JP2935658B2 - Apparatus and method for determining direction of uneven surface with inclination direction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an apparatus and a method for determining the inclination direction of an uneven surface having an inclination direction.

[0002]

2. Description of the Related Art As a member having a concavo-convex surface having an inclination direction, there is, for example, a paper feed roller 1 as shown in FIG. There are many types of paper feed rollers 1 that can not be said unconditionally.
Usually, it is formed of a rubber material and has a cylindrical shape with a diameter of about 20 to 80 mm, a width of about 10 to 50 mm, and a thickness of about 5 to 20 mm.

[0003] The outer peripheral surface of the paper feed roller 1 is a polished surface 1a having minute irregularities to prevent slippage of the paper. The height H of the convex portion 1a1 of the polishing surface 1a is about 0.2 mm, and the convex portion 1a1 is inclined at an angle θ to one of the circumferential directions (the X direction shown in FIG. Shape. The X direction shown in FIG. However, the height H, the inclination angle θ, and the interval of the convex portion 1a1 have a variation within an allowable value. Polished surface 1
The direction of the polished eyes in a is substantially in the direction of the roller axis, but is rather random. This is because it is not necessary to control the regularity of the polished surface 1a so precisely because the paper feed roller 1 has a function of contacting the paper with an appropriate frictional force to feed the paper reliably. And for reasons of processing by current processing machines. In FIG. 2,
Although the unevenness of the polished surface 1a is exaggerated, the inclination direction of the polished surface 1a is often difficult to discern with the naked eye.

The above-described paper feed roller 1 has a polishing surface 1a.
Since the sheet feeding performance varies depending on the inclination direction (the inclination direction of the convex portion 1a1), it is necessary to check the inclination direction when mounting the apparatus on a copying machine or the like. For this reason, the marking 1b is provided on the end face of the paper feed roller 1 to indicate the inclination direction. When supplying the paper supply roller 1 to this marking device, the inclination direction is correctly determined, and the supply must be performed in a fixed direction. No. Further, even after the marking, each paper feed roller 1
It is necessary to check whether or not the marking 1b is correctly applied. At present, these discriminating operations are performed visually by an operator.

[0005]

In the conventional direction discrimination by visual observation, a discrimination error may occur, and the accuracy is lacking. There is also a need for improvement in terms of work efficiency and cost.

The present invention provides an apparatus and method capable of reliably and automatically determining the direction of an uneven surface having an inclined direction, such as the polished surface 1a of the paper feed roller 1, with a relatively simple configuration. What you want to do.

[0007]

In order to achieve the above-mentioned object, the present invention provides an uneven surface having a convex portion having a slope in a predetermined direction. ,
A pair of light projecting means for projecting light toward different areas corresponding to the respective areas, a photographing means for photographing the uneven surface from a predetermined position, and an image obtained by the photographing means, the brightness of the areas on the uneven surface is determined. A direction discriminating apparatus provided with an information processing unit for discriminating the inclination direction of the uneven surface by comparison.

The present invention is also directed to a method for forming a projection on a concave-convex surface in which a convex portion of a surface is inclined in a predetermined direction. By projecting light, different types of shadows are created in each area of the uneven surface, and a reference value indicating the brightness of each area is calculated from an image obtained by photographing the uneven surface from a predetermined position. In addition, the present invention provides a direction discrimination method for comparing the lightness and darkness of the areas based on the reference value and discriminating the inclination direction of the uneven surface.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to discriminate the direction of a polishing surface 1a of a paper feed roller 1 shown in FIG. 2 will be described.

As shown in FIG. 1, a photographing means 2 is provided in a direction perpendicular to a polishing surface 1a of a paper feed roller 1 having an inclined direction.
Are arranged, and the light projecting means 3 and the light projecting means 4 are arranged in two diagonally symmetrical directions with respect to the photographing means 2. The photographing means 2 is a solid-state image sensor such as CC
D camera, still video camera, etc.
Reference numeral 4 denotes a fluorescent lamp, for example. In the state shown in FIG. 1, the light projecting means 3 tilts the convex portion 1 a 1 of the polishing surface 1 a (in FIG.
Direction), and the light projecting means 4 is located in the opposite direction. When the inclination direction of the polishing surface 1a is opposite to that in FIG. 1, the light projecting means 3 is located in the reverse direction and the light projecting means 4 is located in the forward direction.

When the light is projected onto the separate areas 1c and 1d of the polished surface 1a by the above-mentioned light projecting means 3 and 4, the shadow density of the areas 1c and 1d formed by the light is different from each other. Become. That is, when the direction of inclination of the polishing surface 1a is the X direction shown in FIG. 1, a thin shadow is projected on the area 1c projected by the light projecting means 3 located in the forward direction with respect to the direction of inclination of the projection 1a1. The area 1d projected by the light projecting means 4 located in the opposite direction has a dark shadow. Then, in this way, the predetermined area 1
The polished surface 1a having different types of shadows c and 1d is photographed by the photographing means 2 arranged in the vertical direction, and the image is sent to the information processing device 5 such as a personal computer.

The information processing device 5 extracts image data of the areas 1c and 1d from the image of the polished surface 1a sent from the photographing means 2, and extracts the image data of each of the areas 1c and 1d from the extracted image data. A reference value indicating brightness is calculated and calculated. Then, based on this reference value, the areas 1c, 1d
The brightness of the polished surface 1a is determined by comparing the brightness and darkness of each other. That is, in the state shown in FIG. 1, the magnitude of the reference value indicating the brightness of each of the areas 1c and 1d is such that area 1c> area 1d, so that the area 1c is located in the forward direction and the area 1d is located in the opposite direction. Can be determined, whereby the inclination direction X of the polishing surface 1a can be determined.

As a method of image recognition, a pattern matching method, a feature extraction method, and the like are generally used. However, a feature amount of a shape to be recognized, such as the polished surface 1a of the paper feed roller 1, is used. For objects that are very small and have a fairly random regularity, these techniques are considered unfamiliar. Further, the present invention provides a dimensional shape of an object,
It is not intended to precisely recognize the area etc.
Since it is simply intended to accurately determine only the direction of inclination of the uneven surface having the inclination direction, as described above, by comparing the brightness of the sampling areas,
It is most appropriate for simplifying the discrimination device, shortening the processing time, and reducing the cost.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A reference value indicating the brightness of each of the areas 1c and 1d of the polished surface 1a can be calculated by the following method, for example.

At the time when the information processing apparatus 5 captures an image from the photographing means 2, the image information of each pixel is digital image data of 256 gradations (each point has a brightness of 0 to 16 in hexadecimal).
ff, and the larger the value, the brighter,
The smaller the value, the darker. ). Information processing device 5
Extracts the image data of the areas 1c and 1d from the image data, and calculates the standard deviation value of the image data for each of the areas 1c and 1d. This standard deviation value becomes a reference value indicating the brightness of each of the areas 1c and 1d. In calculating the reference value, all image data included in the areas 1c and 1d may be used, or image data appropriately sampled from all the image data may be used.

The formula for calculating the standard deviation is: σ = ｛(｛Xi ² / n) − (― Xi / n) ² ｝ ^1/2
(N is a positive integer). For example, the image data of the area corresponding to the area 1c: (250, 70, 21
0, 120) Image data of the area corresponding to the area 1d: (220, 180, 20)
When 0,190) (case of n = 4), the area 1c: ΣXi / n = (250 + 70 + 210 + 120) / 4 = 162.5 ΣXi 2 / n = (250 2 +70 2 +210 2 +120 2) / 4 = 31475 σ _{^{c = (31475-162.5 2) 1/2 =}} 71.195 area 1d: ΣXi / n = (220 + 180 + 200 + 190) / 4 = 197.5 ΣXi 2 / n = (220 2 +180 2 +200 2 +190 2) / 4 = 39225 σ _d = (39225-197.5 ² ) ^1/2 = 14.790 From the above, the reference value indicating the brightness is σ _c > σ _d , and the inclination direction of the polished surface 1a is X in FIG. The direction can be determined. The size of the areas 1c and 1d to be sampled varies depending on the size of the sheet feeding roller 1 and the like, but it is preferable that n = about 1000 for each area.

As another calculation method, the image data of the sampling area is binarized by a predetermined threshold value to obtain [0].
A method is also conceivable in which the brightness is determined by comparing the number of dots between [0] and [0] or between [1] and [1] between the areas. However, it is difficult to determine the threshold value for an object such as the polished surface 1a of the paper feed roller 1 where the shadow contrast is not so clear in the area 1c and the area 1d. It is preferable to use the above-described method because it is easily affected by manufacturing errors between lots.

[0018]

As described above, according to the present invention,
With a relatively simple structure, the inclination direction of the uneven surface with inclination direction can be automatically and reliably determined in a short time, so not only the reliability and efficiency of the identification work are improved, but also the cost is reduced. It is very advantageous.

[Brief description of the drawings]

FIG. 1 is a diagram conceptually showing an embodiment of a discrimination device.

FIG. 2 is a perspective view showing a sheet feeding roller (FIG. A) and a partially enlarged view of the polishing surface viewed from an end surface side (FIG. 2b).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Paper feed roller 1a Polished surface (irregular surface) 1c area 1d area 2 Photographing means 3 Light emitting means 4 Light emitting means 5 Information processing device

Claims (2)

(57) [Claims] 1. A projection on a surface having a convex portion having an inclination in a predetermined direction projects light from a direction opposite to a direction in which the projection is inclined toward different areas corresponding to the respective directions. A pair of light emitting means, a photographing means for photographing the uneven surface from a predetermined position, and an image obtained by the photographing means, comparing the lightness and darkness of the areas of the uneven surface, the inclination direction of the uneven surface And an information processing means for judging the direction of the uneven surface having an inclined direction. 2. A light projecting on a concave / convex surface having a convex portion of a surface inclined in a predetermined direction from a normal direction and a direction opposite to the inclination direction of the convex portion toward different areas corresponding to the respective directions. Thereby, different types of shadows are created in the respective areas of the uneven surface, and a reference value indicating the brightness of each area is calculated from an image obtained by photographing the uneven surface from a predetermined position. A method of determining the direction of an uneven surface having a tilt direction, comprising comparing the lightness and darkness of the areas based on a reference value and determining the inclination direction of the uneven surface.