Device including light emitting diode as light sensor and light source

• US 20050036294A1
• Filed: 08/12/2003
• Published: 02/17/2005
• Est. Priority Date: 08/12/2003
• Status: Active Grant

• Current Assignee: Overhead Door Corporation (Sanwa Holdings Corp.)
• Original Assignee: Overhead Door Corporation (Sanwa Holdings Corp.)
• Inventors: McMahon, Michael T.
• Granted Patent: US 7,042,341 B2
• Time in Patent Office: Days
• US Class Current: 362/23
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/37 Converter circuits
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

A battery operated controller for a door operator includes a keypad backlit by a light emitting diode operably connected to a microcontroller which also controls operation of the controller. The microcontroller periodically measures ambient light as sensed by the light emitting diode and when a voltage level related to a predetermined light intensity decreases below a predetermined level the light emitting diode is energized to provide backlighting for the controller keypad. The intensity of backlighting may be varied in accordance with the amount of ambient light illuminating the keypad and above a certain intensity of ambient light the light emitting diode is de-energized to conserve battery power.

Claims

1. In a battery operated device:

a member adapted to show visible light from a light source comprising a light emitting diode;

a circuit including said light emitting diode for generating visible light to illuminate said member; and

a microcontroller operably connected to said light emitting diode for sensing ambient light on said device and for energizing said light emitting diode when ambient light is less than a predetermined intensity.

2. The device set forth in claim 1 wherein:

said member comprises a light transmitting switch actuator pad and said light emitting diode is disposed to backlight said pad.

3. The device set forth in claim 1 wherein:

said microcontroller is programmed to periodically de-energize said light emitting diode, measure the intensity of ambient light illuminating said light emitting diode and energize said light emitting diode if the measured intensity is less than a predetermined amount.

4. The device set forth in claim 3 wherein:

said microcontroller includes means for converting a voltage signal from said light emitting diode to a digital signal and comparing said digital signal to a preset signal corresponding to a level of ambient light intensity.

5. The device set forth in claim 1 wherein:

said device comprises a controller for a door operator including at least one switch actuator comprising a light transmitting member and said light emitting diode is positioned such as to backlight said switch actuator and to sense ambient light transmitted from said switch actuator to said light emitting diode.

6. The device set forth in claim 5 wherein:

said controller includes a battery operably connected to a circuit including said light emitting diode for supplying power to said controller to effect operation of a door.

7. A battery operated controller for a door operator comprising:

a light transmitting pad member including plural switch actuators operable to show visible light from a light source comprising a light emitting diode;

a circuit including said light emitting diode for generating visible light to illuminate said pad member; and

a microcontroller operably connected to said light emitting diode for sensing ambient light transmitted by said pad member to said light emitting diode and for energizing said light emitting diode when said ambient light is less than a predetermined intensity, said microcontroller being programmed to de-energize said light emitting diode, measure a voltage related to the intensity of ambient light transmitted to said light emitting diode and energize said light emitting diode if the measured intensity is less than a predetermined amount.

8. A method for illuminating a keypad of plural switch actuators for a door operator controller, said door operator controller comprising a battery operated device including a light transmitting pad member including plural switch actuators formed thereon, a light emitting diode disposed in proximity to said pad member for transmitting light from said light emitting diode to said switch actuators and for receiving ambient light imposed on said pad member, a circuit including said light emitting diode for generating visible light from said light emitting diode to illuminate said pad member, including said switch actuators, and a microcontroller operably connected to said light emitting diode for sensing light transmitted by said pad member to said light emitting diode and for energizing said light emitting diode to transmit visible light through said pad member to said switch actuators, said microcontroller including a light emitting diode input/out line operably connected to said light emitting diode;

causing said microcontroller to configure said light emitting diode input/output line for receiving an analog input signal;

reading the voltage generated by said light emitting diode related to light cast on said light emitting diode and converting said voltage signal to a digital signal;

comparing said digital signal to a present digital signal representing a predetermined intensity of ambient light;

configuring said light emitting diode input/output line for an output signal and applying voltage to said light emitting diode to generate visible light if the voltage level read was less than the present signal in said microcontroller.