JPH0594557A - Bar code reader - Google Patents

Abstract

PURPOSE:To accurately read out bar code information even when a bar code other than a previously programmed standard is stuck to the surface of an object and to attain accurate reading even in a state separated from a bar code by changing a distance between the upper surface of a base and an image pickup means in a camera housing by a distance changing means. CONSTITUTION:The image pickup means 46 utilizing a CCD and a fixed focus lens 48 to be an optical system are approximately horizontally stored in the camera housing 38 so as to be directed to the head of the housing 38 and a mirror 50 for directing its optical axis to the lower base 34 is fixed to the head of the housing 38. The housing 38 is vertically moved along a supporting member 36 projected from the base 34 to the upper direction or the means 46 and the lens 48 in the housing 38 are horizontally moved relatively to the mirror 50 to move the area of field depth. Thereby accurate reading can also be attained even in a state separated from a bar code.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar code reader.

[0002]

2. Description of the Related Art Bar code readers are roughly classified into two types. In one type, the bar code is scanned by the laser light, the intensity of the reflected light from the bar code is detected by the light receiving element, and the symbol information is displayed as black and white of the bar code. The bar code information is read. In the other format, the bar code information as the symbol information displayed by the black and white of the bar code is read by an image sensor such as a CCD.

The former laser type bar code reader can read bar code information from the bar code even when the bar code is separated from the scanner. It is expensive because a large input is required to drive the laser light emitting means, and the laser optical scanner mechanism causes the reading device to become large in size and the structure to become complicated.

The latter CCD type bar code reader is C
Since the optical system combined with the CD is constructed with a fixed focus and a fixed magnification, the bar code information cannot be read from the bar code unless the scanner is placed on the bar code. It is inexpensive because it does not require any input, and there is no structure that makes the reader larger and the structure more complicated. Such a CCD type bar code reader is disclosed in, for example, Japanese Utility Model Publication No. 60-5407.

As shown in FIG. 5, the CCD bar code reader disclosed in this publication has an optical system 1 such as a lens.
0 and a CCD image sensor 12 and CC as image pickup means
Amplifier circuit 1 for amplifying the output from the D image sensor 12
4 and a scanning control circuit 16 for controlling scanning of the CCD image sensor 12 are stored in the camera housing 18. The amplifier circuit 1 is provided at a portion of the camera housing 18 far from the optical system 10 and the CCD image sensor 12.
A cable 20 for output from the optical disc 4 and input to the scanning control circuit 16 is connected to the optical system 10 and the CCD image.
A transparent box 22 supported by a plurality of columns 22a is connected to the facing portion of the disensor 12.

The flat protruding end of the transparent box 22 is pressed onto a bar code 26 printed on a bar code label affixed on the article 24 or directly printed on the article 24. ..

[0007]

The height of the transparent box 22 is
The bar code 26 pressed against the flat protruding end of the transparent box 22 is preset to a predetermined value so that an image is formed on the CCD image sensor 12 via the optical system 10. Barcodes 2 located on both sides of the fixed focus optical system 10
6 schematically shows the relationship between the CCD 6 and the CCD image sensor 12, the following equation is derived. B / A = b / a, 1 / a + 1 / b = 1 / fa a distance from the bar code 26 as a subject to the center (principal point) of the lens that is the optical system 10, b ... lens center CCD as the image pickup means from (main point)
Distance to the image sensor 12, A ... Size of the bar code 26 as a subject, B ... Size of the bar code 26 reflected on the CCD image sensor 12 as an image pickup means, f ... The lens Focal length.

As is clear from the above two equations,
When the size A of the bar code 26 as the subject changes, the distance a from the bar code 26 as the subject to the center (principal point) of the lens that is the optical system 10 or another focal length is provided. Since the bar code 26 cannot be imaged on the CCD image sensor 12 unless it is replaced with a lens, the above-mentioned conventional CCD bar code reader does not conform to a standard other than a predetermined standard. The size of the bar code cannot be read.

In the conventional CCD bar code reader described above, the protruding end of the transparent box 22 must be pressed against the bar code 26 even if the bar code is of a predetermined standard. Since the bar code 26 cannot be read, the bar code
When the article marked with the dot 26 is a bag filled with liquid or powder, the protruding end of the transparent box 22 may damage the bag and the liquid or powder inside may be ejected. ..

Although the laser type bar code reader can read the bar code information from the bar code even when the bar code is separated from the scanner, it is a predetermined method. Since it is necessary to obtain the reflected light with an intensity within the range, there is a readable distance within a predetermined range, and bar code information is read from a bar code that passes outside this readable range. I can't. Further, in the laser type bar code reader, since the laser beam scanning direction of the scanner is predetermined, the bar code is set in a predetermined direction with respect to the predetermined laser beam scanning direction. If you do not point it, you cannot read the bar code.

For this reason, in the laser type bar code reader, once the bar code cannot be read, the distance from the scanner is changed or the bar code in the laser light scanning direction is changed. -Several trials such as changing the direction of the code are required, which wastes the labor of the operator and reduces the bar code reading work efficiency.

In the conventional bar code readers of the laser type and the CCD type, when the bar code information cannot be read from the bar code by the scanner of these devices, the bar code information cannot be read. , A number printed on the bar code and representing the bar code information is input by the operator to the bar code reader using the keyboard. However,
There are too many bar code information among many standard bar codes, and it takes a lot of time to input the bar code information using the keyboard. Required, CODE49 or D
The so-called 1.5-dimensional bar code such as ata code and 2-dimensional bar code have a large amount of bar code information so that key input is practically impossible.

The present invention has been made under the above circumstances, and an object of the present invention is to make a bar code even when a bar code of a standard other than the one intended to be read in advance is attached to the surface of an object.
With a CCD type bar code reader which can accurately read bar code information from a code and which is inexpensive and can not be displaced in the scanning direction with respect to the bar code. Even if it is present, the bar is released even if it is separated from the bar code.
It is an object of the present invention to provide a bar code reader which can accurately read code information.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned object, a bar code reader according to the present invention comprises a base,
A camera housing having a support member provided on the base and protruding upward from the base, and having an image pickup means and its optical system supported by the support member and holding the image pickup means and the optical system above the base. And a distance changing means for changing the distance between the upper surface of the base and the image pickup means in the camera housing, and the bar code placed on the base is provided by the image pickup means via an optical system. It is characterized by reading.

[0015]

In the bar code reader according to the present invention, which is characterized as described above, the bar code information is accurately read out from the bar code. At the same time, in order to accurately read the bar code information from the bar code of the standard other than the one scheduled to be read in advance, the distance change means protrudes upward from the base upper surface and the base. The bar code is imaged on the image pickup means by changing the distance between the image pickup means in the camera housing supported by the support member.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 schematically shows the construction of a bar code reader according to the first embodiment of the present invention.

This bar code reader has a bar code of 3
Is a bar code label with 0 printed on it?
Base 3 for placing an object 32 on which the code 30 is printed
4, a columnar support member 36 extending substantially vertically upward is fixed to the base 34.

A camera housing 38 extending above the base 34 in a substantially horizontal direction is attached to the support member 36 so as to be vertically movable. The camera housing 38 is formed on the support member 36 so as to extend in the vertical direction. Rack 36a
By rotating the vertical movement control handle 40 that drives a pinion (not shown) that meshes with, it is possible to move vertically along the support member 36 by a distance corresponding to the rotation direction and amount of rotation.

The outer surface of the support member 36 is further provided with an index 42 for knowing the relative movement distance of the camera housing 38 with respect to the support member 36, and further with respect to the base 34, and the camera housing 38 has an index. An arrow 43 for pointing 42 is attached.

The camera housing 3 for the support member 36
The relative position of 8 in the vertical direction can be fixed by tightening a clamp knob 44 provided on the camera housing 38.

In the camera housing 38, an image pickup means 46 using a CCD (charge coupled device) and a fixed focus lens 48 as an optical system thereof are stored in a substantially horizontal state toward the tip of the camera housing 38. .. A mirror 50 for directing the optical axes of the image pickup means 46 and a fixed focus lens 48 as an optical system to the lower base 34 is provided at the tip of the camera housing 38, and the fixed focus as an optical system is still provided. The lens 48 is replaceable.

A photographing window 52 for passing the optical axis is formed on the lower surface of the tip of the camera housing 38.
An illumination device 54 that illuminates the lower side is installed around the photographing window 52.

Below the photographing window 52 at the tip of the camera housing 38 on the base 34, the relative position of the camera housing 38 in the vertical direction with respect to the support member 36, the number of pixels of the image pickup means 46, and the fixed focus lens 48. Reading jig 5 showing the upper limit of the depth of field determined by the focal length and resolution
6 is provided. Here, the lower limit of the depth of field is the upper surface of the base 34.

The reading jig 56 includes an auxiliary column 56a which stands up substantially vertically from the upper surface of the base 34 and an auxiliary column 56a.
Extending substantially horizontally from the upper surface of the base 34 to the auxiliary column 5
Horizontal support member 56b capable of moving up and down relative to 6a
The horizontal support member 56b supports the visual field frame 56c which shows the visual field of the image pickup means 46 through which the optical axis X extending downward from the photographing window 52 passes. The vertical position of the horizontal support member 56b relative to the auxiliary column 56a can be fixed by the clamp knob 56d.

Between the fixed focus lens 48 and the position below the field frame 56c of the reading jig 56 on the upper surface of the base 34, the size of the image pickup means 46 is 1/2 inch and the focal length f of the fixed focus lens 48 is 25 mm. When the distance is about 350 mm, the depth of field A becomes 25 mm and the bar code 30 can be read.
The maximum dimension of is 60 mm x 60 mm. The resolution at this time is 0.25 mm.

In this case, the horizontal support member 56b of the reading jig 56 is 25 mm which is the depth of field A from the upper surface of the base 34.
The height of the article 32 placed on the upper surface of the base 34 is fixed within 25 mm, and the image pickup means 46 in the camera housing 38 is fixed to the height of 20 mm. If the width of the bar is 0.25 mm or more, the bar code 30 can be read. Further, the boring size of the field frame 56c of the horizontal supporting member 56b of the reading jig 56 is 60 mm × 60.
set to mm.

In the bar code reader according to the first embodiment constructed as described above, the article 32 having a height of 25 mm or less is attached to the upper surface thereof by a continuous conveying means such as a belt conveyor. Even when the bar code 30 is continuously conveyed so as to pass through the field frame 56 of the horizontal support member 56b of the reading jig 56, the minimum bar width of the bar code 30 is 0.25 mm. The bar code 30 on the articles 32 that are continuously conveyed can be read if the conveyance speed is appropriate.

The horizontal support member 56 of the reading jig 56 is provided.
After confirming the readable depth of field A of the bar code 30 and the field of view, b can be removed from the auxiliary column 56a if it interferes.

The auxiliary column 56a of the reading jig 56 is
Instead of being on the upper surface of the base 34, it may be hung so as to project downward from the camera housing 38 substantially vertically as shown in FIG. In this case, the area that can be freely used on the upper surface of the base 34 can be enlarged.

FIG. 3A shows a second embodiment of the present invention constructed so as to be convenient for reading a bar code 62 attached to the upper surface of an article 60 having a height of 25 mm or more. A bar code reader according to the present invention is shown. In this embodiment, the same parts as those in the first embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted.

In this embodiment, in order to make it convenient to freely move the article 60 having a height of 25 mm or more on the upper surface of the base 34, the reading jig 56 used in the first embodiment is used. Not used.

In this embodiment, the index 42 is marked on a moving index plate 64 which is vertically movable relative to the support member 36. An auxiliary index 66 is marked on the surface of the support member 36 along the movement trajectory of the movement index plate 64. Auxiliary index 66
Is a movement indicator plate 64 arranged at the lower end position indicated by the chain double-dashed line
The scale number of the auxiliary index at the position corresponding to the lower end of the mark is set to 0 as shown in FIG.
From above to above, the scale of the auxiliary index is marked in mm order, and predetermined numbers are shown at predetermined intervals of the scale, for example, as shown in FIG. 3 (b).

First, with the auxiliary index 66 placed at the lower end position indicated by the chain double-dashed line, as in the case of the first embodiment described above, the position below the field frame 56c of the reading jig 56 is set on the upper surface of the base 34. And the distance between the fixed focus lens 48 and the fixed focus lens 48 is about 350.
It is assumed that the vertical position of the camera housing 38 is fixed to be mm.

When reading the bar code 62 on the upper surface of the article 60 having a height of 25 mm or more, first, the movement index plate 64 is moved by the height of the article 60, for example, 50 mm, as shown in FIG. As shown in b), the graduation position of the index on the movement index plate 64 indicated by the arrow 43 before moving the camera housing 38 upward relative to the support member 36 is indicated by the arrow 43. Are moved upward relative to the support member 36 until is shown again. In this case, the depth of field A is 75 mm from the position 50 mm from the upper surface of the base 34.
Position.

In the case of the second embodiment which is characterized as described above, the upper and lower parts of the camera housing 38 required for reading the bar code 62 on the upper surface of the article 60 having a height of 25 mm or more. It is possible to easily set a new directional position.

In the first embodiment, the modification thereof, and the second embodiment described above with reference to FIGS. 1 to 3, the base is located within the depth of field A of the image pickup means 46 and the fixed focus lens 48. Three
In order to arrange the bar code 30 or 62 on the article 32 or 60 on the upper surface of 4, the camera housing 38 was moved in the vertical direction relative to the support member 36.
The same effect can be obtained by moving the image pickup means 46 and the fixed focus lens 48 horizontally relative to the mirror 50 in the camera housing 38 as in the third embodiment shown in FIG. I can. In this embodiment as well, the same parts as those in the first embodiment described above are designated by the same reference numerals, and detailed description thereof will be omitted.

In this embodiment, it is not necessary to move the camera housing 38 in the vertical direction relative to the support member 36. Therefore, in the first embodiment, the rack 36a provided on the surface of the support member 36 and the rack 36a The vertical movement control handle 40 provided on the camera housing 38 for driving the meshing pinion (not shown) is omitted.

Instead, the moving base 7 in which the image pickup means 46 and the fixed focus lens 48 extend horizontally in the camera housing 38 along the longitudinal direction of the camera housing 38.
0a, the moving base 70a extends horizontally in the camera housing 38 along the longitudinal direction and is fixed on a fixed base 70b fixed in the horizontal direction along the longitudinal direction of the camera housing 38. It is free to move. The camera housing 38 has a movable base 70b with respect to a fixed base 70b.
A horizontal movement knob 80 for relatively moving a is provided.

First, the reading jig 5 is placed on the upper surface of the base 34.
When the relative position of the moving base 70a to the fixed base 70b is adjusted so that the distance between the lower position of the field frame 56c of 6 and the fixed focus lens 48 is about 350 mm, the image pickup means 46 and the fixed focus are adjusted. Depth of field of lens 48 A (2
The lower limit of the height (5 mm) can be set to the upper surface of the base 34, and in this embodiment, the upper limit of the depth of field A (height of 25 mm) is set on the upper surface of the base 34. The horizontal support member 56b of FIG.

When reading the bar code 62 on the upper surface of the article 60 having a height of 25 mm or more as shown in FIG. 3, the bar code 62 is a fixed focus lens which is the lower limit of the depth of field A. The horizontal movement knob 80 of the camera housing 38 is used so that it is located between a position of about 350 mm from the position 48 and a position of about 325 mm from the fixed-focus lens 48 corresponding to the upper limit of the depth of field A of 25 mm. The moving base 70a is moved in the camera housing 38 relative to the fixed base 70b.

Various numerical values in the operating procedure in the above-mentioned first to third embodiments are CCDs constituting the image pickup means 46.
The dimensions (screen size, number of pixels) of the image sensor and the focal length f of the fixed-focus lens 48 are specified. These dimensions (screen size, number of pixels) and focal length f
As a matter of course, changing the above changes the above-mentioned various numerical values. The resolution, depth of field, and readable bar code size of the image pickup means 46 are determined by the relative size between the image pickup means 46 and the fixed focus lens 48.

[0042]

As described above in detail, in the bar code reader according to the present invention, the bar code of the standard other than the one scheduled to be read in advance is attached to the surface of the object. In this case, the bar code information can be accurately read from the bar code by changing the distance between the upper surface of the base and the image pickup means in the camera housing by the distance changing means. In addition, the bar code information is accurate even at a distance from the bar code although it is a CCD bar code reader which is inexpensive and is not displaced in the scanning direction with respect to the bar code. Can be read.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing the configuration of a bar code reader according to a first embodiment of the present invention.

FIG. 2 is a diagram schematically showing a modification of the bar code reader of FIG.

FIG. 3 (a) is a diagram schematically showing the construction of a bar code reader according to a second embodiment of the present invention, and FIG.
FIG. 4 is an enlarged view of a part of the bar code reader of FIG.

FIG. 4 is a diagram schematically showing the configuration of a bar code reader according to a third embodiment of the present invention.

FIG. 5 is a diagram schematically showing a configuration of a conventional bar code reader.

FIG. 6 is a diagram schematically showing the relationship between a bar code as a subject and a CCD image sensor as an image pickup means located on both sides of a fixed focus lens.

[Explanation of symbols]

30 ... Bar code, 32 ... Object, 34 ... Base, 36 ... Support member, 36a ... Rack, 38 ... Camera housing, 4
0 ... Vertical movement control handle, 42 ... Index, 43 ... Arrow, 4
4 ... Clamp knob, 46 ... Imaging means, 48 ... Fixed focus lens, 50 ... Mirror, 52 ... Photographing window, 54 ... Illumination device, 56 ... Reading jig, 60 ... Object, 62 ... Barco
Reference numerals 64, 64 ... Moving index plate, 66 ... Auxiliary index, 70a ... Moving base, 70b ... Fixed base, 80 ... Horizontal moving knob.

Claims (4)

[Claims] 1. A pedestal, a support member provided on the pedestal and projecting upward from the pedestal, an imaging means and an optical system thereof, and supported by the support member, the imaging means above the pedestal. A bar-coupler mounted on the base is provided with a camera housing for holding the optical system and a distance changing means for changing the distance between the upper surface of the base and the imaging means in the camera housing.
A bar code reader characterized in that the image is read by an imaging means via an optical system. 2. A reading control indicating an upper limit of the depth of field of the image pickup means which changes corresponding to a distance between the upper surface of the base and the image pickup means in the camera housing which is changed by the distance change means. The device according to claim 1, further comprising a tool.
A bar code reader according to claim 1. 3. The bar code reader according to claim 1, wherein the distance changing means moves the camera housing up and down along the support member. 4. The distance changing means moves the image pickup means and its optical system in the camera housing to change the distance between the upper surface of the base and the image pickup means in the camera housing. A bar code reader according to claim 1.