JP2783629B2 - Barcode reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION 【Overview】

Regarding the bar code reader, with the aim of providing a bar code reader with a wide reading area, a plurality of lenses with different focal lengths held in a frame are sequentially inserted into the beam optical path system from the light source, and the focus position is periodically determined. It is configured to emit different scanning beams.

[Industrial applications]

The present invention relates to a barcode reader. In recent years, POS systems have been introduced in department stores, supermarkets, and the like for the purpose of streamlining product management and checkout operations. This system performs product management by reading a barcode attached to a product with a barcode reader device, and a barcode reader device with high barcode reading efficiency is required.

[Prior art]

FIG. 4 shows an optical system in a conventional bar code reader. Reference numeral 3 denotes a laser tube as a light source, 4 denotes a mirror for changing an optical path, and a beam from the light source 3 is converged by a lens 2; A predetermined beam diameter is obtained at a predetermined height.

[Problems to be solved by the invention]

However, in the above conventional example, since the beam is narrowed by one kind of lens 2, the focal length is predetermined at one place, and the bar code can be read only in the vicinity thereof, and the reading area is narrow. Had the disadvantage that SUMMARY OF THE INVENTION The present invention has been made to solve the above-described drawbacks, and has as its object to provide a barcode reader having a wide reading area.

[Means for Solving the Problems]

According to the present invention, the above object is achieved by sequentially inserting an appropriate number of lenses selected from a plurality of lenses having different focal lengths held in an intermittently driven frame into a beam optical path system from a light source and periodically adjusting a focal position. Is achieved by providing a bar code reader that emits different scanning beams. A frame 1 for intermittently rotating the plurality of lenses 2
The plurality of lenses 2 may be held on a frame 1 that reciprocates intermittently.

[Action]

Based on the above configuration, in the present invention, a plurality of scanning beams focused at different positions over time are formed by sequentially inserting lenses 2 having different focal lengths into the optical path system. As a result, a plurality of different reading areas are formed on the apparatus main body 5, and the barcode located in any one of the areas is read by the scanning beam forming the area.

【Example】

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a bar code reader according to an embodiment of the present invention, in which 3 is a laser tube as a light source, 6 is a polygon mirror, and 4 is a mirror for changing the optical path. Reference numeral 1 denotes a frame which rotates intermittently by a driving device (not shown), and is inserted between the light source 3 and the polygon mirror 6. A plurality of lenses 2, 2,... Are fixed on a circumference around the rotation axis 7 of the frame 1, and one of them is always on a line connecting the light source 3 and the polygon mirror 6. It is to be inserted. The focal lengths of these lenses 2 are set at appropriate heights H1, H2,.
The beam diameter is narrowed to a value that can read, for example, 0.8 to 2 times the barcode size at a position having a barcode, and a value is formed so as to form a barcode reading area near the beam diameter. By making them different, a plurality of reading areas are formed. Therefore, according to this embodiment, after the beam from the light source 3 is narrowed down by one of the lenses 2 held on the frame 1 that rotates intermittently at a rotation speed of about 1/10 of the rotation number of the polygon, A scanning beam is formed by being reflected by the mirror 6, and is emitted from the window 8 to the outside of the apparatus main body 5. As a result, a plurality of reading areas that change with time are formed on the apparatus main body 5,
The barcode is read by any of the scanning beams. FIG. 2 shows another embodiment of the present invention.
Is a mirror for changing the optical path, and 6 is a polygon mirror. The frame 1 according to this embodiment is formed in an elongated rectangular shape so that three lenses 2A, 2B, and 2C having different focal lengths are arranged side by side in the same manner as shown in FIG. Is reciprocated intermittently so that any one of the lenses 2 is inserted into the beam optical path. Therefore, according to this embodiment, since the beam from the light source 3 is focused by the lens 2 at the upper portions H1, H2, and H3 of the apparatus main body 5, three reading areas can be obtained.

【The invention's effect】

As is apparent from the above description, according to the barcode reader of the present invention, a plurality of barcode reading areas are formed on the apparatus main body, and if the barcode is located in any of them, the barcode can be surely read. Since reading is possible, the reading area can be substantially widened.

[Brief description of the drawings]

 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing another embodiment of the present invention, FIG. 3 is a side view thereof, and FIG. 4 is a diagram showing a conventional example. In the figure, 1 is a frame, 2 is a lens, and 3 is a light source.

Claims (3)

(57) [Claims] 1. A scanning beam having a focal point periodically different from a plurality of lenses selected from a plurality of lenses having different focal lengths, which are held by an intermittently driven frame, are sequentially inserted into a beam optical path system from a light source. Bar code reader that irradiates light. 2. The bar code reader according to claim 1, wherein said frame is driven intermittently. 3. The bar code reader according to claim 1, wherein said frame is driven intermittently.