Lighting control device

Abstract

To provide a lighting control device for a vehicle lamp that can emit light with good appearance even when different types of lamps are driven simultaneously.SOLUTION: In the present disclosure, a vehicle lamp (2) includes a first lamp (21) and a second lamp (22, 23) of different types. For example, the first lamp may be configured as a light bulb, and the second lamp may be configured as a light-emitting diode. A lighting control device (5) for a vehicle lamp according to the present disclosure includes a current detection unit (54) and a control unit (55). The current detection unit is configured to generate an output corresponding to the magnitude of a current flowing through the first lamp. The control unit is configured to control the energization state of the second lamp on the basis of the output of the current detection unit.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a lighting control device for vehicle lamps.

Background Art

[0002] As a vehicle turn signal, one using a light-emitting diode with low power consumption is known. When a light bulb, that is, a bulb, is used as a turn signal, when an electric current flows through the filament, the filament gradually emits light while the temperature rises. Thus, the brightness change characteristic of the light bulb becomes non-linear. On the other hand, when a light-emitting diode is used as a turn signal, the light emission amount changes with a steep response characteristic.

[0003] Therefore, the device described in Patent Document 1 changes the duty ratio and period of a pulse signal so that the brightness change characteristic of the light-emitting diode becomes a characteristic approximated to the brightness change characteristic of the light bulb. Thereby, even when a light-emitting diode is used, a brightness change characteristic similar to that of the light bulb can be obtained, the sense of incongruity with the brightness change characteristic of the light bulb is eliminated, a visually soft brightness change characteristic is obtained, and a high-class feeling can be obtained. Further, since the digital control feeling is eliminated, a natural brightness change characteristic can be obtained without tiring the eyes.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] For example, among the direction indicators at the front of the vehicle body and those at the rear of the vehicle body, it is possible that one uses a light bulb and the other uses a light-emitting diode. Alternatively, for example, while the direction indicators at the front and rear of the vehicle body use light bulbs, the auxiliary direction indicators provided on the door mirror or the like may use light-emitting diodes. In this way, when different types of direction indicators are mixed in the same vehicle, if they light up or blink simultaneously in different ways, it will look bad and lead to a decline in marketability.

[0006] In this regard, even if the luminance change characteristics of the light-emitting diode are made non-linear in the same way as those of the light bulb by using the technology disclosed in Patent Document 1, differences in appearance will occur due to factors such as individual differences and changes over time of the light bulb. The present invention has been made in view of the circumstances exemplified above. That is, the present invention provides a lighting control device for vehicle lamps that enables good-looking lighting even when driving different types of lamps simultaneously.

Means for Solving the Problem

[0007] The lighting control device (5) according to claim 1 is a lighting control device for vehicle lamps (2) including a first lamp (21) and second lamps (22, 23) of different types from each other, a current detection unit (54) provided to generate an output corresponding to the magnitude of the current flowing through the first lamp, a control unit (55) provided to control the energization state of the second lamp based on the output of the current detection unit, and is provided with.

[0008] In the lighting control device having such a configuration, the current detection unit generates an output corresponding to the magnitude of the current flowing through the first lighting fixture among the first lighting fixture and the second lighting fixture having different types from each other. Then, the control unit controls the energization state of the second lighting fixture based on the output of the current detection unit. Then, the energization state of the second lighting fixture is controlled according to the magnitude of the current flowing through the first lighting fixture. Thereby, the difference in the lighting manner between the first lighting fixture and the second lighting fixture having different types from each other can be favorably suppressed. Therefore, according to such a configuration, even when the first lighting fixture and the second lighting fixture having different types from each other are driven simultaneously, it is possible to cause them to emit light with a good appearance.

[0009] In each column of the application documents, each element may be provided with a reference sign in parentheses. However, such reference signs merely show an example of the correspondence relationship between the same element and the specific means described in the embodiments described later. Therefore, the present invention is not limited by the description of the above reference signs at all.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0011] (Embodiment) Hereinafter, exemplary embodiments and specific examples of the present invention will be described with appropriate reference to the drawings. Referring to FIG. 1, the system 1 constitutes a direction indicator mounted on an automobile as a vehicle traveling on a road, and includes a turn signal 2, an operation input unit 3, an operation state detection unit 4, and a lighting control device 5.

[0012] The turn signal 2 as a vehicle lamp is a so-called direction indicator lamp. In this embodiment, it includes a front turn signal 21, an auxiliary turn signal 22, and a rear turn signal 23. The front turn signal 21 is provided at the front end of the vehicle body. The auxiliary turn signal 22 is provided on the door mirror. The rear turn signal 23 is provided at the rear end of the vehicle body. The front turn signal 21 as the first lamp and the auxiliary turn signal 22 or the rear turn signal 23 as the second lamp have different types of lamp configurations. Specifically, the front turn signal 21 is composed of a light bulb. On the other hand, the auxiliary turn signal 22 and the rear turn signal 23 are composed of light-emitting diodes. The "light-emitting diode" includes an inorganic semiconductor LED and an organic EL element. LED is the abbreviation of Light Emitting Diode. EL is the abbreviation of electroluminescence.

[0013] The operation input unit 3 is a component for receiving an input operation by the driver of the vehicle. In this embodiment, it has a configuration as a so-called turn signal lever. The operation state detection unit 4 is a so-called turn signal switch, which is provided to detect the operation state of the operation input unit 3 and input an input signal corresponding to such an operation state to the lighting control device 5.

[0014] The lighting control device 5 has a configuration as a body ECU, which is an electronic unit for centrally controlling vehicle interior and exterior lighting, doors, windows, mirrors, wipers, etc. ECU is the abbreviation of Electronic Control Unit. In this embodiment, the lighting control device 5 includes a front turn signal drive circuit 51, an auxiliary turn signal drive circuit 52, a rear turn signal drive circuit 53, a current detection unit 54, and a control unit 55 as components for controlling the lighting state of the turn signal 2.

[0015] The front blinker drive circuit 51 is a drive circuit for the front blinker 21 and is electrically connected to the front blinker 21. The auxiliary blinker drive circuit 52 is a drive circuit for the auxiliary blinker 22 and is electrically connected to the auxiliary blinker 22. The rear blinker drive circuit 53 is a drive circuit for the rear blinker 23 and is electrically connected to the rear blinker 23. The current detection unit 54 is provided to generate an output corresponding to the magnitude of the current flowing through the front blinker 21 as the first lighting device of the present invention. The control unit 55 is provided to control the drive states, i.e., the energization states, of the front blinker 21, the auxiliary blinker 22, and the rear blinker 23.

[0016] The control unit 55 includes an input acquisition unit 551, an arithmetic unit 552, an output unit 553, and a memory unit 554. The input acquisition unit 551 is provided to acquire the input signal from the operation state detection unit 4. The arithmetic unit 552 is a processor composed of a CPU or an MPU, and is provided to generate a drive signal for driving the blinker 2 based on the input signal acquired by the input acquisition unit 551 and output it to the output unit 553. The drive signal is an on / off signal of a drive element such as a MOSFET provided in each of the front blinker drive circuit 51, the auxiliary blinker drive circuit 52, and the rear blinker drive circuit 53. The output unit 553 is provided to output the drive signal to the front blinker drive circuit 51, the auxiliary blinker drive circuit 52, and the rear blinker drive circuit 53. The memory unit 554 is a storage medium for storing programs, data, etc. necessary for the arithmetic processing or determination processing by the arithmetic unit 552, and has a configuration as a non-transitory physical storage medium such as a ROM or a non-volatile rewritable memory. The non-volatile rewritable memory is a storage device that can rewrite information while the power is on and holds the information in a non-rewritable state while the power is off, and is, for example, a flash memory or the like.

[0017] In this embodiment, the control unit 55 is configured to control the energization states of the auxiliary blinker 22 and the rear blinker 23 as the second lighting device based on the output of the current detection unit 54. Specifically, a conversion table T and an initial value P are stored in advance in the memory unit 554. The conversion table T is correspondence information that defines the relationship between the detection parameter corresponding to the output of the current detection unit 54 and the control parameter corresponding to the energization state of the light-emitting diodes constituting the auxiliary blinker 22 and the rear blinker 23. The detection parameter is a value corresponding to the current value. The control parameter is a value corresponding to the duty ratio in PWM. PWM is the abbreviation of Pulse Width Modulation. The initial value P is the duty ratio at the on-time, that is, the energization start time. In this way, the control unit 55 is configured to control the energization states, that is, the duty ratios, of the auxiliary blinker drive circuit 52 and the rear blinker drive circuit 53 according to the magnitude of the current flowing through the front blinker 21.

[0018] Hereinafter, the effects achieved by the configuration of this embodiment will be described together with the outline of the operation of the same configuration. An input signal corresponding to the operation mode of the operation input unit 3 by the driver of the vehicle is generated by the operation state detection unit 4 and input to the control unit 55. Then, the arithmetic unit 552 determines the lighting or blinking mode of the blinker 2 based on the input signal and generates a control signal. As a result, the blinker 2 lights or blinks based on the control signal output from the lighting control device 5.

[0019] Incidentally, as described above, in this embodiment, the front blinker 21 provided at the front end of the vehicle uses a light bulb, while the auxiliary blinker 22 provided on the door mirror and the rear blinker 23 provided at the rear end of the vehicle use light-emitting diodes. Therefore, when viewed from the outside of the vehicle, the front blinker 21, and the auxiliary blinker 22 and the rear blinker 23, which are of different types from each other, may be within the same field of view. In particular, the front blinker 21 and the auxiliary blinker 22 are likely to be within the same field of view.

[0020] Here, in Fig. 2, (a) shows the characteristics when the bulb constituting the front blinker 21 is on, as the time change of the voltage value corresponding to the output of the current detection unit 54. On the other hand, (b) in Fig. 2 shows the characteristics when the light-emitting diodes constituting the auxiliary blinker 22 and the rear blinker 23 are on. The dashed line extending vertically in Fig. 2 indicates the on-time point. As shown in (a) in Fig. 2, since the bulb emits light by the temperature of the filament rising, the light emission amount gradually increases as the temperature of the filament gradually rises. In contrast, the light-emitting diode rapidly rises in light emission amount from the on-time point. Therefore, when direction indicators of different types, that is, with different on-time response characteristics, are mixed in the same vehicle, if they light up or blink simultaneously in different lighting manners, it will look bad and lead to a decline in marketability.

[0021] Therefore, in this embodiment, the control unit 55 controls the energization state of the auxiliary blinker 22 and the rear blinker 23 based on the output of the current detection unit 54 corresponding to the magnitude of the current flowing through the front blinker 21. That is, the control unit 55 determines the duty ratio of the auxiliary blinker 22 and the rear blinker 23 based on the conversion table T defining the correspondence between the detected current value and the duty ratio and the output of the current detection unit 54. Specifically, the control unit 55 controls to gradually increase the duty ratio in PWM as shown in (c) in Fig. 2 according to the rising characteristics of the bulb as shown in (a) in Fig. 2. Note that at the on-time point, since the magnitude of the current flowing through the front blinker 21 is 0, the control unit 55 determines the duty ratio at the on-time point based on the initial value P.

[0022] As described above, in this embodiment, the magnitude of the current flowing through the front blinker 21 is detected in real time, and based on such detection results, the duty ratio in the auxiliary blinker 22 and the rear blinker 23 is varied, so that it is possible to make the blinking patterns of the entire blinker 2 uniform. In particular, the occurrence of a difference in appearance in the time range immediately after the start of lighting, where the rise of the light amount of the front blinker 21 is slow, is suppressed as much as possible. Also, the occurrence of a difference in appearance due to the influence of individual differences or changes over time of the bulbs is suppressed as much as possible. Therefore, according to this embodiment, even when driving different types of lighting fixtures simultaneously, it is possible to emit light with a good appearance.

[0023] (Modification example) The present invention is not limited to the above-described embodiments and specific examples. Therefore, appropriate changes can be made to the above-described embodiments and the like. Hereinafter, typical modification examples will be described. In the description of the following modification examples, the differences from the above-described embodiments and the like will be mainly described. Also, in the above-described embodiments and the following modification examples, parts that are identical or equivalent to each other are given the same reference numerals. Therefore, in the description of the following modification examples, for components having the same reference numerals as those in the above-described embodiments and the like, the descriptions in the above-described embodiments and the like can be appropriately incorporated, unless there is a technical contradiction or specific additional explanation.

[0024] The present invention is not limited to the specific applications and device configurations shown in the above-described embodiments. That is, for example, the vehicle as the application target of the present invention is not limited to ordinary motor vehicles under the Road Traffic Law, and may be a large-sized motor vehicle, a motorcycle, or a motorized bicycle.

[0025] The present invention is not limited to a configuration that suppresses the difference in the lighting mode among the front blinker 21, the auxiliary blinker 22, and the rear blinker 23. That is, for example, the auxiliary blinker 22 may be omitted. Alternatively, the auxiliary blinker 22 may be provided at a plurality of locations (for example, on the door mirror and the side surface of the vehicle body). When the auxiliary blinker 22 is provided at a plurality of locations, the present invention can also be suitably applied to a configuration that suppresses the difference in the lighting mode between the auxiliary blinkers 22 of different types, for example. Further, the vehicle lamp as the application target of the present invention is not limited to the blinker 2. That is, the present invention can be suitably applied to an application in which a plurality of types of lamps having different rising characteristics of current or voltage are simultaneously lit or blinked.

[0026] The operation input unit 3 is not limited to the blinker switch. That is, for example, as the operation input unit 3 and the operation state detection unit 4, a configuration corresponding to voice input by the driver's speech or operation by the foot may be used. Alternatively, for example, as the operation input unit 3 and the operation state detection unit 4, a configuration that reads gestures by the driver's finger, line of sight, or face direction may be used.

[0027] There is no particular limitation on the configuration of the lighting control device 5 either. That is, for example, in FIG. 1, the auxiliary blinker drive circuit 52 and the rear blinker drive circuit 53 may be integrated. Also, in the present embodiment, the control unit 55 has a configuration as an in-vehicle microcomputer. That is, the control unit 55 includes an arithmetic unit 552 as a processor and a memory unit 554 as a storage medium that is communicably connected to the arithmetic unit 552. However, the present invention is not limited to such an aspect. That is, for example, all or part of the control unit 55 may be configured with a digital circuit, such as an ASIC or an FPGA, that is configured to be able to realize the above functions or operations. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field Programmable Gate Array. That is, in the control unit 55, the in-vehicle microcomputer part and the digital circuit part may coexist.

[0028] The present invention is not limited to the specific operation modes shown in the above embodiments. That is, for example, with respect to the conversion table T and the initial value P, it is possible to perform appropriate learning correction during actual use with respect to the initial setting values at the time of product shipment. Specifically, for example, the difference between the rising characteristic of the current detection value at the time of product shipment and the rising characteristic of the current detection value at the time of this startup may be calculated, and the conversion table T and the initial value P may be corrected according to such a difference.

[0029] It goes without saying that the elements constituting the above embodiments are not necessarily essential except in cases where it is explicitly stated that they are particularly essential and cases where they are considered to be clearly essential in principle. Further, when numerical values such as the number, numerical value, amount, and range of components are mentioned, the present disclosure is not limited to that specific number except in cases where it is explicitly stated that it is particularly essential and cases where it is clearly limited to a specific number in principle. Similarly, when the shape, direction, positional relationship, etc. of components are mentioned, the present disclosure is not limited to that shape, direction, positional relationship, etc. except in cases where it is explicitly stated that it is particularly essential and cases where it is clearly limited to a specific shape, direction, positional relationship, etc. in principle.

[0030] Modification examples are also not limited to the above examples. For example, all or part of one of a plurality of modification examples and all or part of another one can be combined with each other as long as they do not technically conflict.

Explanation of Signs

[0031] 2 Blinker (Vehicle Lamp) 21 Front Blinker (First Lamp) 22 Auxiliary Blinker (Second Lamp) 23 Rear Blinker (Second Lamp) 5 Lighting Control Device 54 Current Detection Unit 55 Control Unit 551 Input Acquisition Unit 552 Calculation Unit T Conversion Table (Correspondence Information)

Claims

1. A lighting control device (5) for a vehicle lamp (2), wherein the vehicle lamp includes a first lamp (21) and second lamps (22, 23) of different types from each other, a current detection unit (54) provided to generate an output corresponding to the magnitude of the current flowing through the first lamp, and a control unit (55) provided to control the energization state of the second lamp based on the output of the current detection unit. A lighting control device comprising the above.

2. The control unit controls the energization state of the second lamp based on correspondence relationship information that defines the relationship between a detection parameter corresponding to the output of the current detection unit and a control parameter corresponding to the energization state of the second lamp. The lighting control device according to Claim 1.

3. The first lamp is constituted by a light bulb, and the second lamp is constituted by a light-emitting diode. The lighting control device according to Claim 1 or 2.

4. The control unit controls the duty ratio of the second lamp according to the magnitude of the current flowing through the first lamp. The lighting control device according to Claim 3.

5. The vehicle lamp is a direction indicator lamp. The lighting control device according to Claim 1.

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