CN100388127C - Writing unit adjustment device using beam characteristic evaluation method - Google Patents

Abstract

The invention discloses a writing unit adjusting device adopting a light beam characteristic evaluation method, which is characterized in that it has a writing unit for forming an electrostatic latent image on the surface of a latent image carrier with a light beam emitted by a laser light source equipped with an optical scanning system. a unit; an imaging unit with at least the latent image carrier inside; and a moving assembly that relatively moves the writing unit and the imaging unit along the main scanning direction to adjust the deviation along the main scanning direction of the light beam.

Description

Writing unit adjustment device using beam characteristic evaluation method

The present invention application is a divisional application of 98117250.4.

technical field

The present invention relates to an evaluation device for image forming devices such as laser printers and copiers, and more specifically, the present invention relates to requirements for the light beam irradiated from a writing unit of an image forming device to a latent image carrier such as a photosensitive drum or a photosensitive belt. A method for evaluating characteristics, a beam characteristic evaluation device for performing such a beam characteristic evaluation, and an adjustment device for a writing unit for adjustment using this evaluation method.

Background technique

As we all know, the original image forming devices such as laser printers, copiers, and facsimile machines usually use the light beam emitted by the writing unit to scan along the main scanning direction on the surface of the photosensitive drum as a latent image carrier at the imaging unit. Scanning is performed while scanning in the sub-scanning direction to write on the surface of the photosensitive drum to form an electrostatic latent image, which is developed by attaching toner to the surface of the photosensitive drum on which this electrostatic latent image is formed The toner image is fixed when the toner image is transferred to copy paper, and an image is formed on the copy paper.

An optical scanning system for beam scanning is provided in this writing unit, and scanning in the main scanning direction with respect to the surface of the photosensitive drum can be performed by this optical scanning system, and scanning in the sub scanning direction with respect to the surface of the photosensitive drum can be performed. It is performed by the rotation of the photosensitive drum.

However, in these image forming apparatuses, when writing is performed on the surface of a photosensitive drum to be read, it is necessary to evaluate whether or not the light beam of this writing unit has required characteristics.

Taking a copier as an example, when the image information on the original is read sequentially and converted into a light beam, if the beam writing position on the surface of the photosensitive drum deviates from the predetermined reference position during design, It becomes impossible to form an image corresponding to the image information on the document at this reference position. In particular, two laser light sources for generating light beams are set in the writing unit, and the surface of the photosensitive drum is scanned along the main scanning direction with two beams of light at the same time, and writing is implemented on the surface of the photosensitive drum at twice the conventional speed. In the image forming device that is imported, in the process of scanning along the main scanning direction, if the writing position of one beam deviates from the writing position of the other beam, the original image cannot be faithfully reproduced, so it is necessary to adjust the position of one beam The writing position is evaluated, and the writing position of the other beam is evaluated.

In the case of a writing unit that uses one light beam to write to the photosensitive drum, it is also necessary to calculate each writing position on each surface of the polygonal prism that constitutes the optical scanning system along the main axis. Positional deviation in the scanning direction (inhomogeneity in pitch in the main scanning direction) and positional deviation in the sub-scanning direction on each surface of the polygonal prism (inhomogeneity in pitch in the sub-scanning direction) were evaluated.

In the case of using a writing unit that writes to a photosensitive drum with several beams of light, in addition to the above-mentioned evaluation, the pitch between the beams is also one of the objects to be evaluated.

By extracting two points on the original corresponding to the main scanning direction Q1 and taking two points corresponding to these two points in the copied image on the transfer paper, the distance between the two points on the original can be calculated. The distance between the two points in the copied image is compared with the distance between the two points in the copied image, which is limited to the occasion of equal copying. When the distance between the two points on the original and the distance between the two points in the copied image do not correspond exactly, that is When a magnification error occurs, the image cannot be faithfully reproduced on the transfer paper, so it is necessary to evaluate the magnification error. For enlargement and reduction, if the ratio of the copied image formed on the transfer paper to the image on the original is not equal to the ratio of enlargement and reduction, there will be a ratio error, and the image cannot be faithfully reproduced at this time. Therefore, it is also necessary to evaluate the magnification error for this occasion.

Furthermore, if there is a deviation between the left dot and the right dot along the sub-scanning direction, it means that the scanning line is inclined, and this scanning line inclination should also be evaluated.

Three points can be taken from the left side to the right side of the original along the main scanning direction. Among the dots, the center point along the main scanning direction is used as the reference, and the distances from the left and right points are not equal, then the formed copy image will have a problem of left-right imbalance, so it is necessary to compare the distance from the center point to the left point and the distance between the left and right points. Evaluate whether the distance from the midpoint to the point on the right is equal.

For this occasion, if the difference between the writing position of the left dot and the writing position of the middle dot in the sub-scanning direction is the same as the difference between the writing position of the right dot and the writing position of the middle dot Equal, that is, scan line distortion occurs, and the image cannot be faithfully reproduced in this case, so it is necessary to evaluate the scan line distortion.

The structural form of a currently known device that can be used to evaluate the characteristics of a light beam along the main scanning direction is shown in FIG. 1 (see Japanese Patent Application Laid-Open No. 5-284293).

In Fig. 1, 1 is writing unit (optical unit), and the inside of this writing unit 1 is provided with beam light source (laser light source) that is made of semiconductor laser 2, polygonal prism (rotating polygonal mirror) 3 and fθ Lens 4. The semiconductor laser 2 is modulated and driven by an optical analog modulator 5 . The optical analog modulator 5 is used to modulate the intensity of the laser light emitted from the semiconductor laser 2 with respect to the document image. The laser light emitted from the semiconductor laser 2 is deflected and scanned by the rotation of the polygon mirror 3 .

A pair of photoelectric conversion elements 7a, 7b spaced apart by a certain distance in the main scanning direction is provided at a corresponding surface 6 of the scanned surface corresponding to the surface of the photosensitive drum provided at the image forming unit. Directly in front of the photoelectric conversion elements 7a, 7b, light-shielding plates 8a, 8b having pinholes (circular small holes) for improving light-receiving positional accuracy (writing positional accuracy) are provided. The distance between the pair of pinholes is L.

The semiconductor laser 2 is usually in a light-emitting state during the scanning process, and the light beam P1 is scanned along the main scanning direction Q1 by the rotation of the polygonal prism 3. After the photoelectric conversion element 7a receives the light beam P1, the photoelectric conversion element 7b will receive the light beam P1, Using the difference in reception time and the distance L, the actual scanning speed of the light beam P1 for this writing unit 1 can be calculated. When the actually measured scanning speed of the light beam P1 is faster or slower than the predetermined scanning speed during design, it indicates that there is a deviation in the reference position for writing.

Evaluate whether the scanning speed of the actual measurement beam is within the allowable error range of the predetermined scanning speed at the time of design. When it exceeds the allowable error, the scanning speed of the writing unit should be within the allowable error range The rotation speed of the polygonal prism 3 etc. is adjusted in a certain way.

This original beam characteristic evaluation device cannot directly obtain the writing position. If it must be required to solve the writing position, it needs to solve the problem between the output signal output by the photoelectric conversion element 7a and the output signal output by the photoelectric conversion element 7b. The actual scanning speed is obtained by dividing this time by the distance L, and then the calculation of converting the scanning speed to the writing position is performed, so the calculation of the writing position is quite complicated. Therefore, the evaluation it can perform on the evaluation characteristics of the beam to be evaluated is limited.

If the beam diameter of the beam P1 on the surface of the photosensitive drum deviates from the predetermined design value, the edge of the image formed on the transfer paper will be blurred, and the scanning line will be broken and the image quality will be reduced. And so on. Therefore, it is necessary to evaluate the beam diameter or beam shape on the scanned surface of the beam.

In the past, the beam diameter was evaluated by measuring the diameter of the beam in a stationary state by placing a pinhole or slit at a position corresponding to the surface of the photosensitive drum and installing a light receiving element directly behind it. This conventional beam diameter measurement method cannot be used to measure the beam diameter in the scanning state.

In order to be able to measure the diameter of the beam in the scanning state, a beam characteristic evaluation method and a beam characteristic evaluation device have been proposed (see Japanese Patent Application Laid-Open No. 4-351928), which can be shown in Figure 2. A one-dimensional CCD9 is arranged on the corresponding surface 6 of the corresponding scanned surface on the surface of the photosensitive drum, and an objective lens that makes this beam P1 imaged on the corresponding surface of the scanned surface is set in the optical path of the light beam P1 that advances towards this one-dimensional CCD9 10. While moving the spot S of the light beam P to the direction shown by the arrow Q1 along the main scanning direction, the one-dimensional CCD9 is scanned and driven n times along the direction shown by the arrow Q2, and the brightness of each pixel C1-Cn is used The storage circuit in which the signal is accumulated and stored in one scan, and the beam diameter is calculated from the signal given by this storage circuit.

However, this original evaluation method is to scan and drive the one-dimensional CCD9 along the direction shown by the arrow Q2, and then scan and drive the one-dimensional CCD9 along the direction shown by the arrow Q2. In order to make the one-dimensional CCD9 The scanning time is t1, and it is necessary to move the light beam P1 along the main scanning direction (the direction indicated by the arrow Q1) within the scanning time t1. Therefore, this evaluation method is equivalent to the construction method in which n one-dimensional CCDs 9 are arranged at equal intervals while keeping the light spot S stationary as shown in FIG. 3 .

As shown in Figure 3, this evaluation method is to make the light beam P1 move along the main scanning direction within the time t1 of one scan of the one-dimensional CCD9, and the light spot S is read by the one-dimensional CCD9 in the selective state. And from the pixel information reading that is implemented when the pixel Ci of the one-dimensional CCD 9 is driven and scanned to the pixel information that is implemented when the adjacent pixel Ci+1 is driven and scanned, there is a driving and scanning time interval Δt therebetween, Since the movement of the light beam P1 along the main scanning direction (the direction shown by the arrow Q1) makes it equivalent to the image reading of the light spot S carried out when the one-dimensional CCD9 carries out oblique drive scanning with respect to the light beam P1, so the beam diameter Errors are prone to occur during quantization processing. Moreover, the evaluation error generated during the quantization of the beam diameter will increase with the increase of the scanning speed of the beam P1.

Therefore, such a conventional beam characteristic evaluation method (beam diameter evaluation method) has a problem that it is difficult to further improve the evaluation accuracy of the beam diameter.

As described above, for the required beam characteristics, conventionally, the writing position characteristics on the surface of the photosensitive drum include pitch non-uniformity in the main scanning direction, pitch non-uniformity in the sub-scanning direction, pitch between beams, magnification Error, left and right equalization (magnification error deviation), scanning line distortion, beam diameter, beam shape, etc. are processed by various special evaluation devices for these beam characteristics, so the evaluation of beam characteristics is quite complicated and cannot be done under the same conditions. Under the comprehensive evaluation, the reliability of the implementation evaluation is difficult to be convincing.

Moreover, for the evaluation method of the spot diameter or the spot shape, it is still necessary to further improve the accuracy of the evaluation of the spot diameter or the spot shape in the scanning state.

Furthermore, it is necessary to find a reference position when performing these evaluations.

For example, Japanese Patent Application Laid-Open No. 8-86616 discloses a three-dimensional image measurement device, which includes a method that can rotate along the center of the intersection point of the cross narrow slit and can move in parallel in the up, down, left, and right directions. The laser head installation table for the laser head that generates cross-slit-shaped light on the three-dimensional measurement object; the CCD camera for taking pictures of this measurement object; the image signal obtained by the CCD camera for processing A computer composed of an image processing unit and a laser head operation control unit. This three-dimensional image measurement device sets the lens center of the CCD camera and the front end center of the laser head on the X-axis in the three-dimensional absolute coordinate system, and arranges the imaging surface of the CCD camera on a plane parallel to the X-Y plane.

This image measurement device can adjust the position of the area type (Aria type) CCD of the CCD camera to the area type CCD that matches the imaging position of the area type CCD as a specific position, so there is a reference for measurement The position of the reference pixel is not specific, so the problem of the deviation between the reference pixel and the laser position cannot be grasped correctly.

Contents of the invention

A first object of the present invention is to provide a beam characteristic evaluation method and a beam characteristic evaluation device capable of evaluating various beam characteristics required for a beam with only one device.

A second object of the present invention is to provide a beam characteristic evaluation method and a beam characteristic evaluation device which can accurately evaluate the beam diameter or beam shape even when the beam is scanned in the main scanning direction.

A third object of the present invention is to provide a beam characteristic evaluation device that can accurately obtain a reference position.

A fourth object of the present invention is to provide an optimum writing unit adjustment device that performs adjustment based on evaluation results given by such an evaluation device.

To achieve the above object, the present invention takes the following technical solutions:

The writing unit adjustment device is characterized in that it has: a writing unit (1) for forming an electrostatic latent image on the surface of the latent image carrier with an optical scanning system built in, and at least a built-in an imaging unit of the latent image carrier; and a movement in which the writing unit and the imaging unit relatively move along the main scanning direction for adjusting a deviation (ΔX) along the main scanning direction (Q1) of the light beam In the component, the main scanning direction (Q1) is a direction perpendicular to the traveling direction of the light beam incident from the writing unit (1) toward the imaging unit (53).

The writing unit adjusting device is characterized in that a developing unit is arranged in the imaging unit.

The writing unit adjustment device is characterized in that the moving assembly is composed of a guide hole extending along the main scanning direction formed on the main body of the image forming device and a guide hole formed in the writing unit and the One of the imaging units is formed by a support pin fitted into the guide hole.

The writing unit adjusting device is characterized in that the moving assembly is composed of an adjusting screw and an elastic assembly, and the adjusting screw moves one of the writing unit and the imaging unit along the main scanning direction, The elastic member applies elastic force to the unit such that the front end of the adjustment screw abuts against the unit moved by the adjustment screw.

The writing unit adjusting device is characterized in that the moving assembly is composed of an adjusting screw and a hub portion, and the adjusting screw moves one of the writing unit and the imaging unit along the main scanning direction, The hub portion is provided on a unit that is moved based on the adjustment screw, and is screwed to the adjustment screw.

The writing unit adjustment device is characterized in that it has: a writing unit, which is equipped with an optical scanning system and a synchronous sensor for determining when writing to the latent image carrier, and is used to make the light beam emitted by the laser light source appear on the latent image. An electrostatic latent image is formed on the surface of the carrier; and a moving assembly is used to adjust the deviation of the writing unit relative to the latent image carrier along the main scanning direction of the light beam, and make the synchronous sensor move along the The main scanning direction is a direction perpendicular to the traveling direction of the light beam incident from the writing unit toward the imaging unit.

The writing unit adjusting device described above is characterized in that the moving assembly is abutted against by a movable body holding the synchronous sensor, a guide shaft guiding the movable body in the main scanning direction, and a front end. An adjustment screw on the movable body to move the movable body, and an elastic member for applying elastic force to the movable body in a direction abutting against the front end of the adjustment screw.

The described invention can be used to solve the above-mentioned first problem and the second problem, and its characteristic is that it is by making the beam light source that the surface to be scanned be used for line scanning be scanned within the scanning time corresponding to the single-point light emission during the scanning process. The method of emitting light is used to evaluate the required beam characteristics.

The described invention can be used to solve the above-mentioned first problem and the second problem, and its characteristic is that it separates and sets at least two light beam detection components along the scanning direction of the scanned surface by a predetermined distance, by making the scanned surface The beam light source for line scanning emits light during the scanning time corresponding to the single-point light emission during the scanning process, so that the beam is irradiated at the beam detection component on the scanning start side, and passes through the scanning speed predetermined by the design. After the extinguishing time calculated from the predetermined distance, the beam light source is made to emit light again within the scanning time corresponding to the single-point light emission, so that the light beam is irradiated on the beam detection component at the end of scanning, and according to The detection results of each beam detection component are used to evaluate the required beam scanning characteristics.

The beam characteristic evaluation method is based on the characteristics that the beam light source is a semiconductor laser, the beam detection component is an area-type solid-state imaging element, and the light beam is detected by the solid-state imaging element. The scan characteristic is evaluated by calculating the deviation between the position on the imaging plane and the reference position predetermined at the time of design.

The described light beam characteristic evaluation method is based on, and its characteristic is further that the scanning time and the extinguishing time are determined according to the time-base pulse signal sent by the time-base pulse oscillator, and the beam light source is compared with Lighting is performed before the counting of the number of time-base pulses corresponding to the single-point light-emitting is completed, and extinguishing is performed before the counting of the number of time-base pulses corresponding to the extinguishing time is completed.

The described invention is characterized by:

A lighting control circuit that makes the beam light source for line scanning of the scanned surface emit light within the scanning time corresponding to the single-point lighting during the scanning process;

A light beam detection component arranged on the scanned surface for detecting the light beam emitted by the light beam light source;

An evaluation processing component for evaluating required beam characteristics based on the detection results of the beam detection component.

The described light beam characteristic evaluation device is based on, and its characteristic is further that the described light beam light source is assembled in the writing unit with optical scanning system, and the described light beam detection component is an area-type solid-state imaging element, and the described evaluation The processing component calculates the writing position with the desired beam characteristic according to the detection result given by the area-type solid-state imaging element.

The said light beam characteristic evaluation device is based, and its characteristic further lies in that two of said area-type solid-state imaging elements are arranged at least at a predetermined distance apart along the main scanning direction, and are provided with a scanning speed predetermined by design. The computing component used to calculate the extinguishing time with the predetermined distance is to extinguish the beam light source within the extinguishing time after the beam is irradiated to the beam detection component on the scanning start side. After the above-mentioned extinguishing time, the beam light source is made to emit light again within the scanning time corresponding to the single-point light emission in the scanning process, so that the light beam is irradiated on the beam detection component at the scanning end side, and according to each beam detection component The test results are used to evaluate the required beam scanning characteristics.

The described invention is characterized by:

A lighting control circuit that makes the beam light source for row scanning the scanned surface installed in the writing unit with an optical scanning system emit light within the scanning time corresponding to the single-point lighting during the scanning process;

An area-type solid-state imaging element for detecting the light beam emitted by the light source, which is arranged on the scanned surface;

An evaluation processing unit for evaluating required beam characteristics based on the detection results of the area-type solid-state imaging element.

The beam characteristic evaluation device is based on, and its characteristic is further that at least two of the area-type solid-state imaging elements are arranged at a predetermined distance along the main scanning direction, so that the laser light source is directed toward the scanning The area-type solid-state imaging element on the starting side emits light according to the scan time corresponding to the single-point light emission, and then turns off, and after the turn-off time calculated by the predetermined scanning speed and the predetermined distance at the time of design, the above-mentioned light is turned on again. The beam light source emits light within the scan time corresponding to the single-point light emission, and the evaluation processing unit calculates the writing position detected by the area-type solid-state imaging element on the scanning start side to the area-type solid-state imaging element on the scanning end side. The distance between the writing positions is detected, and this distance is compared with the predetermined distance to calculate a magnification error.

The beam characteristic evaluation device is based on, and its characteristic is further that three of the above-mentioned area-type solid-state imaging elements are arranged at predetermined distances along the main scanning direction, and one of the three area-type solid-state imaging elements is arranged at a central position , one of the remaining two area-type solid-state imaging elements is disposed on the scanning start side, the other area-type solid-state imaging element is disposed on the scanning end side, and the area-type solid-state imaging element disposed at the central position to the other two The distances between the two area-type solid-state imaging elements are equal, and the laser light source is extinguished after the area-type solid-state imaging element facing the scanning start side emits light for the scanning time corresponding to the single-point light emission. After the extinguishing time calculated by the scanning speed and the predetermined distance, the other area-type solid-state imaging element emits light again within the scanning time corresponding to the single-point light emission, and the evaluation processing component passes through the area from the scanning start side. The distance between the read position detected by the area-type solid-state imaging element at the center and the writing position detected by the area-type solid-state imaging element at the center is the same as the distance between the write position detected by the area-type solid-state imaging element at the center and the By comparing the distances between the writing positions detected by the area-type solid-state imaging element on the end side, the left-right image balance as the scanning characteristic was evaluated.

The beam characteristic evaluation device is based on, and its characteristic further is that it also has a time-based pulse oscillator for determining the scanning time corresponding to the single-point light emission and the extinguishing time, so that the The laser light source emits light before the counting of the number of time base pulses corresponding to the single-point light emission is completed, and is turned off before the counting of the number of time base pulses corresponding to the extinguishing time is completed.

The said light beam characteristic evaluation device is based, and its characteristic further lies in that it is also provided with an arithmetic component for calculating the extinguishing time according to the predetermined scanning speed and the predetermined distance during design.

The described light beam characteristic evaluation device is based on, and its characteristic further lies in that the described writing unit is provided with the synchronous sensor that determines the writing time base pulse usefulness of both sides of the main scanning direction, and the described laser light source is started by scanning The light is continuously emitted until detected by the synchronous sensor on the scanning start side, and after the light beam is detected by the synchronous sensor on the scanning start side, the extinguishing used in the single-point lighting operation is carried out.

The beam characteristic evaluation device is based on the above, and its characteristic further lies in that two laser light sources are provided, so that two beams of light can be used to implement writing on the scanned surface.

The said light beam characteristic evaluation device is based on the basis, and its characteristic further lies in that said evaluation processing component is based on the light receiving position of the light beam emitted by one laser light source and received by said area-type solid-state imaging element and by another calculate the pitch between the light beams from the light-receiving position of the light beam emitted by the laser light source and received by the area-type solid-state imaging element, and solve the problem at least two positions at a certain interval along the main scanning direction The parallelism of the two beams is evaluated by measuring the pitch between the beams.

Based on the beam characteristic evaluation device, its characteristic further lies in that the evaluation processing component calculates the beam center of each area-type solid-state imaging element along the sub-scanning direction, and calculates the beam center according to each beam center. The distortion of the scan line is evaluated.

The above-mentioned light beam characteristic evaluation device is based on, and its characteristic further lies in that the described writing unit has a synchronous sensor for determining the writing time base pulse on the scanning start side, and the described area-type solid-state imaging element can scan along the main scanning direction. Move, the light emission control circuit implements control in such a way that the laser light source forms a single-point light emission after the extinguishing time related to the distance between the synchronous sensor and the area-type solid-state imaging element has elapsed.

Said light beam characteristic evaluating device is based on the fact that its characteristic further lies in calculating said extinguishing time by using said distance and theoretical predetermined scanning speed.

The described invention is a beam characteristic evaluation device, which has:

A lighting control circuit that makes the beam light source for scanning the surface to be scanned emit light within the scanning time corresponding to one light emission during the scanning process;

An area-type solid-state imaging element for detecting the light beam emitted by the light beam source controlled by the light-emitting control circuit at the scanned surface;

An evaluation processing component for calculating the beam diameter of the beam on the scanned surface.

Said light beam characteristic evaluation device is based on the further characteristic of evaluating the diameter of said light beam at least at two positions along said light beam scanning direction.

The beam characteristic evaluation device is based on, and its characteristic further is to make the beam scan along the main scanning direction, and the calculation component calculates the beam diameter along the main scanning direction and the beam diameter along the main scanning direction. Beam diameter in the orthogonal sub-scan direction.

Based on the beam characteristic evaluation device, its characteristic further lies in that the evaluation processing component calculates the center of the beam according to the beam diameter along the main scanning direction and the beam diameter along the sub-scanning direction. Location.

The beam characteristic evaluation device is based on, and its characteristic is further that the evaluation processing component is based on the beam diameter along the main scanning direction and the beam diameter along the sub-scanning direction, on the scanned surface Beam shape evaluation.

Based on the beam characteristic evaluation device, its characteristic further lies in that the evaluation processing component calculates the beam intensity distribution along the main scanning direction and the beam intensity distribution along the sub-scanning direction on each pixel of the area-type solid-state imaging element. By means of the intensity distribution of the beam, the center position of the beam is solved.

The said invention is a light beam characteristic for evaluating the beam diameter of the beam emitted from the laser light source for writing on the latent image carrier provided in the writing unit with the optical scanning system on the scanned surface. Evaluation device, characterized in that it has:

implementing a luminescence control loop for luminescence during the scan time corresponding to a single point luminescence during the scan;

An area-type solid-state imaging element for detecting the light beam emitted from the laser light source that controls light emission from the light emission control circuit, provided on the corresponding surface to be scanned corresponding to the scanned surface;

An evaluation processing component for calculating the beam diameter of said beam on said scanned corresponding surface.

Based on the beam characteristic evaluation device, its characteristic further lies in that the beam is linearly scanned along the main scanning direction, and the evaluation processing component calculates the beam diameter along the main scanning direction and the beam diameter along the main scanning direction. The beam diameter in the sub-scanning direction that is perpendicular to the direction.

Based on the beam characteristic evaluation device, its characteristic further lies in that the evaluation processing component calculates the center position of the beam according to the beam diameter along the main scanning direction and the beam diameter along the sub-scanning direction .

The said light beam characteristic evaluation device is based on the basis, and its characteristic is further in that said writing unit is equipped with a synchronous sensor for determining the time base pulse for writing into the latent image carrier, and said optical scanning system is equipped with fθ lens, the area-type solid-state imaging element is arranged at an image height position corresponding to the optical axis position of the fθ lens on the corresponding surface to be scanned, and the light-emitting control circuit is synchronized with the Single-point light emission is performed after a extinguishing time dependent on the distance between the sensor and the area-type solid-state imaging element.

The beam characteristic evaluation device is based on, and its characteristic is further to evaluate the writing position, magnification error, image balance, scanning line distortion along the main scanning direction, and parallelism of the beam according to the beam center position .

The invention described above is a method for evaluating beam characteristics, which is characterized in that the beam light source used for linearly scanning the scanned surface emits light within the scanning time corresponding to the single-point light emission during the scanning process, and obtains The diameter or shape of the beam.

Said invention is characterized in that by making the writing unit for forming an electrostatic latent image on the surface of the latent image carrier by the beam emitted by the laser light source equipped with the optical scanning system, according to the deviation of the beam in the main scanning direction relative to the The above-mentioned latent image carrier is adjusted in the manner of relative movement along the main scanning direction.

Said invention is characterized in that by making the writing unit for forming an electrostatic latent image on the surface of the latent image carrier by the light beam emitted by the laser light source equipped with the optical scanning system, according to the deviation of the light beam in the main scanning direction relative to at least The adjustment is carried out in the manner of relatively moving the imaging unit with one latent image carrier inside along the main scanning direction.

Said invention is characterized in that it has a writing unit for forming an electrostatic latent image on the surface of a latent image carrier with a light beam emitted by a laser light source equipped with an optical scanning system, and at least the imaging unit of said latent image carrier is built in , and a moving assembly that relatively moves the writing unit and the imaging unit along the main scanning direction in order to adjust the deviation of the light beam along the main scanning direction.

The adjusting device for the writing unit is based, and its characteristic further lies in that a developing component is arranged in the imaging unit.

The adjustment device for the writing unit is based, and its characteristic is further that the moving assembly is formed on the main structure of the image forming device, and is formed on the guide hole extending in the length direction of the main scanning direction and formed One of the writing unit and the imaging unit is constituted by a support pin for fitting into the guide hole.

Said adjustment device for the writing unit is based and further characterized in that said moving assembly is composed of an adjustment screw for moving one of said writing unit and said imaging unit in the main scanning direction and by means of said An elastic member is configured to apply elastic force to the unit in such a manner that the movement of the adjustment screw comes into contact with the tip of the adjustment screw provided on the unit.

The adjusting device for the writing unit is based, and further characterized in that the moving assembly is composed of an adjusting screw for moving one of the writing unit and the imaging unit in the main scanning direction and through the The movement of the adjustment screw constitutes a hub screwed with said adjustment screw provided on the unit.

The characteristic of said invention is to form the writing unit for the electrostatic latent image on the surface of the latent image carrier by making the light beam emitted by the laser light source equipped with the optical scanning system built in, based on the writing unit from this writing unit to the described The two directions of the beam traveling direction and the main scanning direction of the imaging unit are adjusted relative to the latent image carrier along the sub-scanning direction relative to the beam deviation in the sub-scanning direction.

The characteristic of the described invention is to form the writing unit for the electrostatic latent image on the surface of the latent image carrier by making the light beam emitted by the laser light source equipped with the optical scanning system built in, based on and from the writing unit radiated to the The beam deviation in the sub-scanning direction, which is perpendicular to the two directions of the incident beam traveling direction of the imaging unit and the main scanning direction, relatively moves along the sub-scanning direction relative to the imaging unit with at least one latent image carrier installed therein way to implement adjustments.

Said invention is characterized by having a writing unit for forming an electrostatic latent image on the surface of a latent image carrier with a light beam emitted from a laser light source equipped with an optical scanning system; at least an imaging unit with a latent image carrier built in; for adjustment and The direction of the light beam incident on the imaging unit by this writing unit and the two directions of the main scanning direction are offset by the light beam in the sub-scanning direction perpendicular to each other, so that the writing unit and the imaging unit are aligned along the sub-scanning direction. A moving component that moves relative to the scan direction.

The adjusting device of the writing unit is based on the above, and its characteristic further lies in that a developing unit is arranged in the imaging unit.

The adjustment device of the writing unit is based on the basis, and its characteristic further lies in that the moving assembly is composed of a guide hole extending along the sub-scanning direction formed on the main structure of the image forming device and a guide hole formed in the writing unit. unit and a support pin on one of the imaging units that fits into the guide hole.

The adjusting device of the writing unit is based, and its characteristic is further that the moving assembly is composed of an adjusting screw for moving one of the writing unit and the imaging unit in the sub-scanning direction and by the adjusting An elastic member that applies elastic force to the unit in such a manner that the screw moves and comes into contact with the tip of the adjustment screw provided on the unit.

The adjusting device for the writing unit is based, and further characterized in that the moving assembly is composed of an adjusting screw for moving one of the writing unit and the imaging unit in the sub-scanning direction and by the The movement of the adjustment screw constitutes a hub screwed with said adjustment screw provided on the unit.

Said invention is characterized in that an electrostatic latent image is formed on the surface of said latent image carrier by means of a beam of light emitted from a laser light source emitted from a synchronous sensor equipped with an optical scanning system and a synchronous sensor for determining a time base pulse for writing to a latent image carrier. The writing unit of the image, according to the deviation of the beam along the main scanning direction relative to the latent image carrier, by making the synchronous sensor move along the main scanning direction, the The offset in the main scanning direction relative to the latent image carrier is adjusted.

Said invention is characterized in that it has an electrostatic latent image formed on the surface of said latent image carrier by a beam of light emitted by a laser light source having a built-in optical scanning system and a synchronous sensor for determining the timing pulse for writing to the latent image carrier. The writing unit used; in order to adjust the deviation of the writing unit relative to the latent image carrier along the main scanning direction of the light beam and make the synchronous sensor move along the main scanning direction. .

The adjusting device of the writing unit is based, and its characteristic is further that the moving assembly consists of a movable body that holds the synchronous sensor, guides the movable body to the guide shaft in the main scanning direction, An adjustment thread whose front end is in contact with the movable body and which can move the movable body, and an elastic member which applies an elastic force to the movable body in a direction in which the front end of the adjustment thread contacts the movable body are constituted .

The characteristic of the invention lies in that the laser light source for linearly scanning the scanned surface is made to emit light within the scanning time corresponding to the single-point emission, and the light beam for detecting the reference position on the scanned surface is made to emit light. The area-type solid-state imaging element moves sequentially along the traveling direction of the light beam, and the area-type solid-state imaging element is used to acquire beam images at various positions.

The said invention is based on the light beam characteristic evaluation method as claimed in claim 48, and its characteristic is further based on the data acquired at each position in the traveling direction of the light beam by the area-type solid-state imaging element. For each beam image, calculate the beam diameter of the beam at each position, and then evaluate the beam diameter with respect to the depth direction.

The beam characteristic evaluation method is based on, and its characteristic further lies in solving the depth curve representing the relationship between the beam diameter and the depth from the beam diameter and depth, specifying the beam waist diameter position according to the depth curve, and by The difference between this beam waist diameter position and said reference position solves for a correction amount for the beam waist diameter position.

Said invention is characterized in that it has a single-point light emission control circuit that makes the laser light source of the light beam for linearly scanning the scanned surface emit light within the scanning time corresponding to the single-point light emission; the scanned surface is used as a reference position An area-type solid-state imaging element that moves along the advancing direction of the light beam and detects the light beam; and calculates based on the light beams detected by the area-type solid-state imaging element at various positions in the advancing direction of the light beam Evaluation processing unit for output beam diameter.

Based on the beam characteristic evaluation device, its characteristic further lies in that the evaluation processing component solves the depth curve representing the relationship between the beam diameter and depth from the beam diameter and depth, and specifies the beam according to the depth curve. The waist diameter position, and the correction amount of the beam waist diameter position is obtained from the difference between the beam waist diameter position and the reference position.

The above-mentioned invention is characterized in that it has a single-point light emission that makes a laser light source for linearly scanning a beam of light on a surface to be scanned provided in a writing unit having an optical scanning system emit light within a scanning time corresponding to the single-point light emission. Control circuit; a region-type solid-state imaging element that moves along the traveling direction of the light beam with the scanned surface as a reference position and detects the light beam; The light beam detected by the area-type solid-state imaging element is used to calculate the evaluation processing assembly for the beam diameter; and a synchronous sensor for determining the writing clock at the start of scanning along the main scanning direction is provided in the writing unit, so The above-mentioned laser light source emits light continuously before being detected by the synchronous sensor on the scanning start side, and after the light beam is detected by the synchronous sensor on the scanning starting side, it is extinguished for single-point light emission, and the single-point light emission control circuit Control is performed so that the above-mentioned laser light source emits light after the write timing time elapses.

The above-mentioned light beam characteristic evaluation device is based on, and its characteristic is further in that it is calculated based on the distance from the synchronous sensor to the area-type solid-state imaging element along the main scanning direction and the predetermined scanning speed during design. An operation component for writing timing, and a clock pulse oscillator for determining the scanning time corresponding to the single-point light emission and the pulse time of the writing time base, so that the laser light source is controlled by the Before the synchronous sensor detects the light beam, the light is turned off from the moment when the light beam is detected by the synchronous sensor to before the counting of the clock number corresponding to the write time base pulse time is completed, and then the single point The lighting control loop emits light until the counting of the number of clocks corresponding to the single-point lighting is completed.

The characteristic of the above-mentioned invention is that by making the laser light source of the light beam for linearly scanning the surface to be scanned on the imaging unit emit light within the scanning time equivalent to single-point light emission, and make the detection of the scanned surface as a reference position The area-type solid-state imaging element of the light beam moves sequentially along the traveling direction of the light beam, and the beam image at each position is acquired by using the area-type solid-state imaging element. For each beam image acquired at each position in the traveling direction of the beam, the beam diameter in the relative depth direction is calculated by calculating the beam diameter of the beam at each position, and the beam diameter and depth are used to solve A depth curve representing the relationship between the beam diameter and the depth is obtained, and the beam waist diameter position is specified according to the depth curve, and the correction amount of the beam waist diameter position is calculated from the difference between the beam waist diameter position and the reference position After using this beam characteristic evaluation method to obtain the correction amount of the beam waist diameter position, in order to adjust the optical path length from the laser light source to the writing target surface, increase and decrease the imaging unit and The write moves at least one of the two cells in a spaced manner between the cells.

The feature of the invention is that the laser light source for linearly scanning the writing target surface on the imaging unit emits light within the scanning time equivalent to single-point light emission, and detects all the laser beams that use the scanned surface as a reference position. The area-type solid-state imaging element of the light beam moves sequentially along the traveling direction of the light beam, using the area-type solid-state imaging element to acquire beam images at various positions, according to the area-type solid-state imaging element in the light beam Each beam image acquired at each position in the traveling direction of the beam, the beam diameter in the relative depth direction is calculated by calculating the beam diameter of the beam at each position, and the representation is calculated from the beam diameter and depth The depth curve of the relationship between the beam diameter and the depth, according to the depth curve, the beam waist diameter position is specified, and the correction amount of the beam waist diameter position is calculated from the difference between the beam waist diameter position and the reference position, which An adjustment device for a writing unit has the functions of increasing and The optical path length adjusting assembly of at least one of the imaging unit and the writing unit is moved in such a manner as to reduce the space between the two units.

The adjustment device of the writing unit is based on, and its characteristic is further that the optical path length adjustment component that can change the optical path length between the surface of the latent image carrier and the writing unit is formed on the image The main structure of the forming device is composed of a guide hole on the wall and a guide pin provided on one of the writing unit and the imaging unit for fitting with the guide hole.

The feature of the invention is that the laser light source for linearly scanning the beam to be scanned emits light within the scanning time equivalent to single-point light emission, and the area-type detection of the beam with the scanned surface as a reference position is made. The method in which the solid-state imaging element moves sequentially along the traveling direction of the light beam, using the area-type solid-state imaging element to acquire beam images at various positions, according to the movement direction of the light beam by the area-type solid-state imaging element Each beam image obtained at each position of the beam, by calculating the beam diameter of the beam at each position, the beam diameter in the relative depth direction is solved, and the beam diameter and the depth are calculated according to the beam diameter and depth The depth curve of the relationship between the depths, the beam waist diameter position is specially specified according to the depth curve, and the correction amount of the beam waist diameter position is calculated from the difference between the beam waist diameter position and the reference position, using this A beam characteristic evaluation method adjusts the length of the optical path from the laser light source to the scanned surface after obtaining the correction amount of the beam waist diameter position.

The feature of the invention is that it has an optical path length adjustment component, by making the laser light source of the light beam for linearly scanning the surface to be scanned emit light within a scanning time equivalent to a single-point light emission, and making the detection of all the light beams with the surface to be scanned as a reference position The area-type solid-state imaging element of the light beam moves sequentially along the traveling direction of the light beam, and the beam image at each position is acquired by using the area-type solid-state imaging element. For each beam image obtained at each position in the traveling direction of the beam, the beam diameter in the relative depth direction is calculated by calculating the beam diameter of the beam at each position, and the beam diameter and depth are calculated to obtain A depth curve representing the relationship between the diameter of the beam and the depth, according to which the depth curve specifically specifies the beam waist diameter position, and the correction amount of the beam waist diameter position is calculated from the difference between the beam waist diameter position and the reference position, The adjustment device for the writing unit has the function of adjusting the optical path length from the laser light source to the scanned surface after obtaining the correction amount of the diameter position of the beam waist by using the beam characteristic evaluation method.

The adjusting device of the writing unit is based on the above, and its characteristic further lies in that the laser light source has a semiconductor laser, a collimating lens for converting the light beam emitted by the semiconductor laser into a parallel light beam, and a mirror for holding the collimating lens. a barrel, the lens barrel is formed with a threaded portion along the optical axis direction, and a threaded portion for threaded connection with the threaded portion is formed at the position where the lens barrel as the structural wall of the writing unit is arranged, and the The optical path length adjustment assembly consists of these two threaded parts.

The described invention is a method of imaging the beams given by the laser light source used for linearly scanning the surface to be scanned on the area-type imaging element arranged at the corresponding surface to be scanned, so as to obtain the required beam characteristics. The beam characteristic evaluation device used in the evaluation method of evaluation, the device has:

Determine the reference laser light source corresponding to the predetermined reference position during design along the main scanning direction and the sub-scanning direction of the light beam on the scanned surface, and hold the reference laser light source with a holding member in a rotatable manner The holding part and the angular position determination part used to determine the rotational angular position of the reference laser light source make the said angle in such a way that the beam exit light predetermined in design coincides with the rotational center of the holding part. a position determination reference base for positioning the position determination component, and the area-type imaging element receives the light emitted by the reference laser light source at at least two rotational angle positions when the holding component rotates around the rotation center The form of the reference beam specifically specifies a reference pixel corresponding to the reference position on the area-type imaging element.

Said light beam characteristic evaluating device is based, and further characterized in that said position determining reference base extends along said main scanning direction.

The beam characteristic evaluation device is based on the basis, and its characteristic further lies in that the reference laser light source is a semiconductor laser.

The beam characteristic evaluation device is based on, and its characteristic further lies in that the laser light source is arranged in a writing unit equipped with an optical scanning system.

The said light beam characteristic evaluation device is based on the basis, and its characteristic further lies in that said evaluation is carried out in such a way that said laser light source emits light within the scanning time equivalent to single-point light emission during the scanning process.

Said invention is a light beam given by a laser light source provided in a writing unit having an optical scanning system for linearly scanning a scanned surface of a latent image carrier provided in an imaging unit, in A beam characteristic evaluation device used in an evaluation method for evaluating required beam characteristics by means of forming an image on an area-type imaging element installed on a corresponding scanned surface corresponding to the scanned surface, the device has the above-mentioned The writing unit is positioned relative to the imaging unit to determine the position of the light beam emitted by the laser light source on the scanned surface along the main scanning direction and the sub-scanning direction and the reference position predetermined in design. The corresponding reference laser light source, the holding member for holding the reference laser light source, and the angular position determining member that holds the holding member in a rotatable manner and is used to determine the rotational angular position of the reference laser light source are arranged in the said The angle position determining part implements a position reference base for positioning determination in such a way that the outgoing light of the light beam emitted by the writing unit predetermined at the position determining base coincides with the rotation center of the holding part. seat, and the manner in which the area-type solid-state imaging element receives the reference light beam emitted by the reference laser light source at at least two rotational angle positions when the holding member rotates, the area-type imaging element is specifically designated to be related to the The reference pixel corresponding to the reference position.

Based on the beam characteristic evaluation device, its characteristic further lies in the symmetrical position where the rotational angle position is 180 degrees.

The above-mentioned light beam characteristic evaluation device is based on the further characteristic that the angular position determining member is disposed on the position determining reference base along the main scanning direction in a replaceable manner.

The light beam characteristic evaluation device is based on the above, and its characteristic further lies in that it is further provided with an adjustment component that adjusts the imaging surface of the area-type imaging element to the corresponding surface to be scanned.

The feature of the invention is that a laser light source arranged in a writing unit with an optical scanning system, which is used for linearly scanning the scanned surface of the latent image carrier arranged in the imaging unit, is equivalent in the scanning process. emit light during the scanning time of the single-point light emission, so that the light beam emitted by the laser light source is arranged at least two positions spaced apart along the main scanning direction at the corresponding scanned surface corresponding to the scanned surface The way of imaging on the area-type imaging element, the beam characteristic evaluation transposition of the evaluation method for evaluating the required beam characteristics, the device has a position determining part for positioning the writing unit relative to the imaging unit, Determine the reference laser light source corresponding to the reference position predetermined during design on the scanned surface along the main scanning direction and the sub-scanning direction of the light beam emitted by the laser light source, and keep the cylindrical shape of the reference laser light source The holding member has a circular fitting hole rotatably fitted to the cylindrical holding member, and an angular position determination member for determining the rotational angular position of the reference laser light source is arranged on the said reference laser light source. A position determination reference for positioning the angular position determination member at the position determination base so that the beam output light emitted from the writing unit predetermined during design coincides with the rotation center of the cylindrical holding member base, and the area-type imaging element receives the reference beam emitted by the reference laser light source at at least two rotational angle positions when the cylindrical holding member rotates, on the area-type imaging element Specifically designate a reference pixel corresponding to the reference position.

The above-mentioned light beam characteristic evaluation device is based on, and its characteristic further lies in that a coupling pin is provided at the angular position determination component, and a coupling for coupling with the coupling pin is provided at the cylindrical holding member. hole.

Based on the light beam characteristic evaluation device, its characteristic further lies in that the rotational angle positions are symmetrical positions with a distance of 180 degrees.

The above-mentioned light beam characteristic evaluation device is based on the further characteristic that the angular position determining member is disposed on the position determining reference base along the main scanning direction in a replaceable manner.

The light beam characteristic evaluation device is based on the characteristic that the angular position determining means are arranged at intervals along the main scanning direction in a manner corresponding to the aforementioned area-type imaging element.

The light beam characteristic evaluation device is based on the above, and its characteristic is further that after the specified reference pixel on a certain area-type imaging element rotates around the cylindrical holding member, the specified reference pixel on the remaining area-type imaging elements The pixels do not rotate around the cylindrical holding member.

Description of drawings

FIG. 1 is a schematic explanatory diagram showing a conventional example of a beam scanning characteristic evaluation device.

FIG. 2 is a schematic explanatory diagram showing a conventional example of a beam scanning characteristic evaluation device, which is a schematic explanatory diagram showing a state in which a beam diameter during beam scanning is measured by a one-dimensional linear CCD.

Fig. 3 is a schematic explanatory diagram showing a case where the beam diameter during scanning is similarly measured using the one-dimensional linear CCD shown in Fig. 2 while keeping the beam during scanning as shown in Fig. 2 stationary.

Fig. 4 is a schematic perspective view showing the internal structure of a writing unit according to the present invention.

Fig. 5 is a schematic explanatory view for explaining the principle of the first embodiment of the light beam characteristic evaluation device constructed according to the present invention, showing an example in which three CCD cameras are arranged at intervals along the main scanning direction.

FIG. 6 is an explanatory diagram schematically showing an area-type imaging element of the CCD camera shown in FIG. 5 .

FIG. 7 is a schematic diagram illustrating an ideal image (light spot) predetermined in design of scanning on a surface to be scanned by using the writing unit shown in FIG. 4 .

FIG. 8 is a schematic explanatory diagram illustrating a time base pulse for controlling single-point light emission of the light beam shown in FIG. 5 .

FIG. 9 is a schematic explanatory view showing a light spot formed on an area-type imaging element of the CCD camera shown in FIG. 5 .

Fig. 10 is a schematic explanatory diagram for explaining a second embodiment of the evaluation device, which is a schematic diagram showing two CCD cameras arranged at intervals along the main scanning direction.

FIG. 11 is a schematic explanatory view showing a time-base pulse for performing single-point light emission control on a light beam as shown in FIG. 10 .

Fig. 12 is a schematic explanatory view showing a third embodiment of the evaluation apparatus, which is a schematic view showing a case where a CCD camera is provided at a central position in the main scanning direction.

FIG. 13 is a schematic explanatory view showing a time-based pulse for performing single-point light emission control on a light beam as shown in FIG. 12 .

FIG. 14 is a schematic explanatory view showing a spot (laser spot) formed on the area-type imaging element shown in FIG. 12 .

FIG. 15 is a schematic explanatory diagram for explaining the calculation of the beam intensity distribution curve based on the light spots shown in FIG. 14 .

FIG. 16 is a diagram illustrating the beam intensity distribution curve for determining the center position of the beam by using the evaluation processing circuit based on the beam intensity distribution curve shown in FIG. 15 .

Fig. 17 is a schematic explanatory view showing a fourth embodiment of the evaluation apparatus, which is a schematic diagram showing a configuration example in which a CCD camera is movable in the main scanning direction and in the depth direction.

Fig. 18 is a flowchart showing an example of processing in the beam characteristic evaluation apparatus shown in Fig. 17 .

Fig. 19 is a schematic explanatory diagram for explaining an example of evaluation characteristics of the light beam characteristic evaluation device of the present invention, wherein:

(a) is a schematic diagram showing the deviation of the writing position along the main scanning direction,

(b) is a schematic diagram showing the deviation of the writing position along the sub-scanning direction,

(c) is a schematic explanatory diagram for explaining the pitch non-uniformity of each surface on the polygonal prism along the main scanning direction,

(d) is a schematic explanatory diagram illustrating pitch unevenness of each surface on the polygonal prism along the sub-scanning direction,

(e) is a schematic explanatory diagram of the magnification error,

(f) is a schematic explanatory diagram of scanning line inclination,

(g) is a schematic explanatory diagram of the magnification error deviation,

(h) is a schematic explanatory diagram of scanning line distortion,

(i) is a schematic illustration of the depth curve,

(j) is a schematic illustration of the pitch between beams.

FIG. 20 is a schematic explanatory diagram illustrating the configuration of the writing position adjustment structure in the main scanning direction, which is a schematic explanatory diagram illustrating the offset state of the beam center with respect to the reference position on the writing start side along the main scanning direction.

Fig. 21 is a schematic explanatory diagram showing an example of a writing position adjusting unit for adjusting the deviation of the beam center from the reference position on the writing start side shown in Fig. 20 in the main scanning direction, and it schematically shows A partial cross-sectional view of the position adjustment structure of the synchronous sensor is shown.

FIG. 22 is a schematic explanatory diagram illustrating a write adjustment timing pulse for a synchronous sensor.

FIG. 23 is a schematic explanatory diagram showing the writing position adjustment structure 1 in the main scanning direction for moving the writing unit or the imaging unit, which is a schematic diagram showing the relative positional relationship between the writing unit and the imaging unit.

FIG. 24 is a schematic partial cross-sectional view showing an adjustment structure for adjusting the write start timing by moving the imaging unit in the main scanning direction relative to the write unit shown in FIG. 23 .

FIG. 25 is a schematic explanatory diagram showing the writing position adjustment structure 2 in the main scanning direction for the movement of the writing unit or the imaging unit, which is to move the imaging unit along the main scanning direction relative to the writing unit shown in FIG. 23 . A schematic partial cross-sectional view of an adjustment structure for adjusting the write start time base pulse by moving relative to the direction.

FIG. 26 is a schematic explanatory diagram showing the writing position adjustment structure 3 in the main scanning direction for the movement of the writing unit or the imaging unit, which is to move the imaging unit along the main scanning direction relative to the writing unit shown in FIG. 23 A schematic partial cross-sectional view of an adjustment structure for adjusting the writing start timing pulse relative to the movement.

FIG. 27 is a schematic explanatory diagram showing the writing position adjustment structure 4 in the main scanning direction for the movement of the writing unit or the imaging unit, which moves the writing unit along the main scanning direction relative to the imaging unit shown in FIG. 23 A schematic partial cross-sectional view of an adjustment structure for adjusting the writing start timing pulse relative to the movement.

FIG. 28 is a schematic explanatory diagram showing the writing position adjustment structure 5 in the main scanning direction for moving the writing unit or the imaging unit, which is to move the writing unit along the main scanning direction relative to the imaging unit shown in FIG. 23 A schematic partial cross-sectional view of an adjustment structure for adjusting the writing start timing pulse relative to the movement.

FIG. 29 is a schematic explanatory diagram illustrating a writing position adjustment structure in the sub-scanning direction for movement of the writing unit or the imaging unit, which illustrates the offset of the beam center in the sub-scanning direction with respect to the reference position on the writing start side. A schematic illustration of a state.

FIG. 30 is a schematic explanatory diagram illustrating a writing position adjustment structure in the sub-scanning direction for movement of the writing unit or the imaging unit by making the writing unit opposed to the imaging unit shown in FIG. 23 in the sub-scanning direction. A schematic partial cross-sectional view of an adjustment structure for adjusting the write start timing by moving.

FIG. 31 is a schematic explanatory diagram showing a fourth embodiment using a light beam characteristic evaluation device,

(a) is a schematic explanatory diagram illustrating a beam characteristic evaluation device for evaluating a beam depth profile when a CCD camera is moved along the main scanning direction and the sub-scanning direction,

(b) is a schematic diagram showing an example of a depth profile obtained by the beam characteristic evaluation apparatus shown in FIG. 31( a ).

FIG. 32 is a schematic explanatory diagram showing a depth adjustment structure using a laser diode assembly, which shows the adjustment of the position of the collimator lens in the direction of the optical axis based on the depth curve obtained by the beam characteristic evaluation device shown in the fourth embodiment. , and then a schematic partial cross-sectional view of the optical path length adjustment structure for adjusting the optical path length.

FIG. 33 is a schematic explanatory diagram showing a depth adjustment structure 1 composed of a writing unit or an imaging unit, and it shows that the writing unit and the imaging unit are adjusted according to the depth curve obtained by the beam characteristic evaluation device shown in the fourth embodiment. A schematic partial cross-sectional view of an optical path length adjustment structure that adjusts the distance between units and further adjusts the optical path length.

Fig. 34 is a schematic explanatory diagram showing a depth adjustment structure 2 composed of a writing unit or an imaging unit, and it shows that the writing unit and the imaging unit are adjusted according to the depth curve obtained by the beam characteristic evaluation device shown in the fourth embodiment. A schematic partial cross-sectional view of an optical path length adjustment structure that adjusts the distance between units and further adjusts the optical path length.

Fig. 35 shows a specific structure of the evaluation apparatuses 1 to 4, which is a schematic side view showing the state when the writing unit is mounted on the image forming apparatus.

Fig. 36 is a schematic plan view showing a state when the writing unit is mounted on the image forming apparatus.

FIG. 37 is a schematic view showing the external shape of the writing unit shown in FIGS. 35 and 36 .

Fig. 38 is a schematic front view showing a state when the writing unit is mounted on the image forming apparatus.

Fig. 39 is a partially enlarged plan view showing the arrangement relationship between the position determination reference base mounted on the reference base mounting part and the CCD camera.

Figure 40 is a schematic explanatory diagram showing the position determination reference base shown in Figure 39, wherein Figure (a) is a plan view, and Figure (b) is a schematic diagram obtained when observing Figure (a) along the direction indicated by arrow c1 , Figure (c) is a schematic diagram obtained when observing Figure (b) along the direction indicated by arrow c2, and Figure (d) is a schematic diagram obtained when observing Figure (b) along the direction indicated by arrow c3.

Fig. 41 is a partially enlarged plan view showing the arrangement relationship between the position determination reference base mounted on the reference base mounting part and the CCD camera.

Fig. 42 is a schematic explanatory diagram showing the position determination reference base shown in Fig. 39 and Fig. 41, wherein Fig. (a) is a plan view, and Fig. (b) is an observation diagram (a) along the direction indicated by arrow c4 Figure (c) is a schematic diagram obtained when observing Figure (a) along the direction indicated by arrow c5, and Figure (d) is a schematic diagram obtained when observing Figure (c) along the direction indicated by arrow c6.

Fig. 43 is a schematic explanatory diagram showing the LD holding plate shown in Fig. 41, wherein Fig. (a) is a side view, and Fig. (b) is a schematic diagram obtained when Fig. (a) is observed along the direction indicated by arrow c7 .

Fig. 44 is a schematic explanatory diagram for explaining a designated area-type CCD reference pixel using a reference laser light source.

Figure 45 is a partial enlarged schematic view showing the LD holding plate and the position determination block parts, wherein figure (a) is a schematic view showing the state before the LD holding plate is rotated 180 degrees, and figure (b) is a schematic view showing that the LD holding plate is rotated 180 degrees Schematic diagram of the state after rotation.

Fig. 46 is a schematic plan view showing a state when the writing unit is mounted on the image forming apparatus.

Fig. 47 is a schematic side view showing the state when the writing unit is mounted on the image forming apparatus, which is a schematic view showing the state before the writing unit is clamped.

Fig. 48 is a schematic side view showing the state in which the writing unit is installed, which is a schematic view showing the state before the writing unit is clamped.

Fig. 49 is a plan view showing the positional relationship between the CCD camera module mounted on the support base shown in Fig. 47 and the reference laser diode.

Fig. 50 is a plan view showing a position determination reference base and a position determination block attached to the writing unit.

Fig. 51 is an enlarged plan view showing the position determination block shown in Fig. 49 .

Fig. 52 is a schematic explanatory diagram showing the composition of the writing position adjustment structure in the main scanning direction for moving the paper stack position, wherein (a) is a schematic diagram showing the internal structure of the image forming unit, and (b) Figure (a) is a schematic diagram showing the arrangement state of the LEDs, and Figure (c) is a schematic diagram showing the side guide plate for installing the paper stacking tray.

Fig. 53 is a schematic diagram showing an example of adjustment when a magnification error and a scanning line inclination are bad, where figure (a) shows an example of adjustment used when evaluating a magnification error, and figure (b) shows an adjustment based on the scanning line An instance of skewed evaluation implementation adjustments.

Specific Embodiments of the Invention

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

4 shows a writing unit equipped with a beam light source (laser light source) as an evaluation object of the beam characteristic evaluation method of the present invention, and a latent image carrier for writing with a beam emitted from this writing unit. An oblique view of an example of the positional relationship between the photosensitive drums.

In Fig. 4, 11 and 12 are laser diodes (semiconductor lasers), 13 and 14 are collimating lenses, 15 is an optical component for light path synthesis, 16 is a 1/4 wave plate, and 17 and 18 are beam shaping optical systems. These optical elements 11-18 constitute a laser light source unit (beam light source) Sou. The two beams P1 emitted by this laser light source part Sou are parallel beams composed of collimated beams P1 and P2, and are guided to a polygonal prism 19 that constitutes a part of the optical scanning system. The respective surfaces 20a-20f on 19 are deflected and reflected in the main scanning direction Q1.

The deflected and reflected light beams are guided to mirrors 21 and 22 constituting a part of the fθ optical system, and the light beams deflected and reflected by the mirror 22 pass through the fθ optical system 23 and are guided to obliquely arranged mirrors. 24, and then guided to the surface 26 of the photosensitive drum 25 as a latent image carrier by the obliquely arranged reflector 24. The light beam P1 linearly scans the surface 26 of the photosensitive drum 25 along the main scanning direction Q1. This surface 26 is the scanned surface scanned by the light beam P1, and writing can be performed on this scanned surface.

The laser light source unit Sou, the polygonal prism 19, the reflection mirrors 21, 22, the fθ optical system 23, and the oblique reflection mirror 24 are mounted on the writing unit 1, and the photosensitive drum 25 is mounted on the imaging unit (described later). .

The writing unit 1 is provided with synchronous sensors 27 , 28 at both longitudinal sides (in the main scanning direction Q1 of the beam) of the obliquely disposed mirror 24 . The synchronization sensor 27 is used to determine the timing pulse at the start of writing, and the synchronization sensor 28 is used to determine the timing pulse at the end of writing.

The characteristics of the light beam P1 emitted from this writing unit 1 were evaluated. In this FIG. 4 , the writing to the surface 26 of the photosensitive drum 25 is carried out with two scanning lines. As far as the principle of beam characteristic evaluation is concerned, it is not essential for the case of one laser diode and the case of two laser diodes. Therefore, with reference to Table 1 obtained when there is one laser diode, the evaluation items of the characteristics of the light beam constituted according to the present invention will be described below.

[Table 1]

In the beam characteristic evaluation items shown in Table 1, a is the writing position in the main scanning direction, b is the writing position in the sub-scanning direction, c is the unevenness of the main scanning pitch, d is the skew of the sub-scanning surface, e is the diameter of the main scanning beam, f is the diameter of the sub-scanning beam, g is the magnification error, h is the tilt of the scanning line, i is the deviation of the magnification error, j is the distortion of the scanning line, k is the scanning time, l is the depth, m is the distance between beams Pitch (for the case of using a writing unit that can irradiate several beams at the same time (see USP96-675722): the implementation form given by this patent, due to the configuration of the laser diode 11 or 12 (so-called LD) The direction is along the sub-scanning direction, and two are arranged, so the pitch between beams is along the sub-scanning direction).

Each evaluation item will be described in detail below.

a: Evaluation of the writing position in the main scanning direction

The light beam emitted from the LD is reflected by the polygonal prism 19 and irradiated on the photosensitive drum through the fθ optical system, and the position in the main scanning direction when writing to this photosensitive drum is started, that is, the base pulse is evaluated.

For example, as shown in FIG. 19(a), when the center of the predetermined writing position (writing time base pulse) is taken as "0", the writing position on the area-type imaging element described later is taken as zz, there is a deviation Δx along the main scanning direction between the writing position center O and the writing position zz. This amount of deviation Δx is evaluated.

b: Evaluation of the writing position in the sub-scanning direction

The light beam emitted from the LD is reflected by the polygonal prism 19 and irradiated on the photosensitive drum through the fθ optical system, and the position in the sub-scanning direction when writing to this photosensitive drum is started, that is, the base pulse is evaluated.

For example, as shown in FIG. 19(b), when the center of the predetermined writing position (writing time base pulse) is taken as "0", the writing position on the area-type imaging element described later is In the case of zz, there is a deviation Δy in the sub-scanning direction between the writing position center O and the writing position zz. This deviation amount Δy is evaluated.

c: Evaluation of main scan pitch non-uniformity

By making the light beam carry out a certain mode of writing along the main scanning direction, the required image is formed, and several reflective surfaces (for example, 6 reflective surfaces) are formed at the side faces of the polygonal prism 19. Reflective writing is performed on a light beam, so the writing position (writing position) of the light beam changes with the accuracy of each reflection surface.

Therefore, it is possible to evaluate the standard deviation of the center position of the spot S in the main scanning direction corresponding to each surface by reflecting the light beam by each surface of the polygon mirror 19 .

For example, when there are six reflecting surfaces, the light beams reflected by the respective surfaces 20a to 20f are picked up by a CCD camera as described later. The writing position on the area-type imaging element of such a CCD camera is shown in FIG. 19(c).

When the writing center positions of each surface are kz1, kz2, kz3, kz4, kz5, kz6 relative to the reference center position "O", the deviations along the main scanning direction are Δx1, Δx2, Δx3.

For this occasion, the average value Δx of the standard deviation of the main scanning direction on each surface can be obtained as:

Δx=(2Δx1+2Δx2+2Δx3)/6

Accordingly, the pitch determined by the accuracy of each surface of the polygonal prism 19 can be evaluated.

Here, in order to evaluate this standard deviation, the reference center position "O" can also be used to take one of the center positions of each light spot S reflected by each surface as a reference position, and to measure the unevenness of the main scanning pitch. sex is evaluated.

For example, it is possible to take the center position of the initially taken-out spot S as a reference, or to calculate the difference between the center positions of each spot S, and to take the center position of the spot S with the smallest error as the reference position, or to take the center position of the spot S as the reference position. The one with the highest consistency rate in S is used as the benchmark.

d: Evaluation of the skew of the sub-scanning surface

By making the light beam write several times along the main scanning direction, the required image is formed, and several reflective surfaces (for example, 6 reflective surfaces) are formed at the side faces of the polygonal prism 19, when passing through these reflective surfaces When reflective writing is performed by a light beam, the writing position (writing position) of the light beam changes with the accuracy of each reflecting surface.

Therefore, it is possible to evaluate the standard deviation of the center position of the light spot S in the main scanning direction corresponding to each surface by reflecting the light beam by each surface of the polygon mirror 19 .

For example, when there are six reflecting surfaces, the light beams reflected by the respective surfaces 20a to 20f are picked up by a CCD camera as described later. The writing position on the area-type imaging element of such a CCD camera is shown in FIG. 19( d ).

When the writing center positions of each surface are kz1, kz2, kz3, kz4, kz5, kz6 with respect to the reference center position "O", the deviations along the sub-scanning direction are Δy1, Δy2, Δy3.

For this occasion, the average value Δy of the standard deviation of the sub-scanning direction on each surface can be obtained as:

Δy=(2Δy1+2Δy2+2Δy3)/6

Accordingly, the pitch determined by the accuracy of each surface of the polygonal prism 19 can be evaluated.

Here, in order to evaluate this standard deviation, the reference center position "O" can be used, and one of the center positions of the light spots S reflected from each surface can be taken as a reference position to evaluate the skew of the sub-scanning surface.

For example, the center position of the spot S obtained initially can be taken as a reference, or the difference between the center positions of each spot S can be calculated, and the center position of the spot S with the smallest error can be taken as the reference position, and the spot can also be taken as The one with the highest consistency rate in S is used as the benchmark.

e: Evaluation of the diameter of the main scanning beam

Evaluation of the beam diameter of the spot S along the main scanning direction.

f: Evaluation of sub-scanning beam diameter

Evaluation of the beam diameter of the spot S along the sub-scanning direction.

g: Evaluation of magnification error

Evaluation of whether the spot S interval at two points is a predetermined interval. That is, the evaluation is performed based on whether this interval is shorter or longer than the predetermined interval.

For example, as shown in FIG. 19(e), the writing reference position on the transfer paper predetermined during design and corresponding to two points on the original along the main scanning direction Q1 is obtained. The ratio of the distance L4 between Z1 and Z2 to the distance L5 between the writing positions Z1' and Z2' on the scanned surface obtained through actual measurement can be used to evaluate the magnification error.

h: evaluation of scan line tilt

The light beam is scanned along the main scanning direction to obtain one scanning line. Whether or not this scanning line is parallel to the main scanning direction is evaluated.

For example, as shown in FIG. 19(f), the deviation d0 of the writing position Z1' obtained from the main scanning start side with respect to the sub scanning direction Q3 and the reading position obtained from the main scanning end side are obtained. The difference between the deviation d1 of Z2' relative to the sub-scanning direction Q3 is used to evaluate the total deviation Δd by using the obtained difference and the distance L6 to the scanning line inclination angle θ.

i: Evaluation of magnification error deviation

In item g, the magnification error is evaluated by evaluating the writing position of two light spots S. Here, the magnification between each light spot is compared by taking out three or more light spots S with an area-type imaging element. , and then evaluate the deviation of each interval.

For example, as shown in FIG. 19(g), the distance L7 from the reading position Zm' at the center to the writing position Z1' on the writing start side obtained by measurement, and the distance L7 from the reading position Zm' at the center are calculated. The distance L8 from the writing position Zm' to the writing position Z2' on the writing end side is used to evaluate the magnification error deviation (left-right average difference).

j: Evaluation of scan line distortion

In item h, it is evaluated by whether the light beams in the main scanning direction determined by the writing positions of two light spots S scan in parallel. The inclination of each light spot relative to the main scanning direction is evaluated, and the scanning line distortion is further evaluated.

For example, as shown in FIG. 19(h), the deviation d2 of the writing position Z1' on the writing start side obtained from the measurement with respect to the sub-scanning direction Q3 is calculated, and the writing position located in the middle is obtained from the measurement. The deviation d4 of the entry position Zm' relative to the sub-scanning direction Q3, and the deviation d3 of the writing position Z2' on the writing end side relative to the sub-scanning direction Q3 obtained by measuring, and further evaluate the scanning line distortion.

k: evaluation of scan time

When two CCD cameras are used, the scanning time of the beam can be calculated by counting the time between taking out the light spot by one CCD camera and taking out the light spot by the other CCD camera, and can use the scanning time The scanning speed is obtained by dividing by the distance between the two CCD cameras.

In this case, a CCD camera can also be replaced by a synchronous sensor (scanning start detection sensor, scanning end detection sensor) provided at the writing unit 1 for synchronous detection. This point will be described in detail below.

l: evaluation of depth

By moving the CCD camera in a direction orthogonal to the main scanning direction (along the same direction as the optical axis of the beam emitted by the CCD camera), the beam is fixed relative to the main scanning direction, and the moving direction of the beam is measured On the beam diameter, use the design position for depth evaluation.

For example, the CCD camera can be moved and stopped at equal intervals along the direction of the light beam, and the beam diameter D of the spot S at each stop position can be solved in turn, so as to obtain the beam diameter curve as shown in Figure 19 (i). Depth curve) Qm. Moreover, Bw is a beam converging part.

This allows the depth of the beam to be evaluated.

m: evaluation of the pitch between beams

This is an evaluation of the pitch between several beams irradiated simultaneously.

For example, as shown in FIG. 19(j), the center positions KK and KK' of two light spots S received by an area-type imaging element are calculated, and the distance ΔKK along the sub-scanning direction is calculated. way, the pitch interval ΔKK of the two beams is evaluated.

The light beam characteristic evaluation device shown in FIG. 5 can be used to evaluate all evaluation items a to k, m except evaluation item 1, ie depth evaluation.

[The first embodiment of the evaluation device]

An embodiment of the evaluation device will be described below with reference to FIG. 5 .

In FIG. 5, 29 is a pulse motor for driving the polygon mirror 19, and 30 is a drive control circuit for driving and controlling this pulse motor. At the corresponding surface 31 to be scanned corresponding to the surface 26 of the photosensitive drum 25, area-type imaging elements (imaging surfaces) of CCD cameras 32 to 34 are arranged at equal intervals from the scanning start side to the scanning end side of the light beam P1. 32a-34a.

In other words, it is possible to place the CCD cameras 32 to 34 on the beam irradiation unit (latent image carrier) that is irradiated by the beam emitted from the writing unit of the image forming device (copier, etc.) mounted on the writing unit. At the irradiation start position (the light irradiation start position of the largest paper size), the light irradiation end position, and the intermediate position, the positions at the time of actual use were evaluated.

The light emission of the laser diode 11 or 12 is controlled by the single-point light emission control circuit 35 . This one-point light emission control circuit 35 has a clock pulse oscillator 36 for oscillating and emitting a time base pulse for measuring time, and a counter circuit 37 for counting the time base pulse. The single-point lighting control circuit 35 also receives a synchronous pulse from the synchronous sensor 27 .

A control circuit 38 constituted by a personal computer controls the single-point lighting control circuit 35 and the drive control circuit 30 . An input panel 39 for image processing is also provided at this control circuit 38 . Here, this input panel 39 is a component with three input systems, that is, it can adopt an image processing panel with such as R, G, B input systems.

The area-type imaging element 32a is arranged on the start side of the main scanning direction, the area-type imaging element 34a is arranged on the end side of the main scanning direction, and the area-type imaging element 33a is arranged at the central position of the main scanning direction. The image output of 34 a is supplied to the control circuit 38 through the input panel 39 . This control circuit 38 has a computing circuit 40 and an evaluation processing circuit 41 as computing components.

A reference pixel K serving as a coordinate origin for arithmetic processing in each pixel of each of the area-type imaging elements 32 a to 34 a is set as shown in FIG. 6 . This reference pixel K corresponds to a reference writing position predetermined during design. The setting of the reference pixel K can be performed as described later, and here the distance from the reference pixel K to the reference pixel K is set as L1. And the ideal pixel (light spot S) predetermined by design should be scanned on the scanned surface as shown in FIG. 7 . The reference symbol R1 is the beam diameter of the ideal spot S.

The control circuit 38 corrects this reference pixel K to "0" at the origin position. As shown in Fig. 8, the calculation circuit 40 calculates the scanning time T between the area-type imaging elements according to the distance L1 and the predetermined scanning speed during design, and calculates the scanning time T according to the scanning time T and the predetermined light spot S along the design time. From the diameter R1 in the scanning direction, the scanning time t corresponding to the single-point light emission is calculated. The signal representing the scanning time T, t is input into the counter circuit 37 of the single-point lighting control circuit 35 .

This scan time T and the single-point light-emitting scan time t can be defined according to the number of time base pulses output by the clock pulse oscillator 36, and the single-point light-emitting control circuit 35 makes the counter circuit 37 be controlled by the extinguishing time of the laser diode 11 or 12. Count the number of time base pulses corresponding to the scanning time T, and control the luminous emission of the laser diode 11 or 12 in the extinguished state, and also make the counter circuit 37 start to scan from the luminous moment of the laser diode 11 or 12 The number of time base pulses corresponding to the time t is counted, and the extinguishing of the laser diode 11 or 12 is controlled. This means that the scanning time T is defined as the extinguishing time of the laser diode 11 or 12 (time-base pulse time for writing).

Before the laser diode 11 or 12 utilizes the single-point light-emitting control circuit 35 to input the synchronous pulse given by the synchronous sensor 27, it implements the control of continuous light emission; Implement temporary extinguishing control, after the scanning time T and the scanning time t corresponding to the single-point lighting given by the single-point lighting control circuit 35 are passed, the lighting is carried out until the scanning time T is passed again. Turn off during the scan time T and the scan time t corresponding to the single-point light emission given by the single-point light emission control circuit 35 . Furthermore, when the synchronous pulse from the synchronous sensor 28 is input to the single-point light emission control circuit 35 , light emission is performed again after the time (approximately 2T) for returning to the scanning start side has elapsed.

In FIG. 8 , the black dots represent the state when a spot S corresponding to single-point light emission is formed (the state in which the laser diode 11 or 12 emits light), and the white dots represent the state where no light spot S corresponding to single-point light emission is formed. The state of the light spot S (the state in which the laser diode 11 or 12 is turned off).

In this way, when the single-point light emission control circuit 35 is used to control the light emission of the laser diode 11 or 12 in the scanning time corresponding to the single point light emission during the scanning process, as shown in FIG. Spots S are formed at the elements 32a to 34a.

If the center positions O1, O2, and O3 of the spot S along the main scanning direction Q1 are calculated by the evaluation processing circuit 41, the deviation d along the main scanning direction can be calculated relative to the reference pixel K. In FIG. 9, the deviation amount d=x1 to the right of the reference position on the writing start side, the deviation amount d=x3 to the left side of the reference position on the writing end side, and the deviation amount d=x2 at the central position = 0 for an instance.

Furthermore, if the center positions O1', O2', and O3' of the spot S along the sub-scanning direction Q3 are calculated by the evaluation processing circuit 41, the deviation amount d along the sub-scanning direction Q3 can be calculated with respect to the reference pixel K. An example in which the amount of deviation d' in the sub-scanning direction is d'=0 is shown in FIG. 9 .

In FIG. 8, the distance L1 between the area-type imaging element 32a on the main scanning start side and the area-type imaging element 33a at the central position and the area-type imaging element 34a on the scanning end side to the central position are the distance L1. An example in which the distances L1 between the imaging elements 33a are equal to each other has been described, but the present invention is not limited thereto.

[Second Example of Evaluation Device]

FIG. 10 shows the second embodiment of this evaluation device. Here, the input panel 39 adopts a single image processing panel, and evaluates the deviation of two writing reference positions predetermined during design. This evaluation device is provided with an input panel selector switch 43, and the single-point light emission control circuit 35 switches the input panel selector switch 43 in such a manner that the area-type image pickup element 34a also reads an image while the area-type image pickup element 32a takes out an image. . The other structural configurations are the same as those in the evaluation device shown in Fig. 8, so they are denoted by the same reference numerals, and their detailed descriptions are omitted. FIG. 11 shows the control time base pulse used by the single-point lighting control loop 35, and the scanning time (extinguishing time) T can be obtained by dividing the predetermined scanning speed by the distance L2 during design.

This beam characteristic evaluation device is provided with CCD cameras located at two separated positions along the main scanning direction, so it can be used for evaluation of evaluation items a to h, evaluation items k, m. Of course, if the same three CCD cameras as in the embodiment shown in FIG. 5 are installed, the evaluation items a to k, m can be evaluated.

[Third Example of Evaluation Device]

FIG. 12 shows a third embodiment of this evaluation device. Here, the input panel 39 adopts a single image processing panel, and evaluates relative to a deviation of a writing reference position predetermined during design.

Here, one CCD camera 43 is provided, and this CCD camera 43 is mounted on a movable body 45 provided on a guide shaft 44 extending longitudinally in the main scanning direction. The reciprocating motion of the movable body 45 along the guide shaft 44 can be controlled by the control circuit 38, and the CCD camera 43 can be set at the required writing reference position.

That is, since the CCD camera 43 is moved in the main scanning direction and positioned at a desired position, evaluation items a to f and evaluation items k and m can be evaluated. By setting the movement position of this CCD camera to the same position as the evaluation positions shown in FIGS. 5 and 10 , evaluation items a to k, m can be similarly evaluated.

If the distance between the setting positions of the synchronous sensor 27 to the CCD camera 43 is taken as L3, and the predetermined writing speed is divided by the distance L3 during design, the area-type imaging of the synchronous sensor 27 to the CCD camera 43 can be solved. Scanning time (see FIG. 13 ) T required for the reference pixel K in the element 43a.

Therefore, if the laser light source part Sou is turned off during the period from when the synchronization sensor 27 detects the synchronization pulse to the end of the scanning time T, after this scanning time T passes, the single-point light emission control circuit 35 turns on the laser light within the scanning time t at the same time. When the light source Sou emits light, a light spot S corresponding to single-point light emission during scanning can be formed on the area image sensor 43a of the CCD camera 43 as shown in FIG. 14 .

The center position of the light spot S in each of the above-mentioned evaluation devices can be obtained by the following method.

Each pixel of the area-type imaging element 43a is defined as Zij. Z1j, Z2j, ..., Zij, ..., Znj represent pixels arranged along the main scanning direction Q1, Zi1, Zi2,..., Zij,..., Zim represent pixels arranged along the sub-scanning direction Q3, and the label i (from 1 to n Integer) represents the i-th number from the left, and the label j (integer from 1 to m) represents the j-th number from the bottom.

Furthermore, when the sum Wj of the output signals output by the respective pixels Z1j, Z2j, . . . , Zij, . When Wj=Z1j+Z2j+...+Zij+...+Znj), the beam intensity distribution curve B1 along the sub-scanning direction Q3 as shown in FIG. When the sum Wi of the output signals output by each pixel Zi1, Zi2, . . . , Zij, . Zi1+Zi2+...+Zij+...+Zim), the beam intensity distribution curve B2 along the main scanning direction Q1 as shown in FIG. 15 can be obtained.

Fig. 16 shows an example of solving the beam intensity profile in this way, which shows the beam intensity profile B2 along the main scanning direction Q1.

The evaluation processing circuit 41 sets a threshold value P1h with respect to the beam intensity distribution curve B2, sets the serial numbers of pixels along the main scanning direction Q1 corresponding to the cross-cutting intensity of this threshold value P1h as Xi, X2, and solves Get the pixel number Xim equivalent to the average value of the sum of the numbers Xi and X2. In this way, the center position O1 of the light beam P1 along the main scanning direction Q1 can be calculated. Using the difference between the center position O1 and the reference pixel K, the deviation d along the main scanning direction Q1 can be obtained. The central position O1' along the sub-scanning direction Q3 can be obtained by performing similar processing on the beam intensity distribution curve B1, and the deviation d' can be obtained from the difference between this central position O1' and the reference pixel K.

By calculating the difference between serial numbers X1 and X2, the beam diameter D along the main scanning direction Q1 can also be calculated, and by performing similar processing on the beam intensity distribution curve B1, the beam diameter D' along the sub-scanning direction Q3 can also be calculated.

Here, the threshold value P1h is set so that the square component from the peak value Pmax to e (natural logarithm) becomes 1.

Here, based on the sum Wj of the output signals output by the respective pixels Z1j, Z2j, . . . , Zij, . The sum Wi of the output signals output by Zij,..., Zim can solve the central position O1, O1' of the beam P1, so that the beam intensity distribution curves B1, B2 can be drawn by several pixels close to the peak value Pmax, and this beam can be taken The peak of the intensity distribution curves B1, B2 is taken as the center of the beam P1, and the pixel corresponding to this peak can be taken as the center pixel of the beam P1.

Since the output of each pixel is to be quantized, and each quantized output distribution of these pixels is in a three-dimensional form, the pixel corresponding to its center of gravity position can also be taken as the light beam P1 along the main scanning direction Q1 and the sub-scanning direction Q3 The central positions O1, O1' of .

The CCD camera 43 is configured at a predetermined reference writing position during design (at a position where the image height on the optical axis of the fθ optical system 23 is 0), when there is a slight deviation from this reference writing position When measuring the beam diameter, the correct beam shape cannot be obtained, so it is necessary to correct the scanning time T shown in Figure 13 according to the deviation d, and make the laser light source Sou emit light at the position where the image height is 0.

[Fourth Example of Evaluation Device]

FIG. 17 shows a fourth embodiment of this evaluation device, which is provided with a guide shaft 46 in the depth direction (optical axis direction) Q4 orthogonal to the main scanning direction Q1, so that the movable body 45 can move along the The guide shaft 44 reciprocates in the main scanning direction Q1 and is capable of reciprocating in the depth direction Q4 along the guide shaft 46 . If such a structure is adopted, a CCD camera 43 can be used to evaluate the beam characteristics in the desired writing reference position predetermined during design.

This fourth embodiment can evaluate the evaluation items a to k, m, and it can also evaluate the evaluation item 1 since the CCD camera 43 can move in the depth direction Q4.

And in the evaluation device shown in Fig. 5, Fig. 10, Fig. 12 also can be equipped with the assembly that makes CCD camera 43 move along depth direction, if carry in the evaluation device shown in Fig. 5, Fig. 10, Fig. 12 With such a moving assembly, the evaluation item 1, namely depth, can also be evaluated by using the evaluation device shown in Fig. 5, Fig. 10, and Fig. 12 .

The evaluation of Q4 along the beam traveling direction (depth direction) can be performed as follows.

That is, the CCD camera 43 shown in FIG. 31( a ) is mounted on the movable body 45 , and the movable body 45 is mounted on the guide shaft 44 extending in the depth direction Q4 . Move the movable body 45 sequentially at equal intervals along the depth direction Q4 of the light beam P1, and when the beam diameter D of the spot S of the light beam P1 (see Fig. 14 and Fig. 16 ) is sequentially obtained from the stop position of the movement, the solution can be obtained. A beam diameter curve (depth curve) Qm with respect to the depth direction Q4 as shown in FIG. 31(b) is obtained.

Here, the beam diameter curve Qm is obtained with respect to the main scanning direction Q1, but the beam diameter curve may also be obtained with respect to the sub-scanning direction Q3.

The evaluation of the position from this beam diameter curve Qm to the beam converging part Bw is the appropriate amount of beam converging part correction ΔW obtained from the reference writing position along the depth direction Q4 and the position of the beam converging part Bw, which are predetermined during design. definite.

Fig. 18 shows a flow chart as an example of controlling the evaluation device shown in Fig. 17, the control loop 38 is first set in the initial state (step S1), and then the pulse motor 29 is started to rotate (step S2). The control circuit 38 outputs a signal to the single-point emission control circuit 35 to emit light from the laser diode 11 or 12 (laser light source unit Sou) when the pulse motor 29 reaches a constant speed after a certain period of time (step S3). On the other hand, whether the single-point lighting control circuit 35 detects whether a synchronous pulse is input by the synchronous sensor 27, when the synchronous pulse is not detected after a predetermined time, an error occurs to the control circuit 38 output signal (program step S4, program step S5 ). The control loop 38, when the input has an error signal, outputs a signal (program step S6) that the laser diode 11 or 12 (laser light source portion Sou) is extinguished to the single-point light emitting control circuit 35, and simultaneously stops the pulse according to this error signal. Rotation of the motor 29 (program step S7), and it is judged whether the detection is finished (program step S8).

When the single-point lighting control circuit 35 detects the synchronous pulse within a predetermined time, the laser diode 11 or 12 (laser light source part Sou) is extinguished at the same time as the synchronous signal is detected, and the counter circuit 37 counts to the time determined according to the scanning time T. At the timing of the base pulse number, a single-point light emission signal is output to the laser diode 11 or 12 (laser light source unit Sou) (step S9). The control circuit 38 obtains the image of the light spot S through this single-point light emission (program step S10). The evaluation processing circuit 41 performs calculations based on the actually obtained image of the spot S, and evaluates various required characteristics of the light beam P1 (step S11). This evaluation result is then output to a monitor (not shown in the figure) or a recording unit (not shown in the figure) (step S12). Then, the control circuit 38 outputs a signal to turn off the laser diode 11 or 12 (laser light source unit Sou) to the single-point emission control circuit 35 (step S6), and stops driving the pulse motor 29 at the same time. When the measurement is to be repeated, the processing from step S1 to step S12 is performed again.

The evaluation of the characteristics of the beam P1 can be performed by processing the center positions O1, O1', beam diameters D1, D1', deviations d, d' of the beam P1.

By calculating the ratio of the beam diameters D1 and D1', it is also possible to evaluate whether the shape of the beam P1 is an ellipse whose major axis is along the main scanning direction Q1, an ellipse close to a circle, or an ellipse whose major axis is along the sub-scanning direction Q3.

[Concrete configuration of the first to fourth evaluation devices]

The implementation of the above evaluation transposition will be described below.

FIG. 35 and FIG. 36 show schematic diagrams of the writing unit 1 installed on the image forming device, where 100 is the base of the image forming device. On this base 100, a writing unit position determining member 101 as shown in FIGS. 35 and 36 is provided.

The external shape of the writing unit 1 is shown in FIG. 37 . On one side wall of the writing unit 1, position determination protrusions 102, 102 are provided, and on the other side wall of the writing unit 1, position determination protrusions are provided. Use holes 103,103. The writing unit 1 is also formed with an elongated slit hole 104 extending along the main scanning direction, and the laser beam P1 passes through this elongated slit hole 104' to the photosensitive drum not shown in the figure. irradiated.

The writing unit position specifying member 101 has upright wall portions 105, 105 as shown in FIGS. 36, 38, and 39 . A through hole 106 is formed at the upright wall portion 105 , and a position determination pin 107 is fixedly connected to the upright wall portion 105 . The outer wall 108 of the upright wall portion 105 is configured as a position determining surface for positioning the writing unit 1 in the main scanning direction. The front end portion of the writing unit position specifying member 101 is configured as a reference base mounting portion 109 as shown in FIG. 39 . A reference base mounting pin 110 protrudes from this reference base mounting portion 109 .

A position determination reference base 111 as shown in FIGS. 40( a ) to 40 ( d ) is attached to such a reference base mounting pin 110 . The position determination reference base 111 extends in the lengthwise direction of the main scanning direction. Position determination pins 112 and position determination block mounting holes 113 are formed on the upper surface of the position determination reference base 111 . A fitting hole 114 into which the reference base attachment pin 110 is fitted is formed in a lower portion of the position determining reference base 111 .

The upper surface of this position determination reference base 111 is inclined, and at this upper surface, reference position determination upright plate portions 113a are formed at predetermined intervals along the longitudinal direction thereof. Furthermore, a position determining block member 115 as an angular position positioning determining member as shown in FIG. 41 is mounted on this upper surface. The position determining block member 115 has upstanding plates 116, 117 and a flat plate 118 as shown in FIGS. 42(a)-42(d). An LD holding plate 119 as a cylindrical holding member is attached to the upstanding plate 116 . A circular fitting hole 120 is formed at the upright plate 116 , and a fitting pin 121 is fixedly connected thereto. An abutment portion 121 abutting against the CCD camera is formed on the upright plate 117 . A fitting hole 122 is formed at the contact portion 121 . Furthermore, the circular fitting hole 120 is precisely machined into a perfect circular shape.

A cylindrical hub 123 as shown in FIG. 43( a ) is formed at the LD holding plate 119 . The profile of this cylindrical hub 123 is also precisely machined. The cylindrical hub 123 fits into the circular fitting hole 120 . On the disc portion 119a of the LD holding plate 119, a laser diode position determining hole 124, a laser diode mounting screw hole 125, and an angular position determining coupling hole 126 are formed as shown in FIG. 43(b). Here, the angular position determining coupling holes 126 are provided around the cylindrical hub 123 at intervals of 90 degrees.

On the LD holding plate 119 is mounted a reference laser diode (semiconductor laser) 127 as shown in FIG. 41 as a reference laser light source for determining a reference position determined in advance during design. The installation base 128 is fixed on the base 100 , the support base 129 is fixed on the installation base 128 , and the sliding base 131 is slidably disposed on the support base 129 . The CCD camera assembly 130 is provided at the slide base 131 . The CCD camera assembly 130 is composed of a slide base 131' and a CCD camera 132. An abutment plate 131'a is formed upright at the slide base 131'. A micrometer 133 is installed at the slide base 131 . The micrometer 133 has a function as an adjusting means for adjusting the imaging surface 130a of the area-type imaging element to a position corresponding to the surface to be scanned corresponding to the surface to be scanned. The front end portion of the CCD camera unit 130 is in contact with the contact portion 121 .

On the sliding base 131, a curved plate portion 134 as shown in FIG. The sliding direction is adjusted by a micrometer 133 installed at the position of the scanned corresponding surface 31 corresponding to the surface (scanned surface) of the photosensitive drum, and the curved plate portion 134 is installed by fixing screws 36 and fixed on the support base. 129 on.

Here, three CCD camera assemblies 130 are arranged at equal intervals along the longitudinal direction of the position determining reference base 111, and as shown in FIG. 44, this interval is L10. In Fig. 44, the CCD camera assembly 130 on the left side is arranged at the position of the writing start side, the CCD camera assembly 130 in the center is arranged at the writing center position, and the CCD camera assembly 130 on the right side is arranged at the writing end side. location.

The laser light source unit Sou and the optical scanning system according to the first embodiment of the present invention are arranged inside the writing unit 1, and the scanned surface on the photosensitive drum is linearly scanned by the laser light source for writing.

The center of the circular fitting hole 120 should be consistent with the outgoing trajectory (exiting light) Qn in the main scanning direction and sub-scanning direction of the predetermined beam P1 as shown in FIG. The emitted reference laser beam does not have to be emitted along this exit track Qn. Generally speaking, when a single reference laser beam is emitted, the reference laser beam used can be specially designated to be located on the extension line of the exit track Qn as the area-type imaging element 130a The reference pixel K at the reference position.

First, the reference laser diode 127 is directed toward the CCD camera unit 130 on the writing start side. As shown in Fig. 45(a), the LD holding plate 119 is fitted into the circular fitting hole 120, and the joint pin 121 is fitted in an angular position determination joint hole 126 on the LD holding plate 119, so that the LD The holding plate 119 rotates with the center of the circular fitting hole 120 as the center of rotation, and then the joint pin 121 is brought into contact with the peripheral wall 126a of the joint hole 126 for determining the angular position on the LD holding plate 119 along the rotational direction, and the reference laser diode is determined. 127 angular position.

The reference laser diode 127 is controlled to emit light by an unshown light emission control circuit (the light emission control circuit of the writing unit 1 may also be used). At this time, the outgoing direction of the laser beam is assumed to be the Qm direction as shown in FIG. 44 . Let the coordinates of the light-receiving pixel G of the area-type imaging element 130a that receives the laser beam in this emission direction Qm be G(x1, y1). Then, release the engagement between the joint pin 121 and the joint hole 126 for determining the angular position as shown in FIG. ', and make the peripheral wall 126a' of the coupling hole 126' for determining the angular position on the LD holding plate 119 contact the coupling pin 121 in the rotational direction, thereby determining the angular position of the reference laser diode 127.

Then, the reference laser diode 127 is controlled to emit light by a light emission control circuit not shown in the figure (the light emission control circuit of the writing unit 1 may also be used). The emission direction of the laser beam at this time is assumed to be the Qm' direction as shown in FIG. 43 . Let the coordinates of the light-receiving pixel G of the area-type imaging element 130a that receives the laser beam in this emission direction Qm' be G(x2, y2).

At this time, the coordinates K (X10, Y10) of the reference pixel K located on the extension line of the emission track Qn on the writing start side are:

X10={(x1-x2)/2}+x2

Y10={(y1-y2)/2}+y2

Therefore, for the reference laser diode 127 , the position of the reference pixel K can be calculated with high precision without using a laser whose outgoing optical axis has been precisely adjusted.

Next, the coordinates K (X12, X12, Y12) will be explained when the solution is performed.

First, the reference laser diode 127 is directed toward the CCD camera assembly 130 at the central position, and the reference laser diode 127 is made to emit light.

The emission direction of the laser beam at this time is assumed to be the Qm" direction. The coordinates of the light-receiving pixel G of the area-type imaging element 130a receiving the laser beam in the emission direction Qm' are G(x3, y3).

The coordinates K (X12, Y12) of the reference pixel K on the extension line of the emission track Qn' at the writing center position and the coordinates K (X10) of the reference pixel K on the extension line of the emission track Qn on the writing start side. , Y10), and the coordinates G(x3, y3) of the light-receiving pixel G that receives the laser beam in this outgoing direction Qm' and the area-type imaging element 130a that receives the laser beam in this outgoing direction Qm' The difference between the coordinates G(x2, y2) of the light-receiving pixels G of G is equal.

Therefore, there are:

X12-X10=x3-x2

Y12-Y10=y3-y2

Right now:

X12=X10+x3-x2={(x1-x2)/2}+x3

Y12=Y10+y3-y2={(y1-y2)/2}+y3

Similarly, the coordinates K (X14, Y14) of the reference pixel K of the area-type imaging element 130a of the CCD camera 132 disposed at the writing end position can be solved from the coordinates G(x5+y5) of the light-receiving pixel G, That is:

X14={(x1-x2)/2}+x5

Y14={(y1-y2)/2}+y5

Therefore, after the coordinates of the reference pixel K are specially set for a certain CCD camera 132 by the rotation of the LD holding plate 119, the special designation of the reference pixel K of the remaining CCD cameras 132 can be done without rotating the LD holding plate 119. under conditions.

FIG. 39 shows a schematic diagram when the position determining block part 115 as the angular position determining part is disposed at the central position.

By moving the slide base 131 in its longitudinal direction with the micrometer 133, the beam diameter in the depth direction can be measured.

Its specific structure can be configured to replace a position determination block component 115 to obtain the composition form of the reference pixel K at each position, or a position determination block component 115 can be slidably set on the position determination reference base 111 The configuration may also be a configuration in which position specifying block members 115 are respectively provided at each of the writing start side position, the central position, and the writing end side position.

【Deformation example】

46 to 51 are schematic diagrams showing modified embodiments of the above-mentioned specific structure, wherein FIG. 46 to FIG. 48 show a schematic diagram of the state in which the writing unit 1 is installed on the image forming apparatus, that is, it is set upright on the base 100 There is a pillar 140, and a writing unit position determining member 101 is fixed at the upper end of the pillar 140, where the writing unit position determining member 101 is in the shape of a flat plate.

An opening portion 141 is formed at the center of the writing unit position determining member 101 . Three fastening devices 142 are provided on the writing unit position determining part 101, and 143 is a fastening lever. The writing unit 1 is fastened at the writing unit position determining part 101 by this fastening device 142 . The installation base 128 is fixed on the base 100 , the support base 129 is fixed on the installation base 128 , and the sliding base 131 is slidably disposed on the support base 129 .

A CCD camera assembly 130 is provided at such a slide base 131 . The CCD camera assembly 130 is composed of a CCD camera 132 and a sliding base 131'. An abutting portion 131'a is formed upright on the slide base 131'. Furthermore, a micrometer 133 is mounted on the sliding base 131, and the micrometer 133 has a function of adjusting the area-type imaging element 130a to the position of the corresponding surface of the current scan.

On the support base 129, as shown in FIG. 49, a clamping frame 144 is fixed, and 145 is a guide hole. This guide hole 145 extends along the sliding direction of the slide base 131 . The sliding base 131 is installed by a fixing pin 136 and is fixed on the supporting base 129 .

A position determination reference base 111 as shown in FIG. 50 is attached to the writing unit position determination member 101 . This position determining reference base 111 is fixed on the writing unit position determining part 101 by fastening means 142 . A contact portion 147 is formed at the lower portion of the position determining reference base 111 . On the upper portion of this position determining reference base 111, a position determining block member 115 as shown in FIG. 51 is attached.

A circular fitting hole 120 is formed at the position determining block member 115 , and a coupling pin 121 is formed therein. An LD holding plate 119 is mounted on this position determining block part 115 . A reference laser diode 127 is mounted on the LD holding plate 119 . The center of the circular fitting hole 120 points to the same direction as the outgoing trajectory Qn predetermined during design.

For this modified embodiment, the reference pixel K using the reference laser diode 127 can be specially designated, the writing unit 1 is removed from the writing unit position determining part 101, and the reference laser diode 127 is set on the writing unit on the position determining component 101. The position determining reference base 111 is removed, and the writing unit 1 is set on the writing unit position determining member 101 .

[Adjustment device for response evaluation results]

Next, an adjustment device that operates based on the evaluation results of the first to fourth evaluation devices will be described.

FIG. 20 shows an adjustment device that performs an operation based on the evaluation performed on the evaluation item a.

[Structure to adjust the writing position in the main scanning direction by the movement of the synchronous sensor]

FIG. 20 shows the structure of the writing start position adjustment assembly when the beam center O1 on the spot S deviates by ΔX from the reference pixel K (reference writing position Z1 ) on the writing start side only along the main scanning direction.

With respect to the writing position Z1 on the writing start side, when the beam center O1 has only a deviation ΔX along the main scanning direction Q1, the synchronous sensor 27 is moved along the main scanning direction Q1 orthogonal to the beam traveling direction, and then adjusted. .

This synchronization sensor 27 is mounted on a movable body 47 shown in FIG. 21 which is movably provided on a guide shaft 48 extending along the main scanning direction Q1. This guide shaft 48 straddles the structural constituting walls 49, 49' which constitute a part of the writing unit 1, and an adjusting screw 50 is also arranged on the structural constituting wall 49, so that the adjusting screw 50 can be screwed into the The structure is formed on the threaded portion 51 at the wall 49 .

Bridged between the movable body 47 and the structurally forming wall 49 is a tension spring 52 as an elastic element, which presses the movable body 47 against the structurally forming wall 49 . The front end portion 50 a of the adjustment screw 50 is in contact with the wall portion of the movable body 47 .

By freely adjusting the forward and reverse rotation of the screw 50, the movable body 47 can be slightly moved along the main scanning direction Q1, so as shown in FIG. Adjust the distance L6 between them, so that in the main scanning direction, the writing reference position Z1 predetermined in design can be consistent with the beam center O1, and the writing time base pulse at the reading and writing start position can be corrected .

[Structure to adjust the reading position in the main scanning direction by the movement of the writing unit or imaging unit 1]

In the above example, the writing timing pulse at the writing start position where the synchronous sensor 27 moves along the main scanning direction is corrected, but in this first modified embodiment, the writing unit 1 and The imaging unit 53 is relatively moved along the main scanning direction Q1 to adjust the writing time base pulse as required.

FIG. 23 shows the positional relationship between the writing unit 1 and the image forming unit 53, where a developing unit 54, a transfer unit 55 and a charging unit 56 are provided at least in the rotating area of the photosensitive drum 25 on the image forming unit 53. . Also, the transfer unit 55 and the charging unit 56 may be integrally formed. The cleaning component and the discharging component (not shown in the figure) of the latent image carrier may also be integrated with the imaging unit 53 . The sub-scanning direction Q3 is perpendicular to the optical axis of the light beam irradiated to the photosensitive drum 25 .

As shown in FIG. 24 , a guide hole 58 extending in the longitudinal direction of the main scanning direction Q1 is formed at the main structure constituting wall 57 of the image forming apparatus, and a support is protruded at the imaging unit constituting wall 53 a constituting the imaging unit 53 . pin 53b, and the protrusion is provided with a hub portion 53c. A threaded portion 53d is formed on the boss portion 53c, and the support pin 53b is fitted into the guide hole 58. As shown in FIG.

An adjustment screw 59 is provided on the main structure constituting wall 57, and this adjustment screw 59 is screwed to the threaded portion 53d on the hub portion 53c. When the adjusting screw 59 is adjusted, the imaging unit 53 can move in the main scanning direction Q1 relative to the writing unit 1, so that the position adjustment of the imaging unit (photosensitive drum 25) 53 relative to the light beam P1 can be carried out in the main scanning direction Q1, and then The correction of the write timing pulse at the write start position predetermined during design can be realized with respect to the main scanning direction.

[Structure to adjust the writing position in the main scanning direction by the movement of the writing unit or imaging unit 2]

In the adjustment structure 1, the imaging unit 53 is moved along the main scanning direction Q1 through the screw connection between the adjusting screw 59 and the threaded part 53d on the hub part 53c, so that the imaging unit 53 moves in the main scanning direction relative to the light beam P1. Q1 performs position adjustment. In this modified embodiment 2, as shown in FIG. 25, the imaging unit 53 is provided on a guide rail 60 extending in the main scanning direction Q1 so as to be movable. This imaging unit 53 is pulled in a direction toward the main structure constituting wall 57 by a spring 61 as an elastic member. A threaded portion 62 is formed on the main structure constituting wall 57 , and the adjusting screw 59 is screwed to the threaded portion 62 , and the front end portion 59 a of the adjusting screw 59 is in contact with the imaging unit structure constituting wall 53 a.

When the adjusting screw 59 is turned in a direction in which the front end portion 59a of the adjusting screw 59 presses against the structural wall 53a of the imaging unit to weaken the force, the imaging unit 53 will move in the direction shown by the arrow a1 under the elastic force of the spring 61. When the adjustment screw 59 is rotated in a direction in which the front end portion 59a of the adjustment screw 59 presses the structural wall 53a of the imaging unit to increase the force, the imaging unit 53 will restrain the spring 61 under the pressing action of the adjustment screw 59. In this way, the position of the imaging unit 53 of the light beam P1 relative to the main scanning direction Q1 can be adjusted.

[Structure to adjust the writing position in the main scanning direction by the movement of the writing unit or imaging unit 3]

As shown in FIG. 26 , the structure of the adjustment structure 3 is that the imaging unit 53 is movably arranged on the guide rail 60 extending along the main scanning direction Q1, and a rack portion 63 is also formed at the imaging unit 53 , and on the other On the one hand, the main structure constitutes the wall 57 and is also provided with an adjustment shaft 64 for operation and installation. A pinion 65 meshing with the rack portion 63 is provided on the shaft portion of the adjustment shaft 64. By making the pinion 65 and the gear The engagement of the rail portion 63 enables the imaging unit 53 to move along the main scanning direction Q1.

[Structure 4 in which the writing position in the main scanning direction is adjusted by the movement of the writing unit or the imaging unit]

The adjustment structure 1 to the adjustment structure 3 all move the imaging unit 53 along the main scanning direction Q1, and then adjust the position of the imaging unit 53 of the light beam P1, and in this variant embodiment 4, as shown in FIG. 27, the imaging unit 53 is fixed, and the position of the light beam P1 in the main scanning direction Q1 is adjusted by moving the writing unit 1 in the main scanning direction Q1. At a position corresponding to the writing unit 1 on the main structure constituting wall 57, a guide hole 66 extending in the longitudinal direction of the main scanning direction Q1 is formed, and a supporting pin 67 is protruded from the writing unit constituting the wall 1b. , and the protrusion is provided with a hub portion 68 . A threaded portion 69 is formed at the hub portion 68 , and the support pin 67 is fitted into the guide hole 66 .

An adjusting screw 70 is provided on the main structure constituting wall 57 , and the adjusting screw 70 is also disposed on the writing unit structural constituting wall 1 b , and the adjusting screw 70 is screwed to the threaded portion 69 of the hub portion 68 . When the adjusting screw 70 is adjusted, the writing unit 1 will move relative to the imaging unit 53 along the main scanning direction Q1 , so as to realize the position adjustment of the imaging unit 53 of the light beam P1 along the main scanning direction Q1 .

[Structure 5 in which the writing position in the main scanning direction is adjusted by the movement of the writing unit or the imaging unit]

The adjustment structure 1 to the adjustment structure 4 all set the imaging unit 53 on the bottom and the writing unit 1 on the top, and adjust the position of the imaging unit 53 of the light beam P1 along the main scanning direction Q1, and in this deformation In Embodiment 5, the writing unit 1 is disposed on the bottom, the imaging unit 53 is disposed on the top, and the position of the imaging unit 53 along the main scanning direction Q1 of the light beam P1 is adjusted.

In this modified embodiment 5, as shown in FIG. 28, the imaging unit 53 is fixed, and the writing unit 1 is disposed on a guide rail 71 extending in the main scanning direction Q1 so as to be movable. This writing unit 1 is pulled in the direction of the main structure constituting the wall 57 by a spring 72 as an elastic component. A threaded hole 73 is formed in the main structure constituting wall 57, and an adjusting screw 74 is screwed into the threaded hole 73, and a front end 74a of the adjusting screw 74 is in contact with the writing unit structure constituting wall 1b.

When the adjusting screw 74 is rotated in a direction in which the front end 74a of the adjusting screw 74 is pressed against the wall 1b of the writing unit structure and the force is weakened, the writing unit 1 will follow the direction indicated by the arrow a3 under the elastic force of the spring 72. When the front end 74a of the adjustment screw 74 presses the front end 74a of the adjustment screw 74 to press the writing unit structure to form the wall 1b and rotate the adjustment screw 74 in the direction of strengthening the force, the writing unit 1 will be pressed by the adjustment screw 74. Next, restrain the elastic force of the spring 72 to move in the direction indicated by the arrow a4, so that the position of the imaging unit 53 of the light beam P1 along the main scanning direction Q1 can be adjusted.

[Structure to adjust the writing position in the main scanning direction by moving the stacked paper position]

FIG. 52 is a schematic diagram showing a structure for adjusting the writing position by sliding the stacked paper position in the main scanning direction Q1.

As shown in FIG. 52(a), this embodiment provides LED1-LEDn for side rails near the surface 26 of the photosensitive drum 25. As shown in FIG. These LED1 to LEDn are arranged along a direction corresponding to the main scanning direction Q1 as shown in FIG. 52( b ).

Light emission control of these LED1-LEDn is performed in accordance with the paper size. These LED1 to LEDn can be used so as not to attach the developing toner along the lateral track of the photosensitive drum 25 (conveyance direction (sub-scanning direction Q3 )) in accordance with the paper size. That is, LED1 to LEDn are used to expose both ends of the photosensitive drum 25 .

Paper stack trays 100 , 101 are provided at the image forming unit 53 . Here, a side guide fixing plate mounting portion 102 is also provided at the paper stacking tray 100 . A side guide fixing plate 103 is provided on the side guide fixing plate mounting portion 102, and a side guide body 104 is mounted on the side guide fixing plate 103 so as to be slidable relative to the paper size. The sliding direction of this lateral guide 104 corresponds to the main scanning direction Q1 (direction orthogonal to the sheet conveyance direction).

The side guide fixing plate 103 can be slid and adjusted relative to the side guide fixing plate installation part 102 in the same direction as the side guide body 104, in order to correct the writing position according to the evaluation results of the evaluation device 1 ~ evaluation device 4 The writing position is adjusted along the main scanning direction Q1 by the amount, and an elongated hole 105 is also provided, and a scale corresponding to the writing position correction amount is also provided in the elongated hole 105 . After such adjustments are made to the side guide fixing plate 103, it is fixed to the side guide fixing plate mounting portion 102 with a fixing pin or the like.

For example, if the lateral length A3 is taken as the lateral dimension, the CPU controls LED1, LED2, LEDn-1, and LEDn to emit light. If it is assumed that the writing position of only one LED is located along the main scanning When the direction Q1 (in Fig. 52(a) is the case where the writing position is biased upwards) is corrected, the light emission control of LEDs of various sizes can be implemented by this part, and for the paper whose lateral length is A3 In this case, light emission control can be performed on LED1, LEDn-2, LEDn-1, and LEDn.

If offset adjustment is performed on the desired writing position along the main scanning direction Q1, the paper transport position can also be offset. Furthermore, in the process of conveying the paper to the photosensitive drum 25 , the paper may be slid in the main scanning direction Q1 while being conveyed.

[A structure for adjusting the writing position in the sub-scanning direction by the movement of the writing unit or the imaging unit]

This adjustment structure can be based on the results of the evaluation (evaluation item b) of the sub-scanning writing position as shown in FIG. The traveling direction of the light beam on the photosensitive drum is adjusted with the sub-scanning direction Q3 orthogonal to the main scanning direction Q1.

In other words, this adjustment structure can make necessary adjustments to the writing time base pulse through the relative movement of the writing unit 1 and the imaging unit 53 along the sub-scanning direction Q3, so as shown in FIG. 29 , it It is an adjustment component that can make the beam center O1' of the light spot S deviate by Δy only along the sub-scanning direction Q3 to adjust the writing start position.

As shown in FIG. 30, an adjustment screw 75 constituting a part of the moving unit is formed at the main structure constituting wall 57, and a guide hole 76 extending in the sub-scanning direction Q3 is formed. A support pin 77 is provided at the writing unit 1, and a hub portion 78 is formed. A threaded portion 79 is formed at the hub portion 78 , so that the adjusting screw 75 can be threadedly connected to the threaded portion 79 on the hub portion 78 . When the adjusting screw 75 is adjusted, the writing unit 1 can move relative to the imaging unit 53 along the sub-scanning direction Q3, so that the position of the imaging unit 53 of the light beam P1 along the sub-scanning direction Q3 can be adjusted.

This adjustment structure is to move the writing unit 1 along the sub-scanning direction Q3, and then adjust the position of the imaging unit 53 of the light beam P1 along the sub-scanning direction Q3. A supporting pin 77 and a hub portion 78 are formed as a part of the moving assembly to move the imaging unit 53 in the sub-scanning direction Q3, thereby adjusting the position of the imaging unit 53 of the light beam P1.

Its structural composition can also be a constitution in which the moving assembly is rotated through an adjustment shaft provided with an operating knob, and then the pinion gear meshes with the pinion gear.

[Structure of depth adjustment by laser diode (LD) module]

Here, the length of the optical path can be adjusted in such a way that the collimator lenses 13 and 14 can be moved along the optical path of the light beam P1 by correcting the appropriate amount ΔW based on the beam convergence part obtained during the depth evaluation. This optical path length will be described below with reference to FIG. 32 Adjust components.

The mounting base 81 of the laser diode 11 (12) is fixed by a pin 82 on the wall 1b of the writing unit structure, and the mounting hole 83 and the collimating lens of the laser diode 11 (12) are arranged on this mounting base 81 13(14) mounting holes 84. The laser diode 11 ( 12 ) is fitted and fixed in the mounting hole 83 . The collimator lens 13 ( 14 ) is held in a lens barrel 85 , and a male screw portion 86 is formed on the outer peripheral portion of the lens barrel 85 . A female thread portion 87 is formed in the mounting hole 84 , and the lens barrel 85 can be held on the mounting base 81 in a relatively movable manner through the screw connection between the male thread portion 86 and the female thread portion 87 .

The position adjustment of the beam converging part Bw is achieved by moving the collimating lenses 13 (14) of the laser diodes 11, 12 along the optical axis direction Q5 relative to the collimating lenses 13 (14) of the laser diodes 11, 12 by rotating the lens barrel 85. Achieved. After adjusting the beam converging portion Bw, the lens barrel 85 can be fixed on the installation base 81 with, for example, an adhesive or the like.

[Structure 1 in which depth adjustment is performed by a writing unit or an imaging unit]

In the above-mentioned example, the collimating lenses 13, 14 are moved along the direction of their optical axes, thereby adjusting the diameter of the waist of the light beam. As shown in FIG. The installation hole 88a and the threaded installation part 88b extending in the direction of the writing unit are provided with a guide pin 89 fitted with the guide hole 58 on the structural wall 1b of the writing unit, and the writing unit 1 is pushed upward by the elastic force of the tension spring 90. and the threaded part 92 threadedly connected with the adjusting screw 91 is provided on the threaded mounting part 88b. The front end 91a of the adjusting screw 91 is in contact with the guide pin 89, and the writing is adjusted by the rotation of the adjusting screw 91. The distance between the unit 1 and the imaging unit 53 can change the length of the optical path, and further adjust the position of the beam waist diameter relative to the surface 26 of the photosensitive drum 25 .

[Structure 2 in which depth adjustment is performed by a writing unit or an imaging unit]

Adjustment structure 1 is provided with an adjustment screw 91 for adjusting the distance between the writing unit 1 and the imaging unit 53, while in adjustment structure 2, as shown in Figure 34, an adjustment knob is provided at the wall 57 of the main structure. 94, an eccentric cam 96 is provided at the shaft portion 95 of the adjusting knob, and a contact portion 97 that is in contact with the cam surface 96a on the eccentric cam 96 is provided at the writing unit 1. The tension spring 90 between the pins 89 can form a structure of sliding connection between the contact portion 97 and the cam surface 96a, and the optical path length between the writing unit 1 and the imaging unit 53 can be changed by rotating the adjusting knob 94, Positional adjustment of the beam waist diameter can thereby be performed with respect to the surface 26 of the photosensitive drum 25 .

The structural composition of the optical path length adjustment assembly can also be a form in which the pinion is meshed with the pinion by adjusting the thread.

The configuration here is such that the writing unit 1 is moved in the sub-scanning direction, but a configuration in which the imaging unit 53 is moved may also be employed.

[Adjustments based on evaluation results related to other evaluation items]

(a) If the evaluation of the evaluation items c and d is outside the allowable range, it is considered that the polygonal prism 19 is faulty, so it is preferable to replace the polygonal prism 19 mounted on the writing unit 1 .

(b) When the evaluation of the evaluation items e and f is outside the allowable range, the aperture diameter of the diaphragm member (not shown in the figure) provided in the optical path between the laser diode LD and the polygonal prism 19 should be evaluated. Adjustment. This diaphragm part is usually arranged directly behind the conventional collimator lens along the beam traveling direction. The adjustment of the opening diameter of the diaphragm part can be realized by adjusting the opening diameter of the diaphragm part through a mechanical adjustment assembly, or by taking out the diaphragm part currently configured in the optical path from the optical path and replacing it with another The opening diameter is achieved by way of the diaphragm part.

(c) According to the evaluation items g and i, that is, the evaluation of magnification error and magnification error deviation, it is better to adjust by replacing the fθ lens and mirror.

When the light beam reflected by the polygonal prism 19 is guided to the fθ lens 23 of the optical system of the photosensitive drum 25, and the optical elements such as the reflector 24 have optical defects, the result that affects the optical path length in the left and right directions of the optical axis O10 occurs. The possibility is quite high.

When there is only a magnification error as an evaluation item g, as shown in FIG. 53( a ), the mirror 24 or the fθ lens 23 can be rotated along its optical axis O10 to adjust it to a predetermined angle.

(d) It is preferable to adjust by replacing the fθ lens 23 or the mirror 24 according to the evaluation items h and j, ie, the evaluation of the scanning line inclination and the scanning line curve.

When the fθ lens 23, mirror 24 and other optical components in the optical system that guide the light beam reflected by the polygon mirror 19 to the photosensitive drum 25 have optical defects, the result that affects the optical path length in the left and right directions of the optical axis occurs. The possibility is quite high.

For the occasion where there is only the tilt of the scanning plane as the evaluation item h, then as shown in Figure 53 (b), the fθ lens 23 can be rotated along its optical axis O10 to adjust to a predetermined angle, and can be adjusted along the direction shown by the arrow O11 The direction adjusts the inclination angle of the mirror 24 .

(e) Adjustment can be performed by rotating the components mounted on several LDs along the optical axis to a predetermined angle based on the evaluation of the evaluation item m, that is, the pitch interval.

(f) The adjustment may be performed by adjusting the rotation speed of the polygon mirror 19 based on the evaluation item k, that is, the evaluation of the scanning time. This is similar to that shown in FIG. 53(a), and the scanning time can be adjusted by rotating the mirror 24 or the fθ lens 23 along its optical axis O10 to adjust it to a predetermined angle.

(g) It can be adjusted by the description shown in FIGS. 32 to 34 based on evaluation item 1, that is, evaluation of depth.

Claims (7)

1. A writing unit adjusting device, characterized in that, have: A writing unit (1) for forming an electrostatic latent image on the surface of the latent image carrier with an optical scanning system installed therein; an imaging unit incorporating at least said latent image carrier; and a moving assembly for relatively moving the writing unit and the imaging unit along the main scanning direction in order to adjust the deviation (ΔX) along the main scanning direction (Q1) of the light beam, The main scanning direction (Q1) is a direction orthogonal to a traveling direction of a light beam incident from the writing unit (1) toward the imaging unit (53). 2 . The writing unit adjustment device according to claim 1 , wherein a display unit is arranged in the imaging unit. 3 . 3. The writing unit adjusting device according to claim 1, wherein the moving assembly is composed of a guide hole extending along the main scanning direction formed on the main body of the image forming device and a guide hole formed on the main body of the image forming device. The writing unit is constituted by a supporting pin on one of the imaging units and fitted into the guide hole. 4. The writing unit adjusting device according to claim 1, wherein the moving assembly is composed of an adjusting screw and an elastic assembly, and the adjusting screw makes one of the writing unit and the imaging unit Moving in the main scanning direction, the elastic member applies elastic force to the unit such that the front end of the adjustment screw abuts against the unit moved based on the adjustment screw. 5. The writing unit adjusting device as claimed in claim 1, wherein the moving assembly is composed of an adjusting screw and a hub portion, and the adjusting screw makes one of the writing unit and the imaging unit Moving in the main scanning direction, the hub portion is provided on a unit that is moved based on the adjustment screw, and is screwed to the adjustment screw. 6. A writing unit adjusting device, characterized in that, have: The writing unit is equipped with an optical scanning system and a synchronous sensor for determining when the latent image carrier is written, and is used to make the beam emitted by the laser light source form an electrostatic latent image on the surface of the latent image carrier; and a moving component, in order to adjust the deviation of the writing unit relative to the latent image carrier along the main scanning direction of the light beam, and move the synchronous sensor along the main scanning direction, The main scanning direction is a direction orthogonal to a traveling direction of a light beam incident from the writing unit toward the imaging unit. 7. The writing unit adjusting device according to claim 6, characterized in that, The moving assembly is composed of a movable body holding the synchronous sensor, a guide shaft guiding the movable body in the main scanning direction, and a front end abutting on the movable body to move the movable body. An adjusting screw and an elastic component that applies elastic force to the movable body in a direction abutting against the front end of the adjusting screw.

Images