Abstract: Disclosed herein is a vehicle headlamp which comprises an ellipsoidal light reflector having first and second focuses; a light source positioned at the first focus, so that light rays produced by the light source are reflected forward by the light reflector and converged at the second focus; a converging lens positioned in front of the second focus; a shading device positioned near the second focus for partially shading the light rays which have been reflected by the light reflector; and control means for controlling the shading characteristic of the shading device in accordance with an operation mode of the vehicle, wherein said shading device comprises a liquid crystal matrix which has a plurality of small light transmitting elements independently and electrically controlled by said control means.

Abstract: To accurately shade headlamp light for both a leading vehicle running on the same lane and an opposed vehicle running on an opposed lane, the headlight apparatus for an automotive vehicle comprises a movable headlamp, a light sensor attached on the pivotal headlamp for detecting presence of a leading vehicle, an adjusting mechanism for adjusting the optical axis of the headlamp, a controller for actuating the adjusting mechanism in response to sensor signals of the light sensor to move the headlamp so that angle of headlamp optical axis can be adjusted according to distance to a leading vehicle, and a shading plate disposed independently from the optical axis motion of the headlamp for shading light for an opposed vehicle.

Abstract: Disclosed are a system and a method for improving the visibility of objects within the visual field of a vehicular driver while driving under optically adverse conditions. The system includes an optical filter with a pass band in the visible light range disposed in front of the eyes of the driver, and a light transmitter sending out a beam of visible light with frequency components within the pass band toward the object. In addition, this system protects the driver from being dazzled by light from an approaching vehicle in the opposite lane. The method includes the steps of allowing transmission of visible light with a first frequency component to the driver and transmitting visible light with a second frequency component into the visual field, the second frequency component being a subset of the first frequency component.

Abstract: An apparatus for improving the visibility of objects within the visual field of a vehicle driver and a process therefor are disclosed. The apparatus includes a light caster casting intense visible light toward a reflective object at a frequency no lower than critical fusion frequency, an image pickup device picking up an image of the object and outputting corresponding image data, an image data amplifier, a picture signal generator and a display. The image data are processed to yield a picture signal which yields a clear picture of the object on the display. The apparatus can give the driver of a vehicle a clear picture of the objects within forward visual field of the vehicle at night without dazzling the drivers of vehicles in the opposite lane.

Abstract: A drowsiness alarm system and method for use in automotive vehicles is set to a stand-by state in response to a specific sequence of steering wheel maneuvers which may reflect driver drowsiness, for example, a relatively long period during which the steering wheel is not turned followed by an abrupt steering adjustment. From the standby state, an alarm or display alerting the driver will be generated in response to another sequence of steering maneuver confirming driver drowsiness. The second sequence of maneuvers may be selected from among a number of conventional steering behavior criteria. If driver drowsiness is not confirmed within a predetermined period of time after initiation of the stand-by state, the system is reset to its initial state.

Abstract: A system and method for detecting driver drowsiness in an automotive vehicle employs means for detecting changes in steering direction of a steering wheel on the basis of steering pulses, each steering pulse being produced whenever the steering wheel is rotated through a predetermined angle, and determines that the vehicle driver is drowsy when the number of steering pulses within a fixed interval of time exceeds a first reference value and the number of steering reversals within the fixed interval of time is below a second preset reference value.

Abstract: A fatigue alarm system and method for an automotive vehicle driver is adapted to measure periods of time during which the vehicle is driven and to subtract therefrom periods of time during which the driver rests. The driver rest periods are distinguished from brief stops of the vehicle in order to accurately measure the adjusted period of driving time. In order to distinguish rest periods from brief traffic stops, the duration of vehicle stops are measured and compared with a given value. When the vehicle stop periods are shorter than the given value, the vehicle is judged to be stopped briefly, i.e. that the driver is not resting, and the measured driving period is incremented by the measured vehicle stop period. On the other hand, when the stop periods are longer than the given value, the driver is judged to be resting. In this case, the measured stop time is subtracted from the measured driving time after being adjusted by a suitable proportionality factor.

Abstract: A drowsiness alarm system for a vehicle detects and signals that the vehicle driver is drowsy on the basis of the duration during which no steering adjustments are made and the magnitude and speed of abrupt steering adjustments immediately following the non-steering period. Parameters compared to the magnitude and speed of the abrupt steering adjustments in order to recognize steering behavior reflecting drowsiness are adjusted in accordance with the duration of the non-steering period.

Abstract: A doze warning system has a circuit 20 for producing pulse signals representative of left- and right-hand steering angle variations, circuits 30 and 40 counting the pulse signal and producing a warning signal when the counter value reaches a threshold value, and a circuit 60 for producing a reset signal to clear the counter value when a difference between a number of pulse signals representative of the left-hand steering angle variations and a number of pulse signals representative of the right-hand steering angle variations exceeds a given value, or of a condition wherein the left-hand or right-hand pulse signals inputted exceeds a predetermined pulse number. The reset signal generating circuit detects a steering angle variation in excess of the threshold value in a normal driving condition such as passing through a curved road and produces the reset signal to inhibit production of the warning. By this reset signal generating circuit function, the warning system is prevented from malfunctioning.

Abstract: A system and method for detecting driver drowsiness on the basis of steering pulses, each steering pulse being produced whenever a steering wheel is rotated through a predetermined angle and indicating the direction of rotation of the steering wheel, comprising means for detecting the roughness of the road surface on which the vehicle is travelling and interrupting the detection of driver drowsiness for a fixed interval of time when the road surface roughness exceeds an acceptable level, i.e. a level conductive to accurate drowsiness detection.

Abstract: A warning device for a vehicle comprises a steering angle detector 10 producing steering angle pulses S.sub.2, S.sub.3 indicative of the steering angle and the steering direction whenever the variation of the steering angular position exceeds a predetermined angle, a dozing detecting circuit 16 which distinguishes that the driver is in normal condition when excessively frequent steering operations in one direction are performed and distinguishes that the driver is dozing to produce a warning signal when steering operations, each of which does not exceed the predetermined angle in one direction, are repeated at a rate greater than a predetermined frequency, and a warning means 26 for producing visible or audible warning in response to the warning signal, whereby, the warning device can accurately detect dozing of the driver and produce a warning to make the driver wake up.

Abstract: A warning device for a vehicle includes a steering angle detector (10) producing steering angle pulses (S.sub.2, S.sub.3) indicative of the steering angle and the steering direction whenever the variation of the steering angular position exceeds a predetermined angle. A dozing detecting circuit (16) distinguishes that the driver is in a normal condition when excessively frequent steering operations in one direction are performed or when the interval of the steering angle pulse is longer than a predetermined value, and produces a warning signal when steering operations, each of which does not exceed the predetermined angle in one direction, are repeated at a rate greater than a predetermined frequency. A warning device (26) produces a visible or audible warning in response to the warning signal, whereby the warning device can accurately detect dozing of the driver and produce a warning to make the driver wake up.

Abstract: A sensor responsive display device includes a common display section for displaying various messages and/or warnings for a given period of time, and plural individual display sections, each corresponding to one of the messages and/or warnings displayed in the common display section.

Abstract: A warning device detects abrupt steering when the driver is dozing at the wheel and recognizes dozing of the driver to give a warning. The warning device comprises a sensor 20 for detecting steering variation angle, circuit 120, 130 for detecting abrupt steering based on detected right- and left-hand steering angle variations, and circuits 142, 146 for operating a warning means 30 when abrupt steering to the left and abrupt steering to the right are consecutively detected within a given period.

Abstract: An alarm system for a vehicle driver to prevent from dozing at wheel. The system includes structure for detecting drowsiness of the driver on a basis of abnormal steering change repetitions for a fixed period of time in a monotonous driving state defined, for example, as the transmission gear position being maintained at an overdrive or top position. The alarm system produces an alarm to the driver to prevent the driver from increasing the state of drowsiness.

Abstract: An alarm device is adapted to detect accumulation of fatigue of an automotive vehicle driver and to set an alarm time clock to produce an alarm. The detection of accumulation of fatigue is based on selected driving conditions of the vehicle and the period of time during which the detected driving condition is maintained. Fatigue data obtained based on the driving condition and the time is accumulated to determine a correction or updated value of the set time to be compared with the actual driving time. An alarm device will be activated when the driving time reaches the updated time.

Abstract: A drowsiness alarm system for a vehicle detects the driver's increasing state of drowsiness on a basis of abnormal steering change repetitions for a fixed period of time in a monotonous driving state defined, for example, as the gear shift lever being placed at an overdrive or top position. The alarm system produces an alarm to the driver to prevent the driver from increasing the state of drowsiness.

Abstract: A drowsiness alarm system for a vehicle which gives an alarm to the vehicle driver when detecting a vehicle steering condition such as to indicate a state of drowsiness, thus preventing driving in an increasing state of drowsiness. The drowsiness alarm system, according to the present invention, comprises: (a) a steering angle detection circuit which outputs a first pulse whenever the vehicle driver turns the steering wheel in either of the clockwise and anticlockwise directions in excess of a predetermined angle; (b) a quick steering detection circuit which outputs a second pulse whenever the number of the first pulses reaches a predetermined number within a predetermined period of time; and (c) an alarm unit which gives an alarm in a predetermined form to the vehicle driver in response to the second pulse fed from the quick steering detection circuit.

Abstract: According to the present invention there is provided a drowsiness alarm system which comprises: (a) a steering angle pulse generation circuit which produces first and second angle pulses at respective output terminals whenever the steering wheel is rotated clockwise and counterclockwise, respectively, through an angle equal to a predetermined angular increment; (b) curved road detection circuit responsive to the first and second steering pulses which counts the number of the first and second steering pulses separately and detects whether the vehicle travels on a curved road depending on whether the counted number of either of the first and second steering pulses reaches a first predetermined number within a predetermined period of time or depending on whether the difference of the counted number between the first and second steering angle pulses reaches a second predetermined number within the predetermined period of time; (c) a first counting circuit which counts the number of the first and second steering a

Abstract: A safety assurance system is disclosed for use in road vehicles. The system comprises a generator for providing a warning signal in response to a predetermined condition such as dozing of the driver. A rest signal is generated when the road vehicle is at rest, and a reset switch enables the driver to manually provide a reset signal. A first alarm signal is provided which is generated in response to the warning signal until the rest signal is generated. Also provided is a second signal which is generated in response to the warning signal until the rest signal or reset signal is generated. Thus, warning signals are generated that are terminated automatically when the vehicle comes to a stop or are terminated by manual operation of a reset signal.