JP4021578B2 - Method and apparatus for destructive inspection of photosensitive drum - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
More particularly, the present invention relates to a destructive inspection method (or anti-destructive method) for examining delamination that occurs in a photosensitive layer by applying a high voltage to the photosensitive layer of a photosensitive drum rotating in a drum shape. The present invention relates to a voltage inspection method) and an inspection apparatus thereof.
[0002]
[Prior art]
Conventionally, a photosensitive layer made of a material such as a CdS-based material or a selenium-based material has been formed on the surface of a photoreceptor used in an image forming apparatus such as a laser printer or an electrophotographic machine. Scratches on the photosensitive layer, dents, cavities, exfoliation, when the abnormal portion such as with an electrically non-uniform site due to adhesion of foreign matter or the like is present, the resulting image, so-called white spot phenomenon occurs. Therefore, in advance, such a defect is inspected to determine a defective photoconductor.
[0003]
Therefore, as these prior inspection methods, for example, in Japanese Patent Application Laid-Open No. 57-169665, a conductive chuck and a conductive roller are connected to the photosensitive member, a high voltage is applied to the photosensitive member, and the photosensitive member is rotated. A detection method is described in which a defective portion is detected as having a defective portion when a current (overcurrent) of a predetermined value or more flows while moving. The above proposal is a method for detecting the excessive current generated in this way. However, when a high voltage is applied, even if there is a defective portion on the photoreceptor, the breaker is not used to damage the photoreceptor. Therefore, the apparatus may stop when a defective part occurs.
[0004]
In order to avoid the above problem, Japanese Patent Application Laid-Open No. 61-142456 provides a non-contact electrode, and when a defective portion exists on the photoconductor when this high voltage is applied, the defective portion and the normal portion. There has been proposed a method of detecting the presence or absence of a defective portion by measuring the fluctuation of the potential. However, this proposal has a drawback that a new device for detecting a change in potential must be assembled, resulting in high cost of the device. In addition, in order to detect such a potential difference, a constant and stable voltage must be applied to the entire photoconductor, and such a condition setting requires extremely high accuracy, which makes operation complicated. However, it is not always preferable as an inspection method.
[0005]
Also, in the inspection method in which a conductive brush is brought into contact with the surface of the photosensitive member instead of the conductive roller described in Japanese Utility Model Publication No. 6-21973, the photosensitive layer of the photosensitive drum charged when this high voltage is applied. The tip of the conductive brush moves up and down, left and right due to electrical repulsion with the surface of the surface, and discharge may occur between the conductive brush and the exposed base portion of the photosensitive drum, which hinders handling. May come.
[0006]
[Problems to be solved by the invention]
As described above, various inspection methods and apparatuses have been proposed in the past for inspecting such a photoreceptor in advance. However, in reality, it is not a satisfactory inspection method.
[0007]
Under such circumstances, if the photosensitive layer of the photosensitive drum is electrically non-uniform due to some factor, for example, its electrostatic resistance varies, it is inaccurate as a product. Such products must be inspected and removed in advance. An object of the present invention is to provide an inspection method capable of easily and reliably inspecting and extracting such defective products as compared with the prior art. Another object of the present invention is to provide a destructive inspection apparatus that is simple and inexpensive in comparison with the conventional apparatus used for this inspection.
[0008]
[Means for Solving the Problems]
As a result of intensive studies in view of the above-mentioned problems, the present inventors have determined the withstand voltage to be applied to the photosensitive member that causes the coating film of the photosensitive layer to be destroyed by the applied voltage when a high voltage is applied to the drum-type photosensitive member. As a result of the investigation, it was found that the inspection can be easily performed as compared with the conventional method, and the present invention has been completed. That is, in the present invention, the substrate of the photosensitive drum provided with the photosensitive layer on the drum-type substrate is conducted through the conductive chuck supported so as to slide on one end surface thereof, while the photosensitive layer is The conductive drum is rotated to apply an applied voltage to the surface of the photosensitive layer in a state in which the conductive drum is conducted through a conductive brush contacting the surface and a high voltage is applied between the conductive chuck and the conductive brush. The present invention provides a method for inspecting a destruction of a photosensitive drum, characterized in that, in a withstand voltage test performed by scanning, the destruction of a coating film generated in the photosensitive layer and the withstand voltage applied at that time are obtained.
[0009]
Accordingly, the withstand voltage applied to the photosensitive member causing the coating layer to be destroyed in the photosensitive layer of the photosensitive member according to the present invention is shown in FIG. 1 when there is an electrically non-uniform portion in the photosensitive layer of the photosensitive drum. In the destructive inspection apparatus according to the present invention, the photosensitive layer 1 of the photosensitive member is made conductive by the conductive chuck 3 and the conductive brush 6, and then a high voltage is applied between the two by the power source 7 to rotate the photosensitive drum. When the applied voltage is scanned on the surface of the photosensitive layer and there is an electrically nonuniform portion as described above in the photosensitive layer, an excessive current flows through the portion, and the coating film at that portion is destroyed. As a result, a defective part can be inspected and extracted by a very simple determination.
[0010]
Further, the present invention provides a destructive inspection apparatus that applies a high voltage to a photosensitive drum provided with a photosensitive layer on a drum type substrate to cause coating film destruction on the photosensitive layer, and the substrate of the photosensitive drum A conductive chuck that supports the end surface of the photosensitive member so as to slide, a conductive brush provided to contact the surface of the photosensitive layer, and the photosensitive layer via the conductive chuck and the conductive brush. The present invention provides a destructive inspection device for a photosensitive drum, characterized by having a power source for applying a high voltage. Therefore, as shown in FIG. 1, the drum type photoconductor destructive inspection apparatus according to the present invention comprises a conductive chuck 3 that supports the photosensitive drum so as to slide, a conductive brush 6 that contacts the photosensitive layer 1, and It is well understood that this is a very simple device having a power source 7 for applying a high voltage to both of them, and in particular, a device for detecting current as in the prior art is not required. A destructive inspection apparatus for a photosensitive drum.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
As already described, the inspection method of the present invention for inspecting whether there is a defective portion in the photosensitive layer of the photosensitive drum determines the presence or absence of a destructive film generated in the photosensitive layer based on the presence or absence of extremely simple conduction. In addition, as already described above (see FIG. 1), the inspection method used for the inspection method is an extremely simple system as compared with a conventionally used device. It is also characterized by being low in cost.
[0012]
In the following, an embodiment of a method for inspecting destructiveness of a photosensitive drum and an inspection apparatus for the same according to the present invention will be described in detail with reference to FIGS.
[0013]
Therefore, in the present invention, as shown in FIG. 1, the conductive chuck 3 is supported on one side end face of the base 2 of the photosensitive drum so as to slide on the side face of the base. Accordingly, the conductive chuck 3 is electrically connected to the base body 2 through this sliding surface. On the other hand, the conductive brush 6 is provided on the surface of the photosensitive layer 1 so that the tip of the conductive brush 6 fixed to the brush fixing member 5 can be brought into contact with or separated from the photosensitive layer 1 vertically. It has been. Thereby, the surface of the photosensitive layer 1 is made conductive through the tip of the conductive brush 6.
[0014]
Therefore, the photosensitive drum 2 is rotated by a motor, and then the conductive brush 6 is brought into full electrical contact with the surfaces of the conductive chuck 3 and the photosensitive layer 1 so as to be electrically conductive. A high voltage is applied to the photosensitive layer 1 of the photosensitive drum by the test power source 7. In this way, if the photosensitive layer surface is scanned with the applied voltage and there is a portion where a current exceeding a certain current value flows, the film at that portion is peeled and broken. Since the presence or absence of the peeling can be easily confirmed by the presence or absence of conduction in conjunction with the applied voltage at this time, it is determined that the withstand voltage failure is based on the applied voltage value at that time, and peeling of the defective part linked to the applied voltage value It is possible to know the destruction (see FIG. 5 described later).
[0015]
In the present invention, the withstand voltage P of the photosensitive layer is expressed by the following equation (1): P ≧ alog r · s ² (1)
In the formula, the coefficient a is in the range of 0.9 × 10 ^{2 to} 1.2 × 10 ² ,
r is the electrostatic resistance of the photosensitive drum ( Ω / cm ² ),
s is the thickness (mm) of the photosensitive layer of the photosensitive drum .
It is preferable to satisfy the voltage obtained by the empirical formula represented by:
That is, the applied withstand voltage P is the electrostatic resistance ( Ω / cm ² ) of the photosensitive drum in the equation. ) A function related to r. Thus, it can be seen that an electrically non-uniform portion existing in the photosensitive layer can be determined by the correlation between the electrostatic resistance value and the withstand voltage P described above.
[0016]
Therefore, in the present invention, the width L0 of the conductive brush 6 (see FIG. 1) is not particularly limited with respect to the photosensitive layer width of the photosensitive drum, but preferably, a high voltage is applied, From the viewpoint that a conductive brush can be simultaneously contacted and conducted under the same conditions over the entire width of the photosensitive layer to inspect the entire photosensitive layer, the width L0 of the brush should be at least equal to the width of the photosensitive layer. Is more preferred. However, conventionally, a brush width L0 smaller than the photosensitive layer width has been used from the viewpoint of preventing arc discharge generated during this test. Therefore, in the conventional test apparatus, in order to inspect the entire surface of the photoreceptor surface, it is necessary to repeat the test by moving the brush to the left and right with respect to the photosensitive layer. For this reason, not only the inspection efficiency is lowered, but also a drive device for the above movement is required, which increases the cost of the device.
[0017]
Therefore, in the present invention, as shown in FIG. 2 and FIG. 3, by providing the non-conductive (insulating) holding members 4 at both ends of the conductive brush 6, the above-described problems can be solved, and the above-mentioned problem can be solved. This makes it possible to improve the efficiency of the destructive inspection test.
[0018]
That is, as shown in FIG. 5 to be described later, since this destructive inspection test (withstand voltage test) applies a high voltage, conventionally, in such a test, static electricity usually accumulates in the periphery of the photosensitive drum. In particular, the tip of the conductive brush 6 is electrically repelled, and the tip of the brush is uneven, which tends to hinder measurement. Further, there is a tendency that arc discharge occurs in the exposed metal portion at the periphery of the photosensitive drum which is easily electrically conductive under such a high voltage.
[0019]
In order to effectively prevent these electric repulsion and arc discharge, in the present invention, preferably, the holding member 4 is provided on the brush fixing member 5 along both ends of the conductive brush 6 as shown in FIG. Is preferred. Moreover, in this invention, examples, such as (a)-(c) shown in FIG. 3, can be mentioned as a shape or attachment form of such a holding member 4, for example.
[0020]
In the holding member 4 thus provided, the length L2 of the holding member 4 is normally set to L1> L2 with respect to the bristle length L1 of the conductive brush 6, as shown in FIG. Is preferred. That is, in FIGS. 3A to 3C, the shape of the holding member 4 is L1 = L2 and L1 <L2 regardless of the synthetic resin such as acrylic, polycarbonate, polyethylene, etc. In this case, scratches are generated on the surface of the photosensitive layer.
[0021]
The holding member 4 is not particularly limited to inorganic or organic materials as long as it is a non-conductive insulator. For example, flakes such as natural mica, asbestos, sepiolite, crystal, marble, synthetic mica, Fiber materials, plate-like mineral materials, porcelain materials such as corundum, mullite, fiber materials, plate-like quartz, glass materials such as lead and alkali, various insulating papers, natural fiber materials such as cotton yarn, hemp yarn, silk yarn, Synthetic resin moldings such as natural resins such as copal and shellac, polyethylene, polypropylene, polystyrene, polycarbonate, polyamide, methacryl, polyester, polyacetal, polyvinyl chloride, epoxy and fluororesin, synthetic fiber processed products thereof, or synthesis thereof Various metal parts coated with resin paint, natural rubber and isoprene, butadiene, styrene butadiene rubber, chloro Ren, mention may be made of synthetic rubber such as nitrile rubber and butyl rubber.
[0022]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.
[0023]
Example 1
A withstand voltage test device of the present invention (destructive test apparatus), a photoreceptor drum type as shown in FIG. 1, the substrate surface is a selenium on a substrate 2 made of aluminum photosensitive layer, respectively 10, 20, 30 , 40 and 50 μm layer thicknesses are prepared, and then electrically non-uniform portions of the photosensitive layers of these photoreceptor samples [expressed in terms of electrical resistance, 1 to 50 ( (TΩ · cm ² ) in a non-uniform region. ] Were prepared, and using the withstand voltage test apparatus (destructive inspection apparatus) of the present invention, the coating film peeling of these photoreceptor samples and the withstand voltage P at that time were examined.
Test Method The photoconductor sample is inserted so that one side end face thereof is in contact with the conductive chuck 3, and then set so that the tip of the conductive brush 6 is in contact with the surface of the photosensitive layer of the sample. Next, in a state where a high voltage (applied voltage) is applied between the conductive brush 6 and the conductive chuck 3, the applied voltage is changed over a range of 780 to 1120V while rotating these photoconductor samples. Then, the surface of the photosensitive layer is scanned to visually observe whether peeling failure occurs in the photosensitive layer, and at the same time, the applied voltage value is confirmed as the withstand voltage P.
As described above, the presence or absence of peeling occurred in the photosensitive layer of each sample was visually confirmed, and at the same time, the voltage applied between the conductive chuck 3 and the conductive brush 6 was confirmed, and the result was FIG. 5 shows the applied voltage value that causes the coating film to be destroyed with respect to the electrical resistance value of the electrically nonuniform defective portion.
[0024]
As a result, with respect to the resistance value of the electrically non-uniform portion in each sample shown in FIG. 5, the applied voltage value of the electrically non-uniform portion in the photosensitive layer is destroyed. It can be seen that it was measured as the withstand voltage. In addition, as is clear from FIG. 5, peeling destruction and its resistance against a wide range of electrically non-uniform parts indicated on the basis of the thickness of the photosensitive layer and the electrostatic resistance existing in the layer. It is well understood that the relationship of the applied voltage P is clearly shown, and it is also well understood that these withstand voltage P can be determined from visual observation of peeling and breaking of the photosensitive layer.
[0025]
Example 2
The width L0 (see FIG. 1) of the conductive brush 6 with respect to the width of the photosensitive layer to be brought into contact with the photosensitive layer of the photosensitive drum is changed, and the test is performed over an applied voltage of 200 to 4000 V, and both ends of the photosensitive drum and the drum of the test apparatus are tested. The location where the metal surface in the vicinity of the mounting was exposed and the occurrence of arc discharge from the tip of the conductive brush were examined. As a result, when the width L0 of the brush in contact with the photosensitive layer is equal to or smaller than the width of the photosensitive layer, also in the test apparatus of the present invention, The occurrence of arc discharge from the above location was not observed at all. Therefore, if the brush width L0 is equal to or less than at least the entire width of the photosensitive layer, arc discharge does not occur even when the test method and apparatus of the present invention are used.
[0026]
Example 3
About the effect which provided the holding member 4 of the shape shown to (a), (b) and (c) of FIG. 3 in the conductive brush 6 using the acrylic material as a material of a member similarly to Example 2, Except for contact with a conductive brush having the same width as the entire width of the photosensitive layer, the same conditions as in Example 2 were tested for the occurrence of arc discharge from the same locations as in Example 2. There was no abnormality at all. In addition, the entire photosensitive layer can be tested without any trouble with a single scan, which eliminates the need to repeat the test by driving the brush left and right during the test as in the past. Could be done. Note that the holding member 4 having the shape shown in FIG. 3A was tested under the same conditions, except that the material was replaced with polycarbonate, polyethylene, silicone, alkyd melamine, epoxy, and capacitor paper. Similarly, there was no arc discharge.
[0027]
Comparative Example 1
In Example 3, the holding member 4 has the same shape as that shown in FIG. 3A, except that the material is replaced with a member in which the metal surface of aluminum, iron and copper is exposed. When the test was conducted over the range of the applied voltage of 250 to 4000 V, arc discharge was generated in this applied voltage range in all these members.
[0028]
【The invention's effect】
According to the present invention, destructive inspection method for inspecting, excised defective photosensitive member used in a variety of image formation, a due cause Shirobo switch or the like at the time of actual image forming, present in the photosensitive layer A method that can accurately determine the presence or absence of film breakage that occurs in the photosensitive layer without the need for complicated current checks when applying high voltages as in the past, for defective parts of electrically non-uniform parts. Can be provided.
In addition, the destructive inspection apparatus of the present invention used for this inspection is provided with a simple non-conductive member on the conductive brush in order to prevent arc discharge that occurs when a high voltage is applied. Since the current detection and drive device related to the conductive brush provided are not required and the configuration of the device is simple, a destructive inspection device can be provided which is less expensive than the conventional one.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing an inspection apparatus of the present invention.
FIG. 2 is a conceptual diagram of an inspection apparatus according to the present invention in which a holding member is provided on a conductive brush.
FIG. 3 is a perspective sectional view showing the shape of an example of a holding member.
FIG. 4 is a cross-sectional view showing the length (L2) of the portion in contact with the conductive brush in the attachment portion of the holding member and the length (L1) of the conductive brush.
5 is a graph showing the relationship between the withstand voltage applied to the photoreceptor layer and the non-uniform portion of the photoreceptor layer represented by the electrical resistance value during the destructive test of Example 1. FIG.
[Explanation of symbols]
1. 1. Photosensitive layer of photosensitive drum 2. Rotating type substrate of photosensitive drum 3. Conductive chuck 4. holding member 5. Brush fixing member a 6. Conductive brush Withstand voltage test power supply L0. Conductive brush width L1. Conductive brush hair length L2. Length of holding member

Claims (5)

  The photosensitive drum provided with a photosensitive layer on a drum-type substrate is electrically connected through a conductive chuck supported so as to slide on one end surface thereof, while the photosensitive layer is in contact with the surface thereof. Withstand voltage that is conducted by rotating the photosensitive drum and scanning the surface of the photosensitive layer with the high voltage applied between the conductive chuck and the conductive brush. In the test, a method for inspecting the destruction of the photosensitive drum, wherein the coating film destruction occurring in the photosensitive layer and the applied voltage at that time are obtained. The withstand voltage P applied to the photosensitive layer is expressed by the following formula (1): P ≧ alog r · s ² (1)
In the formula, the coefficient a is in the range of 0.9 × 10 ^{2 to} 1.2 × 10 ² ,
r is the electrostatic resistance of the photosensitive drum ( Ω / cm ² ),
s is the thickness (mm) of the photosensitive layer of the photosensitive drum.
The destructive inspection method for a photosensitive drum according to claim 1, represented by:   A destructive inspection apparatus that applies a high voltage to a photosensitive drum provided with a photosensitive layer on a drum-type substrate to cause coating film destruction on the photosensitive layer, slides on one end surface of the substrate of the photosensitive drum A conductive chuck that supports the conductive layer, a conductive brush that is in contact with the surface of the photosensitive layer, and a power source that applies a high voltage to the photosensitive layer through the conductive chuck and the conductive brush. And a destructive inspection apparatus for a photosensitive drum.   The photoconductor drum destructive inspection apparatus according to claim 3, wherein holding members are provided at both ends of the conductive brush.   The photoconductor drum destructive inspection apparatus according to claim 4, wherein the holding member is non-conductive.

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