JP2008263311A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely avoid an abrupt stop of reading operation of a read means through simple and speedy processing. <P>SOLUTION: A compression rate decision unit 83 computes a compression rate associated with image data having been compressed by a compression/decompression unit 77, decides whether an arithmetic result associated with the compression rate is less than a predetermined threshold (for example, 30%), and stores the image data having been compressed in a predetermined area of a RAM 75 when it is decided that the arithmetic result associated with the compression rate is less than the predetermined threshold, but stores bitmap data before the compression in an HDD 63 as a temporary storage location when it is decided that the arithmetic result associated with the compression rate exceeds the predetermined threshold. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides, for example, an image forming apparatus having a function of compressing bit map data read by the reading unit and storing it in an image memory in an image forming apparatus such as a multi-function machine equipped with a reading unit such as a scanner. Relates to the device.

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a printer or a multifunction peripheral, image data is divided into a plurality of bands in order to reduce the storage capacity for image data read by a reading unit such as a scanner, and a bit is assigned to each band. After development into map data, the bitmap data is compressed and stored in an image memory.

  In such an image forming apparatus, when the image data read by the reading unit is stored in the image memory, the reading operation of the reading unit is stopped when the compression rate of the image data is lower than a predetermined threshold. Some have adopted a configuration. In this case, when the read document image has low redundancy, a situation in which the reading operation of the reading unit stops suddenly may occur.

  As one of approaches for solving such inconveniences, data compression means capable of compressing image data with compression methods having different compression ratios, and storage means for storing data relating to images compressed by the data compression means Reading means for reading a document and outputting image data; image data stored in the storage means; free space in the storage means; and information on the amount of original from the reading means. Control means for performing control to change the compression method, calculate the amount of data per image from the image data stored in the storage means, and determine that there is not enough free space in the storage means compared to the amount of originals In such a case, a technique has been proposed in which the data compression method is changed and the data is compressed and stored in the storage means (Patent Document 1). According to the technique of Patent Document 1, it is possible to cause an unexpected situation of the user such that the reading operation of the reading unit suddenly stops even when the original image read by the reading unit has low redundancy. Can be avoided.

  However, in the technique described in Patent Document 1, since the excess or deficiency of the free capacity of the storage means is sequentially determined and data compression is performed by changing the compression rate based on the determination result, the processing is complicated. It took a relatively long time.

JP 2001-45247 A

  The problem to be solved is that in the prior art, the processing for avoiding the reading operation of the reading means from stopping suddenly is complicated and requires a relatively long time.

  The present invention provides a reading unit that reads a document image and outputs image data related to the document image for the purpose of reliably avoiding a sudden stop of the reading operation of the reading unit through simple and rapid processing. A compression means for compressing the bitmap data based on the image data; and a storage means for storing the data relating to the image, and after the compression processing is performed on the bitmap data by the compression means An image forming apparatus having a function of storing the data in the storage unit; a large-capacity storage unit for storing various types of data; a compression rate related to image data after compression processing by the compression unit; Compression rate determination means for determining whether or not the calculation result related to the compression rate is equal to or less than a predetermined threshold value, and the calculation result related to the compression rate is equal to or less than a predetermined threshold value When the determination is made, the image data after the compression processing is stored in the storage means, while when the determination is made that the predetermined threshold value is exceeded, the bitmap before the compression processing is stored. The main feature is that it is configured to include storage control means for performing control for storing data in the large-capacity storage means.

  In the present invention, the storage control means stores the image data after compression processing by the compression means in the storage means when it is determined that the calculation result of the compression rate determination means is equal to or less than a predetermined threshold value. On the other hand, when it is determined that the predetermined threshold value is exceeded, control is performed to store the image data before compression processing in the compression unit in the large-capacity storage unit. When image data whose compression rate exceeds a predetermined threshold value that triggers when the reading operation suddenly stops, unlike normal processing, the bitmap data before compression processing by the compression means, Temporarily storing the data in the large-capacity storage unit can reliably prevent the reading operation of the reading unit from suddenly stopping. Therefore, the initial purpose can be achieved through simple and rapid processing.

  The determination that the calculation result of the compression rate determination means is equal to or less than a predetermined threshold value was made for the purpose of reliably avoiding the sudden stop of the reading operation of the reading means through simple and rapid processing. When the image data after the compression processing by the compression means is stored in the storage means, while it is determined that the predetermined threshold value is exceeded, the bitmap data before the compression processing by the compression means is This is realized by storage control means for performing control to be stored in the large capacity storage means.

  Hereinafter, an image forming apparatus according to the present invention will be described in detail with reference to the drawings. In the following, a digital multi-function peripheral will be described as an example of the image forming apparatus according to the present invention.

[Schematic configuration around the digital MFP]
FIG. 1 is a schematic configuration diagram around a digital multi-function peripheral.

  This digital multi-function peripheral can use at least one function among print output, fax transmission, mail transmission, and data transmission, and is controlled by the main control unit 11 including a microcomputer and a dedicated hardware circuit. The As an input / output device connected to the main control unit 11 and responsible for various functions, this machine includes a scanner unit 21, an image processing unit 31, an engine unit 41, an operation panel unit 51, a facsimile communication unit 61, and an HDD (hard disk drive) 63. And a network I / F (interface) unit 65.

  The main control unit 11 includes a scanner controller 13 that performs operation control for realizing a scanner function, a facsimile controller 15 that performs operation control for realizing a facsimile function, and a printer controller that performs operation control for realizing a printer function. 17 and a copy controller 19 for controlling the operation for realizing the copy function are incorporated, and the overall operation of the apparatus is controlled.

  The scanner unit 21 (corresponding to the “reading unit” of the present invention) includes an image irradiation lamp 23 and a CCD (Charge Coupled Device) sensor 25 constituting a scanner (not shown). The scanner unit 21 irradiates the document with the image irradiation lamp 23 and receives the reflected light with the CCD sensor 25 to read an image from the document, and image data corresponding to the read image is described later with the printer controller 17. After performing predetermined processing, the image data is transferred to the image processing unit 31.

  The image processing unit 31 includes a correction unit 33, an image processing unit 35, and an image memory (corresponding to “storage means” of the present invention) 37. The image processing unit 31 processes the image data read by the scanner unit 21 with the correction unit 33 and the image processing unit 35 as necessary, and stores the processed image data in the image memory 37, the engine unit 41, Output to the facsimile communication unit 61 or the like. The correction unit 33 performs predetermined correction processing such as level correction and Y correction on the image data read by the scanner unit 21. The image processing unit 35 performs various types of processing such as image data compression or expansion processing and enlargement or reduction processing.

  The engine unit 41 includes a sheet conveying unit 43 including a sheet feeding cassette and a sheet feeding roller (not illustrated), an image forming unit 45 including a photosensitive drum, an exposure device, a developing device, and the like (not illustrated), a transfer roller (not illustrated), and the like. And a fixing unit 49 including a fixing roller (not shown). The engine unit 41 includes image data read by the scanner unit 21, image data transmitted from a client PC (personal computer) via a LAN (Local Area Network) via the network I / F unit 65, a facsimile communication unit 61 is used to print an image on paper using image data such as fax data received from an external facsimile machine or the like. Specifically, the paper transport unit 43 transports the paper to the image forming unit 45, the image forming unit 45 forms a toner image corresponding to the image data, the transfer unit 47 transfers the toner image to the paper, The fixing unit 49 fixes the toner image on a sheet to form an image.

  The operation panel unit 51 includes a touch panel unit 53 and an operation key unit 55. The operation panel unit 51 is used for a user to perform operations related to a scanner function, a facsimile function, a printer function, a copy function, and the like, and gives an operation command and the like by the user to the main control unit 11.

  The touch panel unit 53 is composed of a touch panel unit that combines a touch panel and a color LCD (Liquid Crystal Display), and displays various operation screens, for example, information regarding the document size, copy size, number of copies, etc. when executing the copy function. In addition, operation buttons for inputting various operation commands are displayed when the user touches the corresponding part. The touch panel unit 53 is used when displaying a grayscale image of a document image in a form related to a design change applied to the display screen.

  The operation key unit 55 includes a plurality of operation keys for receiving user operation inputs. For example, a key input operation of a required function can be performed from various functions such as a copy function, a printer function, a scanner function, and a facsimile function. This is used when the user selectively executes, or when the user inputs a copy number or a copy execution command.

  The facsimile communication unit 61 transmits image data of a document read by the scanner unit 21 to a destination facsimile device or the like via a public line, and receives image data transmitted from the facsimile device or the like.

  An HDD (hard disk drive, corresponding to the “mass storage unit” of the present invention) 63 provisionally stores image data read by the scanner unit 21 and various data such as an output format set in the image data. Remember me. The image data stored in the HDD is not only used inside the image forming apparatus, the program, and the recording medium, but also can be confirmed from a client PC or the like via the network I / F unit 65 if necessary. It is transferred to a predetermined folder such as a PC or FTP server.

  The network I / F unit 65 uses a network interface (10 / 100Base-TX) or the like, and controls transmission / reception of various data to / from a client PC connected via the LAN.

[Schematic configuration around the printer controller]
In the digital multi-function peripheral configured as described above, the printer controller 17 plays an important role as described below in order to reliably avoid the reading operation of the scanner unit 21 from being stopped suddenly through simple and quick processing. Plays.

  FIG. 2 is a schematic configuration diagram of the printer controller, and FIG. 3 is a block diagram focusing on the functional aspects of the printer controller. In FIG. 2 and FIG. 3, common reference numerals are assigned to common components, and duplicate descriptions thereof are omitted.

  As shown in FIG. 2, the printer controller 17 includes a CPU 71 that performs overall control of operations related to the printer function, a ROM 73 that stores a control program for operating the CPU 71, font data, and the like, and data generated during various processes. A RAM 75 (corresponding to the “storage means” of the present invention) to be stored and a compression / decoder (corresponding to the “compression means” of the present invention) that compresses and decodes the image data by performing an encoding process. ) 77 is connected via a bus 79.

  The CPU 71 has a function of expanding the bitmap data of the image divided in band units into a predetermined area in the RAM 75.

  The RAM 75 stores a storage area for compressed data, a development area for developing bitmap data of an image divided in band units, and data received from a client PC or the like via the network I / F unit 65. This includes an input buffer area and a system work area.

  The compressor of the compressor / decoder 77 has a function of compressing band-unit bitmap data expanded in the RAM 75, and the compressed data after such compression processing is stored in a predetermined area in the RAM 75 by DMA (Direct Memory Access). ) Transferred and stored.

  On the other hand, paying attention to the function, the printer controller 17 includes a bitmap data generation unit 81, a compression / decoder 77, a RAM 75, a compression rate determination unit (the “compression rate determination unit” and “storage control” of the present invention). 83 ”and an information amount determination unit (corresponding to“ information amount determination means ”and“ storage control means ”of the present invention) 85.

  The bitmap data generation unit 81 divides the image data read by the scanner unit 21 into units called bands, and sequentially develops image data for one band into a bitmap and stores it in a predetermined development area in the RAM 75. . A band refers to a band-like block obtained by dividing an entire image for one page into a plurality of rectangular areas.

  The compression rate determination unit 83 calculates the compression rate related to the image data after compression processing by the compression / decoder 77, and whether the calculation result related to the compression rate is equal to or less than a predetermined threshold (for example, 30%). Determine whether or not. The compression rate determination unit 83 stores the image data after compression processing in a predetermined area in the RAM 75 when it is determined that the calculation result related to the compression rate is equal to or less than a predetermined threshold value. It has a function. Note that, as a function of the compression rate determination unit 83, when it is determined that the calculation result related to the compression rate exceeds a predetermined threshold value, control is performed to store the bitmap data before compression processing in the HDD 63. You may comprise as follows.

  The information amount determination unit 85 calculates the information amount related to the image data after the compression processing when it is determined that the calculation result related to the compression ratio exceeds a predetermined threshold value. It is determined whether or not the calculation result relating to is less than or equal to a predetermined threshold value (for example, 512 KB). Also, the information amount determination unit 85 stores the compressed image data in a predetermined area in the RAM 75 when it is determined that the calculation result related to the information amount is equal to or less than a predetermined threshold value. On the other hand, it has a function of performing control to store the bitmap data before compression processing in the HDD 63.

[Processing procedures related to data storage in digital multifunction devices]
Next, the operation of the image forming apparatus (digital multifunction peripheral) according to the present invention will be described with reference to FIG. FIG. 4 shows a processing procedure related to data storage in the image forming apparatus according to the present invention.

  As shown in FIG. 4, first, the bitmap data generation unit 81 converts the image data for one band into a bitmap and stores it in a predetermined development area in the RAM 75 (step S1). In response to this, the compressor / decoder 77 reads the bitmap data from the decompressed area in the RAM 75 and executes the compression process (step S2). When the compression processing in step S2 is completed, the compression rate determination unit 83 calculates the compression rate related to the image data after the compression processing by the compression / decoder 77, and the calculation result related to the compression rate is a predetermined threshold. The compression rate determination related to whether or not the value (for example, 30%) or less is executed (step S13). The processing in step S13 is an abnormal processing target that is different from normal processing because image data whose compression rate exceeds a predetermined threshold (30%) may consume excessive storage in the RAM 75. It is provided for handling.

  As a result of the compression rate determination in step S13, when it is determined that the calculation result related to the compression rate is equal to or less than a predetermined threshold (30%), the compression rate determination unit 83 displays the image after compression processing. Data is stored in a predetermined area in the RAM 75 (step S14). The processing in step S14 is processing that is normally performed on normal image data.

  On the other hand, when it is determined that the calculation result relating to the compression ratio exceeds a predetermined threshold (30%) as a result of the compression ratio determination in step S13, the information amount determination unit 85 performs the compression process. The amount of information related to the subsequent image data is calculated, and information amount determination regarding whether or not the calculation result related to the information amount is equal to or less than a predetermined threshold (for example, 512 KB) is executed (step S15). In the process of step S15, the amount of information is predetermined for the image data that is to be treated as an abnormal process target because the compression ratio exceeds a predetermined threshold (30%) in step S13. The image data that is equal to or smaller than the threshold value (512 KB) does not necessarily consume excessively the storage area in the RAM 75, and is provided for relief so that it can be handled as a target of normal processing.

  As a result of the information amount determination in step S15, when it is determined that the calculation result related to the information amount is equal to or less than a predetermined threshold value (512 KB), the information amount determination unit 85 moves the processing flow to step S14. The image data after the compression processing is stored in a predetermined area in the RAM 75 as usual.

  On the other hand, as a result of the information amount determination in step S15, when it is determined that the calculation result related to the information amount can exceed the predetermined threshold value (512 KB), the information amount determination unit 85 performs the original amount before the compression process. Bitmap data is stored in the HDD 63, which is a temporary storage location (step S16). The process in step S16 is a process performed on the image data determined to be handled as an abnormality process target.

  When the data storage process in step S14 or S16 is completed, the CPU 71 determines whether or not all jobs have been completed (step S17). As a result of the determination in step S17, when it is determined that the job is still continuing, the CPU 71 returns the process flow to step S11 and causes the following process to be executed. On the other hand, when it is determined that all jobs have been completed, the CPU 71 ends all processing.

  Note that the image data (original bitmap data before compression processing) determined to be handled as an abnormality processing target in step S16 is appropriately extracted from the HDD 63 as a so-called off-line processing after a series of processing ends. Thus, by compressing to a predetermined information amount size by applying different compression ratios or adopting different compression methods, the data is stored in a predetermined area in the RAM 75.

[Effect of Example]
As described above, according to the image forming apparatus (digital multifunction peripheral) according to the present invention, the compression rate determination unit 83 calculates the compression rate related to the image data after compression processing by the compression / decoder 77, and It is determined whether the calculation result related to the compression ratio is a predetermined threshold value (for example, 30%) or less, and a determination is made that the calculation result related to the compression ratio is equal to or less than the predetermined threshold value. When the image data after compression processing is stored in a predetermined area in the RAM 75 while it is determined that the calculation result relating to the compression ratio exceeds a predetermined threshold, the bitmap before the compression processing is stored. Since control is performed to store data in the HDD 63, which is a temporary storage location, the compression ratio that triggers when the reading operation of the scanner unit 21 stops suddenly, the compression rate has a predetermined threshold value. Exceeding image data When this occurs, unlike the normal processing, the bitmap data before the compression processing by the compression / decoder 77 can be temporarily stored in the HDD 63. As a result, the reading operation of the scanner unit 21 suddenly occurs. Stopping can be reliably avoided. Therefore, the initial purpose can be achieved through simple and rapid processing.

  Further, according to the image forming apparatus (digital multifunction peripheral) according to the present invention, the information amount determination unit 85 performs the compression when it is determined that the calculation result related to the compression rate exceeds a predetermined threshold value. While calculating the information amount related to the processed image data, it is determined whether the calculation result related to the information amount is a predetermined threshold value (for example, 512 KB) or less, and the calculation result related to the information amount is When it is determined that the value is equal to or less than the predetermined threshold value, the compressed image data is stored in a predetermined area in the RAM 75, and the bitmap data before the compression process is stored in the HDD 63. Therefore, the initial purpose can be achieved as described above. In addition, the image data whose information amount is equal to or less than a predetermined threshold value (512 KB) with respect to the image data that is to be handled uniformly as the target of the abnormal processing necessarily consumes the storage area in the RAM 75 excessively. However, since it is decided to rescue it so that it is handled as a target of normal processing, flexible operation relating to compressed data storage can be achieved.

[Others]
The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist of the invention read from the claims and the entire specification or the technical idea, and image formation accompanied by such changes The apparatus is also included in the scope of the technical scope of the present invention.

1 is a schematic configuration diagram around an image forming apparatus (digital multifunction peripheral) according to the present invention. 1 is a schematic configuration diagram of a printer controller that forms part of an image forming apparatus according to the present invention. FIG. 3 is a block diagram focusing on the functional aspects of the printer controller. It is a flowchart figure which shows the process sequence which concerns on the data storage in the image forming apparatus which concerns on this invention.

Explanation of symbols

11 Main control unit 21 Scanner unit (reading means)
37 Image memory (storage means)
63 HDD (mass storage means)
71 CPU
73 ROM
75 RAM (storage means)
77 Compressor / Decoder (Compression means)
81 Bitmap data generation unit 83 Compression rate determination unit (compression rate determination unit and storage control unit)
85 Information amount determination unit (information amount determination means and storage control means)

Claims (2)

Reading means for reading an original image and outputting image data relating to the original image, compression means for compressing bitmap data based on the image data, and storage means for storing data relating to the image An image forming apparatus having a function of storing the bitmap data in the storage unit after the compression unit performs compression processing on the bitmap data,
Large-capacity storage means for storing various data;
A compression rate determination unit that calculates a compression rate related to image data after compression processing by the compression unit, and determines whether the calculation result related to the compression rate is equal to or less than a predetermined threshold
When it is determined that the calculation result related to the compression ratio is equal to or less than a predetermined threshold value, the compressed image data is stored in the storage unit, and exceeds a predetermined threshold value. Storage control means for performing control to store the bitmap data before the compression processing in the large-capacity storage means when the determination is made,
An image forming apparatus comprising: The image forming apparatus according to claim 1,
When it is determined that the calculation result related to the compression ratio exceeds a predetermined threshold, the information amount related to the image data after the compression processing is calculated, and the calculation result related to the information amount is It further comprises information amount determination means for determining whether or not it is a predetermined threshold value or less,
The storage control means
When it is determined that the calculation result related to the amount of information is equal to or less than a predetermined threshold value, the image data after the compression processing is stored in the storage unit, and exceeds a predetermined threshold value. When the determination is made, control is performed to store the bitmap data before the compression processing in the large-capacity storage unit.

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