Through-display proximity sensors with reduced temperature dependence
AssigneeApple Inc.
InventorsTong Chen, Wenrui Cai, Clint M. Perlaki, James J. Dudley, Xiao Xiang
Life of this patent
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Abstract
An optical sensing systems for through-display sensing. The optical sensing system includes a transmit side and a receive side. The transmit side includes at least two polarization-locked laser elements that are oriented to emit polarized light in two separate orientations orthogonal to one another through an inter-pixel region of the display. The different polarizations decrease temperature dependence of crosstalk magnitude.
Claims20
An optical sensing system comprising:
- a transmitter side comprising:
- a first die comprising a first polarization-locked vertical cavity surface emitting laser (VCSEL) element configured to emit polarized light with a first orientation;
- and
- a second die comprising a second polarization-locked VCSEL element configured to emit polarized light with a second orientation orthogonal to the first orientation;
- and
- a receiver side comprising a photodiode configured to receive a reflection of light emitted from either the first polarization-locked VCSEL element or the second polarization-locked VCSEL element.
A portable electronic device comprising:
- a housing;
- a display within the housing defining:
- an interior surface;
- an active display area;
- and
- an exterior surface;
- and
- an optical sensing system disposed on the interior surface, and oriented to emit light through the active display area to propagate from the exterior surface to illuminate an object within a field of view of the portable electronic device, the optical sensing system comprising:
- a first polarization-locked laser element configured to emit polarized light;
- a second polarization-locked laser element configured to emit polarized light, the second polarization-locked laser element oriented orthogonally with respect to the first polarization-locked laser element;
- and
- a photodiode configured to receive a reflection of light emitted from either the first polarization-locked laser element or the second polarization-locked laser element to determine whether an object is present within the field of view.
A method of operating an optical proximity sensing system behind a display of an electronic device, the method comprising:
- emitting first laser light at a first polarization orientation though an inter-pixel region of the display;
- emitting second laser light at a second polarization orientation orthogonal to the first polarization orientation through the inter-pixel region of the display;
- receiving, through the inter-pixel region of the display, a reflection of one or both of the first laser light or the second laser light at photodiode and in response determining that an object is present within a field of view of the electronic device.
Dependencies are inferred from the claim text.