JPH0525544U - Bar code scanner - Google Patents

Abstract

(57) [Summary] [Objective] The reading operation is facilitated by increasing the depth of field for a barcode to be read as much as possible without reducing the amount of light incident on the light receiving surface of the photoelectric conversion element. A photoelectric conversion element 11 is arranged in a case C, one end of which is open for reading a bar code, so that a light receiving surface 11a faces the opened entrance end.
And a diaphragm 14 arranged on the optical axis in front of the photoelectric conversion element, and a diaphragm 14 arranged immediately after the condenser lens on the optical axis. The barcode scanner 10 has a rectangular shape with parallel and vertical side edges with respect to the direction in which the barcodes 12 to be aligned.
Make up.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a barcode scanner for optically reading a barcode printed or affixed to a product or the like.

[0002]

[Prior Art]

 Conventionally, such a bar code scanner is configured as shown in FIG. 3, for example. That is, the barcode scanner 1 has a CCD or the like arranged so that the light receiving surface 2a faces the opened entrance end in the case C whose one end is open for reading the barcode. The photoelectric conversion element 2 and the barcode 3 printed or attached on the surface of a product or the like (not shown) which is located at a predetermined position near the entrance end of the case C are received by the photoelectric conversion element 2. In order to form an image on the surface 2a, between the condenser lens 4 arranged in front of the light receiving surface 2a on the optical axis of the photoelectric conversion element 2, and between the condenser lens 4 and the photoelectric conversion element 2. And a diaphragm 5 having a circular opening 5a disposed on the optical axis in the vicinity of the condenser lens 4.

In the bar code scanner 1 having such a configuration, the bar code 3 (see FIG. 4) positioned at a predetermined position near the entrance end of the case C has a photoelectric conversion element via the condenser lens 4. An image is formed on the two light receiving surfaces 2a. At this time, since the diaphragm 5 is provided immediately after the condenser lens 4, the depth of field for the image of the barcode formed on the light receiving surface 2a becomes large, so that the barcode 3 Even if the position is shifted slightly back and forth on the optical axis, the barcode 3 is in focus. As a result, the photoelectric conversion element 2 accurately converts the image of the bar code 3 into an electric signal, and the control circuit or the like (not shown) performs appropriate processing so that the bar code can be read. There is.

[0004]

[Problems to be solved by the device]

 According to the barcode scanner 1 configured as described above, in order to accurately read the barcode, the image of the barcode 3 is accurately received by the photoelectric conversion element 2 based on the optical characteristics of the lens 4. It needs to be imaged on the surface 2a. If the aperture of the aperture 5 is reduced, the depth of field of the optical system including the lens 4 increases, so that the barcode 3 is in focus even if the barcode 3 is apart from the entrance end to some extent. Although the image is formed in this state, when the aperture of the diaphragm 5 becomes small, the amount of light incident on the light receiving surface 2a of the photoelectric conversion element 2 decreases, and the bar code 3 cannot be read accurately. For this reason, the aperture of the diaphragm 5 cannot be made very small, and thus there is a limit to increasing the depth of field of the barcode scanner 1, and the barcode scanner 1 can be used for the barcode 3 to be read. Since it was necessary to position it to some extent accurately, there was the problem that the barcode printed on a curved surface such as a can could not be read, and the reading operation was troublesome even with a flat surface.

In view of the above points, the present invention makes it possible to easily perform the reading operation by reducing the amount of light incident on the light receiving surface of the photoelectric conversion element and increasing the depth of field for the barcode to be read as much as possible. The purpose is to provide a barcode scanner.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a photoelectric conversion device in which one end is opened for reading a barcode and the light receiving surface is opposed to the opened entrance end. In a bar code scanner including an element, a condenser lens arranged on the optical axis in front of the photoelectric conversion element, and a diaphragm arranged on the optical axis immediately after the condenser lens, The diaphragm was constructed to be rectangular with side edges parallel and perpendicular to the side-by-side orientation of the bar code to be read.

[0007]

[Action]

 According to the above configuration, the barcode is imaged on the light-receiving surface of the photoelectric conversion element via the condenser lens and the diaphragm, whereby the photoelectric conversion element converts the barcode image into an electrical signal. After conversion, appropriate processing is performed by a control circuit or the like, and thus the barcode is read. At this time, since the diaphragm is formed in a rectangular shape corresponding to the direction of the barcode to be read, the barcode has a side edge length that is long in the direction in which it is aligned and the direction perpendicular to it. An image is formed on the light receiving surface of the photoelectric conversion element with a depth of field that is the aperture. Moreover, the amount of light that reaches the light-receiving surface of the photoelectric conversion element is larger than that of a circular diaphragm because the diaphragm is square, and therefore the depth of field is large and the amount of light incident on the light-receiving surface is large. Therefore, it becomes possible to read the barcode more accurately.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In FIG. 1, a bar code scanner 10 includes a CCD or the like arranged in a case C, one end of which is open for reading a bar code, such that a light receiving surface 11a faces the opened entrance end. The photoelectric conversion element 11 and the bar code 12 printed or attached on the surface of a product or the like (not shown) which is located at a predetermined position near the entrance end of the case C are provided on the light receiving surface of the photoelectric conversion element 11. In order to form an image on 11a, a condenser lens 13 arranged in front of the light receiving surface 11a on the optical axis of the photoelectric conversion element 11, and the condenser lens 13 and the photoelectric conversion element 11 And a diaphragm 14 disposed on the optical axis in the vicinity of the light collecting lens 13.

The above-mentioned configuration is similar to that of the conventional barcode scanner 1 shown in FIG. 3, but in the barcode scanner 10 according to the present invention, the diaphragm 14 is read as shown in FIG. A rectangular opening 14a having side edges extending in a parallel direction (x direction in the drawing) and a vertical direction with respect to the line direction of the barcodes 12 to be arranged is provided.

The bar code scanner 10 according to the present invention is configured as described above, and the bar code 12 positioned at an appropriate position near the entrance end of the case C is passed through the condensing lens 13, An image is formed on the light receiving surface 11a of the photoelectric conversion element 11. At that time, since the diaphragm 14 having the rectangular opening 14a is provided immediately after the condenser lens 13, the depth of field regarding the image of the barcode formed on the light receiving surface 11a is large. Therefore, even if the position of the bar code 12 is slightly shifted back and forth on the optical axis, the bar code 12 is in focus. As a result, the photoelectric conversion element 11 accurately converts the image of the bar code 12 into an electric signal, and the control circuit (not shown) or the like performs appropriate processing so that the bar code can be read. ing.

In this case, since the light emitted from the bar code 12 reaches the light receiving surface 11a of the photoelectric conversion element 11 through the aperture 14 having the rectangular opening 14a, The bar code 12 is connected to the light-receiving surface 11a of the photoelectric conversion element 11 with a depth of field in which the length of the side edge of the opening 14a of the aperture 14 is the diameter in the x direction and the direction perpendicular thereto. It will be made to be an image.

Moreover, the amount of light reaching the light-receiving surface 11a of the photoelectric conversion element 11 is larger than that in the case of a circular diaphragm because the aperture 14a of the diaphragm 14 is square. Therefore, due to the increased depth of field, the bar code 12 is not accurately positioned with respect to the condensing lens 13 and the photoelectric conversion element 12, but the photoelectric conversion element can be positioned through this diaphragm 14. Since it can be imaged on the light receiving surface 11a of 11, the bar code scanner 10 does not need to be accurately positioned with respect to the bar code 12 to be read when reading the bar code, so Reading of the bar code 12 is completed by a simple operation of bringing the bar code scanner 10 close to the bar code 12 so that the bar code 12 is located in front of the entrance end. ..

Further, since the amount of light incident on the light receiving surface is large, the opening 14a of the diaphragm 14 can be made smaller, and the barcode can be more accurately read. Thus, an accurate bar code can be read by an easy reading operation.

Since the aperture 14a of the diaphragm 14 is formed in a rectangular shape, the aperture in the diagonal direction is substantially increased, but when reading the barcode 12, the depth of field in the diagonal direction is slightly smaller. Even if this happens, the depth of field in the x direction is substantially determined by the length of the aperture 14 in the x direction, so the influence of the above-mentioned oblique blur on the reading performance is very small. is there.

[0015]

[Effect of the device]

 As described above, according to the present invention, since the diaphragm is formed in a rectangular shape corresponding to the direction of the barcode to be read, the barcode is arranged in the direction parallel to the barcode and the direction perpendicular to the barcode. An image is formed on the light receiving surface of the photoelectric conversion element with a depth of field where the length of the side edge is the aperture. Also, the amount of light that reaches the light-receiving surface of the photoelectric conversion element is larger than that of a circular diaphragm because the diaphragm is square, which has a large depth of field and is incident on the light-receiving surface. Due to the large amount of light, it is possible to read barcodes more accurately. Therefore, the barcode can be read accurately without positioning the barcode scanner with respect to the barcode, and the barcode reading operation becomes easy. Thus, according to the present invention, an extremely excellent bar code which facilitates reading operation by reducing the depth of field for the bar code to be read without reducing the amount of light incident on the light receiving surface of the photoelectric conversion element. A scanner is provided.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of an embodiment of a barcode scanner according to the present invention.

FIG. 2 is a front view of a diaphragm in the embodiment of FIG.

FIG. 3 is a perspective view showing a configuration of an example of a conventional barcode scanner.

FIG. 4 is a partial plan view showing a part of a barcode to be read.

[Explanation of symbols]

 10 Bar Code Scanner 11 Photoelectric Conversion Element 11a Light-Receiving Surface 12 Bar Code 13 Condenser Lens 14 Aperture 14a Aperture Opening

Claims (1)

[Scope of utility model registration request] 1. A photoelectric conversion element arranged such that a light receiving surface faces an opened entrance end in a case whose one end is open for reading a barcode, and the photoelectric conversion element. In a bar code scanner including a condenser lens disposed on the optical axis in front of and a diaphragm disposed immediately after the condenser lens on the optical axis. A barcode scanner having a rectangular shape having side edges parallel and perpendicular to the direction in which the barcodes are arranged.