JPH01173077A - Toner sensor - Google Patents

Abstract

PURPOSE:To automatically detect a waste toner by providing a magnetic field generating means for forming a magnetic field through a magnetic toner in a toner box. CONSTITUTION:After the printing operation of a copying machine is operated, a magnetic toner left behind on a photosensitive drum 1 is scraped down by a cleaning blade 3, becomes a waste toner 4 and is collected in a waste toner box 2. In such a way, when the inside of the box 2 is filled with the waste toner 4, a magnetic field by a permanent magnet 5 is formed through the waste toner 4 filled between the magnet 5 and a reed switch 6. By this magnetic field, the reed switch 6 becomes ON, and a toner full signal is outputted from a Schmitt trigger gate 10. This signal, for instance, is inputted to the input port of a CPU, or inputted to a pilot lamp, etc., and it is informed that the toner is full.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to copying machines such as dry type electronic copying machines and optical printers that use magnetic toner that can detect toner full (waste toner full) and toner empty (supplied toner has run out). related to toner sensors in machines.

[Conventional technology]

In conventional dry type electronic copying machines and optical printers, a vibration detection type sensor using a piezoelectric element, for example, has been used as a toner sensor for detecting toner full or toner empty.

[Problem that the invention seeks to solve]

The vibration detection type sensor used in the conventional copying machine is expensive, so if the sensor is incorporated into regularly replaced parts such as a developing device or a photosensitive drum unit of the copying machine and made disposable, the cost will be high. Furthermore, since the sensor uses a piezoelectric element, there are problems such as malfunctions due to electrical noise or vibrations of a copying machine or the like.

An object of the present invention is to provide a toner sensor that can solve the above-mentioned conventional problems.

[Means for solving problems]

The toner sensor according to the present invention includes: (1) In a copying machine using magnetic toner, a toner box containing magnetic toner and a toner sensor disposed outside the toner box form a magnetic field through the magnetic toner in the toner box. a magnetic field generating means configured to
a magnetic field responsive element that is disposed outside the toner box and separated from the magnetic field generating means and detects the presence or absence of magnetic toner in the toner box in response to the magnetic field generated through the magnetic toner; It is characterized by comprising the following.

Further, the toner sensor according to the present invention is provided in (2) a copying machine using magnetic toner, which is disposed in a toner box containing waste toner, and outside a toner discharge port of the waste toner box, and located inside the toner discharge port. a magnetic field generating means configured to form a magnetic field through the waste toner; and a magnetic field generating means arranged outside the toner discharge port and isolated from the magnetic field generating means, and configured to form a magnetic field through the waste toner. It is characterized by comprising a magnetic field responsive element that responds to detect toner full.

Furthermore, the toner sensor according to the present invention includes (3) a toner box for supplying magnetic toner to a sleeve in a copying machine using magnetic toner, and a toner sensor disposed outside a toner supply port of the toner box, a magnetic field generating means configured to form a magnetic field through the toner in the mouth; and a magnetic field generating means disposed outside the toner supply port and separated from the magnetic field generating means, the magnetic field being formed through the toner in the toner supply port. and a magnetic field responsive element that responds to the magnetic field and detects toner empty when the amount of toner in the toner supply port decreases.

[For production]

According to the present invention, a magnetic field generating means such as a permanent magnet or an electromagnet, and a magnetic field responsive element such as a reed switch or a Hall element are arranged on the outside of the toner box. A magnetic field is formed when toner is present, and a magnetic field-responsive element is turned on and off depending on the presence or absence of this magnetic field.Thereby, for example, by turning on and off an electric signal, it is easy to check the presence or absence of magnetic toner in a toner box. And it can be detected reliably.

〔Example〕

FIG. 1 is a schematic diagram showing a toner sensor according to an embodiment of the present invention, in which 1 is a photosensitive drum of a copying machine, 2 is a waste toner box, 3 is a cleaning blade, and 4 is a waste toner (
magnetic toner), 5 is a permanent magnet, 6 is a reed switch, 7
1 is a contact point, 8 is a pull-up resistor, 9 is a capacitor, 10 is a Schmitt trigger gate (11 is a TF multiplied signal (toner full signal)), 21 is a waste toner outlet, 22 is a power supply, and 23 is a ground.

In FIG. 1, a permanent magnet 5 is placed outside the waste toner outlet 21 of the waste toner box 2, and when the waste toner outlet 21 is filled with waste toner 4, a magnetic field is generated through the waste toner 4. are arranged to form a moreover,
A reed switch 6 is disposed outside the waste toner outlet 21, facing the permanent magnet 5, and detects toner full in response to a magnetic field formed via the waste toner 4 in the waste toner outlet 21. . A pull-up resistor 8 and a capacitor 9 are connected in series between the power supply 22 and the ground 23, and each terminal of the reed switch 6 is connected to the ground 23 on one side and to the pull-up resistor on the other through a contact point 7. 8 and a capacitor 9, and the connection points are connected to a Schmitt trigger gate 10, forming an operating circuit for toner full detection in which a TF multiplied signal is output from the Schmitt trigger gate 10.

In FIG. 1, the magnetic toner left on the photosensitive drum 1 after the printing operation of the copying machine is removed by the cleaning blade 3.
The waste toner is scraped off and becomes waste toner 4 and accumulates in the waste toner box 2. When the waste toner box 2 is filled with the waste toner 4 in this way, since the waste toner 4 is a magnetic material, it is permanently stored through the waste toner 4 filled between the permanent magnet 5 and the reed switch 6. A magnetic field is formed by the magnet 5, the reed switch 6 is turned on by this magnetic field, and a toner full signal (TF multiplied signal is output from the Schmitt trigger gate 10. This FT signal is transmitted to the CPU (
(not shown) or is input to an indicator light or the like to notify that the toner is full. In the above embodiments, for example, an electromagnet may be used instead of the permanent magnet 5, or a Hall IC may be used instead of the reed switch 6.

FIG. 2 is a schematic diagram of the main parts of an embodiment in which the toner sensor of the present invention is applied to a copying machine capable of detecting toner empty, and the same parts as shown in FIG. 1 are given the same reference numerals and explained. do.

In FIG. 2, 12 is a magnet roller of a copying machine that uses magnetic toner, 13 is a sleeve, 14 is a doctor blade, 15 is a toner box that supplies magnetic toner to the sleeve 13, and 16 is a toner empty signal (TE double signal,
Reference numeral 24 indicates a toner supply port for supplying the magnetic toner 4' from the toner box 15 to the sleeve 13, and the other parts are the same as those described with reference to FIG.

In FIG. 2, the toner supply port 2 of the toner box 15
A permanent magnet 5 is placed on the outside of the magnetic toner 4 when the toner supply port 24 is filled with magnetic toner 4'.
′ is arranged to form a magnetic field through the magnetic field. Further, the magnetic toner 4' in the toner supply port 24 is reduced in response to the magnetic field formed outside the toner supply port 24 through the magnetic toner 4' in the toner supply port 24, facing the permanent magnet 5. A reed switch 6 is provided to detect when the toner is empty.

In FIG. 2, when the copying machine is operated, the magnetic toner 4' in the toner box 15 is supplied to the sleeve 13 by the magnet roller 12. As shown in FIG. Magnetic toner 4' in this case
The supply amount is determined by the doctor blade 14. When the magnetic toner 4' is consumed by the photoconductor, the magnetic toner 4' in the toner box 15 decreases, and when the level drops below a predetermined value, the magnetic field formed by the permanent magnet 5 and the magnetic toner 4' decreases. disappears (or becomes weak), the reed switch 6 turns off, and the Schmitt trigger gate 10 outputs the toner empty signal (TE double signal 1).
6 is output. This TE multiplied signal, for example, the CPU (
(not shown), an indicator light, etc., to notify that the toner is empty. In the second embodiment, an electromagnet may be used instead of the permanent magnet 5, and a Hall IC may be used instead of the reed switch 6.

In the embodiment shown in FIG. 2, for example, when the contact point 7 is disconnected and the operating circuit for toner empty detection is opened, the pull-up resistor 8 causes the gate input of the Schmitt trigger gate 10 to go high ( The output 16 is regarded as a TE multiplied signal to become L (low). Therefore, the device shown in this embodiment has a fail-safe function as is. However, the first
In the embodiment shown in the figure, if the contact point 7 is disengaged and the operating circuit for waste toner full detection is released, the gate output 1 of the Schmitt trigger gate 10
1 becomes L, which is considered to be a normal state in which the waste toner is not full, resulting in a malfunction.

The third embodiment shown in FIG. 3 eliminates the above malfunction,
This is an embodiment in which a fail-safe function is provided in which when a contact point or the like is disconnected and the operating circuit for detecting waste toner full is opened, the waste toner is determined to be full.

In FIG. 3, the same parts as those shown in FIG. 1 will be described with the same reference numerals. 7' is the contact point, 1
7 is a switch type Hall IC.

18 is TF double signal, this switch type Hall IC17
Terminal Q is connected to ground 23, and terminal Ql is connected to pull-up resistor 8.
By connecting the terminal vec to the power supply 22 at the connection point between the capacitor 9 and the capacitor 9, in this third embodiment, the switch type Hall IC 17 is used in the H active state, and for example, when the contact point etc. are disconnected, the waste toner full is detected. When the operating circuit is opened, a TF multiplied signal is output from the Schmitt trigger gate 10, and a fail-safe function can be achieved in which it is assumed that the waste toner is full. The other configurations and their functions are the same as those described with reference to FIG.

In the above-mentioned embodiment, in a copying machine having an operating circuit for toner empty detection shown in FIG. The iron powder inside may be attracted to the permanent magnet 5, and the original characteristics of two-component development may not be obtained.

The fourth embodiment shown in FIG. 4 is an embodiment for solving the above-mentioned disadvantages.

In FIG. 4, the same parts as those shown in FIGS. 2 and 3 are designated by the same reference numerals and will be explained. 4 shown in Figure 4.
In this embodiment, compared with the second embodiment shown in FIG. 2, the magnetic field of a magnet roller 12 is used instead of the permanent magnet 5 of FIG. 2 as a magnetic field generating means, and the magnetic field of FIG. A switch type Hall IC 17 is used in place of the reed switch 6, and each terminal of this switch type Hall IC 17 is connected via a contact point 7' in the same manner as in the case of FIG. When the toner empty state is detected, the Schmitt trigger gate 10 outputs a TE multiplied signal. In the fourth embodiment shown in FIG. 4, by using the magnetic field of the magnet roller 12 instead of the permanent magnet 5 of FIG. 2, when a two-component toner is used, iron powder in the toner is is not attracted to the permanent magnet 5, so the original characteristics of two-component development can be obtained. Other configurations and functions are shown in Figures 2 and 3.
It is similar to that described with respect to the figure. Note that in FIG. 4, a reed switch 6 may be used instead of the switch type Hall IC 17. Furthermore, in Figure 4,
It is also possible to use a Hall IC that operates in an alternating magnetic field as the switch type Hall IC 17.

〔Effect of the invention〕

As described above, according to the toner sensor of the present invention, toner full or toner empty can be automatically detected at low cost and reliably. Further, these toner sensors for detecting toner full or toner empty can be incorporated into a developing unit of an electrophotographic device or the like and used as a disposable device. Furthermore, by providing a fail-safe function to the operating circuit that detects toner full and toner empty, it is possible to prevent malfunctions of the copying machine.

[Brief Description of the Drawings] Fig. 1 is a schematic diagram of the main parts of an embodiment in which the toner sensor of the present invention is applied to a copying machine that detects when waste toner is full, and Fig. 2 shows a copying machine in which the present invention is applied to a copying machine that detects when toner is empty. 3 is a schematic diagram of the main part of an embodiment in which the present invention is applied to a copying machine that detects when waste toner is full and has a fail-safe function. FIG. 2 is a schematic diagram of a main part of an embodiment of the present invention in which a magnet roller is used as a magnet roller. 2...Waste toner box, 4...Waste toner, 4'.
... Magnetic toner, 5... Permanent magnet, 6... Reed switch, 8... Pull-up resistor, 9... Capacitor, 10... Schmitt trigger gate, 12... Magnet roller, 15. ...Toner box, 17...
Switch Type Hall IC0 Applicant Representative Patent Attorney Takeshi Suzue Industry 1 Figure 2 Figure 3

Claims (7)

[Claims] (1) In a copying machine that uses magnetic toner, there is a toner box containing magnetic toner, and a magnetic field that is arranged outside the toner box and forms a magnetic field via the magnetic toner in the toner box. a generating means, the magnetic field generating means being disposed outside the toner box and separated from the magnetic field generating means, and detecting the presence or absence of magnetic toner in the toner box in response to the magnetic field generated through the magnetic toner. A toner sensor comprising a magnetic field responsive element. (2) The toner sensor according to claim 1, wherein a reed switch is used as the magnetic field responsive element. (3) Switch type Hall I as the magnetic field responsive element
Claim 1 (1) characterized in that C is used.
) Toner sensor described in section. (4) In a copying machine using magnetic toner, a magnetic field is formed through a toner box containing waste toner and the waste toner disposed outside the toner discharge port of the waste toner box and within the toner discharge port. a magnetic field generating means configured as above, and a magnetic field responsive device disposed outside the toner discharge port separately from the magnetic field generating means, and detecting toner full in response to the magnetic field formed through the waste toner. A toner sensor characterized by comprising: an element. (5) A switch type Hall IC is used as the magnetic field responsive element for detecting the toner full, and an operating circuit of the switch type Hall IC is connected to the switch type Hall IC.
The toner sensor according to claim 4, further comprising a fail-safe mechanism that determines that the toner is full when the toner sensor is opened by a switch other than the above switch. (6) In a copying machine that uses magnetic toner, a toner box that supplies magnetic toner to a sleeve and a toner box that is disposed outside a toner supply port of the toner box and that forms a magnetic field through the toner in the toner supply port. a magnetic field generating means configured as above; and a magnetic field generating means arranged outside the toner supply port and separated from the magnetic field generating means, and responsive to the magnetic field formed via the toner in the toner supply port, and configured to supply the toner. A toner sensor comprising: a magnetic field responsive element that detects toner empty when toner in the mouth decreases. (7) The toner sensor according to claim 6, wherein a magnet roller is used as the magnetic field generating means used to detect the toner emptyness.