JP6737249B2 - Fixing device, image forming device, and heater device - Google Patents

Description

The present invention relates to a fixing device that fixes toner on a sheet, an image forming apparatus including the fixing device, and a heater device.

The electrophotographic image forming apparatus includes a fixing device. The fixing device includes a heating rotator and a pressure rotator for fixing the unfixed toner image on the sheet. The heating rotator and the pressure rotator are in pressure contact with each other to form a nip.

The sheet carrying the unfixed toner passes through the nip. Heat and pressure are applied to the sheet passing through the nip by the heating rotator and the pressure rotator. As a result, the unfixed toner is fixed on the sheet.

The fixing device further includes a heater device serving as a heat source of the heating rotator. For example, the heater device may include a resistor formed on a base material (see, for example, Patent Document 1).

JP, 2009-244595, A

A plurality of electrodes and a plurality of linear conductors that electrically connect the plurality of electrodes and the resistor are formed on the base material for supplying power to the planar heating portion. .. It is desired that the space occupied by the plurality of electrodes and the linear conductor on the base material is small.

An object of the present invention is to provide a fixing device, an image forming device, and a heater device that can reduce the space occupied by a plurality of electrodes and a plurality of linear conductors on a base material.

A fixing device according to one aspect of the present invention includes a heating unit and a heater device. The heating unit heats the unfixed toner image on the sheet. The heater device can heat the heating unit. The heater device includes a base material, a common electrode, a first independent electrode and a second independent electrode, a common conductor, a first independent conductor, a second independent conductor, a first resistor, and a second resistor. ,including. The base material has a first direction along the width direction of the sheet as a longitudinal direction. The common electrode, the first independent electrode, and the second independent electrode are formed on the main surface of the base material. The common conductor has a first common conductor portion formed on the main surface, and a first direction at a position on one side of a second direction orthogonal to the first direction with reference to the first common conductor portion. Two second common conductor portions that are formed at a distance from each other, and two third common conductor portions that are electrically connected to the first common conductor portion and the two second common conductor portions. And is electrically connected to the common electrode. The first independent conductor is formed along the first direction at a position on one side in the second direction with respect to the two second common conductor portions, and is electrically connected to the first independent electrode. Has been done. The second independent conductor is formed along the first direction at a position on the other side in the second direction with respect to the first common conductor portion, and is electrically connected to the second independent electrode. There is. The first resistor is formed between the first common conductor portion and the first independent conductor, and at least one of the first common conductor portion and the two third common conductor portions, and It is electrically connected to the first independent conductor. One of the two second resistor bodies is formed between one of the two second common conductor portions and the second independent conductor, and one of the two second common conductor portions or the two of the two second common conductor portions. One of the third common conductor portions is electrically connected to the second independent conductor, and the other of the two second resistors is the other of the two second common conductor portions and the second independent conductor. It is formed between them and is electrically connected to the other of the two second common conductor portions or the other of the two third common conductor portions.

An image forming apparatus according to another aspect of the present invention includes the fixing device.

A heater device according to yet another aspect of the present invention heats an object. The heater device includes a base material, a common electrode, a first independent electrode and a second independent electrode, a common conductor, a first independent conductor, a second independent conductor, a first resistor, and a second resistor. ,including. The base material has the first direction as the longitudinal direction. The common electrode, the first independent electrode, and the second independent electrode are formed on the main surface of the base material. The common conductor has a first common conductor portion formed on the main surface, and a first direction at a position on one side of a second direction orthogonal to the first direction with reference to the first common conductor portion. Two second common conductor portions that are formed at a distance from each other, and two third common conductor portions that are electrically connected to the first common conductor portion and the two second common conductor portions. And is electrically connected to the common electrode. The first independent conductor is formed along the first direction at a position on one side in the second direction with respect to the two second common conductor portions, and is electrically connected to the first independent electrode. Has been done. The second independent conductor is formed along the first direction at a position on the other side in the second direction with respect to the first common conductor portion, and is electrically connected to the second independent electrode. There is. The first resistor is formed between the first common conductor portion and the first independent conductor, and at least one of the first common conductor portion and the two third common conductor portions, and It is electrically connected to the first independent conductor. One of the two second resistor bodies is formed between one of the two second common conductor portions and the second independent conductor, and one of the two second common conductor portions or the two of the two second common conductor portions. One of the third common conductor portions is electrically connected to the second independent conductor, and the other of the two second resistors is the other of the two second common conductor portions and the second independent conductor. It is formed between them and is electrically connected to the other of the two second common conductor portions or the other of the two third common conductor portions.

According to the present invention, it is possible to provide a fixing device, an image forming device, and a heater device that can reduce the space occupied by a plurality of electrodes and a plurality of linear conductors on a substrate.

FIG. 1 is a diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a configuration of the fixing device shown in FIG. FIG. 3 is a diagram showing a configuration of the heater device shown in FIG. FIG. 4 is a diagram showing a first configuration example of the heater device shown in FIG. FIG. 5 is a diagram showing a second configuration example of the heater device shown in FIG. FIG. 6 is a diagram showing a third configuration example of the heater device shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. The following embodiments are examples of embodying the present invention, and do not limit the technical scope of the present invention.

[Embodiment]
In FIG. 1, the image forming apparatus 1 is, for example, a copying machine, a printer or a facsimile, or a multifunction machine having a copy function, a print function, and a fax function.

The image forming apparatus 1 prints an image based on the image data on, for example, a rectangular sheet according to the print setting information. The image forming apparatus 1 discharges the sheet on which the image is printed as a printed matter to the outside.

The image data indicates the image to be printed. The image includes a plurality of pixels. Each of the plurality of pixels has color information.

Hereinafter, description will be continued regarding the case where the image is a full-color image.

The print setting information indicates a sheet size and a sheet orientation for the sheet to be used in the printing.

The sheet size includes, for example, the lengths of the long side and the short side of the sheet.

In the image forming apparatus 1, the sheet conveyance path A is formed. The conveyance path A can convey a plurality of types of unprinted sheets having different sheet widths.

Hereinafter, the sheet conveying direction in the sheet feeding unit 3 described below is referred to as a conveying direction B. A direction orthogonal to the transport direction B is referred to as a sheet width direction C.

The sheet orientation indicates whether the sheet is fed in the conveyance direction B in a portrait orientation or in a landscape orientation. In the case of the portrait orientation, the long side is parallel to the transport direction B, and in the case of the landscape orientation, the short side is parallel to the transport direction B.

The sheet size and the sheet orientation may be automatically determined by the control unit 2 described later.

The image forming apparatus 1 includes a control unit 2, a paper feeding unit 3, an image forming unit 4, and a fixing device 5 for generating the printed matter.

The control unit 2 is a device that executes various data processes and further controls various devices included in the image forming apparatus 1. The control unit 2 includes, for example, a processor, a non-volatile memory, and a main memory including a RAM (Random Access Memory). The control unit 2 may be composed of one or a plurality of electronic circuits.

In the control unit 2, the processor executes a program stored in advance in the nonvolatile memory while using the main memory as a work area.

The control unit 2 acquires the image data and the print setting information from an external device communicably connected to the image forming apparatus 1 during execution of the program. A personal computer is exemplified as the external device.

The control unit 2 can also obtain the image data from a scanner or a fax receiver (not shown) provided in the image forming apparatus 1.

The control unit 2 further performs color separation processing on the received image data to generate image data of YMCK colors. Here, Y is yellow, M is magenta, C is cyan, and K is black.

The control unit 2 controls the driving of a plurality of devices included in the image forming apparatus 1 based on the print setting information, and also transmits the image data of each color of YMCK to the image forming unit 4.

The sheet feeding unit 3 is a device including a plurality of sheet feeding trays 31 on which a plurality of sheets can be placed. Hereinafter, the sheet placed on the sheet feeding unit 3 is referred to as an unprinted sheet.

Specifically, the unprinted sheets are placed on the plurality of paper feed trays 31 in the portrait orientation or the landscape orientation.

The plurality of types of unprinted sheets, that is, the plurality of unprinted sheets having different sheet widths are placed on the plurality of paper feed trays 31. The plurality of unprinted sheets having the same size are usually placed on each of the plurality of paper feed trays 31.

Note that a plurality of unprinted sheets having the same size but different orientations in the plurality of paper feed trays 31 are also included in the concept of the plurality of types of unprinted sheets.

The paper feed unit 3 may include one paper feed tray on which the plurality of types of unprinted sheets can be placed.

1 and 2, the control unit 2 selects one paper feed tray 31 of the paper feed unit 3 based on the print setting information. As a result, the unprinted sheet having the sheet size and the sheet orientation specified by the print setting information is selected from the plurality of types of sheets.

The control unit 2 further controls driving of a paper feed roller or the like (not shown) corresponding to the selected paper feed tray 31. As a result, the unprinted sheets are sequentially fed to the transport path A one by one from the selected paper feed tray 31.

In FIG. 1, an image forming unit 4 is a device that forms an image on a sheet by a well-known electrophotographic method. The image forming unit 4 includes a photoconductor drum, a charger, an exposure device, a developing device, a primary transfer device, an intermediate transfer belt, and a secondary transfer roller.

Here, when the image forming apparatus 1 is capable of full-color printing by a so-called tandem system, the image forming unit 4 uses a combination of the photosensitive drum, the charger, the exposure device, the developing device, and the primary transfer device for each YMCK color. Prepare

Based on the received image data, the control unit 2 generates raster image data of YMCK by well-known color separation processing and outputs the raster image data to the image forming unit 4.

Under the control of the control unit 2, the image forming unit 4 forms each toner image of YMCK on the peripheral surface of the corresponding photosensitive drum on the basis of the raster image data for each color. The image forming unit 4 further transfers the toner image on each of the photosensitive drums onto the outer peripheral surface of the intermediate transfer belt. Here, the respective toner images are combined in the same area on the outer peripheral surface, whereby a combined toner image is formed.

In the image forming unit 4, the intermediate transfer belt is rotated by the driving of a driving roller and a driven roller (not shown) to carry the synthetic toner image and convey it toward a secondary transfer area D described later.

The secondary transfer roller is pressed against the intermediate transfer belt from a position facing the driven roller with the intermediate transfer belt interposed therebetween. As a result, the secondary transfer area D is formed on the transport path A.

Under the control of the controller 2, the synthetic toner image and the unprinted sheet are fed from the upstream side of the transport path A into the secondary transfer area D.

Under the control of the controller 2, the secondary transfer roller and the intermediate transfer belt rotate, and the secondary transfer roller is given an electric charge having a polarity opposite to that of the composite toner image. As a result, the toner image on the intermediate transfer belt is transferred to the unprinted sheet passing through the secondary transfer area D.

From the secondary transfer area D, the transferred sheet is sent to the downstream side of the transport path A.

Hereinafter, the sheet to which the synthetic toner image has been transferred is referred to as a transferred sheet. The toner image carried on the transferred sheet is referred to as an unfixed toner image.

The fixing device 5 fixes the unfixed toner image on the transferred sheet by a well-known heat belt method or heat roller method.

Hereinafter, the fixing device 5 of the thermal belt type will be described with reference to FIG.

In FIG. 2, the fixing device 5 includes a heating unit 51, a pressure unit 52, and a heater device 53.

The heating unit 51 heats the unfixed toner image on the transferred sheet. The heating unit 51 includes a heating roller 511, a fixing roller 512, and a fixing belt 513.

The heating roller 511 contains a halogen heater 514 inside a cylindrical cored bar.

The fixing roller 512 is provided at a position apart from the heating roller 511.

The fixing belt 513 is an example of an object to be heated by the heater device 53, and is stretched around the heating roller 511 and the fixing roller 512.

Each of the rollers 511 and 512 and the fixing belt 513 extends in the sheet width direction C of the transferred sheet fed to the heating unit 51.

In the case of the heat roller method, the heating unit 51 includes a heating roller. In this case, the heating roller is an object to be heated by the heater device 53.

The pressure unit 52 is, for example, a rotating pressure roller. The pressure unit 52 is pressed against the fixing belt 513. As a result, a nip E is formed between the pressure unit 52 and the fixing belt 513. The nip E is provided on the transport path A.

The transferred sheet is fed into the nip E from the upstream side of the transport path A. The sheet width of the transferred sheet is indicated by the print setting information and can change for each printing. Therefore, the width of the heating roller 511, the fixing roller 512, and the fixing belt 513 in the sheet width direction C is the maximum sheet width plus a predetermined margin.

By the way, in recent image forming apparatuses, the rotation speed of the fixing belt has been increased due to the increased printing speed and the like. As a result, the fixing belt cannot receive a sufficient amount of heat from the halogen heater through the heating roller during one rotation.

In order to solve the above problems, a fixing device including a heater device serving as a heat source of a fixing belt in addition to a heating roller has been conventionally proposed.

Further, another conventional fixing device includes a heater device that directly heats the fixing belt, instead of the halogen heater in the heating roller.

In this embodiment, the fixing device 5 includes a heater device 53 capable of heating the fixing belt 513 in addition to the halogen heater 514, as shown in FIG.

The fixing device 5 may include a heater device 53 instead of the heating unit 51 itself or the halogen heater 514 built in the heating unit 51.

Further, the heater device 53 can be applied to various applications such as a heating/discharge type print head or an antifogging heater, in addition to the heating application of the fixing belt 513.

The heater device 53 is capable of heating the heating portion 51, and extends along the surface of the heating portion 51 in the width direction of the transferred sheet.

The heater device 53 is in contact with the fixing belt 513 in the heating unit 51 or a member such as the fixing roller 512 that comes into contact with the fixing belt 513.

As shown in FIG. 3, the heater device 53 includes a base material 531, a common electrode 532, a first independent electrode 533 and a second independent electrode 534, a common conductor 535, a first independent conductor 536, and a second independent electrode. It includes a conductor 537, a first resistor 538, and two second resistors 539.

In addition, the heater device 53 additionally includes a third independent electrode 5310, two third independent conductors 5311, and a third resistor 5312.

The base material 531 is, for example, a flexible substrate or a rigid substrate made of an electrically insulating material such as resin. The base material 531 is supported by a bracket or the like (not shown).

Here, in the base material 531, the first direction X along the sheet width direction C of the transferred sheet is the longitudinal direction.

Further, hereinafter, a direction orthogonal to the first direction X will be referred to as a second direction Y.

Further, in the present embodiment, one of the first directions X may be the +X direction and the other of the first directions X may be the -X direction. Further, one of the second directions Y may be referred to as +Y direction and the other of the second directions Y may be referred to as −Y direction.

The base material 531 includes a rectangular main surface F1 extending in the X direction. The length of the main surface F1 in the first direction X may be substantially the same as the width of the fixing belt 513, for example.

Further, hereinafter, an imaginary line passing through a predetermined position in the first direction X on the main surface F1 and parallel to the second direction Y is referred to as a reference line G. The reference line G is shown by a dashed line in FIG.

A common electrode 532, a plurality of independent electrodes 533, 534, 5310, a common conductor 535, a plurality of independent conductors 536, 537, 5311, and a plurality of resistors 538, 539, 5312 are provided on the main surface F1. Has been formed.

By the way, it is desired that the space occupied by the components of the heater device 53 on the main surface F1 is small. Therefore, the heater device 53 is configured as follows.

Each of the electrodes 532 to 534 and 5310 is a power feeding electrode, and is formed at the end portion of the heater device 53 on the −X direction side on the main surface F1.

The electrodes 532 to 534 and 5310 may be formed on the heater device 53 other than the end portion on the −X direction side.

The electrodes 532 to 534 and 5310 have the same shape, for example. Examples of the shape include a rectangular shape and a circular shape.

In addition, each of the electrodes 532 to 534 and 5310 is arranged with a space in the first direction X from the adjacent electrode. The electrodes 532 to 534 and 5310 are arranged in the order of, for example, the first independent electrode 533, the third independent electrode 5310, the common electrode 532, and the second independent electrode 534 in the −X direction.

Each of the electrodes 532 to 534 and 5310 is electrically connected to a power supply circuit (not shown) provided outside the heater device 53, and receives either DC power or AC power from the power supply circuit.

Further, for example, the common electrode 532 may be connected to the reference potential point of the power supply circuit. The reference potential point is, for example, the ground potential point. In this case, the first independent electrode 533 is connected to the first power supply potential point that makes a predetermined potential difference with respect to the reference potential point.

The second independent electrode 534 and the third independent electrode 5310 are connected to a second power source potential point and a third power source potential point that form a predetermined potential difference with respect to the reference potential point.

The first power source potential point, the second power source potential point, and the third power source potential point may have the same potential or different potentials.

The common conductor 535 is a meander conductor pattern made of a low resistance conductive material. The common conductor 535 is formed by printing or sputtering, for example. Examples of the low-resistance conductive material include metal materials suitable for feeding power to the resistors 538, 539, 5312, such as copper or aluminum.

The common conductor 535 is collectively formed on the main surface F1 by the printing or the like together with the electrodes 532 to 534, 5310 and the independent conductors 536, 537, 5311, etc., for example.

The common conductor 535 is electrically connected to the common electrode 532 on the main surface F1 via the conductor pattern H6 at the end on the −Y direction side.

Specifically, the common conductor 535 includes a first common conductor portion H1, two second common conductor portions H2, and two third common conductor portions H3. Further, the common conductor 535 additionally includes two fourth wiring portions H4 and two fifth wiring portions H5.

In the example shown in FIG. 3, each of the conductor portions H1 to H5 is formed on the main surface F1 and has a linear shape in a plan view from the direction orthogonal to the main surface F1. The planar shape of each of the conductor portions H1 to H5 may be a curved shape such as an arc shape.

The first common conductor portion H1, each second common conductor portion H2, and each fourth common conductor portion H4 are formed along the first direction X. On the other hand, each third common conductor portion H3 and each fifth common conductor portion H5 are formed along the second direction Y.

The first common conductor portion H1 and each fourth common conductor portion H4 are end portions of the common conductor 535 on the −Y direction side. On the other hand, each second common conductor portion H2 is an end portion of the common conductor 535 on the Y direction side.

The first common conductor portion H1 is located in the central portion of the common conductor 535 in the first direction X and has a shape symmetrical with respect to the reference line G. Note that the position of the first common conductor portion H1 in the second direction Y may be appropriately determined.

Further, the first common conductor portion H1 has an end portion J11 on the +X direction side and an end portion J12 on the −X direction side.

The two second common conductor portions H2 are formed at positions symmetrical to each other with respect to the reference line G. Similarly, each of the third common conductor portions H3, each of the fourth common conductor portions H4, and each of the fifth common conductor portions H5 are formed at positions symmetrical to each other with respect to the reference line G. Below, with respect to each of the two second common conductor portions H2, the two third common conductor portions H3, the two fourth common conductor portions H4, and the two fifth wiring portions H5, the +X direction side with respect to the reference line G Only those that are in are explained.

The second common conductor portion H2 is spaced from the first common conductor portion H1 in the first direction X at a position on the +Y direction side, that is, a position on one side of the second direction Y orthogonal to the first direction X. It is formed by opening.

The second common conductor portion H2 is adjacent to the first common conductor portion H1 on the +X direction side in a plan view from the second direction Y. The second common conductor portion H2 has an end portion J21 on the +X direction side and an end portion J22 on the −X direction side.

The third common conductor portion H3 is electrically connected to the first common conductor portion H1 and the second common conductor portion H2. More specifically, the third common conductor portion H3 is electrically connected to the end portion J11 and the end portion J22.

The fourth common conductor portion H4 is adjacent to the second common conductor portion H2 on the +X direction side in a plan view from the second direction Y. The fourth wiring portion H4 has an end portion J41 on the +X direction side and an end portion J42 on the −X direction side.

The fifth wiring portion H5 is electrically connected to the end portions J21 and J42.

Next, an example of the lengths L1, L2, L3 in the first direction X of the first common conductor portion H1, each second common conductor portion H2, and the fourth wiring portion H4 will be described.

The length L1 corresponds to the minimum sheet width of the plurality of types of unprinted sheets that can be heated in the heating unit 51.

The length L3 has a value based on the maximum sheet width among the plurality of types of unprinted sheets.

The length L2 has a value based on the intermediate sheet width in the plurality of types of unprinted sheets.

Specifically, it is assumed that the unprinted sheet having the sheet width of L4 to L6 is placed on the sheet feeding unit 3. Here, the lengths L4, L5, and L6 are the minimum value, the intermediate value, and the maximum value of the lengths L4 to L6. The length L1 corresponds to the length L4. The length (L1+2×L2) corresponds to the length L5. The length (L1+2×L2+2×L3) corresponds to L6.

Each of the first independent conductor 536, the second independent conductor 537, and the third independent conductor 5311 includes a plurality of linear conductor patterns.

The first independent conductor 536 is formed along the first direction X at a position on the +Y direction side with respect to the two second common conductor portions H2. The first independent conductor 536 is electrically connected to the later-described first resistor 538 and the first independent electrode 533.

The second independent conductor 537 is formed along the first direction X at a position on the −Y direction side with respect to the first common conductor portion H1. The second independent conductor 537 is electrically connected to both of two second resistors 539 described below and the second independent electrode 534.

One and the other of the two third independent conductors 5311 are formed along the first direction X at positions on the +Y direction side and the −Y direction side of the first independent conductor 536, respectively.

One side and the other side of the third independent conductor 5311 are electrically connected to the third resistor 5312 on the +X direction side and the −X direction side, respectively. Further, one side and the other side of the third independent conductor 5311 are electrically connected to the third independent electrode 5310 from the +Y direction side and the −Y direction side, respectively.

Each resistor 538, 539, 5312 contains a high resistance material.

An example of the high resistance material is a ceramic material having PTC (Positive Temperature Coefficient) characteristics. Besides, examples of the high resistance material include a polymer material containing carbon having the PTC characteristics, or a high resistance metal material such as nickel chromium.

The first resistor 538 has a shape symmetrical with respect to the reference line G, and is formed between the first common conductor portion H1 and the first independent conductor 536.

The first resistor 538 is electrically connected between at least one common conductor portion of the first common conductor portion H1 and the two third common conductor portions H3 and a first independent conductor 536 described later. ing. Note that FIG. 3 shows an example in which the first resistor 538 is connected only to the first common conductor portion H1.

When a voltage is applied between the common electrode 532 and the first independent electrode 533, a current flows through the first resistor 538. As a result, the first resistor 538 generates heat.

The first resistor 538 is formed in the area surrounded by the first common conductor portion H1 and the two third common conductor portions H3. As a result, the space occupied by the common conductor 535 and the independent conductors 536, 537, 5311 on the main surface F1 is reduced.

The two second resistors 539 have the same planar shape as each other, and are formed at symmetrical positions with respect to the reference line G. Of the two second resistors 539, only the one formed on the +X direction side will be described below. Further, the second resistor 539 on the +X direction side is hereinafter referred to as one of the second resistors 539.

One of the second resistors 539 is formed between one of the two common conductor portions H2 and the second independent conductor 537.

One of the second resistors 539 is electrically connected to one of the two second common conductor portions H2 or one of the two third common conductor portions H3 and the second independent conductor 537. Note that FIG. 3 shows an example in which the second resistor 539 is connected to the second common conductor portion H2.

When a voltage is applied between the common electrode 532 and the second independent electrode 534, the two second resistors 539 generate heat.

When the common conductor 535 includes the fifth common conductor portion H5, one of the two second resistors 539 is electrically connected to one of the fifth common conductor portion H5 and the second independent conductor 537. Good.

Also, one of the two resistors 539 is formed in the area of the −Y direction side of the second common conductor portion H2 and the +X direction side of the third common conductor portion H3. As a result, the space occupied by the common conductor 535 and the like can be reduced.

When the common conductor 535 includes the fifth common conductor portion H5, one of the two resistors 539 is one of the third common conductor portion H3, one of the second common conductor portion H2, and one of the fifth wiring portion H5. Will be surrounded by.

The two third resistors 5312 also have the same shape and are formed at positions symmetrical to each other with respect to the reference line G. Therefore, only the third resistor 5312 on the +X direction side will be described below. Further, the third resistor 5312 on the +X direction side is hereinafter referred to as one of the third resistors 5312.

One of the third resistors 5312 is formed between one of the two common conductor portions H4 and the third independent conductor 5311. Note that the example of FIG. 3 shows an example in which the third resistor 5312 is connected to the fourth wiring portion H4.

Further, one of the two third resistor bodies 5312 is electrically connected to one of the two fourth common conductor portions H4 or one of the two fifth common conductor portions H5 and the third independent conductor 5311. .. Note that FIG. 3 shows an example in which the third resistor 5312 is connected to the fourth common conductor portion H4.

When a voltage is applied between the common electrode 532 and the third independent electrode 5310, a current flows through the two third resistors 5312, and as a result, the two third resistors 5312 generate heat.

The two third resistors 5312 are formed in the area of the +Y direction side of the fourth common conductor portion H4 and the +X direction side of the fifth common conductor portion H5.

In the heater device 53, the first resistor 538 is arranged in the −Y direction with the first common conductor portion H1 of the common conductor 535 having the meander shape as a reference, and the two second resistors 539 are the common conductor. It is formed in the +Y direction with reference to the two second common conductor portions H2 of 535. As a result, the three resistors 538, 539 can be connected to the two independent electrodes 533, 534 via the two independent conductors 536, 537. Therefore, the number of independent conductors in the heater device 53 is smaller than in the case where a total of three resistors are connected to two independent electrodes by using three independent conductors. Thereby, the space occupied by the common conductor 535 and the like on the main surface F1 can be reduced.

Further, the first independent conductor 536 and the second independent conductor 537 are connected to the first independent electrode 533 and the second independent electrode 534 from the +Y direction side and the −Y direction side of the common conductor 535 on the main surface F1. Thereby, both independent conductors 536 and 537 can be arranged on the main surface F1 without intersecting each other on the main surface F1. As a result, the base material 531 can be a single-sided base material, and the heater device 53 can be manufactured at low cost.

Further, one and the other of the two third independent conductors 5311 are electrically connected to the third resistor 5312 on the +X direction side and the −X direction side, respectively. Further, one side and the other side of the third independent conductor 5311 are formed along the first direction X at positions apart from the first independent conductor 536 in the +Y direction and the −Y direction. One and the other of the two third independent conductors 5311 are electrically connected to the third independent electrode 5310 from the +Y direction side and the −Y direction side, respectively, without intersecting the other wiring and each electrode on the main surface F1. ing.

Here, the first independent electrode 533, the third independent electrode 5310, the common electrode 532, and the second independent electrode 534 are formed in this order in the order of the electrodes 532 to 534 and 5310 along the first direction X. From this arrangement, the two third independent conductors 5311 can be electrically connected to the third independent electrode 5310 without intersecting with other wiring and each electrode on the main surface F1. Therefore, even when the heater device 53 additionally includes the two third resistors 5312, the base material 531 can be a single-sided base material.

The control unit 2 causes the halogen heater 514 to generate heat by supplying a control signal to the power supply circuit before the conveyance of the unprinted sheet is started.

Further, the control unit 2 selects one to be used for the printing from the independent electrodes 536, 537, 5311 based on the print setting information. The control unit 2 may select all the independent electrodes 536, 537, 5311 regardless of the print setting information. That is, an independent electrode capable of uniformly heating the unused sheet fed to the fixing nip E may be selected.

The control unit 2 further applies a control signal to the power supply circuit to apply a voltage between the selected independent electrode and the common electrode 532. This causes the resistor between the selected independent electrode and the common electrode 532 to generate heat.

The control unit 2 further starts the rotational driving of the fixing belt 513. As a result, the heat from the halogen heater 514 is transmitted to the fixing belt 513. Further, heat from the heater device 53 is transmitted to the fixing belt 513 via the fixing roller 512. As a result, the fixing belt 513 is heated.

The temperature of the outer peripheral surface of the fixing belt 513 is detected as a fixing temperature by a temperature sensor (not shown). The control unit 2 performs feedback control based on the detection result of the temperature sensor so that the fixing temperature becomes the target value.

When the fixing temperature reaches the target value, the control unit 2 starts the conveyance of the unprinted sheet.

When the conveyance of the unprinted sheet is started, the transferred sheet passes through the nip E. While passing through the nip E, the pressure from the pressure unit 52 and the heat from the fixing belt 513 are applied to the transferred sheet. As a result, the unfixed toner image is fixed on the transferred sheet.

From the nip E, the sheet on which the toner image is fixed is sent out as a printed matter. The printed matter is discharged to a discharge tray.

[Example of configuration of each heating unit]
Next, a specific configuration example of the heater device 53 will be described with reference to FIGS. 4 to 6, illustration of the resistors 539 and 5312 on the −X direction side with respect to the reference line G is omitted.

In FIG. 4, resistors 538, 539, 5312 are resistance films containing the ceramic material or the polymer material. This also applies to the heater device 53 shown in FIG. The resistors 538, 539, 5312 are made of one sheet-shaped member.

The first resistor 538 is in contact with at least the third common conductor portion H3.

Further, the first independent conductor 536 includes at least one first electrode portion K1 formed on the first resistor 538 along the second direction Y.

The first electrode portion K1 faces the third common conductor portion H3 in the first direction X. The first electrode portion K1 is not in direct contact with the first common conductor portion H1.

In the example shown in FIG. 4, the first independent conductor 536 is branched into a plurality on the main surface F1. In this case, the first independent conductor 536 includes a plurality of first electrode portions K1 formed at the branch destinations.

The plurality of first electrode portions K1 are formed on the first resistor 538 along the second direction Y. Further, the plurality of first branch portions K1 face the third common conductor portion H3 or the second branch portion K2 described later in the first direction X.

When the first independent conductor 536 has a plurality of first electrode portions K1, the common conductor 535 has one or a plurality of second electrode portions K2 branched from the first common conductor portion H1 toward the +Y direction. doing.

Each second electrode portion K2 is formed on the first resistor 538 along the second direction Y. Note that each of the second electrode portions K2 is not in direct contact with the first independent conductor 536.

When the electrode portions K1 and K2 are directly formed on the main surface F1, the electrode portions K1 and K2 are covered with the first resistor 538.

On the other hand, when the first resistor 538 is directly formed on the main surface F1, the electrode portions K1 and K2 are formed on the first resistor 538. In other words, the electrode portions K1 and K2 are formed on the main surface F1 via the first resistor 538.

Here, the term “formed on the principal surface F1” includes the meaning of “formed on the principal surface F1” and the meaning of “formed on the principal surface F1 via something”.

The second resistor 539 is in contact with at least the third common conductor portion H3.

Further, the second independent conductor 539 includes at least one third electrode portion K3 formed on the second resistor 539 along the second direction Y.

The third electrode portion K3 faces the third common conductor portion H3 in the first direction X and is not in contact with the second common conductor portion H2.

The second independent conductor 539 has a plurality of third electrode portions K3 when it is branched into a plurality on the main surface F1.

The plurality of third branch portions K3 are formed on the second resistor 539 along the second direction Y. In addition, the plurality of third branch portions K3 face the third common conductor portion H3, the fifth common conductor portion H5, or a fourth electrode portion K4 described later in the first direction X.

The common conductor 535 has one or a plurality of fourth electrode portions K4 branched from the second common conductor portion H2 in the −Y direction.

Each fourth electrode portion K4 is formed on the second resistor 539 along the second direction Y. The tip of each fourth electrode portion K4 is physically separated from the second independent conductor 537.

The third resistor 5312 is in contact with the fifth common conductor portion H5.

In addition, the third independent conductor 5311 includes one or a plurality of fifth electrode portions K5 formed on the third resistor 5312 along the second direction Y.

Each of the fifth electrode portions K5 faces the third common conductor portion H3 or a sixth electrode portion K6 described later in the first direction X and is not in contact with the fourth common conductor portion H4.

Further, the common conductor 535 has one or a plurality of sixth electrode portions K6 branched from the fourth common conductor portion H4 in the +Y direction.

Each sixth electrode portion K6 is formed on the third resistor 5312 along the second direction Y. The tip of each sixth electrode portion K6 is physically separated from the third independent conductor 5311.

Further, in FIG. 5, the first resistor 538 is in contact with the first common conductor portion H1, but is not in contact with each third common conductor portion H3.

The first independent conductor 536 includes a first electrode portion P1 that is in contact with the first resistor 538. Further, the first electrode portion P1 faces the first common conductor portion H1 in the second direction Y. The first electrode portion P1 extends in the first direction X between the two third common conductor portions H3. However, the first electrode portion P1 is not in contact with each third common conductor portion H3.

The second resistor 539 is in contact with the second common conductor portion H2, but is not in contact with the third common conductor portion H3 and the fifth common conductor portion H5.

The second independent conductor 537 includes a second electrode portion P2 that is in contact with the second resistor 539.

The second electrode portion P2 faces the second common conductor portion H2 in the second direction Y. The second electrode portion P2 extends in the first direction X between the first common conductor portion H1 and the fourth common conductor portion H4. However, the second electrode portion P2 is not in contact with the common conductor portions H1 and H4.

The third resistor 5312 is in contact with the fourth common conductor portion H4, but is not in contact with the fifth common conductor portion H5.

The third independent conductor 5311 includes a third electrode portion P3 formed on the third resistor 5312.

The third electrode portion P3 is formed on the +X direction side of the second common conductor portion H2 and faces the fourth wiring portion H4 in the second direction Y. However, the third electrode portion P3 is not in contact with the fifth wiring portion H5.

Each of the resistors 538, 539, 5312 may be a meander pattern formed of the high resistance metal material on the main surface F1 as shown in FIG.

1 Image Forming Device 5 Fixing Device 51 Heating Unit 53 Heating Device 531 Base Material 532 Common Electrode 533 First Independent Electrode 534 Second Independent Electrode 535 Common Conductor H1 First Common Conductor H2 Second Common Conductor H3 Third Common Conductor 536 First independent conductor 537 Second independent conductor 538 First resistor 539 Second resistor

Claims (7)

A heating unit that heats the unfixed toner image on the sheet,
A fixing device comprising: a heater device capable of heating the heating unit,
The heater device is
A base material whose longitudinal direction is the first direction along the width direction of the sheet,
A common electrode, a first independent electrode and a second independent electrode formed on the main surface of the base material;
The first common conductor portion formed on the main surface, the first common conductor portion as a reference, at a position on one side in a second direction orthogonal to the first direction, with an interval in the first direction. The common electrode includes two second common conductor portions that are formed and two third common conductor portions that are electrically connected to the first common conductor portion and the two second common conductor portions. A common conductor electrically connected to
A first independent conductor which is formed along the first direction at a position on one side of the second direction with reference to the two second common conductor portions and which is electrically connected to the first independent electrode. When,
A second independent conductor which is formed along the first direction at a position on the other side in the second direction with respect to the first common conductor portion and which is electrically connected to the second independent electrode;
It is formed between the first common conductor portion and the first independent conductor, and electrically connected to at least one of the first common conductor portion and the two third common conductor portions and the first independent conductor. A first resistor that is electrically connected,
One is formed between one of the two second common conductor portions and the second independent conductor, and one of the two second common conductor portions or one of the two third common conductor portions. , The second independent conductor is electrically connected to the second independent conductor, the other is formed between the other of the two second common conductors and the second independent conductor, and the other of the two second common conductors is formed. Two second resistors that are electrically connected to the other or the other of the two third common conductor portions;
Fixing device including. The first common conductor portion has a shape symmetrical with respect to a reference line along the second direction at a predetermined position in the first direction on the main surface,
The two second common conductor portions are formed at positions symmetrical to each other with respect to the reference line,
The fixing device according to claim 1. The total length of the first common conductor portion in the first direction and the total length of the first common conductor portion and the two second common conductor portions in the first direction may be a target of heating. Corresponding to the widthwise length of the seed sheet,
The fixing device according to claim 1. The first resistor is a resistive film that contacts the third common conductor portion,
The first independent conductor is formed on the first resistor along the second direction, and faces the third common conductor portion in the first direction.
One and the other of the two second resistors are resistive films in contact with one and the other of the two third common conductor portions,
The second independent conductor is formed on the two second resistors along the second direction and faces one and the other of the two third common conductor portions in the first direction. ,
The fixing device according to claim 1. The first resistor is a resistive film in contact with the first common conductor portion,
The first independent conductor is in contact with the first resistor and faces the first common conductor portion on one side in the second direction,
One and the other of the two second resistors are resistive films in contact with one and the other of the second common conductor portion,
The second independent conductor is in contact with each of the two second resistors and faces one and the other of the two second common conductor portions on the other side in the second direction.
The fixing device according to claim 1. An image forming apparatus comprising the fixing device according to claim 1. A heater device for heating an object,
A base material whose longitudinal direction is the first direction,
A common electrode, a first independent electrode and a second independent electrode formed on the main surface of the base material;
The first common conductor portion formed on the main surface, and the first common conductor portion as a reference, at a position on one side in a second direction orthogonal to the first direction, a space is provided in the first direction. Two second common conductor portions that are formed to be open, and two third common conductor portions that are electrically connected to the first common conductor portion and the two second common conductor portions, and A common conductor electrically connected to the common electrode,
A first independent conductor which is formed along the first direction at a position on one side of the second direction with reference to the two second common conductor portions and which is electrically connected to the first independent electrode. When,
A second independent conductor which is formed along the first direction at a position on the other side in the second direction with respect to the first common conductor portion and which is electrically connected to the second independent electrode;
It is formed between the first common conductor portion and the first independent conductor, and electrically connected to at least one of the first common conductor portion and the two third common conductor portions and the first independent conductor. A first resistor that is electrically connected,
One is formed between one of the two second common conductor portions and the second independent conductor, and is formed between one of the two second common conductor portions or one of the two third common conductor portions. , The second independent conductor is electrically connected to the second independent conductor, the other is formed between the other of the two second common conductors and the second independent conductor, and the other of the two second common conductors is formed. Two second resistors that are electrically connected to the other or the other of the two third common conductor portions;
Heater device including.

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