JPH05324897A - Photographing range display device for bar code reader - Google Patents

Abstract

PURPOSE:To accurately read a bar code despite even though area and height of the bar code carrier are large by using plural pairs of spot light sources and optical element which convert the spot light sources into the linear bright lines and showing the photographing range of a bar code reader by plural bright lines. CONSTITUTION:A bar code reader consists of pairs of spot light sources 10a, 10b, 10c and 10d and their respectively corresponding cylindrical lenses 11a, 11b, 11c and 11d which are arranged in a rectangular shape around a photographing lens 15 of a TV camera. The linear bright lines 12a, 12b, 12c and 12d projected by those four pairs of light sources and lenses overlap with each other only at both ends of each bright line. Thus, the dispersing angles and the image forming distances of the beams of those cylindrical lenses are set so that the photographing range of the camera is shown. As a result, the bar code on its carrier can be easily set within the photographing range of the camera.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing range display device for a bar code reading device, which enables a bar code to be arranged within a bar code readable range of the bar code reading device.

[0002]

2. Description of the Related Art In recent years, a bar code reading device has been used in which a bar code is photographed by a television camera and the bar code is read from the photographed image. In this case, it is necessary to arrange the bar code within the image capturing range of the TV camera.

Conventionally, for example, Japanese Patent Application No. 3-255556.
As shown in No. 6, a monitor television is used to confirm that the bar code is placed within the above-mentioned photographable range.

Alternatively, in the conventional bar code reader of the stand type, as shown in FIG. 9A, the photographing range 5 of the photographing lens 4 of the television camera 3 supported by the column 2 above the base 1 is used. A printable or engraved seal or a sealable printable range 5 is attached to the upper surface of the stand 1, or as shown in FIG. A frame body 6 indicated by a peripheral edge is attached to the upper surface of the base 1 at a predetermined distance above the upper surface.

[0005]

In the conventional bar code reader using the monitor TV, the monitor TV is expensive and the price of the conventional bar code reader as described above is increased.

In the conventional bar code reading apparatus, the photographable area 5 is displayed by printing or marking on the upper surface of the base 1 or by sticking a seal having the photographable area 5 printed thereon.
When the barcode or the barcode label is printed or attached to the surface of the carrier having a larger area than the photographable range 5, the photographable range 5 is hidden by the carrier,
I cannot confirm the possible shooting range 5.

In the conventional bar code reading device in which the photographable range 5 is displayed by the frame 6 on the upper surface of the base 1, the bar code is placed on a carrier larger than the gap between the upper surface of the base 1 and the frame 6. This cannot be applied when the code is printed or the barcode label is attached, and the barcode is printed even when the barcode is printed or the barcode label is attached to the carrier smaller than the above gap. Alternatively, the work of passing the carrier to which the barcode label is attached into the gap between the upper surface of the base 1 and the frame 6 is complicated, and the frame 6
The shadow of the frame body 6 in which the light obliquely incident on the bar code is projected onto the bar code causes an erroneous reading of the bar code. Furthermore, if the distance between the bar code on the carrier arranged in the gap between the upper surface of the base 1 and the frame body 6 and the frame body 6 is large, the frame body 6 is horizontally separated from the frame body 6. When the body 6 is observed, a bar code that seems to be arranged in the image-capturing range 5 of the frame body 6 is not likely to be in the image-capturing range 5, and there is a high possibility that a parallax will occur.

The present invention has been made under the above circumstances, and an object of the present invention is that it can be used regardless of the size or height of the area of the carrier of the bar code, which may cause erroneous reading of the bar code or the above. It is an object of the present invention to provide a photographing range display device for a bar code reading device that does not cause parallax and is inexpensive and easy to use.

[0009]

In order to achieve the above-mentioned object of the present invention, a photographing range display device for a bar code reader of the present invention comprises a point light source and an optical device for converting the point light source into a linear bright line. It is characterized in that a plurality of combinations with elements are used and the photographing range of the bar code reader is displayed by a plurality of linear bright lines.

[0010]

A plurality of combinations of a point light source and an optical element for converting the point light source into a linear bright line are used, and the plurality of linear bright lines display the photographing range of the bar code reader.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to FIGS. 1 to 8 in the accompanying drawings.

In the first embodiment of the present invention, a point light source,
Four combinations with a cylindrical lens as an optical element for converting the point light source into a linear bright line are used, and the four photographing combinations display a rectangular photographing range of a camera for a barcode reader. The above four combinations are arranged together with the camera above the bar code reading base, and are projected on the upper surface of the base in a rectangular shape corresponding to the rectangular photographing range of the camera.

The rectangular photographing range indicated by the four linear bright lines projected from the above four combinations above the base is a carrier of a bar code simply placed on the upper surface of the base. It will always be projected on top. Needless to say, the four linear bright lines do not cause their own shadows on the carrier, and since the parallax does not occur as in the above-described conventional photographing range display device for bar code readers, the bar on the carrier does not generate. The code can be placed exactly in the rectangular shooting range of the camera. First, the interaction between the point light source and the cylindrical lens used in the first embodiment will be described with reference to FIG.

In FIG. 3, light emitted from a point light source 10 such as a light emitting diode passes through a cylindrical lens 11 to form a linear bright line 12 and is imaged. This is because the cylindrical lens 11 refracts light only in its width direction (direction orthogonal to the longitudinal direction).

In detail in FIG. 4, in order to show the state where the cylindrical lens 11 exerts a refracting action, the light from the point light source 10 is seen from the side of the cylindrical lens 11 in FIG. 4A. It is clear that the refraction of the cylindrical lens 11 causes the cylindrical lens 11 to be focused and imaged at one point in the width direction of the cylindrical lens 11. In order to show the state where the cylindrical lens 11 does not exhibit the refraction effect, FIG. 4B is a view of the cylindrical lens 11 seen from above. In the longitudinal direction of the cylindrical lens 11, the cylindrical lens 11 does not exhibit the refraction effect and It shows that the light travels straight after passing and is not refracted, which clearly shows that the above-mentioned image formation constitutes the linear bright line 12.

The length 1 (small el) of the linear bright line 12 thus configured is in the direction in which the light from the point light source 10 does not exert the refracting action of the cylindrical lens 11 (longitudinal direction of the cylindrical lens 11). It is determined by the angle at which the light beam spreads and the distance until the light from the point light source 10 forms an image in the direction in which the cylindrical lens 11 exhibits the refracting action.

For example, as shown in FIG. 4B, the point light source 1
A direction in which light from 0 does not exert the refraction effect of the cylindrical lens 11 (longitudinal direction of the cylindrical lens 11)
In FIG. 1, 1/2 of the angle at which the light beam spreads is shown as θ as the divergence angle of the light of the point light source 10, and the distance until the light from the point light source 10 forms an image in the direction in which the cylindrical lens 11 exhibits the refraction action is d. Shown is the length l of the linear bright line 12.
Is defined by l = 2d · Tanθ.

Here, the divergence angle θ of the light is determined by the diaphragm 13 disposed between the point light source 10 and the cylindrical lens 11 or the length of the cylindrical lens 11 in the longitudinal direction.
Can be set arbitrarily, and the image forming distance d of the light can be set by the refractive power of the cylindrical lens 11.
The desired length l of the linear bright line 12 can be obtained by arbitrarily combining the values of the types.

FIG. 1 shows a photographing range display apparatus for a bar code reading apparatus according to a first embodiment of the present invention, which is constructed by arranging four combinations of such point light sources and cylindrical lenses in a rectangular shape. A schematic of 14 is shown.

In this figure, four point light sources and corresponding four cylindrical lenses are designated by reference numeral 10a,
10b, 10c, 10d and 11a, 11b, 11c,
The line-shaped bright lines shown by 11d and projected by the respective sets are shown by reference numerals 12a, 12b, 12c, 12d. These four combinations are arranged in a rectangular shape around the taking lens 15 of the television camera of the barcode reading device, and each of the four linear bright lines 12a, 12b, 12c, 12d forming the rectangular shape is only at both ends. The values of the above two types are set so as to overlap with each other and display the photographic range of the camera.

FIG. 2 shows the photographing range 5 of the photographing lens 4 of the television camera 3 supported by the column 2 above the base 1 in the above-mentioned conventional bar code reader of the stand type. Four linear bright lines 12a, 12 on the surface
The photographing range display device 14 for the bar code reading device of FIG. 1 arranged around the photographing lens 4 for displaying b, 12c and 12d is shown.

In this case, four linear lines showing a photographable range 5 from the periphery of the photographing lens 4 of the upper television camera 3 on the upper surface of the carrier of the bar code placed on the upper surface of the base 1. The bright lines 12a, 12b, 12c, 12d are projected. Since the photographable range 5 is directly displayed on the upper surface of the carrier, the conventional parallax problem described above does not occur, and it is easy to arrange the bar code on the carrier within the photographable range 5. Further, the problem of the conventional shadow described above does not occur, and the reading error of the bar code does not occur.

FIG. 5 shows a toric lens 16 used in place of the cylindrical lens 11. The toric lens 16 is the cylindrical lens 11
Does not have a refracting action, but has a slight refracting action also in its own longitudinal direction.

FIG. 5A shows a cylindrical lens 1.
4A is a side view of the cylindrical lens 11 in order to show the state in which the toric lens 16 exhibits the refracting action, the toric lens 16 is placed in the side direction in order to show the state in which the toric lens 16 exerts the refracting action. It is the figure seen from the one. Here, the light from the point light source 10 is the toric lens 16
It is clear that the refraction effect of the light is focused on one point in the width direction of the toric lens 16 to form an image.

FIG. 5B shows a cylindrical lens 1
As compared with FIG. 4B in which the cylindrical lens 11 is viewed from above in order to show the state in which 1 does not exhibit the refracting action, the toric lens 16 exerts a slight refracting action in its longitudinal direction. It shows that the light is contracted in the longitudinal direction after passing.

That is, the same divergence angle θ as in the case of FIG.
The length l'of the linear bright line 17 formed by the light incident from the point light source 10 to the toric lens 16 at the same image forming distance d as in the above case is shown by the chain double-dashed line in FIG. 5B. It becomes shorter than the length l of the linear bright line 12 in the case of FIG.

Therefore, the linear bright line 17 formed by the toric lens 16 is brighter than the linear bright line 12 formed by the cylindrical lens 11 using the same point light source 10. Therefore, when using a light source with low brightness and large divergence angle θ, the cylindrical lens 1
It has been shown that it is preferable to use the toric lens 16 rather than 1.

In FIG. 6, instead of the cylindrical lens 11, a partial cylindrical mirror 1 formed by a part of a cylinder is used.
The situation of the third embodiment in which the linear bright line 19 is formed by using 8 is shown. In this embodiment, since the optical axis 20 from the point light source 10 to the linear bright line 19 can be bent at the partial cylindrical mirror 18, it is possible to increase the degree of freedom in the construction of the photographing range display device for the bar code reader. ..

Further, in the fourth embodiment shown in FIG. 7, the point light source 10 is arranged behind the cylindrical lens 11 and laterally by disposing the mirror 21 behind the cylindrical lens 11. Also in this third embodiment, FIG.
The same effect as the third embodiment can be obtained.

FIG. 8 shows the photographing range 5 of the photographing lens 4 of the television camera 3 supported by the column 2 above the base 1 in the conventional bar code reader of the stand type described above. Four linear bright lines 12a, 12 on the upper surface
There is shown a photographing range display device 23 for a bar code reader according to a fifth embodiment of the present invention, which is arranged independently of the photographing lens 4 for displaying b, 12c and 12d.
In this case, the four point light sources 10a, 10a in the photographing range display device 14 for the bar code reader shown in FIG.
b, 10c, 10d and the corresponding four cylindrical lenses 11a, 11b, 11c, 11d can be configured by removing the taking lens 4 of the television camera 3 from the center of the four groups, so that the configuration shown in FIG. Further, it is possible to make the configuration more compact than that of the bar code reader photographing range display device 14.

[0031]

As described in detail above, the photographing range display device for a bar code reader of the present invention can be used regardless of the size or height of the area of the bar code carrier.
It does not cause erroneous reading of the bar code or the parallax, and is inexpensive and easy to use.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a photographing range display device for a bar code reading device according to a first embodiment of the present invention, which is configured by arranging four combinations of a point light source and a cylindrical lens in a rectangular shape.

FIG. 2 shows a photographing range of a photographing lens of a television camera supported by a support column above a base in a conventional stand-type bar code reader by displaying four linear bright lines on the upper surface of the base. The first is placed around the taking lens for
FIG. 3 is a perspective view showing a photographing range display device for a bar code reader according to the embodiment of FIG.

FIG. 3 is a diagram for explaining the interaction of the combination of a point light source and a cylindrical lens used in the first embodiment of FIG.

FIG. 4A is a side view showing a state in which light from a point light source is focused and imaged at one point in the width direction of the cylindrical lens by the refraction of the cylindrical lens in the combination of FIG. ) Indicates that the cylindrical lens does not exert a refracting action in the longitudinal direction of the cylindrical lens and the light goes straight even after passing through the cylindrical lens and the light is not refracted, whereby the image of (a) forms a linear bright line. FIG.

FIG. 5 (a) is a second embodiment of the present invention in which a point light source and a toric lens are combined, and light from the point light source is focused on one point in the width direction of the toric lens by the refracting action of the toric lens. It is a side view which shows a mode that it is imaged, and (b) shows that the toric lens exerts a slight refraction action in the longitudinal direction of the toric lens and the light is slightly refracted after passing through the toric lens. The top view which shows that an image forms a linear bright line.

FIG. 6 is a perspective view showing that a linear bright line is formed according to a third embodiment of the present invention by combining a point light source and a partial cylindrical mirror.

FIG. 7 is a perspective view showing that a linear bright line is formed according to a fourth embodiment of the present invention by combining a point light source, a cylindrical lens and a mirror.

FIG. 8 shows the photographing range of a photographing lens of a television camera supported by a column above a base in a conventional stand-type bar code reading device by displaying four linear bright lines on the upper surface of the base. FIG. 9 is a perspective view showing a photographing range display device for a bar code reading device according to a fifth embodiment of the present invention, which is arranged independently of the photographing lens.

FIG. 9 (a) shows a photographable area of a photographing lens of a TV camera supported by a column above a base, and a seal on which the photographable area of the photographing lens is printed or stamped or the photographable area is printed. FIG. 7B is a perspective view showing a conventional photographing range display device for a bar code reading device, in which (b) is a frame body showing the photographable range of the photographing lens of the television camera at the inner peripheral edge from the upper surface to the upper surface of the base. It is a perspective view which shows the conventional imaging range display device for barcode readers which is attached so as to be spaced apart by a predetermined distance above.

[Explanation of symbols]

10, 10a, 10b, 10c, 10d ... Point light source, 1
1, 11a, 11b, 11c, 11d ... Cylindrical lens, 12, 12a, 12b, 12c, 12d ... Linear bright line, 16 ... Toric lens, 17 ... Linear bright line, 18
... Partial cylindrical mirror, 19 ... Linear bright line, 21 ... Mirror, 2
2 ... Linear bright line.

Claims (1)

[Claims] 1. A bar code reader for displaying a photographing range of a bar code reader by using a plurality of combinations of a point light source and an optical element for converting the point light source into a linear bright line. Imaging range display device.