Abstract: A document reading device comprises a plurality of distance sensors, an original document size detection board, and a main unit control board. The plurality of distance sensors measure distance as for each certain position of an original document table. The original document size detection board comprises an EEPROM for storing a threshold value and an original document size detection CPU 1 for implementing a program for original document size detection. The original document size detection board judges the presence or the absence of an original document at each preset position of an original document table by comparing each threshold value from the plurality of distance sensors with the threshold value, detects the size of an original document according to the judging result from the original document size detection board, and outputs data indicative of the detected original document size. The main unit control CPU 2 implements a program for original document reading control.

Abstract: A light-emitting elements emits a light beam onto a predetermined sensing position, and a reflected beam from an original is received by a light-receiving element. The light-receiving element, which is a position sensitive detector for detecting a spot position of the reflected beam, releases a pair of currents that vary according to the spot position. A signal processing circuit detects the presence or absence of the original based on the ratio of the currents. The pair of currents released by the light-receiving element fluctuate in response to changes in reflection factor due to the individual color of the original, while the ratio of the pair of currents does not fluctuate even if the reflection factor changes. Thus, detection accuracy is improved, and erroneous detection can be prevented in comparison with an arrangement wherein the presence or absence of the original is detected by detecting and comparing the amount of light.

Abstract: A light emitting element and a light receiving element are installed on a wiring board mounted in a housing case. Light emitted from the light emitting element is irradiated on an object to be detected through a first lens installed in the housing case. Light reflected by the object to be detected is received by the light receiving element through a second lens installed in the housing case. The housing case is formed of a grounded conductive material, and the wiring board is formed of a material having a coefficient of linear expansion equivalent to that of the housing case.

Abstract: A semiconductor integrated circuit includes a circuit that has characteristics that can be changed by an electrical signal supplied from the outside of the integrated circuit. An output terminal that is used during the normal action of the semiconductor circuit is used as the output of the filter when testing the characteristics of the filter. A switching from the output terminal during normal action and during testing of the filter is performed by a plural mode switch.

Abstract: In a dc electric fuel pump control apparatus for controlling the quantity of fuel supplied to a vehicle engine in accordance with an engine operating parameter condition such as an intake air flow condition or engine speed condition, when controlling a voltage applied to a fuel pump operating motor by closing or opening a fixed-resistor short-circuiting switch circuit in accordance with the magnitude of the operating parameter relative to a predetermined value, an increase or decrease of a battery power source voltage from a predetermined value is detected to increase or decrease the predetermined value of the engine operating parameter. Where a variable resistor is used in place of the fixed resistor, its resistance value in a low battery power source voltage condition is controlled lower than that in a high battery power source voltage condition.