Patent Application
20140152632
This relates generally to electronic devices and, more particularly, to electronic devices with displays and light sensors.
Electronic devices often include displays. For example, cellular telephones and portable computers often include displays for presenting information to a user.
Electronic devices also often include light sensors. For example, an electronic device may include an ambient light sensor that senses the amount of light in the environment surrounding the device. The brightness of display images generated by the display is sometimes adjusted based on the amount of ambient light. For example, in bright sunlight, the display brightness may be increased and in a dark room, the display brightness can be decreased.
In a typical device, a light sensor that is formed from a chip package having a photodiode is laterally displaced from an active display region of the display along a front face of the device. Additional space is therefore provided in common devices at the top, bottom, or side of the active display area to accommodate the light sensor.
This type of additional space for a common light sensor package can result in an undesirable increase in the size and thickness of the device.
It would therefore be desirable to be able to provide improved electronic devices with light sensors and displays.
An electronic device is provided with a display such as an organic light-emitting diode display mounted in an electronic device housing. The electronic device is also provided with one or more light sensors.
The display includes multiple display layers such as one or more light-generating layers, a touch-sensitive layer, and a cover layer. The cover layer may, for example, be a layer of rigid transparent material such as glass or transparent plastic.
The light sensor is formed from one or more solar cells such as a thin-film photovoltaic solar cell. The thin-film solar cell light sensor is configured as a solar cell ambient light sensor that is coupled to circuitry in the device. The circuitry includes a printed circuit board and, if desired, additional control circuitry for operating device components such as the display and the solar cell ambient light sensor.
During operation, a voltage is generated on the thin film solar cells in response to ambient light that falls on the thin film solar cells. The voltage is read (sampled) by the control circuitry and an ambient light intensity is determined based on the sampled voltage.
The solar cell ambient light sensor is mounted to a layer of the display such as a display cover layer, a display color filter layer, or an innermost layer of the display. In one suitable example, the solar cell ambient light sensor is mounted to an innermost layer of the display and receives the ambient light through substantially all of the layers of the display.
In configurations in which the solar cell ambient light sensor is mounted to a display cover layer or a display color filter layer, the solar cell ambient light sensor may receive light through a partially opaque masking layer that is formed on the cover layer or the color filter layer. The partially opaque masking layer may block a portion of the light that falls on the masking layer and may transmit another portion of the light. As examples, the partially opaque masking layer may block a fraction of all wavelengths of light or may block some wavelengths of light while passing other wavelengths of light.
The device may be provided with multiple solar cell ambient light sensors. Each solar cell ambient light sensor may receive light having a common set of wavelengths or some solar cell ambient light sensors may be configured to detect light having a first range of wavelengths and other solar cell ambient light sensors may be configured to detect light having a different range of wavelengths. The circuitry may adjust the brightness of the display based on the detected light from the solar cell ambient light sensors.
Further features, their nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.
Electronic devices may be provided with displays and solar cell ambient light sensors. Illustrative electronic devices that have displays and solar cell ambient light sensors are shown in
Electronic device 10 of
Light sensors 40 may be formed from thin-film photovoltaic cells that include a semiconductor substrate such as an amorphous silicon substrate, a cadmium telluride substrate, or a copper indium gallium deselenide substrate on which a voltage is generated in response to incident light. Light sensors 40 may include additional layers of material such as a glass layer, a metal foil layer, a zinc oxide layer, a carbon paste layer, a tin oxide layer or other oxide layer, a cadmium stannate layer, a cadmium sulfide layer, or other layers of material. Circuitry in the device such as control circuitry that is coupled to the light sensor samples the voltage and determines, for example, an ambient light intensity from the sampled voltage.
In the example of
In some configurations, peripheral portions of display 14 are provided with a partially or completely opaque masking layer. As shown in
In the examples of
A light sensor such as light sensors 40 that is located in inactive area IA is attached to a display cover layer or a display color filter layer (as examples). Portions of the display cover layer and/or the display color filter layer include a partially opaque masking layer that hides internal components such as the light sensor from view by a user.
Light sensors 40 in inactive area IA receive ambient light through the display cover layer and/or the display color filter layer, and the partially opaque masking layer. Light having a given range of wavelengths passes through the masking layer (e.g., an ink filter layer) onto the light sensors. However, this is merely illustrative. If desired, the masking layer may allow a fraction of light of all wavelengths to pass through the masking layer.
The illustrative configurations for device 10 that are shown in
Housing 12 of device 10, which is sometimes referred to as a case, is formed of materials such as plastic, glass, ceramics, carbon-fiber composites and other fiber-based composites, metal (e.g., machined aluminum, stainless steel, or other metals), other materials, or a combination of these materials. Device 10 may be formed using a unibody construction in which most or all of housing 12 is formed from a single structural element (e.g., a piece of machined metal or a piece of molded plastic) or may be formed from multiple housing structures (e.g., outer housing structures that have been mounted to internal frame elements or other internal housing structures).
Display 14 may be a touch-sensitive display that includes a touch sensor or may be insensitive to touch. Touch sensors for display 14 may be formed from an array of capacitive touch sensor electrodes, a resistive touch array, touch sensor structures based on acoustic touch, optical touch, or force-based touch technologies, or other suitable touch sensor components.
Displays for device 10 may, in general, include image pixels formed from light-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells, electrowetting pixels, electrophoretic pixels, liquid crystal display (LCD) components, or other suitable image pixel structures. In some situations, it may be desirable to use OLED components to form display 14, so configurations for display 14 in which display 14 is an organic light-emitting diode display are sometimes described herein as an example. Other types of display technology may be used in device 10, if desired.
A display cover layer may cover the surface of display 14 or a display layer such as a color filter layer or other portion of a display may be used as the outermost (or nearly outermost) layer in display 14. The outermost display layer may be formed from a transparent glass sheet, a clear plastic layer, or other transparent member.
A schematic diagram of device 10 is shown in
With one suitable arrangement, storage and processing circuitry 400 is used to run software on device 10 such as internet browsing applications, email applications, media playback applications, operating system functions, software for capturing and processing images, software for implementing functions associated with gathering and processing sensor data, etc.
Input-output circuitry 32 is used to allow data to be supplied to device 10 and to allow data to be provided from device 10 to external devices.
Input-output circuitry 32 can include wired and wireless communications circuitry 34. Communications circuitry 34 may include radio-frequency (RF) transceiver circuitry formed from one or more integrated circuits, power amplifier circuitry, low-noise input amplifiers, passive RF components, one or more antennas, and other circuitry for handling RF wireless signals. Wireless signals can also be sent using light (e.g., using infrared communications).
Input-output circuitry 32 of
Sensors 38 of
It can be challenging to mount electrical components such as the components of
The display may include features that allow ambient light to pass through the display onto the solar cell ambient light sensor (e.g., opaque masking material that allows transmission of light of some wavelengths, openings such as microperforations in a layer of the display, etc.).
Storage and processing circuitry 400 samples voltages, electrical charges, or other electrical signals from solar cell ambient light sensors of sensor 38. Storage and processing circuitry 400 converts the sampled signals into ambient light intensities. Storage and processing circuitry 400 controls other aspects of the operation of device 10 using the converted ambient light intensities. For example, storage and processing circuitry can increase or decrease the display light from the device display based on the ambient light intensity.
Ambient light signals gathered using solar cell ambient light sensor (solar cell ALS) 40 are routed to printed circuit board 42 through flexible printed circuit 44. Flexible printed circuit 44 is attached to a portion of solar cell ALS 40 using electrical coupling material 502 (e.g., anisotropic conductive film (ACF), solder, or other electrically conductive adhesive material). An opposing end of flexible printed circuit 44 is attached to a portion of PCB 42 using electrical coupling material 52 (e.g., anisotropic conductive film (ACF), solder, or other electrically conductive adhesive materials, or mechanical connector structures).
In the example of
Solar cell ALS 40 may be located near a portion of display 14 where emission of display light from display 14 is minimal so that the display light does not disrupt the operation of light sensor 40. However, this is merely illustrative. If desired, solar cell ALS 40 and/or a surface of display 14 may be provided with a light filtering or light reflecting film (e.g., a filter that prevents display light from display 14 from reaching light sensor 40 while allowing ambient light to reach light sensor 40 through the filter) or solar cell ALS 40 may be sampled during “off” periods of display illumination (e.g., between display pixel refreshes).
In one suitable example, flexible circuit 44 is a single layer flexible printed circuit. However, if desired, flexible circuit 44 may include additional printed circuit layers. Flexible circuit 44 may be attached to ambient light sensor 40 along an edge of display 14, along substantially all of an inner surface of display 14, or in other discrete locations behind portions of display 14.
Solar cell ambient light sensor 40 may has a thickness T. Thickness T may, for example, be less than 10 microns. Other examples of suitable thicknesses T for sensor 40 are less than 20 microns, less than 40 microns, less than 50 microns, between 5 microns and 10 microns, between 1 micron and 20 microns, or less than 250 microns.
An exploded perspective view of an illustrative display of the type that may be used in the electronic device 10 is shown in
Touch-sensitive layer 14B may incorporate capacitive touch electrodes such as horizontal transparent electrodes 320 and vertical transparent electrodes 340. Touch-sensitive layer 14B may, in general, be configured to detect the location of one or more touches or near touches on touch-sensitive layer 14B based on capacitive, resistive, optical, acoustic, inductive, or mechanical measurements, or any phenomena that can be measured with respect to the occurrences of the one or more touches or near touches in proximity to touch sensitive layer 14B.
Software and/or hardware may be used to process the measurements of the detected touches to identify and track one or more gestures. A gesture may correspond to stationary or non-stationary, single or multiple, touches or near touches on touch-sensitive layer 14B. A gesture may be performed by moving one or more fingers or other objects in a particular manner on touch-sensitive layer 14B such as tapping, pressing, rocking, scrubbing, twisting, changing orientation, pressing with varying pressure and the like at essentially the same time, contiguously, or consecutively. A gesture may be characterized by, but is not limited to a pinching, sliding, swiping, rotating, flexing, dragging, or tapping motion between or with any other finger or fingers. A single gesture may be performed with one or more hands, by one or more users, or any combination thereof.
Cover layer 14C may be formed from plastic or glass (sometimes referred to as display cover glass) and may be flexible or rigid. If desired, the interior surface of peripheral portions of cover layer 14C may be provided with an opaque masking layer on such as black ink.
A solar cell ambient light sensor can be attached to one or more of display layers 14A, 14B, and/or 14C. The solar cell ambient light sensor may be configured to receive ambient light from the environment surrounding device 10 through cover layer 14C, through touch-sensitive layer 14B, and/or through one or more of light-generating layers 14A.
In the example of
Masking material 62 blocks more light than it passes. As examples, masking material 62 may allow at least two percent, at least 4 percent, at least 10 percent, at least 50 percent, between 1 percent and 10 percent, between 0.01 percent and 3 percent, between 0.1 percent and 0.3 percent, between 0.1 percent and 0.5 percent, or less than 1 percent of light at some or all wavelengths to pass through the masking material onto sensor 40.
As shown in
Device 10 may include a single light sensor 40 mounted at a discrete location on cover layer 14C, may include a single extended light sensor 40 that receives light through substantially all of cover layer 14C, may include a light sensor 40 that extends along one or more edges of cover layer 14C, or may include multiple light sensors 40 mounted at multiple locations on cover layer 14C.
As examples, light sensor 40 of
In configurations in which device 10 includes multiple solar cell ambient light sensors 40 on cover layer 14C, light sensors 40 may be configured to receive light of different wavelengths (e.g., by providing each light sensor with a color filter or by forming each light sensor from materials that are sensitive to light of a given set of wavelengths) or light of a common wavelength. As examples, light sensor 40 may include two or more adjacent light sensors on cover layer 14C that receive light of a common color, two or more adjacent light sensors on cover layer 14C that receive light of different colors, two or more light sensors at separate locations on cover layer 14C that receive light of a common color, or two or more light sensors at separate locations on cover layer 14C that receive light of different colors.
In the example of
Light-generating layers 14A include additional layers such as thin-film transistor layer 78. Light-generating layers 14A may also include layers 76 formed above TFT layer 78 and layers 80 formed below TFT layer 78. Layers 76 and 80 may include light-polarizing layers, glass layers, layers of organic emissive material, encapsulation layers, substrate layers, liquid crystal layers, or other suitable display layers for generating display light for electronic device displays.
Device 10 may include a single light sensor 40 mounted at a discrete location on any of light generating layers 14A, may include a single extended light sensor 40 that receives light through substantially all of any of light generating layers 14A, may include a light sensor 40 that has a shape that is substantially the same as the shape of inactive area IA, may include multiple light sensors 40 mounted at multiple locations on a single one of light-generating layers 14A, or may include multiple light sensors 40 mounted at multiple locations on more than one of light-generating layers 14A.
As examples, light sensor 40 of
In configurations in which device 10 includes multiple solar cell ambient light sensors 40, light sensors 40 may be configured to receive light of different wavelengths (e.g., by providing each light sensor with a color filter or by forming each light sensor from materials that are sensitive to light of a given set of wavelengths) or light of a common wavelength. As examples, light sensor 40 may include two or more adjacent light sensors that receive light of a common color, two or more adjacent light sensors that receive light of different colors, two or more light sensors at separate locations that receive light of a common color, or two or more light sensors at separate locations that receive light of different colors.
In the example of
Solar cell ambient light sensor 40 receives ambient light 62 through substantially all of the layers of display 14 (i.e., through cover layer 14C, through touch-sensitive layer 14B, and through light-generating layers 14A). Only a portion of ambient light 62 passes through display 14. Some of ambient light 62 (e.g., greater than 99.8 percent, greater than 99 percent, greater than 98 percent, or greater than 50 percent) is blocked by display 14 from reaching sensor 40.
Device 10 may also include internal support structures such as display chassis structure 82. Display chassis structure 82 may be formed from metal, plastic, other materials or combinations of materials. In one suitable example, structure 82 is metal. Structure 82 helps support display 14 within device 10.
A solar cell ambient light sensor such as sensor 40 of
Control circuitry such as storage and processing circuitry 400 (
If desired, the thickness of display 14 may be further reduced by providing an opening in display chassis structure 82, as shown in
In the example of
In a configuration for display 14 of the type shown in
Organic-light-emitting diode layer 154 includes thin-film transistor (TFT) layer 153 and a layer of organic light-emitting material such as emissive layer 155. TFT layer 153 includes an array of thin-film transistors. The thin-film transistors may be formed from semiconductors such as amorphous silicon, polysilicon, or compound semiconductors (as examples). Organic emissive layer 155 may be formed from organic plastics such as polyfluorene or other organic emissive materials. Encapsulation layer 156 covers emissive layer 155 and, if desired, some or all of TFT layer 153.
During operation, signals are applied to the organic light-emitting diodes in layer 154 using the signal lines so that an image is created on display 14. Image light 70 from the organic light-emitting diode pixels in layer 154 is emitted upwards through transparent glass layer 152 for viewing in direction 65 by viewer 63. Color filter layer 150 may include a circular polarizer layer that suppress reflections from the metal signal lines in layer 154 that might otherwise be visible to viewer 63. Solar cell ambient light sensor 40 is attached to encapsulation layer 156 and receives light through cover layer 14C, touch-sensitive layer 14B, and light-generating layers 14A. However, this is merely illustrative. Sensor 40 may be attached to any of display layers 14C, 14B, 150, 152, 153, 156, and/or other suitable display layers.
In a configuration for display 14 of the type shown in
Organic light-emitting diode layer 154 is formed on the upper surface of substrate 158. An encapsulation layer such as encapsulation layer 156 encapsulates organic light-emitting diode layer 154. During operation, individually controlled pixels in organic light-emitting diode layer 154 generate display image light 70 for viewing in direction 65 by viewer 63. Color filter layer 150 may include a circular polarizer layer that suppresses reflections from metal signal lines in layer 154. Solar cell ambient light sensor 40 is attached to substrate 158 and receives light through cover layer 14C, touch-sensitive layer 14B, and light-generating layers 14A. However, this is merely illustrative. Sensor 40 may be attached to any of display layers 14C, 14B, 150, 153, 156, 158, and/or other suitable display layers.
In a configuration for display 14 of the type shown in
If desired, a solar cell ambient light sensor may be attached to lower polarizer layer 176 and receive light through cover layer 14C, touch-sensitive layer 14B, upper polarizer 178 color filter layer 172, liquid crystal layer 170, thin-film-transistor layer 174, and lower polarizer layer 176.
In this type of configuration, sensor 40 is interposed between polarizer 176 and backlight structures such as backlight unit 180 that generate backlight for the liquid crystal display. However, this is merely illustrative. If desired, a solar cell ambient light sensor 40 may be attached to an interior surface of backlight unit 180 and receive ambient light through cover layer 14C, touch-sensitive layer 14B, upper polarizer 178, color filter layer 172, liquid crystal layer 170, thin-film-transistor layer 174, and lower polarizer layer 176, and backlight unit 180. Backlight unit 180 or other portions of display 14 may, for example, include features that enhance the transmission of ambient light through display 14 to sensor 40. If desired, one or more solar cell ambient light sensors such as sensors 40 may be attached to any of cover layer 14C, touch-sensitive layer 14B, and/or any of layers 178, 172, 170, 174, 176, 180 or any other suitable display layers.
Masking materials 60-1 and 60-2 may each block a respective portion of ambient light 62 from reaching sensors 40-1 and 40-2. Masking materials 60-1 and 60-2 may block light having a common set of wavelengths or material 60-1 may block light having different respective sets of wavelengths. For example, material 60-1 may transmit infrared light while blocking visible light and material 60-2 may transmit some visible light while blocking infrared light. Ambient light intensities for ambient light having various wavelengths can be combined (e.g., using storage and processing circuitry 400 of
Masking materials 60-1, 60-2 and, if desired, additional masking materials such as masking material 60-3 may be formed on a display layer such as display layer 190. Display layer 190 may, as examples, represent cover layer 14C or color filter layer 74.
The example of
Differences in ambient light levels at different wavelengths are used to determine a type of light source that is illuminating the device (e.g., indoor lighting, outdoor lighting, sunlight, incandescent lighting, fluorescent lighting, light-emitting diode lighting, etc.). The color and intensity of images formed using display 14 are modified based on the detected light source type and light intensity.
The foregoing is merely illustrative and various modifications can be made by those skilled in the art without departing from the scope and spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination.
