JP2002108584A - Image processing apparatus and image forming apparatus - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To execute DMA data transfer at an optimal timing when an image editing request such as image movement is made at the time of output of input data, thereby improving the productivity of the image forming apparatus. Improve. In an image forming apparatus that performs DMA data transfer based on descriptor information stored in a descriptor area, an image memory having a descriptor area for storing descriptor information and an image data area for storing image data, In the descriptor information stored in the script area of the image memory 52, an image input / output DMAC 51 instructing and setting operations such as image movement and binding margin when data to be transferred is completed.
At the end of the operation, indicates whether or not to transmit an interrupt signal, and refers to the number of data transfer lines stored in the descriptor information of the descriptor in which the interrupt has occurred according to the presence or absence of the interrupt. A memory control unit 53 for adding the total transfer end line number.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DM for performing DMA data transfer (input / output) to an image memory based on descriptor information stored in a descriptor area.
The present invention relates to an image processing apparatus having an A controller and an image forming apparatus that forms an image based on image data processed by the image processing apparatus.

[0002]

2. Description of the Related Art Image forming apparatuses such as copiers, facsimile machines, printers and scanners have become widespread, and with the advance of digital technology, these image forming apparatuses have also been digitized. In a digitized image forming apparatus,
Image processing is being actively performed and edited by applying an image memory. Among them, there is a function called an electronic sort which stores the image data of a plurality of originals in a memory, collectively outputs a designated number of copies, and eliminates the sorting operation. In order to perform this electronic sort function, it is necessary to hold a plurality of image data, and to store the image data as it is in a semiconductor memory, a memory corresponding to the data amount of the number of stored images is required. Since the memory cost is enormous, it consists of two memories, a semiconductor memory for controlling the image forming apparatus and a storage memory for storing image data.
A secondary storage device such as a hard disk which is less expensive than a semiconductor memory is used as the storage memory.

A semiconductor memory is used as a storage memory, and image data is compressed by a compression process to reduce the amount of data per sheet, thereby reducing the total memory amount.

A plurality of image input / output units such as an image scanner, a printer controller, a file server, and a facsimile controller share the same image memory.

Such a configuration and method are generally used.

On the other hand, in order to execute input / output of image data to / from an image memory, a DMA (Direct Memory) is used.
For example, the use of a memory controller (hereinafter, referred to as a "DMA controller") using a data access method is disclosed in Japanese Patent Laid-Open No. 6-103225.
It is proposed in Japanese Patent Publication No.

A conventional DMA controller transfers data to a specific area of an image memory based on memory area management information called a descriptor. It is also possible to divide a memory area for storing one image into a plurality of descriptors and perform data transfer. For example, by using an image memory in the form of a ring buffer, a memory smaller than the capacity of image data can be used. Input and output of image data can be executed with a capacity.

On the other hand, for image data inputted from the image input means, centering (for a transfer paper having a size larger than the input image data, the image data is arranged at the center of the transfer paper and outputted). Conventionally, when realizing an image editing / processing function of inputting with a margin such as movement or binding margin, a memory larger than the input image data (equivalent to the transfer paper size) is conventionally used. Image editing is performed by the image processing means while securing an area. In this case, when the image editing function is selected, the memory capacity required for processing increases, and preprocessing (memory data clearing outside the input image data area, (Initialization) occurs, and an extra processing time is required, so that a phenomenon occurs in which the productivity of the image forming apparatus is reduced according to the selected function. Also, as a result of performing the image moving process, even if there is no need to output or there is input data that is no longer to be saved, it is considered that the process may be performed while retaining the memory area corresponding to the input data. Can be

A DMA having a structure for transferring data to a specific area of an image memory using a descriptor
The controller designates specific data of the minimum unit (one pixel) (data corresponding to white in a margin area) for an area other than the input image data, and continuously supplies the specific data for a certain period of time. It is also possible to control the operation of outputting the data. Therefore, the memory capacity required for the editing process varies depending on the selected function, but since it is a memory area of about one pixel to several pixels, the increase in the memory capacity described above is minimized and the preprocessing is performed. Can be made to be almost zero. Furthermore, for input data, data transfer to memory (save)
For those that do not need to be, by controlling the operation so that the input data is not transferred to the image memory,
It is also possible to save image memory capacity. In consideration of moving the image after inputting or outputting the image data, it is possible to selectively instruct whether to discard the input data or not.

In an image forming apparatus having a plurality of image input / output means, a plurality of image input / output requests are made at the same time. In this case, in the operation control of the image memory, it is essential to simultaneously process a plurality of data transfers based on a plurality of data transfer requests so that the idle time for execution is minimized. If there is an image processing execution request for this input / output operation, for example, an operation of outputting image data input from a scanner to a plotter will be described as follows. Scanner input (Image 1) Request 2. Plotter output (image 1) + binding margin (required during operation of request 1) Request 3. 3. Scanner input (image 2) (required during operation of request 2) Plotter output (image 2) + binding margin (required during operation of requirement 3) requirement 5. In response to a series of requests for scanner input (image 3) (required during operation of request 4), the same memory area is read out and plotted for request 2 during data transfer (input) of request 1. Is possible, the time from the start of the request until the output of the image 1 can be shortened, so that the productivity of the image forming apparatus is improved.

Similarly, during the data transfer (output) of request 2,
If the image data transfer (input) of the request 3 is executed while securing another memory area, the time required to process the entire request is greatly reduced. Further, the same memory area used for the request 2 as the memory area for the data transfer of the request 3 is selected, and operation control is performed so as to overwrite the portion of the memory area where the data transfer of the image 1 has been completed. As a result, the required capacity of the image memory can be reduced, and the cost of the apparatus can be reduced.

[0012]

However, in the case of performing the above-described control, the output of the data area for which the input operation has not been completed is prohibited in consideration of image processing such as a binding margin, or Processing such as prohibiting data input such as overwriting to a memory area for which output has not been completed is required. Specifically, an image moving operation in which image data at a position earlier than the first image in the sub-scanning direction of the input image data is output as a start point and margin data is added to the rear end of the operation sub-scanning direction, that is, In the case of an operation of skipping the leading end portion of the input image and adding margin data (binding margin) called “minus binding margin” to the rear end side, at least the number of image input lines corresponding to the output start point of the image data is input. Output must be inhibited until the data transfer is completed.

In order to transfer a large amount of image data to the image memory to the image memory at a high speed as described above, the execution timing of the data transfer including the control for prohibiting the above-mentioned operation is required. In order to make the setting, a means for detecting an operation state including an image processing operation for minimizing a time loss and performing accurately is indispensable.

The present invention has been made in view of such a situation of the prior art, and an object thereof is to provide an optimum method when an image editing request such as image movement is made when input data is output. Execute DMA data transfer at the timing,
An object of the present invention is to provide an image processing apparatus capable of improving the productivity of image formation.

Another object of the present invention is to execute a DMA data transfer at an optimal timing when a request for image editing such as image movement is made at the time of output of input data.
An object of the present invention is to provide an image forming apparatus capable of forming an image with high productivity.

[0016]

In order to achieve the above object, the present invention provides an image memory having a descriptor area for storing descriptor information and an image data area for storing image data. A DMA controller that performs DMA data transfer of the image data based on the descriptor information, and an image processing apparatus that performs DMA data transfer based on descriptor information stored in the descriptor area;
The DMA controller includes, in the descriptor information stored in the descriptor area, means for setting processing when data to be transferred is completed, and whether or not to transmit an interrupt signal when the set processing is completed. Means for instructing whether or not there is an interrupt, and means for referring to the number of data transfer lines stored in the descriptor information of the descriptor in which the interrupt occurred and adding the total number of transfer end lines in one screen. A configuration was provided.

In this case, when inputting the image data into the descriptor information, the DMA controller divides the descriptor in one screen into a plurality of equal parts in advance and outputs the image data to the image data being transferred. When a request is issued and there is a request to output image data starting from a line position earlier than the image head in the sub-scanning direction with respect to the image data, the total number of transfer end lines in one screen is added. Means for comparing the number of lines obtained by the means with the number of output start lines to determine whether or not the total number of transfer end lines in one screen has reached the number of output start lines; It is determined whether or not output is possible. The request to output image data starting from a line position ahead of the image head in the sub-scanning direction with respect to the image data includes, for example, setting of image movement and binding margin. Also,
The DMA controller sets the descriptor in one screen to only three divisions, and sets the first division line number to one line,
The second is the maximum number of settable image output start lines, and the third is the remaining number of lines.

According to the present invention, there is provided an image forming apparatus comprising: an image processing apparatus having the above-described configurations; and an image forming means for forming an image based on image-processed image data.
The input image data is subjected to image processing by the image processing apparatus, and an image is formed based on the image-processed data. Specifically, in an image forming apparatus having a controllable means by dividing a storage area into at least one or more descriptor areas, by providing attribute data for controlling the operation of each descriptor area, To improve the use efficiency of the storage area and reduce the load on the control means such as the CPU for controlling the storage device, and to shorten and simplify the preparation period required for controlling the input and output of image data. Was made easier.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an overall configuration of a digital copying machine according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a relationship between a document table and a document placed thereon in FIG. 3, FIG. 3 is a timing chart for explaining an image synchronization signal output from the IPU of FIG. 1, FIG. 4 is a block diagram showing details of a storage unit of FIG. 1, and FIG. 5 shows a configuration of a memory control unit of FIG. FIG. 6 is a block diagram showing the operation of the video input DMAC according to this embodiment.

The digital copying machine according to the present embodiment functions as a reading unit 10, an image forming unit 20, and an image processing apparatus that stores image data read by the reading unit 10 and forms an image with the image forming unit 20. And a control unit 40 that performs the control.

The reading unit 10 includes a document table 11, an exposure lamp 12 for exposing a document placed on the document table 11,
A plurality of reflection mirrors 13 and a CCD (image sensor) 1
4 and an image processing unit (hereinafter referred to as “IP
U ”) and a scanner controller 16. Further, the image forming unit 20 includes the photosensitive drum 2
2, a charging charger 21, a writing unit 23, a developing device 24, which is disposed along the outer circumference of the photosensitive drum 22;
An image forming system including a transfer charger 28, a separation charger 29, a cleaning device 34 and a static elimination charger 35, a paper feed tray 26, a registration roller 27, and a fixing device 3.
1. A paper feeding and fixing system including a paper discharge roller 32 and a paper discharge tray 33, and a plotter control unit 36 for controlling the image forming system, the paper feeding and fixing system, the writing unit 23, and the like. The control unit 40 includes a system control unit 41, an operation unit 42, a storage unit 43,
It comprises an AX section 44 and a selector section 45.

The reading unit 1 having the above-described components.
The process of reading 0 and the image forming process of the image forming unit 30 will be briefly described.

In the reading section 10, the original D is
Scan light is exposed by a movable exposure lamp 12 along the line, light reflected from the document is guided to a CCD 14 by a plurality of reflection mirrors 13, and photoelectric conversion is performed by the CCD 14 to generate an electric signal corresponding to the intensity of the light. The image data converted into the electric signal by the CCD 14 is input to the IPU 15 and
The PU 15 performs image data processing such as shading correction on the input image data, and further performs A / D
It is converted into an 8-bit digital signal. Further, image processing such as scaling processing and dither processing is performed, and an image signal is sent to the image forming unit 20 together with an image synchronization signal. Scanner controller 1
6 performs detection of various sensors, control of a drive motor, and the like, and sets various parameters in the IPU 15 to execute the above process. The above is the reading process.

In the image forming section 20, a photoreceptor drum 22, which is uniformly charged by a charging charger 21 and rotates at a constant speed, is provided.
Is exposed with a laser beam modulated by the image data from the writing unit 23. An electrostatic latent image is formed on the surface of the photoreceptor drum 22, and the latent image is developed with a toner by the developing device 24 to be visualized as a toner image. On the other hand, the sheet on which the image is to be transferred is carried out of the sheet feeding tray 26 by the sheet feeding roller 25 in advance, and waits at the position of the registration roller 27. Then, the photosensitive drum 22 is conveyed in a timely manner with the leading end of the image forming position, the toner on the photosensitive drum 22 is electrostatically transferred to transfer paper by a transfer charger 28, and the transfer paper is transferred to the photosensitive drum 22 by a separation charger 29. Separate from afterwards,
The fixing device 31 heats and fixes the toner image on the transfer paper,
The paper is discharged to a paper discharge tray 33 by a paper discharge roller 32. The toner remaining on the photosensitive drum 22 after the electrostatic transfer is removed from the photosensitive drum 22 by the cleaning device 34, and further, the photosensitive drum 2 is removed by the discharging charger 35.
The static elimination of the two surfaces is performed. The plotter control unit 36 performs detection of various sensors in the image forming unit and controls a drive motor and the like in order to execute the above process. The above is the image forming process.

The image synchronization signal output from the IPU 15 of the reading unit 10 is as shown in the timing chart of FIG. In the figure, / FGATE is a frame gate signal, which is a signal representing an image effective range for an image area in the sub-scanning direction. Image data is valid while this signal is at low level (low active).
This / FGATE is a line synchronization signal (/ LSYN
Asserted or negated at the falling edge of C). / LSYNC is asserted for a predetermined number of clocks at the rising edge of the pixel synchronization signal (PCLK), and after the rising of this signal, the image data in the main scanning direction becomes valid after a predetermined clock. The image data sent is
There is one for one cycle of PCLK, which is divided into a portion corresponding to 400 DPI from the portion indicated by arrow Z in FIG. The image data is transmitted as raster format data with the arrow Z at the top. The effective sub-scanning range of image data is usually determined by the size of the transfer paper.

As shown in FIG. 1, the control section 40 of the digital copying machine comprises a system control section 41, an operation section 42, a storage section 43, a FAX section 44 and a selector section 45.
The system control unit 41 detects an input state of the operator to the operation unit 42, sets various parameters to the reading unit 10, the storage unit 43, the image forming unit 20, and the FAX unit 44,
A process execution instruction is performed by communication. Further, the status of the entire system is displayed on a display unit (not shown) provided in the operation unit 42. The instruction to the system control unit 41 is given by a key input to the operation unit 42 by the operator.

The FAX unit 44 performs binary compression of the transmitted image data based on the FAX data transfer rules such as G3 and G4 in accordance with an instruction from the system control unit 41.
Transfer to a telephone line. Also, the fax line 44 from the telephone line
The data transferred to the image forming unit 20 is restored to binary image data, sent to the writing unit 23 of the image forming unit 20, and visualized. The selector unit 45 changes the state of the selector according to an instruction from the system control unit 41, and reads the source of image data for forming an image, the storage unit 43, the FAX
Select from one of the sections 44.

The storage unit 43 normally stores image data of a document input from the IPU 15 and is used for copy applications such as repeat copy and rotation copy. The storage unit 43 is also used as a buffer memory for temporarily storing the binary image data from the FAX unit 44. These data storage instructions are given by the system control unit 41.

As shown in FIG. 4, the storage unit 43 stores an image input / output DMA controller (hereinafter, referred to as an “image input / output DMA controller”).
C) 51, image memory 52, memory control unit 5
3. It is composed of an image transfer DMAC 54, a code transfer DMAC 55 and a compression / expansion unit 56. Image input / output DM
The AC 51 is composed of a CPU and a logic circuit, communicates with the memory control unit 53 to receive a command, performs an operation setting according to the command, and as status information for notifying the state of the image input / output DMAC 51. Send. When an image input command is received, the input image data is packed as 8-pixel memory data in accordance with the input image synchronization signal, and is output to the memory control unit 53 together with the memory access signal as needed. When an image output command is received, image data from the memory control unit 53 is output in synchronization with an output image synchronization signal. Also,
The image memory 52 stores image data, and is configured by a semiconductor storage element such as a DRAM. The total memory capacity of the image memory is, for example, 4 Mbytes of A3 size of binary image data having a writing density of 400 DPI and 4 Mbytes of electronic sort storage memory, for a total of 8 Mbytes. The image memory 52 is controlled by reading and writing from the memory control unit 53.

The memory control unit 53 is composed of a CPU and a logic circuit, communicates with the system control unit 41, receives a command, and sets an operation according to the command. The memory control unit 53 also transmits status information to notify the state of the storage unit 43. The operation commands from the system control unit 41 include image input, image output, compression, decompression, and the like. Image input and image output commands are transmitted to the image input / output DMAC 41, compression-related commands are transmitted to the image transfer DMAC 54, code The data is transmitted to the transfer DMAC 55 and the compression / decompression device 56.

As shown in FIG. 5, the memory controller 53 includes an arbiter 57 and an access controller 58. The arbiter 57 includes an image input / output DMAC 51, an image transfer DMA
C54, adjusts the memory access request signal from the code transfer DMAC 55, and outputs an access permission signal. The arbiter 57 has a built-in refresh control circuit (not shown).
1. In the order of the image transfer DMAC 54 and the code transfer DMAC 55, a memory access permission signal is actively output to the permission destination under the condition that the memory access is inactive. Also,
A memory address is selected together with the memory access permission signal, and a trigger signal indicating the start of memory access is output to the access control circuit 58. On the other hand, the access control circuit 58 divides the input physical address into a row address and a column address corresponding to a DRAM which is a semiconductor memory by a signal from the access control circuit 58, and outputs it to an 11-bit address bus. In addition, according to the access start signal from the arbiter 57, it outputs a DRAM control signal (RAS, CAS, WE).

Referring back to FIG. 4, the image transfer DMAC 54 will be described. The image transfer DMAC 54 is composed of a CPU and a logic circuit, communicates with the memory control unit 53, receives a command, and sets an operation according to the command. And sends it as status information to inform the status. When a compression command is received, a memory access request signal is output to the memory control unit 53, and when the memory access permission signal is active, image data is received and transferred to the compression / expansion unit 56. Image transfer DMA
C54 also incorporates an address counter (not shown) that counts up in response to a memory access request signal, and outputs a 22-bit memory address indicating a storage location where image data is stored.

The code transfer DMAC 55 is composed of a CPU and a logic circuit, communicates with the memory control unit 53, receives a command, performs an operation setting in accordance with the command, and transmits as status information to notify a state. I do. When a decompression command is received, a memory access request signal is output to the memory control unit 53, and when the memory access permission signal is active, image data is received and transferred to the compression / decompression unit 56. Also, an address counter that counts up in response to a memory access request signal is built in, and indicates a storage location where image data is stored.
Outputs a 2-bit memory address. This code transfer D
The descriptor access operation of the MAC 55 and the image transfer DMAC 54 will be described later.

The compression / expansion unit 56 is also composed of a CPU and a logic circuit, communicates with the memory control unit 53, receives a command, sets an operation according to the command, and transmits it as status information to inform the status. I do. Note that the binary data is processed by the MH encoding method.

The overall operation of the storage unit configured as described above includes an image transfer DMAC 54 for transferring image data to a predetermined image area of the image memory 52 in accordance with an instruction from the system control unit 41 during image input and data storage. Write and read by. At this time, image transfer D
The MAC 54 counts the number of image lines.

Next, the descriptor access operation and the data transfer operation of the image transfer DMAC 54 will be described with reference to FIG. In this embodiment, the video input DMAC
Constitute the image transfer DMAC. Video input DMA
C61 includes a descriptor storage register 62 and a data transfer control unit 63 including a CPU and the like. As shown in the figure, the image data is divided into four bands, band 1, band 2, band 3, and band 4, and the image data of the number of lines set in each band is transferred.

The procedure for adding the total number of transfer lines in one image will be described below. First, when the video input DMAC 61 receives the transfer command, the DMA starts, and the descriptor 1 is stored in the internal descriptor storage register 62 in advance at the a address which is the chain destination address set by the CPU (not shown) of the data transfer control unit 63. Read access is performed, and the contents of the descriptor 1 in the memory are loaded into the descriptor storage register 62. The loaded content is composed of four words, and includes a chain destination address indicating the storage address of the next descriptor, a data storage (transfer) destination address indicating the head address of the data to be transferred, and a data amount of the data to be transferred. This is format information indicating the number of data transfer lines indicated by the number of lines, and whether or not to generate a CPU interrupt when the transfer of the set number of lines is completed. In the least significant bit of the format information, a bit indicating whether or not a CPU interrupt is to be generated when the transfer of the set number of lines has been completed is, for example, "0", a CPU interrupt is generated, and "1" is generated. The CPU interrupt is arranged as a mask. Thus, the video input DMAC 61
The DMA of the descriptor system is divided into data of one screen in units of transfer by the descriptor, and an interrupt is issued after each transfer, so that the current accurate number of transfer lines is stored in the transfer line number register in the video input DMAC 61. For example, management can be performed without polling by the CPU of the data transfer control unit 63 or the like.

In FIG. 6, one image data is divided into four bands, and the bits of the four descriptors are 0, 0, 0, 0 in order from 1 to 4. When the transfer of the image data of each band is completed, a CPU interrupt is generated, and the generation of the interrupt causes the number of lines set in each descriptor to be, for example, the data transfer control unit 63.
, The number of transfer end lines can be detected.

In the case of the "minus binding margin" in which the leading end of the image is skipped and a margin is provided at the trailing end, it is necessary to detect the timing of the DMA transfer start of image data output after the image for the binding margin is input. . This is because the number of input image lines is detected by a CPU interrupt, and is compared with the number of output start lines (the number of lines for the binding margin) to detect the timing of DMA transfer start of image data output.

Here, according to FIG. 7, the DM of the image data output is
The detection of the start of the A transfer will be described. FIG. 7 is a flowchart for detecting the timing of the start of the DMA transfer when the binding margin is provided. When a CPU interrupt occurs, the number of transfer lines set in the descriptor is detected (step 701), and it is checked whether the total number of transfer lines is equal to or greater than the number of output start lines (step 7).
02). If the total transfer line number is equal to or greater than the output start line number, data output is enabled (step 703). If the total transfer line number is equal to or less than the output start line number, data output is disabled (step 704). Accordingly, even when a plotter output request is issued for image data to which data from an image input device such as a plotter is being input and a sub-scanning minus binding margin is requested for the image data, the total transfer is performed. By managing the number of lines, if the relationship between the number of binding lines and the total number of transfer lines is such that the number of binding lines ≦ the total number of lines, it is possible to determine that plotter data can be output.

In the above-described embodiment, the case where the input image data is divided into four bands has been described. However, the number of divisions is not limited to this, and as shown in FIG. Is also good. The case of dividing into three bands will be described with reference to FIG. FIG. 8 is a diagram illustrating the configuration of a descriptor when input image data is divided into three bands.

As shown in FIG. 8, the transfer data as the input image data is divided into three bands of bands 1, 2 and 3, and the first divided line number A, the data transfer line number A, is 1, 2 The number B of data transfer lines, which is the first number of divided lines, can be set. The maximum number of image output start lines (number of image moving lines), the number C of data transfer lines, which is the third number of divided lines, is the number of lines of the remaining image. 3 shows the configuration of each descriptor. If there is no image movement, the first CPU interrupt is the timing for starting DMA transfer of image data output. If there is an image shift, the second CPU interrupt is performed regardless of the number of shift lines.
The U interrupt is the timing for starting the DMA transfer of the image data output. Thus, one to be transferred
By dividing the screen data into three lines, one line, the maximum binding line, and the remaining input lines, there is no binding margin in the sub-scanning direction of the binding margin, or if it is positive, the interruption of the first descriptor has occurred. In this case, it is determined that plotter output is possible. In the case of a minus binding margin in the sub-scanning direction, it is possible to determine that plotter output is possible if an interrupt of the second descriptor has occurred. And the number of interrupts to the CPU is reduced, resulting in a CP
The processing load on U can be reduced.

Although the above embodiment has been described by taking a digital copying machine as an example, an image input / output device such as a facsimile, a printer, a scanner, a network file server, or a digital composite device having a plurality of functions among these devices. The present invention is also applicable to a machine type image forming apparatus.

[0045]

As is apparent from the above description, according to the first aspect of the present invention, the DMA controller performs processing when the data to be transferred is completed in the descriptor information stored in the descriptor area. Means for setting whether an interrupt signal is transmitted when the set processing is completed, and data stored in descriptor information of the descriptor in which the interrupt has occurred, according to the presence or absence of the interrupt. Referring to the number of transfer lines, 1
Means for adding the total number of transfer end lines in the screen, so that the data of one screen is divided by the unit of transfer by the descriptor, and an interrupt is issued after each transfer, so that the current accurate number of transfer lines can be obtained. Can be managed without polling the transfer line number register in the DMA controller by, for example, a CPU that controls a storage device, and the productivity of image formation can be improved.

According to the second aspect of the present invention, when inputting image data into descriptor information, the DMA controller divides a descriptor in one screen into a plurality of equal parts in advance, and converts the descriptor into image data being transferred. If an image data output request is issued and there is a request to output image data starting from a line position earlier than the image head in the sub-scanning direction with respect to the image data, the total transfer end line in one screen Means for comparing the number of lines obtained by the means for adding the number with the number of output start lines to determine whether or not the total number of transfer end lines in one screen has reached the number of output start lines; It is determined whether or not the image data can be output, so that the plotter can properly determine whether or not the data can be output. In other words, even when a plotter output request is issued for image data being input from the image input unit and a sub-scanning minus binding margin is requested for the image data, the total number of transfer lines is managed. Therefore, if the relationship between the number of binding lines and the total number of transfer lines is such that the number of binding lines ≦ the total number of lines, it can be determined that the plotter can output data.

According to the third aspect of the present invention, the request to output image data starting from a line position earlier than the head of the image in the sub-scanning direction with respect to the image data is set for image movement and binding margin. With respect to these processes, it is possible to favorably determine whether the plotter can output data.

According to the fourth aspect of the present invention, the data of one screen to be transferred is divided into one line, a maximum binding margin line, and the remaining input lines. 1 if there is no binding allowance or plus
If an interrupt for the descriptor has occurred, it is determined that plotter output is possible.
If an interrupt for the descriptor has occurred, it is possible to determine that plotter output is possible. Optimal determination control and the number of interrupts to the CPU that controls the storage device are suppressed depending on the binding direction, resulting in a processing load on the CPU. Can be reduced.

According to the fifth aspect of the present invention, an image is formed based on the image data processed by the image processing apparatus according to any one of the first to fourth aspects. Therefore, when an image editing request such as image movement is made at the time of output, DMA data transfer is executed at an optimal timing, and an image can be formed with high productivity.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining an overall configuration of an embodiment of the present invention.

FIG. 2 is a diagram for explaining a relationship between the document table of FIG. 1 and a document placed thereon.

FIG. 3 is a timing chart for explaining an image synchronization signal output from the IPU of FIG. 1;

FIG. 4 is a block diagram for explaining a configuration of a storage unit in FIG. 1;

FIG. 5 is a block diagram for explaining a configuration of a memory control unit in FIG. 4;

FIG. 6 is a diagram for explaining the configuration of a video input DMAC used in this embodiment together with image data.

FIG. 7 is a flowchart for detecting a timing of starting a DMA transfer when a binding margin is provided.

FIG. 8 is a diagram illustrating a configuration of a descriptor when input image data is divided into three bands.

[Explanation of symbols]

 Reference Signs List 10 reading unit 20 image forming unit 41 system control unit 42 operation unit 43 storage unit 44 FAX unit 45 selector unit 51 image input / output DMAC 52 image memory 53 memory control unit 54 image transfer DMAC 55 code transfer DMAC 56 compression / expansion unit 61 video input DMAC 62 Descriptor storage register 63 Data transfer control unit 63

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yasuhiro Hattori 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Yasumitsu Shimizu 1-3-6 Nakamagome, Ota-ku, Tokyo Share Ricoh Company (72) Inventor Takao Okamura 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Company (reference) 2C061 AP03 AP04 AP07 AQ06 HJ08 HK23 HS07 2C087 AA03 AA09 AC08 BA03 BA14 BB10 BC01 BD40 BD41 BD42 CA02 CA04 2C187 AC07 AD03 5B021 AA05 AA19 BB11 BB12 CC06 CC08 QQ04

Claims (5)

[Claims] 1. An image memory having a descriptor area for storing descriptor information and an image data area for storing image data, and performing DMA data transfer of the image data stored in the image memory based on the descriptor information. An image processing apparatus comprising a DMA controller and performing DMA data transfer based on descriptor information stored in the descriptor area, wherein the DMA controller transfers the data into the descriptor information stored in the descriptor area. Means for setting processing when data is completed; means for instructing whether or not to transmit an interrupt signal when the set processing is completed; and descriptor for the descriptor in which the interrupt has occurred according to the presence or absence of the interrupt. The data transfer line stored in the information Means for referring to the number of inputs and adding the total number of transfer end lines in one screen. 2. When inputting the image data in the descriptor information, the DMA controller divides a descriptor in one screen into a plurality of equal parts in advance, and requests the image data during data transfer to output image data. If there is a request to output image data starting from a line position earlier than the image head in the sub-scanning direction with respect to the image data, a means for adding the total number of transfer end lines in one screen Means for comparing the obtained number of lines with the number of output start lines to determine whether or not the total number of transfer end lines in one screen has reached the number of output start lines. 2. The image processing device according to claim 1, wherein it is determined whether output is possible. 3. A request for outputting image data starting from a line position earlier than the image head in the sub-scanning direction with respect to the image data is image movement and / or binding margin setting. Item 3. The image processing device according to Item 2. 4. The DMA controller divides a descriptor in one screen into three, and sets the first number of divided lines to one.
The image processing apparatus according to claim 1, wherein the second line is a settable maximum image output start line number, and the third line is a remaining line number. 5. An image processing apparatus according to claim 1, further comprising: an image forming unit configured to form an image based on the image processed image data. An image forming apparatus that performs image processing by the image processing apparatus and forms an image based on the image-processed data.