Touch/proximity-sensing using reflective optical sensor and a light pipe

• US 20070228263A1
• Filed: 04/02/2007
• Published: 10/04/2007
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Masstech Group Inc (Telestream Holdings Corp.)
• Original Assignee: Masstech Group Inc (Telestream Holdings Corp.)
• Inventors: Shen, Sudy, Praisler, Dan
• Granted Patent: US 7,485,843 B2
• Time in Patent Office: Days
• US Class Current: 250/221
• CPC Class Codes: H03K 17/9631 using a light source as part of the switch
• CPC Class Codes: H03K 17/9638 using a light guide

Abstract

The disclosure is directed to a touch proximity sensing system detecting the presence or absence of a triggering object. The system includes a reflective optical sensor, an active surface, and a light pipe in combination. The reflective optical sensor has an emitter for creating a light and a receiver for detecting a reflected light of the emitter. The active surface is suitable for receiving the triggering object, such as a stylus or finger, or the like. The light pipe is disposed between the reflective optical sensor and the active surface. The length of the light pipe is such that the reflective optical sensor and the active surface are spaced-apart from each other. The light pipe transports the light from the emitter to the active surface. In the presence of the triggering object, light from the emitter is reflected and the light pipe transports the reflected light to the receiver.

Claims

1. A touch proximity sensing system detecting the presence or absence of a triggering object, the system comprising:

a reflective optical sensor having an emitter for creating a light and a receiver for detecting a reflected light of the emitter;

an active surface for receiving the triggering object; and

a light pipe disposed between the reflective optical sensor and the active surface and having a length such that the reflective optical sensor and the active surface are spaced-apart from each other over the length of the light pipe;

wherein the light pipe transports the light from the emitter along the length to the active surface, and, in the presence of the triggering object reflecting the light from the emitter to cause the reflected light of the emitter to be transported from the active surface to the receiver to detect the presence of the trigger object.

2. A touch proximity sensing system detecting the presence or absence of a triggering object for effecting a change in a device, the system comprising:

a reflective optical sensor having an emitter for creating a subject light and a receiver for detecting at least a selected amount of the subject light, wherein detection of the at least a selected amount of light effects a change in the device;

a light pipe having a length and first and second ends, wherein light entering one end is transported to the other end, wherein the first end is disposed proximate the reflective optical sensor for receiving and transporting the subject light along the length of the light pipe;

a translucent active member having an inner surface disposed proximate the second end of the light pipe and having an active surface opposite the inner surface, wherein the second end of the light pipe is disposed proximate the inner surface and on an active region of the active member;

wherein the presence of the triggering object proximate the active region causes a reflection of at least the selected amount of the subject light to be transported along the light pipe to the receiver and the absence of the triggering object proximate the active region does not cause at least the selected amount of the subject light to be transported along the light pipe to the receiver.