JPH0112277Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a fixing device for an electrophotographic apparatus.

Generally, an electrophotographic apparatus has a configuration as shown in FIG. In the figure, 1 is a photoconductive drum;
2 is a charging device, 3 is a pattern generator that generates character pattern information such as a kanji pattern, and 4 is an optical fiber tube (hereinafter referred to as OFT) as an exposure device consisting of a cathode ray tube (CRT) and a large number of optical fibers. , 5 is a developing device, 6 is a recording paper made of continuous paper (hereinafter also referred to as Z paper), 7 is a transfer device, 8 is a cleaner brush, 9 is a fixing device, 10
1 is a continuous paper supply device, and 11 is a continuous paper stack. In the figure, arrow A indicates the rotation direction of the photoconductive drum 1, and arrow B indicates the traveling direction of the recording paper 6.

Next, the operation will be explained.

First, when the photoconductive drum 1 rotates, the charging device 2
As a result, the photoconductive drum 1 is uniformly charged with a positive charge (although this may be a negative charge, the discussion will be continued as a positive charge hereinafter) due to the corona discharge. Then, character pattern information such as a kanji pattern is generated in the pattern generator 3, which is displayed as an image by the CRT of the OFT 4, and the light is guided linearly by an optical fiber, and the light of the character pattern is photoconductive. The drum 1 is irradiated. Then, the uniformly charged positive charge on the photoconductive drum 1 is removed only in the portion irradiated with light, forming an electrostatic latent image of the character pattern, and thus exposure is performed. When the electrostatic latent image reaches the position of the developing device 5, the developing device 5 applies positively charged toner to the portion of the character pattern that is the electrostatic latent image.
A toner powder image is formed on the photoconductive drum 1.
This toner powder image is transferred to a recording paper 6 by a transfer device 7.
The character pattern is transferred onto the recording paper 6, and the toner is further heated and melted and fixed by the fixing device 9, thereby recording the character pattern on the recording paper 6. The toner remaining on the drum 1 without being transferred during the transfer process is scraped off by the cleaner brush 8, and the same printing process as above is repeated.

Incidentally, in such an electrophotographic apparatus, the conventional fixing device 9 was constructed as shown in FIG. In the figure, 21 is an infrared lamp that irradiates the recording paper 6 with infrared rays, and this lamp itself is 21.
a and an infrared reflecting plate 21b. 23
24 is a suction hole provided in this contact heating plate 23; 25 is a cartridge heater built into the contact heating plate 23; 26 is a contact heating plate that heats the Z paper 6 by contacting it; A temperature sensor embedded in the heating plate 23; 27 a cover provided to cover all the suction holes 24 of the contact heating plate 23;
8 is a pipe connected to the cover 27, 29 is the hole 24 of the contact heating plate 23, the cover 27 and the pipe 2.
By suctioning air through 8, the recording paper 6
This is a suction blower that allows the contact heating plate 23 to be brought into contact with the contact heating plate 23 and adsorbed thereto.

In this fixing device 9, the recording paper 6 having the toner powder image transferred from the photoconductive drum 1 by the transfer device 7 is transferred to a contact heating plate 23 heated to a predetermined temperature by a suction blower 29. It moves while being attracted, receives contact heating for a certain period of time, and is heated and fixed by infrared rays irradiated from the infrared lamp 21 at the top. At this time, contact heating plate 2
The temperature of No. 3 is determined by the temperature sensor 2 installed in the center.
The predetermined temperature is maintained by controlling the cartridge heater 25 to turn on and off depending on the detected temperature in step 6.

However, in this conventional fixing device 9, the cover 27 covers all the suction holes 24 of the contact heating plate 25.
is provided, and the Z paper 6 is sucked by the suction blower 29 through all the suction holes 24, so when the width of the Z paper 6 is narrow, air is sucked even from the part where the Z paper 6 is not present. As a result, heat may escape from the suction holes 24 that are not covered by the width of the paper, and the suction efficiency is poor, resulting in poor fixing stability.

This idea was devised in view of the above-mentioned conventional problems. Multiple partition plates are provided on the cover that covers the suction holes of the contact heating plate, and by adjusting the rotation angle of the rotating shaft, the partition plates can be placed at appropriate positions. To provide a fixing device for an electrophotographic device that improves suction efficiency and stabilizes fixing by making an opening closeable and sucking Z paper only through a suction hole in a portion with paper width. The purpose is to

An embodiment of this invention will be described below with reference to the drawings.

FIG. 3 shows a fixing device for an electrophotographic apparatus according to an embodiment of this invention. In the figure, the same symbols as in FIGS. 1 and 2 indicate the same parts, 30a to 30e are partition plates provided in the cover 27, 31a to 31e
3 is an opening provided in each partition plate 30a to 30e;
2 is this cover 27 and partition plates 30a to 30e
33 is an adjustment knob provided at the tip of the rotating shaft 32 for rotating the rotating shaft 32; 34a to 34e are a plurality of different rotation angles of the rotating shaft 32; Closing plates 35 are attached at different angles to the rotating shaft 32 so that one of the openings 31a to 31e of the partition plates 30a to 30e is closed, and 35 presses the closing plate 34 to close the opening 31. It's a spring.

Next, the operation will be explained.

As shown in FIG. 3, when the paper width of the Z paper 6 is approximately half the width of the contact heating plate 23 and the Z paper 6 is placed on the right half of the contact heating plate 23, the cover Adjust the adjustment knob 33 outside 27 to close the opening 31c of the third partition plate 30c from the left among the partition plates 30a to 30e to the closing plate 34c of the rotating shaft 32.
so that it is occluded. Then, the pipe 28 of the suction blower 29 and the three partition spaces from the right end in the cover 27 and the six suction holes 2 located under the Z paper 6
4 are in communication and the Z paper 6 is sucked only through these six suction holes 24, so the suction is performed efficiently without heat escaping from other suction holes, and as a result, the fixing performance is also stabilized. .

In addition, when the paper width of the Z paper 6 is approximately equal to the width of the contact heating plate 23, the rotation axis 3 is adjusted by the adjustment knob 33.
It is sufficient to adjust the rotation angle of Z paper 6 to open all the openings 31 of the partition plate 30 and perform suction using the suction blower 29.
When using the paper, the openings 31 of the partition plate 30 may be closed at appropriate locations so that all of the suction holes 24 below the paper width communicate with the suction blower 29.
In this way, suction can be performed efficiently and the fixing performance can be stabilized, as in the above case.

Although the above description has been given of the case where the operator manually rotates the adjustment knob 33 to make adjustments according to the paper width of the Z paper 6, this may of course be done automatically. In order to do this, a paper width detection means detects the positions of both ends of the Z paper 6, and a detection signal from this paper width detection means rotates the rotation shaft 32 to an angle that closes the opening of the partition plate at a position corresponding to the paper width. What is necessary is just to provide a rotating shaft driving means for driving.
However, since the configuration of the paper width detection means would be complicated if it were to detect both ends of the Z paper, one end of the Z paper may be fixed and only the other end may be detected.

Note that this invention is not limited to the above embodiment, and the structure of the closing plate 34 for closing the opening 31 of the partition plate 30 and other details can be improved and changed as appropriate.

As described above, according to this invention, in the fixing device of an electrophotographic apparatus, a plurality of partition plates are provided on the cover that covers the suction holes for suctioning the recording paper to the contact heating plate, and the rotating shaft passing through the cover is attached to the We installed a closing plate that can close one of the openings of the multiple partition plates according to the width of the paper so that suction can be performed only from the suction holes covered by the Z paper, so that heat does not escape from the suction holes that are not covered by the Z paper. There is no escape, suction can be performed efficiently, and fixation can be stabilized.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a general electrophotographic apparatus, FIGS. 2a and 2b are schematic side views and partial perspective views of a fixing device of a conventional electrophotographic apparatus, and FIGS. 3a and b are views of a conventional electrophotographic apparatus. FIG. 2 is a longitudinal cross-sectional view of a fixing device according to an embodiment and a cross-sectional front view of a rotating shaft provided with a closing plate. 1... Photoconductive drum, 6... Recording paper, 7... Transfer device, 23... Contact heating plate, 24... Suction hole,
27... Cover, 28... Pipe, 29... Suction blower, 30... Partition plate, 31... Opening, 32...
...rotation shaft, 34...occlusion plate.

Claims (1)

[Claims for Utility Model Registration] (1) In a fixing device of an electrophotographic device that heats and fixes a recording paper onto which a toner powder image on a photoconductive drum has been transferred by a transfer device, the above-mentioned recording paper having a plurality of suction holes is provided. A contact heating plate that contacts and heats the paper, a cover that covers all the suction holes of this contact heating plate, a suction blower connected to this cover via a pipe, and several rooms inside the cover. a plurality of partition plates that partition the plurality of partition plates, an opening provided in each of the plurality of partition plates, and an opening provided in each of the plurality of partition plates that penetrates the cover and the partition plate and rotates one of the plurality of partition plates at a plurality of different rotation angles. A fixing device for an electrophotographic apparatus, comprising: a rotating shaft having a plurality of closing plates for respectively closing openings. (2) A paper width detection means for detecting the position of one end or both ends of the recording paper, and a blocking plate of the rotating shaft that uses a detection signal from the paper width detection means to close an opening in a partition plate at a position corresponding to the paper width. 2. A fixing device for an electrophotographic apparatus according to claim 1, characterized in that the fixing device includes a rotating shaft driving means for rotationally driving up to an angle.