JPS5940677Y2 - optical reader - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an optical reading device that optically reads barcodes printed on, for example, price tags.

Devices that optically read barcodes printed on price tags by sliding on them generally have the tip of a main body a, two layers of optical fibers b and c inside and outside, and a light emitting element d, as shown in FIG. Light is emitted from the tip through the optical fiber b, and the light reflected by the member to be read enters the light receiving element e through the optical fiber C.

However, when reading a barcode or the like with the reading device configured as described above, the tip surface of the optical 7-eye bar must be brought into close contact with the barcode.

This is because the light emitted from the optical fiber diverges and irradiates a wide range of the member to be read, so the range increases as the tip surface moves away from the member to be read.

Furthermore, since the optical fiber for light reception also has similar optical characteristics at its end face, as it moves away from the member to be read, information other than the reading point enters, causing a decrease in resolution.

Further, the optical 7 eyeglass has drawbacks such as loss of light amount due to wire breakage, attenuation, etc., and is not durable.

This idea was devised based on the above circumstances, and its purpose was to place a pinhole on the imaging plane and place a light-receiving element at a distance behind the pinhole to expand the light-receiving area. It is an object of the present invention to provide an optical reading device that can improve the sensitivity of light reception.

Hereinafter, this invention will be explained based on one embodiment shown in the drawings.

Reference numeral 1 in FIGS. 2 to 4 indicates a cylindrical main body, and a light guide path 2 is bored in the axis of the main body.

Concave portions 3 and 4 are provided at the tip and end portions of the main body 1, and internal threads 3a, 4 are provided on the inner peripheral surface of these open ends.
A is engraved.

A lens 5 is housed in a concave portion 3 on the tip side of the main body 1, and a male threaded portion 1 protruding from the back of the light emitting element holder 6 is screwed into the female thread 3a.

The back of the light emitting element holder 6 presses the lens 5 against the inner bottom surface of the concave portion 3, and a through hole 8 concentrically facing the light guide path 2 is bored in the center thereof.

Furthermore, a light emitting element 9 consisting of a plurality of light emitting diodes is attached to the front part of the light emitting element holder 6 in an inclined manner so as to condense light onto one point on the member 10 to be read.

Further, a flange portion 11 is provided at the tip of the main body 1, and a threaded portion 12 is carved in the outer peripheral wall.

A connector 13 is screwed onto the outer periphery of the main body 1.

An annular protrusion 14 is provided on the outer circumferential wall of the connector 13, an engagement groove 15 is provided on the distal end of the twist, and a threaded portion 16 is provided on the distal end.

A cover 17 that surrounds the light emitting element holder 6 is fitted to the tip side of the annular projection 14 of the connector 13, and the tip end is tapered and the distal end is fitted with an engaging projection 18 provided on the inner circumferential surface thereof. is engaged with the engagement groove 15.

Furthermore, a cylindrical case 19 is screwed into the threaded portion 16 on the distal side of the annular projection 14 of the connector 13, and extends rearward from the distal end of the main body 1.

On the other hand, a pinhole 20 facing the light guide path 2 is housed in the inner bottom of the recessed part 4 provided at the end of the main body 1, and the female thread 4a has a threaded part 22 of the light receiving element holder 21.
is screwed on.

The pinhole 20 is fixed to the inner bottom surface of the concave portion 4 by pressure on the tip end surface of the threaded portion 22.

Furthermore, a through hole 23 that faces the light guide path 2 concentrically is formed in the 6th part of the threaded part 22 of the light receiving element holder 21, and a light receiving element 24 that faces the pinhole 20 and is spaced apart from the pinhole 20 is formed in this through hole 23. It is installed.

The size of this pinhole 20 is b-d when the required resolution is d, as shown in FIG.

(Here, a represents the distance from the front main surface of the lens 5 to the member to be read 10, and b represents the distance from the rear main rod to the pinhole 20.

) Therefore, the size of the pinhole 20 determines the reading range in the member to be read 10 and the resolution.

Furthermore, by arranging the light receiving element 24 apart from the pinhole 20, the light that has passed through the pinhole 20 is incident on a wide range of the light receiving element 24, thereby improving the light receiving S/N ratio.

Further, the light receiving element holder 21 has an arcuate portion 25 along the inner surface shape of the case 19, and a plurality of fitting holes 26, 26 are provided on the upper surface of the arc portion 25.

A fitting hole 26 is provided in the upper part of this light receiving element holder 21.
．． Wiring board 28 having a protrusion 27°27 that fits into 26
is attached to the light receiving element 24 and the case 1.
It is electrically connected to a multi-core cord 29 led out from the end of 9.

Further, a female screw 30 is carved on the inner circumferential surface of the distal end of the case 19, and a metal fitting 33 is screwed into the female screw 30, which has a through hole 32 in the end wall 31 for fitting the multicore cord 29. has been done.

In this receiver, a tightening rubber 34 and a washer 35, which fit into the multi-core cord 29, are housed in the metal fitting 33.

A cord protector 36 that fits into the multicore cord 29 is provided on the distal side of the washer 35, and a fastener 38 whose tip abuts on the washer 35 is engaged with this collar portion 37.

This fastener 38 is attached to the female thread 30 of the case 19.
By screwing this in, the one-shaft 35
The multicore cord 29 is gripped by compressing the tightening rubber 34 through the deformation of the tightening rubber 34.

Therefore, when reading a recorded image such as a bar code printed on a member 10 to be read such as a price tag, the light emitting elements 9...
When the light emitting elements 9 emit light, the light from these light emitting elements 9 is condensed onto a recorded image.

The reflected light is focused on the pinhole 20 through the lens 5, but since the light receiving element 24 is spaced behind the pinhole 20, it enters the light receiving element 24 within the actual range.

The signal current received by the light receiving element 24 in this manner is amplified by the electronic components provided on the wiring board 28 and further led out via the multicore cord 29.

In the above embodiment, the main body and the case have a double-tube structure, and internal components are assembled on each side.
The present invention is not limited to this embodiment, and the main body and the case may be integrated.

As explained above, this idea is based on placing a pinhole on the image plane and installing a light-receiving element at a distance behind the pinhole, so that the light that passes through the pinhole enters a wide range of the light-receiving element, which increases the light-receiving sensitivity. It is possible to obtain a highly reliable optical reading device.

In addition, since the lens, pinhole,
Moreover, the positioning of the light receiving optical system such as the light receiving element can be performed extremely easily and reliably.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional optical reading device, Fig. 2 is an overall longitudinal sectional view showing an embodiment of this invention, Fig. 3 is an exploded perspective view, and Fig. 4 is a position of the optical system. It is an explanatory diagram showing a relationship. 1...Body, 5...Lens, 9...
... Light emitting element, 10 ... Member to be read, 20.
...Pinhole, 24... Light receiving element.

Claims (1)

[Scope of utility model registration request] A viewing element is installed at the tip of the main body and illuminates the object to be read.
In a device that optically reads this reflected light by imaging it with a lens, a pinhole is created between the body and the body by screwing a light-receiving element holder equipped with a light-receiving element into the other end of the body equipped with the lens. An optical reading device characterized by having a configuration in which it is held in place.