JP7516908B2 - Image forming apparatus, image forming method, and program - Google Patents

Description

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

Image forming devices that print images read using a scanning function have been proposed in the past. In addition, conventional technology employs technology that automatically determines whether a read image is color or monochrome, and switches subsequent processing depending on the result of the determination (for example, Patent Document 1).

In conventional technology, even when monochrome printing was selected, an image may be printed in monochrome using a portion (e.g., K version) of the printing data (e.g., CMYK data) for color printing. However, when monochrome printing is performed using printing data for color printing, some images may not be displayed properly. In consideration of the above circumstances, the present invention aims to reduce the inconvenience of monochrome images not being displayed properly.

In order to solve the above problem, an image forming apparatus of the present invention includes a reading unit that reads an image, a determination unit that determines whether the image is color during a reading period from when image reading is started to when it is finished, a first generation unit that generates first print data for printing the image in color during the reading period, a second generation unit that generates second print data for printing the image in monochrome during the reading period, a first control unit that prints the image using the first print data if the determination unit determines that the image is color, a second control unit that prints the image using the second print data if the determination unit does not determine that the image is color, a print execution unit that prints the image, a first memory unit that stores the first print data during the reading period, and a second memory unit that stores the second print data during the reading period, and the print execution unit prints the image using the print data stored in the first memory unit, and the second control unit overwrites the first print data stored in the first memory unit with the second print data stored in the second memory unit if the determination unit does not determine that the image is color.

In the configuration of the present invention, both first print data for color printing and second print data for monochrome printing are generated, and when the image is monochrome, the second print data is used to print the image. Therefore, for example, monochrome images are more likely to be printed appropriately compared to a configuration in which the first print data that is originally used for color printing is used for monochrome printing.

The present invention makes it possible to prevent the inconvenience of monochrome images not being displayed properly.

FIG. 1 is a diagram illustrating a schematic configuration of an MFP, which is an example of an image forming apparatus. FIG. 2 is a diagram illustrating a hardware configuration of an MFP. FIG. 2 is a functional block diagram of the image forming apparatus. FIG. 2 is a diagram for explaining a specific example of the operation of the image forming apparatus. 11 is a flowchart of a specific example of a process performed by the image forming apparatus during reading.

First Embodiment
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. Fig. 1 is a diagram for explaining the schematic configuration of an MFP (Multifunction Peripheral Product Printer) 1 which is an example of an image forming apparatus according to the present invention.

As shown in FIG. 1, the MFP 1 has a manual feed tray 36 and a paper feed tray 34. Print paper (an example of a recording medium) fed from the manual feed tray 36 is transported directly to the registration rollers 23 by the paper feed rollers 37. On the other hand, print paper fed from the paper feed tray 34 is transported by the paper feed rollers 35 through the intermediate rollers 39 to the registration rollers 23.

The MFP1 has photoconductor drums 14 (K, C, M, Y). As shown in FIG. 1, the photoconductor drums 14 include photoconductor drum 14K on which a black image is formed, photoconductor drum 14C on which a cyan image is formed, photoconductor drum 14M on which a magenta image is formed, and photoconductor drum 14Y on which a yellow image is formed.

The MFP1 includes a scanner unit 27. The scanner unit 27 reads an image displayed on a document in response to a user's operation. When the image is read by the scanner unit 27, read data (RGB format) representing the image is generated. As will be described in detail later, the read data is converted into print data (CMYK format, K format). An area of each of the photoconductor drums 14 corresponding to the print data is irradiated by the writing unit 16, and an electrostatic latent image corresponding to the image to be printed is created.

The printing paper transported to the registration rollers 23 is transported to the transfer belt 18 (image carrying means) at a timing when the electrostatic latent image formed on the photosensitive drum 14 coincides with the leading edge of the printing paper. The printing paper transported to the transfer belt 18 passes through a paper adsorption nip formed by the transfer belt 18 and a paper adsorption roller 41. In addition, when the printing paper passes through the above paper adsorption nip, the printing paper is adsorbed to the transfer belt 18 by the bias applied to the adsorption roller 41.

As shown in FIG. 1, the MFP 1 is provided with multiple transfer brushes 21 (K, C, M, Y). Each of the transfer brushes 21 faces the corresponding photoconductor drum 14 via the transfer belt 18. A transfer bias (positive) of the opposite polarity to the toner charging polarity (negative) is applied to the transfer brush 21.

As shown in FIG. 1, pressure rollers 20 (K, C, M, Y) are provided to hold the transfer belt 18 against the photosensitive drums 14 at a predetermined pressure. The image on the photosensitive drum 14 is transferred to the image bearing surface M of the transfer belt 18 by the transfer brush 21 corresponding to that photosensitive drum 14. In this embodiment, the images of each color formed on each of the photosensitive drums 14 are transferred to the printing paper in the order of yellow, black, cyan, and magenta.

The print paper onto which the images of all the photosensitive drums 14 have been transferred is curvature-separated from the transfer belt 18 by the drive roller 19 and transported to the fixing section 24. As shown in FIG. 1, the fixing section 24 is composed of a fixing belt 25 and a pressure roller 26. As the print paper passes through the fixing section 24, the images transferred to the print paper are fixed. After passing through the fixing section 24, the print paper is discharged from the paper discharge rollers 31 to the FD tray 30.

Figure 3 is a diagram showing the hardware configuration of the MFP 1. As shown in Figure 3, the MFP 1 includes a controller 1010, a short-range communication circuit 1020, an engine control unit 1030, an operation panel 1040, and a network I/F 1050.

The controller 1010 has a CPU 1001, which is the main part of the computer, a system memory (MEM-P) 1002, a north bridge (NB) 1003, a south bridge (SB) 1004, an ASIC (Application Specific Integrated Circuit) 1006, a local memory (MEM-C) 1007, which is a storage unit, a HDD controller 1008, and a HD 1009, which is also a storage unit, and is configured such that the NB 1003 and the ASIC 1006 are connected by an AGP (Accelerated Graphics Port) bus 1021.

The CPU 1001 is a control unit that performs overall control of the MFP 1. The NB 1003 is a bridge that connects the CPU 1001 with the MEM-P 1002, the SB 1004, and the AGP bus 1021, and has a memory controller that controls reading and writing to the MEM-P 1002, a PCI (Peripheral Component Interconnect) master, and an AGP target.

The MEM-P 1002 is composed of a ROM 1002a, which is memory for storing programs and data that realize the various functions of the controller 1010, and a RAM 1002b, which is used for expanding the programs and data, and as a drawing memory during memory printing. The programs stored in the RAM 1002b may be provided by recording them in an installable or executable format on a computer-readable recording medium such as a CD-ROM, CD-R, or DVD.

SB1004 is a bridge for connecting NB1003 with PCI devices and peripheral devices. ASIC1006 is an IC (Integrated Circuit) for image processing purposes that has hardware elements for image processing, and acts as a bridge connecting AGP bus 1021, PCI bus 1022, HDD 1008, and MEM-C 1007.

The ASIC 1006 is made up of a PCI target and AGP master, an arbiter (ARB) that is the core of the ASIC 1006, a memory controller that controls the MEM-C 1007, multiple DMACs (Direct Memory Access Controllers) that rotate image data using hardware logic, and a PCI unit that transfers data between the scanner unit 1031 and the printer unit 1032 via the PCI bus 1022. Note that a USB (Universal Serial Bus) interface or an IEEE 1394 (Institute of Electrical and Electronics Engineers 1394) interface may be connected to the ASIC 1006.

The MEM-C 1007 is a local memory used as an image buffer for copying and a code buffer. The HD 1009 is a storage for storing image data, font data used during printing, and forms. The HD 1009 controls the reading and writing of data from and to the HD 1009 under the control of the CPU 1001. The AGP bus 1021 is a bus interface for a graphics accelerator card proposed to speed up graphic processing, and by directly accessing the MEM-P 1002 with high throughput, the graphics accelerator card can be made faster.

The short-distance communication circuit 1020 is also equipped with a short-distance communication circuit 1020a. The short-distance communication circuit 1020 is a communication circuit such as NFC or Bluetooth (registered trademark). The engine control unit 1030 is further composed of a scanner unit 1031 and a printer unit 1032. The operation panel 1040 is also equipped with a panel display unit 1040a such as a touch panel that displays the current setting values and selection screens and receives input from the operator, and an operation panel 1040b consisting of a numeric keypad that receives setting values for image formation conditions such as density setting conditions, a start key that receives a copy start instruction, etc.

The controller 1010 controls the entire MFP 1, for example, drawing, communication, and input from the operation panel 1040. The scanner unit 1031 or the printer unit 1032 includes an image processing section that performs error diffusion, gamma conversion, and the like.

The MFP1 can sequentially switch between the document box function, copy function, printer function, and facsimile function using the application switching key on the operation panel 1040. When the document box function is selected, the mode becomes document box mode, when the copy function is selected, the mode becomes copy mode, when the printer function is selected, the mode becomes printer mode, and when the facsimile mode is selected, the mode becomes facsimile mode.

The network I/F 1050 is an interface for data communication using a communication network. The short-range communication circuit 1020 and the network I/F 1050 are electrically connected to the ASIC 1006 via the PCI bus 1022.

Figure 3 is a functional block diagram of the image forming device 100 (MFP1). As shown in Figure 3, the image forming device 100 includes a reading unit 101, a determination unit 102, a first generation unit 103, a second generation unit 104, a first control unit 105, a second control unit 106, a switching unit 107, a first storage unit 108, a second storage unit 109, and a print execution unit 110. Each function of the image forming device 100 is realized by the CPU 1001 executing the above-mentioned programs.

The reading unit 101 is a means for reading an image, and is realized by, for example, the scanner unit 27 (see FIG. 1). Specifically, the reading unit 101 first reads a start reading line of the image that extends in the main scanning direction. After that, the reading unit 101 sequentially shifts the lines to be read in the sub-scanning direction. When the reading unit 101 reads an image, read data representing the image is generated. The read data is, for example, data in RGB format.

The determination unit 102 determines whether the image is color during the reading period from when image reading begins to when it ends. Specifically, the determination unit 102 determines whether each pixel of the image read by the reading unit 101 includes a color pixel. For example, if the image includes pixels with a saturation equal to or greater than a predetermined threshold, the image is determined to be color.

The determination unit 102 of this embodiment determines whether or not a line contains color pixels each time the line is read. Hereinafter, the determination by the determination unit 102 may be simply referred to as a "color determination." Note that the trigger for performing the color determination is not limited to the above example. For example, the color determination may be performed when a predetermined number of lines have been read.

During the reading period, the first generation unit 103 generates first print data for color printing the image. Specifically, the first generation unit 103 generates the first print data by converting the read data (RGB format) into CMYK format. In addition, the first generation unit 103 generates first print data for each line of the image read. In other words, the first print data in this embodiment is data representing one line of the image. Once the first print data is generated, it is stored (accumulated) in the first storage unit 108 or the second storage unit 109 in sequence according to the mode (first mode, second mode) described below.

During the reading period, the second generation unit 104 generates second print data for printing the image in monochrome. Specifically, the second generation unit 104 generates the second print data by converting the read data (RGB format) into K format. In addition, the second generation unit 104 generates second print data for each line of the image that is read. In other words, the second print data in this embodiment is data that represents one line of the image. Once the second print data is generated, it is stored (accumulated) in the second storage unit 109 or the first storage unit 108 in sequence according to the mode (first mode, second mode) described below.

As can be understood from the above explanation, in this embodiment, each time a line of an image is read, a color judgment for that image, the generation of the first print data (color), and the generation of the second print data (monochrome) are performed substantially simultaneously. In the above configuration, the first print data and the second print data are generated before a color or monochrome decision is reached in the color judgment. Therefore, there is an advantage in that the time until the image is printed is shortened compared to a configuration in which, for example, after a color judgment decision is reached, the first print data or the second print data is generated in accordance with the decision.

The switching unit 107 switches the image forming device 100 between the first mode and the second mode. Specifically, when the user operates the operation unit appropriately, the mode transitions to either the first mode or the second mode. As will be described in detail later, the time required to print a color image tends to be shorter in the first mode than in the second mode. Also, the time required to print a monochrome image tends to be shorter in the second mode than in the first mode. Therefore, the user transitions to the first mode when printing more color images, and transitions to the second mode when printing more monochrome images.

The first storage unit 108 stores the first print data or the second print data. Specifically, during the reading period, the first storage unit 108 stores the first print data in the first mode and stores the second print data in the second mode. As the first storage unit 108, for example, a memory (such as RAM 1002b) provided in the controller 1010 (see FIG. 2) can be used.

The second memory unit 109, like the first memory unit 108, stores the first print data or the second print data. Specifically, during the reading period, the second memory unit 109 stores the second print data in the first mode and stores the first print data in the second mode. As the second memory unit 109, for example, a memory provided in the engine control unit 1030 (see FIG. 2) can be used.

The print execution unit 110 prints an image using the print data (first print data or second print data) stored in the first storage unit 108. Therefore, if the first mode is determined to be monochrome, the first print data in the first storage unit 108 must be overwritten with the second print data in the second storage unit 109. Similarly, if the second mode is determined to be color, the second print data in the first storage unit 108 must be overwritten with the first print data in the second storage unit 109.

The first control unit 105 executes control to print an image in color. Specifically, when the determination unit 102 determines that the image is in color, the first control unit 105 causes the image to be printed using the first print data stored in the first storage unit 108 in the first mode. On the other hand, when the determination unit 102 determines that the image is in color in the second mode, the first control unit 105 overwrites the second print data stored in the first storage unit 108 with the first print data stored in the second storage unit 109, and causes the image to be printed using the first print data stored in the first storage unit 108.

The second control unit 106 executes control to print the image in monochrome. Specifically, when the determination unit 102 determines that the image is monochrome, in the second mode, the second control unit 106 causes the image to be printed using the second print data stored in the first storage unit 108. On the other hand, in the first mode, the second control unit 106 overwrites the first print data stored in the first storage unit 108 with the second print data stored in the second storage unit 109, and causes the image to be printed using the second print data stored in the first storage unit 108.

As can be understood from the above explanation, when printing an image in monochrome, in the second mode, the process of overwriting the printing data in the first storage unit 108 with the printing data in the second storage unit 109 can be omitted. Therefore, the time required to print a monochrome image is likely to be shorter in the second mode compared to the first mode. Similarly, when printing an image in color, in the first mode, the process of overwriting the printing data in the first storage unit 108 with the printing data in the second storage unit 109 can be omitted. Therefore, the time required to print a color image is likely to be shorter in the first mode compared to the second mode.

Figure 4 is a diagram for explaining a specific example of the operation of the image forming device 100 from when an image is scanned to when it is printed (plotted). The arrows in Figure 4 indicate the communication direction of data (scanned data, print data). In the specific example in Figure 4, of the various modes (first mode, second mode), the operation in the first mode is explained.

As shown in FIG. 4, the image forming device 100 includes a module block 20M and a module block 40M. Module block 20M includes modules (21M-23M) that are used until print data is stored in the first storage unit 108. Module block 40M includes modules (41M-43M) that are used from when print data is stored until printing is performed.

The read data generated when the image is read is input to scanner I/F module 21M. Scanner I/F module 21M performs noise removal and format conversion on the read data. Scanner I/F module 21M then inputs the read data to determination unit 102 and image conversion module 22M. As described above, determination unit 102 uses the read data to determine whether the image is color.

The image conversion module 22M uses the read data (RGB format) to generate both the first print data (CMYK format) and the second print data (K format). In the first mode, the second print data is stored in the second storage unit 109. Meanwhile, the first print data is input to the image compression module 24M. The image compression module 24M compresses the first print data to reduce the data volume. In the second mode, the second print data is stored in the first storage unit 108, and the first print data is stored in the second storage unit 109.

In the first mode, the first print data compressed by the image compression module 24M is stored in the first storage unit 108. The modules that make up the module block 20M can be changed as appropriate. For example, a module that changes the image magnification, a module that performs image shifting, a module that performs gamma correction, etc. may be included in the module block 20M.

When the color determination by the determination unit 102 is completed (when a conclusion is reached as to whether the print is color or monochrome), the print data in the first storage unit 108 is input to the module block 40M. The specific example in FIG. 4 assumes the first mode. In the above case, the first print data (color) is stored in the first storage unit 108, and the second print data (monochrome) is stored in the second storage unit 109. Therefore, if it is determined to be color, the first print data in the first storage unit 108 is input to the module block 40M. On the other hand, if it is determined to be monochrome, the second print data in the second storage unit 109 is stored in the first storage unit 108 (the first print data is discarded), and then the second print data is input to the module block 40M.

In the second mode, the second print data is stored in the first memory unit 108, and the first print data is stored in the second memory unit 109. Therefore, if the print mode is determined to be monochrome in the second mode, the second print data in the first memory unit 108 is input to the module block 40M. On the other hand, if the print mode is determined to be color, the first print data in the second memory unit 109 is stored in the first memory unit 108 (the second print data is discarded), and then the first print data is input to the module block 40M.

When print data is input to module block 40M, the print data is expanded by image expansion module 41M. The print data is then input to resolution conversion module 42M. Resolution conversion module 42M converts the resolution to suit printing. After the resolution has been converted, the print data is input to plotter I/F module 43M. Plotter I/F module 43M converts the format of the print data according to the printing method (inkjet recording method, electrophotographic recording method) and prints it out.

As can be understood from the above explanation, the first print data (color) and the second print data (monochrome) are stored separately in the first storage unit 108 and the second storage unit 109. If both the first print data and the second print data were stored in the first storage unit 108, it may be necessary to have five or more channels from the image conversion module 22M to the first storage unit 108. In the configuration of this embodiment, the number of channels from the image conversion module 22M to the first storage unit 108 can be four or less. This has the advantage of suppressing the inconvenience of an increase in the circuit size of the image forming device 100.

Figure 5 is a flow chart of a specific example of the reading process of the image forming device 100. The image forming device 100 starts the reading process when image reading is started. The specific example in Figure 5 shows the reading process in the first mode among the various modes.

When the reading process is started, the image forming device 100 starts reading the image (S1). That is, the reading period begins. When the reading period begins, read data (RGB format) is generated sequentially for each line of the image. In addition, the image forming device 100 generates both first print data (CMYK format) and second print data (K format) for each read data (each line of the image) (S2). In the first mode, the image forming device 100 stores the first print data in the first storage unit 108 (S3). Meanwhile, the second print data is stored in the second storage unit 109.

Then, the image forming device 100 determines whether the scanned data converted to print data in step S2 contains color pixels (S4). That is, a color determination is performed. If it is determined that color pixels are included (S4: Yes), the image forming device 100 starts printing using the first print data stored in the first storage unit 108, and discards the second print data stored in the second storage unit 109 (S5).

On the other hand, if it is determined in step S4 that no color pixels are included, the image forming device 100 determines whether or not the image reading is complete (S6). That is, it determines whether or not read data (RGB format) for all lines of the image has been generated. If it is determined that the image reading is not complete (S6: No), the image forming device 100 returns the process to step S2. That is, if read data for all lines of the image has not been generated, the process returns to step S2.

As shown in FIG. 5, steps S2 and S3 are repeatedly executed until it is determined in step S4 that the image is color, or until it is determined in step S6 that image reading has been completed. Also, if all lines of the image do not contain color pixels, step S6 is determined as "Yes" and processing proceeds to step S7. In other words, if the image read is monochrome, processing proceeds to step S7.

In step S7, the second print data (K format) stored in the second storage unit 109 is transferred to the first storage unit 108. Specifically, the first print data stored in the first storage unit 108 is overwritten with the second print data stored in the second storage unit 109. In addition, after the second print data is stored in the first storage unit 108, printing using the second print data is started. After executing step S7, the image forming device 100 ends the reading process.

<Summary of the functions and effects of the exemplary embodiment>
<First aspect>
The image forming device (100) of this embodiment includes a reading unit (101) that reads an image, a determination unit (102) that determines whether the image is color during the reading period from when image reading begins to when it ends, a first generation unit (103) that generates first print data for printing the image in color during the reading period, a second generation unit (104) that generates second print data for printing the image in monochrome during the reading period, a first control unit (105) that prints the image using the first print data if the determination unit determines that the image is color, a second control unit (106) that prints the image using the second print data if the determination unit does not determine that the image is color, and a print execution unit (110) that prints the image.

In this embodiment, both first print data for color printing and second print data for monochrome printing are generated, and when the image is monochrome, the second print data is used to print the image. Therefore, for example, monochrome images are more likely to be printed appropriately compared to a configuration in which the first print data that is originally used for color printing is used for monochrome printing.

<Second aspect>
The image forming apparatus of this aspect includes a first storage unit (108) that stores the first print data during the reading period, and a second storage unit (109) that stores the second print data during the reading period, and the print execution unit prints an image using the print data stored in the first storage unit, and the second control unit overwrites the first print data stored in the first storage unit with the second print data stored in the second storage unit when the determination unit does not determine that the image is color. This aspect has the advantage that the number of channels can be reduced in some cases compared to a configuration in which both the first print data and the second print data are stored in a common storage unit.

<Third aspect>
The image forming apparatus of this aspect includes a switching unit (107) for switching between a first mode and a second mode, the first storage unit stores the first print data in the first mode and the second print data in the second mode during a reading period, the second storage unit stores the second print data in the first mode and the first print data in the second mode during a reading period, the first control unit overwrites the second print data stored in the first storage unit with the first print data stored in the second storage unit when the determination unit determines that the print is color, and the second control unit overwrites the first print data stored in the first storage unit with the second print data stored in the second storage unit when the determination unit does not determine that the print is color. This aspect has the advantage of being able to shorten the time required for printing by appropriately switching the mode depending on whether more color images or more monochrome images are printed.

<Fourth aspect>
The image forming method of this aspect includes a step (S1) of reading an image, a step (S4) of determining whether the image is color during the reading period from the start to the end of the image reading, a step (S2) of generating first print data for printing the image in color during the reading period, a step (S2) of generating second print data for printing the image in monochrome during the reading period, a step (S5) of printing the image using the first print data if it is determined that the image is color, and a step (S7) of printing the image using the second print data if it is not determined that the image is color. According to this aspect, the same effect as the first aspect can be achieved.

<Fifth aspect>
The program of this aspect causes a computer to execute each step of the fourth aspect. According to this aspect, the same effects as those of the first aspect can be achieved.

101...reading unit, 102...determination unit, 103...first generation unit, 104...second generation unit, 105...first control unit, 106...second control unit, 107...switching unit, 108...first storage unit, 109...second storage unit, 110...print execution unit.

JP 2006-086629 A

Claims (4)

A reading unit that reads an image;
a determination unit that determines whether the image is in color during a reading period from when reading of the image is started to when reading of the image is ended;
a first generating unit that generates first print data for color printing the image during the reading period;
a second generating unit that generates second print data for printing the image in monochrome during the reading period;
a first control unit that prints the image using the first print data when the determination unit determines that the image is in color;
a second control unit that prints the image using the second print data when the determination unit has not determined that the image is color;
a print execution unit that prints the image ;
a first storage unit that stores the first print data during the reading period;
a second storage unit that stores the second print data during the reading period,
The print execution unit prints the image using the print data stored in the first storage unit,
The second control unit overwrites the first print data stored in the first storage unit with the second print data stored in the second storage unit when the determination unit has not determined that the print data is color.
Image forming device. A switching unit that switches between a first mode and a second mode is provided,
the first storage unit stores the first print data in the first mode and stores the second print data in the second mode during the reading period;
the second storage unit stores the second print data in the first mode and stores the first print data in the second mode during the reading period;
when the determination unit determines that the printing is color, in the second mode, the first control unit overwrites the second printing data stored in the first storage unit with the first printing data stored in the second storage unit;
2. The image forming device of claim 1, wherein, in the first mode, when the determination unit determines that the print data is not color, the second control unit overwrites the first print data stored in the first storage unit with the second print data stored in the second storage unit. Reading an image;
determining whether the image is in color during a period from when reading of the image is started to when reading of the image is ended;
generating first print data for color printing the image during the reading period and storing the first print data in a first storage unit ;
generating second print data for printing the image in monochrome during the reading period and storing the second print data in a second storage unit ;
when it is determined that the image is in color, printing the image using the first print data stored in the first storage unit ;
and if the image is not determined to be in color , overwriting the first printing data stored in the first storage unit with the second printing data stored in the second storage unit, and printing the image using the second printing data stored in the first storage unit . A program for causing a computer to execute the steps according to claim 3 .

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