JP2003142232A - Heater and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater which has low temperature at an electrode part and hardly causes dielectric breakdown of an insulating layer, and an image forming device using the heater. SOLUTION: The heater 32 is equipped with a base material 321 formed of ceramics, on which a resistive heating element layer 322 is formed. An electrode part 324 having a double-layer structure is connected to an end 322a of the resistive heating element layer 322. An electrode layer 325 of the electrode part 324 is formed on the base material 321 so that an end 325a be at a lower side of the end 322a of the resistive heating element layer 322. Also, an electrode layer 326 is formed on the electrode layer 325 so that an end 325a be so that an end 326a be on an end 325b of the electrode layer 325 and an end 326b be at a position 10 to 90 μm away from the end 322a of the resistive heating element layer 322.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater capable of generating heat and an image forming apparatus equipped with this heater.

[0002]

2. Description of the Related Art At present, copying machines utilizing an electrophotographic process are widely used. A copying machine using such an electrophotographic process includes a heater that melts toner by heating and fixes it on a recording medium.

10 and 11 are vertical sectional views schematically showing a conventional heater. As shown in FIG.
The heater 501 includes a base material 502, a resistance heating element layer 503 that generates heat when energized, a pair of electrode portions 504 connected to the resistance heating element layer 503, and a glass layer 505 that protects the resistance heating element layer 503. There is. Here, since the electrode portion 504 may be scraped when a connector (not shown) is connected, the portion 504a of the electrode portion 504 to which the connector is connected has a two-layer structure of electrode layers 506 and 507.

[0004]

By the way, the heater 50 is used.
When the first electrode portion 504 is connected to the connector and energized, the electrode portion 504 becomes hot, and the supporting member and the fixing film located in the peripheral portion of the heater 501 may be melted or burned by heat. is there. It is considered that the reason why the temperature of the electrode portion 504 becomes high is that not only the resistance heating element layer 503 but also the electrode portion 504 generates heat due to power supply from the connector.

For this reason, one end of the electrode layer 507 is formed so as to be in contact with the end of the resistance heating element layer 503,
Attempts have been made to reduce the resistance value of the entire electrode portion 504 to suppress heat generation of the electrode portion 504.

However, when the electrode layer 507 is actually formed, as shown in FIG. 11, the end portion 50 of the electrode layer 507 is formed.
7a often overlaps the end portion 503a of the resistance heating layer 503. When the end portion 507a of the electrode layer 507 overlaps the end portion 503a of the resistance heating element layer 503, the glass layer 505 at the end portion 503a of the resistance heating element layer 503.
However, there is a problem that the thickness becomes thin and dielectric breakdown easily occurs at this portion.

The present invention has been made to solve the above conventional problems. That is, an object of the present invention is to provide a heater in which the temperature of the electrode portion is low and the dielectric breakdown of the insulating layer hardly occurs, and an image forming apparatus using the heater.

[0008]

A heater according to claim 1, wherein: an insulating base material; a resistance heating element layer formed on the base material; a resistance heating element layer formed on the base material and having one end thereof. A first electrode layer connected to one end of, and formed on the first electrode layer,
A pair of electrode portions having one end on the other end of the first electrode layer and the other end on the second electrode layer 10 to 90 μm away from one end of the resistance heating layer; An insulating layer formed on the heating element layer to protect the resistance heating element layer;
It is characterized by having.

In the above-mentioned invention and the following inventions, the definitions and technical meanings of terms are as follows unless otherwise specified.

(Regarding Whole Heater) The use of the heater of the present invention is not particularly limited. For example, it can be incorporated into small equipment such as OA equipment, household electric appliances, precision manufacturing equipment, and the like, and can also be incorporated into image forming apparatuses such as copying machines, facsimiles, and printers.

(Regarding Base Material) The base material may be made of any material as long as the surface has an insulating property. Examples of such a material include ceramics such as alumina and aluminum nitride, glass, and a metal coated with an insulating layer. The shape of the base material may be a flat plate shape, a rod shape, a cylindrical shape, or the like, but is not particularly limited. It should be noted that the flat plate shape is easier to form the resistance heating element layer and the like than the rod shape.

(Regarding Resistance Heating Element Layer) The resistance heating element layer may be made of any material as long as it generates heat when energized. As such materials,
For example, a silver / palladium-based material can be used. The method for forming the resistance heating element layer may be a forming method using a thick film technique such as screen printing, but is not particularly limited.

(Regarding Electrode Section) The electrode section is composed of a first electrode layer and a second electrode layer. The first electrode layer and the second electrode layer may be made of any material as long as they have conductivity. Examples of such a material include a silver-based material, a silver / palladium-based material, and a silver / platinum-based material. Note that the first electrode layer and the second electrode layer can be formed using the same material.

Examples of the method for forming the first electrode layer and the second electrode layer include, but are not particularly limited to, a forming method utilizing a thick film technique such as screen printing. Also,
The order of forming the resistance heating element, the first electrode layer, and the second electrode layer is not particularly limited. For example, the resistance heating element layer may be formed after forming the first electrode layer and the second electrode layer, or the first electrode layer and the second electrode layer may be formed after forming the resistance heating element. It may be formed, and further, after forming the first electrode layer, the resistance heating element layer is formed, and then the second electrode layer is formed.
You may form the electrode layer of.

The second electrode layer is formed on the first electrode layer. Specifically, one end is on the other end of the first electrode layer, and the other end is 10 to 90 from one end of the resistance heating element layer.
.mu.m, preferably 40 to 60 .mu.m apart. Here, the reason why the resistance heating element layer is set to 90 μm from one end is that if it exceeds 90 μm, the temperature of the electrode portion cannot be sufficiently lowered. The distance from one end of the resistance heating element layer to 10 μm is 10
This is because it is difficult to manufacture it with a thickness of less than μm. That is, the second electrode layer is 10 μm away from one end of the resistance heating element layer.
This is because, if it is attempted to manufacture the insulating layer less than the above, the other end of the second electrode layer and one end of the resistance heating element layer overlap with each other, and dielectric breakdown of the insulating layer is likely to occur. This cause is considered to be due to manufacturing variations. For example, when the resistance heating element layer and the second electrode layer are formed by screen printing,
The cause is the alignment of the screen. Specifically, since the screen alignment is currently performed manually, the screen may be displaced, and this screen displacement causes the second electrode layer and the resistance heating element layer to overlap. In addition, the slack of the screen is also a cause. Specifically, when the screen is used for a long period of time, slack may occur on the screen, which causes the second electrode layer and the resistance heating element layer to overlap with each other.

(Insulating Layer) The insulating layer may be made of any material as long as it has an insulating property. Examples of such a material include ceramics such as alumina and aluminum nitride, and glass.

A heater according to claim 1 is formed on a base material and has a first electrode layer having one end connected to one end of a resistance heating element layer and a first electrode layer, the one end of which is the first electrode layer. One electrode layer is provided on the other end, and the other end is provided with a pair of electrode portions having a second electrode layer that is present at a position 10 to 90 μm away from one end of the resistance heating layer, The temperature of the electrode part is low, and dielectric breakdown of the insulating layer is unlikely to occur.

In the heater according to claim 2, the resistance heating element layer has a thickness of 8 to 13 μm, and the first electrode layer has a thickness of 8 to 13 μm.
The thickness is 17 μm, and the thickness of the second electrode layer is 8 to 17 μm. The heater according to claim 2,
Since the thickness of the resistance heating element layer, the first electrode layer, and the second electrode layer is formed within the above range, the resistance heating element layer and the like can be formed in a desired size. That is, in general, when the resistance heating element layer or the like is formed using a paste-like material, the thicker the resistance heating element layer or the like, the more easily the material tends to sag, and the desired size tends not to be obtained. However, when the thickness of the resistance heating element layer or the like is formed within the above range, there is little sagging, and the resistance heating element layer or the like can be formed to a desired size.

According to a third aspect of the heater, one end of the resistance heating element layer is present on the first electrode layer, part of the second electrode layer is covered with an insulating layer, and the first to second electrode layers are covered by the base material. The height of the second electrode layer to the upper surface is smaller than the height from the base material to the top of the resistance heating element layer. The top of the resistance heating element layer is the highest position in the resistance heating element layer.
In the heater according to claim 3, since the height from the base material to the upper surface of the second electrode layer is smaller than the height from the base material to the top of the resistance heating element layer, the insulating layer present on the second electrode layer. Dielectric breakdown is unlikely to occur.

In the heater according to claim 4, one end of the first electrode layer is present on the resistance heating layer, part of the second electrode layer is covered with the insulating layer, and the first electrode layer is covered with the insulating layer. The height of the second electrode layer to the upper surface is smaller than the height from the base material to the top of the first electrode layer. The top of the first electrode layer is the highest position in the first electrode layer.
In the heater according to claim 4, since the height from the base material to the upper surface of the second electrode layer is smaller than the height from the base material to the top of the first electrode layer, the insulation existing on the second electrode layer is included. Dielectric breakdown of layers is unlikely to occur.

An image forming apparatus according to a fifth aspect of the present invention includes a photoconductor, a charging unit for charging the photoconductor, an exposing unit for irradiating the photoconductor with light to form an electrostatic latent image on the photoconductor, and an electrostatic unit. Developing means for forming a toner image by attaching toner to the latent image,
An image forming unit for forming an image on the recording medium, which comprises a transfer means for adhering the toner to the recording medium to transfer the toner image to the recording medium; and heating the toner attached to the recording medium,
A recording medium comprising: the heater according to any one of claims 1 to 4 for melting; a support member for supporting the heater; and a pressure roller for bringing the recording medium into pressure contact with the heater and conveying the recording medium. A toner fixing unit for fixing the toner to the;
A recording medium supply unit that supplies the recording medium to the image forming unit; and a recording medium conveying unit that conveys the recording medium from the image forming unit to the toner fixing unit;

The image forming apparatus includes a copying machine, a facsimile, a printer and the like. The recording medium is
Any material may be used as long as it adheres to the toner. Examples of such a recording medium include paper.

The support member is made of, for example, ceramics such as alumina or aluminum nitride, glass, or synthetic resin. A method of supporting the heater by the supporting member includes, for example, fixing with an adhesive, but is not particularly limited.

An image forming apparatus according to a fifth aspect includes the heater according to any one of the first to fourth aspects, which heats and melts the toner adhering to the recording medium. It is difficult to melt or burn, and it is hard for electronic parts to malfunction. That is, in this heater, since the temperature of the electrode portion is low, the support member and the like are less likely to melt or burn due to the heat generated by the heater. Further, in this heater, the dielectric breakdown of the insulating layer is unlikely to occur, so that there is no leak current generated by the dielectric breakdown, and the electronic component or the like is unlikely to fail.

The image forming apparatus according to the sixth aspect is characterized in that the supporting member has a groove corresponding to the shape of the heater. The groove of the support member may have any shape as long as it corresponds to the shape of the heater. For example, when the heater is rectangular, the groove of the support member is also rectangular. Further, the heater is only embedded in the groove, or is embedded in the groove and is adhered and supported by the support member. In the image forming apparatus according to the sixth aspect, since the supporting member has the groove corresponding to the shape of the heater, the positioning of the heater can be accurately and easily performed.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A copying machine according to a first embodiment of the present invention will be described below.
FIG. 1 is a configuration diagram schematically showing a copying machine according to the present embodiment, and FIG. 2 is a vertical sectional view schematically showing a toner fixing unit according to the present embodiment.

As shown in FIG. 1, the copying machine 1 includes a housing 2 having a lid 2d having openings 2a, 2b and 2c formed on the upper surface and two opposite side surfaces. A glass plate 3 on which a document G to be copied is placed is fitted into the opening 2 a of the housing 2. Also, the housing 2
A paper feed cassette 4 for supplying copy paper P to an image forming unit 20 to be described later is inserted into the opening 2b of the paper, and a discharge tray 5 for discharging the copied copy paper P is provided at the edge of the opening 2c.
Is provided.

In the housing 2, an image reading section 10 for mainly reading an image of an original G, an image forming section 20 for forming an image on a copy sheet P with toner based on image information read by the image reading section 10, A toner fixing unit 30 for fixing the toner attached to the copy paper P, a conveyance system 40 for conveying the copy paper P from the paper feed cassette 4 to the paper discharge tray 5 via the image forming unit 20 and the toner fixing unit 30 are provided. ing.

The image reading unit 10 is arranged near the glass plate 3 and is capable of emitting light, a reflecting mirror 12 for reflecting the light reflected by the original G, and a light for reflecting the light reflected by the reflecting mirror 12. It is composed of a lens 13, a CCD 14 for receiving the light condensed by the lens 13, and the like. Light source 11
An image of the original G is read by irradiating the original G with light from the source and receiving the reflected light reflected by the original G by the CCD 14 via the reflection mirror 12 and the lens 13.

The image forming section 20 includes a rotatable photosensitive drum 21, and a charger 2 for charging the outer peripheral surface of the photosensitive drum 21.
2. An exposure device 23 that irradiates the outer peripheral surface of the photosensitive drum 21 with light to form an electrostatic latent image, a developing device 24 that attaches toner to the electrostatic latent image to form a toner image, and toner on the copy paper P. It is composed of a transfer device 25 for adhering and transferring the toner image, a toner cleaner 26 for removing the toner remaining on the photosensitive drum 21 after the image transfer, and the like.

To form an image in the image forming section 20, first, the outer peripheral surface of the photosensitive drum 21 is charged by the charger 23. Then, based on the image information of the CCD 14, the exposure device 2
The outer peripheral surface of the photosensitive drum 21 is irradiated with light from 3 to form an electrostatic latent image on the photosensitive drum 21. Further, the developing device 24 attaches toner to the electrostatic latent image to form a toner image. Finally, the transfer device 25 adheres the toner to the copy paper P,
The toner image is transferred to the copy paper P.

The transport system 40 includes a rotatable paper feed roller 41 for taking out the copy paper P from the paper supply cassette 4, a transport roller 42 for carrying the copy paper P taken out by the paper feed roller 42 to the image forming section 20, and an image. A conveyance guide 4 that guides the copy paper P discharged from the forming unit 20 to the toner fixing unit 30.
3. The transfer roller 44 is configured to transfer the copy paper P discharged from the toner fixing unit 30 to the paper discharge tray 5.

The toner fixing section 30 has a case 31 as shown in FIG. In the case 31, a flat plate-shaped heater 32 that melts the toner by heating and fixes it on the copy paper P is disposed. The heater 32 is the heater 32.
It is supported by a supporting member 33 having a groove 33a corresponding to the above shape. Specifically, since the heater 32 is formed in a flat plate shape, the support member 33 has a flat plate groove 33a.
Are formed. By forming the groove 33a corresponding to the shape of the heater 32 on the support member 33, the positioning of the heater 32 can be performed accurately and easily.

The outer peripheral surface of the support member 33 is covered with an annular fixing film 34 formed of a heat resistant resin. The fixing film 34 is a pressure roller 35 described below.
The copy sheet P is rotated by being sent out.

Below the heater 32, a pressure roller 35 for pressing the copy sheet P against the heater 32 and sending out the copy sheet P toward the conveying roller 44 is arranged. The pressure roller 35 includes a rotatable roller body 35a,
The roller main body 35a is covered with a heat resistant elastic member 35b such as silicone rubber. By pressing the copy paper P against the heater 32 with the pressure roller 35, the toner is reliably fixed to the copy paper P. Also,
As the pressure roller 35 rotates, the copy paper P supplied between the heater 32 and the pressure roller 35 is sent out toward the transport roller 44.

The heater 32 will be described below. Figure 3
4 is a plan view of the heater 32 according to the present embodiment, and FIG.
Is a vertical sectional view of the heater 32 taken along line AA in FIG. 3, and FIG. 5 is a schematic diagram showing a connection state between the heater 32 and a connector according to the present embodiment.

As shown in FIGS. 3 to 5, the heater 32 is
Length of ceramics such as alumina is about 26
0-300mm, width about 5-15mm, thickness about 0.4
It has a base material 321 of 0.8 mm. On the surface of the base material 321, the resistance heating element layer 3 that generates heat when energized
22 is formed in a substantially U shape. Resistance heating element layer 322
Is formed of a silver / palladium-based material and has a thickness of about 8 to 13 μm.

A thermistor 323 for detecting the temperature of the base material 321 is formed on the back surface of the base material 321. The thermistor 323 includes a temperature sensitive portion formed by mixing oxides of manganese, cobalt, nickel and the like. A thin film electrode made of a platinum layer, a gold layer, or the like is connected to the end of the temperature sensing part. The temperature of the base material 321 is detected by energizing the thin film electrode via a lead (not shown) and detecting the resistance of the temperature sensing part by a temperature control part (not shown). Here, the temperature control unit controls the resistance heating element layer 32 based on the resistance of the temperature sensing unit.
The voltage applied to 2 is changed. The base material 321 is maintained at about 200 ° C. by changing the voltage applied to the resistance heating element layer 322 based on the resistance of the temperature sensing portion.

At both ends 322a of the resistance heating element layer 322, electrode portions 324 for energizing the resistance heating element layer 322 are provided.
Are connected respectively. The electrode portion 324 is the electrode layer 32.
5 and the electrode layer 326 have a two-layer structure. The electrode layer 325 is formed of a silver / palladium-based material and has a thickness of about 8 to 17 μm. The electrode layer 325 is formed so that the end portion 325 a overlaps the end portion 322 a of the resistance heating element layer 322 in order to reliably connect to the resistance heating element layer 322. Specifically, the end portion 325a of the electrode layer 325 is formed below the end portion 322a of the resistance heating element layer 322. Further, the electrode portion 324 has a connector 327.
End 325b of the electrode layer 325 for reliable connection to
Area is larger than the area of other parts. In addition,
The electrode portion 324 is connected to the substantially U-shaped connector 327 in the state shown in FIG.

An electrode layer 326 made of a silver material and having a thickness of about 8 to 17 μm is formed on the electrode layer 325. Specifically, the electrode layer 326 has the end portion 326 a on the end portion 325 b of the electrode layer 325, and the end portion 326.
b is 10 to 90 from the end portion 322a of the resistance heating layer 322.
It is formed so as to exist at a position separated by μm. The electrode layer 326 is about 50 μm from the end of the electrode layer 325.
It is formed inside. Furthermore, the height of the electrode layer 326 from the base material 321 to the upper surface of the electrode layer 326 is the same as that of the base material 32.
It is formed so as to be smaller than the height from 1 to the top portion 322b of the resistance heating element layer 322. By making the height from the base material 321 to the upper surface of the electrode layer 326 smaller than the height from the base material 321 to the top portion 322b of the resistance heating element layer 322, the dielectric breakdown of the glass layer 328 which will be described later and is present on the electrode layer 326. Can be prevented.

The resistance heating element layer 322, the thermistor 323,
The electrode layers 325 and 326 are formed by screen printing. Specifically, it is formed by applying a paste of silver / palladium-based material or the like on a screen having fine holes and extruding it with a squeegee. Here, the end portion 322 a of the resistance heating element layer 322 is connected to the electrode layer 325.
In order to form it on the end portion 325a, first, the electrode layer 325 is formed on the base material 321, and then the resistance heating element layer 322 is formed.

A glass layer 328 for protecting the resistance heating element layer 322 is formed on the resistance heating element layer 322. By forming the glass layer 328, the fixing film 34 is formed.
It is possible to prevent the resistance heating element layer 322 from being scraped. The glass layer 328 is formed from the base material 321 to the glass layer 328.
The height to the upper surface is formed to be about 70 to 90 μm. In addition, the glass layer 328 is also present on a portion of the electrode layer 326 excluding a portion in contact with the connector 327.

In the present embodiment, the end portion 326a is present on the end portion 325b of the electrode layer 325, and the end portion 326b is 10 to 90 μm from the end portion 322a of the resistance heating layer 322.
Since the electrode layer 326 is formed so as to exist at a distant position, the supporting member 33, the fixing film 34, and the like are less likely to melt or burn. In addition, it becomes difficult for the electronic components and the like to break down.

That is, the end portion 326a is located on the end portion 325b of the electrode layer 325, and the end portion 326b is located 10 to 90 μm away from the end portion 322a of the resistance heating layer 322. Form a
The resistance value of the electrode portion 324 as a whole is that the electrode layer 326 is the electrode layer 3
It is smaller than the case where it is formed only on the end portion 325b of 25. Therefore, when electricity is applied, the temperature of the electrode portion 324 becomes lower than that when the electrode layer 326 is formed only on the end portion 325b of the electrode layer 325. As a result, the supporting member 33, the fixing film 34, and the like existing near the electrode portion 324 are less likely to melt or burn.

Further, since the end portion 326b of the electrode layer 326 is separated from the end portion 322a of the resistance heating element layer 322 by 10 to 90 μm, the thickness of the glass layer 328 on the end portion 322a of the resistance heating element layer 322 is: It is thicker than when the resistance heating element layer 322 and the electrode layer 326 overlap each other. Therefore, when electricity is applied, dielectric breakdown of the glass layer 328 is unlikely to occur. As a result, since there is no leak current caused by dielectric breakdown, failure of electronic components and the like is less likely to occur.

(Examples) Examples will be described below. In this example, the heater 32 according to the first embodiment is used.
Was used to measure the temperature of the electrode portion during energization.

The heater and the measurement conditions used in this embodiment will be described below. As the heater of this example, the heater described in the first embodiment was used. A connector was connected to the electrode portion of this heater, electricity was applied, and the temperature of the electrode portion at that time was measured. Here, in order to compare with the heater according to the present embodiment, the temperature of the electrode portion was measured for a conventional heater as a comparative example. The conventional heater is
It is a heater in which the upper electrode layer as shown in FIG. 10 is formed only at the end portion of the lower electrode layer.

The measurement results are shown below. The temperature of the electrode portion of the heater according to this example was lower by about 100 ° C. than that of the electrode portion of the heater according to the comparative example. Therefore, it was confirmed that the heater according to this example is less likely to melt or burn the support member and the fixing film that are present near the electrode portion than the heater according to the comparative example.

(Second Embodiment) The second embodiment of the present invention will be described below.
The embodiment will be described. Note that, in the following, among the embodiments after this embodiment, the description of the contents overlapping with the preceding embodiment may be omitted. In this embodiment mode, an example in which an end portion of an electrode layer exists over an end portion of a resistance heating element layer will be described. FIG. 6 is a plan view of the heater according to the present embodiment, and FIG. 7 is a vertical sectional view of the heater taken along the line AA in FIG.

As shown in FIGS. 6 and 7, the end portion 322 of the resistance heating layer 322 of the heater 32 according to the present embodiment.
The end portion 325a of the electrode layer 325 exists on a. Thus, the resistance heating element layer 322 and the electrode layer 325 are formed.
In order to form the above, first, the resistance heating element 322 is formed on the base material 321.
And then the electrode layer 325 is formed.

The electrode layer 326 is formed so that the height from the base material 321 to the upper surface of the electrode layer 326 is smaller than the height from the base material 321 to the top 325c of the electrode layer 325.

(Third Embodiment) The third embodiment of the present invention will be described below.
The embodiment will be described. In this embodiment, an example using a base material formed in a rod shape will be described. Figure 8
FIG. 9 is a plan view of the heater according to the present embodiment, and FIG. 9 is a vertical sectional view of the heater taken along the line AA in FIG.

As shown in FIGS. 8 and 9, the base material 321 of the heater 32 according to this embodiment is formed in a cylindrical shape, and the resistance heating layer 32 is formed on the surface of the cylindrical base material 321.
2 etc. are formed.

Since the heater 32 of this embodiment uses the base material 321 formed in a cylindrical shape, the same effect as that of the first embodiment can be obtained, and the resistance heating element layer 3 can be obtained.
The warp of the base material 321 due to the heat generation of 22 is reduced.

The present invention is not limited to the description of the above embodiment, and the structure, material, arrangement of each member, etc. can be appropriately changed without departing from the gist of the present invention.

[0056]

As described above in detail, in the heater according to the first aspect, the temperature of the electrode portion is low and the dielectric breakdown of the insulating layer hardly occurs. In the heater according to the second aspect, the resistance heating element layer and the like are formed in a desired size. In the heater according to the third aspect, the dielectric breakdown of the insulating layer existing on a part of the second electrode layer does not easily occur. The heater according to claim 4,
Dielectric breakdown of the insulating layer existing on a part of the electrode layer is unlikely to occur. In the image forming apparatus according to the fifth aspect, the supporting member and the like are hard to melt or burn, and the electronic parts and the like are hard to break down. In the image forming apparatus according to the sixth aspect, the heater can be positioned accurately and easily.

[Brief description of drawings]

FIG. 1 is a configuration diagram schematically showing a copying machine according to a first embodiment.

FIG. 2 is a vertical cross-sectional view schematically showing a toner fixing unit according to the first embodiment.

FIG. 3 is a plan view of the heater according to the first embodiment.

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

FIG. 5 is a schematic diagram showing a connection state between a heater and a connector according to the present embodiment.

FIG. 6 is a plan view of a heater according to a second embodiment.

FIG. 7 is a vertical cross-sectional view of the heater taken along the line AA in FIG.

FIG. 8 is a plan view of a heater according to a third embodiment.

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

FIG. 10 is a vertical sectional view schematically showing a conventional heater.

FIG. 11 is a vertical sectional view schematically showing a conventional heater.

[Explanation of symbols]

1 ... Copier 32 ... Heater 321 ... Base material 322 ... Resistance heating element layer 324 ... Electrode part 325 ... Electrode layer 326 ... Electrode layer 328 ... Glass layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masanori Fukushima             1 Hari, 5-2 Asahi-cho, Imabari-shi, Ehime Prefecture             Son Toshiba Lighting Co., Ltd. F-term (reference) 2H033 AA23 BA11 BA25 BA26 BA31                       BA32 BB29 BE03                 3K034 AA02 AA12 AA34 BA05 BB06                       BB14 BC04 BC12 CA02 CA15                       CA31                 3K058 AA16 AA45 BA18 CE02 CE12                       CE19                 3K092 PP18 QA05 QB02 QB26 QC02                       QC16 QC32 QC38 QC42 RF03                       RF11 RF19 RF22 SS14 VV02                       VV06

Claims (6)

[Claims] 1. An insulating base material; a resistance heating element layer formed on the base material; a first heating element layer formed on the base material and having one end connected to one end of the resistance heating element layer. An electrode layer and one formed on the first electrode layer, one end of which is on the other end of the first electrode layer, and the other end of which is 10 to 90 μm apart from one end of the resistance heating element layer. A heater comprising: a pair of electrode portions having a second electrode layer that is present; and an insulating layer that is formed on the resistance heating element layer and protects the resistance heating element layer. 2. The heater according to claim 1, wherein the resistance heating element layer has a thickness of 8 to 13 μm, and the first electrode layer has a thickness of 8 to 17 μm. A heater having an electrode layer having a thickness of 8 to 17 μm. 3. The heater according to claim 1 or 2, wherein
One end of the resistance heating element layer is present on the first electrode layer, a part of the second electrode layer is covered with the insulating layer, and the second electrode layer is covered with the second electrode layer from the base material. A heater characterized in that the height from the upper surface is smaller than the height from the base material to the top of the resistance heating element layer. 4. The heater according to claim 1 or 2, wherein
One end of the first electrode layer is present on the resistance heating element layer, a part of the second electrode layer is covered with the insulating layer, and the second electrode layer is covered with the second electrode layer from the base material. A heater having a height to an upper surface smaller than a height from the base material to a top portion of the first electrode layer. 5. A photoconductor, a charging unit for charging the photoconductor, an exposing unit for irradiating the photoconductor with light to form an electrostatic latent image on the photoconductor, and a toner for the electrostatic latent image. And an image forming unit for forming an image on the recording medium, which includes a developing unit for forming a toner image on the recording medium and a transferring unit for attaching the toner to the recording medium to transfer the toner image onto the recording medium. A heater according to any one of claims 1 to 4, which heats and melts the toner adhered to the recording medium; a support member for supporting the heater; and the recording medium pressed against the heater. A toner fixing unit for fixing the toner to the recording medium, the recording medium supplying unit supplying the recording medium to the image forming unit, and the image From the forming section to the toner An image forming apparatus, comprising: a recording medium conveying unit that conveys the recording medium to a fixing unit. 6. The image forming apparatus according to claim 5, wherein:
The image forming apparatus, wherein the supporting member has a groove corresponding to the shape of the heater.