JP2000147931A - Image heating device and image recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a universal image heating device using a ceramic heater as a heating body and capable of coping with both of 100 V/200 V commercial power voltage, without causing troubles, and to realize a universal image recorder equipped with the image heating device and capable of coping with both 100 V/200 V power source voltages without troubles. SOLUTION: In addition to two resistors (b) and (c), one conductor (d) is provided in parallel with the resistors on a ceramic plate (a). Patterns are short-circuited (h) on one side in the longitudinal direction of the plate (a), and three electrical contacts (e), (f) and (g) are provided on the other side of the plate (a) in the longitudinal direction, and power is supplied from the contacts. Thus, electrical contacts (j) and (k) for outputting temperature information of a temperature detection means (s) are arranged without causing electrical troubles between the electrical contacts (e), (f) and (g) for supplying power and the electrical contacts (j) and (k) on the other side in the longitudinal direction of the plate (a) on the reverse side to the side where the electric contacts (e), (f) and (g) are provided, whereby the device is made universal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image heating apparatus and an image recording apparatus, such as a copying machine or a printer, provided with the image heating apparatus.

More specifically, a universal image heating device that uses a ceramic heater as a heating element and can be used for both a power supply voltage of 100 V and 200 V, and can be used for both a power supply voltage of 100 V and 200 V provided with the image heating device. The present invention relates to a universal image recording device.

[0003]

2. Description of the Related Art Conventionally, a universal image recording apparatus which can be used for both a power supply voltage of 100 V and 200 V has been commercialized with an image heating apparatus using a halogen heater as a heating element.

However, as for an image recording apparatus provided with an image heating apparatus using a halogen heater as a heating element, the above-mentioned universal type having a power supply voltage has not yet been commercialized. This is because the change in the amount of heat generated by the change in the voltage of the ceramic heater is larger than that in the halogen heater, so that the control cannot be performed with the same resistance value.

The ceramic heater is made of alumina (Al ₂ O)
₃ ) Aluminum nitride (AlN) Silicon carbide (Si
C) etc. The basic structure is a ceramic plate (heater substrate) having electrical insulation, good thermal conductivity and low heat capacity, and a resistor (electric heating resistor) provided on this ceramic plate. Low heat capacity, the temperature rise characteristic that the entire heater including the ceramic plate quickly rises due to the heat generated by the resistor when electricity is supplied to the resistor, and the temperature fall characteristic that the temperature falls quickly when the electricity is cut off Has characteristics.

As means for solving the above-mentioned problem in the case of an image heating apparatus using a halogen heater as a heating element, two kinds of resistors having a resistance of 1: 4 are provided on a ceramic plate, and the power supply voltage value is reduced. A method of switching it according to the situation is conceivable. This method is disclosed in JP-A-7-199702.

[0007]

However, in the above-mentioned means, electrical contacts (electrodes) for supplying power to the resistor are disposed on both sides in the longitudinal direction of the ceramic plate.

In many cases, a thermistor as a temperature detecting element is mounted on a ceramic plate for temperature detection.
In this case, an electric contact for outputting temperature information for connecting the thermistor and the heater control unit is also required on the ceramic plate.

The electrical contact for power supply to the resistor is almost directly connected to the commercial power supply, while the thermistor is often not insulated from the user accessible part. Therefore, sufficient insulation is required between the electrical contact for power supply to the resistor and the electrical contact for temperature information output of the thermistor.

For this reason, as described above, when the electrical contacts for supplying power to the resistor are arranged on both sides in the longitudinal direction of the ceramic plate, it is difficult to arrange the electrical contacts for outputting the temperature information of the thermistor. Become.

Accordingly, the present invention overcomes the above-mentioned problems, and uses a ceramic heater as a heating element and can cope with both of a commercial power supply voltage of 100 V / 200 V without any problem, and a universal image heating apparatus. It is an object of the present invention to make a universal image recording apparatus capable of coping with both the power supply voltages of 100 V and 200 V without any problem.

[0012]

According to the present invention, there is provided an image heating apparatus and an image recording apparatus having the following constitutions.

(1) It has a heating element that generates heat when energized,
In an image heating apparatus that heats an image on a recording material by the heat of the heating element, the heating element has a longitudinal direction perpendicular to a moving direction of the recording material, and a longitudinal dimension of the heating element is equal to or greater than a maximum sheet passing width of the apparatus. A ceramic plate, three or more electrical contacts are provided on the ceramic plate, the electrical contacts are unevenly distributed on one side in the longitudinal direction of the ceramic plate, and two of the electrical contacts are located in the longitudinal direction on the ceramic plate. One of the electrical contacts is connected to a conductor arranged in parallel with the resistor, and all of the resistor and the conductor are connected in the longitudinal direction of the ceramic plate. Is electrically connected to the other side of the electrical contact, and the ratio of the resistance values of the two resistors is 1: 1.48 to 1: 4.76, and the temperature of the ceramic plate is detected. Temperature detection means, Temperature control means for controlling power supply to the resistor in order to bring the temperature of the means to a desired temperature, and one of the outputs of the temperature control means is connected to a resistor having a low resistance value among the resistors. And the other output of the temperature control means is connected to a resistance selection device for selecting and connecting one of the electrical contacts connected to the other resistor and the conductor. An image heating device characterized by the above-mentioned.

(2) a heating element that generates heat when energized;
In an image heating apparatus that heats an image on a recording material by the heat of the heating element, the heating element has a longitudinal direction perpendicular to a moving direction of the recording material, and a longitudinal dimension of the heating element is equal to or greater than a maximum sheet passing width of the apparatus. A ceramic plate, three or more electrical contacts are provided on the ceramic plate, the electrical contacts are unevenly distributed on one side in the longitudinal direction of the ceramic plate, and two of the electrical contacts are located in the longitudinal direction on the ceramic plate. One of the electrical contacts is connected to a conductor arranged in parallel with the resistor, and all of the resistor and the conductor are connected in the longitudinal direction of the ceramic plate. And a temperature detection means for detecting the temperature of the ceramic plate, wherein the resistance value of the two resistors is the same, and the temperature of the temperature detection means is To the desired temperature Temperature control means for controlling the power supply to the resistor, a voltage is applied between the temperature control means and the ceramic plate, between the electrical contacts connected to the resistor, and the electrical contact connected to the conductor is provided. Opening and shorting between the electrical contacts connected to the resistor,
An image heating apparatus, comprising: a resistance value selection device that selects from two types of application of a voltage between an electrical contact connected to a resistor and an electrical contact connected to a conductor.

(3) a heating element that generates heat when energized;
In an image heating apparatus that heats an image on a recording material by the heat of the heating element, the heating element has a longitudinal direction perpendicular to a moving direction of the recording material, and a longitudinal dimension of the heating element is equal to or greater than a maximum sheet passing width of the apparatus. A ceramic plate, three or more electrical contacts are provided on the ceramic plate, the electrical contacts are unevenly distributed on one side in the longitudinal direction of the ceramic plate, and two of the electrical contacts are located in the longitudinal direction on the ceramic plate. One of the electrical contacts is connected to a conductor arranged in parallel with the resistor, and all of the resistor and the conductor are connected in the longitudinal direction of the ceramic plate. Is electrically connected to the other side of the electrical contact, the ratio of the resistance values of the two resistors is 1: 2.48 to 1: 5.76, and the temperature of the ceramic plate is detected. Temperature detection means, Temperature control means for controlling power supply to the resistor in order to bring the temperature of the means to a desired temperature, one of the outputs of the temperature control means being connected to an electrical contact connected to the conductor, An image heating apparatus characterized in that the other output of the control means is connected to a resistance value selection device for selecting and connecting one of the electrical contacts connected to the resistor.

(4) In the image heating apparatus according to any one of the above (1) to (3), regarding the arrangement of the conductor and the resistor on the ceramic plate, the conductor may be arranged at the extreme end. Characteristic image heating device.

(5) The image heating apparatus according to any one of (1) to (4), further comprising: an input voltage detecting means for detecting a voltage of a commercial power supply applied to the apparatus. An image heating apparatus, wherein a resistance value is selected by a resistance value selection device based on a voltage value obtained by the method.

(6) The image heating apparatus according to the above (5), wherein a hysteresis is provided for switching the resistance value of the inputted voltage value by the resistance value selecting device.

(7) In the image heating apparatus according to the above (5) or (6), when the commercial power supply is not applied to the apparatus and when the image recording apparatus is not in the image recording operation, the resistance value is set to the above value. An image heating device, wherein the selection device selects the highest resistance value.

(8) A film having one surface that slides on the heating element and the other surface contacts and moves together with the recording material bearing the image, and the recording material is heated by the heat from the heating element via the film. The image heating apparatus according to any one of (1) to (7), wherein the image is heated.

(9) An image recording apparatus comprising the image heating apparatus according to any one of (1) to (8).

<Operation> According to the present invention, in addition to two resistors on a ceramic plate, one conductor is provided in parallel with the resistor, and these patterns are short-circuited on one side in the longitudinal direction of the ceramic plate. By providing three electrical contacts (electrodes) on the other side and supplying power from there,
The electrical contact for output of temperature information of the temperature detecting means is between the electrical contact for power supply on the other side in the longitudinal direction of the ceramic plate on the opposite side of the ceramic plate on which the electrical contact for power supply is provided. Can be arranged without any electrical problems.

Further, in addition to the above, 100 V / 20
In the case where the resistance value of the ceramic heater is selected by performing the 0V automatic detection, it is proposed to provide a hysteresis for the switching so that the control becomes stable at the boundary of the switching.

Further, by setting the default of the resistance value of the ceramic heater to the 200 V side, the safety at the time of malfunction can be improved.

Thus, a universal image heating apparatus which uses a ceramic heater as a heating element and can cope with both of a commercial power supply voltage of 100 V / 200 V without problems and a problem of both a power supply voltage of 100 V / 200 V provided with the image heating apparatus To make a universal image recording device that can cope with the problem practical.

A) Resistance value ratio 1: 1.48 to 1: 4.76
FIG. 8 shows that the resistance values of the two resistors are R1 and R2, respectively.
(A). SW is a switch,
Closed for 100V system, open for 200V system.

In order to cope with a wide range, it is desirable that the loss of the 100V resistance R1 // R2 and the loss of the 200V resistance R2 are the same.

V1 ² / (R1 // R2) = V2 ² / R1 V1: Input voltage for 100V system V2: Input voltage for 200V system 100V system input voltage: 100V (Japan) to 127V (Mexico) 200V System input voltage: 200V (North Korea)-240V
(India) Therefore, the ratio of R1 and R2 is 1: 4.76 for the combination of 100V and 240V and 1: 1.48 for the combination of 127V and 200V.

Therefore, when a wide range is provided by the configuration of the present invention, the ratio between the resistance values R1 and R2 necessarily falls within this range. If the temperature is out of this range, it is difficult to control the temperature, and there is a possibility that the occurrence of temperature ripple will increase.

B) Resistance ratio 1: 2.48 to 1: 5.76
FIG. 8 shows that the resistance values of the two resistors are R1 and R2, respectively.
(B). SW is a switch,
The R1 side is for the 100 V system, and the R2 side is for the 200 V system.

In order to support a wide range, it is desirable that the loss of the 100V system resistance R1 and the loss of the 200V system resistance R2 are the same.

V1 ² / R1 = V2 ² / R1 V1: Input voltage for 100V system V2: Input voltage for 200V system 100V system input voltage: 100V to 127V 200V system input voltage: 200V to 240V The ratio of R2 is 1: 5.76 for the combination of 100V and 240V and 1: 2.48 for the combination of 127V and 200V.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment (FIGS. 1 to 4) (1) Example of Image Recording Apparatus FIG. 1 is a schematic configuration diagram of an example of an image recording apparatus according to the present invention. The image recording apparatus of this embodiment is a laser beam printer using a transfer type electrophotographic process.

Reference numeral 1 denotes a rotating drum type electrophotographic photosensitive member (hereinafter, referred to as a photosensitive drum) as an image carrier, which is driven to rotate at a predetermined peripheral speed (process speed) in a clockwise direction indicated by an arrow.

The photosensitive drum 1 rotates during its rotation.
First, the toner is uniformly charged to a predetermined polarity and potential by a charging roller 2 as a charging device.

Next, a laser beam scanning exposure L corresponding to a target image information pattern is received by a laser optical system (laser scanner) 3 as an exposure device. As a result, an electrostatic latent image corresponding to the target image information pattern is formed on the surface of the photosensitive drum 1.

The electrostatic latent image formed on the surface of the photosensitive drum 1 is visualized by developing the toner in the developing device 4. As a developing method, a jumping developing method, a two-component developing method, or the like is used, and in many cases, a combination of image exposure and reversal developing is used.

The toner image formed on the surface of the photosensitive drum 1 is transferred to a transfer nip 6 formed by the photosensitive drum 1 and the transfer roller 5 from a paper feed unit 7 to the transfer nip 6 at a predetermined control timing. Recording material (transfer material) fed by
P is sequentially transferred to P. The toner image on the photosensitive drum 1 is sequentially transferred onto the paper P by applying a voltage having a polarity opposite to the charging polarity of the toner to the transfer roller 5.

In the image recording apparatus of this embodiment, the paper supply unit 7 is a cassette paper supply unit, and the recording material P loaded and stored in the paper supply cassette is separated by a paper supply roller 8 and a one-sheet separating member (not shown). The sheet is separated and fed, and is fed to the transfer nip portion 6 at a predetermined control timing through a sheet path 10 including a conveying roller pair 9 and a top sensor 11.

The leading end of the recording material P fed from the cassette sheet feeding section 7 to the transfer nip section 6 through the sheet path 10 is recognized by a top sensor 11 provided in the middle of the sheet path 10 and synchronized therewith. An image is formed on the photosensitive drum 1.

The recording material P on which the toner image has been transferred at the transfer nip 6 is sequentially separated from the surface of the photosensitive drum 1 and passes through a guide 13 to an image heating device (heat fixing device, heat fixing device) 14. The toner image is conveyed and subjected to a heat fixing process for the toner image.

The recording material P on which the image has been fixed by the image heating device 14 passes through a sheet path 16 including a pair of transport rollers 15 and is discharged to a discharge tray 18 by a pair of discharge rollers 17.

On the other hand, contaminants such as transfer residual toner and paper dust remaining on the photosensitive drum 1 after the transfer of the toner image to the recording material P (after paper separation) are removed from the surface of the photosensitive drum 1 by the cleaner 12. The photosensitive drum 1 whose surface has been cleaned is repeatedly subjected to image formation.

(2) Image Heating Device 14 The image heating device 24 in this embodiment is an on-demand type device, and is a film heating device using a cylindrical fixing film disclosed in JP-A-4-44075-44083. It is a system of a pressure roller drive type and a tensionless type. FIG. 4 is an enlarged cross-sectional model view of the image heating device 24.

Reference numerals 20 and 30 denote a fixing member (heating member) and a pressure member, which are in contact with each other to form a fixing nip portion (heating nip portion) N.

The fixing member 20 includes a heater 2 as a heating element.
1, a stay holder 22, a cylindrical heat-resistant film (fixing film) 23, and the like. Pressing member 30
Is an elastic pressure roller.

The heater 21 is a ceramic heater. The configuration of the heater 21 will be described in detail in the following section (3).

The stay holder 22 is a member that holds the heater 21 and prevents heat radiation in the direction opposite to the nip, and is made of a liquid crystal polymer, a phenol resin, PPS, PEEK, or the like. The stay holder 22 of this embodiment is a member having a horizontal cross section of an arc-shaped gutter shape, is heat-resistant, electrically insulative, and can withstand a high load. The heating surface side is exposed downward and is fitted and fixedly supported in a groove provided along the groove.

The fixing film 23 is a cylindrical heat-resistant film, which is loosely fitted to the stay holder 22 including the heater 21 in such a manner that the circumferential length has a margin.
The stay holder 22 supports the fixing film 23 from the inside.

The fixing film 23 has a small heat capacity, and has a total thickness of 100 to enable quick start.
Heat-resistant, thermoplastic polyimide, polyamideimide, PEEK, PES, PPS, P
It is a film based on FA, PTFE, FEP or the like. In addition, a film having sufficient strength to constitute a long-life heat fixing device and having excellent durability has a total thickness of 2 mm.
A thickness of 0 μm or more is required. Therefore, fixing film 2
The total thickness of 3 is optimally 20 μm or more and 100 μm or less. Further, in order to prevent offset and ensure the separating property of the recording material, the surface layer is coated with a heat-resistant resin having good releasability, such as PFA, PTFE, FEP, or silicone resin, or coated alone.

The elastic pressure roller 30 as a pressure member is
It is composed of a metal core 31 and a heat-resistant elastic release layer 32 of silicon rubber or the like provided on the outside thereof.

The elastic pressure roller 30 is held by a bearing member (not shown), and the fixing film 23 is sandwiched between a downward heating surface of the heater 21 fixed and supported on the lower surface side of the stay holder 22. The pressure is sufficiently applied from both ends in the longitudinal direction to form a fixing nip portion N required for heat fixing by the illustrated pressing means.

The elastic pressure roller 30 is driven to rotate in a counterclockwise direction indicated by an arrow by a driving means M (a rotary driving mechanism for pressing). A rotational force acts on the fixing film 23 by the frictional contact between the outer surface of the roller 30 and the outer surface of the fixing film 23 at the fixing nip portion N by the rotational driving of the elastic pressure roller 30, and the fixing film 23 The inner surface follows the outer circumference of the stay holder 22 at a peripheral speed substantially corresponding to the rotational peripheral speed of the elastic pressure roller 30 in the clockwise direction of arrow A while sliding in close contact with the downward heating surface of the heater 21 at the fixing nip portion N. It becomes a rotating state.

In this case, the cylindrical fixing film 23 which is driven to rotate around the outer periphery of the stay holder 22 has a fixing free nip portion N having a peripheral length thereof and a fixing film portion other than the fixing nip portion in the vicinity of the fixing nip portion N. Not in the state).

The fixing film 23 has a heater 2 on the inner side.
1 and a part of the outer surface of the stay holder 22 so as to rotate.
It is necessary to keep the frictional resistance between the fixing film 23 and the fixing film 23 small. Therefore, the heater 21 and the stay holder 22
A small amount of lubricant such as heat-resistant grease is interposed on the surface of. This allows the fixing film 23 to rotate smoothly. Further, the fixing film 23 is dropped to the ground so that the toner is not attached by the charging due to the sliding.

When the elastic pressure roller 30 is driven to rotate, the cylindrical fixing film 23 is driven to rotate around the outer periphery of the stay holder 22 and the heater 21 is rotated.
Is supplied to the fixing nip N
In a state where the temperature has risen to a predetermined level and the temperature has been adjusted,
A recording material P on which an unfixed toner image t is formed and carried is introduced into the fixing nip N, and the recording material P
The non-fixed toner image carrying surface side is in close contact with the outer surface of the fixing film 23, and the fixing nip N is conveyed together with the fixing film 23.

In the process of nipping and transporting the recording material P, the heat of the heater 21 is applied to the recording material P via the fixing film 23, and the unfixed toner image t on the recording material P is applied with heat and pressure. Be established.

When the recording material P passes through the fixing nip portion N, it is separated from the outer surface of the fixing film 23 by a curvature and is conveyed to a paper discharge portion.

(3) Heater 21 and Power Supply System FIG. 3A shows the ceramic heater 21 according to this embodiment.
(B) is a partially cutaway plan view on the heating side of the heater, and (c) is a plan view on the side opposite to the heating side. (A) is an enlarged cross-sectional model diagram along line (a)-(a) in (c).

A is alumina (Al ₂ ) as a heater substrate.
O ₃ ), aluminum nitride (AlN), silicon carbide (S
iC) or other ceramic plate. An elongated and thin wall having a longitudinal direction perpendicular to the film (recording material) moving direction A in the fixing nip N, electrical insulation, good thermal conductivity,
It is a member with low heat capacity. In this embodiment, it is an alumina ceramic plate.

B, c, d denote three parallel strips of the first resistor layer, the second resistor layer, formed on the surface side of the ceramic plate a along the length of the ceramic plate in a strip-like pattern. It is a conductor layer.

The first and second resistor layers b and c are made of, for example, Ag / Pd (silver palladium), RuO ₂ , Ta ₂ N
Is formed by applying a thin strip pattern on the surface of a ceramic plate by thick film printing or the like (screen printing or the like) and baking.

The conductor layer d is formed by applying an electric conductive material such as a silver paste on the surface of a ceramic plate in a thin band pattern by thick film printing or the like, followed by firing.

E, f, and g are first, second, and third power supply electrical contacts (power supply electrode portions) arranged side by side at one longitudinal end of the ceramic plate surface. The first electrical contact e is electrically connected to one end of the first resistor layer b, and the second electrical contact f is electrically connected to one end of the second resistor layer c. The third electrical contact g is electrically connected to one end of the conductor layer d. In addition, the first resistor layer b, the second resistor layer c,
The other end of the conductor layer d has a common fourth electrical contact h.
Are connected to each other. First to fourth electrical contacts ef
G · h is formed by applying an electric conductive material such as a silver paste on the surface of a ceramic plate in a predetermined pattern by thick film printing or the like and firing it.

As a result, a heat generating circuit (primary line, AC line) including the first resistor layer b and the second resistor is formed.

Reference symbol i denotes a heat-resistant and electrically-insulating overcoat layer that protects the surface area of the ceramic plate on which the first resistor layer b, the second resistor layer c, and the conductor layer d are formed. It is a heat-resistant glass coat layer.

Reference numerals j and k denote fifth and sixth electrical contacts for temperature information output (temperature information output electrode portions) arranged side by side on the other end in the longitudinal direction on the surface side of the ceramic plate. The fifth and sixth electrical contacts jk are respectively provided with through holes v
And w, it is electrically connected to two parallel conductor patterns m and n which are formed and provided on the back side of the ceramic plate to substantially the center of the length of the ceramic plate. A thermistor S as a temperature detecting element is provided between the tip portions of the two parallel conductor patterns m and n.

Thus, a temperature information output circuit (secondary line, DC line) including the thermistor S is formed.

The thermistor s is formed by mixing an alloy of cobalt, manganese, nickel, ruthenium or the like, an oxide, or a particle of ceramic such as platinum or barium titanate with a glass paste material, and forming a mixture on a back surface of a ceramic plate a as a heater substrate. Into a thin layer type formed by screen printing, or a chip type thermistor.

The fifth and sixth electrical contacts j and k and the conductor patterns m and n are also coated with an electric conductive material such as silver paste in a predetermined pattern on the front and rear surfaces of the ceramic plate by thick film printing or the like. And fired.

In the ceramic heater 21 described above, the length of the ceramic plate a as the heater substrate is set to be equal to or larger than the maximum paper passing width of the apparatus, and the first and second resistor layers b and.
The effective heat generation length c substantially corresponds to the maximum sheet passing width. Then, first to third electrical contacts ef for power supply
G is the first on one end side of the ceramic plate a in the longitudinal direction.
And the fifth and sixth electrical contacts jk for outputting temperature information are located at the other ends in the longitudinal direction of the ceramic plate a. On the side, the structure is unevenly distributed in portions outside the first and second effective heat generation length regions.

In the ceramic heater 21, the surface of the ceramic plate on which the first and second resistor layers b and c are formed is the heating surface. The heater 21 is fixedly supported by fitting the heater 21 into a groove provided substantially in the center of the lower surface of the stay holder 2 along the longitudinal direction of the member with the heating surface side exposed downward.

An AC connector 24 for power supply is provided at one end of the ceramic heater 21 in the longitudinal direction where the first to third electric contacts efg for power supply are disposed.
A DC connector 25 for taking out temperature information is attached to the other end in the longitudinal direction where the fifth and sixth electrical contacts jk for outputting temperature information are arranged.

FIG. 4 is a block diagram of a power supply system for the ceramic heater 21 described above.

ACV is a commercial power supply (AC100V or A
C200V), and PS is an internal power supply. Internal power supply PS is 100V AC or 200V AC
The power is supplied to a microcomputer CPU as a control unit that controls the image recording apparatus.

The voltage corresponding to the ceramic plate temperature output from the thermistor s of the temperature information output circuit mounted on the ceramic heater 21 is applied to the fifth and sixth electrical contacts j · k of the temperature information output circuit of the heater 21. A / D of the microcomputer CPU via the DC connector 25 connected thereto.
Input to the conversion port TH and the microcomputer CPU
Obtains temperature information of the ceramic heater 21. This is the temperature detecting means.

The microcomputer CPU turns ON / OFF the FSDRV (output port of the CPU) so that the temperature of the ceramic heater 21 detected by the above-mentioned temperature detecting means becomes a desired temperature, and thereby through the phototriac coupler SSR. Triac Q ON / OF
F to control the supply of electric power to the ceramic heater 21. This is the temperature control means.

An open / short switch SW201 is short-circuited when the voltage of the commercial power supply ACV is 100V AC, and opened when the voltage of the commercial power supply is 200V AC. This switch SW201 is a resistance value selecting unit.

In this embodiment, the ceramic heater 21
The resistance values of the first resistor layer b and the second resistor layer c are 1:
The second resistor layer c is higher than the first resistor layer b at a ratio of 3.

One of the outputs of the temperature control means is connected to a first electrical contact e connected to the first resistor layer b having a low resistance value, and the other output of the temperature control means is connected to a resistance As the resistance value selecting means for selecting and connecting one of the second electric contact f and the third electric contact g connected to the second resistor layer c and the conductor d having a high value, Switch SW201.

When the voltage of the commercial power supply ACV is 100 V AC and the switch SW 201 is short-circuited, the first electric contact e of the heating electric path of the ceramic heater 21 →
First resistor layer b → fourth electrical contact h → conductor layer d →
The path of the third electrical contact g is substantially powered and the second
The resistor layer c does not generate heat, and the heater is heated by heat generated only by the first resistor layer b.

When the voltage of the commercial power supply ACV is
V and the switch SW201 is open,
In the path of the first electrical contact e of the heating circuit of the ceramic heater 21 → the first resistor layer b → the fourth electrical contact h → the second resistor layer c → the second electrical contact f. Powered,
The series body of the first resistor layer b and the second resistor layer c generates heat.

With the above configuration, the commercial power supply A
The calorific value of the ceramic heater 21 can be the same when the voltage of CV is both AC100V and AC200V.

The arrangement of the first resistor layer b, the second resistor layer c, and the conductor layer d on the ceramic plate a is shown in FIG. By arranging the resistor layer c and the conductor layer d in this order, the heat generating portion does not change significantly when the voltage of the commercial power supply ACV is either AC100V or AC200V, so that good fixability can be obtained.
However, when a material having good thermal conductivity such as aluminum nitride is used as the ceramic plate a, the above arrangement order does not need to be considered so much.

<Second Embodiment> (FIG. 5) FIG. 5 is a block diagram of a power supply system for the ceramic heater 21 in this embodiment.

In this embodiment, the resistance value selecting means is set to 2
The switch SW301 is linked to the individual connection. Further, the resistance values of the first resistor layer b and the second resistor layer c in the ceramic heater 21 were the same.

That is, in this embodiment, the first electric contact e connected to the first resistor layer b and the second resistor layer c is connected between the temperature control means and the ceramic plate. A voltage is applied between the two electrical contacts f and the third electrical contact g connected to the resistor layer d is opened, and the voltage is applied to the first resistor layer b and the second resistor layer c. The first electrical contact e connected to the second electrical contact f is short-circuited between the first electrical contact e and the second electrical contact f, and the first electrical contact e connected to the first resistor layer b and the second electrical contact c is connected to the first electrical contact e. Two interlocked connections as the resistance value selection means for selecting from two types of application of a voltage between the second electrical contact f and the third electrical contact g connected to the conductor layer d. It has a changeover switch SW301.

The switch SW301 switches to the right when the voltage of the commercial power supply ACV is 100V AC, and switches to the left when the voltage of the commercial power supply is 200V AC.

When the voltage of the commercial power supply ACV is 100 V AC and the switch SW301 is switched to the right, the first
The first resistor layer b and the second resistor layer c generate heat in such a manner that power is supplied to the parallel body of the resistor layer b and the second resistor layer c, and the heater is heated.

When the voltage of the commercial power supply ACV is 200 V AC and the switch SW301 is switched to the left, the first
The first resistor layer b and the second resistor layer c generate heat in a form in which power is supplied to the series body of the resistor layer b and the second resistor layer c, and the heater is heated.

With the above configuration, the commercial power supply A
The calorific value of the ceramic heater 21 can be the same when the voltage of CV is both AC100V and AC200V.

Structures other than those described above are the same as those of the first embodiment.

In this embodiment, the arrangement of the first resistor layer b, the second resistor layer c, and the conductor layer d on the ceramic plate a is the same as that of the first resistor layer b, as shown in FIG. By arranging the resistor layer b, the second resistor layer c, and the conductor layer d in this order, the heat generation portion does not change significantly when the voltage of the commercial power supply ACV is either AC100V or AC200V, so that good fixing performance is obtained. Is obtained. However, when a material having good thermal conductivity such as aluminum nitride is used as the ceramic plate a, the above arrangement order does not need to be considered so much.

Third Embodiment (FIG. 6) FIG. 6 is a block diagram of a power supply system for the ceramic heater 21 in this embodiment.

In this embodiment, the connection selector switch SW401 is used as the resistance value selector. Further, the resistance values of the first resistor layer b and the second resistor layer c in the ceramic heater 21 were the same.

In this embodiment, the ceramic heater 21
The resistance values of the first resistor layer b and the second resistor layer c are 1:
The first resistor layer b is higher than the second resistor layer c by a ratio of 4.

One of the outputs of the temperature control means is connected to a third electrical contact g connected to the conductor layer d, and the other output of the temperature control means is connected to the first resistance layer b.
A resistance changeover means for selecting one of the first electrical contact e connected to the first electrical contact e and the second electrical contact f connected to the second resistor layer c for connection. S
W401.

The switch SW401 switches to the right when the voltage of the commercial power supply ACV is 100V AC, and switches to the left when the voltage of the commercial power supply is 200V AC.

When the voltage of the commercial power supply ACV is 100 V AC and the switch SW 401 is switched to the right, the second
The second resistor layer c generates heat, and the heater is heated.

When the voltage of the commercial power supply ACV is AC 200 V and the switch SW401 is switched to the left, the first
The first resistor layer b generates heat in such a manner that power is supplied only to the resistor layer b, and the heater is heated.

With the above configuration, the commercial power supply A
The calorific value of the ceramic heater 21 can be the same when the voltage of CV is both AC100V and AC200V.

The other configuration is the same as that of the first embodiment.

In this embodiment, the arrangement of the first resistor layer b, the second resistor layer c, and the conductor layer d on the ceramic plate a is the same as that of the first resistor layer as shown in FIG. By arranging the resistor layer b, the second resistor layer c, and the conductor layer d in this order, the heat generation portion does not change significantly when the voltage of the commercial power supply ACV is either AC100V or AC200V, so that good fixing performance is obtained. Is obtained. However, when a material having good thermal conductivity such as aluminum nitride is used as the ceramic plate a, the above arrangement order does not need to be considered so much.

<Fourth Embodiment> (FIG. 7) FIG. 7 is a block diagram of a power supply system for the ceramic heater 21 in this embodiment.

In this embodiment, the open / short switch SW201 as the resistance value selecting means in the block diagram of the power supply system for the ceramic heater 21 in FIG. 4 of the first embodiment is changed to the relay RL501, and the commercial power supply A
CV input voltage detecting means COMP. Is provided, and the relay RL501, which is the resistance value selection means, is switched over at AC150V.

Specifically, the input voltage detecting means COMP.
If the detected voltage is 150 V or more, the relay RL501 is opened, assuming that the voltage of the commercial power supply ACV is AC200V, and if the detected voltage is less than 150V, the relay RL5 is determined that the voltage of the commercial power supply ACV is AC100V.
01 is short.

The other structure is the same as that of the first embodiment.

In this embodiment, similarly to the first embodiment, the voltage of the commercial power supply ACV is 100 V AC and 20 V AC.
The amount of heat generated by the ceramic heater 21 can be the same in both cases of 0V.

The input voltage detecting means COMPM. The control can be stabilized by providing hysteresis to the control. Specifically, the relay RL501 is opened when the detection voltage becomes AC160V or more, and the AC140V
By closing the relay RL501 when it becomes, it becomes possible to prevent the operation from becoming unstable next to the control switching.

[0110] Also, due to some trouble, AC200
If a resistance value of AC100V is selected at the time of V input, heat generation of the ceramic heater occurs instantaneously, so that the relay RL501 is opened by default (AC10
By setting it to 0V input and open except when the heat fixing operation is being performed, it is possible to increase the probability that the resistance value for 200V AC is selected even when a failure occurs in the apparatus.

In the second and third embodiments as well, a relay is used as the resistance value selection means, and the input voltage detection means is provided to control the relay by the detection voltage to switch the resistance value selection. Can be done.

The image heating apparatus for thermally fixing the unfixed toner image t formed and carried on the surface of the recording material P as a permanent fixed image has been described above. It can be used as a device that heats a material to improve the surface properties such as gloss, a device that performs a hypothetical deposition process, and a device that heats a material to be heated.

[0113]

As described above, according to the present invention, it is possible to arrange an electric contact for supplying electric power and an electric contact for extracting temperature information on a ceramic heater without an electric problem. A universal image heating apparatus using a ceramic heater as a heating element and capable of coping with both commercial power supply voltages of 100 V and 200 V, and a universal image heating apparatus including the image heating apparatus and capable of coping with both power supply voltages of 100 V and 200 V without problem Make the image recording device practical.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an example of an image recording apparatus according to a first embodiment.

FIG. 2 is a schematic configuration diagram of an image heating apparatus using a ceramic heater.

FIG. 3 is a configuration explanatory view of a ceramic heater;
(A) is an enlarged cross-sectional model diagram, (b) is a plan model diagram of a partially cutout on the heating surface side of the heater, and (c) is a plane model diagram on the anti-heating surface side.

FIG. 4 is a block diagram of a power supply system for a ceramic heater.

FIG. 5 is a block diagram of a power supply system for a ceramic heater in a second embodiment.

FIG. 6 is a block diagram of a power supply system for a ceramic heater in a third embodiment.

FIG. 7 is a block diagram of a power supply system for a ceramic heater in a fourth embodiment.

FIGS. 8A and 8B are reference diagrams for explaining a resistance value ratio of a resistor, respectively.

[Explanation of symbols]

Reference Signs List 21 ceramic heater a ceramic plate (heater substrate) b first resistor layer b second resistor layer d conductor layer eh first to fourth electrical contacts jk fifth and sixth electrical contacts Contact s Temperature detection means (thermistor) SW201, SW301, SW401, RL501
Resistance value selection means

Claims (9)

[Claims] 1. An image heating apparatus having a heating element that generates heat when energized and heats an image on a recording material by the heat of the heating element, wherein the heating element extends in a direction perpendicular to a moving direction of the recording material. A ceramic plate whose longitudinal dimension is equal to or greater than the maximum paper passing width of the device; and three or more electrical contacts on the ceramic plate; the electrical contacts being unevenly distributed on one side in the longitudinal direction of the ceramic plate; Two of the electrical contacts are connected to a resistor arranged parallel to the longitudinal direction on the ceramic plate, and one of the electrical contacts is connected to a conductor arranged parallel to the resistor. All of the resistor and the conductor are electrically connected on the opposite side of the electrical contact with respect to the longitudinal direction of the ceramic plate, and the ratio of the resistance values of the two resistors is 1: 1.48 to 1. : 4.
76, comprising: temperature detecting means for detecting the temperature of the ceramic plate; and temperature controlling means for controlling power supply to the resistor in order to set the temperature of the temperature detecting means to a desired temperature. One of the outputs of the temperature control means is connected to an electrical contact connected to a resistor having a low resistance value, and the other output of the temperature control means is connected to the other resistor and a conductor connected to a conductor. An image heating device connected to a resistance value selection device that selects one of the contacts and makes a connection. 2. An image heating apparatus having a heating element that generates heat by energization and heating an image on a recording material by the heat of the heating element, wherein the heating element extends in a direction perpendicular to a moving direction of the recording material. A ceramic plate whose longitudinal dimension is equal to or greater than the maximum paper passing width of the device; and three or more electrical contacts on the ceramic plate; the electrical contacts being unevenly distributed on one side in the longitudinal direction of the ceramic plate; Two of the electrical contacts are connected to a resistor arranged parallel to the longitudinal direction on the ceramic plate, and one of the electrical contacts is connected to a conductor arranged parallel to the resistor. The resistor and the conductor are all electrically connected on the opposite side of the electrical contact with respect to the longitudinal direction of the ceramic plate, and the two resistors have the same resistance value. Temperature detection Means for controlling power supply to the resistor in order to set the temperature of the temperature detecting means to a desired temperature; and an electrical contact connected to the resistor between the temperature control means and the ceramic plate. Applying a voltage between them and opening the electrical contacts connected to the conductor, and shorting the electrical contacts connected to the resistor, connecting the electrical contacts connected to the resistor and the conductor An image heating device comprising a resistance value selection device for selecting from two cases in which a voltage is applied between the applied electrical contacts. 3. An image heating apparatus having a heating element that generates heat when energized, and heats an image on a recording material by the heat of the heating element, wherein the heating element extends in a direction orthogonal to a moving direction of the recording material. A ceramic plate whose longitudinal dimension is equal to or greater than the maximum paper passing width of the device; and three or more electrical contacts on the ceramic plate; the electrical contacts being unevenly distributed on one side in the longitudinal direction of the ceramic plate; Two of the electrical contacts are connected to a resistor arranged parallel to the longitudinal direction on the ceramic plate, and one of the electrical contacts is connected to a conductor arranged parallel to the resistor. All of the resistor and the conductor are electrically connected on the opposite side of the electrical contact with respect to the longitudinal direction of the ceramic plate, and the ratio of the resistance values of the two resistors is 1: 2.48-1. : 5.
76, comprising: temperature detecting means for detecting the temperature of the ceramic plate; and temperature controlling means for controlling power supply to the resistor in order to set the temperature of the temperature detecting means to a desired temperature. One of the outputs is connected to an electrical contact connected to the conductor, and the other output of the temperature control means is a resistance value for selecting and connecting one of the electrical contacts connected to the resistor. An image heating device connected to a selection device. 4. The image heating apparatus according to claim 1, wherein a conductor is disposed at an extreme end with respect to an arrangement of the conductor and the resistor on the ceramic plate. Heating equipment. 5. An image heating apparatus according to claim 1, further comprising an input voltage detection means for detecting a voltage of a commercial power supply applied to the apparatus, wherein the input voltage detection means obtains the voltage obtained by the input voltage detection means. An image heating device, wherein a resistance value is selected by a resistance value selection device based on a voltage value. 6. The image heating apparatus according to claim 5, wherein
An image heating apparatus comprising a hysteresis for switching a resistance value by a resistance value selection device with respect to an input voltage value. 7. The image heating apparatus according to claim 5, wherein when no commercial power is applied to the apparatus and when the image recording apparatus is not in an image recording operation, the resistance value selecting apparatus is set to the most. An image heating apparatus characterized by selecting a high resistance value. 8. A film having one surface sliding on a heating member and the other surface contacting and moving with a recording material bearing an image, and the recording material is heated by the heat from the heating member via the film. The image heating apparatus according to claim 1, wherein the image is heated. 9. An image recording apparatus comprising the image heating device according to claim 1. Description: