JPH077131B2 - Locking device key verification mechanism - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a key collating mechanism for a locking device, which is used for collating the locking device and which can obtain emitted light with good directivity and uniformity. .

[Prior Art] Conventionally, in order to effectively use light from a light source at a desired location,
Various methods are known for an optical waveguide that distributes and guides an incident light beam at an emission end. In general, such an optical waveguide realizes a low loss by guiding incident light to the target emission end while being confined inside by the total reflection of the inner wall of the waveguide. An optical fiber is a kind of such an optical waveguide, and is widely used because of its high versatility. When the light of the light source is distributed to a plurality of emission ends using this optical fiber, there are cases where a light splitting member such as a half mirror is used together, or a plurality of fibers are bundled to be used as a fiber bundle.

However, optical fibers generally have a small numerical aperture, alignment of the incident part is difficult, and there is a drawback that the flexibility of the fiber makes the installation work rather complicated unless the emission end is particularly movable. Moreover, there is also a problem that the cost is high due to the precise structure.

Therefore, in many cases, a key collating mechanism of a subcontracting locking device is used in which a transparent material having a high refractive index such as acrylic resin is molded along the desired optical path. Such a key matching mechanism is not very versatile because the spatial arrangement of the entrance end and the exit end is determined in advance, but it is possible to simplify the mounting work, especially for products that are mass-produced. It is preferable when used for.

[Problems to be Solved by the Invention] By the way, in such a key collating mechanism of the locking device, it is more desirable to guide the incident light to the exit end with the least number of reflections. If this is not achieved, the light loss due to reflection will increase, or the light that has passed through several separate reflected light paths will reach the exit end, and as a result, the exit light will be extremely diffused light with poor directivity. . Further, particularly when the light flux is distributed to a plurality of emission ends, it becomes difficult to maintain the uniformity of the light amount at each emission end.

When the incident light is a diffusion system from a point light source, for example, when using a light flux from an LED, a semiconductor laser light source, etc., which is regarded as a point light source with respect to the incident end, as the incident light, It is more difficult to obtain emitted light with good uniformity.

It is an object of the present invention to provide a highly accurate key collating mechanism for a locking device that can obtain emitted light with good directivity and uniformity even when a point light source is used.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the key matching mechanism of the locking device according to the present invention performs matching by making a light beam incident on the photodetectors arranged at a plurality of predetermined positions. A key matching mechanism used for a locking device, comprising a light guide made of a transparent body having a plurality of reflection optical paths that guide diffused light flux to the photodetector by a plurality of reflection surfaces, and the plurality of reflection surfaces are A parabolic surface having a center point of diffusion of the diffused light flux as a focal point and having the reflected light path as an axial direction, and a point light source is arranged at the focal point.

[Operation] In the key matching mechanism of the locking device having the above-described configuration, the diffused light flux from the point light source is reflected by the parabolic reflection surface and becomes a parallel light flux along the desired reflection optical path, so that accurate verification can be realized.

[Examples] The present invention will be described in detail based on the illustrated examples.

The light guide 1 that constitutes a part of the key is integrally formed of a transparent material such as acrylic resin by injection molding or the like. The light guide 1 has one light incident portion 2 on the front surface, and diffused light from a point light source arranged at a point 0 above the light incident portion 2 is incident. The light guide 1 of the present embodiment has a left-right substantially symmetrical structure, and has two light emitting portions 3a to 3d on the left and right. At the bottom of the light incident portion 2 of the light guide 1, a first reflecting surface 4 that horizontally reflects light from above is provided. This first
Second reflection surfaces 5L and 5R are formed by symmetrically dividing the light reflected by the reflection surface 4 into left and right parts and reflecting the left and right parts respectively. Further, two split paths 6a to 6d are provided in the left and right reflection directions, respectively. For example, second
The optical path reflected by the reflecting surface 5R is divided into upper and lower parts, which are divided paths 6a and 6b, respectively. Here, the lights respectively traveling in the divided paths 6a and 6b are emitted from the light emitting portions 3a and 3b. Further, the light reflected by the second reflecting surface 5L is also configured to be emitted from the light emitting portions 3c and 3d by a substantially symmetrical similar path.

Here, the shapes of the first reflecting surface 4 and the second reflecting surfaces 5L and 5R are important. In this case, the cutting surface shown in FIG. It is shaped to be a parabola with. Further, the second reflecting surfaces 5L and 5R are parabolas whose cut surfaces shown in FIG. 1 have a focal point 0'where the point 0 is located at a conjugate position in the plane direction and have axes in the directions of the divided paths 6a to 6d. It is molded like. It is known that in a parabolic reflection surface, a light beam emitted from its focal point is reflected by the reflection surface and then reflected in parallel to its axial direction. Actually, the position of the apparent diffusion center point 0 is slightly distant due to the refraction at the light incident portion 2, so it is more accurate to make that point the focal point. The optical distance up to the point 0 can be adjusted by forming a lens on the light incident part 2.

Since the diffused light flux reflected by the first reflection surface 4 and the second reflection surfaces 5L, 5R travels as a substantially parallel light flux that is uniform with respect to the respective axial directions, that is, the paper surface vertical direction and the paper surface direction,
If the reflecting surfaces after the second reflecting surfaces 5L, 5R are all flat surfaces, they will not diffuse again before reaching the light emitting portion, and the uniformity will not be lost, so it is easy to divide the light quantity evenly. Therefore, it is possible to obtain emitted light with good directivity and uniformity. Since the light guide 1 in this case is flat, if the diffusion in the direction perpendicular to the paper surface is ignored, the first anti-slope 4
May be flat.

In the key matching mechanism of the present embodiment, when the light guide 1 to be matched is placed, the photodetector is arranged at a position where the emitted light can be detected, and all of these detectors are properly illuminated. The key may be collated depending on whether or not is emitted.

[Effects of the Invention] As described above, in the key matching mechanism of the locking device according to the present invention, since the diffused light flux emitted from the point light source is converted into a parallel light flux by the parabolic reflection surface, it is possible to obtain good directivity and uniformity. It is possible to obtain a glint.

[Brief description of drawings]

The drawings show an embodiment of a key collating mechanism of a locking device according to the present invention. Fig. 1 is a plan view of the embodiment, Fig. 2 is a front view, and Fig. 3 is a side view. Reference numeral 1 is a light guide, 2 is a light incident portion, 3a to 3d are light emitting portions, and 4 and 5 are parabolic reflection surfaces.

Claims (1)

[Claims] 1. A key collating mechanism used for a locking device for collating light beams incident on photodetectors arranged at a plurality of predetermined positions, wherein a plurality of reflecting surfaces are used to detect diffused light beams. A light guide made of a transparent body having a plurality of reflected light paths leading to a vessel, wherein the plurality of reflection surfaces are paraboloids whose focal point is the diffusion center point of the diffused light flux and whose reflection optical path is in the axial direction. A key collating mechanism for a locking device, which is characterized in that a point light source is arranged on the inside.