JPS6215817Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a toner supply device for an electrophotographic apparatus.

In dry electrophotography in which an electrostatic latent image formed on copy paper or the like is visualized using toner, it is necessary to sequentially supply consumed toner.

Conventionally, toner has been supplied manually by visually observing the amount of toner consumed, or automatically by detecting the amount of toner consumed by electrical means. Although it is more convenient to supply toner automatically, it requires a means to detect the amount of toner consumed, in other words, the amount of toner consumed, and such a means for detecting the amount of consumption has the disadvantage of being complicated and expensive. .

Therefore, if the consumption amount of toner according to the size of the copy paper is checked in advance and toner is supplied according to the size of the copy paper, the above-mentioned expensive and complicated consumption amount detection means is unnecessary.

Furthermore, from the viewpoint of toner concentration, the timing of toner supply seems to be good, but from the other viewpoint of developer deterioration, the timing of supply has a great significance. That is, the developer is agitated in the developer reservoir and the circumferential surface of the magnetic brush forming sleeve, but when this agitation becomes excessive, its characteristics tend to deteriorate.
This deterioration of the developer poses a serious problem in image formation.

In visualizing the electrostatic latent image formed on the copy paper, the present invention further provides toner supply timing approximately at the same time as the copy paper is brought to the developing section. so that the toner can contribute to development before it becomes overly agitated, in other words, before it loses much of its properties as a developer.
Another objective is to provide a toner supply device that is timely.

The present invention will be explained below with reference to illustrated embodiments.

In FIG. 1, reference numeral 1 designates a guide plate that guides a copy sheet 2 on which an electrostatic latent image is formed and is conveyed in the direction of arrow a by a conveyance device (not shown). The guide plate 1 is formed with a long hole 1a into which a free end 4a of a copy paper detection actuator 4 fixed to the shaft 3 is inserted. The shaft 3 is rotatably supported by a stationary member (not shown), and a two-arm member 5 is firmly fitted on the right side in the figure as a locking arm positioning member for positioning the locking arm, which will be described later. . A weight 6 is fixed to one arm 5a of the two-arm member 5, giving it a tendency to rotate counterclockwise (in FIG. 2) with respect to the shaft 3. The other arm 5b of the two-arm member 5 is divided into two parts, and pushing arms 5b ₁ and 5b ₂ are formed.

A shaft 7 is disposed below the shaft 3 and is connected to a drive device (not shown) and constantly rotates in the direction of arrow b. A cam 8 having a stepped portion 8a and a disc 9 are loosely fitted onto the shaft 7, and are connected via a one-way rotating clutch 10.
A fitting hole 9a is formed in the disc 9, into which one end of a swinging arm (described later) is fitted (see FIG. 2).

An engaging portion 12a of one arm 12 of a locking arm 11 that locks the cam 8 in the first position shown in FIGS. 1 and 2 is engaged with the stepped portion 8a of the cam 8. Therefore, although the shaft 7 is constantly rotating, the rotation of the cam 8 is stopped by the one-way rotating clutch 10.

The locking arm 11 is rotatably supported on a shaft 13, and a short shaft 15 is fixed to the end of the other arm 14.
The pushing arm _5b1 of the two-arm member 5 abuts against the shaft 13 in a clockwise direction (in FIG. 2).
is being swayed to. Therefore, the rotation of the cam 8 is stopped by the action of the weight 6 of the two arm member 5. In addition, the locking arm 11
The inner arm end of the other arm 14 facing the cam 8 has a locking stepped portion that engages with the stepped portion 8a and locks the cam 8 in the second position as shown in FIG. 1
4a is formed.

On the other hand, one end 18a of a swinging member 18, which is a shift member that is supported by a shaft 16 and given swinging behavior by a spring 17, abuts against the end face of the disc 9. The tip of this one end 18a is bent and protrudes toward the disc side. The other end 18b of the swinging member 18 is connected to a spring 1 having a force smaller than that of the spring 17.
9 engages the bent portion 20a of the control member 20, which is given a movement habit in the direction of arrow c (see FIG. 4).

A cam 23 and a pulley 24 are connected to the shaft 21, which is constantly rotating in the direction of arrow d by a drive device (not shown), via a one-way rotating clutch 22.
is installed. However, since the stepped portion 23a of the cam 23 engages with the side edge 20b of the control member 20, the cam 23 and pulley 24 are stopped without rotating.

A belt 27 is stretched between the pulley 24 and a pulley 26 fixed to a shaft 25 rotatably supported by a stationary member (not shown). A disk 28 is fixed to the end of the shaft 25, and a pin 29 is firmly planted in the disk 28 in the axial direction.

Within the rotation locus of the pin 29, a pin 31 is fixedly planted perpendicularly to a shaft 30 rotatably supported by a support member (not shown).
9 and 31 are engageable. A hopper vibration cam 32 is fixed to the end of the shaft 30.

As shown in FIG.
are in contact with each other. The hopper 33 has a V-shaped cross section, stores toner 35 therein, and has a toner discharge port 34 formed at its lower part. A thin leaf spring 37 whose base side edge is fixed to the immovable member 36 is attached to the inner surface of one side of the hopper, with its free side edge facing the toner discharge port 34 . The hopper 33 has one side 33a in contact with the vibration cam 32, and the other side 33b has a short shaft 38 swingably supported by a stationary member (not shown). Furthermore, a magnetic brush forming member 39 is disposed below the discharge port 34.

In FIG. 2 showing the starting position of the toner replenishing device of the present invention configured as described above, when copy paper 2 on which an electrostatic latent image is formed is now being conveyed in the direction of arrow a, The actuator 4 for detecting a copy paper located inside the paper is pushed against its natural tendency as shown in FIG. The actuator 4 continues to swing as long as the copy paper 2 is in this position.

When actuator 4 swings clockwise,
The shaft 3 to which this is fixed rotates in the same direction. The rotation of the shaft 3 causes the two-arm member 5 fixed _thereto to swing against its natural tendency. The locking arm 11, which had been swung clockwise to lock the cam 8 in the first position, is now swung counterclockwise by the pushing arm _5b2 .
The swinging of the locking arm 11 is caused by the engagement portion 12 of the arm 12.
a and the stepped portion 8a of the cam 8 (see Fig. 2)
will have to be removed.

Therefore, when the locking action of the cam 8 is released, the cam 8 follows the rotation of the shaft 7, which is constantly rotating clockwise, through the one-way rotation clutch 10, and rotates at the same time. The disk 9 also rotates in the same direction.

However, on the circumferential surface of the cam 8 that rotates in the clockwise direction, the locking arm 11 that is swung in the counterclockwise direction is
Since the locking step 14a formed on the other arm 14 is in contact, the step 8a of the cam 8 immediately engages with the locking step 14a to position the cam 8 at the second position. to stop its rotation. When the cam 8 is stopped, the disc 9 is also stopped from rotating. The stopping position of the disk 9 is such that the bent end of one end 18a of the swinging member 18 that abuts against the end surface of the disk 9 swings due to its swinging habit and is fitted into the fitting hole 9a. This is the position where The swinging of the swinging member 18 changes from the position shown in FIG. 4 to the position shown in FIG. 5.

That is, one arm 18b of the swinging member 18, which swings clockwise about the shaft 16, pushes the control member 20 engaged therewith against its natural tendency. When the control member 20 moves, the side edges 20 of this
b is disengaged from the stepped portion 23a of the cam 23, so that the cam 23 is transmitted with the rotation of the shaft 21, which is constantly rotating, by the action of the one-way rotary clutch 22. The pulley 24 also rotates at the same time as the cam 23, causing the pulley 26 to rotate in the same direction.

As the pulley 26 rotates, the substantially integral disc 28 rotates through it and the shaft 25 (see FIG. 1), and the pin 29, which abuts the pin 31 of the shaft 30, is moved through the shaft 30 into the hopper. The swing cam 32 is rotated counterclockwise in FIG. Vibration cam 32
When the hopper 33 rotates, the hopper 33 in contact with the circumferential surface of the hopper 33 is vibrated. As the hopper 33 vibrates, the toner 35 stored therein is supplied from the discharge port 34 to the magnetic brush forming member 39 disposed below the discharge port 34 by the action of the leaf spring 37, and the toner 35 stored therein is supplied to the magnetic brush forming member 39 disposed below the discharge port 34, and the toner 35 stored therein is supplied to the magnetic brush forming member 39 disposed below the discharge port 34. It is supplied onto paper 2A to visualize the electrostatic latent image.

The supply of toner 35 from the hopper 33 is as follows:
It does not start immediately when the actuator 4 detects copy paper and swings, but starts when the copy paper 2A shown in FIG. 2 reaches the lower part of the hopper. At this timing, the actuator 4 swings and the cam 8 engages the engaging portion 12a.
In other words, the length of the engaging part 12a and the engaging part 14a and the rotational speed of the cam 8 are copied. It is set according to the paper transport speed. That is, the cam 8 moves from the first position shown in FIG.
During the displacement to the second position shown in the figure, the leading edge of the copy paper reaches the developing section.

In other words, the toner supplying action from the hopper 33 is performed by the vibration cam 32 as a vibration device, the pulleys 24 and 26 driving the vibration cam 32, and the shaft 2 that drives the vibration cam 32.
1 continues while the actuator 4 is in operation while detecting the copy paper 2.
Therefore, if the copy paper that swings the actuator 4 passes, the actuator 4 will
Due to the action of the weight 6, the second arm member 5 and the shaft 3 are
Return to the original position shown in the figure. Due to this swinging of the two arm member 5 from its original position, the locking member 11 is pushed clockwise and engages the step portion 8a of the cam 8 and the engagement step portion 14a.
The connection will be removed. The cam 8 released from the second position rotates in response to the rotation of the shaft 7, and the stepped portion 8a
is engaged with the engaging portion 12a and stopped at the first position.

As the cam 8 returns to its original position, the disc 9
4, the bent end of the swinging member 18 that had been fitted into the fitting hole 9a is pushed out from the hole 9a, and the swinging member 18 is returned to swing as shown in FIG. As a result, when the control member 20 is shifted to its original position due to its habit, the stepped portion 23a of the cam 23 engages with the side edge 20b of the control member 20, and the cam 23 is stopped. When the cam 23 stops, the action of the transmission mechanism below the pulley 24 stops, and the vibration cam 32 also stops its hopper vibration action. The hopper vibration action does not stop immediately after the actuator 4 detects the trailing edge of the copy paper, but after the time required for the vibration cam 32 to stop after the actuator oscillates. Stop. In other words, even after the actuator detects the trailing edge of the copy paper, toner will continue to be ejected from the hopper, albeit in a small amount. on the other hand,
When the hopper vibration action is stopped and toner discharge from the hopper 33 is stopped, a magnetic brush is formed on the circumferential surface of the magnetic brush forming member 39. The magnetic brush comprises an amount of toner sufficient to supply the copy paper from the bottom to the rear end of the magnetic brush forming member. Therefore, even after the vibration to the hopper is finished, the remaining toner formed on the magnetic brush forming member 39 is supplied to the copy paper, and the toner remaining on the magnetic brush forming member 39 is supplied to the copy paper. The electrostatic latent image formed on the copy paper from the front end to the rear end is completely visualized.

In the above, the length of the copy paper 2 in the traveling direction is detected by the actuator 4 and toner is automatically discharged from the hopper 33 according to the detected length, but when there is no copy paper Now you can do this manually. That is, if the control member 20 is shifted as shown in FIG. 5 when the swing member 18 is in the position without copy paper (FIG. 4), the engagement of the control member 20 with the cam 23 is disengaged. The vibration action on the hopper is started, and toner is supplied. Therefore, if one end of the control member of the vibration device is made to protrude outside the machine body, toner can be manually supplied.

As described above, the hopper 33 that stores toner, the vibration device that vibrates the hopper and includes the vibration cam 32 and a mechanism that drives it, and the clutch 22 and cam 23 that control the operation of the vibration device. A control device consisting of a control member 20 that engages and disengages, an actuator 4 that detects copy paper, and a control device such as the swinging member 18 that operates in conjunction with this during the detection operation of the actuator. According to the toner supply device of the present invention, which is comprised of a holding device consisting of an upper arm member 5, a locking member 11, a cam 8, a disk 9, etc., the toner supply device is configured to supply toner according to the size of the copy paper. Since this can be done automatically, there is no wastage of toner, and since toner is replenished purely mechanically, the supply timing and supply amount can be determined very appropriately, and the operation is reliable.

Furthermore, according to the present invention, toner is supplied each time a copy paper is detected, so that the toner supplied to the copy paper via the magnetic brush forming member is removed from the developer pool or excess on the surface of the magnetic brush forming sleeve. This means that the material does not undergo significant friction, and its properties do not deteriorate. This is extremely effective in visualizing the electrostatic latent image formed on copy paper.

Furthermore, the purely mechanical construction of the present invention can significantly reduce the cost compared to a method that electrically detects copy paper and controls toner supply. Furthermore, since there is no need to provide a mechanism for detecting toner concentration by setting the toner supply timing, costs can be further reduced.

In the illustrated embodiment, the cam 8 and the disk 9 are separate bodies (substantially integrated), but the disk 9
By forming the fitting hole 9a formed in the cam 8 in the cam 8, the disc 9 can be omitted. Further, in order to operate the control member 20, the swing member 18 is used as a shift member in the embodiment, but the cam 8 and the control member 20 are brought close to each other, and the control member 20 is pushed by the cam 8. In this way, the cam 8 may also function as a shift member.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the present invention;
The figure is a side view of the same as the above, Figure 3 is a side view showing the action of the main part of Figure 2, Figure 4 is a plan view explaining the arrangement of members that control the operation of the vibration device, and Figure 5 is the same as the above. It is a diagram. 2... copy paper, 4... actuator, 5...
...Two-arm member, 6...Locking member, 8...Cam, 9...
... Disk, 10, 22 ... One-way rotating clutch, 1
8... Swinging member, 20... Control member, 23... Cam, 32... Hopper vibration cam, 33... Hopper.

Claims (1)

[Scope of Claim for Utility Model Registration] A hopper containing toner for visualizing an electrostatic latent image; A vibrating device for vibrating the hopper in order to discharge the toner from the discharge port of the hopper; A magnetic brush forming member disposed below the ejection port for forming a magnetic brush of the ejected toner and supplying the toner to copy paper; and a copy paper on which an electrostatic latent image is formed. a swingable actuator for detecting; a control device including a one-way clutch for controlling the operation of the vibration excitation device; and a control member for engaging and disengaging the clutch; a cam substantially integral with the one-way clutch; a locking arm that locks the cam at a first position when the yuator is not detecting copy paper and a second position when the yuator is detecting copy paper; the locking arm and the actuator; a shift member that positions the control device in an inactive position when the locking arm positioning member provided between the locking arm positioning member and the cam are in a first position and in an active position when in a second position; After the actuator detects the leading edge of the copy paper, when the leading edge of the copy paper reaches a position below the magnetic brush forming member, vibration of the hopper is started. . A toner supply device, wherein the vibration of the hopper is terminated when the trailing edge of the copy paper passes the actuator.