JP5568971B2 - Image forming apparatus and image forming method - Google Patents

Description

  The present invention relates to an image forming apparatus and an image forming method.

  In the field of commercial printing, there is always a high priority for cost reduction, and by using a single image forming device for sheets of various materials, the number of devices and the installation area of the device are reduced. There is movement. On the other hand, the requirements for the image forming apparatus must be satisfied in terms of maintaining and improving the quality of printed matter and productivity.

  The improvement in the quality of commercial printing described here is not only an improvement in image quality, but also an image quality that does not rupture sensuously, that is, an image quality that does not give a sense of incongruity to the appearance such as gloss of the various sheets, This includes achieving a good balance of durability that does not cause degradation such as image peeling due to a load such as friction and bending on the sheet.

  In response to these requirements, conventionally, with regard to a sheet of paper material widely used as a sheet used for image formation, the sheet properties are classified by focusing on the surface condition such as thickness and presence / absence of a coat, and according to this classification A method of automatically adjusting the image forming apparatus is used, and printing is performed by the image forming apparatus adjusted by this adjustment. However, in this classification method, classification is based on only a small part of the sheet properties such as the thickness and surface state of the sheet of paper material, and a wide variety of sheets provided in commercial printing are uniformly classified. It was not enough. Therefore, in recent years, a method for storing adjustment data list data directly associated with individual sheet brands in an image forming apparatus without performing classification based on sheet properties, and automatically adjusting the image forming apparatus based on the stored data. Has been done.

  For example, in Patent Document 1, for the purpose of adjusting a plurality of image quality adjustment items without depending on human subjectivity, a sample image is formed on a sheet while changing each adjustment item, and a sheet on which a sample image is formed A method and an apparatus configuration are disclosed in which image reading means is read and the result is analyzed to automatically determine the value of each adjustment item that provides the best image quality.

  In the conventional image forming apparatus, the above-described method can be applied to a known sheet brand. However, when a new sheet brand is used, an optimum adjustment value corresponding to this must be obtained. Specifically, it is necessary to obtain an optimum adjustment value for each adjustment item by repeatedly creating an image sample using a sheet of the brand while changing a large number of adjustment items that affect image formation. As described above, the optimum adjustment value described here is not a value that maximizes only the image quality evaluation, but also provides both necessary and sufficient image quality and durability of the formed image for each sheet brand. The value should not adversely affect the image forming productivity as much as possible. This requires the operator to be familiar with the relationship between the factors that reduce image quality, durability, and productivity, and the adjustment values of the image forming apparatus, and it has not been possible to easily find the optimum combination of adjustment values. . Even when finding the optimal combination of adjustment values, the expert will consider various combinations of adjustment values and repeat the work of outputting a sample image with the combined adjustment values each time the adjustment value is changed. Therefore, the time is enormous, and there are problems such as cost increase and timely image setting.

  In Patent Document 1, a sheet on which a sample image is formed is read by an image reading unit, and the result is analyzed to automatically determine the value of each adjustment item that provides the best image quality. The best prints can be obtained by printing, but easy adjustment values to ensure productivity of image formation while satisfying both the necessary and sufficient image quality and durability of the formed image according to the sheet brand. There is much room for improvement because it is not taken into consideration. Further, even if a sample image is output with an optimum adjustment value, it does not necessarily satisfy the image quality required by a person who obtains a printed matter using the apparatus.

  The present invention provides an adjustment for optimizing the productivity of image formation while satisfying both necessary and sufficient image quality and durability of the formed image for a certain brand of sheet used for image formation. It is an object of the present invention to provide an image forming apparatus and an image forming method in which values are easily obtained without requiring an operator to recognize the relationship between poor quality and adjustment values.

The present invention is an image forming apparatus including an image forming unit that forms an image according to image data on a recording material, and a control unit that controls the image forming unit, and the control unit is formed by the image forming unit. The operator selects the variation range of the plurality of adjustment items from the plurality of adjustment items related to the image quality of the image to be printed, and reduces the number of recording materials on which the sample image is formed by reducing the sampling density. Based on the adjustment operation and the first adjustment value range obtained by selecting the sample image formed by the preliminary adjustment operation by the operator, the adjustment item to be adjusted and the sampling density in the preliminary adjustment operation are one step outside. optionally a limiting its range of variation to a value, a sample image formed by the sampling density adjustment value closely operator from among the formed sample image The image forming unit is controlled to perform a readjustment operation in which the sample adjustment values used to generate the selected sample image are aggregated and stored in the storage unit as a second adjustment value range used for actual printing. Yes.

  The image forming apparatus according to the present invention is characterized in that the adjustment value range includes a range in which the adjustment result is good, or includes at least upper and lower adjustment values of the adjustment value range.

  The image forming apparatus according to the present invention is characterized in that the adjustment value range is stored in the storage unit in association with the property or brand of the recording material.

  In the image forming apparatus according to the present invention, the control unit controls the image forming unit so as to form an identifier that can uniquely identify each recording material together with the image sample on the recording material.

  The image forming apparatus according to the present invention includes an image reading unit that reads image information formed on a recording material, and the control unit has an identifier that can uniquely identify each recording material together with the image sample on the recording material. The image forming unit is controlled so as to be formed in a format that can be interpreted by the reading unit, and the sample adjustment values used for generating the sample image read by the image reading unit are aggregated from the sample images formed with the identifier. In addition, it has a function of storing as an adjustment value range used for actual printing.

  The image forming apparatus according to the present invention is characterized in that the identifier includes at least information capable of specifying an adjustment value used for forming the selected sample image.

  In the image forming apparatus according to the present invention, the control unit controls the image forming unit so as to form a sample image using a preset image or any other image as a sample image. It is said.

  In the image forming apparatus according to the present invention, the control unit selects the item to be adjusted among the adjustment items based on at least one of the property or brand of the recording material, the adjustment result previously performed, or the condition specified in advance. It is characterized by changing its fluctuation range.

  In the image forming apparatus according to the present invention, the adjustment item is at least the voltage for transferring the image to the recording material, the pressure, or the temperature at which the image is heated and pressed and fixed on the recording material in the image forming process by the dry electrophotographic method, It is characterized by at least one of pressure and pressurization time.

  The image forming apparatus according to the present invention is characterized by having means for aligning the recording materials image-formed by the image forming unit.

The present invention relates to an image forming method in which an image forming unit is controlled by a control unit to form an image according to image data on a recording material, and the control unit includes a plurality of images relating to the image quality of an image formed by the image forming unit. The operator selects a variation range of a plurality of adjustment items from the adjustment items, and performs a preliminary adjustment operation to reduce the number of recording materials on which a sample image is formed with a sparse sampling density. Based on the first adjustment value range obtained by selecting the formed sample image by the operator, the fluctuation range is limited to a value that is one step outside the adjustment item to be adjusted and the sampling density in the preliminary adjustment operation. , a sample image formed by the sampling density adjustment value closely, arbitrarily chosen by the operator from among the formed sample image samples Aggregate the sample adjustment value used to generate the image, it is characterized by controlling the image forming unit so as to readjust the operation to be stored in the storage unit as the second adjustment value range to be used for actual printing.

  In the present invention, a plurality of adjustment values for obtaining a plurality of sample images for the recording material are stored in the storage unit, and when the sheet is selected, a plurality of different adjustment values are selected for the selected sheet. A plurality of sample images are formed within the range, and the adjustment value used for printing the sample image selected from the sample images is stored in the storage unit as the adjustment value range used for the main printing.

According to the present invention, even when a new recording material that is not set in the apparatus is used, the productivity of image formation is optimized while satisfying both the necessary and sufficient image quality and durability of the formed image. By selecting an arbitrary sample image from the sample images formed on the recording material while automatically changing the values of a plurality of adjustment items for the sample adjustment values used for forming the sample image Since it is stored as the adjustment value range used for the actual printing, the operator can easily obtain the adjustment value range used for the actual printing without having to recognize the quality defect and the relationship between the adjustment values.

1 is a diagram illustrating a schematic configuration of an image forming apparatus according to the present invention. It is an enlarged view which shows the structure of a scanner part. It is an enlarged view which shows the structure of an image formation part. It is an enlarged view which shows the structure of a post-processing part. FIG. 3 is an enlarged view showing a configuration of a fixing unit. FIG. 4 is an enlarged view showing a change in a fixing nip portion that affects image formation. It is a block diagram which shows one structural example of the control system in this invention. It is a flowchart which shows the processing content of the image quality adjustment operation | movement used as the 1st Embodiment of this invention. It is a flowchart which shows the processing content of the image quality adjustment operation | movement used as the 2nd Embodiment of this invention. It is a figure which shows the concept of the control content of an adjustment item, (a) is a conceptual diagram of the sampling density in 1st Embodiment, (b) is a conceptual diagram in case the sampling density in 2nd Embodiment is sparse, (c) ) Is a conceptual diagram when the sampling density is dense in the second embodiment.

  Hereinafter, embodiments according to the present invention will be sequentially described with reference to the drawings. An image forming apparatus 1 shown in FIG. 1 mainly includes a scanner unit 100 serving as an image reading unit, a printer unit 200 serving as an image forming unit, and a discharge unit 300. The scanner unit 100 reads the document 101 as read image data and transmits it to the control unit 400 provided in the printer unit 200. The printer unit 200 receives image data from the control unit 400, forms various images on a sheet as a recording material based on the image data, and discharges the image to the discharge unit 300. The discharge unit 300 aligns the image-formed sheets discharged from the printer unit 200 and holds them in a form that is easy for the user of the apparatus to handle. It becomes a means to align.

  As shown in FIG. 2, the scanner unit 100 includes a document tray 102, a document feeding roller 103, a document transport path 104, a document reading unit 105, and a document discharge tray 106. A document 101 is stacked on the document tray 102, and the document 101 is separated and fed one by one by a document feeding roller 103. The document tray 102 can be raised and lowered according to the remaining amount of the document 101, and is configured so that the height of the document 101 can be optimally adjusted with respect to the document feeding roller 103. The originals 101 separated one by one by the original feeding roller 103 are conveyed from the original conveyance path 104 indicated by the dotted line in FIG. 2 to the original reading unit 105, and after the image is read by the original reading unit 105, The document is discharged and stacked on the document discharge tray 106.

  As shown in FIG. 3, the printer unit 200 includes a paper feeding unit 210, a plurality of image forming units 220a, 220b, 220c, and 220d, an intermediate transfer belt 230 that serves as an intermediate transfer member, and a fixing unit 260. . The sheet feeding unit 210 has a plurality of sheets 211 stacked on a tray (not shown), separated and fed into one sheet by a sheet feeding roller 212, and conveyed along a conveyance path 213 indicated by a dotted line. This tray has a function of adjusting the height of the sheet 211 with respect to the sheet feeding roller 212, similarly to the document tray 102 described above.

  The image forming units 220a to 220d form toner images on drum-shaped photoconductors 220Y, 220M, 220C, and 220K as image carriers by a generally known dry electrophotographic method, and are disposed below the image forming units. The intermediate transfer belt 230 is supported. In this embodiment, the image forming units 220 a to 220 d form toner images of four colors of yellow, magenta, cyan, and black for each unit, and superimpose them on the intermediate transfer belt 230 to form a full color image. Of course, a single color image can be formed by any one image forming unit.

  The intermediate transfer belt 230 is wound around a plurality of rollers. When any of the rollers is driven to rotate, the intermediate transfer belt 230 rotates in the direction of the arrow in the drawing, and the color image formed on the belt is transferred to the transport path 213. To the secondary transfer roller 240 arranged facing the front.

  A secondary transfer backup roller 241 is disposed opposite to the secondary transfer roller 240 with the conveyance path 213 interposed therebetween. The secondary transfer backup roller 241, together with the secondary transfer roller 240, presses the sheet 211 a separated and fed by the sheet feeding roller 212 and the intermediate transfer belt 230. At this time, by applying a high potential difference (secondary transfer bias) between the secondary transfer roller 240 and the secondary transfer backup roller 241 by a high-voltage power source (not shown), the toner image formed on the intermediate transfer belt 230 becomes a sheet. Transferred onto 211a. The toner remaining on the intermediate transfer belt 230 after the transfer is removed by a cleaning unit 250 disposed around the belt.

  The fixing unit 260 is a well-known unit that heats and presses the sheet 211b to which the toner image is transferred, and fixes the toner image to the sheet. The sheet 211c that has passed through the fixing unit 260 and has completed image formation is discharged from the printer unit 200 to the paper discharge unit 300.

  As shown in FIG. 4, the paper discharge unit 300 includes a discharge tray 301 and a jogger 302 that aligns the sheets on the discharge tray 301. In this embodiment, an image-formed sheet 211c is indicated by reference numeral 211d. Align and load.

  Next, details of the fixing unit 260 will be described with reference to FIG. The fixing unit 260 includes a heat roller 261 serving as a heating member and a fixing backup roller 262 serving as a facing member, and these rollers are disposed to face each other so as to sandwich the sheet 211B. Around the heat roller 261 and the fixing backup roller 262, known temperature detecting means 263a, 263b such as a thermopile are arranged. These temperature detection means 263a and 263b detect the surface temperature of each roller and output it to the control means 400 as temperature information. The control unit 400 is configured by a known computer, and based on the temperature information from the temperature detection units 263a and 263b, the adjustment value and the adjustment value range, the heating unit 264a and the like such as a heater disposed inside each roller. The output of H.264b is controlled to control the temperature of each roller at an appropriate temperature.

  In the fixing unit 260, the sheet 211b is passed through a nip 266 formed by the contact between the heat roller 261 and the fixing backup roller 262, and heated and pressurized to dissolve the toner and fix it to the sheet 211b. When the sheet 211b passes through the fixing nip portion 266, a part of the toner on the sheet may be transferred to the heat roller 261. Therefore, a cleaning member that cleans the transferred toner near the outer peripheral surface of the heat roller 261. As shown, a cleaning web 265 is disposed. The toner transferred to the heat roller 261 is removed by the cleaning web 265.

  As shown in FIG. 6, the heat roller 261 and the fixing backup roller 262 are rotatably supported by shafts 265a and 265b, respectively. The heat roller 261 is driven to rotate clockwise in FIG. 6 by a fixing drive motor 267 serving as a driving means, and the fixing backup roller 262 that contacts the heat roller 261 is driven to rotate. The pitch between the axes of the heat roller 261 and the fixing backup roller 262 can be adjusted. FIG. 6 is a diagram for explaining a change in the nip width between the heat roller 261 and the fixing backup roller 262 by adjusting the inter-axis pitch. The fixing backup roller 262 includes a cored bar 262a and an elastic layer 262b formed of a flexible material such as rubber, preferably heat-resistant rubber, on the surface of the cored bar 262a. The fixing backup roller 262 can be moved in a contact / separation direction indicated by arrows a and b with respect to the heat roll 261 by a cam (not shown), and an inter-axis pitch with the heat roll 261 can be changed by rotating the cam. Is held so. This cam is rotationally driven by a cam drive motor 268 serving as a cam drive source shown in FIG.

  As shown in FIG. 6A, the inter-axis pitch P of the heat roll 261 and the fixing backup roller 262 is set to the inter-axis pitch shown in FIG. 6B by driving the cam drive motor 268 and rotating a cam (not shown). When narrowed as P ′, the nip width N between the heat roll 261 and the fixing backup roller 262 shown in FIG. 6A becomes wider like the nip width N ′ in FIG. 6B, and the pressure applied to the sheet 211b. Can be strengthened. When the sheet 211b passes through the fixing unit 260 at a certain speed, the change in the nip width appears as a change in the heating and pressing time for the sheet 211b. When only the heating and pressurizing time is changed without changing the pressure on the sheet 211b, the speed at which the sheet 211b passes through the fixing unit 260 may be changed. The speed at which the sheet 211b passes through the fixing unit 260 can be adjusted by controlling the fixing drive motor 267 and changing the rotation speed of the heat roll 261.

  The control unit 400 is connected to the scanner unit 100, the printer unit 200, and the discharge unit 300 so that they can communicate with each other. In this embodiment, the temperature detection units 263a and 263b, the adjustment operation key 270 serving as the adjustment operation setting unit operated when starting the image adjustment operation, and the image adjustment operation are printed particularly on the input side of the control unit 400. A selection key 271 serving as a selection unit for selecting an arbitrary one from the sample images is connected, and heat generation units 264a and 264b, a fixing drive motor 267, and a cam drive motor 268 are connected on the output side.

  In the image forming apparatus 1 using the dry electrophotographic system, various adjustments such as heating and pressurizing time and heat amount of the fixing unit 260 are widely one of the factors that greatly influence the quality of the formed image. Are known. As an example, by increasing the amount of heat applied to the sheet 211b by the fixing unit 260, the toner can be dissolved more and the surface can be smoothed to give gloss to the image formed on the sheet, and the sheet and the toner can be more closely adhered to each other. Thus, quality defects such as image peeling can be suppressed.

  However, when the amount of heat applied to the sheet 211b becomes excessive, what is normally cooled naturally before reaching the sheet discharge unit 300 is discharged with insufficient cooling, and the discharged sheet 211c is discharged. When stacked in the unit 300, it causes adhesion between sheets. Considering these conditions, the necessary and sufficient amount of heat must be applied.

  The amount of heat applied to the sheet 211b by the fixing unit 260 cannot be directly managed. To change this, the pressure (nip pressure) by both rollers that changes the temperature of at least one of the heat roller 261 and the fixing backup roller 262 can be changed. ) To change the degree of contact between each roller and the sheet 211b, or to change the passing speed of the sheet 211b to change the heating and pressurizing time.

  In addition to these matters, depending on the brand of each sheet 211, it is necessary to consider the situation according to the sheet properties, so that various restrictions are imposed on the above-described heat amount management method. As an example, in a certain brand of sheet 211, when the sheet itself is overheated, gas is generated inside the sheet, and a bubble-like defect occurs in the toner image. In order to avoid this, the temperature of the fixing backup roller 262 is lowered as much as possible to prevent overheating of the sheet, and the temperature of the heat roller 261 is increased in order to compensate for insufficient heating of the toner on the sheet 211, or the above-mentioned It is necessary to take measures such as adjusting to increase the heating and pressurizing time.

  In order to adjust the toner image fixed on the sheet 211 as described above, an adjustment value for changing an adjustment item for adjusting the operation of each component must be determined in consideration of various circumstances as described above. Rather, the conventional method requires skill for those who make adjustments.

  Therefore, in this embodiment, during the image adjustment operation by the image forming apparatus 1 and the work procedure thereof, the sample image for adjustment is automatically changed while the values of a plurality of adjustment items for obtaining the adjustment value range used for the main printing are automatically changed. A plurality of sheets on which the image is formed are collectively output, and an adjustment value range used for actual printing is obtained from the sample adjustment values used for forming the selected sample image from the collectively output sheets, and the values are stored. I did it.

For this reason, the storage unit 401 provided in the control unit 400 stores a plurality of adjustment values from the minimum to the maximum of the components of the image forming apparatus 1 used for the image adjustment operation in advance, and a database is constructed. In this embodiment, the image adjustment operation is performed by the fixing temperature, the sheet passing speed, and the nip pressure in the fixing unit 260. Therefore, the control objects by the control unit 400 are the heat generation units 264a and 264b, the fixing drive motor 267, and the cam drive motor 268. The adjustment value from the minimum to the maximum varies depending on the temperature of each roller that is changed by the control of the heat generating means 264a or the heat generating means 264b, the sheet passing speed that is changed by the control of the fixing drive motor 267, or the control of the cam drive motor 268. The value of the nip width to be used.

  When the adjustment operation key 270 is operated, the control unit 400 has a function of executing an image adjustment operation for storing an optimum adjustment value range in a new brand sheet. The control unit 400 stores the fluctuation range and the sampling density of the adjustment value stored in the storage unit 401, and the fluctuation range and the sampling density can be selected.

  A first embodiment of the image adjustment operation by the control unit 400 will be described using the flowchart shown in FIG. In FIG. 8, when the adjustment operation key 270 for starting the image adjustment operation of the image forming apparatus 1 is operated and turned on by the operator in step S1, the process proceeds to step S2 where adjustment items are set. In this embodiment, since the adjustment operation is performed on the new brand sheet 211, all the adjustment items related to the image quality of the roller temperature, the sheet passing speed, and the nip width are set. The setting of the adjustment item can be realized by connecting a switch for selecting the adjustment item to the operation unit of the image forming apparatus 1 in connection with the control unit 400.

  When the adjustment item is set, in step S3, the fluctuation range and the sampling density are selected by the operator. The fluctuation range is, for example, a temperature range when the roller temperature is taken as an example, and is 100 ° C. to 150 ° C. When the operator does not have knowledge about the adjustment item and its influence, the maximum variation range that each item can take may be set for all the adjustment items. Sampling density means the degree of interval in the adjustment range. For example, the temperature of the roller is adjusted in increments of 5 ° C., for example. If so selected, the control means 400 changes the setting item of the roller temperature in increments of 5 ° C. in the range of 100 ° C. to 150 ° C. Similarly, in the passage speed and the nip pressure, the fluctuation range and the sampling density can be set.

  In step S4, the control unit 400 generates a combination of adjustment values that can be taken as image formation based on the selected adjustment item, the fluctuation range, and the sampling density with reference to a database according to a preset program. . For example, if the combination of the roller temperature a ° C., the passage speed a / sec, and the nip pressure akg / cm is the sample adjustment value 1, the combination of the roller temperature b ° C., the passage speed a / sec, and the nip pressure akg / cm is the sample adjustment value. 2. Such a combination sample adjustment value of possible adjustment values is generated in step S4 and stored in the storage unit 401.

  In step S5, each unit in the printer 200 of the image forming apparatus 1 is actually driven based on one of the generated adjustment value combinations (sample adjustment values), and a sample image for quality evaluation is newly created. Form on a sheet and output. As a result, a sample adjustment value and a sample image sheet corresponding to the adjustment value can be created. For example, when the total number of sample adjustment values generated in step S <b> 4 is 50, the control unit 400 controls the printer unit 20 to form 50 types of sample images on sheets and discharge them to the discharge unit 300.

  In step S6, it is determined whether or not all sample images have been output. Here, when 50 types of sample images are formed, the number of image formations corresponding to the number of generated samples is counted by a known counter or the like, and the sample images are output until the counter reaches the total number of samples. You can do it. When the counter value reaches the total number of samples, the process proceeds to step S7. That is, the output of the sample image in step S5 is repeatedly executed until it is performed for all the sample adjustment values generated in step S4.

  Here, the operator confirms the quality of each of the output sample images by visual inspection or touch, and the sample images that are considered to be appropriate as the image quality, i.e., the sensory necessary and sufficient image quality and the formed images. The sample key 271 is selected by operating the selection key 271 so that the productivity of the image formation is optimized while satisfying both of the above durability. By this selection operation, in step S7, the pass / fail determination result for the output sample image is input. In this embodiment, it is assumed that the selected sample image has a good evaluation, and when 10 sample images are selected, the apparatus is unilaterally good with respect to a sheet having 10 patterns of sample adjustment values. It is not a judgment, but a sample adjustment value for obtaining an appropriate image reflecting the operator's intention.

  In step S8, the sample adjustment values used for the well-evaluated sample images are tabulated and stored in the storage unit 401 as an appropriate adjustment value range corresponding to a new brand sheet.

  In this embodiment, it is not necessary for the operator to have knowledge about the adjustment item and its influence, and by inputting the pass / fail result of the output sample image, it is possible to print the sample image determined to be good according to the determination result. The used sample adjustment value is set in the image forming apparatus 1 as an adjustment value range used in the actual printing. For this reason, without considering a combination of conventional adjustment values, setting an adjustment value range in which image formation productivity is optimized while satisfying both the necessary and sufficient image quality and durability of the formed image. As a result, the adjustment time can be shortened, resulting in cost reduction and timely image setting.

  In this embodiment, since there are a plurality of sample images determined to be good, the sample adjustment values corresponding to the sample images are totaled to obtain the upper and lower limits. However, when there is one sample image for good determination, In this case, the sample adjustment values used for the sample image, that is, the combined adjustment values are stored as an adjustment value range for obtaining an optimum image as it is. In addition, the sample adjustment value is aggregated by a mathematical or statistical method to obtain a range of adjustment values for which the sheet is good.

  For summing up the sample adjustment values corresponding to the sample images determined to be good, if the adjustment item is an adjustment related to the amount of heat given to the sheet by the fixing unit 260 described above, the required nip width can be obtained if the temperature of the fixing unit 260 is low. A large correlation is obtained. By giving an allowable range to the adjustment value, the influence on the productivity of the image forming apparatus 1 can be minimized. In general, the image forming apparatus 1 controls the state of each unit in the printer 200 by the control unit 400 based on the adjustment value at the start of image formation. In addition, the state control of each unit in the bulletin 200 is periodically repeated in order to eliminate the state change due to the time change during printing. Therefore, by giving an allowable range to the adjustment value, the state control may be completed if it is within the allowable range even if the result of the state control of each unit is not optimal. Alternatively, since the state control itself can be omitted if the state of each unit is within the allowable range, the printing stop time can be shortened and the productivity can be improved. That is, according to the configuration of the present embodiment, it is possible to easily obtain the optimum range as the allowable range of the adjustment value.

  Even in the conventional image forming apparatus that associates the brand of the sheet with the adjustment value, the adjustment value corresponding to the brand of the new sheet can be easily obtained by applying the control of this embodiment. The adjustment value range for a new sheet once obtained is stored in the storage unit 401 in association with the brand of the sheet, so that it can be handled as a known brand during subsequent image formation, that is, actual printing. Since the sample image output step and the evaluation step are not required, and the main printing can be performed without performing the image adjustment operation, the printing can be performed quickly and the productivity can be improved.

  Next, a second embodiment of the image adjustment operation of the image forming apparatus 1 by the control unit 400 will be described with reference to FIG.

  In the adjustment item and sampling density determination method based on steps S2 and S3 in FIG. 8, when the operator does not have knowledge of the adjustment item and performs the image adjustment operation on a new brand sheet, the adjustment value of step S4 is changed. The total number of combinations (total number of sample adjustments) cannot be reduced.

  Therefore, the control unit 400 according to the present embodiment is a new one in which a sample image is formed by sparse the adjustment item variation range and sampling density from a plurality of adjustment items related to the image quality of the image formed by the printer unit 200. An adjustment item to be adjusted or its adjustment based on a first adjustment value range obtained by selecting a sample image formed by the preliminary adjustment operation and then selecting a sample image formed by the preliminary adjustment operation. A sample image is formed by limiting the range and making the sampling density of the adjustment values dense, and the sample adjustment values used to generate the sample image arbitrarily selected from the formed sample images are aggregated and actually printed The printer 200 has a function of controlling the printer 200 to perform a readjustment operation stored in the storage unit 401 as the second adjustment value range used in the above.

  In other words, the sampling density of each adjustment item is sparse and the total number of adjustment value combinations is reduced to perform the preliminary adjustment operation first, and then the necessary adjustment items and the fluctuation range of the adjustment value are restored based on the result of the preliminary adjustment operation. The second adjustment operation is performed by setting the sampling density as the original (dense).

  A second embodiment of the image adjustment operation by the control means 400 will be described using the flowchart shown in FIG. In FIG. 9, the description of steps having the same contents as in FIG. 8 is simplified. In FIG. 9, steps S11 to S18 are the contents of the preliminary adjustment operation, and steps S19 to S23 are the contents of the readjustment operation.

  When the adjustment operation key 270 for starting the image adjustment operation of the image forming apparatus 1 is operated and turned on by the operator in step S11, the process proceeds to step S12, and adjustment items are set. The content of step S12 is the same as step S2 of FIG. When the adjustment item is set, the fluctuation range and the sampling density are selected in step S13. The fluctuation range here is basically the same as step S3 in FIG. 8, but the difference from step S3 is that the sampling density is sparse. For example, taking the above roller temperature as an example, the temperature increment is made larger than in step S3. Therefore, the adjustment value to be combined is reduced.

  In step S14, the control unit 400 generates a combination of adjustment values that can be taken as image formation based on the set adjustment items, the fluctuation range, and the density sparse with reference to a database according to a preset program. However, since the sampling density is sparser, that is, rougher than that in step S4 in FIG. 8, the total number of sample adjustment values that are combinations of possible adjustment values is reduced. The generated sample adjustment value is stored in the storage unit 401.

In step S15, based on one of the generated sample adjustment values, each unit in the printer unit 200 is actually driven, and a quality evaluation sample image is formed on a new sheet and output. Thus, the sample adjustment value plurality of adjustment values are combined, although the sample images corresponding to the sample adjustment value can be formed into sheets, suppressed the total number of sample images than in step S5 in FIG. 8 It is done. On the other hand, since the total number of adjustment value combinations (total number of samples) decreases, there is a possibility that the output sample image does not include the sample image formed with the optimum adjustment value. Therefore, the operator needs to select a sheet on which at least one sample image is formed even when the sheet quality is not sufficient.

  In step S16, it is determined whether or not all the sample images have been output, and the output of the sample images is repeatedly executed until the output of the sample images is completed for all of the sample adjustment values generated in step S14.

  Here, the operator confirms the quality of each of the output sample images by visual inspection or touch, and operates the selection key 271 to select a sample image that is regarded as appropriate as the image quality. By this selection operation, in step S17, the pass / fail determination result for the output sample image is input. Also in this embodiment, the selected sample image is evaluated as good. In step S18, the sample adjustment values used for the well-evaluated sample images are tabulated and stored in the storage unit 401 as an adjustment value range.

  Next, in step S19, the sampling density in the adjustment value range stored in step S18 is made dense, and a sample adjustment value that is a combination of fine adjustment values that can be obtained as image formation is referred to the database according to a preset program. And generate. However, since the sampling density is sparse in step S13, the range to be obtained is larger than the range obtained here. Therefore, the variation range used in step S19 generates a sample adjustment value combining the adjustment values as a range from the range obtained here to a value one step outside at the sampling density used in step S13.

  In step S20, a sheet on which a sample image using the sample adjustment values densely generated in the adjustment value range is formed is output, and all the sample images with the dense sample adjustment values are printed in step S21. It is executed until.

  When the sample images for the total number of samples are formed, in step S22, the operator confirms the quality of each of the output sample images by visual inspection or touch, and the sample images that are regarded as appropriate as the image quality. That is, the sample key 271 is selected by operating the selection key 271 so that the image formation productivity is optimized while satisfying both the necessary and sufficient image quality and durability of the formed image. By this selection operation, in step S22, the quality determination result for the output sample image is input. For this reason, the adjustment value that can obtain an appropriate image reflecting the operator's intention is not selected for the new sheet, but the apparatus determines that it is unilaterally good.

  In step S23, the sample adjustment values used for the well-assessed dense sample images are tabulated and stored in the storage unit 401 as an appropriate adjustment value range corresponding to a new brand sheet.

  For this reason, it is not necessary for the operator to have knowledge about the adjustment item and its influence, and it can be used for printing the sample image that is determined to be good according to the determination result by inputting the pass / fail result of the output sample image. The adjustment value thus set is set in the image forming apparatus 1 as the adjustment value range used in the actual printing. As a result, an adjustment value range that optimizes image formation productivity is set while satisfying both the necessary and sufficient image quality and durability of the formed image without considering a combination of adjustment values as in the past. Therefore, the adjustment time can be shortened, leading to cost reduction and timely image setting.

  A change in the total number of adjustment value combinations (total number of samples) in the second embodiment will be described with reference to FIG. FIG. 10 shows the distribution of combinations of adjustment values when adjusting two adjustment items a and b among the adjustment items of the image forming apparatus 1. The adjustment items a and b can be adjusted in 13 stages, respectively, and the dots in the figure represent one of the adjustment value combinations.

  FIG. 10A shows a distribution according to the first embodiment. In the first embodiment, a sheet on which sample images are formed is output for a combination of all adjustment values a and b that can be adjusted in 13 steps, that is, for a total number of 169 samples. Then, the total result of the sample adjustment values input by the operator judging that the sample images are good from the output sample images, that is, the adjustment value range is a range indicated by R1.

  FIG. 10B shows the distribution of adjustment value combinations (samples) when performing a preliminary adjustment operation with a sparse adjustment value sampling density in the second embodiment. Here, since the sampling density of the adjustment items a and b is set in five stages, the total number of samples to be a combination of the adjustment values is 25, and a sheet on which each of the 25 sample images is formed is output. Then, if the sample adjustment values of the sample image that the operator has determined to be good are d1 to d4, a range of d5 to d8 is obtained as a result of the preliminary adjustment operation in step S18 of FIG. The range from d5 to d8 is the first adjustment value range R2.

  FIG. 10C shows a combination of adjustment values (sample adjustment values) when performing the second image adjustment, that is, the readjustment operation with the adjustment value sampling density being dense in the preliminary adjustment operation in the second embodiment. ) Distribution. Here, since the sampling density is the same as that in FIG. 10A, sample adjustment values of a combination of 88 adjustment values are created, and sheets on which sample images using these sample adjustment values are formed are output. Here, with respect to the adjustment values (indicated by filled dots) that are outside d1 to d4 shown in FIG. 10B and have already been used in FIG. 10C, the first adjustment value is set in the preliminary adjustment operation. Since it is clear that it is not included in the range R2, there is no need to output again. The total number of adjustment value combinations (total number of samples) used in the second embodiment is 113, which is the sum of the preliminary adjustment operation shown in FIG. 10B and the readjustment operation shown in FIG. The second adjustment value range R3 is reduced from the total number of samples 169 in the embodiment.

  For this reason, it is possible to set an adjustment value range in which image formation productivity is optimal while considering both the necessary and sufficient image quality and durability of the formed image without considering the combination of adjustment values. The adjustment time can be shortened compared to the first embodiment, leading to cost reduction and timely image setting.

  In each of the above embodiments, since several tens of sheets are handled at a time, as shown in FIG. 4, a discharge unit 300 serving as a means for aligning and stacking sheets, or as shown in FIG. It is desirable for the operation that the image forming apparatus 1 includes the scanner unit 100 that continuously reads the images on the sheet.

  By the way, in each said form, the input of the evaluation result in step S7, S17, and S22 is not based on the output order of a sample image, and an incorrect adjustment result is obtained because the order is mistaken during the pass / fail judgment of the sample image. It is assumed that

  Therefore, in order to make the quality determination of sample images and the process of inputting the evaluation results in steps S7, S17, and S22 easier, the control means 400 forms each sample image together with the sample images in steps S5, S15, and S20. The printer unit 200 may be controlled so that an identifier that can uniquely identify the sheet to be printed is formed on the sheet together with the sample image.

  When an identifier is used in the determination result input process in steps S7, S17, and S22, it is more desirable to read the identifier on the sheet using the scanner unit 100 of the image forming apparatus 1, and in addition to this, the image forming apparatus 1 It is conceivable to use an accompanying operation panel (not shown). However, in this case, it is assumed that the operator must read the identifier visually and input it with a button or the like (operation). Therefore, it is assumed that an incorrect adjustment result is input due to an incorrect reading or an incorrect button operation. Is done. In this respect, if the scanner unit 100 is used, there is no input error or operation error, and the work process can be reduced. Here, if an input is not required for a sheet with a poor sheet quality determination result, the reading time in the scanner unit 100 can be shortened. Further, when the identifier is formed on the sheet by the printer 200, it is preferable that the image is readable by the scanner unit 100.

  The control means 400 holds the information on the sheet formed and output as a sample image until the input process in steps S7, S17, and S22 is completed. However, a sheet that has not been input is regarded as defective and is deleted (erased) without being stored in the storage unit 401. This is because it is expected that it will be difficult to read the identifier and visually interpret the sample image sheet that has not been judged good due to poor image quality. Further, since it is only necessary to input the sheet of the sample image that has been determined to be good, the work time for input can be reduced and the processing load of the control means 400 can be reduced.

  As described above, the adjustment values used in steps S5, S15, and S20 may be specified by the identifier of each sheet. In the image forming apparatus 1, the adjustment values used in steps S5, S15, and S20 may be stored in association with the identifiers. In steps S5, S15, and S20, the adjustment values are stored on the sheet together with the sample images. It may be recorded. In general, since the storage area of the storage unit 401 incorporated in the control device 400 is limited, the latter is more desirable. As a result, it is not necessary to perform steps S6 and S7 and steps S21 and 22 continuously, and flexible operation is possible. For example, in FIG. 8, the operation is interrupted after steps S1 to S6 are performed. In FIG. 9, the operation is interrupted after steps S11 to S21 are performed, and after the image forming apparatus 1 is used for other operations, the steps are performed again. You may perform the process of S7-step S8 and step S22-step S23. Alternatively, when the image forming apparatus 1 is adjusted for a plurality of sheet brands, Steps S1 to S6 and Steps S11 to S21 are performed for a single brand sheet, and the operator performs the pass / fail judgment of the corresponding sheet. The operation time can be shortened by performing steps S1 to S6 and steps S11 to S21 for sheets of other brands. Steps S7 to S8 and steps S22 to S23 may be performed as soon as the sheet pass / fail determination is completed for each brand of the sheet.

  In the above embodiment, the sample image to be formed on the sheet is formed based on the sample data set in advance in the storage unit 401. In addition to this, a sample image is formed using an arbitrary image. You may make it do.

  That is, in the image forming apparatus 1 to which the present invention is applied, no special knowledge is required for the determination of the sheet quality, so that a person other than the operator may determine the sheet quality. The quality of the sheet may be determined not by the operator but by quality determination means. As an example of the quality determination means, an illuminance measuring device that measures the gloss of the sheet on which the sample image is formed can be used. In this case, the sample image formed in steps S5, S15, and S20 can be any image suitable for the person who determines the sheet quality or the illuminance measurement apparatus (quality determination unit). Particularly in the field of commercial printing, the sheet on which the image is formed is a product, and it is often the customer who determines the quality of the product. Therefore, an image designated by the customer is formed on a sheet as a sample image, and the customer makes a pass / fail judgment, and the image forming apparatus 1 is adjusted based on the result. Productivity can be realized. In this case, an arbitrary image corresponds to image data obtained from a person other than these workers.

  As the number of adjustment items set in step S2 increases, the total number of combinations generated in step S4 increases exponentially. As a result, the work time and consumables required for outputting sample images in steps S5 to S6 are increased. As a result, the amount of sheet and toner increases. The total number of combinations in step S4 also increases in proportion to the variation range set in step S3. Therefore, if possible, it is desirable to exclude unnecessary adjustment items or their fluctuation ranges. On the other hand, there is also a problem that a normal adjustment result cannot be obtained when an operator mistakenly excludes necessary adjustment items or when the adjustment item variation range and sampling density are inappropriately set.

  Therefore, in the setting of steps S2 and S3 in FIG. 8 and steps S12 and S13 in FIG. 9, based on the previous adjustment results of the same brand, the adjustment results of sheets having similar properties, and other previously known conditions. The adjustment items and the sampling density can be determined. As an example, when an adjustment range that causes an image defect is known in advance in a certain brand of sheet, the adjustment range that causes an image defect is excluded from the variation range of steps S3 and S13. As another example, when a sheet of a specific brand is sensitive to a change in a specific adjustment item, the specific adjustment item is essential in steps S2 and S12, and the adjustment is performed in steps S3 and S13. By adjusting only the sampling density of the items, precise adjustment can be performed. If the worker has sufficient knowledge about each adjustment item, the worker may make the setting directly.

  In each embodiment, the image adjustment operation has been described by taking the adjustment of the fixing unit 260 that easily affects the sheet properties as an example, but the control target may be another adjustment item as the image adjustment operation. For example, regarding the image quality, the toner image formed on the sheet before fixing is also an element that influences. Therefore, a secondary transfer bias for transferring the toner image from the intermediate transfer belt 230 to the sheet 211 is set as an adjustment item. A plurality of sample images are output with the variation range of the adjustment item as the secondary transfer bias range and the sampling density as the interval for changing the secondary transfer bias, and the output sample images are selected and the adjustment value ranges R1 to R3 May be defined and registered as an adjustment value range.

  In each of the above embodiments, it is possible to easily perform a step of forming a sample image for an image adjustment operation of the image forming apparatus 1 and a step of inputting an adjustment result to the image forming apparatus, and an adjustment operation. It is possible to minimize the amount of consumables used and the amount of work performed by workers.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 100 Image reading means 200 Image forming part 211 Recording material 300 Aligning means 400 Control means 401 Storage part R1 Adjustment value range R2 1st adjustment value range R3 2nd adjustment value range

JP 2009-145692 A

Claims (11)

In an image forming apparatus comprising: an image forming unit that forms an image according to image data on a recording material; and a control unit that controls the image forming unit.
The control means includes
A recording material on which a sample image is formed by an operator selecting a variation range of a plurality of adjustment items from a plurality of adjustment items related to the image quality of an image formed by the image forming unit and making a sampling density sparse Preliminary adjustment operation to reduce the number of sheets,
Based on the first adjustment value range obtained by selecting the sample image formed by the preliminary adjustment operation by the operator, the adjustment item to be adjusted and the sampling density in the preliminary adjustment operation up to a value outside one step The variation range was limited, and the sampling density of the limited variation range was densely formed to form a sample image, which was used to generate a sample image arbitrarily selected from the formed sample images by an operator . aggregate the sample adjustment value you stored in the storage unit as the second adjustment value range to be used for actual printing, the image forming apparatus and controls the image forming unit to perform a re-adjustment operation.   The image forming apparatus according to claim 1, wherein the adjustment value range includes a range in which an adjustment result is good, or includes at least upper and lower adjustment values of the adjustment value range.   The image forming apparatus according to claim 1, wherein the adjustment value range is stored in a storage unit in association with a property or brand of the recording material.   4. The control unit according to claim 1, wherein the control unit controls the image forming unit to form an identifier capable of uniquely specifying each recording material together with the image sample on the recording material. The image forming apparatus described in 1. Image reading means for reading image information formed on the recording material;
The control unit controls the image forming unit to form an identifier that can uniquely identify each recording material together with the image sample on the recording material in a format that can be interpreted by the image reading unit,
A function is provided for summing up the sample adjustment values used for generating the sample image read by the image reading means from the sample images in which the identifier is formed, and storing it as an adjustment value range used for actual printing. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   6. The image forming apparatus according to claim 4, wherein the identifier includes at least information capable of specifying an adjustment value used for forming the selected sample image.   The control unit controls the image forming unit so as to form a sample image using a preset image or an arbitrary image as the sample image. The image forming apparatus according to any one of 6.   The control means changes the item to be adjusted or the variation range thereof among the adjustment items based on at least one of the property or brand of the recording material, the adjustment result previously performed, or a predesignated condition. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The adjustment items include at least the voltage and pressure for image transfer to the recording material, or the temperature, pressure, and pressing time for fixing the image to the recording material by heating and pressing in the image forming process by dry electrophotography. The image forming apparatus according to claim 1, wherein the image forming apparatus is at least one.   10. The image forming apparatus according to claim 1, further comprising means for aligning recording materials on which images are formed by the image forming unit. In an image forming method for forming an image according to image data on a recording material by controlling an image forming unit with a control unit,
The control means includes
The operator selects a variation range of the plurality of adjustment items from a plurality of adjustment items related to the image quality of the image formed by the image forming unit, and reduces the number of recording materials on which the sample image is formed with a low sampling density. And perform the pre-adjustment operation
Based on the first adjustment value range obtained by selecting the sample image formed by the preliminary adjustment operation by the operator, the adjustment item to be adjusted and the sampling density in the preliminary adjustment operation up to a value outside one step. The variation range was limited, and the sampling density of the limited variation range was densely formed to form a sample image, which was used to generate a sample image arbitrarily selected from the formed sample images by an operator . aggregate the sample adjustment value you stored in the storage unit as the second adjustment value range to be used for actual printing, the image forming method characterized by controlling the image forming section to operate readjusted.

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