JPH0358114B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device having a function of determining whether the amount of toner in a toner container is smaller than a specified amount.

In a copying device that uses toner to develop an electrostatic latent image on a copying object and transfer it onto recording paper, conventional indications such as insufficient toner for a specified amount of toner are used to determine whether or not the specified amount of toner has been reached. The output of the sensor is directly connected to the display element, and the control circuit that controls the transfer process judges the prescribed amount of toner in response to the toner sensor output as it is, without performing any special processing.
However, when detecting powder such as toner,
As the amount of toner decreases and approaches the threshold level, the toner sensor output becomes unstable, and the conventional method determines that there is no toner even though there is actually a specified amount of toner. An inconvenience has arisen in that the display loses points. In particular, in a copying machine equipped with a toner stirring rod that moves periodically, when the toner is low, the toner moves as the stirring rod moves, causing the amount of toner in the area where the toner sensor is placed to increase or decrease. There was an inconvenience that the toner amount insufficient display decreased in points. In addition, in copying machines that have toner sensors that use piezoelectric vibrators, temporary vibrations of the machine can cause the toner sensors to malfunction, and even when there is sufficient toner, it is determined that there is a shortage of toner, and the toner insufficient amount is displayed. There were times when I had to put it away.

It is an object of the present invention to provide a developer detection method that eliminates the above-mentioned drawbacks and also allows a user to immediately display a display indicating that a specified amount of toner has been reached when replenishing toner. With the purpose of
In order to achieve this object, the present invention includes a container that contains toner for developing an electrostatic latent image, a stirring member that periodically stirs the toner in this container, and a toner that detects the amount of toner in this container. When the output state of the sensor and the toner sensor indicating that the amount of toner is smaller than the specified amount continues for a period longer than the stirring cycle of the stirring member, it is determined that the amount of toner in the container is smaller than the specified value. A developing device is provided, including a determining means for outputting a signal indicating the present invention.

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view of a developing device built into a copying machine. In the figure, 1 is a developing device hopper, 2 is a developing sleeve rotatably provided at the lower end of the developing device hopper 1, and the tip of a blade 3 supported by the developing device hopper 1 is attached to this developing sleeve 2. The parts are in contact. A stirring rod 5 rotatably supported by a stirring rod drive shaft 4 is provided in the developer hopper 1, and the rotation of the stirring rod 5 stirs the toner 6 filled in the developer hopper 1. Let's do it. A toner sensor 7 is a level determining means for determining whether the amount of toner has reached a specified amount. The stirring rod drive shaft 4 receives power from the main body drive system (not shown), and rotates at a substantially constant speed when the main body is driven, so the toner stirring rod 5 also rotates periodically, and this period is about 30 seconds. It is.

FIG. 2 is a block diagram showing the overall system configuration of the copying apparatus. 10 is a central processing unit (hereinafter abbreviated as CPU) that monitors the operation of the entire system.
The above-mentioned toner sensor 7 is connected to this input port PAφ, and the output port
A display lamp 12 is connected to PEφ via a drive circuit 11 to display the current state of the toner with respect to the specified amount, for example, an insufficient amount of toner.
In addition to this, a copy number, paper or jam lamp display circuit 13 is connected to the CPU 10. A key input circuit 14 and a copy sequence control circuit 15 are further connected to the CPU 10, and a predetermined copy sequence is performed in response to each key input. The above-mentioned toner sensor 7 has a logic level "1" which detects that the amount of toner is below a specified amount;
Alternatively, it is configured to output a logic level "0" when it detects that the amount of toner has reached a predetermined amount. When the logic level "1" indicating that the toner level of the input sensor 7 of the input port PAφ is less than the specified amount continues for a time longer than the stirring period of the toner stirring rod 5 of 30 seconds, for example, T ₁ = 40 seconds, the CPU 10 outputs the output port.
Set the logic level of PEφ to “1” and
For example, if the logic level "0" indicating that the toner of the input sensor 7 of PAφ has reached the specified amount is T ₂
= 1 second, the logic level of the output port PEφ is set to “0”. Therefore, when PEφ of the CPU 10 is “1”, the drive circuit 11 is activated, the toner amount insufficient indicator lamp 12 lights up, and PEφ is “0”.
At this time, the drive circuit 11 does not operate and the toner amount insufficient indicator lamp 12 does not light up.

FIG. 3 shows an example of a toner amount monitoring program and a flow chart included as processing contents of the CPU 10. In the figure, F1 is a flag that indicates whether the toner has reached the specified amount or is below the specified amount; if the toner has reached the specified amount, "φ"; If the amount of toner is less than the specified amount, it is set to "1". F2 is a flag for determining whether or not the counter CNT for counting T ₁ (40 seconds) and T ₂ (1 second) mentioned above is set, and when it is "1", CNT is set.

When the CPU 10 is initial reset, program execution starts from the start. Note that the loop passing through the judgment block _S2 is programmed to complete one circuit every 100 msec.

When starting from the start, _F1 is set to "φ" in step _S1 , and if PAφ is φ, it is determined as YES in decision block _S2 , and at this time, CNT
is not set, the program sequentially executes steps S ₂ →S ₃ →S ₁₇ →S ₁₈ →S ₁₉ that constitute a loop. That is, in step _S17 , it is determined whether or not there is an external key input, and in step _S18 , the number of copies is checked, the paper out lamp is turned on based on the number of copies, the paper out lamp is turned on based on this, and the display control of the japler lamp etc. is performed based on the paper jam detection. ₁₉ controls the normal copy sequence operation. At this time, the indicator lamp 12 remains off.

In this state, when the toner sensor 7 generates an output indicating that the amount of toner is less than the specified amount, PAφ becomes 1 as described above, and therefore, NO is determined in the decision block _S2 . Therefore, the program processing moves to judgment step _S4 . At this time
Since CNT is not set, F ₂ = “φ”, so F2 is set to “1” in step 13 to set CNT.
is set. The content of F1 is determined in step 14, and since F1 is currently “φ”, step 15 is executed.
399 is set in CNT, and step S ₁₇ → S ₁₈ →
S ₁₉ →S ₂ . If PAφ is still "1", F2 has already become "1", so steps _S2 → _S4 → _S5 are performed and CNT is decremented. CNT becomes 398 with one decrement operation, and it is checked in decision block _S6 whether or not a borrow has occurred. At this time, since no borrow occurs, the processing procedure becomes S ₅ →S ₆ →S ₁₇ →S ₁₈ →S ₁₉ →S ₂ . Continuing, if PAφ is “1”, S ₂ → S ₄ in the same way
→S ₅ →S ₆ →S ₁₇ →S ₁₈ →S ₁₉ repeat loop 399
Repeat the loop. In other words, when PAφ is “1” for 39.9 seconds, it is determined that a borrow has occurred in judgment block _S6 , and the process moves to _S6 → _S7 → _S8 → _S9 → _S10 , and PEφ is set to “1”. The indicator lamp 12 lights up to indicate that the amount of toner is less than the specified amount. Also, before said loop completes 399 times
When PAφ becomes “φ”, S ₂ →S ₃ →S ₁₇ →S ₁₈ →S ₁₉
→S ₂ , and the fact that PAφ becomes “1” is ignored.

Also, if the amount of toner is less than the specified amount (F ₁ = “1”),
Assume that the indicator lamp 12 indicates that the amount of toner is insufficient. At this time, PAφ is “1”, so S ₂
→S ₃ →S ₁₇ →S ₁₈ →S ₁₉ →S ₂ loop is executed repeatedly. If the copy operation is repeated as it is, the desired copy will not be obtained, so toner is replenished based on the display on the display lamp 12. As a result, when the toner reaches the specified amount, PAφ becomes “φ”.
Therefore, S ₂ →S ₄ →S ₁₃ →S ₁₄ →S ₁₆ and CNT is set to 9 in step 16. continuation
When PAφ is “φ”, S ₂ →S ₄ →S ₅ →S ₆ →S ₁₇ →
Repeat the execution of the loop S ₁₈ → S ₁₉ → S ₂ , and if it is repeated 10 times, a borrow will occur at step S ₆ , so S ₆
→S ₇ →S ₈ →S ₁₁ →S ₁₂ , and in step S ₁₂ PEφ is set to “0”, so the indicator lamp 12 is turned off. At this time, if PAφ becomes "1" before the above 10 loops are completed, S ₂ → S ₃ → S ₁₇ → S ₁₈ →
S ₁₉ →S ₂ , and the input of “0” to PAφ is ignored.

Figures 4A and 4B show time charts of the toner sensor output and display lamp based on the operation described above. When the display lamp is off, the output state when the toner is less than the specified amount is 40 as shown in P ₁ . When it lasts less than a second, the state does not change,
When the above output state continues for 40 seconds or more as shown in _P2 , it is determined that the amount of toner has fallen below the specified amount, and the indicator lamp 12 is turned on to indicate that the amount of toner is insufficient. Conversely, when the indicator lamp 12 is on, even if the output state indicating that the toner level exceeds the specified value for less than 1 second as shown in P ₃ continues, the state does not change, and the state does not change as shown in P ₄ . When the output state indicating that the amount of toner per second exceeds the specified value continues, it is determined that the amount of toner has reached the specified amount and the display lamp 12 is turned off.

In addition, in the above embodiment, T ₂ = 1 second, but T ₂
= 0 seconds, and the desired purpose can be achieved by displaying an insufficient amount of toner when the output state indicating that the amount of toner is at least below the specified amount continues for longer than the stirring period.

As explained above, in the developing device according to the present invention, the output state of the toner sensor indicating that the amount of toner is smaller than the specified amount continues for a period longer than the stirring period of the toner stirring member in the toner storage container. Since the present invention is equipped with a discrimination means that outputs a signal indicating that the amount of toner in the container is smaller than the specified amount, errors in determining the level of toner relative to the specified amount can be prevented, and furthermore, display contents such as toner shortage can be accurately displayed. At the same time, unnecessary toner replenishment can be eliminated.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a developing device built into a copying machine, FIG. 2 is a block diagram showing the system configuration of the copying machine according to the present invention, and FIG. 3 is a diagram of the central processing unit shown in FIG. Flowcharts of the toner monitoring program included in the processing contents, FIGS. 4A and 4B are flowcharts of the toner sensor and display lamp shown in FIG. 2, respectively. 5... Stirring rod, 6... Toner, 7... Toner sensor, 10... Central processing unit, 12... Toner amount insufficient indicator lamp, 15... Copy sequence control circuit.

Claims (1)

[Scope of Claims] 1. A container containing toner for developing an electrostatic latent image, a stirring member that periodically stirs the toner in the container, a toner sensor that detects the amount of toner in the container, and a toner sensor that detects the amount of toner in the container. When the output state of the toner sensor indicating that the amount of toner is smaller than the specified amount continues for a period longer than the stirring cycle of the stirring member, a signal indicating that the amount of toner in the container is smaller than the specified value is output. and a developing device. 2. The determining means determines when the output state of the toner sensor indicating that the amount of toner has reached a specified amount continues for a period shorter than the stirring period of the stirring member;
The developing device according to claim 1, wherein the developing device outputs a signal indicating that the amount of toner in the container has reached a specified value.