JPH0313806Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial application field" This invention projects light onto a barcode, receives the reflected light, converts it into an electrical signal, and detects the barcode from the electrical signal. The present invention relates to a photo sensor used for barcode succession.

"Prior Art" FIG. 5 shows a conventional photo sensor of this type. A case 11 is vertically divided into two parts, and a lens (objective lens) 12 is attached to the tip of the split surface, and an optical fiber 13 is accommodated in the case 11 with one end face facing the lens 12. Case 1
A light emitting element 14 and a light receiving element 15 are disposed within the rear end of the optical fiber 1.
6 and 17, respectively, and are optically coupled. The lens 12, the optical fibers 13, 16, and 17, the light emitting element 14, and the light receiving element 15 are fitted into positioning recesses formed in the dividing surface of the case 11.

The light from the light emitting element 14 is transmitted through optical fibers 16 and 13.
The reflected light passes through the lens 12 and is projected onto the barcode 18, and the reflected light enters the optical fiber 13 through the lens 12, and from there the light is transmitted to the optical fibers 13, 17.
The light is guided to the light receiving element 15 through the light receiving element 15, where it is converted into an electrical signal.

Since the conventional photo sensor has such a configuration, the optical fiber 1 is attached to the end face of the optical fiber 13.
6 and 17, and the optical fiber 13
It is necessary to bring the cores of the optical fibers 16, 17 close to each other so that the cores of the optical fibers 16, 17 are in contact with each other. In order to connect these optical fibers 13, 16, 17, processing is carried out, such as making the cross section of the end of the fiber into a shape close to a semicircle.
The assembly work was difficult.

``Means for Solving the Problems'' According to this invention, one end of the optical fiber is connected to an objective lens for projecting light onto the barcode and receiving the reflected light, as in the past, but the other end of the optical fiber The ends are respectively coupled to a light emitting element and a light receiving element via a second lens. That is, no optical fiber is used to connect the optical fiber and the light-emitting element to the light-receiving element, which greatly simplifies manufacturing and assembly. Note that, if necessary, a light-shielding plate is placed between the light-emitting element and the light-receiving element to block light from the light-emitting element from directly entering the light-receiving element. In addition, a diaphragm is placed between the objective lens and the optical fiber to block unnecessary light incident obliquely and to allow only light parallel to the axis of the optical fiber to pass between the optical fiber and the objective lens. It is preferable.

"Embodiment" FIG. 1 shows an embodiment of this invention, and parts corresponding to those in FIG. 5 are given the same reference numerals. In this invention, a second lens 21 is disposed between the rear end face of the optical fiber 13 and the light emitting element 14 and the light receiving element 15 to optically couple them. In order to facilitate this coupling at a short distance, the light emitting element 14 and the light receiving element 15 are arranged close to each other. Further, in this example, a light shielding plate 22 is interposed between the light emitting element 14 and the light receiving element 15 in order to block the light from the light receiving element 15 from directly entering the light receiving element 15, protruding toward the second lens 21 side. . Furthermore, in this embodiment, the optical fiber 1
A diaphragm 23 is disposed between the optical fiber 13 and the lens 12, and the axis of the optical fiber 13 and the optical axis of the lens 12 are arranged almost on the same straight line, and oblique unnecessary light other than light parallel to this straight line is blocked. It is configured to block as much of the light as possible from entering the fiber 13 to prevent blurring of the light projected onto the barcode 18 due to aberrations of the lens 12.

Light 24 from the light emitting element 14 is incident on the core of the end face of the optical fiber 13 by the second lens 21, travels straight through the optical fiber 13, and is projected onto the barcode 18 by the lens 12. Barcode 1
The reflected light 25 from 8 is incident on the optical fiber 13 by the lens 25 , passes through the core of the optical fiber 13 , and is incident on the light receiving element 15 by the second lens 21 . At this time, a portion of the reflected light 25 reaches the light emitting element 14 side, resulting in a loss, but a similar loss has also occurred in conventional photosensors of this type.

In the configuration shown in FIG. 1, it is preferable that the light emitting element 14 and the light receiving element 15 be as close as possible. From this point of view, as shown in FIGS. 2 to 4, pellet light emitting elements 33,
The light receiving elements 34 are attached and each one of the electrodes is electrically connected to each other. light emitting element 33,
The other electrodes of the light receiving element 34 are connected to one end surface of each of the terminals 35 and 36, respectively. Terminals 31, 32,
35 and 36 are arranged substantially parallel to each other, and their ends on the side of the light emitting element 33 and the light receiving element 34 are molded in a package 37 made of a translucent synthetic resin material. A groove 38 is formed on the front end surface (upper surface in the figure) between the light emitting element 33 and the light receiving element 34 of the package 37, and a light shielding plate (not shown) is inserted into the groove 38. and can be shielded from light.

"Effects of the Invention" As described above, according to the photosensor of this invention, optical coupling between the optical fiber 13 and the light emitting element 14 or 33 and the light receiving element 15 or 34 is performed by the second lens 21, Therefore, there is no need for difficult processing and assembly for coupling the optical fibers 16, 17 and the optical fiber 13 as explained with reference to FIG. 5, and the second lens 21 can be a simple lens made of a synthetic resin material. Optical coupling between the optical fiber 13 and the light emitting element and the light receiving element can be achieved very easily.

Since the light is focused by the second lens 21, the light from the light emitting element 14 or 33 can be used effectively, and the reflected light can be effectively input to the light emitting element 15 or 34, so that a light emitting element and a light receiving element that are less expensive can be used. be able to.

Further, when the configurations shown in FIGS. 2 to 4 are adopted, the light emitting element and the light receiving element can be brought very close to each other, the overall structure can be downsized, and light can be used effectively. Moreover, it can be handled as one part, which simplifies the assembly work.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of the photosensor according to this invention, Fig. 2 is a plan view showing another example of the light emitting element and light receiving element portion, and Fig. 3 is the AA of Fig. 2.
4 is a left side view of FIG. 2, and FIG. 5 is a sectional view showing a conventional photosensor.

Claims (1)

[Claims for Utility Model Registration] A first lens that is to be opposed to the barcode that is to be inherited, one end of which is opposed to the first lens, and the light emitted from the one end is transmitted to the bar code through the first lens. an optical fiber that projects light onto a barcode and makes the reflected light from the barcode enter the one end of the barcode via the first lens; a diaphragm having an aperture diameter smaller than the diameter of the optical fiber; a light emitting element provided on the other end side of the optical fiber; a light receiving element provided in parallel with the light emitting element and converting light into an electrical signal; these light emitting elements and the light receiving element; a second lens disposed between the element and the other end of the optical fiber, which allows light from the light emitting element to enter the core of the optical fiber, and allows light reflected from the core of the optical fiber to enter the light receiving element; A photo sensor for barcode succession, comprising: