a light receiving part of a general optical characteristic measuring apparatus, the power supply and the signal line often come from the opposite side of the light receiving part. However, in the case of the configuration of the optical characteristic measuring apparatus of the present embodiment, if the power source and the signal line are arranged on the opposite side of the light receiving unit 2, the power source / signal line mounting unit and the stage may interfere with each other. . In addition, when the stage is driven, various inconveniences such as the power source and the signal line being caught by the lower stage occur.

  Therefore, in the optical characteristic measuring apparatus according to the present embodiment, the power supply and the signal line are arranged so as to extend from the side surface of the light receiving unit 2 as shown in FIG. Thereby, it is possible to prevent the interference between the light receiving unit 2 and the stage and the catching of the line as described above.

  Next, FIG. 7 is a side view when the scanning optical system unit 1 is attached to the optical characteristic measuring apparatus of the present embodiment.

  As shown in FIG. 7, the scanning optical system unit 1 is positioned on the mounting base 8 installed on the fixed base 5. Here, positioning is performed using the front mounting base 8a and the rear mounting base 8b. Further, the height is adjusted so that the position of the surface to be scanned (image surface) and the position of the light receiving unit 2 coincide. The optical characteristics are measured in such a state, and the scanning position in the sub-scanning direction and the laser beam position interval between stations are adjusted based on the result. This makes it possible to complete a scanning optical system unit with higher writing accuracy.

Further, the scanning optical system unit 1 measured by the optical characteristic measuring apparatus of the present embodiment may be attached to the image forming apparatus in a detachable state. By making it attachable to and detachable from the image forming apparatus, the scanning optical system unit 1 can always be measured by the optical characteristic measuring apparatus of this embodiment.
FIG. 11 is a diagram showing a configuration when the scanning optical system unit 1 of the present embodiment is attached to form the image forming apparatus 10.

  In addition to the scanning optical system unit 1 described above, the image forming apparatus 10 according to the present exemplary embodiment includes a paper feeding unit 11, a registration roller 12, a paper transport belt 13, a charging unit 14, a peeling unit 21, and a static eliminating unit. 22, a belt cleaning unit 23, a fixing unit 24, and a paper discharge roller 25.

  The image forming apparatus 10 also includes drum-shaped image carriers 16Y, 16M, 16C, and 16K corresponding to toners of yellow (Y), magenta (M), cyan (C), and black (K). Yes. Further, around the image carrier 16, charging units 17Y, 17M, 17C, and 17K for uniformly charging the surface of the image carrier 16 and the electrostatic latent image on the image carrier 16 are developed with toner. A developing unit 18, a transfer unit 19 for transferring the developed electrostatic latent image onto a sheet, and a cleaning unit 20 for wiping off transfer residual toner remaining on the surface of the image carrier 16 after transfer are provided.

  Further, the scanning optical system unit 1 has a polygon mirror having two stages, an upper stage and a lower stage, and the laser beam 15Y corresponding to the toner of each color with respect to the image carriers 16Y, 16M, 16C, and 16K. , 15M, 15C, and 15K, respectively.

  The transfer units 19 for each color and the peeling unit 21 are arranged in a paper transport path on which the paper transport belt 13 is provided. A fixing unit 24 is disposed on the downstream side of the sheet conveying belt 13 in the sheet conveying direction. On the other hand, a registration roller 12 and a charging unit 14 are disposed on the upstream side of the sheet conveying belt 13.

  A paper feed unit 11 is disposed below the image carrier 16, that is, below the image forming apparatus 10. A paper feed roller near the paper feed unit aligns the paper in the paper feed unit 11. Paper is being fed one by one. Further, the sheet picked up from the sheet feeding unit by the sheet feeding roller is fed to the sheet conveying belt 13 through a sheet feeding path curved in a U shape between the sheet feeding unit 11 and the registration roller 12. Will be.

  These units and units are centered on the image carrier 16, Y (charge → exposure → development → transfer) → M (charge → exposure → development → transfer) → C (charge → exposure → development → transfer) → K An image is formed on the transfer sheet by executing an electrophotographic process of (charging → exposure → development → transfer) → fixing.

  Specifically, first, a sheet is conveyed from the sheet feeding unit 11 to the registration roller 12 through the sheet feeding path by the sheet feeding roller. The registration roller 12 feeds the fed paper (transfer paper) to the paper transport belt 13 at a timing.

  At this time, the charging unit 17Y related to yellow toner charges the surface of the image carrier 16Y. Then, the scanning optical system unit 1 irradiates the surface of the image carrier 16Y with a laser beam 15Y corresponding to yellow toner for exposure, and the developing unit 18 develops the electrostatic latent image.

  In accordance with this timing, the sheet is charged by the charging unit 10 and then conveyed by the sheet conveying belt 13. Then, the developed electrostatic latent image is transferred onto this sheet by the transfer unit 19Y.

After the image is transferred to the paper, the transfer residual toner remaining on the image carrier 16Y and not transferred onto the paper is removed by the cleaning unit 20. And it prepares for the next image output.
On the other hand, the paper on which the image has been transferred is subjected to the same image formation by a series of units relating to the next magenta toner, cyan toner, and black toner by the paper transport belt 131.

In this way, when all the images of the respective color toners are transferred onto the sheet, the sheet is separated from the sheet conveying belt 13 by the peeling unit 21 and sent to the fixing unit 24. The paper sent to the fixing unit 24 is discharged by the paper discharge roller 25 through the paper conveyance path after the image transferred onto the paper is fixed.
On the other hand, the sheet transport belt 13 after the sheet is released by the peeling unit 21 is neutralized by the neutralizing unit 22, and further, dust and the like attached to the surface is removed by the belt cleaning unit 23.
In this way, an image is formed.

  As described above, according to the optical characteristic measuring apparatus of the scanning optical system of this embodiment, it is possible to accurately measure the beam position interval between stations in the entire main scanning region of the scanning optical system such as the tandem method.

  In addition, since the light receiving unit is installed in a state of being substantially perpendicular to the moving plane, the light spot on the surface to be scanned can be directly measured. In addition, by calculating the beam position interval between the stations of the scanning optical system from the amount of movement of the light receiving unit in the station direction and the sub-scanning detection position of the beam before and after the movement, the beam position interval between the stations can be accurately determined. Measurement is possible.

  In addition, at an arbitrary movement position, the amount of deviation of the light receiving unit from the ideal movement plane connecting the image plane positions of the stations is measured in advance or measured in real time and automatically corrected by a Z stage or the like. Thus, even if there is a deflection of the moving stage, the light receiving unit can always be placed on an ideal scanning plane, and the beam position interval between stations can be accurately measured.

In addition, as a linear motion stage in which the moving means of the light receiving unit is combined, a sliding member that prevents the body from falling over is provided between the vicinity of both ends in the longitudinal direction of the stacked stages and the fixed base of the entire optical property measuring apparatus. As a result, the deflection of the moving stage can be prevented, the light receiving unit can always be placed on an ideal scanning plane, and the beam position interval between stations can be accurately measured. Furthermore, by setting the difference in thermal expansion coefficient between the falling prevention sliding member and the base material of the linear motion stage to 2.2 × 10 ⁻⁶ or less, even if there is a temperature change of 30 ° C., for example, The influence of deflection can be suppressed to 5 μm or less.

  Further, since the power source / signal line of the light receiving part is connected to the side part other than the bottom face, the line does not become an obstacle when the light receiving part is installed or moved.

  Further, according to the scanning optical system unit of the present embodiment, it can be attached to the optical characteristic measuring device of the scanning optical system in a measurable state, so that it is possible to accurately measure the beam position interval between stations.

  Furthermore, according to the image forming apparatus of the present embodiment, since the scanning optical system unit measured by the optical characteristic measuring device of the scanning optical system of the present embodiment described above can be used, an image with reduced color misregistration can be used. Output is possible.

It is a block diagram which shows the structural example of the optical characteristic measuring apparatus of this embodiment. It is a block diagram which shows the other structural example of the optical characteristic measuring apparatus of this embodiment. It is a figure which shows the principle which calculates the position space | interval of the laser beam between each station of this embodiment. It is a figure showing typically an example of the state where X stage 3a of this embodiment bent. It is a figure which shows typically an example about the correction | amendment with respect to the bending of the X stage 3a of this embodiment. It is a figure which shows the case where the bending of the stage of the optical characteristic measuring apparatus of this embodiment is prevented using a fall prevention member. It is a side view at the time of attaching the scanning optical system unit 1 to the optical characteristic measuring apparatus of this embodiment. In the optical characteristic measuring apparatus of this embodiment, it is a figure which shows the arrangement | positioning state of the power supply from the light-receiving part 2, and a signal line. It is a figure which shows the output intensity when a laser beam is irradiated to the line CCD of this embodiment. It is a figure which shows the output intensity when a laser beam is irradiated to the area CCD of this embodiment. 1 is a diagram illustrating a configuration of an image forming apparatus according to an exemplary embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Scan optical system unit 2 Light-receiving part 3a X stage 3b Y stage 3c Z stage 4 Fixed member 5 Fixed base 6 Displacement meter 7 Fall prevention sliding member 8 Mounting base

Claims (10)

An optical characteristic measuring device for measuring a scanning position and a light intensity pattern of the scanning optical system of an optical unit having a light source, a polygon mirror, and a folding mirror and including a scanning optical system that scans an image plane,
A light receiving unit for receiving a light beam emitted from the optical unit;
The direction perpendicular to the main scanning direction of the scanning optical system and the rotation axis of the polygon mirror is defined as the sub-scanning direction, and the distance between the light beams farthest in the sub-scanning direction among the light beams emitted from the optical unit is When the sub-scanning width of the scanning optical system and the scanning width of the scanning optical system in the main scanning direction are set as the main scanning width, the light receiving unit can be moved to any position in the plane that is equal to or larger than the sub-scanning width and larger than the main scanning width. Moving means,
The moving means is configured by combining a plurality of stages, and holds the light receiving unit, and the stage is attached to both ends of the stage that can move the holding unit in the sub-scanning direction of the scanning optical system. An optical property measuring apparatus having a sliding member to be supported. An optical characteristic measuring device for measuring a scanning position and a light intensity pattern of the scanning optical system of an optical unit having a light source, a polygon mirror, and a folding mirror and including a scanning optical system that scans an image plane,
A light receiving unit for receiving a light beam emitted from the optical unit;
The direction perpendicular to the main scanning direction of the scanning optical system and the rotation axis of the polygon mirror is defined as the sub-scanning direction, and the distance between the light beams farthest in the sub-scanning direction among the light beams emitted from the optical unit is When the sub scanning width of the scanning optical system and the scanning width of the scanning optical system in the main scanning direction are set as the main scanning width, the light receiving portion is moved at least in the sub scanning direction in a plane that is equal to or larger than the sub scanning width and larger than the main scanning width. Possible moving means,
The moving means includes a stage, a sliding member that supports the stage at both ends of the stage that holds the light-receiving unit and that can move the holding unit in the sub-scanning direction of the scanning optical system. Have
2. An optical characteristic measuring apparatus according to claim 1, wherein a plurality of the light receiving sections are provided in the main scanning direction of the stage.   3. The optical characteristic measuring apparatus for a scanning optical system according to claim 1, wherein the light receiving unit is arranged in a direction perpendicular to a moving plane by the moving unit. The light receiving unit is
An amount of movement in the width direction of the scanning optical system;
At any position in the main scanning direction, depending on the position in the sub-scanning direction of the light beam emitted from the optical unit before the movement and the position in the sub-scanning direction of the light beam emitted from the optical unit after the movement,
3. The optical characteristic measuring apparatus for a scanning optical system according to claim 1, wherein a position interval of light beams emitted from the optical unit is calculated. In an arbitrary position of the light receiving unit,
First measuring means for measuring in advance a difference between the position of the light receiving unit on the ideal moving plane connecting the image plane positions of the scanning optical system and the position of the light receiving unit on the actual moving plane Have
3. The optical characteristic measuring apparatus for a scanning optical system according to claim 1, wherein the difference is corrected based on a measurement result of the first measuring means. In an arbitrary position of the light receiving unit,
The difference between the position of the light receiving unit on the ideal moving plane connecting the image plane positions of the scanning optical system and the position of the light receiving unit on the actual moving plane is performed while measuring the optical characteristics. Having a second measuring means;
3. The optical characteristic measuring apparatus for a scanning optical system according to claim 1, wherein the difference is corrected based on a measurement result of the second measuring means. 3. The optical characteristic measurement of a scanning optical system according to claim 1, wherein the stage and the sliding member are made of a material having a difference in thermal expansion coefficient of 2.2 × 10 ⁻⁶ or less. apparatus.   3. The optical characteristic measuring apparatus for a scanning optical system according to claim 1, wherein a power source and a signal line of the light receiving unit are connected to a portion other than a surface facing the light receiving unit.   9. A scanning optical system unit detachable from an image forming apparatus and capable of being measured with respect to the optical characteristic measuring apparatus for a scanning optical system according to claim 1. .   An image forming apparatus comprising the scanning optical system unit according to claim 9.

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