JP4494718B2 - Image forming apparatus and memory control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus including a page memory having a function of storing an input image and printing out the stored image in an image forming apparatus such as a digital copying machine, a facsimile, a printer, and a scanner. It is about.
[0002]
[Prior art]
In recent years, image forming apparatuses frequently process data for full-color images, and the memory capacity for handling color images has also increased. In such an image forming apparatus, there is a conventional example in which the use efficiency of a page memory that processes image data of a color image in units of pages is improved (for example, Patent Document 1).
[0003]
In this conventional image forming apparatus, yellow (Y), magenta (M), cyan (C), and black (K) image forming units are provided in tandem along the intermediate transfer belt. The image forming apparatus can form an image without increasing the memory capacity even if the image cannot store color image data in the memory.
[0004]
The image forming apparatus includes a resolution conversion unit that converts the resolution of image data and a determination unit that determines whether or not the memory overflows. If it is determined that the memory overflows, the image data whose resolution has been reduced by the resolution conversion means is compressed and stored in the memory so that a color image can be obtained even with a small memory capacity. Yes.
[0005]
An example of managing page memories in other image forming apparatuses will be described. In this image forming apparatus, a part of the page memory can be used to input a read image of an original without occupying the entire page memory for image forming data transfer during image forming performed for printing. Increasing the use efficiency of page memory has been done.
[0006]
In particular, a full-color image forming apparatus that prints images by forming two-side images side by side on the intermediate transfer unit, combining a plurality of colors, and then transferring them to transfer paper forms the original images on the intermediate transfer unit side by side. For this reason, for example, the page memory required for full color uses page memory for 2 planes × 4 colors, that is, 8 pages.
[0007]
At this time, if the page memory for 8 pages is used in the printing operation due to the limitation on the system configuration such as when the page memory is small, the image forming apparatus cannot perform the original reading operation that operates in parallel. Productivity decreases.
[0008]
Therefore, the page memory used exclusively for printing so that the image data is read by the document reading means, the image data stored in the HDD is expanded to the page memory, and the two sides are arranged on the intermediate transfer unit to perform image formation. Management of a page memory that has been acquired in advance has been proposed.
[0009]
This page memory dedicated for printing is used to read an image for printing from the HDD to the page memory. In addition, the print-only page memory is acquired in advance so that image data input processing such as document reading is interrupted during full-color printing so that the page memory for printing does not run out, and use by input processing is prohibited. As a result, a state in which the page memory for printing cannot be acquired during full-color printing is avoided, and the image forming apparatus outputs normal full-color printing without color misregistration.
[0010]
[Patent Document 1]
JP 2000-253223 A
[0011]
[Problems to be solved by the invention]
However, the page memory management dedicated to printing in the image forming apparatus having such a configuration cannot be said to be sufficiently managed, and depending on the situation, the inter-color (M, C, Y, K) during full color printing. In this case, there is a problem that a page memory for printing cannot be obtained.
[0012]
The present invention provides page memory management that realizes a parallel operation of image input / output using a page memory without causing a page memory for printing to be acquired or a state in which acquisition is delayed. An object of the present invention is to provide an image forming apparatus and a memory control method.
[0013]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides an image formation that stores input image data and image data to be printed using a memory area in which a plurality of page memories having a prescribed size are continuously arranged. In the apparatus, page memory acquisition means for acquiring a page memory for storing the input image data and image data to be printed, and a part of the page memory acquired by the page memory acquisition means for storing image data to be printed Selecting means for selecting as a print-only page memory that is a page memory for printing, a print page memory setting means for setting the page memory selected by the selection means as the print-only page memory, and stored in the page memory The entered Storage means for further storing image data, Entered A page memory in which image data is not stored in the storage means is prohibited from being set as the print-only page memory. Entered When the image data is stored in the storage unit, the page memory can be set as the print-only page memory.
[0015]
In order to solve the above problem, the present invention provides: Select after the page memory acquisition means has acquired the page memory It is characterized by that.
[0016]
In order to solve the above problem, the present invention provides: Select a page memory that is contiguous with the page memory that is already set as a print-only page memory It is characterized by that.
[0017]
In order to solve the above problem, the present invention stores input image data and image data to be printed using a memory area in which a plurality of page memories having a prescribed size are continuously arranged. In the memory control method, a page memory acquisition stage for acquiring a page memory for storing the input image data and image data to be printed, and an image for printing a part of the page memory acquired in the page memory acquisition stage A selection stage for selecting as a print-only page memory, which is a page memory for storing data, a print page memory setting stage for setting the page memory selected in the selection stage as the print-only page memory, and the page memory Remembered The entered More image data In memory And storing a storage step, Entered A page memory in which image data is not stored in the storage stage is prohibited as the print-only page memory, Entered When the image data is stored in the storing step, the page memory can be set as the print-only page memory.
[0021]
As described above, according to the present invention, the page memory for printing cannot be acquired or a state in which the acquisition is delayed does not occur, and the parallel operation of image input / output using the page memory can be performed more efficiently. It is possible to provide an image forming apparatus that performs page memory management and a memory control method.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, Embodiment 1 of the present invention will be described.
[0023]
The structure of an image forming apparatus according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a configuration diagram of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a configuration diagram of the image forming unit. FIG. 3 is a block diagram showing the configuration of the control unit. FIG. 4 is a development view showing images of two surfaces formed on the intermediate transfer belt. FIG. 5 is a block diagram showing the internal configuration of the image processing unit. FIG. 6 is a block diagram showing the internal configuration of the memory controller and the image memory.
[0024]
As shown in FIG. 1, the image forming apparatus includes a scanner unit 1, a printer unit 2, and a paper feed unit 3. The scanner unit 1 sends image information of a document placed on a contact glass 11 to a color CCD image sensor (hereinafter referred to as a color CCD) 13 by an optical scanning unit 12 having a light source, a plurality of mirrors, and a lens. The color CCD 13 separates the colors into red R, green G, and black K, reads each color, and converts it into an electrical image signal.
[0025]
The image signal that has been color-separated into red R, green G, and black K undergoes color conversion processing, is converted into a color component composed of black K, cyan C, magenta M, and yellow Y, and is sent to the printer unit 2.
[0026]
The printer unit 2 includes an image forming unit 21, a fixing unit 22, and a transfer paper transport unit 23. As shown in FIG. 2, the image forming unit 21 includes a photoreceptor 24, a revolver unit 25, a transfer unit 26, and a writing unit 27. The printer unit 2 includes a static elimination lamp 28, a charging charger 29, a revolver unit 25, a toner adhesion amount sensor 30, a pre-transfer static elimination lamp 31, a transfer unit 26, and a drum cleaning unit 32 along the rotation direction of the photosensitive member 24. Is provided.
[0027]
The revolver unit 25 includes developing devices 251, 252, 253, and 254 for each color of black K, cyan C, magenta M, and yellow Y, and a revolver home position sensor 255.
[0028]
The transfer unit 26 is wound around a plurality of rollers, and includes an intermediate transfer belt 261 having a reference mark 262, a belt transfer charger 263, a mark sensor 264 for reading the reference mark 262, a paper transfer charger 265, and A belt cleaning portion 266 is provided.
[0029]
The intermediate transfer belt 261 has, for example, twice the longitudinal length of A4 and twice the circumference of the photosensitive member 24 including the interval between the transfer sheets (inter-paper). Two screen images of the same color can be formed on the intermediate transfer belt 261 by two rotations. The transfer paper transport unit 23 provided on the upstream side of the paper transfer charger 265 is disposed upstream of the registration roller 231 for feeding the transfer paper and a predetermined distance Lr from the registration roller 231 to detect the leading edge of the transfer paper. A leading edge detection sensor S1.
[0030]
Next, the paper feed unit 3 shown in FIG. 1 will be described. The paper feed unit 3 includes a plurality of paper feed trays 41, 42, and 43. Each of the paper feed trays 41 to 43 has a paper feed claw 44 and a paper feed roller 45, and transfer paper detection sensors S2, S3, and S4 for detecting the transfer paper are provided on the exit side of the paper feed roller 45, respectively. It has been. The transfer paper fed from the paper feed unit 3 is sent to the transfer paper transport unit 23 by a transport roller 46 provided at the outlet of the paper feed unit 3.
[0031]
Next, the control unit of the image forming apparatus will be described with reference to FIG. The control unit 5 of the image forming apparatus controls operations of the scanner unit 1, the printer unit 2, and the paper feed unit 3 as shown in FIG. 3. Further, the control unit 5 includes a central control unit 51 that displays an operation state and the like on the display unit 4, a transfer sheet interval detection unit 52, an operation mode change unit 53, and an image processing unit (hereinafter referred to as IPU) 100.
[0032]
Among these, the transfer sheet detection unit 52 receives the transfer sheet detection signals from the leading edge detection sensor S1 provided in the printer unit 2 and the transfer sheet detection sensors S2, S3, and S4 provided in the sheet feeding unit 3. . In response to the input transfer sheet detection signal, the transfer sheet interval detection unit 52 detects the rear end of the first transfer sheet to be fed and 2 when chamfering is performed for forming two images on the intermediate transfer belt 261. The distance from the leading edge of the transfer paper sent to the sheet is detected.
[0033]
The operation mode changing unit 53 detects when the interval between the first transfer sheet and the second transfer sheet detected by the transfer sheet interval detection unit 52 becomes longer than a predetermined reference value due to a delay in timing. The operation mode for two-sided printing is invalidated, and the operation mode is changed to an operation mode for forming an image for each side on the intermediate transfer belt 261.
[0034]
The contents of the processing when a full color image is formed for one side by the image forming apparatus configured as described above will be described with reference to FIG. 2 again.
[0035]
The image forming unit 21 rotates the intermediate transfer belt 261 of the photosensitive member 24 and the transfer unit 26. The image forming unit 21 starts reading the black K image data at a predetermined timing after the mark sensor 264 of the transfer unit 26 detects the reference mark 262 of the intermediate transfer belt 261. Based on the black K image data, the optical writing unit 27 forms an electrostatic latent image on the photosensitive member 24.
[0036]
The electrostatic latent image formed on the photosensitive member 24 is visualized by the black K developing unit 251 of the revolver unit 25. The visualized black image K is primarily transferred to the intermediate transfer belt 261 by the belt transfer charger 263 at a timing based on the reference mark 262 of the intermediate transfer belt 261 detected by the mark sensor 264.
[0037]
When the primary transfer of the black image K of the first color is completed, the revolver unit 25 rotates and the cyan C developing device 252 contacts the photoconductor 24. Thereafter, a cyan image C is formed on the photoreceptor 24. The formed cyan image C is primarily transferred to the intermediate transfer belt 261 at a timing based on the detection of the reference mark 262 by the mark sensor 264, and the first color black image K and the second color cyan image C are superimposed. Is done. This image formation and primary transfer are repeated for each image of magenta M and yellow Y, and a full-color toner image is formed on the intermediate transfer belt 261.
[0038]
The full color toner image formed on the intermediate transfer belt 261 is secondarily transferred to the transfer paper sent from the transfer paper transport unit 23 by the paper transfer charger 265, and the transfer paper on which the full color toner image is transferred is transported on the transfer paper. The belt 33 is sent to the fixing unit 22 where it is fixed and discharged. A belt cleaning unit 266 is brought into contact with the intermediate transfer belt 261 on which the toner image is secondarily transferred to the transfer paper. The belt cleaning unit 266 removes the toner remaining on the surface of the intermediate transfer belt 261 and prepares for the next image formation.
[0039]
When an image of one color is formed, it is not necessary to superimpose toner images of different colors on the intermediate transfer belt 261. Therefore, image formation is started without particularly detecting the reference mark 262. In this image formation, writing at a predetermined timing, development, primary transfer, secondary transfer, and cleaning of the intermediate transfer belt 261 are sequentially performed. Further, when a plurality of images are continuously formed, image formation is performed at a necessary image interval regardless of the rotation of the intermediate transfer belt 261.
[0040]
Next, a description will be given of a two-chamfer operation mode in which a full-color image is formed on the intermediate transfer belt 261 by two sides. First, when the intermediate transfer belt 261 rotates and the mark sensor 264 detects the reference mark 262, a first black image K1 is formed on the photosensitive member 24. As shown in the development view of FIG. 4, the formed black image K1 is transferred to the intermediate transfer belt 261 by the belt transfer charger 263 at a timing based on the detection of the reference mark 262 of the intermediate transfer belt 261 by the mark sensor 264. Primary transfer.
[0041]
Subsequently, a second black image K2 is formed on the photosensitive member 24. The formed black image K2 is primarily transferred to an area after the area where the black image K1 of the intermediate transfer belt 261 is transferred. When the secondary transfer of the black images K1 and K2 of the first color is completed, the revolver unit 25 rotates and the cyan C developing device 252 is brought into contact with the photosensitive member 24. Then, the first cyan image C1 is formed on the photoconductor 24. The formed cyan image C1 is primarily transferred to the intermediate transfer belt 261 at a timing based on the detection of the reference mark 262 by the mark sensor 264. Then, the first color black image K1 and the second color cyan image C1 are superimposed.
[0042]
Thereafter, a second cyan image C2 is formed on the photoreceptor 24. The formed cyan image C2 is primarily transferred to the intermediate transfer belt 261 and superimposed with the black image K2. This image formation and primary transfer are repeated for each image of magenta M and yellow Y, and a first full-color image FC1 and a second full-color image FC2 are formed on the intermediate transfer belt 261.
[0043]
The registration roller 231 rotates at a constant secondary transfer timing after the image formation of the yellow Y image, which is the final color of the image FC1 on the first surface, is started. Then, the first full-color image FC1 is secondarily transferred and fixed on the transfer paper, and the second full-color image FC2 is secondarily transferred and fixed to the transfer paper.
[0044]
The image formation control timing when the two images FC1 and FC2 are formed on the intermediate transfer belt 261 in this way will be described with reference to FIG. La shown in FIG. 4 is a distance between the leading edge of the first-side image FC1 and the leading edge of the second-side image FC2.
[0045]
If this La is made constant regardless of the image length, that is, the length of the transfer paper to be secondarily transferred, various image formation control timings can be simplified regardless of the transfer paper size.
[0046]
Further, the distance LD1 between the image FC1 on the first surface and the image FC2 on the second surface, that is, the interval between the two transfer sheets sent during the two-chamfering is the maximum transfer sheet length for performing the two-chamfering, for example, a length of A4 size. Or the shortest length of LT size.
[0047]
The interval LD1 is determined to be an operable length according to the transfer paper feed interval, the return speed of the scanner unit 1, and the like. A distance LD2 from the end of the image FC2 on the second surface to the start end having the reference mark 262 of the intermediate transfer belt 261 is a portion that does not affect the sheet interval of the transfer sheet. The distance LD2 is determined by the color changing speed of the revolver unit 25, the return speed of the scanner unit 1, and the like, and normally LD1 = LD2.
[0048]
Next, the internal configuration of the IPU 100 will be described with reference to FIG. The document image information from the optical scanning means 12 is photoelectrically converted by the color CCD 13 and further converted into a digital signal by the A / D converter 61.
[0049]
The image signal converted into the digital signal is subjected to shading correction by the shading correction unit 62 and then subjected to MTF correction and γ correction by the MTF correction / γ correction unit 63. The image signal that has passed through the scaling unit 72 that performs the scaling process is enlarged / reduced in accordance with the scaling ratio, and is sent to the selector 64.
[0050]
In the selector 64, the destination of the image signal is switched to the writing γ correction unit 71 or the memory controller 65. The image signal that has passed through the writing γ correction unit 71 is corrected for writing γ according to the image forming conditions, and is sent to the writing unit 57. The memory controller 65 and the selector 64 are configured to be able to input and output image signals in both directions.
[0051]
Although not clearly shown in FIG. 5, in addition to the image data input from the scanner unit 1, the IPU 100 supplies image data supplied from the outside such as data output from a data processing device such as a personal computer. In addition, it has a function of inputting / outputting a plurality of data. Further, a CPU 68 for setting the memory controller 65 and the like and controlling the scanner unit 1 and the writing unit 57, and a ROM 69 and a RAM 70 for storing programs and data thereof are provided.
[0052]
Further, the CPU 68 writes and reads data in the image memory 66 via the memory controller 65. The memory controller 65 and CPU 68 and the display unit 4 are also configured so that image data 73 can be input and output bidirectionally via the I / O port 67.
[0053]
Next, the internal details of the memory controller 65 and the image memory 66 in FIG. 5 will be described with reference to FIG. FIG. 6 is a diagram showing details of each storage device of the storage means in the present embodiment, and the image memory 66 is also connected to each storage device.
[0054]
The memory controller 65 includes an input data selector 201, an image composition unit 202, a primary compression / decompression unit 203, an output data selector 204, and a secondary compression / decompression unit 205. Setting of control data in each block is performed by the CPU 68. Note that the addresses and data in FIG. 5 are for image data, and the data and addresses connected to the CPU 68 are not shown. The memory controller 65 and the CPU 68 correspond to selection means, print page memory setting means, and page memory acquisition means.
[0055]
On the other hand, the image memory 66 includes primary and secondary storage devices 206 and 207. The primary storage device 206 corresponding to the page memory has a data transfer speed required for writing / reading data to / from a specified area of the memory or reading data from a specified area of the memory at the time of image output. For example, a memory capable of high-speed access such as a DRAM is used.
[0056]
Note that “continuous” page memory is an address on two page memories, for example. Two page memories that do not belong to the two page memories do not exist between the minimum address and the maximum address. It means that the page memory is arranged on the memory.
[0057]
The primary storage device 206 is shared for storing image data input to the image forming apparatus and image data output to the printer unit 2 that forms an image. The primary storage device 206 has an interface unit with a memory controller that can be divided into a plurality of page memories having a prescribed size and can simultaneously input and output image data. The secondary storage device 207 corresponding to the storage means is a large-capacity nonvolatile memory for combining input images, sorting, and storing data. If the primary storage device 206 has a sufficient capacity for processing image data and is non-volatile, it is not necessary to input / output data to / from the secondary storage device 207.
[0058]
If the secondary storage device 207 can write / read data almost synchronously with the data transfer speed required at the time of image input / output, the data can be directly written / read to / from the secondary storage device 207. It becomes possible. In such a case, it is possible to process data without distinguishing between primary and secondary.
[0059]
If the secondary storage device 207 cannot write / read data in synchronization with the data transfer speed required at the time of image input / output, for example, a storage medium such as a hard disk or a magneto-optical disk is used as the secondary storage device 207. Even when it is used, data input / output to / from the secondary storage device can be processed according to the data transfer capability of the secondary storage device 207 via the primary storage device.
[0060]
Here, a specific usage example of the primary storage device 206 and the secondary storage device 207 in each application will be given.
[0061]
Example 1: One copy in a copy application
In the case of one copy, first, image data from the scanner unit 1 is input to the primary storage device 206. The image data is output to the image forming unit 21 at almost the same timing, but at the same time, the image data is stored in the secondary storage device 207. If the image formation is completed normally, the image data stored in the secondary storage device 207 is deleted without being used. However, in the case of a jam or the like, an image can be created by reading image data from the secondary storage device 207.
[0062]
Example 2: Sorting in a copy application (multiple copies)
Even in the case of two or more copies, image data from the scanner unit 1 is first input to the primary storage device 206. In the first copy, as in Example 1, the image data is output from the primary storage device 206 to the image forming unit 21, and at the same time, the image data is stored in the secondary storage device 207.
[0063]
The second and subsequent copies of image data are output from the secondary storage device 207 to the primary storage device 206 and then to the image forming unit 21, so that the scanner unit 1 does not need to read the second and subsequent copies. When the required number of copies is completed, the image data stored in the secondary storage device 207 is deleted.
[0064]
Example 3 Image storage from a scanner
In this case, the image data from the scanner unit 1 is stored in the secondary storage device 207 via the primary storage device 206. At this time, the image data remains stored unless intentional erasure is performed.
[0065]
Example 4 Printing from an external input device (for example, a personal computer)
In this case, it is almost the same as Example 1 and Example 2, and the input source of the image data is not the scanner unit 1 but an external input device.
[0066]
Example 5 Image storage from an external input device
In this case, it is almost the same as Example 3, and the input source of the image data is not the scanner unit 1 but the external input device.
[0067]
Example 6 Printing accumulated images
When the images accumulated in Examples 3 and 5 are printed, they are printed by the secondary storage device 207 to the primary storage device 206 and the image forming unit 21.
[0068]
Next, an operation example of the memory controller 65 will be described. Here, an example in which the secondary storage device 207 cannot write / read data substantially in synchronization with the data transfer speed required at the time of image input / output is shown.
[0069]
First, storage in the image memory 66 by image input will be described.
[0070]
The input data selector 201 selects image data to be written to the primary storage device 206 in the image memory 66 from a plurality of data. The image data selected by the input data selector 201 is supplied to the image composition unit 202, and composition is performed as necessary. The image data processed by the image composition unit 202 is compressed by the primary compression / decompression unit 203, and the compressed image data is written in the primary storage device 206.
[0071]
The image data written in the primary storage device 206 is further compressed by the secondary compression / decompression 205 unit as necessary, and then stored in the secondary storage device 207.
[0072]
Next, image output that is reading from the image memory will be described.
[0073]
At the time of image output, image data stored in the primary storage device 206 is read out. When image data to be output is stored in the primary storage device 206, the primary compression / decompression unit 203 decompresses the image data in the primary storage device 206. The decompressed image data or the image data after image composition of the decompressed image data and the input image data is selected by the output data selector 204 and output.
[0074]
When the image to be output is stored in the secondary storage device 207, the output target image data stored in the secondary storage device 207 is expanded by the secondary compression / decompression unit 205. After the decompressed image data is written in the primary storage device 206, the above-described image output operation is performed.
[0075]
Next, input / output control of image data using the page memory will be described. The page memory is configured in the primary storage device 206, and temporarily stores image data in units of one page memory.
[0076]
The normal page memory changes its size in accordance with the resolution and the like, but manages the memory capacity of A4 size unit as one page memory unit. For example, when an A3 size input is made, image input is performed using two page memories. Further, in the case of color input, image data of magenta M, cyan C, yellow Y, and black K, which are color components of the color, is input from the scanner unit 1 to the page memory for each color component.
[0077]
The same applies to output. If there is a color component to be printed on the page memory, the image data developed on the page memory is output to the printer unit 2. When the color component of the designated image does not exist on the page memory and exists in the secondary storage device 207, the designated data is first read from the secondary storage device 207 to the page memory, and then the image data is transferred to the printer unit 2. Is output. In the case of a color copier, there is a so-called ACS (Auto Color Select) mode function that automatically determines the color of an image of a document and performs copying in either monochrome or full color. Further, the size of the original and the size of the transfer paper to be output are automatically determined or set or set by the operator. The CPU 68 can refer to the size.
[0078]
FIG. 7 shows how the document reading state, the page memory state, the image storage state in the HDD, and the image forming state when image formation for two surfaces is executed on the intermediate transfer unit with the passage of time. It is explanatory drawing which shows whether it changes to. Note that time elapses from the top to the bottom of the figure. Here, the description will be made on the assumption that 10 page memories are full-color image forming apparatuses having (P1 to P10).
[0079]
In this description, it is assumed that the image data storage speed from the page memory to the HDD and the image data transfer speed from the HDD to the page memory are faster than the document reading linear speed of the scanner unit. The image data is stored in the HDD from the page memory after the reading operation of the corresponding document is completed. In the initial state, P9 and P10 are assigned as print-dedicated page memories set as page memories dedicated to image data output. No input other than image data read from the HDD is allowed in the print-only page memory and the allocated page memory.
[0080]
Next, the symbols in FIG. 7 will be described. FIG. 7 shows “original reading”, “image accumulation”, and “image formation”.
[0081]
Among these, “original reading” indicates which original is being read. In addition, “image accumulation”, “image accumulation” further indicates “memory → HDD” and “HDD → memory”. “Memory → HDD” indicates image data stored in the HDD from the memory, and “HDD → memory” indicates image data stored in the memory from the HDD.
[0082]
“Image formation” indicates image data formed on the intermediate transfer portion. For example, it is shown that image data “Y1” and “Y2” are simultaneously formed on two surfaces of the intermediate transfer portion. Similarly, other image data “M1” and “M2” are simultaneously formed on the two surfaces of the intermediate transfer portion. This two-sided image transfer to the intermediate transfer portion side by side is hereinafter referred to as two-sided drawing. The intermediate transfer unit is an intermediate transfer belt 261.
[0083]
Next, the page memories “P1” to “P10” will be described. First, “P1” to “P10” indicate “page memory 1” to “page memory 10”. FIG. 7 shows the image data stored in the page memories “P1” to “P10” surrounded by a square. Within this square, there are further characters such as “Y1” and “M2”, and Y and M represent the color of the image data. Further, “1” of “Y1” indicates that the image data of the document 1.
[0084]
Therefore, in FIG. 7, for example, P1 which is the page memory 1 indicates that Y-color image data of the document 1 is first stored.
[0085]
Some squares are shaded. The shaded squares indicate the image data after being stored in the HDD. For example, the image data “Y1” is shaded at the same time as the image data “Y1” is stored in the HDD, as shown in the “image storage” column indicating the state of “memory → HDD”. Yes.
[0086]
The two black and white arrows indicate that the page memory in which the arrows are overwritten is set as the print-only page memory. For example, a white arrow extending from “Y1” of P1 to “Y1” shaded indicates that P1 is set as a print-only page. The arrow shown in black is also used for the same meaning.
[0087]
Hereinafter, the processing content of FIG. 7 is demonstrated.
[0088]
When reading of the document 1 is started by optical scanning of the scanner unit, input of read image data of the document 1 to each of the page memories P1 to P4 is started. The yellow Y image data 1, the magenta M image data 1, the cyan C image data 1, and the black K image data 1 are hereinafter referred to as Y1, M1, C1, and K1, respectively.
[0089]
After the input of the image data to the page memory, a sequence for transferring the images for the two surfaces side by side to the intermediate transfer unit is started.
[0090]
First, since Y1 that is the first image formation exists on the page memory P1, output of Y1 is started from P1 to the intermediate transfer portion. In this case, since image formation is performed from P1, the assignment of the page memory of P1 to the print-only page memory is changed (P9 → P1: white arrow).
[0091]
Further, the image data of the document 1 is stored in the HDD. The image in the page memory is guaranteed until the image data is stored in the HDD.
[0092]
Then, after the replacement operation to the document 2 by ADF (Auto Document Feeder) is completed, the reading operation of the document 2 is started. Similarly to Y1 image formation, Y2 of the original 2 serving as the second surface exists on P5, and therefore Y2 is output to the intermediate transfer section from P5. Since the output is performed from P5, the print-only page memory is changed to P5 (P10 → P5: black arrow).
[0093]
During Y2 image formation, the state of each page memory is as follows.
[0094]
P1: Y1 image data has been stored in the HDD
P2: Print page memory for creating M1 image data
P3: Finish storing C1 image data in HDD
P4: Store K1 image data in HDD
P5: Y2 image data is being output. Start storing on HDD
P6: Waiting to start storing in M2 image data HDD
P7: Waiting for accumulation in C2 image data HDD
P8: Waiting for storage in K2 image data HDD
P9: Empty (image data can be input)
P10: Empty (image data can be input)
Therefore, when the document replacement is completed by the ADF, the document 3 can be read using the page memories P1, P3, P4, and P9, and the document 3 reading operation is started.
[0095]
Next, image formation of M1 is executed. In this case, the image is already stored in the HDD at the image formation timing of M1. Since M1 exists on the page memory of P2, the assignment of the print-only page memory assigned to P1 is changed to the page memory of P2 (P1 → P2: white arrow). Similarly, at the time of M2 image formation, the assignment to the print-only page memory is changed from P5 to P6 (black arrow).
[0096]
C1 is imaged after M2 is imaged. In this case, the C1 image data is already stored in the HDD and does not exist in the page memory. Therefore, the image data C1 is read from the HDD to the print-only page memory. In this case, the print-only page memory is P2.
[0097]
In this manner, image data is read out to the page memory allocated to the print-dedicated page memory first of the two print-dedicated page memories.
[0098]
The page memories other than the print-only page memory are vacant in accordance with the completion state of image storage in the HDD and the state of starting the reading of the next document by document replacement by ADF. Specifically, in FIG. 7, the page memories P5, P7, P8, and P10 are vacant around M2 image formation. At that time, the reading operation of the document 4 is performed.
[0099]
In the next C2 image formation as well as C1, since the C2 image data does not exist on the page memory, the C2 image data is read from the HDD to the print-dedicated page memory P6.
[0100]
As described above, in the management of the page memory, two print-dedicated page memories are provided and the print-dedicated page memory is allocated when two-sided printing is performed. Then, the image data used for image formation is read from the HDD, the remaining 8 pages of page memory are used, and the original is read.
[0101]
Print-only page memory is a full-color image forming apparatus that uses multiple page memories in a single input / output, efficiently and reliably acquires a small number of installed page memories, and efficiently executes input / output in parallel. is there. Then, the means for dynamically selecting and setting the print-dedicated page memory is controlled to further increase the use efficiency of the page memory.
[0102]
In the first embodiment, allocation as a print-only page memory is performed for a page memory in which image data to be printed exists. Accordingly, a print-dedicated page memory is allocated to the page memory for which input of image data to be printed is completed. There is no problem if the image data storage process in the HDD is executed immediately after the input of the image data and the storage of the image data in the HDD is completed before the printing is completed.
[0103]
However, if there is a delay in the process of storing image data on the page memory in the HDD performed after the input is completed, the completion of the storage process on the HDD and the print end timing for the page memory are reversed (see FIG. 8). . That is, there is a case where image data storage processing is performed even after printing is completed.
[0104]
In the management method shown in FIG. 7, the page memory in the above-described state is set as a print-only page memory. Even if image data is read from the HDD for the next image data preparation, the page memory cannot be used because the image data is being stored in the HDD. As a result, the acquired print-dedicated page memory becomes unusable, and the page memory that should have been usable for printing is being used in the previous image data accumulation process, and therefore the unusable state occurs.
[0105]
If there is space in the page memory, you can use it, but the page memory that is free when the number of page memories used for input / output is large and the input / output operates in parallel, like a full-color image forming device. There are few. Therefore, since the page memory for printing cannot be acquired during the two-chamfering operation, the preparation for forming the image data is delayed, and color misregistration of the image occurs.
[0106]
Therefore, in the allocation of the print-dedicated page memory, when image data is input to the page memory and not stored in the HDD, setting as a print-dedicated page memory is prohibited. Hereinafter, the process of inputting image data into the page memory and storing it in the HDD is referred to as an input process.
[0107]
As a result, there is no waiting for acquisition of the print-dedicated page memory during the two-sided operation, and it is possible to acquire the print-dedicated page memory that can surely prepare for image data image formation. In other words, by prohibiting the migration of the print-dedicated page memory setting to the page memory during input processing, even if a print request occurs while image data is being stored in the HDD, the original print-dedicated page memory is used. The print request can be executed.
[0108]
Also, as shown in FIG. 9, when the print-dedicated page memory setting is prohibited and the print-dedicated page memory is set for the page memory during the input process, the print-dedicated page memory increases. Less page memory is needed. For this reason, acquisition of a page memory for input processing fails and input processing is limited. Therefore, it is more efficient in page memory management to move the setting to a page memory that can be set as a print-only page memory in response to a change in the page memory usage state.
[0109]
Therefore, according to the present invention, when the use of the page memory during the input process, which is a change in the use state of the page memory, is completed, the print-only page memory setting is immediately performed based on the page use state.
[0110]
As a result, even if the page memory setting for printing is prohibited when the page memory during the input process is used for printing, the page memory setting for printing is changed to this page memory as soon as the completion of the input process can be confirmed. By setting to, you can make effective use of page memory.
[0111]
However, if the print-only page setting is performed for changes in the usage status of all page memories, the efficiency is poor. Therefore, the print-only page memory setting is performed in the following case, which is the most efficient change of the page memory use state in confirming whether or not the print-only page memory can be set.
-When the use of page memory in image data input processing ends
・ At the start of image data output processing
Specifically, the area A in FIG. 9 corresponds to the above contents. This area A is used only for output after the use of the page memory by the input processing is completed. Therefore, the page memory after area A can be set as a print-only page memory. At this time, the print-only page memory setting of the original print-only page memory (unused state) is canceled, and the print-only page memory is set in this page memory.
[0112]
Even if the setting of the print-dedicated page memory is prohibited for the page memory being input, when a new image data output request is generated, the setting as the print-dedicated page memory is performed. Thus, by moving the unused print-dedicated page memory to the print-dedicated page memory that is executing printing, the unused print-dedicated page memory can be used as a page memory that can be used for input processing.
[0113]
FIG. 10 is a flowchart showing the contents executed by the CPU 68 based on the program in which the above-described control contents are described.
[0114]
In step S41, the CPU 68 checks whether or not there is an image data output request. If it is an image data output request, the print-only page memory is set as described above.
[0115]
If there is no image data output request, the CPU 68 confirms the presence or absence of a page memory use state change notification in step S42.
[0116]
When there is an image data output request in step S41 or there is a change in the page memory usage state in step S42, the CPU 68 performs an output page memory acquisition process in step S43.
[0117]
In step S44, the CPU 68 confirms whether or not the page memory has been successfully acquired. If it can be acquired, the CPU 68 determines in step S45 whether or not the acquired page memory used in the output process is being used in the input process. During the input process, the CPU 68 prohibits the movement process of the print-only page memory setting in step S46 and does not select another page memory as the print-only page memory.
[0118]
When the input process is not being performed in step S45, the CPU 68 determines in step S47 whether the acquired page memory is being used in the output process.
[0119]
Since the page memory is unused when it is unused in the input / output process, the CPU 68 selects and sets the page memory as a print-dedicated page memory in step S48. In step S47, when the output processing is in use, the CPU 68 checks in step S49 whether or not this page memory has already been set as a print-only page memory. If it is not set as a print-only page memory, the CPU 68 selects and sets the page memory as a print-only page memory in step S48.
[0120]
Next, FIG. 11 will be described. FIG. 11 is a flowchart showing the operation of the page memory use state change notification. Regarding the page memory use state change notification, if the movement operation of the print-only page setting is performed in response to the change in the use state of all the page memories, the efficiency is poor.
[0121]
Therefore, the page memory usage state change notification is performed in two cases, ie, the end of use of the page memory in the image data input process, which is the most efficient page memory use state change, and the start of use in the image data output process. ing.
[0122]
Hereinafter, the contents of the flowchart of FIG. 11 will be described. In step S10, the CPU 68 performs a page memory use state change notification by detecting the end of the process of the page memory used in the input process. When detecting the end of the process, the CPU 68 performs a page memory use state change notification process in step S12 and ends the process.
[0123]
In step S11, the CPU 68 detects the start of page memory acquisition processing for use in output processing. When the start process is detected, the CPU 68 performs step S12 and ends the process. If the start process is not detected in step S11, the CPU 68 ends the process.
[0124]
By controlling the page memory as described above, the page memory for printing cannot be acquired between colors (M, C, Y, K) during full-color printing in the two-sided processing of the image forming apparatus. , The situation that acquisition is delayed does not occur. Accordingly, it is possible to realize parallel operation of image data input / output using a more efficient page memory.
[0125]
Next, as Embodiment 2 of the present invention, the size of A3 (hereinafter referred to as “large”) exceeds the size of A4 (hereinafter referred to as “small size”) assumed by one page memory as the size of the document processed by the image forming apparatus. A case where only one surface image can be transferred to the intermediate transfer portion as in the case of size) will be described. Hereinafter, the fact that only one surface of the image can be transferred to the intermediate transfer portion is referred to as “one-sided”.
[0126]
FIG. 12 is a diagram showing document reading, a page memory state, an image storage state in the HDD, and an image forming state when one-sheet cutting is executed. Since image data cannot be input with one page memory, image data input processing to the page memory after acquiring four frames (eight page memories) using two consecutive page memories as one frame as one unit I do.
[0127]
As in the description of the first embodiment, as an initial state, P9 and P10 are allocated as a page-dedicated page memory set of one frame as a page memory dedicated to image data output. The preparation of image data to be imaged in the page memory is assumed to be triggered by the start of image formation of the image data in the page memory in which the print-only page memory is set.
[0128]
In FIG. 12, first, when image reading of the document 1 is started, image formation of Y1 is started. As described above, the page memories P1 and P2 are allocated as the print-only page memory set 1.
[0129]
As the next image formation image data preparation, since the image formation start of Y1 is used as a trigger, P3 and P4 in which M1 is stored are allocated as the print-dedicated page memory group 2. At the start of image formation of M1, P5 and P6 in which the next C1 is stored are allocated as the print-only page memory set 1. The image data for K1, which is the next image forming color, is prepared at the start of C1 image formation. Since K1 is the last image formation, two print-only page memory groups 1 exist at the end of C1 image formation. , 2 is reduced to one print-dedicated page memory.
[0130]
That is, when the image formation of C1 immediately before the last image formation color is completed, the two print-dedicated page memory groups are reduced to one, and at this time, 4 frames (page memory for 8 pages) are obtained. The document 2 can be read and the reading operation of the document 2 can be performed.
[0131]
Further, when reading one-sided original document continuously, preparation of image data of Y2 as the next image formation color is started when the image formation of K1 is started. Will increase to two.
[0132]
Here, as a reference example, let us consider a case where a print-only page memory is used to print a small size color and then perform a large size color print.
[0133]
As shown in FIG. 13, in the arrangement state of the print-dedicated page memory after the small size full-color printing, consider a case where a large-size color copy is performed subsequently from the state assigned to P2 and P9 as the print-dedicated page memory.
[0134]
As described above, when A3 full-color image data is input, it is impossible to input a document read image with one page memory. Therefore, two consecutive page memories are regarded as one frame, and four frames (page memory for eight pages) are allocated. After the acquisition, the image data is input to the page memory.
[0135]
However, there are eight page memories (P1, P3 to P8, P10) except for the print-only page memories P2 and P9 that cannot be used for input because they are dedicated for printing. However, because the print dedicated page memory allocation position is inappropriate, it is not possible to obtain two sets of two consecutive page memories. Prior to the execution of such a large-size color copy, unless a rearrangement process that optimizes the print-dedicated page memory is performed, large-size image data cannot be input.
[0136]
Further, in the processing of FIG. 13, the rearrangement processing of the print-only page memory was performed, but the optimization was not successful. For this reason, FIG. 13 shows an example of arrangement of a print-only page memory in a state where large-size full color input processing cannot be performed. In this example, the print-only page memory is continuously rearranged, but is arranged without considering the set of set page memories.
[0137]
Here, when the page memories P1 to P6 exist and the print-dedicated page memory is P2, a method of an arrangement example of the print-dedicated page memory considering the set of set page memories will be described. In such a case, the print-only page memory is allocated so as to match the combination pattern of P1-P2, P3-P4, and P5-P6. Combinations such as P2-P3 and P4-P5 are not performed.
[0138]
In this way, two consecutive page memories are grouped into one group, and a combination that maximizes the number of groups is performed. By this combination, the maximum number of page memories can be acquired without waste. Note that “P1-P2” represents a combination of P1 and P2, and other numbers similarly represent a combination of page memories. In general, when the necessary page memory is n image data, n consecutive page memories are set as one group, and a combination that maximizes the number of groups is performed.
[0139]
In the second embodiment, the following control is performed as a process for optimizing the layout of the print-only page memory. First, in this control, print-only page memories are continuously arranged. The setting of the print-only page memory is performed in consideration of grouping. The optimization assignment for setting the print-only page memory is performed prior to the page memory acquisition process for the image data input / output process. Also, optimization processing is executed when the page memory usage state changes, and optimization processing is performed in real time based on the latest page memory usage status.
[0140]
In addition, when the page memory is acquired at the time of input / output and cannot be acquired in the current page memory state, a plurality of pre-processing (a, b below) for acquiring the page memory is continuously performed. This pre-processing is processing for creating a page memory that can be used by manipulating image data on the page memory, although acquisition of the page memory is currently impossible. Then, the print dedicated page memory optimized allocation arrangement process is executed with the highest priority before the preprocess is executed.
[0141]
B: When the input process is completed, this page memory can be overwritten, so that it can be used.
[0142]
B: When there is image data in the middle of aggregation, which is a process of printing a plurality of originals on one sheet of recording paper, and when the aggregation of the image data is not completed, the image data in the middle of the aggregation is first transferred to the HDD. To save the page memory.
[0143]
By performing the control as described above, the page memory acquisition impossible state caused by inappropriate placement of the print-only page memory as shown in FIG. 13 is avoided. FIG. 14 shows the situation.
[0144]
As shown in FIG. 14, the print-only page memory is optimally arranged in consideration of grouping prior to acquisition of page memory for input / output. As a result, even when there is an A3 full color input request, acquisition of the page memory for input is successful.
[0145]
In FIG. 14, P9 and P2 are initially set as print-only page memories. When an input request for image data of an A3 full-color document is generated, the print-only page memory set in P2 is set in P10. By doing so, it is possible to input image data of an A3 full-color document.
[0146]
FIG. 15 is a flowchart showing the above-described control contents, and the print-only page memory acquisition control will be described with reference to FIG. In step S20, the CPU 68 confirms whether or not a page memory acquisition request is generated by an image data input / output request. If there is no image data input / output request, the CPU 68 confirms whether or not the page memory use state has changed in step S21.
[0147]
When the image data input / output request is made at step S20, or when the page memory use state is changed at step S21, the CPU 68 obtains the image number and the color component of the image data requested to obtain the page memory at step S22. . Further, in step S23, the CPU 68 resets the determination flag that has been executed for the pre-processing for acquiring the page memory (a and b).
[0148]
In step S24, the CPU 68 determines whether or not the page memory having the image number of the page memory acquisition request has already been acquired. When the page memory has not yet been acquired, the CPU 68 performs an optimal layout process for the print-only page memory in step S25. In step S26, the CPU 68 performs page memory acquisition processing for an image data input / output request.
[0149]
In this way, if the page memory used for image data input / output is optimized after optimizing the print-only page memory every time, the probability that it can be acquired for the subsequent input / output also increases, and the page memory is more effective. Can be used.
[0150]
In step S27, the CPU 68 checks whether or not the page memory has been acquired. When acquisition is possible, the CPU 68 sets the page memory to the acquisition state at the image number of the image data requested to be acquired in step S28, and ends the process. If acquisition is not possible, the CPU 68 confirms in step S29 whether or not pre-processing for acquiring the page memory has been executed. When the preprocess is not executed, the CPU 68 executes the preprocess at step S30 and performs the process at step S25.
[0151]
As described above, after the optimum layout processing of the print-only page memory in step S25 is executed, the processing is performed in the order of the preprocessing in step S30.
[0152]
Also, in the pre-processing performed in step S30, the image data in the page memory is overwritten. Therefore, when the image data stored before this overwriting is used, the data from the HDD is again stored. A call occurs. In the preprocessing, the image data being aggregated is saved once in the HDD. When the aggregation is continued, the saved image data needs to be called from the HDD again.
[0153]
On the other hand, the optimum arrangement processing of the print-dedicated page memory in step S25 does not generate extra processing especially for image data because the print-dedicated page memory is reallocated. For this reason, the optimum layout processing of the print-only page memory is configured such that the page memory acquisition processing can be performed more efficiently by executing the processing in the order described above.
[0154]
Further, in step S21 in the flowchart of FIG. 15, the CPU 68 executes step S22 and subsequent steps even when a page memory use state change occurs. This is to optimize the print-only page memory allocation when the page memory is acquired because it is used for input / output processing, or when the page memory that has been used for input / output processing is released. Thus, an optimum print-only page memory allocation is performed for the latest page memory state. In particular, if step S22 and subsequent steps are performed at the timing when the page memory is released, the effect on page memory acquisition is high.
[0155]
Next, a flowchart showing the print-only page memory optimum arrangement process in the process S25 of FIG. 15 will be described with reference to FIG.
[0156]
In step S31, the CPU 68 confirms whether the print-only page memory is continuously arranged. In step S32, the CPU 68 confirms whether the print-only page memory is arranged in consideration of grouping that maximizes the number of groups. When arranged in step S31 and step S32, the CPU 68 ends the process assuming that it is optimized.
[0157]
If not, the CPU 68 checks in step S33 whether there is an unused print-only page memory. When there is not, the CPU 68 ends the process because the optimum placement process cannot be performed any more.
[0158]
In step S33, when there is an unused print-dedicated page memory, the CPU 68 uses the unused print-dedicated page memory to perform a process of searching for a group combination having the maximum number of groups.
[0159]
As described above, it is possible to acquire a page memory for printing between colors (M, C, Y, K) during full-color printing by controlling the page memory in the process of taking one side of the image forming apparatus. Alternatively, it is possible to realize efficient page memory management that does not cause a delay in acquisition.
[0160]
【The invention's effect】
As described above, according to the present invention, the page memory for printing cannot be acquired, and a state in which acquisition is delayed does not occur, and more efficient parallel image data input / output using the page memory is possible. It is possible to provide an image forming apparatus and a memory control method that perform page memory management for realizing the operation.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention.
2 is an enlarged configuration diagram illustrating an image forming unit of the image forming apparatus in FIG. 1;
3 is a block diagram illustrating a configuration of a control unit of the image forming apparatus in FIG. 1. FIG.
FIG. 4 is a development view showing images of two surfaces formed on an intermediate transfer belt.
5 is a block diagram showing an internal configuration of the image processing unit in FIG. 3. FIG.
6 is a block diagram showing an internal configuration of a memory controller and an image memory in FIG. 5. FIG.
FIG. 7 is a diagram for explaining each state in two-chamfered page memory control.
FIG. 8 is a diagram for explaining a state in which image storage in the HDD during image input processing is delayed
FIG. 9 is a diagram illustrating a state in which page memory dedicated to printing is allocated to another page memory due to prohibition of printing dedicated page memory allocation during image input processing;
FIG. 10 is a flowchart showing a move processing operation for print-only page memory settings.
FIG. 11 is a flowchart showing an operation of a page memory use state change notification;
FIG. 12 is a diagram for explaining each state in one-chamfered page memory control;
FIG. 13 is a diagram for explaining an arrangement state of a print-only page memory after small size full-color printing
FIG. 14 is a diagram for explaining an arrangement state of a print-only page memory for full-color printing from a small size to a large size.
FIG. 15 is a flowchart showing the operation of page memory acquisition processing;
FIG. 16 is a flowchart showing a print-only page memory optimum arrangement process in the page memory acquisition process;
[Explanation of symbols]
1 Scanner section
2 Printer section
3 Paper feeder
4 display section
5 Control unit
21 Imaging Department
22 Fixing part
23 Recording paper transport section
24 photoconductor
26 Transfer unit
65 Image memory controller
66 Image memory
67 I / O port
100 Image processing unit (IPU)
201 Input data selector
202 Image composition unit
203 Primary compression / decompression unit
204 Output data selector
205 Secondary compression / decompression unit
206 Primary storage device
207 Secondary storage device
231 Registration Roller
261 Intermediate transfer belt

Claims (4)

In an image forming apparatus that stores input image data and image data to be printed using a memory area in which a plurality of page memories having a prescribed size are continuously arranged.
Page memory acquisition means for acquiring a page memory for storing the input image data and image data to be printed;
Selecting means for selecting a part of the page memory acquired by the page memory acquiring means as a print-only page memory that is a page memory for storing image data to be printed;
Print page memory setting means for setting the page memory selected by the selection means as the print-only page memory;
Storage means for further storing the input image data stored in the page memory,
A page memory in which the input image data is not stored in the storage means is prohibited from being set as the print-only page memory, and when the input image data is stored in the storage means, the page memory An image forming apparatus which is settable as a dedicated page memory.   The image forming apparatus according to claim 1, wherein the selection unit selects the page memory after the page memory acquisition unit acquires the page memory.   The image forming apparatus according to claim 2, wherein the selection unit selects a page memory arranged continuously with a page memory already set as a print-only page memory. In a memory control method for storing input image data and image data to be printed using a memory area in which a plurality of page memories having a prescribed size are continuously arranged,
A page memory acquisition step of acquiring a page memory for storing the input image data and image data to be printed;
A selection step of selecting a part of the page memory acquired in the page memory acquisition step as a print-only page memory that is a page memory for storing image data to be printed; and the page memory selected in the selection step. A print page memory setting stage to set as the print-dedicated page memory;
A storage step of further storing the input image data stored in the page memory in a storage means ;
A page memory in which the input image data is not stored in the storage stage is prohibited from being set as the print-only page memory. When the input image data is stored in the storage stage, the page memory is A memory control method characterized by being settable as a dedicated page memory.

Images