JPS61281265A - Developing device for picture tone selectable single copying machine - Google Patents

Abstract

PURPOSE:To supply a developing agent having a different characteristic to a developing sleeve by freely attaching and detaching the developing agent room to and from the developing sleeve, rotating the developing agent accommodating part and making the different developing agent room opposite to the developing sleeve. CONSTITUTION:In one developing container 3 equipped with one developing sleeve 4, a developing agent accommodating part 5 having plural developing agent rooms 6B, 6G and 6R is rotatably arranged and either of the developing rooms is selected. Consequently, a large space is unnecessary compared with the conventional device requiring plural developing devices. The number of the developing agent rooms is limited concerning one developing agent accommodating part 5 an the number cannot be increased. Then, the upper edge of the developing container 3 is open and the developing agent accommodating part 5 is constituted freely attachably and detachably as shown by an arrow A through the open edge.

Description

Detailed Description of the Invention Technical Field The present invention develops a latent image formed on a latent image carrier such as a photoconductor with different development characteristics by bringing a developer with different characteristics into contact with the latent image. It relates to a developing device.

Here, developer characteristics include differences in color, differences in copy density relative to original density (generally referred to as developer contrast characteristics), or ratio of change in copy density to change in original density (generally referred to as developer r characteristics). ), etc. For example, when color is considered as a developer property, a monochrome copying machine with color selection (mono-multicolor (sometimes called a copying machine) is well known.

Prior Art Conventionally, in monochromatic copying machines capable of selecting colors as described above,
A plurality of developing devices are arranged facing a latent image carrier such as a photoreceptor, and developers of different colors are stored in the developing devices, and one of the developing devices is selected to perform the developing operation. There are some devices that allow copying to be performed in a desired color.

However, this apparatus requires a large space around the latent image carrier due to the use of a plurality of developing devices, which poses a problem in downsizing the entire copying machine.

In addition to the above-mentioned copying machine, the developing device of the latent image carrier 1 and other devices to be arranged around the latent image carrier are formed in advance as one unit, and a plurality of such units are prepared. , there is also a case where developers of different colors are stored in developing devices in individual units. In this copying machine, there is usually only one developing device installed in the copying machine, and when changing colors and performing I copying work, the entire unit must be replaced. Although this method requires a small space for the developing device on the copying machine side, it is uneconomical because a unit must be prepared for each color. Moreover, the work for replacement is troublesome.

OBJECTS In view of the above points, the present invention provides a developing device that does not require a large space and is easy to operate for changing colors and other developer characteristics. The purpose is to

Another object of the present invention is to provide a developing device in which a large number of types of developer characteristics can be changed.

composition The above object is achieved by the following configuration.

A developing sleeve arranged to face the latent image carrier and housed in a developing container; and a plurality of developer chambers arranged within the developing container at appropriate intervals from the developing sleeve and containing developers having different development characteristics. A developer storage section equipped with
By rotating the developer storage section and making different developer chambers face the developing sleeve, it is possible to supply developers with different characteristics to the developing sleeve, and furthermore, it is possible to supply at least one developer chamber to the developing sleeve. Make it removable.

The present invention will be explained below with reference to Examples. FIG. 1 is a side view of the main parts of a copying machine using one embodiment of the present invention. In the figure, a drum-shaped photoreceptor 1 serving as a latent image carrier is coated with a static image on its surface by a well-known exposure operation. An image is formed and rotated clockwise.

The developing device 2 includes a developing container 3, a developing sleeve 4 disposed at a position below the developing container 3 facing the photoreceptor 1, and a developing sleeve 4 located within the developing container 3 at an appropriate distance from the developing sleeve 4. It has a developer storage section 5 arranged therein. The developing sleeve 4 rotates counterclockwise.

The developer storage section 5 includes a plurality of (three in the figure) developer chambers 6B.
.
G is stored.

Further, each of the developer chambers 6B, 6R, and 6G is individually provided with a sponge roller 8. These sponge rollers can rotate about the axis 9 in either the forward or reverse direction. The figure shows the case of clockwise rotation.

A part of the sponge roller 8 is each developer chamber 6B.

A developer supply opening 10 is formed between the sponge roller 8 and each of the developer chambers 6BI6G and 6R.

In the illustrated state, the sponge roller 8 of the black developer chamber 6B
is facing the developing sleeve 4, but if the roller 8 rotates in this state, the black developer 6 near the roller 8
B mechanically follows roller 8 and moves clockwise,
As a result, the developer is delivered to the developing sleeve 4 through the developer replenishment opening 1O.

The developer sent to the developing sleeve 4 is conveyed toward the photoreceptor 1 according to the rotation of the developing sleeve 4 while being made into a thin layer by the thinning blade 11 that is in contact with or close to the developing sleeve 4, and then [Photoreceptor] Electrostatically adheres to the electrostatic latent image on the photoreceptor and develops the latent image.

Black development is performed as described above. When the operator wishes to make a copy of another color instead of black copying, for example, a green copy, the entire developer storage section 5 should be aligned with the central axis 12.
0 and then 1 to move the developer replenishment opening 10 of the green developer chamber 6G to a position facing the developing sleeve 4.
If the developing work is performed using the same action as explained above,
The desired green color reproduction is achieved.

Incidentally, when changing the color, the previous developer (black developer in the above case) remaining around the developing sleeve 4 must be removed from around the sleeve. Therefore, before or after rotating the developer storage section 5, the developing sleeve 4 and the photoreceptor 1 are rotated with the sponge roller 8 stopped, thereby removing the residual developer through the photoreceptor 1. Removal work will be carried out. At this time, if the thinning blade 1 is fully moved to leave a wide gap between the developing sleeve 4 and the blade 11, the residual developer can be quickly removed.

In this embodiment, a developer storage section 5 having a plurality of developer chambers 6B and 6GI6R is rotatably arranged in one developer container 3 equipped with one development sleeve 4. Rotate to select one of the developing chambers. Therefore, a large space is not required compared to a conventional device that requires a plurality of developing devices. Therefore, the copying machine can be made smaller.

As is clear from the above description, the greater the number of developer chambers provided in the developer storage section 5, the more types of colors that can be changed. However, in reality, there is a limit to the number of developer chambers in one developer storage section 5.
The number cannot be increased unnecessarily. Therefore, in this embodiment, the upper end of the developer container 3 is left open, and the developer storage section 5 is detachable as shown by arrow A through the open end.

A developer storage section having the same shape as the illustrated developer storage section 5 is separately prepared, and a developer of a color other than black, green, and red is placed in the developer storage section. When changing colors between black, green, and red, rotate the developer storage unit 5 as described above. In addition, instead of replacing the entire developer storage section 5, each of the developer chambers 6B, 6G, and 6R is removably attached to the developer storage section 5, and when changing colors, the developer chambers 6B, 6G, and 6R are removably attached to the developer storage section 5. Alternatively, only the drug chamber may be replaced.

Thus, reproduction products can be obtained in many colors with a simple operation.

In the above embodiments, the case where color is selected as an element of image tone selection has been exemplified. However, there are various elements other than color that should be selected. For example, so-called r (gamma) characteristics, contrast, etc. can be used as selection factors.

Figure 2 shows how the image density of a reproduction product (copy) changes with respect to the original image density when copying is performed using the same developing device with three types of developers with different gamma characteristics and contrasts. It represents.

The γ characteristic is the ratio of change in copy density to change in original density, and is expressed as the slope of a straight line or curve in the figure. -Contrast is expressed as a difference (C) in copy density with respect to a certain original density.

If three types of developers having the three characteristics a+b+c shown in FIG. 2 are placed in the developing chambers 6B, 6G, and 6R shown in FIG. I can do it. If a normal reproduction product is obtained when using a developer with characteristic A, a developer with characteristic A produces a so-called high-tone image, and a developer with characteristic C produces a so-called soft-tone image.

Note that developers having different Sr characteristics or contrast can be made by changing the properties of toner and the like constituting the developer, for example, the charging characteristics.

Effects According to the present invention, operations for changing developer characteristics can be easily performed. Also, there are many types of developer properties that can be changed.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of one embodiment, and FIG. 2 is a graph showing an example of developer characteristics. 1... Photoreceptor (latent image carrier), 7B/7G, 7R... Developer, 3... Developer container, 4
°...Developing sleeve, 6B, 6G, 6R...Developer chamber, 5...Developer storage section ~ Gland-←r''%5-Mourning

Claims (3)

[Claims] (1) In a developing device that develops a latent image formed on a latent image carrier with different characteristics by contacting the latent image with a developer having different developing characteristics, the developing device is arranged opposite to the latent image carrier and is The developing sleeve is housed in a container, and a developer storage section is provided with a plurality of developer chambers arranged at appropriate intervals from the developing sleeve in the developer container and storing developers having different development characteristics. By rotating the developer storage section and making different developer chambers face the developing sleeve, developers with different characteristics can be supplied to the developing sleeve. A developing device characterized in that it is removable. (2) The developing device according to claim 1, wherein the plurality of developer chambers can be attached and detached together with the developer storage section at the same time. (3) The developing device according to claim 1, wherein the plurality of developer chambers are individually removable from the developer storage section.