Ricoh Company, Ltd.

Other

Opticon, Inc.

Jun Akedo

Hiroshi Kobayashi

Haruhiko Machida

Hiroyoshi Funato

Hideaki Ema

Tomoyuki Yamaguchi

Yasushi Ide

Makoto Harigaya

Takao Tawara

Yoshiyuki Iwashita

Makoko Harigaya

An optical movement measuring method and apparatus measures a movement of an object. A light from a light source is irradiated on a diffraction grating which is provided on the object so as to generate diffracted lights of different order of diffraction. The diffraction grating has light transmitting portions and light blocking portions which are alternately and periodically arranged. Interference fringes which comprises bright and dark stripes which occur alternately and are generated by overlapping spots of diffracted lights of different order of diffraction are detected, and a movement of the object is measured based on a counted number of stripes of the detected interference fringes.

Optical movement measuring method and apparatus using interference

In a method for detecting a moving amount of a detected body, light emitted from a light source is irradiated onto the detected body and light reflected from the detected body or light transmitted therethrough is detected by a photodetector. This method has the steps of emitting incoherent light from the light source through a small opening of a light-interrupting plate; irradiating the incoherent light onto the detected body having a monoperiodic structure to obtain a divergent transmitting or reflecting light beam; forming a shadow picture diffraction-interference pattern by the divergent transmitting or reflecting light beam; and detecting a moving amount of the shadow picure diffraction-interference pattern caused by a movement of the detected body in a direction crossing the irradiated light beam by the photodetector to detect the moving amount of the detected body. In case that the detected body is cylindrical, this method may have the steps of emitting incoherent light from the light source through a small opening of a light-interrupting plate; irradiating the incoherent light through a collimator lens onto the detected body having a monoperiodic structure to obtain a divergent reflecting light beam; forming a shadow picture diffraction-interference pattern by the divergent reflecting light beam; and detecting a moving amount of the shadow picture diffraction-interference pattern caused by a movement of the detected body in a direction crossing the irradiated light beam by the photodetector to detect the moving amount of the detected body.

Moving amount detecting method using a shadow picture diffraction

A rotation quantity measuring method and system measures a rotation quantity of an object body. The rotation quantity is measured by irradiating a light from a light source on a grating pattern which is formed on a peripheral surface of a cylindrical body which rotates integrally with the object body, and detecting a shadow picture pattern which is generated by a reflected light received from the grating pattern based on a diffraction caused by the grating pattern. Then, the rotation quantity of the object body is measured based on a movement of the shadow picture pattern as the object body rotates.

Rotation quantity measuring method and system

A masking layer is formed on the light-emitting mirror surface of a semiconductor laser body. The masking layer is capable of blocking light emitted from the semiconductor laser body and of being thermally melted and evaporated by exposure to the emitted light. When the masking layer is formed on the light-emitting mirror surface of the semiconductor laser body, a small light-emitting hole is defined in the masking layer by the heat of the emitted light which is effective to prevent the material of the masking layer from being evaporated on a portion of the light-emitting surface.

Method of manufacturing masked semiconductor laser

A masking layer is formed on the light-emitting mirror surface of a semiconductor laser body. The masking layer is capable of blocking or cutting off light emitted from the semiconductor laser body and of being made optically transparent by exposure to the light emitted from the semiconductor laser body dependent on the amount of energy of the emitted light. When the light is emitted from the semiconductor laser body on which the masking layer is deposited, a small light-emitting hole is defined in the masking layer, the light-emitting hole having a desired diameter commensurate with the amount of energy of the emitted light which is applied to the masking layer.

A scanning device for reading bar codes symbols comprising at least two moveable, preferably rotatably driven, reflective surfaces, such as mirrors, which direct a light source, preferably from a laser, in a scanning pattern towards the object to be scanned. At least one of said reflective surfaces having an associated lens means to modify the light beam associated with its reflective surface, and means adapted to move each of said reflective surfaces and the associated lens into a path adapted to intersect with said beam of light. Means are provided to direct the beam of light outside the scanning device as a sweep beam onto the bar code symbol to be read and optical means and sensing means are provided to collect the light reflected from the bar code symbol and generate data therefrom.

Pattern recognition device

An object to be measured for the amount of movement thereof has a uniformly periodic structure. The object is illuminated with divergent light emitted from a coherent spot light source. By positionally adjusting the spot light source, the object, and a light sensor, an enlarged shadow-picture-like diffraction pattern of the uniformly periodic structure is generated at a position in which the light sensor is disposed. The shadow-picture-like diffraction pattern is moved when the object is moved across the divergent light from the spot light source. The amount of movement of the shadow-picture-like diffraction pattern is detected by the light sensor for thereby measuring the amount of movement of the object.

Growing community of inventors

Tokyo, Japan

Jun Akedo