JPS6249383A - Image forming device - Google Patents

Abstract

PURPOSE:To feed toner without the generation of dirt or the like in a device by providing a means for detecting and displaying that the volume of toner reaches the prescribed quantity to be replenished and a means for detecting that the volume of toner reaches the prescribed quantity to stop image forming operation. CONSTITUTION:Toner 25 fed into a hopper 21 is consumed in accordance with the use of the device. When the toner 25 is consumed up to the quantity sensed by a toner sensor 23, a signal is inputted from a detecting circuit 26 to a control circuit 28, which turns on a toner feed lamp 29 to inform the necessity of toner replenishment. When the toner is consumed furthermore and its residual reaches the quantity sensed by a toner sensor 24, a signal is inputted from a detecting circuit 27 to the control circuit 28, which stops the copying operation while keeping the lamp 29 ON. The device can be efficiently used without any trouble by replenishing new toner before the consumption of toner up to the quantity to be sensed by the toner sensor 24.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to image forming apparatuses such as copying machines and various printers.

(Prior Art) Conventionally, this type of image forming apparatus turns on a toner replenishment lamp when the amount of toner in the developing device decreases below a certain level.

(b) Automatically stop the image forming operation (2) Some devices are configured to allow the image forming operation to continue.

(Problems to be Solved by the Invention) However, such prior art has the following problems.

In case (a), since the image forming operation suddenly stops during use, there is an inconvenience that necessary documents cannot be copied until toner is replenished. In particular, there is a problem in that when there is no replenishment toner on hand, the image forming apparatus remains in the body IF state for a long period of time, which greatly impedes business operations.

In the case of (b), the toner can be used continuously even after the toner replenishment lamp is turned on, so the user may continue to use the toner without replenishing the toner. In this case, there is a problem that density unevenness, white streaks, etc. may occur due to lack of toner. Further, there is a problem in that more toner is consumed than necessary, and if toner is replenished when there is almost no toner in the developing device, phenomena such as toner blowing out occur, which stains the inside of the image forming device.

Therefore, the present invention has been made to solve the above problems of the prior art, and its purpose is to prevent the image forming operation from suddenly stopping when the amount of toner decreases below a certain amount. It is an object of the present invention to provide an image forming apparatus that can replenish toner without causing density unevenness, white streaks, etc., even when used continuously, and without the risk of staining the apparatus.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an image forming apparatus in which image formation is performed using a developer supplied within a developing device, in which the amount of developer is means for detecting and displaying that the amount of developer has reached a predetermined amount for replenishing the developer before reaching a predetermined amount at which the image forming operation should be stopped; The image forming apparatus is configured to include means for stopping the image forming operation.

(Example) The present invention will be explained below based on the illustrated example. Fourth
In the figure, the symbol l represents a photosensitive drum. An optical system 2 is provided above the photosensitive drum 1. This optical system 2 includes a fixed document table 3, a document irradiation lamp 4,
It consists of movable mirrors 5, 6°7, a lens 8, and a fixed mirror 9. Further, in a position close to the upper part of the photoreceptor drum l, there is an exposure duct (10) that surrounds the original image light beam irradiated from the optical system 2 to the photoreceptor drum 1 and isolates it from the surroundings.
is provided. Next, each device installed around the photoreceptor drum 1 will be explained in order in the rotational direction of the photoreceptor drum 1, that is, clockwise in FIG. A blank exposure bag att is provided for erasing electrostatic load on unnecessary portions of the image forming apparatus. Further, a developing device M12 is provided at a side position of the photoreceptor drum l. Details of these developing devices 12 will be described later. Further, a paper feed section (
A pair of timing rollers 14 are provided for aligning the transfer paper sent from the photoreceptor drum (not shown) with the developed powder image on the photoreceptor drum. Further, at a position below the photoreceptor drum l, there is a transfer charger 15 for transferring the developed powder image on the photoreceptor drum onto a transfer paper, and a separation charger for peeling the transfer paper from the photoreceptor drum l. 16 are provided. Further, a conveyance bell 1-17 for conveying the transfer paper to a fixing device (not shown) is provided at a position adjacent to the separation charger 16. Furthermore, a cleaner 18 for removing untransferred residual developer on the photoreceptor drum 1 is provided above the conveyor belt 17 and on the side of the photoreceptor drum 1.

Further, a photoreceptor drum l is disposed diagonally above the cleaner 18.
A pre-exposure irradiation lamp 19 is provided to remove any residual charge on the photoreceptor. Further, a charger 20 for uniformly charging the surface of the photosensitive drum 1 is provided at a position close to the top of the photosensitive drum 1.

FIG. 1 shows the above-mentioned developing device, in which numeral 21 denotes a hole and a hole for accommodating toner, and 22 denotes a developing sleeve.

23 and 24 are toner sensors using piezo vibrators. These toner sensors 23 and 24 detect the pressure of the toner in front of them by vibration, and the relationship between the remaining amount of toner and the detected pressure changes as shown in FIG. Therefore, in the figure, if a threshold level is provided for the detection pressure PTH, the presence or absence of toner at the positions where the toner sensors 23 and 24 are provided can be detected.

25 is toner.

The toner sensors 23 and 24 are arranged vertically at the bottom of the hopper 21. The toner sensor 24 is disposed at a position where it can detect a limited amount of toner that may cause various problems due to toner consumption beyond this amount, such as density unevenness, white streaks, or toner blow-out when toner is subsequently replenished.

The toner sensor 23 detects the amount of toner detected by the toner sensor 24 so that no problems such as agglomeration will occur even if a predetermined amount of toner is newly replenished. The sensor is placed at a position that detects the amount of remaining toner.

FIG. 3 is a block diagram showing the control system of this embodiment. 2
6.27 is a detection circuit that detects the presence or absence of toner by detecting the signals from the toner sensors 23 and 24; 28 is a control circuit; when a no-toner signal is input from the toner sensor 23, toner replenishment is performed; The lamp 29 is turned on, and when a no-toner signal is input from the toner sensor 24, the copying operation is stopped.

In the image forming apparatus according to the second embodiment of the present invention, the amount of toner is detected and replenished as follows. That is, by replenishing the hopper 21 of the developing device 12,
After sufficient toner 25 is supplied into the hopper 21, the toner 25 in the hopper 21 is consumed as the device is used. but,
Toner 2 until the amount of toner detected by toner sensor 23
5 is consumed, the control circuit 28 is sent via the detection circuit 26.
A signal is input to the control circuit 28, and the toner replenishment lamp 2
9 is lit to notify the user that toner needs to be replenished. Even if this toner replenishment lamp 29 is lit, the copying operation can continue.

After that, if the device is continued to be used without replenishing toner and the toner is further consumed and the remaining amount reaches the level detected by the toner sensor 24, the control circuit 2
8, the control circuit 28 stops the copying operation with the toner supply lamp 29 turned on.

In this process, immediately after the toner replenishment lamp 29 lights up, or for a predetermined number of sheets.

For example, if new toner is replenished before making about 500 copies, that is, before the toner acid detected by the toner sensor 24 has been consumed, the apparatus can be used thereafter without any problem.

Therefore, 1. For example, when the image forming apparatus is in emergency use, even if the toner replenishment lamp 29 lights up, an appropriate amount of copies can be made without toner replenishment, so the copying operation can be completed by toner replenishment work. Furthermore, even if toner cannot be replenished immediately, for example, there is no toner on hand to replenish, it is possible to avoid the inconvenience of being forced to stop for a long period of time.

However, if the apparatus is continued to be used without replenishing toner after the toner replenishment lamp 29 lights up, the copying operation will automatically stop as detected by the toner sensor 24. Therefore, it is possible to prevent the occurrence of density unevenness, white streaks, or toner blow-out during toner replenishment due to toner shortage in the developing device 12.

FIG. 5 shows a second embodiment of the image forming apparatus according to the present invention, and the same parts as in the first embodiment are denoted by the same reference numerals. , only the toner sensor 23 is disposed in the hopper 21 of the developing bag 2t12. That is, when the toner sensor 23 detects that there is no toner, the control circuit 28 turns on the toner supply lamp 28 and counts the number of copies. Start. After copying, for example, approximately 500 sheets of a standard original, the control circuit 28 automatically stops the copying operation until the amount of toner reaches which the copying operation should be stopped.

According to this embodiment, only one toner sensor is required, which reduces costs, and displays the number of copies that can be made from the time the toner replenishment lamp turns on until the copying operation stops, making it easier to use. It's even more convenient. The other configurations and functions are the same as those in the first embodiment, so their explanations will be omitted.

FIG. 6 shows a third embodiment of the image forming apparatus according to the present invention, and the same parts as in the first embodiment are denoted by the same reference numerals. device 12
A case 30 for storing toner 25 is provided in the hopper 21 so as to be slidable up and down.
ffZfB is detected by a sensor 31 such as a pressure-sensitive rubber that converts pressure into a resistance value, and the remaining amount of toner is detected in an analog manner. In other words, this sensor 3
1 is connected to a constant voltage power supply 32, and the current value is measured. This current value changes as shown in FIG. 7 according to the amount of toner consumption.

Here, as shown in FIG. 7, two threshold levels are set for the current value, namely ITI(1 and ITH2).
, I TH2 corresponding to the toner consumption amounts W1 and W2, respectively, in the embodiment shown in FIG.

This corresponds to the amount of toner detected by the toner sensors 23 and 24. Therefore, the current value is at the threshold level IT
When the toner replenishment lamp 29 is turned on when it is below HI,
The copy operation is stopped when the threshold level I TH2JJ is lowered. The other configurations and functions are the same as those in the first embodiment, so their explanation will be omitted.

(Effects of the Invention) The present invention has the above configuration and operation, and displays the replenishment of developer before the amount of developer reaches a predetermined amount at which the image forming operation should be stopped, and then stops the image forming operation. Since the image forming operation is stopped when the required amount is reached, the image forming operation will not suddenly stop when the developer replenishment message appears, and the image quality will not deteriorate in case of an emergency. To prevent deterioration of image quality and staining of the inside of the device, etc., by replenishing the developer within a predetermined range after the developer replenishment display appears. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing a developing device of a first embodiment of an image forming apparatus according to the present invention, and FIG. 2 is a graph showing the relationship between the remaining amount of toner and pressure detected by a toner sensor.
FIG. 3 is a block diagram showing a control system, FIG. 4 is a schematic diagram showing an embodiment of an image forming apparatus according to the present invention, and FIG. 5 is a longitudinal section showing a developing device according to a second embodiment of the present invention. FIG. 6 is a vertical sectional view showing a developing device according to a third embodiment of the present invention,
FIG. 7 is a graph showing the relationship between toner consumption and current. Explanation of symbols 12... Developing device 23.24... Toner sensor 25... Toner 28... Control circuit 29... Toner replenishment lamp Fig. 2 Fig. 3 Fig. 4 15 τ N To Engineering

Claims (1)

[Claims] In an image forming apparatus that forms an image using a developer supplied into a developing device, detecting that the amount of developer has reached a predetermined amount for replenishing before reaching a predetermined amount at which the image forming operation should be stopped. An image forming apparatus comprising: display means; and means for detecting that the amount of developer has reached a predetermined amount at which the image forming operation should be stopped and stopping the image forming operation.