JPS6344829Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a developing device used in an electrostatic recording device such as a facsimile machine or a copying machine. In particular, the present invention relates to the position of the spikes of developer in the developing portion of a developing device using a two-component developer. The purpose is to provide a means to easily and directly set the

Conventionally, developing devices using two-component developers are
A hollow sleeve is rotatably supported in the developer housing, a magnet support member that penetrates into the sleeve is fixed to the developer housing, a magnet is provided on the magnet support member, and developer is put into the developer housing. There is a method in which the sleeve is rotated, developer is attached to the sleeve surface, and the electrostatic latent image on the photoreceptor is developed by sliding the raised portion of the sleeve on the sleeve using the magnetic force of a magnet.

In order to develop the electrostatic latent image on the photoreceptor, the amount of developer that rises like a spike due to the magnetic force of the magnet on the sleeve that functions as a magnetic brush, the strength of the magnetic force, the circumferential speed of the sleeve, the sleeve's Since the resolution of the image changes depending on the direction of rotation, it is necessary to determine the above details in advance when making a developing device.However, in conventional developing devices, a sleeve in the developing area is used to adjust the subtle tone of the image. By adopting a structure that allows the magnets to be moved closer or farther apart, the amount of developer and the strength of the magnetic force can be varied.

In such conventional developing devices, in order to adjust the spikes of the developer, the magnet support member inside the hollow sleeve must be configured to be concentric with the sleeve and rotatable, and the photoreceptor and developer must be connected to each other. The above purpose has been achieved by fixing the magnet supporting member to the housing of the developing device at an arbitrary position where the magnet approaches or separates from the developing position in sliding contact. However, since the magnet is inside the sleeve, it is not possible to check how far it has been displaced relative to a predetermined reference position. It was necessary to find a reference position and an optimal position.

In another conventional example, one end of a magnet support member provided concentrically with the sleeve protrudes to the outer wall of the developer housing, and scales are provided on the end surface of the protruding magnet support member and on the outer wall surface of the developer housing. There is one that allows you to check the position and the deviation between the reference position and the set position. However, the scale does not show changes in the position of the spikes on the circumference of the sleeve, so fine adjustments must be made through trial and error.
Fine adjustment becomes more delicate as the diameter of the sleeve becomes smaller, and it is necessary to adjust the center position of the spike in units of 1 mm or less on the circumference of the sleeve, and conventional methods have no means of enlarging the displacement of the scale. There were some methods that used this, but they were not sufficient.

Instead of the above-mentioned trial-and-error adjustment, the present invention adjusts the slight changes in the developer's stand-up by adjusting the relative position of the stand-up and the indicator provided on the surface of the developer housing. This makes it possible to set the ear standing position more easily and directly than in the past. Hereinafter, embodiments of the present invention in which the display portion is formed into a convex shape will be described in detail with reference to the drawings.

FIG. 1 shows a cross-sectional view of an embodiment of the developing device of the present invention, in which a developing device housing 1 rotatably supports a sleeve 2, and the sleeve 2 is rotated as shown by an arrow 3 by a rotational driving means (not shown). Rotate.

A magnet support member 4 penetrates into the sleeve 2 . The magnet support member 4 is coaxially supported by the sleeve 2 and rotatably supported by the developer housing 1. FIG. 2 is a perspective view showing a part of the developing device of the embodiment shown in FIG. This is done by tightening the end of the magnet support member 4 that has penetrated into the boss portion 17 with the fixing screw 18 from the side.

A main magnet 5 and a sub-magnet 6 are fixed to the magnet support member 4 in a spaced manner. The main magnet 5 and the sub magnet 6 are provided at a predetermined angle, such as 90°, with respect to the center 7 of the magnet support member 4. A protrusion 9 is provided on the side wall 8 of the developer housing 1 in correspondence with the position of the sub-magnet 6. A developer housing 1 contains a developer 10. A doctor blade 11 is provided on the bottom of the developer housing 1, and an auxiliary magnet 12 is provided on the magnet support member 4. The developer 10 passes through the gap between the doctor blade 11 and the sleeve 2 while remaining attached to the periphery of the sleeve 2 and reaches the photosensitive drum 13.
Move towards.

The developer 10 rises like a spike due to the magnetic force of the main magnet 5, comes into soft sliding contact with the surface of the photosensitive drum 13, and develops the electrostatic latent image. After developing the photosensitive drum, the developer moves upward, forms spikes 14 again by the sub magnet 6, is scraped off from the sleeve 2 by the scraper 15, and falls onto the stirring member 16. The developer that is stirred by the rotating stirring member 16 and frictionally charged by the toner and the carrier advances from the doctor blade 11 toward the photosensitive drum 13 as the sleeve 2 rotates. A lid 19 is removably provided on the developing device housing 1. The convex portion 9 is provided so as to be in contact with the bristles 14 produced by the sub-magnet when the main magnet 5, which forms the bristles for developing the photosensitive drum, reaches a predetermined reference position. Since the sub-magnet 6 raises the standing ears 14 in the shape of a mountain, the standing ears are set at the reference position by aligning the apex of the standing ears with the convex portion 9. Lid 19
is removable from the developer housing 1, and is removed when adjusting the bristles to make delicate adjustments to the bristles while observing the relationship between the bristles 14 and the convex portion 9 from above the developing device.

FIG. 3 shows another embodiment of the present invention in which two convex portions are made to correspond to the width of the spikes 14 produced by the sub-magnet 6, and the same parts as in FIGS. 1 and 2 have the same number. is attached. In this embodiment, since the width of the spike 14 corresponds equally to the interval between the protrusions, in order to align the central part of the spike and the center of the protrusion, two points, the rise and fall of the spike, must be set. This is done in correspondence to the two convex portions.

FIG. 4 shows another embodiment in which a convex portion is provided on the upper surface of the side wall of the developer housing. The same parts as in FIGS. 1 and 2 are given the same numbers. In this embodiment, in order to align the center portion of the raised spike with the center portion of the convex portion, look from above the developing device housing. In this embodiment, since the two side walls of the developer housing are provided with convex portions, a ruler or the like is directly brought into contact with the convex portions, and the cross section of the spike, the straight line 21 of the rising edge of the spike, and the straight line of the falling edge are drawn. 22 to correspond to the straight line surface of the straight ruler.

FIG. 5 shows another embodiment of the present invention in which the width of the convex portion corresponds to the width of the spike 14 produced by the sub-magnet 6. The same parts as in FIGS. 1 and 2 are designated by the same numbers. It is attached. In this embodiment, since the width of the spike 14 corresponds equally to the width of the convex part, in order to match the center part of the spike 14 with the center part of the convex part, the two places, the rising and falling part of the spike, should be aligned with the convex part. This is done to correspond to the stepped part.

FIG. 6 shows another embodiment of the invention with double protrusions. The same parts as in FIGS. 1 and 2 are given the same numbers. In this example, in order to align the central part of the raised panicle with the central part of the convex part, two places, the apex of the raised panicle and the central part of the convexity, and the rise and fall of the raised panicle, must be made to correspond to the width of the convex part. Perform heavy positioning.

FIG. 7 shows another embodiment of the present invention in which a plurality of protrusions are provided at equal intervals on the side wall of the developer housing.
The same numbers are used for the same parts as in Fig. 1 and Fig. 2. In this embodiment, the protrusions are provided at equal intervals, so that the positioning of the protrusions can be performed in stages by matching any protrusion with the protrusions.

As described above, in the developing device of the present invention, by providing a convex portion on the side wall of the developer housing and bringing it into direct contact with the developer spikes, the relative position between the developer spikes and the reference position can be directly confirmed. There are advantages.

Furthermore, the present invention has the advantage that the width of the convex portion corresponds to the width of the standing ear, so that the position of the standing ear can be precisely and delicately adjusted to the reference position.

Further, the present invention has the advantage that by providing a plurality of convex portions on the side wall of the developer housing, it is possible to confirm the relative relationship between the reference position of the spike, the adjustment range, and the limit.

Furthermore, the developing device of the present invention has the advantage that the position of the spikes of developer can be set and adjusted in stages by providing a number of convex portions at equal intervals on the side wall of the developing device housing to form a scale. .

In each of the above-mentioned embodiments, the display section is formed with a convex shape, but the present invention is not limited to this.If the display section is formed with a concave shape, each of the above embodiments is possible. Exactly the same effect can be obtained, and various modifications can be made without changing the gist of the present invention, such as using a display board (marker) with adhesive.

As is clear from the above description, in the developing device of the present invention, subtle changes in the stand of the spikes can be directly adjusted by the matching position of the display section provided on the surface near the end surface of the sleeve of the developing device housing. , it is possible to easily and directly set the position where the developer spikes stand, and its industrial value is great.

[Brief description of the drawings]

1 and 2 are a sectional view and a partially cutaway perspective view of essential parts showing one embodiment of the present invention, and FIGS. 3 and 4.
5, 6, and 7 are partially cutaway perspective views showing other embodiments of the present invention. 1...Developer housing, 2...Sleeve, 4
... Magnet support member, 5 ... Main magnet, 6 ... Sub-magnet, 8 ... Side wall of developer housing, 9 ... Convex portion,
10...Developer, 18...Fixing screw, 19...
lid.

Claims (1)

[Utility Model Claims] (1) A developing device comprising a developing device housing, a hollow sleeve rotatably mounted on the developing device housing, a magnet support member penetrating into the sleeve and fixable to the developing device housing, a primary magnet mounted on the magnet support member, and a secondary magnet mounted on the magnet support member at a distance from the primary magnet, the developing device being characterized in that an indicator is provided on a surface of the developing device housing near an end face of the sleeve to indicate the position of the developer brushes corresponding to the position of the secondary magnet. (2) A developing device as described in utility model claim (1), characterized in that the width of the indicator corresponds to the width of the developer brushed on the circumference of the sleeve by the secondary magnet. (3) A developing device as described in utility model claim (1), characterized in that the indicator is divided into a plurality of parts. (4) A developing device as described in utility model claim (3), characterized in that the indicator is composed of a plurality of equally spaced parts and is used as a scale.