JPS5925218B2 - Multicolor developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multicolor developing device, and more particularly, to a multicolor developing device in which a plurality of developing units are movably supported along the same circumference.

2. Description of the Related Art As a developing device for an electrophotographic multicolor copying machine, one in which a plurality of developing devices of each color are arranged in parallel in the vicinity of a photoreceptor in the direction in which the photoreceptor carrying an electric latent image advances is known.

However, with this type of developing device, it is necessary to take measures to prevent other developing devices from operating while one developing device is operating, such as not rotating the magnetic brush or moving it away from the developing position. be. Further, especially in magnetic brush development, since the magnetic brush rotates during development and toner particles are scattered, each developing device must have a suction duct to prevent the toner particles from entering other developing devices. Therefore, the above-mentioned type of developing device requires a complicated mechanism to prevent color mixing, and since the developing device group occupies a large space around the photoconductor, it is necessary to use a complicated mechanism to prevent color mixing.
Space for the fixing device, etc. is being squeezed. The present invention provides a developing device that eliminates the above-mentioned drawbacks.The present invention provides a developing device that supports a plurality of developing units movably along the same circumference. Each of the two axes parallel to the circumferential center axis is the rotation axis of the support arm supporting each side end of the development unit, and the distance between the development unit support axes of each support arm is set equal to the distance between the rotation axes. , the developing unit is pivotally supported between the support arms in a quadrilateral four-section mechanism.

The illustrated example is constructed using four developing units 31 to 34, each containing a different colored toner powder, magnetic brushes 311 to 341, and toner stirring screws 312 to 342. is installed.

The developing devices 31 to 34 are connected to each arm 71, 81, 72, 82, 73 of a pair of left and right cross-shaped rotating side plates T0 to 80.
, 83, 74, and 84 in parallel with each other. 711~
Reference numerals 741 and 811 to 841 are their supporting shafts, and reference numerals 75 and 85 are rotating shafts of the side plates 70 and 80, respectively.

In this case, the lengths of the arms of the side plates 70 and 80 (the length from the rotating shaft to the supporting shaft) are all the same length a. Further, the side plates 70 and 80 are arranged so that the axes of the rotating shafts 75 and 85 are shifted by a distance b, and the supporting shafts on the side plate 70 side of each developing device and the side plate 8
The axial distance of the support shaft on the 0 side is also set to b. In other words, when looking at the side view (FIG. 3) of the above device, each developing device 3
Regarding 1 to 34, the support arms of the left and right side plates 70 and 80 are two opposing sides (both side lengths are a), and the left and right side plates 70, 8
A parallelogram-shaped translation mechanism is constructed, with two opposing sides (both side lengths are b) between the rotation axes 75 and 85 of 0 and between the support axes of the left and right side plates.

Therefore, by driving the shafts 75 and/or 85, the left and right side plates 70
and 80 are rotated in the same direction and at the same speed, each of the developing devices 31 to 34 rotates around the midpoint M connecting the shafts 75 and 85, with the opening always facing upward.
Therefore, the above-mentioned developing device is disposed below the electrophotographic photoreceptor 1, and when the photoreceptor 1, on which the first color exposure is completed and an electrostatic latent image has been formed, rotates to the developing section, Prior to or in synchronization with this, a developing device 31 corresponding to the exposed color is installed in the developing section.
(FIG. 4A) and rotate the magnetic brush to visualize the electrostatic latent image on the photoreceptor 1. Next, when the development corresponding to the first exposure color is completed and the exposure of the second color is performed, the entire developing device is rotated by a predetermined angle (900 degrees in the figure), and the process shown in Figure 4 is completed. After that, the developing device 31 is separated from the developing section as shown in FIG.
2 is set at the developing position.

When the second color exposure is completed and the photoreceptor on which the electrostatic latent image has been formed begins to rotate, the magnetic brush rotates to perform development. Thereafter, the above steps are repeated to perform multicolor development. According to the above development position, only the developing device that performs development is set close to the photoconductor, and the other developing devices are located away from the photoconductor, so there is a risk of color mixing as in the conventional parallel type. Gender disappears.

Furthermore, since each developing device is always moved with its opening facing upward, toner powder does not fall out of the developing device. Therefore, it is compactly constructed without requiring a complicated device for preventing mixing, and the drawbacks of the conventional devices described above are eliminated. Next, in principle, the developing device of the present invention has a side plate 7 that supports each developing device.
The projected distance b between the support shaft on the 0 side and the support shaft on the side plate 80 side must be equal to the distance b between the rotation axes 75 and 85 of the side plates 70 and 80 with high accuracy.

Therefore, as shown in FIG. 5, if one side 14 of each developing device is rotatably supported on the side plate, and the other side 13 is supported with a degree of freedom in the horizontal direction (elongated hole, etc.), high precision can be achieved. It can be assembled and has practical effects. The turret type developing device of the present invention can be used both as a multicolor electrophotographic device for a transfer type copying machine and as a multicolor electrophotographic device for a so-called electrofax type copying machine using photosensitive paper. Furthermore, by replacing the illustrated magnetic brush developing device with a wet developing device, it can be used as a wet developing multicolor electrophotographic apparatus.

[Brief explanation of the drawing]

The drawings show an embodiment of the apparatus of the present invention, in which Fig. 1 is a perspective view, Fig. 2 is a cross-sectional view of the device disposed below the drum-type electrophotographic photoreceptor, Fig. 3 is a side view, and Fig. 3 is a side view. 4A, 4B, and 4C are state explanatory diagrams of the rotational movement process, and FIG. 5 is a perspective view of the main part showing the supporting shaft of the developing device. 31 to 34 are developing units; 70 and 80 are a pair of left and right rotating side plates for supporting the developing units, which face each other with their rotational axes shifted; 75 and 8
5 is their rotation axis, 711-741, 811-841
is the developer pivot shaft.

Claims (1)

[Claims] 1. In a multi-color developing device in which a plurality of developing units are movably supported along the same circumference, each of the two axes parallel to the center axis of the circumferential movement of the developing unit is supported at each side end of the developing unit. The distance between the supporting axes that rotatably support the developing unit of each supporting arm is set equal to the distance between the rotating axes. A multicolor developing device characterized in that a parallelogram is formed between the developing units and the developing unit is pivotally supported.