JP4353407B2 - Image forming apparatus maintenance system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust and maintain an image position shift of a recording medium. <P>SOLUTION: In the case when the trouble of the image position shift is detected on the recording medium with the image formed by an image forming device 101 owned by the user, the image-formed recording medium 102 is handed to a service provider. The service provider measures an image position with the use of an exclusive image position measuring instrument 103, calculates a shift amount to a regulation position, generates data necessary for adjustment and maintenance of the image formation device, and transmits the data to the image forming device 101. <P>COPYRIGHT: (C)2005,JPO&amp;NCIPI

Description

  The present invention relates to an image forming apparatus (image setter, DI machine, etc.) for a recording medium used in the printing industry, such as a printed circuit board, a mask film for making a printing plate, a CTP plate, etc., and a laser printer used in an office. In particular, the present invention relates to a maintenance system that corrects misalignment that occurs with respect to a specified position where a plurality of light sources mounted on a writing head of an image forming apparatus form an image on a recording medium.

Examples of this type of prior art include the following.
(1) The first to nth lights are sequentially turned on for each column of the laser spots of the light source member of the writing means, and the passage time of the beam detector is detected, and the passage time and the external from the reference signal generator From the time difference from the time of the reference signal, it can be seen how much each laser spot is displaced in the main scanning direction, so this is performed for each row, the light source member is rotated around the optical axis, and the position deviation of the light source is There is a method of correcting so as to be minimized (see, for example, Patent Document 1).

However, in this method, since the positional deviation of the light source is adjusted without actually drawing on the medium, it is necessary to adjust the sensor mounting position to be the same as the writing position on the medium. When applied to a device that forms a density image, it is necessary to constantly maintain the measurement system of the device that the user has, and it costs a lot to maintain the device, and the device is equipped with a measurement system. Cost increases.
(2) A plurality of light beams from a light source that emits a plurality of light beams are deflected by a light deflector common to the plurality of light beams, and each of the deflected light beams is scanned and imaged optically. In a multi-beam scanning device that collects light toward the surface to be scanned by the system, forms a plurality of light spots separated from each other in the sub-scanning direction on the surface to be scanned, and simultaneously scans a plurality of scanning lines on the surface to be scanned. A method of adjusting the position and / or direction of a light beam, wherein refractive optical systems P1 and P2 having no imaging function are arranged in the optical path of at least one light beam, and the space of the refractive optical systems P1 and P2 There is a method of adjusting the position and / or direction of the light beam transmitted through the refractive optical systems P1 and P2 by changing the general state (see, for example, Patent Document 2). This method also has the same problem as the above (1).
(3) An image forming apparatus having a writing system for writing an image and a reference density pattern on a photoconductor with a plurality of laser beams, and a density detecting means for detecting the pattern density of the reference density pattern after development. Image forming including a processing step of correcting beam misalignment of the plurality of laser beams during warm-up after the power of the image forming apparatus is turned on, and a processing step of correcting misalignment of the plurality of laser beams again after density correction There is an apparatus (for example, refer to Patent Document 3). This device also has the same problem as the above (1).
(4) A laser device that outputs image data as laser scanning light, and a paper feeding unit in which the main scanning direction of the laser device is a paper width direction, and at least two paper feeding units for feeding the paper. A test pattern having a sheet feeding device, a sheet feeding unit mark indicating which sheet feeding unit is feeding, and a position detection mark written at a predetermined position in the width direction of the sheet size is used as image data. Means for storing, means for printing a test pattern on a sheet fed from a corresponding sheet feeding section, a sheet feeding section mark in a test pattern image printed on the sheet, and a position detection mark; Is detected on the document table, and the test pattern position detection mark and the position detection mark in the printed image in the paper feed unit represented by the paper feed unit mark There is a digital image forming apparatus provided with means for calculating the amount of deviation in the paper width direction and means for correcting the output timing of the laser scanning light in the main scanning direction based on the calculated amount of deviation (for example, Patent Literature 1). 4). However, since this apparatus has one light source, it cannot be applied to an apparatus having a plurality of writing elements that is assumed in the present invention.
(5) An apparatus that forms one image with corrected misalignment by sequentially driving from a light source with a large misalignment with respect to a predetermined position and performing image formation by changing the writing timing of the plurality of light sources. Yes (see, for example, Patent Document 5). However, this device is not clear how to determine the quantitative value of the deviation amount, and there is no efficient automated correction process. , It is not possible to deal with a case where a deviation occurs when the user uses the product after purchase.
(6) Quantifies the problems (sensory defects, etc.) that the user felt when using the device (printer) and sends them to the device management side, while the device management side sends them from the user side By returning to the user the action information based on the quantified information that has been provided (information on the user's own instructions for maintenance, etc.), the user can easily deal with various problems of the device, There is also a network system in which the maintenance service side can efficiently manage devices (see, for example, Patent Document 6). However, in this system, it is necessary for the user to take quantitative data, and the user must prepare a dedicated device. It should be noted that this service for improving the performance of the apparatus is not targeted, and is for providing information for the user himself to perform maintenance, and thus differs from the system form proposed by the present invention.
(7) The present invention relates to correction of misalignment of an image formed on a medium by a plurality of light sources. In particular, there is a method of correcting misalignment in the main scanning direction by performing conversion of image data or transfer control of image data (for example, patents). Reference 7). This method also has the same problem as the above (5).
(8) The present invention relates to correction of misalignment of images formed on a medium by a plurality of light sources, and in particular, there is a method of correcting misalignment in the sub-scanning direction by performing conversion of image data or transfer control of image data (for example, (See Patent Document 8). This method also has the same problem as the above (5).
(9) When a failure occurs in an image forming apparatus such as a facsimile, a printer, a copying machine, or a printing machine, the management apparatus transmits the data to the center system in response to a system that automatically notifies the management apparatus. There is an image forming apparatus management system that automatically searches equipment databases and technical databases to extract service areas in charge, automatically transmits necessary information, and performs remote management at low cost and high reliability (for example, Patent Document 9). See). However, in order to automatically report an apparatus failure, it is necessary to mount a large number of detection means and measurement means in the apparatus, which greatly increases the apparatus cost. In addition, it is necessary to constantly monitor the status of user-owned devices, and it is also necessary to consider the response to the occurrence of network failures, which is very important for the construction, management, and maintenance of highly reliable and ready network systems. Labor and cost are required.

JP 2002-307748 A JP 2002-174785 A Japanese Patent No. 3298042 Japanese Patent No. 3078421 Japanese Patent No. 3067942 JP 2001-344087 A JP 2002-264373 A JP 2002-264291 A JP 2001-77965 A

  As a method of adjusting a plurality of writing elements mounted on the writing means of the image forming apparatus described above, a method of performing the position detection means of the beam emitted from the writing elements and the position correction means in the image forming apparatus. And a method of measuring the amount of deviation based on the result of drawing on the recording medium and performing correction by changing the drive timing of each writing element during image formation.

  In the former method, it is necessary to mount a special measurement mechanism in the image forming apparatus, and when a plurality of writing positions are adjusted at a high resolution of 1200 dpi or higher, the measurement mechanism also requires high accuracy. Inevitable rise in Furthermore, it is necessary to perform calibration periodically, and there is a problem that a burden is continuously imposed on the user. In particular, in order to detect a plurality of beam positions at a time in a head whose beam interval is several tens or several hundreds of dots away, a lot of detection means are required, and the cost increase is more remarkable. In addition, in the case of a resolution of 2400 dpi or higher, there is a concern that the manufacturing efficiency is lowered because a lot of accuracy is required for adjusting the detection means.

  On the other hand, in the latter method, it is necessary to measure the shift amount of the image position on the recording medium with a microscope or the like, which requires a lot of time and labor. In addition, there is a problem that the user has to prepare the measuring means and the process independently, which requires a lot of time and cost for system construction.

  Also, as a form of prior art related to the maintenance service method, it consists of a user-owned target device and a user information management server on the service provider side, and a communication means for connecting the user and the service provider. Service provision to the user is as follows: (a) when an inquiry or request from the user occurs, (b) when the service provider detects a failure of the user-owned device, (c) In most cases, software upgrade related to device operation such as addition of a new function occurs.

Among these, (a) is a repair request that is entered as a complaint when the writing device is misaligned in the user. In this case, the service person collects the entire device and brings it to the service provider side. Work such as disassembling and installing a dedicated measuring device. Accordingly, the user is forced to use an alternative device during that time, and costs are incurred due to transport operations, and the image forming apparatus cannot be used for a while.
Although (b) saves a little time and effort for management and communication of the apparatus failure on the user side, if the image forming apparatus has conditions such as high resolution, wide width, multiple writing elements, etc., the image forming apparatus owned by all users Since each of them has a failure detection means, a state measurement means, and an analysis result transmission means, a great increase in cost is inevitable.
With regard to (c), it is only necessary to determine the provision time for the convenience of the service provider, the fact that no special detection means is required in the image forming apparatus main body, and transmission of information to the computer used by the user. Although there is no significant cost increase for (a) and (b), a specific function is insufficient for the purpose of maintaining the writing means of the image forming apparatus. Don't be.

The present invention has been made in view of the above problems,
In the present invention, as a result of repeated examination of the writing unit maintenance system of the image forming apparatus, it is possible to reliably write the image forming apparatus without incurring the cost required for the fault self-diagnosis function or the deviation amount measuring unit. A system capable of maintaining the means was proposed.

  Accordingly, an object of the present invention is to provide an image forming apparatus owned by a user, an image shift measuring apparatus on a recording medium owned by a service provider, a communication means such as a network connecting both apparatuses, and a recording medium created by the image forming apparatus. In addition, if necessary, the management server of each device becomes a component, and when the user discovers a problem of image misregistration on the recording medium, the created recording medium is handed over to the service provider, The service provider collects data using a dedicated displacement amount measuring device, and changes the light source position, beam direction, image data form, data transfer control system timing determination parameters, etc. of the image forming device based on the obtained data Data to be transmitted to the image forming apparatus or the image forming apparatus management server, and finally the light source of the image forming apparatus To provide a maintenance system for an apparatus for forming a high-quality image with no image positional deviation on a recording medium having a function of changing a position, a beam direction, an image data form, a timing determination parameter of a data transfer control system, etc. is there.

The present invention includes an image forming apparatus in which a plurality of write elements independent of the drum that rotates has a write means mounted, a recording medium which is drawing by the image forming apparatus, which is formed on the recording medium In a system including an image position measuring device for measuring an image position, a service provider obtains a recording medium drawn by a user-owned image forming apparatus, and the service provider uses the image position measuring device to record the recording medium. Means for measuring each image position by a plurality of writing elements formed on a medium, and an image forming apparatus or image forming used for drawing on the recording medium from a single or a plurality of image forming apparatuses held by a user A unit for transmitting measurement data to a server connected to the apparatus, and a plurality of writing elements mounted on a writing unit possessed by the image forming apparatus owned by the user are formed on a recording medium. That the image position shift, and means for correcting on the basis of the measurement data received from the service provider, said means for correcting, prior to drawing on the recording medium, a plurality of the on the basis of the measurement data By rearranging the image data corresponding to the writing element, the writing element corrects the positional deviation of the image formed on the recording medium, and the positional deviation in the main scanning direction which is the rotation direction of the drum. The write element is formed on the recording medium by changing the phase of the transfer clock of the image data corresponding to the plurality of write elements based on the correction data transmitted from the service provider to the image forming apparatus. Correction data transmitted to the image forming apparatus from the service provider for the positional deviation in the sub-scanning direction orthogonal to the main scanning direction. Based, by moving the position less than the dot intervals of the write means or said write element, the write element is the most important feature to correct the positional deviation of the image formed on the recording medium.

(1) The cost can be reduced and the misalignment correction between the plurality of write elements can be performed.
(2) A single image position measuring device can manage a plurality of users.
(3) Information that can accurately perform the position correction of the writing means, the image rearrangement for correcting the image position, or the generation of parameters for determining the transfer timing of the image data for the image position correction. Can be used, and the deviation correction of the writing means can be performed using the information.
(4) Information that can be easily measured by performing position correction of the writing means, image rearrangement that corrects the image position, or generation of parameters that determine the transfer timing of image data for image position correction Can be used, and the deviation correction of the writing means can be performed using the information.
(5) It is possible to transmit correction data to a remote user via the network and correct the image forming position of the writing means.
(6) Even when a network failure occurs at the remote user side, correction data is sent from the service provider side base where the image position measurement device is installed to the service person in charge of the user, and the service person visits the user directly. The image forming position of the writing means possessed by the image forming apparatus owned by the remote user can be corrected.
(7) The image forming position on the medium can be corrected by the writing means without any correction or change on the system side.
(8) The image forming position on the recording medium can be corrected by the writing unit of the image forming apparatus without extending the data processing time during image formation.
(9) It is not necessary to mount the high resolution moving means of the writing element in the writing means, and it becomes possible to suppress the extension of the data processing time.
(10) It is possible to provide a recording medium that facilitates maintenance management of the image forming apparatus and an image forming apparatus maintenance system using the recording medium.
(11) It is possible to provide an image position measuring apparatus on a recording medium that facilitates maintenance management of the image forming apparatus, and an image forming apparatus maintenance system using the image position measuring apparatus.
(12) It is possible to provide an image position measuring method capable of measuring a printing plate on which optical image information is difficult to recognize optically, and an image forming apparatus maintenance system using the image position measuring method.
(13) Image data that makes it easy to detect the amount of deviation of the image position formed on each medium by each writing element, a recording medium on which the main image data is formed, and a maintenance system for an image forming apparatus using the recording medium Can be provided.
(14) It is possible to provide an image forming apparatus maintenance system that can be used for manufacturing processes and maintenance by a single apparatus, and that can improve apparatus operating efficiency.
(15) It is possible to provide an image forming apparatus capable of forming a high-density image without contact and capable of changing the beam irradiation direction by moving the lens.

  It has been realized that the writing means of the image forming apparatus is reliably maintained without burdening the user with the cost required to mount the failure self-diagnosis function and the deviation amount measuring means in the image forming apparatus.

  The present invention relates to adjustment / maintenance of an image forming apparatus having a writing unit equipped with a plurality of writing elements, and in particular, corrects misalignment of individual image positions formed on a recording medium by a plurality of writing elements, The present invention relates to a system for adjusting and maintaining a device capable of forming a high-quality image without conspicuous joints.

  The proposed system includes an image forming apparatus to be maintained, a recording medium drawn by the image forming apparatus, and an image formed by each writing element on the recording medium by reading image information on the recording medium. It consists of an image position measuring device that measures the amount of positional deviation.

  The writing element can be a non-contact writing device such as a printing plate, a mask film, a single mode or multimode semiconductor laser or LED for manufacturing a circuit board, an LED, or other laser light source, an inkjet head or an electronic device. Laser heads for photographic processes, writing heads for silver halide photography, and the like are desirable, but devices that perform writing by contact such as thermal heads are also targeted. One device may include not only a single element but also a plurality of elements in a one-dimensional array or a two-dimensional array.

  The position of the image formed on the recording medium is a writing element mounting error, a writing means mounting error mounting the writing element, a writing element contact condition, or a writing element beam irradiation direction variation, and image data. Deviation occurs due to various factors including other factors such as deviation in the irradiation beam direction of each writing element caused by expansion and contraction of the member due to variations in the transfer timing, environmental conditions such as temperature and humidity. When such a deviation occurs, the images formed by the plurality of writing elements are separated or overlapped in a strip shape, and the original image data cannot be reproduced. Therefore, in order to prevent such a situation from occurring or to improve such a situation, it is necessary to adjust and maintain the apparatus.

  As described above, the cause of the image misalignment is not only the irradiation beam position variation, but also the timing of the data transfer system and the influence of expansion / contraction due to the environmental conditions of the equipment members. A method of adjusting the beam irradiation position based on the result of measurement alone is insufficient as an adjustment method. On the other hand, according to the method of adjusting the writing system based on the image position actually formed on the recording medium, the misalignment amount including all error factors can be measured, so that the reliability of the adjustment is improved. .

  FIG. 1 shows a first system configuration according to an embodiment of the present invention. In FIG. 1, a service is provided to a user having one image forming apparatus. FIG. 2 shows a second system configuration according to the embodiment of the present invention. In FIG. 2, a service is provided to a user having a plurality of image forming apparatuses. FIG. 3 shows a third system configuration according to the embodiment of the present invention. In FIG. 3, a service is provided to a plurality of users having a single or a plurality of image forming apparatuses. 1, 2, and 3, 101 is an image forming apparatus, 102 is a recording medium, and 103 is an image position measuring apparatus. The data measured by the image position measuring device 103 is transferred only to the device 101 that has formed an image on the recording medium 102.

  Hereinafter, an example of service provision will be described. First, a service provider who performs maintenance of the image forming apparatus 101 (this is not limited to an apparatus manufacturer, and includes various forms such as a company that specializes in maintenance services and a company that performs sales and maintenance). A recording medium 102 drawn by the image forming apparatus is obtained from a user of the forming apparatus 101. You can obtain the service directly from the user, take it to the service provider, send it by mail or courier, and use whatever method is convenient for you and the service provider. Is adopted.

  Next, the image position measurement device 103 owned by the service provider is used to read the image information on the obtained medium 102, measure the image position formed on the recording medium by each writing element, and further, the deviation from the specified position. The amount is calculated, and finally, data necessary for adjustment / maintenance of the image forming apparatus 101 is generated. The generated data is transferred to the image forming apparatus 101 or a controller that controls the image forming apparatus 101. This is performed using a network using an Ethernet cable such as 10BaseT or 100BaseTX in addition to USB, IEEE1394, RS232C, or other serial or parallel interfaces.

  In addition, as a form of sending measurement data via a network, a method of directly transferring data from a service provider to each user as shown in FIG. 4 and a method of transferring measurement data through a service person as shown in FIG. 5 are adopted. Is done. However, in FIGS. 4 and 5, the measurement data is transferred directly from the image position measurement device 103 to the user via the network, but in addition to this, from another server or computer connected to the network from the image position measurement device 103. The transmitted form is also included.

Finally, the image forming apparatus 101 corrects the image writing position based on the transferred measurement data.
In particular,
(1) Before drawing on the recording medium 102, rearrangement of image data (change of arrangement of image data corresponding to each writing element) is performed based on the measurement data. In other words, the image data is moved in the direction opposite to the direction shifted in accordance with the shift amount (the direction in which the shift is canceled), and the position of the image formed on the recording medium is corrected. However, it is necessary to correct the misalignment of less than one dot interval in the sub-scanning direction together with the moving stage control of the writing means. That is, when the rotation direction of the drum is the main scanning direction and the movement direction of the writing element is the sub-scanning direction as in the apparatus shown in FIG. 6, if the writing system is insufficiently adjusted, As shown in FIGS. 7A and 7B, the joints of the images by the writing elements are opened or overlapped to form an image as shown in FIG. 8A, for example. If this deviation is less than the dot interval that requires correction, it is necessary to insert correction data at the boundary and simultaneously insert blank data in an image other than the target writing element so that other writing elements are not driven. There is. When writing image data inserted at this boundary or the like, it is necessary to move the writing means less than the dot interval in order to correct the deviation less than the dot interval. In this way, image data is rearranged and stage control is also performed. The image rearrangement and the stage movement amount at this time are performed based on measurement data generated by the image position measurement apparatus.

  Further, the correction in dot units in the sub-scanning direction is shared by each writing element in accordance with the amount of deviation as shown in (b) and (c) of an image having a deviation as shown in FIG. 9A. The amount of image data is changed. However, FIG. (C) is an example of a half dot unit.

Furthermore, as a method of drawing on the medium using the rearranged image data, there are methods shown in FIGS. FIGS. 10 and 11 are examples in which each writing means has a different amount of deviation, and the method of FIG. 10 starts writing the writing means having different deviation amounts apart and finishes writing at the same time. On the other hand, the method of FIG. 11 shows a method of starting writing at the same time and finishing writing separately. In the example of FIG. 10, the gap with the adjacent writing means is the largest, and the writing means 4 on the head moving direction side starts image formation first, and the gap with the adjacent writing means is the second largest. In addition, the difference in the number of lines in the amount of deviation from the writing means 3 and 5 on the head moving direction side continues until the image forming for one line is completed. Next, the writing means 3 and 5 start image formation for the second rotation of the drum, and thereafter only the writing means 3, 4 and 5 perform image formation until the fourth rotation of the drum, and the writing means from the fifth rotation. 1 and 2 start image formation, and all writing units simultaneously complete image formation. However, this is an example in the case where there is no deviation less than the line width at the writing position of all the writing means. If there is a deviation less than the line width, the correction is performed in the middle or at the end. If the amount of deviation less than the line width is the same in all writing means, the writing time can be shortened because writing can be performed simultaneously with the same scanning density movement at the end. On the other hand, in the example of FIG. 11, all the writing means start writing simultaneously, and image formation is finished in order from the writing means whose writing position interval with the writing means adjacent in the head movement direction is narrower. In this method, all writing means are driven first, and therefore, there is an advantage that it is easy to determine a writing means having a failure. This example is also an example in the case where there is no deviation less than the line width at the writing position of all the writing means. If there is a deviation less than the line width, the correction is performed in the middle or first. When the amount of deviation less than the line width is the same for all writing means, the writing time can be shortened because writing can be performed simultaneously by moving at the same scanning density first.
(2) Change the position of the writing element or the beam irradiation direction. In other words, the writing element is moved slightly in the direction opposite to the image displacement direction, or a lens or a mirror is arranged between the writing element and the recording medium so that the beam irradiation direction is opposite to the displacement direction. In other words, the position of the image formed on the recording medium is corrected. Regarding the movement of the writing element, a mechanism capable of moving each writing element as shown in FIG. 12 is required. FIG. 12A shows an example in which image formation is performed in a state where the writing position of each writing element is shifted. FIG. 12B shows an image obtained by correcting the position of the writing element having a shift. It is an example in the case of forming. In order to change the position, an actuator capable of minute displacement such as a piezo element or a voice coil motor is used for each writing element. On the other hand, FIG. 13 shows an example of a method for correcting the irradiation position of the beam by displacing the lens. If the condensing lens is displaced to the left as in this example, the irradiation position moves to the right side. Conversely, if the condensing lens is displaced to the right, the irradiation position moves to the left side, and can be used for irradiation position correction. However, a lens that can be used in this way needs to have characteristics that the irradiation surface is focused and the beam shape change is minimal even when the lens is displaced. Although not shown, in the case of a writing method in which a beam is reflected on a mirror and irradiated onto a medium, the irradiation position is corrected by changing the direction of the mirror. The lens is moved using a voice coil motor or a piezo element.
(3) Change the timing of the image transfer clock to each writing element. That is, the position shift in the main scanning direction is corrected by changing the phase of the transfer clock of the image data corresponding to the plurality of writing elements. Note that the above-described methods (1) and (2) are used for correcting the deviation in the sub-scanning direction. FIG. 14 and FIG. 15 show the deviation correction in the main scanning direction. FIG. 14A shows an example in which the writing position is corrected in 1/4 dot units, and FIG. 14B shows an example in which the writing position is corrected in 1/16 dot units. As an actual example, as shown in FIG. 15, the phase of the pixel data transfer clock is changed to perform dot-by-dot correction or correction less than the dot interval, or only the dot phase correction is changed to change the clock phase. For the unit correction, a method such as correction of image data is used. The clock phase can be changed by preparing a plurality of clocks having different phases in advance and selecting an optimum clock from them, or changing the regular clock phase by a shift register or the like.

  There are two ways to express the measurement deviation data of the drawing result. As shown in FIG. 16, one is based on the writing position of a certain writing element, and the writing position by another writing element uses the count value from the reference position as measurement data. Measurement data is acquired such as 0 if the position is the same as the position in the main scanning direction, -1 if the position is advanced by 1 dot, and +1 if it is sent. In the sub-scanning direction, the number of dots from the position in the reference sub-scanning direction is counted and used as measurement data. The light source 2 is n + 2 and the light source 3 is 2n. Another measurement method uses a relative deviation amount between the writing position of the image formed by the writing element to be measured and the writing position of the image formed by the adjacent writing element as a measurement value. As shown in FIG. 17, there is a method of measuring the amount of deviation between the dot position of the rightmost column of the image formed by the writing element of the light source 1 and the dot position of the column first formed by the light source 2 to obtain measurement data. is there. In FIG. 17, the deviation in the main scanning direction is -1 for the light source 2 and 2 for the light source 3, and the deviation in the sub-scanning direction is +1 because the light source 2 has a one-dot gap, and the light source 3 is overlapped by two dots. Therefore, it becomes -2.

  As an example of an apparatus for measuring image deviation from a recording medium on which an image has been drawn, as shown in FIGS. 18 and 19, a method of conveying a recording medium and reading it with an optical element such as a CCD, or an optical system by fixing the recording medium There is a method to move and read the object. Although not shown, it is also possible to employ a method in which a recording medium is wound around a drum and rotated with high precision, and the reading head is moved in a direction perpendicular to the drum rotation direction at high density. In order to measure the deviation, it is better to have a dedicated scale. For example, the ideal position of the image as shown in FIG. 20 is clear and does not overlap with the image of the adjacent writing element. When the data in which the image is arranged at the position is used or when the ideal position of the image is clear and the same pattern as the image formed by the adjacent writing element is overlapped as shown in FIG. It is desirable to use data whose amount of overlap can be recognized.

  In addition, in order to accurately associate the measured recording medium with the apparatus that has drawn on the recording medium, it is desirable to write in advance information that can identify the image forming apparatus together with the image as shown in FIG. The form of information may be a numerical value or a character as shown in FIG. 22A, or a barcode or a symbol as shown in FIG. In this case, however, the image position measuring device needs to have a function of analyzing information.

  As shown in FIG. 23, the image position measuring device has an advantage that it can be used for measuring the deviation of the writing head in the manufacturing process of the image forming apparatus and can be used for maintenance after shipment, thereby improving the operating efficiency. However, more than that reason, if the image position measuring device used at the time of manufacture differs from the image position measuring device used for maintenance after shipment due to subtle reading errors of the image position measuring device, more ideal correction becomes difficult. Therefore, the image position measuring apparatus for manufacturing and maintenance is preferably the same.

  The target recording media include printing plates (PS plates and various photosensitive and heat sensitive CTP plates), mask films for preparing printing plates, mask films used for circuit board manufacturing, direct drawing type circuit boards, inkjet printer paper, All recording media for image forming apparatuses having multiple writing elements, such as paper for electrophotographic printers, are targeted. As the printing plate, as shown in FIGS. 24 to 26, a material using a fluorine-containing acrylate resin whose wettability to ink changes by heating can be used.

  FIG. 27 shows a system configuration example equipped with the above image forming apparatus. The format of the transfer data may be text or binary, but the contents differ depending on the correction mechanism / function of the image forming apparatus.

  28A and 28B, the two types of media shown in FIG. 28A are used, and the three types of light sources shown in FIG. 28B are used to form images under various conditions shown in FIG. 28C. The deviation data is measured by an image position measuring device using an E reading element and a light source, and then image correction or writing element position adjustment (using the D actuator) or image transfer timing adjustment is performed. As a result of image formation, it was confirmed that image formation with extremely excellent quality was performed.

  Specifically, with a 150 mW output, 830 nm LD, a transparent film for preparing a printing plate having a leuco dye and a developer in the recording layer and a light absorption layer thereon, under various conditions shown in FIG. As a result of image formation at 1200 to 2540 dpi, a high-definition image without deviation could be formed.

  In addition, as a printing medium, image formation is performed on (1) a printing plate in which carbon is added to a sea-island structure of a fluororesin and a urethane resin whose wettability changes by heating, and (2) Presstek PEARL Dry plate. As a result of offset printing, a clear and high gradation image of 175 lines could be obtained.

1 shows a first system configuration according to an embodiment of the present invention. 2 shows a second system configuration according to an embodiment of the present invention. 3 shows a third system configuration according to an embodiment of the present invention. The 1st form which sends measurement data is shown. The 2nd form which sends measurement data is shown. 2 shows a configuration example of an image forming apparatus. An example in which the joints of images by the writing elements are opened or overlapped is shown. The example of an image with which the joint of the image opened or overlapped is shown. A correction method for each dot in the sub-scanning direction will be described. The 1st correction method of an image writing position is shown. The 2nd correction method of an image writing position is shown. An example in which the image position is corrected by moving the writing element will be described. An example of a method for correcting the irradiation position of the beam by displacing the lens will be described. An example of correcting the writing position in dot units is shown. An example in which the positional deviation in the main scanning direction is corrected by changing the phase of the transfer clock of the image data will be described. The 1st method of expressing the measurement shift data of a drawing result is shown. The 2nd method of expressing the measurement shift data of a drawing result is shown. An example of an apparatus for measuring an image shift from a recording medium on which a drawing has been performed will be described. It is a continuation of FIG. The 1st example of a scale for measuring deviation is shown. The 2nd example of a scale for measuring deviation is shown. An example is shown in which information that can identify the image forming apparatus is written in advance together with an image in order to accurately correspond the measured recording medium and the apparatus that has drawn an image on the recording medium. An example will be described in which the image position measuring device is used for writing head misalignment measurement in the manufacturing process of the image forming apparatus and is used for maintenance after shipment. An example of a recording medium is shown. The other example of a recording medium is shown. The other example of a recording medium is shown. 1 shows a system configuration example equipped with an image forming apparatus. Various conditions when performing image formation according to the present invention will be described.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Image forming apparatus 102 Recording medium 103 Image position measuring apparatus

Claims (4)

And an image forming apparatus in which a plurality of write elements separate a drum that rotates has a write means mounted, a recording medium which is drawing by the image forming apparatus, the image position formed on the recording medium measured In a system including an image position measuring apparatus, a service provider obtains a recording medium drawn by a user-owned image forming apparatus, and the service provider is formed on the recording medium using the image position measuring apparatus. Means for measuring each image position by a plurality of writing elements, and connected to the image forming apparatus or the image forming apparatus used for drawing on the recording medium from a single or a plurality of image forming apparatuses owned by the user. The image position formed on the recording medium by the means for transmitting the measurement data to the server and the plurality of writing elements mounted on the writing means possessed by the image forming apparatus owned by the user Deviation, and means for correcting on the basis of the measurement data received from the service provider,
The correcting means rearranges image data corresponding to the plurality of writing elements based on the measurement data before drawing on the recording medium, so that the writing elements are placed on the recording medium. While correcting the positional deviation of the image to be formed,
Regarding the positional deviation in the main scanning direction which is the rotation direction of the drum, the phase of the transfer clock of the image data corresponding to the plurality of writing elements is based on correction data transmitted from the service provider to the image forming apparatus. By correcting the positional deviation of the image formed on the recording medium by the writing element,
Regarding the positional deviation in the sub-scanning direction orthogonal to the main scanning direction, the position of the writing means or the writing element is moved by less than the dot interval based on correction data transmitted from the service provider to the image forming apparatus. Thus, a maintenance system for an image forming apparatus , wherein the writing element corrects a positional deviation of an image formed on a recording medium .   An image based on received measurement data and means for transmitting measurement data from one image position measuring device only to a specified image forming device among a single or a plurality of image forming devices respectively held by a plurality of different users. 2. The maintenance system for an image forming apparatus according to claim 1, further comprising means for correcting an image position shift on a recording medium on which the forming apparatus draws an image.   Means for selecting any one writing element for forming an image at the reference position on the recording medium from among a plurality of writing elements mounted on the writing means of the image forming apparatus, and elements other than the reference elements Means for calculating a theoretical value of an image position to be formed on the recording medium in a state in which all the writing elements are free of position errors based on the reference position information, and each of the writing elements formed on the recording medium by all the writing elements. A means for measuring an image position; a means for calculating an error amount between the measured value (hereinafter, actually measured value) and the theoretical value; and measuring an error amount between the actually measured value and the theoretical value. 2. The maintenance system for an image forming apparatus according to claim 1, wherein the maintenance system is data.   Means for selecting any one writing element for forming an image at a reference position on a recording medium from among a plurality of writing elements mounted on writing means of the image forming apparatus; a reference element; and By measuring the interval between the image boundaries formed by the adjacent elements on the recording medium, and then successively repeating the measurement of both image intervals between the adjacent writing elements, all the writing elements and their 2. An image boundary interval measurement value formed on a recording medium by all writing elements and their adjacent elements is used as measurement data, and has means for measuring an image boundary interval with an adjacent element. Maintenance system for image forming apparatus.

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