Fujitsu Corporation

Copal Company Limited

Yoshihiro Oyama

Takeshi Ishii

Tatsuo Sasaki

Tamotsu Takahashi

Shinichi Sato

Hiroaki Katoh

Mitsuo Watanabe

Hiroaki Kawai

Ichiro Shinoda

Toshimasa Miyazaki

Kazumasa Moriya

Tomoyuki Kashiwazaki

Nobuyuki Kitamura

Motohiko Itoh

Yukio Yoshikawa

Yoshitaka Murakawa

Motohiko Ito

An optical scanner includes a light source including a laser diode for emitting a laser beam, and an optical deflector such as a rotary polygonal mirror for deflecting the laser beam to thereby produce a scanning laser beam. The laser diode is protected from being overheated by arranging the light source in a heat insulating chamber or by cooling the light source with the air flow circulated by the rotation of the rotary polygonal mirror in cooperation with a curved guide plate.

Optical scanner having laser diode as light source

A compact type bar code reader for detecting a bar code symbol provided on a surface of an article. The bar code reader includes a laser beam generation unit for generating the laser beam to be irradiated onto a bar code symbol, and a focus unit for determining a focus of the laser beam, and a scanning pattern forming unit for forming various scanning patterns of the laser beam. The bar code reader also includes a light reflection unit for reflecting the laser beam to and from the bar code symbol, a light collection unit for collecting the laser beam reflected from the bar code symbol, and a light reception unit for receiving the laser beam collected by the light collection unit, and converting it to an electrical signal. The above units are included in a casing so that the laser beam generation unit, the focus unit, the light collection unit, and the light reception unit are arranged at a lower portion of the casing, and the scanning pattern forming unit and light reception unit are arranged at a lower portion of the casing. The light path of the laser beam is formed in such a way that an emitted light path from the laser beam generation unit to the bar code symbol becomes considerably long, and a reflected light path from the bar code symbol to the light reception unit becomes shorter than the emitted light path.

Compact type bar code reader

A semiconductor laser driving circuit has a semiconductor laser for emitting a laser beam according to a drive power. A photodetector is provided for effecting photo-electric conversion of the laser beam to output a corresponding electric signal. A monitoring circuit is connected for monitoring the electric signal to output a monitor signal indicative of variation in intensity of the laser beam. A controlling circuit is connected for comparing the monitor signal with a given reference signal to output a control signal according to difference therebetween. A powering circuit is operative according to the control signal to apply to the semiconductor laser a drive power effective to eliminate the difference. An abnormality detecting circuit is provided for comparing the monitor signal with a given limit signal which is set different from the reference signal to detect abnormality to output an abnormality signal.

Semiconductor laser driving circuit

An article detection device includes: a light emission unit for emitting a detection light for irradiation onto an article, and a light reception unit for receiving a light reflected from the article. The article detection device also includes; an analog-to-digital converter for converting the reflected light to a digital signal, a first register for storing the digital signal after being sampled using a first sampling signal having a first period, and a second register for storing the digital signal after being sampled using a second sampling signal having a second period shorter than the first period. The article detection device further includes a control unit for generating the first and second sampling signals to be sent to the first and second registers, reading the digital signal stored in the first and second registers, calculating a difference between the digital signals in the first register and second register, comparing an absolute value of the difference with a predetermined threshold value, and detecting the article when the absolute value is larger than the threshold value.

Article detection device and method with shift registers and sampling

Growing community of inventors

Tokyo, Japan

Yoshihiro Oyama