JP2015080963A - Marker lamp for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a marker lamp capable of meeting the need for miniaturization.SOLUTION: A voltage supply part 11 supplies an operation voltage for bringing an organic EL element 10 as a power source into a lighting operation. A voltage measurement part 12 periodically measures a photovoltaic voltage generated in the organic EL element, without reference to a lighting/lights-out state of the organic EL element 10. A voltage control part 13 shuts off supply of the operation voltage when the photovoltaic voltage is measured by the voltage measurement part 12.

Description

  The present invention relates to a marker lamp mounted on a vehicle.

  There is known a marker lamp that detects the brightness around a vehicle and increases or decreases the amount of light emitted from a light source based on the detected brightness (see, for example, Patent Document 1).

JP 2012-077614 A

  In order to detect the brightness around the vehicle, an optical sensor is required. The additional equipment of the optical sensor is a hindrance to downsizing required for the marker lamp.

  Therefore, an object of the present invention is to provide a marker lamp that can meet the demand for miniaturization.

In order to achieve the above object, one aspect of the present invention is a sign lamp mounted on a vehicle,
An organic EL element as a light source;
A voltage supply unit for supplying an operating voltage for lighting the organic EL element;
A voltage measuring unit that periodically measures the photovoltaic voltage generated in the organic EL element regardless of the light-off state of the organic EL element;
A voltage control unit that cuts off the supply of the operating voltage when the photovoltaic voltage is measured by the voltage measuring unit.

  According to such a configuration, since the organic EL element as the light source can be used as a sensor for detecting the brightness around the vehicle, no additional equipment for the optical sensor is required. Therefore, it is possible to provide a marker lamp that can meet the demand for miniaturization.

  It is good also as a structure provided with the voltage removal part which removes the voltage accumulate | stored in the said organic EL element at the time of interruption | blocking of the supply of the said operating voltage.

  According to such a configuration, the potential of the organic EL element is reliably reset prior to the measurement of the photovoltaic voltage by the voltage measuring unit. As a result, only the potential based on the photovoltaic voltage can be reliably measured. Therefore, it is possible to accurately measure the brightness around the vehicle while satisfying the demand for downsizing the marker lamp.

  It is good also as a structure provided with the light quantity determination part which determines the light quantity at the time of lighting operation of the said organic EL element based on the said photovoltaic voltage which the said voltage measurement part measured.

  According to such a configuration, it is possible to adjust the light amount according to the brightness around the vehicle while satisfying the demand for downsizing the marker lamp.

  It is good also as a structure provided with the output part which outputs the information corresponding to the said photovoltaic voltage which the said voltage measurement part measured to the control apparatus mounted in the said vehicle.

  According to such a configuration, information obtained by using the organic EL element as an optical sensor can be used for controlling each part of the vehicle. Therefore, various controls according to the brightness around the vehicle can be performed while satisfying the demand for downsizing the marker lamp.

  The measurement period of the photovoltaic voltage by the voltage measuring unit may be on the order of 10 milliseconds.

  According to such a configuration, it is possible to reliably and accurately grasp the ambient brightness according to the situation that changes every moment when the vehicle is traveling.

  The supply cutoff time of the operating voltage by the voltage controller may be 100 microseconds or less.

  According to such a configuration, the turn-off operation of the organic EL element can be prevented from being visually recognized by a subsequent vehicle or the like. As a result, the organic EL element is used as a light sensor, but the use as a light source is not hindered.

It is a figure explaining the structure of the marker lamp which concerns on one Embodiment of this invention. It is a functional block diagram which shows the structure of the light source part with which the marker lamp of FIG. 1 is provided. It is a time chart which shows operation | movement of the light source part of FIG. It is a figure which shows the specific example of the circuit which implement | achieves the function of the light source part of FIG.

  Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In each drawing used in the following description, the scale is appropriately changed to make each member a recognizable size.

  FIG. 1A is a perspective view schematically showing the rear part of the vehicle 1. A marker lamp 3 according to an embodiment of the present invention is attached to a back door 2 that opens and closes a passenger compartment space at the rear of the vehicle. The marker lamp 3 is configured to serve as both a tail lamp and a stop lamp. That is, the marker lamp 3 is lit in conjunction with the headlamp during night driving or in bad weather, and is configured to emit light with a higher luminous intensity when the brake is operated.

  FIG. 1B is a horizontal sectional view schematically showing the configuration of the marker lamp 3. For example, the indicator lamp 3 is provided with a translucent cover 5 made of resin, for example, in a housing 4 made of resin, thereby defining a lamp chamber 6. A light source unit 7 is accommodated in the lamp chamber 6. The light source unit 7 includes an organic EL element 10 as a light source. The light emitted from the organic EL element 10 is visually recognized behind the vehicle 1 through the translucent cover 5.

  FIG. 2 is a functional block diagram showing the configuration of the light source unit 7. FIG. 3 is a time chart showing the operation of the light source unit 7. The light source unit 7 includes a voltage supply unit 11, a voltage measurement unit 12, and a voltage control unit 13 in addition to the organic EL element 10 described above.

  The voltage supply unit 11 supplies an operating voltage for lighting the organic EL element 10. In the example shown in FIG. 3A, the organic EL element 10 is turned on when the voltage supply unit 11 is turned on, and the organic EL element 10 is turned off when the voltage supply unit 11 is turned off. The vertical axis in the figure indicates whether the voltage supply unit 11 is in an operating state or a non-operating state, and does not indicate the value of the operating voltage.

  The organic EL element 10 has a property of generating a photovoltaic power corresponding to the intensity of incident light. In the marker lamp 3 according to the present embodiment, attention is paid to the fact that the organic EL element 10 can be used as an optical sensor by acquiring the value of the parameter relating to the photovoltaic power. Specifically, the voltage measurement unit 12 measures the photovoltaic voltage generated in the organic EL element 10.

  As shown in FIG. 3B, the voltage measuring unit 12 is a photovoltaic voltage generated in the organic EL element 10 regardless of whether the organic EL element 10 is turned on or off, that is, regardless of the operating state of the voltage supply unit 11. Is measured periodically. The measurement cycle is 10 milliseconds.

  As described above, the voltage measuring unit 12 measures the photovoltaic voltage regardless of whether the organic EL element 10 is turned on or off. However, when the organic EL element 10 is turned on, the voltage measuring unit 12 detects the brightness around the vehicle. In addition, the organic EL element 10 cannot be used as an optical sensor. The voltage control unit 13 blocks the supply of the operating voltage to the organic EL element 10 by the voltage supply unit 11 when the photovoltage is measured by the voltage measurement unit 12.

  As a result, as shown in FIG. 3 (a), during the lighting operation of the marker lamp 3, the organic EL element is supplied from the voltage supply unit 11 each time the photovoltaic voltage is measured periodically by the voltage measurement unit 12. The supply of the operating voltage to 10 is cut off. Thereby, the organic EL element 10 is turned off. During the extinguishing period, the organic EL element 10 can be used as a photosensor, and the photovoltage is measured by the voltage measuring unit 12. The extinguishing period of the organic EL element 10 is 100 microseconds.

  As described above, according to the configuration of the marker lamp 3 according to the present embodiment, the organic EL element 10 as the light source can be used as a sensor for detecting the brightness around the vehicle. No equipment is required. Therefore, it is possible to provide a marker lamp that can meet the demand for miniaturization.

  In the marker lamp 3 according to the present embodiment, the measurement period of the photovoltaic voltage by the voltage measuring unit 12 is 10 milliseconds. According to such a configuration, it is possible to reliably and accurately grasp the ambient brightness according to the situation that changes every moment when the vehicle is traveling.

  However, the measurement period of the photovoltaic voltage by the voltage measuring unit 12 is not limited to 10 milliseconds. As long as the brightness of the surroundings can be grasped according to the situation that changes every moment when the vehicle is traveling, the measurement cycle can be set appropriately. For example, appropriate changes can be made within a range of the order of 10 milliseconds.

  In the marker lamp 3 according to the present embodiment, the cutoff time of the operation voltage supply to the organic EL element 10 by the voltage control unit 13 is 100 microseconds. According to such a configuration, it is possible to prevent the turning-off operation of the organic EL element 10 from being visually recognized. As a result, the organic EL element 10 is used as an optical sensor, but the use as a light source is not hindered.

  However, the interruption time of the operation voltage supply to the organic EL element 10 is not limited to 100 microseconds. As long as it is longer than the operation response speed related to turning on / off of the organic EL element 10 and the turn-off operation is not visually recognized, the cutoff time can be set appropriately. For example, an appropriate change can be made in the range of several microseconds to 100 microseconds.

  As indicated by a broken line in FIG. 2, the light source unit 7 may further include a voltage removing unit 14. The voltage removing unit 14 removes the voltage accumulated in the organic EL element 10 when the voltage control unit 13 interrupts the supply of the operating voltage to the organic EL element 10.

  The organic EL element 10 has a property of storing the supplied operating voltage in the element. Therefore, even when the organic EL element 10 is switched from the lit state to the unlit state, the potential of the element may not be zero immediately. In such a state, the potential based on the photovoltaic voltage due to the photoelectric effect and the potential based on the voltage accumulated in the element during the lighting operation cannot be distinguished, and the brightness around the vehicle cannot be accurately detected.

  Therefore, as shown in FIG. 3C, when the supply of the operating voltage from the voltage supply unit 11 to the organic EL element 10 is cut off, the voltage removal unit 14 removes the voltage accumulated in the organic EL element 10. Do. For example, the voltage accumulated in the organic EL element 10 is discharged by short-circuiting the organic EL element 10 and the ground circuit.

  According to such a configuration, the potential of the organic EL element 10 is reliably reset prior to the measurement of the photovoltaic voltage by the voltage measurement unit 12. As a result, only the potential based on the photovoltaic voltage can be reliably measured. Therefore, it is possible to accurately measure the brightness around the vehicle while satisfying the demand for downsizing the marker lamp 3.

  As indicated by a broken line in FIG. 2, the light source unit 7 may further include a light amount determination unit 15. The light quantity determination unit 15 determines the light quantity during the lighting operation and the relighting operation of the organic EL element 10 based on the photovoltaic voltage measured by the voltage measurement unit 12. Specifically, the light quantity determination unit 15 determines the value of the operating voltage supplied to the organic EL element 10 by the voltage supply unit 11.

  For example, when the measured photovoltaic voltage is low, the light amount determination unit 15 determines that the periphery of the vehicle is relatively dark, and the amount of light during the lighting operation of the organic EL element 10 is such that the following vehicle does not feel glare. suppress. That is, the value of the operating voltage supplied from the voltage supply unit 11 to the organic EL element 10 is reduced. On the contrary, when the measured photovoltaic voltage is high, the light quantity determination unit 15 determines that the brightness around the vehicle is sufficient, and the light quantity at the time of the lighting operation of the organic EL element 10 is determined by the following vehicle even in the brightness. Is large enough to see the lighting. That is, the value of the operating voltage supplied from the voltage supply unit 11 to the organic EL element 10 is increased.

  Further, for example, when the measured photovoltaic voltage is low, the light amount determination unit 15 determines that there is no approaching vehicle or the like, and increases the light amount of the organic EL element 10 in order to improve the visibility of the own vehicle. That is, the value of the operating voltage supplied from the voltage supply unit 11 to the organic EL element 10 is increased. On the contrary, when the measured photovoltaic voltage is high, the light amount determination unit 15 determines that there is an approach of the following vehicle and the like, and reduces the light amount of the organic EL element 10 in order to suppress glare given to the following vehicle or the like. To do. That is, the value of the operating voltage supplied from the voltage supply unit 11 to the organic EL element 10 is increased.

  According to such a configuration, it is possible to adjust the amount of light according to the brightness around the vehicle while satisfying the demand for downsizing the marker lamp 3.

  As indicated by a broken line in FIG. 2, the light source unit 7 may further include an output unit 16. The output unit 16 outputs information corresponding to the photovoltaic voltage of the organic EL element 10 measured by the voltage measuring unit 12 to the control device 80 mounted on the vehicle.

  The information may be the photovoltaic voltage itself indicating the brightness around the vehicle, or may be something that is given meaning to the value of the photovoltaic voltage. For example, depending on whether the detected change in brightness is periodic or aperiodic, the change is caused by a lamp of a succeeding vehicle (headlight, fog lamp, etc.) (change is aperiodic) Or whether it is caused by street light or road illumination light (changes are periodic). If the brightness is constant, the current time (daytime or nighttime) and weather conditions (clear weather, cloudy weather, rainy weather, dense fog, etc.) can be identified according to the value. Information as listed above may be output from the output unit 16. Control device 80 controls each part of the vehicle based on the information received from output unit 16.

  According to such a configuration, information obtained by using the organic EL element 10 as an optical sensor can be used for controlling each part of the vehicle. Therefore, light quantity adjustment and various controls according to the brightness around the vehicle can be performed while satisfying the demand for downsizing the marker lamp 3. For example, the driver may be notified of the rapid approach, passing, and environmental information of the recognized succeeding vehicle to the driver through voice and images.

  FIG. 4 is a specific example of a circuit for realizing the function of the light source unit 7 described above. The lighting circuit 20 functions as the voltage supply unit 11 and the voltage control unit 13 described above. The on / off of the operating voltage supply shown in FIG. 3A is switched by turning on / off the switch SW1.

  The voltage removal unit 14 includes resistors R1 and R2 and a transistor Tr1. When the supply of the operating voltage to the organic EL element 10 is interrupted, the discharge signal becomes active and the transistor Tr1 is turned on. Thereby, the power supply side terminal of the organic EL element 10 is short-circuited to the ground potential, and the voltage accumulated in the organic EL element 10 is discharged.

  If the value of the discharge current is within the safe operation region of the transistor Tr1, the resistor R1 may be omitted. In the example shown in FIG. 4, a MOSFET is used as the transistor Tr1. However, a bipolar transistor may be used as long as a sufficient on / off operation speed is ensured and the saturation voltage at the time of on does not affect the voltage generated by the external light.

  The voltage measuring unit 12 includes a sample / hold circuit 21 and a buffer circuit 22. The sample / hold circuit 21 includes a resistor R3, a diode D1, an operational amplifier A1, a switch SW2, and a capacitor C1. The buffer circuit 22 includes an operational amplifier A2.

  Periodic measurement of the photovoltaic voltage of the organic EL element 10 by the voltage measuring unit 12 is performed by turning on the switch SW2 at a predetermined period (every 10 milliseconds in the above example). A signal for turning on / off the switch SW2 may be generated by hardware by a logic circuit, or may be generated by software using a microcomputer.

  The sample / hold circuit 21 holds the value acquired by measuring the photovoltaic voltage when the organic EL element 10 is turned off even when the organic EL element 10 is turned on. The acquired value is held until the next measurement of the photovoltaic voltage. The resistor R3 and the diode D1 clamp the input voltage of the operational amplifier A1 to the power supply voltage Vcc when the potential of the organic EL element 10 during lighting is higher than the power supply potential Vcc of the operational amplifier A1. Since the photovoltage has high output impedance, the operational amplifier A1 is required to have high input impedance. For this reason, it is preferable to use an operational amplifier A1 having an FET input. In the example shown in FIG. 4, the circuit configuration is a voltage follower, but an operational amplifier having a gain may be used as long as it has a high input impedance.

  A voltage corresponding to the photovoltaic voltage is generated between both terminals of the capacitor C1. The voltage, that is, a signal indicating the brightness around the vehicle is sent to each unit including the light amount determination unit 15 and the output unit 16 via the operational amplifier A2 that constitutes the buffer circuit 22. The operational amplifier A2 also preferably has a high input impedance.

  The output unit 16 includes a comparator. The analog signal output from the operational amplifier A2 is converted into a digital signal by passing through the comparator. It is preferable that the signal output to the control device 80 on the vehicle side is converted into a digital signal that is not easily affected by noise. If the installation environment is less susceptible to noise, the signal output to the vehicle-side control device 80 may be an analog signal.

  The above embodiment is for facilitating understanding of the present invention, and does not limit the present invention. The present invention can be modified and improved without departing from the spirit of the present invention, and it is obvious that the present invention includes equivalents thereof.

  The marker lamp 3 on which the light source unit 7 is mounted is not limited to the tail lamp and the stop lamp. The present invention can be applied to various indicator lamps such as fog lamps, clearance lamps, and DRL (Daytime Running Lamps).

  1: vehicle, 3: indicator lamp, 10: organic EL element, 11: voltage supply unit, 12: voltage measurement unit, 13: voltage control unit, 14: voltage removal unit, 15: light quantity determination unit, 16: output unit

Claims (5)

A sign light mounted on a vehicle,
An organic EL element as a light source;
A voltage supply unit for supplying an operating voltage for lighting the organic EL element;
A voltage measuring unit that periodically measures the photovoltaic voltage generated in the organic EL element regardless of the light-off state of the organic EL element;
A marker lamp comprising: a voltage control unit that cuts off the supply of the operating voltage when the photovoltaic voltage is measured by the voltage measuring unit.   The marker lamp according to claim 1, further comprising a voltage removing unit that removes a voltage accumulated in the organic EL element when the supply of the operating voltage is interrupted.   3. The marker lamp according to claim 1, further comprising: a light amount determining unit that determines a light amount during a lighting operation of the organic EL element based on the photovoltaic voltage measured by the voltage measuring unit.   The marker lamp as described in any one of Claim 1 to 3 provided with the output part which outputs the information corresponding to the said photovoltaic voltage which the said voltage measurement part measured to the control apparatus mounted in the said vehicle.   The measurement period of the photovoltaic voltage by the voltage measurement unit is on the order of 10 milliseconds, and the supply interruption time of the operating voltage by the voltage control unit is 100 microseconds or less. The marker lamp according to one item.

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