JPS6240714B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light reflecting mirror of an optical fixing device for fixing a toner image formed on recording paper.

Conventionally, this type of optical fixing device is shown in FIGS.
- As shown in FIG. 2, which schematically shows the A cross section, the light from the flash lamp FL1 is reflected by a light reflecting mirror 2 having an arcuate cross section, and is irradiated through a glass plate 3. The toner on the recording paper 4 is heated and melted by the light emitted from the flash lamp 1, and the toner image 4a is fixed on the recording paper 4.

As described above, the conventional optical fixing device uses the reflecting mirror 2 with an arcuate cross section, so the energy distribution of the irradiated light on the recording paper 4 is at its maximum near directly below the flash lamp 1, and increases as it moves away from this area. This results in a decreasing non-uniform distribution. Therefore, flash lamp 1
The toner image located immediately below exhibits sufficient fixing properties, and a phenomenon occurs in which the toner image located far away from the directly below becomes fixed. Further, when the input to the flash lamp 1 is increased in order to eliminate unfixed portions of the toner image on the recording paper 4, there is a drawback that a toner burn-in phenomenon occurs and the image is disturbed.

This invention was made to eliminate the above-mentioned drawbacks of the conventional technology.
An object of the present invention is to provide a light reflecting device that can obtain a uniform irradiation light distribution on the irradiation surface with a simple design by horizontally disposing it in a three-sided reflecting mirror that opens in a shape that widens toward the irradiation surface. .

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

In FIG. 3, reference numeral 5 denotes a three-sided reflecting mirror that is substantially symmetrical on the left and right and has an opening that widens toward the irradiation surface. The flash lamp 1 consists of left and right side plate reflectors 7 and 8 that are inclined outwardly and downwardly.
The center of the tube is 1/2φ~ with respect to the front plate reflector 6.
It is horizontally arranged within the three-sided reflecting mirror 5 at a vertical position of 3/2φ (where φ is the diameter of the flash lamp tube). The left and right side plate reflectors 7 and 8 are configured so that, with respect to one horizontal plane, the image point at the center of the tube of the flash lamp 1 by the both side plate reflectors is located at the intersection of the lower edge of the reflective surface of the both side plate reflectors and the horizontal plane. 1/2 left and right
It is constructed to have an inclination that exists between vertical planes passing through horizontal positions shifted by φ. The irradiation surface is provided by the recording paper 4, and the one horizontal surface is provided by the glass plate 3. Since the other configurations are the same as those of the conventional device, the explanation thereof will be omitted.

Hereinafter, for convenience of explanation, the effects of the present invention will be described in detail with reference to FIG. 4, which schematically represents the three-sided reflecting mirror 5. In the same figure, points a, b, c and d
are the reflective surfaces of the plate reflectors 6, 7, and 8 and the glass plate 3
Point e is the tube center position of the flash lamp (hereinafter abbreviated as F/L) 1, and points f, q and h are the plate reflector 7, 8 and 6 are represented. Also, the angle θ ₁ is the angle between the line R perpendicular to the horizontal line and the reflective surface of the side plate reflector 7, and the angle θ
₂ is the angle between the line and the reflective surface of the side plate reflector 7, _θ3 is the angle between the line and the reflective surface of the side plate reflector 8, and angle _θ4 is the angle between the line and the reflective surface of the side plate reflector 8, and the line It represents the angle made with the line C perpendicular to . Note that the trapezoid ABCD is symmetrical with respect to the perpendicular line A passing through the right and left bisecting point p of the front reflecting mirror, with the perpendicular line A being the y-axis direction and the horizontal line D representing the recording paper 4 being x.
In the axial direction. Points a', o', and d' on horizontal line D indicate the intersections of extensions of perpendicular line B, perpendicular line A, and perpendicular line C, respectively, and horizontal line D.

In the above schematic diagram, if the light emission center of the flash lamp 1 is the same as the center of the tube of F/L1, the irradiation intensity distribution of the direct light from the flash lamp 1 irradiated onto the recording paper 4 is calculated by the following formula. It is expressed as follows.

I=I ₀ cosθ/r=I ₀・y/r ² …(1) However, I: amount of light received on the irradiation surface (Y-axis component);
I ₀ : Amount of light emitted from F・L1 per unit angle; θ:
^{LO ' e _} Since (y/r ² ) decreases as it moves away from the paper 4 in the axial direction, the difference in the amount of irradiation light between the ends a', d' and the center o' of the recording paper 4 becomes smaller and becomes uniform.

(b) Effect of the position of the front plate reflecting mirror 6 The effect of the light reflected by the front plate reflecting mirror 6 on the recording paper 4 is that the light emitted from the image point h at the center of F/L1 is directly irradiated onto the recording paper 4. Therefore, the closer the front plate reflector 6 is to the center e of F・L1, the more the recording paper 4
The irradiation intensity increases. However, when the front plate reflecting mirror 6 and the F/L1 are arranged close to each other, the position where the mirror can be approached is limited by the tube diameter φ of the F/L1 and the trigger line. That is, in FIG.
It is necessary that eP>φ/2, and in fact, from the viewpoint of efficiency, it is preferable that φ/2<eP<3/2φ.

(c) Effect of the inclination of the side plate reflectors 7 and 8 The theoretically possible inclinations of the side plate reflectors 7 and 8 are as follows:
As shown in FIG. 5, (a) both side plate reflectors intersect on the front plate reflector 6 (hereinafter referred to as case 1), and (b) both side plate reflectors 7 and 8 are respectively front plate reflectors. 6, that is, an inclination within the range of both inclinations (hereinafter referred to as case 3) when the respective reflecting surfaces exist on perpendicular lines B and C (hereinafter referred to as case 2). In the same figure, case 3a is the reflection of the both side plate reflectors 7 or 8 when the image point f or q of the tube center e of F/L1 by the both side plate reflectors 7 or 8 is on the perpendicular line B or C, respectively. It corresponds to the inclination of the surface, that is, the posture. Case 3b shows another posture in which the side plate reflecting mirrors 7 and 8 are in a position between cases 1 and 2. That is, in case 3a, the light emitted from the tube center e is reflected by the lower edges of both side plate reflectors 7 and 8, and then the reflected light is irradiated perpendicularly to the glass plate 3.

In other words, case 3a is a case where both side plate reflectors 7 and 8 are placed on the respective bisectors of <eaf and <edg in FIG. 4, and in this case, θ ₁ = θ ₂ and θ ₃
= θ ₄ .

In both cases 3a and 3b, the image point f of the tube center e formed by the side plate reflector 7 exists on a circular arc centered on point a and having a radius of. The same applies to the image point g of the tube center e formed by the side plate reflecting mirror 8, which is located on a circular arc with a radius centered on the point d.

Figure 5B shows that the recording paper 4 is placed on top of that in Figure 4, =25mm, =50mm and =50mm.
When the light reflectance is 90
% _{, the} results of measurement using the slope of each case as _a parameter are shown. R ₃ b, and the sum distribution of each
They are expressed as T ₁ , T ₂ , T ₃ a and T ₃ b.

It is understood from this figure that (y/r ² ) max is maximum in case 3a, and the distribution is most uniform in case 3a. In other words, when the inclinations of the side plate reflectors 7 and 8 are such that the image point at the center of the tube of F and L1 is on a perpendicular to the irradiation surface at the point where the lower edge of each reflection surface intersects with the irradiation surface. A uniformly distributed maximum irradiation intensity is obtained when the slope is .

However, in reality, the light emitting point of F・L1 is not fixed at the center of the tube of F・L1 and may move within the tube, so when this is taken into account,
Pipe center e of F/L1 by side plate reflectors 7 and 8
The image points f and g of
It is preferable that the tube be located between vertical planes passing through points shifted left and right by the tube radius φ/2.

In addition, since the light emitting point of F/L1 is likely to occur along the trigger line, it is preferable that the trigger line is parallel to the pipe length direction and on the perpendicular line A. By doing so, the light emitting point of F/L1 approaches the center of the light reflecting device, and the irradiated light distribution becomes more uniform.

Although the irradiation light distribution in FIG. 5 was measured for a line, it is obvious that a similar uniform distribution can be obtained for a line ''.

As described above, the present invention uses the front and left and right side plate reflectors to construct a three-sided reflector and houses a flash lamp therein. As for the inclination of the side plate reflector, the image point at the center of the flash lamp tube due to these angles is 1/2φ (φ: lamp (Pipe diameter) Select the inclination that exists within the two vertical planes that pass through the shifted points, and select the distance between the reflective surface of the front plate reflector and the center of the flash lamp tube from the range of 1/2φ to 3/2φ. This alone makes it possible to make the irradiation light distribution on the irradiation surface much more uniform than when using a conventional concave reflecting mirror. Therefore, according to the present invention, there is provided a light reflecting device for an optical fixing device, which can fix a toner image on a recording paper in any part of the recording paper without too much or too little with a simple design and manufacturing procedure. be able to.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a conventional example of a light reflecting device;
The figure is a schematic diagram of the A-A view in Figure 1,
The figure is a schematic sectional view of one embodiment of the light reflecting device according to the present invention, FIG. 4 is a schematic diagram of FIG. 3, and FIG. 5 is a diagram of the irradiation light distribution of the above embodiment. 1 is a flash lamp, 5 is a three-sided reflector, 6 is a front plate reflector, and 7 and 8 are side plate reflectors.
In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1 A three-sided reflective mirror with a substantially symmetrical shape that spreads toward the left and right, consisting of a front plate reflector that is parallel to a horizontal plane, and left and right side plate reflectors whose lower edges intersect with the horizontal plane and are at an angle to the horizontal plane. The center of the mirror and tube is 1/2φ to 3/2φ with respect to the above front plate reflector (however,
A flash lamp is disposed horizontally within the three-sided reflector at a vertical position of φ: tube diameter), and an image point of the side plate reflector at the center of the tube of the flash lamp is set at a vertical position of the side plate reflector. It exists between two vertical planes that pass through a horizontal position shifted by 1/2φ to the left and right from the intersection of the lower edge of the reflective surface and the above one horizontal plane, and the above 1
A light reflecting device characterized in that an irradiation surface is one horizontal plane or another horizontal plane located a little distance below the horizontal plane.