JP2005028755A - Image forming apparatus and method of forming image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To arbitrarily change an image quality mode corresponding to a residual capacity of a memory and to form an image by the image quality mode based on image information compressed corresponding to the residual capacity of the memory. <P>SOLUTION: This image forming apparatus 100 forms an image based on the image quality mode. The apparatus comprises a memory means 10 for storing the image information by compressing it, an image forming means 20 for forming an image based on the image quality mode by sequentially reading the image information from the memory means 10, and a control means 30 for controlling the input or output of the memory means 10 and the image forming means 20. The control means 30 detects the residual capacity of the memory means 10 when the image information is stored in the memory means 10, and then the image quality mode corresponding to the residual capacity thereof is selected to be set. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is applied to a copying machine, a printing machine, a facsimile machine, and a complex machine of these, etc., which compresses and stores arbitrary image information and sequentially reads out the stored image information to form an image using an electrophotographic method. The present invention relates to a suitable image forming apparatus and image forming method.
[0002]
[Prior art]
Usually, a digital multi-function peripheral equipped with a plurality of functions such as a scanner, a printer and a facsimile stores the digitized image information in a memory such as a DRAM (Dynamic Random Access Memory) and an HDD (Hard Disk Drive) and reuses it. An electronic RDH (Recycle Document Handler) function is provided. An image forming apparatus such as a digital multi-function peripheral equipped with this electronic RDH function cannot add a memory, so even if the memory capacity is not sufficient, a large amount of image information can be stored in a small capacity memory. In general, a function for compressing image information is provided so that it can be stored.
[0003]
However, when the image information is compressed and stored in the memory, the image information stored in the memory is sequentially read out and expanded, and an image is formed based on the expanded image information, the compression when storing in the memory When the rate is increased, the amount of image information that can be stored in the memory can be increased, but the image quality deteriorates. On the other hand, if the compression rate of the image information is kept low in order to suppress the deterioration of the image quality, the image information that can be stored in the memory is reduced, so that the performance (performance) of the image forming apparatus cannot be fully utilized. There is a high possibility of adversely affecting the processing efficiency of the image forming job.
[0004]
Therefore, in the conventional image forming apparatus, an attempt has been made to set the compression rate and the image quality, which are in a trade-off relationship with each other, in a well-balanced manner based on the memory capacity installed in the image forming apparatus. However, even in such a well-balanced image forming apparatus, if a large amount of image information is stored in the memory with the default image quality setting, the image information will exceed the memory capacity, resulting in a memory overflow. The forming device had to interrupt the image input. In order to solve such a problem of the conventional image forming apparatus, for example, when the image information related to the image read by the scanner exceeds a predetermined storage capacity, it is detected that the remaining capacity of the memory is small and a memory over signal is generated. There has been proposed an image forming apparatus that includes detection means for outputting and that avoids memory overflow by compressing image information relating to an image read after the output of the memory over signal and storing it in a memory (see Patent Document 1). ).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-130285 (paragraph numbers [0083] to [0086])
[0006]
[Problems to be solved by the invention]
By the way, according to the conventional image forming apparatus, since the compression of the image information is started after detecting that the remaining capacity of the memory is reduced during the execution of the image forming job, the image forming job is being processed. The image quality has deteriorated. For this reason, even if a memory overflow can be avoided by compressing the image information, there is a problem in that an image forming job that requires high image quality must be re-executed after all.
[0007]
Therefore, the present invention solves the above-described problem, and can arbitrarily change the image quality mode according to the remaining memory capacity at the start of the job, and is compressed according to the remaining memory capacity at the start of the job. An object of the present invention is to provide an image forming apparatus and an image forming method capable of forming an image in an image quality mode based on image information.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, an image forming apparatus according to the present invention includes a compression unit that compresses image information, and a plurality of image quality modes that are compressed at different compression rates, and based on these image quality modes. An image forming apparatus, a storage unit that compresses and stores image information, an image forming unit that sequentially reads image information from the storage unit and forms an image based on an image quality mode, and the storage unit and image formation Control means for controlling the input / output of the means, and when the image information is stored in the storage means at the start of the job, the control means detects the remaining capacity with respect to the storage means, and the image quality corresponding to the remaining capacity The mode is selected and set.
[0009]
According to the image forming apparatus of the present invention, when an image is formed based on the image quality mode, the remaining capacity is detected by the control unit with respect to the storage unit that stores image information for forming the image. The image quality mode corresponding to this remaining capacity is selected and set by this control means. Then, the image information is compressed by the compression means at a compression rate according to the selected image quality mode and stored in the storage means, and the image information stored in the storage means is sequentially read out and the set image quality mode is set. Is controlled by the control means so that an image based on the above is formed by the image forming means.
[0010]
Accordingly, since the image quality mode can be arbitrarily changed according to the remaining memory capacity of the storage means, an image can be formed in the image quality mode based on the image information compressed corresponding to the remaining memory capacity. In addition, since the storage interruption of image information due to a shortage of remaining memory capacity as in the conventional method can be prevented, the stop of image formation due to the storage interruption of image information can be avoided. In addition, since the image quality mode is set according to the remaining memory capacity at the start of the job, the image quality mode is switched during the job execution, and the image quality deteriorates in the middle, so this job must be re-executed after all. Such problems can be avoided.
[0011]
The image forming method according to the present invention has a plurality of image quality modes in which image information is compressed at different compression rates to form an image, and arbitrary image information is compressed and stored in a memory based on the image quality mode. In addition, the image information is sequentially read out from the memory to form an image. At the start of the job, when the image information is stored in the memory, the remaining capacity is detected with respect to the detected remaining capacity. A corresponding image quality mode is selected and set.
[0012]
According to the image forming method of the present invention, the image quality mode can be arbitrarily changed according to the remaining capacity of the memory, so that the image can be displayed in the image quality mode based on the image information compressed corresponding to the remaining capacity of the memory. Can be formed. In addition, since the storage interruption of image information due to a shortage of remaining memory capacity as in the conventional method can be prevented, the stop of image formation due to the storage interruption of image information can be avoided. In addition, since the image quality mode is set according to the remaining memory capacity at the start of the job, the image quality mode is switched during the job execution, and the image quality deteriorates in the middle, so this job must be re-executed after all. Such problems can be avoided.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The best mode for carrying out an image forming apparatus and an image forming method according to the present invention will be described below with reference to the accompanying drawings.
[0014]
[First Embodiment]
FIG. 1 is a block diagram illustrating a configuration example of an image forming apparatus 100 according to the present embodiment, and FIG. 2 is a block diagram illustrating a configuration example of a main part of the image forming apparatus 100. In the present embodiment, when an image is formed based on the image quality mode, there is provided control means for detecting the remaining capacity of the storage means and selecting and setting the image quality mode corresponding to the remaining capacity of the storage means. Thus, the image quality mode can be arbitrarily changed according to the remaining memory capacity of the storage means.
[0015]
An image forming apparatus 100 shown in FIG. 1 includes a storage unit 10, an image forming unit 20, a control unit 30, a user interface unit 40, and an input unit 50. The storage unit 10, the image forming unit 20, the user interface unit 40, and an input The means 50 are connected to each other via the control means 30.
[0016]
The storage means 10 comprises a DRAM (Dynamic Random Access Memory) 11 and a nonvolatile memory 12, compresses arbitrary image information and stores it in the DRAM 11, and stores image information to be stored over a long period of time. To store. The nonvolatile memory 12 also stores various setting information that is set and referred to by the control means 30.
[0017]
The image forming unit 20 includes a printer unit 21 and a printer driving unit 22, and sequentially reads image information from the storage unit 10 to form an image based on the image quality mode. The printer unit 21 includes a writing unit 21a, and the printer driving unit 22 includes a pulse width modulation (PWM) conversion unit 22a and a laser modulation unit 22b as shown in FIG. The image forming operation by 21a is controlled.
[0018]
The PWM conversion unit 22a converts the density level of one pixel unit into the laser beam emission time by a laser diode (LD: Laser Diode, not shown) of the writing unit 21a according to the image information read from the DRAM 11 of the storage unit 10. Modulate. The laser modulator 22b generates a laser modulation signal based on the laser beam emission time modulated by the PWM converter 22a.
[0019]
The control unit 30 includes a control unit 31 and an image processing unit 300. The control unit 31 includes a RAM 31a, a CPU (Central Processing Unit) 31b, and a ROM (Read Only Memory) 31c. The CPU 31b executes a control program stored in the ROM 31c while the RAM 31a functions as a work area. The input / output of the storage unit 10, the image forming unit 20, the user interface unit 40, and the input unit 50 is controlled, and the entire image forming apparatus 100 is controlled.
[0020]
As shown in FIG. 2, the image processing unit 300 includes an A / D (Analog / Digital) conversion unit 301, a shading correction unit 302, a spatial filter / magnification conversion processing unit 303, a memory control unit 304, and an image compression / decompression unit 305. When the image information is stored in the storage means 10, the remaining capacity of the DRAM 11 of the storage means 10 is detected under the control of the control unit 31, and the image quality mode corresponding to the detected remaining capacity is selected. Set.
[0021]
The A / D conversion unit 301 converts image information input as an analog signal from a charge coupled device (CCD) 51a included in the input unit (scanner unit) 50 into digital information.
[0022]
A shading correction unit 302 performs shading correction (white level correction) on the image information digitized by the A / D conversion unit 301. A spatial filter / magnification conversion (magnification) processing unit 303 divides the image information after shading correction into a character area, a halftone area, and a halftone area, and MTF (Modulation) is applied to the character area. When performing transfer processing (enhancement correction) emphasis correction and edge emphasis, the halftone dot region is subjected to smoothing processing (smoothing: smoothing) and image processing is performed so as to obtain a smooth gradation. Apply scaling.
[0023]
The memory control unit 304 is connected to the image compression / decompression unit 305 and the DRAM 11 and controls input / output of the image compression / decompression unit 305 and the DRAM 11. An image compression / decompression unit (compression unit) 305 compresses image information to be stored in the DRAM 11 and decompresses image information read from the DRAM.
[0024]
The user interface unit 40 includes at least a liquid crystal display device (LCD: Liquid Crystal Display), an operation display device 41 including a transparent touch panel, and a speaker 42, and setting item buttons and numeric buttons displayed on the LCD 41 are pressed. It is a touch panel type user interface that accepts various settings and input of information by being operated as described above, and displays the operation content by the accepted operation.
[0025]
The user interface unit 40 functions as a notification unit that notifies the setting relating to the image quality mode. When the image quality mode is set by the control unit 30, the user interface unit 40 displays the set image quality mode on the LCD 41 and also notifies the speaker 42 by voice. To do.
[0026]
The scanner unit 50 includes a reading unit 51 and a reading drive unit 52, and the reading unit 51 includes a CCD 51a. The CCD 51 a reads an arbitrary image under the control of the reading drive unit 52 based on an instruction input via the user interface unit 40. Accordingly, the scanner unit 50 receives and receives image information related to the read image.
[0027]
Here, an outline of the image forming operation by the image forming apparatus 100 configured as described above will be described. The image forming apparatus 100 includes an image quality mode A that forms a high-quality image corresponding to a low compression rate, an image quality mode B that forms an image with a normal (medium quality) image quality corresponding to a medium compression rate, And an image quality mode C for forming an image with low quality image quality prioritizing compression corresponding to a high compression rate.
[0028]
The image quality mode A is, for example, a high image quality mode in which image information input from the scanner unit 50 and subjected to image processing by the shading correction unit 302 and the spatial filter / magnification processing unit 303 is compressed to about 80%. B is a normal image quality mode in which image information after image processing is compressed to about 50%, and image quality mode C is a compression priority mode in which image information after image processing is compressed to about 25%.
[0029]
A threshold for the remaining capacity (memory remaining amount) of the DRAM 11 for selecting such an image quality mode is set in the nonvolatile memory 12. When the DRAM 11 has a total storage capacity of 256 MB (Megabyte), for example, if the memory remaining amount X is 64 MB or more, the image quality mode A is selected and set. If the memory remaining amount X is less than 64 MB and 32 MB or more, The image quality mode B is selected and set, and if the memory remaining amount X is less than 32 MB, a threshold for each memory remaining amount X is set via the user interface unit 40 so that the image quality mode C is selected and set. The setting information is stored in the nonvolatile memory 12 of the storage means 10.
[0030]
When a document is placed on the scanner unit 50 and execution of an image forming job is instructed by pressing a copy button displayed on the LCD 41 of the user interface unit 40, the remaining memory capacity X of the DRAM 11 is, for example, “40 MB”. Thus, the image quality mode B corresponding to this remaining memory capacity “40 MB” is set by the control means 30.
[0031]
As a result, an image quality mode with a higher compression rate can be selected and set as a default setting by the control means 30 in accordance with the remaining memory capacity X at the time when an image forming job is received. Storage interruption can be prevented from occurring during execution of an image forming job. Therefore, job interruption due to this storage interruption can also be prevented, and recovery work for such job interruption can be eliminated. For this reason, the processing efficiency of the image forming job can be improved.
[0032]
When the default (initial setting) image quality mode of the image forming apparatus 100 is set to the image quality mode A, the fact that the image quality mode B has been set by the control means 30 is displayed on the LCD 41 and “to the normal image quality image quality mode”. The voice is notified from the speaker 42 as “changed”. As a result, when the image quality level drops from high image quality to normal image quality by changing the image quality mode, it is possible to avoid a situation where a job to form an image with high image quality is mistakenly executed with normal image quality. Can be prevented.
[0033]
The permission / rejection is selected via the user interface unit 40 for the setting relating to the image quality mode notified by the LCD 41 or the speaker 42. Here, when the user interface unit 40 is operated so that the image quality mode B is permitted, the image quality mode setting is confirmed, and an image forming job is executed in the image quality mode B. On the other hand, when the image quality mode B is rejected, the user interface unit 40 (operation means) is operated to change the image quality mode to, for example, the image quality mode A.
[0034]
As a result, the image quality mode other than the image quality mode set by the control means 30 can be changed. Therefore, when the memory remaining amount X is small, an image forming job that does not require a large memory capacity due to the small number of documents. The image can be set and executed so as to form an image in a high-quality image mode A desired by the user.
[0035]
The LCD 41 and / or the speaker 42 of the user interface unit 40 notifies the information regarding the remaining memory capacity X such as “the current remaining memory capacity is 40 MB”. As a result, when the image quality mode set by the control means 30 is changed, the remaining memory capacity can be accurately grasped before the job execution, so that the image quality mode has a high probability of occurrence of a memory overflow (Overflow) during the job execution. Can be avoided.
[0036]
The user interface unit 40 includes setting means for setting the control means 30 to prohibit the change and setting to the image quality mode corresponding to the remaining memory capacity X. As a result, when it is not necessary to set the image quality mode by the control means 30, the control means 30 sets the image quality mode corresponding to the remaining memory amount X before pressing the copy button displayed on the LCD 41. Can be initially set to prohibit. Accordingly, the notification of setting of the image quality mode change by the control means 30 and the selection operation of acceptance (permission) / rejection for the change setting can be omitted, so that the operability is improved.
[0037]
When the setting of the image quality mode by the control means 30 or the change of the image quality mode by the operation of the user interface 40 is confirmed, the CCD 51a is driven by the reading drive unit 52, and the reading of the document image is started by the scanner unit 50.
[0038]
The original placed on the scanner unit 50 is fed to the reading position of the CCD 51a, the original image is read by the CCD 51a, and image information is input. Image information input from the scanner unit 50 is digitized by the A / D conversion unit 301, subjected to shading correction by the shading correction unit 302, and subjected to image processing by the spatial filter / magnification processing unit 303.
[0039]
The image information processed in this way is compressed by the image compression / expansion unit 305 under the control of the memory control unit 304 and then temporarily stored in the DRAM 11 as compressed image information. The compressed image information held in the DRAM 11 is read at a predetermined timing, is decompressed by the image compression / expansion unit 305, and is supplied to the PWM conversion unit 22a.
[0040]
In the decompressed image information, the density level of one pixel unit is modulated by the PWM conversion unit 22a to the laser beam emission time by the LD (not shown) of the writing unit 21a, and the laser beam emission time modulated here is modulated. Based on the above, a laser modulation signal is generated by the laser modulator 22b. Laser light is emitted from the LD of the writing unit 21a by this laser modulation signal, and an electrostatic latent image is formed on a photosensitive drum (not shown), which is visualized with toner. As a result, the image forming unit 20 sequentially reads out image information from the storage unit 10 and forms an image based on the image quality mode on an arbitrary print medium such as a sheet by a known electrophotographic method to make a copy (image forming job). finish.
[0041]
When multiple copies are set, the image information held in the DRAM 11 is repeatedly read as many times as the number of copies, decompressed by the image compression / decompression unit 305, and supplied to the PWM conversion unit 22a. (Electronic RDH function). This makes it possible to quickly output a set number of copies without reading the original image again.
[0042]
The image information held in the DRAM 11 is deleted from the DRAM 11 after the end of the image forming job when long-term storage of the image information is not set. On the other hand, when long-term storage of this image information is set, the image information held in the DRAM 11 is deleted from the DRAM 11 after being stored in the nonvolatile memory 12. As a result, the DRAM 11 can free the storage capacity for the next image forming job.
[0043]
As described above, according to the image forming apparatus 100 as the present embodiment, it is possible to prevent image information storage interruption due to insufficient memory capacity by selecting and setting the image quality mode according to the remaining memory capacity at the start of the job. Since the recovery work for job interruption can be eliminated, the processing efficiency can be improved. In addition, it is not necessary to increase the compression rate in accordance with the decrease in the remaining memory capacity while the image information is being stored, so that it is possible to prevent image quality deterioration due to the increase in the compression rate. Therefore, it is possible to form an image while maintaining the highest image quality possible with the remaining amount of memory detected before storing the image information.
[0044]
Next, an operation example of the image forming apparatus 100 will be described as an embodiment of the image forming method according to the present invention with reference to the flowcharts shown in FIGS.
[0045]
[First Image Forming Method]
FIG. 3 is a flowchart illustrating a first image forming method by the image forming apparatus 100. In this first image forming method, when a copy of a document image is printed by the image forming apparatus 100, the above three types of image quality modes are prepared, and the remaining memory capacity of the DRAM 11 having a total storage capacity of 256 MB. It is assumed that 64 MB is set in advance as a threshold value for setting the image quality mode A and 32 MB is set as a threshold value for setting the image quality mode B in X and stored in the nonvolatile memory 12. Note that these settings relating to the image quality mode are not notified.
[0046]
With this as a precondition, first, in step S11 of the flowchart shown in FIG. 3, it is determined whether or not the “copy start” button displayed on the LCD 41 is pressed (pressed). If the button is not pressed (No), In step S11, the process waits until the start button is pressed. If the button is pressed (Yes), the process proceeds to the next step S12.
[0047]
In step S12, the control unit 30 detects the remaining memory capacity X of the DRAM 11. If the remaining memory capacity X is 64 MB or more, the process proceeds to step S13a, the image quality mode A is set, and then the process proceeds to step S14. If the remaining memory capacity X is 32 MB or more and less than 64 MB, the process proceeds to step S13b, the image quality mode B is set, and then the process proceeds to step S14. If the remaining memory capacity X is less than 32 MB, the process proceeds to step S13c, the image quality mode C is set, and then the process proceeds to step S14.
[0048]
In the last step S14, a job for forming an image on a copy sheet by the above-described known electrophotographic method is executed and the process is terminated.
[0049]
According to the first image forming method, the image is formed based on the image quality mode selected by the threshold value preset in the memory remaining amount X of the DRAM 11, so that the storage of the image information due to the memory shortage can be prevented. Therefore, since the stop of image formation due to the interruption of the storage of the image information can be avoided, the restoration work for the stop of the image formation can be eliminated, so that the image formation efficiency can be improved.
[0050]
[Second Image Forming Method]
FIG. 4 is a flowchart showing a second image forming method by the image forming apparatus 100. In this second image forming method, when a copy of a document image is printed by the image forming apparatus 100, 64 MB is set as a threshold for setting the image quality mode A to the remaining memory capacity X of the DRAM 11 having a total storage capacity of 256 MB. Is preset and stored in the nonvolatile memory 12, and when the remaining memory capacity of the DRAM 11 does not reach the threshold value of 64 MB, it is assumed that the image quality mode B is set and the setting relating to the image quality mode is notified. It is assumed that the initial (default) setting of the image quality mode is the image quality mode A that forms an image with high image quality.
[0051]
With this as a precondition, first, in step S21 of the flowchart shown in FIG. 4, it is determined whether or not the “copy start” button displayed on the LCD 41 is pressed (pressed). If the button is not pressed (No), In step S21, the process waits until the start button is pressed. If the button is pressed (Yes), the process proceeds to the next step S22.
[0052]
In this step S22, the memory remaining amount X of the DRAM 11 is detected by the control means 30, and when the remaining memory amount X is 64 MB or more, the process proceeds to step S23a, the image quality mode A is set, and then the process proceeds to step S25. If the remaining memory amount X is less than 64 MB, the process proceeds to step S23b, the image quality mode B is set, and the image quality mode setting is changed in step S24 by a warning display by the LCD 41 and / or a voice warning by the speaker 42. After the notification, the process proceeds to step S25.
[0053]
In the last step S25, a job for forming an image on a copy sheet by the above-described known electrophotographic method is executed and the process is terminated.
[0054]
According to the second image forming method, as in the first image forming method described above, an image can be formed on the basis of the image quality mode selected by the threshold value preset in the memory remaining amount X of the DRAM 11. Since the operator can be notified of the change in the image quality mode, the operator can avoid a situation in which the image forming job is executed without noticing the change in the image quality mode from the high image quality to the normal image quality.
[0055]
Therefore, it is possible not only to avoid image information storage interruption due to memory shortage and image formation stoppage due to image information storage interruption, but also to avoid image formation in an undesired image quality mode. This can prevent wasteful use of consumables such as paper and toner as a recording medium.
[0056]
[Third image forming method]
FIG. 5 is a flowchart illustrating a third image forming method by the image forming apparatus 100. In the third image forming method, when a copy of an original image is printed by the image forming apparatus 100, 64 MB is set as a threshold for setting the image quality mode A to the remaining memory X of the DRAM 11 having a total storage capacity of 256 MB. Is preset and stored in the nonvolatile memory 12, and when the remaining memory capacity of the DRAM 11 does not reach the threshold value of 64 MB, it is assumed that the image quality mode B is set and the setting relating to the image quality mode is notified. In addition, it is assumed that permission (OK) / rejection (NO) can be selected for the setting relating to the notified image quality mode.
[0057]
With this as a precondition, first, in step S31 of the flowchart shown in FIG. 5, it is determined whether or not the “copy start” button displayed on the LCD 41 is pressed (pressed). If the button is not pressed (No), In step S31, the process waits until the start button is pressed. If the button is pressed (Yes), the process proceeds to the next step S32.
[0058]
In step S32, the memory remaining amount X of the DRAM 11 is detected by the control means 30, and when the remaining memory amount X is 64 MB or more, the process proceeds to step S33a, the image quality mode A is set, and then the process proceeds to step S35.
[0059]
If the remaining memory capacity X is less than 64 MB, the process proceeds to step S33b, the image quality mode B is set, and the image quality mode setting is changed in step S34 by a warning display by the LCD 41 and / or a voice warning by the speaker 42. Along with the notification, the user is asked whether to accept or reject the setting change to the image quality mode B.
[0060]
If the change to the image quality mode B is rejected via the user interface unit 40 (No), the process proceeds to step S33a, the image quality mode A is set, and then the process proceeds to step S35. When the change to the image quality mode B is permitted (Yes), the setting of the image quality mode B is confirmed and the process proceeds to step S35.
[0061]
In the last step S35, a job for forming an image on a copy sheet by the above-described known electrophotographic method is executed and the process ends.
[0062]
According to the third image forming method, as in the second image forming method described above, the operator can be notified of the setting change of the image quality mode. Therefore, the operator can change the image quality mode from the high image quality to the normal image quality. It is possible to avoid a situation where an image forming job is executed without being noticed. In addition to this, since the operator can select and change the setting of the image quality mode, for example, although the remaining amount X of the memory is as small as less than 64 MB, even in the high image quality mode with a low compression rate due to the small number of copies For an executable image forming job, copying can be executed by selecting the image quality mode A at the operator's own discretion.
[0063]
Note that the threshold value set for the remaining memory capacity of the DRAM 11 is not limited to 64 MB and 32 MB set in the present embodiment, and is arbitrary in view of the amount of input image information and the total storage capacity of the DRAM 11. Can be set to Also, the compression rate corresponding to each image quality mode is not particularly limited, and in this embodiment, compression rates of 80%, 50%, and 25% are used for explanation, but specific values of the compression rate are used. Can be arbitrarily set under the balance between the total storage capacity of the DRAM 11 mounted on the image forming apparatus 100 and the image quality.
[0064]
[Second Embodiment]
FIG. 6 is a block diagram illustrating a configuration example of a multipurpose machine (Multipurpose Machine) 200 as the present embodiment. The multi-purpose machine 200 is an example of an image forming apparatus. As the plurality of input units 60 other than the scanner unit 50, the image forming apparatus 100 shown in FIG. A print controller 61 and a modem 62 are provided.
[0065]
The print controller unit 61 has an Ethernet (R) port (Ethernet (R) Port) compliant with the IEEE 802.3 standard as an interface for connecting to a communication network such as a LAN (Local Area Network) 70a. Image information is input from an information processing apparatus such as a personal computer.
[0066]
The modem unit 62 includes a communication modem that supports a communication standard based on the ITU-T recommendation, and is connected to an open IP (Internet Protocol) network 70b or the like by this communication modem, and arbitrary information is transmitted via the IP network 70b. Image information is input from the processing device and accepted (facsimile function).
[0067]
Since the multipurpose machine 200 has a plurality of reception paths (input means) for receiving input of image information, the DRAM 11 is often pressed unexpectedly. Therefore, the multipurpose machine 200 is more likely to fall into a memory overflow than the image forming apparatus 100.
[0068]
However, similarly to the image forming apparatus 100, the multi-purpose machine 200 also detects the remaining memory capacity X of the DRAM 11 and selects an image quality mode corresponding to the remaining memory capacity X when storing image information in the DRAM 11. Therefore, even when an emergency FAX is received via the modem unit 62 when the remaining memory capacity X of the DRAM 11 decreases, for example, A FAX can be stored in the DRAM 11 without receiving an error.
[0069]
Next, an operation example of the multi-purpose machine 200 will be described as an example of another image forming method according to the present invention with reference to a flowchart shown in FIG.
[0070]
In this image forming method, when a copy of an original image is printed by the multi-purpose machine 200, the color mode is used as a threshold value for setting the image quality mode A to the remaining memory capacity X of the DRAM 11 having a total storage capacity of 256 MB. 64 MB for forming a color image and 32 MB for forming a monochrome (monochrome) image in the monochrome mode are preset and stored in the non-volatile memory 12, and the remaining memory capacity of the DRAM 11 is different from each other. When the threshold value in the mode is not reached, it is assumed that the image quality mode B is set and the setting related to the image quality mode is notified. It is assumed that the initial (default) setting of the image quality mode is the image quality mode A that forms an image with high image quality.
[0071]
With this as a precondition, first, in step S41 of the flowchart shown in FIG. 7, it is determined whether or not the “copy start” button displayed on the LCD 41 is pressed (pressed). If the button is not pressed (No), In step S41, the process waits until the start button is pressed. If the button is pressed (Yes), the process proceeds to the next step S42.
[0072]
In step S42, the color mode setting is discriminated by the control means 30, and when color copy (image formation) is set, the process proceeds to step S43a, and the control means 30 detects the remaining memory capacity X of the DRAM 11. The When the remaining memory capacity X is 64 MB or more (Yes), the process proceeds to step S44a, the image quality mode A is set, and then the process proceeds to step S46. If the remaining memory capacity X is less than 64 MB (No), the process proceeds to step S44b, the image quality mode B is set, and in step S45, the change of the image quality mode is notified by a warning display on the LCD 41, and then step Proceed to S46.
[0073]
On the other hand, if monochrome copying is set in step S42, the process proceeds to step S43b, and the control unit 30 detects the remaining memory capacity X of the DRAM 11. If the remaining memory capacity X is 32 MB or more (Yes), the process proceeds to step S44a, the image quality mode A is set, and then the process proceeds to step S46. If the remaining memory capacity X is less than 32 MB (No), the process proceeds to step S44b, the image quality mode B is set, and in step S45, the change in image quality mode setting is notified by a warning display on the LCD 41, and then step Proceed to S46.
[0074]
In the last step S46, a job for forming an image on a copy sheet by the above-described known electrophotographic method is executed and the process is terminated.
[0075]
According to the image forming method using the multi-purpose machine 200, an image can be formed on the remaining memory capacity X of the DRAM 11 based on the image quality mode selected by the threshold values set for the color mode and the monochrome mode. An image can be formed with an image quality corresponding to a compression rate selected in consideration of a difference in information amount between image information for forming an image and image information for forming a monochrome image.
[0076]
Note that the image information for forming a color image has a larger amount of information per unit area than the image information for forming a monochrome image. The threshold value for the color mode is set higher than the threshold value for forming the monochrome image, such as 64 MB for the color mode and 32 MB for the monochrome mode. It is not limited to 64 MB and 32 MB, and can be arbitrarily set in view of the amount of input image information and the total storage capacity of the DRAM 11.
[0077]
【The invention's effect】
According to the image forming apparatus of the present invention, when forming an image based on the image quality mode, the remaining capacity of the storage unit is detected at the start of the job, and the image quality mode corresponding to the remaining capacity of the storage unit is selected. Control means for setting is provided.
[0078]
With this configuration, the image quality mode can be arbitrarily changed according to the remaining memory capacity of the storage means, so that an image can be formed in the image quality mode based on the image information compressed corresponding to the remaining memory capacity. . In addition, since the storage interruption of image information due to a shortage of remaining memory capacity as in the conventional method can be prevented, the stop of image formation due to the storage interruption of image information can be avoided. In addition, since the image quality mode is set according to the remaining memory capacity at the start of the job, the image quality mode is switched during the job execution, and the image quality deteriorates in the middle, so this job must be re-executed after all. Such problems can be avoided.
[0079]
According to the image forming method of the present invention, when the image is formed based on the image quality mode, the remaining capacity of the memory is detected when the image information is stored in the memory at the start of the job. An image quality mode corresponding to the detected remaining memory capacity is selected and set.
[0080]
With this configuration, the image quality mode can be arbitrarily changed according to the remaining memory capacity, so that an image can be formed in the image quality mode based on the image information compressed corresponding to the remaining memory capacity. In addition, since the storage interruption of image information due to a shortage of remaining memory capacity as in the conventional method can be prevented, the stop of image formation due to the storage interruption of image information can be avoided. In addition, since the image quality mode is set according to the remaining memory capacity at the start of the job, the image quality mode is switched during the job execution, and the image quality deteriorates in the middle, so this job must be re-executed after all. Such problems can be avoided.
The present invention is applied to a copying machine, a printing machine, a facsimile machine, a multi-function machine, etc. that compresses and stores arbitrary image information, and sequentially reads the stored image information to form an image using an electrophotographic method. Very suitable.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration example of an image forming apparatus 100. FIG.
2 is a block diagram illustrating a configuration example of a main part of the image forming apparatus 100. FIG.
3 is a flowchart showing a first image forming method by the image forming apparatus 100. FIG.
4 is a flowchart illustrating a second image forming method by the image forming apparatus 100. FIG.
FIG. 5 is a flowchart showing a third image forming method by the image forming apparatus 100;
6 is a block diagram illustrating a configuration example of a multipurpose machine 200. FIG.
FIG. 7 is a flowchart showing another image forming method by the multipurpose machine.
[Explanation of symbols]
10 Memory means
20 Image forming means
30 Control means
305 Compression means
40 User interface
41 LCD
42 Speaker
50 Scanner unit
60 Multiple input means
61 Print controller
62 Modem part
100 Image forming apparatus
200 Multipurpose machine

Claims (9)

A compression unit that compresses image information; and a plurality of image quality modes that are compressed at different compression rates, and an apparatus that forms an image based on the image quality mode,
Storage means for compressing and storing the image information;
Image forming means for sequentially reading image information from the storage means to form an image based on the image quality mode;
Control means for controlling the input and output of the storage means and image forming means,
The control means includes
When storing image information in the storage means at the start of a job,
Detecting a remaining capacity with respect to the storage means;
An image forming apparatus, wherein the image quality mode corresponding to the remaining capacity is selected and set. The image forming apparatus according to claim 1, further comprising a notification unit configured to notify a setting relating to the image quality mode. The image forming apparatus according to claim 2, further comprising a selection unit that selects permission / rejection for the setting related to the image quality mode notified by the notification unit. 4. The image forming apparatus according to claim 1, further comprising: a unit that prohibits the control unit from setting an image quality mode according to the remaining capacity. 5. The image forming apparatus according to claim 1, further comprising an operation unit that is operated to change the image quality mode. The image forming apparatus according to claim 1, further comprising a setting unit configured to set a threshold for the remaining capacity for selecting the image quality mode. The image forming apparatus according to claim 6, wherein a threshold value for the remaining capacity for selecting the image quality mode can be set independently in a color mode and a monochrome mode. The image forming apparatus according to claim 1, further comprising: a plurality of input units that receive the image information. It has a plurality of image quality modes that form images by compressing image information at different compression ratios. Arbitrary image information is compressed and stored in a memory based on the image quality mode, and image information is sequentially stored from the memory. A method of reading and forming an image,
When storing image information in the memory at the start of the job,
Detecting the remaining capacity of the memory;
An image forming method, wherein the image quality mode corresponding to the detected remaining capacity is selected and set.

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