JP2005266243A - Digital image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a digital image forming apparatus in which a high image quality printing result can be obtained by accurately adjusting density. <P>SOLUTION: The image forming apparatus includes: a toner quantity calculation means (controller 105) for calculating a quantity of toner to be used in the stage of a digital image before image formation; a waste toner quantity calculation means (controller 105) for calculating a proper quantity of waste toner from the quantity of toner used; and a waste-toner quantity detection means (printer engine 106) for detecting an actual quantity of waste toner. A quantity of waste toner as the result of present printing is calculated by obtaining quantities of waste toner from the waste-toner quantity detection means before and after printing. According to the quantity of waste toner, density is adjusted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a digital image forming apparatus, and more particularly to an adjustment technique for adjusting print density according to the amount of waste toner.

In an electrophotographic image forming apparatus, a toner image formed on a photoreceptor is transferred onto a sheet, and the printing density at that time depends on the amount of toner transferred. Conventional print density adjustment is performed by a user or a service person looking at the print result. There are the following patent documents as related technologies.
Japanese Patent Laid-Open No. 07-110646 JP-A-10-340033

However, in the conventional technique, printing is performed, paper is output, and the density is adjusted by looking at the result, so that the paper is wasted and it takes time to make a determination. By the way, the waste toner has been developed on the photoconductor but has not been transferred to the paper. Therefore, a large amount of waste toner means that the printed image has a higher density than the digital image. It will be low.
In addition, even when toner is present on the photosensitive member during paper jam, it may not be transferred to the paper. If the paper jam is removed in this state, the toner on the photosensitive member becomes waste toner as it is. This waste toner is not related to density adjustment because what is to be transferred to the sheet is not transferred.
In addition, there are papers suitable for transfer in the digital image forming apparatus and papers that are not, and the amount of waste toner that seems to be appropriate differs depending on the type of paper, so that it is necessary to consider it.
The present invention has been made in view of such a background, and an object of the present invention is to provide a digital image forming apparatus capable of accurately adjusting a density and obtaining a high-quality print result.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a toner amount calculation means for calculating a toner amount to be used in a previous stage of creating a digital image, and an appropriate waste toner amount is calculated from the used toner amount. It has a waste toner amount calculation means and a waste toner amount detection means for detecting the actual waste toner amount, and is used for this printing by acquiring the waste toner amount from the waste toner amount detection means before and after printing. The amount of waste toner is calculated, and the density is adjusted according to the amount of waste toner.
According to a second aspect of the present invention, in the digital image forming apparatus according to the first aspect, when a paper jam occurs, the amount of waste toner before printing is obtained again after the photoconductor cleaning after the jam removal is performed, and the waste toner when the paper jam occurs. The main feature is a digital image forming apparatus that does not detect the minute as data for density adjustment.
According to a third aspect of the present invention, in the digital image forming apparatus according to the first aspect, there is a predicted value of the waste toner amount for each type of paper to be used, and it is determined whether or not the waste toner amount is large from each predicted value. The main feature is a digital image forming apparatus that adjusts the density in consideration of the type of paper.
According to a fourth aspect of the present invention, the digital image forming apparatus according to the first aspect is characterized in that the digital image forming apparatus has switching means for switching whether or not automatic density adjustment with waste toner is performed.
According to a fifth aspect of the present invention, in the digital image forming apparatus according to the first aspect, the waste toner amount detection means is provided for each color of CMYK.

In the present invention, a higher quality printing result can be obtained by increasing the density when the amount of waste toner is larger than the amount considered to be appropriate.
Further, by removing the waste toner at the time of paper jam from the determination of whether or not to adjust the density, more accurate density adjustment can be performed.
Further, more accurate density adjustment can be performed by considering waste toner for each type of paper. In addition, the user can select whether or not to perform automatic density adjustment. The density adjustment function of the present invention can also be applied to a color digital image forming apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a digital copying machine according to an embodiment of the present invention. This configuration is a copying machine 100 as an image processing apparatus, and a contact glass 206 is provided on the upper surface of the copying machine 100. In addition, an automatic document feeder (hereinafter simply referred to as ADF) 201 is provided on the upper side of the copying machine 100, and this ADF 1 is connected to the copying machine 100 via a hinge or the like (not shown) so as to open and close the contact glass 206. Has been. The ADF 201 separates documents one by one from a document tray 202 as a document placing table on which a document bundle composed of a plurality of documents can be placed, and faces the contact glass 206 from the document bundle placed on the document tray 202. The separation / conveying means that conveys the original and the document conveyed toward the contact glass 206 by the separation / conveying means are conveyed / stopped to a reading position on the contact glass 206, and the copy disposed below the contact glass 206 The document that has been read by the reading means (a known exposure lamp 251, mirrors 252, 255, 256, lens 253, CCD 254, etc.) 250 of the machine 100 is unloaded from the contact glass 206. The paper feed motor is driven by an output signal from the controller, and when the paper feed start signal is input from the copying machine 100, the controller drives the paper feed motor forward / reversely. When the paper feed motor is driven in the forward direction, the feed roller 203 rotates in the clockwise direction so that the uppermost original is fed from the original bundle and conveyed toward the contact glass 206. When the leading edge of the document is detected by the document set detection sensor 207, the controller rotates the paper feed motor in reverse based on the output signal from the document set detection sensor 207. This prevents subsequent documents from entering and prevents separation.
Further, when the document set detection sensor 207 detects the trailing edge of the document, the controller counts the rotation pulse of the conveyor belt motor from this detection point, and when the rotation pulse reaches a predetermined value, the controller By stopping the driving and stopping the feeding belt 204, the document is stopped at the reading position of the contact glass 206. Also, when the trailing edge of the document is detected by the document set detection sensor 7, the controller drives the paper feed motor again, separates the subsequent document as described above, and conveys the document toward the contact glass 206. When the pulse of the paper feed motor from the time when the original is detected by the original set detection sensor 207 reaches a predetermined pulse, the paper feed motor is stopped and the next original is put on standby. When the original stops at the reading position of the contact glass 206, the original is read and exposed by the copying machine 100. When this reading and exposure are completed, a signal is input from the copier 100 to the controller. When this signal is input, the controller drives the conveyor belt motor to rotate forward, and the document is transferred from the contact glass 206 by the conveyor belt 216. It is carried out to the discharge roller 205.

As described above, a document bundle placed on the document tray 202 in the ADF 201 with the image surface of the document facing up is pressed from the top document to the contact glass 206 when the print key on the operation unit is pressed. It is fed to a predetermined position. The fed original is read by the reading unit 250 after the image data of the original on the contact glass 206 is discharged to the discharge port A (discharge port at the time of reverse document discharge) by the feeding belt 204 and the reverse driving roller. Further, when it is detected that there is a next document on the document tray 202, it is fed onto the contact glass 206 in the same manner as the previous document.
The transfer sheets stacked on the first tray 208, the second tray 209, and the third tray 210 are fed by the first sheet feeding unit 211, the second sheet feeding unit 212, and the third sheet feeding unit 213, respectively, and are conveyed vertically. The unit 214 is transported to a position where it abuts on the photoreceptor 215. The image data read by the reading unit 250 is written on the photoconductor 215 by a laser from the writing unit 257, and a toner image is formed by passing through the developing unit 227. Then, the toner image on the photosensitive member 215 is transferred while the transfer paper is conveyed by the conveying belt 216 at the same speed as the rotation of the photosensitive member 215. Thereafter, the image is fixed by the fixing unit 217 and conveyed to the paper discharge unit 218. The transfer paper conveyed to the paper discharge unit 218 is discharged to the paper discharge tray 219 when the staple mode is not performed.

FIG. 2 is a block diagram of the digital image forming apparatus according to the embodiment of the present invention. This digital image forming apparatus is a digital multi-function peripheral having a copy / printer / fax function.
The digital image forming apparatus includes a host interface device 101 such as Centronics for operating as a printer, an interface device 102 for a telephone line for operating as a FAX, an operation panel 103 for inputting data and displaying data, A scanner device 104 for operating as a copy / fax, a controller 105 in which control software, emulation software for interpreting data from a host, and the like are stored, and a printer engine 106 for printing image data are configured. The controller 105 of the present invention includes a toner amount calculation unit and a waste toner amount calculation unit. The printer engine 106 includes waste toner amount detection means for detecting the amount of waste toner.

FIG. 3 is a flowchart showing the operation during image formation by the digital image forming apparatus of the present invention. The image to be printed is developed into a digital image by the controller 105 in any case of copy / printer / fax (S201). By developing the digital image, the black area and the white area on the paper are determined, and the amount of toner to be used is calculated (S202).
Also, the amount of waste toner before printing and the amount of waste toner after printing are acquired from the waste toner detection means (S203), and digital image printing is executed (S204). Then, the amount of waste toner after printing is acquired (S205). If the amount of waste toner is larger than expected (YES route in S206), control is performed to increase the density (S207), and the initially set density is applied (S207). S208) Returning to step S204, printing is executed. If the amount of waste toner is smaller than predicted in step S206 (NO route in S206), printing is terminated there.
Since the waste toner is developed on the photoreceptor but not transferred to the paper in this way, the amount of waste toner is large, which means that the printed image has a higher density than the digital image. Is supposed to be low. By increasing the density when the amount of waste toner is large, a higher quality printing result can be obtained.

  In the digital image forming apparatus according to the second embodiment, when a paper jam occurs, the amount of waste toner before printing is re-acquired after the paper jam is removed, and the amount of waste toner at the time of paper jam is not detected. In the case of paper jam, even if there is toner on the photoconductor, it may not be transferred to the paper. If the paper jam is removed in this state, the toner on the photoconductor becomes waste toner as it is. The waste toner is not related to the density adjustment because the toner to be transferred to the paper is not transferred. Considering such waste toner makes it possible to adjust the density more accurately.

  In the digital image forming apparatus according to the third embodiment, the amount of waste toner is detected separately depending on the type of paper. Consider paper that is suitable for transfer and paper that is not. For example, the amount of waste toner differs between plain paper and OHP paper even when the same image is printed. Considering such waste toner makes it possible to adjust the density more accurately.

  In the digital image forming apparatus according to the fourth embodiment, the operation panel 103 includes switching means for switching between automatic density adjustment valid / invalid. In this way, the user can select whether or not to perform automatic density adjustment.

  In the digital image forming apparatus according to the fifth embodiment, when the printer engine 106 is a color printer engine, a waste toner amount detection unit is provided for each color of CMYK. In this way, the automatic density adjustment function can be applied to the color image forming apparatus.

1 is a schematic configuration diagram of a digital copying machine according to an embodiment of the present invention. 1 is a block diagram of a digital image forming apparatus according to an embodiment of the present invention. 6 is a flowchart showing an operation during image formation by the digital image forming apparatus of the present invention.

Explanation of symbols

103 Operation panel (switching means)
105 Controller (toner amount calculation means, waste toner amount calculation means)
106 Printer engine (waste toner amount detection means)

Claims (5)

  Toner amount calculation means for calculating the amount of toner used in the previous stage of creating a digital image, waste toner amount calculation means for calculating an appropriate waste toner amount from the used toner amount, and waste for detecting the actual waste toner amount A toner amount detecting unit, and calculating the waste toner amount used for the current printing by acquiring the waste toner amount from the waste toner amount detecting unit before and after printing, and density according to the waste toner amount A digital image forming apparatus characterized by adjusting the angle.   2. The digital image forming apparatus according to claim 1, wherein when a paper jam occurs, the amount of waste toner before printing is obtained again after the photoconductor cleaning after the jam is removed, and the waste toner content during the paper jam is used for density adjustment. A digital image forming apparatus which is not detected as data.   2. The digital image forming apparatus according to claim 1, wherein each paper type to be used has a predicted value of waste toner amount, and whether or not the waste toner amount is large is determined from each predicted value, and the paper type is also taken into consideration. A digital image forming apparatus characterized in that density adjustment is performed.   2. The digital image forming apparatus according to claim 1, further comprising a switching unit for switching whether or not to perform automatic density adjustment with waste toner.   2. The digital image forming apparatus according to claim 1, wherein said waste toner amount detecting means is provided for each color of CMYK.

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