JPH02272685A - Bar code reader - Google Patents

Abstract

PURPOSE:To improve radiation efficiency by the small quantity of light by using a cylinder provided with a light transmitting slit opened in a lighting direction and a light source for supplying optical energy into the cylinder to constitute a light source body. CONSTITUTION:The light source body 1 is constituted of the cylinder 7 provided with the light transmitting slit 10 opened in the lighting direction and the light source 8 for supplying optical energy into the cylinder 7. Light (a) supplied from the light source 8 is fully reflected on the inner periphery of the cylinder 7 and radiated from the slit 10, so that the uniform light can be efficiently radiated from the slit 10, a part of the reflected light (b) enters into the cylinder 7 again through the slit 10, fully reflected in the cylinder, and then radiated from the slit 10. Consequently, radiation efficiency can be improved by the small quantity of light.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a barcode reading device, and more particularly to a barcode reading device that can provide efficient illumination with less light energy.

[Conventional technology]

Generally, the reading head of a barcode reader using a COD image sensor etc. has an LED (red diode).
A light source for barcode illumination is provided.

As shown in FIG. 5, this type of conventional device has an LED 21 as a light source, and the light a from this is passed through a cylindrical lens 22 onto a barcode 23 on which information to be read is recorded. The diffused light C due to diffused reflection other than the reflected light A out of the light A that has reached this point is reflected by the condensing lens 2.
The light is focused on the COD image sensor 25 through the COD image sensor 25.

The shading of the light C focused on the COD image sensor 25 is converted into an electrical signal and output, and the information of the barcode 23 is read based on this output signal.

By the way, in order to read the information of this barcode 23 accurately, it is required that the light energy from the above-mentioned LED 21 be uniformly and sufficiently irradiated onto the barcode 23.

In order to satisfy this requirement, conventionally, as shown in FIG. 6, a large number of LEDs 21, 21,
. . 21 is arranged in advance to emit sufficient light energy.

[Problem to be solved by the invention]

However, in the case of using a large number of LEDs 21, 21, .
There is a problem in that it is difficult to realize how to arrange the lights, and the amount of light energy diffused into the atmosphere increases, resulting in extremely low lighting efficiency.

In order to solve this problem, conventionally, the light amount of the LED 21 is reduced in advance to about 1/2 power, and when the amount of light C focused on the COD image sensor 25 changes, that is, the bar code 23 is detected by the output change of the COD image sensor 25 itself, the LED 2
A device has been proposed in which the amount of light of No. 1 is increased to full power to improve illumination efficiency.

However, even with this method, since the LED 21 is always lit, a large number of LEDs 21, 21...2
1, the problem of poor illumination efficiency still remains.

There is also a method (not shown) in which a single LED or semiconductor laser is placed as a point light source, and the light from this is converted into a line light source through a cylindrical lens, etc., and used for illumination. Conceivable. However, even with this, the lighting efficiency cannot be sufficiently improved.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the problems of the above-mentioned conventional techniques, and to provide a barcode reading system that can sufficiently improve lighting efficiency without increasing the number of light sources such as LEDs. The goal is to provide equipment.

[Means to solve the problem]

To achieve the above object, the present invention provides a barcode reading device comprising a light source for barcode illumination in a reading head, wherein the light source has a transparent slit opening in the direction of illumination. Another invention is characterized by comprising a cylindrical body having a cylindrical shape and a light source for supplying light energy into the cylindrical body. Another invention is characterized in that a cylindrical lens is disposed to detect the presence of a barcode to be read, and another invention is characterized in that a sensor for detecting the presence of a barcode to be read is disposed in the vicinity of the reading head section. That is.

[Effect]

According to the present invention, the light supplied from the light source is totally reflected on the inner peripheral surface of the cylindrical body and then emitted from the transparent slit, and a uniform amount of light is efficiently emitted from the slit. Moreover, a part of the reflected light enters the cylinder through the slit again, where it is totally reflected again and is emitted from the slit, so the irradiation efficiency can be significantly improved with a small amount of light.

According to another invention, since the light emitted from the slit is focused by a cylindrical lens, the light is accurately focused onto the barcode, and the illumination efficiency can be greatly improved.

According to another invention, a sensor detects the presence of a barcode, so if the barcode is not in the position where it should be read, the light source can be turned off or the light intensity reduced, thus saving energy. can be achieved.

〔Example〕

Hereinafter, one embodiment of a barcode reading device according to the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 shows the configuration of a reading head section of a barcode reading device, and in the figure, reference numeral 1 indicates a light source for illuminating the barcode. The light a from the light source 1 passes through the cylindrical lens 2 and reaches the barcode 3 on which the information to be read is recorded, and the diffused light C due to diffused reflection other than the reflected light out of the light a that reaches this point is condensed. The light is focused on a CCD image sensor 5 through a lens 4. The shading of the light C focused on this CCD image sensor 5 is converted into an electrical signal, which is output from this CCD image sensor 5, and the information of the barcode 3 is read based on this output signal. ing.

FIG. 2 shows the main part of this embodiment. The light source body 1 is composed of a hollow cylindrical body 7 and a light source 8.8 consisting of two LEDs or the like arranged at both ends of the body 7. Both ends of the cylindrical body 7 are closed with caps 9, 9, and the entire inner surface of the cylindrical body 7 is finished to be smooth so that light can be totally reflected. Preferably, the cylindrical body 7 is formed of a plastic material or the like, and the inner surface thereof is coated with a highly reflective metal or the like. Further, a light-transmitting slit 10 that opens in the illumination direction is formed in a part of the cylinder 7, and this slit 10 is formed so as to extend at least over the entire reading width of the barcode 3.

Next, to explain the operation of this embodiment, as shown in FIG. 3 and FIG. is emitted through the slit 10 in the direction in which the barcode 3 is irradiated. As is clear from FIG. 1, this emitted light a passes through the cylindrical lens 2 and reaches the barcode 3 on which information to be read is recorded. The reflected light of the light a that has reached this point passes through the cylindrical lens 2 and enters the cylindrical body 7 again, as is clear from FIG.
Here, it is totally reflected, and a part of the light a is emitted again through the slit 10 in the direction in which the barcode 3 is irradiated.

Further, as described above, the diffused light C due to diffused reflection other than the reflected light S is focused on the CCD image sensor 5 through the condensing lens 4, and the light C focused on the CCD image sensor 5 is The shading is converted into an electrical signal and output. Information on the barcode 3 is then read based on this output signal.

In this way, according to this embodiment, the light energy emitted from the light source 8 disposed inside the cylinder body 7 is effectively utilized while being totally reflected on the inner circumferential surface of the cylinder body 7, so that the barcode The amount of light over the entire reading width of 3 is made uniform, and
Even if the number of light sources 8 is small, various effects such as being able to secure a sufficient amount of light can be obtained.

Although one embodiment has been described above, other embodiments may be used, such as omitting the cylindrical lens 2 disposed in front of the slit 10, using the light source 8 as a single point light source, or using the light source 8 as a cylindrical lens 7. It is possible to arrange it outside and introduce only the light energy into the inside of the cylinder 7, or to omit the condensing lens 4 arranged in front of the CCD image sensor 5.

Further, a mechanical, electronic, or optical sensor (not shown) for detecting the presence of the barcode 3 is installed in parallel near the reading head, and based on the operation of this sensor, the barcode 3 is detected. It is possible to use the light source 8 at full power when reading, and turn off the light source 8 at times other than when reading.

If the sensors are arranged in parallel in this way, the light source 8
There is no need to keep the lights on when not in use, further saving energy.

Furthermore, a stamping means or the like is installed in parallel near the reading head section, and when the reading of the barcode 3 is completed, based on the completion signal etc., the barcode 3 is printed on the product (not shown), etc. It is possible to configure it so that a seal is affixed. If these stamping means are provided in parallel, in addition to the above-mentioned effect, it is possible to obtain the effect that erroneous operations such as data duplication reading can be prevented by stamping.

As the stamping means, for example, a printing stamp or the like is fixed to the tip of the solenoid, and the solenoid is activated to print based on the above-mentioned end signal, or an inkjet or the like is provided, and the above-mentioned end signal is applied. Various means can be used, such as ejecting ink onto the product based on a signal or the like, or burning a part of the product with a laser beam or the like. Further, as the above-mentioned end signal, for example, the current value of a buzzer emitted at the end of reading the bar code 3 may be detected and used as the end signal.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in a barcode reading device including a light source for barcode illumination in a reading head, the light source has a transparent It consists of a cylindrical body with a slit and a light source for supplying light energy into the cylindrical body, so the light supplied from the light source is totally reflected on the inner peripheral surface of the cylindrical body, and then the light is transmitted through the cylinder. A uniform amount of light is emitted efficiently, and some of the reflected light passes through the slit and enters the cylinder, where it is totally reflected again and emitted from the slit. Therefore, the irradiation efficiency can be significantly improved with a small amount of light.

[Brief explanation of drawings]

FIG. 1 is a side view showing an embodiment of the barcode reading device according to the present invention, FIG. A perspective view, FIG. 5 is a side view showing a conventional barcode reading device, and FIG. 6 is a perspective view similarly showing a light source. 1... Light source body, 2... Cylindrical lens, 3...
...Barcode, 4...Condensing lens, Death...CCD
Image sensor, 7...Cylinder, body...Light source, 10...
·slit.

Claims (1)

[Claims] 1. In a barcode reading device including a light source for illuminating the barcode in the reading head, the light source is a cylinder having a translucent slit that opens in the direction of illumination. and a light source for supplying light into the cylinder. 2.Claim 1, characterized in that a cylindrical lens for converging light is arranged in front of the slit.
The barcode reader described. 3. The barcode reading device according to claim 1, further comprising a sensor for detecting the presence of a barcode to be read, which is arranged in the vicinity of the reading head section.