JPS58214174A - Picture recording device - Google Patents

Abstract

PURPOSE:To prevent the extinguishment of toner charge by stirring the development in response to the measured time of a timer which mesures the non- driving time of a developing device during which no recording is carried out and then to perform recording of pictures with reduced fog and a high contrast even after a recording device is left for a long period of time in a non-recording state. CONSTITUTION:A control circuit 1 contains a timer 2 and a driving circuit 3 for development device, and a motor 4 is driven by the circuit 3 to stir the developer. In a non-recording mode the timer 2 works to count time (t), and the timer 2 works at a step 3 if no recording input is supplied at a step 2. Then the motor 4 starts stirring the development via the circuit 3 at a step 5 when time (t) exceeds time t0. This stirring is continued for time t1. The operation of the motor 4 is stopped when t>t0+t1 is satisfied, and the timer 2 is reset at a step 8 to the step 2. this action is repeated. The motor 4 is driven for a fixed time t1 with each time t0 when no recording is carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image recording device, and particularly to an image recording device such as a copying machine or a laser beam printer that performs dry development using a two-component dry developer consisting of toner and carrier. be.

Dry two-component development in image recording such as electrophotography consists of a well-known carrier and toner, and by frictionally charging the carrier and toner, the carrier and toner are charged with charges of different polarity to form a charge latent image. Toner is electrostatically attached to a photoreceptor and visualized into a desired image to obtain a recorded image. The developer can be attached to the photoconductor by bringing the developer into contact with the photoconductor while rotating a rolled magnet, or by forming a magnetic roller on the surface of a non-magnetic roll with a magnet fixed inside. There is. In addition, friction between the carrier and the toner can be carried out on the surface of the magnetic or non-magnetic roll, the so-called sleeve surface, or furthermore, a rotating screw or rotating blade may be provided in the part that supplies the developer to the sleeve. This is done by stirring a developer consisting of toner.

When the developing device in such a conventional image recording apparatus remains inactive for a long period of time, the following problems occur.

For example, when recording is attempted after the power has been turned on but has been stopped for a long time, the first few images often end up with high density and foggy images. This is because the charge on the toner disappears when it is left for a long time, and when it is reused, it is developed without sufficient stirring and friction.

Of course, the characteristics of the charge amount of the toner when it is attempted to perform development again after being left alone depend on the characteristics of the toner carrier developing device. For this reason, efforts are being made to improve the toner and carrier through research and development of materials and to improve the initial stirring characteristics.

In addition, some efforts have been made to improve the agitation ability of the developing device. However, as a general trend, the problems that occur when the device is stopped for a long time as described above are unavoidable. It is an object of the present invention to provide an image recording apparatus that can record clear images with less fog immediately after starting the next image recording even if left unused for a long time.

In order to achieve the above object, the present invention provides a timer means for measuring the time when the developing device is in a non-driving state in which no recording is performed, and the developing device We adopted a configuration in which the developer is idle-driven to agitate the developer consisting of toner and carrier.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 is a block diagram showing an outline of a control circuit of a developing device of an image recording apparatus of the present invention. In the figure, a control circuit 1 includes a timer 2 and a developing device drive circuit 3, and a developing device for stirring developer The motor 4 is driven via a developing device drive circuit 3.

Here, the control circuit 1Vi is a part (not shown) of the recording apparatus that controls the drive sequence of the photosensitive tram, the charging sequence, the temperature control of the fixing device, etc., and the feeding and conveyance of the recording member. The control circuit 1 is the central part that operates each unit in a predetermined sequence based on the signals from the main body operation part in the case of a copying machine A, and the control circuit 1 is the central part that operates each unit in a predetermined sequence based on the signals from the main body operation part, and in the case of a laser beam printer, etc. It is configured to operate each unit in a predetermined sequence based on instructions from the controller.

Further, when the recording operation is not performed, the timer 2 as a part of the above-mentioned control circuit operates and is configured to count the time t. A first embodiment of processing in the image recording apparatus of the present invention will be described in detail.

First, in step 1 of FIG. 2, the timer 2 of the control circuit 1 is reset, and then in step 2, it is determined whether or not image recording is to be performed.

If a recording command is input from the outside, the process moves to step 9, where the control circuit 1 controls each of the above-mentioned devices according to a known procedure, thereby performing an image recording operation.

If no recording command is input in step 2, the process moves to step 3 and timer 2 is started. timer 2
The measured time (non-driving time of the developing device) t is t. When this value is exceeded, the process moves from step 4 to step 5, where the motor 4 of the developing device is activated via the developing device drive circuit 3 and agitation of the developer is started. (If a recording command is input in step 4, normal recording operation is performed in step 9 after passing through step 2.) This entire drive operation takes time 1. Continue to climb,
In step 6, the measurement time t of timer 2 is t. When it becomes larger than +t1, in step 7, the motor 4 of the developing device
will be stopped. Then, in step 8, timer 2 is reset, and the process returns to step 2.

If no recording command is input in step 2, the operations in steps 3 to 8 are performed again. However, if no recording operation is performed, a certain period of time t. The motor 4 of the developing device is driven for a predetermined time t1 every time. Here time t. and t are determined by the toner, carrier, and agitation capacity of the developer used. That is, t is the time when the developer is left without stirring without causing any practical problems. , and the time required for the toner left alone to obtain a steady amount of triboelectric charge is tl. Generally t. The longer the agitation time 1, the greater the toner charge attenuation.
．． It will take a long time, but this time t. A person skilled in the art may appropriately set the mountain.

In the first embodiment described above, when the developing device is not driven for a certain period of time or more, idle driving is performed to stir the developer, but in the second embodiment shown below as a flowchart in FIG. The stirring operation by driving is performed in accordance with the open time of the timer 2 as a preparatory fence for the image recording operation.

In step 1 of FIG. 3, the timer 2 is first reset, and in the subsequent step 2, it is determined whether there is a record command, and if there is no record command, the process moves to step 3 and the timer 2 is started. Subsequently, the process returns to step 2, and if there is a recording command, processing is performed in a preparation phase consisting of steps 4, 5.6 or steps 4, 5.7 prior to the recording operation (step 8).

That is, the time t measured by the timer 2 that was started first in step 4 is a time t that causes no practical problem even if the developer is left without being stirred. If it is within the range, the process moves from step 4 to step 8 without idle driving, and a recording operation is performed.

Also, in step 5, the measurement time t of the timer 2 is t
. If <1<12 (t2 will be explained later)
Then move on to step 6 and set measurement time 1 (1゜<1<12)
After the motor 4 is driven via the developing device drive circuit 3 for a time t3 corresponding to the time t3 to stir the developer, a recording operation is performed in step 8.

Also, in step 5, the timer 2's body side time is 1>
If it is 12, the process moves to step 7 and the measurement time is 1.
After the motor 4 is driven for a time t4 corresponding to (=1>12) and the developer is stirred, a recording operation is performed in step 8.

That is, in the first embodiment, the constant time t is used except during recording operations. Okini 1v! 7. The developer is stirred for a certain period of time t1, but in the second embodiment described above, a certain threshold value I2' is set before the recording operation.
The non-driving time t of the developing device is detected depending on whether or not this time has been exceeded, and the developer is stirred by idle driving only during a time j3+t or t4 corresponding to the non-driving time t. Moreover, this time t2 is provided to be larger, and the non-driving time is divided into smaller parts, and the stirring operation is performed accordingly.In this way, an image recording apparatus with less waste can be provided.

As is clear from the above description, the present invention provides a timer means for measuring the time during which the developing device is in a non-driving state where no recording is performed, and according to the time measured by the timer means. To provide an image recording device which can prevent the toner charge from disappearing by adopting a configuration that stirs the developer, and can record clear images with less fog immediately after being left alone for a long time without recording. be able to.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the image recording apparatus of the present invention, and FIGS. 2 and 3 are flowcharts 1 for explaining the processing procedure of the image recording apparatus of the present invention. 1... Control circuit 2... Timer 3...
・Developing device drive circuit 4...Motor Fig. 1 4 Fig. 2

Claims (2)

[Claims] (1) In an image recording device that generates a latent image on a photoreceptor by frictionally charging a two-component dry developer consisting of toner and carrier, recording is not performed and the developing device is in a non-driving state. Provide a means of measuring time,
An image recording apparatus characterized in that when the non-driving time of the developing device exceeds a predetermined time, the developing device is idle-driven and the developer is stirred. (2) The idle driving time is determined according to the length of the non-driving time. 3. The image recording apparatus according to claim 1, wherein the developing device is idle-driven and the developer is stirred prior to the recording operation.