JP2002278336A - Fixing device - Google Patents

Abstract

(57) [Abstract] [Problem] To simplify the work of replacing the fixing lamp,
The fixing lamp mounted in the heating roller is held at a correct position without displacement in the heating roller. A lamp cartridge (27) is heated by a heating roller (14).
In addition to restricting the inclination of the lamp cartridge when attaching and detaching the lamp cartridge, the lamp cartridge engages with the first lamp holder (28) in a state where the lamp cartridge is mounted on the heating roller, and moves the lamp cartridge in the axial direction and the circumferential direction. A regulating member (65) for regulating is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for fixing a toner on a recording material.

[0002]

2. Description of the Related Art As a fixing device of a printing apparatus known as a laser printer, a copying machine, etc., a recording material holding a toner image is heated and pressed while being conveyed by a heating roller and a pressure roller to record a toner image. 2. Description of the Related Art There is known a fixing device configured to fix a material. A lamp serving as a heat source is provided inside the heating roller. In general, the number of lamps provided inside the heating roller increases as the printing apparatus has a higher printing speed. In such a heating roller having a plurality of lamps, for example, when the heating roller reaches the end of its life and the heating roller is to be replaced, first remove the lamps one by one from the heating roller, and then remove the heating roller. It is removed from the fixing device and replaced with a new heating roller. Therefore, the number of times of attaching / detaching the lamp to / from the heating roller is required by the number of lamps, and the working efficiency is poor. In order to improve such a problem, for example, Japanese Patent Laid-Open Publication No. Hei.
A configuration described in Japanese Patent No. 04633 is proposed. Japanese Patent Laid-Open Publication No. 5-504633 discloses a configuration in which a lamp is pulled out from the rear side of a fixing device while a heating roller is attached to the fixing device.

[0003]

As a lamp used in this type of fixing device, there is an elongated lamp having a diameter of about 10 mm and a length of 600 mm or more. In the case of the configuration disclosed in the official gazette, the mounting and dismounting of the heating roller is performed in a state where the lamp is exposed. There was a danger of scratching or breaking the lamp.

SUMMARY OF THE INVENTION It is an object of the present invention to simplify the work of exchanging a fixing lamp and to ensure that a fixing lamp mounted in a heating roller is held at a correct position in a heating roller without displacement. It is in.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heating roller having a plurality of fixing lamps therein, and a pressure roller provided so as to be able to press against the heating roller to hold a toner image. The fixing device fixes the toner image to the recording material while holding and conveying the recording material while pressing and heating the recording material at a pressure contact portion between the heating roller and the pressure roller, and holds one end of the fixing lamp. And a second lamp holder for holding the other end of the fixing lamp, the inclination of the lamp cartridge when attaching and detaching the lamp cartridge to and from the heating roller. Regulating and engaging with the first lamp holder in a state where the lamp cartridge is mounted on the heating roller,
This is achieved by providing a regulating member that regulates the axial and circumferential movement of the lamp cartridge.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, a laser beam printer using an electrophotographic method is exemplified as a printing apparatus to which the present invention is applied, and the overall configuration thereof will be described with reference to FIG.

In FIG. 9, reference numeral 1 denotes a laser beam printer, and the photosensitive drum 21 starts rotating in the direction of an arrow based on a printing operation start signal from a controller 22 thereof.
The photosensitive drum 21 rotates at a speed corresponding to the printing speed of the laser beam printer 1, and continues to rotate until the printing operation ends. When the photosensitive drum 21 starts rotating, a high voltage is applied to the corona charger 2, and the surface of the photosensitive drum 21 is uniformly charged with, for example, a positive charge.

The rotary polygon mirror 3 is a laser beam printer 1
As soon as the power is turned on, the motor starts rotating, and the constant-speed rotation is maintained with high accuracy while the power is turned on. Light output from a light source 4 such as a semiconductor laser is reflected by the rotating polygon mirror 3 and irradiated while scanning the photosensitive drum 21 through the fθ lens 5.

When the character data or graphic data converted into the dot image is sent from the controller 22 to the laser beam printer 1 as an on / off signal of the laser beam, the portion where the laser beam is irradiated on the surface of the photosensitive drum 21 and the irradiation are performed. And a so-called electrostatic latent image is formed. When the photosensitive drum area holding the electrostatic latent image reaches a position facing the developing device 6, toner is supplied to the electrostatic latent image, and a portion on the photosensitive drum 21 where the charge on the photosensitive drum 21 has disappeared due to the irradiation of the laser beam. For example, the toner charged to a positive charge is attracted by static electricity,
A toner image is formed thereon.

The continuous paper 7 stored in the paper hopper 11 is transferred to the photosensitive drum 21 by the paper transport tractor 8 in synchronization with the timing at which the toner image of the print data formed on the photosensitive drum 21 reaches the transfer position. And transfer device 1
It is transported between 0.

The toner image formed on the photosensitive drum 21 is sucked onto the paper 7 by the action of the transfer unit 10 which applies a charge of the opposite polarity to the toner image on the back side of the paper 7.

In this way, the sheet 7 set in the sheet hopper 11 is transferred to the sheet transport tractor 8 and the transfer unit 1.
0, the sheet is conveyed to the fixing device 12 via the sheet conveying tractor 9 and the buffer plate 24. The sheet 7 that has reached the fixing device 12 is preheated by a preheater 13, and is then heated by a pair of fixing rollers including a heating roller 14 having a fixing lamp (hereinafter referred to as a “heater lamp”) 25 and a pressure roller 15. The toner image is fused and fixed on the sheet 7 while being conveyed while being heated and pressurized by the formed nip portion.

The paper 7 sent out by the heating roller 14 and the pressure roller 15 is sent out to the stacker table 19 by the paper sending out roller 16 and
The swinging fins 17 are alternately folded along the perforations by the swinging operation of the swing fins 17, and the folding state is adjusted by the rotating paddle 18.
Stacked on top of 9. The area that has passed the transfer position of the photosensitive drum 21 is cleaned by the cleaning device 20, and is prepared for the next printing operation.

In FIG. 9, reference numeral 23 denotes a display screen for displaying information based on the state of the laser beam printer 1 during a printing operation. Further, the above-described buffer plate 24 is provided between the paper transport tractor 9 and the fixing rollers
This is to absorb the slack or tension generated in the sheet 7 when the sheet conveyance speed difference occurs between the sheets 5.
Reference numeral 26 denotes a web member provided so as to be in contact with the surface of the heating roller 14 and to be able to be wound, and is used for cleaning the surface of the heating roller 14 and applying a release agent to the surface of the heating roller 14. Things.

Next, a detailed configuration of an example of the lamp cartridge will be described with reference to FIG. The lamp cartridge 27 includes a plurality (four in this embodiment) of heater lamps 25 for the heating roller 14 described in FIG.
A first lamp holder 28 that holds one end of each heater lamp 25, and a second lamp holder 28 that holds the other end of the heater lamp 25.
, And a protection member holding portion 30 provided around the heater lamp 25 held by the first lamp holder 28. Here, when the lamp protection member described later is mounted, the protection member holding portion 30
This is provided to hold the lamp protection member, and the means is not particularly limited. In this embodiment, the protection member holding portion 30 is formed by a tapered surface.

The first lamp holder 28 has a hole 31 into which one end of the heater lamp 25 is inserted, as shown in FIG.
A hole 32 for inserting the spacer 33 is provided. Each of the holes 31 and 32 is a through-hole, and when the heater lamp 25 is inserted into the hole 31, care is taken so that a power supply line 63 (see FIG. 5) provided in each heater lamp goes out. A spacer 33 is fitted into the hole 32.

Each heater lamp 25 is inserted into the hole 31 and
Each component is fixed with a screw 37 so that the lamp holder 28 is sandwiched between the plate 34 and the plate 36. In FIG. 2, reference numeral 35 denotes a spring. The spring 35 is provided in a groove provided on the back surface of the lamp holder 28, and applies a predetermined pressing force to the two heater lamps facing each other to prevent rattling of the heater lamp in the hole 31.

FIG. 4 shows a rear surface of the lamp holder 28 (a front view seen from the direction of the screw 37 in FIG. 2). In FIG. 4, reference numeral 38 denotes a groove for installing the spring 35. Reference numeral 39 denotes a concave portion formed on the front portion of the lamp holder 28. The concave portion 39 serves to prevent the rotation of the lamp cartridge mounted on the heating roller, and the reference numeral 39a designates an axial restriction. A regulating member 6 provided on the fixing device main body side.
5 (hereinafter referred to as “lamp holder stopper”) (FIG. 5,
The position of the lamp cartridge 27 is regulated by inserting the lamp holder 27 into the recess 39 (see FIGS. 6 and 7A), and the lamp holder stopper 65 is retracted from the recess 39 (FIG. 7B).
), The restriction of the position of the lamp cartridge 27 in the axial direction and the circumferential direction is released.

On the other hand, the second lamp holder 29 has a hole 4 for inserting the other end of the heater lamp 25 as shown in FIG.
0 and a hole 41 into which the spacer 42 is inserted. The holes 40 and 41 are also through holes as in the case of the first lamp holder 28, and the heater lamp 25
Power supply line 6 provided for each heater lamp when
3 (see FIG. 5) is taken out. A spacer 42 is fitted into the hole 41. Each heater lamp 25 is inserted into the hole 40, and each component is fixed with the screw 45 so that the lamp holder 29 is sandwiched between the plate 43 and the plate 44. If necessary, a spring may be provided similarly to the first lamp holder 28.

Next, the configuration around the heating roller with the lamp cartridge mounted will be described with reference to FIG.

The heating roller 14 comprises a metal tube 14a made of, for example, aluminum and a surface layer 14b made of Teflon (registered trademark), silicon rubber or the like provided on the tube 14a. Is provided with an absorber 14c for preventing heat release. Both ends of the raw tube 14a are connected to a holding member 4 having centering members 46 and 47.
It is supported by the frame 50 of the fixing device via 8, 49. Here, a bearing 51 is provided on the holding member 48, and the bearing 51 is coupled to the heating roller 14 together with the centering member 46. Further, the bearing 51 is formed by a plurality of springs 52 and a guide plate 53 by the heating roller 1.
4 are arranged so as to be able to absorb the thermal expansion and the dispersion of the surrounding support members. The holding member 48 and the frame 5
0 is fixed by a thumbscrew 54.

On the other hand, the holding member 49 includes the heating roller 14
A gear 55 is provided for receiving a driving force from a driving motor (not shown) for driving the housing 5. The housing 5 includes bearings 56 and 57 attached to the frame 50.
It is supported by 8,59. Further, the centering members 46 and 47 are provided with protrusions 60 for more securely connecting to the heating roller 14, and are engaged with grooves 61 provided at both ends of the heating roller 14.

Further, in order to prevent heat from flowing out of the heating roller 14 to the centering members 46 and 47 and to prevent damage at the engaging portion between the projection 60 and the groove 61, the distance between both ends of the heating roller 14 and the centering members 46 and 47 is reduced. A collar 62 made of a heat-resistant plastic is inserted into the hole except for the projection 60. In FIG. 5, a line indicated by reference numeral 63 drawn from both ends of the lamp cartridge 27 is a power supply line of the heater lamp 25.

In the above configuration, the lamp cartridge 2
7 is inserted through a through hole 48a provided in the holding member 48, and is mounted in the heating roller 14 as shown in FIG. Here, the reason why the shapes of the first lamp holder 28 and the second lamp holder 29 are different is to prevent the lamp cartridge 27 from being erroneously inserted.

The lamp cartridge 27 is connected to the heating roller 14.
When pulling out of the printing device, the operator is
(See FIG. 6), a cylindrical member 64, which is a lamp protection member, is inserted through a through hole 59a provided in a housing 59 as shown in FIG. Push in until it is held by the tapered surface 30 provided on the first lamp holder 28.

When the setting of the tubular member 64 is completed, the operator moves to the front side of the printing apparatus, retracts the lamp holder stopper 65 from the concave portion 39 (see FIG. 4) of the lamp holder 28 (see FIG. 7), and The restriction on the position of the cartridge 27 in the axial direction and the circumferential direction is released. When the lamp cartridge 27 is pulled out from this state, the lamp cartridge 27 and the tubular member 64 are pulled out together, and FIG.
It is taken out in the state like.

When the lamp cartridge 27 is inserted into the heating roller 14, the lamp holder 65 is moved to the state shown in FIG. 7C, and the cartridge shown in FIG. The guide portions 65a, 65b, 65c are used as guides for insertion. At this time, it is possible to prevent the lamp cartridge 27 from being damaged by interfering with the portion 14c in the heating roller 14 in FIG. After the insertion is completed, the lamp holder stopper 65 is
(FIG. 7A)
(See) The position of the lamp cartridge 27 is regulated. After that, when the printing apparatus is moved to the rear side and the tubular member 64 is pulled out, the mounting is completed.

The cylindrical member 64 is provided with the lamp cartridge 2.
Each time the replacement of 7 is repeated, the deterioration of both end portions 64a in FIG. 8 progresses, but the 64a portion is reinforced to reduce the deterioration,
Although there is no particular limitation on the means, in this embodiment, an adhesive is applied to form 64a.

[0029]

As described above, according to the present invention, when the fixing lamp is attached to and detached from the heating roller, the fixing lamp is protected by the lamp protection member, so that the attaching and detaching operation of the fixing lamp can be efficiently performed. It can be performed safely, and the fixing lamp mounted in the heating roller is held at a correct position without being displaced in the heating roller, so that the range of the heating area in the axial direction of the heating roller is stabilized, Fixing defects due to excessive heating or insufficient heating can be reduced. Further, it is possible to reduce the deterioration of the lamp protection member due to the repeated mounting and dismounting of the fixing lamp, and to reduce the damage of the fixing lamp due to erroneous insertion by providing a guide when the fixing lamp is mounted.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a lamp cartridge according to the present invention.

FIG. 2 is an overall perspective view of a first lamp holder.

FIG. 3 is an overall perspective view of a second lamp holder.

FIG. 4 is a rear view of the first lamp holder.

FIG. 5 is a sectional view of a heating roller.

FIG. 6 is a sectional view showing a state where a lamp protection member is inserted into a heating roller.

FIG. 7 is a front view showing an operation state of a lamp holder stopper.

FIG. 8 is an overall perspective view of a lamp cartridge on which a lamp protection member is mounted.

FIG. 9 is an overall configuration diagram of a printing apparatus.

[Explanation of symbols]

25: fixing lamp, 27: lamp cartridge, 28:
First lamp holder, 29... Second lamp holder, 30
... Protective member holding part, 64. Lamp protecting member, 64a. Lamp protecting member reinforcing part, 65. Lamp holder stopper (regulating member).

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takeshi Onodera 1060 Takeda, Hitachinaka-shi, Ibaraki F-term in Hitachi Koki Co., Ltd. (reference) 2H033 AA36 BA08 BA11 BA26 BB12 BB18 BB21 BB28 2H071 BA03 BA16 BA22 BA27 BA29 BA36 DA12 3K058 AA13 AA83 BA18 CE16 CE21 DA02 GA06

Claims (2)

[Claims] A heating roller provided with a plurality of fixing lamps therein; and a pressure roller provided so as to be able to press against the heating roller, and a recording material holding a toner image is applied to the heating roller by the heating roller. A fixing device that nips and conveys the toner image on a recording material while heating and pressurizing the fixing roller at a pressure contact portion of a pressure roller, wherein the fixing lamp portion includes a first lamp holder that holds one end of the fixing lamp; A lamp cartridge having a second lamp holder for holding the other end of the fixing lamp; regulating the inclination of the lamp cartridge when attaching and detaching the lamp cartridge to and from the heating roller; In a state where the lamp cartridge is mounted on the heating roller, the first lamp holder engages with the first lamp holder, so that the A fixing device provided with a regulating member for regulating movement. 2. The fixing device according to claim 1, wherein the first lamp holder is provided with a protection member holding portion for holding a lamp protection member attached when the fixing lamp is attached or detached. Fixing device.