JPH03233783A - Bar-code reader - Google Patents

Abstract

PURPOSE:To make the bar-code position visible from the upper part of the bar-code reader and to prevent the adverse influence from being exerted on read by diffusing a disturbance light by constituting a part of a case of a read tip part of a light control material by which a transmission state is varied with an incident angle of light. CONSTITUTION:The bar-code reader is constituted of a light source 3 for illuminating a bar-code 2, a sensor 7 for photodetecting a reflected light from the bar-code 2, and a light control material 10 which is a bar-code reader for executing a decoding processing based on a sensor signal, and by which a transmission state is varied with an incident angle of light. In such a way, a bar-code position is visible from the upper part of the bar-code reader, and also, a disturbance light is diffused and no adverse influence is exerted on reading, and the bar-code is read quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a barcode reader that reads barcode information.

[Prior Art] A barcode reader that reads information on barcodes attached to various products generally includes a light projector that emits light onto the barcode, and a light projector that emits light reflected from the barcode. It is composed of a light receiving section that receives light, and a decoding circuit section that processes the output of the light receiving section and reads (deciphers) barcode information.

FIG. 3 shows a typical example of a conventional barcode reader.

Here, 1 is a label on which the barcode 2 is printed, 14 is a light source in which a plurality of LEDs (light emitting diodes) 15 with a peak wavelength of 660 nm are arranged horizontally to illuminate the barcode 2, and 5 is a barcode. 2 is a mirror for deflecting the reflected light from 2; 6 is a condensing lens; 7 is a CCD (solid-state imaging device) image sensor; 8 is a mirror that performs reading processing and external communication processing based on the output of the CCD image sensor. This is a read processing circuit. Further, 9 is a cable for external communication processing and power supply, and 11 is a case.

In the conventional barcode reader shown in Fig. 3, the reading depth is not very deep, so the reader is forced to touch the barcode to read it, but as shown in Fig. 4, the vertical dimension L (truncation) of the barcode 2 is In recent years, barcodes have become smaller and smaller, and in order to read a barcode, it is necessary to fit the readout line over the entire barcode width within this truncation width, as shown at 17, for example.

In other words, if it is off like (8), it cannot be read.

However, in conventional contact-type leagues, the barcode and reading line were covered in the reading opening, making it difficult to read and taking time to read. As a means to solve this problem, it has been proposed to cut the reading port into a concave shape to prevent it from being covered in the reading port, as shown in FIG.

[Problems to be Solved by the Invention] However, in the above-mentioned prior art, as shown in FIGS. 2 and 6, the disturbance light 13 such as fluorescent light or sunlight is reflected in the direction in which the barcode 2 is specularly reflected toward the light receiving axis. When the light enters the sensor, the received light signal is disturbed, making it difficult to read the signal. Another problem is that because the light source that illuminates the barcode 2 has a diffusion characteristic, it is not possible to determine which position on the barcode is the reading position, and the reading line cannot be specified, making the reading operation time-consuming. was there.

SUMMARY OF THE INVENTION In order to solve the problems of the prior art, an object of the present invention is to provide a barcode reader that can accurately read received light signals without being affected by ambient light such as fluorescent lights or sunlight. do.

A second object of the present invention is to provide a barcode reader that controls the diffusion characteristics of a light source that illuminates a barcode, clarifies the barcode reading position, and specifies the reading line.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following configuration. That is, the barcode reader of the present invention includes a light source that illuminates the barcode, a sensor that receives reflected light from the barcode, and a barcode reader that performs decoding processing based on the sensor signal, and includes a reading tip. The case is characterized in that at least a part of the case is made of a light control material whose transmission state changes depending on the incident angle of light.

In the configuration of the present invention, it is preferable that the sensor is an image sensor.

Further, in the configuration of the present invention, the light source is preferably a light source that illuminates a region including the image receiving target position of the image sensor in a strip shape.

Further, in the configuration of the present invention, the light source is preferably a light source that illuminates a region including the image receiving target position of the image sensor in a strip shape and is arranged so that its light emitting axis and light receiving axis substantially coincide. .

[Function] According to the configuration of the present invention described above, at least a part of the case of the reading tip is made of a light control material whose transmission state changes depending on the incident angle of light, so that the barcode position can be read from above the barcode reader. In addition to being visible, ambient light is diffused and does not adversely affect reading, allowing for faster reading.

According to the preferred embodiment of the present invention, since an image sensor is used as the sensor, barcode reading processing can be performed efficiently.

Further, according to the preferred embodiment of the present invention, a light source that illuminates the area including the image receiving target position of the image sensor in a strip shape is used as the light source, so that the reading line can be quickly and accurately identified.

According to a preferred aspect of the present invention, the light source is a light source that illuminates a region including the image receiving target position of the image sensor in a strip shape and is arranged so that its light emitting axis and light receiving axis substantially coincide. By using this, the reading line and the strip-shaped slit light can be aligned within a certain range, and the reading depth can be increased.

[Example] The present invention will be described in more detail below using an example.

Figure 1 shows an embodiment of the present invention. Here, ■ is a label printed with a barcode 2, and 3 is an LED with a peak wavelength of 660 nm for which a strip-shaped slit light with a width of 3 mm is set.
This is a projection light source composed of a cylindrical lens placed in front of the cylindrical lens, and the projection light source is arranged so that the projection axis and the reception axis almost coincide, as shown in FIG. 2(B). 4 is the illumination light from this projecting light source 3; 5 is a mirror for bending the reflected light from the barcode 2; 6 is a condenser lens; 7 is 204
An 8-pixel CCD image sensor, 8 is a reading processing circuit that performs reading processing and external communication processing based on the output of this CCD image sensor. Also, 9 is
Cable for external communication processing and power supply, 1
1 is a case. 10 is a light control material whose transmission state changes depending on the incident angle of light;
), light from above 12 is transmitted through, but light from 13 directions (disturbance light) is diffused or reflected. For example, the visibility control board manufactured by Sumitomo Chemical Co., Ltd. ( It can be easily configured using products such as the product name Nirmisti (trade name: Nirmisti).

According to this embodiment, even if sunlight of 5000 lux is incident as disturbance light at an angle of 13 in the specular reflection direction with respect to the light receiving axis, the minimum bar width of 5 mm for truncation is 0.15.
mm C0DE128, C0DE39, NW7, wpc
It was confirmed that various codes such as can be read with good visibility.

FIG. 7 shows the reading time ratio of a conventional reader and an embodiment of the present invention for reading C0DEL28, measured with truncation as the horizontal axis. One embodiment of the invention had the effect of shortening the reading time by 20%. Furthermore, if the truncation was 3 mm, the reading time could be reduced by 35% compared to the conventional one.

In addition, in this example, the light emitting axis and the light receiving axis are arranged so that they coincide, so the reading depth is increased by 50% compared to the conventional method15
It became mm. It was also confirmed that disturbance light up to 10,000 lux could be read without any problem.

[Effects of the Invention] As explained above, according to the present invention, at least a part of the case of the reading tip is made of a light control material whose transmission state changes depending on the incident angle of light, so that barcodes can be read from above the barcode reader. In addition to being able to visually confirm the position, ambient light is diffused and does not adversely affect reading, and reading time can be shortened, achieving the remarkable effect of being extremely effective in shortening checkout time at POS registers, etc. .

Further, according to a preferred embodiment of the present invention, since an image sensor is used as the sensor, barcode reading processing can be performed efficiently.

Further, according to the preferred embodiment of the present invention, a light source that illuminates the area including the image receiving target position of the image sensor in a strip shape is used as the light source, so that the reading line can be quickly and accurately identified.

According to a preferred aspect of the present invention, the light source is a light source that illuminates a region including the image receiving target position of the image sensor in a strip shape and is arranged so that its light emitting axis and light receiving axis substantially coincide. By using this, the reading line and the strip-shaped slit light can be aligned within a certain range, and the reading depth can be increased.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an apparatus according to an embodiment of the present invention, FIG. 2 (A) is an enlarged view of the same main part, FIG. 2 (B) is a schematic diagram of the same, and
The figure is a schematic diagram showing a conventional device, Figures 4 and 5 are explanatory diagrams of truncation, Figure 6 is a schematic diagram showing an example of disturbance light, and Figure 7 is a reading time of an embodiment of the present invention. It is a figure which shows an example of a shortening effect. 1...Label, 2...Barcode, 3...Light source,
4...Slit light, 5...Mirror 6...Lens, 7...Image sensor, 8...Decoder, 9...
Cable, 10... Light control material, 11... Case,
12... Barcode viewing direction, 13... Disturbing light incident direction, 14... LED holder 15... LED'
, 16... Reading opening tip notch, 17° 8... Reading line. Reading time ratio Figure 7

Claims (4)

[Claims] (1) A light source that illuminates a barcode, a sensor that receives reflected light from the barcode, and a barcode reader that performs decoding processing based on the sensor signal, and at least part of the case of the reading tip. A barcode reader characterized in that the barcode reader is made of a light control material whose transmission state changes depending on the angle of incidence of light. (2) The barcode reader according to claim 1, wherein the sensor is an image sensor. (3) The barcode reader according to claim 2, wherein the light source is a light source that illuminates an area including the image receiving target position of the image sensor in a strip shape. (4) The barcode according to claim 2, wherein the light source is a light source that illuminates a region including the image receiving target position of the image sensor in a strip shape and is arranged so that its light emitting axis and light receiving axis substantially coincide. leader.