JP2006258877A - Induction heating fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce or eliminate a probability of erroneous connection by simplifying a step of connecting an induction coil and a driving circuit. <P>SOLUTION: A plurality of terminals led from the induction coil are held by a holding member, and the induction coil is connected to the driving circuit by an operation of coupling the holding member and a board case in which a driving circuit board is stored. The holding member and the board case are provided with control means for preventing erroneous connection. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fixing device for fixing a toner image on a recording material by heat and pressure, and more particularly to an induction heating fixing device.

  In image formation by an electrophotographic process, a fixing technique for fixing a toner image by heat and pressure is generally used. From the viewpoint of energy saving, a quick start of a fixing device is demanded. There is induction heating fixing technology.

  Thus, in the induction heating fixing device, since a high frequency high current is supplied to the fixing device, the connection between the fixing device and a driving circuit board on which a driving circuit for driving the fixing device is mounted is generally used. There are problems with electrical connections.

  The connection method in the conventional induction heating fixing apparatus will be described with reference to FIGS.

  FIG. 1 is a schematic diagram of an induction heating fixing device. In the drawing, an induction heating fixing device 10 is provided with a heating roller 11, a pressure roller 12, a cleaning web 13, a temperature sensor 14, and a separation claw 15 for heating. By passing a recording material carrying an unfixed toner image through the nip portion N between the roller 11 and the pressure roller 12, the toner image is heated and fixed in the nip portion N. An induction coil unit 20 is installed in the heating roller 11, and an induction current is induced in the heating roller 11 by an induced current flowing in the induction coil unit 20, whereby the heating roller 11 generates heat and reaches a temperature necessary for fixing. To rise. The temperature of the heating roller 11 is controlled based on the temperature detected by the temperature sensor 15, and the heating roller 11 is maintained at an appropriate fixing temperature.

  FIG. 2 shows a circuit example of the induction coil in the heating roller 11. The induction coil includes an induction coil 21 that generates heat at the axial center of the heating roller 11 and an induction coil 22 that generates heat at both ends, and the terminals of these induction coils 21 and 22 come out at one end of the heating roller 11. Yes.

  FIG. 3 shows the structure of the induction coil unit 20, and the induction coils 21 and 22 are each wound around a bobbin 24 supported by a coil chassis 23 to form a coil that generates an induction magnetic field. A core 25 made of a magnetic material such as iron or ferrite is disposed inside the coils 21 and 22. A cylindrical induction coil unit 20 formed by the coil chassis 23 is inserted into the heating roller 11.

  As shown in FIGS. 4 to 6, the electric wires 21 </ b> A and 21 </ b> B, which are extensions of the induction coil 21 covered with the litz wire, and the electric coils 22 </ b> A and 22 </ b> B, which are extensions of the induction coil 22, store the drive circuit board 30. The substrate case 31 is passed through a hole 31 </ b> A provided in the substrate case 31 and connected to the drive substrate 30.

  The electric wires 21 </ b> A, 21 </ b> B, 22 </ b> A, and 22 </ b> B are each fixed to a terminal block 32 formed on the drive substrate 30 with screws 33.

  In this way, the terminals of the induction coils 21 and 22 are connected to the drive board 30 by the screws 33. In this method, as shown in FIG. 5, the electric wires 21A, 21B, 22A, and 22B are bent, and in FIG. , The length of the terminal line indicated by L becomes longer. For this reason, unnecessary radiation of the electromagnetic wave R is generated from the terminal line indicated by L, and it is necessary to prevent leakage of excessive electromagnetic waves as a countermeasure.

  In addition, the electric wires 21A, 21B, 22A, and 22B must be correctly connected. If the wires 21A, 21B, 22A, and 22B are connected incorrectly, currents that are incompatible with their characteristics are supplied to the coils 21 and 22, and the electric wires 21A, 21B, 22A, and 22B do not operate correctly or fail. Such a situation occurs.

  For this reason, although there exists a method of using the coating material of a different color for electric wire 21A, 21B, 22A, 22B etc., a misconnection cannot be eliminated completely still.

  As described above, the induction coil terminal connection in the induction heating fixing device has a problem that is not found in general electrical connection, but Patent Documents 1 and 2 disclose a method for connecting the induction coil terminal.

  That is, Patent Document 1 discloses that the electric wire of the induction coil and the drive board are connected by direct connection of male and female contacts. Japanese Patent Application Laid-Open No. H10-228561 discloses that when a misconnection is detected, the CPU detects it and does not supply power to the coil.

Patent Document 2 discloses that an electric wire of an induction coil and a terminal of a circuit board are detachably connected by male and female terminals.
JP 2003-347032 A JP 2004-220037 A

  In Patent Documents 1 and 2, the drive circuit board and the induction coil are electrically connected using plug-in male and female terminals, but the wires are connected in the assembly process in order to connect the individual wires individually. There is a problem that the number of processes increases and a long time is required for assembly, resulting in an increase in manufacturing cost. Moreover, since a plurality of electric wires are individually connected, there is a problem that the probability of erroneous connection is high. Patent Document 1 discloses detecting an erroneous connection, but this is a countermeasure when an erroneous connection occurs, and this cannot reduce or eliminate the occurrence probability of an erroneous connection.

  An object of the present invention is to solve the above-described problems in the prior art in the manufacture of induction heating and fixing devices, enable assembly in a short time, and reduce or eliminate the probability of erroneous connection.

The object is achieved by the following invention.
(Claim 1)
A fixing device in which a heating member and a pressure member are pressed to form a nip, and a recording material is sandwiched and conveyed by the heating member and the pressure member to perform fixing. The heating member is heated by induction heating. In the induction heating fixing device to be heated,
A holding member for holding a plurality of electric wires drawn from the induction coil in a state where the terminals of the electric wires protrude from the holding surface, and
A drive circuit board having a drive circuit for driving the induction coil and a plurality of connectors corresponding to the terminals;
An induction heating fixing device, wherein the induction coil is electrically connected to the drive circuit by causing the drive circuit board to approach the holding member to bring the terminal and the connector into male-male contact.
(Claim 2)
The induction heating fixing device according to claim 1, wherein the drive circuit board is housed in a board case.
(Claim 3)
The induction heating fixing device according to claim 1, wherein the induction coil is attached to a coil chassis to form an induction coil unit, and the holding member is fixed to the induction coil unit. .
(Claim 4)
The induction heating fixing device according to claim 1, wherein a plurality of the induction coils are provided, and the number of the terminals is twice that of the induction coils.
(Claim 5)
A fixing device in which a heating member and a pressure member are pressed to form a nip, and a recording material is sandwiched and conveyed by the heating member and the pressure member to perform fixing. The heating member is heated by induction heating. In the induction heating fixing device to be heated,
A holding member for holding a plurality of electric wires drawn from the induction coil;
A driving circuit for driving the induction coil, a driving circuit board having a plurality of connectors corresponding to the electric wires, and
A support member for supporting the drive circuit board;
An induction heating fixing device, wherein the holding member and the support member are provided with restricting means for restricting a coupling direction between them.
(Claim 6)
The holding member holds the electric wire in a state where the terminal of the electric wire protrudes from a holding surface, and makes the drive circuit board approach the holding member, whereby the terminal of the electric wire and the connector are brought into male-female contact. The induction heating fixing device according to claim 5, wherein the induction coil is electrically connected to the drive circuit.
(Claim 7)
The induction heating fixing device according to claim 5 or 6, wherein the induction coil is attached to a coil chassis to form an induction coil unit, and the holding member is fixed to the induction coil unit. .

  According to the invention of any one of claims 1 to 4, a plurality of terminals of the electric wire drawn out from the induction coil are held by the holding member, and connected to the drive circuit board by plug-in male and female contacts. The induction coil can be electrically connected to the drive circuit, and the assembly cost can be reduced. In addition, since a plurality of terminals are connected together, the probability of erroneous connection can be made much lower than when individual terminals are connected. Moreover, since the length of the electric wire between an induction coil and a drive board | substrate can be shortened, the unnecessary radiation of electromagnetic waves can be reduced.

  According to the invention of claim 3 or claim 6, since the induction coil and the drive circuit are electrically connected by coupling between units, the assembly process is further simplified.

  According to the invention of claim 4, the probability of occurrence of erroneous connection between the induction coil and the drive circuit becomes zero.

  Hereinafter, the present invention will be described with reference to embodiments, but the present invention is not limited to the embodiments.

  FIG. 7 is a schematic view of an induction heating fixing device according to an embodiment of the present invention. In the present embodiment, the induction coil having the circuit configuration shown in FIG. 2 and the induction coil unit having the structure shown in FIG. 3 are used.

  In the drawing, a heating roller 11, a pressure 12, a cleaning web 13, a temperature sensor 14, and a separation claw 15 are provided in the induction heating fixing device 10, and the nip portion N between the heating roller 11 and the pressure roller 12 is undetermined. The toner image is heated and fixed at the nip portion N by passing the recording material carrying the attached toner image. An induction coil unit 20 is installed in the heating roller 11, and an induction current is induced in the heating roller 11 by an induced current flowing in the induction coil unit 20, whereby the heating roller 11 generates heat and heat necessary for fixing is generated. appear. The temperature of the heating roller 11 is controlled based on the temperature detected by the temperature sensor 15, and the heating roller 11 is maintained at an appropriate fixing temperature.

  The fixing roller 11 has a base made of a metal pipe such as iron, aluminum, and stainless steel, and the base generates Joule heat by an induced current. The fixing roller 11 may have a heat-resistant elastic layer such as silicon rubber on the surface or a release layer such as a fluororesin on the elastic surface, or a release layer provided on the surface of the base.

  The heating roller 12 is preferably one in which a heat resistant elastic layer such as silicon rubber is provided on a base made of a metal pipe such as iron, aluminum or stainless steel.

  The induction coil unit 20 is disposed outside the heating roller 11, or a heating belt is used as a heating member instead of the illustrated heating roller, and the roller that supports the heating belt is a dielectric heating element, and the heating belt is supported by the roller. It is possible to adopt any conventionally known dielectric heating method such as heating.

  The induction coil unit 20 has the circuit configuration and the cross-sectional structure shown in FIGS. 2 and 3, and the induction coil unit 20 has a uniform temperature distribution so that the temperature is controlled separately at the center and both ends in the axial direction of the heating roller 11. Electric power is supplied to 21 and 22. For the coils 21 and 22, it is preferable to use a litz wire composed of a bundle of a plurality of wires.

  The power supplied to the induction coil unit 20 is feedback-controlled by the temperature detected by the temperature sensor 15.

  As shown in FIG. 3, the induction coils 21 and 22 generate an induction current in a divided region in the direction of the rotation axis of the heating roller 11 to cause the heating roller 11 to generate heat. However, as shown in FIG. The present invention is not limited to the division, and it can be divided into an appropriate plural number, and an induced current can be generated in each divided region.

  As shown in FIG. 2, the terminals of the induction coil have terminals twice as many as the number of divisions of the induction coil so that the wires 21A and 21B are drawn from the induction coil 21 and the wires 22A and 22B are drawn from the induction coil 22, respectively. .

  As shown in FIG. 8, the holding member 34 is fixed to one end of the induction coil unit 20 disposed in the heating roller 11, and the board case 31 that houses the drive circuit board 30 is coupled to the holding member 34.

  9 and 10 are diagrams showing the connection between the induction coil and the drive circuit board. 10 is a cross-sectional view of the coupling portion between the induction coil unit and the substrate case as viewed from above, and FIG. 9 is a cross-sectional view taken along line YY in FIG.

  The electric wires 21A, 21B, 22A, 22B drawn from the coil unit 20 are held by a holding member 34 made of a heat-resistant resin, and the terminals of these electric wires protrude from the end surface of the holding member 34 as shown in FIG.

  The drive circuit board 30 on which the drive circuit for the induction coil is mounted is housed in a board case 31 made of a heat-resistant resin, and the terminals of the electric wires 21A, 21B, 22A, 22B are directly connected to the circuit board 30.

  FIG. 12 is an enlarged view showing the connection between the electric wires 21A, 21B, 22A, 22B and the drive circuit board 30, and the terminals of the electric wires 21A, 21B, 22A, 22B protrude from the holding member 34 as shown. On the other hand, the drive circuit board 30 in the board case 31 is provided with four connectors 35 corresponding to the electric wires 21A, 21B, 22A, 22B. Each of the connectors 35 is a pair of electrodes made of an elastic conductive plate material, that is, a metal plate such as a copper plate, and constitutes a male and female contact with the terminals of the electric wires 21A, 21B, 22A, and 22B. The drive circuit board 31 is provided with an insertion hole 36 corresponding to the connector 35.

  By connecting the case 31 containing the drive circuit board 30 close to the induction coil unit 20 as shown by an arrow X and connecting them, the terminals and connectors of the electric wires 21A, 21B, 22A, 22B as shown in FIG. The male and female contacts 35 are electrically connected, and the induction coils 21 and 22 are electrically connected to the drive circuit.

  Thus, the terminals of the plurality of electric wires 21A, 21B, 22A, 22B are connected to the connector 35 of the drive circuit board by coupling the board case 31 to the induction coil unit 20, so that a single connection process can be used. The electrical connection between the induction coils 21 and 22 and the drive circuit 30 is established. In addition, since the electrical connection is not formed through the connection process of the individual terminals, the probability of erroneous connection is significantly reduced.

  Further, as shown in FIG. 11, the holding member 34 is formed with a projection 37 for preventing erroneous connection, and the board case 31 is formed with an engagement hole 31 </ b> B corresponding to the projection 37. When the board case 31 is brought close to the holding member 34 in the X direction and coupled to each other, the projection 37 and the engagement hole 31B function as a restricting means, and the electric wires 21A, 21B, 22A, 22B and the connector 35 Will contact you in a regular relationship.

  With this configuration, it is possible to reliably prevent the board case 30 from being coupled to the induction coil unit 20 in the wrong direction, and the erroneous connection between the electric wires 21A, 21B, 22A, 22B and the connector 35 is completely prevented.

  14 and 15 show another example of the connection structure of the electric wires 21A, 21B, 22A, and 22B.

  As shown in FIGS. 14 and 15, the connector 35 is formed on the surface of the drive circuit board 30 on the side facing the induction coil unit 20. Therefore, in the example of FIGS. 14 and 15, the terminals of the electric wires 21 </ b> A, 21 </ b> B, 22 </ b> A, and 22 </ b> B can be connected to the connector 35 without providing the insertion hole 36 in FIGS. 12 and 13.

It is the schematic of the conventional induction heating fixing apparatus. It is a figure which shows the circuit example of an induction coil. It is a figure which shows the structure of an induction coil unit. It is a figure which shows the example of a connection of the conventional induction coil. It is a figure which shows the example of a connection of the conventional induction coil. It is a figure which shows the example of a connection of the conventional induction coil. 1 is a schematic view of an induction heating fixing device according to an embodiment of the present invention. It is sectional drawing seen from the upper direction of the induction heating fixing apparatus of FIG. It is sectional drawing along line YY in FIG. It is sectional drawing which looked at the coupling | bond part of an induction coil unit and a substrate case from upper direction. It is a perspective view before the coupling | bonding part of the board | substrate case of an induction coil unit. It is a figure which shows a structure. It is an enlarged view which shows an example of the connection of the electric wire of an induction coil, and a drive circuit board | substrate. It is an enlarged view which shows an example of the connection of the electric wire of an induction coil, and a drive circuit board | substrate. It is an enlarged view which shows an example of the connection of the electric wire of an induction coil, and a drive circuit board | substrate. It is an enlarged view which shows an example of the connection of the electric wire of an induction coil, and a drive circuit board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Induction heating fixing apparatus 11 Pressurization apparatus 13 Cleaning web 14 Temperature sensor 15 Separation claw 20 Induction coil unit 21, 22 Induction coil 21A, 21B, 22A, 22B Electric wire 30 Drive circuit board 31 Board case 34 Holding member 35 Connector 37 Protrusion

Claims (7)

A fixing device in which a heating member and a pressure member are pressed to form a nip, and a recording material is sandwiched and conveyed by the heating member and the pressure member to perform fixing. The heating member is heated by induction heating. In the induction heating fixing device to be heated,
A holding member for holding a plurality of electric wires drawn from the induction coil in a state where the terminals of the electric wires protrude from the holding surface, and
A drive circuit board having a drive circuit for driving the induction coil and a plurality of connectors corresponding to the terminals;
An induction heating fixing device, wherein the induction coil is electrically connected to the drive circuit by causing the drive circuit board to approach the holding member to bring the terminal and the connector into male-male contact. The induction heating fixing device according to claim 1, wherein the drive circuit board is housed in a board case. The induction heating fixing device according to claim 1, wherein the induction coil is attached to a coil chassis to form an induction coil unit, and the holding member is fixed to the induction coil unit. . The induction heating fixing device according to claim 1, wherein a plurality of the induction coils are provided, and the number of the terminals is twice that of the induction coils. A fixing device in which a heating member and a pressure member are pressed to form a nip, and a recording material is sandwiched and conveyed by the heating member and the pressure member to perform fixing. The heating member is heated by induction heating. In the induction heating fixing device to be heated,
A holding member for holding a plurality of electric wires drawn from the induction coil;
A driving circuit for driving the induction coil, a driving circuit board having a plurality of connectors corresponding to the electric wires, and
A support member for supporting the drive circuit board;
An induction heating fixing device, wherein the holding member and the support member are provided with restricting means for restricting a coupling direction between them. The holding member holds the electric wire in a state where the terminal of the electric wire protrudes from a holding surface, and makes the drive circuit board approach the holding member, whereby the terminal of the electric wire and the connector are brought into male-female contact. The induction heating fixing device according to claim 5, wherein the induction coil is electrically connected to the drive circuit. The induction heating fixing device according to claim 5 or 6, wherein the induction coil is attached to a coil chassis to form an induction coil unit, and the holding member is fixed to the induction coil unit. .

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