Low beam intensity control unit

• US 10,144,341 B2
• Filed: 09/19/2016
• Issued: 12/04/2018
• Est. Priority Date: 09/19/2016
• Status: Active Grant

• Current Assignee: Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Original Assignee: Toyota Motor Engineering & Manufacturing North America Incorporated (Toyota Motor Corporation)
• Inventors: Dalal, Sunil
• Primary Examiner(s): Chan, Wei
• Application Number:
  US15/268,673
• Publication Number:
  US 20180079352A1
• Time in Patent Office: 806 Days
• Field of Search: 362489, 362505, 362511, 362154, 362490, 362507, 340435, 340439, 340436, 340575, 340576, 340903
• CPC Class Codes: B60Q 1/0076 Switches therefor B60Q1/1446, B60Q1/343, B60Q1/40 take precedence
• CPC Class Codes: B60Q 1/1423 Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
• CPC Class Codes: B60Q 2300/054 Variable non-standard intensity, i.e. emission of various beam intensities different from standard intensities, e.g. continuous or stepped transitions of intensity
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/50 responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: H05B 47/125 by using cameras
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A vehicular lighting system includes low beam headlamps, high beam headlamps and a control unit configured so that during operation of the lighting system, the control unit determines the operational status of the high beam headlamp and selectively adjusts the illuminating intensity of the low beam headlamp. In particular, the brightness of the low beam headlamp can be increased during periods where the high beam is not being, thereby allowing the low beam to more closely approximate the brightness of the high beam, but without the glare associated with conventional high beam patterns. In this way, artificially low illuminating intensity limitations placed on the low beam headlamps can be overcome during periods where the lighting system is operating but the high beams are not in use. In one preferred configuration, at least the low beam headlamps are made from numerous individual light-emitting diodes that can be separately controlled in order to achieve the adjustments in low beam headlamp illuminating intensity.

Claims

1. A vehicular lighting system comprising:

at least one low beam headlamp;

at least one high beam headlamp;

a control unit defining at least one processor and memory therein such that the control unit is configured to deliver a pulsed power source as a way to energize the low beam headlamp and high beam headlamp with a predetermined illuminating intensity, the control unit comprising;

a pulse width modulator connected to the processor to deliver a level of the illuminating intensity to the low beam headlamp; and

a multiplexer connected to at least one of the pulse width modulator and the processor to provide a communication link with each of the low beam headlamp and the high beam headlamp; and

a wiring connected to the low and high beam headlamps and the control unit such that during operation of the lighting system, the control unit automatically determines the operational status of the high beam headlamp based on a signal from a sensor and automatically sends out a control signal through the wiring to selectively adjust the illuminating intensity of the low beam headlamp when such operational status of the high beam headlamp is determined to be off.

2. The lighting system of claim 1, wherein the control unit is configured to increase the illuminating intensity of the low beam headlamp when the operational status of the high beam headlamp is off.

3. The lighting system of claim 2, wherein at least the low beam headlamp defines a continuously variable architecture.

4. The lighting system of claim 3, wherein the continuously variable architecture comprises a plurality of light-emitting diodes disposed within each low beam headlamp.

5. The lighting system of claim 4, wherein each of the plurality of light-emitting diodes are individually adjustable through the control unit.

6. The lighting system of claim 5, wherein each individual light-emitting diode of the plurality of light-emitting diodes is adjustable through the duty cycle of a pulse width modulated signal that is delivered from the control unit to the low beam headlamp.

7. The lighting system of claim 3, wherein the control unit is configured to increase in illuminating intensity through adjustment of the duty cycle of a pulse width modulated signal that is delivered from the control unit to the low beam headlamp.

8. The lighting system of claim 3, wherein the control unit is configured to increase in illuminating intensity by selectively illuminating a larger portion of the plurality of light-emitting diodes than when both the low beam headlamp and the high beam headlamp are being illuminated.

9. The lighting system of claim 2, wherein the control unit is configured to the increase in illuminating intensity up to a maximum illuminating intensity.

10. The lighting system of claim 1, wherein the sensor is connected to the control unit such that the operation of the control unit automatically determines that the operational status of the high beam headlamp takes place based the signal received from the sensor.

11. A vehicle comprising:

a wheeled chassis defining a passenger compartment therein;

a motive power unit;

a guidance apparatus connected to the wheeled chassis and motive power unit; and

a lighting system comprising

at least one low beam headlamp;

at least one high beam headlamp;

a control unit defining at least one processor and memory therein such that the control unit is configured to deliver a pulsed power source as a way to energize the low beam headlamp and high beam headlamp with a predetermined illuminating intensity, the control unit comprising;

a pulse width modulator connected to the processor to deliver a level of the illuminating intensity to the low beam headlamp; and

a multiplexer connected to at least one of the pulse width modulator and the processor to provide a communication link with each of the low beam headlamp and high beam headlamp; and

a wiring connected to the low and high beam headlamps and control unit such that during operation of the lighting system, the control unit automatically determines the operational status of the high beam headlamp based on a signal from a sensor and automatically sends out a control signal through the wiring to selectively adjust the illuminating intensity of the low beam headlamp when such operational status of the high beam headlamp is determined to be off.

12. The vehicle of claim 11, wherein each low beam headlamp comprises a plurality of light-emitting diodes.

13. The vehicle of claim 12, wherein the control unit is configured to increase in illuminating intensity of the low beam headlamp through adjustment of the duty cycle of a pulse width modulated signal that is delivered from the control unit to the light-emitting diodes.

14. The vehicle of claim 12, wherein the control unit is configured to increase in illuminating intensity is provided by selectively illuminating a larger portion of the plurality of light-emitting diodes than when both the low beam headlamp and the high beam headlamp are being illuminated.

15. The vehicle of claim 12, wherein the control unit is configured to the increase in illuminating intensity up to a maximum illuminating intensity.

16. The vehicle of claim 12, further comprising the sensor connected to the control unit such that the operation of the control unit to automatically determine the operational status of the high beam headlamp takes place based the signal received from the sensor.

17. A method of automatically operating vehicular headlamps with a lighting system, the method comprising:

operating a control unit that makes up a portion of the lighting system to illuminate a region in front of a vehicle with at least one of a low beam headlamp and a high beam headlamp wherein the at least one low beam headlamp is configured to operate with adjustable illuminating intensity, the control unit defining at least one processor and memory therein such that the control unit is configured to deliver a pulsed power source as a way to energize the low beam headlamp and high beam headlamp with a predetermined illuminating intensity, the control unit comprising;

a pulse width modulator connected to the processor to deliver a level of the illuminating intensity to the low beam headlamp; and

a multiplexer connected to at least one of the pulse width modulator and the processor to provide a communication link with each of the low beam headlamp and high beam headlamp;

automatically receiving a signal from a sensor to determine an operational status of the high beam headlamp; and

automatically increasing the illuminating intensity of the low beam headlamp based on instructions from the control unit in situations where the high beam headlamp is not illuminating the region.

18. The method of claim 17, wherein each low beam headlamp comprises a plurality of light-emitting diodes.

19. The method of claim 18, wherein the control unit is configured to adjust the duty cycle of a pulse width modulated signal that is delivered to the low beam headlamp.

20. The method of claim 18, wherein the control unit is configured to increase in illuminating intensity up to a maximum illuminating intensity.