Electronic device with chip-on-glass ambient light sensors

• US 9,477,263 B2
• Filed: 10/27/2011
• Issued: 10/25/2016
• Est. Priority Date: 10/27/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Hotelling, Steven P., Zheng, Dong
• Primary Examiner(s): CHANG, CHARLES S
• Application Number:
  US13/283,446
• Publication Number:
  US 20130106813A1
• Time in Patent Office: 1,825 Days
• Field of Search: 345/207, 349/12
• US Class Current: 1/1
• CPC Class Codes: G06F 1/1626 with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 1/1637 Details related to the display arrangement, including those related to the mounting of the display in the housing
• CPC Class Codes: G06F 1/1684 Constructional details or arrangements related to integrated I/O peripherals not covered by groups G06F1/1635 - G06F1/1675
• CPC Class Codes: G06F 1/3265 Power saving in display device
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

An electronic device may have a display with a brightness that is adjusted based on ambient light data from one or more ambient light sensors. An ambient light sensor may be formed from a semiconductor substrate such as a silicon substrate. Sensor structures may be formed in the silicon substrate. Conductive vias or other conductive paths may be used to interconnect sensor structures on a frontside surface of the ambient light sensor to contacts on a backside surface of the ambient light sensor. The ambient light sensor may be mounted on a substrate layer in the electronic device. The substrate layer may be a planar layer of glass or plastic such as a transparent display layer. The contacts of the ambient light sensor may be mounted to corresponding contacts on the surface of the substrate layer. The substrate layer may be a thin-film transistor layer in a liquid crystal display.

Claims

1. An electronic device, comprising:

a display; and

an ambient light sensor having a frontside surface with light sensor structures configured to receive ambient light and having a backside surface with backside contacts that are mounted to associated contacts on at least part of the display, wherein the ambient light sensor comprises vias that form an electrical path between the frontside surface of the ambient light sensor and the backside surface of the ambient light sensor.

2. The electronic device defined in claim 1 wherein the display comprises a liquid crystal display having a thin-film transistor layer on which the associated contacts are formed and wherein ambient light sensor is mounted on the thin-film transistor layer by mounting the backside contacts to the associated contacts on the thin-film transistor layer.

3. The electronic device defined in claim 1 wherein the display comprises a touch sensor layer on which the associated contacts are formed and wherein the ambient light sensor is mounted to touch sensor layer by mounting the backside contacts to the associated contacts on the touch sensor layer.

4. The electronic device defined in claim 1 wherein the display comprises at least one transparent substrate layer on which the associated contacts are formed and wherein the ambient light sensor is mounted to transparent substrate layer by mounting the backside contacts to the associated contacts on the transparent substrate layer.

5. The electronic device defined in claim 1 wherein the display comprises a rectangular thin-film transistor layer having four corners and wherein the ambient light sensor is mounted in one of the four corners.

6. The electronic device defined in claim 5 further comprising at least one additional ambient light sensor mounted to the thin-film transistor layer in at least another one of the four corners.

7. The electronic device defined in claim 1 wherein the ambient light sensor is formed from an integrated circuit and wherein the integrated circuit includes analog-to-digital converter circuitry.

8. The electronic device defined in claim 1 wherein the backside contacts on the backside surface of the ambient light sensor comprise gold.

9. The electronic device defined in claim 1 further comprising conductive adhesive between the backside contacts on the backside surface of the ambient light sensor and the associated contacts on the display.

10. An electronic device, comprising:

a glass substrate having conductive traces; and

an ambient light sensor having contacts that are electrically connected to the traces, wherein the ambient light sensor comprises a semiconductor substrate having doped regions in a frontside surface through which ambient light is received and a backside surface on which the contacts are formed.

11. The electronic device defined in claim 10 wherein the glass substrate comprises a thin-film transistor layer in a liquid crystal display.

12. The electronic device defined in claim 11 wherein the semiconductor substrate comprises a layer of silicon, wherein the ambient light sensor comprises a layer of glass, and wherein ambient light is received by the layer of silicon through the layer of glass.

13. The electronic device defined in claim 10 further comprising conductive adhesive with which the contacts are connected to the traces.

14. An electronic device, comprising:

a display having at least one transparent display layer; and

at least one ambient light sensor formed from doped regions in a silicon substrate having first and second opposing surfaces, wherein the ambient light sensor receives light through the first surface and has contacts on the second surface of the silicon substrate and wherein the contacts are attached to conductive structures on the transparent display layer.

15. The electronic device defined in claim 14 further comprising conductive material with which the contacts are attached to the conductive structures, wherein the transparent display layer comprises thin-film transistors.

16. The electronic device defined in claim 15 wherein the display comprises a liquid crystal display, wherein the transparent display layer comprises a glass layer, and wherein the thin-film transistors and the conductive structures are formed on the glass layer.

17. The electronic device defined in claim 14 wherein the at least one ambient light sensor comprises a plurality of ambient light sensors that are formed from silicon substrates having contacts that are attached to the conductive structures on the transparent display layer, the electronic device further comprising a display cover layer having an opaque masking layer with a plurality of transparent ambient light sensor windows through which ambient light reaches the ambient light sensors.