JPH0546594B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is an optical system that uses a hologram to scan a light beam and receives reflected light from a barcode symbol on an object to be scanned to read barcode information. It relates to a symbol reading device.

[Prior Art] FIG. 2 shows the configuration of a conventional optical barcode reading device using a hologram. In general, a hologram can be regarded as a convex lens made up of a diffraction grating, but when used as a scanning device, it scans the light beam by itself, converges the light beam on the surface to be scanned, and reflects light from the surface to be scanned. Since it is possible to simultaneously collect light and remove disturbance light contained in the collected light, the device is much simpler and cheaper than an optical system using a rotating mirror. FIG. 2 shows a case in which the hologram is placed around the disk and scanned.

In FIG. 2, a light beam 30 emitted from a light source 1
passes through the lens 2, is reflected by the mirror 3, and then enters the hologram disk 5 through the hole in the mirror 4. In the hologram 5, the hologram segments 6, 7, and 8 are deflected differently depending on the rotation of the disk 5. The light is reflected by the plane mirror 9 and becomes several types of scanning lines 15 on the plane mirrors 10, 11, 12, 13, and 14. Plane mirror 10, 11, 1
2, 13, and 14 are fixed so as to form various scanning patterns 17 on the scanning surface 16 with respect to the deflection of each part of the hologram disk. That is,
This scanning pattern scans the barcode label 18 moving on the scanning surface 16. The information in the barcode, which is composed of black bars on a white paper, is converted into the strength of the reflected light and is passed through the plane mirrors 10, 11, 12, 13,
It is reflected by holograms 14 and 9 and enters holograms 6, 7, and 8. This reflected light is focused onto the photoelectric conversion element 19 via the mirror 4 by the hologram. The collected light is converted into an electrical signal and read by the signal processing circuit 20.

The above barcode reading devices can be used as POS (pint of
When used in the system, the reading operation is as shown in FIG. This is done by moving. At this time, the scanning line of the light beam from the reading window 24 scans the barcode of the product 23, and the barcode is read.

[Problem that the invention seeks to solve]

Generally, in a POS system, the smaller the external dimensions of the barcode reader, the more efficiently the store area can be used and the easier the layout design will be. A general reading operation in Europe is performed by a person 21 sitting on a chair 27 and moving the product 23 along the reading window 24 of the barcode reading device 25, as shown in FIG. For this reason, the feet 28 of the person 21 enter the lower surface 29 of the barcode reading device 25, so the smaller the device height H is, the better from an ergonomic point of view.

The conventional barcode reading device shown in FIG. 2 has the drawback that the external dimensions (particularly the height H) cannot be reduced due to restrictions on the arrangement of optical components inside the device.

FIG. 5 shows a sectional view taken along arrow A-A' in FIG.
Since the diameter direction of the hologram disk 5 is the direction of the device height H, the device height H cannot be made smaller than the outer diameter A of the hologram disk. In order to reduce H, if the diameter direction of the hologram disk 5 is set in the device width W direction as shown in Fig. 6, H will become smaller but W will become larger. It's summery.

[Means for solving problems]

It is an object of the present invention to provide an optical symbol reading device that eliminates the above-mentioned drawbacks, facilitates layout design in a POS system, makes efficient use of store floor area, and can be operated from a sitting position.

According to the present invention, an optical symbol reading device is obtained that includes a hologram light deflector and a fixed plane mirror, and the radiation direction of the scanning pattern is substantially opposite to the direction of incidence of the light beam on the hologram light deflector.

[Example] FIG. 1 shows an example of the present invention. In Figure 1,
A sectional view taken along arrow B-B' is shown in FIG. The hologram disk 5 is placed at an angle with respect to the device housing,
The fixed mirror was arranged so that the direction of incidence of the light beam 30 on the hologram disk 5 and the direction of the scanning pattern group 17 were exactly opposite to each other.

A light beam 30 emitted from a light source 1 is reflected by a mirror 31, passes through a lens 2, is reflected by a mirror 3, and passes through a hole in a mirror 4 to be perpendicularly incident on a hologram disk 5. In the hologram disk 5, different deflections are performed by the hologram segments 6, 7, and 8 as the disk 5 rotates, and the scanning line by the hologram segment 6 is reflected by the fixed reflecting mirrors 32 and 33. The scanning line from the reflecting mirror 32 is reflected to the reflecting mirror 39, and the scanning line from the reflecting mirror 31 is reflected to the opposite mirror 40.

On the other hand, the scanning lines by the hologram segment 7 are reflected by the reflecting mirrors 34, 35, and 36, and the scanning lines by the hologram segment 8 are reflected by the reflecting mirrors 37, 38, and form a scanning line group 42 on the reflecting mirror 41. Reflector 32, 33, 34, 35, 36, 37, 3
8, 39, and 40 are fixed so that the scanning pattern 17 is formed with respect to the deflection of each part of the hologram disk, and the radiation direction of the scanning pattern is exactly opposite to the direction of incidence of the light beam 30 on the hologram disk. ing. Information on the reflected light from the scanning surface 16 is transmitted to the reflecting mirrors 32, 33, 34, 35, 36,
37, 38, 39, 40 and enters the hologram segments 6, 7, 8. This reflected light is focused by the hologram segment onto the photoelectric conversion element 19 via the mirror 4. The collected light is converted into an electrical signal and read by the signal processing circuit 20.

〔Effect of the invention〕

As described above, by configuring a hologram disk and a fixed reflector, it is possible to reduce the external dimensions of the device without being constrained by the outer diameter of the hologram disk, which facilitates the layout design of the POS system and improves the layout of the store. It becomes possible to realize an optical symbol reading device that can efficiently use the sales floor area and can be operated from a sitting position without causing any ergonomic problems.

[Brief explanation of drawings]

Fig. 1 shows an embodiment of the present invention, Fig. 2 shows a conventional optical symbol reading device, Figs. 3 and 4 show how this type of device is used, and Fig. 5 and FIG. 6 is a diagram showing the relationship between the incident light beam and the emitted scanning beam in a conventional device,
FIG. 7 is a diagram showing the relationship between an incident light beam and a scanning beam in the present invention.

Claims (1)

[Claims] 1 Comprising a light source, a hologram disk with a plurality of hologram light deflection elements arranged on the same circumference, a plurality of fixed plane mirrors, and a photoelectric conversion element, the light beam from the light source is made perpendicularly incident on the hologram disk. In an optical symbol reading device that scans and receives reflected light from an object to be scanned to read barcode information, the hologram disk is arranged at an angle with respect to the housing of the optical symbol reading device, and the hologram disk is arranged at an angle with respect to the housing of the optical symbol reading device, Multiple X patterns with different intersection angles
A group of X-shaped scanning patterns arranged horizontally in a row so as to form a diamond-shaped combination;
A scanning pattern that is a combination of a plurality of parallel linear scanning patterns so as to intersect all of a group of linear scanning patterns, wherein the radiation direction of the scanning patterns is substantially opposite to the direction of incidence of the light beam on the hologram disk. An optical symbol reading device characterized in that the constituent elements are arranged separated into a fixed plane mirror and constituent elements other than the fixed plane mirror with the hologram disk as a boundary.