JPH05101233A - Label medium and optical identification system - Google Patents

Abstract

PURPOSE:To provide a label medium and an optical identification system to arrange a light emitting element and a light receiving element approximately on a single straight and to miniaturize a device together with reduction of the cost. CONSTITUTION:A label medium 1 includes a reflecting part 11 having such a surface shape, e.g. 8 concave part having two sloping surfaces R1 and R2 crossing rectangularly to each other where the directions of the reflected light and the incident light are set in parallel to each other. Furthermore a light absorbing part, a light dispersing part, etc., having the optical response characteristics different from the part 11 are added with the prescribed relation so that each combination of these parts corresponds to each information. In such a constitution, a light emitting element 2A and a light receiving element 2B can be placed close to each other. Furthermore the scales of a device end a system can be reduced together with reduction of the cost. Then it is possible to identify the information on the commodities, the rotary mode, the linear shift mode, etc., with use of the medium 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a label medium, and more particularly to a label medium and an optical identification system suitable for identifying information embodied on the label medium by an optical method.

[0002]

2. Description of the Related Art At present, a so-called bar code, which is a label medium in which strip-shaped black and white patterns are alternately arranged on a surface of a tape-shaped sheet according to a predetermined rule, is very widespread. The bar code label medium has an advantage that not only can it be produced by a simple printing technique, but also a very large amount of code information can be displayed by variously setting the number and arrangement mode of the black and white patterns. In addition, a sheet of paper or the like on which such a bar code is printed is attached to the surface of a product or the like, the bar code portion is irradiated with light (laser light) and scanned, and the reflected light from the surface of the sheet is detected by a photoelectric detector. An optical identification system that detects the barcode information and recognizes the barcode information in correspondence with the intensity pattern of the reflected light is also widely used.

[0003]

As described above, a bar code using a band-shaped alternating pattern of black and white is mainstream as a conventional label medium. However, such a barcode label medium has the following problems. That is, in order to efficiently receive the reflected light from the label medium, it is optimal to irradiate the laser light in the direction perpendicular to the label medium and receive the light with a photodetector arranged on the same vertical line. Normally, it is extremely difficult to vertically irradiate a laser beam onto a bar code label medium attached to a product, because an operator such as a cashier at a checkout office handles the product by hand. Therefore, the angle of incidence of laser light on the surface of the bar code typically varies over a wide range rather than at right angles. As a result, the reflection angle of the reflected laser light also changes over a wide range, so the light-receiving area (light-receiving angle) of the photodetector has to be large in order to receive this reflected light, which complicates the configuration of the photodetector and increases the optics. Of the entire device of the dynamic identification system,
This causes problems such as increased costs. On the other hand, in order to receive the reflected laser light with respect to the incident laser light, a method in which a photodetector having a relatively narrow light receiving area (light receiving angle) is installed in the symmetrical direction of the normal angle of the incident surface is also conceivable. , For the same reason, not only the light receiving area must be widened, but also the light emitting diode that emits the laser light and the photodetector must be installed a predetermined distance apart, resulting in an increase in the overall size of the installation and cost. The problem of growth remains. These problems similarly occur with optical identification systems that identify bar codes on the label media.

Therefore, an object of the present invention is to provide a label medium and an optical identification system in which the light emitting element and the light receiving element can be arranged on substantially the same straight line, and the size and cost of the apparatus can be reduced. is there.

[0005]

In order to solve the above-mentioned problems, the label medium according to the present invention comprises a first portion comprising a reflecting portion having a shape for making the outgoing direction of reflected light with respect to incident light parallel to the incident light direction. And a second portion having a light response characteristic different from that of the reflecting portion are arranged in a predetermined relationship. Further, the optical identification system according to the present invention has a first portion including a reflecting portion having a shape that makes the outgoing direction of the reflected light with respect to the incident light parallel to the incident light direction, and a light response characteristic different from that of the reflecting portion. A label medium, which is arranged in a predetermined relationship with a second portion, is attached to an object, the first portion and the second portion of the label medium are irradiated with light from a light emitting element, and the reflected light is emitted as the light. Light is received by a light receiving element that is arranged in parallel with and close to the element, and the information determined by the predetermined relationship of the label medium is identified based on the change in the light receiving level by the light receiving element.

[0006]

In the present invention, for example, 2 which intersect at right angles to each other
A reflecting portion having a shape such that the outgoing direction of reflected light with respect to incident light is parallel to the incident light direction, such as a concave portion having two inclined surfaces, and a light absorbing portion or a scattering portion having different light response characteristics from the reflecting portion. By arranging each of them in a predetermined relationship so that each combination corresponds to individual information, it is possible to dispose the light emitting element and the light receiving element in close proximity.
Further, such a label medium is attached to an object, the label medium is irradiated with light from a light emitting element, and the reflected light is received by a light receiving element arranged in parallel and close to the light emitting element, and based on a change in light receiving level by the light receiving element. Individual information of the label medium determined by the predetermined relationship is identified.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of a label medium according to the present invention, and shows an example in which the directions of incident laser light and reflected laser light on the surface of the label medium 1 are made to coincide with each other.
In this embodiment, the label medium 1 is configured such that the reflecting portions 11 and the flat portions 12 are alternately provided on the surface of the label medium 1, and the reflecting portions 11 have reflecting slopes (R1 and R) at an angle of 45 degrees from the adjacent flat portions.
2) Groove shape (so-called corner cube part)
And is formed so that the crossing angle of the slope is a right angle. As shown in FIG. 1, the parallel incident laser light emitted from the light emitting diode 2A is reflected by the reflecting surface R1 and then re-reflected by the reflecting surface R2. Eventually, the reflected laser light is parallel to the incident laser light and is in the opposite direction. Becomes Therefore, it is possible to accurately detect the reflected laser light by disposing the light receiving diode 2B, which is a photodetector, in parallel with the laser diode 2A.

The present embodiment is a label medium having the above-mentioned structure, and the flat portion 12 is, for example, a light absorbing portion or a scattered light portion, so that the flat portion 12 and the reflecting portion 11 are flattened based on the change in the light receiving level of the light receiving diode 2B. The part 12 can be identified.
Of course, the flat portion 12 does not necessarily have to be flat,
The reflecting portion for absorbing and scattering may have a shape having a photoresponse characteristic. If the arrangement of the reflecting portion 11 and the flat portion 12 on the label medium 1 thus configured is performed based on the same principle as the conventional barcode, the code information defined by the arrangement can be identified, and the conventional barcode can be identified. It can have a function.

FIG. 2 shows another embodiment of the present invention,
This is an example in which a group of corner cubes is configured by a plurality of rows of corner cubes, each row of which includes corner cubes 11a, 11b, ..., 11n.

FIG. 3 shows an example of a label medium in which a groove type reflection portion is formed. At this time, in the direction parallel to the groove, the relationship between the incident laser light and the emitted laser light is the same as in a normal mirror.

In FIG. 4, a collimator lens 20 is used to output a light beam emitted from the light emitting laser diode 2A onto the label medium surface as a light beam having a thickness equal to the widths of the reflection portion (corner cube portion), the diffusion portion and the reflection portion. An example of making the light incident is shown. This is because the wider the thickness (width) of the incident light beam, the smaller the spread of the emitted light beam due to interference. Therefore, as described above, maximum efficiency is achieved with the same width. As mentioned above,
When the corner cube is used on the surface of the label medium, the light source and the light receiver can be arranged in the same direction, but there is a limit to the manufacturing accuracy of the corner cube, etc., and the influence of the mounting accuracy of the label medium on the object to be attached. As a result, the emitted light flux fluctuates.
Therefore, in the embodiment shown in FIG. 5, the light receiving surface of the photodiode or the like is widened.

[0012] The above is a description of a corner cube composed of two 45-degree slopes, but the present invention essentially uses a reflecting portion having a shape such that incident light and reflected light are always parallel. Therefore, it is possible to form hemispherical microcells on the label medium surface instead of the corner cube portion. In this case, since the light ray that has passed through the vicinity of the center of the hemisphere is reflected in the direction parallel to the incident light ray, the efficiency is reduced as compared with the case where the corner cube portion is used, but it is used for the same purpose. can do. This has the advantage that the label medium can be manufactured easily and at low cost. In particular, when the hemisphere is formed in the shape of a light incident direction, the label medium can be easily produced by applying the surface tension of ink or toner by applying a printing technique or the like. It is extremely valuable.

Next, an example of using the label medium according to the present invention will be described with reference to FIG. The embodiment of FIG. 6 shows an application example to an encoder that measures a rotation mode such as a rotation speed of a shaft of a motor. In the present embodiment, the shaft 1 of the object to be measured
The tape-shaped label medium 11 as shown in FIG. 1 is attached in close contact with the adhesive 00 by using an adhesive agent. It can be attached to. The surface of the tape-shaped label medium 11 attached to the shaft 100 is irradiated with laser light from a light emitting laser diode 2A provided in a fixed portion independent of the rotating system, and reflected light from the surface is received by a light receiving diode 2B. The light is received, converted into an electric signal, and sent to the amplifier 3. The reflected light is repeatedly blinked due to the difference in the reflection characteristic of the surface of the encoder 11. That is, the level of reflected light from the reflection part 11 is high, and the level of reflected light from the flat part 12 such as the light absorbing part and the scattering part is low. The amplifier 3 amplifies the electric signal from the light receiving diode 2B. The A / D converter 4 samples the output signal from the amplifier 3 using a sampling pulse having a frequency that is an integer multiple of the pulse generated by the sampling pulse generator 7 based on the pulse for rotating the measured body, It is quantized and converted into a digital signal. The storage unit 5 stores the digital signal from the A / D converter 4 in association with the address signal generated by the address control unit 8 based on the sampling pulse generated from the sampling pulse generation unit 7.

By the way, there is a limit to the mounting and mounting accuracy of the above label medium. Therefore, in this embodiment,
After mounting the label medium on the shaft, the mounting state is once measured and stored. At the time of measurement, a correction process is performed by referring to the measured value to obtain position information of the measured object. This correction is performed as follows. First, the attachment state of the attached label medium is measured. For example, when the drive motor is a stepping motor, it is rotated at a low speed by a known fine step drive method or the like. After the backlash of the system is removed, stabilize it and then perform the measurement for correction. The calculation unit (CPU) 6 calculates the reflected light intensity stored in the storage unit 5 as a function of time, and the label medium 11 when the measured object rotates at a constant rotation speed.
The position where the scale is present is stored in the correction value storage unit 10 as a correction value.

Generally, when the object to be measured rotates in a practical state, the rotation angle per pulse of the driving stepping motor is large and the rotation speed is also large. Therefore, it is difficult to accurately rotate the object to be measured with respect to time, as in the case of storing the correction value, and a rotation error occurs. This rotation error is usually much larger than the angular error of the motor itself used for driving. Therefore, in the present embodiment, the above-described correction is performed so that the rotation mode of the measured object in a practical state can be accurately measured.
Further, at the time of measurement, a motor or the like for driving the measured object is rotated at a desired speed and a desired timing. However, the shaft to be measured does not always reach the desired rotation angle due to the electrical / mechanical inertia. By using the label medium of this embodiment, it is possible to accurately measure the position of the object to be measured.

In the processing at the time of measurement, the reflected light information from the label medium 11 is stored in the storage unit 5 via the light receiving diode 2B, the amplifier 3 and the A / D converter 4 as in the case of the above correction. The measured values stored in the storage unit 5 are calculated by the calculation unit 6
Is compared with the correction value stored in the correction value storage unit 10, and the correction processing is performed to calculate the accurate rotation angle of the measured object. The measured value thus obtained is displayed on the display unit 9. Further, as described above, the label medium to which the code information corresponding to each product is attached is attached to the product, and it can be applied to an optical identification system such as a normal barcode identification. The label medium according to the present invention can be used for various purposes in addition to the above-described use as code information and rotation mode measurement. For example, the label medium is fixed to the moving body and the position of the moving body is identified.

[0017]

As described above, since the label medium and the optical identification system according to the present invention have the reflecting portion formed on the surface in parallel with the incident light direction of the reflected light direction, the light emission The element and the light receiving element can be arranged close to each other, the cost of downsizing the device or the system can be reduced, and by using such a label medium, identification of product information, rotation, mode, linear movement mode, etc. can be performed. Its industrial utility value is extremely high.

[Brief description of drawings]

FIG. 1 is a diagram showing the directions of incident light and reflected light of laser light for a label medium according to the present invention.

FIG. 2 shows another embodiment of the label medium according to the present invention,
It is a figure which shows the example which has arrange | positioned the reflection part which consists of a corner cube in multiple rows.

FIG. 3 is a view showing still another embodiment of the label medium according to the present invention and showing an example in which a groove type reflection portion is formed.

FIG. 4 shows another embodiment of the label medium according to the present invention,
It is a figure which shows the example which makes an incident light beam equal to the width of a corner cube part, a diffusion part, and a reflection part using a collimator lens.

FIG. 5 is a view showing still another embodiment of the label medium according to the present invention, in which the light receiving surface of the light receiving diode is widened.

FIG. 6 is a configuration diagram showing an application example of a label medium according to the present invention to an encoder for measuring a rotation mode of a motor shaft.

[Explanation of symbols]

1 Label medium 2A
Light emitting diode 2B Light receiving diode 3
Amplifier 4 A / D converter 5
Storage unit 6 Calculation unit 7 Sampling pulse generation unit 8 Address control unit 9
Display unit 10 Correction value storage unit 11
Reflecting part 12 Flat part 100
Motor shaft

Claims (7)

[Claims] 1. A first portion comprising a reflecting portion having a shape for making the outgoing direction of reflected light with respect to the incident light parallel to the incident light direction, and a second portion having a light response characteristic different from that of the reflecting portion. A label medium characterized by being arranged in the following relationship. 2. The first portions intersect at right angles to each other.
2. A recess having two slopes.
Label medium described in. 3. The label medium according to claim 1, wherein the first portion is a hemispherical reflecting material protruding toward the incident light side. 4. The label medium according to claim 1, wherein the second portion is a light absorbing portion or a scattering portion. 5. The label medium according to claim 1, wherein the first portion and the second portion are arranged alternately. 6. The label medium according to claim 1, wherein the label medium has a tape shape. 7. A first portion comprising a reflecting portion having a shape for making the outgoing direction of the reflected light with respect to the incident light parallel to the incident light direction, and a second portion having a light response characteristic different from that of the reflecting portion. Attached to an object, the label medium having the following relationship: the first portion and the second portion of the label medium.
The light from the light emitting element is irradiated to a portion, and the reflected light is received by the light receiving element which is arranged in parallel and close to the light emitting element, and in the predetermined relationship of the label medium based on the change of the light receiving level by the light receiving element. An optical identification system characterized by identifying fixed information.