JP2008292367A - Device for inspection appearance of photosensitive drum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for inspecting appearance capable of reducing imaging frequencies for a photosensitive drum significantly, inspecting an appearance of a photosensitive drum simply without an engineer with a special knowledge, and having operability without adjustment for optimizing an optical wavelength for each type of photosensitive drums. <P>SOLUTION: The device for inspecting an appearance of a photosensitive drum includes a lighting device 1 having a light source for illuminating inspection light to a photosensitive drum W of an object to be inspected, and an imaging device 2 for imaging the surface of a photosensitive drum which is illuminated by the inspection light. The imaging device is a two-dimensional imaging device that images the photosensitive drum two-dimensionally, which has a display 20 for displaying the image of the photosensitive drum which is imaged above. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photosensitive drum for inspecting the presence or absence of abnormalities such as convex and concave point defects and coating unevenness of a photosensitive layer in a photosensitive drum such as an OPC drum mounted in an electrophotographic copying machine, an electrophotographic printer, a laser printer or the like. The present invention relates to a visual inspection apparatus for use.

  In the OPC drum, an organic photosensitive layer is formed on the entire outer peripheral surface. As shown in Patent Document 1, a projector using a fluorescent lamp such as a three-wavelength tube, and an OPC drum are conventionally used. An appearance inspection apparatus having a line sensor for imaging the surface of W is used to inspect the presence or absence of the abnormality in the organic photosensitive layer, and products having no abnormality by this inspection are shipped as products.

  In other words, as shown in FIG. 7, in this appearance inspection apparatus, a cylindrical OPC drum W is horizontally disposed between a projector 91 and a line sensor 92, and the line sensor 92 is a line sensor 92. The organic photosensitive layer of the previous OPC drum W is imaged in one dimension. Therefore, when inspecting one OPC drum W, it is necessary to image the organic photosensitive layer on the entire outer periphery of the OPC drum W by the line sensor 92 by rotating the OPC drum W or the like.

  Therefore, this appearance inspection apparatus rotates the OPC drum W slightly around the axis, thereby sequentially positioning different outer peripheral surfaces of the OPC drum W in front of the line sensor 92 and imaging with the line sensor 92. Repeatedly, dozens to hundreds of times.

  However, when the number of times of imaging is thus large, the appearance inspection by the appearance inspection apparatus is performed in a practical inspection time, so that one imaging time has to be shortened, and the exposure time of the line sensor 92 is shortened. turn into. For this reason, the appearance inspection has a drawback that the image on the outer peripheral surface of the OPC drum W taken by the line sensor 92 is dark and it may be difficult to determine whether the organic photosensitive layer is abnormal.

  Further, when the surface of the OPC drum W is imaged using the line sensor 92, it is necessary to accurately adjust the focal length from the line sensor 92 to the surface of the OPC drum W that is an inspection object. Therefore, in this inspection, when the distance between the line sensor and the OPC drum becomes longer or shorter due to the movement of the axis line when the OPC drum W rotates, the captured image is out of focus. Therefore, there is a possibility that the abnormality of the organic photosensitive layer cannot be recognized and the presence / absence of the abnormality cannot be determined.

As described above, the inspection by the appearance inspection apparatus has a drawback that the number of times of imaging is large and it is difficult to determine the presence or absence of an abnormality, so that an engineer having specialized knowledge is required and handling is poor.
In addition, it is necessary to optimize the emission wavelength of the light source of the projector and to adjust the focal length between the OPC drum and the line sensor for each type of OPC drum or for each inspection item such as point defect or coating unevenness. There is a drawback that it is bad.
JP 2003-121377 A

  In view of the above circumstances, the present invention can remarkably reduce the number of times of imaging with respect to a photosensitive drum such as one OPC drum, and can easily perform photosensitive of an OPC drum or the like without requiring an engineer having specialized knowledge. Easy-to-handle visual inspection device that can perform visual inspection of drums, and also good visual inspection device that does not require adjustment such as optimizing the wavelength of light for each type of photosensitive drum such as OPC drum. It is an issue to provide.

  According to the first aspect of the present invention, there is provided an illuminating device having a light source that irradiates inspection light onto a photosensitive drum that is an object to be inspected, and an imaging device that images the surface of the photosensitive drum irradiated with the inspection light by the illuminating device. In the appearance inspection apparatus for a photosensitive drum for inspecting the photosensitive drum for defects such as point defects and coating unevenness in the photosensitive drum, the imaging device is a two-dimensional image that images the photosensitive drum two-dimensionally. An imaging apparatus having a display unit that displays the imaged image of the photosensitive drum.

  According to a second aspect of the present invention, in the visual inspection apparatus for a photosensitive drum according to the first aspect, the illumination device is disposed outside the outer peripheral surface of the cylindrical photosensitive drum and is emitted from the light source. The two-dimensional imaging device is configured such that the obtained light becomes the inspection light of red visible light having a wavelength of 600 to 750 nm and is applied to the photosensitive layer formed on the outer peripheral surface of the photosensitive drum. Is a plurality of photosensitive drums disposed outside the outer peripheral surface of the photosensitive drum and on the illuminating device side along the axial direction of the photosensitive drum, and exposed to the inspection light. It is characterized by imaging a layer.

A third aspect of the invention is an appearance inspection apparatus for a photosensitive drum according to the second aspect, wherein the photosensitive layer is an area sensor for imaging the photosensitive layer in black and white.
Here, imaging in black and white means imaging using a change in brightness from white to black.

  According to a fourth aspect of the present invention, in the visual inspection apparatus for a photosensitive drum according to any one of the first to third aspects, the illumination device uses a light emitting diode as the light source, An optical filter for adjusting the wavelength of light of the light source is installed between the photosensitive drum and the photosensitive drum.

  According to the appearance inspection apparatus according to any one of claims 1 to 4, since the two-dimensional imaging device is used as the imaging device, the surface of the photosensitive drum irradiated with the inspection light is two-dimensionally imaged, Since it can be displayed, the number of times of imaging can be remarkably reduced and the exposure time of the imaging apparatus can be sufficiently taken. Thus, by taking a sufficient exposure time, it is possible to display the image of the surface of the photosensitive drum having an appropriate brightness on the display unit and easily determine whether the photosensitive layer is abnormal. In addition, unlike a line sensor that captures images in a one-dimensional manner, there is no risk that the captured image will be out of focus due to slight fluctuations in focal length, and it can be simplified by visually observing the captured image displayed on the display unit. The presence or absence of abnormality of the photosensitive layer can be determined.

  At that time, even if the photosensitive drum is irradiated with near-infrared light having a wavelength of more than 750 nm as inspection light, the wavelength is too long and the photosensitive drum is an OPC drum having an organic photosensitive layer formed on the outer peripheral surface. It is difficult to detect coating unevenness due to streaks appearing in the coating direction of the organic photosensitive layer. On the other hand, even if the photosensitive drum is irradiated with blue or green inspection light having a wavelength of less than 600 nm, the inspection light is scattered because the wavelength is too short. Even if the organic photosensitive layer formed on the surface has abnormalities such as point defects, coating unevenness, scratches, dirt or foreign matter, it is hidden by the scattered inspection light, so the image displayed on the display unit is visually observed. However, it is difficult to determine whether there is an abnormality in the organic photosensitive layer.

On the other hand, according to the appearance inspection apparatus according to claim 2, the organic photosensitive layer is irradiated with red visible light having a wavelength of 600 to 750 nm as inspection light on the organic photosensitive layer of the OPC drum that is the inspection object. The presence or absence of any abnormalities such as convex and concave point defects, coating unevenness, scratches, dirt and foreign matters in the layer can be inspected.
In particular, since an organic photosensitive layer of green or yellowish green is originally formed on the surface of the OPC drum, the OPC drum is irradiated with red visible light having a complementary color relationship as the inspection light, thereby causing OPC. When the surface of the drum is directly observed, it is visually recognized as black. In addition, the OPC drum gradually increases in brightness from the upper and lower portions of the surface of the OPC drum in the height direction to the center portion in the height direction before the imaging device on the illumination device side. Therefore, when there is a convex point defect or a thickened portion of the organic photosensitive layer due to coating unevenness in the central portion, a black portion with higher brightness is visually recognized, and a concave point defect or unevenness of the organic photosensitive layer due to coating unevenness is observed. When there is a thinned part or a scratch, a black part with low brightness is visually recognized.
Then, since the organic photosensitive layer is displayed on the display unit in the same manner as when directly viewing it, as a result, the presence or absence of abnormality can be easily determined by viewing the display unit. It is possible to inspect the appearance of the drum.
In addition, as in the invention described in claim 3, by using an area sensor that captures black and white as a two-dimensional imaging device, an appearance inspection can be efficiently performed.

  According to the appearance inspection apparatus of the fourth aspect, since the directional light emitting diode is used as the light source, the inspection light is irradiated only in the direction of the OPC drum W. As compared with the case of irradiation, the photosensitive layer is clearly displayed on the display unit, and it is possible to easily determine whether the photosensitive layer is abnormal. In addition, since an optical filter is installed between the light-emitting diode and the photosensitive drum, even when a photosensitive drum having a photosensitive layer of a different color is installed by changing the type of photosensitive drum, the optical filter operates to inspect. Appearance inspection can be easily performed by adjusting the wavelength of light.

Hereinafter, an appearance inspection apparatus for a photosensitive drum according to the present invention will be described with reference to FIG.
The appearance inspection apparatus of the present embodiment is a convex or concave point defect or coating unevenness in a green or yellow-green organic photosensitive layer formed over the entire outer peripheral surface of a cylindrical OPC drum W that is an object to be inspected. It is a device that inspects for abnormalities such as scratches, dirt, and foreign matter.

This visual inspection apparatus includes a rotary drive device (not shown) that supports an OPC drum W having a length of 200 to 450 mm so as to be rotatable around an axis L in a state where the axial direction is horizontal, An illuminating device 1 that is arranged outside the outer peripheral surface and irradiates the organic photosensitive layer formed on the outer peripheral surface of the OPC drum W with inspection light, and the OPC drum W irradiated with the inspection light by the illuminating device 1. An image pickup apparatus 2 that picks up an image of the outer peripheral surface is schematically configured.
As shown in FIG. 2, the rotary drive device rotates the OPC drum W around the axis L every 60 degrees around the axis L of the OPC drum W, so that the outer peripheral surface of the OPC drum W extends in the circumferential direction. It is designed to move.

The illuminating device 1 arranged outside the outer peripheral surface of the OPC drum W is outward of both end portions in the axial direction of the OPC drum W and horizontally and in the same direction from the extended line of the axial line L of the OPC drum W. One unit is installed at each position.
Each lighting device 1 includes a light source 10 and a variable bandpass filter (optical filter) 11 that adjusts the wavelength of light emitted from the light source 10, and the variable bandpass filter 11 includes the light source 10. And the OPC drum W.

The light source 10 and the variable band pass filter 11 are installed obliquely with respect to the OPC drum W toward the central portion in the axial direction of the OPC drum W, and the wavelength of the light emitted from the light source 10 is changed to the variable band. The inspection light adjusted by the pass filter 11 is applied to the OPC drum W over the entire length in the axial direction.
As this light source 10, a red light emitting diode (LED) of 600 nm to 750 nm is used, and the variable band pass filter 11 includes a plurality of wavelength adjusting units 11a, 11b, and 11c having different wavelength regions, and all of them. The wavelength adjusting units 11a, 11b, and 11c have a diffusion function for diffusing light.

  Thereby, since the red light emitting diode has a wavelength width of 600 nm to 700 nm, the variable band pass filter 11 has a wavelength suitable for the type of the OPC drum W, that is, an organic photosensitive formed on the outer peripheral surface of the OPC drum. Fine adjustment is made to light with a narrow wavelength width having a center wavelength suitable for the color of the layer. In addition, the variable bandpass filter 11 diffuses light by a diffusion function, and uniformly irradiates the organic photosensitive layer of the OPC drum W as inspection light.

  Therefore, the illuminating device 1 composed of the light source 10 and the variable bandpass filter 11 emits red visible light having a specific wavelength complementary to the organic photosensitive layer in the central portion of the OPC drum W in the axial direction. By diffusing and irradiating obliquely toward the surface, the entire length of the OPC drum W is irradiated uniformly.

  A plurality of imaging devices 2 (the main unit) are arranged outside the outer peripheral surface of the OPC drum W and on the illuminating device 1 side so that the entire length of the OPC drum W can be accommodated in the field of view along the axial direction of the OPC drum W. In the embodiment, the three imaging devices 2 are installed, and each imaging device 2 is installed such that adjacent imaging devices 2 partially overlap the end portions of the imaging region in consideration of the angle of view. .

In addition, as each imaging device 2, a CCD area sensor having 300,000 to 1,000,000 pixels that captures the OPC drum W in black and white is used. This imaging device 2 was captured by a plurality of imaging devices 2. It has an image processing function for deleting and overlapping an overlapping portion of the image, and a display portion 20 for displaying an image of the entire length of the OPC drum W from which the overlapping portion is deleted.
And this display part 20 is provided with respect to all the imaging devices 2, and this display part 20 deleted and overlapped the overlapping part based on the some picked-up image by the said image processing function. An image of the entire length of the OPC drum W is displayed.

  Next, an effect | action at the time of test | inspecting the organic photosensitive layer of the outer peripheral surface of the OPC drum W using the above-mentioned external appearance inspection apparatus is demonstrated.

  The OPC drum W is installed in the rotation drive device, the illumination device 1 is operated, and the wavelength adjustment units 11a, 11b, and 11c of the variable bandpass filter 11 according to the organic photosensitive layer on the outer peripheral surface of the OPC drum W or the inspection item. Is switched to adjust the inspection light to irradiate the outer peripheral surface of the OPC drum W, and to operate the imaging device 2 and the rotation driving device.

  Then, the light from the light source 10 is diffused as visible light having a specific wavelength of red by the variable bandpass filter 11, and this red diffused light is uniformly irradiated on the outer peripheral surface of the OPC drum W over the entire length. Thus, the three outer peripheral surfaces of the half peripheral surface of the OPC drum W on the imaging device 2 side are imaged over the entire length by the three imaging devices 2, and the outer peripheral surface of the OPC drum W imaged by these imaging devices 2 is displayed on the display unit. 20 is displayed. At that time, the organic photosensitive layer on the outer peripheral surface of the OPC drum W is displayed in black on the display unit 20, and from the upper and lower portions in the height direction of the outer peripheral surface of the OPC drum W to the central portion in the height direction in front of the imaging device 2. The brightness of the organic photosensitive layer is gradually increased. For this reason, when there is a thickened portion of the organic photosensitive layer due to a convex point defect or coating unevenness in the same central portion, a black portion with higher brightness is displayed, and the organic photosensitive layer due to a concave point defect or coating unevenness is displayed. Since a black part with low brightness is displayed when there is a thinned part, an inspector or the like visually checks the display part 20 to determine whether the organic photosensitive layer is abnormal.

Next, after the OPC drum W is rotated 60 degrees around the axis L by the rotation drive device, the outer peripheral surface of the OPC drum W is similarly imaged by the imaging device 2, and the outer periphery of the OPC drum W after being rotated 60 degrees is repeated. The surface is imaged six times, and the outer peripheral surface of the entire circumference of the OPC drum W is imaged.
At that time, the presence or absence of abnormality of the organic photosensitive layer is determined by visually observing the image of the OPC drum W displayed on the display unit 20 every time the imaging device 2 captures an image.

According to the appearance inspection apparatus of the above-described embodiment, since the CCD area sensor that images the OPC drum W two-dimensionally is used as the imaging device 2, unlike the case where the line sensor is used, the number of imaging is significantly reduced. A sufficient exposure time of the imaging apparatus can be taken. For this reason, it is possible to easily determine whether or not there is an abnormality in the organic photosensitive layer by displaying the captured image of the OPC drum W with appropriate brightness on the display unit 20.
In addition, unlike a line sensor that captures images in one dimension, there is no risk that the captured image will be out of focus due to slight fluctuations in the focal length, and by viewing the image of the OPC drum W displayed on the display unit 20. The presence or absence of abnormality in the organic photosensitive layer can be easily determined.

  At this time, since a directional red light emitting diode is used as the light source 10 of the illumination device 1, the inspection light is irradiated only in the direction of the OPC drum W, so that convex and concave shapes in the organic photosensitive layer are formed. All abnormalities such as point defects, coating unevenness, scratches, dirt, and foreign matters can be clearly displayed on the display unit 20 of the imaging apparatus 2. In particular, when there is a thickened portion of the organic photosensitive layer due to a convex point defect or coating unevenness in the center in the height direction of the OPC drum in front of the imaging device 2, a black portion with high brightness is displayed on the display unit 20. When there is a thinned portion or a flaw in the organic photosensitive layer due to concave point defects or coating unevenness, a black portion with low brightness is displayed on the display unit 20. For this reason, an inspector or the like can easily determine the presence or absence of an abnormality in the organic photosensitive layer by visually observing the display unit 20, and can easily and efficiently perform an appearance inspection.

  In addition, since the variable band pass filter 11 is installed between the light source 10 and the OPC drum W, when the OPC drum W having the organic photosensitive layer having a different color is installed by changing the type of the OPC drum W, By switching the wavelength adjusting units 11a, 11b, and 11c of the variable bandpass filter 11, the wavelength of the inspection light can be adjusted and the appearance inspection can be easily performed.

In addition, this invention is not limited to the above-mentioned embodiment at all, For example, the variable band pass filter 11 does not need to have a spreading | diffusion function. In this case, it is preferable that a separate diffusion plate is provided between the variable band filter 11 and the OPC drum W.
Further, the imaging device 2 captures a photosensitive drum such as the OPC drum W in full color and converts it to black and white by an image processing function, thereby displaying the photosensitive layer on the display unit 20 by a change in brightness from white to black. May be.

First, an appearance inspection apparatus similar to that of the above-described embodiment is prepared, a red LED having a wavelength wavelength of 600 to 750 nm is used as the light source 10, and the wavelength adjusting units 11a and 11b of the variable bandpass filter 11 as necessary. 11c, and adjustment was performed so that red visible light having a center wavelength of 660 nm was irradiated from the illumination device 1 as inspection light. In addition, a black and white CCD area sensor of about 300,000 pixels of 640 × 480 was installed as the imaging device 2.
[Example 1]

Next, the OPC drum W on which the coating unevenness is formed on the organic photosensitive layer on the outer peripheral surface is installed in the rotary drive device as the inspection object 1, and the illumination device 1 irradiates the outer peripheral surface of the inspection object 1 with the illumination device 1. The image displayed on the display unit 20 by imaging the outer peripheral surface of the inspection object 1 irradiated with the inspection light with the imaging device 2 is shown in FIG.
Next, the inspection object 1 is removed from the rotary drive device, and the OPC drum W having a convex point defect in the organic photosensitive layer on the outer peripheral surface is installed in the rotary drive device as the inspection object 2 and imaged in the same manner. The image displayed on the display unit 20 by the above is shown in FIG.

As can be seen from FIGS. 3 and 4, even when a black and white area sensor with a small number of pixels is used as the imaging device 2, the application existing in the circle A in FIG. Unevenness, point defects existing in the circle B in FIG. 4 and the like can be easily detected.
[Example 2]

  Next, the inspection object 2 in which the point defect is detected at the position in front of the imaging device 2 shown in FIG. 4 is rotated 30 degrees counterclockwise about the axis L by the rotation driving device, and the illumination device 1 An image displayed on the display unit 20 by irradiating the outer peripheral surface of the inspection object 2 with the inspection light and imaging the organic photosensitive layer on the outer peripheral surface of the inspection object 2 irradiated with the inspection light with the imaging device 2. Is shown in FIG. Next, after the inspection object 2 is rotated 60 degrees clockwise around the axis L by a rotation drive device, an image displayed on the display unit 20 by imaging similarly is shown in FIG.

  As can be seen from FIGS. 5 and 6, the point defect existing in the circle B in the figure is 30 degrees clockwise from the front of the imaging apparatus 2 from the position rotated 30 degrees counterclockwise from the front of the imaging apparatus 2. It can be detected within the range of the rotated position. For this reason, it has been found that the presence or absence of abnormality of the organic photosensitive layer such as point defects can be reliably determined by rotating the OPC drum W around the axis L by a rotation drive device at an angle of 60 degrees or less.

1 is a schematic plan view showing an appearance inspection apparatus for a photosensitive drum according to the present invention. FIG. 2 is a main part explanatory diagram for explaining a rotation angle of an OPC drum W, and is a side view of the OPC drum W and the imaging device 2 in FIG. 1. It is the same photograph as the image displayed on the display unit 20 by imaging the inspection object 1 with uneven coating on the organic photosensitive layer by the imaging device 2. It is the same photograph as the image displayed on the display unit 20 by imaging the inspection object 2 having a point defect in the organic photosensitive layer by the imaging device 2. This is the same photograph as the image displayed on the display unit 20 by imaging the imaging object 2 after rotating the inspection object 30 degrees counterclockwise. 5 is the same photograph as the image displayed on the display unit 20 by rotating the inspection object 2 of FIG. It is a top view which shows the conventional external appearance inspection apparatus for photosensitive drums.

Explanation of symbols

W OPC drum (photosensitive drum)
DESCRIPTION OF SYMBOLS 1 Illuminating device 2 Imaging device 10 Light source 11 Variable band pass filter (optical filter)
20 display

Claims (4)

An illuminating device having a light source that irradiates inspection light onto a photosensitive drum that is an object to be inspected, and an imaging device that images the surface of the photosensitive drum irradiated with the inspection light by the illuminating device. In appearance inspection equipment for photosensitive drums that inspects for the presence or absence of abnormalities such as point defects or coating unevenness in the photosensitive layer,
The image pickup device is a two-dimensional image pickup device for picking up the photosensitive drum two-dimensionally, and has a display unit for displaying the image of the picked-up photosensitive drum. The illumination device is disposed outside the outer peripheral surface of the cylindrical photosensitive drum, and light emitted from the light source becomes the inspection light of red visible light having a wavelength of 600 to 750 nm. The photosensitive layer formed on the outer peripheral surface is irradiated, and the two-dimensional imaging device is outside the outer peripheral surface of the photosensitive drum and on the illuminating device side, the photosensitive drum 2. The visual inspection device for a photosensitive drum according to claim 1, wherein a plurality of the photosensitive drums are installed along an axial direction of the photosensitive drum and the photosensitive layer on the outer peripheral surface of the photosensitive drum irradiated with the inspection light is imaged.   The visual inspection apparatus for a photosensitive drum according to claim 2, wherein the two-dimensional imaging device is an area sensor that images the photosensitive layer in black and white.   2. The lighting device according to claim 1, wherein a light emitting diode is used as the light source, and an optical filter for adjusting a wavelength of light of the light source is installed between the light emitting diode and the photosensitive drum. 4. An appearance inspection apparatus for a photosensitive drum according to any one of items 1 to 3.