JPH06109789A - Charge measurement device - Google Patents

Abstract

PURPOSE:To provide a charge measurement device having the capability of performing accurate charge measurements at all times by keeping a toner collection amount constant on a toner carrier. CONSTITUTION:This charge measurement device A1 is constituted of a toner suction section 5 for drawing toner 4 from a toner carrier, for example, a photosensitive drum 9, a measurement section 8 (shielded conductor 1, conductor vessel 2, insulation material 3, electrometer 6 and a filter 7) for measuring the charged amount of the toner 4 drawn into the section 5. Also, the section 5 is provided with the a hollow suction nozzle 10 formed in such a way as allowing direct adherence, a suction tube 12 connecting the nozzle 10 to the conductor vessel 2 of the section 8, and an air introduction hole 11 communicated with the tube 12 is formed on the nozzle 10 at a position away from a toner layer. According to this construction, the toner 4 on the drum 9 can be collected with the nozzle 10 kept in contact therewith, and a toner collection amount can be kept constant, thereby ensuring accurate charge measurements at all times.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge measuring device, and more particularly, to a charge measuring device used in a copying machine or the like for measuring the charge amount of toner.

[0002]

2. Description of the Related Art FIG. 7 is a schematic diagram showing a schematic configuration of a reference Faraday gauge A ₀ , and FIG. 8 is a schematic diagram showing a schematic configuration of an example of a conventional charge measuring device A ₀ ′. For example, one of the main factors that influence the print density of an electrostatic copying machine is the amount of toner charge. As a basic device for measuring the charge amount of the toner, there is a reference Faraday gauge A ₀ as shown in FIG. This is a grounded shield conductor 1
The conductor container 2 is disposed in the container with the insulating material 3 interposed therebetween, and the charged toner 4 existing on the toner carrier such as the developing sleeve and the photoconductor drum is transferred to the conductor container 2 and the opening 5 _a ″ of the shield conductor 1. 8 is to measure the ground potential of the conductor container 2 when passing through it in a non-contact manner and using the electrometer 6. This reference Faraday gauge A ₀ is a practical device shown in FIG.
It is a conventional charge measuring device A ₀ ′ as shown in FIG. This conventional device A ₀ ′ is called a suction type Faraday gauge, and is a toner carrier, for example, the charged toner 4 on the photosensitive drum 9.
And a measuring unit 8 for measuring the amount of charge of the toner 4 sucked by the toner suction unit 5 '. In addition to the shield conductor 1, the conductor container 2, the insulating material 3 and the electrometer 6 similar to the reference Faraday gauge A ₀ , the measuring unit 8 is provided with a filter 7 on the bottom of the conductor container 2. Hereinafter, this conventional device A ₀ ′
The operation of will be described. That is, to suck the toner 4 which is charged on the photosensitive drum 9 in the stop by a not-shown suction pump together with the air from the 'front end opening portion 5 _a of' the toner suction portion 5. Of this, air is separated by the filter 7,
Is discharged. On the other hand, the toner 4 remains on the filter 7,
The charge amount is measured by the electrometer 6. Conventionally, the toner A on the photosensitive drum 9 which has been stopped is suctioned and collected in a non-contact manner by this conventional apparatus A ₀ ′ to measure the charge.

[0003]

The conventional charge measuring device A ₀ ′ as described above actually sucks and collects the toner adhering to the photoconductor drum 9 provided in the actual machine, so that the chargeability of the photoconductor drum 9 is improved. Since it can be detected including the above, it is practical, but when the toner 4 on the photosensitive drum 9 is sucked, it is sampled by the flow of air from around the tip opening 5 _a ′ of the toner suction portion 5 ′. The toner area may vary, and the amount of toner 4 collected may change. Therefore, it was difficult to obtain accurate charge measurement data.
In order to solve the above-mentioned problems in the conventional technique, the present invention has improved the charge measuring device and can always perform accurate charge measurement by keeping the amount of toner collected on the toner carrier constant. The purpose is to provide a device.

[0004]

In order to achieve the above object, a first aspect of the present invention is to measure a suction means for sucking charged toner on a toner carrier, and a charge amount of the toner sucked by the suction means. In the charging measuring device including the measuring means, a hollow contact portion formed so as to be capable of directly adhering to the toner carrier, and a tube member connecting the contact portion and the measuring means. And a toner suction port is formed at the contact end of the contact part, and an air suction port communicating with the tube member is formed at a position apart from the toner layer of the contact part. It is configured as a charge measuring device that operates. A second aspect of the present invention is a charge measuring device comprising a suction means for sucking the charged toner on the toner carrier and a measuring means for measuring the charge amount of the toner sucked by the suction means. And a cylindrical abutting portion made of an elastic body, which is rotatably supported at both ends thereof and follows the toner carrying body when brought into contact with the toner carrying body, and is connected to the abutting part. , An air suction tube having one end opened at a position apart from the toner layer, and a tube member connecting the contact portion and the measuring means are provided, and a toner suction port is formed on the outer peripheral surface of the contact portion. A hollow shaft is formed at each end that supports the contact portion, and a first flow path is formed in one of the hollows so as to guide the air taken in from the air suction pipe to the toner suction port. The toner sucked from the suction port is transferred to the above-mentioned pipe member. A charging measuring device, characterized in that to direct the formation of the second flow path.

[0005]

According to the first aspect of the present invention, there is provided a charge measuring device having a suction means for sucking the charged toner on the toner carrier and a measuring means for measuring the charge amount of the toner sucked by the suction means. The suction means is provided with a hollow abutting portion formed so as to be in direct contact with the toner carrier, and a tube member connecting the abutting portion and the measuring means to each other. A toner suction port is formed at the end portion, and an air suction port communicating with the tube member is formed at a position apart from the toner layer at the contact portion. Therefore, the toner is collected in the state where the contact portion is in contact with the stopped toner carrier. At this time, the air flow for collecting toner flows from the air suction port formed at a position separated from the toner layer and does not flow from around the contact end of the contact portion. Since it can be brought into close contact with the body, the collected toner area matches the area of the contact end. As a result, accurate charge measurement can be performed at all times by keeping the amount of toner collected on the toner carrier constant. In the second aspect of the invention, the suction means is a cylindrical support made of an elastic body that is rotatably supported at both ends thereof and that follows the toner carrier when it comes into contact with the toner carrier. A contact portion, an air suction pipe connected to the contact portion and having one end opened at a position away from the toner layer, and a pipe member connecting the contact portion and the measuring means are provided. A toner suction port is formed on the outer peripheral surface of the portion, and the shaft of each end supporting the abutting portion is made hollow so that the air taken in from the air suction pipe is guided to the toner suction port in one side thereof. And a second flow path is formed on the other side so as to guide the toner sucked from the toner suction port to the tube member. Therefore, the toner can be collected while the contact portion is in contact with the rotating or stopped toner carrier. At this time, air flows in from the opening at a position away from the toner layer and does not flow in from the vicinity of the toner suction port of the contact portion, and the toner suction port can be brought into close contact with the toner carrier to suck the toner. Therefore, the collected toner area matches the area of the toner suction port.
As a result, accurate charge measurement can be performed at all times by keeping the amount of toner collected on the toner carrier constant. Further, since the charge can be measured even while the toner carrier is rotating, this charge measuring device can be mounted on, for example, a copying machine to measure the toner charge control including the charge control of the toner carrier for each actual machine. You can

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. The following embodiments are examples of embodying the present invention and are not intended to limit the technical scope of the present invention. Here, FIG. 1 shows a charge measuring device A according to an embodiment of the first invention.
Schematic diagram showing a schematic configuration of a _1, a front view Figure 2 showing the appearance of a toner suction portion of the charging measuring device A ₁ (a) and a side view (b), the conventional apparatus A 3 to the charge measuring device A ₁ comparison Chart of measurement result of the ₀ ', Fig. 4 is a schematic view, FIG. 5 is the shaft support of the suction nozzle of the charging measuring device a ₂ showing an outline configuration of a charging measuring device a ₂ according to the embodiment of the second invention A sectional view and FIG. 6 are schematic views showing an example in which the charge measuring device A ₂ is incorporated in a copying machine. Further, the same reference numerals are given to the same elements as those in the schematic diagram showing the schematic configuration of the reference Faraday gauge A ₀ shown in FIG. 7 and the schematic diagram showing the schematic configuration in an example of the conventional charge measuring device A ₀ ′ shown in FIG. To use. As shown in FIG. 1, the charge measuring device A _{1 according} to one embodiment of the first invention is
A toner suction unit 5 (corresponding to a suction unit) that sucks the toner 4 on the photosensitive drum 9 (corresponding to a toner carrier), and a measuring unit 8 (which measures the charge amount of the toner 4 sucked by the toner suction unit 5 ( (Corresponding to measuring means), and this measuring unit 8 is similar to the conventional example in that it further comprises a shield conductor 1, a conductor container 2, an insulating material 3, an electrometer 6 and a filter 7. However, in this embodiment, the toner suction section 5 is
Hollow suction nozzle 10 (corresponding to a contact portion) formed so as to be directly in contact with each other, and the suction nozzle 10 and the conductor container 2 of the measuring unit 8
And a suction pipe 12 (corresponding to a pipe member) that connects the suction pipe 10 and the suction nozzle 12 at a position apart from the toner layer on the photosensitive drum 9 to the air introduction hole 11 (air suction port). (Equivalent) is formed, which is different from the conventional example. As shown in FIGS. 2A and 2B, an appropriate number of air introduction holes 11 are provided around the suction pipe 12 on the opposite side of the tip opening 10 _a of the suction nozzle 10 so as not to suck the toner. It is formed so as to introduce toward the Matagaibu air to the distal end opening portion 10 _a.

The operation of the device A ₁ will be described below. When measuring the charge, first stop the photosensitive drum 9
The tip opening 10 _a of the suction nozzle 10 of the toner suction unit 5
To abut. At the same time, a suction pump (not shown) is operated to move the external air from the air introduction hole 11 to the suction nozzle 10
Take in. The air taken in is blown onto the charged toner 4 on the photoconductor drum 9 to separate the toner 4 from the photoconductor drum 9. The peeled toner 4 is sucked together with the air, and passes through the suction pipe 12 and the filter 7 of the measuring unit 8.
Reach Here, the charge amount of the toner 4 separated from the air is measured by the electrometer 6. In this way, the toner 4 is collected while the suction nozzle 10 is in contact with the stopped photosensitive drum 9. At this time, since air does not flow from the periphery of the tip opening 10 _a of the suction nozzle 10 and the suction nozzle 10 is fixed on the photosensitive drum 9, the collected toner area is equal to the area of the tip opening 10 _a. . Therefore, by keeping the amount of toner 4 collected on the photosensitive drum 9 constant, it is possible to always perform accurate charge measurement. Next, two kinds of toner are used respectively by the device A ₁ (contact type) for bringing the toner suction part 5 into contact with the photosensitive drum 9 and the conventional device A ₀ ′ (non-contact type) for not contacting these. The results of charge measurement are shown in FIGS. 3 (a) and 3 (b). From the figure, it can be seen that the contact type has less variation in the measured value than the non-contact type, and this difference is particularly remarkable in the contact type one-component toner. Next, an embodiment of the second invention will be described. As shown in FIG. 4, in the charge measuring device A _{2 according} to this embodiment, the toner suction portion 5 '
A cylindrical suction nozzle made of an elastic body that is rotatably supported at both ends thereof (corresponding to the suction means) and that follows the photosensitive drum 9 (corresponding to the toner carrying body) when the drum is brought into contact therewith. 10 '(corresponding to the contact portion) and the suction nozzle 1
0 ', one end of which is opened at a position apart from the toner layer, and an air suction pipe 11', and a suction pipe 12 '(a pipe member) which connects the suction nozzle 10' and a measuring unit 8 '(corresponding to measuring means). considerable) and a provided a form 'toner inlet 10 _a to the outer peripheral surface of the' suction nozzle 10, the air suction pipe 1 the axis of each end for supporting the suction nozzle 10 'on one in the hollow
To form a 1 'toner suction air taken from the outlet 10 _a' intake pipe 13 so as to guide (corresponding to the first channel), while the suction of toner 4 sucked from the toner inlet 10 _a ' It differs from the conventional example in that an air supply pipe 14 (corresponding to the second flow path) is formed so as to be guided to the pipe 12 '. FIG. 5 shows a sectional structure of the shaft support portion of the suction nozzle 10 '. The operation of the device A ₂ will be described below. In this apparatus A ₂ , when measuring the charge, the suction nozzle 10 ′ of the toner suction portion 5 ′ is first brought into contact with the photosensitive drum 9 which is rotating or stopped, and the photosensitive drum 9 is rotated and driven. At the same time, 'suction nozzle 10 by way of and the intake pipe 13' the air suction pipe 11 to the outside air by operating the suction pump (not shown) from the 'opening 11 _a formed in the' air suction pipe 11
Take in. The air taken in is the toner suction port 10 _a ′.
Is sprayed onto the charged toner 4 on the photoconductor drum 9 to separate the toner 4 from the photoconductor drum 9. The peeled toner 4 is sucked together with air and reaches the measuring unit 8'through the air supply pipe 14 and the suction pipe 12 ', where the charge amount is measured.

In this apparatus A ₂ , instead of the measuring section 8 using the filter 7 and the like in the apparatus A _1, a charging measuring terminal 1 for generating an induced charge by the attracted toner 4 is used.
5 is used for the measuring unit 8 ', and the charge measuring terminal 15 can continuously measure the charge. In this way, the toner is collected while the suction nozzle 10 'is in contact with the rotating or stopped photosensitive drum 9. In this case, 'because is in close contact with the photosensitive drum 9, toner area is collected toner inlet 10 _a' air from the surroundings 'toner inlet 10a' of the suction nozzle 10 can not flow into and suction nozzle 10 of the Match the area. As a result, this device A ₂
Also, by keeping the amount of toner 4 collected on the photoconductor 9 constant, accurate charge measurement can always be performed. Further, since the apparatus A ₂ can measure the charge of the toner including the charging performance of the photosensitive drum 9, it is possible to measure the toner chargeability of each actual machine such as a copying machine. FIG. 6 shows an example in which this apparatus A ₂ is incorporated in a copying machine. As shown in FIG. 6, the induced charge generated by the charge measuring terminal 15 of the measuring unit 8 is detected by the charge meter 16. This detection value is processed by the arithmetic circuit 17 and the transfer voltage control circuit 18 is operated so as to obtain a predetermined image density, and the transfer voltage applied to the transfer charger 19 is controlled. As a result, a desired image density can be obtained. In the embodiment according to the second aspect of the invention, the suction nozzle 10 'is pivotally supported at its both ends, one shaft is connected to the air suction pipe 11', and the other shaft is connected to the suction pipe 12 '. However, in actual use, the suction nozzle 10 '
There is no problem even if the shaft is supported only at one end and the shaft has a double pipe structure and the inner and outer pipes are connected to the air suction pipe 11 'and the suction pipe 12', respectively.

[0009]

Since the charge measuring device according to the present invention is configured as described above, the toner is collected while the contact portion of the suction means is in contact with the toner carrier. At this time, since the air does not flow from the periphery of the contact end of the contact portion and the contact portion contacts the toner transport body, the toner area sampled is equal to the area of the contact end portion. Therefore,
By keeping the amount of toner collected on the toner carrier constant, accurate charge measurement can always be performed. Further, if the contact portion is a cylindrical body made of an elastic body that follows the toner transport body, the charge measurement can be performed even while the toner transport body is rotating, so that the measurement efficiency is improved.

[Brief description of drawings]

FIG. 1 is a charge measuring device A according to an embodiment of the first invention.
The schematic diagram which shows the schematic structure of ₁ .

FIG. 2 is a front view (a) and a side view (b) showing an appearance of a toner suction portion of the charge measuring device A ₁ .

FIG. 3 is a comparative chart of the measurement results by the charge measuring device A ₁ and the conventional device A ₀ ′.

FIG. 4 is a charge measuring device A according to an embodiment of the second invention.
_{2 is} a schematic diagram showing a schematic configuration of 2. FIG.

FIG. 5 is a sectional view of a shaft support portion of a suction nozzle of the charge measuring device A ₂ .

FIG. 6 is a schematic diagram showing an example in which the charge measuring device A ₂ is incorporated in a copying machine.

FIG. 7 is a schematic diagram showing a schematic configuration of a reference Faraday gauge A ₀ .

FIG. 8 is a schematic diagram showing a schematic configuration of an example of a conventional charge measuring device A ₀ ′.

[Explanation of symbols]

A ₁ , A ₂ ... Charge measuring device 1 ... Shield conductor 2 ... Conductor container 3 ... Insulating material 4 ... Toner 5, 5 '... Toner suction portion (corresponding to suction means) 6 ... Electrometer 7 ... Filter 8, 8' ... measurement unit (corresponding to a measuring means) 9 ... photosensitive drum (corresponding to the toner conveying member) 10, 10 '... (corresponding to the contact portion) suction nozzle 10 _a ... tip opening 10 _a' ... toner suction port 11 ... air Introducing hole (corresponding to air suction port) 11 '... Air suction pipe 12, 12' ... Suction pipe (corresponding to pipe member) 13 ... Intake pipe (corresponding to first flow path) 14 ... Air supply pipe (second flow) Equivalent to the road)

Claims (2)

[Claims] 1. A charging measuring device comprising: a suction means for sucking charged toner on a toner carrier; and a measuring means for measuring the amount of charge of the toner sucked by the suction means. A hollow abutting portion formed so as to be capable of directly adhering to the toner carrier and a tube member connecting the abutting portion and the measuring means are provided, and a toner suction port is provided at the abutting end portion of the abutting portion. And an air suction port communicating with the tube member at a position apart from the toner layer at the contact portion. 2. A charge measuring device comprising: a suction means for sucking the charged toner on the toner carrier and a measuring means for measuring the amount of charge of the toner sucked by the suction means. A cylindrical abutting portion, which is rotatably supported at both ends thereof and is made of an elastic body that follows the toner carrying body when brought into contact with the toner carrying body, is connected to the abutting portion and has one end Is provided with an air suction tube that opens at a position away from the toner layer, and a tube member that connects the contact portion and the measuring means, and a toner suction port is formed on the outer peripheral surface of the contact portion. A hollow shaft is provided at each end supporting the contact portion, and a first flow path is formed in one of the hollows so as to guide the air taken in from the air suction pipe to the toner suction opening, and the other end is provided with the toner suction opening. Guide the toner sucked from the tube member A charge measuring device characterized in that the second flow path is formed as described above.