JP2677469B2 - Pattern reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern reading device.

[0002]

2. Description of the Related Art For the purpose of identifying / determining various cards and coins, a pattern including the outer shape of the card or the like is automatically read as an object to be read. As a device for performing such pattern reading, conventionally, a device as shown in FIGS. 6A and 6B is intended. FIG. 6A is a plan view showing the pattern reading device, and FIG. 6B is a sectional view taken along line BB of FIG. 6A.

In these drawings, reference numeral 10 indicates a conveying path member. The reading object 0 such as a coin is transported on the transport path member 10 in a fixed direction (arrow direction). Restricting means 12C and 12D are formed on both sides of the transport path of the transport path member 10. The regulating means 12C and 12D are shown in FIG.
As illustrated by the regulating means 12C, it is provided in a convex shape with a step on the conveying path surface. When the object to be read 0 is conveyed in the direction of the arrow, it is regulated by the regulating means 12C and 12D in the direction orthogonal to the conveying direction on the surface of the conveying path, so that deviation from the conveying path is prevented.

A part of the transport path member 10 is formed as a transparent portion 10A made of a glass plate or the like. This transparent part 10
On the back side of A, the one-dimensional image sensor 14 has its light-receiving surface in close contact with the back surface of the transparent portion, and the arrangement direction of the light-receiving elements is
The LEDs 16 are arranged so as to be parallel to the regulation width direction by the regulation means 12C and 12D, and the LEDs 16 are arranged as illumination means on both sides of the image pickup device 14 in a direction orthogonal to the drawing of FIG. 6B.

At the time of reading, the illumination means is caused to emit light to convey the object to be read 0 in the direction of the arrow. The reading object 0 traverses the light receiving portion of the image sensor 14 while being obliquely illuminated by the illuminating means, and is read as a signal for each pixel by the image sensor 14.

Conventionally, such a pattern reading device has the following problems. That is, in FIG. 6A, the symbol X indicates the array width of the light receiving elements in the image pickup device 14, and this width X gives the image pickup width in the image pickup device 14. The problem is that this imaging width X is restricted by the regulation means 12C, 12
It occurs due to the fact that it is larger than the regulation width by D.

The regulation width by the regulation means 12C and 12D is
Since it is smaller than the imaging width of the image sensor 14, when reading the reading object 0, the outer shape of the reading object 0 and the edge portions of the regulation means 12C and 12D (the portions that rise in a convex shape from the transport path member surface) are also read. . FIG.6 (c) shows
The read image obtained by reading the read object 0 is illustrated in an explanatory view. The x direction corresponds to the regulation width direction, and the y direction corresponds to the transport direction. The part indicated by the reference numeral 01 is the read image of the read object, and the parts indicated by the reference numerals 12 on both sides thereof are the read images corresponding to the regulating means 12C, 12D.

On the basis of the read image thus obtained, various image processings such as measurement of the outer diameter of the read object 0 in the x and y directions and determination of the center coordinates are carried out. The pattern of the surface of the read object is cut out according to the outer diameter and the center coordinates.

Of these image processes, the most basic "x
The outer diameter measurement in the direction "will be described. For this measurement, for example, a window as indicated by reference numeral WD is set for the read image shown in FIG. 6C, and in this window WD,
A "histogram" is formed by calculating the sum of pixel densities in the y direction with respect to the pixel width in the x direction. This histogram is, for example, as shown in FIG. The “sharp mountain-shaped portions” appearing at both end portions in the x direction are due to the regulation means portion of the read image.

The outer diameter of the object 0 to be read in the x direction is determined by, for example, the threshold value S1 in the histogram thus obtained.
Is calculated as the difference of the x-coordinates of the intersection of the histogram and the histogram. At this time, there is no problem if the read image of the regulating means and the read image of the reading object are separated, but as in the example of FIG. 6C, the read image of the regulating means and the read image of the reading object. When and are connected, a threshold value S2 is required to separate the outer diameter of the reading object in the x direction from the read image of the regulating means. An error of Δ occurs in the diameter. This error affects the outer diameter in the y direction, the center coordinates, and the like, and also has an adverse effect on the image to be cut out, making it impossible to cut out the correct image.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and provides a novel pattern reading apparatus which is not affected by the noise of the regulating means during the image processing of the read image. For the purpose of provision.

[0012]

A pattern reading device of the present invention is a "device for reading a pattern including an outer shape of an object to be read", which includes a conveying path member, a conveying means, a regulating means, and an illuminating means. , And imaging means.

The "transport path member" guides the object to be read. The "conveying means" conveys the object to be read in a fixed direction along the surface of the conveying path member. The "regulating means" is provided along both sides of the transport path of the transport path member in a convex shape with a step with respect to the surface of the transport path, and prevents the read object to be transported from deviating from the transport path. .

The "illuminating means" illuminates the reading object conveyed on the surface of the conveying path member. The “imaging unit” images the reading object illuminated by the illumination unit.

Illumination and imaging of the object to be read is a "reading area"
However, the regulation width by the regulation means is wider than the "regulation width on the upper side of the reading area (the side on which the object to be read is conveyed toward the reading area)" in the reading area.
In addition, it is set to be larger than the "imaging width in the regulation width direction by the imaging means".

In other words, the regulation width of the regulation means is set to be as narrow as possible within the range necessary to convey the object to be read along the conveying path of the object to be read, and the object to be read on the surface of the conveying member. "Shake" in the direction orthogonal to the conveyance of the object is minimized (this is conventionally used)
However, in the present invention, the regulation width of the regulation means in the reading area is enlarged to be larger than the imaging width in the regulation width direction. When setting the regulation range by regulation means to be large,
The regulation means may be removed in the reading area.

Illumination and imaging of the object to be read transported on the transport path member may be performed on the front surface side of the transport path member or on the back surface side of the transport path member. When performing illumination and imaging on the back side, "at least the reading area portion of the transport path member is made transparent, and illumination and imaging of the reading object are
It is performed through the transparent portion of the transport path member "(claim 2).

As the conveying means, "belt conveying means provided on the surface side of the conveying path" may be used (Claim 3), or "the surface of the conveying path member is horizontally oriented toward the conveying direction of the object to be read. Inclining with respect to "may be used as the conveying means (claim 4). In the latter case, the object to be read is conveyed by the action of gravity.

Although a one-dimensional or two-dimensional image pickup device can be used as the image pickup means, when the image pickup means is provided on the back side of the conveyance path member as in the apparatus of claim 2,
It may be provided "closely or very close to the back surface of the conveyance path member in the reading area" (claim 5), or the image pickup means "takes an image of the one-dimensional or two-dimensional image pickup element and the reading object. It has a lens that forms an image on the light receiving surface of the device. "
It can also be configured (claim 6). In this case, the image pickup means may be a CCD camera, for example.

[0020]

As described above, in the present invention, since the regulation width of the regulation means in the reading area is larger than the imaging width of the imaging means in the regulation width direction, there is no image of the regulation means in the read image.

[0021]

FIG. 1 shows an embodiment in which the present invention is applied to the conventional example shown in FIGS. 6 (a) and 6 (b). In order to avoid complication, the same reference numerals as those in FIG. 6 are used for those which are not considered to be confused.

The difference from the conventional apparatus shown in FIG.
This is that the regulation width by the regulation means 12A and 12B is set to be larger than the imaging width X of the image sensor 14 in the reading area where the illumination (imaging) is performed and the imaging is performed. Therefore, when the reading target object 0 is read, the read image is read as shown in FIG.
Only the image IO is used, and it is possible to accurately measure the outer diameter, determine the center coordinates, and cut out the pattern.

In FIG. 1A, the length Y is the length of the transparent portion 10A in the conveying direction of the object to be read. In principle, this length may be the minimum size required for illumination and imaging of the read object. However, in general, the transport path member 10
Since a minute step is likely to occur at the connecting portion between the transparent portion 10A and the opaque portion, and if the conveyed object to be read is caught in this minute step, the conveyance speed is varied and the reading is easily affected. The length Y is preferably set to be equal to or longer than the length of the reading target in the transport direction.

As in the modified embodiment shown in FIG. 2, the regulation width by the regulation means 12a, 12b may be narrowed again on the lower side of the reading area.

FIG. 3 shows an example of the conveying means in the embodiment of FIG. In this embodiment, the conveying member 10 is arranged substantially horizontally, and the reading object 0 is conveyed by the belt conveying means. The belt conveying means includes pulleys 11 and 13,
The belt 15 is wound around these and has a belt surface close to the surface of the conveying path, and a motor 17 for rotating the belt 15 in the direction of the arrow via the pulley 13. The object to be read 0 sent to the transport path is the belt 15
The surface of the sheet is pressed, is conveyed on the surface of the conveying path with the rotation of the belt 15, is read, and is collected by the stocker 20 after the reading.

FIG. 4 shows an example in which the transport path member 10 is inclined with respect to the horizontal direction in the embodiment of FIG. When the object to be read 0 is sent to the transport path, it is transported while sliding on the surface of the transport path by the action of gravity, and when read, it is collected by the stocker 20. In the case of this example, the image pickup means and the illumination means (not shown) may be provided on the front surface side of the transport path member.

The embodiment of FIG. 5 is an embodiment of the apparatus of claim 6 and is conveyed on the conveying path member 10 while the conveying direction is regulated by the regulating means 12A, 12B (the regulating means 12A is not shown). The reading object 0 is obliquely illuminated by the illumination means 16 from the back side of the conveyance path member, and the reflected light from the illumination portion is imaged by the lens L on the light receiving surface of the two-dimensional image sensor 30. The lens L and the image pickup device 30 constitute an image pickup means.

The image pickup device 30 takes in the formed image of the read object and outputs it as a signal for each pixel. This output is converted into a digital signal by the A / D conversion circuit 32 of the image processing device 40 and stored in the memory 34. Based on the stored contents of this memory, image processing such as outer diameter measurement, center coordinate determination, and pattern cutting is performed. The calculation unit 36 performs this. The object to be read 0 may be conveyed by the belt conveying means as shown in FIG. 3 or by gravity by inclining the conveying path member as shown in FIG.

[0029]

As described above, according to the present invention, a novel pattern reading device can be provided. As described above, in this apparatus, since the edge portion of the regulating means is not read, only the read object can be read well, and good image processing can be performed based on the read image.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining one embodiment of the present invention.

FIG. 2 is a diagram for explaining a modification of the embodiment of FIG.

FIG. 3 is a diagram showing an example of conveyance of an object to be read.

FIG. 4 is a diagram for explaining another example of the conveyance of the reading object.

FIG. 5 is a diagram for explaining another embodiment.

FIG. 6 is a diagram for explaining a conventional technique and its problems.

[Explanation of symbols]

 0 object to be read 10 transport path members 12A, 12B regulating means 14 image sensor

Claims (6)

(57) [Claims] 1. A device for reading a pattern including an outer shape of an object to be read, which conveys the object to be read, and conveys the object to be read in a fixed direction along the surface of the member. Conveyance means and, along both sides of the conveyance path of the conveyance path member, are provided in a convex shape with a step difference with respect to the surface of the conveyance path, and prevent the read object to be conveyed from deviating from the conveyance path. Illumination means for illuminating an object to be read that is illuminated by the illumination means, and illumination means for illuminating the object to be read that is transported on the surface of the transport path member. In a reading area in which imaging is performed, the regulation width by the regulation means is set to be wider than the upper side of the reading area and larger than the imaging width in the regulation width direction by the imaging means. Reader. 2. The transport path member according to claim 1, wherein at least a reading area portion is transparent.
A pattern reading device, wherein illumination and imaging of an object to be read are performed on the back surface side of the transport path member via the transport path member. 3. The pattern reading device according to claim 1, wherein the conveying means is a belt conveying means provided on the surface side of the conveying path. 4. The pattern reading device according to claim 1, wherein the conveying means is configured to incline the surface of the conveying path member with respect to the horizontal direction in the conveying direction of the object to be read. 5. The image pickup means according to claim 2, 3 or 4, wherein the image pickup means is a one-dimensional or two-dimensional image pickup element,
A pattern reading device, wherein the pattern reading device is provided in the reading region in close proximity to or very close to the back surface of the transport path member. 6. The image pickup means according to claim 1, 2 or 3 or 4, wherein the image pickup means comprises a one-dimensional or two-dimensional image pickup element and a lens for forming an image of a read object on a light receiving surface of the image pickup element. A pattern reading device having.