Optical keypad for electronic device

• US 7,924,175 B2
• Filed: 03/26/2007
• Issued: 04/12/2011
• Est. Priority Date: 03/26/2007
• Status: Expired due to Fees

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Gitzinger, Thomas E., Alameh, Rachid M.
• Primary Examiner(s): WONG, ALBERT KANG
• Application Number:
  US11/690,971
• Publication Number:
  US 20080238725A1
• Time in Patent Office: 1,478 Days
• Field of Search: 341/20, 341/22, 341/31, 400/477, 250/221, 250/229
• US Class Current: 341/31
• CPC Class Codes: G06F 3/0202 Constructional details or processes of manufacture of the input device
• CPC Class Codes: H03K 17/9629 using a plurality of detectors, e.g. keyboard
• CPC Class Codes: H03K 17/9636 using a pulsed light source
• CPC Class Codes: H03K 17/9638 using a light guide
• CPC Class Codes: H03K 17/969 having a plurality of control members, e.g. keyboard
• CPC Class Codes: H03K 2217/96042 with illumination

Abstract

Disclosed in a wearable electronic device including an optical keypad supported by a keypad housing. The optical keypad may include a plurality of keys disposed along the keypad housing, and a plurality of illumination sources and optical receivers with a corresponding illumination source and optical receiver for each of the plurality of keys. The keypad signal interface may be limited to three connections, to provide a connection for power, a connection for ground, and a connection for data between the keypad housing and the main housing. The electronic device may also include at least one optical receiver configured to be optically coupled to at least one of the plurality of illumination sources, and configured to convert a received optical signal representing data into an electrical signal representing data. The illumination sources may provide optical signals during key presses, and may in addition provide key illumination for unpressed keys.

Claims

1. An electronic device, comprising:

a main housing;

a keypad housing attached to the main housing and adjustable in position or orientation relative to the main housing;

a plurality of keys disposed along the keypad housing;

a plurality of illumination sources, a corresponding illumination source for each of the plurality of keys;

an optical receiver configured to be optically coupled to at least one of the plurality of illumination sources, and configured to convert a received optical signal representing data into an electrical signal representing data; and

a keypad signal interface electrically connected to the keypad housing, the keypad signal interface including a connection for data between the keypad housing and the main housing, and the connection for data is an electrical connection configured as a data line,

wherein the optical receiver comprises a plurality of optical receivers associated with the plurality of keys, the optical receivers positioned in the keypad housing and providing outputs in response to optical signals, and connected to the data line so that outputs of the plurality of optical receivers are summed to generate a summed output.

2. The device of claim 1, wherein the device is a wireless communication device.

3. The device of claim 1, wherein:

the keypad housing has a linear or curvilinear profile; and

the plurality of keys are disposed in consecutive positions along the keypad housing.

4. The device of claim 1, wherein the keypad housing is slidably coupled to the main housing so as to define a slide, and at least one key of the plurality of keys is configured as a soft key and configured to be activated according to a position of the slide with respect to the main housing.

5. The device of claim 1, wherein the keypad signal interface consists of:

an electrical connection for power between the keypad housing and the main housing; and

an electrical connection for ground between the keypad housing and the main housing.

6. The device of claim 1, wherein:

at least one key of the plurality of keys defines an aperture configured to allow light from a corresponding illumination source to escape the keypad housing to provide key illumination; and

the at least one key of the plurality of keys is configured to be covered during a key press so that light from the corresponding illumination source is reflected to an associated optical receiver to signal the key press.

7. The device of claim 1, wherein:

at least one key of the plurality of keys is partly covered by a deformable dome so as to define an aperture configured to allow light from a corresponding illumination source to escape the keypad housing to provide key illumination;

the dome is configured to reflect light from the corresponding illumination source to an associated optical receiver to signal the key press;

the illumination sources of the plurality of illumination sources have predetermined intensities of illumination; and

the summed output is provided as input to an analog-to-digital (A/D) converter.

8. The device of claim 1, wherein:

the connection for data comprises an optical guide configured to gather an optical signal from a corresponding illumination source for each of the plurality of keys and configured to conduct the optical signal to the main housing; and

the optical receiver is positioned in the main housing and coupled to the optical guide.

9. The device of claim 8, wherein:

the keypad housing has an exterior surface; and

the optical guide includes at least one deformable segment configured to guide light toward the exterior surface of the keypad housing for key illumination, and

configured to guide light toward the main housing for key press detection.

10. The device of claim 9, wherein:

the optical guide includes a deformable segment for each key of the plurality of keys;

the deformable segment is configured so that when the key is not pressed, the deformable segment directs light from a corresponding illumination source toward the exterior surface of the keypad housing proximal a tactilely coded location associated with the key, so that the key is illuminated;

at least one deformable segment is configured to direct light from an adjacent segment toward the main housing; and

the deformable segment is configured so that when the key is pressed, the deformable segment flexes to direct light from the corresponding illumination source toward the main housing.

11. The device of claim 8, wherein:

the optical guide includes a deformable segment for each key of the plurality of keys;

the deformable segment is configured so that when the key is pressed, the deformable segment flexes to direct light from the corresponding illumination source toward the main housing; and

at least one deformable segment is configured to mechanically enable multiple key presses by defining a funnel geometry to capture light from an adjacent segment and direct light from the adjacent segment toward the main housing.

12. The device of claim 8, wherein:

at least one illumination source is configured to generate emissions coded according to a time division multiplexing (TDM) scheme or a frequency division multiplexing (FDM) scheme.