JPH07162633A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent the excessive rise of temperature at a heater part and to improve the durability of an image forming device by changing the range of power supply to the heater of a fixing means in response to the largest size width of image among those received images of different size widths and therefore by controlling the amount of heat. CONSTITUTION:When the image signals are stored in a memory 66 of a facsimile equipment and then received, a control circuit 67 decides the size width of the recording paper. At the same time, the circuit 67 detects the largest one of recording paper size widths and sends this detection information to a control means which controls the power supply range to a heater 60a of a recording part 65. Then a recording operation is started based on the received image signals, and at the same time the energization is started to the heater 6a. Under such conditions, a fixing control means applies the voltage to an electrode 60L and makes a resistance material 60c generate the heat at a prescribed level with reception of the largest recording paper size of A3. Meanwhile the voltage is applied to an electrode 60M with the recording paper size width of A4 and the heat of a prescribed level is generated at the part of the A4 size width. Thus even the images of different size widths can be surely fixed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a fixing means for fixing the visible image on the recording paper by heating and melting the visible image formed on the recording paper by the image forming means with a heating body through a heat resistant film. The present invention relates to an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, a recording paper heating apparatus for heating and fixing an image includes a heating roller maintained at a predetermined temperature,
A heating roller method of heating a recording sheet while conveying it by a pressing roller having an elastic layer in pressure contact with the heating roller is widely used, and in a communication device such as a facsimile,
Since the temperature rise characteristic of the heating element is slow, it is necessary to constantly supply power to the heating element, and the heating element keeps a constant temperature in the power supplying state in any state such as a standby state, a receiving state, a transmitting state, etc. It was made to keep.

[0003]

However, the above heat roller system has the following drawbacks.

It takes a considerable time for the temperature to rise to a predetermined temperature, and during that time, the image forming operation is prohibited.
That is, there is a wait time.

Since the heat capacity is required, a large amount of electric power is required.

Since the roller temperature of the rotating roller is high,
A heat resistant special bearing is required.

Depending on the fixing temperature and the curvature of the roller, the recording paper may be wound around the roller, causing troubles such as jamming of the recording paper.

Since the temperature of the fixing point for fixing the toner on the recording paper is equal to the temperature of the separation point of the recording paper and the heat roller, a high temperature offset depending on the separation temperature is likely to occur and also depends on the separation temperature. The degree of image gloss cannot be controlled.

Further, unlike a copying machine or a printer, in a communication device such as a facsimile, recording is required only at the time of reception, but since the fixing heater is kept in the ON state even at the time of transmission and standby, the ratio of transmission to reception. In many cases, it was very uneconomical. Further, since the temperature inside the machine rises, it becomes necessary to cool it with a fan or the like, and the device becomes large.

On the other hand, recently, a heating member (thermal heater; hereinafter referred to as a heater) which is fixedly supported and a heat-resistant film which is conveyed while being pressed against the heater, presses the recording paper into close contact with the heater. A fixing device having a member and a method of applying heat from a heater to a recording paper through a film to heat and fix an unfixed image formed and carried on the recording paper surface to the recording paper surface has been proposed. (See JP-A-63-313182). In the film heating method using such a thin film, a low heat capacity heater can be used as a heater. Therefore, it is possible to save power and shorten the wait time (quick start) compared to the conventional contact roller heating roller method.

However, even when the recording paper size width is smaller than the maximum recording paper size width of the apparatus (for example, when the recording paper of A4 size width is passed through an apparatus capable of recording up to A3 size width), the heating layer of the heater is used. Since the effective full length area of is the maximum size width of the recording paper, it generates heat with a predetermined amount of heat generation per unit length regardless of the paper passing area or the non-paper passing area of the recording paper.

That is, the heat generation energy of the heat generation layer portion corresponding to the paper passing portion is consumed for image fixing, but the heat generation energy of the heat generation layer portion corresponding to the non-paper passage portion is not consumed for image fixing, so that heat is accumulated. Will be done.

As a result, the heater portion of the non-sheet-passing portion tends to have an abnormal temperature rise (excessive temperature rise), which shortens the durability life due to heat loss of the heater or the heat generating layer, and reduces the durability of the fixing film, the pressure member, and the like. However, there is a problem in that the deterioration of the running property of the fixing film and the instability of the running property of the fixing film occur.

In view of this, the present invention prevents excessive heating of the heater portion due to different size widths of the recording paper, reduces the durability life of the heater or the heat generating layer, and improves the durability of the fixing film, the pressure member, and the like. It is an object of the present invention to provide an image forming apparatus having an economical fixing device that can prevent the deterioration and instability of the running property of the fixing film and further save power.

[0015]

SUMMARY OF THE INVENTION According to the present invention, an image forming means for forming a visible image on a recording sheet and a heating body are brought into close contact with one side of a film moving together with the recording sheet, and a visible image is provided on the other side. The image data is communicated with the fixing means for bringing the recording paper supporting the sheet into close contact with the recording paper and applying heat energy to the recording paper through the film, the control means for starting the power supply to the heating body at the same time as the image formation start command, and the control means. An image forming apparatus having a communication control means, wherein the amount of heat is switched by switching the power supply range to a heating body which is a heat source of the fixing means in accordance with the maximum size width of received images having different size widths received by the communication control means. It is configured to control.

With the above configuration, after storing the received images of different sizes in the memory, the maximum size width of the received image is detected at the start of image recording, and the maximum size width (for example, there are three received images, The size range of the breakdown is A3
When the size width is 1 sheet and the A4 size width is 2 sheets, the A3 size width is set. At this time, the size width of the recording paper is one A3 size width and two A4 size widths of the received image size width. Since the amount of heat is controlled by switching the power supply range to the heating body which is the heat source of the fixing means, it is possible to reliably fix even images of different size widths.

Further, since the power supply range to the heating body is not switched for each different size width, no complicated control means is required.

Further, since the electric power is supplied to the heating body only during recording, it does not affect the temperature rise in the non-sheet-passing portion. Therefore, the durability of the fixing film, the pressure member, etc. is improved, and the fixing film is also improved. Of the fixing device can be stabilized, and the reliability of the fixing device can be improved.

Further, power consumption can be reduced.
Since a cooling means such as a fan is unnecessary, the device can be made compact.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an outline of an entire facsimile apparatus as an embodiment of the present invention will be described with reference to FIGS.

The top cover of the apparatus main body 1 is formed on the original placing table 2 on which a plurality of originals S can be stacked, and an image of the original conveyed from the original placing table 2 to one end of the upper surface of the apparatus main body 1 is formed. An optical reading system 3 for reading information is arranged,
A recording system 4 including a laser beam printer is arranged below the reading system 3. A telephone 22, an operation panel 23, and the like are arranged on the upper surface of the apparatus body 1.

The optical reading system 3 separates the originals S stacked on the original table 2 one by one by a pre-conveying roller 5b that is in pressure contact with the pre-conveying pressing piece 5a and a separation roller 5d that is in pressure contact with the separation pressing piece 5c. Then, the sheet is conveyed to the contact sensor (contact type sensor) 7 by the main conveying roller 5f or the like which is in pressure contact with the sheet feeding roller 5e, and the document S is pressed by the pressing means 6 to the contact type sensor 7
After the image information of the document S is read while pressing the document S to be in close contact with the document S, the document S is discharged to the document discharge tray 8 by the discharge roller 5h which is in pressure contact with the discharge roller 5g.

The contact type sensor 7 is an LE as a light source.
The image information surface of the document S is irradiated with light from D7a, and the reflected light reflected from the image information surface is imaged on the photoelectric conversion element 7c by the short focus imaging lens 7b to read the image information. In the facsimile mode, and to the own recording system 4 in the copy mode.

The original document table 2 is provided with a slider 2a which is slidable in the direction perpendicular to the conveying direction of the original document S (width direction of the original document S). The slider 2a is used to stack the original document on the original document table 2. It is possible to align both sides of the printed document S.

Further, the recording system 4 emits a modulation signal from the laser beam oscillator 9a based on the image signal of the contact type sensor 7 and outputs the modulation beam to the polygon mirror 9b.
The photosensitive drum 10a of the image forming unit 10 is irradiated with the scanning light as scanning light to form image information on the surface of the photosensitive drum 10a, and the recording paper P ′ fed from the paper feeding unit A to the image forming unit 10 is imaged. After the information is transferred and fixed, it is ejected.

The photoconductor drum 10a comprises a primary charger 1
0b, developing roller 10c, cleaning blade 10d
At the same time, the recording cartridge 10e is integrally incorporated into the recording cartridge 10e, and is detachably attached to the apparatus main body 1.

Then, the surface of the photosensitive drum 10a is uniformly charged by the primary charger 10b, and when the surface is irradiated with scanning light from the polygon mirror 9b, a latent image is formed, and this latent image is developed. The toner is supplied from 10c so as to be visualized.

Photosensitive drum 10a of the image forming section 10
A transfer charger 10f is arranged in the peripheral portion of the sheet, and a fixing device 60 and a paper discharge roller 10h are arranged in the recording paper conveyance path downstream of the photosensitive drum 10a. After the toner image formed on the surface of the photoconductor drum 10a is transferred to the recording paper P ′ fed from the section A, the fixing device 60 fixes the toner image on the recording paper P ′, and the paper is discharged by the paper discharge roller 10h. The sheet is discharged to a sheet discharge tray 12 which is detachably provided on the left side surface of the main body 1.

On the left side surface of the main body 1 of the apparatus, a tray 13 for manually feeding recording paper is provided so as to be openable and closable, and the manual tray 13a is opened by tilting the tray 13 to a substantially horizontal state. When the recording paper P ′ is opened and stacked on the stacking tray 13 and inserted into the manual insertion port 13a, the recording paper P ′ is pressed by the pressure contact member 13b.
The roller 11b having the larger diameter of a is pressed into contact with the roller 11b, separated one by one by the roller 11b, and then conveyed by the conveying roller pair 11a between the transfer charger 10f and the photosensitive drum 10a. ing.

An opening / closing lid 14 is provided on the left side surface of the apparatus body 1 so as to be openable / closable, the loading tray 13 is provided on the opening / closing lid 14, and the paper discharge tray 12 is detachably attached. .

By opening the opening / closing lid 14, the recording cartridge 10e can be pulled out of the apparatus main body 1 and replaced.

Further, the opening / closing lid 14 is adapted to interlock with the drum photosensitive preventing shutter 10i provided in the recording cartridge 10e. When the opening / closing lid 14 is opened, the shutter 10i is closed and the opening / closing lid 14 is closed. The shutter 10i is sometimes opened.

Further, an operation button (not shown) of a release lever for unlocking the opening / closing lid 14 is arranged in a recess provided on the front surface of the opening / closing lid 14, and this recess is provided in the discharge tray 1.
It is closed by a protective cover that is integrally provided in 2, and the lock of the opening / closing lid 14 cannot be unlocked by the operation button unless the discharge tray 12 is removed from the opening / closing lid 14.

For this reason, it is possible to prevent the recording cartridge 10e from being damaged by replacing the recording cartridge 10e in a half-open state where the opening / closing lid 14 is not completely opened due to the obstruction of the discharge tray 12. .

Further, the opening / closing lid 14 is opened halfway, and in association with this, the drum photosensitive prevention shutter 10i is also opened halfway, so that it is possible to prevent a situation in which the image quality is deteriorated due to the exposure of the photosensitive drum 10a.

The paper feed section A includes a paper feed cassette 50 mounted on the bottom of the apparatus body 1 so as to be pulled out from the left side surface.
The recording papers P ′ are separated one by one by a circular-shaped feeding roller 36, and the separated recording papers P ′ are formed on the photosensitive drum 10a by a cassette carrying roller pair 38 as a registration roller pair. Image tip and recording paper P '
The sheet feeding timing is set so that the leading ends of the sheets are aligned with each other, and the sheet is fed between the transfer charger 10f and the photoconductor drum 10a through the conveying roller pair 11a.

FIG. 3 is a side view showing the fixing device in an enlarged manner.

The heating element 60a is a linear heating element having a low heat capacity fixedly supported by the apparatus, and a resistance material 60c which is a heat generating layer is formed on an alumina substrate 60b having a thickness of 1.0 mm in accordance with each recording paper size width. It is branched and painted, and electricity is applied from both ends in the longitudinal direction.

Fluorine-based lubricating grease is applied as a lubricant to the sliding surface of the heating element 60a with respect to the fixing film 60e.

The energization is carried out, for example, at a cycle of 100 m DC and 20 m
With a pulse-like waveform of sec, the temperature measuring element 60 such as a thermistor
A pulse according to a desired temperature and energy release amount controlled by d is given by changing its pulse width. The pulse width is 0.5 msec to 5 msec.

As described above, the fixing film 60e moves in the direction of the arrow in the figure by coming into contact with the heating body 60a whose energy and temperature are controlled.

As an example of the fixing film 60e, a heat-resistant film having a thickness of 20 μm, for example, polyimide, polyetherimide, PES, PFA is prepared by adding a conductive material to a fluororesin such as PTFE or PAF at least on the image contact surface side. An endless film having a mold layer coated with 10 μm is used. That is, the film generally has a total thickness of 100 μm, more preferably less than 40 μm.

The fixing film is driven by the driving roller 60f and the driven member 60g and tension to move in the arrow direction without wrinkles. The pressure roller 60h is a roller having a rubber elastic layer with good releasability such as silicon rubber, and has a total pressure of 4 to
The heating element 60a is pressed by 10 kg through the fixing film 60e, and is rotated in pressure contact with the fixing film 60e. The visible image on the recording paper P ′ is guided to the fixing unit 60 by the guide 60i, and the fixed image is obtained by the above heating.

FIG. 4 is a schematic block diagram showing the circuit configuration of the facsimile apparatus according to this embodiment.

The reading unit 61 is for reading a document at the time of transmission or copying, and the operation unit 62 is for performing an operation for setting a transmission / reception operation. The NCU (network control unit) 63 transmits / receives data via a communication line, and the modem 64 demodulates an analog signal sent from the NCU 63 into a digital signal or modulates the digital signal into an analog signal. It is sent to the NCU 63.

The memory 66 processes the data demodulated by the modem 64 by the control circuit 67 and stores the data. The recording unit 65 receives the data stored in the memory 66 from the control circuit 67 and records the data.

FIG. 5 is a flow chart showing the operation of the facsimile apparatus in this embodiment.

First, when a calling signal is input, a called confirmation signal (automatic reception) is sent (S1), and a digital identification signal (notifying the other party of the standard function of CCITT recommendation) is sent to perform one's facsimile function. Notify the sender (S
2).

For example, when the original document on the transmission side is A3 size,
The sending side is informed whether the facsimile function on the receiving side has A3 size, and if there is, there is recording paper in the recording paper storage section. Based on the result, the transmission side determines whether the original is sent in the same size or reduced to B4 size or A4 size and sent to the reception side.

Then, a reception command for instructing the reception mode is received from the transmission side (S3). Furthermore, before sending an image through the line, a training check confirmation signal that is a signal for sending at the image transmission rate to check whether the probability of a transmission error occurring is small (this signal is the image signal actually sent (Modulated by the same modem as) is received (S4). Then, if there is no transmission error, a reception preparation confirmation signal is sent to notify the transmission side that reception preparation is completed (S5).

After that, wait until the image signal is received,
When the reception is started, the image signal is stored in the memory (S
6, S7). Then, when the reception of the image signal is completed (S
8), it is determined whether or not a procedure end signal indicating the end of the procedure (indicating that one page has been transmitted and there is no next original) is received (S9), and when the procedure end signal is received, the image is displayed. A message confirmation signal indicating that the message has been normally received is sent to the transmitting side (S10). Then, the process ends by receiving the line disconnection command (S11).

At the same time, the recording paper size for recording the received image is determined (S12). When this recording paper size is determined, at the same time, the maximum size width of the recording paper sizes is detected, and the detection information is sent to the control means for controlling the power supply range to the heating body 60a, and the power to the heating body 60a is supplied. The supply range is determined (S13).

Then, the recording operation is started based on the received image signal (S14), and the heating element 6 is
Power supply to 0a is started (S15). Thus, the image signal is read from the memory 66, the laser beam of the recording unit 65 is turned on and off based on the image signal, an electrostatic latent image is formed on the photosensitive drum 10a, and the developing device
This latent image is visualized.

The recording paper fed from the recording paper storage section and conveyed to the registration roller position is the photosensitive drum 10.
After the visible image is transferred at the transfer position on a, the image is conveyed to a fixing device and heated and fixed.

Then, wait until the image recording operation as described above is completed (S16), and turn on the power to the heating element 60a.
Set to FF (S17).

When the procedure end signal is not received in S9, the transmission of one page is completed, and when the multi-page signal indicating that there is the next original is received, the image signal is normally received, and A message confirmation signal indicating that the original can be received immediately is sent to the other party (S19).
Then, the image signal of the next original is received and stored in the memory 66 (S20, S21). Then, after waiting for the image signal reception (S22), the process returns to S9.

As described in the above embodiments, in addition to switching the electric power supply range to the heating body which is the heat source of the fixing means in accordance with the maximum size width of received images having different size widths, When outputting a plurality of received documents received, the power supply range to the heating body which is the heat source of the fixing unit may be switched in units of one communication document.

In this case, the basic operation is the same as the flowchart of FIG. 5, and when outputting the received document from the memory 66, the power supply range is controlled in communication document units.

As described above, since one communication is one unit, for example, assuming that there are three communications a day, one A3 is for the first communication, one A4 is for the second communication, and A4 is 5 for the second communication.
When the number of sheets is 5, the number of sheets of B5 is 3, and the number of sheets of B5 is 5 sheets, the first communication is the A3 size width, the second communication is the A4 size width, the third communication is the B5 size width, and so on. 1
By switching the power supply range of the heating element to the maximum size range of the communication unit, it is possible to further reduce the power consumption, and especially for a user with a large amount of communication, there is an advantage that the device reliability and economy can be improved. is there.

Next, FIG. 6 is an enlarged plan view for explaining an example of the structure of the heating element 60a used in each of the above embodiments.

In each of the above embodiments, the maximum recording paper size width is A3 size. When the maximum recording paper size width A3 is received, a signal is sent from the fixing control means to the heating body 60a, so that a voltage is applied to the electrodes 60L at both ends of the resistance material 60c, which is a heating layer, and the heating layer is heated. By energizing the resistance material 60c, which is the heat generating layer, the resistance material 60c, which is the heat generating layer, generates heat with a predetermined amount of heat generation per unit length in each portion of the effective length region, which hinders the visible image fixing process for the maximum recording paper size width. Executed without.

Next, in the case of a small size recording paper, for example, an A4 size paper, a signal is sent from the fixing control means to the heating body 60a, so that the electrodes 60L and 60L on both ends of the resistance material 60c which is the heat generating layer are formed. When a voltage is applied to the electrodes 60M at both ends of the resistance material 60c-3, which is a branched heating layer that branches from the A4 size width portion, and the resistance material 60c, which is a heating layer, is energized, it corresponds to the sheet passing portion. The portion of the resistance material 60c that is the heat generating layer, that is, the portion of A4 size width,
Heat is generated with a predetermined heat generation amount per unit length, and the visible image fixing process is performed on the small size width recording paper.

In this case, the resistance material portion 60c which is the heat generating layer corresponding to the non-sheet passing portion is the resistance material portion 6 which is the heat generating layer.
0c and the resistance material 60c-3 that is the branch heating layer form a parallel energization circuit, and the current is shunted to both. as a result,
The heat generation amount of the resistance material portion which is the heat generating layer corresponding to the non-paper passing portion is lower than that of the resistance material portion which is the heat generating layer of the paper passing portion. As a result, excessive temperature rise in the non-sheet passing portion of the heating element 60a is suppressed.

FIG. 7 is an enlarged plan view for explaining another example of the structure of the heating element 60a.

As in the case shown in FIG. 6, when the maximum recording paper size width A3 of the apparatus is received, a signal is sent from the fixing control means to the heating body 60a, so that the resistance material 60c, which is the heat generating layer, is transferred. By applying a voltage to the electrodes A on both ends and energizing the resistance material 60c which is a heat generating layer, the resistance material 60c which is a heat generating layer generates heat with a predetermined heat generation amount per unit length in each part of the effective length region. However, the visible image fixing process for the maximum recording paper size width is executed without any trouble.

Next, in the case of a small size recording paper, for example, A4 size paper, a signal is sent from the fixing control means to the heating body 60a, and a voltage is applied to the electrode point C on the resistance material 60c which is a heat generating layer. By applying the voltage and energizing the resistance material 60c which is the heat generating layer, the portion of the A4 size width generates heat with a predetermined heat generation amount per unit length, and the visible image fixing process for the small size recording paper width is executed without any trouble. It
In this case, since no current flows in the non-sheet passing portion (outside the A4 size width area), heat is not generated and excessive temperature rise does not occur.

[0067]

As described above, according to the present invention,
After storing the received images of different size range in memory,
Maximum size width of received image or 1 when starting image recording
The maximum size width of each communication document is detected, and the amount of heat is controlled by switching the power supply range to the heating body, which is the heat source of the fixing unit, to the maximum size width. Can be established.

Further, since the power supply range to the heating body is not switched for each different size width, complicated control means is not required.

Furthermore, since the electric power is supplied to the heating element only during recording, it does not affect the temperature rise in the non-sheet passing portion. Therefore, the durability of the fixing film, the pressing member, etc. can be improved, and the running property of the fixing film can be stabilized.
The reliability of the fixing device can be improved and the power consumption can be reduced.

Further, since a cooling means such as a fan is unnecessary, the apparatus can be made compact, and the noise of the apparatus can be reduced regardless of whether it is in standby or in operation.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of a facsimile apparatus according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the outer appearance of the facsimile apparatus according to the above embodiment.

FIG. 3 is an enlarged side view showing the fixing device of the facsimile apparatus according to the above embodiment.

FIG. 4 is a block diagram showing a circuit configuration of a facsimile apparatus according to the above embodiment.

FIG. 5 is a flowchart showing the operation of the facsimile apparatus according to the above embodiment.

FIG. 6 is an enlarged plan view illustrating a configuration example of a heating body used in the above-described embodiment.

FIG. 7 is an enlarged plan view illustrating another configuration example of the heating element used in the above-described embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Device main body, 2 ... Original document mounting table, 3 ... Optical reading system, 5 ... Recording system, 10 ... Image forming part, 26 ... Telephone, 50 ... Paper feed cassette (recording system storage part), 60 ... Fixing device, P '... Recording paper, S ... Manuscript.

Claims (2)

[Claims] 1. An image forming means for forming a visible image on a recording sheet, a heating member is closely attached to one side of a film that moves together with the recording sheet, and a recording sheet supporting the visible image is closely attached to the other side. An image having fixing means for applying heat energy to recording paper through the film, control means for starting power supply to the heating body at the same time as an image formation start command, and communication control means for communicating image data In the forming device, the heat supply amount is controlled by switching the power supply range to the heating body which is the heat source of the fixing unit in accordance with the maximum size width of the received images having different size widths received by the communication control unit. A characteristic image forming apparatus. 2. The heat quantity is controlled according to claim 1, when a plurality of received documents received by the communication control means are output, a power supply range to a heating body which is a heat source of the fixing means is switched for each communication document. An image forming apparatus comprising: