Light source turn-on/off controller

• US 8,400,062 B2
• Filed: 09/06/2012
• Issued: 03/19/2013
• Est. Priority Date: 08/07/2007
• Status: Active Grant

• Current Assignee: ROHM Co., Ltd.
• Original Assignee: ROHM Co., Ltd.
• Inventors: Kanda, Takumi, Bandai, Junji, Tanaka, Masahide
• Primary Examiner(s): VU, DAVID HUNG
• Application Number:
  US13/605,623
• Publication Number:
  US 20120326607A1
• Time in Patent Office: 194 Days
• Field of Search: 315/82, 315/83, 315/77, 315/185.R, 315/291, 315/192, 315/307, 315/308
• US Class Current: 315/82
• CPC Class Codes: B60Q 1/381 with several light sources activated in sequence, e.g. to create a sweep effect
• CPC Class Codes: B60Q 1/486 for indicating that vehicle is in a parked state
• CPC Class Codes: H05B 45/32 Pulse-control circuits
• CPC Class Codes: H05B 45/325 Pulse-width modulation [PWM]
• CPC Class Codes: H05B 45/3574 Emulating the electrical or functional characteristics of incandescent lamps
• CPC Class Codes: H05B 45/395 Linear regulators
• CPC Class Codes: H05B 47/10 Controlling the light source

Abstract

A light source turn-on/off controller includes an input section of a turn-on/off timing signal, a PWM signal generating section for generating a pulse signal responding to a rise or a fall of the timing signal, a duty cycle of the pulse signal changing so as to simulate a rise or a fall of emission in turn-on or turn-off of a filament, an emission control section for controlling an emitting section responding to the pulse signal from the PWM signal generating section, and a storage section for storing a control data table for duty cycle control by the PWM signal generating section. The control data table includes a rise table to be referred to in the rise of emission and a fall table to be referred to in the fall of emission, and each of the rise table and the fall table indicates association between elapsed time from the rise or the fall of the timing signal and the duty cycle of the pulse signal, and a relationship between the tables indicates that they cannot be superposed on each other.

Claims

1. A light source turn-on/off controller comprising:

an input section of a turn-on/off timing signal;

a PWM signal generating section for generating a pulse signal having the duty cycle that varies so as to simulate the rise or the fall of light emission in turn-on or turn-off of the filament responding to a rise or a fall of the timing signal, an emission control section for controlling an emitting section responding to a pulse signal from the PWM signal generating section, a storage section for storing a plurality of control data tables for the duty cycle control by the PWM signal generating section, and a control section for switching from a midpoint of changing the duty cycle by one of the control data tables to control by another control data table at the same duty cycle.

2. The light source turn-on/off controller according to claim 1, wherein the plurality of control data tables includes a first control data table for the emission rise control and a second control data table for the emission fall control.

3. The light source turn-on/off controller according to claim 2, wherein the control section performs the switching to the emission fall control at a midpoint of the emission rise control.

4. The light source turn-on/off controller according to claim 3, wherein the emission control section controls a winker of a vehicle, and the control section stops the blink of the winker after the switching.

5. The light source turn-on/off controller according to claim 2, wherein the control section performs the switching to the emission rise control at a midpoint of the emission fall control.

6. The light source turn-on/off controller according to claim 5, wherein the emission control section controls a winker of a vehicle, and the control section controls the winker to blink by the emission rise control at a midpoint of the emission fall control.

7. The light source turn-on/off controller according to claim 1, wherein the control section controls the PWM signal generating section to continue the PWM control with a predetermined value when the duty cycle controlled by the control data table reaches the predetermined value.

8. The light source turn-on/off controller according to claim 7, wherein the predetermined value is a duty cycle corresponding to a tail in the fall of the light emission.

9. The light source turn-on/off controller according to claim 7, wherein the emission control section controls a parking brake lamp emitting section, and the predetermined value is a duty cycle for turning on the parking lamp.

10. The light source turn-on/off controller according to claim 1, further comprising a plurality of emission control sections for respectively controlling a plurality of emitting sections responding to a pulse signal from the PWM signal generating section, and a selection signal input section for receiving a selection signal for determining one of the plurality of emission control sections from which the pulse signal should be delivered.