JPS58221868A - Method for controlling replenishment of toner - Google Patents

Abstract

PURPOSE:To prevent excessive replenishment of a toner and to maintain good developing conditions by regulating the replenishment of the toner for the time (number of copies) required for agitation after replenishing of the toner. CONSTITUTION:Whether copying of two copies ends or not is checked and in the case of YES, a flag for replenishing a toner is turned off in a program which is beforehand so set that the replenishment of the toner is not carried out during the two copies after the replenishment of the toner. A sub-program for checking the toner control is called during copying by the main program, and whether a toner check pulse is completed or not is checked. In the case of YES, whether the replenishment of the toner is under prohibition (during the two copies after the replenishment of the toner) or not is checked. In the case of NO, whether the density of the next toner is lower than a preset specified concn. of the toner or not is checked and in the case of YES, a solenoid for replenishing the toner is turned on, by which a supply roll for the toner is rotated at a specified angle, and a specified amt. of the toner is replenished. A lamp for prohibiting the replenishment of the toner is turned on and the main program is resumed after the replenishment of the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a toner replenishment control method in an electrostatic recording device such as an electrophotographic copying machine.

For example, when copying is performed using an electronic copying device, etc., a developer container is filled with a mixture of toner and carrier in a certain ratio, and the electrostatic latent image on the support, that is, the photosensitive plate is developed with the developer. However, as the number of copies increases, the amount of toner in the developer in the developer container decreases, resulting in a decrease in image density of the image to be developed.

To prevent this phenomenon, install a toner supply container.
When the image density or the amount of toner in the developer container decreases, toner is sequentially replenished into the developer container, but the amount of toner consumed varies depending on the density of the original image. If the toner is continuously developed, the amount of toner in the developer container decreases rapidly, and the image density becomes inconsistent.

Therefore, for example, in two-component development using a developer containing a mixture of toner and carrier, various automatic toner replenishment methods have been employed in order to maintain constant image density. For example, there is a method of measuring the transmittance of toner that diffuses and falls in a developer container using a phototube, a method of measuring the electrical resistance of a mixture of toner and carrier in a developer container,
Another method is to measure the reflectance of the mixture using a phototube. A standard electrostatic latent image is always provided on the side edge of the photoreceptor drum over the entire circumference of the drum, and this latent image is developed using a developing device to form a toner image. The amount of toner in the developer is measured by a method such as measuring this toner image using a phototube, and the insufficient toner is replenished.

A common problem in these various toner density detection and toner replenishment methods based on the detection is that sufficient accuracy and accuracy cannot be obtained for two-toner replenishment to be successful. The reason for this is the lack of accuracy in toner concentration detection, and many proposals have been made to improve the accuracy. However, even these proposals did not yield satisfactory results.

As a result of various studies in this regard, the present inventors have found that the above-mentioned problem is caused by the following phenomenon.

In an automatic replenishment system that replenishes toner in response to a toner replenishment command signal that is based on the toner 11 degree detection signal, the toner agitation is still insufficient immediately after replenishment, so the following occurs. A phenomenon occurs.

(1) The toner concentration in the developer is not uniform, and due to this, an increase in toner concentration due to replenishment is not detected.

(2) The toner is not sufficiently charged due to insufficient agitation of the developer, and as a result, even though the toner concentration in the developer is sufficiently high, the density of the image is still low. It doesn't go up. Therefore, in a system that uses the image density detection signal for toner replenishment, an increase in toner density in the developer is not detected.

This indicates that there is a risk of oversupply of toner.

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner replenishment control method that enables proper toner replenishment. This is achieved by a toner replenishment control method characterized by prohibiting toner replenishment regardless of the density.

Hereinafter, the present invention will be explained in detail using the drawings.

Figure 1 shows an example of a toner supply section, with a hopper L
A certain amount of toner T is fed into a groove 3a provided on the surface of the supply roller 3 by a concentration detection section (not shown) and rotation of the supply roller 3 at a constant angle based on the concentration detection section. The structure is such that it is transported into the current vessel 2. Here, 41' is a roller pressing spring that prevents unnecessary toner from flowing out and falling, and 5 is a scraping plate that ensures that the entire amount of toner in the groove 3a falls.

FIG. 2 shows a flowchart of a control program related to toner replenishment of an electrophotographic copying machine having a toner supply section shown in the at diagram, for example. FIG. 21(a) is a main program, and FIG. 2(b) is a subprogram. Show the program. This embodiment shows an electrophotographic copying machine with a movable optical bench. In FIG. 2(a), it is first checked whether the optical bench has returned to its normal position, and when it has returned, a counter is displayed. 1 is added.

Next, it checks whether toner replenishment is prohibited, and in this program, which is set to prohibit toner replenishment for two copies after unexpected toner replenishment, it checks whether or not two copies have been completed, and after two copies have elapsed. The program turns off the toner replenishment flag when the During copying by this main program, a toner control check subprogram is called. FIG. 2 (bl indicates this.

It is checked whether or not the toner check pulse (in this embodiment, 7 pulses have been applied in advance to 1O7 Hals) has been completed, and when it has been completed, toner replenishment is prohibited (during 2nd copy after toner replenishment). Check whether or not. If toner replenishment is not prohibited, it is checked whether the next toner concentration is lower than a preset constant toner concentration, and if it is low, the toner replenishment solenoid is turned on, and in this embodiment, it is turned off at 91 pulses from optical return. becomes. When the toner replenishment solenoid is turned ON for a predetermined pulse period, the supply roller 3 rotates by a predetermined angle, and a predetermined amount of toner is replenished. After replenishing toner, the toner replenishment prohibition lamp is O.
It becomes N and returns to the main program. Flow chart middle R
The symbol st indicates a return to the main program.

Figure 3 shows a time chart of the operation of the counter and toner replenishment solenoid, and shows that after toner replenishment, in this embodiment, no toner replenishment signal is accepted during the second copy. There is.

FIG. 4 shows a block diagram of the control unit according to the present invention, which is obtained by a toner density signal to the CPU, a microswitch signal from the second paper feed unit based on copying, and an encoder provided at the periphery of the photoreceptor drum. The pulse information is used to control the operation of the toner replenishment solenoid according to the flowchart shown in FIG. 2 and the time chart shown in FIG.

The toner replenishment method according to the present invention explained in the embodiments above is as follows:
Toner replenishment is regulated for the time required for stirring (number of copies) after toner replenishment, and the present invention prevents excessive toner replenishment, which often occurred in the past, and maintains good current conditions. Now you can.

Note that in this embodiment, the toner replenishment signal is not received during a preset number of copies (2 copies in this embodiment) after toner is replenished by toner concentration detection, but this is of course limited. Instead, it is also possible to perform toner replenishment based on toner density detection and then not issue a toner replenishment signal for a preset number of copies, which is included in the present invention.

The method of the present invention can be used in an automatic toner replenishment method based on detection signals from various toner concentration detection methods. As mentioned above, there are two ways to detect toner concentration: one is to directly measure the toner concentration in the toner agent photoelectrically or electrically, and the other is to indirectly measure it by measuring the density of the applied image compensation. .

In the indirect measurement method, the density of the developed image compensation is not only affected by the toner concentration in the developer, but also by the potential of the latent image, the properties of the developer, that is, the carrier, and the toner. However, since the change in toner density mainly reflects the image density, image density detection can also be said to be one aspect of toner density detection in the present invention.

Further, in the above embodiment, toner is not replenished for a predetermined number of copies after toner is replenished by toner concentration detection, but the present invention is not limited to this. In the figure, the drum module information that enters the CPU is used to prevent all toner replenishment signals from being received until the count value of encoder pulses reaches a predetermined value after detecting the 1 toner concentration, or to not receive toner replenishment signals. You may choose not to emit it. For example, such a toner replenishment control method is effective when a telegraph signal is reproduced as an image and recorded on continuous paper.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one example of a toner supply section, FIG. 2 is a flowchart of an embodiment of the present invention, FIG. 3 is a time chart, and FIG. 4 is a 7' lock diagram of the control section. show. ■・・・Hopper 2・・・Existing machine 3・・・Supply roller 3a...Groove T...
...Toner Agent Yoshimisato Kuwahara Figure 1 Section 4 Figure 162 Figure C3) (of

Claims (1)

[Claims] A toner replenishment control method characterized in that, after toner replenishment, toner replenishment is prohibited during a preset machine operation period, regardless of toner density or image density.