JP2012098474A - Toner adhesion amount measuring device, measuring method thereof and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce distortion of a reflection waveform caused by a scratch on a surface of a carrier and realize enhancement of detection accuracy of a toner adhesion amount adhered to the carrier.SOLUTION: A toner adhesion amount measuring device comprises: a laser light source 301 for radiating light to a toner image conveyed together with a carrier 101 or 106 and to a surface of the carrier 101 or 106; a line sensor 304 for receiving reflection light reflected from the toner image of the light irradiated from the laser light source 301; and a toner adhesion amount arithmetic section 307 for calculating a toner adhesion amount of the toner image by detecting variation of the reflection light received by the line sensor 304. The toner adhesion amount measuring device is further configured such that a plane of incidence, which is formed by an irradiation axis of the light irradiated from the laser light source 301 and a light receiving axis of the reflection light received by the line sensor 304, and a carrier conveyance direction 308 of the above described conveyance are not at right angles to each other.

Description

  The present invention relates to a technique for measuring a toner adhesion amount in a toner image formed on a carrier of an image forming apparatus.

  The color of an image formed by an image forming apparatus using an electrophotographic method varies depending on changes in various physical parameters even if the apparatus setting at the time of image formation is constant. In particular, the development / transfer process has a high contribution to color variation. This is because the latent image potential, toner replenishment amount, transfer efficiency, and the like change due to environmental fluctuations such as temperature and humidity, and adhere to the photosensitive drum and transfer belt (hereinafter referred to as “carrier” as necessary). This is because the amount of toner adhered is not stable. Therefore, it is necessary to measure the adhesion amount of toner on the photosensitive drum or the transfer belt, and control the exposure amount, development voltage, transfer current and the like based on the measurement result to stabilize the development / transfer process.

  In general, these controls are performed when a change in the printer environment occurs, such as after replacement of a toner cartridge, after printing a predetermined number of sheets, or after powering on the printer body. When measuring the toner adhesion amount, a plurality of toner patches having various densities from low density to high density are formed on a photosensitive drum or a transfer belt (carrier). Then, the toner adhesion amount of these toner patches is measured by a toner adhesion amount measuring device, and various controls are performed under appropriate image forming conditions based on the measurement result.

  Prior art relating to a method for measuring the toner adhesion amount is described in Patent Literature 1 and Patent Literature 2 below. Specifically, Patent Document 1 detects the amount of reflected light when the carrier is irradiated with light and the amount of reflected light when the toner patch is irradiated with light. A method for measuring and controlling the image density parameter based on the measured value is disclosed. Patent Document 2 discloses a method for detecting the toner adhesion amount by measuring the thickness (layer thickness) of a toner patch using a laser displacement meter. Then, spot light is irradiated onto the image carrier and the toner image, and the reflected light is imaged at a position corresponding to the layer thickness of the toner patch adhering to the carrier, and the toner adhesion amount is measured by changing the imaging position. Then, feedback control of the image density parameter of the imaging system is performed based on the result of the layer thickness measurement.

JP-A-8-327331 JP-A-4-156479

  The photosensitive drum and the transfer belt carrier have streak-like scratches on the surface as the circumferential direction rotates, and the optical reflectance of the surface changes. In the toner adhesion amount measuring device that measures the height of the toner patch by detecting the reflection position of the light irradiated on these carriers or the change in the amount of reflected light, the distortion of the reflected waveform due to these scratches ( As a result, the measurement error increases.

  The present invention has been made in view of such problems, and it is possible to reduce the distortion of the reflected waveform due to scratches on the surface of the carrier, and to improve the detection accuracy of the amount of toner attached to the carrier. Objective.

The toner adhesion amount measuring device of the present invention is a toner adhesion amount measuring device for measuring the toner adhesion amount of a toner image formed on a carrier of an electrophotographic image forming apparatus, wherein the toner image is the carrier image. A light irradiating means for irradiating light on the toner image and the surface of the carrier, and a light receiving means for receiving reflected light reflected by the toner image and the light emitted from the light irradiating means; A toner adhesion amount calculating means for calculating a toner adhesion amount of the toner image by detecting a change in reflected light received by the light receiving means, and a light irradiation axis by the light irradiation means and the light receiving means. An angle formed between the incident surface formed by the light receiving axis of the reflected light and the transport direction of the carrier by the transport is a non-right angle.
The present invention also includes a toner adhesion amount measuring method using the above-described toner adhesion amount measuring device and an image forming apparatus including the toner adhesion amount measuring device.

  According to the present invention, the angle formed between the incident surface (the surface formed by the light irradiation axis and the light receiving axis of the reflected light) and the carrying direction of the carrier is set to a non-perpendicular (non-vertical) angle. As a result, the distortion of the reflected waveform due to scratches on the surface of the carrier is reduced (see FIG. 13), and the detection accuracy of the amount of toner attached to the carrier can be improved.

1 is a schematic diagram illustrating an example of a schematic configuration of an electrophotographic image forming apparatus according to a first embodiment of the present invention. FIG. 3 is a control block diagram illustrating an example of controlling an image forming process by measuring a toner adhesion amount according to the first exemplary embodiment of the present invention. 1 is a schematic diagram illustrating an example of a schematic configuration of a toner adhesion amount measuring device according to a first exemplary embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a first embodiment of the present invention and illustrating a relationship 1 between a toner adhesion amount measuring device and a carrier conveyance direction. FIG. 4 is a block diagram illustrating an example of an internal configuration of a toner adhesion amount calculation unit illustrated in FIG. 3 according to the first embodiment of this invention. FIG. 6 is a schematic diagram illustrating a second embodiment of the present invention and illustrating a relationship 2 between a toner adhesion amount measuring device and a carrier conveyance direction. FIG. 10 is a schematic diagram illustrating a third embodiment of the present invention and illustrating a relationship 3 between a toner adhesion amount measuring device and a carrier conveyance direction. FIG. 10 is a schematic diagram illustrating a relationship 4 between a toner adhesion amount measuring device and a carrier conveyance direction according to a fourth embodiment of the present invention. FIG. 10 is a characteristic diagram illustrating an example of a relationship between an angle θ formed by an incident surface and a carrier transport direction and the amount of reflected light due to a flaw according to the fourth embodiment of the present invention. It is a schematic diagram which shows an example of schematic structure of the toner adhesion amount measuring apparatus which concerns on the 5th Embodiment of this invention. FIG. 10 is a schematic diagram illustrating a fifth embodiment of the present invention and illustrating a relationship 5 between a toner adhesion amount measuring device and a carrier conveyance direction. It is a photograph which shows an example of the distortion 1 of the reflected waveform by the damage | wound of a support body surface. It is a photograph which shows an example of the distortion 2 of the reflected waveform by the damage | wound of a support body surface.

  Hereinafter, embodiments (embodiments) for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
First, a first embodiment of the present invention will be described.
In the first embodiment of the present invention, a case will be described in which the incident surface is parallel to the carrier transport direction in a −45 ° to 0 ° irregular reflection system.

FIG. 1 is a schematic diagram illustrating an example of a schematic configuration of an electrophotographic image forming apparatus according to a first embodiment of the present invention.
An image forming apparatus 100-1 shown in FIG. 1A includes a photosensitive drum 101 as an image carrier, an exposure laser 102, a polygon mirror 103, a charging roller 104, a developing device 105, a transfer belt 106, and a toner adhesion amount measuring device. 107 and a fixing device 110. Here, the toner adhesion amount measuring device 107 measures the toner adhesion amount of the toner image formed on the carrier of the electrophotographic image forming apparatus 100-1. Further, the toner image is conveyed along with the carrier (101 or 106).

  First, the image forming apparatus 100-1 charges the surface of the photosensitive drum 101 with the charging roller 104, and creates an electrostatic latent image with the exposure laser 102 and the polygon mirror 103. Next, the image forming apparatus 100-1 forms a toner patch 108 on the photosensitive drum 101 with the developing device 105, and measures the toner adhesion amount of the toner patch 108 with the toner adhesion amount measuring device 107 installed at a position after development. To do. Then, after measuring the toner adhesion amount, the toner patch 108 is transferred to the printing paper 109, fixed by the fixing device 110, and output as a printed matter.

  Further, as in the image forming apparatus 100-2 shown in FIG. 1B, the toner adhesion amount may be measured on the transfer belt 106 after the toner patch 108 is transferred from the photosensitive drum 101 to the transfer belt 106.

  The toner adhesion amount measuring device 107 is an application example of the toner adhesion amount measuring device of the present invention that measures the toner adhesion amount of the toner image formed on the carrier of the electrophotographic image forming apparatus 100. It is.

FIG. 2 is a control block diagram illustrating an example when the image forming process 201 is controlled by the toner adhesion amount measurement 207 according to the first embodiment of this invention.
The image forming process 201 includes process steps of charging 202, exposure 203, development 204, transfer 205, and fixing 206. Then, after development 204 or after transfer 205, toner adhesion amount measurement 207 is performed, and the measured toner adhesion amount is fed back to transfer control 208, development control 209, and exposure control 210, and each process is controlled. To do. For example, in the transfer control 208, the transfer current in the transfer 205, in the development control 209, the development bias voltage and the toner replenishment amount in the development 204, and in the exposure control 210, the gradation γ characteristics in the exposure 203 are measured. Correction control is performed according to the above.

FIG. 3 is a schematic diagram showing an example of a schematic configuration of the toner adhesion amount measuring apparatus 107 according to the first embodiment of the present invention.
As shown in FIG. 3, the toner adhesion amount measuring device 107 includes a laser light source 301, a condensing lens 302, a light receiving lens 303, a line sensor 304, a control unit 305, a buffer amplifier 306, and a toner adhesion amount calculation unit 307. It is configured.

  In the example shown in FIG. 3, the laser light source 301 and the condensing lens 302 cause the surface of the photosensitive drum 101 or the transfer belt 106 and the surface of the toner patch 108 to tilt in the Y-axis direction with a 45 ° (−45 °) inclination. Laser light is irradiated. The light reflected on the surface of the toner patch 108 is imaged on the line sensor 304 by the light receiving lens 303 installed in the direction perpendicular to the reflecting surface (Z-axis direction). Further, in order to detect that the reflected light spot changes in the Y-axis direction due to the height change of the light irradiated with the inclination of 45 °, the line sensor 304 is installed so that the pixel arrays are arranged in the Y-axis direction. Further, the carrier transport direction 308 is also the Y-axis direction. The formed reflected light is converted into a voltage waveform indicating the distribution of reflection by the line sensor 304, and signal processing (to be described later) is executed by the toner adhesion amount calculation unit 307 via the buffer amplifier 306 to calculate the toner adhesion amount. Is done. Then, the image forming apparatus 100 performs color stabilization control based on the toner adhesion amount calculated by the toner adhesion amount calculation unit 307.

  Note that the laser light source 301 in the present embodiment is a configuration serving as an application example of the light irradiation unit of the present invention that irradiates the toner image and the surface of the carrier (101 or 106) with light. Further, the line sensor 304 in the present embodiment has a configuration that is an application example of the light receiving means of the present invention. The line sensor (light receiving means) 304 detects the position of the feature point of the reflected light that has changed depending on the surface of the carrier (101 or 106) and the surface of the toner image.

FIG. 4 shows the first embodiment of the present invention and is a schematic diagram showing a relationship 1 between the toner adhesion amount measuring device 107 and the carrier conveying direction 308.
As shown in FIG. 4, the surface of the carrier (101 or 106) is contacted by a rotating roller, a cleaning blade, or the like, so that there are scratches (striated scratches 401) extending in the carrier conveyance direction 308. In the irradiation / light reception conditions of the present embodiment, the incident surface 404 (the surface formed by the irradiation axis 402 and the light receiving axis 403) and the carrier transport direction 308 are parallel (non-right angle (non-vertical)), and therefore the line sensor 304. The reflected waveform picked up in (5) is less distorted by scratches, and the detection accuracy of the toner adhesion amount is improved. The angle formed by the irradiation axis 402 and the light receiving axis 403 may be an angle other than −45 °.

FIG. 5 is a block diagram illustrating an example of an internal configuration of the toner adhesion amount calculation unit 307 in FIG. 3 according to the first embodiment of this invention.
The toner adhesion amount calculation process will be described with reference to the block diagram of FIG.
As shown in FIG. 5, the toner adhesion amount calculation unit 307 includes a reflection data storage unit 501 and a toner adhesion amount calculation unit 502.

The reflection waveform output from the line sensor 304 is stored in the reflection data storage unit 501 after impedance adjustment by the buffer amplifier 306. The toner adhesion amount calculation unit 502 calculates the reflection position by detecting the center of gravity of the reflection data stored in the reflection data storage unit 501 and the reflected light amount by detecting the area. Then, these processes are executed for the reflection waveform from the carrier (101 or 106) and the reflection waveform from the toner patch 108, respectively, and the change amount of the calculated value is calculated as the final toner adhesion amount.
In the calculation of the center of gravity for reflection position detection, the following formula (1) is used.

  As a calculation method other than the center of gravity, for example, the waveform may be fitted with a quadratic function (the following formula (2)), and the parameter B may be calculated as the center value of the waveform. Alternatively, the center X coordinate of the clipped waveform flat portion may be detected without fitting.

  In the toner adhesion amount calculation unit 502, the thickness h of the toner patch 108 is calculated from the obtained movement amount L of the reflection position, the irradiation angle θ of the laser light source 301, the optical magnification M of the light receiving lens 303, and the pixel pitch p of the line sensor 304. (Layer thickness) is calculated, and the toner adhesion amount is calculated using the following formula (3).

  In addition, the following mathematical formula (4) is used in the area calculation for detecting the amount of reflected light.

  As a calculation method other than the area, for example, the peak vertex may be detected, and the amount of reflected light may be calculated using the Y coordinate (peak height) of the vertex. Further, the reflection waveform from the carrier (101 or 106) and the reflection waveform from the toner patch 108 are measured a plurality of times, the thickness h and the light quantity S are calculated for each waveform, and the average height h ′ and The average light quantity S ′ may be used as the toner adhesion amount.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.
Hereinafter, a method for measuring the toner adhesion amount in the second embodiment of the present invention will be described.
In the present embodiment, a case will be described in which the incident surface is parallel to the carrier transport direction in the 0-45 ° irregular reflection system. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 6 is a schematic diagram showing a relationship 2 between the toner adhesion amount measuring device 107 and the carrier conveying direction 308 according to the second embodiment of the present invention.
As shown in FIG. 6, the laser beam is irradiated with an irradiation axis 602 perpendicular to the surface of the carrier (101 or 106), and the line sensor 304 is installed at a 45 ° position with respect to the light receiving axis 603. Also in the present embodiment, the incident surface 604 is parallel (non-right angle (non-perpendicular)) to the streak 601 that is generated in parallel to the carrier transport direction 308, and therefore, the waveform distortion due to the streak 601 is small. The detection accuracy of the toner adhesion amount is improved.

(Third embodiment)
Next, a third embodiment of the present invention will be described.
Hereinafter, a method for measuring the toner adhesion amount according to the third embodiment of the present invention will be described.
In the present embodiment, a case will be described in which the incident surface is parallel to the carrier transport direction 308 in a −45 ° to 45 ° regular reflection system. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 7 shows a third embodiment of the present invention and is a schematic diagram showing a relationship 3 between the toner adhesion amount measuring device 107 and the carrier conveying direction 308.
As shown in FIG. 7, the laser light is irradiated in the Y-axis direction with an inclination of 45 ° (−45 °) with respect to the surface of the carrier (101 or 106) (see the irradiation axis 702), and the line sensor 304 receives light. It is installed at a 45 ° position on the shaft 703 (−45 ° to 45 ° regular reflection system). Also in the present embodiment, the incident surface 704 is parallel (non-right angle (non-perpendicular)) to the streak 701 generated parallel to the carrier transport direction 308, and therefore, the waveform distortion due to the streak 701 is small. The detection accuracy of the toner adhesion amount is improved.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described.
Hereinafter, a method for measuring the toner adhesion amount according to the fourth embodiment of the present invention will be described.
In the present embodiment, a case will be described in which the angle formed by the direction of reflection position change and the carrier transport direction 308 is 45 ° in a −45 ° to 0 ° irregular reflection system. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 8 is a schematic diagram showing a relationship 4 between the toner adhesion amount measuring device 107 and the carrier conveying direction 308 according to the fourth embodiment of the present invention.
As shown in FIG. 8, the line sensor 304 is installed with an inclination of 45 ° from the Y axis with respect to the streak 401 in the conveyance direction. Also in this case, the angle of the incident surface 804 that is a surface formed by the irradiation axis 802 and the light receiving axis 803 is not perpendicular to the scratch direction (non-right angle (non-vertical)), so The distortion of the waveform due to the toner is small, and the detection accuracy of the toner adhesion amount is improved. In addition, as long as the angle formed by the incident surface 804 and the carrier conveyance direction 308 is not a right angle (not 90 °), any angle other than 45 ° may be used.

FIG. 9 shows the fourth embodiment of the present invention, and is a characteristic diagram showing an example of the relationship between the angle θ formed by the incident surface and the carrier transport direction 308, and the amount of reflected light due to scratches.
From the characteristic diagram of FIG. 9, there is a possibility that waveform distortion may occur in the range of 90 ° to 70 ° because the light quantity component from the scratch exists. Therefore, it is desirable to design θ at an arbitrary angle between 0 ° and less than 70 °. In addition, it is not limited to the −45 ° to 0 ° system irregular reflection, and other angles of irregular reflection or regular reflection system may be used.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described.
Hereinafter, a method for measuring the toner adhesion amount according to the fifth embodiment of the present invention will be described.
In the present embodiment, a case where the amount of toner adhesion is detected by detecting only the amount of reflected light by using a photodiode 1001 instead of the line sensor 304 will be described. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 10 is a schematic diagram illustrating an example of a schematic configuration of a toner adhesion amount measuring apparatus 107 according to the fifth exemplary embodiment of the present invention.
In the example shown in FIG. 10, the laser light source 301 and the condensing lens 302 cause laser light in the Y-axis direction at a 45 ° (−45 °) inclination with respect to the surface of the carrier (101 or 106) and the surface of the toner patch 108. Is irradiated. The reflected light is reflected on the photodiode 1001 installed in the direction perpendicular to the reflecting surface (Z-axis direction). The toner adhesion amount calculation unit 307 calculates the toner adhesion amount by detecting the voltage output from the photodiode 1001 based on the reflected light amount changed between the carrier (101 or 106) and the toner patch.

FIG. 11 is a schematic diagram showing a relationship 5 between the toner adhesion amount measuring device 107 and the carrier conveyance direction 308 according to the fifth embodiment of the present invention.
As shown in FIG. 11, the surface of the carrier (101 or 106) comes into contact with a rotating roller, a cleaning blade, or the like, so that there are scratches (striated scratches 401) extending in the carrier conveyance direction 308. In the irradiation / light reception conditions of the present embodiment, the incident surface 1103 that is the surface formed by the irradiation axis 1101 and the light receiving axis 1102 and the carrier transport direction 308 are parallel (non-right angle (non-vertical)). Reflected light having a uniform distribution is incident on. For this reason, the photodiode 1001 outputs a stable voltage with little change in the amount of diffuse reflection due to the presence or absence of scratches. The output voltage from the photodiode 1001 is input to the toner adhesion amount calculation unit 307 through the buffer amplifier 306, and the toner adhesion amount is calculated. The angle formed by the irradiation axis 1101 and the light receiving axis 1102 may be an irregular reflection type having an arbitrary angle other than 45 °, or a regular reflection type. Further, as long as the incident surface (1103) and the carrier transport direction 308 are not perpendicular (non-perpendicular), an angle other than parallel may be used.

(Other embodiments)
The present invention can also be realized by executing the following processing. That is, software (program) that realizes the functions of the above-described embodiments is supplied to a system or apparatus via a network or various storage media, and a computer (or CPU, MPU, or the like) of the system or apparatus reads the program. It is a process to be executed.
This program and a computer-readable recording medium storing the program can be included in the present invention.

101 or 106 carrier, 107 toner adhesion amount measuring device, 108 toner patch, 301 laser light source, 302 condenser lens, 303 light receiving lens, 304 line sensor, 305 control unit, 306 buffer amplifier, 307 toner adhesion amount calculation unit, 308 Carrier transport direction

Claims (6)

A toner adhesion amount measuring device for measuring a toner adhesion amount of a toner image formed on a carrier of an electrophotographic image forming apparatus,
The toner image is conveyed together with the carrier,
A light irradiation means for irradiating light on the surface of the toner image and the carrier;
A light receiving unit that receives the toner image and reflected light reflected by the light irradiated from the light irradiation unit;
A toner adhesion amount calculating means for calculating a toner adhesion amount of the toner image by detecting a change in reflected light received by the light receiving means;
A toner characterized in that an angle formed between an incident surface formed by an irradiation axis of light by the light irradiation unit and a light reception axis of reflected light by the light receiving unit and a conveyance direction of the carrier by the conveyance is non-right angle Adhesion amount measuring device.   2. The toner adhesion amount measuring apparatus according to claim 1, wherein an angle formed between the incident surface and a conveyance direction of the carrier by the conveyance is set to 0 ° to less than 70 °. The light receiving means is
3. The toner adhesion amount measuring apparatus according to claim 1, wherein a position of a feature point of the reflected light changed according to a surface of the carrier and a surface of the toner image is detected. The light receiving means is
3. The toner adhesion amount measuring apparatus according to claim 1, wherein a light amount of the reflected light changed according to a surface of the carrier and a surface of the toner image is detected. Including the toner adhesion amount measuring device according to claim 1,
An image forming apparatus, wherein color stabilization control is performed based on a toner adhesion amount calculated by the toner adhesion amount calculation means. A toner adhesion amount measuring method for measuring a toner adhesion amount of a toner image formed on a carrier of an electrophotographic image forming apparatus,
The toner image is conveyed together with the carrier,
A light irradiation step of irradiating light from a light irradiation means to the surface of the toner image and the carrier;
A light receiving step of receiving the toner image and reflected light reflected by the light irradiated from the light irradiating means by a light receiving means;
A toner adhesion amount calculation step of calculating a toner adhesion amount of the toner image by a toner adhesion amount calculation means by detecting a change in reflected light received by the light receiving means;
A toner characterized in that an angle formed between an incident surface formed by an irradiation axis of light by the light irradiation unit and a light reception axis of reflected light by the light receiving unit and a conveyance direction of the carrier by the conveyance is non-right angle Adhesion amount measurement method.

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