JPH096181A - Recorder - Google Patents

Abstract

PURPOSE: To provide a recorder capable of preventing the wrinkles and curling of recording paper, the occurrence of a failure in fixing, etc., and realizing a fixing heater control capable of saving power. CONSTITUTION: The recorder provided with a fixing heater is provided with a temperature detecting means 3 detecting temp. in the vicinity of the fixing heater 2, a temperature rising grade calculating part 6 for obtaining a temperature rising value within a specified time at the time of energizing the fixing heater by the temp. detected by the temperature detecting means 3, a heater energizing control part 5 for controlling the energization of the heater, in accordance with the temperature rising value obtained by the temperature rising grade calculating part 6 and moreover, a heater energizing control part 5a for stopping the energization at the timing of the detection of a prescribed temp. (a) lower than a normal set temp. (c), when the temperature rising value obtained by the calculating part 6 is a prescribed value A or more, at the time of controlling the energization of the heater for keeping the temp. in the vicinity of the fixing heater 2 a fixing temp. and at the timing of the detection of a prescribed temp. (b) higher than the normal set temp. (c), when the temperature rising value is a prescribed value B or below.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic recording apparatus equipped with a fixing heater for use in a facsimile machine, a copying machine, a printer and the like, and more particularly to wrinkles and curls of recording paper and defective fixing. The present invention relates to a recording device including a fixing heater control unit that can prevent the fixing heater.

[0002]

2. Description of the Related Art An electrophotographic recording device is used in an image forming apparatus such as a facsimile machine, a copying machine and a printer. This recording device is a fixing device for thermally fixing a toner image formed on a recording sheet. As a fixing heater. That is, the fixing heater is energized to raise the temperature near the heater to the fixing temperature, and the toner image or the like is fixed at the fixing temperature. Specifically, it is provided with a fixing roller having a heater inside, and a pressure roller in pressure contact with the fixing roller,
The toner is fixed by passing the recording paper having the unfixed toner through the nip portion of both rollers. Therefore, at the time of fixing, it is necessary to keep the vicinity of the fixing heater at the fixing temperature. However, if the fixing temperature is kept at a time other than the fixing time, unnecessary power is consumed and the temperature inside the apparatus rises. The problem occurs.

Therefore, in the prior art, while the vicinity of the fixing heater is normally kept at a preheating temperature lower than the fixing temperature, the fixing is started by starting the rise from the preheating temperature to the fixing temperature immediately before fixing. The temperature is raised to the fixing temperature at the start. For example, in the case of a facsimile machine, the start-up is set at the time of an incoming call. However, in practice, the time required to rise from the preheating temperature to the fixing temperature tends to vary due to the fluctuation of the power supply voltage and the fluctuation of the ambient temperature. Therefore, if the start-up start time and the fixing start time are set in accordance with the average start-up time, the fixing may start before the fixing temperature is reached. appear. To solve such a problem, there is a method of starting the start-up earlier or starting the fixing later than the maximum start-up time. However, this method wastes power and delays the output of recording paper. Occurs.
The fixing temperature control device disclosed in Japanese Utility Model Laid-Open No. 2-134565 is intended to solve the above problems, and is provided with a fixing temperature rise degree measuring means, and is measured by the fixing temperature rise degree measuring means. The fixing start timing is advanced when the fixing temperature rise degree is large, and the fixing start timing is delayed when the fixing temperature rise degree is small.

[0004]

FIG. 8 shows that the temperature in the vicinity of the fixing heater is maintained at a substantially preheated temperature after the recording apparatus is powered on, and then when the recording (writing) request is made, the temperature is changed to the fixing temperature. It shows the temperature in the vicinity of the fixing heater during the period when the temperature is raised and maintained at almost the fixing temperature.
As shown in the figure, when rising to the fixing temperature, a maximum ripple inrush temperature higher by r than the fixing temperature occurs. The rush temperature r is larger as the rising is steeper, and is smaller as the rising is gentle.

In the prior art disclosed in Japanese Utility Model Laid-Open No. 2-134565, the steep rise, that is, the fixing temperature increase degree (temperature increase gradient) is obtained, but the inrush temperature r Do not consider. Therefore, there is a possibility that the temperature near the fixing heater is the inrush temperature, and the fixing is performed immediately after the startup. If the startup is steep and the inrush temperature r is large,
Wrinkles and curls may be formed on the recording paper by the heater that is overheated.

Further, in order to reduce the temperature ripple at the time of start-up as shown in FIG. 8, generally, when the temperature rises, the fixing heater is turned off at a predetermined temperature T which is slightly lower than the fixing temperature, and the fixing temperature is lowered. When it descends after exceeding it, energization is restarted at a temperature slightly higher than the fixing temperature, but even when the start-up is gentle, the timing of turning off the energization is the above-mentioned predetermined temperature T.
When it is detected, as shown in FIG. 9, the temperature in the vicinity of the fixing heater is kept at a temperature lower than the fixing temperature, resulting in defective fixing.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems of the prior art as described above, to prevent wrinkles and curls of recording paper, and to prevent defective fixing, and to further reduce power consumption. It is to provide a recording device that can realize heater control.

[0008]

As a first means, in a recording apparatus equipped with a fixing heater, a temperature detecting means for detecting a temperature in the vicinity of the fixing heater and a temperature detected by the temperature detecting means A temperature rise gradient calculation unit that obtains a temperature rise value within a predetermined time when the fixing heater is energized,
The heater energization control unit performs heater energization control according to the temperature increase value calculated by the temperature increase gradient calculation unit. As a second means, in the above,
During heater energization control for maintaining the temperature in the vicinity of the fixing heater at the fixing temperature, when the temperature increase value obtained by the temperature increase gradient calculation unit is equal to or higher than the predetermined value A, the predetermined temperature a lower than the standard set temperature c is detected. The heater energization control unit is configured to turn off the power at the above timing, and turn off the power at the timing when the predetermined temperature b higher than the standard set temperature c is detected when the temperature rise value is equal to or less than the predetermined value B.

As a third means, in the above, during the heater energization control for holding at the fixing temperature, the energization of the first time or the first predetermined number of times is performed at the timing when the predetermined temperature a lower than the standard set temperature c is detected. The subsequent energization disconnection is provided with a heater energization control section which is performed at the timing when the standard set temperature c or the predetermined temperature d (a <d <c) is detected. As a fourth means, in the first means, the preheating temperature is set low when the temperature rise value obtained by the temperature rise gradient calculation unit is large, and the preheating temperature is set high when the temperature rise value is small. The heater energization controller is provided.

[0010]

As described above, in the first means, the heater energization control can be performed according to the temperature gradient when the temperature is raised to the fixing temperature.
With the second and third means, the rush temperature at the time of rising to the fixing temperature can be reduced, and at the time of fixing, the temperature is not kept lower than the desired fixing temperature. In the fourth means, the rise time to the fixing temperature can be made almost constant, and the preheating temperature can be set low when the temperature rises sharply.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a facsimile machine including a recording apparatus according to an embodiment of the present invention. As shown,
The above-mentioned facsimile device includes a control unit 11 for managing and controlling the entire device according to a built-in program, a keyboard for an operator to give an instruction to the facsimile device, and a display means for the facsimile device to give a message to the operator. Image information read from the operation display unit 12 and the scanner 14, image information data compressed by the encoding / decoding unit (DCR) 18, received compressed image information data,
A RAM 13 for temporarily storing image information expanded by the DCR 18, a plotter 1 for outputting the received image information expanded by the DCR 18 via the RAM 13, and a remote facsimile device via the public telephone network. From a network control unit (NCU) 16 for setting up a call, a communication control unit 17 for performing facsimile transmission / reception according to the G3 transmission procedure, a modem 19 including a low speed modem and a high speed modem, an image memory 20 for storing image information, etc. It is configured.

When transmitting image information with such a facsimile apparatus, the scanner is first controlled by the control unit 11.
The image information is read into the RAM 13 by 14. The image information is D
It is compressed by CR18 and stored again in RAM13. In addition, the control unit 11 obtains call-out designation information such as a destination specified by the operation display unit 12, and the NCU 16 to which the destination information has been passed sets a call with the specified destination. Subsequently, phase B is performed by the communication control unit 17 via the low-speed modem.
Then, the process moves to phase C, and the compressed image information data in the RAM 13 is modulated by the high speed modem in the modem 19 and sent out via the NCU 16.

At the time of reception, after the call is set up by the NCU 16, the phase B is entered, predetermined communication is performed via the low speed modem, and the phase C is entered to receive the compressed image information data. The image information data is NCU16, communication control unit
The data is stored in the RAM 13 via 17, expanded by the DCR 18, and output to the plotter 1 via the RAM 13.

Further, in the recording apparatus of the above embodiment, the plotter 1 is realized by an electrophotographic image forming apparatus or the like,
As shown in the figure, in the fixing heater 2 for fixing the toner image on the recording paper and the plotter control unit 4 for controlling the plotter 1,
A heater energization control unit 5 that controls the fixing heater 2 according to the temperature detected by the temperature detection unit (for example, a thermistor) 3 and a temperature rise gradient calculation unit 6 that obtains a temperature rise value within a predetermined time when the fixing heater is energized are provided. There is. For example,
The plotter control unit 4 includes a CPU, and the temperature rise gradient calculation unit 6 shares the CPU, and the CPU calculates the temperature rise gradient according to the temperature detected by the temperature detection unit 3.

FIG. 2 shows the temperature in the vicinity of the fixing heater 2 detected by the temperature detecting means 3, similar to FIG. In the recording apparatus of this embodiment, as shown in FIG. 2, the temperatures a ₁ and a ₂ near the fixing heater 2 are set at the times t ₁ and t ₂ during the rise from the preheating temperature to the fixing temperature due to the writing request generated by the incoming call or the like. detects, calculates the temperature rise value a ₂ -a ₁ therebetween at a temperature rise gradient calculating section 6. Then, the heater energization control unit 5 performs various heater energization controls according to the temperature rise value.

FIG. 3 is an operation flow chart showing one of such heater energization control. The heater energization control section 5a differs according to the temperature rise value T = a ₂ -a ₁ when rising to the fixing temperature. The energization to the fixing heater 2 is turned off at the detected temperature. The operation will be described below with reference to FIGS. As shown in FIG. 3, when the control unit 11 issues a write request to the plotter control unit 4 due to reception or the like (S1), the heater energization control unit 5a in the plotter control unit 4 starts a timer (S2). Then, the energization state of the fixing heater 2 at that time is checked (S3). Since it was in the preheating state until then, the heater energization control unit 5a repeatedly turns on and off the fixing heater 2, and when it is on, the heater energization control unit 5a turns on a flag set in a predetermined memory area. Therefore, the energization state is checked depending on whether the flag is on. Then, if the power is off, the power is turned on (S4). After that, even if the preheating temperature is detected, the energization is kept on.

After starting the timer, the heater energization control unit 5a monitors whether the time t indicated by the timer reaches t ₁ (S5), and when it reaches t ₁ , the temperature a detected by the temperature detecting means 3 is detected. ₁ is acquired (S6). The temperature detected by the temperature detecting means 3 is input as an analog value to the heater energization control section 5a. This analog value is converted into a digital value by an AD converter incorporated in the energization control section 5a and a predetermined value is obtained. It is stored in the memory area. Next, the heater energization control unit 5a monitors that the time t indicated by the timer reaches t ₂ (S7), and when it reaches t ₂ , acquires the temperature a ₂ detected by the temperature detecting means 3 (S8). Then, the temperature rise gradient calculator 6 calculates T = a ₂ −a ₁ (S
9).

Next, the heater energization control unit 5a compares T with predetermined values A and B (S10, S12), and if T is equal to or greater than A, sets temperature a in a predetermined memory area (S11). As shown in FIG. 2, the temperature a is lower than the standard set temperature c which is set slightly lower than the fixing temperature. That is, when the temperature rises sharply, a low temperature is set. On the contrary, if T is less than B (a value smaller than A), that is, if the rise of the temperature is gentle, a temperature b higher than the standard set temperature c is set in the predetermined memory area (S13). If B <T <A, the standard set temperature c is set in a predetermined memory area (S14).

Thereafter, the heater energization control section 5a monitors the temperature detected by the temperature detecting means 3, and when the detected temperature reaches the temperature set in the predetermined memory area (S15).
The energization to the fixing heater 2 is turned off (S16). As described above, in the above-described embodiment, when the temperature rises to the fixing temperature, if the rise is steep, the energization is turned off at a temperature lower than the standard, so that the ripple rush temperature r can be reduced. Further, when the rising is gentle, since the energization is turned off at a temperature higher than the standard (lower than the fixing temperature), the problem that the fixing temperature becomes low as shown in FIG. 9 does not occur.

Further, the heater energization control unit 5b, during the heater energization control for maintaining the fixing temperature, the first or the first predetermined number of energization interruptions after the start of the rise to the fixing temperature is lower than the standard set temperature c. The set temperature a is detected at the timing, and the subsequent energization is performed at the standard set temperature c or the predetermined temperature d (a <d <c).

As shown in FIG. 4A, when the temperature near the fixing heater in the embodiment of FIG. 3 shown by the solid line is higher than the temperature near the fixing heater in the prior art shown by the dotted line, the ripple rush is generated. Although it is improved in that the temperature r is small (r ₂ <r ₁ ), in the embodiment of FIG. 3, there is a possibility that it may eventually settle below the fixing temperature (defective). is there. That is, in the embodiment using the heater energization control unit 5b, the improvement is made as shown in FIG. 4B, and finally the temperature does not fall below the fixing temperature.

Next, FIG. 5 shows an operation flow of the embodiment by the heater energization control section 5b. In this flow chart, the function of setting the temperature b shown in the embodiment of FIG. 3 is omitted.
Further, an example is shown in which after the temperature is raised, the first energization is performed at the timing when the set temperature a is detected (when T is A or more), and the second and subsequent energization is performed at the timing when the standard set temperature c is detected. ing. Steps 1 to 9 are the same as in the case of FIG.

As shown in FIG. 5, in this embodiment, when the set temperature is reached, the fixing heater 2 is turned off (S1
6) After recognizing the decrease in the detected temperature (S17), when the energization ON temperature (a temperature slightly higher than the fixing temperature) is detected (S1)
8) If the fixing is not completed yet (S19), the heater energization controller 5b turns on the energization to the fixing heater 2 (S20). Then, the standard set temperature c is set in a predetermined memory area.
Is set (S14), and the same operation is repeated until fixing is completed.

Further, in the embodiment using the heater energization control section 5c, the preheating temperature is set low when the temperature rise value is large, and the preheating temperature is set high when the temperature rise value is small. However, the temperature rise value in this case is, as shown in FIG. 2, the temperature rise value A ₂ -A ₁ in the period from T ₁ to T ₂ during the time when the temperature near the fixing heater rises to the preheating temperature when the power is turned on. And The operation of this embodiment will be described below with reference to the operation flow shown in FIG.

First, immediately after the power is turned on (S21), the heater energization control unit 5c starts a timer (S22), and further energizes the fixing heater 2 (S23). afterwards,
Monitoring the time t indicated by the timer (S24), to reach T ₁ when acquires the temperature A ₁ detected from the temperature detection means 3 (S2
5) When the temperature reaches T ₂ (S26), the temperature A ₂ is acquired (S27). Then, the temperature rise gradient calculation unit 6 calculates T
= Calculating the A ₂ -A ₁ (S28). Next, in correspondence with the temperature rise value T, a low preheating temperature is set if T is large, and a high preheating temperature is set if T is small in a predetermined memory area (S29). FIG. 7 shows an example of a correspondence table between the temperature rise value T and the set temperature.

Thereafter, when the temperature detected by the temperature detecting means 3 reaches the temperature set in the predetermined memory area (S30), the heater energization controller 5c turns off the energization to the fixing heater 2 (S31). ). After that, in order to maintain the temperature in the vicinity of the preheating temperature, the heater energization control unit 5c repeatedly turns on and off the energization of the fixing heater 2.

The reason why the preheating temperature may be low when the temperature rises sharply as described above is that it is not necessary to shorten the rise time to the fixing temperature more than necessary. That is, when the rising is steep, the preheating temperature is lowered, and when the rising is gentle, the preheating temperature is raised to make the rising time almost constant. By doing so, it is possible to reduce power consumption during preheating when the temperature rises sharply.

Although FIG. 1 shows an embodiment in which the recording apparatus is used in a facsimile apparatus, the present invention can be similarly implemented when the recording apparatus is used in a copying machine or a printer. Further, the present invention can be applied not only to an electrophotographic recording device, but also to a heater such as an inkjet recording device for controlling energization of a heater for drying recorded ink.

[0029]

As described above, according to the present invention,
First, since the heater energization control according to the temperature gradient at the time of rising to the fixing temperature is performed, the ripple inrush temperature at the time of rising to the fixing temperature can be made small, and the temperature lower than the fixing temperature is maintained at the time of fixing. Since it does not occur, it is possible to prevent wrinkles and curls of the recording paper and improper fixing. Secondly, the rise time to the fixing temperature can be made almost constant, and when the temperature rises steeply, the preheating temperature can be set low, so that the fixing failure will occur even if the fixing is started after a fixed time from the generation of the recording request. It does not occur, and further power saving becomes possible.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of a facsimile device including a recording device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a temperature of a main part of a recording apparatus showing an embodiment of the present invention.

FIG. 3 is an operation flowchart of a main part of a recording apparatus showing an embodiment of the present invention.

FIG. 4A and FIG. 4B are other explanatory views of the temperature of the main part of the recording apparatus showing the embodiment of the present invention.

FIG. 5 is another operation flow chart of the main parts of the recording apparatus showing the embodiment of the present invention.

FIG. 6 is another operational flowchart of the main part of the recording apparatus showing the embodiment of the present invention.

FIG. 7 is a table diagram of a management table implemented by a recording apparatus according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram for explaining a problem to be solved by the present invention.

FIG. 9 is another explanatory diagram for explaining the problem to be solved by the present invention.

[Explanation of symbols]

1 ... Plotter, 2 ... Fixing heater, 3 ... Temperature detecting means, 4
... Plotter controller, 5 ... Heater energization controller, 6 ... Temperature rise gradient calculator.

Claims (4)

[Claims] 1. A recording apparatus provided with a fixing heater,
A temperature detecting means for detecting a temperature in the vicinity of the fixing heater; a temperature rising gradient calculating section for obtaining a temperature rising value within a predetermined time when the fixing heater is energized by the temperature detected by the temperature detecting means; A recording apparatus, comprising: a heater energization control unit that performs heater energization control according to the temperature increase value obtained by the calculation unit. 2. The recording apparatus according to claim 1, wherein the temperature increase value calculated by the temperature increase gradient calculating unit is a predetermined value A or more during heater energization control for maintaining a temperature near the fixing heater at a fixing temperature. When, the power is cut off at the timing when the predetermined temperature a lower than the standard set temperature c is detected,
When the temperature rise value is below the predetermined value B, the standard set temperature c
The recording apparatus according to claim 1, further comprising a heater energization control unit that turns off the energization at a timing when a predetermined temperature b higher than the above is detected. 3. The recording apparatus according to claim 2, wherein during heater energization control for maintaining the temperature near the fixing heater at the fixing temperature, the first or the first predetermined number of interruptions of energization are lower than a standard set temperature c. 2. A heater energization control unit is provided, which is performed at the timing when the temperature a is detected, and the subsequent energization interruption is performed at the timing when the standard set temperature c or a predetermined temperature d (a <d <c) is detected. The recording device described. 4. The recording apparatus according to claim 1, wherein the preheating temperature is set low when the temperature rise value obtained by the temperature rise gradient calculation unit is large, and the preheat temperature is set high when the temperature rise value is small. The recording apparatus according to claim 1, further comprising: a heater energization control unit that controls the operation.