JP2017133963A - Testing device and testing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a testing device capable of preventing decrease in precision of a withstand voltage test on a photoreceptor drum.SOLUTION: A testing device 1 tests a withstand voltage of a photoreceptor drum D. The testing device 1 comprises a metal member 10, a power supply 20, and an ammeter 30. The metal member 10 is arranged facing an outer peripheral surface DS of the photoreceptor drum D, and extends along an axial direction F of the photoreceptor drum D. The power supply 20 applies voltage to the metal member 10. The ammeter 30 measures a current flowing through the photoreceptor drum D when a voltage is applied to the metal member 10. The metal member 10 is arranged at predetermined distance L from the photoreceptor drum D. Of the outer peripheral surface DS of the photoreceptor drum D, the surface portion facing the metal member 10 is changed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a test apparatus and a test method.

  Conventionally, an electrophotographic image forming apparatus is known. In general, an electrophotographic image forming apparatus forms an image on a transfer object by executing processes such as charging, exposure, development, and transfer.

  The photosensitive drum included in the image forming apparatus includes a photosensitive layer that forms the outer peripheral surface of the photosensitive drum. In the exposure process, an electrostatic latent image is formed on the photosensitive layer. In the developing process, the electrostatic latent image is developed as a toner image with charged toner. After the developed toner image is transferred to the transfer target, the toner remaining on the photosensitive layer is charged. When the pressure resistance of the photosensitive drum is low, the charged toner may be discharged toward the photosensitive drum and cause dielectric breakdown in the photosensitive drum.

  Therefore, Patent Document 1 discloses a photosensitive drum pressure resistance test apparatus that performs a pressure resistance test of a photosensitive drum. In the photosensitive drum pressure resistance test apparatus, a conductive brush is brought into contact with the outer peripheral surface of the photosensitive drum. Then, a withstand voltage test power source applies a predetermined high voltage between the photosensitive drum and the conductive brush. By detecting the value of the current flowing between the conductive brush and the conductive holding member with the current detector, the photosensitive drum pressure resistance test apparatus performs a pressure resistance test of the photosensitive drum.

JP-A-11-327360

  However, in the photosensitive drum pressure resistance test apparatus described in Patent Document 1, since the conductive brush is in contact with the outer peripheral surface of the photosensitive drum, the conductive brush may be deteriorated. Due to the deterioration of the conductive brush, the accuracy of the pressure resistance test of the photosensitive drum may be reduced.

  The present invention has been made in view of the above problems, and provides a test apparatus and a test method for preventing a decrease in accuracy of a pressure resistance test of a photosensitive drum.

  The test apparatus according to the first aspect of the present invention tests the pressure resistance of the photosensitive drum. The test apparatus includes a metal member, a power source, and an ammeter. The metal member is disposed so as to face the outer peripheral surface of the photosensitive drum, and extends along the axial direction of the photosensitive drum. The power source applies a voltage to the metal member. The ammeter measures the current flowing through the photosensitive drum when the voltage is applied to the metal member. The metal member is disposed at a predetermined distance from the photosensitive drum. Of the outer peripheral surface of the photosensitive drum, the surface facing the metal member is changed.

  A test method according to a second aspect of the present invention includes a procedure for applying a voltage to a metal member disposed at a predetermined distance from the photosensitive drum, and a procedure for measuring a current flowing through the photosensitive drum. And changing the surface of the outer peripheral surface of the photosensitive drum facing the metal member. The metal member is disposed to face the outer peripheral surface of the photoconductive drum, and extends along the axial direction of the photoconductive drum.

  The image forming apparatus according to the present invention prevents a decrease in accuracy of the pressure resistance test of the photosensitive drum.

1 is a configuration diagram showing a test apparatus according to Embodiment 1. FIG. 3 is a flowchart illustrating a method for a pressure test of a photosensitive drum using the test apparatus according to the first embodiment. FIG. 3 is a configuration diagram illustrating a test apparatus according to a second embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof is not repeated.

(Embodiment 1)
FIG. 1 is a configuration diagram illustrating a test apparatus 1 according to the first embodiment. The test apparatus 1 tests the pressure resistance of the photosensitive drum D. First, the photosensitive drum D will be described prior to the description of the test apparatus 1. The photosensitive drum D is attached to, for example, an image forming apparatus that forms an image on a transfer target body by electrophotography. The photosensitive drum D has a substantially cylindrical shape and extends in the axial direction F along the axis A of the photosensitive drum D. The photosensitive drum D includes a photosensitive layer DP that constitutes the outer peripheral surface DS of the photosensitive drum D. In FIG. 1, the area indicated by hatching corresponds to the photosensitive layer DP. The photosensitive drum D carries a toner image formed of charged toner on the photosensitive layer DP. The photosensitive layer DP is formed of, for example, an organic photoreceptor.

  Next, the test apparatus 1 will be described. The test apparatus 1 includes a metal member 10, a power source 20, an ammeter 30, a pair of gripping members 40, and a rotation mechanism 50.

  The pair of gripping members 40 grips both ends of the photosensitive drum D. The pair of gripping members 40 face each other with the photosensitive drum D interposed therebetween. The pair of gripping members 40 have conductivity. The pair of gripping members 40 is also referred to as a conductive chuck.

  The rotation mechanism 50 rotates each of the pair of gripping members 40 about the axis A. That is, the rotation mechanism 50 rotates the photosensitive drum D around the axis A of the photosensitive drum D by rotating each of the pair of gripping members 40. The direction in which the rotation mechanism 50 rotates each of the pair of gripping members 40 may be a clockwise direction or a counterclockwise direction. The rotation mechanism 50 rotates each of the pair of gripping members 40 at a speed of, for example, 10 rpm to 300 rpm (preferably 40 rpm to 100 rpm). The speed at which the rotation mechanism 50 rotates the pair of gripping members 40 may be set based on the printing speed of the image forming apparatus on which the photosensitive drum D is mounted.

  The metal member 10 is disposed to face the outer peripheral surface DS of the photosensitive drum D. Further, the metal member 10 is disposed at a predetermined distance L with respect to the photosensitive drum D. The predetermined distance L is, for example, 5 mm or more and 20 mm or less. That is, the metal member 10 and the photosensitive drum D are not in contact. Details of the predetermined distance L will be described later. The metal member 10 extends along the axial direction F of the photosensitive drum D. In the axial direction F, the width W1 of the metal member 10 is equal to or greater than the width W2 of the photosensitive layer DP.

  In the present embodiment, the metal member 10 is a sheet metal and has a saw shape. The metal member 10 includes a plurality of convex portions 11. The plurality of convex portions 11 are opposed to the outer peripheral surface DS of the photosensitive drum D. Each of the plurality of convex portions 11 is formed at equal intervals along the axial direction F in the present embodiment. However, each of the plurality of convex portions 11 may not be formed at equal intervals. The tips of each of the plurality of convex portions 11 are pointed. Of the plurality of protrusions 11, the length from the protrusion 11 closest to one end of the metal member 10 to the protrusion 11 closest to the other end of the metal member 10 is equal to or greater than the width W2 of the photosensitive layer DP. The metal member 10 need not be a sheet metal.

  The power source 20 is connected to the metal member 10 and applies a voltage to the metal member 10. The voltage that the power source 20 applies to the metal member 10 is, for example, 3 kV to 15 kV. When a voltage is applied to the metal member 10, the metal member 10 is charged. An electric field is formed between the charged metal member 10 and the photosensitive drum D. When the pressure resistance of the photosensitive drum D is low, a current (leakage current) may flow through the photosensitive drum D according to the strength of the electric field between the metal member 10 and the photosensitive drum D.

  While the power source 20 is applying a voltage to the metal member 10, the rotation mechanism 50 rotates the photosensitive drum D. That is, while the power source 20 is applying a voltage to the metal member 10, the rotation mechanism 50 rotates the photoconductor drum D so that the surface of the outer peripheral surface DS of the photoconductor drum D facing the metal member 10 is rotated. Change it. When the photosensitive drum D includes a region with a low withstand voltage locally, a current may flow through the photosensitive drum D when the low withstand voltage region faces the metal member 10 to which a voltage is applied.

  The ammeter 30 is connected to the photosensitive drum D through at least one of the pair of gripping members 40. The photosensitive drum D is grounded via an ammeter 30. The ammeter 30 measures the value of the current flowing through the photosensitive drum D when a voltage is applied to the metal member 10. When the value of the current flowing through the photosensitive drum D measured by the ammeter 30 is equal to or greater than the threshold value, it is determined that the withstand voltage of the photosensitive drum D is defective. On the other hand, when the value of the current flowing through the photosensitive drum D measured by the ammeter 30 is less than the threshold value, it is determined that the withstand voltage of the photosensitive drum D is good. The threshold value is 3 mA, for example. In this embodiment, even if the photosensitive drum D includes a region where the breakdown voltage is locally low, it is determined that the breakdown voltage of the photosensitive drum D is defective.

  Here, when the pressure resistance of the photosensitive drum D is low, dielectric breakdown is caused in the photosensitive drum D. When dielectric breakdown is caused in the photosensitive drum D, black spots (so-called leak black spots) are generated in an image formed on the transfer target. Therefore, a threshold for testing the withstand voltage of the photosensitive drum D may be determined based on the value of the current that causes dielectric breakdown in the photosensitive drum D.

  The photosensitive drum D is less likely to cause dielectric breakdown as the photosensitive layer DP is thicker. On the other hand, in the photosensitive drum D, the thinner the photosensitive layer DP, the easier it is to cause dielectric breakdown. Therefore, the metal member 10 is arranged at a predetermined distance L that is determined according to the thickness of the photosensitive layer DP with respect to the photosensitive drum D.

  Further, the metal member 10 is arranged at a predetermined distance L that is determined according to the voltage (maximum voltage value) of the power supply 20 with respect to the photosensitive drum D. That is, the predetermined distance L is determined according to the thickness of the photosensitive layer DP and / or the voltage applied to the metal member 10 by the power source 20.

  As described above with reference to FIG. 1, according to the first embodiment, a voltage is applied to the metal member 10 disposed at a predetermined distance L with respect to the photoconductive drum D to apply the voltage of the photoconductive drum D. The pressure resistance is tested. Therefore, the deterioration of the metal member 10 due to the contact with the photosensitive drum D can be suppressed. As a result, a decrease in accuracy of the pressure resistance test of the photosensitive drum D due to the deterioration of the metal member 10 is prevented.

  Further, according to the present embodiment, the metal member 10 includes the plurality of convex portions 11 that face the outer peripheral surface DS of the photosensitive drum D. When the metal member 10 does not include the plurality of convex portions 11, the electric field formed between the metal member 10 and the photosensitive drum D may be nonuniform due to the surface roughness of the metal member 10. Accordingly, the electric field formed between the metal member 10 and the photosensitive drum D becomes uniform as compared with the case where the metal member 10 does not include the plurality of convex portions 11. As a result, it is possible to prevent a decrease in the test accuracy of the pressure resistance of the photosensitive drum D due to the non-uniform electric field formed between the metal member 10 and the photosensitive drum D.

  Furthermore, according to the present embodiment, the width W1 of the metal member 10 is equal to or greater than the width W2 of the photosensitive layer DP. Further, while the power source 20 applies a voltage to the metal member 10, the photosensitive drum D is rotating. That is, the entire area of the photosensitive layer DP faces the metal member 10. Therefore, even when the photosensitive drum D includes a region having a locally low breakdown voltage, a current equal to or greater than the threshold value flows through the photosensitive drum D. As a result, it is possible to prevent a decrease in the test accuracy of the pressure resistance of the photosensitive drum D.

  Further, according to the present embodiment, the metal member 10 is disposed with respect to the photosensitive drum D at a predetermined distance L that is determined according to the thickness of the photosensitive layer DP. Therefore, the pressure resistance of the photosensitive drum D can be tested according to the characteristics of the photosensitive drum D. As a result, it is possible to prevent a decrease in the test accuracy of the pressure resistance of the photosensitive drum D.

  Furthermore, according to the present embodiment, the metal member 10 is arranged at a predetermined distance L that is determined according to the voltage applied to the metal member 10 by the power source 20. Therefore, the pressure resistance of the photosensitive drum D can be tested according to the characteristics of the power supply 20. As a result, it is possible to prevent a decrease in the test accuracy of the pressure resistance of the photosensitive drum D.

  Furthermore, according to this embodiment, the metal member 10 is a sheet metal. Compared with the case where the metal member 10 is a brush, the surface area of the metal member 10 is small. Therefore, the metal member 10 is less likely to absorb moisture than the brush. When the metal member 10 absorbs moisture, the value of the current flowing through the photosensitive drum D changes, and the accuracy of the pressure resistance test of the photosensitive drum D may be reduced. As a result, it is possible to prevent a decrease in accuracy of the pressure resistance test of the photosensitive drum D caused by the metal member 10 absorbing moisture.

  Next, with reference to FIG. 1 and FIG. 2, a test method for the withstand voltage of the photosensitive drum D executed by the test apparatus 1 will be described. FIG. 2 is a flowchart illustrating a method for testing the withstand pressure of the photosensitive drum D using the test apparatus 1 according to the first embodiment.

  In step S <b> 10, the rotation mechanism 50 rotates the photosensitive drum D around the axis A. That is, the rotation mechanism 50 changes the surface facing the metal member 10 in the outer peripheral surface DS of the photosensitive drum D. In step S <b> 20, the power source 20 applies a voltage to the metal member 10. As a result, the metal member 10 is charged. In step S <b> 30, an electric field is formed between the charged metal member 10 and the photosensitive drum D. In step S40, a current flows through the photosensitive drum D. In step S <b> 50, the ammeter 30 measures the value of the current flowing through the photosensitive drum D.

  If the value of the current flowing through the photosensitive drum D is equal to or greater than the threshold value, it is determined that the pressure resistance of the photosensitive drum D is defective. Further, when the value of the current flowing through the photoconductive drum D measured by the ammeter 30 is less than the threshold value, it is determined that the withstand voltage of the photoconductive drum D is good.

  As described above with reference to FIGS. 1 and 2, according to the first embodiment, a voltage is applied to the metal member 10 disposed at a predetermined distance L with respect to the photoconductor drum D, and the photoconductor drum The pressure resistance of the photosensitive drum D is tested by measuring the current flowing through D. Therefore, it is possible to test the pressure resistance of the photosensitive drum while suppressing deterioration of the metal member 10 due to contact with the photosensitive drum D. As a result, it is possible to prevent a decrease in the test accuracy of the pressure resistance of the photosensitive drum D.

(Embodiment 2)
Next, with reference to FIG. 3, a test apparatus 1 according to Embodiment 2 of the present invention will be described. The test apparatus 1 according to the second embodiment is described with reference to FIG. 1 except that a moving mechanism 60 that moves the metal member 10 is provided instead of the rotation mechanism 50 provided in the test apparatus 1 according to the first embodiment. Since the configuration is the same as that of the test apparatus 1 described above, the description of the overlapping parts is omitted.

  The test apparatus 1 further includes a moving mechanism 60. The moving mechanism 60 moves the metal member 10 along the circumferential direction of the outer peripheral surface DS of the photosensitive drum D. That is, the moving mechanism 60 moves the metal member 10 around the axis A of the photoconductor drum while maintaining a predetermined distance L between the photoconductor drum D and the metal member 10. The moving mechanism 60 changes the surface of the outer peripheral surface DS of the photosensitive drum D that faces the metal member 10 by moving the metal member 10. At this time, the photosensitive drum D is gripped by the pair of gripping members 40 and does not rotate.

  The power source 20 applies a voltage to the metal member 10 while the moving mechanism 60 moves the metal member 10. The ammeter 30 measures the current flowing through the photosensitive drum D while a voltage is applied to the metal member 10.

  As described above with reference to FIG. 3, according to the second embodiment, the moving mechanism 60 moves the metal member 10 along the outer peripheral surface DS of the photosensitive drum D. Further, in the axial direction F, one end to the other end of the photosensitive layer DP of the photosensitive drum D faces the metal member 10. Accordingly, even when the entire region of the photosensitive layer DP faces the metal member 10 and the photosensitive drum D includes a region having a locally low withstand voltage, a current flows through the photosensitive drum D. As a result, it is possible to prevent a decrease in accuracy of the pressure resistance test of the photosensitive drum D.

  Further, according to the second embodiment, the metal member 10 moves along the circumferential direction of the outer circumferential surface DS while leaving a predetermined distance L with respect to the photosensitive drum D. Therefore, contact between the metal member 10 and the photosensitive drum D can be prevented. As a result, deterioration due to the metal member 10 coming into contact with the photosensitive drum D can be suppressed, and a decrease in accuracy of the pressure resistance test of the photosensitive drum D can be prevented.

  The embodiment of the present invention has been described above with reference to the drawings (FIGS. 1 to 3). However, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof (for example, (1) to (4) shown below). In order to facilitate understanding, the drawings schematically show each component as a main component, and the thickness, length, number, and the like of each component shown in the drawings are different from the actual for convenience of drawing. . In addition, the material, shape, dimensions, and the like of each component shown in the above embodiment are merely examples, and are not particularly limited, and various changes can be made without departing from the effects of the present invention. is there.

  (1) As described with reference to FIGS. 1 and 3, the metal member 10 includes a plurality of convex portions 11. However, the metal member 10 may not include the plurality of convex portions 11. Further, the metal member 10 may include a single convex portion 11.

  (2) As described with reference to FIGS. 1 and 3, each of the plurality of convex portions 11 has a pointed tip. However, the tip of each of the plurality of convex portions 11 may have, for example, a shape in which a sharp tip is curved.

  (3) As described with reference to FIG. 1, in the first embodiment, the photosensitive drum D rotates and the metal member 10 is fixed. On the other hand, as described with reference to FIG. 3, in Embodiment 2, the metal member 10 is rotated and the photosensitive drum D is fixed. However, both the photosensitive drum D and the metal member 10 may rotate. At this time, when the surface of the outer peripheral surface DS of the photosensitive drum D facing the metal member 10 is changed, the rotation direction of the photosensitive drum D may be different from the rotation direction of the metal member 10. It may be.

  (4) As described with reference to FIG. 1, the predetermined distance L is determined according to the thickness of the photosensitive layer DP and / or the voltage applied to the metal member 10 with respect to the photosensitive drum D. However, the predetermined distance L may be determined according to the material of the photosensitive layer DP of the photosensitive drum D.

  The present invention can be used in the field of test equipment and test methods.

DESCRIPTION OF SYMBOLS 1 Test apparatus 10 Metal member 20 Power supply 30 Ammeter 50 Rotating mechanism 60 Moving mechanism A Axis line D Photoconductor drum DS Outer peripheral surface DP Photosensitive layer F Axial direction L Predetermined distance

Claims (8)

A test device for testing the pressure resistance of the photosensitive drum,
A metal member disposed opposite to the outer peripheral surface of the photosensitive drum and extending along the axial direction of the photosensitive drum;
A power source for applying a voltage to the metal member;
An ammeter that measures a current flowing through the photosensitive drum when the voltage is applied to the metal member;
The metal member is disposed at a predetermined distance from the photosensitive drum;
The test apparatus, wherein a surface of the outer peripheral surface of the photosensitive drum facing the metal member is changed.   The test apparatus according to claim 1, wherein the metal member includes a plurality of convex portions facing the outer peripheral surface of the photosensitive drum. The photosensitive drum includes a photosensitive layer constituting the outer peripheral surface,
The test apparatus according to claim 1, wherein a width of the metal member is equal to or greater than a width of the photosensitive layer in the axial direction.   The test apparatus according to claim 3, wherein the metal member is arranged at a predetermined distance that is determined according to a thickness of the photosensitive layer with respect to the photosensitive drum.   The test apparatus according to claim 1, wherein the metal member is disposed at a predetermined distance that is determined according to the voltage with respect to the photosensitive drum. A rotation mechanism for rotating the photosensitive drum around the axis of the photosensitive drum;
The said rotation mechanism changes the said surface facing the said metal member among the said outer peripheral surfaces of the said photoconductor drum by rotating the said photoconductor drum. The test apparatus described. A moving mechanism for moving the metal member along the outer peripheral surface of the photosensitive drum;
The said moving mechanism changes the said surface facing the said metal member among the said outer peripheral surfaces of the said photosensitive drum by moving the said metal member, The any one of Claims 1-6. Testing equipment. A test method for testing the pressure resistance of a photosensitive drum,
A procedure for applying a voltage to a metal member disposed at a predetermined distance from the photosensitive drum;
Measuring the current flowing through the photosensitive drum;
Changing the surface of the outer peripheral surface of the photosensitive drum that faces the metal member,
The test method, wherein the metal member is disposed to face the outer peripheral surface of the photosensitive drum and extends along an axial direction of the photosensitive drum.

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