JP2007248483A - Position adjustment method and device for sensor-mounted substrate and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably obtain sensor outputs when detecting with a plurality of sensors. <P>SOLUTION: The position adjustment device for a sensor-mounted substrate has an attached powder quantity detecting means. This means has, on the same substrate, the plurality of sensors 5, each being composed of a pair of a light emitting element 5a and a light receiving element 5b, emits light from each light emitting element 5a to a powder on an intermediate transfer belt (reflecting body) 13, and reads the level of a light quantity signal by the light receiving elements 5b, thereby detecting an amount of attached powder. The position adjustment device includes: a sensor position shifting means by which the substrate with the sensors 5 mounted on them is shifted parallel to a tangent touching the curved face of the intermediate transfer belt 13; a reflection output detecting means 31 that measures the output signals of all the sensors 5 during the shift, which are detected by the sensors 5 mounted on the substrate; and an arithmetic means that determines the angle of rotation and the position of the substrate in the direction of the tangent, based on the output characteristics of the sensors, measured by the refection output detecting means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic copying machine, a printer, a facsimile, an image forming apparatus such as a digital multi-function machine having these functions combined, and an image carrier or transfer used in an image forming unit of the image forming apparatus. The present invention relates to a method and an apparatus for adjusting the position of a sensor mounting substrate for detecting powder on a material carrier.

  As this type of technology, for example, the inventions described in Patent Documents 1 and 2 are known. Of these, the invention described in Patent Document 1 includes a density sensor, measures the developer density detection test pattern created on the photoconductor and the density of the background of the photoconductor, and develops based on the measurement results. In the image forming apparatus for controlling the density of the agent, the test pattern creation timing is controlled so as to create the test pattern at the reflected light measurement position on the background of the photoconductor, and the density of the test pattern at the background density measurement position Means for controlling the measurement timing of the density sensor to measure the density, means for obtaining a developer density based on the measured density, means for comparing the obtained developer density with a predetermined developer density, and the developer density is The present invention relates to an image forming apparatus provided with means for supplying a developer when a predetermined density is not reached.

  Further, the invention described in Patent Document 2 is attached to the photosensitive member in an image forming apparatus provided with a photosensitive member rotatably attached and a charger, an exposure device, and a developing device so as to surround the photosensitive member. A detection unit for measuring the amount of adhered toner, a sensor provided in the detection unit, having a predetermined distance characteristic and a predetermined angle characteristic, and a distance and an angle of the sensor with respect to an object to be measured are changed. Sometimes the distance and angle between the detection surface of the sensor and the photoconductor are adjusted so that the detection output of the sensor is in the vicinity of the prescribed peak positions of the distance characteristic and the angle characteristic in the detection output characteristic of the sensor. A sensor displacement mechanism, a cover provided in the detection unit and protecting the detection surface of the sensor from scattered toner and paper pieces, and provided in the detection unit. The operates independently of the cover, an image forming apparatus having a cleaning mechanism for cleaning the detection surface of the sensor.

Among these, in Patent Document 2, when the sensor is installed as described above, a sensor displacement mechanism is installed so that the relative position between the sensor and the reading target surface is a predetermined distance and angle, and the sensor output signal has a peak. It is described that the sensor position is adjusted to a position in the vicinity.
JP 2004-77598 A Japanese Patent No. 3668658

  By the way, with the downsizing of the image forming apparatus, there is a case where the reading target surface of the sensor is set to a curved surface portion. This is because the developing device is arranged on the transfer belt flat surface portion, and if the sensor reading target surface is set to the flat surface portion of the transfer belt, the transfer belt unit becomes larger by installing the sensor.

  However, if the sensor reading target surface is set to a curved surface, depending on the sensor mounting position, the distance and angle between the sensor and the detection target surface may deviate from the position that can be detected by the sensor or the detection range. The output signal decreases. When the output signal decreases in this way, there is a case in which the maximum rated current is not supported in response to increasing the current in order to increase the light amount of the light emitting element. Therefore, in the case of adjusting such a plurality of sensors, in the prior art, adjustment mechanisms are required as many as the number of sensors. Further, if each sensor is an independent substrate, it is necessary to connect an electric wire to each substrate, which takes time in the assembly process or increases the number of steps.

  The present invention has been made in view of such a state of the art, and an object of the present invention is to make it possible to stably obtain sensor outputs when detection is performed by a plurality of sensors.

  In order to achieve the object, the first means is that a plurality of sensors each having a light emitting element and a light receiving element are mounted on the same substrate, and from the light emitting element to the powder on the image carrier or transfer material carrier. A method for adjusting the position of a sensor mounting substrate that irradiates light, reads a light amount signal level by the light receiving element, and detects the amount of powder adhered, wherein the sensor mounting substrate is connected to an image carrier or a transfer material carrier. Measuring the output signals of all the sensors during movement detected by translation with respect to the tangential line, and determining the position and rotation angle of the substrate in the tangential direction based on the measured output characteristics of the sensor; Features.

  The second means is characterized in that, in the first means, the light irradiation portion of the sensor is a curved surface portion of an image carrier or a transfer material carrier.

  A third means is characterized in that, in the first or second means, the output signal of the sensor is a regular reflection output signal.

  A fourth means is characterized in that, in the first or third means, the transfer material carrier is an intermediate transfer belt.

  According to a fifth means, in any one of the first to fourth means, the position in the tangential direction is determined based on a sensor output at one end of the sensor mounting board, and the rotation angle is determined from a peak of another sensor output. It is determined.

  A sixth means is any one of the first to fourth means, wherein the position in the tangential direction is determined based on a sensor output located near the center of the mounting substrate, and the rotation angle is a sensor located near the center. It is determined based on the output and the sensor output at the end.

  Seventh means includes mounting a plurality of sensors each having a light emitting element and a light receiving element on the same substrate, irradiating the powder on the image carrier or transfer material carrier from the light emitting element, and receiving the light. An apparatus for adjusting a position of a sensor-mounted substrate that includes a powder adhesion amount detection unit that reads a light amount signal level by an element and detects the amount of powder adhesion, and the substrate on which the plurality of sensors are mounted is an image carrier or a transfer material. A moving means for parallel movement and / or rotation with respect to a tangent to the carrier; a measuring means for measuring output signals of all sensors detected by a plurality of sensors mounted on the substrate; and the measuring means And adjusting means for determining a position and a rotation angle of the substrate in the tangential direction based on the output characteristics of the sensor measured by the above.

  The eighth means is characterized in that, in the seventh means, the light irradiation portion of the sensor is a curved surface portion of an image carrier or a transfer material carrier.

  A ninth means is characterized in that, in the seventh or eighth means, a read output from the light receiving element is inputted to a waveform measuring means and converted into a light amount signal level.

  According to a tenth means, in any one of the seventh to ninth means, the light receiving element is a regular reflection light receiving element.

  An eleventh means is characterized in that, in any of the seventh to tenth means, the transfer material carrier is an intermediate transfer belt.

  A twelfth means is characterized in that, in any of the seventh to eleventh means, a driving means for driving the parallel movement means is provided in the apparatus.

  A thirteenth means is any one of the seventh to twelfth means, wherein the adjusting means determines the position in the tangential direction based on a sensor output at one end of the sensor mounting board, and sets the rotation angle to another It is determined from the peak of the sensor output.

  The fourteenth means is any one of the seventh to twelfth means, wherein the adjusting means determines the position in the tangential direction based on a sensor output near the center of the mounting board, and It is determined based on the sensor output near the center and the sensor output at the end.

  The fifteenth means is characterized in that the image forming apparatus includes a sensor-mounted substrate position adjusting device according to any one of the seventh to fourteenth means.

  In the embodiments described later, the light emitting element is 5a, the light receiving element is 5b, the sensor is denoted by reference numeral 5, the image carrier or transfer material carrier is the intermediate transfer belt (reflector) 13, and the sensor mounting substrate is the substrate. 15a, the powder adhesion amount detection means corresponds to the reflection output detection means 31, the movement means corresponds to the sensor position movement means 34, the measurement means corresponds to the reflection output detection means 31 and the recording means 32, and the adjustment means corresponds to the calculation means 33. To do.

  According to the present invention, the output signals of all the sensors detected during movement are measured by moving the sensor mounting substrate parallel to the tangent to the image carrier or transfer material carrier, and the output characteristics of the measured sensors are measured. Therefore, the position of the tangential direction of the substrate and the rotation angle are determined. Therefore, when detection is performed by a plurality of sensors, the sensor output can be stably obtained.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing a schematic configuration of a color printer according to an embodiment of the present invention. This color printer is an indirect transfer tandem color printer. In the figure, a color printer 1 includes a paper feed cassette 2 for supplying paper before printing, CMYK color developing units 3a, 3b, 3c, 3d, CMYK color photosensitive drums 4a, 4b, 4c, 4d, And a reflective sensor (photoreflector) 5 having a light emitting element and a light receiving element, and the photosensitive drums 4a to 4d are in contact with each other, and an intermediate stretched between a tension roller 6 and a driving roller 7 for transferring a toner image. Transfer belt 13, tension roller 6 that prevents sagging of intermediate transfer belt 13, driving roller 7 for driving intermediate transfer belt 13, cleaning device 8 that removes toner on the transfer belt without being transferred to the paper, and paper are conveyed. Conveying path 9, fixing unit 10 that fixes toner on the paper with heat, pressure when transferring toner on the transfer belt to the paper A secondary transfer roller 11 to be added and a paper feed roller 12 for feeding the paper in the paper feed cassette to the conveyance path. The intermediate transfer belt 13 is formed by superimposing images formed on the photosensitive drums 4a to 4d. The formed full-color toner image is transferred onto the paper by the secondary transfer roller 11.

  FIG. 2 is a block diagram showing a control circuit of the adjusting mechanism of the sensor 5. This adjustment mechanism detects a light amount adjusting means 30 that emits light from the light emitting element 5a in the sensor 5, a light receiving element 5b that receives light from the light emitting element 5a reflected from the reflector 13, and a signal received by the light receiving element 5b. The detection unit 31 includes a recording unit 32 that records a detected signal, a calculation unit 33 that calculates data of an output value recorded by the recording unit 32, and a sensor position moving unit 34 that moves the sensor 5. The light receiving element 5b is composed of a regular reflection light receiving element that receives regular reflection light. Therefore, the light receiving element 5b outputs a regular reflection output signal. FIG. 3 is a flowchart showing an operation procedure of sensor position adjustment adjusted by such an adjustment mechanism.

  In this operation procedure, first, the light amount adjusting unit 30 causes the light emitting element 5a to emit light and irradiates the reflector with light (step F1). Next, the reflected light from the reflector is detected by the light receiving element 5b, the light quantity level of the reflected light is measured, and the signal is stored by the recording means 32 (step F2). Thereafter, when the reflected signal can be recorded, the sensor position moving means 34 moves the sensor position by a predetermined distance in the X direction to search for the sensor output signal as shown in FIG. 4 (steps F3 and F4). In order to obtain the maximum value of the sensor output of all the sensors on the substrate, the sensor output is moved for a certain distance and then stopped (step F5).

  Here, it is assumed that n sensors 5 are mounted at equal intervals R on the same substrate 15a as shown in FIG. Here, 5 (1S), 5 (2S)... 5 (nS) represent the sensor 5 having a set of individual light emitting and light receiving elements. θ represents the rotation direction of the sensor position adjusting means during adjustment. Further, there is provided a disk 14 for adjusting the angle while the left end sensor 5 (1S) is fixed, and a sensor base 15 which is integrated with a substrate 15a on which a plurality of sensors 5 are mounted and holds the substrate 15a on the same surface. It has been. In the figure, since the substrate 15a is integrally held on the sensor base 15, the disk 14 and the sensor base 15 are integrally moved and rotated. When moving the sensor in the X direction, the sensor base 15 is moved in the X direction, and when rotating to adjust the angle, the disk 14 is rotated.

  FIG. 6 shows the result (transition of the output waveform) of storing the output waveform of the sensor output when the sensor 5 is moved by the sensor position moving means 34 in the recording means 32. The horizontal axis X is the distance moved by the sensor position adjusting means, and the vertical axis Y is the sensor output signal detected by the light receiving element. The peak values 1P, 2P,... Of the sensors 5 (1S), 5 (2S),... Are determined by the calculating means 33 from the relationship between the movement amount recorded in the recording means 32 and the sensor output (FIG. 6) (step F6). ), The movement amounts 1X, 2X,... Corresponding to the peak values for each sensor are detected (step F7).

Next, in the calculation means 33, the horizontal axis shown in FIG. 7 is the distance 1R, 2R between the sensors when the sensor 5 (1S) is a reference, and the vertical axis is the peak of 5 (1S) from the peak movement amount of each sensor. A characteristic is obtained which is obtained by subtracting the hourly movement amount 1X (step F8). From this characteristic, in order to calculate the distance to move the sensor and the angle to rotate, y = ax + b (1)
Is calculated.

The coefficient a in the equation (1) is
a = {Σ ((iR) (iX-1X)) − Σ (iR) Σ (iX−1X)} / {n (Σ (iR) ² ) − (Σ (iR)) ² } (2 )
And the intercept b is
b = {Σ (iR) ² Σ (iX-1X) −Σ ((iR) (iX−1X)) Σ (iR)} / {n (Σ (iR) ² − (Σ (iR)) ² } · (3)
It is. However, in (2) and (3), Σ means that all values substituted from i = 1 to n in the following formula are added.

The calculating means 33 sends the value obtained by the equation (1) to the sensor position moving means. Then, with the sensor 5 (1S) shown in FIG. 5 fixed, the sensor position adjustment means 34 moves the sensor base 15 on which the board 15a is installed by a distance (1X + b) in the X direction (step F9), and the left end of the sensor is moved. The disk is rotated by an angle θ while the sensor is fixed so as not to move (step F10). However, the rotation angle θ is
θ = sin ⁻¹ (a ² / √ (a ² +1))
Sought by.

  Considerable accuracy is required for the driving accuracy of the sensor position moving means 34 for moving the sensor 5. Therefore, it is desirable that the sensor position moving means 34 be capable of feedback control, and a stepping motor that is accurate in driving is desirable.

  Such readjustment of the position of the sensor 5 is executed when a predetermined condition is satisfied as shown in the flowchart of FIG. That is, if the conditions such as after the reference time elapses, after replacement parts replacement work, and after printing the reference number of sheets (step F11-present), the respective sensors 5 (1s) to 5 (ns) are shown in the flowchart of FIG. The ratio of the sensor output result after the adjustment in the procedure and the current sensor output is compared (step F12). As a result, if the output ratios of the sensors are greatly different (step F12—NO), the sensor position is considered to be shifted, and the sensor position adjustment shown in the flowchart of FIG. 3 is performed.

  With this configuration, it is determined whether or not to adjust the sensor position after a predetermined time (reference time) when the possibility of displacement will increase, after replacement parts replacement work, after printing the reference number of sheets, etc. If there is a need for adjustment, the adjustment operation is performed, so that highly accurate sensor position adjustment is always possible.

As described above, according to the present embodiment,
1) The sensor position can be easily adjusted near the peak position of the sensor output. Thereby, sensor output can be stably obtained by a plurality of sensors.
2) The light receiving element is a regular reflection light receiving element and uses a regular reflection output, so that the positions of the sensor and the reading target surface can be easily found. Thereby, the adjustment for stably obtaining the sensor output signal by the plurality of sensors can be easily performed.
3) Even if the surface to be read is a curved surface portion of the intermediate transfer belt, a sensor output waveform with a sufficient output can be obtained, so that the positions of a plurality of sensors can be easily optimized.
4) Since other sensor outputs are viewed on the basis of the end sensor, it can be easily adjusted near the peak of the sensor output by only one direction and rotation for movement.
5) Since the rotation angle is determined by another sensor with reference to the sensor in the vicinity of the center, it can be easily adjusted near the peak of the sensor output by only one direction and rotation for movement.
6) The sensor position can be easily adjusted near the peak position of the sensor output, and the sensor output can be stably obtained by a plurality of sensors.
7) Since the device is provided with means for moving the sensor in parallel, even if the sensor deviates from a predetermined position due to an accident, it can be easily returned to the optimum position again.
The effects such as the above can be achieved.

1 is a diagram illustrating a schematic configuration of a color printer according to an embodiment of the present invention. It is a block diagram which shows the control circuit of the adjustment mechanism of a sensor. 3 is a flowchart showing an operation procedure of sensor position adjustment adjusted by an adjustment mechanism and a control circuit of FIG. 2. It is a figure for demonstrating the movement operation | movement of a sensor. It is a figure which shows the state in which n sensors are mounted on the same board | substrate at equal intervals. It is a figure which shows transition of the output waveform of a sensor output when a sensor is moved. It is a figure which shows the approximate straight line of the least squares method used in order to approximate the distance between sensors, and the peak position of a sensor output. It is a flowchart which shows the process sequence when setting the readjustment start timing of a sensor position.

Explanation of symbols

1 Color printer 2 Paper cassette
3a, 3b, 3c, 3d Developing unit 4a, 4b, 4c, 4d Photoreceptor 5 Sensor 5a Light emitting element 5b (Regular reflection light) Light receiving element 6 Tension roller 7 Drive roller 13 Reflector (intermediate transfer belt)
DESCRIPTION OF SYMBOLS 15 Sensor stand 15a Board | substrate 30 Light quantity adjustment means 31 Detection means 32 Recording means 33 Calculation means 34 Sensor position moving means

Claims (15)

A plurality of sensors each composed of a light emitting element and a light receiving element are mounted on the same substrate. Light is emitted from the light emitting element to the powder on the image carrier or the transfer material carrier, and the light quantity signal level is set by the light receiving element. A method for adjusting the position of a sensor-mounted substrate that reads and detects the amount of powder attached,
Measuring the output signals of all sensors at the time of movement detected by moving the sensor mounting substrate parallel to and / or rotating with respect to the tangent to the image carrier or transfer material carrier;
A position adjustment method for a sensor mounting substrate, wherein the position and rotation angle of the substrate in the tangential direction are determined based on the measured output characteristics of the sensor.   2. The position adjustment method for a sensor mounting substrate according to claim 1, wherein the light irradiation portion of the sensor is a curved surface portion of an image carrier or a transfer material carrier.   3. The sensor mounting substrate position adjusting method according to claim 1, wherein the output signal of the sensor is a regular reflection output signal.   4. The method for adjusting the position of a sensor mounting substrate according to claim 1, wherein the transfer material carrier is an intermediate transfer belt. The position in the tangential direction is determined based on the sensor output at one end of the sensor mounting substrate,
5. The position adjustment method for a sensor mounting substrate according to claim 1, wherein the rotation angle is determined from a peak of another sensor output. The position in the tangential direction is determined based on a sensor output near the center of the mounting board,
5. The position adjustment method for a sensor mounting substrate according to claim 1, wherein the rotation angle is determined based on a sensor output near the center and a sensor output at an end portion. 6. A plurality of sensors each composed of a light emitting element and a light receiving element are mounted on the same substrate. Light is emitted from the light emitting element to the powder on the image carrier or the transfer material carrier, and the light quantity signal level is set by the light receiving element. In the position adjustment device of the sensor mounting substrate provided with the powder adhesion amount detection means for reading and detecting the adhesion amount of the powder,
Moving means for translating and / or rotating a substrate on which the plurality of sensors are mounted with respect to a tangent to the image carrier or the transfer material carrier;
Measuring means for measuring output signals of all the sensors at the time of movement detected by a plurality of sensors mounted on the substrate;
Adjusting means for determining a position and a rotation angle of the substrate in the tangential direction based on output characteristics of the sensor measured by the measuring means;
An apparatus for adjusting the position of a sensor-mounted substrate, comprising:   8. The position adjusting device for a sensor mounting substrate according to claim 7, wherein a light irradiation portion of the sensor is a curved surface portion of an image carrier or a transfer material carrier.   9. The position adjustment device for a sensor mounting substrate according to claim 7, wherein a read output from the light receiving element is input to a waveform measuring means and converted into a light amount signal level.   The position adjusting device for a sensor mounting substrate according to any one of claims 7 to 9, wherein the light receiving element is a regular reflection light receiving element.   The position adjusting device for a sensor mounting substrate according to any one of claims 7 to 10, wherein the transfer material carrier is an intermediate transfer belt.   The position adjusting device for a sensor mounting substrate according to any one of claims 7 to 11, further comprising driving means for driving the parallel moving means. The adjusting means includes
Determine the position in the tangential direction based on the sensor output of one end of the sensor mounting substrate,
The position adjustment device for a sensor mounting substrate according to any one of claims 7 to 12, wherein the rotation angle is determined from a peak of another sensor output. The adjusting means includes
The position in the tangential direction is determined based on a sensor output near the center of the mounting board,
The position adjustment device for a sensor mounting board according to any one of claims 7 to 12, wherein the rotation angle is determined based on a sensor output near the center and a sensor output at an end.   15. An image forming apparatus comprising the sensor mounting substrate position adjusting device according to claim 7.

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