JP6948573B2 - Toner charge measuring device, toner charge measuring method, and image forming device - Google Patents

Description

The present invention relates to a toner charge amount measuring device, a toner charge amount measuring method, and an image forming device.

A toner charge measuring device collects toner on a developing sleeve with a suction mechanism, measures the charge and weight of the collected toner, and measures the toner charge based on the charge and weight of the collected toner. It is calculated (see, for example, Patent Document 1).

On the other hand, in a certain image forming apparatus, a measuring device for detecting the toner charge is provided in a part of the developing roll in the developer, the toner at the time of detecting the toner charge is collected, and the weight of the collected toner is measured in the load cell. The toner charge amount (charge per unit weight) is measured and calculated (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 5-11511 Japanese Unexamined Patent Publication No. 2001-42644

However, in the above-mentioned apparatus, the charge amount of the toner adhering to the developing roller (including the developing sleeve, the developing roll, etc.) is measured, but the charge amount of the toner adhering to the photoconductor drum is not directly measured. .. Therefore, due to an error in the amount of toner charged in the photoconductor drum, the subsequent transfer process (transfer of the toner image from the photoconductor drum to the intermediate transfer belt or printing paper) may not be performed accurately.

The present invention has been made in view of the above problems, and includes a toner charge amount measuring device, a toner charge amount measuring method, and an image forming device for accurately measuring the charge amount of toner adhering to a photoconductor drum. The purpose is to get.

The toner charge amount measuring device according to the present invention includes a suction device, a suction path member arranged at a position where toner can be sucked on the surface of the photoconductor drum and to which a negative pressure generated by the suction device is applied. A particle size distribution measuring device that measures the particle size distribution of the toner sucked through the suction path member during the measurement period, and measures the electric charge of the toner sucked through the suction path member during the measurement period. It is provided with a charge measuring device for calculating the toner charge amount, and a charge amount calculation unit for calculating the toner charge amount in the measurement period based on the measured particle size distribution of the toner and the measured charge. Further, it has the following configuration (A) or (B). (A) An auxiliary suction device is further provided, and the suction device is built in the particle size distribution measuring device, and the auxiliary suction device applies a negative pressure to the suction path member in parallel with the suction device. Apply. (B) The suction device increases the suction flow rate in the next measurement period when the number of toner particles measured by the particle size distribution measurement device in the measurement period is less than the threshold value.

In the method for measuring the amount of toner charge according to the present invention, a negative pressure is applied by a suction device to a suction path member arranged at a position where toner can be sucked on the surface of the photoconductor drum to apply toner on the surface of the photoconductor drum. A step of sucking, a step of measuring the particle size distribution of the toner sucked through the suction path member in a predetermined measurement period by a particle size distribution measuring device , and a step of measuring the particle size distribution of the toner sucked through the suction path member in the measurement period, and through the suction path member in the measurement period. It includes a step of measuring the charge of the sucked toner and a step of calculating the amount of toner charge in the measurement period based on the measured particle size distribution of the toner and the measured charge. Further, it has the following configuration (A) or (B). (A) The suction device is built in the particle size distribution measuring device, and a negative pressure is applied to the suction path member in parallel with the suction device by the auxiliary suction device. (B) When the number of toner particles measured by the particle size distribution measuring device in the measurement period is less than the threshold value, the suction device increases the suction flow rate in the next measurement period.

The image forming apparatus according to the present invention includes the above-mentioned toner charge amount measuring device, and controls the transfer bias for transferring the toner image from the photoconductor drum based on the calculated toner charge amount.

According to the present invention, a toner charge amount measuring device, a toner charge amount measuring method, and an image forming device for accurately measuring the charge amount of toner adhering to the photoconductor drum can be obtained.

The above or other objects, features and advantages of the present invention will be further clarified from the following detailed description along with the accompanying drawings.

FIG. 1 is a block diagram showing a configuration of a toner charge amount measuring device according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the operation of the toner charge amount measuring device according to the second embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1.

FIG. 1 is a block diagram showing a configuration of a toner charge amount measuring device according to an embodiment of the present invention.

The toner charge amount measuring device shown in FIG. 1 uses a developing mechanism including a photoconductor drum 1 and a developing roller 2 that imitates a predetermined image forming device (actual machine), and the toner adhering to the photoconductor drum 1 is used. Measure the amount of charge. The developing mechanism includes a driving device such as a motor for driving the photoconductor drum 1 and the developing roller 2, a high-voltage circuit for applying a charging voltage to the photoconductor drum 1, and a high-voltage circuit for applying a developing bias to the developing roller 2. An exposure apparatus or the like that irradiates the photoconductor drum 1 with light to form an electrostatic latent image is included. That is, the toner is adhered to the electrostatic latent image on the photoconductor drum 1 in the same environment as the predetermined image forming apparatus (actual machine).

The toner charge amount measuring device shown in FIG. 1 includes a suction path member 11, a particle size distribution measuring device 12, a charge measuring device 13, a processor 14, and an auxiliary suction device 15.

The particle size distribution measuring device 12 includes a particle counting device 21 and a suction device 22.

The suction path member 11 is a hollow tube or the like, and is arranged at a position where toner can be sucked on the surface of the photoconductor drum 1, and a negative pressure generated by the suction device 22 is applied. Specifically, the open end of the suction path member 11 is arranged at a predetermined distance (for example, about 1 mm) from the surface of the photoconductor drum 1, and the negative pressure generated by the suction device 22 causes a predetermined flow rate together with the surrounding air. Toner is sucked through its open end.

The particle counting device 21 counts the toner particles in the air flowing through the flow path extending from the suction path member 11 at a predetermined flow rate, and counts the number of toner particles that have passed through the particle counting device 21 in a predetermined measurement period. Measurement is performed for each particle size range, and the measurement result is output as particle size distribution data.

In this way, the particle size distribution measuring device 12 measures the particle size distribution of the toner sucked through the suction path member 11 in a predetermined measurement period tm. For example, the particle size distribution measuring device 12 repeatedly measures the particle size distribution of the toner sucked through the suction path member 11 in a plurality of measurement periods tm set at a predetermined cycle or continuously.

The charge measuring device 13 measures the charge of the toner sucked through the suction path member 11 during the measurement period tm by, for example, the Faraday cage method. Specifically, the charge measuring device 13 is provided at the rear stage of the particle counting device 21 and at the front stage of the suction device 22, and the collecting unit 31 collects the toner particles flowing through the flow path, and the measurement period is tm. Measure the charge of the collected toner.

The processor 14 is, for example, a computer equipped with a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc., and loads a program into the RAM from a storage device, a ROM, etc. (not shown). , Operates as various processing units by executing with the CPU. Here, the processor 14 operates as a charge amount calculation unit 41 and a related parameter measurement unit 42.

The charge amount calculation unit 41 calculates the toner charge amount (toner charge charge per unit weight) in each measurement period tm based on the measured toner particle size distribution and the measured charge.

The related parameter measuring unit 42 measures the value of the parameter related to the toner charge amount in the electrophotographic printing process together with the toner charge amount described above. Here, this parameter is the rotation speed of the photoconductor drum 1, the rotation speed of the developing roller 2 that supplies toner to the photoconductor drum 1, the ambient temperature, the ambient humidity, and the inside of the developing device that supplies toner to the photoconductor drum 1. Includes at least one of the toner-to-carrier ratios in.

Further, the auxiliary suction device 15 applies a negative pressure to the suction path member 11 in parallel with the suction device 22.

In this embodiment, the suction device 22 is built in the particle size distribution measuring device 12, and the auxiliary suction device 15 determines the flow rate at the open end of the suction path member 11 rather than the flow rate in the case of only the suction device 22. Enlarge.

Next, the operation of the toner charge amount measuring device will be described.

Toner is adhered to the photoconductor drum 1 by operating the above-mentioned developing mechanism.

Then, the suction device 22 (or the suction device 22 and the auxiliary suction device 15) continuously operates in a predetermined measurement period tm, and the flow path and the suction path member passing through the particle size distribution measuring device 12 and the charge measuring device 13. A negative pressure is applied to 11, and the toner adhering to the photoconductor drum 1 is sucked together with air at a predetermined flow rate.

As a result, the toner adhering to the photoconductor drum 1 separates from the photoconductor drum 1 and travels together with air in the suction path member 11, and has a predetermined ratio according to the flow rate ratio of the suction device 22 and the auxiliary suction device 15. Toner (toner particles) flows into the particle size distribution measuring device 12.

The particle size distribution measuring device 12 measures the particle size distribution of the inflowing toner particles in the measurement period tm. Here, the particle size distribution measuring device 12 optically measures the number and particle size of the inflowing toner particles, and discharges the inflowing toner particles without collecting them.

The air containing the toner particles discharged from the particle size distribution measuring device 12 in the flow path flows into the charge measuring device 13.

The charge measuring device 13 collects the toner particles in the collecting unit 31 among the air containing the inflowing toner particles, and discharges the air to the suction device 22. Then, the charge measuring device 13 measures the charge of the collected toner particles in the measurement period tm.

Then, the charge amount calculation unit 41 acquires the particle size distribution data of the measurement period tm from the particle size distribution measuring device 12, and also acquires and acquires the charge data of the measurement period tm from the charge measuring device 13. The toner weight of the measurement period tm is calculated based on the particle size distribution data, and the charge of the measurement period tm based on the charge data is divided by the toner weight to specify the toner charge amount.

Based on the particle size distribution data, the sum of products of the particle weights corresponding to the plurality of particle sizes and the count values (number of toner particles) of the plurality of particle sizes is calculated as the toner weight in the measurement period tm.

Further, the related parameter measurement unit 42 measures the values of the above parameters in the measurement period tm, and stores the toner charge amount and the parameter values in a non-volatile storage device (not shown) for each measurement period tm. ..

Based on the toner charge amount measured in this way, the transfer bias of the above-mentioned predetermined image forming apparatus (actual machine) and the like are determined. At that time, based on the correspondence between the parameter values measured together and the transfer bias, the parameter values in the above-mentioned predetermined image forming apparatus (actual machine) are measured, and the transfer corresponding to the parameter values is performed. The amount of fluctuation of the bias may be specified, and the transfer bias or the like may be corrected according to the amount of fluctuation.

As described above, according to the first embodiment, the suction path member 11 is arranged at a position where toner can be sucked on the surface of the photoconductor drum 1, and the negative pressure generated by the suction device 22 is applied. .. The particle size distribution measuring device 12 measures the particle size distribution of the toner sucked through the suction path member 11 in a predetermined measurement period tm. The charge measuring device 13 measures the charge of the toner sucked through the suction path member 11 during the measurement period tm. The charge amount calculation unit 41 calculates the toner charge amount in the measurement period tm based on the measured toner particle size distribution and the measured charge.

As a result, the amount of charge of the toner adhering to the photoconductor drum 1 is directly and accurately measured.

Embodiment 2.

In the toner charge amount measuring device according to the second embodiment, when the number of toner particles measured by the particle size distribution measuring device 12 in the measurement period tm is equal to or more than a predetermined threshold value, the charge amount calculation unit 41 of the embodiment The toner charge amount in the measurement period is calculated based on the measured toner particle size distribution and the measured charge as in 1, but the toner particles measured by the particle size distribution measuring device in the measurement period tm. If the number is less than the above threshold, the toner charge amount in the measurement period tm is not calculated. That is, for the measurement period tm in which the number of toner particles is less than the above threshold value, the error in the calculation result of the toner charge amount may be large, so the calculation result of the toner charge amount is not adopted.

Further, in the second embodiment, when at least one of the suction device 22 and the auxiliary suction device 15 has the number of toner particles measured by the particle size distribution measuring device 12 during the measurement period less than the above-mentioned threshold value, the next measurement is performed. Increase the suction flow rate during the period tm. As a result, in the next measurement period tm, a sufficient number of toner particles can be obtained in the particle size distribution measuring device 12.

FIG. 2 is a diagram illustrating the operation of the toner charge amount measuring device according to the second embodiment.

The suction device 22 (or the suction device 22 and the auxiliary suction device 15) starts the suction operation at the default flow rate f1, and when, for example, the number of counted toner particles is equal to or greater than a predetermined threshold Nth at the measurement timing T1. , The charge amount calculation unit 41 calculates the toner charge amount as described above.

Further, for example, when the number of counted toner particles is less than the predetermined threshold Nth at the measurement timing T2, the charge amount calculation unit 41 does not calculate the toner charge amount, and the measurement period tm (that is, measurement). Cancel the measurement of the toner charge amount at the timing T2).

Further, for example, at the measurement timing T2, when the number of counted toner particles is less than the predetermined threshold Nth, the suction device 22 (or the suction device 22 and the auxiliary suction device 15) sets the suction flow rate to the default flow rate f1. To change the flow rate from f2 (f2> f1).

As the suction flow rate increases, the number of toner particles counted in the next measurement period tm increases. Then, for example, at the measurement timing T3, when the number of counted toner particles becomes the predetermined threshold value Nth or more, the charge amount calculation unit 41 calculates the toner charge amount as described above.

Since other configurations and operations of the toner charge amount measuring device according to the second embodiment are the same as those of the first embodiment, the description thereof will be omitted.

As described above, according to the second embodiment, the error of the measurement result of the toner charge amount is reduced.

Embodiment 3.

The image forming apparatus according to the third embodiment of the present invention is a printer, a multifunction device, or the like, which includes an electrophotographic printing mechanism and a controller for controlling the printing mechanism, and also includes the first embodiment or the second embodiment. Built-in toner charge amount measuring device.

The printing mechanism includes a photoconductor drum, a developing device, an exposure device, a transfer roller, and the like, and applies a predetermined high voltage (charging voltage, development bias, transfer bias, etc.) to the photoconductor drum, the developing device, the transfer roller, and the like. Further equipped with a high voltage circuit. A charging voltage is applied to the photoconductor drum, light is applied to the photoconductor drum by the exposure device to form an electrostatic latent image of the printed image, and toner is adhered to the electrostatic latent image by the developing roller of the developing device. The image is formed and the transfer roller transfers the toner image from the photoconductor drum to the intermediate transfer belt or printing paper. When the toner image is transferred to the intermediate transfer belt, the toner image is secondarily transferred from the intermediate transfer belt to the printing paper.

In the third embodiment, for example, at the time of calibration, toner is sucked from the photoconductor drum of the printing mechanism, the toner charge amount is calculated as described above, and after the measurement, the controller is based on the calculated toner charge amount. Therefore, the transfer bias for transferring the toner image from the photoconductor drum is controlled.

Since other configurations and operations of the toner charge amount measuring device in the third embodiment are the same as those in the first embodiment or the second embodiment, the description thereof will be omitted.

As described above, according to the third embodiment, the toner charging characteristics peculiar to the image forming apparatus are measured for the toner adhering to the photoconductor drum inside the image forming apparatus. Therefore, for example, the transfer process is appropriately executed by repeatedly measuring the toner charge amount in response to the time-dependent change of the photoconductor drum and updating the transfer bias or the like based on the measured toner charge amount.

It should be noted that various changes and modifications to the above-described embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the intent and scope of the subject and without diminishing the intended benefits. That is, such changes and amendments are intended to be included in the claims.

For example, in the above embodiment, the particle size distribution measuring device 12 may exclude the counting result of the particles whose particle size is out of the predetermined range from the particle size distribution data. That is, in that case, particles having a particle size outside the predetermined range are regarded as particles other than toner, not toner particles, and are excluded from the particle size distribution data.

The present invention can be applied to, for example, specifying the charge amount characteristics of toner adhering to the photoconductor drum of an electrophotographic image forming apparatus and an electrophotographic image forming apparatus.

1 Photoreceptor drum 2 Developing roller 11 Suction path member 12 Particle size distribution measuring device 13 Charge measuring device 14 Processor 15 Auxiliary suction device 21 Particle counting device 22 Suction device 31 Collection unit 41 Charge amount calculation unit 42 Related parameter measurement unit

Claims (8)

With a suction device,
A suction path member arranged on the surface of the photoconductor drum at a position where toner can be sucked and to which a negative pressure generated by the suction device is applied.
A particle size distribution measuring device that measures the particle size distribution of the toner sucked through the suction path member in a predetermined measurement period, and a particle size distribution measuring device.
A charge measuring device that measures the charge of the toner sucked through the suction path member during the measurement period, and a charge measuring device.
A charge amount calculation unit that calculates the toner charge amount in the measurement period based on the measured particle size distribution of the toner and the measured charge.
Equipped with an auxiliary suction device
The suction device is built in the particle size distribution measuring device.
The auxiliary suction device applies a negative pressure to the suction path member in parallel with the suction device.
A toner charge measuring device characterized by. Said auxiliary suction device, when the number of particles toner measured by the particle size distribution measuring apparatus in the measurement period is less than the threshold value, according to claim 1, characterized in that to increase the suction flow rate in the next measurement period The toner charge amount measuring device according to this. With a suction device,
A suction path member arranged on the surface of the photoconductor drum at a position where toner can be sucked and to which a negative pressure generated by the suction device is applied.
A particle size distribution measuring device that measures the particle size distribution of the toner sucked through the suction path member in a predetermined measurement period, and a particle size distribution measuring device.
A charge measuring device that measures the charge of the toner sucked through the suction path member during the measurement period, and a charge measuring device.
A charge amount calculation unit for calculating the toner charge amount in the measurement period based on the measured particle size distribution of the toner and the measured charge is provided.
The suction device, the case number of particles of the toner measured by the particle size distribution measuring apparatus in the measurement period is less than the threshold value, features and to belt donors to increase the suction flow rate in the next measurement period charge Quantitative measuring device. When the number of toner particles measured by the particle size distribution measuring device in the measurement period is equal to or greater than a predetermined threshold value, the charge amount calculation unit calculates the toner charge amount in the measurement period, and the charge amount calculation unit calculates the toner charge amount in the measurement period. Any one of claims 1 to 3 , wherein when the number of toner particles measured by the particle size distribution measuring device is less than the threshold value, the toner charge amount during the measurement period is not calculated. The toner charge amount measuring apparatus according to this. Further, a related parameter measuring unit for measuring the value of a parameter related to the toner charge amount together with the toner charge amount in the electrophotographic printing process is provided.
The parameters are the rotation speed of the photoconductor drum, the rotation speed of the developing roller that supplies the toner to the photoconductor drum, the ambient temperature, the ambient humidity, and in the developer that supplies the toner to the photoconductor drum. Include at least one toner to carrier ratio,
The toner charge amount measuring device according to any one of claims 1 to 4 , wherein the toner charge amount measuring device is characterized. A step of applying a negative pressure to a suction path member arranged at a position where toner can be sucked on the surface of the photoconductor drum by a suction device to suck the toner on the surface of the photoconductor drum.
A step of measuring the particle size distribution of the toner sucked through the suction path member in a predetermined measurement period by the particle size distribution measuring device, and a step of measuring the particle size distribution.
The step of measuring the electric charge of the toner sucked through the suction path member during the measurement period, and
A step of calculating the toner charge amount in the measurement period based on the measured particle size distribution of the toner and the measured charge, and
Equipped with a,
The suction device is built in the particle size distribution measuring device.
Applying a negative pressure to the suction path member in parallel with the suction device by the auxiliary suction device.
A method for measuring the amount of toner charged. A step of applying a negative pressure to a suction path member arranged at a position where toner can be sucked on the surface of the photoconductor drum by a suction device to suck the toner on the surface of the photoconductor drum.
A step of measuring the particle size distribution of the toner sucked through the suction path member in a predetermined measurement period by the particle size distribution measuring device, and a step of measuring the particle size distribution.
The step of measuring the electric charge of the toner sucked through the suction path member during the measurement period, and
A step of calculating the toner charge amount in the measurement period based on the measured particle size distribution of the toner and the measured charge, and
With
When the number of toner particles measured by the particle size distribution measuring device in the measurement period is less than the threshold value, the suction device increases the suction flow rate in the next measurement period.
A method for measuring the amount of charge of toner. The toner charge amount measuring device according to any one of claims 1 to 5 is provided.
Controlling the transfer bias for transferring the toner image from the photoconductor drum based on the calculated toner charge amount,
An image forming apparatus characterized by.

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