JPS5955467A - Picture forming device - Google Patents

Abstract

PURPOSE:To suppress the heat generation and noise of a driving motor for a rotary polygon mirror and to prevent the thermal diffusion of a heat fixation device by enclosing the driving motor with a partition, blowing external air into the formed closed space, and providing the heat fixation device closely to the partition. CONSTITUTION:Copying operation is carried out repeately and the driving motor 5 for the rotary polygon mirror and the heat fixation device 22 rises in ambient temperature, but the space S formed of an optical table 8 and the partition 28 while surrounding the driving motor 5 is ventilated to be cooled by the external air flowing therein through the opening 29 of a front side plate 29. Then, the ambient air of the heat fixation device 22 close to the surface of the partition 28 is also cooled. Consequently, the temperature rise of the driving motor 5 is suppressed to obtain stable operation, and the conduction of heat radiated from the heat fixation device 22 to a photosensitive drum 3 is also suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic photographic recording apparatus 7, particularly an image writing means using a laser oscillator and a rotating polygon mirror, image fixing by heat, and a recording apparatus having a heat exchanger. .

Recently, a new type of copier called an intelligent copier has been introduced. While conventional copying machines obtain copies of original images purely optically, intelligent copying machines convert original images into electrical signals and send them to image recording devices such as laser beam printers, Ink Geno 1 printers, etc. Transmit and obtain a copy.

Such a copying machine can easily perform various image processing after converting an image into an electrical signal, so it has advanced functions that allow remote image transmission, image editing, etc. that were previously impossible.

By the way, a laser beam printer (hereinafter referred to as LBP) is used as an image recording device for the Inchlinen 1 copying machine.
When using LBP, there are various problems in operating LBP with its conventional performance.

For example, recording scanning density and recording speed can be mentioned, but regarding recording scanning density, for example, 1, 1) Because it handles images, the standard is 99 da scans per /mm, which is sufficient for image quality. However, since copiers handle not only text but also halftone images such as photographs, Unless the scanning level is around m, per m/o scanning, faithful reproduction cannot be achieved. When it comes to recording speed, LBP has both high and low speeds!
Although the situation is polarized, high-speed machines are large and expensive, while low-priced machines cannot be applied to small office machines. On the other hand, low-speed aircraft are small and
Although it is inexpensive, it is much slower than the copying speed of a normal copying machine. The reason for this is that low-speed LBPs are generally used in the impact printer field to convert recording devices to non-impact devices. This is because it is difficult to handle and handle.

As mentioned above, when using a small, low-speed LBPi as an image recording device for an intelligent copier, it is important to increase the recording scanning density and recording speed in order to maintain the performance of conventional copiers. is required. The seven means to achieve this are to increase the speed of rotation of the rotating polygon mirror that scans the photoreceptor with laser light. The speed increase) circle is 7 times faster and the recording speed (
Since the speed is increased to about il-3 times j(, the overall speed will be increased by about S times.

However, as the speed of the rotating polygon mirror increases, a problem arises in that the heat generation and noise of the drive motor for the rotating polygon mirror increases dramatically.

However, image forming apparatuses equipped with a thermal fixing device have the disadvantage that the heat generated by the thermal fixing device gradually diffuses into the surroundings, raising the temperature of the electrophotographic photosensitive drum, cream, and developing device. .

Elevating the temperature of the photosensitive drum makes electrostatic image formation unstable, so a number of countermeasures have been taken, but none have been satisfactory in terms of functionality and cost. In addition, increasing the temperature of the cleaner and developing device causes the toner to solidify and crosslink, resulting in unstable microscopic images and mechanical failure. The purpose is to prevent the heat generated by the rotating polygon mirror drive motor from affecting other components, and to prevent heat diffusion from the heat fixing device. Furthermore, it is possible to provide a compact image forming apparatus by ideally arranging the rotating polygon mirror and the heat fixing device.

1 and 3 are a schematic sectional view and a partial perspective view showing an embodiment of an image forming apparatus according to the present invention. (1)
is a reading section that optically reads the original image and converts it into an electrical signal. , +21 is the recording section, drum, (4)
is a rotating polygonal mirror that emits a laser beam (
L) Scan the k deflection. (5) is a drive motor that fully rotates the rotating polygon mirror (4), (6) is an imaging lens, and (7) is a folding mirror that deflects the laser beam (L)' toward the photosensitive drum (3). do. (8) is a holding stand that holds optical related members, (?, /θ, //) is a charger, in order:
It has the function of uniformly charging the photosensitive drum (3), then acting on the photosensitive member simultaneously with beam exposure to form an electrostatic latent image, and transferring the toner image to transfer paper. , t+21 is a developing device which uses all of the I/N to develop the latent image, and (13) is a cleaner that removes the 1/S'' gold that was not transferred to the transfer paper. (/ll, 15) is the upper/F paper feed cassette, (
/Otsu, /7) are upper and lower paper feed rollers, (7g, /9
) is a registration roller that adjusts the transfer paper feed so that the image on the photoreceptor and the transfer paper match. (2IJl is a separation roller that separates the transfer paper from the drum. (21)
(2) is the transfer paper transport member, (2) is the roller with a built-in heater, (2) is the tray, (3) is the bottom plate of the recording section, (2) is the gol,
The leg, wall) is a partition wall surrounding the drive motor (5) of the rotating polygon mirror. A part of the wall shown in the figure, 2g', hangs above the front of the fuser on the side where the paper enters the fuser, and is heated by the heat dissipation of the fuser, and the photoconductor of the rising air. It is designed to prevent movement in that direction.

In Figure 2, 29.3θ) is the front plate and rear plate, and the holding stand (
8) connects these together as a stay. (3I) is the front bar, (support) is the heat exhaust duct, and (blade) is the heat fan that discharges all the heated air to the outside of the device. When the 11L source metal is introduced, the heating steel of the heat fixing device 22) is energized at the same time.

The rotating polygon mirror (4) and the heat exhaust fan (O) begin to turn 1i. and the surface of the heat roller (a) of the heat fixing device (22)), 11. Fixed+? Reached j'A degree, rotated a lot...1 mirror (4)
When the rotation speed reaches the specified rotation speed, water: "r synchronization signal" and several check items are checked, and if it is a royal palace,
It becomes ready (ready) state.

Place the original on the original platen (/a) of the reading unit (1), press the copy button, and the DL optical system (not shown) scans the original, and the resulting optical image is displayed like a CCI). It is converted into an electric signal by a solid-state image pickup device, and the recording section (2) illuminates the photosensitive drum (3) with a laser beam (L) & blinks in accordance with the signal. Then, using the well-known electrostatographic recording process, the paper feed power nut (/ri, /3
The toner image is transferred onto the transfer paper fed from ;) and transported to the heat fixing device () by a conveying member (21).

Then, the toner is fused to the transfer paper by a heat fixing device (〃),
The copied paper is taken out from the tray fZ511 K Jul Z
By repeating the copying process, the drive element of the rotary hook 1 and the mirror (
5) and the temperature around the heat fixing device (22).
In the space (S) surrounding the drive motor (5) formed by the optical bench (8) and the partition wall (28), air is blown by the heat control fan (O), and the front print is The drive motor (5) and the partition wall (28) are cooled by the outside air flowing in through the provided opening 11 (2?a).

Ru. The heat fixing device (221), which is close to the difficult surface of the partition wall, is also cooled. As a result, the temperature rise of the drive motor (5) is suppressed, and the drive motor (5) continues to operate stably. The fuser is still warm and the propagation of emitted heat to the photosensitive drum (3) is also suppressed (0 feeling).In general, the state of layer image formation in the tram (3) changes dramatically as the temperature rises.
As a result of the above, even if Le If;' is used for a while, the image quality does not deteriorate.

Still, by providing a partition (28) between the drive motor (5) and the heat constant II device (22), the Jul heat fan (33)
), the outside air flowing in is directly connected to the fixing heat roller (a).
There is no need for complete cooling. This has the effect of reducing the power supply time to the temperature-controlled heat fixing device (Z heater (34)) and suppressing the amount of power consumption. If you put insulation f) J (a) on
Furthermore, this effect increases. In addition, prevention of burns when coming into contact with the partition wall (28) d=, dew condensation and water droplets falling on the partition wall of water vapor evaporated from the transfer paper at the start of operation of the device I-'
It also prevents ffi.

As mentioned above, another problem associated with increasing the speed of the rotating polygon mirror (4) is rotation noise. The noise is mainly air-borne sound generated from the bearings. This rotational sound spreads in all directions, but the sound source is blocked by the front and rear side plates (,29, Jθ) connected to phase/j, the holding table (8), and the partition wall, so the sound source is not transmitted to the outside. The level of noise leaking will be much lower1.As shown in Figure 1, the bulkhead (28
) The effect will be further increased by placing a sound-absorbing material (37) such as glass wool on the surface of the drive motor (5) side of the drive motor (5). Opposite the intake opening (, 29a), the front cover (31)
Sound absorbing material (t, 38) laid on the inner surface and rear side plate (exhaust duct facing the opening 1" (3θa) for exhaust ventilation) +32)
The sound is absorbed by the sound absorbing material laid on the inner surface. +
14, on the air side of JJ1, if the sound source, the opening (3θa), and the exhaust heat fan (33) are arranged so that they are not lined up, the sound insulation effect will be greater.In the above embodiment, the intake opening l ( , :
15'a)'I was provided on the front side plate +291, but in addition to this, there is a constant thickness 1
3. An opening (A) having the same length as the heat roller (A) may be provided. 1, which is the part indicated by (A) in FIG. In order to form a J-ten, it is possible to strongly block the heat around the heat fixing device (22) from penetrating toward the photosensitive drum (3) horn.1 In this case, the hanging part 2g'f is not provided, The intake air amount L-I A may be set at a position 1d slightly higher than the fixing devices f, o).

As described above, in an electrostatic photographic recording apparatus having a rotating polygon mirror and a heat fixing device, there is a partition wall surrounding the drive motor of the rotating polygon mirror, and ventilation through the closed space formed by this partition wall. Since a heat fixing device is provided in the vicinity of the partition wall, it is possible to suppress the temperature rise and noise of the rotating polygon mirror drive motor due to the increased speed of the rotating polygon mirror. 1. The heat generated by the heat fixing device causes the photosensitive tram to
jl, fl, and A can be completely prevented.

In addition, by handling three units, which are large heat generation sources, with one ventilation space and ventilation means, there is an advantage that the cost and the efficiency of the equipment are greatly reduced.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the image forming apparatus, and Figure 7 is a rotating polygon mirror.
FIG. 3 is a perspective view showing the configuration of a heat fixing unit. (4) is a rotating polygon mirror, (5) 6-1 is its drive motor, (8) is a holding table, (2I) is a conveying section, ri) is a heat fixing device, the example is a partition wall, and (29a) is for air intake. opening, (3θa) is an exhaust opening, 132) is an exhaust duct, (leakage is a heat exhaust fan, (A) is a heat insulation hole, (37 to 32) is a sound absorbing material. Special S/+ Applicant: Canon stock association

Claims (1)

[Claims] /) Using a rotating mirror, a laser beam is scanned onto the surface of a photoreceptor to form an electrostatic latent image, and the developed image is transferred to a transfer paper using a developing device. An image forming device (VC) that fixes an image using a heat fixing device, which includes a partition wall surrounding the drive motor of the rotating polygon mirror, and a ventilation means for ventilating a closed space formed by the partition wall. 2) The closed space 1 is located on three sides of the heat fixing device, and a part of the closed space 1 is located on three sides of the heat fixing device. 8. The image forming apparatus according to claim 7, which is disposed near the transfer paper holder L1 of the fixing device. 3) Heat fixing the intake opening of the closed space? : ÷ transfer paper entry (''near {<<Image forming device provided/or as described in the scolding section.