JPH0444183A - Bar code scanner - Google Patents

Abstract

PURPOSE:To read a bar code even at the time of scanning it with a ball lens slightly floated from the bar code face by constituting a bar code contact part of the ball lens to softly bring it into contact with the bar code face. CONSTITUTION:A bar code contact part 13, 15 to be brought into contact with the bar code face, a light emitting part 17 which irradiates the bar code face with light through the bar code contact part 13, 15, and a light receiving part 23 which receives light reflected from the bar code face are provided. An optical system consists of a ball lens 15 constituting the bar code contact part 13, 15 and a convex lens 19 provided on the optical axis of the ball lens 15, and the image of reflected light from the bar code face is formed on the light receiving part 23 by this optical system. Thus, this scanner is inexpensive and is easy to assemble, and the bar code face is not damaged to correctly read the bar code though infants use it somewhat violently.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a barcode scanner, and particularly to a barcode scanner used in a learning machine for young children.

(Prior Art) Barcode scanners are broadly classified into sapphire type and convex lens type.

In the sapphire method, as shown in Figure 3, the barcode surface 5
A barcode abutting portion for scanning 1 is formed of a sapphire ball lens 53 having a high refractive index. When parallel illumination light is applied to this sapphire ball lens 53, it is focused on the surface of the ball lens 53. Therefore, as the ball lens 53 is slid over the barcode surface 51, an image spreads on the cup of the ball lens 53 and a large amount of reflected light is generated, so that an optical system can be formed by itself without being combined with other lenses. This reflected light is received by a light receiving section of a phototransistor 57 provided on the optical axis of the ball lens, and converted into a signal. or,
A light shielding plate 59 is provided at the back of the light emitting section 55 to block the light from the light emitting section 55 and to receive only the reflected light from the barcode surface 51.

As shown in FIG. 4, the convex lens method is basically the same principle as photography, in which illumination light is emitted from a light emitting part 61 of a light emitting diode provided close to the barcode surface 51 to the barcode surface 51. The reflected light from the barcode surface 51 is imaged by a convex lens 63 onto a slit portion 65 with a diameter of 01 to 0.2 mm, and the negative portion thereof is extracted by a light receiving portion 67 of a photodiode provided on the optical axis of the convex lens 63 and converted into a signal. There is.

Further, a protective glass 69 is provided at the barcode abutting part that directly touches the barcode surface 51, and the light emitting part 61 and the convex lens 6 are provided with a protective glass 69.
A light shielding plate 71 is provided between 3 and 3 in order to block the light from the light emitting section 61 and receive only the reflected light from the barcode surface 51.

(Problem to be Solved by the Invention) However, although the sapphire method has a simple optical system and does not require much precision and is easy to assemble, the sapphire ball lens 53 has a shallow depth of focus, so it is one inch from the barcode surface 51. However, if you move away, the focus will deteriorate and the reading accuracy will deteriorate.

Further, the sapphire ball lens 53 is expensive by itself, so it is not suitable for a learning machine for young children.

Furthermore, since the illumination light is also focused close to the surface of the ball lens 53, it tends to become a bin spot, making it difficult to align the light receiving axis with the illumination point.

In addition, since the convex lens method has a deep focal depth of the optical system, it is sufficient even if the protective glass 69 of the barcode abutting part is about 2 mm away from the barcode surface 51 or if the inclination is large when it touches the barcode surface. Although this method can read the barcode surface 51 and has good decomposition performance, this method has the following drawbacks. Since there is nothing to condense the illumination light from the light emitting section 61 and the illumination light is weak, it is necessary to provide the light emitting section 61 close to the barcode surface 51, and skill is required to obtain the precision of the slit 65. Advanced technology is required for processing and assembly.

(Means for Solving the Problems) In order to solve the above problems, the present invention includes a barcode abutting section that contacts the barcode surface, and a light emitting section that irradiates light onto the barcode surface through the barcode abutting section. , an optical system is formed by a ball lens that forms a barcode abutting part, and a convex lens provided on the optical axis of the ball lens. The system was configured to image the reflected light from the barcode surface onto the light receiving section.

(Operation) According to the above means, when a young child traces the barcode surface of the teaching material on which the barcode is displayed with the barcode contact part of the barcode scanner connected to the learning machine for young children shown in the figure, the light emitting part The light emitted from the barcode is reflected by the barcode surface and converted into a signal by the light receiving section, and the learning machine responds to this signal to proceed with learning.

(Example) Next, embodiments of the present invention will be described based on the attached drawings.

FIG. 1 is a perspective view of a barcode scanner according to the present invention with main parts cut away, and FIG. 2 is a diagram showing the principle of the scanner.

The barcode scanner 1 has a pen-like shape, and includes two substantially cylindrical cases 3.5 that engage with each other and have a thick base and a thin tip. It consists of a pliers tube 7 having a shape. A cord 9 for connecting to the illustrated learning machine for young children extends from the base of the case 3.5, and a curved portion 11 is formed at the boundary between the base and the tip to make it easier to grip when held. ing.

A hole 13 with a diameter of ψ6 mm is provided at the tip of the pliers 7, and a ball lens 15 is fitted into the hole 13 and fixed therein. On the back of the ball lens 15, light emitting sections 17 each consisting of a light emitting diode are provided on both sides of the optical axis m of the ball lens 15.

As shown in FIG. 2, the light emitting section 17 is installed at an angle such that the optical axes p and q of the emitted illumination light are focused on the optical axis m near the surface of the tip of the ball lens 15. Also, on the optical axis m of the ball lens 15 on the back of the light emitting part 17, there is an effective aperture φ3 m at a predetermined distance from the ball lens 15.
m convex lenses 19 are provided. A light-receiving section 23 consisting of a phototransistor having a light-receiving element 21 installed is provided on the optical axis ml further behind this convex lens '19.

At the back of the light receiving section 23, there is an IC board 2 for amplifying and processing the signal converted from light into an electrical signal by the light receiving section 23.
5 is provided. Further, the IC board 25 is covered with a foldable shield plate 27 to prevent noise.

When a child holds this barcode scanner 1 in his or her hand and traces the barcode surface 29 of the teaching material shown in FIG. It is reflected by the code surface 29 and the light receiving part 23
It is converted into an electrical signal, and the learning machine responds to this signal to proceed with learning.

At this time, even if an infant rubs the barcode surface 29 strongly, since the barcode contact part 15 is a ball lens and the contact is soft, there will hardly be any streaks or irregularities on the barcode surface 29 that would make it unreadable. .

In the barcode scanner of the present invention described above, the optical system is made of the ball lens 15 and the convex lens 19.
The depth of focus can be relatively wide, and the ball lens 1
5 can be read even if it is scanned in a state where it is slightly lifted from the barcode surface 29. Furthermore, since the light from the light emitting section 17 passes through the ball lens 15 and is irradiated onto the barcode surface 29, the illumination area is wide and the light condensing property is high, so that high-intensity illumination is possible. Furthermore, by adding a convex lens, more reflected light is returned, so an expensive photodiode is not required and the light can be received by a phototransistor. Furthermore, since special precision is not required during processing and assembly, the optical axis of the optical system can be aligned at the level of a molded product using a mold, and therefore assembly is easy and does not require special skill.

(Effects of the Invention) As described in detail above, the present invention is inexpensive, easy to assemble, and can be read correctly without damaging the barcode surface even if a child uses it somewhat roughly.

[Brief explanation of the drawing]

Fig. 1 is a perspective view with the main parts of the barcode scanner of the present invention cut away, Fig. 2 is a view showing the optical system, Fig. 3 is a view showing the sapphire optical system, Fig. 4 1 is a diagram showing a convex lens type optical system. In the drawing, 1 is a barcode scanner, 15 is a ball lens, 17 is a light emitting part, 19 is a convex lens, 23 is a light receiving part, 2
9 is the barcode surface, and m is the optical axis of the ball lens.

Claims (3)

[Claims] (1) Equipped with a barcode contact section that scans the barcode surface, a light emitting section that irradiates light onto the barcode surface through the barcode contact section, and a light receiving section that receives light reflected from the barcode surface. In the barcode scanner, an optical system is formed by a ball lens forming the barcode contact portion and a convex lens provided on the optical axis of the ball lens, and the optical system detects light reflected from the barcode surface. A barcode scanner that forms an image on the light receiving section. (2) The barcode scanner according to claim 1, wherein the light emitting section is a light emitting diode. (3) The barcode scanner according to claim (1), wherein the light receiving section is a phototransistor.