Patent Application
20130342859
This patent application is based on and claims priority pursuant to 35 U.S.C. §119 to Japanese Patent Application No. 2012-143026, filed on Jun. 26, 2012, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.
1. Technical Field
The present invention generally relates to an image forming apparatus, such as, a copier, a printer, a facsimile machine, or a multifunction machine including at least two of these functions, that forms images on sheets of recording media subject to post processing such as stapling, punching, and the like; and also relates to an image data converter to convert image data used by an image forming apparatus and a method of converting image data therefor.
2. Description of the Background Art
Post processing or sheet processing, such as punching or stapling, is often performed on sheets of recording media on which images are formed by image forming apparatuses such as copiers, printers, or multifunction machines having these capabilities. For example, sheets are punched by punch units including a punch and a die to engage the punch. Alternatively, a bundle of sheets is stapled by staplers including a staple pusher to push staples into the sheets. The staple penetrates the bundle, and ends thereof are bent to bite into the bottom face of the bundle to fix the staple.
If areas in which images are formed are processed, for example, stapled or punched, it is possible that toner on the sheet is transferred to post-processing devices such as punch units, staplers, or the like. Specifically, toner on the sheet may adhere to a punch or a die of the punch unit. Similarly, toner may adhere to a staple pusher of the stapler when a bundle of sheets is stapled. Toner adhering to the post-processing device can cause malfunction of the post-processing device or adhere to subsequent sheets to be processed. Accordingly, it is possible that images formed by the image forming apparatus are disturbed.
One embodiment of the present invention provides an image forming apparatus to form an image on a sheet of recording media on which post processing is executed. The image forming apparatus includes an image forming device to form the image on the sheet according to a toner adhering amount of each pixel and position data indicating a position of the pixel on the sheet, a storage device to store post-processing position data that indicates a position of post processing on the sheet, a retriever to retrieve the post-processing position data from the storage device, and a converter to convert the toner adhering amount of the pixel designated by the post-processing position data.
Another embodiment provides an image data converter to convert image data according to which an image is formed on a sheet of recording media subject to post processing. The image data converter includes a storage device to store post-processing position data that indicates a position of post processing on the sheet, a retriever to retrieve the post-processing position data from the storage device, and a converter to convert lightness of each color of a pixel designated by the post-processing position data.
Yet another embodiment provides an image data converting method to convert image data according to which an image is formed on a sheet of recording media that is to be processed by a post-processing device. The method includes a step of retrieving post-processing position data that indicates a position of post processing on the sheet, and a step of converting lightness of each color of a pixel designated by the post-processing position data.
A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
In describing preferred embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner and achieve a similar result.
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views thereof, image forming systems according to embodiments of the present invention are described.
It is to be noted that the suffixes Y, M, C, and K attached to each reference numeral indicate only that components indicated thereby are used for forming yellow, magenta, cyan, and black images, respectively, and hereinafter may be omitted when color discrimination is not necessary.
In the embodiments described below, an image forming apparatus form images according to a toner adhering amount of each pixel and position data indicating a position of the pixel on the sheet, and post processing is performed at positions on the sheet indicated by post-processing position data. In this configuration, the image forming system includes a storage device to store post-processing position data indicating the position where post processing is made on the sheet on which an image is formed, a retriever to retrieve the post-processing position data, and a converter to convert, image formation data such as toner adhering amount or lightness, of each pixel designated by the post-processing position data so that toner is not applied to such positions.
As shown in
The image forming apparatus 1 is configured to form images on sheets of recording media such as plain paper, cardboard, overhead projector(OHP) film, or the like, and the sheet processing apparatus 2 performs post processing, such as punching, stapling, or the like, of the sheets on which images are formed.
A hardware configuration of the image forming apparatus 1 is described below.
In the configuration shown in
In a center area of the image forming apparatus 1, an intermediate transfer belt 143 is looped around a driving roller 141, a driven roller 142, and a secondary-transfer roller 145. Four photoreceptor drums 122, namely, 122C, 122M, 122Y, and 122K, are disposed to contact the intermediate transfer belt 143. On the photoreceptor drums 122C, 122M, 122Y, and 122K respective color toner images are formed with cyan (C), magenta (M), yellow (Y), and black (K) toners. Across the intermediate transfer belt 143, primary-transfer rollers 144C, 144M, 144Y, and 144K are disposed facing the photoreceptor drums 122C, 122M, 122Y, and 122K, respectively. The toner images formed on the photoreceptor drums 122C, 122M, 122Y, and 122K are transferred onto an identical area of a surface of the intermediate transfer belt 143, thereby forming a multicolor toner image.
Additionally, a roller 146 is disposed at a position facing the secondary-transfer roller 145 (hereinafter “secondary-transfer facing roller 146”. The sheet and the intermediate transfer belt 143 carrying the multicolor toner image are pressed between the secondary-transfer roller 145 and the secondary-transfer facing roller 146.
A charging unit 123C is provided adjacent to the photoreceptor drum 122C and configured to charge the surface of the photoreceptor drum 122C uniformly. Additionally, an exposure unit 124C is provided adjacent to the photoreceptor drum 122C and configured to form an electrostatic latent image on the charged surface of the photoreceptor drum 122C. Specifically, the exposure unit 124 forms the electrostatic latent image based on the amount of toner applied or adhering to the photoreceptor drum 122C (i.e., toner adhering amount), and the toner adhering amount corresponds to a dot area ratio for each color determined by the controller 10. A developing device 125C disposed adjacent to the photoreceptor drum 122C develops with toner the electrostatic latent image on the photoreceptor drum 122C. The primary-transfer roller 144C applies a primary-transfer bias to the intermediate transfer belt 143 interposed between the primary-transfer roller 144C and the photoreceptor drum 122C. It is to be noted that the primary-transfer bias in the preset embodiment is electrical charges in the polarity opposite to that of electrical charge on the surface of the photoreceptor drum 122C.
The photoreceptor drum 122C, the charging unit 123C, the exposure unit 124C, and the developing device 125C together form an image forming unit 12C that serves as an embodiment of the image forming device. The image forming apparatus 1 further includes image forming units 12M, 12Y, and 12K each having a configuration similar to that of the image forming unit 12C except the color of toner used therein, and thus descriptions thereof are omitted.
The image forming apparatus 1 further includes a sheet feeder 13 to transport sheets to the position between the secondary-transfer roller 145 and the secondary-transfer facing roller 146. The sheet feeder 13 includes a sheet tray 131, a feed roller 132, a conveyance belt 133, and a pair of registration rollers 134. The sheet tray 131 contains sheets of recording media, and the feed roller 132 is rotatable to transport the sheet from the sheet tray 131 to the conveyance belt 133. The feed roller 132 sends out sheets from the sheet tray 131 one by one from the top to the conveyance belt 133.
The conveyance belt 133 transports the sheet forwarded by the feed roller 132. The registration rollers 134 are disposed upstream from the secondary-transfer roller 145 in the direction in which the conveyance belt 133 moves. The registration rollers 134 forward the sheet to the secondary-transfer roller 145, timed to coincide with the arrival of the toner image formed on the intermediate transfer belt 143.
A fixing device 15 is provided to fix the toner image transferred onto the sheet from the intermediate transfer belt 143. Specifically, with simultaneous application of heat and pressure thereto, a resin component of toner is fused and bonded to the sheet. The fixing device 15 includes a fixing roller 153 and a facing roller 155 facing the fixing roller 153. Additionally, a conveyance belt 151 is provided to transport the sheet to the fixing roller 153 after the toner is transferred thereto by the secondary-transfer roller 145. The conveyance belt 151 may be continuous with the conveyance belt 133 as shown in
On an outer face of the image forming apparatus 1, a control panel 18 is provided. The control panel 18 includes a panel display 181 and an input device 182. The panel display 181 displays setting values, selection screens, or both and accepts instructions from users. The panel display 181 can be, for example, a touch panel. The user can select the type and conditions of processing of sheets on which images are formed (i.e., post processing). The input device 182 includes numeric keys, a start key, and the like. For example, the user designates the number of copies using the numeric keys and instructs the apparatus to start image formation. It is to be noted that the term “post processing” used in this specification means sheet processing, such as punching or stapling, performed by the sheet processing apparatus 2.
The image forming apparatus 1 includes the controller 10 to control the above-described respective components. Referring to
The CPU 1011 executes data processing, computation, and control of the above-described components according to programs stored in the main memory 1012. The main memory 1012 serves as a memory storage area for the controller 10 and includes a read only memory (ROM) 1012a and random access memory (RAM) 1012b. The ROM 1012a stores programs and data to implement the functions of the controller 10. Alternatively, the program stored in the ROM 1012a can be recorded on computer-readable recording media such as a compact disc read only memory (CD-ROM), a floppy disk (FD), a compact disc-recordable (CD-R), a digital versatile disc (DVD) in the file form installable into or executable by the controller 10.
The RAM 1012b is used for expansion of programs and data and as a drawing memory. The NB 1013 serves as a bridge connecting the CPU 1011 to the main memory 1012, the SB 1014, and the AGP bus 1015. The SB 1014 serves as a bridge between the NB 1013 and peripheral devices. The AGP bus 1015 is a bus interface for graphics accelerator cards proposed to accelerate graphics processing. The ASIC 1016 includes a memory controller to control the local memory 1017 and multiple direct memory access controllers (DMACs) to execute rotation and the like of image data according to hardware logic. The ASIC 1016 is connected via the PCI bus 1020 to the network I/F 1021 such as a universal serial bus (USB) interface, an institute of electrical and electronics engineers (IEEE) 1394 interface.
The local memory 1017 is used as a buffer for images to be copied or codes. The RD 1018 stores image data, font data used in printing, and forms. The HDD 1019 controls data retrieval from and data writing in the HD 1018, controlled by the CPU 1011. The network I/F 1021 transmits data to and from external devices such as data processing devices via a communication network.
A functional configuration of the controller 10 of the image forming apparatus 1 is described below with reference to
The controller 10 controls operation of the image forming apparatus 1 and, as shown in
In the storage unit 1900, a post-processing management database (DB) 1901 such as a post-processing management table shown in
In
The data transceiver 191 is implemented by the network I/F 1021 shown in
The input receiver 192 accepts various types of data input by the user via the control panel 18 shown in
The data generator 194 executes color space conversion and under color removal (UCR) of the RGB image data received by the data transceiver 191 or accepted by the image reading controller 193. With such image data processing, the data generator 194 converts the RGB image data into area ratios Rc, Rm, Ry, and Rk of dots formed with cyan (C), magenta (M), yellow (Y), and black (B) toners and generates image formation data that correlates the dot area ratio with the coordinate representing the position of each pixel.
It is to be noted that the data generator 194 may further execute adjustment of shading, positional deviation, and gamma in addition to color space conversion and under color removal. It is to be noted that the term “dot area ratio” means the ratio of the area in which dots are formed with each color toner in the area of a single pixel. Additionally, the dot area ratio can represent the amount of toner adhering to the photoreceptor drum 122 since the amount of toner transferred to the photoreceptor drum 122 by the image forming unit 12 corresponds to the dot area ratio.
The data converter 195 converts the image formation data generated by the data generator 194 according to the post-processing data. Specifically, the writing and retrieval unit 199 retrieves the post-processing coordinate based on the post-processing type and the processed area data included in the post-processing data received by the data transceiver 191. The data converter 195 converts the dot area ratio of each color of the pixel at the position designated by the post-processing coordinate to Rc=0, Rm=0, Ry=0, and Rk=0. The data converter 195 is an embodiment of the converter.
The image formation controller 196 includes an image formation control unit 1962 to control the image forming units 12, a sheet feeding control unit 1963 to control the sheet feeder 13, a transfer control unit 1964 to control the primary-transfer rollers 144, the secondary-transfer roller 145, and the intermediate transfer belt 143, and a fixing control unit 1965 to control the fixing device 15.
A hardware configuration of the sheet processing apparatus 2 is described below with reference to
The sheet processing apparatus 2 includes a controller 20.
In the present embodiment, the sheet processing apparatus 2 punches or staples the sheets on which images are formed by the image forming apparatus 1. As shown in
The second conveyance channel 222 includes the punch unit 23. The punch unit 23 is designed to punch sheets, controlled by the controller 20, and includes a punch 231 and a die 232. The punch 231 and the die 232 face each other. The sheets are punched when the punch 231 engages holes formed in the die 232 with the sheets interposed therebetween.
The third conveyance channel 223 is provided with the stapler 24 designed to staple the sheets, controlled by the controller 20. Neither the punch unit 23 nor the stapler 24 is provided in the first conveyance channel 223, and the first conveyance channel 223 extends to a sheet outlet. The conveyance channels 222 and 223 extend further from the punch unit 23 and the stapler 24, respectively, to the sheet outlet.
Referring to
A functional configuration of the sheet processing apparatus 2 is described below.
As shown in
Referring to
Referring to
Specifically, the data generator 194 converts color space of the RGB image data and removes under color from the RGB image data, thereby obtaining the dot area ratios Rc, Ry, and Rk, which represent the area ratios of dots formed with cyan, magenta, yellow, and black toners, respectively. It is to be noted that the data generator 194 may further execute known image processing of the RGB image data such as color correction, spatial frequency correction, or the like. Further, the data generator 194 computes the dot area ratio of every pixel on the sheet and generates the image formation data that includes the position of every pixel on the sheet and the dot area ratio corresponding to that position.
Subsequently to generation of the image formation data, at S23 the data converter 195 converts the image formation data according to the post-processing data received at S21. At S231 shown in
For example, when the post-processing type is “punching” and the processed area data is “left”, the writing and retrieval unit 199 retrieves a group of post-processing coordinates (108, 312) to (142, 346) and (108, 936) to (142, 968) from the post-processing management table (shown in
Additionally, when the post-processing type is “stapling” and the processed area data is “upper right”, the writing and retrieval unit 199 retrieves a group of post-processing coordinates (896, 128), (896, 129), and (897, 129) to (927, 186) from the post-processing management table (shown in
As described above, the image formation data generated by the data generator 194 are converted by the data converter 195.
Referring back to
At S25, controlled by the image formation control unit 1962, the image forming units 12 forms the toner images on the respective photoreceptor drums 122 according to the image formation data converted by the data converter 195. Specifically, initially the charging unit 123C uniformly charges the surface of the rotating photoreceptor drum 122C. The exposure unit 124C directs a laser beam onto the charged surface of the photoreceptor drum 122C according to the dot area ratio Rc of the image formation data. Thus, an electrostatic latent image, constructed of electrostatic electrical charges according to the dot area ratio, is formed on the photoreceptor drum 122C.
Subsequently, the developing device 125C develops the electrostatic latent image with cyan toner. Thus, a cyan toner image is formed on the photoreceptor drum 122C. Magenta, yellow, and black toner images are formed on the photoreceptor drums 122M, 122Y, and 122K, respectively, through processes similar to those for cyan, and thus the descriptions thereof are omitted.
At S26, transfer of the toner images from the respective photoreceptor drums 122 is performed controlled by the transfer control unit 1964.
Specifically, the primary-transfer rollers 144 apply the primary-transfer bias to the intermediate transfer belt 143. Then, the toner images are transferred from the respective photoreceptor drums 122 onto the intermediate transfer belt 143 (primary image transfer).
The intermediate transfer belt 143 onto which the toner images are transferred moves in the direction indicated by arrow Y2 shown in
At S27 the fixing device 15 fixes the toner image on the sheet, controlled by the fixing control unit 1965. Specifically, the conveyance belt 151 transports the sheet onto which the toner image is transferred to the fixing roller 153. When the sheet reaches the position where the fixing roller 153 contacts the fixing belt 152, the fixing roller 153 presses the sheet against the facing roller 155. Since the fixing roller 153 is heated by the heat generator 156, the sheet is heated at a predetermined fixing temperature while being pressed. Then, the toner on the sheet is fused. As the fixing roller 153 and the facing roller 155 press the fused toner, the resin component in toner is fixed on the sheet. Subsequently, at S28 the sheet is discharged from the image forming apparatus 1 through the discharge opening.
Next, sheet processing in the sheet processing apparatus 2 is described with reference to
As shown in
When the post-processing type is “punching” (Yes at S32), at S33 the switch controller 292 switches the position of the channel changer 21 to transport the sheet through the second conveyance channel 222. When the sheet transported through the second conveyance channel 222 reaches the punch unit 23, at S34 the punch unit 23 punches a hole in the processed area indicated by the post-processing data received by the data transceiver 291.
When the post-processing type is not “punching” (No at S32), at S35 the switch controller 292 further judges whether or not the post-processing type is “stapling”. When the post-processing type is “stapling”, (Yes at S35), at S36 the switch controller 292 switches the position of the channel changer 21 to transport the sheet through the third conveyance channel 223. When the sheet transported through the third conveyance channel 223 reaches the stapler 24, at S37 the stapler 24 staples the processed area indicated by the post-processing data received by the data transceiver 291. When the post-processing type is not “stapling”, (No at S35), at S36 the switch controller 292 switches the position of the channel changer 21 to transport the sheet through the first conveyance channel 223. Thus, the sheet is transported through the first conveyance channel 223.
At S39 the sheet punched, stapled, or transported through the first conveyance channel 223 is discharged through the sheet outlet and stacked on the discharge tray 25 at S40.
Thus, according to the first embodiment, the image forming apparatus 1 converts into “0” the dot area ratio at the position subject to post processing (sheet processing) by the sheet processing apparatus 2. Accordingly, toner does not adhere to the punch unit 23 or the stapler 24 when the sheet processing apparatus 2 performs post processing such as punching or stapling. Therefore, malfunction of the punch unit 23 and the stapler 24 can be inhibited. Additionally, adhesion of toner to sheets in subsequent sheet processing can be prevented, thus inhibiting occurrence of image failure.
The first embodiment also provides a method of converting image data according to which an image is formed on a sheet of recording media subject to post processing. The method includes a step of storing post-processing position data that indicates the position to be processed by the sheet processing device, a step of retrieving the post-processing position, and a step of converting toner adhering amount of each color of a pixel designated by the post-processing position data such as post-processing coordinates. This method can be made into programs executable by the image forming apparatus 1, data processing devices, or computers and recorded in non-transitory recording media readable by the image forming apparatus 1, data processing devices, or computers.
Although the controller 10 of the image forming apparatus 1 includes the data converter 195 in the above-described first embodiment, alternatively, an RGB image data converter 33 may be included in a data processing device 3, such as a computer, that transmits data via a communication network to the image forming apparatus 1 as in a second embodiment described below. The image forming apparatus 1, the sheet processing apparatus 2, and the data processing device 3 according to the second embodiment are described below with reference to
A hardware configuration of the data processing device 3 is described below.
Referring to
Next, a functional configuration of the data processing device 3 is described below with reference to
The data processing device 3 includes a data transceiver 31, an input receiver 32, an RGB image data converter 33, and a writing and retrieval unit 39, which are directed by the CPU 301 according to the programs for data processing devices. The data transceiver 31 receives data from and transmits data to the image forming apparatus 1 via the communication network or the like. The input receiver 32 can be implemented by the keyboard I/F 307, the mouse I/F 308, or both and configured to accept information input by the user via a keyboard or a mouse. The RGB image data converter 33 can convert the RGB image data generated or received by the data processing device 3. The writing and retrieval unit 39 and the storage unit 3000 are similar to the writing and retrieval unit 199 and the storage unit 1900 according to the first embodiment, respectively, and thus descriptions thereof are omitted. It is to be noted that the data processing device 3 is an embodiment of an image data converter.
Additionally, the image forming apparatus 1 and the sheet processing apparatus 2 in the second embodiment are similar to those in the first embodiment except that the data converter 195 is not included in the image forming apparatus 1. Thus, their descriptions are omitted.
Operations of the respective apparatuses and the data processing device 3 in the second embodiment are described below with reference to
As shown in
In the second embodiment, the RGB image data represents an image using the lightness of red, green, and blue, and the RGB image data converter 33 converts the color of the pixels in the processed area into white. Specifically, at S43 the RGB image data converter 33 converts the lightness of the respective colors of the pixel positioned at the post-processing coordinate retrieved at S42 into 255 (R=255, G=255, and B=255). The data transceiver 31 transmits the converted RGB image data to the image forming apparatus 1 via the communication network or the like.
According to the RGB image data received from the data processing device 3, the image forming apparatus 1 performs the steps at S21, S22, and S24 through S28 shown in
Therefore, when an image is formed according to the image formation data, toner is not applied to the processed area.
Thus, the second embodiment also provides a method of converting image data according to which an image is formed on a sheet of recording media subject to post processing. The method includes a step of retrieving post-processing position data that indicates a position of post processing on the sheet on which the image is formed, and a step of converting lightness of each color of a pixel designated by the post-processing position data such as post-processing coordinates. This method can be made into programs executable by the data processing device 3 and recorded in non-transitory recording media readable by the data processing device 3 or computers.
Thus, according to the second embodiment, the data processing device 3 converts each color lightness at the position on the sheet where post processing is made so that the position is kept white. Accordingly, toner does not adhere to the punch unit 23 or the stapler 24 when the sheet processing apparatus 2 performs post processing such as punching or stapling. Therefore, malfunction of the punch unit 23 and the stapler 24 can be inhibited. Additionally, adhesion of toner to sheets in subsequent sheet processing can be prevented, thus inhibiting occurrence of image failure.
Although the above-described embodiments concern image formation using cyan, magenta, yellow, and black toners, alternatively, transparent toner (i.e., clear toner) may be used in addition to the four color toners. Transparent toner can be constructed of resin particles. When superimposed on colored toner, the transparent toner can keep the colored toner visible.
Additionally, although the post-processing coordinate is retrieved from the post-processing management table in the post-processing management DB 1901 using the post-processing type and the processed area data as the search keys, the post-processing coordinate may be retrieved otherwise. For example, when the sheet processing apparatus 2 includes the punch unit 23 but does not include other post-processing devices (such as the stapler 24), the search key may be only the processed area data. Yet alternatively, for example, when the sheet processing apparatus 2 does not include other post-processing devices than the punch unit 23 and the punched position is fixed, the storage unit 1900 stores fixed values as the post-processing coordinate. In such a case, the search key is not necessary to retrieve the post-processing coordinate.
Further, although the data generator 194 generates the image formation data according to the RGB image data received by the data transceiver 191, the RGB image data based on which the data generator 194 generates the image formation data may be read by the image reading device 11 and accepted by the image reading controller 193. In such case, the data generator 194 can convert the image formation data based on the post-processing data input by the user using the control panel 18 and accepted by the input receiver 192.
Additionally, although the image formation data is generated based on the RGB image data in the second embodiment, the image formation data can be generated based on monochrome or single color image data when images are formed using a single color toner (e.g., black toner). In this specification, image data means either RGB or monochrome image data.
It is to be noted that the order of steps in the above-described methods is not limited thereto.
Numerous additional modifications and variations are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the disclosure of this patent specification may be practiced otherwise than as specifically described herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-143026 | Jun 2012 | JP | national |
