Abstract: The present invention relates to an ambient light detector that detects a change in light amount of ambient light. The ambient light detector consists of ambient light detecting means for detecting light entering from circumferences and outputting an electrical signal corresponding to the light amount thereof; amplifying means for amplifying the output from the ambient light detecting means; signal producing means for producing a slice level signal based on the output from the amplifying means; comparing means for comparing the output of the amplifying means with the slice level signal; and judging means for judging the level of the output from the amplifying means and then outputting a control signal to control the amplifying factor of the amplifying means, according to the judging result. Ambient light can be stably detected without depending on installation mode or external environment.

Abstract: A process for reading optical codes includes reading an optical code by irradiating a scan ing beam onto an optical code and detecting a reflected beam of the scanning beam from the optical code. A determination is made if the optical code and an optical code reader are moving relative to each other, and data of the optical code are invalidated if it is determined that the optical code and the optical code reader are moving relative to each other, and data of the optical code are validated if it is determined the optical code and the optical code reader are not moving relative to each other.

Abstract: A proximity sensor receives light beams reflected from a goods. A proximity sensor control unit determines that the goods exists when a light quantity of the reflected light received by the proximity sensor exceeds a determination threshold value. The determination threshold value increases as elapsed time since the bar code was read last time becomes longer, and, as a result, a detection sensitivity decreases. A CPU restores a duty of irradiation of the laser beam back to 100% and resumes rotations of a motor for driving an operation optical system when the proximity sensor control unit determines that the goods exists.

Abstract: A bar-co reader and a bar-code reading method each of which can perform an accurate, quick reading operation. The bar-code reader scans a bar-code with electromagnetic radioactive rays and then extracts data regarding a bar-width thereof based on the reflected rays; demodulates the bar-width data and creates the demodulated data; judges the presence or absence of a bar-code reproducible combination in the demodulated data and judges. the type of combination when the reproducible combination exists; and synthesizes the demodulated data or the character forming the demodulated data according to the type of combination. The bar-code reader and bar-code reading method can be applicable to scanners such as POS systems used in supermarkets, distribution industries, and the like.

Abstract: A binary device suitable for a bar code reader performs a binary signal conversion, without depending on a laser beam scanning rate.

Abstract: A bar code recognizing/demodulating circuit compares with each other a demodulated data string including a start bar but excluding an end bar and a demodulated data string including the end bar but excluding the start bar among a variety of demodulated data strings obtained by a scan/convergence optical system scanning a bar code. A total sum of the numbers of digits of the two demodulated data strings is detected, and whether the total sum is larger than the number of digits of the bar code to be read is checked. If larger than the number of digits of the bar code, whether data of overlapped portions of the two demodulated data strings coincide with each other is checked. If coincident, demodulated data corresponding to the whole bar code are synthesized based on the two demodulated data strings.

Abstract: The present invention relates to a semiconductor laser control method used preferably for a reading control system such as a bar code reading device and to a semiconductor laser control device employing the above method. The object of the invention is to provide a semiconductor laser control device which can be controlled based on the output of a semiconductor laser, provides a stable laser output in a noise environment, enables easy output adjustment, and is immune to external thermal or electrical noises. In the semiconductor laser control method where the light amount of a light amount to current controllable semiconductor laser is subjected to a feedback control with a predetermined time constant while it is monitored, when the light amount is less than a predetermined value, the semiconductor laser is subjected to an feedback control with a first time constant. When the light amount is more than a predetermined value, the semiconductor laser is subjected to a feedback control with a second time constant.

Abstract: A process for reading optical codes includes reading an optical code by irradiating a scanning beam onto an optical code and detecting a reflected beam of the scanning beam from the optical code. A determination is made if the optical code and an optical code reader are moving relative to each other, and data of the optical code are invalidated if it is determined that the optical code and the optical code reader are moving relative to each other, and data of the optical code are validated if it is determined the optical code and the optical code reader are not moving relative to each other.

Abstract: The present invention relates to a semiconductor laser control method used preferably for a reading control system such as a bar code reading device and to a semiconductor laser control device employing the above method. The object of the invention is to provide a semiconductor laser control device which can be controlled based on the output of a semiconductor laser, provides a stable laser output in a noise environment, enables easy output adjustment, and is immune to external thermal or electrical noises. In the semiconductor laser control method where the light amount of a light amount to current controllable semiconductor laser is subjected to a feedback control with a predetermined time constant while it is monitored, when the light amount is less than a predetermined value, the semiconductor laser is subjected to an feedback control with a first time constant. When the light amount is more than a predetermined value, the semiconductor laser is subjected to a feedback control with a second time constant.

Abstract: A bar code scanner includes a detection unit for detecting light reflected from a bar code and generating a detection signal, a conversion unit for generating detected bar code data based on the detection signal, an input interface unit receiving external bar code data generated externally, a data control unit for generating output bar code data by using the detected bar code data and/or the external bar code data from the input interface unit, and an output interface unit for sending out the output bar code data.

Abstract: A binarizing circuit includes a binary signal generating unit for generating a binary signal from an input signal, supplied from an external unit, in accordance with a processing characteristic, a detecting unit for detecting a state of the input signal, and a control unit for controlling, based on the state of the input signal detected by the detecting unit, the processing characteristic in accordance with which the binary signal generating unit generates the binary signal from the input signal. The bar-code reader includes a reading unit for optically reading an article on which a bar code is formed, the above binarizing circuit, and a decoding unit for decoding the binary signal output from the binarizing circuit so that data represented by the bar code is obtained.

Abstract: The present invention relates to a semiconductor laser control method used preferably for a reading control system such as a bar code reading device and to a semiconductor laser control device employing the above method. The object of the invention is to provide a semiconductor laser control device which can be controlled based on the output of a semiconductor laser, provides a stable laser output in a noise environment, enables easy output adjustment, and is immune to external thermal or electrical noises. In the semiconductor laser control method where the light amount of a light amount to current controllable semiconductor laser is subjected to a feedback control with a predetermined time constant while it is monitored, when the light amount is less than a predetermined value, the semiconductor laser is subjected to an feedback control with a first time constant. When the light amount is more than a predetermined value, the semiconductor laser is subjected to a feedback control with a second time constant.

Abstract: The present invention relates to an ambient light detector, a laser lighting control device using the same suitable for a bar code reader, and a bar code reader. The object is to require no explanation on a special operation and to realize an easy device design and a low manufacturing cost. Each device includes an ambient light detector to detect light around a peripheral device, and judging device to provide a signal indicating that an ambient light detected by the ambient light detector has exceeded a predetermined value over a predetermined time.

Abstract: A bar code reader employs plural scanners for scanning a bar code mark with respective, plural optical scanning beams, counters connected with the scanners respectively producing numerical data representing the widths of corresponding black and white bars of the bar code. A composer selects the numerical data from the scanners so as to produce composed numerical data, and a decoder decodes the composed numerical data and produces a bar code data signal output. The composer, upon detecting a false data such as an overflow error data or waveform error data present in the respective numerical data output of a first selected scanner, switches therefrom to the respective numerical data output of a second scanner.