JPH09128473A - Barcode reader - Google Patents

Abstract

(57) Abstract: A bar code reader capable of reading a bar code at a position farther from a reading port than a conventional means is provided. SOLUTION: A light projecting means 14 is a light source 15 arranged in a row.
And a cylindrical surface 17 parallel to the arrangement direction of the light sources 15.
The illumination light emitted from the light source 15 to the barcode 19 is compressed by the cylindrical surface 17 parallel to the array of the light sources 15 of the condenser lens 18 and the light of the imaging lens. With respect to the reading field of view on a plane composed of the axis and the arrangement direction of the light-receiving element rows, the illumination light that intersects far away is more compressed than the illumination light that intersects near, so that the cylindrical surface 17 of the condensing lens 18 is compressed. The curvature is synthesized with a plurality of radii of curvature.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a bar code reader for optically reading bar code information.

[0002]

2. Description of the Related Art In recent years, bar code readers have been widely used in the distribution sector. However, it is required that bar codes can be read accurately regardless of the distance between the bar code and the reading opening of the bar code reader. Is important.

A conventional bar code reader will be described below with reference to the drawings. FIG. 7 is a partially cutaway perspective view showing the configuration of a conventional barcode reader. In the figure,
Reference numeral 1 denotes a reading opening opened at the tip end of a casing 2, and 3 denotes a light condensing means for irradiating light from a light source 4 having a plurality of light-emitting diodes arranged in a straight line and having a cylindrical surface 5 parallel to the arrangement direction of the light sources 4. A light projecting means 8 for compressing the light by the lens 6 and irradiating the light onto the bar code 7; an image forming lens 8 for reflecting light from the bar code 7 and forming an image through a mirror 9;
Reference numeral 0 denotes a light-receiving element array that is arranged on a straight line and converts an image formed by the imaging lens 8 into an electric signal. Reference numeral 11 denotes a signal processing circuit that processes an output of the light-receiving element array 10 to perform a barcode decoding process. It is.

[0004] The interrelationship and operation of the above components will be described below. When the bar code 7 is brought close to the reading opening 1, the light projecting means 3 irradiates the bar code 7 with light, and the reflected light forms an image on the light receiving element array 10 by the imaging lens 8, and the light receiving element array 10 Into an electric signal, and the signal processing circuit 11
Decodes the electrical signal.

FIG. 8 is a side view showing an optical path when light rays emitted from the light source 4 at an angular interval of 5 ° pass through the condenser lens 6. In the drawing, the curvature of the cylindrical surface 5 of the condenser lens 6 is uniform, and the irradiation light from the light source 4 is compressed symmetrically about the axis B. The entire surface of the cylindrical surface 5 is thinly and textured, and the light from the light source 4 is diffused to some extent by the cylindrical surface 5, so that the irradiation light from the light source 4 is bright near the optical axis of the light emitting diode,
Lighting unevenness, which is dark between the optical axes of the light emitting diodes, is mitigated.

[0006]

In such a conventional bar code reader, when the bar code 7 is read away from the reading opening 1, the light emitted from the light source 4 spreads and advances, and the bar code 7 is subjected to graining. Since the light is diffused by the cylindrical surface 5, the amount of light irradiated on the barcode 7 is reduced, and there is a problem that the barcode cannot be read accurately.

As shown in FIG. 9, when the compression of light by the condenser lens 6 is increased to suppress the spread of the irradiation light from the light source 4, the imaging lens 8 for forming an image on the light receiving element array 10 is formed. When the bar code 7 is read away from the reading port 1, the irradiation light from the reading position is deviated, and the reading of the bar code is not accurate. There was a problem that it could not be done.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a bar code reader that can accurately read a bar code even at a position away from a reading port.

[0009]

According to the first aspect of the present invention, there is provided a light projecting means for irradiating light onto a bar code, an image forming lens for forming an image of reflected light from the bar code, and A light receiving element array that converts the optical information imaged by the imaging lens into an electric signal, and a signal processing circuit that processes the electric signal to detect bar code information; The light projecting means includes a light source arranged in a row and a condenser lens having a cylindrical surface parallel to the arrangement direction of the light sources, and is formed on a plane formed by the optical axis of the imaging lens and the direction in which the light receiving element rows are arranged. On the other hand, a bar code reader that combines the curvature of the cylindrical surface of the condenser lens with a plurality of radii of curvature so as to compress the light from the light source that intersects farther than the light from the light source that intersects closer. A.

Thus, at a position far from the reading opening, the spread of the light beam irradiated to the reading field of view can be suppressed, and the irradiation illuminance required for reading the bar code can be obtained. The range in which the reading visual field intersects with the irradiation light can be increased without significantly suppressing the spread of the light beam of the irradiation light applied to the reading visual field. Further, according to the present invention, there is provided a light projecting means for irradiating light onto a bar code, an image forming lens for forming an image of reflected light from the bar code, and the image forming lens arranged linearly. A light receiving element array for converting optical information imaged by an optical signal into an electric signal, and a signal processing circuit for processing the electric signal to detect bar code information, wherein the light projecting means is arranged in a line. The light source provided is provided with a condensing lens having a cylindrical surface parallel to the arrangement direction of the light sources, and the condensing lens is subjected to texturing and a region to be subjected to texturing on the cylindrical surface or a surface facing the cylindrical surface. Light from the light source, which intersects a plane formed by the optical axis of the imaging lens and the direction in which the light receiving element rows are arranged, passes through the grained area. More diffuse, light from the light source intersect at far is a bar code reader to avoid spread by passing through the area that is not embossed.

Thus, at a position far from the reading opening, the illuminating light applied to the reading visual field is not diffused on the cylindrical surface, so that it is possible to obtain the irradiation illuminance required for reading the bar code and to obtain a position close to the reading opening. In this case, the illumination light applied to the reading field is diffused on the cylindrical surface to reduce illumination unevenness. Further, the present invention according to claim 3 is a light projecting means for irradiating light on a bar code,
An image forming lens for forming an image of reflected light from the barcode, a light receiving element array arranged on a straight line for converting optical information formed by the image forming lens into an electric signal, and processing the electric signal. In a bar code reader provided with a signal processing circuit for detecting bar code information, the light projecting means comprises light sources arranged in rows and a condenser lens having a cylindrical surface parallel to the arrangement direction of the light sources, It is a barcode reader in which the direction of light projection is adjusted by moving and adjusting a condenser lens in the curvature direction of the cylindrical surface with respect to the light source.

Thus, the light projecting direction can be changed by moving and adjusting the condenser lens in the curvature direction of the cylindrical surface with respect to the light source, and the range where the reading field and the illumination light intersect can be increased.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention according to claim 1 is a linearly arranged array of a light projecting means for irradiating light on a bar code, an imaging lens for focusing reflected light from the bar code. In the bar code reader including a light receiving element array that converts the optical information formed by the imaging lens into an electric signal and a signal processing circuit that processes the electric signal and detects bar code information, The light means includes light sources arranged in rows and a condenser lens having a cylindrical surface parallel to the arrangement direction of the light sources, and with respect to a plane formed by the optical axis of the imaging lens and the arrangement direction of the light receiving element rows. A bar code reader that combines the curvature of the cylindrical surface of the condenser lens with a plurality of radii of curvature so that the light from the light source intersecting at a distance is more compressed than the light from the light source intersecting at a near distance. The present invention according to claim 2, wherein the light projecting means for irradiating light onto a bar code, an image forming lens for forming an image of reflected light from the bar code, and the image forming means arranged in a straight line In a bar code reader comprising a light receiving element array for converting optical information imaged by a lens into an electric signal, and a signal processing circuit for processing the electric signal to detect bar code information, the light projecting means is arranged in a row. A light source disposed on the light source and a condenser lens having a cylindrical surface parallel to the arrangement direction of the light sources. Light from the light source intersects closely with a plane formed by the optical axis of the imaging lens and the direction in which the light receiving element rows are arranged, and passes through the grained area. The light from the light source, which is more diffused and intersects at a distance, is a bar code reader which is prevented from being diffused by passing through a non-textured area. A light projecting means for irradiating light, an image forming lens for forming an image of reflected light from the bar code, and a light receiving element array arranged on a straight line and converting optical information formed by the image forming lens into an electric signal And a signal processing circuit for processing the electric signal to detect bar code information, wherein the light projecting means comprises a light source arranged in a row and a cylindrical surface parallel to the arrangement direction of the light source. A bar code reader having a condensing lens having: It is da.

Hereinafter, embodiments of the present invention will be described. (Embodiment 1) An embodiment of the bar code reader of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially cutaway perspective view showing the structure of this embodiment. In the figure, reference numeral 12 denotes a reading opening opened at the tip of a casing 13, and 14 denotes light emitted from light emitting diodes 15, 16 serving as light sources.
6, light projecting means for compressing the light by a condenser lens 18 having a cylindrical surface 17 parallel to the arrangement direction E and irradiating the bar code 19, 20 is an imaging lens for forming an image of light reflected from the bar code 19, 21 is A light receiving element array for converting an image formed by the imaging lens 20 into an electric signal, and a signal processing circuit 22 for processing the output of the light receiving element array 21 and performing bar code decoding processing.

The mutual relationship and operation of the above-mentioned components will be described. When the bar code 19 is brought closer to the reading opening 12, the light projecting means 14 irradiates the bar code 19 with light, and the reflected light forms an image on the light receiving element array 21 by the imaging lens 20, and the light receiving element array 21 Is converted into an electric signal, and the signal processing circuit 22 decodes the electric signal. The basics of the above operation are the same as those of the conventional example. This embodiment differs from the conventional example in the configuration of the light projecting means 14.

FIG. 2 is a side view of essential parts showing the structure of the light projecting means 14 in the present embodiment. In the figure, f, g, and h indicate the areas of the cylindrical surface, respectively. In the present embodiment, the radius of curvature of the cylindrical surface 17 of the condenser lens 18 is gradually changed from 4.5 mm in the region to 4.5 mm in the region G and 6 mm in the region C.
And

FIG. 3 shows the light emitting diode 15 or 1 of the light source.
Light rays emitted at an angle interval of 6 to 5 ° are collected by the condenser lens 1
It is a side view which shows the optical path when passing through 8. FIG. In a reading field of view lying on a plane formed by the optical axis of the imaging lens 20 and the arrangement direction of the light receiving element rows 21, the light rays intersecting far away are strongly compressed as compared to the light rays n intersecting near each other. Spread is suppressed.

As described above, in the present embodiment, at the position distant from the reading port 12, the spread of the light beam of the irradiation light with which the reading visual field is irradiated is suppressed, and the illumination illuminance required for reading the bar code is reduced. Obtainable. Further, at a position close to the reading opening 12, the spread of the light beam of the illumination light applied to the reading field of view is not so much suppressed,
The range where the reading field and the illumination light intersect can be increased.

(Embodiment 2) An embodiment of the present invention according to claim 2 will be described below with reference to the drawings. FIG. 4 is a perspective view showing the configuration of the condenser lens 18 in the present embodiment. In the present embodiment, only the region の of the cylindrical surface 17 of the condenser lens 18 is subjected to graining. As shown in FIG. 3, a ray group nu which intersects closely with the reading field of view on a plane formed by the optical axis of the imaging lens 20 and the arrangement direction of the light receiving element rows 21 is in the area ヲ of the cylindrical surface 17. Is diffused to some extent by unevenness of the surface due to graining. Also,
A ray group that intersects at a distance travels without being diffused by passing through the area w.

As described above, according to the present embodiment, at the position distant from the reading port 12, the irradiation light irradiating the reading field is not diffused on the cylindrical surface 17, and the illumination necessary for reading the bar code is obtained. The illuminance can be obtained. At a position near the reading opening 12, the illumination light applied to the reading field of view is diffused by graining on the cylindrical surface 17, so that the illumination light has bright light axes of the light emitting diodes 15, 16 and the light emitting diode 15,
Illumination unevenness, which is dark between the 16 optical axes, can be reduced.

(Embodiment 3) An embodiment of the present invention according to claim 3 will be described below with reference to the drawings. FIG. 5 is an exploded perspective view of a main part showing the configuration of the optical system.
In the figure, an inner casing (upper) 23 and an inner casing (lower) 24 are arranged at predetermined positions with a substrate on which light emitting diodes 15 and 16 are disposed, a condenser lens 18, an imaging lens 20, and a light receiving element array 21. And fixed to the casing 13. The condenser lens 18 has a rib 25 on an end face, is fitted in a groove 26 provided in an inner casing (lower) 24, and is slidably attached to the cylindrical surface 17 in the direction of curvature. The leaf spring portion 27 formed on the inner casing (lower) 24 urges the condenser lens 18, and by turning the screw 28 attached to the inner casing (upper) 23, the curvature direction of the condenser lens 18 is changed. The position is adjusted. For example, when the condenser lens 18 is moved 0.5 mm downward in the direction of curvature as compared to the position shown in FIG. 3, the light emitted from the light emitting diode 15 or 16 emits light as shown in FIG. The direction of changes.

As described above, according to this embodiment, it is possible to make adjustment so as to increase the range in which the reading field and the illumination light intersect.

[0024]

According to the bar code reader of the present invention, the illumination light emitted from the light source to the bar code is compressed by the cylindrical surface parallel to the arrangement of the light sources of the condenser lens. Moreover, the curvature of the cylindrical surface of the condensing lens is set so that the illumination light that intersects far away from the plane formed by the optical axis of the imaging lens and the direction in which the light receiving element rows are arranged is more compressed than the illumination light that intersects closer. Are combined with a plurality of radii of curvature, it is possible to suppress the spread of the light beam of the illumination light with which the reading field of view is radiated at a position away from the reading port, and obtain the illumination illuminance necessary for reading the barcode. Further, at a position close to the reading opening, the spread of the light beam of the illumination light applied to the reading visual field can be suppressed so much that the range where the reading visual field intersects with the illumination light can be increased. Further, according to the bar code reader of the present invention according to claim 2, the cylindrical surface or the surface facing the cylindrical surface is divided into a region subjected to graining and a region not subjected to graining, and the optical axis of the imaging lens is Illumination light from a light source that intersects a plane consisting of the direction in which the light receiving element rows are arranged passes through the grained area, and at a position distant from the reading opening, illumination light applied to the reading field is cylindrical. And the illumination intensity required for reading the bar code can be obtained. Further, at a position near the reading opening, the illumination light applied to the reading field is diffused on the cylindrical surface, so that the unevenness of the illumination can be reduced. According to the bar code reader of the present invention, the direction of light projection is changed by moving and moving the condenser lens in the curvature direction of the cylindrical surface with respect to the light source, so that the reading field and the illumination light are changed. Can be adjusted so as to increase the range of intersection.

By the above means, it is possible to realize a bar code reader which can read a bar code at a position farther from the reading port than in the past.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a configuration of an embodiment of a bar code reader according to the present invention according to claim 1;

FIG. 2 is a side view showing a configuration of a light projecting means in one embodiment of the bar code reader of the present invention according to claim 2;

FIG. 3 is a side view showing an optical path of light emitted from a light source of the light projecting unit in the embodiment.

FIG. 4 is a perspective view showing a configuration of a condenser lens in the embodiment.

FIG. 5 is an exploded perspective view of a main part showing a configuration of an optical system in the bar code reader according to the present invention according to claim 3;

FIG. 6 is a side view showing the optical path of light emitted from the light source of the light projecting unit when the light projecting direction is adjusted in the embodiment.

FIG. 7 is a partially cutaway perspective view showing the configuration of a conventional barcode reader.

FIG. 8 is a side view showing an optical path of light emitted from a light source of a light projecting unit in a conventional example.

FIG. 9 is a side view showing an optical path of light emitted from a light source of a light projecting unit in a conventional example.

[Explanation of symbols]

 Reference Signs List 14 Projecting means 15, 16 Light emitting diode (light source) 17 Cylindrical surface 18 Condensing lens 19 Bar code 20 Imaging lens 21 Light receiving element row F Curvature direction ヲ Textured area

[Procedure amendment]

[Submission date] April 12, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

[0019] As described above, in the present embodiment, in the position away from the read port 12, the spread is suppressed in light of the illumination light irradiated on the reading field Li, the illumination intensity necessary for reading a bar code Obtainable. Further, at a position close to the reading opening 12, the spread of the light beam of the illumination light applied to the reading field of view is not so much suppressed,
The range where the reading field and the illumination light intersect can be increased.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2 is a side view showing a configuration of a light projecting unit in the same embodiment .

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4 is a bar code reader of the present invention according to claim 2;
1 is a perspective view showing a configuration of a condenser lens according to an embodiment.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

FIG. 5 is a bar code reader of the present invention according to claim 3;
FIG. 3 is an exploded perspective view of a main part showing a configuration of an optical system in one embodiment .

[Procedure Amendment 5]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

[Procedure correction 6]

[Document name to be amended] Drawing

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

[Figure 5]

[Procedure amendment 7]

[Document name to be amended] Drawing

[Correction target item name] Fig. 8

[Correction method] Change

[Correction contents]

[Figure 8]

[Procedure amendment 8]

[Document name to be amended] Drawing

[Correction target item name] Figure 9

[Correction method] Change

[Correction contents]

FIG. 9

Claims (3)

[Claims] 1. A light projecting means for irradiating light onto a bar code, an image forming lens for forming an image of reflected light from the bar code, and optical information arranged linearly and formed by the image forming lens. A bar code reader comprising a light receiving element array for converting the electric signal into an electric signal, and a signal processing circuit for processing the electric signal to detect bar code information. With a condenser lens having a cylindrical surface parallel to the arrangement direction of the light source, compared to light from the light source that intersects closely with a plane formed by the optical axis of the imaging lens and the direction in which the light receiving element rows are arranged, A bar code reader in which the curvature of the cylindrical surface of the condenser lens is synthesized by a plurality of radii of curvature so as to further compress the light from the light source intersecting at a distance. 2. A light projecting means for irradiating light onto a bar code, an image forming lens for forming an image of reflected light from the bar code, and optical information arranged linearly and formed by the image forming lens. A bar code reader comprising a light receiving element array for converting the electric signal into an electric signal, and a signal processing circuit for processing the electric signal to detect bar code information. A light-collecting lens having a cylindrical surface parallel to the arrangement direction of the light sources, wherein the light-collecting lens is divided into a region subjected to graining and a region not subjected to graining for the surface facing the cylindrical surface or the cylindrical surface, Light from the light source, which intersects closely with a plane formed by the optical axis of the imaging lens and the direction in which the light receiving element rows are arranged, is diffused by passing through the grained area, and A bar code reader in which light from the intersecting light source is prevented from being diffused by passing through a non-textured area. 3. A light projecting means for irradiating light onto a bar code, an image forming lens for forming an image of reflected light from the bar code, and optical information arranged linearly and formed by the image forming lens. A bar code reader comprising a light receiving element array for converting the electric signal into an electric signal, and a signal processing circuit for processing the electric signal to detect bar code information. A bar having a condensing lens having a cylindrical surface parallel to the arrangement direction of the light sources, and adjusting the light projection direction by moving and adjusting the condensing lens in the curvature direction of the cylindrical surface with respect to the light source. Code reader.