JPS59172081A - Bar-code reader - Google Patents

Abstract

PURPOSE:To recognize a scanning light pattern to make the reading operation of the bar-code possible by using a semiconductor laser as a light source and simultaneously using another light source which can be recognized visually. CONSTITUTION:The light from a semiconductor laser light source 1 is irradiated to a read face 6 through a projection lens 2, a reflective mirror 3, a rotary mirror 4, and a reflective mirror 5 to form a bar-code scanning pattern 9. A pattern guide 8 is irradiated with a light source 7 which can be sensed visually, and its silhouette is projected to the read face 6. Similarly, the silhouette of a pattern guide of the bar-code forming reflective mirror 5 irradiated with the light source 7 is projected to the read face. Thus, the position and the size of the scanning light pattern of the semiconductor laser can be confirmed. The reflected light from the read face 6 is made incident to a photoelectric transducer 14 through the reflective mirror 5, the rotary mirror 4, the reflective mirror 3, a mirror 11, a condenser lens 12, and an optical fiber 13 through which only the spectrum of the semiconductor laser is transmitted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a bar code reading device that uses a semiconductor laser as a light source.

Conventional Structures and Problems Known barcode reading devices include stationary scanners in which the reading unit is fixed (-) and hand scanners in which the reading unit is operated by hand.

Conventional stationary Sugana light source r (Ha, He-N e laser was used. He → is laser oscillates at a wavelength in the visible range of 6328 people and has excellent incoherence,
It requires a high-voltage power supply, has a large volume, and has a short lifespan due to rapid degassing and deterioration of the cathode material.
It was around the same time, which caused practical inconvenience.

Recently, a semiconductor laser has been realized in place of a He-Ne laser as the light source. Semiconductor lasers are small and
It also does not require a high-voltage power supply and has a long life, but the oscillation wavelength is 7.
Since it is in the near-infrared region of 600A to 8500A, visibility is poor, and even when scanning is performed using a semiconductor laser as a light source, the locus of the scanning light cannot be seen, making it unclear whether the bar code can be read within the range. Unfortunately, with the He-'He laser, in order to miniaturize the device, it was possible to limit the orientation of the barcode (!:) because the trajectory of the scanning light could be seen, but with semiconductor I can't see just one trajectory with the laser/Kome ATt There is a possibility that I will continue to stare at it with my eyes even though the laser is being output, so there is a problem with completely one trajectory.

OBJECTS OF THE INVENTION The present invention aims to eliminate the above-mentioned conventional problems and to enable the safe use of a semiconductor laser as a light source for a barcode reading device.

Structure of the Invention In order to achieve the above object, the present invention uses a semiconductor laser as a light source and at the same time uses a visible light source so that the position and size of the scanning light pattern of the semiconductor laser can be confirmed. This provides the effect of recognizing the scanning light pattern and enabling barcode reading operations.

DESCRIPTION OF EMBODIMENTS The structure of an embodiment of the present invention will be described below with reference to the drawings. Figure 1 shows the overall configuration of the academic system of this device.
In the figure, 1 is a semiconductor laser)'L (Bii, 2C1 projection lens, 3 is a reflection mirror, 4 is a rotating mirror, 5 is a reflection mirror for barcode pattern formation, 6 is a barcode reading surface, 7 is a visual A detectable light source, 8 a barcode pattern guide plate (slit plate), 9 an invisible barcode pattern projected on the reading surface 6, 10 a barcode reading window, 11 a perforated mirror, and 12 a light condenser. Lens 13 is an optical filter that passes only the spectrum of the semiconductor laser, 1
4 is a photoelectric conversion element.

FIG. 2 shows visually perceivable light curves, for example, a spectral curve A of tungsten light and a spectral curve B of semiconductor laser light.

Next, the operation of the above embodiment will be explained. In FIG. 1, light emitted from a semiconductor laser light source 1 is focused on a reading surface 6 by a projection lens 2 to a suboto size (spot diameter) smaller than the resolution of a bar code pattern. The focused light passes through the hole of the perforated mirror 11, hits the reflection mirror 3, and is converted into scanning light VC by the 1"11 turning mirror 4.
Become. In this case, a similar result can be obtained by using a vibrating mirror instead of the rotating mirror 40. The scanning light hits the pattern forming reflection mirror 5Vc and passes through the entire reading window 10 to form a barcode scanning pattern 9 on the reading surface 6.

However, in this state it cannot be detected visually. ? J2 The pattern guide plate 8 shows a guide image similar to the scanning pattern 9 on the reading surface 6 by illuminating the pattern guide 8 with a visually perceivable light source 7 and projecting its silhouette onto the reading surface 6. Similarly, the shadow of the pattern guide of the reflecting mirror 5 for barcode formation irradiated by the light source 7 becomes the same as the barcode scanning pattern 9, and can be visually detected, and the direction of the light emitted from the light source 7 to the reading surface 6 is the same as that of the barcode scanning pattern 9. Since it is in the same direction as the scanning light from the semiconductor laser, the scanning surface 6 is
A similar effect can be obtained by passing the light over the

FIG. 3 shows the structure of an embodiment of the pattern guide plate 8, in which 301 (r: J - a material that does not allow light to pass through the coffin of the light source γ, 302 a H4 [or slit portion that allows light to pass through), Reading surface 6, j: Captures the VC visible scanning pattern.1 On the other hand, if 301 is made of a material that allows the light from light source 7 to pass through, and 302'f is made of a material that does not allow light to pass through, the reading surface 6 has a surrounding area. It becomes visible and the scanning pattern becomes dark. With either pattern guide plate, an image similar to the scanning pattern 9 can be obtained. The signal obtained by scanning the barcode can be obtained along the light path. can.

That is, through the reflective mirror 5, the rotating mirror 4, the reflective mirror 3, the reflected light is reflected by the perforated mirror 11, and the light is reflected by the condensing lens 12.
After passing through the optical filter 13, the light is converted into an electric signal r (r) by the photoelectric conversion element 14.If the wavelength spectrum of the semiconductor laser and the wavelength spectrum of the light source 7 are completely separated, there is no problem. If the respective wavelength spectra overlap, this can be easily realized by inserting into the pattern guide plate 8 an optical filter that does not allow the wavelength spectrum of the semiconductor laser to pass through.

The advantages and disadvantages of the invention are as described above, and the following effects are achieved.

1) The position and size of the scanning light pattern of a semiconductor laser, which was previously impossible, can be visually sensed by combining the rIT optical beam area source, making it possible to read barcodes with awareness of the scanning pattern. Operation is possible with Vrc.

2) By providing a pattern guide in the same direction as the scanning light from the reading surface, a similar scanning pattern can be obtained above the reading surface.

3) By separating the wavelength spectra of the scanning light and the light source for irradiating the guide plate, or by providing an optical filter on the guide plate, there is no adverse effect on the S/'N ratio of the reception of one scanning light.

[Brief explanation of the drawing]

Fig. 1 U- Whole optical system 1f in one embodiment of the present invention
FIG. 2 is a wavelength spectrum diagram of a light source, and FIG. 3 is an enlarged plan view of a pattern guide plate in an embodiment of the present invention. 1. Semiconductor laser light source, 4° co-rotating mirror, 5. Reflection mirror for barcode pattern formation, 6.Barcode reading surface, 7. Visually perceptible light source, 8. Barcode pattern guide plate, 14.・Photoelectric conversion element.

Claims (1)

[Scope of Claims] 1) A semiconductor laser, an optical system that projects the light of the semiconductor laser onto a reading device, an optical scanning converter that converts the semiconductor laser light that has passed through the optical system into scanning light, and the scanning light an optical scanning system comprising a reflective mirror that projects a scanning pattern onto a reading surface; a visible light source; and a guide plate that projects an image that is illuminated by the light source and whose shape matches the position of the scanning pattern onto the reading surface. A barcode reading device comprising: the guide plate and the visible light source being provided substantially on an extension of the reading direction in which the scanning pattern is projected. 2) The barcode reading device according to claim 1, wherein the guide plate is made of a member that removes the wavelength spectrum of the semiconductor laser.