JPS59121578A - Bar code reader - Google Patents

Abstract

PURPOSE:To detect a bar code formed on a transparent or transluscent object to be processed as a pattern with good accuracy by irradiating light from the back side of the object to be processed where the bar code is formed to detect a transmitted light pattern by a photodetector. CONSTITUTION:The light from a light source 4 is projected on a mirror 7, its reflected light 8 irradiates the bar code 2 from the back side of a printed distributing board 1 and the tilt angle of the light source 4, the mirror 7 and the photodetector 3 is set so as to make this transmitted light 9 enter the photodetector 3. Further, the bar code 2 read sequentially by sliding a scanning mechanism 5 on a guard rail. The transmitted light 9 is formed on a photodetecting surface in the photodetector 3 by a lens 10 fitted to the tip of the photodetector 3. The detected signal is transmitted to a decode circuit 11, where the signal is decoded and read as information.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) TECHNICAL FIELD OF THE INVENTION The present invention relates to a device line for reading seven barcodes formed on a processed object having good light transmittance.

(1)) Background of the technology Barcodes are displayed as characters consisting of a combination of numbers, alpha bentonoha (black part) and space (white part 9), and the necessary information is displayed by arranging them in one rM &' array. It is something to do.

A barcode system is a method in which a barcode is printed on the object to be processed, and then read by a reading device, which can be used to increase sales of parts, reduce inventory, etc.
It is used.

Until recently, this system was used to simulate the original finished product, but its scope of use has expanded and it has also come to be used to manage products during production.

In other words, in the past, barcodes were almost always printed on the 4th generation, and therefore barcode reading devices were
The reader) detects patterns by detecting the reflected light projected onto the barcode from a light source.

However, as a result of the expanded range of applications, barcodes are attached to a wide range of materials, including metals and non-metals, and in some cases, materials are transparent or semi-transparent.

In this way, detection of a barcode pattern using reflected light from a transparent or semi-transparent material has poor contrast, making it impossible to accurately detect a barcode pattern, especially when the material is dirty.

(C) Prior Art and Problems The reading rack of a conventional barcode reader is a barcode formed using black ink on white paper, and in this case, the projected light is totally reflected on the white part. Pattern detection using reflected light C is performed with high accuracy because it is absorbed in the barcode space (white part), but if the material is transparent and the front or back side is contaminated, Reflections become more complex and less accurate.

In other words, some light is reflected by the front surface, some light is reflected by the back surface, and some light is absorbed by contaminated parts.) As a specific example, barcodes are used in the production of multilayer printed wiring boards. Let me explain the case.

Opaque materials such as phenolic resin are also used as the material for printed wiring boards, but for slave devices, materials with excellent electrical properties such as glass epoxy and polyimide are used as the material for the board [7]. An example of this is using a multi-layer stack. In other words, the copper foil of the copper-clad laminate is made by photo-etching the copper foil of the copper-clad laminate, which is made of a copper foil with a thickness of several 1.00 μm and a thickness of 30 to 70[:/1m:], and these units are printed. The distribution boards are called prepreg and are stacked with bonding sheets made of organic insulation sheets of the same length sandwiched between them, and these are crimped with a press.
7-).

Currently, multi-layer wiring is carried out with up to 14 layers in many cases, but in the process of laminating this unit of printed wiring board, there is no need to make mistakes in the lamination order or the front and back sides. No.

Therefore, only one corner of the printed wiring board of the unit is used for Fushio Σ915.
The process is to write necessary information such as the number J and the figure number on each unit with a barcode 1', and then stack the printed wiring boards of this unit in the correct order with M'.

'□4-Copper wire in rope (') units: A bar code is also formed and used at the same time, in which a pattern is formed by photo-etching the laminated board. .

The printing arrangement of the unit that is laminated in this way and becomes the intermediate layer, ζ'
! The surface of the +ig pattern is black and dusty due to the oxidation treatment, so the barcode is also black and smudged.

However, since it is made of polyimide, etc., it is transparent or translucent, so it is possible to print the unit using a barcode pattern. Use a white T to write down the barcode on the wiring board.
'＋i Place the printed wiring board, which is the object to be processed, on the support stand and cool down the bar (black part) and the space (white ↑:;3). Ta. 1. However, in this case, as described in the section ``Light'', the space (reflection of the white part) occurs due to the travel of the printed wiring board and the back surface in contact with the white holding base, so it becomes bright, especially when it comes to the printed wiring board. If there is a gap between the barcode and the white holder, there is a problem in that the light is scattered even more and the barcode pattern cannot be detected.

(d) Purpose of the Invention An object of the present invention is to provide a barcode reading device capable of accurately detecting a barcode formed on a processed object made of a transparent or translucent material. shall be.

(e) Structure of the Invention The object of the present invention can be achieved by irradiating light from the back side of an object to be processed on which a bar code is formed, and detecting the turn of the transmitted light using a photodetector.

(f) Embodiments of the Invention The non-invention is that when the object to be processed is made of a transparent or semi-transparent body, pattern detection using transmitted light is much more accurate than detecting reflected light from a barcode. This was done by focusing on the point of climbing.

Figure 1 is a reader-style binding for carrying out the present invention.
FIG.

In other words, the offshore printed wiring board 10 which is the object to be processed
In this example, the substrate has a J diameter of 0.1πm to 271
It is made of 11 glass epoxy thin plates,
A barcode 2 is formed in one corner of the copper foil blackened with copper oxide.

In the barcode reading device (barcode reader) according to the present invention, the photodetector 3 and the button <+94 are integrally attached to the moving mechanism 5, and the barcode reader according to the present invention slides on the guardrail 6. ℃・ru.

In other words, the light from the original d imaginary 4 force and ra is projected onto the mirror 7, and the reflected light 8 from the mirror 7 illuminates the barcode 2 from the back side of the printed wiring, 1 and 1, and this transmitted light 9 The angle of the light source 4, mirror 7, and photodetector 3 is set so that the light enters the photodetector 3, and the barcode 2 is sequentially read by sliding the scanning mechanism 5 onto the card rail.

At J 1, the transmitted light 9 is imaged by the lens 10 attached to the tip of the photodetector 3 on the photodetecting surface Km of the photodetector 3, but the pattern of the barcode 2 is For accurate detection, it is necessary to make the size of the light detection surface sufficiently smaller than the image formation pattern.

The signal detected in this way is sent to the Tecode circuit 1 and decoded as information! Being exposed.

Next, FIG. 2 shows another 43. 'Q #jJJ, using a fixed light source, irradiates light 12 from the back side of the unit printed wiring board 1, which is the object to be processed, with the barcode 2 as the main beam. Similarly to the above case, the bar code pattern may be detected by scanning the detector 3, and the record status information may be read out by the code circuit 11.

As mentioned above, barcodes formed on transparent or translucent objects can be read clearly by using transmitted light instead of reflected light as in the conventional method. .

(g) Effects of the Invention By implementing the present invention, barcodes can be used in production processes that use a large number of F-1 type transparent thin plates, such as the production of polygon* printed wiring boards. It was possible to reduce errors and increase production efficiency.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the structure of a code reading device according to the present invention, and FIG. 2 is a perspective view showing another structure. In the figure, 1 is a printed wiring board, 2 is a - code, and 3 is a printed wiring board.
is the photodetector, 4 is the light source, 7 is the mirror 11 Figure O 2nd f2t ↑ ψ11

Claims (3)

[Claims] (1) In a reading device consisting of a light source that irradiates the barcode formed on the object to be processed, a photodetector that detects the pattern of the barcode, and a decoding circuit, the photodetector manually detects the transmitted light pattern of the barcode. A barcode reading device characterized in that it is configured to. (2) A patent claim characterized in that a light source and a photodetector are integrated and move over the barcode, and a mirror is used to illuminate the barcode from the back side with reflected light from the light source. The barcode reading device according to scope 1. (3) A patent claim in which the light source is provided to illuminate the barcode from the back side, and the tip detector is configured to move on the barcode is a q-te feature. The barcode reading device according to scope 1.