JPS6199117A - Bar code reader - Google Patents

Abstract

PURPOSE:To obtain a small-sized and lightweight bar code reader without receiving the influence of disturbance such as electrical noise by providing a condenser lens to one aperture end of a cylindrical holding member and inserting an optical fiber into said member from the other aperture end thereby constituting a wand. CONSTITUTION:The optical fiber cable 2 is inserted into the cylindrical holding member 1 from one aperture end and a cap 5 opened at the top end is provided to the other end of the member 1. The condenser lens 6 is fixed by means of a holding ring 7 between the aperture at the top end of the member 1 and the aperture of the cap 5. An optical connector 8 which is made incident with light and takes out the light reflected from bar codes is provided at the other end of the cable 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a barcode reading device that optically reads barcodes.

[Conventional technology and problems]

Conventional barcode reading devices house a light source consisting of an LED or the like in a bent-type case called a wand, an optical sensor consisting of a phototransistor, etc., a drive circuit that drives the light source, and amplification of the output signal of the optical sensor. It is formed by housing an amplifier etc.

The wand and the main body of the signal processing device are connected by a coaxial cable or the like.

As mentioned above, in the conventional device, ■ Since elements such as LEDs and photodiodes that mutually convert optical signals and electrical signals are provided especially at the tip of the wand, they are not affected by external electrical noise. This has the disadvantage that it is easy to use and easily breaks down. In particular, phototransistors, which are optical sensors, discard even weak electrical noise as signals, so motors, etc.
When I entered the 10F barcode, I sometimes read the barcode by mistake (misreading). Furthermore, if water droplets are attached to the bar code or if the person using the bar code has wet hands, water may enter the sensor portion and cause electrical leakage.

■ Furthermore, since the light source drive circuit, detection signal amplification circuit, etc. are housed in a vent-type case, there is an inconvenience that the wand itself becomes large and heavy. Furthermore, when these signal processing circuits are housed in a vent-type case, it is difficult to sufficiently shield electrical noise from the outside, and the reliability of the read results also decreases.

[Purpose of the invention]

The present invention was made in order to overcome the drawbacks of the above-mentioned prior art, and is free from the influence of disturbances such as electrical noise.
The object of the present invention is to provide a compact and timeless barcode reading device.

[Summary of the invention]

In order to achieve the above object, the present invention provides a condensing lens at one open end of a cylindrical holding member, and inserts an optical fiber from the other open end to form a wand. The present invention provides a barcode reading device provided with an optical connector that inputs light at the other end and extracts reflected light from the barcode.

[Embodiments of the invention]

Hereinafter, some embodiments of the present invention will be described with reference to FIGS. 1 and 2 of the accompanying drawings. FIG. 1 is a configuration diagram when the bent-type case of the same embodiment is cut in the longitudinal direction. An optical fiber cable 2 coated with synthetic resin or the like is inserted into the plastic holding member 1 from one open end.

A pipe-shaped cover 3 is attached to one end of the optical fiber cable 2 within the holding member 1, thereby fixing the holding member 1 and the optical fiber cable 2. Note that the inner surface of the holding member 1 is treated so as not to reflect light (for example, the inner surface is painted black). The insertion port of the optical fiber cable 2 into the holding member 1 is sealed with a protective tube 4,
At the other end of the holding member 1 is a cap 5 with an open tip.
is provided. This cap 5 can be moved back and forth by loosening a screw 9 (1 in the figure is variable). A spherical condensing lens 6 is fixed between the tip opening of the holding member 1 and the opening of the cap 5 by a holding ring 7. Note that the condenser lens 6 may be a combination of a plurality of convex lenses, but a spherical lens is cheaper and easier to mount. An optical connector 8 is attached to the other end of the optical fiber cable 2 for inputting light in the direction of arrow a and outputting light in the direction of arrow A. connected to the main body of the device.

The main body of the device (not shown) includes a light source such as an LED for inputting light in the direction of arrow a, a drive circuit for driving the light source, and a drive circuit for converting the optical signal emitted in the direction of arrow A into an electrical signal. An optical sensor such as a phototransistor, and a layer width circuit for amplifying the output of the optical sensor are provided.

FIG. 2 is a cross-sectional view of the optical fiber cable shown in FIG. 1. The optical fiber cable 2 may include a plurality of light emitting optical fibers 11 and a plurality of light receiving optical fibers 12 as shown in FIG. The light-receiving optical fibers 12 may be gathered at the center, or the light-emitting optical fibers 11 may be arranged at the center as shown in FIG. 2(C).
may be collected. Further, as shown in FIG. 2(d), the light emitting optical fibers 11 may be gathered on one side, and the light receiving optical fibers 12 may be gathered on the other side. Further, as shown in FIG. 2(e), the optical fiber cable 2 may be configured with one light-emitting optical fiber 11 and one light-receiving optical fiber 12, and as shown in FIG. 2(f). The optical fiber cable 2 may be constructed by arranging one light-receiving fiber 12 at the center of a plurality of light-emitting optical fibers 11 as shown in FIG.

It should be noted that the optical fiber cable 2 according to the present invention does not function as an image guide like a fiberscope, for example, but can simply function as a light guide, so the arrangement of optical fibers at one end and the other end are different. The arrangement of the optical fibers at the ends does not need to match (the fibers may be twisted), and the characteristics will not deteriorate even if the optical fiber is composed of only two optical fibers, one for light emission and one for light reception.

Next, the operation of the embodiment shown in FIGS. 1 and 2 will be explained. Light emitted from a light source of the device main body (not shown) enters in the direction of arrow a in FIG. . At this time, since the inner surface of the holding member 1 is painted black so as not to reflect light, only light along the axial direction of the optical fiber cable 2 reaches the focusing lens 6. Therefore, the tip opening of the cap 5 has a diameter of 0.31 mm.
A light spot of about m1 is formed. In addition, to adjust the formation position of the optical spot, loosen the screw 9 and move the cap 5 to align the tip surface of the optical fiber cable 2 with the condensing lens 6.
This is done by changing the distance between (p in the figure). Further, as described above, the light spot formed at the tip opening of the kill tube 5 is, for example, a light spot with a diameter of about 0.3 mm, and is not a uniform surface illumination like a fiber scope.

When there is a black bar on the barcode at the position of the light spot, there is little reflected light, and when there is no black bar, there is a lot of reflected light. This reflected light passes through a focusing lens 6 to a receiving optical fiber 12.
and is transmitted through the optical fiber cable 2 as an optical signal. The light emitted from the connector 8 in the direction of the arrow 8 is converted into an electrical signal by an optical sensor in the main body of the device (not shown) and subjected to signal processing.

〔Effect of the invention〕

As described above, in the present invention, a condensing lens is provided at one open end of a cylindrical holding member, an optical fiber is inserted from the other open end to form a wand, and the other end of this optical fiber is provided with a condensing lens. Since the optical connector is provided to input the light and take out the reflected light from the barcode, it is possible to obtain a compact and lightweight barcode reading device that is not affected by disturbances such as electrical noise.

In particular, ■ Eliminate troubles caused by noise and reduce the possibility of misreading, ■ Eliminate the possibility of noise (microwave) radiation from the wand to the outside, ■ Eliminate the risk of electrical leakage due to water, and ■ Connect electronic circuits to the main body of the device. By providing a bar code, costs are reduced and reliability is improved, so it is particularly effective when controlling the output of a microwave oven, setting cooking time, etc. using a bar code. In addition, electronic sewing machines,
It can be applied not only to inputting operation data of electrical appliances such as coolers using barcodes, but also to all fields.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the optical fiber cable shown in FIG. 1. 1... Holding member, 2... Optical fiber cable, 3...
... Cover, 4... Protective tube, 5... Key 17 knob, 6... Condensing lens, 7... Retaining ring, 8...
- Optical connector, 9... Screw, 11... Light emitting fiber, 12... Light receiving fiber.

Claims (1)

[Claims] 1. A cylindrical holding member, a condenser lens provided at one open end of the holding member, and a condenser lens inserted into the holding member from the other open end of the holding member. an optical fiber bundle consisting of a light-emitting and light-receiving optical fiber, and a light that enters the light-emitting optical fiber and extracts the light reflected by the barcode in front of the condenser lens from the light-receiving optical fiber. A barcode reading device comprising a connector. 2. The barcode reading device according to claim 1, wherein the distance between the tip end surface of the optical fiber bundle and the condensing lens is variable. 3. The barcode reading device according to claim 1 or 2, wherein the light projecting optical fiber comprises a plurality of optical fibers. 4. The barcode reading device according to claim 1, wherein the light-receiving optical fiber includes a plurality of optical fibers. 5. The barcode reading device according to any one of claims 1 to 4, wherein the condenser lens is a spherical lens.