JP2002264404A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen an input/output process between a frame memory and a hard disk and transfer image data in conformity with an imaging timing by holding image data developed on the frame memory. SOLUTION: A memory controller 27 has a primary compression/expansion part 27c and a secondary compression/expansion part 27e. An image memory 28 has a primary storage (frame memory) 28a and a secondary storage (hard disk) 28b. Inputted image data is primary compressed at the primary compression/expansion part 27c, and developed and stored at the frame memory 28a to each color of imaging colors Y, M, C and K. Thereafter, the data is secondary compressed at the secondary compression/expansion part 27e and stored into the hard disk 28b. When the image data developed to the frame memory 28a is judged as is still necessary, the data is retained in the frame memory 28a. Data retained in the frame memory 28a is used in conformity with the imaging timing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus having an image storage device such as a frame memory and a hard disk.

[0002]

2. Description of the Related Art Regarding the prior art, for example,
Japanese Patent Application Laid-Open No. 58768 proposes an image forming apparatus capable of grasping the compression and decompression time of an image when a frame memory and a hard disk are used and performing a smooth printing operation.

[0003]

When a color image is formed, it is necessary to develop several colors from a hard disk (hereinafter, referred to as HDD) to a frame memory. When compressed and stored, unnecessary decompression and HDD access occur,
The processing becomes heavy, and depending on the case, there is a possibility that the development of the image may not be completed by the desired image forming timing.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances. After image data is once expanded in a frame memory, it is determined whether or not the image data is a necessary image. By leaving the image data and compressing the input of other image data, such processing can be minimized, and image transfer can be started by the required image forming timing,

[0005] The same image data cannot be used continuously.
For example, in an operation mode such as electronic sorting, the image data from the HDD must be developed in a frame memory and the image data must be transmitted. If the prepared frame memory is used at random for image input and image transfer, ,
In some cases, it may not be possible to transfer the image at the timing when the image forming side wants the image data to be transferred, and by preparing a frame dedicated to reading the image from the HDD according to the image size, To be able to transfer images at the right time,

[0006] In order to perform a two-seat operation mode in which two identical images or different images are generated by one image forming operation, a frame dedicated to image reading from the HDD corresponding to the image size is prepared for two colors. The purpose of the present invention is to make it possible to transfer an image in accordance with the image forming timing.

[0007]

According to a first aspect of the present invention, there is provided an input means for inputting image data, and a first compression / decompression method for the image data.
First compressing / expanding means for expanding, first storing means for storing primary compressed image data, and second compressing / expanding image data stored in the first storing means. Compression / decompression means, second storage means for storing the secondary-compressed image data, and image forming means for forming image data, wherein the first storage means is provided with the first compression means A frame memory capable of expanding and storing the image data primarily compressed by the expansion / decompression means for each of the image forming colors YMCK, wherein the second storage means stores the image data YMCK by the second compression / expansion means.
A hard disk capable of inputting and outputting the next compressed image data to and from the frame memory, and holding, in the frame memory, image data that is determined to be continuously necessary among a plurality of image data expanded in the frame memory It is characterized by the following.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the frame memory has a dedicated frame for reading out and expanding the secondary compressed image data from the hard disk. It is characterized in that an image is formed using image data developed in a dedicated frame.

According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the image forming apparatus has a two-sheet image forming function of generating two images by one image forming, and the frame memory. In this case, two dedicated frames are held, and the area of the frame memory is divided into an input data area and an output data area and controlled using the two dedicated frames.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an example of a main configuration of an image forming apparatus to which the present invention is applied. In the drawing, reference numeral 10 denotes an image forming apparatus. Feeding device 11, automatic sorting device 12, document reading unit 1
3, an image writing unit 14, a photosensitive drum 15, a fixing unit 16, a double-sided paper feeding unit 17a, and paper feeding units 17b, 17c, and 17d.

First, the original reading unit 13 irradiates the original with a light source, scans the original, reads the reflected light from the original with the CCD sensor, processes the image, and transmits it to the image writing unit 14.

The image writing unit 14 modulates the driving of an LD (laser diode) according to the image data. An LD is applied to the photosensitive drum 15 which is uniformly charged and rotates.
The latent image is written by a laser beam from the printer, and toner is adhered to the electrostatic latent image by a developing unit (not shown) to visualize the electrostatic latent image.

The image formed on the photosensitive drum 15 is transferred to recording paper fed from paper feed units 17a to 17d, sent to a fixing unit 16, and thermally fixed by a fixing roller and a pressure roller. The recording paper after fixing is discharged to the automatic sorting device 12 at the time of single-sided discharge, and to the double-sided paper feed unit 17a at the time of double-sided or single-sided.

FIG. 2 is a block diagram showing an example of an image processing unit to which the present invention is applied. In the figure, reference numeral 20 denotes an image processing unit, which is a CCD image sensor 21 and an A / D converter. Converter 22, shading correction unit 23, selector unit 24, scaling unit 25, writing unit 26, memory controller 27, image memory 2
8, a CPU 29, a ROM 30, a RAM 31, and an I / O port 32. The light emitted from the variable magnification exposure lamp irradiates the original surface, the reflected light from the original surface is imaged by the exposure lens in the CCD image sensor 21, received and photoelectrically converted, and the A / D converter 22 performs digital conversion. Convert to a signal.

The image signal converted into the digital signal is subjected to shading correction by a shading correction unit 23, and then corrected by an image processing unit (not shown).
The selector unit 24 switches the destination of the image signal to the scaling unit 25 or the memory controller 27. Magnification unit 25
The image signal that has passed through is scaled according to the scaling factor and sent to the writing unit 26. An image signal can be input and output between the memory controller 27 and the selector unit 24.

Although not explicitly shown in FIG. 2, the image processing unit 20 is provided with a plurality of data so as to be able to process image data supplied from the outside in addition to image data input from the document reading unit 13. It has a function to select the input and output of. A CPU 29 for setting the memory controller 27 and controlling the document reading unit 13 and the image writing unit 14, and a ROM 30 and a RAM 31 for storing programs and data thereof. Further, the CPU 29 performs data writing and reading of the image memory via the memory controller 27. The image storage means in the present invention comprises a memory controller 27 and an image memory 28.

FIG. 3 is a block diagram showing an example of the internal configuration of a memory controller 27 and an image memory 28 to which the present invention is applied. The memory controller 27 includes an input data selector 27a, an image synthesizer 27b, and a primary compression / compression unit. Extension part 27
c, output data selector 27d, secondary compression / expansion 2
7e, the image memory 28 comprises a primary storage device (frame memory) 28a and a secondary storage device (HDD) 28b. The setting of control data for each block in the memory controller 27 is performed by the CPU 29. The addresses and data shown in FIG. 2 indicate image data, and FIG.
2, data and addresses connected to the CPU 29 are not shown.

The image memory 28 includes a primary storage device 28a and a secondary storage device 28b. In the primary storage device 28a, data is written to a designated area of the memory, or
At the time of image output, data can be read from a specified area of the memory in synchronization with a data transfer rate required at the time of image input / output. Further, the primary storage device 28a is configured to be able to divide into a plurality of areas according to the size of the image data to be processed and to simultaneously execute input and output of image data. The secondary storage device 28b is a large-capacity memory for storing images that can be subjected to synthesis and sorting of input images.

Next, an operation example of the memory controller 27 will be described below. First, with respect to image input, the input data selector unit 27a outputs one of the image memories 28 of the image data.
The image data to be written to the next storage device 28a is selected. When combining is necessary, the image data is supplied to the image combining unit 27b and combined with the data already stored in the image memory 28. The image data processed by the image synthesis unit 27b is compressed by the primary compression / decompression unit 27c,
The compressed image data is written to the primary storage device 28a. The image data written to the primary storage device 28a is
If necessary, the data is further compressed by the secondary compression / decompression unit 27e, and then stored in the secondary storage device 28b.

Next, regarding image output, 1 is set at the time of image output.
The image data recorded in the next storage device 28a is read. If the target image is stored in the primary storage device 28a, the image data in the primary storage device 28a is expanded by the primary compression / expansion unit 27c, and the expanded data is output to the output data selector unit 27d. Select with and output.

If the image data to be output is not stored in the primary storage device 28a, the secondary storage device 28
For the image data to be output stored in b,
The image is expanded by the secondary compression / expansion unit 27e, and the expanded image data is written into the primary storage device 28a, and then the above-described image output operation is performed.

FIG. 4 is a front view showing an example of an operation unit of the image forming apparatus 10. In the figure, reference numeral 40 denotes an operation unit, and the operation unit 40 is a liquid crystal display (LC).
D) etc., a display unit 41, a start key 42,
It comprises a clear stop key 43, a reset key 44, a numeric keypad 45, and a mode setting key 46. Start key 42
Is used to execute the copy. The clear stop key 43 is used for interrupting the copying operation or resetting the number of copies. The reset key 44 is used when resetting the copy mode. The ten keys 45 are used for setting the number of copies and inputting various values. The mode setting key 46
Used to set the cover mode, duplex mode, sort mode, etc.

FIG. 5 is a diagram showing an example of a flow up to image data input / output and image formation by conventional memory control control. The horizontal axis represents time. Primary storage device 28
The image data which has been compressed to a is compressed and stored in the secondary storage device 28b as backup data for recovery. After the compression storage, the image data on the primary storage device 28a becomes unnecessary. Therefore, when the next input image data is present and there is no free space, the image data is compressed and stored on the primary storage device 28a by overwriting. Then, compression storage is performed in the secondary storage device 28b.

The stored image data is stored in the primary storage device 2
If image data remains in the primary storage device 2a,
If the image data is expanded in the primary storage device 28a and no image data remains in the primary storage device 28a, the secondary image storage device 28b
From the primary storage device 28a to the output data selector 2a.
Image data is read out at a necessary timing through 7d. FIG. 5 shows the state of input and output from the secondary storage device 28b.

FIG. 6 is a flowchart illustrating an example of image data input processing to which the present invention is applied. First,
If there is an image data input request, it is checked whether there is a free space in the primary storage device 28a for image data input (step S1). At this time, in the color image forming operation, it is necessary to store image data for each color of CMYK, and a memory area for the image forming color is required.

Next, when there is an empty space in the primary storage device 28a (in the case of YES), the image data is compressed and stored as it is (step S2). If there is no necessary memory free area in the primary storage device 28a (in the case of NO), image data for which image data has been input to the secondary storage device 28b is searched from the currently used memory area ( Step S
3). As a result of the search, it is better to hold the image data of the memory area in the primary storage device 28a as it is in the current operation mode (same image repeat imaging mode) in the secondary storage device 28b. ON /
If the output processing is reduced, the image data is not written into the memory area (step S4). In this case, a necessary memory area is secured again after waiting for another memory area to be in an empty state or a state of being transferred to the secondary storage device 28b (step S5). FIG. 7 is a diagram showing an example of the flow of image data input / output to / from the secondary storage device 28b and image formation in the same image repeat mode.

The input data 1 shown in FIG. 7 is input only once in the secondary storage device 28b, and the input data 2 to n-1 is input / compressed once. Only one expansion / output before the image and no final input data n, there is no image data waiting for the next input. Therefore, only one input to the secondary storage device 28b is required, and the primary storage device is used for the image forming operation. It becomes possible to use the image data on 28a. 1
The number of times of reading from the secondary storage device 28b can be reduced by determining the frame from which the next image data is read in consideration of the order in which the image data loaded into the next storage device 28a is read.

Here, the image data in the primary storage device 28a shown in FIGS. 5 and 7 is not overwritten by the next image data even if the data is already stored in the secondary storage device 28b. This shows a state in which image data remains in the storage device 28a. FIG. 5 shows a state in which image data is stored by sequentially using areas that have been stored in the secondary storage device 28b. FIG. 7 shows a case in which data storage in the secondary storage device 28b is completed. However, when the image is used immediately, writing to the memory area is avoided, and the image can be formed without reading from the secondary storage device 28b.

As shown in FIG. 5, when controlling the image memory, if all the primary storage areas of the primary storage device 28a are controlled equally, the input of the image data takes precedence. As a result, it becomes impossible to use the primary storage area for decompression / output from the secondary storage device 28b when necessary from the image forming timing. However, by preparing a primary storage area for decompression / output from the secondary storage device 28b, it is possible to prepare image data in the primary storage device 28a by a desired image forming timing.

FIG. 8 is a diagram showing an example of the flow of image data input / output to / from the secondary storage device 28b and image formation in the two-sheet taking mode. Here, the two-sheet mode is a mode in which two images are formed and transferred at a time. The primary storage area in the primary storage device 28a used for the expansion / output only area from the secondary storage device 28b cannot be adjusted to the image data request timing on the image forming side by using only one color. In this case, a primary image area for two colors is prepared as an area for expansion / output from the secondary image device 28b. By controlling the primary storage area by dividing it into an input data area and an output data area, it is possible to read out the output data of the image at the requested timing, for example, when it is necessary to superimpose images such as during full-color operation. Becomes The primary image area for decompression / output shown in FIGS. 7 and 8 does not need to be a fixed area, and is not necessarily a primary area.
8a may be set randomly in the region within 8a.

[0031]

According to the first aspect of the present invention, it is determined whether or not the image data in the primary storage device is to be retained according to the operation mode. In addition, complicated and heavy input / output processing can be reduced.

According to the second aspect of the present invention, by providing a primary image area dedicated to decompression / output of image data from the secondary image device, desired image data can be output without delay in image forming timing. Becomes possible.

According to the third aspect of the present invention, the primary image area dedicated to decompressing / outputting image data from the secondary image apparatus is provided in accordance with the operation mode, so that it is possible to respond to the image forming request without waste. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration example of a main part of an image forming apparatus to which the present invention is applied.

FIG. 2 is a block diagram illustrating an example of an image processing unit to which the present invention is applied.

FIG. 3 is a block diagram showing an example of an internal configuration of a memory controller and an image memory to which the present invention is applied.

FIG. 4 is a plan view illustrating an example of an operation unit of the image forming apparatus.

FIG. 5 is a diagram showing an example of a flow up to image data input / output and image formation by conventional memory control control.

FIG. 6 is a flowchart illustrating an example of image data input processing to which the present invention is applied.

FIG. 7 is a diagram showing an example of the flow of image data input / output to / from a secondary storage device and image formation in the same image repeat mode.

FIG. 8 is a diagram showing an example of a flow up to image data input / output to / from a secondary storage device and image formation in a two-sheet taking mode.

[Explanation of symbols]

10 image forming apparatus 11 automatic document feeder 12
Automatic sorting device, 13 ... Original reading unit, 14 ...
Image writing unit, 15: photosensitive drum, 16: fixing unit, 17a: double-sided paper feeding unit, 17b, 17
c, 17d: paper feed unit, 20: image processing unit,
21: CCD image sensor, 22: A / D converter, 23: Shading correction unit, 24: Selector unit,
25: magnification unit, 26: writing unit, 27: memory controller, 27a: input data selector unit, 27b
.., An image synthesizing unit, 27c, a primary compression / expansion unit, 27d, an output data selector unit, 27e, a secondary compression / expansion unit, 28
... image memory, 28a ... primary storage device, 28b ... secondary storage device, 29 ... CPU, 30 ... ROM, 31 ... RAM,
32 I / O port, 40 operating unit, 41 display unit, 42 start key, 43 clear stop key, 44 reset key, 45 numeric keypad, 46 mode setting key.

Claims (3)

[Claims] An input unit for inputting image data; a first compression / expansion unit for primary compression / expansion of the image data;
First storage means for storing the primary compressed image data, second compression / decompression means for secondary compression / expansion of the image data stored in the first storage means, and secondary compression A second storage unit that stores the image data; and an image forming unit that forms the image data. The first storage unit stores the image data that has been primarily compressed by the first compression / decompression unit. Is stored in a frame memory capable of expanding and storing the image data for each color of the image forming color YMCK, wherein the second storage unit stores the image data secondary-compressed by the second compression / decompression unit with the frame memory. An image forming apparatus, which is a hard disk capable of inputting and outputting data between the plurality of image data expanded in the frame memory and holding image data determined to be necessary continuously in the frame memory. 2. The image forming apparatus according to claim 1, wherein said frame memory is stored in said hard disk from said hard disk.
An image forming apparatus comprising: a dedicated frame for reading out and decompressing next compressed image data, and forming an image using the image data decompressed in the dedicated frame. 3. The image forming apparatus according to claim 1, further comprising a two-sheet image forming function for generating two images by one image forming operation, wherein the dedicated frame is stored in the frame memory. An image forming apparatus, wherein two areas are held, and the area of the frame memory is controlled by dividing the area into an input data area and an output data area using the two dedicated frames.