JPH0795214B2 - Flash fixing device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recording an image using toner, such as a printer and a facsimile machine, and particularly, flash fixing suitable for heating and fixing toner powder on recording paper. Regarding the device.

[Conventional technology]

This recording device is used in printers, fax machines, etc.
A toner powder is used for an image, a recording method by electrostatic force is used for development, and a toner image is heated and fixed by flash light of a xenon flash lamp or the like for fixing.

In this type of fixing device, it is desired that a sharp image can be obtained without the gas generated from the toner being abruptly heated by the toner from polluting the lamp peripheral members such as a flash lamp or a lamp house. FIG. 3 is a sectional side view of a conventional flash fixing device N. 1 is a flash lamp, 2 is a lamp house, 3 is a glass plate, 4 is a reflector plate, 5
Is an outlet, 6 is a suction port, 7 is a recording paper, 8 is a toner image, 9 is fine particles contained in the gas generated from the toner, 10
Is the flow direction, and 12 is the flow distribution with the flow direction being positive.
Due to the flash light of the flash lamp, the toner 8 arranged on the upper surface of the recording paper 7 is heated and melted and fixed on the recording paper 7.
At that time, gas is generated from the image 8 due to rapid heating of the toner, and the gas is a glass plate 3 which is a part of the lamp house 2.
However, there is a defect that the amount of flash light is reduced by adhering to the lamp peripheral members. In the conventional apparatus, as shown in FIG. 3, air is blown out and suction is provided to remove the gas. But,
Even with this method, it is impossible to completely eliminate the above drawbacks, and it is necessary to regularly clean the glass plate or the like. The reason for this is that the blowout flow is a wall-attached jet along the glass plate 3 as shown in the flow velocity distribution 12, and therefore the flow velocity is high even in the immediate vicinity of the glass plate 3 and there is an air flow toward the glass plate 3, which causes contamination The fine powder will be carried to the glass plate, but this point has not been considered in the past.

The gas described in this specification is not necessarily in a gas phase state, and refers to all the substances released into the air by heating the toner, and the state is mainly in the gas phase, but fine particles are contained in the gas. Even if there is, it is called gas including fine particles.

Note that, as a device related to this kind of device, there is, for example, Jitsukai 56-3562.

[Problems to be solved by the invention]

The prior art described above does not consider the adherence of the wall of the blowout flow, and has a problem in that the lamp peripheral member such as a glass plate is contaminated.

An object of the present invention is to eliminate the contamination of the lamp peripheral members with gas.

[Means for solving problems]

The above object is achieved by separating the blowout flow from the lamp peripheral member and making the airflow a free jet so that the airflow toward the N lamp peripheral member is eliminated.

[Action]

Figure 4 shows the free jet flow field. Reference numeral 5 is a blowout port, 12 is a flow velocity distribution, 11 is a boundary line between the jet flow and the still air, and 13 is a streamline of air or gas sucked from the still air into the jet flow. In this way, the air flows from the still air into the jet while being entrained, and in the case of a two-dimensional free jet, the width of the N jet region increases in proportion to the length in the flow direction, and the maximum flow velocity in the flow cross section is It decreases in proportion to the −1/2 power, and eventually the jet area disappears. N Therefore, the gas and air entrained in the jet area will not go out of the jet area until the flow velocity decreases and the jet area disappears.

Therefore, since the free jet is provided between the lamp peripheral member and the recording paper, and the lamp peripheral member is not present inside the jet area, the gas does not touch the lamp peripheral member and these members are not contaminated. .

〔Example〕

 An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a sectional side view of the flash fixing device of the present invention. 1 is a flash lamp, 2 is a lamp house, 3 is a glass plate, 4 is a reflection plate, 5 is an outlet, 6 is a suction port, 7 is a recording paper, 8 is a toner image, and 9 is included in the gas generated from the toner. The fine particles are shown in the figure, 10 is the direction of the flow velocity, and 11 is the boundary between the jet and the still air. As shown in the figure, by providing the blow-out control plate 15 at the blow-out port 5, the flow separates from the peripheral members of the lamp and becomes a free jet. In one example, the distance from the outlet to the inlet is 50 mm and the outlet width is 2 mm. In this case, the width of the jet area at the suction position is 12 mm. The suction port width must be wider than this, and it is 13 mm with allowance. The distance from the recording paper to the jet center position is 8 mm. Since the gas generated from the toner has a rising speed in the blowing velocity, if it is too low, the jet region may be interrupted. 30 toner surface
Since it is heated to about 0 ° C, the upward component of the upward velocity of gas due to natural convection is about 0.3 m / S at the jet center position. The method for determining the blowout velocity by the approximate method will be described below. The width of the jet area at the central position in the flow direction of the jet is
6 mm. If the jet lump that has flowed out of the outlet reaches the inlet earlier than the time when the upward flow of gas travels this distance, the gas will not pass through the jet area. The flow velocity calculated from this condition is the average flow velocity of the jet center velocity, and is 2.5 m / S from the above conditions. Here, the average velocity of the jet center velocity is
It is 0.75 times the flow velocity at the outlet. Therefore, the outlet flow velocity is 3.3m / S. However, since this calculation is an approximate calculation using the average value, in this embodiment, the blowout flow velocity is set to 5 m / S with 1.5 times the margin. As a result, the gas generated from the toner is drawn into the free jet and reaches the suction port without going out of the jet region. As described above, according to the present embodiment, the gas that causes stains generated from the toner does not reach the glass plate 3, so that the glass plate 3 is not stained.

FIG. 2 is a sectional side view of a flash fixing device showing another embodiment. The glass plate is removed from the flash fixing device shown in FIG. The glass plate is provided to protect the flash lamp 1 and the lamp peripheral members such as the reflector 4 from dirt. If a glass plate is provided,
The flash light is absorbed by the glass, which causes various problems such as loss of fixing energy and danger of ignition during jam due to heating of the glass. As shown in FIG. 1, by separating the flow from the peripheral member of the lamp and free-flowing the gas, the gas that causes contamination does not go out of the jet area. Therefore, in this case, the glass plate is no longer needed, and the flash lamp 1 and the reflector peripheral members such as the reflector 4 are not contaminated even if the embodiment of FIG. 2 is used. As described above, according to this embodiment, the glass plate can be eliminated, so that the fixing energy loss due to the absorption of N flash light in the glass plate,
It has various effects such as the danger of ignition at the time of jamming due to heating of glass, the weight saving of the fixing device, and the cost reduction.

A two-dimensional free jet is used for the flow, common to the two embodiments described above.

[Advantages of the Invention] According to the present invention, by separating the blowout flow from the lamp peripheral member to form a free jet flow, the air flow toward the lamp peripheral member is eliminated, and thereby the gas generated from the toner is generated by the lamp. Since it can be prevented from reaching the peripheral members, there is an effect that the lamp peripheral members are not polluted.

[Brief description of drawings]

FIG. 1 is an illustration of a flash fixing device according to an embodiment of the present invention, FIG. 2 is an illustration of a flash fixing device of another embodiment, FIG. 3 is an illustration of a conventional flash fixing device, and FIG. FIG. 6 is a diagram showing a flow field of a free jet. 1 ... Flash lamp, 2 ... Lamp house, 3 ...
Glass plate, 4 ... Reflector plate, 5 ... Air outlet, 6 ... Suction port, 7 ... Recording paper, 8 ... Toner, 9 ... Fine particles contained in gas generated from toner, 10 ... Flow velocity Direction, 11 ……
Boundary between jet and static air, 12 ... Velocity distribution, 13 ... Streamline of air or gas sucked into the jet from still air, 15 ... Blowout control plate.

Front Page Continuation (72) Shinichi Nishino 2-6-2 Otemachi, Chiyoda-ku, Tokyo Nikki Koki Co., Ltd. (72) Masato Yamada 2-6-2 Otemachi, Chiyoda-ku, Tokyo Inside the Ritsuko Kikai Co., Ltd. (72) Inventor Shigetaka Fujiwara 4026 Kuji Town, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hiritsu Manufacturing Co., Ltd. (56) Reference JP-A-60-55731 (JP, A) JP-A-54- 77143 (JP, A) JP-A-56-125781 (JP, A)

Claims (1)

[Claims] 1. A flash fixing device comprising a heating source, a recording sheet, and a heating source peripheral member such as a reflecting plate, and having an air flow in a gap between the heating source peripheral member and the recording sheet. Is a free jet of 5 m / s or more, and the blowing port and the suction port are set so that the boundary of the free jet from the blowing port of the air flow to the suction port exists away from the heating source peripheral member and the recording paper. A flash fixing device, wherein the flash fixing device is provided separately from a heating source peripheral member and the recording paper, and the suction port is wider than the blowing port.