Nippondenso Co., Ltd.

Hiromitsu Takai

Hiroshi Yamamoto

Masahiro Hara

Akira Shibata

Toshiyasu Sakai

Atutoshi Okamoto

Atsutoshi Okamoto

Takeshi Matsushima

Mutsushi Yamashita

Tadao Oshima

Tadao Ohshima

Apparatus for optically reading printed information by radiating light onto printed information to be reflected thereby, receiving the reflected light through an optical system and converting the image of the reflected light into a corresponding electric signal. The light source employs red light emitting diodes which radiate highly bright red light having a wavelength peak at about 660 nm so that the image sensor can receive a highly contrasting reflected light from the information printed in black on a white base. The light source further or alternatively employs infrared light emitting diodes for radiating the light having a peak wavelength at about 925 nm so that the image sensor can also received a highly contrasting reflected light from information printed in black on a blue or green base.

Apparatus for optically reading printed information

Apparatus for reading optical information such as a bar code capable of reflecting ambient light and including a hand-held reader containing an image sensor. The hand-held reader is constructed so that ambient light illuminates the optical information, whereby an image of the optical information is imaged by ambient light reflected from the optical information on the image sensor so that the image is converted into an electric signal. The hand-held reader further includes a light detector for detecting intensity of the ambient light and the image sensor is controlled so that the exposure time thereof is changed in accordance with intensity of the ambient light detected by the light detector.

Optical information reading apparatus

A detecting apparatus for compensating for changes in supply voltage to a physical parameter sensor. The apparatus includes an input element, such as a heatsensitive resistor connected to a voltage source to produce a voltage signal (C.sub.S) corresponding to a physical factor, e.g., a temperature. A constant voltage circuit or a voltage divider connected to the same voltage source as the input element produces a reference voltage signal (C.sub.R) corresponding to a predetermined reference value of the input element. Both voltage signals (C.sub.S, C.sub.R) are applied to a microcomputer in which a correction value (C.sub.C) is calculated on the basis of the both voltage signals (C.sub.S, C.sub.R) and a theoretical set value (C.sub.O) of the reference voltage signal (C.sub.R). The detected physical factor by the input element is corrected by the correction value (C.sub.C).

Detecting apparatus using a digital computer

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Obu, Japan

Hiromitsu Takai