JPH0520751B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a developer remaining amount detection device in a dry type developing device used in an electrophotographic copying process or the like.

2. Description of the Related Art In general, in the developing device of a powder image transfer type electrophotographic copying machine, developer, especially toner, is consumed each time a copy is made. When the remaining amount of toner in the premises becomes low, it is necessary to replenish the supply tank with new toner. To do this, it is necessary to detect the amount of developer stored in the developer tank and supply tank.

Conventionally, this type of developer amount detection has been carried out by attaching a pressure sensitive element or a magnetic detection element to the side wall of the developer tank or replenishment tank to detect the remaining amount of developer.

Problems to be solved by the invention However, pressure-sensitive elements and magnetic detection elements are expensive;
It also has the disadvantage of lacking detection stability and low reliability.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a developer remaining amount detecting device that is cheaper, more compact, and more reliable than a developer remaining amount detecting device using a pressure-sensitive element or a magnetic detection element.

Means for Solving the Problems The present invention includes a detection member having an arm pivotally supported in a swingable manner in a developer chamber and provided so as to be reciprocatable between a first position and a second position; a rotatably provided regulating means that periodically contacts the arm while stirring the developer in the developer chamber and forcibly moves the detection member to a first position; The developer remaining amount detection device includes a biasing device that biases the detection member in the direction of the position, and a detection device that detects that the detection member is located at the second position.

In other words, the detection member is pushed up to the first position when the arm and the regulating means come into contact with each other, and when the pushing up action of the regulating means is released, it is lowered by the biasing means and stopped by the resistance of the developer. . Therefore, when the developer is in an empty state, the detection member is moved back and forth between the first position and the second position due to the regular contact between the arm and the regulating means. Furthermore, the detection means detects that the detection member is located at the second position, and the detection is displayed externally.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the accompanying drawings.

In FIG. 1, a developing device includes a rotatable magnetic roller 1 having a plurality of magnetic poles in a housing 21 of the developing device, and a sleeve 2 made of a non-magnetic material and rotatable relative to the magnetic roller 1. roller 3
is arranged close to the surface of the photoreceptor drum 22. Further, the outer circumferential surface of the sleeve 2 has minute irregularities formed by sandblasting with 240 mesh or the like. The developer is held and conveyed on the outer peripheral surface of the sleeve 2 in the direction of arrow b by the rotation of the magnetic roller 1 in the direction of arrow a and the rotation of the sleeve 2 in the direction of arrow b. In order to regulate the layer thickness of the developer on the surface of the sleeve 2 held and conveyed in the direction of the development area A, it is located upstream of the development area A in the developer conveyance direction and maintains a predetermined gap _l1 with respect to the surface of the sleeve 2. As shown in FIG.
Fixedly installed. The support member 5 is made of a non-magnetic material and is attached to the housing 21. The regulation plate 6 is
A layer thickness regulating member 4 is disposed on the upstream side in the developer transport direction and extends in the axial direction of the sleeve 2 so as to face the surface of the sleeve 2, and controls the regulating plate 6, the housing 21, the developing roller 3, and the layer thickness. The regulating member 4 and the supporting member 5 form a first developer chamber 7 within the magnetic field area of the magnetic roller 1 to accommodate the developer conveyed by the developing roller 3 . The guide plate 8 extends in the axial direction of the sleeve 2 on the upstream side of the first developer chamber 7 in the developer conveyance direction, has a tip portion protruding into the first developer chamber 7, and has a distal end protruding from the surface of the sleeve 2 and the regulating plate. They are disposed with predetermined gaps l ₂ and l ₃ from the lower end of the housing 21, respectively, and are attached to the bottom of the housing 21. A developer supply path 9 is formed near the lower end of the regulation plate 6 and the guide plate 8 . The regulating plate 6 and the guide plate 8 are made of, for example, a non-magnetic metal plate.

A second developer chamber 10 for storing developer is provided behind the developer supply path 9, and a third developer chamber 11 is provided above the second developer chamber 10. The second developer chamber 10 includes a developer supply means for stirring the developer and supplying the developer into the developer supply path 9, and a developer supply means for detecting the empty state of the developer in the second developer chamber 10. A developer remaining amount detection device is installed.

The developer supply means is composed of a rotatably supported agitation supply member 12 using a vane plate or a crank rod, etc., and the agitation supply member 12 is connected to the drive system of the sleeve 2 through a speed reduction means such as a gear. They are connected to each other (not shown) and can rotate at a constant speed in the direction of arrow d, and this rotation agitates the developer in the second developer chamber 10 and transports it to the developer supply path 9 side. The developer remaining amount detection device has an arm 13 pivotably supported on the side wall of the casing 21, and a second
A detection member 14 is provided so as to be movable back and forth between a first position Y ₁ at the upper part of the developer chamber 10 and a second position Y ₂ at the lower part thereof, and a detection member 14 is arranged to periodically come into contact with the lower end of the arm 13 . 14 to the first position _Y1 .
and a biasing means using an appropriate weight of the detection member 14 including the arm 13 in order to bias the detection member 14 in the direction of the second position;
The second developer chamber 10 is configured with a detection means for appropriately detecting that the second developer chamber 10 is located at the position _Y2 using a switching means, and an external display is displayed when the second developer chamber 10 becomes empty.
The lower end of the arm 13 that comes into regular contact with the rotation of the agitation and supply member 12 allows the arm 13 to swing even when the agitation and supply member 12 rotates in the direction opposite to the arrow d direction, and the detection member including the arm 13 In order to reduce the size of the developing device, the arm 13 is formed into a substantially arc shape, and the arm 13 is pivotally supported at a position that enables smooth rocking regardless of the direction of rotation of the agitation supply member 12. There is.

A swingably supported partition plate 15 is provided between the second developer chamber 10 and the third developer chamber 11, and a developer supply path 16 is formed between the partition plate 15 and the bottom surface of the housing 21. It is formed. The swinging of the partition plate 15 causes the heavy pressure of the developer in the third developer chamber 11 and the weight of the partition plate 15, as well as the agitation supply member 12 and the protrusion 15a provided on the partition plate 15 to periodically come into contact with each other. It is configured to do this.

Next, the operation of the developing device having the above configuration will be explained.

First, the first developer chamber 7 is loaded with a developer consisting of a mixture of a magnetic carrier and magnetic toner, and after the device is pre-operated, the third developer chamber 11 and the second developer chamber 10 are filled with a magnetic toner. Toner developer is loaded. At this time, only the magnetic carrier may be loaded into the first developer chamber 7. In addition, in the case of one-component development using only a magnetic toner developer without using a magnetic carrier, the developer is loaded into the first developer chamber 7 through the third and second developer chambers 11 and 10. It's okay. In this state, the electrostatic latent image can be developed by this apparatus.

Here, the developer is held and conveyed on the outer peripheral surface of the sleeve 2 in the direction of the arrow b by the rotation of the magnetic roller 1 in the direction of the arrow a and the rotation of the sleeve 2 in the direction of the arrow b.
When passing through the first developer chamber 7, the magnetic carrier and the magnetic toner are mixed and stirred, and each is triboelectrically charged.
As a result of this mixing and agitation, the magnetic carrier, which is the developer, and the magnetic toner are constantly integrated at a mixing ratio within a certain range at this point, and a magnetic brush made of the developer is reliably formed in the development area A. be done. The magnetic brush formed here rubs the surface of the photoreceptor drum 22, and develops the electrostatic latent image on the surface into a visible image. After being subjected to development, the developer remaining on the outer circumferential surface of the sleeve 2 reaches the first developer chamber 7 again, where it is mixed and stirred with the developer supplied from the second developer chamber 10, and then mixed with the developer supplied from the second developer chamber 10. Subjected to development. At this time, the developer in the first developer chamber 7 is
Since the magnetic force of the magnetic roller 1 constantly attracts the developer toward the surface of the sleeve 2, the developer near the surface of the sleeve 2 is held and transported in the direction of arrow b by the rotation of the developing roller 3, and is regulated by the layer thickness regulating member 4. The remaining developer flows in the direction of arrow e, is uniformly mixed and agitated throughout, and is prevented from flowing in the axial direction of the sleeve 2.

The developer is supplied to the first developer chamber as follows.

The developer stored in the second developer chamber 12 is conveyed to the developer supply path 9 side by rotation of the agitation supply member 12 in the direction of arrow d, and is conveyed to the developer supply path 9 side by the magnetic roller 1.
Guide plate 8 for pulsating action based on rotation in the direction of arrow a.
The developer rises along the surface on the regulating plate 6 side, and is supplied into the first developer chamber 7 through the developer supply path 9 . The supplied amount corresponds to the amount by which the developer in the first developer chamber 7 is reduced.

The developer stored in the third developer chamber 1 is
The partition plate moves upward when the agitation supply member that rotates the partition plate 15 comes into contact with it, and after the contact is released, the partition plate moves downward due to the weight of the partition plate 15 and the heavy pressure of the developer in the third developer chamber 11. 15, the developer is replenished into the second developer chamber 10 through the developer supply path 16. The supply amount is replenished in accordance with the internal pressure of the second developer chamber 10, and a space is always maintained in the upper layer of the second developer chamber 10.

Next, the operation of the developer remaining amount detection device will be explained.

The detection member 14 is activated by rotating the agitation supply member 12, which is used as a regulating means, in the direction of the arrow d, and the substantially arcuate lower ends of the agitation supply member 12 and the arm 13 come into contact with each other and are pushed up, using the support shaft 17 as a fulcrum. Move up to the first position Y ₁ position. When the pushing-up operation by the agitation supply member 12 is released and the lower ends of the agitation supply member 12 and the arm 13 are brought into contact with each other and separated, the detection member descends under its own weight. Normally, the amount of developer in the second developer chamber 10 is stored up to the vicinity of the first position _Y1 , and in order to receive resistance from this developer,
The detection member 14 is reciprocated near the first position _Y1 . Further, when the developer in the third developer chamber 11 decreases and the developer in the second developer chamber 10 further decreases, the detection member 14 moves between the first position _Y1 and the second position Y2 _.
It will be moved back and forth between.

On the other hand, the end of the support shaft 17 that pivotally supports the arm 13 of the detection member 14 projects to the outside of the casing 21 as shown in FIG. 2, and a magnet 19 is fixed to this projecting end via a lever 18. ing. That is, the magnet 19 can swing together with the detection member 14 via the support shaft 17, and the solid line position in FIG. 3 corresponds to the first position Y ₁ of the detection member 14, and the dotted line position corresponds to the second position Y ₂ . do. Further, a reed switch 20 is installed adjacent to the second position of the magnet 19. This reed switch 20 has the magnet 19 in the second position.
It remains on only when it is located at the position corresponding to Y ₂ or very close to it, and turns off when it leaves.

Therefore, when the detection member 14 is lowered to the second position _Y2 and reciprocated, the empty state of the developer in the second and third developer chambers 10 and 11 is detected.
Displayed externally.

Effects of the Invention As is clear from the above explanation, according to the present invention,
a detection member having an arm pivotally supported in a swingable manner within the developer chamber and provided so as to be able to reciprocate between a first position and a second position; a rotatably provided regulating means that periodically contacts the arm and forcibly moves the detection member to the first position; and a biasing means that biases the detection member toward the second position; By including a detection means for detecting that the detection member is located at the second position, a reed switch or the like can be used as the detection means for the detection member, and an inexpensive and reliable developer empty detection can be performed. can be obtained.

Furthermore, even if the agitation supply member used as a regulating means for removing the developer in the first developer chamber is rotated in the opposite direction, the detection member can be moved back and forth as usual, which prevents damage to the detection member, etc. There is no. Furthermore, by forming the lower end of the arm that contacts the regulating means into a substantially arc shape, the developing device can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a developing device showing an embodiment of the developer remaining amount detecting device of the present invention, and FIG. 2 is a schematic diagram of the main part of FIG. 1. 3...Developing roller, 10...Second developer chamber, 1
2... Stirring supply member, 13... Arm, 14...
Detection member, 19... magnet, 20... reed switch, 22... photosensitive drum.

Claims (1)

[Claims] 1. A detection member having an arm pivotably supported in a swingable manner in a developer chamber that stores the developer, and provided to be able to reciprocate between a first position and a second position; a rotatably provided regulating means that periodically contacts the arm while stirring the agent and forcibly moves the detection member to the first position; and biasing the detection member in the direction of the second position. What is claimed is: 1. A developer remaining amount detecting device comprising: a biasing means for detecting a second position of the detecting member; and a detecting means for detecting that the detecting member is located at a second position.