JP2008132857A - Vehicular light lighting circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular light lighting circuit with a current control means controlling a current passing through a light source to make the visibility of the light source in a lit state appropriate regardless of the state of a visual range around a vehicle, which is capable of lighting the light source even if the current control means fails. <P>SOLUTION: This vehicular light lighting circuit 10 has a first current passage A1 for feeding the current through the light source 11, a second current passage A2 for changing the current passing through the light source 11, the current control means 18 controlling the current passing through the second current passage A2 so that the light source 11 is illuminated according to the state of the visual range from a visual range state obtaining means, and a switch means 14 capable of switching on/off the first current passage A1. The light circuit lights the light source 11 with predetermined brightness S1 when the first current passage A1 is in conduction, and the current is not supplied to the second current passage A2. The current control means 18 passes the current through the second current passage A2 according to a condition signal only when the first current passage A1 is in conduction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicular lamp lighting circuit capable of adjusting the brightness of a light source that is lit.

  2. Description of the Related Art Conventionally, as a lamp used in a vehicle, as an example, there is one in which a light source unit in which an LED (light emitting diode) is used as a light source is applied to a stop lamp. In such a vehicle lamp, a current of a predetermined magnitude is supplied to the light source unit when the foot brake is stepped on, and no current is supplied to the light source unit when the foot brake is not stepped on. It has a vehicular lamp lighting circuit (see, for example, Patent Document 1). In this vehicular lamp, the light source section as a stop lamp can be turned on with a predetermined brightness in accordance with an operation performed on the foot brake.

  By the way, in this vehicular lamp, even if the light source part is lit at the same brightness, depending on the visibility state around the vehicle, for example, depending on the illuminance outside the vehicle, the presence or absence of fog, rain, dust, splash, smoke, etc. The visibility from around the vehicle will change.

Therefore, a current control unit capable of controlling the current flowing through the light source unit, and a visibility state obtaining unit capable of obtaining a visibility state around the vehicle and generating a condition signal according to the obtained visibility state, from a power source. A vehicle lamp lighting circuit that is provided in a current path to the light source unit and operates the current control unit according to the condition signal generated by the visibility state acquisition unit is considered. In this vehicular lamp lighting circuit, the current flowing through the light source unit is adjusted in accordance with the state of view surrounding the vehicle. For example, the light source is operated under the condition that the visibility of the light source unit in the lit state from around the vehicle is reduced. By increasing the current flowing through the part to brighten the light source part, the visibility of the light source part in the lit state can be made appropriate regardless of the visibility state around the vehicle.
JP 2004-235498 A

  However, in the conventional vehicle lamp lighting circuit described above, since the current control means is provided in the current path from the power source to the light source section, the light source section cannot be turned on if a failure occurs in the current control means. End up.

  The present invention has been made in view of the above problems, and controls current flowing through a light source unit so that the visibility of the light source unit in a lighting state is appropriate regardless of the visibility state around the vehicle. It is an object of the present invention to provide a vehicular lamp lighting circuit that has a means for lighting a light source unit even when the current control means fails.

  In order to solve the above-mentioned problem, the vehicular lamp lighting circuit according to claim 1 is a first current path for causing a current to flow through the light source unit to light the light source unit used in the vehicular lamp with a predetermined brightness. A second current path for changing a current flowing through the light source unit to light the light source unit brighter than the predetermined brightness, and a visibility state around the vehicle can be obtained and A visibility state acquisition means capable of generating and outputting a corresponding condition signal, and a current for controlling the current flowing in the second current path so that the light source unit becomes bright according to the condition signal from the visibility state acquisition means Control means and switch means capable of interrupting the first current path according to an operation performed, the first current path is made conductive by the switch means, and a current flows through the second current path. If not The light source unit is turned on at the predetermined brightness, and the current control unit applies the second current path according to the condition signal only when the first current path is turned on by the switch unit. It is characterized by flowing an electric current.

  According to the above configuration, since the brightness of the light source unit is changed according to the visibility state around the vehicle by the current control means, the visibility of the light source unit in the lit state is appropriately set regardless of the visibility state around the vehicle. Can be.

  Further, the current control means changes the brightness of the light source unit by controlling the current flowing in the second current path. When no current flows in the second current path, the current from the first current path Since the light source unit can be turned on with a predetermined brightness, even if the current control unit fails, the light source unit can be turned on with a predetermined brightness according to the operation performed on the switch unit. it can.

  The vehicular lamp lighting circuit according to claim 2 is the vehicular lamp lighting circuit according to claim 1, wherein when the first current path is turned on by the switch means, the light source unit is turned on. A power source and the light source unit are connected so that a current of a predetermined magnitude flows through the light source unit so that the light source is lit at the predetermined brightness, and the second current path is connected to the light source unit from the predetermined size. The power source and the light source unit are connected in parallel with the first current path so as to flow a large current, and the current control unit receives a current flowing through the light source unit according to the condition signal from the visibility state acquiring unit. The current flowing through the second current path is increased so as to increase from the predetermined magnitude.

  According to the above configuration, since the current control means increases the current flowing through the second current path connected in parallel to the first current path, the brightness of the light source unit is increased. Even if a failure occurs, the light source unit can be turned on with a predetermined brightness by the current from the first current path in accordance with the operation performed on the switch means.

  The vehicular lamp lighting circuit according to claim 3 is the vehicular lamp lighting circuit according to claim 2, wherein the first current path connects the power source and the light source unit via a resistor. It is configured.

  According to the above configuration, the first current path is configured to connect the power source and the light source unit via the resistor, and it is very rare that a failure occurs in the first current path. Even when the means fails, the light source unit can be turned on with a predetermined brightness in accordance with the operation performed on the switch means.

  The vehicular lamp lighting circuit according to claim 4 is the vehicular lamp lighting circuit according to claim 1, wherein the light source unit includes a plurality of light sources, and the first current path includes the switch means. When the light source group is turned on, a part of the light source group is turned on so that a current flows through a part of the light source group so that the light source unit is turned on at a predetermined brightness by turning on a part of the light source group. And the second current path connects the power source and the other part of the light source group so that a current flows to the other part of the light source group, and the current control means includes the visibility state acquiring means. The current in the second current path is controlled so as to flow a current having a magnitude corresponding to the condition signal from the other light source group to the other part of the light source group.

  According to the configuration described above, the current control unit changes the brightness of the light source unit by controlling the current in the second current path connected to the other part of the light source group. Even in this case, a part of the light source group can be turned on in the first current path in accordance with the operation performed on the switch means, so that the light source unit can be turned on with a predetermined brightness.

  The vehicular lamp lighting circuit according to claim 5 is the vehicular lamp lighting circuit according to claim 4, wherein the first current path connects the power source and a part of the light source group via a resistor. It is characterized by being connected.

  According to the configuration described above, the first current path connects the power source and a part of the light source group via the resistor, and it is very rare that a failure occurs in the first current path. Even when the control means is out of order, the light source unit can be turned on with a predetermined brightness according to the operation performed on the switch means.

  The vehicular lamp lighting circuit according to claim 6 is the vehicular lamp lighting circuit according to claim 4 or 5, wherein the light source unit includes a part of the light source group constituting the light source unit. The light source group is scattered so as to be able to emit light from the entire region, and the other part of the light source group is mixed with a part of the light source group so as to be able to emit light from the entire region of the light source unit. To do.

  According to the above configuration, the light source unit can be efficiently set to a predetermined brightness by lighting a part of the light source group, and the light source unit can be efficiently brightened by lighting the other part of the light source group. Can do.

  The vehicular lamp lighting circuit according to claim 7 is the vehicular lamp lighting circuit according to any one of claims 1 to 6, wherein at least the brightness around the vehicle is in the visibility state. Is included.

  According to the above-described configuration, the brightness around the vehicle greatly affects the visibility of the light source unit in the lit state, and can be easily detected by using, for example, an illuminance sensor. By using it as a reference for changing the brightness of the light source unit, the visibility of the light source unit can be easily made appropriate.

  The vehicular lamp lighting circuit according to claim 8 is the vehicular lamp lighting circuit according to any one of claims 1 to 7, wherein the vehicle has a sudden deceleration. Detectable sudden deceleration detection means is provided, and the current control means is configured such that when the sudden deceleration detection means detects that the vehicle is suddenly decelerated, the brightness of the light source unit changes at a constant cycle. It is characterized by controlling the current in the second current path.

  According to the above-described configuration, the brightness of the light source unit can be changed at a constant period during sudden braking of the vehicle. For example, by applying the light source unit to a stop lamp or a turn lamp, an operation by a passenger is required. It is possible to alert the rear of the vehicle without having to do so.

  In the vehicle lamp lighting circuit of the present invention, the current flowing through the light source unit is controlled by the operation of the current control means so that the visibility of the light source unit in the lit state is appropriate regardless of the visibility state around the vehicle. In addition, the light source unit can be turned on even when the current control means fails.

  Embodiments of a vehicle lamp lighting circuit 10 according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view schematically illustrating a vehicle C in which the vehicular lamp lighting circuit 10 according to the first embodiment is employed, and FIG. 2 is a configuration diagram schematically illustrating the configuration of the vehicular lamp lighting circuit 10. It is.

  As shown in FIG. 1, the vehicular lamp lighting circuit 10 is applied as a circuit for lighting an LED unit 11 that constitutes a light emitting unit as a stop lamp of the vehicle C, and a brake device 12 ( The LED unit 11 is turned on / off in accordance with the operation performed in FIG.

  As shown in FIG. 2, the vehicular lamp lighting circuit 10 includes a power circuit 13 and a switch circuit 14, a resistor 15 and an LED unit 11 connected in series. The electronic control unit 16 (hereinafter, also simply referred to as an ECU 16 (Electronic Control Unit)) is configured as an electric circuit connected in parallel. A switch circuit 14 is provided for the operation of this electric circuit.

  The switch circuit 14 is configured to be interlocked with the operation of the brake device 12 of the vehicle C. When the brake device 12 is in an OFF state, the switch circuit 14 is in an open state (open posture), and when the brake device 12 is in an ON state. It is in a conducting state (closed posture).

  The power supply circuit 13 is a power supply device mounted on the vehicle C. In the first embodiment, the power supply circuit 13 uses a battery mounted on the vehicle C, and the LED unit 11 is turned on and off when power is supplied from the battery circuit according to the switching of the switch circuit 14. .

  In the first embodiment, the LED unit 11 uses a light emitting diode 17 (hereinafter referred to as an LED 17) that is a semiconductor light emitting element as a light source. For example, although not shown, the LED unit 11 is configured by connecting a plurality of light source rows in which a plurality of LEDs 17 are connected in series, and connecting each of the light source rows with a limiting resistor in series with each LED 17. The LED unit 11 has one terminal connected to the power supply circuit 13 via the resistor 15 and the switch circuit 14, and the other terminal connected to the power supply circuit 13. In this embodiment, the LED unit 11 is employed in a light emitting unit (see FIG. 1) as a stop lamp of the vehicle C as described above as an example of a lamp used in the vehicle. A resistor 15 is provided between the LED unit 11 and the power supply circuit 13.

  The resistor 15 is connected between the connection point a on the switch circuit 14 side and the connection point b on the LED unit 11 side (in series with the LED unit 11), and is supplied with power from the power supply circuit 13. The function of adjusting the current flowing through each LED 17 to an appropriate magnitude is provided. In the first embodiment, the resistor 15 is connected when only the main circuit configured in cooperation with the power supply circuit 13, the switch circuit 14, and the LED unit 11 is turned on by the switch circuit 14 in the ON state (between connection points a and b). Thus, the current i2 flowing through the LED unit 11 is set to a predetermined magnitude I1 so that the LED unit 11 is lit at a predetermined brightness S1 (see FIG. 3). An ECU 16 is provided to change the brightness of the LED unit 11 in the lighting state.

  The ECU 16 has a value larger than the current of the above-described magnitude I1 in order to make the brightness of the LED unit 11 in the lighting state brighter than the brightness S1 (see FIG. 3) according to the visibility state around the vehicle C. Is configured to flow through the LED unit 11. The ECU 16 includes a current adjustment circuit 18 connected to the connection point a, and a resistor 19 connected in series between the current adjustment circuit 18 and the connection point b. The resistor 19 has a function of adjusting the current from the current adjusting circuit 18 so as to adjust the current flowing through each LED 17 to an appropriate magnitude when power is supplied from the power supply circuit 13.

  The current adjustment circuit 18 changes the magnitude of the current i2 flowing through the LED unit 11 by controlling the current i1 flowing through the resistor 19 to the connection point b. In the first embodiment, the current adjustment circuit 18 supplies a current i1 whose magnitude is adjusted according to signals from the illuminance sensor 20 and the light transmission sensor 21 provided in the vehicle C.

  Although not shown, the illuminance sensor 20 is provided in the vehicle C so that the illuminance around the vehicle C can be detected. The illuminance sensor 20 is configured to generate an illuminance detection signal corresponding to the detected illuminance and output the illuminance detection signal to the current adjustment circuit 18.

  Although not shown in the drawings, the light transmittance sensor 21 is provided in the vehicle C so that the light transmittance around the vehicle C can be detected. The light transmittance sensor 21 is configured, for example, such that the light emitting device and the light receiving device face each other at a predetermined interval so that the light emitted from the light emitting device is received by the light receiving device, and measures the amount of light received by the light receiving device. Can be realized. The light transmittance sensor 21 can detect the influence on visibility due to the presence or absence of fog, rain, dust, splash, smoke, or the like around the vehicle C. The light transmission sensor 21 is configured to generate a light transmission detection signal corresponding to the light transmission of the detected light and output the light transmission detection signal to the current adjustment circuit 18.

  The current adjustment circuit 18 obtains the necessary brightness for the LED unit 11 in consideration of the illuminance detection signal from the illuminance sensor 20 and the light transmission detection signal from the light transmission sensor 21, in order to obtain the necessary brightness. The current i1 set so as to flow the current of the magnitude I2 (> I1) to the LED unit 11 is passed. The current adjustment circuit 18 can be realized, for example, by generating a gate current of the FET in consideration of the illuminance detection signal and the light transmission detection signal, and adjusting the drain-source current with this gate current. .

  Here, taking the illuminance detection signal and the light transmission detection signal into consideration means the following. Since the illuminance detection signal represents the illuminance around the vehicle C, the visibility of the stop lamp deteriorates as the illuminance increases, that is, the surrounding of the vehicle C becomes brighter. If the predetermined brightness S1 is sufficient, the brightness of the LED unit 11 is increased according to the increase in sufficient illuminance. Further, since the light transmittance detection signal represents the light transmittance in the atmosphere around the vehicle C, the light transmittance is large, that is, the light of the stop lamp is increased so that the light easily passes through the atmosphere around the vehicle C. Since the visibility is improved, if the LED unit 11 has a predetermined brightness S1 when the transmittance is large, the brightness of the LED unit 11 is increased according to the decrease in the transmittance. An acceleration sensor 22 is electrically connected to the current adjustment circuit 18.

  The acceleration sensor 22 can detect acceleration / deceleration generated in the vehicle C, generate an acceleration / deceleration detection signal corresponding to the detected acceleration / deceleration, and output the acceleration / deceleration detection signal to the current adjustment circuit 18. Is formed. When the current adjustment circuit 18 detects that the vehicle C has suddenly decelerated based on the acceleration / deceleration detection signal from the acceleration sensor 22, the current adjustment circuit 18 operates to cause the current i1 to flow intermittently.

  As described above, in the first embodiment, the LED unit 11 functions as a light source unit, and from the power supply circuit 13 constituting the main circuit to the LED unit 11 through the switch circuit 14 and the resistor 15, It functions as a first current path A1 that is lit at brightness S1, and from the ECU 16 to the LED unit 11, a second current i2 that flows through the LED unit 11 is changed in order to increase the brightness of the LED unit 11. It functions as a current path A2. Further, the current adjustment circuit 18 and the resistor 19 of the ECU 16 function as current control means for controlling the current i1 flowing through the second current path A2 so that the LED unit 11 becomes bright, and the illuminance sensor 20 and the light transmittance sensor 21. Functions as a visual field state acquisition unit 23 that acquires a visual field state around the vehicle C and generates and outputs a condition signal corresponding to the acquired state. Further, the current adjustment circuit 18 functions as a sudden deceleration detection unit capable of detecting that the vehicle C has suddenly decelerated in cooperation with the acceleration sensor 22.

  Next, the operation of the vehicular lamp lighting circuit 10 according to the present invention will be described along the graph of FIG. In FIG. 3, the horizontal axis indicates time t, and the vertical axis indicates the brightness of the LED unit 11. In FIG. 3, for the sake of explanation, it is assumed that the switch circuit 14 is in an open state when the time t is 0, the switch circuit 14 is in a conductive state at the time t1, and the switch circuit 14 is opened again at the time t4. It is assumed that the ECU 16 has started operation at time t2 between time t1 and time t4, and that the current adjustment circuit 18 (ECU 16) has failed at time t3.

  In the vehicular lamp lighting circuit 10, when the brake device 12 is stepped on and turned on at time t1, the switch circuit 14 is turned on. At this time, in Example 1, since the ECU 16 has not started the operation, the LED unit 11 is turned on by the current (magnitude I1) from only the first current path A1, and therefore the LED unit 11 is bright. It is turned on at S1.

  When the time t2 is reached, the ECU 16 starts its operation, that is, the current adjusting circuit 18 considers the input illuminance detection signal from the illuminance sensor 20 and the light transmittance detection signal from the light transmittance sensor 21 to thereby determine the LED. Since it is determined that the brightness of the unit 11 needs to be increased, the current i2 flowing to the LED unit 11 becomes larger than the magnitude I1 by passing the current i1 to the connection point b, and the brightness of the LED unit 11 is bright. Brighter than S1. In the first embodiment, it is assumed that the illuminance around the vehicle C and the light transmittance are changed as appropriate, and the brightness of the LED unit 11 is changed over time in accordance with the changes.

  When the time t3 is reached, a failure has occurred in the ECU 16, and the current i1 from the second current path A2 to the connection point b is lost. Then, in the vehicular lamp lighting circuit 10, only the main circuit is in a conductive state, so that the LED unit 11 is turned on by a current having a magnitude I 1 from the first current path A 1. 11 will be lit at brightness S1.

  When the time t4 is reached, the switch circuit 14 is opened and the LED unit 11 is turned off as the brake device 12 is turned off.

  As described above, in the vehicular lamp lighting circuit 10, while the brake device 12 is in the ON state, the ECU 16 operates so that the visibility state around the vehicle C (illuminance and light transmission in the first embodiment) is achieved. The brightness of the LED unit 11 can be changed as appropriate according to the degree. Thereby, irrespective of the visibility state around the vehicle C, the LED unit 11 (stop lamp in the first embodiment) can be lit with appropriate visibility.

  Further, in the vehicular lamp lighting circuit 10, even if the ECU 16 fails, the LED unit 11 is connected to the LED unit 11 through the switch circuit 14 and the resistor 15 from the power supply circuit 13 to the LED unit 11 with a predetermined brightness S1. Since there is no influence from the viewpoint of lighting, the LED unit 11 can be turned on and off at the brightness S1 in accordance with an operation to the brake device 12 (interruption by the switch circuit 14), so that it functions as a brake light. Will not be damaged. Thereby, the fail-safe property of the LED unit 11 (stop lamp in Example 1) intended to send a signal to a person outside the vehicle C can be ensured.

  Furthermore, in the vehicular lamp lighting circuit 10, the main circuit (first current path A <b> 1) for ensuring fail-safety is configured by the LED unit 11 from the power supply circuit 13 through the switch circuit 14 and the resistor 15. That is, since the first current path A1 is constituted by only the resistor 15, it is very rare that a failure occurs in the first current path A1, and therefore, the operation to the brake device 12 (interruption by the switch circuit 14) is performed. Accordingly, since the LED unit 11 can be turned on and off, the function as a brake light is not impaired. Thereby, the fail-safe property of LED unit 11 (a stop lamp in a present Example) aiming at sending a signal to the person outside the vehicle C is securable.

  In the vehicular lamp lighting circuit 10, the LED unit 11 has a predetermined brightness S1 only when necessary according to the visibility state acquired by the visibility state acquisition means 23 (illuminance sensor 20 and light transmittance sensor 21 in the first embodiment). Therefore, it is possible to suppress unnecessary power consumption since the appropriate visibility is ensured by making it brighter.

  The vehicular lamp lighting circuit 10 is configured as an electric circuit in which an ECU 16 is connected in parallel to a main circuit configured by connecting a switch circuit 14, a resistor 15 and an LED unit 11 in series to a power circuit 13. Since it can be formed by connecting the ECU 16 and the resistor 19 (second current path A2) in parallel between the connection point a and the connection point b of the electric circuit configured as the main circuit, it is realized easily and simply. be able to.

  When the vehicle lamp lighting circuit 10 detects that the vehicle C has suddenly decelerated, the current adjustment circuit 18 operates to flow the current i1 intermittently. The stop lamp (LED unit 11) can be moved back and forth at a certain interval from the state of lighting at the above brightness, that is, the brightness of the stop lamp can be changed at a certain interval. Thereby, it is possible to make a person outside the vehicle C recognize that the vehicle C has decelerated rapidly without any operation by the occupant.

  Therefore, in the vehicular lamp lighting circuit 10 according to the first embodiment, the visibility of the LED unit 11 in the lit state is increased regardless of the visibility state around the vehicle C by the operation of the current control means (the current adjusting circuit 18 and the resistor 19). The current flowing through the LED unit 11 can be controlled so as to be appropriate, and the LED unit 11 can be lit even when the current control means fails.

  Next, the vehicle lamp lighting circuit 100 according to the second embodiment will be described. As shown in FIG. 4, the vehicular lamp lighting circuit 100 according to the second embodiment divides each LED 170 of the LED unit 110 into two LED groups 170a and 170b, and turns on the LED unit 170 by lighting one LED group 170a. In this configuration, the brightness is set to a predetermined brightness S1 and the other LED group 170b is turned on to make the LED unit 11 brighter than the predetermined brightness S1. On the other hand, the vehicular lamp lighting circuit 10 according to the first embodiment is configured to increase the brightness by increasing the current flowing through the LED unit 11. The vehicular lamp lighting circuit 100 has the same basic configuration as the vehicular lamp lighting circuit 10 of the first embodiment, and therefore, the same functional parts are denoted by the same reference numerals as those of the first embodiment, and the detailed description thereof will be given. Is omitted. 4 is a configuration diagram schematically showing the configuration of the vehicular lamp lighting circuit 100, and FIG. 5 is an explanatory diagram schematically showing a state in which the stop lamp is viewed from the rear side of the vehicle. In FIG. 5, for the sake of explanation, the positions where the LEDs 170 constituting the LED group 170 a are arranged are indicated by ◯, and the positions where the LEDs 170 constituting the LED group 170 b are arranged are indicated by Δ.

  In the vehicular lamp lighting circuit 100, as shown in FIG. 4, the LED unit 110 is different from the LED unit 11 of the first embodiment, and each LED 170 used as a light source includes two LED groups 170a and 170b. It is divided into two parts. The LED group 170a is set so that the LED unit 110 can be lit at a predetermined brightness S1 when lit. The LED group 170b is set such that the LED unit 110 can be lit brighter than the predetermined brightness S1 by being lit when the LED group 170a is lit. In other words, the LED unit 110 can be lit with the predetermined brightness S1 only by the LED group 170a, and can be lit brighter than the predetermined brightness S1 by adding the LED group 170b to the LED unit 170a. It is configured to be able to.

  As shown in FIG. 5, the LED group 170 a and the LED group 170 b are arranged in the stop lamp housing 24 over the entire desired light emitting area (area constituting the light source unit) in the second embodiment. Are interspersed so as to be mixed substantially evenly. Specifically, in the second embodiment, the LEDs 170 are arranged in the stop lamp housing 24 so that a plurality of rows with equal intervals in the horizontal direction are arranged at equal intervals in the vertical direction and the LED groups 170a are viewed in the horizontal alignment direction. And the LED groups 170b are alternately arranged. For this reason, in the LED unit 110, when only the LED group 170a is turned on and when only the LED group 170b is turned on, the LED unit 110 is substantially the same so as to cover all of the desired light emitting areas. It is possible to light with uniform brightness. The LED group 170a and the LED group 170b of the LED unit 110 are turned on by currents from different current paths.

  The vehicular lamp lighting circuit 100 is branched at a connection point c leading to the switch circuit 14, one of which is connected to the LED group 170 a of the LED unit 110 via the resistor 150, and the other is connected to the LED unit 110 via the ECU 160. LED group 170b. Here, since the switch circuit 14, the resistor 150, and the ECU 160 have the same configuration as in the first embodiment, detailed description thereof is omitted.

  In the vehicular lamp lighting circuit 100, a circuit from the power supply circuit 13 to the power supply circuit 13 through the switch circuit 14, the resistor 150, and the LED group 170a is configured. As the switch circuit 14 is opened and closed, the LED group 170a is turned on. A main circuit to be turned off is formed. By this main circuit, when only the LED group 170a is turned on (a state in which the switch circuit 14 is in a conductive state and the ECU 160 is not operated), the main circuit is turned on so that the LED unit 110 is turned on at a desired brightness S1. It is configured. For this reason, the LED group 170a functions as one of the light source groups that light the LED unit 110 with a predetermined brightness S1, and a portion from the connection point c through the resistor 150 to the LED group 170a is the first current path A1 ′. Is functioning as

  Further, in the vehicular lamp lighting circuit 100, a circuit from the power supply circuit 13 to the power supply circuit 13 through the ECU 160 and the LED group 170b is configured, and when the ECU 160 is operated when the switch circuit 14 is turned on. In addition to the LED group 170a, the LED group 170b is turned on, and the LED unit 110 is turned on at a brightness brighter than the desired brightness S1. For this reason, the LED group 170b functions as the other of the light source groups that are lit in addition to the LED group 170a in the lit state so that the LED unit 110 is lit brighter than the predetermined brightness S1, and the ECU 160 is connected from the connection point c. The portion that reaches the LED group 170b via the second electrode functions as the second current path A2 ′.

  In the vehicle lamp lighting circuit 100 according to the second embodiment, when the switch circuit 14 is turned on and the LED group 170a is turned on, the ECU 160 considers data from the illuminance sensor 20 and the light transmittance sensor 21. The brightness required for the LED unit 110 is obtained, and a current i1 ′ set so that a current of magnitude I2 ′ for achieving the required brightness is supplied to the LED group 170b is supplied. As described above, in the vehicular lamp lighting circuit 100 according to the second embodiment, the brightness of the LED unit 110 can be increased by appropriately lighting the LED group 170b on the LED group 170a that is in the lit state. The effect of the graph of FIG. 3 can be obtained in the same manner as the vehicular lamp lighting circuit 10.

  As described above, in the vehicular lamp lighting circuit 100, while the brake device 12 is in the ON state, the ECU 160 operates so that the visibility state around the vehicle C (the transmission of illuminance and light in the first embodiment). The brightness of the LED unit 110 can be changed as appropriate according to the degree. Thereby, irrespective of the visual field state around the vehicle C, the LED unit 110 (in the second embodiment, the stop lamp) can be turned on with appropriate visibility.

  Further, in the vehicular lamp lighting circuit 100, even when the ECU 160 fails, the LED unit 110 is connected at a predetermined brightness S1 to the circuit from the power supply circuit 13 through the switch circuit 14 and the resistor 150 to the LED group 170a. Since there is no influence from the viewpoint of lighting, the LED unit 110 is turned on and off with the brightness S1 by turning on only the LED group 170a according to the operation to the brake device 12 (interruption by the switch circuit 14). Therefore, the function as a brake light is not impaired. Thereby, the fail safe property of the LED unit 110 (stop lamp in this embodiment) intended to send a signal to a person outside the vehicle C can be ensured.

  Further, in the vehicular lamp lighting circuit 100, the main circuit (first current path A1 ′) for ensuring fail-safeness is a circuit that extends from the power supply circuit 13 to the LED group 170a through the switch circuit 14 and the resistor 150. In other words, since the first current path A1 ′ is composed of only the resistor 150, it is very rare that a failure occurs in the first current path A1 ′. 14), the LED group 170a can be turned on and off, so that the function as a brake light is not impaired. Thereby, the fail safe property of the LED unit 110 (stop lamp in this embodiment) intended to send a signal to a person outside the vehicle C can be ensured.

  In the vehicular lamp lighting circuit 100, an LED group 170a for ensuring fail-safe properties is provided in the first current path A1 ′, and an LED group 170b for lighting the LED unit 110 brighter than a predetermined brightness S1 is provided. Since it is provided in the second current path A2 ′ connected in parallel with the first current path A1 ′, the LED group 170a may be turned off due to the influence of the failure occurring in the second current path A2 ′. Can be further reduced, and the fail-safe property of the LED unit 110 (stop lamp in this embodiment) can be ensured.

  In the vehicular lamp lighting circuit 100, the LEDs 170 of the LED unit 110 are mixed inside the stop lamp housing 24 so that the LEDs 170 are substantially evenly mixed over the entire desired light emitting area (area constituting the light source unit). Therefore, when the LED unit 110 is lit at a predetermined brightness S1 (only the LED group 170a is lit), the LED unit 110 is lit brighter than the predetermined brightness S1. When (the LED group 170a and the LED group 170b are turned on), it can be seen that the light emitting area, that is, the region emitting light as a stop lamp does not change, and the person outside the vehicle C feels uncomfortable. Can be prevented.

  In the vehicular lamp lighting circuit 100, the LED unit 110 has a predetermined brightness S1 only when necessary according to the visibility state acquired by the visibility state acquisition means 23 (illuminance sensor 20 and light transmittance sensor 21 in the first embodiment). Therefore, it is possible to suppress unnecessary power consumption since the appropriate visibility is ensured by making it brighter.

  In the vehicular lamp lighting circuit 100, when it is detected that the vehicle C has suddenly decelerated, the current adjustment circuit 180 operates to flow the current i1 ′ intermittently. The stop lamp (LED unit 110) can be moved back and forth at a certain interval from the state of lighting at a higher brightness, that is, the brightness of the stop lamp can be changed at a certain interval. Thereby, it is possible to make a person outside the vehicle C recognize that the vehicle C has decelerated rapidly without any operation by the occupant.

  Therefore, in the vehicular lamp lighting circuit 100 according to the second embodiment, the LED unit 110 in the lit state can be visually recognized regardless of the visibility state around the vehicle C by the operation of the current control unit (the current adjustment circuit 180 and the resistor 190 of the ECU 160). The current flowing through the LED unit 110 can be controlled to make the performance appropriate, and the LED unit 110 can be lit even when the current control means fails.

  In each of the above-described embodiments, a stop lamp is shown as an example of a vehicle lamp device according to the present invention. For example, a tail lamp, a turn lamp, a head lamp, a room lamp, a side turn lamp, and a door mirror turn lamp can be used. The present invention may be applied and is not limited to the above-described embodiment.

  In each of the above-described embodiments, the LED unit 11 including a plurality of LEDs 17 is shown as an example of the light source unit. However, if the light source unit can emit light to the outside, for example, a filament bulb is used. It may be present and is not limited to the above-described embodiments.

  Further, in each of the above-described embodiments, the illuminance and the light transmittance are detected as the visibility state around the vehicle C. However, the visibility of the LED unit 11 in the lighting state may be affected. What is necessary is just to be a thing, and it is not limited to each above-mentioned Example.

  In Example 2 described above, the LED group 170a and the LED group 170b are interspersed so as to be substantially evenly mixed in a desired light emitting region. However, the LED group 170a causes the LED unit 110 to have a predetermined brightness S1. As long as the LED unit 110 can be lit brighter than the predetermined brightness S1 by being lit and the LED group 170b being added to the lit LED group 170a and being lit, they are not mixed. The present invention is not limited to the second embodiment.

  In the second embodiment described above, the LED groups 170a and the LED groups 170b are alternately arranged when viewed in the horizontal direction, but only the LED group 170a is turned on and only the LED group 170b is turned on. It is only necessary to be able to illuminate with substantially uniform brightness so as to cover all of the desired light emitting regions in substantially the same light emitting state. It is not something.

1 is a perspective view schematically showing a vehicle in which a vehicle lamp to which a vehicle lamp lighting circuit of the present invention is applied is adopted. It is a block diagram which shows schematically the structure of a vehicle lamp lighting circuit. It is a graph for demonstrating operation | movement of the vehicle lamp lighting circuit. It is a block diagram which shows schematically the structure of the vehicle lamp lighting circuit of Example 2. FIG. It is an explanatory view for schematically showing a state where a stop lamp is viewed from the rear side of the vehicle, and for explaining a position where each LED is arranged.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 100 Vehicle lamp lighting circuit 11, 110 LED unit (as light source unit) 13 Power supply circuit 14 Switch circuit (as switch means) 15, 150 Resistor 17, 170 LED (as light source)
170a LED group (as part of light source group) 170b LED group (as other part of light source group) 18, 180 Current adjustment circuit 19, 190 (as current control means) Resistance 20 (as current control means) Illuminance sensor 21 (as visibility state acquisition means) 21 Light transmittance sensor (as visibility state acquisition means) 22 Acceleration sensor (as sudden deceleration detection means) C Vehicle S1 Predetermined brightness A1, A1 ′ First current path A2, A2 'second current path

Claims (8)

A first current path for causing a current to flow through the light source unit for lighting a light source unit used in a vehicle lamp with a predetermined brightness;
A second current path for changing a current flowing through the light source unit to light the light source unit brighter than the predetermined brightness;
Visibility state acquisition means capable of acquiring a visibility state around the vehicle and capable of generating and outputting a condition signal corresponding to the visibility state;
Current control means for controlling the current flowing in the second current path so that the light source unit becomes bright in response to the condition signal from the visibility state acquisition means;
Switch means capable of interrupting the first current path according to the operation performed,
When the first current path is turned on by the switch means and no current is passed through the second current path, the light source unit is turned on at the predetermined brightness.
The vehicle lamp lighting circuit according to claim 1, wherein the current control means allows a current to flow through the second current path in response to the condition signal only when the first current path is turned on by the switch means. . When the first current path is rendered conductive by the switch means, a power source and the light source unit are configured to flow a predetermined amount of current to the light source unit so that the light source unit is turned on at the predetermined brightness. And connect
The second current path connects the power source and the light source unit in parallel with the first current path so that a current larger than the predetermined magnitude flows through the light source unit.
The current control unit increases the current flowing through the second current path so that the current flowing through the light source unit increases from the predetermined magnitude in response to the condition signal from the visibility state acquisition unit. The vehicular lamp lighting circuit according to claim 1.   The vehicular lamp lighting circuit according to claim 2, wherein the first current path is configured by connecting the power source and the light source unit via a resistor. The light source unit is composed of a plurality of light sources,
When the first current path is turned on by the switch means, a current is supplied to a part of the light source group to light the light source unit with a predetermined brightness by turning on a part of the light source group. Connect the power source and a part of the light source group to flow,
The second current path connects the power source and the other part of the light source group so that a current flows through the other part of the light source group,
The current control means controls the current of the second current path so that a current having a magnitude corresponding to the condition signal from the visibility state acquisition means flows to the other part of the light source group. The vehicle lamp lighting circuit according to claim 1.   5. The vehicular lamp lighting circuit according to claim 4, wherein the first current path is configured by connecting the power source and a part of the light source group via a resistor. 6.   The light source unit is scattered so that a part of the light source group can emit light from the entire region of the light source unit, and the other part of the light source group can emit light from the entire region of the light source unit. The vehicular lamp lighting circuit according to claim 4, wherein the vehicular lamp lighting circuit is configured to be mixed with a part of the light source group.   The vehicular lamp lighting circuit according to any one of claims 1 to 6, wherein the visibility state includes at least brightness around the vehicle. The vehicle is provided with sudden deceleration detection means capable of detecting that the vehicle has suddenly decelerated,
The current control means controls the current of the second current path so that the brightness of the light source section changes at a constant cycle when the sudden deceleration detection means detects that the vehicle is suddenly decelerated. The vehicular lamp lighting circuit according to any one of claims 1 to 7, characterized in that:

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