JPH0637422Y2 - Thermal fixing device in electrophotographic apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a heat fixing device in an electrophotographic apparatus.

2. Description of the Related Art Conventionally, a heater is inserted inside to develop an electrostatic latent image formed on the outer periphery of a photoconductor, transfer the developed toner image to a sheet, and fix the toner image on the sheet. There is a heat fixing device in which a sheet is held by a cylindrical heater roller and a press roller.

Problems to be solved by the invention Although such a heat fixing device is incorporated in one frame as a unit, when replacing the heater, the heater roller must be removed from the frame, and maintenance and inspection work is required. Is extremely annoying. Also, if the terminal plate for connecting the power supply to the heater is exposed to the outside, care must be taken not to touch the terminal plate when performing maintenance and inspection of other parts. If it is covered with a cover, there is a problem that it is difficult to replace the heater.

Means for Solving the Problems A rotatable photoconductor, an electrostatic latent image forming means for forming an electrostatic latent image on the outer periphery of the photoconductor, a developing device for developing the electrostatic latent image, and the photoconductor. A transfer unit that transfers the toner image of the body to a sheet, a cylindrical heater roller that has a rod-shaped heater inside and rotates at both ends, and a rotation that presses the sheet passing through the transfer unit to the heater roller. In an electrophotographic apparatus equipped with a free press roller, openings are formed on both sides of a heater frame, and ring-shaped bearings for rotatably supporting the outer circumferences of both ends of the heater roller are provided around these openings. A pair of left and right heater covers are provided on both outer sides of the frame, and terminal plates elastically contacting the end portions of the heaters are attached to the inner sides of the heater covers so as not to be exposed to the outside. At least one side of the heater cover was formed with a through hole facing the end of the heater via the terminal plate.

Therefore, the electrostatic latent image forming means forms an electrostatic latent image on the outer periphery of the photoconductor, and the electrostatic latent image is developed by the developing device.
The toner image on the photoconductor is transferred to the paper by the transfer unit, and the paper is held by the heater roller and the press roller to fix the toner image on the paper. When replacing the heater, one of the terminal plates is retracted from one end of the heater, the heater is inserted into and removed from the through hole of the heater cover, the heater is held elastically by simply contacting the heater with the terminal plate. It is connected to a power supply, which allows the heater to be attached and detached without disassembling the heater roller from the heater frame. In addition, there is no risk of contact with the terminal board during maintenance and inspection, which simplifies the work and improves safety.

Embodiment An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 3, on both sides of the base 1, a frame 2 is held by a hinge 3 so as to be vertically rotatable. Further, clamps 5 that engage with pins 4 that are erected on both sides of the base 1 are rotatably attached to both sides of the frame 2 on the side of the free rotation end. Although not shown, the casing of the electrophotographic apparatus is formed by a lower case that supports the base 1 and an upper case that holds the frame 2 and the drum frame 6. Also, the drum frame 6 has
A rotatable photoconductor 7, a charging charger 8 that charges the outer peripheral surface of the photoconductor 7, a developing device 9, a blade 10 that wipes off the residual toner on the photoconductor 7, and an electrostatic latent image on the photoconductor 7. A static eliminator 11 for erasing an image is held. An exposure device 12 for scanning a laser beam is held on the outer peripheral surface of the photoconductor 7 on the frame 2, and the exposure device 12 and the charging charger 8 are held.
The electrostatic latent image forming means 13 is formed by the.

Next, the base 1 holds a transfer charger 14 as a transfer portion, and also holds a cylindrical heater roller 15 and a press roller 16 having openings at both ends. And
As shown in FIG. 1, a heater frame 17 is provided. This heater frame 17 is fixed to the base 1,
Openings 18 are formed on both side surfaces thereof, and ring-shaped bearings 19 that rotatably support the outer circumference of the heater roller 16 are screwed to the peripheral edges of these openings 18. Further, as shown in FIG. 2, a notch 20 and three annular grooves 21 are formed on the outer periphery of one end of the heater roller 15, and a protrusion 22 that engages with the notch 20 is provided and a motor (not shown). Gears driven to
Is fitted to one end of the heater roller 15. Three grooves
A retaining ring 24 is fixed to the 21. The outer retaining ring 24 and the intermediate retaining ring 24 prevent the gear 23 from moving in the thrust direction, and the inner retaining ring 24 and the intermediate retaining ring 24 are connected to each other. Bearing 19
The heater roller 15 is prevented from moving in the thrust direction by contacting both side surfaces of the heater roller 15. Further, heater covers 25 are fixed to both sides of the heater frame 17 by screws 26 and 27, and these heater covers 25 are connected to a power source and elastically attached to both ends of a rod-shaped heater 28 in the heater roller 15. The terminal plate 29 that is in contact with is held, and through holes 30 that face each other are formed at both ends of the heater 28.

In such a structure, in the process of rotating the photoconductor 7 once, first, the outer periphery of the photoconductor 7 is charged by the charging charger 8, and the electrostatic latent image is formed by scanning the charged portion with a laser beam from the exposure device 12. The electrostatic latent image is formed by the developing device 9, the toner image on the photoconductor 7 is transferred onto the sheet by the transfer charger 14, and the sheet is held by the heater roller 15 and the press roller 16 to sandwich the sheet. Fix the toner image.

When replacing the heater 28, one of the terminal plates 29 is bent and retracted from one end of the heater 28, and the heater 28 is taken out from the through hole 30 of the heater cover 25. This allows the heater 28 to be installed without removing the heater roller 15 from the heater frame 17.
The attachment / detachment work of can be performed extremely easily.

EFFECTS OF THE INVENTION Since the present invention is configured as described above, one terminal plate can be retracted from one end of the heater, and the heater can be inserted into and removed from the through hole of the heater cover. The heater can be held and connected to the power supply simply by contacting it with the power supply.This allows the heater to be attached and detached without disassembling the heater roller from the heater frame. There is no danger of coming into contact with the plate, work is simple, and safety is improved.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a vertical sectional front view showing a heater roller and a heater supporting structure, and FIG. 2 is a partial exploded perspective view showing a connecting structure of a heater roller and a gear. FIG. 3 is a side view showing the entire structure. 7 ... photoreceptor, 9 ... developer, 13 ... electrostatic latent image forming means, 14 ... transfer charger (transfer section), 15 ... heater roller, 16 ... press roller, 17 ... heater frame, 18 …… Opening, 19 …… Bearing, 25 …… Heater cover,
28: heater, 29: terminal plate, 30: through hole

Continuation of the front page (56) Reference JP-A-59-116775 (JP, A) JP-A-61-134777 (JP, A) JP-A-60-14269 (JP, A) JP-A-60-260075 (JP , A) JP 61-23182 (JP, A) Actually opened 60-65759 (JP, U) Actually opened 62-38673 (JP, U) Actually opened 63-132972 (JP, U) Actually opened 63-2968 (JP, U) Actual opening Sho 59-176055 (JP, U) Actual opening Sho 58-185865 (JP, U) Actual opening Sho 61-46570 (JP, U) Actual opening Sho 62-27367 (JP, U) Actual opening Sho 62-7192 (JP, U) Actual opening Sho 58-157350 (JP, U) Actual opening Sho 62-186169 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A rotatable photoconductor, an electrostatic latent image forming means for forming an electrostatic latent image on the outer periphery of the photoconductor, a developing device for developing the electrostatic latent image, and toner for the photoconductor. A transfer unit that transfers an image to a sheet, a cylindrical heater roller that has a rod-shaped heater inside and rotates at both ends, and a rotatable press that presses the sheet passing through the transfer unit against the heater roller. In an electrophotographic apparatus including a roller, openings are formed on both sides of the heater frame, and ring-shaped bearings that rotatably support the outer circumferences of both ends of the heater roller are provided around these openings. A pair of left and right heater covers are provided on the outside, and a terminal plate that elastically contacts the end of the heater is attached to the inside of each of the heater covers so as not to be exposed to the outside, and the heater cover is attached. Thermal fixing device in an electrophotographic apparatus, characterized in that the formation of the hole facing the end portion of the heater through the terminal board on at least one side of the chromatography.