Koito Manufacturing Company, Ltd.

Kentarou Murakami

Masayasu Ito

Takao Muramatsu

Atsushi Uesugi

Hitoshi Takeda

Satoshi Kikuchi

Toshiyuki Tsuchiya

Tomoyuki Ichikawa

Takeshi Masuda

Hidetada Tanaka

Yuta Maruyama

Satoshi Yamamura

Takayoshi Kitagawa

Naoki Kawabata

Shohei Yanagizu

Tatsuro Hayashi

Takeshi Toda

Yuki Kubo

A scanning light source includes a semiconductor light source and a motor, and scans output light of the semiconductor light source in front of a lamp according to the movement of the motor. A constant current driver supplies a driving current Ito the semiconductor light source according to a light source control signal. A light source control signal generator generates the light source control signal so as to obtain a light distribution pattern that corresponds to light distribution instruction data. A delay time measurement device measures the delay time required for the transition of the on/off states of the semiconductor light source from the change of the light source control signal.

Automotive lamp

An automotive lamp includes a variable light distribution lamp and a controller. When a first light distribution pattern is to be changed to a second light distribution pattern, and when a difference in the number of shaded portions between the first light distribution pattern and the second light distribution pattern is one, the controller switches a control method for gradually changing the light distribution pattern according to a position relation between the shaded portions included in the first light distribution pattern and the shaded portions included in the second light distribution pattern.

Vehicular lamp

A scanning light source includes a light source, and scans the output light of the light source ahead of a lamp. A control apparatus controls the lighting on/off state of the semiconductor light source in synchronization with the scanning operation of the scanning light source. The control apparatus judges the presence or absence of an abnormal state with at least one from among (i) a timing immediately before switching from a lighting-on state to a lighting-off state and (ii) a timing immediately before switching from a lighting-off state to a lighting-on state as a judgment timing.

A vehicular lighting device includes a scanning light source that includes a semiconductor light source and a motor, and scans a region in front of the lighting device, with light emitted from the semiconductor light source, in accordance with motion of the motor, and a lighting circuit that changes the light quantity of the semiconductor light source in synchronization with the motion of the motor, during a normal lighting period, so as to obtain a predetermined light distribution pattern. The lighting circuit starts the motion of the motor, in response to a lighting command for headlight flashing during a stop period of the motor, and continuously lights the semiconductor light source asynchronously with the motion of the motor, during a start-up period that precedes the normal lighting period.

Vehicular lighting device

A vehicle lamp includes a first lamp unit that includes a light source, a driving unit, and a reflective body that is driven by the driving unit to repeat a periodic motion and thus scans an exit beam from the light source; and a controlling unit that controls the first lamp unit. The controlling unit instructs that the driving unit be driven until a first duration Thas passed even in a case where the controlling unit has received an illumination instruction instructing the first lamp unit to emit a beam and then received a stop instruction instructing the first lamp unit to stop emitting a beam.

Vehicle lamp with controlling unit and reflective body

A lighting circuit drives a light source including N (N represents an integer of 2 or more) multiple light-emitting elements coupled in series. A bypass switch circuit includes N multiple bypass switches, each coupled in parallel to a corresponding light-emitting element. A constant current driving circuit supplies a driving current stabilized to a target current to the light source. A light distribution controller controls the bypass switch circuit. For a given light distribution pattern, the duty ratio D(%) is determined for each of the N multiple light-emitting elements. Multiple light-emitting elements are formed as control units having a sum total of duty ratios that is less than 100%. The light distribution controller controls the multiple bypass switches such that the multiple light-emitting elements included in the same control unit are not turned on at the same time.

Lighting circuit

A vehicular lighting device includes a scanning light source. The scanning light source includes a semiconductor light source, and scans the output light of the semiconductor light source in a forward region ahead of the lighting device. A lighting circuit changes the light amount of the semiconductor light source in multiple levels in synchronization with the scanning of the scanning light source.

A blade receives light emitted from a light source and repeats a predetermined periodic motion to scan the front of a vehicle with reflected light of the emitted light. A position detector generates a position detection signal Sindicating a timing at which a predetermined reference point of the blade passes a predetermined position. Based on the position detection signal S, a period calculator calculates a period Tp of the periodic motion of the blade. A light intensity calculator receives light-distribution-pattern information Sto be formed in front of the vehicle and calculates light intensity to be generated by the light source at each time based on the position detection signal Sand the period Tp. A driver turns on a semiconductor light source so as to obtain the light intensity calculated by the light intensity calculator at each time.

Lighting circuit and vehicular lighting device

The control part controls a timing of changing the light emission intensity of the first light source and a timing of changing the light emission intensity of the second light source such that a first light-shielding portion is formed in a part of the first irradiation pattern, a second light-shielding portion is formed in a part of the second irradiation pattern so as to overlap with the first light-shielding portion, and a range of the first light-shielding portion and a range of the second light-shielding portion are deviated from each other.

Optical unit

A vehicular lamp is provided with a plurality of light emitting units and configured to independently control ON/OFF of the light emitting units. The plurality of light emitting units are disposed so that a desired light distribution is formed by overlapping scanning of illumination spots formed on a virtual screen by emitted lights thereof. The plurality of light emitting units are divided in a plurality of channels, the same direct drive current is supplied to at least one light emitting unit of all of the light emitting units included in the same channel, and the direct drive current is constantly maintained during a scanning period. The current amount of drive current for each channel is set in accordance with a light distribution mode, and ON/OFF of each light emitting unit is switched at a predetermined timing determined in accordance with the light distribution mode during a scanning period.

A lighting circuit, which is mounted in a vehicle lamp, can change the luminance at high speeds. The lighting circuit is used together with a semiconductor light source and makes up a vehicle lamp. A switching converter supplies power to the semiconductor light source. A converter controller controls the switching converter. A current detection circuit detects a current Iwhich is supplied from the switching converter to the semiconductor light source. A hysteresis comparator compares the detected current value with an upper threshold voltage and a lower threshold voltage and generates a control pulse according to the results of the comparison. A threshold voltage generating circuit receives a variable control voltage which indicates a target amount of a current and generates the upper threshold voltage and the lower threshold voltage according to the control voltage.

Vehicle lamp and lighting circuit thereof

A dimming control systemincludes: light source units each having a respective LED; and a control unit connected to the light source units via power supply lines. The control unit is connected to each of the light source units in series. The control unit includes: switch portions that control dimming of the LEDs by repeating an ON/OFF operation in a predetermined cycle; current detection circuits and voltage detection circuits that detect a current or a voltage supplied via the power supply lines; and a CPU that determines there is an abnormality in the power supply lines or the light source units when a value of the detected current or voltage exceeds a predetermined range while the switch portions are ON.

Dimming control system for vehicular lamp

In conduction of light emitting diodes LEDsto, a switching signalis converted into a voltage Vor 0V through a signal converterin accordance with a logic level thereof. The voltage obtained by the conversion is compared with a voltage Von both ends of a resistor Rthrough an operational amplifierto open/close an output loop by an NMOS transistor, a current If of the light emitting diodes LEDstois limited to a current Ifso as not to exceed a maximum current, and a current defined with an ON duty of the switching signalis caused to flow as a mean current to the light emitting diodes LEDstoto inhibit an overshoot current from flowing to the light emitting diodes LEDstowhile the output loop is closed.

Light emitting apparatus with current limiting

A power supply device includes: a regulator transformer; a primary switch for selectively supplying a current to the regulator transformer; a control circuit for reducing to 0, following each election made at the primary switch, the minimum value of a current output by the secondary side of the regulator transformer; and a coupling transformer for magnetically coupling routes along which a plurality of loads are connected in parallel to the secondary side of the regulator translator in a direction in which magnetic flux along each of the routes is offset by a current change. In this case, the control circuit increases the maximum value of the output current on the secondary side larger than twice of the target value of the current supplied to the loads.

Power supply device and vehicle lamp

A power supply unit comprises: a voltage output section for supplying a voltage to a plurality of loads connected in parallel with each other; and a plurality of output side coils provided respectively corresponding to the plurality of loads, the plurality of output side coils being trans-connected with each other, the plurality of output side coils being connected with the corresponding loads in series. An electric current to be supplied from the voltage output section to the corresponding load flow in each output side coil.

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Shizuoka, Japan

Kentarou Murakami