JPS6012134Y2 - Fusing device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a fixing device used for fixing toner in a copying machine.

Conventionally, in this type of fixing device, as shown in FIG. 1, a discharging linear heating element 2 is disposed within the concave curved surface of a reflecting mirror 1 formed into a concave curved surface forming a part of an ellipse. As shown in Figure 2, the radiant heat distribution on the fixing surface is high at the center of the fixing width 1;
On the contrary, it was lower at the periphery and was not uniform.

On the other hand, in flash fixing using the dischargeable linear heating element 2, the fixing width 1 is generally 70 to 10 orrr!
The area is relatively wide, about n, and the radiant heat distribution within the fixing width 1 is required to be uniform.

This depends on the characteristic of flash fixing that fixing within a certain width is instantaneously performed, and since the lighting time (discharge time) of the linear heating element 2 is different from the fixing time, the radiant heat distribution is If it is not uniform, uneven fixing will occur depending on the distribution.

However, in the conventional fixing device described above, uneven fixing occurs because the radiant heat distribution is not uniform, and if multiple exposures are repeated to avoid this, not only does it consume a large amount of power, but the fixing efficiency deteriorates. Furthermore, more radiant heat than necessary is accumulated in some areas, reducing reliability.

The present invention eliminates the drawbacks of the conventional ones mentioned above,
This was developed with the aim of providing a fixing device that uniformizes the distribution of radiant heat within the fixing width.The required deep area of the reflecting mirror is formed into a hyperbolic concave part, and the part that follows this concave curve is is formed into a concave curved surface that forms part of an ellipse,
By aligning the focal lines of these biconcave curved surfaces and arranging a discharge linear heating element on this common focal line, we made use of the difference in the reflection state due to the biconcave curved surfaces to achieve a distantly related purpose. This is what I did.

The present invention will be explained below with reference to embodiments shown in the drawings.

FIG. 3 shows an embodiment of the present invention, in which a reflecting mirror 10 is shown.
consists of a first reflecting mirror 11 and second reflecting mirrors 12 located on both sides of the first reflecting mirror 11.

Among these, the first reflecting mirror 11 occupies a required deep area of the reflecting mirror 10, is formed into a hyperbolic concave curved surface, and has a notch 13 in the center.

Further, the second reflecting mirror 12 following the first reflecting mirror 11 is formed into a concave curved surface forming a part of an ellipse.

The focal line F1 of the biconcave curved surfaces of the first reflecting mirror 11 and the second reflecting mirror 12 coincide with each other, and the dischargeable linear heating element 14 is disposed on this common focal line F1. .

Furthermore, the radiant heat from the linear heating element 14 reflected by the first reflecting mirror 11 reaches the center from both ends of the fixing width l of the fixing surface, so that the Since the radiant heat from the first reflecting mirror 11 overlaps, the distribution of the radiant heat reflected by the first reflecting mirror 11 is high at the center of the fixing width 1 and low at the periphery.

On the other hand, the radiant heat from the linear heating element 12 reflected by the second reflecting mirror 12 reaches only the peripheral portion of the fixing width I of the fixing surface.

Note that the direct radiant heat from the linear heating element 14 that is not reflected by both the reflecting mirrors 11 and 12 reaches the entire area of the fixing surface, as shown by diagonal lines in FIG.

Further, F2 in FIG. 3 is an imaginary light source.

According to the above-described configuration, the distribution of the radiant heat from the first reflecting mirror 11 on the fixing surface is such that the central part is higher than the peripheral part as described above, but the radiant heat distribution from the second reflecting mirror 12 is corrects the radiant heat distribution from the first reflecting mirror 11, so the radiant heat distribution by the fixing device of the present invention becomes substantially uniform over the entire fixing width 1, as shown in FIG.

At this time, the direct radiant heat from the linear heating element 14 follows Lambard's law, so the radiant heat distribution is high in the center and low in the periphery. The configuration of the mirror 12 increases the amount of radiant heat that reaches the periphery to provide the uniform radiant heat distribution described above.

The radiant heat distribution by the fixing device of the present invention shown in FIG. 4 described above is more suitable for obtaining an extremely good fixing state than the radiant heat distribution by the conventional fixing device shown in FIG.

As explained above, the fixing device according to the present invention forms a requisite deep region of the reflecting mirror into a hyperbolic concave curved surface, and forms the part following this concave curved surface into a concave curved surface that forms a part of an ellipse. By aligning the focal lines of these biconcave curved surfaces and arranging a discharge linear heating element on this common focal line, the radiant heat distribution can be made almost uniform, resulting in efficient and high quality fixing. be able to.

In the above-described embodiment, the first reflecting mirror and the second reflecting mirror are made discontinuous, but in a quadratic curve, innumerable curves sharing one focal line can be drawn, so the first reflecting mirror forming a hyperbola can be drawn. Needless to say, there are cases where the reflecting mirror and the elliptical second reflecting mirror can be connected.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the outline of a conventional fixing device, FIG. 2 is a graph showing the radiant heat distribution by the fixing device in FIG. 1, and FIG.
The figure is an explanatory diagram showing an embodiment of the fixing device according to the present invention.
The figure is a graph showing the radiant heat distribution by the fixing device of FIG. 3. 1.10... Reflecting mirror, 2,14... Linear heating element, 11... First reflecting mirror, 12... Second reflecting mirror, Fl...・, F2・・・Focus (focal line)
, 1...Fixing width.

Claims (1)

[Scope of utility model registration request] In a fixing device in which a part of the heat from a discharging linear heating element is reflected by a reflecting mirror, a required deep area of the reflecting mirror is formed into a concave curved surface forming a hyperbola, and a concave curved surface is formed following this concave curved surface. A fixing device characterized in that the portion is formed into a concave curved surface forming a part of an ellipse, the focal lines of these biconcave curved surfaces are made to coincide, and the linear heating element is disposed at this common focal line. .