JPH11138938A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus for outputting a sheet of a low cost in case of outputting a deteriorated image which can not be stored in an image memory at the time of compressing the image data by using a predetermined compression system. SOLUTION: Image data divided at respective lines are input from a host interface 304, compressed by a predetermined compression system by a compressor 306, and stored in a page memory 308 set in a RAM. The compressed data stored in the memory 308 is expanded by an expander 307, sent to a printer engine interface 305, and then printed by a printer engine. An error sensor 309 judges a data mount of the image data from a host apparatus to be input via a host interface 304. And, if the sensor 309 judges that, even if the data is compressed, it cannot be stored in the memory 308, a preset sheet is supplied to the interface 305, and it instructs to print the sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a plurality of paper feed stages, and selecting one of the paper feed stages to form an image on fed paper.

[0002]

2. Description of the Related Art When printing (image formation) image data transferred from an information processing device (host device), divided image data for each predetermined line transferred from the host device is compressed by a predetermined compression method. There is known an image forming apparatus in which a compressed image data is stored in a page memory in a printer controller of an image forming apparatus, decompressed, transferred to a printer engine and printed. In such a method, data may not be stored in a page memory in the printer controller depending on a compression method, an image type such as character data or picture data, a size, or the like. In such a case, printing is generally performed by further compressing the data so as to fit in the page memory.

The image forming mode (print mode) includes various modes such as a high definition mode, a fine mode, a draft mode, and a toner save mode.
In general, the same paper is used in any mode.

[0004]

By the way, when printing is performed as in the former case, the printing result often does not have the image quality desired by the user due to the compression being performed twice. If the desired image quality is not obtained, the user generally corrects the type and size of the original image and executes printing again. For this reason, when an image is compressed and does not fit in the page memory, the printing result is not particularly dependent on the quality of the paper. However, since there is no difference in control from normal printing, the same paper as in normal printing is selected and used. Therefore, when expensive paper is used, the cost of paper naturally increases.

Similarly, in the latter case, even in a low quality mode such as the draft mode or the toner save mode, it is not possible to perform printing on the same paper as in the case of high quality printing such as the high definition mode or the fine mode. This was wasteful and increased paper costs.

The present invention has been made in view of such a situation of the prior art, and a first object of the present invention is to store image data in an image memory when image data is compressed using a predetermined compression method. An object of the present invention is to provide an image forming apparatus capable of outputting a degraded image which cannot be output on inexpensive paper.

A second object of the present invention is to provide an image forming apparatus capable of outputting an inexpensive sheet in a mode in which a paper feed stage is selected in accordance with an image forming mode and image quality deterioration is permitted. is there.

A third object is to provide an image forming apparatus which allows a user to arbitrarily select inexpensive paper and form an image.

[0009]

In order to achieve the above object, a first means has a plurality of paper feed stages, and forms an image on a sheet supplied from any of these paper feed stages. Compression means for compressing image data transferred from the information processing apparatus side, storage means for storing compressed image data, and decompression means for reading and decompressing compressed image data from the storage means Means for determining whether or not the compressed image data can be stored in the storage means, and if it is determined by the determination means that the compressed image data cannot be stored in the storage means, printing is performed when storage is possible. Means for selecting a paper feed tray different from the paper feed tray containing the paper to be fed and performing image formation on the paper supplied from the selected paper feed tray.

The second means is characterized in that in the first means, the paper supplied from the selected paper feed stage is a low-quality paper or a paper on which a single-sided image has been formed.

The third means has a plurality of paper feed stages, and an image forming apparatus for forming an image on a sheet supplied from any one of these paper feed stages. Means for determining a mode, and a paper feeder corresponding to the mode is selected from the plurality of paper feeders in accordance with the image forming mode determined by the determiner, and supplied from the selected paper feeder. Means for forming an image on a sheet of paper.

A fourth means is that, in the third means, when the image forming mode is a mode which allows deterioration of image quality, the paper supplied from the selected paper feed stage is of low quality. Or a sheet on which a single-sided image has been formed.

[0015] The fifth means includes the first or third means,
Means for the user to select and input a paper type or paper feed stage, and select a desired paper feed stage from the plurality of paper feed stages according to the paper type or paper feed stage input by the input means And means for forming an image on the paper supplied from the selected paper feed stage.

[0014]

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

FIG. 1 is a block diagram showing a schematic configuration of a printer controller provided in the image forming apparatus according to the present embodiment. In the figure, the printer controller basically includes a CPU 301, a ROM 302, a RAM 303, a host interface (host I / F) 304, an engine interface 305, a compressor 306, and a decompressor 307.

The CPU 301 executes overall system control, image processing, and the like.
01 and static information such as various parameters are stored in the RAM 303.
01, and stores control codes and image data created by the CPU 301 processing print data. The host interface 304 is used for exchanging print commands and commands with the host device.
Is used to output commands and print data to the printer engine. A compressor 306 compresses the image data transferred from the host device and stores the compressed image data in a page memory. A decompressor 107 decompresses the compressed image data stored in the page memory and converts the compressed image data via a printer interface 305 into a printer engine. Output to

FIG. 2 is a diagram showing a system configuration including an image forming apparatus in the present embodiment. The system according to this embodiment includes an image forming apparatus PR having a scanner and a printer function, and three host computers PC1, PC
2, the host computer PC and the PC 3 via a network such as a LAN.
Print data from PC1, PC2, PC3
And a parallel I / F or a parallel I / F
It can be directly received and output via F.

FIG. 3 shows an image forming apparatus P according to this embodiment.
It is a schematic block diagram which shows R. As shown in FIG. 1, a document table 2 of an automatic document feeder (hereinafter, referred to as "ADF") 1
The document bundle placed with the document image side down on the
When the start key 34 at 0 (FIG. 4) is depressed, the original is fed from the lowest document to the reading position of the process on the contact glass 6 by the feed roller 3 and the feed belt 4. Contact glass 6 by reading unit 50
After reading the image data of the upper document, the read document is discharged by the feed belt 4 and the discharge roller 5. Further, when the document set detection sensor 7 detects that the next document is present on the document table 2, the document is fed onto the contact glass 6 in the same manner as the previous document. The feed roller 3, the feed belt 4, and the discharge roller 5 are driven by a transport motor (not shown).

The transfer sheets stacked on the first tray 8, the second tray 9, and the third tray 10 are fed by the first sheet feeding device 11, the second sheet feeding device 12, and the third sheet feeding device 13, respectively. ,
The sheet is transported by the vertical transport unit 14 to a position where it contacts the photoconductor 15. The image data read by the reading unit 50 is written on the photoconductor by the laser light from the writing unit 57, and passes through the developing unit 27 to form a toner image. The toner on the photoconductor 15 is transferred while the transfer paper is conveyed by the conveyance belt 16 at the same speed as the rotation of the photoconductor 15. Thereafter, the image is fixed by the fixing unit 17, and the image is discharged to the finisher 100 of the post-processing device by the sheet discharging unit 18. In this embodiment, the third tray 10
A transfer paper (paper) of lower quality than other trays is stored in the tray, and is set as a paper storage stage for error.

The finisher 100 normally transfers the transfer paper conveyed by the paper discharge unit 18 of the main body to the discharge rollers 1.
It can be guided in the 02 direction and the stapling section. Further, by switching the branch deflecting plate 101 upward, the sheet can be discharged to the sheet discharge tray (stacker tray) 104 via the transport roller 103. Further, by switching the branch deflecting plate 101 downward, the sheet can be conveyed to the staple tray 108 via the conveying rollers 105 and 107. The transfer paper stacked on the staple tray 108 is aligned with the jogger 109 for paper alignment every time one sheet is discharged, and a copy is completed and the stapler 106 binds the paper. The transfer paper group bound by the stapler 106 is stored in the stapling completed paper discharge tray (fall tray) 110 by its own weight.

A normal paper discharge tray 104 is a paper discharge tray that can move back and forth, and moves back and forth for each paper discharge tray section, for each document, or for each copy sorted by the image memory, and copies that are discharged. Sort paper easily.

When images are formed on both sides of the transfer paper,
The transfer paper fed and imaged from each of the paper feed trays 8 to 10 is not guided to the paper discharge tray 104 side, and the branch pawl 112 for path switching is set on the upper side, so that the double-sided paper feed is once performed. Stock in the unit 111. Thereafter, the transfer paper stocked in the duplex paper supply unit 111 is re-fed from the duplex paper supply unit 111 in order to transfer the toner image formed on the photoconductor 15 again, and the branch claws 112 for path switching are moved. It is set on the lower side and guided to the paper discharge tray 104. The double-sided paper supply unit 111 is used for forming images on both sides of the transfer paper in this manner.

The photoreceptor 15, the transport belt 16, the fixing unit 17, the paper discharging unit 18 and the developing unit 27 are driven by a main motor (not shown), and each of the paper feeding units 11 to 13 supplies a driving force of the main motor (not shown). The transmission is controlled by a paper clutch. The transmission of the driving force of the main motor to the vertical transport unit 14 is controlled by an intermediate clutch.

The reading unit 50 includes an illumination light source 51 and a first mirror 52 mounted on the first traveling body,
The second and third mirrors 5 mounted on a traveling body and receiving the reflected light from the first mirror 52 and guiding the reflected light to the imaging lens 53 side
5 and 56, and a CCD 54 for reading a document image formed on a reading surface by the image forming lens 53. The original image read by the CCD 54 is
The light emitted from the laser generator 58 passes through the fθ lens 59 and is reflected by the mirror 60 to scan the surface of the photoconductor 15.

FIG. 4 shows the operation unit 30. In the figure, an operation unit 30 includes a liquid crystal touch panel (display) 31, a numeric keypad 32, a clear / stop key 3
3, a print key 34, a mode clear key 35, and an initial setting key 38 are provided.
1, a mode setting function key 37 is set, and a message indicating the number of copies and the state of the image forming apparatus is displayed. Also, a key 39 for switching between a copy function, a printer function, and a storage copy function is set.

FIGS. 5 and 6 are views showing examples of the display on the liquid crystal touch panel 31 of the operation unit 30. FIG. As can be seen from the figure, when the operator touches a key displayed on the liquid crystal touch panel 31, the key indicating the selected function is inverted to black. Further, when it is necessary to specify the details of a function such as a scaling value at the time of performing scaling, by touching a key, a detailed function setting screen is displayed. As described above, since the liquid crystal touch panel uses the dot display device, the optimum display at that time can be graphically performed.

FIG. 5 shows a screen for selecting and setting a copy function. In FIG. 5, a message area for displaying a message such as "I can copy" or "Please wait" is displayed on the upper left, and a message area on the right. Is the copy number display area that displays the number of sheets set, below it is an automatic density key that automatically adjusts the image density, an automatic paper selection key that automatically selects the transfer paper, and a process that aligns copies one by one in page order Key, a stack key to specify the process of sorting copies by page, a staple key to specify the process of binding the sorted items one by one, a 1: 1 key to set the magnification to 1: 1, Set the zoom ratio key to set the reduction ratio, the two-sided key to set the duplex mode, the erase / move key to set the binding margin mode, etc., and the printing of stamps, dates, pages, etc. Print key to is provided. In the figure, the selected mode is shaded with the corresponding key.

FIG. 6 shows an operation screen for the printer function.
On this operation screen, an online / offline key for setting permission of a print request, a forced ejection key for forcibly ejecting an image that has not been ejected in a data-in state, a data-in display indicating a data input state of image data, and setting of transfer paper A display indicating the status, a display indicating the type of transfer paper stored in each of the paper feed trays 9 to 10, and a selection display of a print mode such as a draft mode or a toner save mode can be made. The operation of the image forming apparatus configured as described above and the operation from reading an image to forming a latent image on the recording surface of the photoconductor will be described below. Here, the latent image is a potential distribution generated by converting an image into optical information and irradiating the image on the surface of the photoconductor.

First, the reading unit 50 includes a contact glass 6 on which a document is placed and an optical scanning system. The optical scanning system includes an exposure lamp 51, a first mirror 52, and a lens 5.
3, a CCD image sensor 54, a second mirror 55, a third mirror 56, and the like. The exposure lamp 51 and the first mirror 52 are fixed on a first carriage (not shown), and the second mirror 55 and the third mirror 56 are fixed on a second carriage (not shown). When reading a document, the first carriage and the second carriage are mechanically scanned at a relative speed of 2: 1 so that the optical path length does not change. This optical scanning system is driven by a scanner drive motor (not shown).

The original image is read by the CCD image sensor 54, and is converted from an optical signal to an electric signal and processed. The image magnification can be changed by moving the lens 53 and the CCD image sensor 54 left and right in FIG. That is, the position of the lens 53 and the CCD image sensor 54 in the left-right direction in the figure is set corresponding to the designated magnification.

The writing unit 57 comprises a laser output unit 58, an imaging lens 59 and a mirror 60.
Inside the laser output unit 58, there is provided a polygon mirror that rotates at a constant high speed by a motor and a laser diode as a laser light source.

The laser light emitted from the laser output unit 58 is deflected by the polygon mirror that rotates at a constant speed, passes through the imaging lens 59, is turned back by the mirror 60, and is condensed on the surface of the photoreceptor to form an image. . The deflected laser light is exposed and scanned in a so-called main scanning direction orthogonal to the direction in which the photoconductor rotates, and performs recording in units of lines of an image signal output by a selector 64 of an image processing unit described later.
An image, that is, an electrostatic latent image is formed on the surface of the photoconductor by repeating main scanning at a predetermined cycle corresponding to the rotation speed and the recording density of the photoconductor.

The laser beam output from the writing unit 57 is irradiated on the photoconductor 15 of the image forming system. The main scanning synchronization signal is applied to the laser beam irradiation position near one end of the photoconductor 15 (not shown). Is provided. Based on the main scanning synchronization signal output from the beam sensor, control of image recording timing in the main scanning direction and generation of a control signal for input / output of an image signal described later are performed.

When used as a printer, the aforementioned printer controller controls the laser output unit 5 of the writing unit 57 based on image data input from any of the host computers PC1 to PC3.
8 is driven to scan with a laser beam to form an electrostatic latent image on the photoreceptor surface as described above, and an image is formed through a developing step, a transfer step, and a fixing step.

FIG. 7 is an explanatory diagram showing the data flow of the printer controller configured as shown in FIG. In the figure, image data divided for each predetermined line is input from a host interface 304, compressed by a compressor 306 by a predetermined compression method, and stored in a page memory 308 set in a RAM 303. The compressed data stored in the page memory 308 is decompressed by the decompressor 307, sent to the printer engine interface 305, and printed by the printer engine. The error detection unit 309 determines the amount of image data input from the host device via the host interface 304 by the error detection unit 309 configured by the program of the CPU 301 of the printer controller. When it is determined that the image data cannot be stored in the page memory 308, in other words, when the data amount of the compressed image data exceeds the storage capacity that can be stored in the page memory 308, it is determined that the image data cannot be stored (error), and compression is performed again. Stored in the page memory 308. Since the image data thus stored cannot obtain the desired image quality as described above, the error detecting unit 309 supplies a preset sheet to the engine interface 305 and instructs the engine interface 305 to print on the sheet. I do.

That is, for image data that reliably expands the compressed image data to the original image data, normal or good quality paper is supplied and printed, but as described above, desired image quality can be obtained. For image data that is likely to be impossible, that is, image data that needs to be compressed twice, there is a high possibility that printing will be performed again, so low-cost paper is automatically supplied and printed. Therefore, in such a case, the previously set paper feed tray for the error, in this case, the third tray 10 is selected, and low-quality, low-cost paper is selected from the paper feed tray (third tray) 10. Supply. Needless to say, the paper feed tray for the error can be appropriately set according to the number of paper feed trays and the frequency of use of the image forming apparatus.

The processing procedure at this time is shown in the flowchart of FIG. In this process, a process of compressing image data of a predetermined line and storing it in the page memory 308 is executed (step 801), and the compressed data is stored in the page memory 308.
(Step 802). If the data can be stored in the page memory 308 by this check, the first tray 8 or the second
Is selected (step 803), and printing is performed on ordinary paper. On the other hand, if it does not fit, that is, if an overflow results in a memory error, the third tray 10 which is a paper feed tray containing paper for error is selected (step 804), and the quality is higher than that of paper for normal printing. Prints on the error paper that is falling.

FIG. 9 is a flowchart showing a processing procedure for selecting a paper feed stage according to the image forming mode. In this process, first, it is checked whether or not the image forming mode is a special (printing) mode (step 901). If the image forming mode is a special printing mode such as the draft mode or the toner save mode, the third sheet feeding stage for an error is set. The tray 10 is selected (step 902), and printing is performed on a sheet of lower quality than the sheet for normal printing. If the printing mode is not the special printing mode, the first sheet feeding stage in which the sheet for normal printing is stored is set. The user selects the tray 8 or the second tray 9 to perform printing. This image forming mode can be set by the host computers PC1 to PC3 that transfer image data.
Further, it can be set by the operation panel 30 of the image forming apparatus PR.

FIG. 10 is a flowchart showing a processing procedure for arbitrarily setting the paper feed tray by the user. The setting by the user is performed by inputting from a display or a keyboard of the host computer PC1 to PC3 which requests printing by the driver software, or by selecting and inputting from the operation panel 30 of the image forming apparatus PR. That is, on the image forming apparatus PR side, first, the input of the sheet feeding tray selection from the host computer PC1 to PC3 or the operation panel 30 of the image forming apparatus PR is confirmed, and the sheet feeding tray for error (the third tray 10) is set. It is checked whether or not to perform (step 1001). If an error paper feed tray (third tray 10) is set in this check, a paper feed tray (third tray 10) containing error paper is selected (step 1002), and the normal print paper tray is selected. Print on error paper, which is lower in quality than other paper. On the other hand, if the error paper feed tray (third tray 10) is not set in step 1001, the normal print paper feed tray (first tray 8 or second tray 9) is selected (step 1001).
3) Printing is performed on paper for normal printing.

[0040]

As described above, according to the first aspect of the present invention, the compression means for compressing the image data transferred from the information processing apparatus, the storage means for storing the compressed image data, and the storage means Expanding means for reading out the compressed image data from the means and expanding the image data; means for judging whether or not the compressed image data can be stored in the storage means; and determining that the compressed image data cannot be stored in the storage means. If it is determined, a paper feed tray different from the paper feed tray containing the paper to be printed when the paper can be stored is selected, and image formation is performed on the paper supplied from the selected paper feed tray. Means for performing image formation, it is possible to select a sheet different from normal image output for image output where image quality is expected to be degraded, and to form an image. Choose It becomes possible to.

According to the second aspect of the present invention, since the paper supplied from the selected paper feed stage is a low quality paper or a paper on which an image has been formed on one side, waste of high quality paper is suppressed. Paper cost can be reduced and resource saving can be achieved.

According to the third aspect of the present invention, a means for determining an image forming mode in which an image is to be formed, and a plurality of paper feed stages from the plurality of paper feed stages in accordance with the image forming mode determined by the determining means. There is provided a means for selecting a paper feed stage and forming an image on the paper supplied from the selected paper feed stage, so that the paper can be selected according to the image forming mode. Further, when the compressed image data is used, it is not necessary to determine whether or not the image data can be stored in the storage means, so that the hardware configuration can be simplified.

According to the fourth aspect of the present invention, when the image forming mode is a mode in which the deterioration of the image quality is allowed, the paper supplied from the selected paper feed stage is a low-quality paper or Since the single-sided image is formed on the paper, waste of high-quality paper can be suppressed, paper cost can be reduced, and resource saving can be achieved.

According to the fifth aspect of the present invention, the user selects and inputs a paper type or paper feed stage, and the paper type or paper feed stage is input according to the paper type or paper feed stage input by the input means. Means for selecting a desired paper feed stage from the plurality of paper feed stages and performing image formation on sheets supplied from the selected paper feed stage.
When a low-quality image is formed, the user can freely select a sheet on which an image is to be formed, thereby suppressing waste of high-quality paper.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a printer controller of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a system configuration of a system using the image forming apparatus according to the embodiment.

FIG. 3 is a schematic configuration diagram illustrating a mechanical configuration of the image forming apparatus according to the embodiment.

FIG. 4 is a diagram illustrating an operation panel of the image forming apparatus of FIG. 3;

FIG. 5 is a diagram illustrating an example of a display state of the operation panel in FIG. 4;

6 is a diagram showing another example of the operation panel display state of FIG.

FIG. 7 is an explanatory diagram showing a data flow of the printer controller configured as shown in FIG. 1;

FIG. 8 is a flowchart illustrating a processing procedure of a process of compressing image data and selecting a paper feed tray according to a compressed state.

FIG. 9 is a flowchart illustrating a processing procedure of processing for selecting a paper feed tray according to an image forming mode.

FIG. 10 is a flowchart illustrating a processing procedure of a process in which a user sets whether or not to select a paper feed tray for an error.

[Explanation of symbols]

 301 CPU 302 ROM 303 RAM 304 Host interface 305 Engine interface 306 Compressor 307 Decompressor 308 Page memory 309 Error detector

Claims (5)

[Claims] An image forming apparatus that has a plurality of paper feed stages and forms an image on a sheet supplied from any of these paper feed stages. Compression means for compressing; storage means for storing the compressed image data; decompression means for reading and decompressing the compressed image data from the storage means; and whether the compressed image data can be stored in the storage means. Means for judging whether or not the sheet can be stored in the storage means. Means for forming an image on the paper supplied from the selected paper feed stage. 2. The image forming apparatus according to claim 1, wherein the paper supplied from the selected paper feed tray is a low-quality paper or a paper on which a single-sided image has been formed. 3. An image forming apparatus which has a plurality of paper feed stages and forms an image on a sheet supplied from any of these paper feed stages, determines an image forming mode in which an image is to be formed. Means, and a paper feeder corresponding to the mode is selected from the plurality of paper feeders according to the image forming mode determined by the determiner, and the paper supplied from the selected paper feeder is selected. An image forming apparatus for forming an image. 4. When the image forming mode is a mode in which deterioration of image quality is allowed, the paper supplied from the selected paper feed tray is a low-quality paper or a paper on which single-sided image has been formed. The image forming apparatus according to claim 3, wherein: 5. A means for a user to select and input a paper type or a paper feed stage, and a plurality of paper feed stages selected from the plurality of paper feed stages in accordance with the paper type or the paper feed stage input by the input means. 4. The image forming apparatus according to claim 1, further comprising: means for selecting a paper feed stage and performing image formation on paper supplied from the selected paper feed stage. apparatus.