JPS5915955A - Toner replenishment controlling system - Google Patents

Abstract

PURPOSE:To always decide exactly the quantity of replenishment of a toner irrespective of the number of sheets of copying, by executing the control of a toner replenishment time in the course of operation of a developing device, for instance, executing the charging of a time constant capacitor in a prescribed time in the course of operation of the developing device. CONSTITUTION:Reference voltage from a standard toner density passive reflector and voltage signal (b) corresponding to the toner concentration on a sleeve are supplied to an amplifier Q1 and are amplified by one stage, and are supplied to an impedance converting transistor (TR) Q3. A comparator Q2 generates a comparison output (e) only when both end voltage C of a capacitor C1 is larger than the signal voltage (b) corresponding to the toner concentration on the sleeve. Since standard toner density in the passive reflector is already known, a charging time of a passive reflector signal in the capacitor C1 corresponding to said density can also be set to a prescribed time in advance. A CPU 11 waits for completion of charging of the capacitor C1 and ends a charging time of a charging and discharging signal (f). As a result, the quantity of replenishment of a toner can be controlled at all times irrespective of the number of sheets of copying.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner replenishment control system for a copying machine, and particularly to control of a l/toner replenishment circuit.

Conventionally, in this type of toner replenishment control system, the toner replenishment circuit performs replenishment while the developing device is stopped. To determine the amount of toner to be combined; keep in mind the time to determine the time between toner and 7 times. Charge the voltage-to-hour conversion capacitor in the circuit, and replenish toner at the same time as the developer operates according to the charging time. was being carried out.

This conventional method has the following deficiencies.

1) Since the chargeability of the capacitor in the Ij pressure one-hour conversion circuit becomes U when copying one sheet and when copying multiple sheets, an error occurs in the Ij pressure one-hour conversion circuit, and the developing device The amount of toner to be replenished cannot be determined accurately.

2) Since the rest time of the developing device changes between full-size development and half-size development, it is necessary to charge the capacitor in the two-way voltage one-hour conversion circuit. , the amount changes in response to these size changes, and the toner replenishment layer to the developer is not precisely defined.

Therefore, one object of the present invention is to eliminate the conventional drawbacks mentioned in (-) and to provide toner complementation by appropriately controlling the toner replenishment layer. It is an object of the present invention to provide a toner replenishment control system that allows the toner replenishment to be determined more accurately.

In order to achieve such an object, the present invention operates a time circuit that determines toner replenishment time while the developing device is operating.
For example, a voltage one-hour conversion capacitor in the toner replenishment circuit is charged, and the toner replenishment time is controlled from there.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the toner replenishment control system of the present invention,
Here, ] is a developing device sleeve, 2 is a developing motor that rotates the developing device sleeve 1, 3 is a toner container that supplies toner to the developing device sleeve 1, and 4 is provided inside the toner container).
A toner stirring screw 5 is a toner delivery screw for delivering the toner in the toner hopper 6 to the toner container 3.

7 is disposed close to the developing sleeve l, and detects the toner concentration of the toner 8 on the developing device sleeve 1 and the concentration of a standard toner concentration reflecting plate 9, which will be described later in 212 (:A) and (B), respectively. a toner concentration detection (ATR) head that converts the voltage signal into a voltage signal;

I, a toner replenishment control circuit (ATR) which determines the amount of toner replenishment in response to the toner concentration detection voltage signal from the toner concentration detection controller 8; 11, this toner replenishment control circuit 10;
It is a microcomputer (CPU) that controls the In this embodiment, the microcomputer 11 is a well-known one-chip microcomputer, such as μD.
8085 yen can be used.

The SLI is a hopper solenoid that is activated by 4=J in response to a toner replenishment control signal from the toner replenishment control circuit 1o.
This solenoid SLl operates the toner replenishment clutch of the toner delivery screw 5. SL2 is a head removal solenoid for the developing device. In addition to the toner replenishment control circuit 1O, the microcomputer 11 also operates a toner concentration detection hand door, a developing motor 2, and a loading solenoid SL2.
It also controls the following.

! - A detailed example of the toner a degree detection head 7 described above is shown in FIG.
Shown in A) and (B). Here, 12 is a transparent glass plate that separates the sleeve chamber of the developing sleeve 1 from the toner concentration extraction head 7.
On the side of the window 7, there is a glass plate 1 adjacent to the glass plate 12.
A standard toner concentration reflecting plate 9 is disposed which is movable along the toner. This reflection plate 8 is driven by a solenoid SL3,
It moves on the glass plate 12 as shown in FIGS. 2(A) and 2(B).

Reference numeral 13 denotes a light source of reflected light, such as a lamp, and the light is incident on the toner on the developing sleeve 1 via the reflection plate 9 or the glass plate 12 controlled by the solenoid SL3. Standard toner concentration Reflected light from the toner on the reflecting plate 9 or the developing sleeve 1 is received by a light receiver, for example, a photodiode 14, and the standard toner density from the reflecting plate S or the toner density on the developing sleeve 1 is adjusted. Detect current.

Note that in the standard toner concentration reflector 9, the lamp 13
Paint with a cotton-like toner density shall be applied to the sides. A current change signal from the photodiode 14 is supplied to an amplification converter AMP and converted into a voltage change signal a.

The above-mentioned toner replenishment control circuit IO amplifies the voltage change signal corresponding to the toner concentration on the standard toner concentration violation plate 3 and the developing sleeve 1 sent from the toner concentration detection door, and drives the toner concentration detection solenoid SLI. A specific example of the circuit for this purpose is shown in FIG.

In FIG. 3, Ql is an amplifier and Q2 is a comparator. vee is the IA pressure at 7 of the amplifier Q1. Q
3 is a transistor for impedance conversion, Q4 is a transistor switch for holding the It level of capacitor CI for voltage one-hour conversion, Q5 is a constant current circuit transistor for linearly discharging the charged potential of capacitor C1, and Q6 is a constant current circuit transistor. A switch transistor that operates the current circuit transistor Q5, Ql is an inverter transistor, Q
8 is supplied with the voltage output from comparator Q2 and drives the hopper replenishment solenoid SLI.
J#lI is a transistor that starts the movement of the toner replenishment lens SLI.

The above-mentioned amplifier Q1 is supplied with the reference voltage from the standard toner concentration reflector plate and the sleeve upper side voltage as the voltage conversion signal a from the amplifier AMP shown in FIGS. 2(A) and 2(B) for one-stage amplification. After that, the output is supplied to the impedance conversion transistor Q3. comparator. 2 is the voltage C1 corresponding to the voltage d across the capacitor CI.
That is, the reference voltage from the standard toner concentration reflector plate is compared with the toner concentration voltage S, and a comparison output e is generated only when the voltage C across the capacitor C1 is greater than the sleeve-1 agent signal voltage S. Furthermore, in FIG. 3, D l, D
2. D3 is a diode, ZDl and Zn2 are Zener diodes, R1-R18 are resistors, VRI and V
H2 is a variable resistor, and c2 and C3 are capacitors.

The operation of the toner replenishment control circuit according to the present invention having the above configuration will be explained with reference to the timing chart shown in FIG.

First, the CPU II generates a developer drive signal i shown in FIG. 4 at an appropriate development timing, and this drive signal i operates the development motor 2 and the tipping solenoid SL2 to perform a development operation. At this time, the signal a from the head 7 is a signal from the reflection plate 9, and at the same time as the developer drive signal i, the CP
Under the control of the charge/discharge signal f output from U11, the reflector signal passed through the amplifier 1 and the transistor Q3 charges the capacitor C1.

Here, since the standard toner I rate in the reflector 9 is known, the charging time of the reflector signal in the capacitor C1 corresponding to it can also be set to a predetermined time, and the charging time in the charge/discharge signal R is It can be determined in advance by CPU II. Therefore, the CPU
II waits for the completion of charging of the capacitor C1 and terminates the charging time of the charge/discharge signal f, thereby terminating the signal f as shown in FIG. At the same time, the CPU II sends out the standard density reflector +I]4' removal signal g, and on the other hand, the linear discharge switch transistor Q5 operates, and the capacitor CI
The voltage d across the line causes a surface line discharge as shown in FIG.

At the same time, the CPU II activates the solenoid SL3 to move the first reflecting plate 9 back from above the glass plate 12, switches the head output a to a toner signal representing the concentration of the toner in the developing sleeve 1-1, and sends the developing sleeve 1 to the developing sleeve 1-1. Supplies sleeve stopper signal voltage. And comparator Q
The other input terminal of 2 is supplied with a voltage C representing the toner standard concentration corresponding to the standard toner concentration reflector 9 charged in the capacitor C1.

As shown in FIG. 4, the discharge straight line due to the voltage C across the capacitor falls at a constant gradient that depends only on the voltage representing the standard IA degree of toner from the reflecting plate 9, and the sleeve stopper signal voltage As shown in FIG. 4, the sleeve voltage S1 or S2 increases or decreases depending on the concentration of the toner, and the duration of the comparison output e from the comparator Q2 changes accordingly. Accordingly, the on/off time of the replenishment solenoid SLI changes, and the number of rotations of the toner replenishment screw 5 changes 1, thereby making it possible to replenish an appropriate amount of toner.

The CPU II terminates the bull density reflector release signal g before the end of the appropriate development time, disabling the output of transistor Q4, thereby advancing the toner standard density reflector 3 onto the glass plate 12, and discharging the capacitor C1. 1 to the developer motor 2 and the heading solenoid SL2.
The number i is stopped, and the developing operation is completed in the following steps.

In the above example, toner replenishment was performed by detecting the density by light reflection in the toner density detection head, but the amount of toner replenishment was controlled by detecting the toner itself in addition to hair. Good too.

As is clear from the above, according to the present invention, the control of toner supply, which was conventionally performed when the developer is stopped, is performed during the operation of the developer. By carrying out this operation during a predetermined period of time while the developing unit is in operation, the amount of toner replenishment can be determined accurately regardless of the number of copies or the copy size. As a result, according to the present invention, the service life of the toner itself can be extended, and the present invention is extremely effective in ensuring accurate toner replenishment amount when used in Color/Herance's important color copying machines. be.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the toner replenishment control force type according to the present invention, FIGS. 2(A) and (B) are diagrams showing an example of the toner concentration detection head, and FIG. 3 is a diagram showing an example of the toner concentration detection head according to the present invention. FIG. 4 is a circuit diagram showing an example of the configuration of the toner replenishment control circuit in FIG. L...Developer sleeve, 2...Developing motor, 9...Toner container, 4...Toner stirring screw, 5...Toner delivery screw, 6...Toner replenishment hopper, 7... - Toner concentration detection head, 8... Toner on the developer sleeve, :]... Marked toner density reflection plate, 10... Toner replenishment control circuit, 11... Microcomputer 9 (CPU), 12・
...Transparent glass plate, 13...Light source, 14...Light receiver, SLl...Hoppan Remade. SL2... Solenoid for raising the ears, SL3... Reflector control solenoid, Ql... Jacket width device, C2... Comparator, C3... Transistor for impedance conversion. C4... Transistor switch, C5... Constant current circuit transistor, C6... Switch transistor, Ql... Impark transistor, C8... Driver transistor, Q9... Gate transistor, D1-D3...・Diode, 201.202... Zener diode, R1-RI
8...Resistor, VRI, VR2...Variable resistor, C1...Capacitor for voltage one-time conversion, C2, C3...
...Capacitor.

Claims (1)

[Claims] A means for detecting the amount of toner in the developing device, a means for determining the amount of toner to be replenished according to the detection output thereof, and a means for replenishing the amount of toner to be replenished by one core per total of the toner to be replenished by the means. In the toner replenishment control method, which includes a time circuit that determines the time, and means for replenishing toner to the developing device according to the toner complementary time described in +iiij, the time circuit is operated during the operation of the developing device described in No. 111. The toner replenishment control force type is characterized in that the toner replenishment time is determined based on the toner replenishment time.