JPH10129611A - Method for reading marking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To read optically a marking formed on an eneven surface. SOLUTION: This object for observation, where a marking 7 is formed as an object for reading having a marking face 9 with a face angle βwhich is bigger than a face angle α on a face having a projected face 8 with the face angler α, is provided with a detector in a direction facing the marking 7. A reflected light from the projected face 8 is reflected outside the detector toward the marking 7, a light source for lighting is placed at a position which leads the reflected light from the marking 9 to the detector, and while the projected face 8 as a background is deleted optically in an observing direction by the detector, only the reflected light from the marking face 9 is detected from the detector for reading optically the marking 7 which is the object for reading.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for optically reading a mark formed on an object under observation under appropriate illumination.

[0002]

2. Description of the Related Art Inscriptions such as product identification numbers and manufacturing data are stamped on a flat surface of a product or a product package.
The inscription on such a flat surface can be
By giving the lightness difference between the stamp and its background, C
The optical disc can be optically identified by a detector such as a CD camera. However, when the mark is formed on an uneven surface instead of a flat surface, a difference in light intensity (brightness difference) between reflected light from the mark as a reading target and light reflected from the uneven surface as a background hardly appears. In addition, since a complicated irregular reflection phenomenon occurs due to the uneven surface and the marking, it is difficult to perform conventional general optical reading on the marking on the uneven surface.

As shown in FIG. 1, many drugs 3 such as tablets and capsules are contained in an extrudable package 1. In this package 1, a transparent plastic sheet 2 as a transparent packaging base material contains
Are formed in order to accommodate the recesses. The depressions 4 are closed by a metal foil 5. Here, since the metal foil 5 is thermally welded to the surface of the plastic sheet 2 by the press-fitting surface 6 of the lattice-shaped recess, for example, the metal foil 5 is protruded at the portion surrounded by the press-fitting surface 6. 8 are formed. The mark 7 to be read is formed by pressing a depression from the surface of the metal foil 5 with a stamping die.

When optically reading the inscription 7 as described above, illumination light is usually irradiated onto the entire area of the metal foil 5 by epi-illumination, and this illumination light is formed on the surface of the metal foil 5. The light is reflected by both the smooth convex surface 8 and the mark 7, thereby causing complicated irregular reflection. Therefore, a lightness difference hardly appears between the two, and optical reading becomes almost impossible.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to make it possible to optically read a mark formed on an uneven surface.

[0006]

The inventor of the present invention has observed the details of many packages 1 of this kind which are currently used, and has obtained the following conclusions.

As shown in FIG. 2, the surface angle α of the convex surface 8 having a hemispherical or truncated quadrangular pyramid shape formed on the surface of the metal foil 5 by press bonding differs depending on the product.
It is formed in a range of 15 degrees. In contrast, stamp 7
Is formed deep in the thickness direction of the metal foil 5 and the plastic sheet 2, and the slope angle formed thereby, that is, the surface angle β of the marking surface 9 is set in a range of about 30 degrees to 40 degrees. For this reason, the plane angle β is always larger than the plane angle α, and is formed with an angle difference of 20 degrees or more.

Accordingly, the present invention relates to a package of a drug or the like in which a metal foil is heat-sealed on the surface of a transparent plastic sheet, and a convex surface having a surface angle α is formed on the surface of the metal foil by pressure bonding for heat welding. Formed on the surface of the metal foil,
In the observation object on which the marking is formed as the reading object having the marking angle of the surface angle β larger than the surface angle α, the detector is arranged at a position opposite to the marking and the reflection from the convex surface with respect to the marking. Light is reflected out of the detector, a light source for illumination is placed at a position where the reflected light from the marking surface is guided to the detector, and the convex surface as the background is optically erased in the observation direction from the detector, The detector detects only the reflected light from the marking surface and optically reads the marking to be read.

In another aspect of the invention, a light source is also arranged on the back side of the object to be observed, and when the whole or a part of the mark penetrates the object to be observed, the reflected light and the reflected light from the surface to be marked are detected by the detector. Simultaneously detect the transmitted light from the stamp of the penetrating state,
The inscription to be read is optically read.

[0010]

FIG. 3 shows an embodiment of the present invention, in which an inscription 7 made up of one or more characters, figures and symbols is implemented on a package 1 as an object to be observed by a reading method of the present invention. An example is shown. Package 1 is
After storing the medicine 3, the vertical / horizontal 2 [mm], depth 60
The engraved mark 7 of characters or symbols having a size of about [μm] is guided to the position of the table 10 for reading. With the table 10 facing the mark 7 on the vertical direction, a CCD
When the detector 11 such as a camera has a predetermined close-up distance of, for example, 200
They are arranged facing the direction of the marking 7 with a distance of about [mm]. Note that the image data as the output of the detector 11 is output to the image processing device 12.

The illumination light source 13 has, for example, a built-in ring-shaped optical fiber. The illumination light source 13 is directed in the direction of the engraving 7, and the reflected light from the crimping surface 6 and the convex surface 8 serving as the background is directed in a direction other than the detector 11. The direction is set based on the directivity of the direction in which the reflected light from the marking surface 9 of the marking 7 is guided to the detector 11. The setting position (mounting height) of the light source 13 is obtained from the direction of light having an angle of incidence (reflection angle) between the optical axis of the detector 11 and the normal to the marking surface 9 as the incident angle. Note that the package 1 is prepared in case that all or a part of the inscription 7 is formed so as to penetrate at least the metal foil 5 of the package 1.
A light source 14 of an appropriate surface or point is arranged on the back surface, that is, on the lower side.

When reading the mark 7 such as a character or a symbol, the light source 13 emits light for illumination toward the surface of the metal foil 5 from a direction of 360 degrees. Illumination light hitting the surface of the metal foil 5, that is, the pressure contact surface 6 and the convex surface 8, is reflected in a direction other than the detector 11, as shown in FIG. Also, engraving 7
The illumination light that has hit the marking surface 9 is reflected by that surface and guided to the detector 11 as reflected light. Therefore, the detector 11 does not receive the reflected light from the crimping surface 6 or the convex surface 8, in other words, captures only the reflected light from the inscription 7 while erasing the reflected light from the convex surface 8 in particular, and obtains an image thereof. The signal is sent to the image processing device 12.

Here, as shown in FIG. 5, the image processing device 12 performs, for example, a process of smoothing (moving average smoothing) the signal, and uses a threshold level corresponding to the shape of the mark 7 to perform the process. The binarization is performed, and then the position of the inscription 7 is determined by using the histogram of the binarized data.

It is to be noted that all or a part of the inscription 7 is made of the metal foil 5.
Alternatively, when the light source 14 is formed to penetrate the plastic sheet 2, the lower light source 14
To make the light directly incident on the detector 11, the detector 11 detects the transmitted light from the light source 14 in addition to the reflected light from the light source 13, and detects the transmitted light from the light source 14 in the same manner as described above. Identification will be performed.

[0015]

According to the present invention, it is possible to read a mark on an uneven surface of the surface of a metal foil after heat welding, which has been impossible in the prior art, and it can be effectively used for, for example, quality control of chemicals and process control. . Also, if the light source is arranged on the back side, even if the stamp is formed in a state penetrating the metal foil,
Since detection by transmitted light is possible, the state in which the mark cannot be read is reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a portion of a drug package.

FIG. 2 is an enlarged sectional view of a surface shape and an imprint of a medicine package.

FIG. 3 is a block diagram when the engraving reading method of the present invention is performed.

FIG. 4 is an explanatory diagram of a light reflection state.

FIG. 5 is a flowchart of an engraving reading step.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Package 2 Plastic sheet 3 Drug 4 Depression 5 Metal foil 6 Crimping surface 7 Marking 8 Convex surface 9 Marking surface 10 Table 11 Detector 12 Image processing device 13 Light source 14 Light source

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G06T 1/00 G06F 15/62 400 G06K 9/20 360 15/64 C

Claims (2)

[Claims] 1. A package of a drug or the like in which a metal foil is thermally welded to a surface of a transparent plastic sheet, wherein a convex surface having a surface angle α is formed on the surface of the metal foil by pressure bonding for thermal welding. On the surface of the metal foil, on the observation target in which the marking as a reading target having a marking surface with a surface angle β greater than the surface angle α is formed, a detector is arranged at a position opposite to the marking, The reflected light from the convex surface is reflected out of the detector, and the light source for illumination is placed at the position where the reflected light from the marking surface is guided to the detector, and the convex surface as the background is optically observed in the observation direction from the detector. A method for reading an inscription, wherein the detector detects only reflected light from the inscription surface while optically erasing, and optically reads the inscription to be read. 2. A package of a drug or the like in which a metal foil is thermally welded to a surface of a transparent plastic sheet, wherein a convex surface having a surface angle α is formed on the surface of the metal foil by pressure bonding for thermal welding. On the surface of the metal foil, on the observation target in which the marking as a reading target having a marking surface with a surface angle β greater than the surface angle α is formed, a detector is arranged at a position opposite to the marking, The reflected light from the convex surface is reflected out of the detector, and the light source for illumination is arranged at a position where the reflected light from the marking surface is guided to the detector, and the light source is also arranged on the back side of the observation object, When all or part of the stamp penetrates the object to be observed In the observation direction from the detector, while the convex surface as the background is optically erased, the reflected light from the stamp surface and the penetrating state by the detector The transmitted light from the Detected, the reading method of marking, wherein reading the marking to be read optically.