LIGHT SOURCE TURN-ON/OFF CONTROLLER

• US 20110181197A1
• Filed: 07/04/2008
• Published: 07/28/2011
• Est. Priority Date: 08/07/2007
• Status: Active Grant

• Current Assignee: ROHM Co., Ltd.
• Original Assignee: ROHM Co., Ltd.
• Inventors: Bandai, Junji, Kanda, Takumi, Tanaka, Masahide
• Granted Patent: US 8,283,867 B2
• Time in Patent Office: Days
• US Class Current: 315/268
• 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 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, wherein

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.

2. The light source turn-on/off controller according to claim 1, wherein temporal change ratios of the duty cycles set in the rise table and the fall table are not equal to each other when comparing absolute values of them at the start of the rise of light emission and at the start of the fall of the same.

3. The light source turn-on/off controller according to claim 2, wherein contents of the rise table and the fall table are determined by considering a difference between behavior at turn-on of the filament when rush current occurs and behavior at turn-off of the filament when natural cooling occurs.

4. The light source turn-on/off controller according to claim 2, wherein contents of the rise table and the fall table are determined by considering a color temperature variation of the filament and human luminosity.

5. The light source turn-on/off controller according to claim 1, wherein the control data table has contents in which a decrease of luminance in the emitting section due to a rounded portion of the pulse signal in a tail of the fall of emission.

6. The light source turn-on/off controller according to claim 5, wherein the control data table has contents in which an influence of the rounded portion of the pulse signal when the duty cycle is small is corrected.

7. 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.

8. The light source turn-on/off controller according to claim 7, 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.

9. The light source turn-on/off controller according to claim 8, wherein the control section performs the switching to the emission fall control at a midpoint of the emission rise control.

10. The light source turn-on/off controller according to claim 9, wherein the emission control section controls a winker of a vehicle, and the control section stops the blink of the winker after the switching.

11. The light source turn-on/off controller according to claim 8, wherein the control section performs the switching to the emission rise control at a midpoint of the emission fall control.

12. The light source turn-on/off controller according to claim 11, 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.

13. The light source turn-on/off controller according to claim 7, 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.

14. The light source turn-on/off controller according to claim 13, wherein the predetermined value is a duty cycle corresponding to a tail in the fall of the light emission.

15. The light source turn-on/off controller according to claim 13, 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.

16. The light source turn-on/off controller according to claim 7, 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.

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

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

a emission control signal generating section for generating a control signal for a light source other than a filament to emit light simulating a rise or a fall of light emission in turn-on or turn-off of the filament responding to a rise or a fall of the timing signal, wherein

the emission control signal generating section supplies a plurality of control signals to a plurality of light sources respectively, and a delay is provided between the plurality of control signals so that total sum of output energy of the plurality of control signals varies so as to simulate energy output variation of the rise or the fall of light emission in turn-on or turn-off of the filament.

18. The light source turn-on/off controller according to claim 17, wherein the emission control signal generating section has an output energy difference between the control signals based on energy output variation of the rise or the fall of light emission in turn-on or turn-off of the filament.

19. The light source turn-on/off controller according to claim 17, wherein the emission control signal generating section has a delay between the control signals based on the energy output variation of the rise or the fall of light emission in turn-on or turn-off of the filament.

20. The light source turn-on/off controller according to claim 19, wherein the emission control signal generating section delays the plurality of control signals in a turned-off state in the order opposite to that in a turned-on state.