Abstract: The present disclosure provides a vehicular lamp including bypass circuits parallel to light emitting devices to precisely cope with an abnormality of the bypass circuit side. The vehicular lamp includes: one or more bypass units connected in parallel to at least a part of a plurality of light emitting devices to form a bypass route of the emission driving current so that the light emitting device is turned OFF according to a bypass control signal, or to cut off the bypass route; abnormality detecting units configured to generate state signals each of which indicates an normal state or an abnormal state of each of the bypass units; and a control unit configured to control the formation of the bypass route. When the generated state signal indicates that each of the bypass units is abnormal, supply of the emission driving current from the light source power supply is reduced or stopped.

Abstract: Disclosed is a light source control device including a power conversion unit and a control unit. The power conversion unit includes a transfer capacitor provided between a primary side circuit and a secondary side circuit. The primary side circuit is configured such that a first inductor stores energy when a first switching element is ON. The secondary side circuit is configured such that the second inductor limits a changing speed of the driving current. The power conversion unit is configured such that the driving current is raised when the first switching element is ON. The control unit turns OFF when the magnitude of the driving current exceeds the first threshold value, and turns ON the first switching element when the magnitude of the driving current falls below the second threshold value smaller than the first threshold value.

Abstract: Disclosed is a light source control device including a power conversion unit and a control unit. The power conversion unit includes a transfer capacitor provided between a primary side circuit and a secondary side circuit. The primary side circuit is configured such that a first inductor stores energy when a first switching element is ON. The secondary side circuit is configured such that the second inductor limits a changing speed of the driving current. The power conversion unit is configured such that the driving current is raised when the first switching element is ON. The control unit turns OFF when the magnitude of the driving current exceeds the first threshold value, and turns ON the first switching element when the magnitude of the driving current falls below the second threshold value smaller than the first threshold value.

Abstract: A discharge lamp lighting circuit includes a DC/DC converter which generates from an input voltage a drive voltage to be applied to a discharge lamp of a driven object. A first drive voltage generating path has one end to which the input voltage is applied, and at the other end of which is an output capacitor on an output side of the DC/DC converter. A second drive voltage generating path has one end to which the input voltage is applied, and at the other end of which is the output capacitor. The second drive voltage generating path is different from the first drive voltage generating path. A control circuit controls ON/OFF of the first drive voltage generating path. The discharge lamp lighting circuit is arranged so that the voltage of the output capacitor when the first drive voltage generating path is in an ON-state becomes higher than the voltage of the output capacitor when the first drive voltage generating path is not so.

Abstract: A vehicular rear panel with a new configuration is provided. The vehicular rear panel according to an aspect of the present disclosure is made of a resin material and disposed on a rear vehicle body part. The vehicular rear panel includes a light guiding unit configured to guide light from the light source along an extending direction of the vehicular rear panel and a light emitting unit configured to emit light in the light guiding unit to a rear side of a vehicle.

Abstract: A discharge lamp lighting circuit includes a DC/DC converter which generates from an input voltage a drive voltage to be applied to a discharge lamp of a driven object. A first drive voltage generating path has one end to which the input voltage is applied, and at the other end of which is an output capacitor on an output side of the DC/DC converter. A second drive voltage generating path has one end to which the input voltage is applied, and at the other end of which is the output capacitor. The second drive voltage generating path is different from the first drive voltage generating path. A control circuit controls ON/OFF of the first drive voltage generating path. The discharge lamp lighting circuit is arranged so that the voltage of the output capacitor when the first drive voltage generating path is in an ON-state becomes higher than the voltage of the output capacitor when the first drive voltage generating path is not so.

Abstract: A discharge lamp lighting circuit for supplying an AC power to a discharge lamp includes first and second converters for receiving a DC voltage and stepping up the voltage. A controlling circuit drives the first and second converters CON1, CON2 alternately at a first frequency and stops an operation of a side that is not driven such that the AC power is supplied to the discharge lamp to execute a lighting operation.

Abstract: A discharge lamp lighting circuit is provided. The discharge lamp lighting circuit includes an inverter circuit which has two output ends; a series resonant circuit which includes a capacitor, an inductor and a transformer, coupled in series; a driving portion; and a controlling portion which provides a control signal for controlling said inverter circuit, said controlling portion including a first signal producing portion which produces a first signal indicative of a phase of a current flowing through said series resonant circuit; and a second signal producing portion which produces a second signal indicative of a phase of the AC voltage output from said inverter circuit, said controlling portion producing the control signal on the basis of a phase difference between the first and second signals, wherein one component of said series resonant circuit is coupled between one of said output ends, and a detection point.

Abstract: A discharge lamp lighting circuit includes a power supplying portion having a series resonant circuit containing transistors and a bridge driver, and a control portion for generating a control signal Sc1 to control a driving frequency of the bridge driver. The control portion has a sample hold portion for generating a constant control signal S1, a frequency follow-up control portion for generating a control signal S2 in such a manner that a phase difference between a voltage and a current in the series resonant circuit is approximately zero, and a power control portion for generating a control signal S3 in such a manner that a magnitude of an AC power approximates a steady value. The control signal S1 is selected from a time t3 to a time t4, the control signal S2 is selected from the time t4 to a time t5, and the control signal S3 sent from the power control portion 13 is selected as the control signal Sc1 after the time t5.

Abstract: A discharge lamp lighting circuit for supplying an AC power to a discharge lamp includes first and second converters for receiving a DC voltage and stepping up the voltage. A controlling circuit drives the first and second converters CON1, CON2 alternately at a first frequency and stops an operation of a side that is not driven such that the AC power is supplied to the discharge lamp to execute a lighting operation.

Abstract: A discharge lamp lighting circuit includes a power supplying portion having a series resonant circuit including transistors and a bridge driver, a starting portion for applying a high voltage pulse to a discharge lamp to promote a lighting operation, a lighting confirming portion for generating a lighting confirmation signal Sf indicating that a lighting operation for the discharge lamp fails or is successful by the high voltage pulse, and a control portion for generating a control signal Sc to control a driving frequency of the bridge driver. The lighting confirming portion generates a lighting confirmation signal Sf based on a relationship of the magnitude between a lamp voltage equivalent signal VS and a predetermined voltage V4 at a time that a predetermined time ?t passes since the application of the high voltage pulse to the discharge lamp.

Abstract: A discharge lamp lighting circuit is provided. The discharge lamp lighting circuit includes a power supplying portion which comprises an inverter circuit comprising a switching element; a series resonant circuit comprising a capacitor, and at least one of an inductor and a transformer; and a driving circuit which drives said switching element, said power supplying portion converting DC power to AC power and supplying the AC power to a discharge lamp; and a controlling portion which produces a frequency control signal for controlling a frequency of a drive signal output from said driving circuit, the controlling portion including a phase difference detecting portion which detects a phase difference between an input voltage and an input current that are supplied from said inverter circuit to said series resonant circuit; and a control signal producing portion which produces the frequency control signal in accordance with the phase difference.

Abstract: A discharge lamp lighting circuit is provided. The discharge lamp lighting circuit includes an inverter circuit which has two output ends; a series resonant circuit which includes a capacitor, an inductor and a transformer, coupled in series; a driving portion; and a controlling portion which provides a control signal for controlling said inverter circuit, said controlling portion including a first signal producing portion which produces a first signal indicative of a phase of a current flowing through said series resonant circuit; and a second signal producing portion which produces a second signal indicative of a phase of the AC voltage output from said inverter circuit, said controlling portion producing the control signal on the basis of a phase difference between the first and second signals, wherein one component of said series resonant circuit is coupled between one of said output ends, and a detection point.

Abstract: A discharge lamp lighting circuit is provided. The discharge lamp lighting circuit includes a power supplying portion which comprises an inverter circuit comprising a switching element; a series resonant circuit comprising a capacitor, and at least one of an inductor and a transformer; and a driving circuit which drives said switching element, said power supplying portion converting DC power to AC power and supplying the AC power to a discharge lamp; and a controlling portion which produces a frequency control signal for controlling a frequency of a drive signal output from said driving circuit, the controlling portion including a phase difference detecting portion which detects a phase difference between an input voltage and an input current that are supplied from said inverter circuit to said series resonant circuit; and a control signal producing portion which produces the frequency control signal in accordance with the phase difference.

Abstract: A circuit includes a transformer 7 for transmitting power to a discharge lamp 10 and for supplying a starting signal to the discharge lamp. The circuit includes a direct current-alternating current converting circuit 3 for supplying an output of the transformer 7 to the discharge lamp 10 after carrying out a direct current-alternating current conversion, and a starting circuit 4 for applying the starting signal to the discharge lamp 10. A primary side of the transformer 7 has a first capacitor 11, a circuit portion 13 including a rectifying element, and a switching element 14. The transformer 7 has an auxiliary winding 7v for supplying a voltage for generating the starting signal to the starting circuit. A second capacitor 12 is interposed between the auxiliary winding and the circuit portion 13 and prevents absorption of energy by the capacitor 11 in generating the starting signal and prevents attenuation of the starting signal.

Abstract: In a lighting circuit for a discharge lamp, the discharge lamp is kept lit without fail when a DC input voltage becomes low, while avoiding a complicated circuit configuration and control method. A DC-AC converter circuit receives a DC input voltage and converts it to an AC voltage and boosts the AC voltage. The DC-AC converter circuit is controlled by a control means having a circuit for detecting the DC input voltage “+B” to perform a lighting control of the discharge lamp. The lighting circuit comprises a transformer for AC conversion, switching elements, and resonance capacitor. The switching elements are driven to cause a series resonance of the resonance capacitor and an inductance component of the transformer for AC conversion or an inductance element.

Abstract: A discharge lamp lighting circuit includes a power supplying portion having a series resonant circuit including transistors and a bridge driver, a starting portion for applying a high voltage pulse to a discharge lamp to promote a lighting operation, a lighting confirming portion for generating a lighting confirmation signal Sf indicating that a lighting operation for the discharge lamp fails or is successful by the high voltage pulse, and a control portion for generating a control signal Sc to control a driving frequency of the bridge driver. The lighting confirming portion generates a lighting confirmation signal Sf based on a relationship of the magnitude between a lamp voltage equivalent signal VS and a predetermined voltage V4 at a time that a predetermined time ?t passes since the application of the high voltage pulse to the discharge lamp.

Abstract: A discharge lamp lighting circuit includes a power supplying portion having a series resonant circuit containing transistors and a bridge driver, and a control portion for generating a control signal Sc1 to control a driving frequency of the bridge driver. The control portion has a sample hold portion for generating a constant control signal S1, a frequency follow-up control portion for generating a control signal S2 in such a manner that a phase difference between a voltage and a current in the series resonant circuit is approximately zero, and a power control portion for generating a control signal S3 in such a manner that a magnitude of an AC power approximates a steady value. The control signal S1 is selected from a time t3 to a time t4, the control signal S2 is selected from the time t4 to a time t5, and the control signal S3 sent from the power control portion 13 is selected as the control signal Sc1 after the time t5.

Abstract: A discharge lamp lighting circuit 1 is provided with a DC-AC conversion circuit 3 having a plurality of switching elements 5H, 5L and a series resonance circuit (8, 9, 7p), and control means 17 for preventing a situation in which the drive frequency of the switching element remains less than its specified minimum frequency. When the discharge lamp is lit, driving control of the switching element is carried out in a frequency range higher than the series resonance frequency. By using a driving situation detection circuit 15, a driving situation of the switching element is monitored based on a relation with a phase of a lamp current which flows through the discharge lamp. If the drive frequency of the switching element becomes less than the specified minimum frequency, the drive frequency is increased, and thereby, a lower limit of the drive frequency is automatically restricted.

Abstract: A control section is used to control a DC-to-AC converter circuit to perform lighting control of a discharge lamp. A transformer, switching elements, and a capacitor for resonance are included. The switching elements are driven and serial resonance of the capacitor and the inductance component of the transformer or an inductance element is produced. Before the discharge lamp is turned on, control is performed to cause the driving frequency of the switching elements to gradually approach Foff and to supply a start signal to the discharge lamp. Once the discharge lamp is turned on, control is performed to continuously change the driving frequency from f1 assumed before the discharge lamp is turned on to f2. A residence time in a frequency range lower than Fon is secured then the frequency is shifted to a frequency range fb higher than Fon, or an inductive range fb.