JPS638779A - Image processing device - Google Patents

Abstract

PURPOSE:To prevent the generation of image processing defects by successively controlling intervals of carried forms in accordance with the variance in temperature of a fixing device which thermally fixes an image to a sheet material. CONSTITUTION:When a form passes the fixing device after start of copying, the heat of the fixing device is taken off because the temperature of the form is approximately equal to the air temperature on the outside of a machine. When the temperature of the fixing device falls, the temperature of the fixing device is raised between forms because a microcomputer lights a heater. The temperature of the fixing device is monitored to discriminate whether the temperature of the fixing device is lower than a certain value or not, and the delay time of a form supply permitting signal is calculated based on the temperature if it is lower than the certain value. This delay time and the prescribed temperature for monitor are determined before program generation based on preliminarily experimented or calculated data such as the variance in temperature due to the temperature and the size of forms, materials of the fixig device, etc. It is judged whether the delay time is set or not after a certain time elapses; and if the delay time is set, the form supply permitting output is outputted after this time elapses.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to image processing apparatuses, and more particularly, to image processing apparatuses such as copying apparatuses that copy originals on document plates and apparatuses that obtain reproduced images based on image signals. It is related to the device.

[Conventional technology]

Conventionally, in this type of image processing apparatus, using an electrostatic recording method, paper (including various types of paper,
For example, copying machines and laser beam printers have been proposed in which a reproduced image is created on a sheet material (referred to as a sheet material), and a fixing device applies heat to fix the reproduced image to the paper.

[Problem that the invention seeks to solve]

However, in conventional systems, the image forming speed is constant, so when the paper temperature is low, heat is taken away from the fixing device, and when the paper interval is short, the image formation (printout?) on the scheduled number of sheets is completed. In some cases, the temperature dropped below the fixing temperature.

Therefore, conventional devices require complex processing such as detecting the temperature of the fixing device and stopping printing when the temperature drops below the fixable temperature, or raising the temperature of the fixing device when the external temperature is low. The operation was complicated because of interruptions in the middle.

[Configuration to solve the problem]

An object of the present invention is to provide an image processing apparatus that can eliminate the complexity of the conventional control described above and at the same time be simpler for the operator and realize higher functionality, and has the following configuration. That is, the image processing apparatus of the present invention uses temperature changes in a fixing device that fixes an image to a sheet material using heat.
It is characterized by sequential control of paper conveyance intervals.

Further, the present invention is characterized in that the temperature change of the fixing device is predicted in advance, the conveyance interval of the sheet material is determined, and the regeneration operation is performed based on the conveyance interval.

〔Example〕

FIG. 5 shows an external view of the apparatus of this embodiment. 1 is a document reading device (hereinafter referred to as a "reader") that reads a document on a platen and converts it into an electrical signal. Reference numeral 2 represents an operation section of the reader, the details of which will be described later.

Reference numeral 3 denotes an image forming apparatus (hereinafter referred to as a "printer") that performs an image forming operation based on electrical signals from a reader. 4 is a recycled paper cassette of the printer.

Reference numeral 5 denotes a paper discharge tray on which recycled paper is loaded. Riichida 1
and printer 3 are connected by a signal line (not shown),
It communicates image signals, information signals, etc.

Next, using FIG. 6, the internal configuration of the reader I and printer 3 will be shown and explained below.

The original is placed face down on the original platen glass 12, and is pressed onto the glass by the original platen cover 13. The document is illuminated by a fluorescent lamp llK, and the reflected light is reflected by a mirror 15. The light is focused on the surface of the CCD 16 via the lens 10 and the lens 14. Mirror 15 and mirror 10 move at a relative speed of 2:1. These optical systems are powered by a DC servo motor 17.
The robot moves at a constant speed while applying PLL. CCD
The image focused above is output as a serial image signal by a control circuit to be described later.

The image signal bit-serially processed by the reader 1 is input to the laser scanning optical system unit 18 of the printer 3. This unit consists of a semiconductor laser, a collimator lens, a rotating polygon mirror, an Fθ lens, and a tilt correction optical system.

The image signal from the reader 1 is applied to a laser, undergoes electro-optical conversion, and is irradiated via a collimator lens to a polyhedral mirror that rotates at high speed.The reflected light is incident on and scanned by a photoreceptor 32 via a mirror 19. . A pre-discharge 21 is used as a process component that enables image formation on the photoreceptor 32.
．． Pre-exposure lamp 20, negative charger 22, secondary charger 23
, pre-exposure lamp 24, developing device 25, paper feed cassette 4, paper feed roller 26, paper feed guide 27, registration roller 28,
A transfer charger 29, a conveyance belt 30, a fixing device 31, and a paper discharge tray 5 are arranged. The printer is a so-called laser beam printer, and its recording method, an electrostatic recording method, is a well-known technique, so a detailed explanation will be omitted.

The recording paper is fed from the paper cassette 4 by the paper feed roller 26, is conveyed by the registration roller 28 in synchronization with the latent image on the photoreceptor 32, and the latent image is transferred onto the paper by the transfer charger 29. It is conveyed by a conveyor belt 30, fixed by a thermal fixing device 31, and discharged outside the machine.
The paper is stacked on the paper discharge tray 5.

FIG. 4 shows a timing chart of the image forming operation in this embodiment, which will be explained below.

When the copy start key is pressed on the reader 1, the reader instructs the printer to start copying via the communication interface. When receiving a copy start instruction from the printer printer, the motor and other parts start operating, and when the initialization of each part is completed, a paper feed enable signal is output to the reader. The reader monitors the paper feed enable signal, and upon receiving the paper feed enable signal, outputs a paper feed instruction to the printer. When the printer receives the paper feed instruction, it feeds the paper from the paper cassette, and when the paper reaches the registration rollers, it outputs to the reader that it is ready to receive images. When the reader receives this signal, it operates its optical system, reads the document, and starts outputting image signals. When the printer receives the image signal, it operates the registration rollers at a timing such that the leading edge aligns with the leading edge of the paper.

After the paper is sent out by the registration rollers, the latent image is transferred onto the paper, and the paper passes through a conveyor belt and a fixing device and is then ejected to a paper ejection tray.

Then, the printer outputs a paper feed ready signal at the next paper feed timing, which is predetermined based on mechanical precision, and continues until the specified number of copies have been completed and a copy start instruction is output from the reader. The above image forming operation is repeated. The faster the timing of feeding the next paper, the greater the number of copies that can be made per unit time, but the shortest paper interval is determined by the return time of the reader's optical system and the paper conveyance accuracy of the printer.

The relationship between the density of the fixing device 31 and the passage of copy paper through the fixing device will be explained with reference to FIG.

The fixing device 31 of this embodiment is composed of two rollers, and fixing is performed by passing the paper between the two rollers. The fuser has a heater inside the roller to warm the roller. To adjust the temperature, a microcomputer detects the value of the thermistor that is in contact with the roller via the A/D converter shown in Figure 4, and adjusts the temperature to 0 of the heater via the I10 port.
This is done by performing N10FF.

Now, when the power of the printer is turned on, the microcomputer of the printer turns on the heater to maintain a constant temperature (200° C. in this embodiment) while detecting the temperature. Then, when the temperature reaches 200°C (1 point), repeat the 0N10FF operation of the heater to maintain that temperature. When copying starts and the paper passes through the fixing device, the temperature of the paper is almost the same as the temperature outside the machine, so the heat of the fixing device is taken away (portion A in the figure). When the temperature of the fixing device decreases, the microcomputer turns on the heater, so the temperature increases between sheets (section B in the figure).

In this way, the heat of the fuser is usually taken away as the paper passes through,
However, when the temperature of the paper is very low, such as on a winter morning, when copying with the same paper spacing, the paper spacing will recover (as shown by the dotted line in the figure). The temperature will not recover and will drop below the lower limit of fixing temperature at which fixing will no longer be possible.

Therefore, in this example, under similar conditions, 1 in the figure
As shown by the dotted chain line, by widening the paper gap from B to C,
It is controlled so that it does not fall below the fixing lower limit.

Next, FIG. 2 shows a flow chart of the operation of the microcomputer of the printer, which will be explained below.

Information such as errors and paper size and instructions from the reader are communicated with the printer reader (S801).

In this embodiment, the communication between the reader and the printer is carried out by the reader taking the leadership and the printer communicating in a subordinate manner. Then, there are errors in various parts of the printer (paper jam, no paper in the specified tray, etc.).

5802 It is difficult to determine whether there is a door open, etc.)
), if there is an error, return to communication with the reader. Next, determine if there is a copy start instruction from the reader (5803)
, if there is a start instruction, the printer starts operating each part of the printer and performs preprocessing (S804). Preprocessing refers to high voltage output for electrostatic recording. Then, when the preprocessing is completed, it is communicated that paper feeding is possible (S806).

Then, if there is a paper feeding instruction from the reader (S809), paper feeding is started from the specified paper feeding stage.

Then, wait for it to reach the registration roller (S81).
1) Outputs image reception permission to the reader (S812).

Then, it waits for the image signal to be received (S813), and when it is received, the registration roller is operated at the appropriate timing (S814). Then, the user waits while monitoring the fuser temperature until the next paper feed is possible (S819,
5822). This time is predetermined based on the return time of the reader, the paper conveyance accuracy of the printer, etc.

Fuser temperature monitoring monitors whether the temperature of the fuser is below a certain temperature, and if it is below a certain temperature, a delay time is calculated based on the temperature to delay the paper feed ready signal. (S823). The delay time and the specified temperature for monitoring are determined before the program is created based on pre-experimented or calculated changes in temperature caused by paper temperature, paper size, fixing device material, etc. .

Then, after a certain period of time has elapsed, it is determined whether there is a delay time opening (5820), and if there is a delay time, it waits for that time to elapse (S821), and outputs that paper feeding is possible.

Then, it is determined whether an error (paper jam, no paper, etc.) has occurred (5815), and if an error has occurred, each part of the printer is stopped and the copying operation is ended (3818).
. Also, if there is no error, information is communicated with the reader (
In step S816), it is determined whether there is a copy stop instruction from the reader (5817), and if there is a copy stop instruction, each part of the printer is stopped, the copy operation is ended, and the process returns to normal processing. Further, if there is no copy stop instruction, the printer waits for a paper feed instruction.

FIG. 3 diagrammatically shows the operation of the reader's microcomputer, which will be explained below.

The status of the printer is received through communication with the printer, and if there is an error in the printer, it is displayed on the error display section 609 of the operation unit (S701, 5703). If there is no error in the printer and the copy start key is not pressed (S702
), check the key power and if there is any input (S709)
, performs key-specific processing (S710).

For example, if the paper feed tray selection key 614 is used, processing is performed to change the paper feed film display and paper size display section. Then, instruct the printer about the specified paper feed stage (571
2), various information (paper size, error information, etc.) from the printer is received via communication (3718), and the process returns to error check (S701).

If the start key is pressed, the paper feed stage instruction (S714
), a copy start instruction (S716) is issued to the printer via communication. Then, it waits for a message that paper feeding is possible to be received from the printer via communication, and then outputs a paper feeding instruction (S
717. 8718). Then, it waits until the image can be received (S719), reads the image, and outputs an image signal (S720).

In this embodiment, an image is automatically output when the image reading circuit shown in FIG. 3 is started. Then, it is determined whether the specified number of copies has been completed (5721), and once the specified number of copies have been completed, the process waits for the reading to be completed (S722).
, outputs a copy stop instruction to the printer (S725
), return to normal processing. If the specified number of copies have not been completed or if paper is waiting to be fed, information is communicated with the printer (S726), and if there is an error in the printer, a copy stop instruction is issued (S727). Also, when the stop key is pressed, a copy stop instruction is issued (S
728).

If a printer error occurs and there is no power to press the stop key, the process returns to waiting for paper to be fed.

As explained above, according to this embodiment, cold paper can be copied using simple control in which the printer monitors the temperature of the fuser and sequentially controls the paper conveyance interval according to temperature changes. An image processing apparatus that is easier to use for the operator can be realized without operations such as fixing failure or copying being interrupted. Next, another embodiment will be explained.

The relationship between the density of the fixing device and the passage of copy paper through the fixing device will be explained with reference to FIG.

The fixing device of this embodiment is composed of two rollers.
Fusing is performed by passing the paper between the rollers of the book. The fuser has a heater inside the roller to warm the roller. To adjust the temperature, a microcomputer detects the value of the thermistor that is in contact with the roller via the A/D converter shown in Figure 4, and adjusts the temperature to 0 of the heater via the I10 port.
This is done by performing N10FF.

Now, when the power of the printer is turned on, the microcomputer of the printer turns on the heater to maintain a constant temperature (200° C. in this embodiment) while detecting the temperature. Then, when the temperature reaches 200℃ (point I!), turn on the heater ○N10FF to maintain that temperature.When copying starts and the paper passes through the fuser, the temperature of the paper is almost the same as the temperature outside the machine. The heat from the fuser is taken away from the fuser (the part with the person in the diagram).When the temperature of the fuser decreases, the microcomputer turns on the heater, so the temperature increases between the sheets (
(Part B in the figure).

In this way, the heat of the fuser is usually taken away as the paper passes through,
However, when the temperature of the paper is very low, such as on a winter morning, when copying with the same paper spacing, the paper spacing will recover as shown by the dotted line in the figure. The temperature no longer recovers, and after a while, fixing becomes impossible (the temperature drops below the lower limit of fixing).

Therefore, in this embodiment, when the copying operation is started under similar conditions, the dot-dashed line in the figure As shown, by widening the paper spacing from B to C, control is performed so that the fixing lower limit is not exceeded.

Next, FIG. 11 shows a flowchart of the operation of the microcomputer of the printer, which will be explained below.

The printer communicates with the reader information such as errors and paper size, and instructions from the reader (S801).

In this embodiment, the reader and the printer communicate with each other in a manner in which the reader takes the leadership role and the printer is subordinate to the other. Then, it is determined whether an error has occurred in each part of the printer (paper jam, no designated paperboard, door oven, etc.) (5802), and if there is an error, the process returns to communication with the reader. Next, it is determined whether there is a copy start instruction from the reader (5803), and if there is no start instruction, the process returns to communication with the reader.

When there is a start instruction, it is determined whether the outside temperature is the specified temperature or not, and if it is above the specified temperature, the waiting time is set to ensure paper spacing based on the return time of the reader's optical system and the printer's paper conveyance accuracy. (S804, 5806).

This specified temperature is determined based on the paper size, paper temperature, and temperature change data of the fixing device obtained through experiments and actual measurements. In addition, if the temperature is below the specified temperature, the waiting time is set to ensure the paper spacing, which is determined based on the paper size and paper temperature (measured from the actual temperature change of the fuser, etc.) in the same way as determining the specified temperature. (S805).

Then, start the operation of each part of the printer (5807),
After waiting for the pre-rotation to end (S808), a paper feed enable signal is output (S809). When a paper feeding instruction is received from the reader (S810), paper feeding is started from the designated paper feeding stage (S811). Then, it waits for the paper to reach the registration rollers (S812), and notifies the reader that it is possible to receive images (S813). When an image signal is received from the reader (S814), the dystroller is activated at the appropriate timing (S815). And 5805.5
After waiting for the waiting time determined in step 806 (S816), the next paper feed enable signal is output.

When waiting for paper feed instructions, an error (paper jam, no paper, etc.)
It is determined whether an error has occurred (5817), and if an error has occurred, each part of the printer is stopped to cancel the copying operation (S820). If there is no error, information communication is performed with the reader (381g), and when a copy stop instruction is received (S819), each part is stopped, the copy operation is completed, and normal communication is resumed. If a copy stop message is not received, the process continues to wait for a paper feed instruction.

Note that the operation of the reader microcomputer is the same as that shown in FIG.

Further, the timing chart of the image forming operation is also similar to that shown in FIG.

As explained above, according to this embodiment, at the start of a copy operation, the printer predicts the change in fuser temperature based on the outside temperature (equivalent to paper temperature), paper size, and number of copies, and Simple control of the conveyance interval eliminates abnormal operations such as defective fixing and interruptions in copying, making it possible to create an image processing device that is easier to use for the operator. .

The configuration common to the first embodiment and the second embodiment will be described below.

FIG. 7 is a block diagram showing an example of the internal configuration of the reader 1. As shown in FIG.

The optical lens 14 captures an original image placed on an unillustrated original table by C.
Used to image onto CD16.

The original image is sequentially scanned by an optical system (not shown), but since such a reading technique is a well-known technique, detailed explanation will be omitted.

The CCD 16 converts the shading of the original image into an electrical signal.

This electrical signal is amplified by the amplifier circuit 302 and converted into an analog signal.
A digital converter (A/D converter) 303 converts each pixel into a multi-value digital signal. Further, the digital signal is processed by a shading correction circuit 304 to remove shading caused by uneven light emission of the light source, uneven luminous intensity distribution of the optical system, uneven sensitivity of COD, etc., and then sent to a binarization circuit 305.
and is converted into a binary digital image signal VDO.

Binarization can be performed using two methods: a method using a constant binary level given by the latch circuit 307, and a method using a binary level periodically changed within a predetermined matrix size by the dither ROM 308. A selector 306 selects and switches between two types of binarization processing using the dither method. The dither method is a method of pseudo-reproducing halftones using binary signals, and is widely used in facsimiles and the like.

In this embodiment, it is possible to obtain an optimal copy image by selecting a method that gives a constant binary level for text documents, etc., and a dither method for documents that require gradation, such as photographs. It has become.

Dither ROM 308 sequentially reads dither patterns stored at addresses given by counter 309. Note that the CCD 16 is driven by a CCD drive circuit 301.

The ND-converted image information is stored in an image memory 318, which is connected to the CPU bus and accessed by the CPU to perform document recognition, AE (ground skipping), and the like. The CPU 310 operates according to a control program written in the ROM 311 and the RAM 312 .

110 Po) 315. Timer circuit 316. Serial circuit 317. A key display drive circuit 313 is used to control the entire reader.

The key display drive circuit 313 is a circuit for scanning the key matrix of the operation unit 314 and driving a display such as an LED. Further, the serial circuit 317 is a circuit used for giving control commands to the printer and document feeding device, and conversely for receiving and receiving information.

FIG. 8 is a block diagram showing an example of the internal configuration of the printer.

As shown in FIG. 4, the serial signal from reader 1 is
The signal is input to the serial circuit 501 and processed by the CPU 500. The serial circuit 501 is also used for exchanging information with the sorter 5.

The CPU 500 operates according to a control program stored in the ROM 503, and operates based on the control program stored in the RAM 504. A timer circuit 502 and an I10 board 505 are used to control the entire printer, paper deck, and duplex unit.

The input interface 507 performs input processing of sensor signals such as paper detection in the printer. Also, the AD converter 5
The temperature of the fixing device is also detected via 17. (In the case of the second embodiment, the temperature outside the machine is also detected.) A drive circuit 508 is a circuit for driving a motor, a high voltage transformer, etc. (not shown).

A display circuit 506 is used to display printer status such as out of print paper and occurrence of a jam.

The VDO signal (image signal) sent from the reader is input to the laser driver 509, and the semiconductor laser 510
It is converted into laser light based on the VDO signal. The laser beam is focused by a collimator lens 511, and scanned by a polygon mirror 512 in a direction substantially parallel to the rotation axis of the photosensitive drum 32, which is rotated by a predetermined amount. The scanned laser light undergoes light intensity correction by the f-theta lens 513, and is irradiated onto the photosensitive drum 32 to form a latent image based on the VDO signal.

Image formation in printers uses a so-called electrostatic recording method, in which the required portions of the charge applied to the photosensitive drum 32 are removed using laser light, which is then developed using a developer and printed onto print paper. This is done by transferring and fixing. Since the electrostatic recording method is a well-known technique, detailed explanation will be omitted.

Now, the laser beam scanned by the polygon mirror 512 is incident on the optical fiber 515 before being irradiated onto the photosensitive drum 32, and when the photodetector 516 detects the incident, it outputs an electric signal (a BD multiplied signal).

If the reader waits for the time from generation of the BD double signal until the laser beam reaches the photosensitive drum 32 and then outputs the VDO signal, a latent image will be formed at an appropriate position on the photosensitive drum 32.

FIG. 9 shows the operating section in this embodiment, which will be explained below.

601 is a copy start key, which starts the copying operation. A reset key 602 is used to reset each setting (magnification, etc.). A stop key 603 instructs to stop the copy operation. A numeric keypad 604 is used to input the number of sheets, and a clear key 605 is used to clear the input.

A number display section 606 displays the number of remaining sheets during input and copying operations. A density display section 607 indicates copy density, and is moved by a density key 608. An error display section 609 displays various errors.

The AE key 610 is used to specify or cancel automatic density adjustment. The photo key 611 specifies the dithering process shown in FIG. The paper size display section 612 displays the paper size of the paper feed stage displayed on the paper feed film display section 613. The paper feed film display section 613 displays the paper feed section selected by the selection key 614. The paper feed stage can be selected from an upper cassette or a lower cassette. The magnification display section 619 displays the magnification selected by the magnification selection key 618 and the magnification specified by the zoom key 617.

〔Effect of the invention〕

Since the image processing apparatus according to the present invention has the above-described configuration, it has the advantage that image processing defects are less likely to occur and good images can be obtained.

[Brief explanation of drawings]

Figure 1 is a temperature change diagram of the fuser, Figure 2 is a control flowchart of the printer's microcomputer, Figure 3 is a control flowchart of the league's microcomputer, Figure 4 is a timing chart during copy operation, and 5 is an external view of the image processing device of this embodiment, FIG. 6 is an internal configuration diagram of the image processing device of this embodiment, FIG. 7 is a league control circuit diagram, and FIG. 8 is a printer control circuit diagram. FIG. 9 is an external view of the operating section of the printer, FIG. 10 is a temperature change diagram of the fixing device of another embodiment, and FIG. 11 is a control flowchart of the microcomputer of the printer of another embodiment. ■ is a league, 2 is an operation unit, 3 is a printer, 4 is a paper cassette, 5 is a paper output tray, 31 is a fuser

Claims (3)

[Claims] (1) In an image processing device that reproduces original images and forms images based on image signals, the paper conveyance interval is sequentially controlled by temperature changes in a fixing device that uses heat to fix images on sheet materials. Image processing device. (2) An image processing device that reproduces original images or forms images based on image signals is equipped with a fixing device that fixes images onto a sheet material using heat, and predicts temperature changes in the fixing device in advance. An image processing apparatus characterized in that a conveyance interval of sheet material is determined and a reproduction operation is performed based on the conveyance interval. (3) The image processing apparatus according to claim 2, wherein the temperature change of the fixing device is predicted based on the outside temperature, the sheet material size, and the number of sheets to be reproduced.