JPS61121023A - Hologram scanner - Google Patents

Abstract

PURPOSE:To increase the focal depth of a scanning light, discharge the scanning light different in direction, or discharge the scanning light different in scan range by dividing the hologram on one slope of a holotop into plural facets. CONSTITUTION:Holograms of facets 21 and 22 are so formed that a scanning light 23 having a focal length A is discharged from the facet 21 and a scanning light 24 having a focal length B (Bnot equal to A) is discharged from the facet 22, thereby increasing the focal depth of the scanning light. Holograms of facets 21 and 22 are so formed that a scanning light 25 discharged from the facet 21 and a scanning light 26 discharged from the facet 22 are different in direction, thereby changing scanning directions of plural scanning lights. Holograms of facets 21 and 22 are so formed that a scanning light 27 from the facet 21 scans from (a) to (b) and a scanning light 28 from the facet 22 scans from (c) to (d), thereby scanning plural scan ranges.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hologram scanner that performs optical scanning using a hologram.

Recently, in order to save labor at registers in supermarkets and the like, barcode reading devices that read barcodes printed on the exterior of products and input them into computers have come into use.

Since a hologram scanner using a hologram passes through the optical scanning section of this barcode reading device, this hologram scanner is often used. Such hologram scanners are required to improve their reading rate.

[Conventional technology]

FIG. 5 is a diagram showing the main parts of a conventional hologram scanner. This is a hollow spinning top-shaped rotating body 1 with holograms 2 and 3 on the bottom slope, and a reflective Fresnel lens 4 on the inside top surface of the hollow top-shaped rotating body 1 (hereinafter referred to as holotop) 5.
While this hologram 5 is rotated by a motor 6, a laser beam 7 is incident through a slit 9 via a mirror 8, and is alternately diffracted by the holograms 2 and 3 to form a scanning beam 1.
Emit 0. Re-imaging light (scattered signal light) 11 from the barcode enters the hologram 2.3 and is diffracted, and then is focused by a reflective Fresnel lens 4 onto a photodetector 12, where the barcode is read.

[Problem that the invention seeks to solve]

With the above configuration, the hologram of one inclined surface emits only one type of scanning beam, and there is a problem in that the above-mentioned reading distance is difficult.

[Means for solving problems]

The present invention provides a hologram scanner that solves the above-mentioned problems, and its means include a hologram scanner characterized in that a hologram having one inclined surface is divided into a plurality of facets in a hologram scanner. Ru.

[For production]

The above hologram scanner has 1 inclined surface 1 of its holotop.
By dividing a hologram into a plurality of facets, a plurality of scanning beams can be emitted from a hologram on one inclined surface, and the reading rate of the hologram scanner can be improved.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention as a perspective view.

In this embodiment, the hologram provided on the slope of the holotop 20 has a plurality of (two in the figure) facets 21 and 22.
The other structure is the same as the conventional example explained in FIG.

This embodiment configured in this manner is multifunctional as described below. In FIG. 2, facets 21 . 22 holograms can be created to increase the depth of focus of the scanning light. Further, as shown in FIG. 3, scanning light 25 emitted from the facet 21 and scanning light 2 emitted from the facet 22.
It is also possible to create a hologram of facets 21 and 22 so as to change the emission direction of the scanning beams 6 and to change the scanning direction of the plurality of scanning beams. Further, as shown in FIG. 4, the scanning light 27 from the facet 21 scans from a to b, and the scanning light 28 from the facet node 22 scans from C to d, so that the holograms of the facets 21 and 22 are scanned. It can also be created to scan multiple scan ranges.

〔Effect of the invention〕

As explained above, according to the present invention, by dividing the hologram on one slope of the holotop into a plurality of facets, for example, the depth of focus of the scanning light can be deepened, the scanning light in different directions can be emitted, and the scanning range can be expanded. It becomes possible to emit different scanning lights, etc., making it possible to make the scanning line multi-functional and improve the reading rate.

[Brief explanation of drawings]

FIG. 1 is a perspective view of essential parts showing an embodiment of the hologram scanner of the present invention, FIGS. 2 to 4 are diagrams for explaining multifunctionality of the holotop in the hologram scanner of the present invention, and FIG. FIG. 2 is a sectional view of a main part of a conventional hologram scanner. In the figure, 20 is a holotop, 21.22 is a facet, 2
3, 24, 25, 26, 27, and 28 indicate scanning lights, respectively.

Claims (1)

[Claims] 1. A hologram scanner characterized in that a hologram having one inclined surface is divided into a plurality of facets in a holotop type hologram scanner.