JPH11344901A - Heating device, fixing device and image forming device provided with the heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and safe heating device by eliminating necessity of a distance between the circuit of a primary side which is a heating element and that of a secondary side that is a temperature detecting body and enhancing the temperature detection accuracy of the temperature detecting body. SOLUTION: The heating device possesses a one-chip IC 109 digitizing the detected temperature information of a thermistor 308 and a transformer 104 transmitting the detected temperature information from the one-chip IC 109 to a temperature controlling circuit 303. The transformer 104 connects the temperature controlling circuit 303 with the one-chip IC 109 by induction coupling and the temperature controlling circuit 303 supplies the one-chip IC with power trough the transformer 104.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating device, a fixing device, and an image forming apparatus provided with the heating device.

[0002]

2. Description of the Related Art Conventionally, as a heating device, a heating device as shown in FIG. 6 has been known and is put to practical use.

[0003] Such a heating device includes a heating element 507 that generates heat when energized from a commercial power supply 501, and a thermistor 508 as a temperature detecting element for detecting the temperature of the heating element 507.
A switching unit 504 capable of switching between conduction and interruption to the heating element 507 from the commercial power supply 501 and a control unit for controlling energization from the commercial power supply 501 to the heating element 507 according to the temperature detected by the thermistor 508. And a temperature control circuit 503.

The switching means 504 includes a triac 504A for switching the conduction from the commercial power supply 501 to the heating element 507 to either conduction or interruption, and a temperature control circuit 5
And a photo triac 504A for driving the triac 504B in response to the control signal from the control unit 03 and switching the triac 504B.

[0005] The commercial power supply 501 is a triac 504B.
And a switching power supply 502 for converting an AC power supply from the commercial power supply 501 into a DC power supply and then supplying the DC current to the temperature control circuit 503.

[0006] Thermistor 508 detects the temperature of heating element 507 that has generated heat when energized from commercial power supply 501, and then temperature control circuit 503 drives phototriac 504A in accordance with the temperature detected by thermistor 508, and triac 504B. And the triac 505 switches between conduction and interruption of conduction from the commercial power supply 501 to the heating element 507,
The temperature of the ceramic heater 506 is controlled.

FIG. 7 shows the ceramic heater 50 shown in FIG.
FIG. 6A is a schematic view of FIG.
6 is a perspective view illustrating one surface of the ceramic heater 506, while FIG. 6B is a perspective view illustrating the other surface of the ceramic heater 506.

In the ceramic heater 506, a thermistor 508, a conductive pattern 603 and a conductive pattern 604 for applying a voltage to the thermistor 508 are provided on the back surface 601 of the substrate mainly composed of ceramics. A heating element 507 is provided on the front surface 602, and the heating element 507 generates heat when a voltage is applied to the end 605 and the end 606 of the heating element 507.

[0009]

However, in the ceramic heater 506, the conductive pattern 603, the conductive pattern 604 and the thermistor 508 on the back surface 601 form a low voltage secondary circuit, and the resistance pattern 606 and the Since the resistance pattern 607 is a primary-side circuit having a high voltage, the thickness of the substrate is required to secure a safety distance between the primary-side circuit and the secondary-side circuit.

As a result, it is difficult to reduce the cost of the ceramic heater because the number of ceramics taken from a fixed size is reduced.

The present invention eliminates the need to increase the distance between the primary circuit, which is a heating element, and the secondary circuit, which is a temperature detector, increases the temperature detection accuracy of the temperature detector, and is inexpensive and safe. The purpose is to provide a simple heating device.

[0012]

According to the present invention, there is provided a heating apparatus for a fixing device, wherein a temperature of a heating element which generates heat when energized from a commercial power supply is detected by a temperature detecting element. An image forming apparatus including the heating device, wherein the switching unit is capable of switching between conduction from a commercial power supply to the heating element and switching off the switching element, and switching of the switching means in accordance with the temperature detected by the temperature detector. In the heating device having a control means for performing, the information conversion means for digitizing the detected temperature information of the temperature detector, and transmission means for transmitting the detected temperature information from the information conversion means to the control means, The transmission unit connects the control unit and the information conversion unit by capacitive coupling or electromagnetic induction coupling, and the control unit supplies power to the information conversion unit via the transmission unit. It is achieved by.

According to the present application, the above object is also achieved by the second invention in the first invention, wherein the heating element is provided on a substrate mainly composed of ceramics.

Further, according to the present application, the above object is also achieved by the third invention in which the temperature detector is provided on the substrate in the second invention.

Further, according to the present application, the above object is also achieved by the fourth invention in any one of the first to third inventions, wherein the information conversion means is a one-chip IC.

Further, according to the present application, the above object is also achieved by the fifth invention in any of the first to fourth inventions, wherein the transmission means is a transformer.

According to the present application, the above object is also achieved by the sixth invention in any one of the first to fourth inventions, wherein the transmission means is a capacitor.

Further, according to the present application, the above object is a fixing device for fixing an unfixed image on a recording medium by heating the unfixed image carried on the recording medium. This is also achieved by the seventh invention including a heating device.

Further, according to the present application, the above object is also achieved by the eighth invention in the seventh invention, wherein the heating element is provided on a substrate mainly composed of ceramics.

Further, according to the present application, the above object is also achieved by the ninth invention in which, in the eighth invention, the temperature detector is provided on the substrate.

According to the present application, the above object is also achieved by the tenth invention in any one of the seventh to ninth inventions, wherein the information conversion means is a one-chip IC.

Further, according to the present application, the above object is also achieved by the eleventh invention in which the transmission means is a transformer in any of the seventh to tenth inventions.

According to the present application, the above object is also achieved by the twelfth invention in any one of the seventh to tenth inventions, wherein the transmitting means is a capacitor.

Further, according to the present application, the above object is an image forming apparatus for recording an image formed by an image forming process according to image information from the outside on a recording medium,
The present invention is also achieved by a thirteenth invention including the fixing device of the seventh invention.

According to the present application, the above object is also achieved by the fourteenth invention in which, in the thirteenth invention, the heating element is provided on a substrate containing ceramic as a main component.

Further, according to the present application, the above object is also achieved by the fifteenth invention in which the temperature detector is provided on the substrate in the fourteenth invention.

According to the present application, the above object is also achieved by the sixteenth invention in any one of the thirteenth to fifteenth inventions, wherein the information conversion means is a one-chip IC. You.

Further, according to the present application, the above object is also achieved by the seventeenth invention in which the transmission means is a transformer in any of the thirteenth invention to the sixteenth invention.

According to the present application, the above object is also attained by the eighteenth invention in any one of the thirteenth to sixteenth inventions, wherein the transmission means is a capacitor.

That is, in the first invention according to the present application, the temperature of the heating element is detected by the temperature detecting element, the information conversion means digitizes the detected temperature information of the temperature detecting element, and then digitized. The detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means transmits the information via the transmission means. Power is supplied from the control means.

Further, in the second invention according to the present application, the temperature detector detects the temperature of the heating element provided on the substrate, and the information conversion means converts the detected temperature information of the temperature detector into digital data. Then, the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means. However, power is supplied from the control means via the transmission means.

Further, in the third invention according to the present application, the temperature detecting element detects the temperature of the heating element, and the information converting means digitizes the detected temperature information of the temperature detecting element provided on the substrate. Then, the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means. However, power is supplied from the control means via the transmission means.

In the fourth invention according to the present application, the temperature of the heating element is detected by the temperature detecting element, and the detected temperature information of the temperature detecting element is digitized by the one-chip IC.
The digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means comprises: Power is supplied from the control means via the.

Further, in the fifth invention according to the present application, the temperature of the heating element is detected by the temperature detector, and the information conversion means digitizes the detected temperature information of the temperature detector, and then digitizes. The detected temperature information is transmitted to the control means by electromagnetic induction coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means transmits the information from the control means via the transformer. Power is supplied.

In the sixth invention according to the present application, the temperature of the heating element is detected by the temperature detecting element, and the information conversion means digitizes the detected temperature information of the temperature detecting element. The detected temperature information is transmitted to the control means by capacitive coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means outputs power from the control means via the capacitor. Is supplied.

Further, in the seventh invention according to the present application, the temperature of the heating element is detected by the temperature detecting element, and the information conversion means digitizes the detected temperature information of the temperature detecting element, and then digitizes. The detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means transmits the information via the transmission means. Power is supplied from the control means.

In the eighth invention according to the present application, the temperature of the heating element provided on the substrate is detected by the temperature detecting element, and the information conversion means digitizes the detected temperature information of the temperature detecting element. Then, the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means. However, power is supplied from the control means via the transmission means.

Further, in the ninth invention according to the present application, the temperature detector detects the temperature of the heating element, and the information converting means digitizes the detected temperature information of the temperature detector provided on the substrate. Then, the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means. However, power is supplied from the control means via the transmission means.

In the tenth aspect of the present invention, the temperature of the heating element is detected by the temperature detecting element, and the detected temperature information of the temperature detecting element is digitized by the one-chip IC.
The digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means comprises: Power is supplied from the control means via the.

Further, in the eleventh invention according to the present application, the temperature detector detects the temperature of the heating element, and the information conversion means digitizes the detected temperature information of the temperature detector.
The digitized detected temperature information is transmitted to the control means by electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means controls via the transformer. Power is supplied from the means.

Further, in the twelfth invention according to the present application, the temperature of the heating element is detected by the temperature detecting element, and the information converting means digitizes the detected temperature information of the temperature detecting element. The converted detected temperature information is transmitted to the control means by capacitive coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means transmits the information from the control means via the capacitor. Power is supplied.

Further, according to the thirteenth aspect of the present invention, the temperature of the heating element is detected by the temperature detecting element, and the information conversion means digitizes the detected temperature information of the temperature detecting element.
The digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means comprises: Power is supplied from the control means via the.

According to the fourteenth aspect of the present invention, the temperature detecting element detects the temperature of the heating element provided on the substrate, and the information converting means converts the detected temperature information of the temperature detecting element into a digital signal. Then, the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and converts the information. The means is supplied with power from the control means via the transmission means.

Further, in the fifteenth invention according to the present application, the temperature of the heating element is detected by the temperature detecting element, and the information converting means converts the detected temperature information of the temperature detecting element provided on the substrate into a digital signal. Then, the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and converts the information. The means is supplied with power from the control means via the transmission means.

Further, in the sixteenth invention according to the present application, the temperature of the heating element is detected by the temperature detecting element, and the detected temperature information of the temperature detecting element is digitized by the one-chip IC.
The digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means comprises: Power is supplied from the control means via the.

Further, in the seventeenth invention according to the present application, the temperature of the heating element is detected by the temperature detecting element, and the information conversion means digitizes the detected temperature information of the temperature detecting element.
The digitized detected temperature information is transmitted to the control means by electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means controls via the transformer. Power is supplied from the means.

In the eighteenth aspect of the present invention, the temperature of the heating element is detected by the temperature detecting element, and the information conversion means digitizes the detected temperature information of the temperature detecting element. The converted detected temperature information is transmitted to the control means by capacitive coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means transmits the information from the control means via the capacitor. Power is supplied.

[0048]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of the present invention; FIG.

(First Embodiment) FIG. 1 is a schematic sectional view showing a schematic configuration of a laser beam printer 10 (hereinafter, referred to as a printer 10) as an example of an image forming apparatus according to a first embodiment of the present invention. is there.

As shown in FIG. 1, the printer 10 has a drum-shaped photosensitive member 12 on which an electrostatic latent image is formed on the outer peripheral surface, and a roller-shaped photosensitive member 12 for charging the outer peripheral surface of the photosensitive member 12 to a specified potential. A charging unit 13, a laser scanner unit 14 for forming an electrostatic latent image on the outer peripheral surface charged to a specified potential by exposure, a developing device 15 for visualizing the electrostatic latent image with a developer, The fixing device 17 includes a roller-shaped transfer body 16 that transfers a visible image (visible image) formed on the outer peripheral surface onto a recording sheet P as a sheet-shaped recording medium.

In the printer 10, first, the charged body 1
The laser scanner unit 14 exposes the outer peripheral surface of the photoreceptor 12 charged to the specified potential in 3 to form an electrostatic latent image on the outer peripheral surface according to image information given to the printer 10 from outside. Is done.

Next, the electrostatic latent image formed on the outer peripheral surface of the photoreceptor 12 is visualized into a visible image by applying a developer from the developing device 15.

On the other hand, the recording paper P on which image information corresponding to the given image information is recorded is placed on the cassette 18 detachably supported by the main body of the printer 10 or on one side surface of the printer 10. Multi paper tray 1
9 to a transfer nip TN formed between the photoconductor 12 and the transfer body 16 at a predetermined timing or the like.

Thus, the recording paper P that has reached the transfer nip portion TN is formed on the outer peripheral surface of the photoreceptor 12, and the carried visual image is transferred from the transfer body 16 by electrical interaction.

Next, the recording paper P having the developed image carried on one surface in an unfixed state (hereinafter, the developed image in the unfixed state is referred to as an unfixed image) is supplied to the fixing device 17 by heat supply. When the pressure is applied, the unfixed image is melted and fixed, so that the recording paper P is recorded with an image corresponding to the given image information, and the formed recording paper P is Tray 2 arranged on the other side of the main body
0 is discharged.

FIG. 2 is a schematic sectional view showing a schematic configuration of the fixing device 17 in the present embodiment.

The fixing unit 17 includes a heating unit 9 serving as a heating device,
A support 8 for fixing and supporting the heating unit 9, a heat-resistant film 6 externally fitted to the heating unit 9 and the support 8, and a rotating body pressurizing the heating unit 9 through the film 6. Roller 7
The film 6 is slid by the rotation of the pressure roller 7, and the recording paper P carrying the unfixed image is passed through the nip N by the pressure contact between the film 6 and the pressure roller 7. The unfixed image is fixed on the recording paper P by the heat of the heating unit 9 via the film 6.

FIG. 3 is a block diagram showing a signal path of a control system of the heating device in the present embodiment.

The heating unit 9 has a heating element 307 that generates heat when energized from the commercial power supply 301, and a thermistor 308 as a temperature detecting element for detecting the temperature of the heating element 307.

The heating element 307 and the thermistor 308 are, as shown in FIG.
6 on the same plane.

The control unit 22 attached to the main body of the printer 10 having the heating unit 9
07, and a temperature control circuit 303 as control means for switching the switching means 304 in accordance with the detected temperature of the thermistor 308. And a transformer 104 as a transmission means capable of transmitting detected temperature information from the one-chip IC 109 to the temperature control circuit 303.

The switching means 304 includes a triac 304B capable of switching the conduction from the commercial power supply 301 to the heating element 307 to either conduction or cutoff, and a phototriac 304A for switching the triac 304B according to a control signal of the temperature control circuit 303. And

The one-chip IC 109 includes the thermistor 30
The analog detection temperature information of No. 8 is digitized by AD conversion means 108 for converting analog information into digital information (hereinafter referred to as AD conversion).

Next, the one-chip IC 109 serializes the digitized detected temperature information by the serial / parallel control means 107 for converting from parallel to serial, and further performs protocol processing to establish a protocol for data communication. It has become.

The detected temperature information from the one-chip IC 109 is transmitted to the temperature control circuit 30 via the transformer 104.
A serial interface circuit (hereinafter, referred to as an I / F circuit) 101 that transmits a carrier wave from a transmitting / receiving unit 105 for transmitting and receiving to a transmitting / receiving unit to a transmitting / receiving unit 102 on a temperature control circuit side and transmits the carrier wave to a temperature control circuit 303. The serialized detected temperature information is output to the temperature control circuit 303 via the control unit 305.

The one-chip IC 109 includes a transformer 1
Power is supplied from the temperature control circuit 303 via the control circuit 04.

The temperature control circuit 303 controls the triac 30 according to the detected temperature information from the thermistor 308.
4B, a control signal is output to the photo triac 304B for switching, and the photo triac 304B outputs a control signal for switching to the triac 304B.
7 is switched to conduction or cutoff.

The temperature control circuit 303 transmits the request for the detected temperature information of the thermistor 308 and the communication protocol via the I / F circuit 101 to the one-chip IC 109 via the transmitting / receiving means 102 on a carrier wave. The carrier is transmitted at a frequency approximately twice as high as that of the carrier transmitted from the transmission / reception unit 105 to the transmission / reception unit 102, so that the information transmitted from the transmission / reception unit 105 and the transmission from the transmission circuit 102 are transmitted. The power supply means 106 for supplying power to the one-chip IC 109 by using carrier energy from the transmission / reception means 102 includes an AD conversion means 108 and a serial / parallel control means. The power is supplied to the transmission / reception means 107 and the transmission / reception means 105.

After confirming that there is no communication error, the serial-parallel control means 107 having received the above-mentioned detected temperature information request and communication protocol causes the AD conversion means 108 to start AD conversion, and as described above, thermistor 308 Is transmitted to the temperature control circuit 303 side.

Therefore, in the present embodiment, by transmitting the detected temperature information of the thermistor 308 to the temperature control circuit 303 via the transformer 104 by electromagnetic induction coupling, the thermistor 308 and the heating element 307 are connected to a low voltage. The relationship between the secondary side circuit and the high voltage primary side circuit can be eliminated, and the distance between the thermistor 308 and the heating element 307 can be eliminated.

In the present embodiment, the thermistor 3
The transmission error can be reduced by digitizing the detected temperature information 08 in the AD conversion means 108.

Further, in the present embodiment, by supplying power from the control means to the one-chip IC 109 via the transformer 104, the information transmitting means 109 can be arranged on the thermistor 308 side with respect to the transformer 104. And transmission errors can be further reduced.

In this embodiment, the I / F circuit 1
01 and the transmitting / receiving means 102 in one one-chip IC 10
3, one-chip IC 103 and one-chip IC 109
And the transformer 104 can be configured as one module 110.

(Second Embodiment) Next, a second embodiment according to the present application will be described with reference to FIG.

Note that the same reference numerals as in the first embodiment denote the same parts in the configuration of the heating device in this embodiment, and a description thereof will be omitted.

FIG. 5 is a block diagram showing a signal path of a control system of the heating device in the present embodiment.

In the heating device according to the present embodiment,
In the first embodiment, the transmitting means is replaced by a capacitor 201 and a capacitor 202 instead of the transformer 104, and the transmitting and receiving means 204 and 203 are replaced by the transmitting and receiving means 102 and 105.

The condenser 201 and the condenser 202
Means that one of the capacitors 201 and 202 is used for transmission and reception from the capacitor 201 to the capacitor 202, and the other is used for transmission and reception from the capacitor 202 to the capacitor 201. It has become.

The one-chip IC 109 includes the thermistor 30
8 is digitized by the AD conversion means 108, the digitized detected temperature information is serialized by the serial / parallel control means 107, and further, protocol processing is performed to establish a protocol for data communication.
The serialized detected temperature information is transmitted to the temperature control circuit 303 via the I / F circuit 101 which transmits the signal on the carrier wave from the transmission / reception means 204 to the transmission / reception means 203 via the capacitor 202 and transmits the detected temperature information to the temperature control circuit 303. It has become.

The one-chip IC 109 includes a transformer 1
Power is supplied from the temperature control circuit 303 via the control circuit 04.

The temperature control circuit 303 controls the triac 30 according to the detected temperature information from the thermistor 308.
4B, a control signal is output to the photo triac 304B for switching, and the photo triac 304B outputs a control signal for switching to the triac 304B.
7 is switched to conduction or cutoff.

The temperature control circuit 303 transmits the request for the detected temperature information of the thermistor 308 and the communication protocol via the I / F circuit to the one-chip IC 109 via the carrier wave from the transmission / reception means 203. The carrier is transmitted at a frequency approximately twice as high as that of the carrier transmitted from the transmitting / receiving means 203 to the transmitting / receiving means 204, so that the information transmitted from the transmitting / receiving means 204 and the information transmitted from the transmitting / receiving means 203 are transmitted. The power supply means 106 uses the carrier energy from the transmission / reception means 203 to separate the information from the incoming information.
The power is supplied to the serial control unit and the transmission / reception unit 204.

After confirming that there is no communication error, the serial control unit that has received the detected temperature information request and the communication protocol causes the A / D conversion unit 108 to start the A / D conversion, and the The detected temperature information is transmitted to the temperature control circuit 303 side.

Therefore, in the present embodiment, the detected temperature information of the thermistor 308 is transmitted to the temperature control circuit 303 via the capacitors 201 and 202 by capacitive coupling, so that the thermistor 308 and the heating element 307 are kept low. The relationship between the high-voltage secondary circuit and the high-voltage primary circuit is eliminated, and the thermistor 308 and the heating element 307 are removed.
This eliminates the need to keep a distance from the user.

In this embodiment, the thermistor 3
The transmission error can be reduced by digitizing the detected temperature information 08 in the AD conversion means 108.

Further, in this embodiment, by supplying power from the control means to the one-chip IC 109 via the capacitors 201 and 202, the information transmitting means 109 is connected to the capacitors 201 and 20.
2 can be arranged on the thermistor 308 side,
The transmission error can be further reduced.

In this embodiment, the A / D conversion means 108, the serial / parallel control means 107, and the power supply means 106
As one one-chip IC, the I / F circuit 101 and the transmitting / receiving means 102 as one one-chip IC 103,
Further, the one-chip IC 103, the one-chip IC 109, the capacitor 201, and the capacitor 202 can be configured as one module 110.

[0088]

As described above, according to the first aspect of the present invention, the temperature detecting element detects the temperature of the heating element, and the information converting means digitizes the detected temperature information of the temperature detecting element. Next, the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further,
The control means controls the switching means in accordance with the detected temperature information of the temperature detection body, and the information conversion means is set so that power is supplied from the control means via the transmission means. Eliminates the need to keep a distance from the heating element,
Temperature detection accuracy can be maintained safely.

According to the second invention of the present application,
The temperature of the heating element provided on the substrate is detected by the temperature detector, and the information conversion means digitizes the detected temperature information of the temperature detector, and then the digitized detected temperature information is subjected to capacitive coupling or electromagnetic induction coupling. Is transmitted to the control means by
The control means controls the switching means in accordance with the detected temperature information of the temperature detection body, and the information conversion means is set so that power is supplied from the control means via the transmission means. Eliminates the need to keep a distance from the heating element,
The substrate can be made thinner, and the temperature detection accuracy can be maintained safely.

Further, according to the third aspect of the present invention, the temperature detecting element detects the temperature of the heating element, and the information converting means digitizes the detected temperature information of the temperature detecting element provided on the substrate. Next, the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means Since the power is set to be supplied from the control means via the transmission means, there is no need to keep the distance between the temperature detection body and the heating element, and the board can be thinned, and the temperature can be detected safely. Accuracy can be maintained.

According to the fourth invention of the present application,
The temperature of the heating element is detected by the temperature detector, the detected temperature information of the temperature detector is digitized by the one-chip IC, and the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling. Further, the control means controls the switching means according to the detected temperature information of the temperature detecting body,
Since the information conversion means is set to be supplied with power from the control means via the transmission means, it is not necessary to keep a distance between the temperature detection body and the heating element, and the temperature detection accuracy can be maintained safely. it can.

Further, according to the fifth aspect of the present invention, the temperature of the heating element is detected by the temperature detector, and the information conversion means digitizes the detected temperature information of the temperature detector, and then digitizes the information. The detected temperature information is transmitted to the control means by electromagnetic induction coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means transmits power from the control means via the transformer. Is set to be supplied, it is not necessary to keep a distance between the temperature detector and the heating element, and the temperature detection accuracy can be maintained safely.

According to the sixth invention of the present application,
The temperature detector detects the temperature of the heating element, the information conversion means digitizes the detected temperature information of the temperature detector, and then the digitized detected temperature information is transmitted to the control means by capacitive coupling. The control means controls the switching means according to the detected temperature information of the detection body, and the information conversion means is set to be supplied with power from the control means via the capacitor. This eliminates the need to maintain a distance from the sensor and safely maintains temperature detection accuracy.

Further, according to the seventh aspect of the present invention, the temperature of the heating element is detected by the temperature detector, and the information conversion means digitizes the detected temperature information of the temperature detector, and then digitizes the information. The detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means, via the transmission means. Since the power is set to be supplied from the control means, it is not necessary to keep a distance between the temperature detector and the heating element, and the temperature detection accuracy can be maintained safely.

According to the eighth invention of the present application,
The temperature of the heating element provided on the substrate is detected by the temperature detector, and the information conversion means digitizes the detected temperature information of the temperature detector, and then the digitized detected temperature information is subjected to capacitive coupling or electromagnetic induction coupling. Is transmitted to the control means by
The control means controls the switching means in accordance with the detected temperature information of the temperature detection body, and the information conversion means is set so that power is supplied from the control means via the transmission means. Eliminates the need to keep a distance from the heating element,
The substrate can be made thinner, and the temperature detection accuracy can be maintained safely.

Further, according to the ninth aspect of the present invention, the temperature detecting element detects the temperature of the heating element, and the information converting means digitizes the detected temperature information of the temperature detecting element provided on the substrate. Next, the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means Since the power is set to be supplied from the control means via the transmission means, there is no need to keep the distance between the temperature detection body and the heating element, and the board can be thinned, and the temperature can be detected safely. Accuracy can be maintained.

According to the tenth aspect of the present invention,
The temperature of the heating element is detected by the temperature detector, the detected temperature information of the temperature detector is digitized by the one-chip IC, and the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling. Further, the control means controls the switching means according to the detected temperature information of the temperature detecting body,
Since the information conversion means is set to be supplied with power from the control means via the transmission means, it is not necessary to keep a distance between the temperature detection body and the heating element, and the temperature detection accuracy can be maintained safely. it can.

Further, according to the eleventh aspect of the present invention, the temperature of the heating element is detected by the temperature detecting element, and the information conversion means digitizes the detected temperature information of the temperature detecting element. The detected temperature information is transmitted to the control means by electromagnetic induction coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means transmits the information from the control means via the transformer. Since the power is set to be supplied, it is not necessary to keep a distance between the temperature detector and the heating element, and the temperature detection accuracy can be maintained safely.

According to the twelfth aspect of the present invention, the temperature of the heating element is detected by the temperature detecting element, and the information converting means digitizes the detected temperature information of the temperature detecting element. The detected temperature information is transmitted to the control means by capacitive coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means outputs power from the control means via the capacitor. Is set to be supplied, it is not necessary to keep a distance between the temperature detector and the heating element, and the temperature detection accuracy can be maintained safely.

Further, according to the thirteenth aspect of the present invention, the temperature of the heating element is detected by the temperature detecting element, and the information conversion means digitizes the detected temperature information of the temperature detecting element. The detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means transmits the information via the transmission means. Since the power is set to be supplied from the control means, it is not necessary to keep a distance between the temperature detector and the heating element, and the temperature detection accuracy can be maintained safely.

According to the fourteenth aspect of the present invention, the temperature detecting element detects the temperature of the heating element provided on the substrate, and the information converting means digitizes the detected temperature information of the temperature detecting element. Then, the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means. However, since the power is set to be supplied from the control means via the transmission means, it is not necessary to keep the distance between the temperature detecting element and the heating element, and the substrate can be thinned, and the temperature can be safely maintained. Detection accuracy can be maintained.

Further, according to the fifteenth aspect of the present invention, the temperature of the heating element is detected by the temperature detecting element, and the information converting means digitizes the detected temperature information of the temperature detecting element provided on the substrate. Then, the digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means according to the detected temperature information of the temperature detector, and the information conversion means. However, since the power is set to be supplied from the control means via the transmission means, it is not necessary to keep the distance between the temperature detecting element and the heating element, and the substrate can be thinned, and the temperature can be safely maintained. Detection accuracy can be maintained.

According to the sixteenth aspect of the present invention, the temperature of the heating element is detected by the temperature detecting element, and the detected temperature information of the temperature detecting element is digitized by the one-chip IC.
The digitized detected temperature information is transmitted to the control means by capacitive coupling or electromagnetic induction coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means comprises: Since the power is set to be supplied from the control unit via the control unit, it is not necessary to keep a distance between the temperature detector and the heating element, and the temperature detection accuracy can be maintained safely.

Further, according to the seventeenth aspect of the present invention, the temperature of the heating element is detected by the temperature detecting element, and the information conversion means digitizes the detected temperature information of the temperature detecting element. The detected temperature information is transmitted to the control means by electromagnetic induction coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means transmits the information from the control means via the transformer. Since the power is set to be supplied, it is not necessary to keep a distance between the temperature detector and the heating element, and the temperature detection accuracy can be maintained safely.

According to the eighteenth aspect of the present invention, the temperature of the heating element is detected by the temperature detecting element, and the information conversion means digitizes the detected temperature information of the temperature detecting element. The detected temperature information is transmitted to the control means by capacitive coupling, and further, the control means controls the switching means in accordance with the detected temperature information of the temperature detector, and the information conversion means outputs power from the control means via the capacitor. Is set to be supplied, it is not necessary to keep a distance between the temperature detector and the heating element, and the temperature detection accuracy can be maintained safely.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view illustrating a schematic configuration of a laser beam pudding as an example of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view illustrating a schematic configuration of a fixing device according to the first embodiment.

FIG. 3 is a block diagram illustrating signal paths between a heating device and a temperature control system according to the first embodiment.

FIG. 4 is a schematic diagram illustrating a schematic configuration of a heating element and a temperature detector provided on a substrate according to the first embodiment.

FIG. 5 is a block diagram illustrating a signal path between a heating device and a temperature control system according to a second embodiment.

FIG. 6 is a block diagram showing signal paths between a heating device and a temperature control system in a conventional heating device.

FIGS. 7A and 7B are schematic views showing a configuration of a heating element and a temperature detector in the heating device shown in FIG. 6, wherein FIG. 7A is a perspective view showing one surface of a ceramic heater, and FIG.
It is a perspective view which shows the other surface of a ceramic heater.

[Explanation of symbols]

 Reference Signs List 9 heating unit (heating device) 10 laser beam printer (image forming device) 17 fixing device (fixing device) 104 transformer (transmission unit) 109 one-chip IC (information conversion unit) 201 capacitor (transmission unit) 202 capacitor (transmission unit) 301 Commercial power supply 303 Temperature control circuit (control means) 304 Switching means 306 Substrate 307 Heating element 308 Thermistor (temperature detecting element) P Recording paper (recording medium)

Claims (18)

[Claims] 1. A heating device for a fixing device, wherein a temperature of a heating element that generates heat by energization from a commercial power supply is detected by a temperature detector, and an image forming apparatus including the heating device is: In a heating apparatus comprising: a switching unit capable of switching between conduction from a commercial power supply to a heating element and switching off and off; and control means for switching the switching unit in accordance with a temperature detected by the temperature detection unit. An information conversion means for digitizing the detected temperature information of the body and a transmission means for transmitting the detected temperature information from the information conversion means to the control means, wherein the transmission means capacitively couples the control means and the information conversion means. Alternatively, the heating device is connected by electromagnetic induction coupling, and the control unit supplies power to the information conversion unit via the transmission unit. 2. The heating device according to claim 1, wherein the heating element is provided on a substrate, and the substrate has ceramics as a main component. 3. The heating device according to claim 2, wherein the temperature detector is provided on the substrate. 4. The heating device according to claim 1, wherein the information conversion means is a one-chip IC. 5. The heating device according to claim 1, wherein the transmission means is a transformer. 6. The heating device according to claim 1, wherein the transmission means is a condenser. 7. A fixing device for fixing an unfixed image on a recording medium by heating the unfixed image carried on the recording medium, the fixing device including the heating device according to claim 1. 8. The fixing device according to claim 7, wherein the heating element is provided on a substrate, and the substrate contains ceramic as a main component. 9. The fixing device according to claim 8, wherein the temperature detector is provided on the substrate. 10. The fixing device according to claim 6, wherein the information conversion unit is a one-chip IC. 11. The fixing device according to claim 7, wherein the transmission unit is a transformer. 12. The fixing device according to claim 7, wherein the transmission unit is a condenser. 13. An image forming apparatus for recording an image formed by an image forming process according to external image information on a recording medium, the image forming apparatus including the fixing device according to claim 7. 14. The heating element is provided on a substrate, and the substrate contains ceramics as a main component.
An image forming apparatus according to claim 1. 15. The image forming apparatus according to claim 14, wherein the temperature detector is provided on a substrate. 16. The image forming apparatus according to claim 13, wherein the information conversion unit is a one-chip IC. 17. The image forming apparatus according to claim 13, wherein the transmitting unit is a transformer. 18. The image forming apparatus according to claim 13, wherein the transmitting unit is a condenser.