JP2023019897A - Fixing device and image forming apparatus - Google Patents

Abstract

To prevent an increase in temperature of a terminal member of a fixing device due to heat from a heater, the terminal member being connected with a connector of an image forming apparatus.SOLUTION: A fixing device 100 comprises a heating roller 110, a first heater 120, a first terminal member 170, a second heater 130, and a second terminal member 180. The heating roller 110 has an opening 110A at an end in an axial direction. The first heater 120 is arranged inside the heating roller 110. The first terminal member 170 is fixed to one end in the axial direction of the first heater 120, and has a first connection part 173 connected to a first connector C1 of an image forming apparatus. The second heater 130 is arranged inside the heating roller 110. The second terminal member 180 is fixed to one end in the axial direction of the second heater 130, and has a second connection part 183 connected to a second connector C2 of the image forming apparatus. When seen from the axial direction, the first connection part 173 is at least partially located outside the opening 110A.SELECTED DRAWING: Figure 4

Description

The present invention relates to a fixing device and an image forming apparatus having multiple heaters.

A fixing device having a plurality of heaters is known (see Patent Document 1). In this fixing device, a plurality of heaters are arranged inside the heating roller. A terminal member is provided at one axial end of the heater and is connected to a connector of the image forming apparatus.

JP 2018-169529 A

By the way, in the fixing device of Patent Document 1, since the connecting portion between the terminal member and the connector overlaps with the opening of the heating roller when viewed from the axial direction, the connecting portion between the terminal member and the connector is heated by the heat emitted from the opening of the heating roller. There was a problem that the temperature rises.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to prevent a terminal member of a fixing device connected to a connector of an image forming apparatus from rising in temperature due to heat from a heater.

A fixing device according to the present invention is arranged in an image forming apparatus and includes a heating roller, a first heater, a first terminal member, a second heater, and a second terminal member. . The heating roller extends axially and has a cylindrical shape. The heating roller has openings at its axial ends. A first heater is disposed inside the heating roller and extends axially. The first terminal member is fixed to one axial end of the first heater and has a first connecting portion connected to a first connector of the image forming apparatus. A second heater is disposed inside the heating roller and extends axially. The second terminal member is fixed to one end in the axial direction of the second heater and has a second connection portion connected to a second connector of the image forming apparatus. At least a portion of the first connecting portion is positioned outside the opening when viewed in the axial direction.

According to this configuration, since at least part of the first connecting portion is positioned outside the opening of the heating roller, it is possible to suppress the temperature rise of the first connecting portion of the first terminal member.

Further, in the above configuration, the second connecting portion may have a configuration in which at least a part of the second connecting portion overlaps the opening when viewed from the axial direction.

Further, in the above configuration, the output per unit length of the end portion of the first heater near the first terminal member is greater than the output per unit length of the end portion of the second heater near the second terminal member. may be configured.

According to this configuration, the temperature of the end portion of the first heater rises more easily than the temperature of the second heater. temperature rise can be suppressed.

In the above-described configuration, the output per unit length of the first heater is higher at both end portions than at the center portion in the axial direction, and the output per unit length of the second heater is at the center portion relative to both end portions in the axial direction. may be configured to be high.

Further, in the above configuration, the first heater may have a higher maximum output than the second heater.

According to this configuration, although the temperature of the first heater is more likely to rise than that of the second heater, since at least a part of the first connection portion is located outside the opening of the heating roller, the first connection of the first terminal member It is possible to suppress the temperature rise of the part.

Further, in the above-described configuration, the first connecting portion may be a plate-like portion extending in an orthogonal direction orthogonal to the axial direction, and the second connecting portion may be a plate-like portion extending parallel to the first connecting portion. good.

According to this configuration, since the first connection portion and the second connection portion face the same direction, the connectors of the image forming apparatus can be connected from the same direction.

In order to solve the above-described problems, an image forming apparatus according to the present invention includes the above-described fixing device, and ten sheets of the maximum width on which the image forming apparatus can form images are continuously fixed by the above-described fixing device. The power consumption of the first heater may be greater than the power consumption of the second heater.

According to the present invention, it is possible to suppress the temperature rise of the terminal member of the fixing device connected to the connector of the image forming apparatus due to the heat from the heater.

1 is a diagram showing an image forming apparatus provided with a fixing device according to an embodiment; FIG. 4 is a perspective view showing a heating roller, first heaters, second heaters and terminal members; FIG. It is an expansion perspective view of the left end part of a 1st heater and a 2nd heater. FIG. 2 is a diagram of the fixing device viewed from the axial direction;

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
In the following description, the directions are based on the user when using the image forming apparatus 1 . That is, in FIG. 1, the right side as viewed from the paper surface is defined as the "front side", the left side as viewed from the paper surface is defined as the "rear side", the near side as viewed from the paper surface is defined as the "left side", and the rear side as viewed from the paper surface is defined as the "right side". do. In addition, the up-down direction toward the paper surface will be referred to as the "up-down direction".

As shown in FIG. 1, the image forming apparatus 1 is, for example, a laser printer. The image forming apparatus 1 includes a feeder section 4 for feeding sheets 3 such as paper and an image forming section 5 for forming an image on the fed sheets 3 in a body frame 2 . .

The feeder section 4 includes a paper feed tray 6 detachably attached to the bottom of the body frame 2 and a paper pressing plate 7 provided inside the paper feed tray 6 . The feeder unit 4 includes a paper feed roller 8 and a paper feed pad 9 provided on the upper front side of the paper feed tray 6, and a paper dust removing roller 10 provided on the downstream side of the paper feed roller 8 in the conveying direction of the sheet 3. , 11. Further, the feeder section 4 includes a registration roller 12 provided downstream of the paper dust removing roller 11 .

In the feeder section 4 configured as described above, the sheet 3 in the sheet feeding tray 6 is pushed toward the sheet feeding roller 8 side by the sheet pressing plate 7, and the sheet feeding roller 8 and the sheet feeding pad 9 feed the sheet 3 one sheet at a time. The paper is separated into individual pieces and sent out, passes through various rollers 10 to 12 so as to make a U-turn on the front side of the body frame 2, and is conveyed to the image forming section 5 from the front side to the rear side of the body frame 2. FIG.

The image forming section 5 includes a scanner section 16 , a process cartridge 17 and a fixing device 100 .

The scanner unit 16 is provided in the upper part of the body frame 2, and includes a laser emitting unit (not shown), a rotationally driven polygon mirror 19, lenses 20, 21, reflecting mirrors 22, 23, 24, and the like. . Then, in the scanner unit 16, the laser beam passes through the path indicated by the dashed line in the figure and irradiates the surface of the photosensitive drum 27 of the process cartridge 17 with high-speed scanning.

The process cartridge 17 is arranged below the scanner section 16 and is detachable from the body frame 2 . The process cartridge 17 is mainly composed of the developer cartridge 28 and the drum unit 51 .

The developer cartridge 28 includes a developer roller 31 , a layer thickness regulating blade 32 , a supply roller 33 and a toner hopper 34 . The toner in the toner hopper 34 is agitated by an agitator (reference numerals omitted) and then supplied to the developing roller 31 by the supply roller 33. At this time, the toner is positively frictionally charged between the supply roller 33 and the development roller 31. be. The toner supplied onto the developing roller 31 enters between the layer thickness regulating blade 32 and the developing roller 31 as the developing roller 31 rotates, and is carried on the developing roller 31 as a thin layer having a constant thickness. be.

The drum unit 51 has a photosensitive drum 27 , a scorotron charger 29 and a transfer roller 30 . In the drum unit 51 , the surface of the photosensitive drum 27 is uniformly charged by the scorotron charger 29 and then exposed by high-speed scanning of the laser beam from the scanner section 16 . Thereby, an electrostatic latent image is formed based on the image data.

Next, due to the rotation of the developing roller 31 , the toner carried on the developing roller 31 is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 27 when the toner is brought into contact with the photosensitive drum 27 . be. The toner is selectively carried on the surface of the photosensitive drum 27 to be visualized, thereby forming a toner image by reversal development. After that, the toner image carried on the surface of the photosensitive drum 27 is transferred onto the sheet 3 by conveying the sheet 3 between the photosensitive drum 27 and the transfer roller 30 .

After the toner image is thermally fixed by the fixing device 100 arranged in the image forming apparatus 1 , the sheet 3 to which the toner image has been transferred is transported to the discharge path 44 by the transport rollers 43 and discharged by the discharge rollers 45 . The paper is discharged onto the paper tray 46 .

The fixing device 100 includes a heating roller 110, a first heater 120, a second heater 130, a pressure roller 140, a temperature detection member 150, a fixing frame 160, a first terminal member 170, and a second terminal member. 180 and a third terminal member 190 .
In the fixing device 100, the heating roller 110 is heated by the first heater 120 and the second heater 130, so that the sheet 3 passes between the heating roller 110 and the pressure roller 140 from the front side to the rear side. In the meantime, the toner image transferred onto the sheet 3 is thermally fixed. Temperature detection member 150 detects the temperature of heating roller 110 .

The heating roller 110 is a roller that rotates around a rotational axis G extending in the left-right direction, that is, in the axial direction. The heating roller 110 extends axially and has a cylindrical shape. The heating roller 110 has an opening 110A at its axial end (see FIG. 2). The pressure roller 140 is a roller that is arranged below the heating roller 110 and presses the heating roller 110 .

As shown in FIG. 2, the first heater 120 and the second heater 130 are halogen lamps configured to generate heat when energized. The first heater 120 and the second heater 130 are arranged side by side in the front-rear direction. Specifically, the first heater 120 is arranged in front of the second heater 130 .

The first heater 120 is arranged inside the heating roller 110 and extends long in the axial direction. The first heater 120 has a filament F, a first glass tube 121 , a first left lead pin 122 and a first right lead pin 123 . The first heater 120 is formed by placing a filament F in a first glass tube 121, sealing both lateral ends of the first glass tube 121, and enclosing an inert gas containing a halogen element therein. ing.

The first glass tube 121 includes a cylindrical first glass tube body portion 121A elongated in the left-right direction, a first left sealing portion 121B that seals the left end of the first glass tube 121, and the first glass tube 121. and a first right sealing portion 121C that seals the right end of the .

The first left lead pin 122 is electrically connected to the filament F inside the first left sealing portion 121B. The first left lead pin 122 extends in the left-right direction and protrudes from the left side surface of the first left sealing portion 121B. The tip of the first left lead pin 122 is fixed to a plate-like first terminal member 170 by welding or the like.
The first right lead pin 123 is electrically connected to the filament F inside the first right sealing portion 121C. The first right lead pin 123 extends in the left-right direction and protrudes from the right side surface of the first right sealing portion 121C. The tip of the first right lead pin 123 is fixed to a plate-like third terminal member 190 by welding or the like.

The second heater 130 is arranged inside the heating roller 110 and extends long in the axial direction. The second heater 130 has a filament F, a second glass tube 131 , a second left lead pin 132 and a second right lead pin 133 . The second heater 130 is formed by placing a filament F in a second glass tube 131, sealing both lateral ends of the second glass tube 131, and enclosing an inert gas containing a halogen element therein. ing.

The second glass tube 131 includes a cylindrical second glass tube body portion 131A elongated in the left-right direction, a second left sealing portion 131B that seals the left end of the second glass tube 131, and the second glass tube 131. and a second right sealing portion 131C that seals the right end of the .

The second left lead pin 132 is electrically connected to the filament F inside the second left sealing portion 131B. The second left lead pin 132 extends in the left-right direction and protrudes from the left side surface of the second left sealing portion 131B. The tip of the second left lead pin 132 is fixed to a plate-shaped second terminal member 180 by welding or the like.
The second right lead pin 133 is electrically connected to the filament F inside the second right sealing portion 131C. The second right lead pin 133 extends in the left-right direction and protrudes from the right side surface of the second right sealing portion 131C. The tip of the second right lead pin 133 is fixed to a plate-like third terminal member 190 by welding or the like.

In the first heater 120, the filaments F at both ends in the axial direction are denser than the filaments F in the central portion, and the output per unit length is higher at both ends than in the central portion in the axial direction. The first heater 120 preferentially heats both ends in the axial direction. On the other hand, in the second heater 130, the filaments F at the center in the axial direction are denser than the filaments F at both ends, and the output per unit length at the center is higher than at both ends in the axial direction. The second heater 130 preferentially heats the central portion in the axial direction.

The output per unit length of the end portion of the first heater 120 near the first terminal member 170 is greater than the output per unit length of the end portion of the second heater 130 near the second terminal member 180 . Also, the output per unit length of the end portion of the first heater 120 near the third terminal member 190 is greater than the output per unit length of the end portion of the second heater 130 near the third terminal member 190 .

In this embodiment, the first heater 120 has a higher maximum output than the second heater 130 . Further, the power consumption of the first heater 120 is greater than the power consumption of the second heater 130 while the fixing device 100 continuously fixes 10 sheets 3 having the maximum width on which the image forming apparatus 1 can form images.

As shown in FIG. 3, the first terminal member 170 is a terminal member made of one sheet metal. The first terminal member 170 is fixed to one end of the first heater 120 in the axial direction. The first terminal member 170 has a first base portion 171 , a first extension portion 172 and a first connection portion 173 .

The first base portion 171 is a plate-like portion perpendicular to the vertical direction. The first base portion 171 has an axially long first slot 171A. The first terminal member 170 is fixed to the fixing frame 160 by screws (not shown) inserted into the first elongated holes 171A. A tip portion of the first left lead pin 122 is fixed to the lower surface of the first base portion 171 behind the first long hole 171A.

The first extending portion 172 is a plate-like portion orthogonal to the axial direction. The first extension portion 172 is a portion that extends upward from the first base portion 171 . The first extending portion 172 is located at the left end portion of the first base portion 171 and connects the first base portion 171 and the first connecting portion 173 .

The first connecting portion 173 is a plate-like portion perpendicular to the axial direction. The first connecting portion 173 extends from the front end portion of the first extending portion 172 in an orthogonal direction orthogonal to the axial direction, specifically forward. The first connection portion 173 is a portion that is connected to the first connector C<b>1 of the apparatus main body of the image forming apparatus 1 . The first connector C1 is connected to a power supply via wiring (not shown). The first connecting portion 173 has a rectangular shape that is elongated in the front-rear direction and has a vertical dimension smaller than that of the first extending portion 172 . The tip of the first connection portion 173 faces forward, and the first connector C1 is fitted from the front.

As shown in FIG. 4, at least a portion of the first connecting portion 173 is positioned outside the opening 110A when viewed in the axial direction. In this embodiment, the first connecting portion 173 is entirely located outside the opening 110A when viewed in the axial direction.

As shown in FIG. 3, the second terminal member 180 is a terminal member made of one sheet metal. The second terminal member 180 is fixed to one axial end of the second heater 130 . The second terminal member 180 has a second base portion 181 , a second extension portion 182 and a second connection portion 183 .

The second base portion 181 is a plate-like portion perpendicular to the vertical direction. The second base portion 181 has an axially long second slot 181A. The second terminal member 180 is fixed to the fixing frame 160 by screws (not shown) inserted into the second elongated holes 181A. A tip portion of the second left lead pin 132 is fixed to the lower surface of the second base portion 181 in front of the second long hole 181A.

The second extending portion 182 is a plate-like portion orthogonal to the axial direction. The second extending portion 182 is a portion that extends downward from the second base portion 181 . The second extending portion 182 is located at the left end portion of the second base portion 181 and connects the second base portion 181 and the second connecting portion 183 .

The second connecting portion 183 is a plate-like portion orthogonal to the axial direction. The second connecting portion 183 extends from the front end portion of the second extending portion 182 in the orthogonal direction, specifically forward. The second connection portion 183 extends parallel to the first connection portion 173 . The second connection portion 183 is a portion that is connected to the second connector C<b>2 of the apparatus main body of the image forming apparatus 1 . The second connector C2 is connected to the power supply via wiring (not shown). The second connecting portion 183 has a rectangular shape elongated in the front-rear direction and is smaller than the second extending portion 182 in the vertical direction. The tip of the second connection portion 183 faces forward, and the first connector C1 is fitted from the front. That is, the ends of the first connection portion 173 and the second connection portion 183 face the same direction, and when the first connector C1 is connected to the first connection portion 173, the second connector C2 is connected to the second connection portion 183. When connecting, connect in the same direction.

As shown in FIG. 4, at least a portion of the second connecting portion 183 overlaps the opening portion 110A when viewed in the axial direction. In the present embodiment, the second connecting portion 183 partially overlaps the opening 110A when viewed from the axial direction.

As shown in FIG. 2, the third terminal member 190 is a terminal member made of one sheet metal. The third terminal member 190 has a third base portion 191 , a third extension portion 192 and a third connection portion 193 .

The third base portion 191 is a plate-like portion perpendicular to the vertical direction. The third base portion 191 has a round hole 191A. The third terminal member 190 is fixed to the fixing frame 160 by screws (not shown) inserted into the round holes 191A. The tip portions of the first right lead pin 123 and the second right lead pin 133 are fixed to the left portion of the third base portion 191 from the round hole 191A.

The third extending portion 192 is a plate-like portion perpendicular to the axial direction. The third extending portion 192 is a portion extending upward from the third base portion 191 . The third extending portion 192 is positioned at the right end portion of the third base portion 191 and connects the third base portion 191 and the third connecting portion 193 .

The third connecting portion 193 is a plate-like portion orthogonal to the axial direction. The third connecting portion 193 extends from the front end portion of the third extending portion 192 in the orthogonal direction, specifically forward. The third connecting portion 193 extends parallel to the first connecting portion 173 . The third connection portion 193 is a portion that is connected to the third connector C3 of the apparatus main body of the image forming apparatus 1 . The third connector C3 is connected to the power supply via wiring (not shown). The third connecting portion 193 has a rectangular shape that is long in the front-rear direction, and has a vertical dimension smaller than that of the third extending portion 192 . The tip of the third connection portion 193 faces forward, and the third connector C3 is fitted from the front. That is, the tips of the first connection portion 173, the second connection portion 183 and the third connection portion 193 face the same direction, and the connection portions corresponding to the first connector C1, the second connector C2 and the third connector C3 connected in the same direction.

The fixing device 100 includes a connecting member 200 that connects the first heater 120 and the second heater 130 . The connecting member 200 is made of a heat-resistant insulating material such as ceramic. As shown in FIG. 3, the connecting member 200 has a first hole 201 into which the first left sealing portion 121B is inserted and a second hole 202 into which the second left sealing portion 131B is inserted.

According to the above, the following effects can be obtained in this embodiment.
Power is input to the first heater 120 from the apparatus main body of the image forming apparatus 1 through the first connection portion 173 of the first terminal member 170 . If the temperature of the first connection portion 173 becomes too high, the wiring may deteriorate.
However, according to the fixing device 100 of the present invention, the first connecting portion 173 of the first terminal member 170 of the fixing device 100 is positioned outside the opening 110A when viewed in the axial direction. Therefore, it is possible to suppress the temperature rise of the first connecting portion 173 of the first terminal member 170 .

Further, in the present embodiment, the output per unit length of the end portion of the first heater 120 near the first terminal member 170 is the output per unit length of the end portion of the second heater 130 near the second terminal member 180 . Greater than the output. That is, the first heater 120 is more susceptible to temperature rise at the ends than the second heater 130 . However, according to the fixing device 100 of the present invention, since the first connection portion 173 is positioned outside the opening portion 110A of the heating roller 110, the temperature rise of the first connection portion 173 can be suppressed.

Also, in the present embodiment, the first heater 120 has a higher maximum output than the second heater 130 . Therefore, the temperature of the first heater 120 is increased more easily than the temperature of the second heater 130 . However, since at least a portion of first connection portion 173 is positioned outside opening portion 110A of heating roller 110, it is possible to suppress the temperature rise of first connection portion 173. FIG.

Further, since the second connection portion 183 extends parallel to the first connection portion 173 and faces in the same direction, the first connector C1 and the second connector C2 of the apparatus main body of the image forming apparatus 1 are connected in the same direction. be able to. Therefore, the image forming apparatus 1 can be easily wired, and the entire apparatus can be made compact.

Although the embodiments and modifications of the present invention have been described above, the present invention is not limited to the above embodiments and modifications. The specific configuration can be changed as appropriate without departing from the gist of the present invention.

In the above-described embodiment, the entire first connection portion 173 of the first terminal member 170 is positioned outside the opening portion 110A of the heating roller 110 when viewed from the axial direction. A configuration may be adopted in which a part is located outside the opening 110A of the heating roller 110 when viewed in the axial direction. Alternatively, the entirety of the second connecting portion 183 may be positioned outside the opening 110A of the heating roller 110 when viewed in the axial direction. Further, at least a portion of the third connecting portion 193 of the third terminal member 190 may be positioned outside the opening 110A of the heating roller 110 when viewed from the axial direction. Also, the first connecting portion 173 and the second connecting portion 183 do not have to extend in parallel.

In the above-described embodiment, the first heater 120 has a higher output per unit length at both ends than at the center in the axial direction. may have the same configuration. In addition, the second heater 130 has a higher output per unit length at the center than at both ends in the axial direction, but the output per unit length in the axial direction is the same at the center and at both ends. It's okay.

Although the first heater 120 has a higher maximum output than the second heater 130 in the above embodiment, the second heater 130 may have a higher maximum output than the first heater 120 .

In the above embodiment, the image forming apparatus 1 is a laser printer, but the present invention is not limited to such a configuration, and the present invention can also be applied to other image forming apparatuses such as copiers and multi-function machines. .

Moreover, each element described in each of the above-described embodiments and modified examples can be arbitrarily combined for implementation.

1 image forming apparatus 100 fixing device 110 heating roller 110A opening 120 first heater 122 first left lead pin 123 first right lead pin 130 second heater 132 second left lead pin 133 second right lead pin 160 fixing frame 170 first terminal member 171 First base portion 172 First extension portion 173 First connection portion 180 Second terminal member 181 Second base portion 182 Second extension portion 183 Second connection portion

Claims (7)

A fixing device arranged in an image forming apparatus,
a heating roller extending in an axial direction and having a cylindrical shape, the heating roller having an opening at an end in the axial direction;
a first heater disposed inside the heating roller and extending in the axial direction;
a plate-shaped first terminal member fixed to one end of the first heater in the axial direction and having a first connection portion connected to a first connector of the image forming apparatus;
a second heater disposed inside the heating roller and extending in the axial direction;
a plate-like second terminal member fixed to one end of the second heater in the axial direction and having a second connection portion connected to a second connector of the image forming apparatus;
with
The fixing device, wherein at least part of the first connecting portion is positioned outside the opening when viewed in the axial direction. 2. The fixing device according to claim 1, wherein at least a part of the second connecting portion overlaps with the opening when viewed in the axial direction. The output per unit length of the end of the first heater near the first terminal member is larger than the output per unit length of the end of the second heater near the second terminal member. 3. The fixing device according to claim 2. the first heater has a higher output per unit length at both ends than at the center in the axial direction;
4. The fixing device according to claim 3, wherein the output per unit length of the second heater is higher at the central portion than at both ends in the axial direction. 5. The fixing device according to claim 1, wherein the first heater has a higher maximum output than the second heater. The first connecting portion is a plate-like portion extending in an orthogonal direction orthogonal to the axial direction,
6. The fixing device according to claim 1, wherein the second connecting portion is a plate-like portion extending parallel to the first connecting portion. An image forming apparatus comprising the fixing device according to any one of claims 1 to 6,
The electric power consumption of the first heater is greater than the electric power consumption of the second heater while the fixing device continuously fixes 10 sheets having the maximum width on which the image forming apparatus can form images. Image forming device.

Images