Transmission type photoelectric sensor, element holder assembled therein and manufacturing method thereof
OwnerTomikazu Sakaguchiinventor
Life of this patent
Estimating the term…
Abstract
An element holder is a single-piece member integrally having a light-blocking component for limiting the spread angle of light. The element holder includes a cylindrical internal path and can detachably hold an optical element on one end. A lens is affixed on the opposite end of the element holder. The element holder is a molded plastic product, and includes a single light-blocking wall integrally molded with the element holder to extend across the internal path in a level approximately equally spaced from the optical element and the lens to limit the spread angle of light.
Claims19
A transmission type photoelectric sensor comprising:
- an optical element;
- a plastic element holder having a base wall which has an aperture and detachably contacts said optical element;
- and
- a lens positioned adjacent to the element holder opposite from the base wall,
- wherein the element holder includes:
- a light path extending from the aperture of the base wall to said lens;
- and
- an intermediate light-blocking wall extending in a substantially equally spaced level from the base wall and the lens to limit the spread angle of light, and
- wherein the element holder is a single-piece molded product including the intermediate light-blocking wall.
A transmission type photoelectric sensor comprising:
- an optical element for emitting or detecting light through a lens;
- a holding portion for holding the optical element;
- an aperture formed in the holding portion in optical alignment with the optical element;
- a sidewall defining a light path from the aperture to the lens;
- a light-blocking wall extending from the sidewall;
- a through hole formed in the light-blocking wall to define a part of the light path;
- and
- an opening formed in the sidewall defining the part of the light path from the aperture to the light-blocking wall to expose the adjacent part of the light path externally through the opening.
A plastic element holder unit to be assembled in a transmission type photoelectric sensor for holding a plurality of optical elements in equal intervals and permitting the optical elements to emit or receive light through lenses, comprising:
- a plurality of element holder portions for holding the individual optical elements therein, each said element holder portion including:
- a base wall for detachably receiving each said optical element;
- an aperture formed in a position of the base wall in optical alignment with the optical element;
- a sidewall defining a light path extending from the base wall to the lens;
- an intermediate light-blocking wall which is integral with the sidewall and extends across the light path from the aperture to the lens to limit the spread angle of light;
- and
- an opening formed in the sidewall defining the part of the light path from the base wall to the intermediate light-blocking wall,
- wherein the element holder is a single-piece product.
A method of manufacturing a plastic element holder to be assembled in a transmission type photoelectric sensor for detachably holding an optical element, which element holder includes a light path extending from an aperture formed in the base wall in optical alignment with the optical element to the lens;
- and an intermediate light-blocking wall extending across the light path in a level substantially equally spaced from the base wall and the lens and having a through hole to limit the spread angle of light, comprising the steps of:
- simultaneously setting a first die for making a lens-side half of the light path from the lens to the intermediate light-blocking wall and movable in parallel to the optical axis and a second die for a element-side half of the light path from the base wall to the intermediate light-blocking wall and movable across the optical axis;
- and injecting a material into a mold to make the lens-side half of the light path, the intermediate light-blocking wall and the element-side half of the light path.
Dependencies are inferred from the claim text.