Ambient Light Sensors With Controlled Angular Responses

An electronic device may include an ambient light sensor. An angular-response controller may overlap the ambient light sensor and may have regions with adjustable transparency to control an angular response of the ambient light sensor. In particular, the angular-response controller may include two light modulator layers, such as liquid crystal layers. Each of the light modulator layers may have transparent portions and opaque portions. To allow on-axis light to pass through to the ambient light sensor while blocking off-axis light, the transparent portions of the two layers may be aligned, and the opaque portions of the two layers may be aligned. In contrast, to allow off-axis light while blocking on-axis light, the opaque portions of the two layers may be offset. The light modulator layers may be adjusted in response to measurements from the ambient light sensor or other sensors in the device, such as motion or orientation sensors.

FIELD

BACKGROUND

Electronic devices such as laptop computers, cellular telephones, and other equipment are sometimes provided with sensors. For example, sensors may be incorporated into a device to provide the device with information on current environmental or device conditions.

SUMMARY

An electronic device may include an ambient light sensor. The ambient light sensor may be formed in an electronic device housing and may be overlapped by a cover layer. An angular-response controller may be included in the housing between the ambient light sensor and the cover layer. The angular-response controller may be formed in an ambient light sensor module with the ambient light sensor, or the angular-response controller may be separate from the ambient light sensor module.

The angular-response controller may have regions with adjustable transparency to control an angular response of the ambient light sensor. In particular, the angular-response controller may include two light modulator layers, such as liquid crystal layers or electrochromic layers. Each of the light modulator layers may have transparent portions and opaque portions. To allow on-axis light to pass through to the ambient light sensor while blocking off-axis light, the transparent portions of the two layers may be aligned, and the opaque portions of the two layers may be aligned. In contrast, to allow off-axis light while blocking on-axis light, the opaque portions of the two layers may be offset.

The light modulator layers may be adjusted in response to measurements from the ambient light sensor or other sensors in the device, such as motion or orientation sensors. For example, motion measurements from a motion sensor may be used to adjust the light modulator layers to allow for light distribution measurements.

In addition to, or instead of, adjusting whether the transparent and opaque portions overlap, the light modulator layers may have adjustable opaque portion densities and/or adjustable colors.

Ambient light sensors and angular-response controllers may be incorporated into any desired electronic devices, such as mobile computers, tablets, cellular telephones, wrist watch devices, or head-mounted devices, as examples.

DETAILED DESCRIPTION

An electronic device may include one or more environmental sensors, such as an ambient light sensor. In particular, the ambient light sensor may be used to measure the intensity of ambient light by generating charge in response to the ambient light that is incident on the sensor.

In some situations, it may be desirable to modify an angular response of the ambient light sensor. As illustrative examples, the angular response may be modified to avoid measuring selected ambient light, to balance the sensitivity of the sensor at different angles, or to determine a lighting distribution.

To modify the angular response of the ambient light sensor, the electronic device may include one or more patterned light modulator layers that overlap the ambient light sensor. In some illustrative embodiments, two patterned light modulator layers may be used, each having opaque regions and transparent regions. To allow more on-axis light to reach the ambient light sensor (while blocking off-axis light), the patterned light modulator layers may have overlapping or nearly overlapping opaque regions and overlapping or nearly overlapping transparent regions. On the other hand, to allow more off-axis light to reach the ambient light sensor (while blocking on-axis light), the patterned light modulator layers may have offset opaque portions (and offset transparent portions). In this way, the amount of on-axis and off-axis ambient light that reaches the ambient light sensor may be controlled.

An illustrative electronic device of the type that may be provided with one or more ambient light sensors is shown inFIG.1. Electronic device10may be a computing device such as a laptop computer, a computer monitor containing an embedded computer, a tablet computer, a cellular telephone, a media player, or other handheld or portable electronic device, a smaller device such as a wristwatch or other device worn on a user's wrist, a pendant device, a headphone or earpiece device, a head-mounted device, a device embedded in eyeglasses or other equipment worn on a user's head, or other wearable or miniature device, a television, a computer display that does not contain an embedded computer, a gaming device, a navigation device, an embedded system such as a system in which electronic equipment with a display is mounted in a kiosk or automobile, equipment that implements the functionality of two or more of these devices, or other electronic equipment.

Input-output circuitry in device10such as input-output devices12may be used to allow data to be supplied to device10and to allow data to be provided from device10to external devices. Input-output devices12may include buttons, joysticks, scrolling wheels, touch pads, key pads, keyboards, microphones, speakers, tone generators, vibrators, cameras, light-emitting diodes and other status indicators, data ports, etc. A user can control the operation of device10by supplying commands through input-output devices12and may receive status information and other output from device10using the output resources of input-output devices12.

Input-output devices12may include one or more displays such as display14. Display14may be a touch screen display that includes a touch sensor for gathering touch input from a user or display14may be insensitive to touch. A touch sensor for display14may be based on an array of capacitive touch sensor electrodes, acoustic touch sensor structures, resistive touch components, force-based touch sensor structures, a light-based touch sensor, or other suitable touch sensor arrangements. Display14may include any desired display technology, and may be an organic light-emitting diode (OLED) display, a liquid crystal display (LCD), a microLED display, or any other desired type of display.

Input-output devices12may also include sensors18. Sensors18may include a capacitive sensor, a light-based proximity sensor, a magnetic sensor, an accelerometer, a force sensor, a touch sensor, a temperature sensor, a pressure sensor, a compass, a microphone, a radio-frequency sensor, a three-dimensional image sensor, a camera, a light-based position sensor (e.g., a lidar sensor), and other sensors. Sensors18may also include one or more light detectors that are configured to detect ambient light (e.g., ambient light sensors). Sensors18may, for example, include one or more monochrome ambient light sensors and one or more color ambient light sensors that are configured to measure ambient light from the environment in which device10is operated. A monochrome ambient light sensor may be used to measure ambient light intensity. A color ambient light sensor may be used to measure the color (e.g., color spectrum, color temperature, color coordinates, etc.) of ambient light and may be used to measure ambient light intensity.

A perspective view of an illustrative electronic device of the type that may include one or more ambient light sensors is shown inFIG.2. In the example ofFIG.2, device10includes a display such as display14mounted in housing22. Display14may be a liquid crystal display, an electrophoretic display, an organic light-emitting diode display, or other display with an array of light-emitting diodes (e.g., a display that includes pixels having diodes formed from crystalline semiconductor dies), may be a plasma display, may be an electrowetting display, may be a display based on microelectromechanical systems (MEMs) pixels, or may be any other suitable display. Display14may have an array of pixels26that extends across some or all of front face F of device10and/or other external device surfaces. The pixel array may be rectangular or may have other suitable shapes. Display14may be protected using a display cover layer (e.g., a transparent front housing layer) such as a layer of transparent glass, clear plastic, sapphire, or other clear layer. The display cover layer may overlap the array of pixels26.

Housing22, which may sometimes be referred to as an enclosure or case, may be formed of plastic, glass, ceramics, fiber composites, metal (e.g., stainless steel, aluminum, etc.), other suitable materials, or a combination of any two or more of these materials. Housing22and display14may separate an interior region of device10from an exterior region surrounding device10. Housing22may be formed using a unibody configuration in which some or all of housing22is machined or molded as a single structure or may be formed using multiple structures (e.g., an internal frame structure, one or more structures that form exterior housing surfaces, etc.). If desired, a wristband, a headband, or other strap may be coupled to a main portion of housing22(e.g., in configurations in which device10is a wristwatch or a head-mounted device).

Pixels26may cover substantially all of the front face of device10or display14may have inactive areas (e.g., notches, recessed areas, rectangular areas, or other regions) that are free of pixels26. The inactive areas may be used to accommodate an opening for a speaker and windows for optical components such as one or more image sensors, analog sensors such as ambient light sensors, optical proximity sensors, three-dimensional image sensors such as structured light three-dimensional image sensors, and/or a camera flash, etc. In an illustrative configuration, pixels26may extend over the entirety of the front surface F of device10and may overlap a sensor, such as an ambient light sensor, in region30. In this type of arrangement, ambient light may pass to the ambient light sensor in region30through the array of pixels26in display14.

However, region30, which may overlap an ambient light sensor in device10, may be formed anywhere on device10. For example, the sensor may be on a rear surface (opposite front surface F), one of the sidewalls between the rear surface and front surface F, on front surface F but not overlapped by display14, or at any other location in device10. Moreover, region30may overlap any desired type of sensor, such as an ambient light sensor, a pressure sensor, an accelerometer, or a sound sensor. In some embodiments, region30may be an opening in housing22(e.g., an opening that is filled with a cover layer that overlaps the sensor), or region30may be a portion of housing22(e.g., a transparent or semi-transparent portion of housing22) that covers the sensor.

Regardless of where an ambient light sensor is located in device10, the ambient light sensor may measure ambient light from a variety of incident angles. An illustrative side view of an ambient light sensor receiving light from different angles is shown inFIG.3

As shown inFIG.3, device10may include ambient light sensor32, which is at least partially overlapped by cover layer34. Cover layer34may be a transparent layer, such as a display cover layer that overlaps a display in device10(e.g., display14ofFIGS.1and2), a transparent housing layer (e.g., a rear housing wall), a window or lens that overlaps ambient light sensor32, or another suitable layer. Cover layer34may be formed from glass, sapphire, ceramic, polycarbonate or other polymer, or other suitable material.

Ambient light sensor32may be formed in region30and may receive on-axis ambient light36and off-axis ambient light38through layer34. Ambient light sensor32may be (or may include) a photodiode or other light-sensitive component that generates charge in response to ambient light.

In general, ambient light sensor32may measure ambient light36and38regardless of the angle of the ambient light. However, it may be desirable to control the angular response of ambient light sensor32. In other words, it may be desirable to change the sensitivity of ambient light sensor32to on-axis and/or off-axis ambient light, so as to avoid measuring ambient light at selected angles, to balance the sensitivity of sensor32, and/or to determine an ambient lighting distribution.

To control the angular response of ambient light sensor32, light modulator layers may be incorporated in device10and may overlap ambient sensor32. The light modulator layers may have adjustable patterns, which may be controlled to adjust the angular response of ambient light sensor32. An illustrative side view of an electronic device that may include patterned light modulator layers is shown inFIG.4.

As shown inFIG.4, angular-response controller49, which may include patterned light modulator layers46and48, may be incorporated between ambient light sensor32and layer34of device10. Patterned light modulator layers46and48may be liquid crystal layers, electrochromic layers, or other layers with adjustable transparency. Patterned light modulator layers46and48may be pixelated (e.g., have an array of individually-controllable pixels with adjustable transparency) or may have regions with adjustable transparency.

Additionally, polarizers40,42, and44may be formed between ambient light sensor32and layer34in angular-response controller49. In other words, polarizers40,42, and44may be interspersed with patterned light modulator layers46and48. Polarizers40,42, and44may be linear polarizers or circular polarizers. Polarizers40and44may be parallel to one another (e.g., may be or may include linear polarizers that are parallel), while polarizer42may be rotated with respect to polarizers40and44. For example, polarizer42may be rotated by at least 25°, at least 45°, at least 60°, at least 80°, or other suitable amount relative to polarizers40and42. In this way, polarizers40,42, and44may attenuate light that reaches ambient light sensor32, while also controlling the polarization of light that reaches ambient light sensor32.

Although not shown inFIG.4, polarizers40,42, and44may be patterned or otherwise formed to allow for areas with different polarizations over ambient light sensor32. Such an arrangement may allow for the detection of light with different polarizations using ambient light sensor32.

The use of polarizers40,42, and44is merely illustrative. If desired, one or more of polarizers40,42, and44may be omitted from device10. For example, in some embodiments, ambient light sensor32may receive light through layer34directly, without any intervening polarizers.

Moreover, althoughFIG.4shows layer34, polarizers40,42, and44, light modulators46and48, and ambient light sensor32stacked without any gaps, this is merely illustrative. If desired, gaps (e.g., air gaps, fluid-filled gaps, or other gaps) and/or additional layers may be incorporated between ambient light sensor32and layer34, such as between each layer.

Angular-response controller49may be formed separately from ambient light sensor32(e.g., angular-response controller49may be an individual component or multiple components, and may be interposed between ambient light sensor32and cover layer34). Alternatively, angular-response controller49and ambient light sensor32may be formed in a single ambient light sensor module47. In other words, angular-response controller49may be packaged with ambient light sensor32and formed behind cover layer34.

In general, light modulators, such as light modulator layers46and48, overlapping ambient light sensor32may be adjusted to adjust the angular response of ambient light sensor32by adjusting the transparency of selected portions of the light modulator layers. An illustrative example of light modulators having patterned transparent portions are shown inFIG.5A.

As shown inFIG.5A, light modulator layers46and48may overlap ambient light sensor32. Although not shown inFIG.5A, polarizers, such as polarizers40,42, and44, may also overlap ambient light sensor32, if desired.

Together, light modulator layers46and48may form angular-response controller49over ambient light sensor32. In particular, light modulator layer46may include transparent portions52and portions50with less transparency. Portions50may be referred to as opaque portions herein. In other words, light modulator layer46may be patterned with transparent portions52and opaque portions50.

In general, opaque portions50may have any suitable transparency that is less than the transparent portions52. For example, transparent portions52may have transparencies of at least 75%, at least 80%, of 100%, of at least 90%, or other suitable transparencies, while opaque portions50may have transparencies of 5% or less, of 10% or less, of 25% or less, or other suitable transparencies. The transparency of transparent portions52and/or opaque portions50may vary across light modulator layer46, if desired.

Each of portions52and50may be individually addressable portions (e.g., portions of light modulator layer46with adjustable transparency), or each of portions52and50may be formed from multiple pixels each having adjustable transparencies. In general, light modulator layer46may be patterned with portions having adjustable transparencies in any suitable manner.

Similarly, light modulator layer48may include transparent portions53and portions51with less transparency. Portions51may be referred to as opaque portions herein. In other words, light modulator layer48may be patterned with transparent portions53and opaque portions51.

In general, opaque portions51may have any suitable transparency that is less than the transparent portions53. For example, transparent portions53may have transparencies of at least 75%, at least 80%, of 100%, of at least 90%, or other suitable transparencies, while opaque portions51may have transparencies of 5% or less, of 10% or less, of 25% or less, or other suitable transparencies. Transparent portions53may have the same transparency as transparent portions52, or transparent portions53may have a different transparency from transparent portions52. Alternatively or additionally, the transparency of transparent portions53may vary across light modulator layer48, if desired. Similarly, opaque portions51may have the same transparency as opaque portions50, or opaque portions51may have a different transparency from opaque portions50. Alternatively or additionally, the transparency of opaque portions51may vary across light modulator layer48, if desired.

Each of portions53and51may be individually addressable portions (e.g., portions of light modulator layer48with adjustable transparency), or each of portions53and51may be formed from multiple pixels each having adjustable transparencies. In general, light modulator layer48may be patterned with portions having adjustable transparencies in any suitable manner.

In the arrangement ofFIG.5A, transparent portions52of light modulator layer46may be aligned (or nearly aligned) with transparent portions53of light modulator layer48, and opaque portions50of light modulator layer46may be aligned (or nearly aligned) with opaque portions51of light modulator layer48. Therefore, on-axis ambient light36may pass through transparent portions52and53and reach ambient light sensor32. In contrast, off-axis ambient light38may be at least partially blocked (e.g., absorbed and/or reflected) by opaque portions50and/or opaque portions51. In this way, angular-response controller49may increase the sensitivity of ambient light sensor32to on-axis ambient light36, while decreasing the sensitivity of ambient light sensor32to off-axis ambient light38.

InFIG.5A, transparent portions52and53may have widths W1, such as widths of 1/12 mm or less, of between 1/12 mm and 1/16 mm, of less than 1/16 mm, of between 0.75 mm and 1.25 mm, of less than 1.5 mm, or other suitable widths. However, this is merely illustrative. If desired, transparent portions52and53may have smaller widths. For example, as shown in illustrativeFIG.5B, transparent portions52and53may have widths W2, such as widths of 1/10 mm or less, of between 1/10 mm and 1/14 mm, of less than 1/14 mm, of less than 0.5 mm, of less than 0.3 mm, of between 0.25 mm and 0.75 mm, or other suitable widths. In other words, transparent portions52and53, as well as opaque portions50and51, may have increased densities. By having transparent portions52and53(and opaque portions50and51) with increased densities, ambient light sensor32may remain more sensitive to on-axis ambient light36than off-axis ambient light38, while making it more difficult for a user of device10to see ambient light sensor32through transparent portions52and53, as an example.

In some embodiments, light modulator layers46and48may have transparent portions52and53, respectively, with adjustable widths/densities. For example, each transparent portion52and53, as well as each opaque portion50and51, may be formed from multiple pixels with adjustable transparencies. In other words, each pixel may be adjusted between being transparent or opaque. In particular, control circuitry, such as control circuitry16of device10, may apply a voltage to each pixel of each light modulator layer and may therefore control the transparency of each pixel. By adjusting the number of pixels in each portion50,51,52, and53, the size of portions50-53(and therefore the densities of the opaque and transparent portions) may be adjusted. However, this is merely illustrative. In some embodiments, each transparent portion52and53, as well as each opaque portion50and51, may be formed from an individually adjustable region of the respective light modulator layer.

AlthoughFIGS.5A and5Bshow transparent portions52having the same widths as transparent portions53, and opaque portions50having the same widths as opaque portions51, this is merely illustrative. In general, any of portions50-53may have different widths and/or alignments to selectively allow light of different angles to pass through angular-response controller49.

InFIGS.5A and5B, angular-response controller49is adjusted to align (or nearly align) transparent portions52and53and to align (or nearly align) opaque portions50and51, and therefore allow more on-axis ambient light36to pass to ambient light sensor32than off-axis ambient light38(e.g., to at least partially block off-axis ambient light38). However, in some situations, it may be desirable to adjust angular-response controller49to allow more off-axis ambient light to pass to ambient light sensor32than on-axis ambient light. An illustrative example is shown inFIG.6.

As shown inFIG.6, light modulator layer46and/or light modulator layer48may be adjusted relative toFIG.5A(orFIG.5B). In particular, transparent portions52of light modulator layer46may be aligned (or nearly aligned) with opaque portions51of light modulator layer48, and opaque portions50of light modulator layer46may be aligned (or nearly aligned) with transparent portions53of light modulator layer48. In other words, transparent portions52may be offset from transparent portions53, and opaque portions50may be offset from opaque portions51. As a result, off-axis ambient light38may pass through transparent portions52and53and reach ambient light sensor32. In contrast, on-axis ambient light36may be at least partially blocked (e.g., absorbed and/or reflected) by opaque portions50and/or opaque portions51. In this way, angular-response controller49may increase the sensitivity of ambient light sensor32to off-axis ambient light38, while decreasing the sensitivity of ambient light sensor32to on-axis ambient light36.

To adjust the transparent and opaque regions of light modulator layer46and/or light modulator layer48, control circuitry, such as control circuitry16of device10, may apply a voltage to light modulator layer46and/or light modulator layer48. For example, the control circuitry may apply a voltage to each pixel (or adjustable portion) of light modulator layer46and/or light modulator layer48, and may therefore control the transparency of light modulator layer46and/or light modulator layer48. In this way, light modulator layer46and/or light modulator layer48may be adjusted between an arrangement in which the transparent portions overlap (e.g., as inFIGS.5A and5B) and an arrangement in which the transparent portions are offset (e.g., as inFIG.6), and the angular response of ambient light sensor32may be adjusted.

Although not shown inFIGS.5-6, the transparent portions and opaque portions may be adjusted to overlap or be offset by any suitable amount to selectively adjust the angular response of the ambient light sensor32. As an example, the transparent portions may be adjusted to be 50% offset to let in certain angles of ambient light between on-axis and off-axis ambient light. In general, the transparent and opaque portions may be adjusted to select for any suitable angle(s) of ambient light.

Additionally, althoughFIG.6shows transparent portions52having the same widths as and being completely aligned with opaque portions51, and opaque portions51having the same widths as and being completely aligned with transparent portions53, this is merely illustrative. In general, any of portions50-53may have different widths and/or alignments to selectively allow light of different angles to pass through angular-response controller49. In some embodiments, for example, transparent portions53may have smaller widths than transparent portions52to further control/tune the angle of light that reaches sensor32.

Top views of an illustrative angular-response controller passing on-axis ambient light and off-axis ambient light, respectively, are shown inFIGS.7A and7B. As shown inFIG.7A, angular-response controller49, when viewed from above, may have transparent regions52and opaque regions50. In particular, opaque regions50may be aligned with opaque regions of a lower light modulator layer. As a result, on-axis light may pass through transparent regions52, while off-axis light may be blocked by opaque regions50(and/or the opaque regions of the lower light modulator layer).

In contrast, as shown inFIG.7B, angular-response controller49, when viewed from above, may have opaque regions50and51visible. In particular, opaque regions51may be opaque regions of a lower light modulator layer, while opaque regions50may be opaque regions of an upper light modulator layer. As a result, on-axis light may be blocked by opaque regions50and51, while off-axis light may pass through at an angle between the upper and lower light modulator layers (e.g., as shown inFIG.6).

AlthoughFIGS.7A and7Bshow angular-response controller49having square regions for opaque portions50and51and transparent portions52, this is merely illustrative. In general, light modulator layers in angular-response controller49may have transparent and opaque regions with any suitable shapes, such as circular shapes, rectangular shapes, elliptical shapes, triangular shapes, trapezoidal shapes, or other shapes.

Moreover, although the light modulator layers inFIGS.7A and7Bhave been described as upper and lower light modulator layers, this is merely illustrative. In general, multiple light modulator layers may be oriented in any suitable direction relative to one another, and one or more of the light modulator layers may be adjusted to adjust the angular response of an ambient light measurement through the light modulator layers.

A flowchart of illustrative steps that may be used to adjust an angular-response controller for an ambient light sensor (e.g., angular-response controller49for ambient light sensor32) is shown inFIG.8.

As shown inFIG.8, flowchart54may begin with optional step56, at which one or more sensor measurements may be made. For example, a motion sensor (e.g., a gyroscope or an accelerometer) may be used to measure a movement of the electronic device (e.g., of the electronic device housing). Alternatively or additionally, an orientation sensor may measure an angle of the housing. However, these examples are merely illustrative. In general, any suitable sensor measurements may be made. Alternatively, step56may be omitted.

At step58, one or more light modulator layers may be adjusted. In particular, the light modulator layers may overlap an ambient light sensor in the electronic device. In some illustrative embodiments, the light modulator layers include two patterned light modulator layers. The patterned light modulator layers may be, as examples, patterned (and/or pixelated) liquid crystal or electrochromic light modulator layers, such as light modulator layers46and48ofFIGS.4-6.

To increase the sensitivity of the underlying ambient light sensor to on-axis light and to reduce the sensitivity of the ambient light sensor to off-axis light, the light modulator layers may be adjusted to have aligned (or nearly aligned) opaque and transparent portions (e.g., as shown inFIGS.5A and5B). Therefore, on-axis ambient light may pass through the aligned transparent portions, while off-axis light may be blocked by the opaque portions.

In contrast, to increase the sensitivity of the underlying ambient light sensor to off-axis light and to reduce the sensitivity of the ambient light sensor to on-axis light, the light modulator layers may be adjusted to have offset opaque portions (e.g., as shown inFIG.6). The offset opaque portions may block on-axis ambient light, while off-axis light may pass at an angle between the offset opaque portions.

AlthoughFIGS.5-6show completely aligned and completely offset opaque portions having the same widths to be selective for on-axis and off-axis light, respectively, these arrangements are merely illustrative. In general, the light modulator layers may be adjusted to have opaque portions that overlap by any suitable amount and to have any suitable widths to select for a desired amount of on-axis vs. off-axis ambient light. For example, the light modulator layers may be adjusted to adjust a field-of-view of the ambient light sensor to match the field-of-view of a nearby camera in the electronic device. In this way, the ambient light measured by the ambient light sensor may match the light received by the camera, and images produced by the camera may be adjusted based on the measured ambient light.

Alternatively or additionally, one or both of the light modulator layers may be adjusted to have a different densities of transparent and opaque portions (e.g., as shown in the difference between the arrangements ofFIGS.5A and5B). By adjusting the light modulator layer(s) to have opaque portions with different densities, the signal-to-noise ratio (SNR) of the underlying ambient light sensor may be adjusted. For example, by increasing the opaque portion density, the SNR of the ambient light sensor may be decreased, which may provide the sensor with a higher dynamic range, while decreasing the opaque portion density may increase the SNR and decrease the dynamic range. Increasing the opaque portion density may also reduce the visibility of the ambient light sensor to a user of the device.

To adjust the light modulator layers, control circuitry, such as control circuitry16ofFIG.1, may apply a voltage to the light modulator layers to adjust the pixels and/or patterned regions of the light modulator layers selectively. In this way, the transparency of each pixel and/or patterned region may be adjusted, and the two light modulator layers may be adjusted to allow more on-axis ambient light to pass than off-axis ambient light, and/or to adjust the SNR of the ambient light sensor.

The adjustment of the light modulator layers at step58may be done in response to sensor measurements, such as the sensor measurements from optional step56. For example, the light modulator layers may be adjusted in response to motion sensor measurements. In some embodiments, if the motion sensor measurements indicate that the housing is moving a small amount (or not moving), then the patterns of the light modulator layers may be adjusted over time to allow on-axis and off-axis light to reach the ambient light sensor selectively and to determine a light distribution profile of the ambient light based on the ambient light sensor measurements and the light modulator layer adjustments. In contrast, if the motion sensor measurements indicate that the housing is moving a large amount (e.g., swinging as the user walks with the phone in their hand), then the light modulator layers may be turned off (e.g., made fully transparent) or nearly turned off to increase the SNR of the ambient light sensor. In particular, when the housing is moving a large amount, the sensor may receive both on-axis and off-axis light from different angles (e.g., the angles may change as the housing is moving), and a light distribution profile may be determined without filtering out on-axis or off-axis light based on the ambient light measurements and the movement of the housing.

Alternatively or additionally, the light modulator layers may be adjusted in response to orientation sensor measurements. In some embodiments, if the housing is held in a portrait orientation, the light modulator layers may be adjusted to allow less off-axis light than when the housing is held in a landscape orientation. In particular, because a user's eyes cover a wider field of view (FOV) of approximately 90° when the housing is in a landscape orientation than when the housing is in a portrait orientation (FOV of approximately 45°), it may be desirable to adjust the light modulator layers to capture more off-axis light that the user will also see when the housing is in the landscape mode. In other words, the light modulator layers may be adjusted between forming a first field of view for the ambient light sensor (e.g., a smaller field of view when the housing is in the portrait orientation) and forming a second field of view (e.g., a larger field of view when the housing is in the landscape orientation) for the ambient light sensor based on the orientation of the housing. However, this is merely illustrative. In general, the light modulator layers may be adjusted in any suitable manner based on measurements from an orientation sensor.

As another example, the light modulator layers may be adjusted to change color. For example, the light modulator layers may be electrochromic layers or other layers with adjustable color. In some embodiments, in response to a color ambient light sensor measurement of the color of ambient light, the color of one or both of the opaque portions of the light modulator layers may be adjusted. As a result, the opaque portions may block desired wavelengths of light selectively, which may adjust the SNR of the underlying ambient light sensor.

Another illustrative adjustment that may be made to the light modulator layers, with or without additional sensor input, is when the user holds the device near their face or head, which may be detected using measurements from one or more motion sensors, orientation sensors, and/or ambient light sensors in the device. In these situations, the light modulator layers may be adjusted to block ambient light that is reflected from the user's face or head, while allowing ambient light from other angles to pass through to the ambient light sensor. In this way, reflections from the face/head may be excluded from the ambient light sensor measurements.

These light modulator adjustments in response to sensor measurements are merely illustrative. In general, sensors in the electronic device may be used to measure any suitable environmental or internal characteristic, and the light modulator layers may be adjusted to adjust the angular response of the underlying ambient light sensor based on the measured characteristic(s).

At step60, the ambient light sensor may be used to produce measurements in response to ambient light. For example, the ambient light sensor may be (or may include) a photodiode or other light-sensitive component that generates charge in response to ambient light. Because of the adjustments to the light modulator layers overlapping the ambient light sensor, the measurements may include more on-axis or off-axis ambient light.

Although step58is shown as occurring before step60, this is merely illustrative. In some embodiments, the light modulator layers may be adjusted while the ambient light sensor is measuring ambient light. Doing so may allow for the ambient light sensor to measure ambient light from different angles during one measurement (e.g., integration of the ambient light sensor). In some illustrative embodiments, the light modulator layers may be adjusted to scan through all ambient light angles (with the exception of directly on-axis ambient light, if desired) during a single integration of the ambient light sensor. This may allow for a light distribution profile to be determined based on the ambient light measurements and the corresponding light modulator layer adjustments made during the integration time. In this way, the ambient light sensor may have spherical or near-spherical sensitivity without moving the electronic device.

In some embodiments, the light modulator layers may be adjusted between capturing wide fields of view (e.g., having high angular responses) and narrow fields of view (e.g., having low angular responses), and the total field of view (e.g., the angular response of the measurement) may be adjusted post-processing. For example, ambient light sensor32may make one or more measurements with a high angular response (e.g., as shown inFIG.6) and with a low angular response (e.g., as shown inFIG.5). After these measurements have been made, control circuitry in device10may calculate and/or adjust an overall angular response of the ambient light measurement based on the high angular response measurements and the low angular response measurements. In other words, the directionality of the ambient light may be determined by varying the angular response during ambient light measurements.

In an illustrative example, multiple measurements may be made with different angular responses (e.g., different directions) to estimate an ambient ultraviolet (UV) index in the environment around device10. If large differences are measured at various narrow angular responses, the sky may be estimated as clear. If small differences are measured at various narrow angular responses, may be estimated to be cloudy. Wide angular responses may also be used to provide additional illumination information, such as the ambient brightness. Additionally or alternatively, light lower than a horizon line may be cut off, which is unnecessary to estimate UV index and may provide undesirable noise. Based on the narrow angular response measurements and/or the wide angular response measurements, a UV index in the environment around device10may be estimated by an ambient light sensor in device10.

In some embodiments, adjusting the angular response of an ambient light sensor may be used to estimate a display brightness and white point. For example, the ambient light sensor may be operated with a narrow angular response (e.g., as shown inFIG.5) to estimate a brightness and white point of a display and with a wide angular response (e.g., as shown inFIG.6) to estimate a brightness and color of ambient light as a whole (which may include the brightness and white point of the display and the brightness and white point of other ambient light). These two measured brightnesses and white points may be compared to estimate the brightness and white point of the display. In these embodiments, the ambient light sensor may be co-located with the display (e.g., at the front and/or back of device10) or otherwise may be oriented to detect light from the display and other ambient light.

In some embodiments, adjusting the angular response of an ambient light sensor may be used to estimate the spectral information of a camera. For example, the ambient light sensor may be co-located with (e.g., adjacent to) the camera. The angular response of the ambient light sensor may be adjusted to match the angular response of the camera. When an image is generated, the spectral information may be determined based on the ambient light sensor measurement, and color reproduction may be improved. Alternatively or additionally, the angular response of the ambient light sensor may be adjusted to be wider than the angular response of the camera. When an image is generated, the white point may be estimated based on the ambient light measurement, and the white point may be used to adjust the final image generated by the camera.

As described above, one aspect of the present technology is the gathering and use of information such as sensor information. The present disclosure contemplates that in some instances, data may be gathered that includes personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, twitter ID's, home addresses, data or records relating to a user's health or level of fitness (e.g., vital signs measurements, medication information, exercise information), date of birth, username, password, biometric information, or any other identifying or personal information.

Therefore, although the present disclosure broadly covers use of information that may include personal information data to implement one or more various disclosed embodiments, the present disclosure also contemplates that the various embodiments can also be implemented without the need for accessing personal information data. That is, the various embodiments of the present technology are not rendered inoperable due to the lack of all or a portion of such personal information data.