JPS6152666A - Recording device - Google Patents

Abstract

PURPOSE:To prevent the fog of an image by counting the number of times of supply of a toner, detecting the deterioration of the toner, and switching a developing bias voltage, in a recording device of an electrostatic type, etc. CONSTITUTION:A recording device is constituted of a photosensitive drum 1, an electrifier 2, an exposing device 3, a developing device 4, a transfer device 5, etc. Also, a toner is fed to the developing device 4 from a supply device 4b, made to adhere to a latent image on the photosensitive drum 1, and transferred to a recording form 6 by the transfer device 5. In this case, a microswitch 11a for detecting the number of times of supply of the toner is provided on the toner supply device 4b, and the number of times is counted by a counter 11b. When the toner is used for many hours, its resistance increases, and a fog is generated in the development. Therefore, by detecting the number of times of supply of the toner, a bias voltage impressed to the developing device is switched appropriately by acontrol circuit 9. Accordingly, a degree of deterioration of the toner is decided, and the developing bias voltage is adjusted, therefore, the fog can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in electrostatic or electrophotographic recording devices.

For example, an electrophotographic recording device utilizes the photoconductivity and electrostatic phenomenon of substances.1 For example, as a toner image forming body, a photosensitive drum in which a photosensitive layer of amorphous selenium is formed on a metal cylindrical surface; A charger uniformly charges the surface of the photosensitive drum by corona discharge etc. to make it photosensitive, and a laser beam modulated by recorded information is irradiated onto the photosensitive drum surface to electrostatically charge it. An exposure device that forms a latent image, a developer that develops the electrostatic latent image formed by the exposure device with toner to form a toner image, and a transfer device that transfers the toner image formed by the development device onto recording paper. The main components include a fixing device that fixes the toner image transferred to the recording paper by heating and melting or the like.

With this configuration, the developing unit develops the toner by electrostatically adhering the toner having a charge of the opposite polarity (for example, positive) to the latent image. 2 Usually, toner is used as a mixture with iron powder, etc. called a carrier (this mixture is called a two-component developer or a car developer), and the toner is
This uses the friction that occurs when toner and carrier are stirred in a container.

On the other hand, developer is supplied to the photosensitive drum by, for example, a developing roller built into a developing device.

The developing roller and the photosensitive drum are electrically connected through the resistance of the developer, and by applying a developing bias voltage (for example, +300 volts) between the developing roller and the photosensitive drum, the necessary voltage for development is created between the developing roller and the photosensitive drum. Ensures proper voltage is maintained.

However, when the developer is used for a long time, the toner adheres to the surface of the carrier and its function as a carrier deteriorates.In addition, the resistance of the developer increases due to the increased resistance of the carrier. The voltage between them increases to exceed the appropriate value. As a result, toner is attracted to the background portion (white portion) of the electrostatic latent image on the photosensitive drum, resulting in so-called "fog".

Therefore, the above-mentioned occurrence of "gagging" caused by deterioration of the developer is corrected by changing (reducing) the developing bias voltage. It is necessary to do this by accurate means.

[Conventional technology]

FIG. 2 is a schematic diagram illustrating the configuration of the first conventional recording apparatus, in which 1 forms a photosensitive layer on a fully curved cylindrical surface as a toner image forming body and rotates in the direction of arrow A. The photosensitive drum 2 is a charger that uniformly charges the surface of the photosensitive drum 1 by corona discharge to impart photosensitivity.

3 is an exposure device used in a latent image forming section that forms an electrostatic latent image by irradiating a laser beam modulated by recorded information onto the surface of the photosensitive drum 1 imparted with photosensitivity; 4 is an exposure device 3; a developing device that develops the electrostatic latent image formed on the photosensitive drum 1 with toner to form a toner image; 4a;
5 is a developing roller built in the developing device 4; 5 is a transfer device that transfers the toner image formed on the photosensitive drum 1 by the developing device 4 onto a recording paper 6 running in the direction of arrow B; 7 is a transfer device for the transfer device 5; Hoppers 8a and 8 for storing the recording paper 6 to be supplied
b constitutes a counting means 8 for counting the number of recording sheets 6 used for recording, 8a is a detector, and 8b is an integration circuit.

Further, 9 and 10 constitute voltage switching means for switching the developing bias voltage applied to the developing device 4 according to the output of the counting means 8, and 9 is a control circuit that outputs a control signal according to the integrated value of the integrating circuit 8b. 10 is a power supply circuit that supplies a developing bias voltage corresponding to a control signal output from the control circuit 9 to the developing roller 4a.

That is, in the conventional example described above, the developing bias voltage is reduced by 100 volts every time, for example, 100,000 sheets of recording paper 6 are used, thereby preventing "fogging" due to developer deterioration.

In addition, as another conventional example, a detection device detects changes in the electrical characteristics of toner and applies an appropriate voltage to necessary members (August 14, 1981: Japanese Patent Application Laid-Open No. 55-10647
8 r Electrostatic latent image developing device j), which corrects the developing bias voltage according to the deterioration of the developer obtained based on the WJ image density of the image transferred to the developing surface or recording paper (1971)
August 29th: JP-A-55-11197 Or Development Method”
), or one that detects deterioration of the developer using a developing capacity sensor and corrects the developing bias voltage (introduced in January 1980).
February 9: Japanese Patent Application Laid-Open No. 56-159671 (r) ``Developer deterioration correction device''), etc. have been proposed.

[Problem that the invention seeks to solve]

In the first conventional example, the degree of deterioration of the developer is determined based on the amount of recording paper used.

Since deterioration in development is not necessarily proportional to the amount of recording paper used, there is a problem that accurate determination cannot be made. In addition, all of the other conventional examples described above have a problem in that the detection devices are complicated and therefore expensive.

[Means for solving problems]

A recording apparatus according to the present invention includes: a toner image forming body on which a toner image is formed; a latent image forming section forming an electrostatic latent image corresponding to recorded information on the toner image forming body; In a recording apparatus equipped with a developing device that develops a latent image with toner, is it possible to apply toner to the developing device from outside?
The above-mentioned problem is solved by providing a counting means for counting the number of times of Ili feeding, and a voltage switching means for switching the developing bias voltage applied to the developing device according to the output of the counting means.

[Effect]

That is, the number of times the toner is replenished is counted by an extremely simple counting means whose main component is a microsinch, etc.
The degree of deterioration of the developer is determined by the number of times the toner is replenished, that is, the amount of toner used.
The degree of deterioration of the illustrative agent can be determined easily and accurately.

〔Example〕

The gist of the present invention will be specifically explained below with reference to an embodiment shown in FIG.

FIG. 1 is a block diagram of one embodiment of the present invention. In FIG. 1, the same reference numerals as in the conventional example in FIG.
a and llb constitute a counting means for counting the number of times that toner is supplied to the developing device 4 from the outside.

11a is a microswitch provided in the toner replenishing section 4b of the imager 4; 11b is a counter that counts the number of times the microswitch lla is activated and generates a carry signal every 32 times; llCl, 11c2, and 11C3 are the counters of the counter 11b. This is a latching type relay that is turned ON sequentially in response to a carry signal, and is used as a memory element that stores the state of the event bias voltage to be applied even when the device power is turned off.

Note that the memory element for the development bias is not limited to the above-mentioned relay, but may also be an EEFROM (electrically e-ROM).
It is also possible to use a rasable PRO old etc. and rewrite the contents of the EEFROM according to the carry signal of the counter lb.

Further, 11dl and 11d2 are AND circuits, 12 is a counter that generates a carry signal when the number of actuations of the micro switch lla is counted 180 times, and 13 is linked to the opening and closing of the developer discharge door 4C at the bottom of the developer 4. It is a micro-sinch that operates by

The toner stored in a dedicated cartridge is manually supplied to the toner replenishing unit 4 each time a toner exhaustion warning signal is issued from a toner detection device (not shown) provided in the developing device 4.
The developing device 4 is replenished from b.

In this way, when the number of toner replenishments reaches 32, the relay 11 is activated by the carry signal from the counter lb.
01 becomes "ON", and when the number of times of toner replenishment reaches 64 times, the relay 11c2 becomes "ON", and then, when the number of times of toner replenishment reaches 96 times, the relay 1103 turns "ON".
become.

The control circuit 9 includes relays 11cl, 11c2 and 1
300 volts when all 1c3 are OFF, 200 volts when relay 11cl is ON Relay 11
When c2 is “ON”, 100 ports and relay 11c3
is ``ON'', the control signal of 0 volts is sent to the power supply circuit 10.
Send to.

The power supply circuit 10 applies a developing bias voltage according to a control signal sent from the control circuit 9 to the developing roller 4a.

Further, the carry signal of the counter 12 is used as a developer replacement request signal S, and the processing is performed in accordance with this signal.

When the operator replaces the developer, the micro switch 13
detects this, and the detection signal causes counter llb
- Counter 12, relay 11c, relay 11c2 and relay 11c3 are reset and return to the initial state.

〔Effect of the invention〕

As explained above, according to the present invention, the degree of deterioration of the developer is accurately determined by a simple means using a microsinch counter, an AND circuit, a relay, etc., and the degree of deterioration of the developer is determined based on the result. It is possible to prevent printing fog by controlling the ai bias voltage.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention. FIG. 2 is a configuration diagram of a conventional example. In the figure. 1 is a photosensitive drum, 2 is a charger. 3 is an exposure device, 4 is a developer. 9 is a control circuit, and 10 is a power supply circuit. 11a and 13 are microsinches. 11b and 12 are counters. 11c1, 11c2 and 11c3 are relays. 11dl and 11d2 are AND circuits.

Claims (1)

[Claims] a toner image forming body on which a toner image is formed; a latent image forming section forming an electrostatic latent image corresponding to recorded information on the toner image forming body; and developing the formed electrostatic latent image with toner. A recording apparatus comprising a developing device, a counting means for counting the number of times toner is replenished from the outside to the developing device, and a voltage switching means for switching a developing bias voltage applied to the developing device according to an output of the counting device. A recording device comprising: