JPS5977462A - Detector of remaining amount of toner - Google Patents

Abstract

PURPOSE:To simplify a device and to reduce power consumption by measuring the propagation speed of an ultrasonic wave by an ultrasonic wave transmitter and a receiver provided to side walls of a toner storage part, and detecting the remaining amount of toner. CONSTITUTION:The ultrasonic wave transmitter 3 and receiver are provided oppositely on the side walls 1a and 1b of a developing device 1 which contains toner. An ultrasonic wave sent out of the transmitter 3 propagates in the toner to reach the receiver 4. Its output is inputted to an AND circuit 6 through an NOT circuit 5. The AND circuit 6 outputs pulses based upon the phase delay of a receive signal corresponding to the remaining amount of toner and they are counted by a counter circuit 7 to display the remaining amount of toner on a display device 8. Consequently, the device is simplified and the power consumption is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner remaining amount detection device in a toner storage section of a dry type electrophotographic copying machine.

Conventionally, to detect the amount of toner remaining in the toner storage section of a developer, etc., changes in the amount of magnetism, changes in the amount of transmitted light, changes in the amount of electrostatic charge, etc. were measured. If toner is locally attached to the area to be measured, it will be detected that a large amount of toner remains in the toner storage compartment σ] even though the amount of toner remaining is actually low, and the reliability of the detection result will be low. Ta.

In order to improve this problem, some devices were equipped with a means to brush off the surface of the sensor that measures these physical quantities with the rotation of the toner dispenser brush, but once the toner stuck to the sensor surface, it was difficult to remove, and the detection section The difference still remained.

The present invention overcomes these difficulties and improves the remaining toner amount detection device by focusing on the fact that the amount of remaining toner is related to the toner density, and that the transmission speed of ultrasonic waves is related to the toner density. Another object of the present invention is to provide a device that detects the remaining amount of toner by measuring the ultrasonic transmission speed.

The present invention will be explained below based on the embodiment shown in FIG.

Reference numeral 1 denotes a developing device 1 that stores toner in a dry type electrophotographic copying machine. In the past, an ultrasonic receiver 4 was provided on the side wall 1b at the location where the ultrasonic wave was generated, and the ultrasonic wave generated from the ultrasonic oscillator 3 propagated through the toner in the side wall 1a''tlb and reached the ultrasonic receiver 4. It is now possible to do so.

Further, 2 is a Schmidt circuit that emits a square wave pulse, and the output of the Schmidt circuit 2 is an ultrasonic transmitter 3 and A,
The signal is sent to the ND circuit 6.

Roughly, the output of the ultrasonic receiver 4 is A through the entire NOT circuit 5.
The signal is transmitted to the ND circuit 6.

Zaranimata AND circuit 6σ) Output 6 and counter circuit 7
If the output from the AND circuit 6 is 2n during the transmission interval 1
J width is the same counter circuit 7) 2c, display device 8
It is designed to be sent to

Schmitt circuit 2'f: Let's make it work, same Yumitsu)
Circuit 2 J: A rectangular wave Noculus Pa is transmitted, and the ultrasonic transmitter 3 operates. and reaches the ultrasonic receiver 4.

Therefore, the speed of the ultrasonic waves propagating through the toner 11 in the developing device 1 increases or decreases depending on the toner density, and the toner density decreases as the remaining amount of toner decreases. Ultrasonic receiver 4 for Pa
The phase 7nT of the received rectangular wave pulse Pb increases or decreases by 1-0 in response to the amount of remaining toner.

This phase delay t], yf1-shaped wave pulse PC with a time width of T
The width of the rectangular wave pulse Pc is wide, as shown in FIG. As shown in the figure, when the width of the rectangular wave pulse Pc becomes narrower, the width of the rectangular wave pulse Pc becomes 0 and the width of the rectangular wave pulse Pc reaches 1 when the counter circuit 7 counts and the remaining amount of toner is displayed on the display W8.
Ru.

In the embodiment of FIG. 1, an ultrasonic oscillator 3 and an ultrasonic receiver 4
and the opposite side of the developing device 1+tllll wall 1aX1. The ultrasonic oscillator 3 and the ultrasonic transmitter 4 are installed on one side wall 1a of the developing unit 1, and the ultrasonic oscillator 3 and The oscillated ultrasonic waves may be reflected by the opposing wall and received by the ultrasonic receiver 4.

As described above, in the present invention, even if the toner is firmly attached to the side wall of the toner storage portion, the ultrasonic waves can pass through this portion, so there is little detection error.

Furthermore, since ultrasonic waves are rectangular waves, there are few errors due to waveform interference.

Briefly, the present invention includes an ultrasonic oscillator, an ultrasonic receiver, and a rectangular wave pulse signal transmitted from the oscillator and received by the receiver.71. The device is extremely simple and inexpensive, and consumes little power.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram illustrating one embodiment of the remaining toner amount detection device related to misfire 131.1, Fig. 2 is an explanatory diagram illustrating another embodiment, and Figs. 3 and 4 are Explanation illustrating the waveforms of the rectangular wave pulses when there is a large amount of toner remaining and when there is little remaining toner in the embodiment shown in FIG. 1]A
It is. DESCRIPTION OF SYMBOLS 1...Developer, 2...Unimit circuit, 3...Ultrasonic generator 4-oscillator, 4...Ultrasonic receiver, 5...NOT circuit, 6
...AND circuit, 7...counter circuit, 8...
Display device t. Agent: Patent attorney Mogai Ehara, 1 person, Figure 3, Figure 4

Claims (1)

[Claims] In the toner storage section of a dry type electrophotographic copying machine, an ultrasonic oscillator operated by an oscillator that emits a rectangular wave pulse signal and an ultrasonic receiver that receives the ultrasonic waves emitted from the ultrasonic oscillator are installed in the toner storage section. 2n, T, knee received pulse signal by the ultrasonic receiver; Amount detection device.