JPH05108860A - Bar code scanner - Google Patents

Abstract

PURPOSE:To read a bar code even when the bar code and a bar code scanner are inclined, and to make the bar code scanner small in size and light in weight. CONSTITUTION:A bar code scanner 1 is constituted of a light source 4 such as a semiconductor laser element, lens 5 which allows an optical beam alphaoutgoing from the light source 4 to be made incident to an optical scanner 6 by focusing it, optical scanner 6 which scans the optical beam alpha shaped by the lens 5 by reflecting it, and a photodetector 8 which detects the reflected quantity of the optical beam alpha scanned on a bar code 7. And also, the optical scanner 6 is constituted of an elastically deformed part 13 having two elastically deformation modes, vibration inputting part 14 provided at one edge of the elastically deformed part 13, scan part 15 for reflecting the optical beam provided at the other edge of the elastically deformed part 13, and driving source 12 which impresses a fine vibration on the vibration inputting part 14. The optical beam alpha outgoing from the light source 4 is reflected by the optical scanner 6, and scanned in two orthogonally crossing directions.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to bar code scanners. More specifically, the present invention relates to a bar code scanner used in a bar code reading device that decodes bar code information by scanning a light beam toward a bar code and receiving reflected light reflected by the bar code.

[0002]

2. Description of the Related Art Conventionally, a pen type, an image sensor type,
Various bar code scanners such as laser type are provided. Of these, the laser-type bar code scanner using laser light can read the bar code even when the distance between the scanner and the bar code is large, so it is used in the fields of logistics and POS (point of sale) fields. Has been.

However, this laser type bar code scanner has a structure in which laser light emitted from a laser light source such as a semiconductor laser device is reflected by a polygon mirror (polyhedral mirror), and the laser light is scanned by rotation of the polygon mirror. Therefore, the laser beam can be scanned only in a fixed scanning direction, and as shown in FIG. 8A, the scanning direction φ of the bar code scanner 51 and the direction of the bar code (bar code label) 52 are If they do not match, normal reading cannot be performed. Therefore, as shown in FIG.
If the scanning direction φ of the and the direction of the bar code 52 are inclined, the bar code 52 cannot be read. To read the bar code 52, the bar code 52 is replaced or the bar code scanner 51 is tilted. It was necessary and there was a problem in operability. Further, since a polygon mirror and a servomotor for rotating the polygon mirror are required, there is a limit to miniaturization.

Further, there has been proposed a bar code scanner in which a laser beam can be scanned in a plurality of directions by using a hologram element or by providing a plurality of mirrors in the scanner, but each component is large. Because
The bar code scanner is also considerably large and heavy. Therefore, a fixed type bar code scanner may be used, but it is inconvenient as a handy type bar code scanner that the operator holds and uses.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the drawbacks of the above-mentioned conventional examples, and an object thereof is to scan a barcode even if the barcode and the barcode scanner are inclined. It is to make the barcode scanner smaller and lighter while making it readable.

[0006]

A bar code scanner according to the present invention is a bar code scanner for scanning a light beam toward a bar code, and comprises an elastic deformation part having at least two elastic deformation modes, and an elastic deformation part. A vibration input section provided at one end, a drive section for reflecting a light beam provided at the other end of the elastically deformable section, and a drive source for applying a minute vibration to the vibration input section, wherein the drive section is in at least two directions. It is characterized by including an optical scanner that can be turned to a full angle, a light source that emits a light beam toward a drive unit of the optical scanner, and a light receiving element that receives reflected light from a barcode.

In particular, the bar code scanner of the present invention is suitable for use as a handy type that can be held in a hand and operated.

[0008]

In the bar code scanner of the present invention, since the optical scanner capable of scanning the light beam in at least two directions is used, even if the bar code is tilted with respect to the bar code scanner, the bar code is scanned. The light beam can be scanned along the light beam, and the tilted bar code can be read by the light receiving element.

Further, since this optical scanner is smaller and lighter than the polygon mirror and the servomotor, the bar code scanner can also be made smaller and lighter. Further, by making it smaller and lighter, a handy type bar code scanner can be manufactured.

[0010]

1 is a schematic diagram showing the configuration of a bar code reader 2 using a bar code scanner 1 according to an embodiment of the present invention. The barcode reader 2 is a barcode scanner 1 designed to be a handy type (a concrete shape is omitted) so that it can be held in a hand, and barcode information based on a signal output from the barcode scanner 1. And a decoder 3 for decoding

The bar code scanner 1 focuses a light source 4 such as a semiconductor laser device or a light emitting diode (LED) which emits a light beam α, and a light beam α emitted from the light source 4 to be incident on the optical scanner 6. Lens 5, an optical scanner 6 for reflecting and scanning the light beam α shaped by the lens 5, and a light receiving element 8 for detecting the reflected light amount of the light beam α scanned on the barcode 7. Has been done.

Thus, when the light beam α is emitted from the light source 4, the light beam α focused and shaped by the lens 5 enters the optical scanner 6. The light beam α incident on the optical scanner 6 is reflected by the optical scanner 6 and emitted to the outside, and at the same time, the light beam α is scanned by the rotation of the reflecting surface of the optical scanner 6. At this time, the scanning range θ of the light beam α
When the barcode (or barcode label) 7 is placed inside, the light receiving element 8 detects the reflected light amount of the light beam α scanned on the barcode 7. Since the black line and the blank part of the barcode 7 have different reflectances, the light receiving element 8 outputs the light receiving signal β corresponding to the combination of the barcodes 7, and the decoder 3 outputs the signal detected by the light receiving element 8 to the barcode. Convert to the original number, symbol, etc. information described in 7.
Decode the barcode 7.

FIG. 2 is a perspective view showing the details of the optical scanner 6. The optical scanner 6 is composed of a thin plate 11 and a small drive source 12 such as a piezoelectric vibrator or a magnetostrictive vibrator that generates minute vibrations. Plate 1
1 has a shape as shown in FIGS. 3 (a) and 3 (b),
A vibration input unit 14 for applying vibration from the driving source 12 is integrally provided at the lower end of the elastic deformation unit 13 having a long narrow width, and the upper end of the elastic deformation unit 13 reflects the light beam α for scanning. The scanning unit (driving unit) 15 is integrally provided. Here, as shown in FIG. 3A, the elastically deformable portion is twisted and deformed around the axis P, and as shown in FIG. 3B, is bent and deformed along the axis P. The bending deformation mode is enabled, and has a resonance frequency of f _T for elastic vibration in the torsion deformation mode and a resonance frequency of f _B for elastic vibration in the bending deformation mode. The scanning unit 15 includes the elastic deformation unit 13
The weight portion 16 is formed in an unbalanced shape with respect to the axis P of the elastic deformation portion 13, and the weight portion 16 is formed in a portion of the elastically deformable portion 13 away from the axis P. Therefore, the scanning unit 15
The center of gravity of is located at a position deviated from the axis P of the elastically deformable portion 13, and is located above the upper end of the elastically deformable portion 13. Further, the scanning section 15 is provided with a mirror surface 17 for reflecting the light beam α. The vibration input unit 14 is fixed to the drive source 12 by being bonded or bonded to the drive source 12 such as a piezoelectric vibrator, and the scanning unit 15
Is freely supported by the elastically deforming portion 13.

The drive source 12 such as a piezoelectric vibrator that applies high frequency vibration (for example, several hundred Hz) to the vibration input section 14 is controlled by a drive circuit, and has a resonance frequency f _{T in the} torsional deformation mode or a resonance frequency in the bending deformation mode. Vibrations of frequency f _B are excited. The drive circuit 21 shown in FIG.
This is an example of the oscillator 22 that continues to output a voltage signal having a frequency that matches the resonance frequency f _T of the torsional deformation mode.
And an amplifier 23 that amplifies the voltage signal output from the oscillator 22, and an oscillator 24 that continues to output a voltage signal of a frequency that matches the resonance frequency f _B of the bending deformation mode.
And an amplifier 25 for amplifying the voltage signal output from the oscillator 24, and a frequency f from both amplifiers 23, 25.
It is composed of a mixing circuit 26 for switching the output voltage of _{T and} the output voltage of frequency f _B and applying them to the drive source 12. Further, by switching the operation of the mixing circuit 26, the frequency f _T output from both amplifiers 23 and 25 is changed.
It is also possible to apply to the drive source 12 a mixing signal obtained by superimposing the voltage signal of the above and the voltage signal of the frequency f _B.

Since the optical scanner 6 is configured as described above, the drive circuit 21 causes the drive source 12 to vibrate at a certain frequency, and this vibration is applied to the vibration input section 14 to reciprocate in the S direction of FIG. When vibrated, an inertial force acts on the scanning unit 15, and the inertial force causes the elastic deformation unit 13 to move.
It elastically deforms and vibrates in the direction in which inertial force is applied. Moreover, when the drive frequency applied to the vibration input unit 14 matches the resonance frequency f _T of the torsional deformation mode or the resonance frequency f _B of the bending deformation mode, which is determined by the spring rigidity of the elastic deformation unit 13, the moment of inertia, etc., The elastic vibration of is amplified by the elastic deformation section 13, and the scanning section 15 is largely rotated.

FIG. 5 shows an example of how to use the bar code scanner 1. When the drive circuit 21 vibrates the drive source 12 at a frequency equal to the resonance frequency f _T of the torsional deformation mode, the elastically deformable portion 13 is torsionally deformed, and FIG.
As shown in FIG. 5, since the scanning unit 15 rotates left and right at an angle of θ _T , the light beam α is reflected on the mirror surface 17 of the scanning unit 15.
Is applied, the light beam α is moved in the horizontal direction X by 2 as shown in FIG.
It is scanned at a scan angle of θ _T. Therefore, as shown in FIG. 6A, when the bar code 7 is placed horizontally, the bar code reader 2 reads the bar code 7 by scanning the light beam α in such a scanning direction. be able to.

When the drive circuit 21 vibrates the drive source 12 at a frequency equal to the resonance frequency f _B of the bending deformation mode, the elastic deformation portion 13 bends and deforms, and the scanning portion 15 as shown in FIG. 3B. Rotates up and down at an angle of θ _B , so that when the light beam α is applied to the mirror surface 17 of the scanning unit 15, the light beam α is vertically scanned at a scan angle of 2θ _B. Therefore, as shown in FIG. 6B, when the bar code 7 is placed vertically, the bar code reader 2 reads the bar code 7 by scanning the light beam α in such a scanning direction. be able to.

Thus, the barcode scanner 1 of the present invention
In this case, since the light beam α can be scanned in two directions (X direction and Y direction) which are orthogonal to each other, even if the barcode 7 is placed horizontally as shown in FIG. )
The barcode can be read even when it is placed as shown in the above, and there is no need to replace the product provided with the barcode 7 or change the direction of the barcode scanner 1 as in the conventional case. At this time, if the scanning direction can be switched by operating a scanning direction switching switch (not shown) provided in the barcode scanner 1, the operation can be facilitated. If the scanning direction switching circuit or the like is used to automatically switch the scanning directions alternately every short time, the barcode 7 placed in any direction can be automatically read.

Further, a signal in which the resonance frequency f _T signal in the torsional deformation mode and the resonance frequency f _{B in} the bending deformation mode are superimposed is applied from the drive circuit 21 to the drive source 12, and the drive source 12 causes the torsional deformation mode to be applied. When the vibration input unit 14 is vibrated in a vibration mode in which the vibration having the resonance frequency f _{T of 1} and the vibration having the resonance frequency f _B of the bending deformation mode are superposed, the elastic deformation unit 13 causes the torsional deformation mode and the bending deformation mode. Since both vibrations are amplified at the same time, the scanning unit 15
Then, the vibration of the rotation angle θ _T around the axis P and the vibration of the rotation angle θ _B around the Q direction are combined, and the light beam α is two-dimensionally scanned. The trajectory of this two-dimensional scan is determined by the ratio of both rotation angles θ _T and θ _B.
The ratio of the rotational angle .theta.B of deformation mode bending rotation angle theta _T of torsional deformation mode, θT: θB = 1: shows a light beam trajectory alpha _t in the case of 1, the trajectory of the light beam alpha _t Draws a Lissajous figure. In this case, since the scan locus inclined by 45 ° from the horizontal direction X and the vertical direction Y is obtained,
By combining the scanning in the X direction and the scanning in the Y direction with this two-dimensional scanning, it becomes possible to read the barcode information even when the barcode 7 is tilted in almost any direction. Note that in FIG. 7, θT: θB =
Although the case of 1: 1 is shown, it goes without saying that this ratio is not limited to 1: 1.

In the bar code scanner of the present invention,
For example, a compact and lightweight 2-axis optical scanner with a size of 15 mm × 15 mm × 10 mm and a weight of 5 gr or less can be mounted, so that the barcode scanner is also compact and lightweight, and is a fixed type conventionally installed in supermarkets and the like. In addition to the multi-axis reading type bar code scanner described above, the present invention can be particularly effective as a handy type bar code scanner in which an operator can easily carry out a bar code reading operation.

In the above embodiment, the material of the plate is not specified, but it is not particularly limited as long as it has the above-mentioned function. Further, the shape of the plate, the type of drive source, etc. are not limited to those in the above embodiment.

[0022]

According to the present invention, even when the bar code is tilted with respect to the bar code scanner, the light beam can be scanned along the bar code and the tilted bar code can be read. Therefore, there is no need to replace the barcode or tilt the barcode scanner,
The barcode can be read quickly and the operability is improved.

Since this optical scanner is smaller and lighter than the polygon mirror and the servomotor, the bar code scanner can be made smaller and lighter.

Accordingly, it is possible to manufacture a small and lightweight handy type bar code scanner, and it is possible to realize a handy type multi-axis scan type bar code scanner which has existed only in the conventional fixed type bar code scanner.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a bar code reader using a bar code scanner according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an optical scanner used in the above barcode scanner.

FIG. 3A is a perspective view showing a twisting deformation mode of the optical scanner, and FIG. 3B is a perspective view showing a bending deformation mode.

FIG. 4 is a block diagram showing a drive circuit for driving an optical scanner.

FIG. 5 is a perspective view showing a trajectory of a light beam when the light beam is scanned by the above barcode scanner.

6A and 6B are perspective views showing a usage state of the above barcode scanner.

FIG. 7 is a diagram showing another locus of the light beam when the light beam is scanned by the above barcode scanner.

8A and 8B are perspective views showing a state in which a laser beam is scanned toward a barcode by a conventional laser barcode scanner.

[Explanation of symbols]

 1 Bar Code Scanner 4 Light Source 6 Optical Scanner 8 Light-Receiving Element 12 Drive Source 13 Elastic Deformation Section 14 Vibration Input Section 15 Scan Section

Claims (2)

[Claims] 1. A bar code scanner for scanning a light beam toward a bar code, the elastic deformation section having at least two elastic deformation modes,
The drive unit includes a vibration input unit provided at one end of the elastic deformation unit, a drive unit for reflecting a light beam provided at the other end of the elastic deformation unit, and a drive source for applying a minute vibration to the vibration input unit. Bar code scanner including an optical scanner capable of rotating in at least two directions, a light source that emits a light beam toward a drive unit of the optical scanner, and a light receiving element that receives reflected light from a bar code .. 2. The bar code scanner according to claim 1, wherein the bar code scanner is a handy type that can be held in a hand and operated.