JP3812659B2 - Fixing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fixing device of a printing apparatus.
[0002]
[Prior art]
As a fixing device of a printing apparatus typified by a laser printer or a copying machine, a recording material holding a toner image is heated and pressed while being nipped and conveyed between a heating roller and a pressure roller so that the toner image is fixed on the recording material. A fixing device having the above-described configuration is known. The heating roller is provided with a lamp serving as a heat source. In general, the number of lamps provided in 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 has reached the end of its life and the heating roller is to be replaced, the heating roller is removed from the fixing device after removing the lamps one by one. As a result, replacement with a new heating roller is performed, and it is necessary to attach / detach the lamp to / from the heating roller by the number of lamps, resulting in poor work efficiency. In order to improve such a problem, for example, a configuration described in JP-T-5-504633 has been proposed. Japanese Patent Laid-Open No. 5-504633 discloses a configuration in which the lamp is pulled out from the rear side of the apparatus with the heating roller attached to the fixing apparatus.
[0003]
[Problems to be solved by the invention]
By the way, 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. There was a risk of damaging the fixing lamp due to external force.
[0004]
An object of the present invention is to reduce the damage of the fixing lamp when the fixing lamp is replaced.
[0005]
[Means for Solving the Problems]
The above object includes a heating roller provided with a fixing lamp inside, and a pressure roller provided so as to be able to come into pressure contact with the heating roller, and a recording material holding a toner image is placed between the heating roller and the pressure roller. In a fixing device that nippings and conveys a toner image on a recording material while being heated and pressurized at a pressure contact portion, the fixing lamp and a power supply line that holds one end of the fixing lamp and is provided at one end of the fixing lamp A first lamp holder having a through-hole for exposing the fixing lamp, and a through-hole for holding the other end of the fixing lamp and exposing a power supply line provided at the other end of the fixing lamp the second constitutes a lamp cartridge having a lamp holder, wherein the first lamp holder and feeder lines issued outside the second lamp holder, the axial direction and the circumferential direction of the fixing lamp It is achieved by providing a regulating member for regulating the movement of.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0007]
First, a laser beam printer using an electrophotographic system will be exemplified as a printing apparatus to which the present invention is applied, and the overall configuration will be described with reference to FIG.
[0008]
In FIG. 3, reference numeral 1 denotes a laser beam printer. The photosensitive drum 21 starts to rotate in the direction of the arrow based on a printing operation start signal from the controller 22. 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 is completed. When the photosensitive drum 21 starts to rotate, a high voltage is applied to the corona charger 2 and, for example, positive charges are uniformly charged on the surface of the photosensitive drum 21.
[0009]
The rotary polygon mirror 3 starts rotating as soon as the laser beam printer 1 is turned on, and maintains constant speed rotation with high accuracy while the power is turned on. Light output from the light source 4 such as a semiconductor laser is reflected by the rotary polygon mirror 3 and irradiated while scanning the photosensitive drum 21 through the fθ lens 5.
[0010]
When character data or graphic data converted into a dot image is sent from the controller 22 to the laser beam printer 1 as a laser beam on / off signal, the surface of the photosensitive drum 21 is irradiated with the laser beam and the non-irradiated portion. Are formed, 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 the portion of the photosensitive drum 21 on which the electric charge has disappeared due to the laser beam irradiation, For example, a positively charged toner is attracted by static electricity and a toner image is formed on the photosensitive drum 21.
[0011]
The continuous sheet 7 stored in the sheet hopper 11 is synchronized with the timing at which the toner image of the print data formed on the photosensitive drum 21 reaches the transfer position by the sheet conveying tractor 8 and the transfer unit. 10 is conveyed toward the middle.
[0012]
The toner image formed on the photosensitive drum 21 is sucked onto the sheet 7 by the action of the transfer unit 10 that applies a charge having a polarity opposite to that of the toner image to the back side of the sheet 7.
[0013]
In this way, the paper 7 set in the paper hopper 11 is transported to the fixing device 12 through the paper transport tractor 8, the transfer device 10, the paper transport tractor 9, and the buffer plate 24. The sheet 7 that has reached the fixing device 12 is preheated by the preheater 13 and then heated and pressed by a nip formed by a pair of fixing rollers including a heating roller 14 having a fixing lamp 25 and a pressure roller 15. The toner image is melted and fixed on the paper 7 while being nipped and conveyed.
[0014]
The paper 7 sent out by the heating roller 14 and the pressure roller 15 is sent out to the stacker table 19 side by the paper feed roller 16 and is alternately folded along the perforation by the swinging motion of the swing fin 17. Further, while the folded state is adjusted by the rotating paddle 18, they are stacked on the stacker table 19. 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.
[0015]
In FIG. 3, reference numeral 23 denotes a display screen for displaying information based on the state of the laser beam printer 1 during the printing operation. The buffer plate 24 is for absorbing slack or tension generated on the paper 7 when a paper transport speed difference occurs between the paper transport tractor 9 and the fixing rollers 14 and 15. Reference numeral 26 denotes a web member provided so as to be able to come into contact with the surface of the heating roller 14 and to be wound, for cleaning the surface of the heating roller 14 and applying a release agent to the surface of the heating roller 14. Is.
[0016]
Next, a detailed configuration of an example of the lamp cartridge will be described with reference to FIG.
[0017]
The lamp cartridge 27 includes a plurality of (four in this embodiment) fixing lamps 25 for the heating roller 14 described in FIG. 3, and a first lamp holder 28 that holds one end of each fixing lamp 25. The second lamp holder 29 that holds the other end of the fixing lamp 25 and a protective member holding portion 30 provided around the fixing lamp 25 held by the first lamp holder 28.
[0018]
As shown in FIG. 1, the first lamp holder 28 includes a hole 31 for inserting one end of the fixing lamp 25 and a hole 32 for inserting a spacer 33. Both the hole 31 and the hole 32 are through-holes, and it is considered that when the fixing lamp 25 is inserted into the hole 31, the power supply line 38 provided in each fixing lamp 25 comes out to the outside. A spacer 33 is fitted into the hole 32.
[0019]
Each fixing lamp 25 is inserted into the hole 31, each part is fixed with a screw 37 so that the lamp holder 28 is sandwiched between the plate 34 and the plate 36, and a regulating member 39 is attached to the fixing lamp power supply line 38 to the first lamp holder 28. Install like pressing. The regulating member 39 is provided to regulate the movement of the fixing lamp 25 in the axial direction and the circumferential direction, and the means is not particularly limited. In this embodiment, a wire band is configured as the regulating member 39. Further, the axial restriction of the fixing lamp 25 may be restricted by providing a flange portion or the like on the spacer 33 to restrict the fixing lamp 25 in the axial direction. In FIG. 1, reference numeral 35 denotes a spring. The spring 35 is installed in a groove provided on the back surface of the lamp holder 28 and applies a predetermined pressing force to the two fixing lamps 25 facing each other to prevent the fixing lamp 25 from rattling in the hole 31. Yes.
[0020]
On the other hand, the second lamp holder 29 also fixes the fixing lamp 25 in the same manner as the first lamp holder 28. However, if necessary, the second lamp holder 29 is equipped with a regulating member 39 and a spring 35 as in the first lamp holder 28. Also good.
[0021]
【The invention's effect】
According to the present invention, the movement of the fixing lamp in the axial direction and the circumferential direction with respect to the lamp holder is restricted, and damage to the fixing lamp due to breakage and bending of the insulator and torsional external force can be reduced.
[Brief description of the drawings]
FIG. 1 is an overall perspective view of a first lamp holder according to the present invention.
FIG. 2 is an overall perspective view of a lamp cartridge according to the present invention.
FIG. 3 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, 33 ... Spacer, 34 ... First plate, 35 ... Spring, 36 ... Second plate, 39 ... Non-rotating.

Claims (1)

A heating roller provided with a fixing lamp inside and a pressure roller provided so as to be able to be pressed against the heating roller are provided, and a recording material holding a toner image is heated at a pressure contact portion between the heating roller and the pressure roller. In a fixing device for nipping and conveying while pressing and fixing the toner image on a recording material, the fixing lamp and one end of the fixing lamp are held and a power supply line provided at one end of the fixing lamp is exposed. A first lamp holder having a through-hole, and a second lamp having a through-hole for holding the other end of the fixing lamp and for providing a power supply line provided at the other end of the fixing lamp. configure the lamp cartridge having a holder, a feed line issued outside the first lamp holder and the second lamp holder, restricting movement in the axial direction and the circumferential direction of the fixing lamp Fixing apparatus characterized in that a regulating member that.

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