JPS62112121A - Hologram scanner - Google Patents

Abstract

PURPOSE:To shorten a distance between a reflection type Fresnel lens and a photodetector by filling a gap between a hologram disk and the Fresnel lens with transparent resin. CONSTITUTION:A hologram rotor 7 is constituted of a rotating disk 71 fixed on a rotation axis, the reflection type Fresnel lens 72 fitted to the disk 71, the transparent resin 73 filled to the recessed part of the lens 72, and a hologram disk 74 joined with the lens 72. Since the gap between the lens 72 and the disk 74 is filled with the transparent resin, scattered signal light is refracted on the border between the disk 74 and air in a process for condensing the scattered signal light to a photodetector by the lens 72 through the lens 72, so that the focal distance of the lens 72 is shortened.

Description

[Detailed Description of the Invention] [Summary] Aiming at downsizing and lowering the cost of barcode reading devices, etc., a condensing/scanning module in which a hologram disk and a reflective Fresnel lens are attached to a rotating body is used. A hologram scanner has been devised. However, in a condensing/scanning module in which there is a hollow space between the hologram disk and the reflective Fresnel lens, there is a limit to the shortening of the distance between the reflective Fresnel lens and the photodetector. Therefore, a transparent resin is filled between the hologram disk and the reflective Fresnel lens to shorten the distance between the reflective Fresnel lens and the photodetector.

[Industrial application field]

The present invention relates to a hologram scanner that diffracts and scans laser light using a hologram and simultaneously focuses signal scattered light from an object to be read using the same hologram.

Recently, barcode reading devices that read barcodes printed on the exterior of products and input them into computers have become widely used in order to save labor at registers in supermarkets and the like. A hologram scanner that uses a hologram as a light converging element and a light deflection element to converge and scan laser light passes through the above-mentioned apparatus, and this hologram scanner is often used as a light scanning section in a barcode reading device.

In early hologram scanners, a disk-shaped hologram focused the scattered signal light, and in order to guide the signal light to a photodetector, a re-imaging optical system was used that assembled individual optical components such as a perforated mirror, Fresnel lens, and filter. This was a factor that hindered the miniaturization and cost reduction of devices. Therefore, a leaf tip scanning module was developed in which a rotating body was equipped with a hologram disk and a reflective Fresnel lens.By using a condensing scanning module in the hologram scanner, the assembly of individual optical parts was reduced, the device was made smaller, and the cost was lowered. However, since many such hologram scanners are placed in the same store, and moreover, they are often installed on counters or tabletops, there is a desire for the development of even smaller and cheaper hologram scanners. There is.

[Conventional technology]

FIG. 3 is a diagram showing the main parts of a conventional hologram scanner, in which FIG. 3(a) shows a holotop type scanning and focusing module, and FIG. 3<bl shows a disk type scanning and focusing module.

In FIG. 3 (al), the holotop type scanning condensing module has a hologram 1 mounted on the bottom slope of a hollow top-shaped rotating body 11.
2.13 and a reflective Fresnel lens 14 on the upper inner surface.
is provided to constitute a hologram rotating body (referred to as a holotop) 1, and this holotop l is rotated by a motor 2 via a rotation shaft. Laser light 31 enters holotop 1 through window 15 via mirror 4, is alternately diffracted by holograms 12 and 13, and is emitted as scanning light 32. In addition, the scattered signal light 33 from the barcode (not shown) is the hologram 1.
2. After entering 13 and being diffracted, the reflective Fresnel lens 1
4, the light is focused on a photodetector 5 and the barcode is read.

However, in the holotop type scanning and focusing module, since the holotop shape is not a perfectly rotating body, windage loss during rotation is large, so a disk type scanning and focusing module, which will be described below, was developed.

In FIG. 3 (bl), the disk-type scanning and focusing module is equipped with a hologram disk 62 having a plurality of holograms on the bottom of a hollow cylindrical rotating body 61, and a reflective Fresnel lens 63 on the inside of the top. A rotating body 6 is configured, and the hologram rotating body 6 is rotated by a motor 2 via a rotating shaft.

The laser beam 31 enters the hologram rotating body 6 through the window 64 via the mirror 4, is diffracted by the hologram disk 62, and emits a scanning beam 32. Scattered signal light 33 from a barcode (not shown) enters the hologram disk 62 and is diffracted, and then is focused on the photodetector 5 by a reflective Fresnel lens 63 to read the barcode.

[Problem that the invention seeks to solve]

However, in both the conventional holotop type scanning and focusing module and the disk type scanning and focusing module, there is an air layer between the hologram and the reflective Fresnel lens, and the distance between the reflective Fresnel lens and the photodetector is small. There is a problem in that there is a limit to how much the distance can be shortened because it depends on the focal length of the reflective Fresnel lens, and it cannot be shortened any further.

Measures for Solving Problems c] FIG. 1 is a diagram showing an embodiment of the present invention. The same objects are represented by the same symbols throughout the plan.

The above-mentioned problem is as shown in FIG. The hologram rotating body 7 is composed of the lens 72, a customs-clearable resin 73 filled in the concave portion of the reflective Fresnel lens 72, and a hologram disk 74 bonded to the reflective Fresnel lens 72 using the resin 73. This problem is solved by the Holo-Shilum scanner of the present invention.

[Effect]

In Figure 1, by filling a transparent resin between the reflective Fresnel lens and the hologram disk, the scattered signal light is focused on the photodetector by the reflective Fresnel lens, and the scattered signal light is transferred to the hologram disk. Refraction occurs at the boundary between the light and the air, reducing the focal length of the reflective Fresnel lens.

As a result, it is possible to realize a scanning leaf tip module that has the advantages of the conventional holotop type scanning and focusing module and disk type scanning and focusing module, and also makes the hologram scanner more -WtH type.

〔Example〕

Hereinafter, embodiments of the present invention will be explained in detail with reference to the figures. Note that FIG. 2 is a diagram showing another embodiment of the present invention.

In FIG. 1, a rotating disk 71 fixed to a rotating shaft, a reflective Fresnel lens 72 attached to the rotating disk 71,
A transparent resin 73 filled in the concave portion of the reflective Fresnel lens 72 and a reflective Fresnel lens 72 using the resin 73.
The hologram disk 74 joined to the hologram disk 74 forms a hologram rotating body 7, and the hologram rotating body 7 is rotated by the motor 2 via the rotation shaft. The laser beam 3I enters the hologram rotating body 7 through the window 75 via the mirror 4, is diffracted by the hologram disk 74, and emits the scanning beam 32. Scattered signal light 33 from a barcode (not shown)
After entering the hologram disk 74 and being diffracted, the light is focused on the photodetector 5 by the reflective Fresnel lens 72 and the bar code is read.

In the process where the scattered signal light is focused on the photodetector by the reflective Fresnel lens, refraction occurs at the boundary between the hologram disk and the air, shortening the distance between the reflective Fresnel lens and the photodetector. It is possible to realize a scanning and focusing module that has the advantages of the holotop type or disk type scanning and focusing module, and also allows the hologram scanner to be made thinner by -N.

Further, in FIG. 2, the hologram disk 74 is based on lff.
It is composed of a hologram 74a formed in 174 b-hi and a cover material 74c, a reflective Fresnel lens 72 is formed on the outside of the cover material 74G, and the cover material 74c on which the reflective Fresnel lens 72 is formed is bonded. By joining the rotary disk 71 fixed to the rotating shaft with a member 76', it is possible to realize a scanning and condensing module having the same advantages as those of the above-mentioned embodiments.

〔Effect of the invention〕

-h As mentioned above, according to the present invention, it is possible to provide a hologram scanner that is even smaller and cheaper.

[Brief explanation of drawings]

Fig. 1 is a diagram showing one embodiment of the present invention, Fig. 2 is a diagram showing another embodiment of the present invention, Fig. 3 is a diagram showing main parts of a conventional hologram scanner, and Fig. 3 ( al is a holotop type scanning condensing module, the third
Figure fbl shows a disk-type scanning and focusing module. In the figure, 2 is a motor, 4 is a mirror, 5 is a photodetector, 7 is a hologram rotating body, 31 is a laser beam, 32 is a scanning beam, 33 is a scattered signal beam,
71 is a rotating disk, 72 is a reflective Fresnel lens, 73 is a resin, 74 is a hologram disk, 7
4a is a hologram, 74b is a substrate, 74c is a cover material, 75 is a window, 76 is an adhesive material, 61.2.17 4Ir Commissioner General! , Display of matter A.1
-” 40 cities 06
0 Year '1 Original Application No. 252262 2 Name of the invention Hologram scanner 3 Relationship with the person making the amendment 1 Patent applicant address 1015 Kamiodanaka, Nakahara-ku, Yozaki City, Kanagawa Prefecture (5
22) Name: Fujitsu Co., Ltd. Company 4, Agent address: 1015 Kamiodanaka, Nakahara-ku, Yogi-shi, Kanagawa Prefecture Tomi
Shitsu Co., Ltd. January 28, 1985 (Shipping date) 6. Subject to amendment

Claims (1)

[Claims] 1) A rotating disk (71) having at least a hologram rotating body (7) that performs laser beam scanning and signal beam focusing, and fixed to a rotating shaft, and the rotating disk (
a reflective Fresnel lens (72) attached to 71);
A transparent resin (73) filled in the concave portion of the reflective Fresnel lens (72), and a hologram disk (74) bonded to the reflective Fresnel lens (72) using the resin (73), A hologram scanner comprising the hologram rotating body (7). 2) Covering material forming the hologram disk (74) (
A reflective Fresnel lens (72) is formed on the outside of the hologram disk (74c), and the surface of the hologram disk (74) on which the reflective Fresnel lens (72) is formed is joined to a rotating disk (71) fixed to a rotating shaft. A hologram scanner according to claim 1.