JPH05266234A - Read range display device for bar code reader - Google Patents

Abstract

PURPOSE:To provide a simple and inexpensive constitution and to easily arrange a bar code in a readable visual field without damaging the accuracy of bar code reading work by external dimensions of an object where a bar code is printed or a bar code label is stuck, the existence of light obliquely thrown to the bar code in the readable visual field on a bar code reader, and oblique observation of the bar code to the readable visual field on the bar code reader. CONSTITUTION:An image forming lens 40 is provided whose optical axis 38 intersects an optical axis 36 of the optical system of a bar code reader, and frames A and B arranged on the optical axis of the image forming lens 40 are provided. This device is characterized by forming the image of the frame A or B by the image forming lens 40 and displaying the bar code readable range of the position of one of both.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar code reading device reading range display device for displaying a bar code readable range of a bar code reading device.

[0002]

2. Description of the Related Art In recent years, a bar code reading device has been known in which a bar code is taken by a television camera and the bar code is read based on the taken bar code image.

The basic structure of a conventional bar code reader of this type is shown in FIGS. 4 (a) and 4 (b).
0, a support column 12 protruding upward from the pedestal 10, and a bar code reading unit 14 attached to the upper part of the support column 12. The barcode reading unit 14 includes a barcode reading window 16 facing the pedestal 10 and a television camera, and the television camera is the barcode reading window 1.
An image of the barcode placed on the pedestal 10 facing 6 is photographed. In the barcode reading unit 14, the barcode is read based on the photographed barcode image.

The bar code reading unit 14 is a support column 12.
The bar code readable range on the pedestal 10 can be changed by moving the TV camera within a predetermined range along the line or moving the television camera in the bar code reading unit 14 within the predetermined range.

In this type of conventional bar code reading apparatus, a monitor TV is connected to the TV camera in the bar code reading unit 14 in order to arrange the bar code within the bar code readable range on the pedestal 10, and as shown in FIG. (A),
As shown in FIG. 4B, a readable field frame 18a, 18b or 20 is provided at a position on the pedestal 10 facing the bar code reading window 16.

The readable field frames 18a, 18 shown in FIG.
b is formed by directly engraving a print on a predetermined position on the upper surface of the pedestal 10 or by sticking a printed matter on which a readable field frame is printed. When the TV cameras are installed at two locations or inside the barcode reading unit 14,
The bar code readable range on the pedestal 10 when it is arranged at a place is shown. This is because the photographing magnification of the barcode in the television camera of the barcode reading unit 14 is changed in two steps according to the width of the line forming the type of barcode to be read, and the photographing magnification is relatively large. In the case of a bar code constituted by a thin line, the bar code is enlarged (that is, the distance between the television camera in the bar code reading unit 14 and the upper surface of the pedestal 10 is reduced),
In the case of a bar code constituted by a relatively thick line, the bar code is made smaller (that is, the distance between the television camera in the bar code reading unit 14 and the upper surface of the pedestal 10 is increased).

The readable field frame 20 shown in FIG.
The frame member is supported by a support pin 20a at a predetermined position on the upper surface of 0 from the upper surface of the pedestal 10 at a predetermined distance.

[0008]

Although the use of a monitor television can easily deal with the change of the bar code readable range,
Increase the price of bar code readers.

In general, the bar code does not exist alone but is installed on some object. There are two methods of installation: a method of directly printing a barcode on the surface of an object or a method of attaching an adhesive label having a barcode printed on the surface of an object.

Therefore, the readable field frame 18 shown in FIG.
If an attempt is made to place a bar code in a or 18b, the readable field of view frames 18a and 18b will be covered by the object on which the bar code is installed, so that the area of the readable field of view will be much larger than the readable field of view frames 18a and 18b. If it is large or the thickness is relatively large, the barcode can be read.
It becomes difficult to dispose in a and 18b. Further, since there are a plurality of readable field frames 18a and 18b, it may be erroneous to select which one.

The readable field frame 20 shown in FIG. 4 (b) causes an operation of replacing the readable field frame with another readable field frame in accordance with a change in the bar code readable range. Further, the work of passing an object provided with a barcode in the gap between the upper surface of the pedestal 10 and the readable field frame 20 is complicated, and moreover, when the readable field frame 20 has light that is obliquely emitted. A shadow of the readable field frame 20 is generated in the readable field frame surrounded by the readable field frame 20 to cause an error in the barcode reading work, and further, the operator's eyes can read the field frame 2.
0 and the barcode reading window 1 of the barcode reading unit 14
As the distance from the optical axis connecting with 6 increases in the horizontal direction, the possibility of deviation of the barcode from the readable visual field of the readable visual field frame 20 increases, and the possibility of error in the barcode reading operation increases.

The present invention has been made under the above circumstances, and an object of the present invention is that the structure is simple and inexpensive, and the external dimensions of an object on which a bar code is printed or a bar code label is affixed and a bar code reader is provided. The accuracy of bar code reading work is impaired by observing the bar code in the readable field of view of the bar and observing the bar code from the bar code reader's readable field of view obliquely. It is an object of the present invention to provide a reading range display device for a bar code reading device, which is easy to arrange a bar code in a readable field of view without being damaged.

[0013]

In order to achieve the above-mentioned object of the present invention, a reading range display device for a bar code reading device of the present invention comprises a light source and an imaging lens for forming an image of the light from the light source. And a mold which is arranged in an optical path between the light source and the imaging lens and which shows a bar code readable range, and an optical axis of the imaging lens is an optical axis of an optical system of the bar code reading device. It is characterized in that they are arranged so as to intersect with each other and an image of the above-mentioned mold is formed.

[0014]

According to the reading range display device for a bar code reading device of the present invention, which is characterized in that it is configured as described above,
The bar code reader's reading is performed by forming an image of a frame showing the bar code readable range by an imaging lens arranged so that the optical axis of the optical system of the bar code reader intersects its own optical axis. The possible range is displayed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bar code reader having a bar code reader reading range display according to an embodiment of the present invention will be described below with reference to FIGS. Figure 1
As shown in, a half mirror 34 is arranged in front of the taking lens 32 of the television camera 30.

In addition to the optical axis 36 of the taking lens 32 of the television camera 30, there is a sub optical axis 38 branched by the half mirror 34. An imaging lens 40, a condenser lens 42, and a light source 44 are arranged in a direction along the sub optical axis 38 and away from the half mirror 34.

Two transparent glass frame plates 46 and 48 are arranged at different positions along the sub optical axis 38 between the image forming lens 40 and the condenser lens 42. Readable field frames A and B having different sizes are formed on the frame plates 46 and 48.

When the light source 44 is turned on, the condenser lens 42
The light collected by the two transparent glass frame plates 4
6 and 48, and as shown in FIG. 2 by the imaging lens 40, two transparent sheets at two different predetermined distances from the imaging lens 40 and two different magnifications. Images A'and B'of the readable field frames A and B on the glass frame plates 46 and 48 are created. Here, the two predetermined distances at which the images A ′ and B ′ are created and the two predetermined magnifications at the above two predetermined distances are the focal length of the imaging lens 40 and the imaging lenses 40 to 2 respectively. It is possible to obtain by a well-known formula from two mutually different distances to one readable field frame A and B.

In the above-described embodiment, as shown in FIG. 1, the light passing through the imaging lens 40 is reflected by the half mirror 34 and is reflected from the imaging lens 40 on the optical axis 36 of the taking lens 32 of the television camera 30. Image A of the readable field frames A and B on the two transparent glass frame plates 46 and 48 at two different predetermined distances and at two predetermined magnifications different from each other.
Create ', B'.

The entire bar code reader of this embodiment has substantially the same construction as that shown in FIGS. 4 (a) and 4 (b). That is, the difference between this embodiment and FIGS. 4A and 4B is that the configuration inside the barcode reading unit 14 is changed as shown in FIG. 1 and that the readable field frames 18a, 18b, 20 and Pin 20
There is no a.

Therefore, by vertically moving the bar code reading unit 14 along the support column 12, the television camera 30
When the position where the image A ′ or B ′ is created on the optical axis 36 of the taking lens 32 is made to coincide with the upper surface of the pedestal 10, the image A ′ or B ′ is displayed on this upper surface. When the image A'is formed on the upper surface, the image B'is greatly blurred on the upper surface and thus cannot be seen. On the contrary, when the image B'is formed on the upper surface, the image A'is formed. It cannot be seen because it is greatly blurred on the upper surface.

Since these images A'and B'are optically projected on the upper surface of the pedestal 10, unless the object placed on the upper surface of the pedestal 10 has a very large thickness, Image A'or B'is displayed on the upper surface. Alternatively, if the thickness of this object can be predicted, the transparent glass frame plate 46 corresponding to the desired image A ′ or B ′ is shifted so that the position where the desired image A ′ or B ′ is created is shifted according to the thickness. Alternatively, 48 may be moved along the sub optical axis 38.

When the image A'or B'is displayed on the upper surface of the pedestal 10, the range where the television camera 30 can reliably read the entire bar code on the upper surface of the pedestal 10 is the image A'displayed on the upper surface of the pedestal 10. Alternatively, it is a range surrounded by B '.

The bar code printed on the object or the bar code on the affixed bar code label is placed in the image A'or B'displayed on the upper surface of the object so that the half mirror 34 is moved. Through TV camera 30
The entire photographing lens 32 is surely photographed, and the bar code reading unit 14 is surely read.

The image A'or B'is displayed on the optical axis 3
The light will not disappear unless it is illuminated with too strong light from the side of 6, and the image from A'or B'is obtained by the light from the side.
There is no shadow in the area surrounded by. Further image A '
Or, since B'is displayed directly on the upper surface of the object, even if the image A'or B'is observed from a position distant to the side from the optical axis 36, the range surrounded by the image A'or B'is the image. A
It does not differ from the actual readable range of the television camera 30 at the position of 'or B'.

The bar code reading unit 14 may be fixed to the support column 12 and the television camera 30 may be movable in the housing of the bar code reading unit 14. In this case, however, the television camera 30 may be moved. In order to change the image of the readable field frame on the transparent glass frame plate created on the upper surface of the pedestal 10 so as to follow the bar code readable area on the upper surface of the pedestal 10 which changes with the change, the barcode reading unit 14 The imaging lens 40 or the transparent glass frame plate in the housing of the sub optical axis 38
Have to move along.

In the above-described embodiment, the two transparent glass frame plates on which the readable field frame is formed are used, but the bar code reading unit 14 with respect to the support column 12 is used.
Is not movable up and down, or when the TV camera 30 is not movable along the optical axis of the taking lens 32 inside the housing of the barcode reading unit 14, a transparent glass frame in which a readable field frame is formed Only one board is required. When the reading position is one as described above, the readable field frame may be a frame plate having an opaque substrate and only the frame line being a transparent portion.

Further, the bar code reading unit 14 can be moved to three or more positions in the vertical direction with respect to the support column 12. In this case, the transparent glass on which the readable field frame is formed is formed. Three or more frame plates will be used.

In the above-described embodiment, the television camera 30, the half mirror 34, the imaging lens 40 on the sub optical axis 38, the condenser lens 42, the light source 44, and the transparent glass frame are provided in the housing of the bar code reading unit 14. Board 4
6 and 48 are arranged, the half mirror 34, the imaging lens 40 on the sub optical axis 38, the condenser lens 42, and the light source 44.
The transparent glass frame plates 46 and 48 can be housed in a housing independent of the housing of the barcode reading unit 14.

Even in this case, when the bar code reading unit 14 is movable with respect to the support column 12 or the television camera 30 is movable within the housing of the bar code reading unit 14, the bar code reading unit 14 is movable.
Of the readable field frame on the transparent glass frame plate created on the upper surface of the pedestal 10 so as to follow the barcode readable area on the upper surface of the pedestal 10 that changes with the movement of the camera or the movement of the television camera 30. For this purpose, the imaging lens 40 or the transparent glass frame plate must be moved along the sub optical axis 38 in the independent housing.

Further, without using the half mirror 34, as shown in FIG.
As shown in FIG.
4 and the transparent glass frame plates 46 and 48 as the sub optical axis 3
8 is the base 10 at a very small angle with the optical axis 36 of the taking lens 32 of the television camera 30 of the barcode reading unit 14.
It is also possible to arrange to intersect on the upper surface of. In this case, the half mirror 34 and the imaging lens 4 on the sub optical axis 38
0, the condenser lens 42, the light source 44, and the transparent glass frame plates 46 and 48 are housed in a housing independent of the housing of the bar code reading unit 14, as in the case described above. The glass frame plates 46 and 48 are moved.

[0032]

As described above in detail, the reading range display device for a bar code reading device according to the present invention has a simple structure and is inexpensive, but it can be used for an object on which a bar code is printed or a bar code label is attached. The external dimensions and the presence of light that is obliquely radiated to the bar code in the readable field of view on the bar code reader and the bar code by observing the bar code obliquely to the readable field of view on the bar code reader The accuracy of the code reading work is not impaired, and the work of placing the bar code in the readable field of view is easy.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a state in which a reading range display device for a barcode reading device according to an embodiment of the present invention is combined with a barcode reading device.

FIG. 2 is a diagram schematically showing an operation principle of the reading range display device for the barcode reading device of FIG.

FIG. 3 is a diagram schematically showing a modified example of a reading range display device for a barcode reading device according to an embodiment of the present invention.

4A and 4B are perspective views schematically showing a barcode reading device combined with two conventional types of reading range display devices for barcode reading devices.

[Explanation of symbols]

10 ... Pedestal, 12 ... Support, 14 ... Bar code reading unit, 16 ... Bar code reading window, 18a, 18b, 20 ...
Readable field frame, 30 ... TV camera, 32 ... Photographing lens, 34 ... Half mirror, 36 ... Optical axis, 38 ... Sub optical axis,
40 ... Imaging lens, 42 ... Condensing lens, 44 ... Light source, 4
6, 48 ... Transparent glass frame plate, A, B ... Readable field frame, A ', B' ... Image.

Claims (1)

[Claims] 1. A light source, an image forming lens for forming an image of light from the light source, and a mold frame arranged in an optical path between the light source and the image forming lens and showing a bar code readable range. A reading range display device for a bar code reading device, wherein the optical axis of the image forming lens is arranged so as to intersect the optical axis of an optical system of the bar code reading device, and an image of the form is formed.