JPH0863085A - Heater control device and recording device including the device - Google Patents

Abstract

(57) [Abstract] [Objective] The object of the first invention of the present application is to optimize the heater control when the AC power supply applied to the heater is abnormal and to prevent the heater failure without increasing the cost. It is to provide a heater control circuit which can be prevented. [Structure] The AC voltage detection circuit 44 detects the voltage value of the AC power supply (step S1), and determines whether the voltage value is below a certain value (step S2). Perform (step S3). However, if it is below a certain value, it is determined that the AC power source is abnormal (step S
4) stop the energization of the heater (step S5),
The timer is started (step S6). And
It is determined whether or not the AC power supply has returned to normal (step S7), the timer is stopped when it returns (step S8), and heater control is performed in consideration of the interruption time (step S9).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater control device and a recording device equipped with the device.

[0002]

2. Description of the Related Art Conventionally, in a recording apparatus such as a facsimile apparatus, an image forming method using a toner such as an electrophotographic method has been adopted. As a method for fixing the toner image on a transfer material, a transfer material is sandwiched. A method of applying heat and pressure to the toner to fuse and fix the toner by using a roller or a film-shaped member for pressure conveyance and a heater is adopted.

Therefore, in order to obtain a good image in such an apparatus, it is necessary to keep the temperature of the heater at a predetermined temperature, and conventionally, a circuit for detecting the voltage value of the AC power supply supplied to the apparatus. Is provided to detect a slight allowable deviation or a slight fluctuation of the AC power supply voltage value, and control is performed to change the wave number of the AC power supply applied to the heater accordingly.

[0004]

However, since the above-mentioned conventional device is not provided with the detecting means for detecting the abnormality of the AC power source supplied to the heater, for example, the on / off of the switch is short due to mischief of a child or the like. It was not possible to detect this even if it was repeated in time, or even if there was a momentary interruption for a very long period due to a poor contact at the outlet or a problem on the side of the power equipment at the outlet.

Moreover, in such a case, although the AC power supply is turned on and off at a cycle of about several 100 ms,
The conventional DC power supply for the heater control circuit is not configured to stop the supply of DC power to the heater control circuit unless the AC power supply is turned off for about 3 seconds or more. The heater was controlled assuming that the AC power supply was normal.

Therefore, there is a problem in that the heater control becomes incorrect and causes a heater failure.

For example, when the heater to which 100V AC is applied is controlled by the wave number control, if the temperature of the heater is raised from 100 ° C. to 200 ° C., the heater control circuit assumes that 100V is being applied. The power is calculated and a predetermined wave number control is performed. However, when a momentary interruption occurs, the energy applied to the heater decreases during that time, and the temperature of the heater remains at the target 20
It never reaches 0 ℃. Therefore, the heater control circuit controls the wave number so as to increase the energy applied to the heater.However, if the occurrence of the instantaneous interruption disappears for some reason at that time, unnecessarily excessive energy is applied to the heater. A phenomenon occurs in which the heater fails, or the heater temporarily becomes higher than the target temperature of 200 ° C., for example, 250 ° C., and the heater control is not normally performed.

On the other hand, if a means for detecting an abnormality of the AC power source is newly provided in order to solve this problem, there is a problem that the cost is increased.

A first object of the present invention according to the present application is to optimize the heater control when the AC power source applied to the heater is abnormal and prevent heater failure without increasing the cost. To provide a circuit.

A second object of the present invention is to provide the above heater control circuit and an on-demand fixing device composed of a film of polyimide or the like having a small heat capacity.
An object of the present invention is to provide a recording apparatus capable of recording excellent images while suppressing the occurrence of heater failure without increasing the cost.

[0011]

According to the first invention of the present application, the above object is to provide a heater, an AC power source as an energy source of the heater, and an AC voltage for detecting a voltage value of the AC power source. In a heater control circuit having a detection circuit and a control unit that controls energization to the heater based on a voltage value detected by the AC voltage detection circuit and maintains the temperature of the heater at a predetermined value, the control unit is AC above
When the voltage value detected by the voltage detection circuit is below a predetermined value, the energization to the heater is stopped, and when the voltage value is above the predetermined value, the energization to the heater is controlled. It is achieved by being set.

According to the second invention of the present application,
The above object is to provide the heater control device according to the first aspect of the present invention, a film-like member disposed so as to be in sliding contact with the heater,
A pressure roller arranged so as to be in pressure contact with the heater via the film-like member, a transfer material transporting means for transporting the transfer material to a pressure contact portion between the pressure roller and the heater, and a transfer material on the transfer material. And an image forming section for forming an unfixed developer image.

[0013]

According to the first invention of the present application, the control unit is
The heater is controlled while the voltage value of the AC power supply is detected by the AC voltage detection circuit as needed, and the temperature of the heater is maintained at a predetermined value. However, if the detected voltage value is below the predetermined value, the instantaneous It is judged that the disconnection has occurred, and the power supply to the heater is stopped. Then, the period from that point until the voltage value becomes equal to or higher than the predetermined value is measured, and after the voltage value becomes equal to or higher than the predetermined value, the energization of the heater is controlled in consideration of the period. Therefore, even if the AC power supply is momentarily cut off, the heater is prevented from being over-energized and the heater is not damaged.

According to the second invention of the present application,
The transfer material carrying the unfixed developer image formed in the image forming portion is conveyed by the transfer material conveying means to the pressure contact portion between the heater and the pressure roller formed through the film-shaped member, and the first member is formed. The proper fixing of the unfixed developer image to the transfer material is performed under the proper temperature control according to the invention.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block configuration diagram of a facsimile apparatus according to the present embodiment. As shown in FIG. 1, the apparatus according to the present embodiment performs reading of documents, communication, and the like with a recording unit 50 including a laser beam printer. It is divided into a facsimile unit 60.

First, the facsimile unit 60 has a first control unit 2 for controlling each unit of the facsimile unit 60.
0 is provided, and the first control unit 20 is connected to the document reading unit 1, the modem control unit 4, the operation panel 5, the sensor 8, the drive system 9, and the memory 13.

The document reading unit 1 reads a transmission document and converts it into image data. The image data is output to the modem control unit 4 by the first control unit 20 and controlled by the modem control unit 4. , A modem 3 which is a modulation / demodulation device, and an NCU 2 which is a network control device. On the contrary, the image data transmitted from the outside is input to the first control unit 20 via the NCU 2, the modem 3, and the modem control unit 4, and once stored in the image memory 10 described later, the first control is performed. The data is output to the recording unit 50 described later by the unit 20.

The operation panel 5 is provided with a display 6 for displaying a facsimile status to the user and a KEY 7 for the user to instruct the facsimile to perform various operations. While operating the KEY 7 while following the message etc., the data is transmitted.

The sensor 9 is for detecting the state of the facsimile, and detects, for example, that a transmission document is set. When the first control unit 20 determines that the original has been set by the sensor 9, a predetermined message is displayed on the display 6 to prompt the user to perform a predetermined operation. As a result, when there is a request to start the transmission operation, the original is read by the original reading unit 1 while the original is being conveyed by the drive system 9 configured by a reading motor or the like for conveying the original. It is designed to send.

The control program by the first control unit 20 as described above is stored in the ROM 12 provided in the memory 13, and the memory 13 further stores an image memory 10 for storing received image data and the like, a power failure, etc. A system RAM 11 is provided which is backed up by a battery or the like so that data is not destroyed even when the commercial power supply is shut off.

Next, the recording section 50 is provided with a second control section 40 for controlling the entire recording section 50. The second control section 40 has a sensor 21, a drive system 22, and a transfer section 2.
6, a scanner unit 27, a printing unit 29, a fixing device 31,
The fan motor drive unit 39, the heater control unit 30, and the AC voltage detection circuit 44 are connected.

The sensor 21 is for detecting various states of the recording unit 50. For example, the sensor 21 detects the presence or absence of a recording material at a predetermined position in the recording unit 50, and the second control unit 40.
On the basis of the information from the sensor 21, the drive system 22 conveys the recording paper to a predetermined position. The drive system 22 includes motors 23 for carrying recording paper or the like.
And plungers 24 for controlling the drive by the motors 23, and clutches 25 having the same function as the plungers 24.

The scanner section 27 is provided with a laser 28, which scans the laser 28 based on the control signal from the second control section 40 and the image data output from the above-mentioned facsimile apparatus section 50, and the printing section. An electrostatic latent image is formed on a latent image carrier such as a photoconductor drum provided in 29.

The printing unit 29 is provided with a developing device in addition to the latent image carrier, and the electrostatic latent image is developed as a developer image by the developing device. The unit 40 drives the latent image carrier and the developing device to form a developer image, and then the high voltage circuit 27 of the transfer unit 26.
Is driven to transfer the developer image onto the recording paper conveyed by the drive system 22.

Then, the recording paper on which the transferred image is formed is conveyed to the thermal fixing device 31, and while the temperature is detected by the thermistor 33, the heater 32 is driven to fix the transferred image on the recording paper by heat. .

FIG. 2 is a structural explanatory view of the heat fixing device 31 of FIG. 1 which is the fixing device of the present invention. The fixing device 31 is an on-demand fixing device that performs a fixing process for fixing a developer image on a recording sheet, and as shown in FIG. 2, a fixing body 110 in which a heater unit 104 is incorporated, and the fixing body 110. It has a pressure roller 120 that heats and presses the recording paper 100 on which the developer image 102 is transferred in cooperation with 110.

The fixing member 110 is a stay 1 having a U-shaped cross section.
05, and the film inner side guide members 106, 107 and 108 and the heater holding member 109 are provided on the outer peripheral portion of the stay 105. The stay 105, the film inner guide members 106, 107 and 108, and the heater holding member 109 cooperate with each other to form a substantially cylindrical member, and the substantially cylindrical member has an outer circumference of several tens of thickness. A thin film member 103 made of polyimide having a thickness of μm is wound around. Grease is applied to the inner surface of the thin film member 103, and the outer surface thereof is surface-treated.

Between the thin film member 103 and the heater holding member 109 as described above, a heater portion 104 that contacts the inner surface of the thin film member 103 is arranged, and the heater portion 104 has a linear resistor body. The heater 32 having
And the thermistor 33 disposed near the heater 32
Is provided.

In such a fixing device, it is necessary to maintain the temperature of the heater 32 at a predetermined value in order to perform good fixing. Therefore, in this embodiment, as shown in FIG. 1, a triac or the like is used. The heater control unit 30 controls the AC voltage applied to the heater 32 to control the temperature.

In this temperature control, an AC voltage detection circuit 44, which will be described later, detects a subtle tolerance or subtle fluctuation of the AC power supply voltage value, and changes the wave number of the AC power supply applied to the heater accordingly. Is.

Further, since the temperature inside the machine rises by driving the heater 32 in this way, the fan motor drive section 39 drives the fan motor section 38 to cool the inside of the machine.

Further, the transfer unit 26 to which a high voltage is applied as described above and the fixing device 31 which is heated to a high temperature by being supplied with AC power are dangerous if the user touches them by mistake. The transfer unit 26 and the fixing device 3
When it is detected that the user has opened the portion that covers 1, the AC power is turned off to protect the user from danger.

A DC power source 42 for converting the energy of the AC power source into DC and operating each section is connected to the recording section 50 and the facsimile apparatus section 60 as described above, and from the AC input section 45. AC power input is
It is supplied at any time through an AC power supply ON / OFF switch 41 that can be operated by the user.

This AC power source not only serves as an energy source for the DC power source 42, but is also applied to the heater 32 while performing predetermined control via the heater control section 30, so that the child may mischief the switch. If the switch is repeatedly turned on and off, or if a very short momentary interruption occurs due to a poor contact at the outlet or a problem with the power equipment at the end of the outlet, normal temperature control cannot be performed.

Therefore, in the apparatus of this embodiment, the AC voltage detection circuit 44 used for controlling the wave number of the heater is used, and the abnormality of the AC power supply is detected based on the AC voltage value obtained from the AC voltage detection circuit 44. ing. Hereinafter, the AC voltage detection circuit 44 in this embodiment will be described in detail.

FIG. 3 shows an example of the configuration of the AC voltage detection circuit 44. In this circuit, the transformer 2 is connected from the power supply line from the AC power on / off switch 41 to the door switch 43.
The AC power supply is separated from the secondary side circuit by 001 and taken out, for example, 100 V is dropped to 12 V to make it easy for the semiconductor circuit to detect the AC voltage. The AC voltage extracted by this transformer 2001 is applied to the diode 2
002, electrolytic capacitor 2005, Zener diode 2004, resistors 2006, 2007, 2008, 200
It is converted into a DC voltage and input to the second control unit 40 via 9, 2010, 2011, the diode 2003, and the capacitor 2012, and becomes close to 5 V as the voltage of the AC 100 V power supply decreases. For example, when the AC voltage is 100V, the value becomes 2.5V, and when the voltage is 85V, the value becomes 3.4V. The second control unit 40 A / D-converts the DC voltage value and inputs the DC voltage value. A subtle change can be detected.

Therefore, even if the AC power supply is momentarily cut or an appropriate voltage drop occurs temporarily, the second control section 40 can detect the decrease of the voltage value and can detect the abnormality of the AC power supply. it can.

That is, in this circuit, the AC voltage is converted into the DC voltage, and the second control unit 40 makes the AC voltage at the timing.
Even if the voltage is detected, the AC voltage value can be detected.

FIG. 4 is a flow chart for detecting an abnormality of the AC power supply in this embodiment. First, the AC voltage detection circuit 4
4 detects the voltage value of the AC power supply (step S1),
It is determined whether the voltage value is below a certain value (step S
2) If it exceeds a certain value, the following process is performed (step S3). However, if it is less than a certain value, it is determined that the AC power source is abnormal (step S4), the power supply to the heater is interrupted (step S5), and the timer is started (step S6). Then, it is determined whether or not the AC power supply has returned to normal (step S7), the timer is stopped when it returns (step S8), and heater control that takes the interruption time into consideration, for example, if the interruption time is short, Normal control is performed after the recovery, and when the interruption time is long and the interruption frequently occurs, control such as shifting to heater failure control is performed (step S9).

As described above, according to the present invention, the voltage detection circuit of the AC power source used for controlling the energization of the heater detects the instantaneous interruption of the AC power source and applies the voltage to the heater.
Since it is possible to optimize the heater control when the C power source is abnormal, it is possible to prevent the heater failure without adding any particular component to the conventional system configuration.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, as shown in FIG. 5, the present invention is applied to a laser printer connected to a data processing device such as a computer, and a printer interface for communicating with the computer for recording. The difference from the first embodiment is that 80 is provided.

Also in this embodiment, the same effect as that of the first embodiment can be obtained.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, the AC voltage detection circuit shown in FIG. 2 is modified. In this embodiment, the AC power supply voltage is not converted into DC, and the AD conversion built in the second control section 40 is performed. It is designed to be taken in with a container. In this case, the second control unit 44 needs to detect the voltage value frequently, but it has better responsiveness than the first and second embodiments and can determine the AC voltage value, and the circuit is simple. I'm done.

[0047]

As described above, according to the first invention of the present application, the voltage detection circuit of the AC power supply used for controlling the energization of the heater detects a momentary interruption of the AC power supply and applies it to the heater. Since it is possible to optimize the heater control when the AC power supply is abnormal, it is possible to prevent the heater failure without adding any particular component to the conventional system configuration.

A second invention according to the present application applies the first invention to an on-demand fixing device, which has a particularly small heat capacity and the heater temperature largely changes even if the AC power source applied to the heater changes a little. As a result, it is possible to provide a recording apparatus that prevents a fixing failure and a heater failure due to inappropriate heater control when the AC power supply is abnormal and forms a good image for a long period of time.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a facsimile apparatus according to a first embodiment of the present invention.

FIG. 2 is a structural explanatory view of the fixing device in the first embodiment of the present invention.

FIG. 3 is a circuit configuration example of an AC voltage detection circuit unit according to the first embodiment of the present invention.

FIG. 4 is a flowchart of heater control in the first embodiment of the present invention.

FIG. 5 is a block configuration diagram of a recording apparatus in a second embodiment of the present invention.

FIG. 6 is an AC voltage detection circuit diagram according to a third embodiment of the present invention.

[Explanation of symbols]

 29 Print Section (Image Forming Section) 32 Heater 40 Second Control Section (Control Section) 44 AC Voltage Detection Circuit 100 Recording Paper (Transfer Material) 103 Thin Film Member (Film Member) 104 Heater Member 120 Pressure Roller

Claims (2)

[Claims] 1. A heater, an AC power source that is an energy source of the heater, and an AC that detects a voltage value of the AC power source.
In a heater control circuit having a voltage detection circuit and a control unit that controls energization to the heater based on a voltage value detected by the AC voltage detection circuit and maintains the temperature of the heater at a predetermined value, the control unit includes: If the voltage value detected by the AC voltage detection circuit is below a predetermined value,
A heater control device, characterized in that it is set to control the energization of the heater when the energization of the heater is stopped and the voltage value exceeds a predetermined value. 2. The heater control device according to claim 1,
A film-like member arranged so as to be in sliding contact with the heater, a pressure roller arranged so as to come into pressure contact with the heater via the film-like member, and a pressure-contact portion between the pressure roller and the heater. A recording apparatus, comprising: a transfer material transporting means for transporting a transfer material; and an image forming section for forming an unfixed developer image on the transfer material.