JP2001056443A - Device and method for forming image and manufacture of image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To individually correct optical scanning characteristics being peculiar to light scanning optical devices loaded in respective image forming devices. SOLUTION: This image forming device is provided with such a system that a latent image corresponding to a recording image is formed by deflecting light beams from a light source side, condensing them on a surface to be scanned as a light spot, optically scanning a latent image carrier 110 disposed by aligning the photosensitive surface thereof with the surface to be scanned by using the light scanning optical device 170 optically scanning the surface to be scanned at an almost uniform speed. Besides, it is provided with a control means 101 controlling the optical device 170. Then, one or more characteristics out of the scanning speed characteristic, the light spot diameter characteristic and the light quantity characteristic are previously measured as the optical scanning characteristic of the optical device 170. Besides, a memory means 103 storing data related to the measured optical scanning characteristic is integrated. Then, the control means 101 is provided with a function correcting the optical scanning characteristic based on the data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus
The present invention relates to an image forming method and a method for manufacturing an image forming apparatus.

[0002]

2. Description of the Related Art Image forming apparatuses utilizing optical scanning are known as digital copiers, laser printers, optical plate making apparatuses, and the like. In these image forming apparatuses, high-definition and colorization of an image to be formed has been advanced, and accordingly, scanning uniformity in optical scanning and “uniformity of light amount and light spot diameter” of a light spot, etc. Demands for optical scanning characteristics are becoming more stringent. If the uniformity of scanning is not sufficient, or if the light amount of the light spot or the diameter of the light spot fluctuates due to the light scanning, "distortion not included in the original image information" is added to the written image, and the image is formed. The resulting image has undesirable effects such as "image distortion, resolution reduction, and density unevenness". When a full-color image is formed by image formation using optical scanning, generally, four color toners are used. However, when each of the four color images to be superimposed on each other is written by optical scanning by a separate optical scanning optical device,
If the optical scanning characteristics are different for each optical scanning optical device, "unevenness of superimposition of each color image" may occur, resulting in image distortion.

The optical scanning characteristics are determined in principle by the design of the optical scanning optical device. For example, the scanning speed characteristic of optical scanning is
It is determined by the fθ characteristic of the fθ lens that focuses the deflected beam as a light spot on the surface to be scanned, and the change in the light spot diameter due to the image height is determined by the field curvature of the fθ lens. As described above, it is possible to correct “optical scanning characteristics determined by design”. For example, if the fθ characteristic is determined, the pixel clock which is a timing for writing a pixel by optical scanning is adjusted, and “the period of the pixel clock is reduced at a high scanning speed”, and conversely, “at a low scanning speed. By increasing the period of the pixel clock,
Even if the scanning speed is not uniform, it is possible to make the distance between the pixels to be written constant so that "optical scanning is performed at a constant speed". In the case where “the light spot diameter changes with the image height of the light spot”, the fluctuation of the light spot diameter can be corrected by “adjusting the light emission amount and the pixel pulse width of the light source” according to the pixel position. it can. When the light amount of the light spot changes according to the image height of the light spot, the light emission amount of the light source may be adjusted according to each pixel position. In an actual optical scanning optical device, apart from the “optical scanning characteristics determined by design” as described above, “individual optical scanning characteristics” due to manufacturing errors and assembly errors of each optical element of the optical scanning optical device. The specific optical scanning characteristics of each optical scanning optical device are the sum of the optical scanning characteristics predetermined by design and the individual optical scanning characteristics. Therefore, the specific optical scanning characteristics of each optical scanning optical device are like the “habit” of each optical scanning optical device, are specific to each optical scanning optical device, and cannot be uniformly corrected.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to individually correct specific optical scanning characteristics of an optical scanning optical device mounted on each image forming apparatus.

[0005]

An image forming apparatus according to the present invention "deflects a beam from a light source side, focuses it as a light spot on a surface to be scanned, and optically scans the surface to be scanned at a substantially constant speed. One or more optical scanning optical devices are used to scan at least one latent image carrier provided with a photosensitive surface in conformity with each scanned surface to form one or more latent images corresponding to recorded images. Forming apparatus "having the following features. That is, the image forming apparatus has "control means for controlling the optical scanning optical device". One or more optical scanning optical devices mounted on the image forming apparatus are provided with a scanning speed characteristic, a light spot diameter characteristic,
One or more of the light amount characteristics are measured as the light scanning characteristics. Further, a memory means for storing data relating to the measured optical scanning characteristics is incorporated. The "control means" has a function of correcting optical scanning based on data stored in the memory means. In the image forming apparatus according to the first aspect, "the memory means can be incorporated in the optical scanning optical device". Claim 1 or 2
In the image forming apparatus described above, “a semiconductor memory can be used as a memory unit”.

As the optical scanning optical device, a conventionally known appropriate device can be used. In addition, as a method for measuring the optical scanning characteristics, a known appropriate method can be used. For example, as a light scanning optical device, a beam radiated from a semiconductor laser as a light source, which is well known in the art, is converted into a beam form (for example, a parallel beam, weak divergence, (A convergent beam), and this beam is converged in the sub-scanning direction by a line image forming optical system such as a cylinder lens to form a long line image in the main scanning direction. An optical deflector such as a rotary polygon mirror having a deflecting / reflecting surface in the vicinity is deflected at an equal angular velocity, and the deflected beam is condensed as a light spot on the surface to be scanned by a scanning imaging lens such as an fθ lens. Optical scanning device "can be used.
4. The image forming apparatus according to claim 1, wherein a "photoconductive photoconductor" is used as the latent image carrier.
The electrostatic latent image formed by the optical scanning can be visualized as a toner image. Such an image forming apparatus can be implemented, for example, as a monochrome or color digital copier, a laser printer, a laser plotter, or the like. The visualized toner image is fixed and recorded on a “sheet-shaped recording medium” such as recording paper or a plastic sheet for an overhead projector. For example, a latent image formed on the photoconductor is developed to obtain a toner image on the photoconductor, and the toner image is transferred directly from the photoconductor to a sheet-shaped recording medium or an intermediate image such as an “intermediate transfer belt”. The toner image transferred via the transfer medium and the transferred toner image can be fixed on the recording medium. Alternatively, a “silver salt film” may be used as the latent image carrier, and the latent image formed by optical scanning may be visualized by “developing with a silver salt photographic process”. Such an image forming apparatus can be implemented, for example, as an optical plate making apparatus.

An image forming method according to the present invention provides an optical scanning optical device that deflects a beam from a light source side, condenses it as a light spot on a surface to be scanned, and optically scans the surface to be scanned at a substantially constant speed. An image forming method for forming one or more latent images corresponding to a recorded image by scanning one or more latent image carriers provided with photosensitive surfaces in conformity with the surfaces to be scanned as described above. It has the following features (claim 6). That is, one or more of the scanning speed characteristics, the light spot diameter characteristics, and the light amount characteristics of one or more optical scanning optical devices are measured in advance as the optical scanning characteristics,
Data on the measured light scanning characteristics is stored in the memory means. Then, the control means for controlling the optical scanning optical device corrects the optical scanning based on the data.
That is, "correction is performed so that the written image is an appropriate image" regardless of the optical scanning characteristics measured in advance. As the light scanning characteristics, at least “scanning speed characteristics” of the above scanning speed characteristics, light spot diameter characteristics, and light amount characteristics.
When measuring in advance, the control means adjusts the pixel clock according to the pixel position according to the scanning speed characteristic, and reduces or eliminates the influence of the fluctuation of the scanning speed on the effect on the written image. (Claim 7). When at least the “light spot diameter characteristic” is measured in advance as the light scanning characteristic, the control unit adjusts “the amount of light emitted from the light source and / or the pixel pulse width according to the pixel position” according to the light spot diameter characteristic. In addition, it is possible to reduce or eliminate "the effect on the written image" of the fluctuation of the light spot diameter (claim 8). In the case where at least “light amount characteristics” are measured in advance as the light scanning characteristics, the control unit adjusts “the light emission amount of the light source according to the pixel position” according to the light amount characteristics, and “writes” the fluctuation of the light amount characteristics. Influence on the image to be reproduced "can be reduced or eliminated (claim 9). Of course, all of the scanning speed characteristics, the light spot diameter characteristics, and the light amount characteristics are measured in advance as the light scanning characteristics, and the control unit adjusts the pixel clock according to the pixel position according to the light scanning characteristics.
By adjusting the amount of emitted light or adjusting the amount of emitted light and the pixel pulse width, it is possible to correct the influence of each of the optical scanning characteristics and write an image. Also, for example,
When the error diffusion method or the dither method is used, the pixel position can be adjusted.

The "method of manufacturing an image forming apparatus" according to the present invention is directed to "light for deflecting a beam from a light source side and condensing it as a light spot on a surface to be scanned, thereby optically scanning the surface to be scanned substantially uniformly. Using one or more scanning optical devices, scanning one or more latent image carriers provided with a photosensitive surface in conformity with each surface to be scanned,
A method for manufacturing an image forming apparatus of a type that forms one or more latent images corresponding to recorded images ”. A manufacturing method according to a tenth aspect includes the following measurement step, storage step, and mounting step. The “measurement step” includes one of scanning speed characteristics, light spot diameter characteristics, and light amount characteristics of one or more optical scanning optical devices.
The above is the step of measuring the optical scanning characteristics in advance. The “storage step” is a step of storing data relating to the measured optical scanning characteristics in the memory means.

The "mounting step" is a step of mounting at least one optical scanning optical device whose optical scanning characteristics have been measured and a memory means on an image forming apparatus main body having control means for controlling the optical scanning optical device. It is. In the image forming apparatus manufactured as described above, the light scanning characteristics of one or more mounted optical scanning optical devices are measured, and data relating to the measurement result is stored in the memory means. In addition, it is possible to execute image writing in which the optical scanning characteristics are corrected. The manufacturing method according to claim 11 includes the following measurement step, first storage step, mounting step, memory means mounting step, and second storage step. The “measurement process” includes scanning speed characteristics, light spot diameter characteristics,
This is a step of preliminarily measuring one or more of the light amount characteristics as an optical scanning characteristic. The “first storage step” is a step of storing data relating to the measured optical scanning characteristics in the server.
The “mounting step” is a step of mounting one or more optical scanning optical devices whose optical scanning characteristics have been measured on an image forming apparatus main body having control means for controlling the optical scanning optical device.
The “memory means mounting step” is a step of mounting a memory means for storing data on the measured optical scanning characteristics in the optical scanning optical device or the image forming apparatus main body. The “second storage step” is a step of storing data stored in the server in a memory unit mounted on the image forming apparatus main body. In the image forming apparatus manufactured as described above, the light scanning characteristics of one or more mounted optical scanning optical devices are measured, and data relating to the measurement result is stored in the memory means. In addition, it is possible to execute image writing in which the optical scanning characteristics are corrected. In the case of the manufacturing method according to the eleventh aspect, the storage of the data relating to the optical scanning characteristics in the memory means is performed in the second storage step which is the last step of the manufacturing. Therefore, the second storage step can be performed even at the site where the image forming apparatus is delivered. The data to be stored in the memory means is `` data on measured optical scanning characteristics '' for each optical scanning optical device to be mounted on the image forming apparatus,
The “measurement result itself” may be stored as this data, and the control unit may calculate the correction amount based on the measurement result, and perform the correction based on the calculation result. Computed correction data (eg, pixel clock cycle at each pixel position) "
May be stored in the memory means, and the control means may control the optical scanning optical device to perform the optical scanning while performing the correction based on the “correction data stored in the memory means”.

[0010]

FIG. 1 shows an embodiment of an image forming apparatus according to the present invention. This image forming apparatus is a laser printer. The laser printer 100 has a “photoconductive photosensitive member formed in a cylindrical shape” as the image carrier 110. Around the image carrier 110, a charging roller 120 as a charging unit, a developing device 130, a transfer roller 140,
A cleaning device 150 is provided. "Corona charger" can be used as the charging means. In addition, an optical scanning optical device 170 that performs optical scanning by the laser beam LB is provided, and “exposure by optical writing (image writing)” is performed between the charging roller 120 and the developing device 130. . In FIG.
Reference numeral 60 denotes a fixing device, reference numeral 180 denotes a cassette, reference numeral 190 denotes a pair of registration rollers, reference numeral 200 denotes a sheet feed roller, reference numeral 210.
Reference numeral 220 denotes a paper discharge roller pair, reference numeral 230 denotes a tray, and reference numeral P denotes transfer paper as a sheet-like recording medium. When forming an image, the image carrier 110, which is a photoconductive photoconductor, is rotated clockwise at a constant speed, the surface thereof is uniformly charged by the charging roller 120, and the light of the laser beam LB of the optical scanning optical device 170 is emitted. Upon receiving the writing exposure, an electrostatic latent image is formed. The formed electrostatic latent image is a so-called “negative latent image”, and the image portion is exposed. This electrostatic latent image is reversely developed by the developing device 130 to form a toner image on the image carrier 110. The cassette 180 accommodating the transfer paper P is detachable from the main body of the image forming apparatus 100, and the uppermost sheet of the stored transfer paper P is supplied by the paper feed roller 200 in a state where it is mounted as shown in the drawing. The leading end of the paper sheet P that has been fed and fed is held by the registration roller pair 190. The registration roller pair 190 sends the transfer paper P to the transfer unit at the same timing as the toner image on the image carrier 110 moves to the transfer position. The transferred transfer paper P is superimposed on the toner image at the transfer section, and the toner image is electrostatically transferred by the action of the transfer roller 140. The transfer paper P on which the toner image has been transferred is sent to the fixing device 160, and the fixing device 1
At 60, the toner image is fixed, and is discharged onto a tray 230 by a pair of paper discharge rollers 220 through a conveyance path 210. The surface of the image carrier 110 after the transfer of the toner image is cleaned by the cleaning device 150 to remove residual toner, paper dust, and the like.

The optical scanning optical device 170 measures the optical scanning characteristics in advance, and reads “data relating to the measured optical scanning characteristics”.
Are stored in the semiconductor memory 103 which is a memory means. The control device 101 as “control means” for controlling the optical scanning optical device 170 controls the optical scanning optical device 170 based on the data stored in the semiconductor memory 103 and changes the period of the pixel clock according to the writing pixel position. By changing or adjusting the light amount of the light source and the pixel pulse width, the effect of the light scanning characteristics on the written image is reduced, or the light scanning is corrected so as not to cause the effect.

The embodiment shown in FIG. 2 is an example in which the image forming apparatus is implemented as an "optical plate making apparatus". The silver salt film 111 as a latent image carrier is pulled out from the “rolled state” and travels while being wound up by the winding roller 115.
At 70, drawing by image writing with a laser beam is performed to form a latent image. This latent image is output to the post-processing device 113.
In the process, the toner is developed, fixed and dried in accordance with the silver halide photographic process, and is taken up by the take-up roller 115. As in the embodiment of FIG. 1, the optical scanning optical device 170 measures the optical scanning characteristics in advance and stores “data relating to the measured optical scanning characteristics” in the semiconductor memory 103. Based on the data stored in the memory 103, the optical scanning optical device 170 is controlled, and the optical scanning is corrected so that the image to be written is not affected by the optical scanning characteristics or is reduced. FIG. 3 shows an example of a specific optical configuration of the optical scanning optical device described with reference to FIGS. The light beam from the semiconductor laser 10 which is the “light source” is coupled to the subsequent optical system by the coupling lens 12 and becomes a parallel light beam or a light beam having a weak divergence or a light converging when passing through the aperture of the aperture 14. The beam periphery is shielded from light and "beam shaped". Next, the beam-shaped light beam is reflected by the mirror 18 while being focused in the sub-scanning direction by the cylinder lens 16 to form a line image long in the main scanning direction. The rotating polygon mirror 20 as an "optical deflector" has a deflecting / reflecting surface near the image forming position of a line image, and deflects a reflected light beam at a constant angular velocity by constant-speed rotation. The deflected light beam passes through the scanning image forming lens 30, and the surface to be scanned 40 (substantially, the photosensitive member 110 or the silver halide film 1
The light is condensed as a beam spot on the photosensitive surface 11), and the scanned surface 40 is optically scanned at a constant speed to write an image.

Here, an example of measurement of optical scanning characteristics in the optical scanning optical device will be described. In FIG. 4, reference numeral 4 indicates "an optical scanning optical device whose optical scanning characteristics are to be measured". Although the optical scanning optical device 4 is actually configured as described with reference to FIG. 3, in FIG. 4, for simplicity of illustration, a semiconductor laser 10 as a light source, a rotary polygon mirror 20, a scanning imaging lens 30 was shown. The optical scanning device 4 is held on the stage 410. The stage 410 is displaced by the drive unit 416 in a “movable stage that can be displaced in the X direction (generally parallel to the optical axis of the scanning imaging lens 30)” in FIG. A position sensor 412 for detecting a position in the X direction is attached. The position display device 413 that receives the output of the position sensor 412 displays the position of the optical scanning optical device 4 in the X direction according to the input signal. Assuming that the scanning direction of the laser beam 5 of the optical scanning optical device 4 held by the stage 410 is the Y direction, a stage 411 that can be displaced in parallel to the Y direction is provided, and is displaced in the Y direction by driving by the driving device 417. It has become.

On the stage 411, an optical grating 46 and a light receiving element 47 are provided while maintaining a predetermined positional relationship. When the optical grating 46 moves in the Y direction, the optical grating 4
The grating surface 6 moves on one plane, and this plane is "a surface equivalent to the surface to be scanned by the laser beam of the optical scanning optical device 4". That is, the optical scanning optical device 4 is designed so that the plane on which the grating surface of the optical grating 46 moves is a surface equivalent to the surface to be scanned, and that the scanning region of the laser beam is “within the displacement region of the optical grating”. The position in the X and Y directions is adjusted so as to fall within the range. The position of the optical scanning optical device 4 thus adjusted is referred to as a “holding reference”. A position sensor 414 is attached to the stage 411 so that the position of the optical grating 46 in the Y direction with respect to the holding reference of the optical scanning optical device 4 can be managed. The position is displayed. Optical grating 46
Is set such that the grid portion is a non-transmissive portion and the non-grid portion is a light transmitting portion, and the “array of the grid portion and the non-grid portion” is parallel to the Y direction. Therefore, the longitudinal direction of the lattice portion is Y
This is a direction perpendicular to the direction (a direction perpendicular to the drawing). In the optical grating 46, both the width of the grating portion and the width of the non-grating portion are W, and W is d / 1.3 ≧ W ≧ for a designed light spot diameter: d in the optical scanning optical device 4. d /
It is set to satisfy 2.7.

The light receiving element 47 has a single light receiving surface, is provided on the opposite side of the stage 410 via the optical grating 46,
The laser beam transmitted through the optical grating 46 is received. The optical grating 6 and the light receiving element 7 will be described more specifically. In the case of examining a beam characteristic with a light spot diameter: d of 70 μm, the width of the optical element is about W = 40 μm, and the number of arrayed grating portions is 40. ５０50, and the “array length of the grating portion in the Y direction” in the optical grating 6 is about 3 to 4 mm. The dimension of the light receiving surface of the light receiving element 7 in the Y direction is 10 mm.
It is about. The photoelectric conversion signal from the light receiving element 47 is amplified by the amplifier 48 and input to the waveform observation unit 49.
Since the laser light received by the light receiving element 47 is periodically intensity-modulated by the optical grating 46, the amplifier 48
The signal input to the waveform observing means 49 from the above becomes a “wave-like one that periodically fluctuates with time”. Waveform observation means 49
Samples the "wave-like input signal" and converts it into data. The waveform observing means 49 has a monitor display section so that the waveform of the input signal can be monitored. If the input signal is displayed on the monitor display section, the waveform observing means 4 shown in FIG.
The waveform as drawn in 9 can be observed. “Measurement data (data obtained by sampling the above waveform)” converted into data by the waveform observation means 49 is input to the controller 419. The controller 419 is configured by an arithmetic processing unit (CPU), various control circuits, and the like, performs “data processing”, and controls the driving device 416 and the driving device 417. A part of the controller 419 constitutes "data processing means" together with the recording device 18, and the controller 419 also controls the data processing means. The controller 419 also controls the optical scanning optical device 4 held by the holding unit.

As shown in FIG. 5A, the laser beam 5
The light transmitting portion 21 and the non-transmitting portion 22 are aligned with the measurement surface (the surface equivalent to the scanned surface).
Are arranged alternately in the scanning direction (the vertical direction in the figure, the Y direction in FIG. 4).
Light-receiving element 47 which receives light transmitted through and converts it into an electric signal
And an amplifier 48 for amplifying the output thereof, and a waveform observing means 49 for measuring a received light amplification signal which is an output of the amplifier 48. When the optical grating 46 is scanned by the laser beam 5, the laser beam 5 is transmitted to the light transmitting portion 2 of the optical grating 46.
The intensity of the laser light that has been intensity-modulated by passing alternately through the non-transmissive portion 1 and that has passed through the optical grating 46 changes sinusoidally as shown by a waveform 25 in FIG. The maximum value per cycle: Pmax is at the center 23 of the light transmitting portion 21 of the optical grating 46, and the minimum value: Pmin is
6 appear corresponding to the center 24 of the light-shielding portion 22. One cycle of the sinusoidal waveform corresponds to a cycle length: H from the light transmitting portion 21 to the non-transmitting portion 22 of the optical grating 6,
The interval between the maximum value: Pmax and the minimum value: Pmin corresponds to (H / 2). The width of the light transmitting portion 21 shown in FIG.
Assuming that 1 and the width of the non-transmissive portion 22: W2, W1 = W2 = W, the maximum value of the "sinusoidal light amount change" of the laser beam 5 transmitted through the optical grating 6 is Pmax, and the minimum value is Pmin. The light spot diameter d of the laser beam 5 is given by d = (2.2 × Pmin / Pmax + 1) × W, and the value of the light spot diameter d is theoretically in the range of 1.3 W ≦ d ≦ 2.7 W. This results in a 1% error. It will be easily understood that the maximum value: Pmax gives the light quantity characteristic of the light spot. When the grating direction of the optical grating 46 (the direction orthogonal to the drawing in FIG. 4) is 90 degrees with respect to the scanning direction of the laser beam 5, the sinusoidal change in the amount of light received by the light receiving element 47 for each period. The maximum value: Pmax and the minimum value: Pmin include information on two optical scanning characteristics of the scanned laser beam 5, namely, “light spot diameter in the scanning direction” and “light amount”. The light quantity of the laser beam transmitted through the optical grating 6 changes in a sinusoidal manner, and the light transmissive part 21 and the non-transmissive part 22 are continuous, so that the sinusoidal change is continuously observed. Since the sizes of the optical grating 46 and the light receiving element 47 are limited, the optical grating 46 and the light receiving element 47 are separated by a predetermined distance from the optical scanning optical device 4 in the scanning direction (Y direction) of the laser beam 5. By displacing and sequentially measuring sinusoidal waveforms at a plurality of measurement positions with the waveform observation device 9 and combining the measured data in the order of the measurement positions, the light spot diameter with respect to the entire scanning width and the light spot characteristic with respect to the light amount Can be captured.

The "measurement data" digitized by the waveform observation means 49 is stored in the recording device 418 via the controller 419. As described above, the light receiving element 4
The maximum value Pmax of the change in the amount of received light in each cycle: Pmax is located at the center 23 of the light transmitting portion 21 of the optical grating 46 and the minimum value is Pmin.
Appear corresponding to the center 24 of the non-transmitting portion 22 of the optical grating 46, respectively. One cycle of the sinusoidal waveform is
Corresponds to the grating period length H from the light transmitting portion 21 to the adjacent light transmitting portion 21, and the interval between the maximum value: Pmax and the minimum value: Pmin corresponds to (H / 2). A time period of the signal corresponding to the intensity of the laser light intensity-modulated by the optical grating 46, for example, a maximum value at an arbitrary period: n: Pmax (n)
From the next cycle: the maximum value of n + 1: Pmax (n + 1): T (n), the grating cycle length of the optical grating 6: H
Is constant, the scanning speed H / T (n) at which the laser beam 5 of the optical scanning optical device 4 scans the recording surface can be known. A combination of these scanning speeds in sequence is nothing more than a "scanning speed characteristic".

In this manner, the scanning speed characteristics, the light spot diameter characteristics, and the light amount characteristics can be known as the light scanning characteristics of the light scanning optical device 4. The data of these measurement results is recorded in the recording device 418. Based on this data, the data necessary for optical scanning correction, the period of each pixel of the pixel clock, the pixel pulse at each pixel position and / or
Alternatively, the light emission amount of the light source is calculated by the controller 419,
The recording device 418 records the data as “correction data”.

Returning to FIG. 4, the rotating polygon mirror in the optical scanning optical device 4 detects the reference of rotation by an appropriate mechanism (not shown). That is, it is possible to detect a state when a specific deflection reflecting surface deflects the laser beam. The laser beam deflected by the deflection reflecting surface is
Prior to optical scanning of the surface to be scanned, the light enters the mirror 43 and is reflected and detected by the optical sensor 45, so that the timing of starting image writing by optical scanning is set. Then, the counter 447 counts the number of outputs of the optical sensor 45 since the state in which the specific deflecting / reflecting surface is performing light deflection as described above, and inputs the result to the controller 419. The laser beam 5 can be specified as "which deflection surface is deflected." Therefore, by using the measuring device of FIG. 4, the light scanning characteristics (scanning speed characteristics, light spot diameter characteristics, light amount characteristics) of the rotating polygon mirror 20 for each deflecting reflection surface can be known.
Therefore, it is possible to obtain correction data for each deflection reflection surface. FIG. 8 shows an example of the “scanning speed characteristic” actually measured by the characteristic measuring apparatus described above, and FIG. 9 shows an example of the “light amount characteristic”.
FIG. 10 shows an example of the “light spot diameter characteristic”. It should be noted that correction of image writing by optical scanning may be actually performed using the average value of the characteristic change indicated by the thick line in FIGS.

FIG. 6 is a conceptual diagram showing an embodiment of the manufacturing method according to claim 10. FIG. 6A is a diagram for explaining the measurement step and the storage step. In this embodiment, the optical scanning optical device 4 includes a control circuit 4A for controlling the operation of itself, and a semiconductor memory 4B as a memory means.
And In FIG. 6A, the characteristic measuring device 6
Reference numeral 0 denotes an apparatus for measuring optical scanning characteristics described in FIGS. At the time of the characteristic measurement, the characteristic measuring device 60 controls the control circuit 4A to perform optical scanning, and measures the optical scanning characteristic as described above. This step is a “measurement step”. The measurement result is recorded in the characteristic measuring device 60. That is,
In the above-described example, the data is recorded on the recording device 418. Then, data relating to the measured optical scanning characteristics (the measurement data itself or correction data based on the measurement data) is written from the characteristic measurement device 60 to the semiconductor memory 4B as actual measurement information. This step is a storage step.
6B, the image forming apparatus 70 is the laser printer described with reference to FIG. 1 or the optical plate making apparatus described with reference to FIG. The image forming apparatus 70 has an image forming apparatus controller 70A (control device 101 shown in FIGS. 1 and 2) as “control means for controlling the optical scanning optical device 4”. The optical scanning optical device 4A (having the semiconductor memory 4B) having the measured value is mounted (mounting step), and at the time of image formation, the image forming apparatus controller 70A reads out the contents (actually measured information) of the semiconductor memory 4B, and The optical scanning is executed while controlling the control circuit 4A with the correction data according to the information, and the image writing with the optical scanning characteristics corrected is realized.

FIG. 7 is a conceptual diagram showing an embodiment of the manufacturing method according to the present invention. FIG. 7A is a diagram for explaining the measurement step and the first storage step. In this embodiment, the optical scanning optical device 4 has a control circuit 4A for controlling its own operation. In FIG. 7A,
The characteristic measuring device 60 is a device for measuring optical scanning characteristics described with reference to FIGS. At the time of characteristic measurement, the characteristic measuring device 60 controls the control circuit 4A to perform optical scanning,
The optical scanning characteristics are measured as described above. This step is a measurement step. The measurement result is recorded in the characteristic measuring device. That is, in the above-described example, the data is recorded on the recording device 418.
Then, data on the measured optical scanning characteristics (measured data itself or correction data based on the measured data)
Is written from the characteristic measuring device 60 to the server 80 as actual measurement information. This step is a “first storage step”. FIG. 7B is a view for explaining a mounting step, a memory means mounting step, and a second storage step. As a control unit for controlling the optical scanning optical device 4, an image forming apparatus controller 70
The optical scanning optical device 4 whose optical scanning characteristics have been measured is mounted on the main body of the image forming apparatus 70 having A (mounting step).
The semiconductor memory 4B, which is a memory means for storing the data on the measured optical scanning characteristics, is mounted on the image forming apparatus main body (memory means mounting step). The word,
The data (actual measurement information) stored in the server 80 is written and stored in the semiconductor memory mounted on the image forming apparatus main body (second storage step). In this embodiment,
The second storage step is performed “via a communication line”. FIG.
(C) illustrates image writing during image formation. At the time of image formation, the image forming apparatus controller 70A reads out the contents (actually measured information) of the semiconductor memory 4B, executes optical scanning while controlling the control circuit 4A with correction data according to the information, and corrects the optical scanning characteristics. Implement writing.

The image forming apparatus according to the embodiment described above with reference to FIGS. 1 to 3 deflects a beam from the light source 10 and focuses it as a light spot on the surface 40 to be scanned. Using at least one optical scanning optical device 170 that optically scans at substantially the same speed, optically scans the latent image carriers 110 and 111 provided with the photosensitive surface in conformity with the surface to be scanned to correspond to a recorded image. An image forming apparatus that forms a latent image, comprising: a control unit 101 that controls an optical scanning optical device 170;
The optical scanning optical device 170 incorporates a memory unit 103 in which at least one of the scanning speed characteristic, the light spot diameter characteristic, and the light amount characteristic is measured as an optical scanning characteristic, and stores data on the measured optical scanning characteristic. 101 has a function of correcting optical scanning based on the data (claim 1). The image forming apparatus according to the embodiment shown in FIG.
The latent image carrier 110 is a “photoconductive photoconductor”, and an electrostatic latent image formed by optical scanning is visualized as a toner image. In the image forming apparatus according to the embodiment shown in FIG. 2, the latent image carrier 111 is a "silver film", and a latent image formed by optical scanning is developed by a silver salt photographic process (claim 5). .

In the image forming apparatus according to the embodiment described with reference to FIGS. 1 to 3, the beam from the light source is deflected and focused as a light spot on the surface to be scanned. Optical scanning device 1 for optically scanning light at substantially constant speed
70 is an image forming method for forming a latent image corresponding to a recorded image by optically scanning the latent image carriers 110 and 111 provided with photosensitive surfaces in conformity with the surface to be scanned. A control unit 101 for measuring the scanning speed characteristic, the light spot diameter characteristic, and the light amount characteristic of the device 170 in advance as an optical scanning characteristic, storing data on the measured optical scanning characteristic in the memory unit 103, and controlling the optical scanning optical device 170. Thus, an image forming method for correcting optical scanning based on the data (claims 6 to 9) is performed.

The manufacturing method conceptually shown in FIG. 6 is that the beam from the light source side is deflected and condensed as a light spot on the surface to be scanned, and the surface to be scanned is made substantially uniform in speed. An optical scanning optical device that optically scans a latent image carrier provided with a photosensitive surface in conformity with a surface to be scanned and optically scans the latent image carrier to form a latent image corresponding to a recorded image. Manufacturing method ", wherein at least one of a scanning speed characteristic, a light spot diameter characteristic, and a light amount characteristic of the optical scanning optical device 4 is measured as an optical scanning characteristic in advance (FIG. 6A);
The data relating to the measured optical scanning characteristics is stored in the memory 4B.
(A) of FIG. 6 and an image forming apparatus 7 having a control unit 70A for controlling the optical scanning optical device 4
The mounting step of mounting the optical scanning optical device 4 and the memory means 4B whose optical scanning characteristics have been measured on the main body 0 (FIG. 6).
(B)) (claim 10). The manufacturing method conceptually showing the embodiment in FIG. 7 is described as “a beam that deflects a beam from the light source side, condenses it as a light spot on the surface to be scanned, and optically scans the surface to be scanned at a substantially constant speed. Using a scanning optical device,
Optical scanning of a latent image carrier provided with a photosensitive surface in conformity with each surface to be scanned to form an image forming apparatus of a type that forms a latent image corresponding to a recorded image. A measurement step (FIG. 7A) of preliminarily measuring one or more of the scanning speed characteristic, the light spot diameter characteristic, and the light amount characteristic of the optical device 4 as an optical scanning characteristic, and the server 80 stores data relating to the measured optical scanning characteristic. A first storing step (FIG. 7A) for storing data in the optical scanning optical device 4;
A mounting step (FIG. 7B) for mounting one or more optical scanning optical devices 4 whose optical scanning characteristics have been measured on the main body of the image forming apparatus 70 having A, and data on the measured optical scanning characteristics. The memory means mounting step of mounting the memory means 4B for storing the image forming apparatus 70 on the main body of the image forming apparatus 70 (FIG. 7B). A second storage step (FIG. 7B) for storing the stored data (claim 11).

In the above-described embodiment of the image forming apparatus, one using one optical scanning optical apparatus has been described. For example, as a color image forming apparatus, a photoconductive photosensitive member and its charging means, An image forming apparatus in which a light scanning optical device as a developing unit and an exposure unit as one unit (a toner color in the developing unit is different for each unit) is combined in a tandem manner with a plurality of units to form an image formed by each unit. In this case, it is possible to consider a method in which the transfer is performed by superimposing and transferring on a common sheet-shaped recording medium.In such a case, the optical scanning characteristics of the optical scanning optical device for each unit are measured in advance, and the result is measured. The data is stored in a memory unit (which may be configured separately or may be configured in common for each unit), and the optical scanning by each optical scanning optical device is corrected based on the stored data. You can do so.

[0026]

As described above, according to the present invention, an image forming apparatus, an image forming method, and a method of manufacturing an image forming apparatus can be realized. According to the manufacturing method of the present invention,
It is possible to manufacture an image forming apparatus having data of optical scanning characteristics unique to each optical scanning optical apparatus mounted on the image forming apparatus in the memory means. By performing the image forming method of the present invention using the image forming apparatus of the present invention manufactured as described above, the specific optical scanning characteristics specific to the mounted optical scanning optical device are corrected. Good optical scanning can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an embodiment of an image forming apparatus of the present invention.

FIG. 2 is a diagram for explaining another example of the embodiment of the image forming apparatus of the present invention.

FIG. 3 is a diagram illustrating an example of an optical scanning optical device used in the embodiment.

FIG. 4 is a diagram for explaining an example of an optical arrangement of a measuring device for measuring an optical scanning characteristic of the optical scanning optical device.

FIG. 5 is a diagram for explaining measurement of optical scanning characteristics by the measurement device.

FIG. 6 is a view conceptually showing an embodiment of a manufacturing method according to claim 10;

FIG. 7 is a view conceptually showing an embodiment of a manufacturing method according to claim 11;

FIG. 8 is a diagram showing an example of a scanning speed characteristic actually measured by the measuring device.

FIG. 9 is a diagram showing an example of a light amount characteristic actually measured by the measuring device.

FIG. 10 is a diagram showing an example of a light spot diameter characteristic actually measured by the measuring device.

[Explanation of symbols]

 110 optical scanning optical device 101 control device (control means) 103 semiconductor memory (memory means)

Claims (11)

[Claims] 1. A method according to claim 1, further comprising the step of: deflecting a beam from a light source, converging the beam as a light spot on the surface to be scanned, and using one or more optical scanning optical devices for optically scanning the surface to be scanned at substantially constant speed. An image forming apparatus of a type that optically scans at least one latent image carrier provided with a photosensitive surface in conformity with a scanning surface to form one or more latent images corresponding to a recorded image, A control unit for controlling the apparatus, wherein the at least one optical scanning optical device is one in which at least one of a scanning speed characteristic, a light spot diameter characteristic, and a light amount characteristic is measured as an optical scanning characteristic; An image forming apparatus incorporating a memory unit storing data on measured optical scanning characteristics, wherein the control unit has a function of correcting optical scanning based on the data. 2. An image forming apparatus according to claim 1, wherein said memory means is incorporated in said optical scanning optical device. 3. An image forming apparatus according to claim 1, wherein said memory means is a semiconductor memory. 4. The image forming apparatus according to claim 1, wherein the latent image carrier is a photoconductive photoconductor, and an electrostatic latent image formed by optical scanning is visualized as a toner image. An image forming apparatus comprising: 5. The image forming apparatus according to claim 1, wherein the latent image carrier is a silver halide film, and a latent image formed by optical scanning is developed by a silver halide photographic process. Image forming apparatus. 6. An optical scanning device for deflecting a beam from a light source side, condensing it as a light spot on a surface to be scanned, and optically scanning the surface to be scanned at a substantially constant speed. An image forming method for optically scanning at least one latent image carrier having a photosensitive surface aligned with a scanning surface to form at least one latent image corresponding to a recorded image, comprising: One or more of scanning speed characteristics, light spot diameter characteristics, and light amount characteristics of the optical device are measured in advance as light scanning characteristics, and data relating to the measured light scanning characteristics are stored in a memory means, and the light scanning optical device is controlled. An image forming method, wherein the optical scanning is corrected based on the data by the control means. 7. The image forming method according to claim 6, wherein at least a scanning speed characteristic is measured in advance as an optical scanning characteristic, and a control means adjusts a pixel clock according to a pixel position according to the scanning speed characteristic. An image forming method. 8. The image forming method according to claim 6, wherein at least a light spot diameter characteristic is measured in advance as the light scanning characteristic, and the control means controls the light source according to the pixel position according to the light spot diameter characteristic. An image forming method comprising adjusting a light emission amount and / or a pixel pulse width. 9. The image forming method according to claim 6, wherein at least a light amount characteristic is measured in advance as the light scanning characteristic, and the control means adjusts the light emission amount of the light source according to the pixel position according to the light amount characteristic. An image forming method. 10. A method according to claim 1, wherein a beam from the light source is deflected and condensed as a light spot on the surface to be scanned. A method for manufacturing an image forming apparatus of a method of optically scanning at least one latent image carrier having a photosensitive surface aligned with a scanning surface to form at least one latent image corresponding to a recorded image, A measuring step of preliminarily measuring at least one of a scanning speed characteristic, a light spot diameter characteristic, and a light amount characteristic of one or more optical scanning optical devices as an optical scanning characteristic; and storing data on the measured optical scanning characteristic in a memory means. A mounting step of mounting at least one optical scanning optical device whose optical scanning characteristics have been measured and the memory means on an image forming apparatus main body having a storing step of storing and a control unit for controlling the optical scanning optical device. Having a process The symptoms, method of manufacturing an image forming apparatus. 11. A method for deflecting a beam from a light source, condensing the beam as a light spot on a surface to be scanned, and using at least one optical scanning optical device for optically scanning the surface to be scanned at a substantially constant speed. A method for manufacturing an image forming apparatus of a method of optically scanning at least one latent image carrier having a photosensitive surface aligned with a scanning surface to form at least one latent image corresponding to a recorded image, A measuring step of preliminarily measuring at least one of a scanning speed characteristic, a light spot diameter characteristic, and a light amount characteristic of at least one optical scanning optical device as an optical scanning characteristic; and storing a data relating to the measured optical scanning characteristic in a server. (1) a storage step; and (c) a mounting step of mounting one or more optical scanning optical devices whose optical scanning characteristics have been measured to an image forming apparatus main body having a control unit for controlling the optical scanning optical device; Data on the optical scanning characteristics Memory means for storing data, a memory means mounting step of mounting the light scanning optical device or the image forming apparatus main body, and a memory means mounted on the image forming apparatus main body,
And a second storage step of storing the data stored in the server.