JPS6010626B2 - Developer remaining amount detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer remaining amount detection device in a developer replenishment device that replenishes developer by replacing a replenishment bolt.

For example, in a dry type developing device for electrophotography, in order to keep the temperature of an image constant, it is necessary to replenish as much toner as is consumed by copying.

For this purpose, the replenishment bolt for replenishing developer must always contain developer, and when the developer runs out, it is necessary to immediately detect and replace the replenishment bolt. However, since dry type developer tends to solidify inside the bolt, it is difficult to accurately detect and display the amount of developer remaining in the container. For this reason, attempts have been made to make the container transparent and visually detect the remaining amount, but since constant monitoring is not possible, it is not always possible to appropriately detect the remaining amount. The object of the present invention is to provide a device that automatically and correctly detects the remaining amount of developer.In a bolt-replaceable developer replenishment device, if the replenishment bolt is not set correctly at a predetermined position during replacement, the replenishment bolt is ejected. In many cases, the outlet does not reach the top of the developing tank, causing the replenishment developer to fall outside the developing tank.

SUMMARY OF THE INVENTION An object of the present invention is to provide a remaining amount detection device that can also detect whether or not a replenishment bolt is set correctly. The present invention has achieved the above-mentioned problems by using an electromagnetic coil to detect changes in the amount of magnetism in the developer caused by changes in the remaining amount of the developer.

The present invention will be explained by way of embodiments with reference to the drawings.

In FIG. 1, a photoreceptor (not shown) is developed using developer 2 in a developing tank 1. As shown in FIG.

The developer consumed during development is replenished from a replenishment bolt 3 set at a predetermined position. The replenishment bolt 3 is sewn at least in an inclined state so that the head is downward.

A dispenser tube 4 is installed in the mouth of the head of the refill bolt 3, and the refill bolt 3 and the dispenser tube 4 are connected to each other.
is supported so that it can rotate. As the dispenser tube 4 rotates, the developer accumulated at the lowest point of the replenishment bolt 3 is scooped up, and once installed in the tube 4, the developer is mixed by the rotating body 5 and the developer is removed from the tube 4.
The developer tank 1 is replenished from the outlet 6 of the developer tank 1 . As a dry developer, a magnetic developer is generally used, such as a developer containing a magnetic carrier such as iron powder, or a developer in which toner itself is magnetic. Therefore, the amount of magnetism changes depending on the amount of developer. When the developer becomes low, it accumulates in the lowest reservoir of the replenishment bolt 3.

A detection coil 7 formed as an electromagnetic coil is provided at a position facing the pool, and a Colpitt type sine wave oscillator A is constructed by a coil L, capacitors CI and C2, and a transistor Q as shown in FIG. When connected to a circuit as a coil, changes in the oscillation frequency obtained by changing the inductance of the coil in response to changes in the remaining amount of developer are detected. The output of emitter A is connected to coupling capacitor C
Phase lock via 3. Loop integrated circuit NE5
6 I (product name of Signetics) and variable resistor VR
The output of the demodulator B is buffered by the amplifier C and output as a remaining amount detection signal via the integrator D.The detection coil 7 is fixed in position and is not used for replenishment. Even when the bolt 3 is pulled and inserted in the direction of the arrow for replacement, the detection coil 7 is always held in the stereotaxic position.

When the developer in the replenishment bolt 3 runs out, the detection of the oscillation frequency indicates that there is no remaining developer.

When the replenishment bolt 3 is replaced, the detection coil 7 again switches the display to indicate that there is a remaining amount of developer. However, if the supplementary bolt 3 is not set correctly, the supplementary bolt 3 and the detection coil 7
A gap of more than a predetermined distance is created between the two. When the distance between the detection coil 7 and the bolt 3 exceeds a predetermined value, the detection coil can detect the amount of magnetism of the developing agent, and the state is the same as that there is no remaining amount of developer, so a message indicating that there is no remaining amount of developer is displayed. It turns out. If you can confirm that there is developer in the replenishment bolt 3 visually or by the weight you hold in your hand, you can sense that there is an abnormality because there is no developer left even though it is displayed. can do. In other words, replenishment bolt 3
Since it is possible to detect an incomplete device, it is possible to ensure that the device is in the correct wearing state. By positioning the detection coil 7 so that the amount of agent remaining is detected normally only when the replenishment bolt is set in the correct position, and when the replenishment bolt is set in the correct position, the state is the same as that there is no remaining amount. It is now possible to not only correctly detect the remaining amount of developer, but also detect abnormalities in the mounting state of the replenishment bolt.

It is also possible to detect an abnormality in the position of the bolt by installing a magnet instead of the detection coil and positioning the bolt so that when the bolt is not in the correct position, the attraction force of the magnet is insufficient.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the relationship between a detection device and a replenishment bolt according to the present invention, and FIG. 2 is a diagram showing an example of a detection circuit. 1...Development tank, 2...Developer, 3...
...Replenishment bolt, 7...Detection coil. Figure 1 Figure 2

Claims (1)

[Claims] 1. In a developer remaining amount detection device in a developing device that replenishes the developer tank by replacing the replenishment bolt, when the replenishment bolt containing magnetic developer is set in a predetermined position, the replenishment bolt is placed in a low position. It has a detection coil made of electromagnetic coils arranged facing each other, and detects the remaining amount by a change in the oscillation frequency that occurs in the detection coil in response to a change in the amount of magnetism caused by a change in the remaining amount of developer, and in this case, the detection coil A developer remaining amount detecting device characterized in that the detecting ability of the detection coil is set so that the remaining amount of developer can be detected only when the distance between the replenishing bolt and the replenishing bolt is within a predetermined range.