JP2765596B2 - Hand-held bar code reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a POS (Point of Seals)
The present invention relates to a hand-held bar code reader used in a system or the like, and more particularly to a hand-held bar code reader of a type using a light beam for scanning a bar code.

[0002]

2. Description of the Related Art A hand-held bar code reader has a hand-held casing which can be operated by grasping with one hand. The hand-held casing has a built-in optical scanning means for a bar code. An elongated bar code reading port is formed in the type casing. When reading a bar code, a bar code reading port of a hand-held casing is applied to a bar code attached to a product or the like so as to cross the bar code, and at this time, the bar code is optically scanned by optical scanning means.

As such an optical scanning means, LE is used.
A type that irradiates and scans a barcode at a time with a D (light emitting diode) array, and a laser beam that is deflected in the longitudinal direction of a barcode reading window of a hand-held casing with a galvanometer mirror or the like and the deflected laser beam is used. A type that scans a barcode is known. In either type, reflected light obtained during optical scanning of a barcode is detected by a photoelectric converter provided in a hand-held casing, and the detected information is processed by a barcode decoding circuit to read the barcode. Will be performed.

[0004]

As apparent from the above description, in the conventional hand-held bar code reader, the bar code reading port of the hand-held casing is connected to a bar for reading the bar code. The code needs to be applied across it, which requires the operator to perform a relative positioning operation between the barcode reading port of the handheld casing and the barcode each time the barcode is read. become. Even if such a relative positioning operation can be performed in a relatively short time, such a positioning operation becomes troublesome and troublesome when sequentially reading a large number of bar codes of products.

In a stationary bar code reader used in a supermarket or the like, a laser beam emitted from a bar code reading window is deflected so as to draw a predetermined intersection pattern trajectory. The bar code is scanned by any of the laser beams forming the bar code, so that the bar code information can be read regardless of the orientation of the bar code. In this case, there is no need to position the barcode in a predetermined direction with respect to the barcode reading window. However, it is almost impossible to apply such a technique to a conventional laser beam type hand-held bar code reader. This is because a spatially bulky optical system is required to draw such an intersection pattern trajectory with a laser beam, and such an optical system cannot be accommodated in a hand-held casing.

Accordingly, it is an object of the present invention to provide a hand-held bar code reader of the type that uses a light beam to scan a bar code, wherein a relative position between a bar code reading port of the hand-held casing and the bar code is provided. It is an object of the present invention to provide a hand-held bar code reader capable of eliminating a positioning operation.

[0007]

According to the present invention, a light beam emitted from a bar code reading port of a hand-held casing is deflected along a line segment having a predetermined length. In a hand-held bar code reader for reading a code, a hologram element is interposed in a deflection area thereof for diffracting the light beam, and the hologram element is at least 180 degrees on a deflection trajectory plane formed by deflection of the light beam. A hand-held bar code reader is characterized by having diffraction characteristics that give it a wide twist.

[0008]

In the hand-held bar code reader according to the present invention, the deflection trajectory formed by the deflection of the light beam emitted from the bar code reading opening of the hand-held casing has at least 180 degrees for the hologram element. , Which changes the relative distance between the barcode reader and the barcode regardless of the orientation of the barcode relative to the barcode reader of the handheld casing. The bar code information can be read. That is, when a twist of at least 180 degrees is given to the deflection trajectory surface formed by the deflection of the light beam, a cross-sectional line that traverses the deflection trajectory surface with respect to the emission direction of the light beam, that is, a deflection trajectory line segment, is hand-held The bar code will pivot in one direction as it moves away from the bar code reader of the casing, so that the bar code is lighted while the relative distance between the bar code reader of the hand held casing and the bar code is changed. As a result, the bar code information can be completely scanned, and the reading of the bar code information is achieved.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a hand-held bar code reader according to the present invention. Referring first to FIG. 1, there is schematically illustrated a first embodiment of a hand-held barcode reader according to the present invention, which is configured in this embodiment for a POS system. Is done. The hand-held bar code reader comprises a hand-held casing 10 which may be formed from a suitable rigid resin material, the hand-held casing 10 being gripped with one hand and operated with a grip 10a. Integrated head part 1
0b. A switch 12 is provided in a boundary area between the grip 10a and the head 10b.
Functions as an operation switch of the hand-held bar code reader, and is operated with the index finger while holding the grip portion 10a with one hand.

The head portion 10b of the hand-held casing 10
Is formed with a bar code reading port 10c, and the bar code reading port 10c is elongated in a direction perpendicular to the plane of FIG. In this embodiment, the barcode reading port 10
A transmission type hologram element 14 is arranged at c, and this hologram element 14 has a diffraction characteristic as described later. A cord connecting portion 10d extends from the rear end side of the grip portion 10a of the hand-held casing 10, and a cord 16
Is connected. The cord 16 extends from the cord connection portion 10d to the main body 18 for reading a bar code. In the main body 18 for reading a bar code, a laser source 20, a bar code decoding / control device 22 and the like are provided. As the laser source 20, a gas laser, a semiconductor laser, or the like is used, and the barcode decoding processing and control device 22 can be constituted by a microcomputer or the like.

A light beam deflecting means 24 is provided in the hand-held casing 10, and the light beam deflecting means 24 is connected to a laser source 20 via an optical fiber 28 passing through the cord 14. The light beam deflecting means 24 is composed of, for example, a galvanomirror, and the laser beam output from the laser source 20 is guided to the light beam deflecting means 22 by the optical fiber 24. Next, the laser beam is repeatedly deflected along the longitudinal direction of the bar code reading port 10c of the hand-held casing 10 by the light beam deflecting means 22, and the deflected laser beam passes through the hologram element 14 and passes through the bar code reading port 10c. Injected.

The emitted laser beam is diffracted by the hologram element 14 in a manner as shown in FIG.
More specifically, FIG. 2 illustrates a case where the emitted laser beam is deflected from one end 14a of the hologram element 14 toward the other end 14b as indicated by an arrow A. Note that the reference sign LA is one end 1 of the hologram element 14.
4B shows the laser beam when it is deflected to the extreme position on the 4a side, and the reference numeral LB denotes the other end 14 of the hologram element 14.
5 shows a laser beam when deflected to an extreme position on the b side. As is apparent from FIG. 2, the laser beam LA is diffracted toward the other end 14b after passing through the hologram element 14, while the laser beam LB is diffracted toward the one end 14a after passing through the hologram element 14. At this time, both laser beams LA and L
The width of B is fixed. In other words, the hologram element 14 diffracts the laser beam so as to impart a 180 ° counterclockwise twist (with respect to the laser beam emission surface of the hologram element 14) to the deflection trajectory plane of the laser beam emitted therefrom. It has become. In short, for example, the twist of the deflecting trajectory surface is caused by turning the tape-like piece 180 degrees counterclockwise around the other end of the tape-like piece in a state where the tape-like piece is fixed to the hologram element 14 at one end thereof and stretched. This corresponds to a twist given to the tape-shaped piece.

When a twist of 180 degrees is given to the deflection trajectory formed by the deflection of the laser beam as described above, as shown in FIG. 2, the deflection trajectory crosses the deflection trajectory with respect to the emission direction of the laser beam. The sectional lines, ie, the deflection trajectory segments a, b, c, d, e, f, and g, rotate counterclockwise as they move away from the barcode reading port 10c of the handheld casing 10, that is, the hologram element 14. Therefore, no matter what direction the barcode is positioned with respect to the barcode reading port 10c of the hand-held casing 10, if the relative distance between the barcode reading port 10c and the barcode is changed, ,
The barcode can be scanned completely with the laser beam emitted from the hologram element 14. In other words, the barcode reading port 1 of the hand-held casing 10 as in the prior art is changed.
For example, the relative distance between the barcode reading port 10c and the barcode is changed without performing relative positioning between the barcode and the barcode in order to make the barcode reading direction coincide with the longitudinal direction of the barcode. By simply moving the bar code reading port 10c up and down, complete scanning of the bar code is achieved.

This point will be described more specifically.
As shown in FIGS. 3 (a), 3 (b) and 3 (c), the products 30 with the barcodes are different from each other with respect to the barcode reading port 10c of the handheld casing 10, that is, the hologram element 14. Even if they are positioned in the same direction, if the relative distance between them is changed, each bar code is formed by the cross section line of the deflecting trajectory plane of the deflecting laser beam, that is, the deflecting trajectory line segments l, m and n. Thus it can be scanned completely.

A photoelectric conversion means 32, which may be constituted by a CCD (charge-coupled device) or the like, is arranged in the hand-held casing 10. The photoelectric conversion means 32 is connected to a bar of the bar code reading main body 18 by a lead 34 passing through the cord 16. It is connected to the code decoding and control device 22. The photoelectric conversion means 32 detects the reflected light obtained when the bar code is scanned as described above as bar code read information, and the bar code read information is taken into the bar code decoding processing and control device 22 via the lead wire 34. The bar code read information is then decoded and output to the POS system host device. The bar code decoding processing and control device 22 also controls the operation of the light beam deflecting means 24, and “ON” / “OFF” is performed by the switch 12.

Various methods can be considered for producing the hologram 14 having the above-described diffraction characteristics. Here, an example of a relatively simple production method will be described.

First, with reference to FIG. 4A, a general method for producing a diffraction hologram element will be described. The diffraction hologram element obtained by this production method is a hand-held bar code reader according to the present invention. Can not be used. In FIG. 4B, reference numeral 36 denotes a recording medium formed by applying a photosensitive emulsion to a transparent film substrate, for example, and a three-dimensional orthogonal coordinate system xyz having a coordinate origin on the recording medium 36 is assumed. The recording medium 36 in the xy plane
Shall be located. The reference light source 38 and the object light source 4 are located in the zy plane of the three-dimensional rectangular coordinate system xyz.
0 are arranged with the y-axis interposed therebetween, both light sources 38
And 40, interference fringes are formed and recorded on the recording medium 36 by the interference of the spherical waves generated from the recording medium 36. This recording medium 3
6 is developed / fixed to obtain a hologram element having diffraction grating fringes. Referring to FIG. 4 (b),
Such a hologram element is indicated by reference numeral 36 ',
Assuming a three-dimensional orthogonal coordinate system xyz similar to that of FIG. 4A for the hologram element 36 ', a laser beam source 38' is arranged as a reproduction light source in the yz plane,
When the laser beam 42 emitted therefrom is deflected along the x-axis and transmitted through the hologram element 36 ', the transmitted laser beam 42' is diffracted so as to deviate from the x-axis.
The direction of deflection of the transmitted laser beam 42 'is parallel to the x-axis (in FIG. 4B, x' and y '
Indicates the x-axis and y-axis projection axes, respectively). In short, even if the hologram element 36 'shown in FIG.
The above-described twist cannot be given to the deflection trajectory formed by the deflection of the transmitted laser beam 42 '.

Next, with reference to FIG. 5A, a method of forming a diffraction hologram which can be used in the hand-held bar code reader according to the present invention will be described. Also in FIG. 5A, a three-dimensional coordinate system xyz similar to that of FIG.
Is assumed. 5A, the reference light source 3
8 and the object light source 40 are arranged at positions shifted from the yz plane to one side of the x-axis (the positive side in the example of FIG. 5A). Is different from the creation method of FIG. A hologram element having diffraction grating fringes is obtained by forming and recording interference fringes on the recording medium 36 by interference of spherical waves generated from both of the light sources 38 and 40, and then developing / fixing the recording medium 36. This is the same as in the case of FIG. Referring to FIG. 5 (b), such a hologram element is indicated by reference numeral 36 ', and also for this hologram element 36', FIG.
Assuming a three-dimensional orthogonal coordinate system xyz similar to the above, a laser beam source 38 ′ is arranged as a reproduction light source in the yz plane as in the case of FIG. When the hologram element 36 'is transmitted through the hologram element 36' by being deflected along the x-axis, the transmitted laser beam 42 'is diffracted so as to rotate about the z-axis unlike the case of FIG. 5 (b), x ′ and y ′ indicate the projection axes of the x-axis and the y-axis, respectively). Needless to say, the hologram element for diffraction 36 ′ as shown in FIG.
Is used, it is possible to impart the above-described twist to the deflection trajectory surface formed by the deflection of the transmitted laser beam 42 ′.

Referring to FIG. 6, there is shown another embodiment of a hand-held bar code reader according to the present invention, in which a reflective hologram element 14 'is used instead of a transmission hologram element 14. Except for this, the embodiment of FIG. 6 is similar to the embodiment shown in FIG. In FIG. 6, the same reference numerals are used for the same components as those shown in FIG. The reflection hologram element 14 'is fixed to the inner top wall surface of the head member 10b of the hand-held casing 10, and this reflection hologram element 14' is also elongated likewise in the direction perpendicular to the plane of FIG. Extend. The laser beam guided from the laser source 20 to the light beam deflecting means 22 by the optical fiber 24 is a reflection type hologram element 1.
The bar code reading port 10c of the hand-held casing 10 is reflected while being repeatedly deflected along the longitudinal direction of the 4 '.
It is ejected from. Of course, the reflection type hologram element 1
4 'also has the same diffraction characteristics as the transmission hologram element 14, so that the deflection trajectory plane formed by the exit deflecting laser beam is given a twist as described in FIG.

In FIG. 6, reference numeral 44 designates a transparent glass plate for closing the bar code reading opening 10c of the hand-held casing 10.
The entry of dust and the like into the inside of the space is prevented. Also, a similar transparent glass plate can be used in the embodiment shown in FIG. 1. In this case, the transmission hologram element 14 may be attached to the inner surface of the transparent glass plate, They may be arranged at separated positions.

[0021]

As is apparent from the above description, in the hand-held bar code reader according to the present invention, each time a bar code is read, the bar code is inserted into the bar code reading port of the hand-held casing. Since relative positioning to the reading position is not required, barcode reading efficiency can be improved compared to conventional hand-held barcode readers.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a hand-held bar code reader according to the present invention.

FIG. 2 is a perspective view illustrating characteristics of a laser beam emitted and deflected from the hand-held bar code reader shown in FIG.

FIG. 3 is a perspective view showing an example of reading a barcode by the hand-held barcode reader shown in FIG. 1;

FIG. 4 is an explanatory diagram for explaining a general method for producing a diffraction hologram element and its diffraction characteristics.

FIG. 5 is an explanatory diagram for explaining a method of producing a hologram element for diffraction used in a hand-held bar code reader according to the present invention and its diffraction characteristics.

FIG. 6 is a schematic sectional view showing another embodiment of the hand-held bar code reader according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Hand-held casing 10a ... Grip part 10b ... Head part 10c ... Barcode reading opening 10d ... Cord connection part 12 ... Switch 14 ... Transmission hologram element 14 '... Reflection hologram element 16 ... Code 18 ... Barcode reading main body 20 ... Laser generation source 22 ... Bar code decoding processing and control device 24 ... Light beam deflecting means 28 ... Fiber 30 ... Product 32 ... Photoelectric conversion means 34 ... Lead wire 36 ... Recording medium 36 '... Diffraction hologram element 38 ... Reference light generation Source 40: Object light source 42: Laser beam 42 ': Transmitted laser beam 44: Transparent glass plate

Continued on the front page (72) Inventor Fumio Yamagishi 1015 Uedanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Fujitsu Limited (72) Inventor Shigeru Noda 1015 Uedanaka, Nakahara-ku, Nakazaki-ku Kawasaki City, Kanagawa Prefecture Fujitsu Limited (58) Survey Field (Int.Cl. ⁶ , DB name) G06K 7/10 G06K 7/12

Claims (3)

(57) [Claims] 1. A hand-held bar code reader for reading a bar code by deflecting a light beam emitted from a bar code reading port (10c) of a hand-held casing (10) along a line segment having a predetermined length. A hologram element (14: 1) is placed in the deflection area to diffract the light beam.
4 ′) is interposed, and the hologram element (14: 1)
4 ') has a diffraction characteristic which gives a twist of at least 180 degrees to a deflection trajectory plane formed by the deflection of the light beam. 2. The hand-held bar code reader according to claim 1, wherein the hologram element is formed as a transmission hologram element (14), the transmission hologram (14) being provided on the hand-held casing (10). It is arranged at or near the barcode reading port (10c),
A hand-held bar code reader, wherein the light beam is emitted from the bar code reading port (10c) after being transmitted through the transmission hologram element (14). 3. The hand-held bar code reader according to claim 1, wherein said hologram element is formed as a reflection hologram element (14 '), said reflection hologram (14') being provided in said hand-held casing (10). ), Wherein the light beam is emitted from the bar code reading port (10c) after being reflected by the reflection hologram (14 '). apparatus.