Control knob with optical shaft encoder and visual feedback of angular position

Patent metadata

Field	Value
Publication number	US-10465915-B2
Application number	US-201615203842-A
Country	US
Kind code	B2
Filing date	Jul 7, 2016
Priority date	Jul 7, 2016
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

A control knob assembly for a consumer appliance is provided. The control knob assembly provides a compact means for determining the angular position of the control knob and illuminating a plurality of indicators to communicate that angular position to a user of the appliance. More specifically, the control knob assembly includes an optical encoder disc that defines a plurality of teeth that are in operable communication with a plurality of optical sensors. The position of the sensors and the spacing of the plurality of teeth are configured to generate signals as the control knob is rotated that allow for the precise determination of the angular position of the control knob. Moreover, the optical encoder disc may fit inside a lighting assembly and may have a low profile, resulting in a compact control knob assembly that may easily fit within the area underneath the control knob and control panel.

First claim

What is claimed is:

1. A control knob assembly comprising:
a panel defining an aperture;
a printed circuit board defining an aperture;
a control knob comprising a stern defining an axial direction and a radial direction, the stern extending through the aperture of the panel and the aperture of the printed circuit board;
an encoder disc operably coupled to the stem, such that the panel is positioned between the control knob and the encoder disc, the encoder disc defining a plurality of teeth; and
a sensor assembly mounted adjacent the encoder disc, the sensor assembly comprising a plurality of sensors for detecting the movement of the plurality of teeth to determine the angular position of the stem.

2. The control knob assembly of claim 1 , wherein the sensor assembly is mounted on the printed circuit board.

3. The control knob assembly of claim 2 , wherein the plurality of sensors comprises a first sensor and a second sensor, the first sensor producing a first pulse signal as the plurality of teeth pass a detection point of the first sensor and the second sensor producing a second pulse signal as the plurality of teeth pass the detection point of the second sensor, the first pulse signal being approximately 90 degrees out of phase from the second pulse signal.

4. The control knob assembly of claim 3 , wherein the plurality of sensors further comprises a third sensor, the third sensor configured for detecting an indicator feature on the encoder disc, the indicator feature corresponding with a zero position of the control knob.

5. The control knob assembly of claim 4 , wherein the encoder disc is made from a material which is detectable by first, second, and third sensors.

6. The control knob assembly of claim 4 , wherein the first, second, and third sensors are each infrared optical sensors comprising an emitter that emits an infrared light beam and a detector that receives the infrared light beam and detects the presence and absence of a tooth of the plurality of teeth of the encoder disc at a detection point of the sensor.

7. The control knob assembly of claim 2 , further comprising a lighting assembly mounted on the printed circuit board and configured to selectively illuminate a plurality of indicators defined on the panel.

8. The control knob assembly of claim 7 , wherein each of the plurality of indicators is a translucent opening in the panel, each of the plurality of indicators corresponding to an angular position of the control knob.

9. The control knob assembly of claim 7 , wherein the lighting assembly comprises a plurality of light sources, each of the plurality of light sources being configured to illuminate one of the plurality of indicators.

10. The control knob assembly of claim 9 , further comprising a light guide positioned between the lighting assembly and the panel, the light guide configured for directing light from each of the plurality of light sources to a corresponding one of the plurality of indicators.

11. The control knob assembly of claim 1 , wherein at least one of the encoder disc and the printed circuit board define a plurality of apertures to provide for an airflow path through the control knob assembly.

12. A cooking appliance, comprising:
a cooking surface including a heating source;
a control panel defining an aperture; and
a control knob assembly for selectively adjusting the amount of heat delivered by the heating source, the control knob assembly comprising:
a printed circuit board defining an aperture;
a control knob comprising a stem defining an axial direction and a radial direction, the stem extending through the aperture of the control panel and the aperture of the printed circuit board;
an encoder disc operably coupled to the stern, the encoder disc being positioned between the control panel and the printed circuit board, the encoder disc defining a plurality of teeth; and
a plurality of sensors mounted on the printed circuit board adjacent the encoder disc such that the plurality of sensors detect the motion of the plurality of teeth to determine the angular position of the stem.

13. The cooking appliance of claim 12 , wherein the sensor assembly comprises a first sensor and a second sensor, the first sensor producing a first pulse signal as the plurality of teeth pass through a detection point of the first sensor and the second sensor producing a second pulse signal as the plurality of teeth pass through a detection point of the second sensor, the first pulse signal being approximately 90 degrees out of phase from the second pulse signal.

14. The cooking appliance of claim 13 , wherein the sensor assembly further comprising a third sensor, the third sensor configured for detecting an indicator feature, the indicator feature corresponding with a zero position of the control knob.

15. The cooking appliance of claim 14 , wherein the encoder disc is made from a material which is detectable by the first, second, and third sensors and is configured with a plurality of apertures allowing for the passage of airflow through the control knob assembly.

16. The cooking appliance of claim 14 , wherein the first, second, and third sensors are each infrared optical sensors comprising an emitter that emits an infrared light beam and a detector that receives the infrared light beam and detects the presence and absence of a tooth of the plurality of teeth of the encoder disc at a detection point of the sensor.

17. The cooking appliance of claim 12 , further comprising a lighting assembly mounted on the printed circuit board and configured to selectively illuminate a plurality of indicators defined on the control panel.

18. The cooking appliance of claim 17 , wherein each of the plurality of indicators is a translucent opening in the control panel, each of the plurality of indicators corresponding to a particular power level selected by the control knob.

19. The cooking appliance of claim 17 , wherein the lighting assembly comprises a plurality of light sources, each of the plurality of light sources being configured to illuminate one of the plurality of indicators.

20. The cooking appliance of claim 19 , further comprising a light guide positioned between the lighting assembly and the control panel, the light guide configured for directing light from each of the plurality of light sources to a corresponding one of the plurality of indicators.

Assignees

• Haier Us Appliance Solutions Inc

Inventors

• Bach James Carter

Classifications

• G01D5/40

  specially adapted for use with infrared light {(mechanical adjustment G01D5/264)} · CPC title

• G01D5/3473

  Circular or rotary encoders · CPC title

• G01D5/342

  the sensed object being the obturating part · CPC title

• F24C3/124 Primary

  Control panels · CPC title

• F24C7/082

  on ranges, e.g. control panels, illumination · CPC title