JPH01189782A - Bar code reader - Google Patents

Abstract

PURPOSE:To remarkably enlarge a reading range to a bar code reading part and a bar code by transmitting plural rays of light from an optical system different in a focal distance to the bar code. CONSTITUTION:A light is emitted in a constant sequence at a prescribed timing controlled by a shift driver 9 from light sources 1-3 according to the input of a power from a power source 20 to respective circuits and it is projected on a half mirror through lenses 4-6. In the mirrors 7, 8, the time division light different in the focal distance in the lenses 4-6 is set to one optical axis and projected on the bar code moving on a prescribed orbit through the central through hole of a reflecting mirror 11. Therefore, the time division light from the bar code 10 goes to a reflected light and is received by a light receiving lens 12 and it is converted to an electric signal by a photodetector 13. Based on this electric signal, the data of the bar code is decoded by a data processing part C.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a barcode reading device that can read a wide range of barcodes from nearby barcodes to distant barcodes.

<Prior Art> Barcodes are attached to articles handled in logistics, markets, etc., and various information regarding the articles can be decoded by optical or electrical search. To read such barcodes, it is usually necessary to set the distance between the article and the barcode reader so that the distance is within a predetermined focal length of the optical system. When a barcode is read by a barcode reading device, the distance from the barcode reading portion of the articles being conveyed one after another is adjusted one by one so that the barcode falls within a predetermined range of the focal length.

<Problems to be Solved by the Invention> However, in such conventional barcode reading devices, since the barcode position, that is, the distance from the barcode reading part, differs depending on the type and size of the article, the above-mentioned size etc. Sort the items according to the size of the item, have them read the above using a barcode reading device, adjust the distance between the barcode and the barcode reading part for each item of different size, etc. It is necessary to increase the thickness and space of the barcode bar, and when reading barcodes by sorting items or adjusting the distances mentioned above, it is inevitable that the cost of the equipment will increase significantly. When increasing the thickness of the bar as described above, there were problems such as limitations due to the current increase in the amount of information and space constraints.

This invention was made by focusing on the above-mentioned conventional problems, and its purpose is to greatly expand the barcode reading area and the reading range up to the barcode with simple and inexpensive installation. An object of the present invention is to provide a barcode reading device that can facilitate reading operations.

<Means for Solving the Problems> A barcode reading device according to the present invention sends out a plurality of lights from optical systems having different focal lengths from a light transmitting section, and reads light that is reflected by a barcode. The light receiving section receives the light and converts it into an electrical signal.Based on the electrical signal from the light receiving section, the data processing device decodes and outputs the data contained in the bar code.

Function> The light transmitting unit in the present invention transmits a plurality of lights with different focal lengths from the same or different light sources to a barcode on an article through optical systems (lens systems) with different focal lengths. . The position (distance) at which this barcode is read is not always constant depending on the size of the item, but it will fall within the reading range of one of the different focal lengths mentioned above, so the reflected light from the barcode will This includes data obtained by reading the barcode at approximately sufficient resolution. Therefore, after the reflected light is received by the light receiving section, the data of the high-resolution light is selected and decoded by the data processing section, thereby ensuring that the desired accurate barcode data is output. You will be able to do so.

<Embodiment of the Invention> FIG. 1 is a block connection diagram of a barcode reading device showing an embodiment of the present invention, where A is a light transmitting section that sends light for reading barcodes, and B is a light transmitting section that transmits light for reading barcodes. C is a data processing section that processes the electric signal obtained by the light receiving section and decodes the barcode data. In addition, in the light transmitting section A, l,
Reference numeral 2.3 denotes a light source that emits light alternately in response to a time-division timing signal from the shift driver 9. Numerals 4, 5, and 6 are lenses for condensing light, which form an optical system having different focal lengths, and lenses whose focal lengths overlap in a predetermined area are used. 7°8 is the lens 4, 5.
This is a half mirror that aligns the light from 6 on the same optical axis. Further, in the light receiving part B, 11 is a reflecting mirror having a through hole near the optical axis, and a bar code 10 attached to the article is used.
The reflected light is reflected onto the light receiving lens 12. 13 is a light receiving element that converts this reflected light into an electrical signal, 14 is an amplifier that converts the electrical signal, and 15 is a bar code signal synchronized with the periodic signal from the shift driver 9 from the output of this amplifier 14. Sampling circuit, 16, 17.
18 is a comparator that converts each barcode signal into pulses. Note that 20 is a power source that supplies the necessary power to each circuit.

Next, the operation will be explained.

First, by applying power from the power supply 20 to each circuit,
Light sources 1 and 2.3 emit light in a fixed order at predetermined timings controlled by a shift driver 9, and these lights pass through lenses 4 and 5°6 to a half mirror 7.
, 8. In half mirrors 7 and 8, lens 4,
5. The time-divided light with different focal lengths in 6 is
The two beams are aligned on the same optical axis, and are irradiated through the central through hole of the reflecting mirror 11 onto the barcode 10 moving along a predetermined trajectory. Therefore, time-divided light from the barcode 10 becomes reflected light and is received by the light receiving lens 12, which is converted into an electrical signal by the light receiving element 13. Further, this time-divided electrical signal is input to the sampling circuit 15, and under the control of the shift driver 9, is input to the data processing section C as a barcode signal synchronized with the above timing, where the barcode data (contents) is inputted to the data processing section C. Decipher and output.

Note that this output can be displayed on a CRT display if necessary.

FIG. 2 shows another embodiment of the invention. This is done by a half mirror 7°8 similar to that shown in Figure 1.
The light aligned on the same optical axis is reflected by a polygon mirror 21 rotating at a predetermined speed and irradiated onto the barcode 10, and the reflected light from the barcode 10 is reflected back to the reflection mirror 11 via the polygon mirror 21. It was intended to be received. Further, 22 is an angle sensor that detects the rotation angle of the polygon mirror 21. According to the output of this angle sensor 22, that is, at a timing corresponding to the rotation angle of the polygon mirror 21, the shift driver 9 moves the light source 1
, 2.3 controls the light emission timing. Also,
23 is a comparator that converts the output of the amplifier 14 into pulses. Note that other blocks that are the same as those shown in FIG. 2 are designated by the same reference numerals, and redundant explanation thereof will be omitted.

In this embodiment, according to the output synchronization signal of the angle sensor 22 of the polygon mirror 21, the shift driver 9 drives the light sources 1, 2.3 one scan at a time in a time-division manner, and the half mirrors 7, 8 align them on the same optical axis. It is sent to the polygon mirror 9 in accordance with the above. The light that scans the barcode 10 with the polygon mirror 9 is light that has passed through optical systems with different focal lengths, and these lights read the barcode 10 one by one, and the scanned light is sent to the reflecting mirror 11. After receiving the signal, the signal is converted into an electric signal as described above, and then pulsed and input to the data processing section C. In this manner, in this embodiment, the light sources 1, 2, .
The timing of light projection from 3 and the output timing of barcode data are controlled.

In each embodiment, the barcode 10 is irradiated with a plurality of lights from optical systems having different focal lengths in a time-sharing manner, and the reflected output is extracted at the time-sharing timing, so that one of the plurality of lights is By selecting the most suitable barcode data, the desired data can be accurately decoded with high precision.

Therefore, barcode data can be read without error, regardless of the type or size of the article.

In addition, in the above embodiment, a case was explained in which a plurality of lights from optical systems with different focal lengths are transmitted onto a barcode on an article in a time-sharing manner. , it may be transmitted onto the barcode of the item simultaneously instead of time-divisionally, and by reading the light reflected from the item through a filter, the barcode data possessed by one predetermined light according to each wavelength and frequency is selected. and output it.

Moreover, in particular, a plurality of lights may be simultaneously transmitted onto the barcode of the article, regardless of the time division timing, wavelength, or frequency of the light, and in this case, the light reflected from the barcode of the article may be Since it contains light focused on the barcode, this focused light can be read as barcode data.

<Effects of the Invention> As detailed above, according to the present invention, the light transmitting unit transmits a plurality of lights from optical systems having different focal lengths toward the barcode, so that the optical system The position of the barcode can be adjusted to any focal point, thus making it possible to read a clear barcode image even if the size of the article attached with this barcode is different. In addition, the light reflected from the barcode is converted into an electrical signal by the light receiving section, and the data contained in this electrical signal is processed by the data processing section.The results are also extremely accurate because they are based on the light reception data of the clear barcode mentioned above. It has the effect of being accurate and reliable. Furthermore, by setting multiple focal lengths in this way, there is no need to divide the items according to their size, or to install a focal length adjustment device, which was required in the past, making the reading process easier. In addition to improving efficiency and reducing the cost of equipment, it also eliminates the need for special, large-width bars and spaces.

[Brief explanation of the drawing]

FIG. 1 is a block connection diagram showing one embodiment of a barcode reading device according to the present invention, and FIG. 2 is a block connection diagram showing another embodiment. A... Light transmitting section, B... Light receiving section, C... Data processing section, 1
o...Barcode, 15...Sampling circuit.

Claims (1)

[Scope of Claims] 1) A light transmitting unit that transmits a plurality of lights from optical systems having different focal lengths toward a barcode, and a light receiving unit that receives reflected light from the barcode and converts it into an electrical signal. and a data processing unit that performs arithmetic processing on the data of the barcode based on the electrical signal from the light receiving unit. 2) The barcode reading device according to claim 1, wherein a plurality of lights from optical systems having different focal lengths are transmitted from the light transmitting section in a time-division manner. 3) The barcode reading device according to claim 1, further comprising a sampling circuit that samples the electrical signal from the light receiving section at the timing of time-divisionally transmitting light from the light transmitting section.