JPH05173652A - Heater device for fixing unit and its temperature controller - Google Patents

Abstract

PURPOSE:To easily perform an appropriate temperature control by increasing the degree of freedom of the thermal load of a heater for the fixing unit. CONSTITUTION:Three resistance bodies 1, 2, and 3 are arranged on an insulation substrate 4 in parallel and a connection terminal 5 to which electric conductors 9, 11, and 13 are connected in common is provided on one end side of those resistance bodies 1, 2, and 3. Electric conductors 10, 12, and 14 are provided on the other-end sides of those resistance bodies 1, 2, and 3, and connection terminals 6, 7, and 8 are connected to those electric conductors 10, 12, and 14. Those connection terminals are selectively fed with electricity to make the resistance bodies 1, 2, and 3 generate heat in plural combinations.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating heater device for a heat fixing device of an electrophotographic apparatus such as a copying machine, a laser printer, and a FAX, and a temperature control device for the heater.

[0002]

2. Description of the Related Art As shown in FIG. 13, a conventional heater has a structure in which one resistor 1 is arranged on a substrate 4 as a heat source at the center of a fixing surface. Conductor wirings 9 and 10 are provided, and connection terminals 5 and 6 are provided, respectively.

In the case of a conventional heating heater using one resistor 1 as a heat source, the load resistance value of the heat source is constant, and in order to control the temperature to a set temperature, the voltage or current applied to the heater is used. It has been proposed to control the current or to control the energization time to the heater.

FIG. 17 shows a conventional heater temperature control device. The heater H is provided with a resistor 1 and the like, and a switch element 35 controls the energization of an AC voltage source to the resistor 1. The temperature information from the thermistor 36 for detecting the temperature of the heater is digitally converted by the A / D converter 37 and input to the microcomputer 38. The microcomputer 38 outputs control information to the control circuit 39 so that the temperature becomes a predetermined temperature based on the input temperature information, and the control circuit 39 controls the switch element 35.

[0005]

By the way, the method of controlling the voltage or current applied to the heater generally complicates the peripheral circuit and consumes relatively large power in the circuit portion other than the heater. The method of controlling the energization time of is adopted.

The following two methods are mainly used for controlling the energization time.
Two schemes have been proposed.

The first control method is zero-cross wave number control for controlling energization / de-energization for each half wave of the power supply waveform shown in the current waveform diagram of FIG.

The second control method is a phase control method for controlling the phase angle to be energized for each half wave of the power supply waveform shown in the current waveform diagram of FIG.

However, the following problems have been pointed out in such conventional control methods.

In the first control method, that is, the zero-cross wave number control method, the amount of electric power that can be supplied to control the temperature of the heater to a predetermined value is binary in ON / OFF in half-wave units of the power source. Therefore, in order to control the temperature accurately, a plurality of half-waves should be turned on / off as one block.
Control such as setting an OFF pattern or setting ON / OFF duty within one block is performed.

However, such control in block units causes a problem that the response time becomes long and the temperature ripple of the heater becomes large.

Further, when ON / OFF is switched for each half wave, a harmonic component is generated in the load current, resulting in power source noise.

On the other hand, when ON / OFF is switched for each half wave, there is a problem that a harmonic noise component is generated in the load current. In the second phase control method, the energization phase angle is 9
In the vicinity of 0 °, a large amount of switching noise occurs because the current suddenly starts to flow. Further, similar to the zero-cross wave number control, there is a problem that a harmonic noise component is generated in the load current.

[0014]

An example of a heating heater device of a fixing device for solving the problems of the present invention is an insulating substrate and at least two resistors arranged in parallel along the length direction on the insulating substrate. A resistor group, one end side of these resistor groups is electrically commonly connected to provide a connection terminal, and the other end side of each resistor group is provided with a connection terminal.

Further, an example of the temperature control device of the heating heater device of the fixing device for solving the problems of the present invention is at least 2
A switch element for controlling energization to each of the resistors in the fixing device heating heater composed of at least two resistors, a temperature detecting means for detecting the temperature of the heater, and a predetermined value based on the detection information of the temperature detecting means. And a control means for controlling the opening and closing of each of the switch elements for each half-wave of the power supply waveform so that the temperature of the switch element is maintained.

[0016]

With the configuration of the heating heater device and the temperature control device described above, the load resistance value of the heater can be changed for each half-wave of the power supply waveform, and the control response of the supplied power to the detected temperature value of the heater is improved. Can be
Moreover, the occurrence of switching noise unlike the conventional phase control method is eliminated.

[0017]

1 shows a first embodiment of a heater device according to the present invention, and FIG. 2 shows a cross section of FIG. 1A-A. In FIG. 1, 1 to 3 are resistors, 4 is an insulating substrate, and 5 is 8
Is a connection terminal for connecting to the outside, and 9 to 14 are conductor wirings. Resistors 1 to 3 are arranged in parallel on the surface of a substrate 4 having electrical insulation and good thermal conductivity, such as ceramics, with appropriate intervals, and both ends of each resistor 1 to 3 are respectively arranged. Conductor wiring 9
~ 14. The conductor wirings 9, 11, 13 on one end side of each of the resistors 1 to 3 are connected to the common connection terminal 5, and the conductor wirings 10, 12, 14 on the other end side are connected to the connection terminals 6 to 8, respectively. The connection terminals 6 to 8 are connected to a plurality of switches provided outside the heater device, and the load resistance value of the heater device can be changed by opening / closing the switches.

The resistance values of the resistors 1 to 3 may be the same or different, but in order to reduce the number of resistors and increase the variable number of resistance values of the heater, the resistance values of the resistors should be changed. Different values are effective.

In this embodiment, the heater is composed of the three resistors 1 to 3, and the resistance ratio is, for example, 1:
When set to 2: 4, the resistance value of the heater is 1/7, 1/6,
..., 1/2, 1, and ∞ can be changed in eight ways, and the heat generation power can be linearly varied in eight steps.

3 to 7 show a second embodiment of the heater device according to the present invention.

FIG. 3 is a surface view of the heater, and FIG. 4 is A of FIG.
-A sectional view, FIG. 5 is a sectional view taken along the line BB of FIG. 3, FIG. 6 is a sectional view taken along the line CC of FIG. 3, and FIG. 7 is an exploded perspective view showing a tomographic structure of the second embodiment shown in FIG. is there.

The first resistor 1 is formed on a substrate 4 which is electrically insulating and has good thermal conductivity, such as ceramics,
Both ends of the resistor 1 are connected to the conductor wirings 15 and 16. The insulating layer 4A is laminated on the insulating layer 4A, and the second resistor 3 is formed on the insulating layer 4A.
Connect to 8. Further, an insulating layer 4B is further laminated thereon, a third resistor 2 is formed on the insulating layer 4B, and both ends of the resistor 2 are connected to the conductor wirings 19 and 20, and connection terminals for connection with the outside are formed. 21 to 24 are provided.

The connection terminal 21 is connected to the conductor wiring 19, and the lower layer conductor wirings 17 and 15 are formed by through holes or the like.
Connect with.

The connection terminal 22 is connected to the conductor wiring 20, and the connection terminal 23 is a through hole or the like for the middle conductor wiring 1.
8 and the connection terminal 24 is connected to the conductor wiring 16 in the lower layer by a through hole or the like.

The insulating substrate 4 and the resistors 1, 2 and 3 respectively provided on the insulating layers 4A and 4B are three-dimensionally arranged in the thickness direction, and one end side is electrically commonly connected to form one connection terminal. Is provided, and the other end is provided with a connection terminal for each of the resistor groups to form a multi-layer heater.

8 to 12 show a third embodiment of the heater device according to the present invention.

FIG. 8 is a surface view of the heater, and FIG. 9 is A of FIG.
-A sectional view, FIG. 10 is a sectional view taken along the line BB of FIG. 8, FIG. 11 is a sectional view taken along the line CC of FIG. 8, and FIG. 12 is a diagram showing a tomographic structure of the third embodiment shown in FIG.

The first resistor 1 is formed on the substrate 4, and both ends of the resistor are connected to the conductor wirings 25 and 26. An insulating layer 4A is laminated on the insulating layer 4A, the second resistor 3 and the third resistor 2 are arranged on the insulating layer 4A in parallel, and both ends of the resistor З are connected to the conductor wirings 27 and 28 to Both ends of the body 2 are connected to the conductor wirings 29 and 30, and the connecting terminals 31 to 31 for connecting to the outside are connected.
34 is provided. The connection terminal 31 is connected to the conductor wiring 27 and the conductor wiring 29, and further connected to the conductor wiring 25 in the lower layer by a through hole or the like.

The connection terminal 32 is connected to the conductor wiring 30, the connection terminal 33 is connected to the conductor wiring 28, and the connection terminal 34 is connected to the conductor wiring 26 in the lower layer by a through hole or the like.

First resistor 1 provided on insulating substrate 4
And a second resistor 2 and a third resistor arranged in parallel on the insulating layer 4A.
The resistor 3 is used to form a plurality of resistors two-dimensionally and three-dimensionally via an insulating layer, and one end is electrically connected to provide one connection terminal, and the other end is the resistor. The heater device is provided with a connection terminal for each group.

In each of the above embodiments, the number of resistors is three, but the number of resistors may be at least two or more. With the above configuration, the same effect can be obtained.

FIG. 16 shows a first embodiment of the heater temperature control device according to the present invention.

The heater temperature control device of this embodiment is a device suitable for controlling the heating heater device having the above-described three resistors, and the resistors 1, 2, 3 provided in the heating heater device H are suitable. The energization control of the commercial power supply 45 to each of these is performed by the switching elements 40, 41, 42 such as a triac. The temperature of the heater is detected by the thermistor 36 and output to the microcomputer 43 via the A / D converter 37 as in the conventional example. The microcomputer 43 performs a calculation for controlling the heater to a predetermined temperature and outputs a control signal to the control circuit 39. The control circuit 39 turns on each of the switch elements 40, 41, 42,
A control circuit for performing off control, which is controlled by the microcomputer 43.

The control circuit 39 includes a switching element 40.
It has a plurality of trigger circuits for controlling each of .about.42 and a zero cross circuit of the power supply waveform, and outputs a trigger signal to each switching element at the time of the zero cross of the power supply waveform according to the control signal output from the microcomputer 43. The switching element is turned on when the trigger signal is input and is turned off at the zero cross of the power supply waveform.
Therefore, the load resistance value of the heater to which the commercial power source is applied changes in half-wave units of the power source cycle.

Next, the relationship between the resistance value configuration of the resistors 1 to 3 and the electric power supplied to the heater will be described using an example.

The resistance values of the resistor 1 (R1), the resistor 2 (R2) and the resistor 3 (R3) are 1: 2: 4, that is, Rl =
When R, R2 = 2R, and R3 = 4R, the combined resistance value R _{total of} the heater and the electric power supplied to the heater are the values shown in Table 1 below, depending on the open / close states of the switching elements SSR1, SSR2, and SSR. However, the supplied power is a value standardized with the maximum value being 1.

[0037]

[Table 1]

As described above, by controlling the opening / closing of the switching elements 41, 42, 43, the load current to the heater and the supplied power can be controlled in half-wave units of the power supply cycle. The state is shown in FIG.

100-a is a load current waveform, which is 100
The signal CONTl of -b is the switch element (40) SSRl
The trigger signal and the signal CONT2 of the switch element (4
1) A trigger signal of SSR2 and a signal CONT3 are trigger signals of the switch element (42) SSR.

The trigger signal of each switch element is "Hi".
It becomes conductive only during a half cycle of gh ". The temperature of the heater is controlled by the heater temperature control device shown in FIG.

The temperature of the heater is detected by the thermistor 36 and converted into a digital quantity by the A / D converter 37. The digitized temperature data is input to the microcomputer 43, compared and calculated with a predetermined temperature, and a control signal is output to the control circuit 39. Note that the present invention can be applied to a configuration other than the above-described resistor and resistance value configuration. By increasing the number of resistors, more accurate temperature control becomes possible, and by changing the resistance value configuration,
It is possible to change the control sensitivity.

FIG. 19 shows a second temperature control device according to the present invention.
An example of is shown.

The temperature control device of the first embodiment described above is
The control circuit 44 had a power supply waveform zero-cross circuit, but in the present embodiment, a zero-cross circuit 46, which is a circuit for detecting a power supply waveform zero-cross, is additionally provided and a detection signal is output to the microcomputer 43.

Further, the control circuit 44 includes the switching element 4
It has a plurality of trigger circuits for controlling 0 to 42, respectively, and outputs a trigger signal to the switching element in the same phase as the control signal output from the microcomputer 43. The microcomputer 43 calculates the opening / closing timing of each switching element in synchronization with the zero-cross pulse output from the zero-cross detection circuit 46, and the control circuit 4
4 outputs a control signal. Therefore, the load resistance value of the heater to which the commercial power supply 45 is applied can change at any timing with reference to the zero cross of the power supply.

FIG. 20 shows the situation. 200-a is a load current waveform, a signal ZCP of the waveform 200-b is a zero cross pulse of the power supply, and a signal CONTl is a switching element S.
The trigger signal of SRl, the signal CONT2 is the trigger signal of the switch element SSR2, and the signal CONT3 is the trigger signal of the switch element SSR3.

Trigger signals are output at arbitrary timings with reference to the signal ZCP, and the load current to the heater and the supplied power can be controlled with higher accuracy. That is, this embodiment is characterized by applying the first embodiment of the temperature control device described above and using resistance value control and phase control together.

[0047]

As described above, according to the heating heater device of the fixing device of the present invention, the load resistance can be changed according to the combination of the resistors to be energized, and the optimum energization heat generation can be obtained. There is an effect that you can.

Further, according to the temperature control device of the present invention, it becomes possible to finely control the amount of power supply in half-wave units of the power supply cycle. Furthermore, harmonic noise of the power supply terminal, which is a problem in the conventional example, can be reduced, and a large-sized and high-performance noise filter is not required, which brings about a great effect in terms of cost. This is a very effective measure against noise, especially in a large-scale device that requires a large amount of power.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a heater device of a fixing device according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a second heating device for a fixing device according to the present invention.
FIG.

4 is a cross-sectional view taken along the line AA of FIG.

5 is a sectional view taken along line BB of FIG.

6 is a sectional view taken along line CC of FIG.

7 is an exploded perspective view of FIG.

FIG. 8 is a third heating device for a fixing device according to the present invention.
FIG.

9 is a cross-sectional view taken along the line AA of FIG.

10 is a sectional view taken along line BB of FIG.

11 is a cross-sectional view taken along the line CC of FIG.

FIG. 12 is an exploded perspective view of FIG.

FIG. 13 is a perspective view of a conventional heater device.

FIG. 14 is a current waveform diagram illustrating zero-cross wave number control.

FIG. 15 is a current waveform diagram illustrating phase control.

FIG. 16 is a block diagram showing a first embodiment of a temperature control device for a heater heater of a fixing device according to the present invention.

FIG. 17 is a block diagram of a conventional temperature control device.

FIG. 18 is an operation waveform diagram of the apparatus shown in FIG.

FIG. 19 is a block diagram showing a second embodiment of the temperature control device.

20 is an operation waveform diagram of the apparatus shown in FIG.

[Explanation of symbols]

 1-3 ... Resistor 4 ... Insulating substrate 5-8 ... Connection terminal 9-14 ... Conductor wiring 36 ... Thermistor 37 ... A / D converter 40-42 ... Switch element 43 ... Microcomputer 44 ... Control circuit 45 ... Power supply

Claims (4)

[Claims] 1. An insulating substrate, and at least two or more resistor groups arranged in parallel along the length direction on the substrate, one end side of these resistor groups being electrically commonly connected. A heating device for a fixing device, characterized in that a connection terminal is provided, and a connection terminal is provided on the other end side of each of these resistor groups. 2. A heating device for a fixing device according to claim 1, wherein at least two or more resistor groups are three-dimensionally arranged by being stacked in the thickness direction. 3. A fixing element heating heater comprising at least two resistors, each of which has a switch element for controlling energization to each resistor, a temperature detecting means for detecting a temperature of the heater, and a temperature detecting means. A temperature control device for a heater of a fixing device, comprising: a control means for controlling opening / closing of each of the switch elements for each half-wave of a power supply waveform so as to reach a predetermined temperature based on detection information. 4. A switch element for controlling energization to each resistor in a fixing device heating heater comprising at least two resistors, a temperature detecting means for detecting the temperature of the heater, and a zero cross of a power source waveform. Zero-cross detecting means for detecting, and so as to reach a predetermined temperature based on the detection information of the temperature detecting means, based on the output of the zero-cross detecting means, each switch element is opened and closed in any phase of the half wave of the power supply waveform. A temperature control device for a heater of a fixing device, comprising: a control unit for controlling.