Lens holder to compensate for optical focal shift by thermo-mechanical expansion

A camera module includes a lens assembly, a lens holder, and an image sensor assembly. The lens assembly includes a lens barrel and multiple lens elements embedded within the lens barrel. A change of temperature causes an optical focal shift that is determined according to an optical thermal shift rate associated with an optical design of the lens assembly. The lens holder has a lens holder CTE to compensate for the optical focal shift by thermo-mechanical expansion. The change of temperature causes a length expansion of the lens holder determined at least in part according to the lens holder CTE. The image sensor assembly includes an image sensor and a substrate coupled to the image sensor, the image sensor to capture light passing through the multiple lens elements and convert the captured light into image signals. The lens holder is attached to the lens barrel and the substrate using adhesives.

BACKGROUND

Technical Field

This disclosure relates generally to a lens holder for a lens assembly and more particularly to a lens holder to compensate for optical focal shift by thermos-mechanical expansion.

Description of the Related Art

The advent of small, mobile multipurpose devices such as smartphones and tablet or pad devices has resulted in a need for high-resolution, small form factor cameras for integration in the devices. A temperature change may result in thermal expansion/contraction, resulting in an optics focus shift. Some small form factor cameras may incorporate optical image stabilization (OIS) mechanisms including actuators to compensate for optics focus shift over temperature. Such OIS mechanisms may increase design complexity, manufacturing difficulty, cost, and reliability risk.

SUMMARY OF EMBODIMENTS

Some embodiments provide a camera module that includes a lens assembly, a lens holder, and an image sensor assembly. The lens assembly has a particular optical design and includes at least a lens barrel and multiple lens elements embedded within the lens barrel. A change of temperature causes an optical focal shift that is determined according to a particular optical thermal shift rate associated with the particular optical design. The lens holder has a lens holder coefficient of thermal expansion (CTE) to compensate for the optical focal shift by thermo-mechanical expansion. The change of temperature causes a length expansion of the lens holder that is determined at least in part according to the lens holder CTE. The image sensor assembly includes at least an image sensor and a substrate coupled to the image sensor. The image sensor is configured to capture light passing through the multiple lens elements of the lens assembly and to convert the captured light into image signals. A first area of the lens holder is attached to the lens barrel of the lens assembly using a lens attach adhesive, and a second area of the lens holder is attached to the substrate of the image sensor assembly using a holder attach adhesive.

Some embodiments provide a mobile device that includes a camera module, a display, and one or more processors. The camera module of the mobile device includes a lens assembly, a lens holder, and an image sensor assembly. The lens assembly has a particular optical design and includes at least a lens barrel and multiple lens elements embedded within the lens barrel. A change of temperature causes an optical focal shift that is determined according to a particular optical thermal shift rate associated with the particular optical design. The lens holder has a lens holder CTE to compensate for the optical focal shift by thermo-mechanical expansion. The change of temperature causes a length expansion of the lens holder that is determined at least in part according to the lens holder CTE. The image sensor assembly of the mobile device includes at least an image sensor and a substrate coupled to the image sensor. The image sensor is configured to capture light passing through the multiple lens elements of the lens assembly of the mobile device and to convert the captured light into image signals. A first area of the lens holder is attached to the lens barrel of the lens assembly using a lens attach adhesive, and a second area of the lens holder is attached to the substrate of the image sensor assembly using a holder attach adhesive. The one or more processors of the mobile device are configured to cause the display of the mobile device to present an image based at least in part on one or more of the image signals from the image sensor of the camera module.

Some embodiments provide an article of manufacture that includes a lens assembly and a lens holder. The lens assembly has a particular optical design and includes at least a lens barrel and multiple lens elements embedded within the lens barrel. A change of temperature causes an optical focal shift that is determined according to a particular optical thermal shift rate associated with the particular optical design. The lens holder has a lens holder CTE to compensate for the optical focal shift by thermo-mechanical expansion. A first area of the lens holder is attached to the lens barrel of the lens assembly using a lens attach adhesive, and the change of temperature causes a length expansion of the lens holder that is determined at least in part according to the lens holder CTE.

DETAILED DESCRIPTION

Introduction

The present disclosure describes a design for a camera, such as a fixed focus rear camera for a mobile device, whereby the mechanical design is developed around an image sensor and optics to provide “athermalization.” In other words, the function of the mechanical design of the package is to compensate for the focal shift of the optics over temperature. The mechanical design, including aspects such as architecture, geometry and material properties, are described further herein. The mechanical design corresponds to a two-body design in which a lens holder has a coefficient of thermal expansion (CTE) designed to thermo-mechanically compensate for an optics focus shift over temperature associated with a particular optical design by thermal expansion.

In contrast to other fixed focus assembly concepts such as threaded lens design or a unibody design, the two-body design of the present disclosure may provide several design advantages. To illustrate, the mechanical design of the present disclosure is a threadless design. Compared to a threaded design, the mechanical design of the present disclosure reduces the impact of torque onto optics reliability. Further, the threadless design avoids “fit” issues due to circularity of lens housing (non-symmetrical) and adds flexibility in the location of the attachment method. Compared to a unibody design, the two-body design of the present disclosure has a separate housing design from lens barrel/optics development. Further, the two-body design decouples functions, with the high CTE lens holder material not limited by lens barrel material requirements.

FIG.1Aillustrates a mobile computing device100with a camera module102, a sensor104, and a light source module106.FIG.1Afurther illustrates a cross-sectional view of detail of the camera module102of the mobile computing device100.FIG.1Adepicts a simplified view of a lens assembly101of the camera module102. In some embodiments, the lens assembly101has a particular optical design that includes at least a lens barrel and multiple lens elements embedded within the lens barrel.FIG.1Bdepicts a detailed view of a particular embodiment of such an optical design, in which the lens assembly101includes a lens barrel102and multiple lens elements103embedded within the lens barrel102. As described further herein, a change in temperature causes an optical focal shift (depicted as a downward arrow labeled “Optics Thermal Focus Shift” inFIGS.1A and1B) that is determined according to a particular optical thermal shift rate associated with the particular optical design (see e.g.FIG.3for the particular optical design depicted inFIG.1B).FIG.1Afurther illustrates that the camera module102also includes a lens holder106having a lens holder CTE to compensate for the optical focal shift by thermo-mechanical expansion (depicted as an upward arrow labeled “Thermo-Mechanical Compensation” inFIGS.1A and1B). The change in temperature causes a length expansion of the lens holder106that is determined at least in part according to the lens holder CTE. As described further herein, the lens holder106is designed to have material properties such that the thermo-mechanical expansion of the lens holder106sufficiently compensates for the optical focal shift to satisfy an image quality metric. To illustrate, the thermo-mechanical expansion of the lens holder106may be sufficient to prevent a loss in image sharpness that may appear visible to a user (also referred to as a “just noticeable” defect).

The detailed cross-sectional view ofFIG.1Aillustrates that the camera module102of the mobile computing device100also includes an image sensor assembly113. The image sensor assembly113includes an image sensor114that is configured to capture light passing through the lens assembly101and to convert the captured light into image signals. The image sensor assembly113includes a substrate110that is coupled to the image sensor114. InFIG.1A, a “rear” side of the mobile device100is illustrated to show that the camera module102may be a fixed focus rear camera. While not shown inFIG.1A, the mobile device100may include a display on a “front” side. Further, the mobile device100ofFIG.1Amay include one or more processors configured to cause the display (on the front side) to present an image based at least in part on one or more of the image signals from the image sensor114.

A first area of the lens holder106may be attached to the lens assembly101using a lens attach adhesive104, and a second area of the lens holder106may be attached to the substrate110using a holder attach adhesive108. As described further herein, both the lens attach adhesive104and the holder attach adhesive108may be selected to form bonds to the lens holder106that are reliable under thermal stress. To illustrate, the lens holder CTE may be relatively high compared to a lens barrel material and/or a substrate material, representing a CTE mismatch. Improper selection of adhesive may result in delamination over thermal stress (i.e. temperature cycling). Accordingly, the lens attach adhesive104may be selected such that the adhesive properties achieve a reliable bond between the lens holder106and the lens barrel102, and the holder attach adhesive108may be selected such that the adhesive properties achieve a reliable bond between the lens holder106and the substrate110.

In some embodiments, the lens attach adhesive104may correspond to an epoxy resin available from Dexerials or Namics having the following material properties: a CTE value within a range of 70 to 100 ppm/° C.; and an elastic modulus value in a range of 2500 to 3000 mPa. In some embodiments, the holder attach adhesive104may correspond to an epoxy resin available from Namics or Henkel having the following material properties: a CTE value within a range of 150 to 180 ppm/° C.; and an elastic modulus value in a range of 300 to 800 mPa.

The detailed cross-sectional view ofFIG.1Afurther illustrates that, in some embodiments, the camera module102may include a filter116, such as an infrared component filter (IRCF). The filter116may be located below the lens assembly101in some embodiments. As such, in some instances, light may pass through one or more lenses of the lens assembly101, then through the filter116, and to the image sensor114. According to some embodiments, there may be a gap portion between the filter116and the image sensor114. In some embodiments, the gap portion may comprise air, or other gasses, such as nitrogen, helium, hydrogen, etc. In some embodiments, a gap portion may be a vacuum layer.

The detailed cross-sectional view ofFIG.1Afurther illustrates that a gap115between the lens assembly101and the lens holder106. The gap115is sufficient to allow for thermo-mechanical expansion of the lens holder106without impacting the lens assembly101via contact during thermal cycling. The detailed cross-sectional view ofFIG.1Afurther illustrates that the image sensor assembly113may include a stiffener118for protection of internal components of the image sensor assembly113, including e.g. a flexible printed circuit (FPC)112to receive image signals from the image sensor114.

FIG.1Aillustrates that, in some embodiments, the lens holder106may include one or more lens barrel ledges119for positioning of the lens assembly101within the lens holder106, as illustrated and further described herein with respect toFIGS.4,5and7A. A camera active alignment process ensures that, at room temperature, the lens focus is aligned at the top of image sensor114for maximum image quality (illustrated by an optical axis120inFIG.1A). As the temperature of the lens assembly101changes (with respect to room temperature), the position of optical focus shifts, either towards or away from the mean position. This results in degraded image quality. In the camera module102of the present disclosure, focal repositioning is achieved by “athermalization,” where the lens holder106expands thermally to re-adjust the lens-to-sensor distance and restore image quality. In order to achieve satisfactory athermalization, a resin material utilized to form the lens holder106may be carefully selected for a desired thermal compensation. The resin material is selected such that a thermo-mechanical compensation rate of the lens holder106is similar to an optics thermal defocus rate associated with the lens assembly101. Relatively similar rates reduce the potential over/under compensation associated with rate differences.

Referring toFIG.1B, a detailed cross-sectional view illustrates a particular embodiment of an optical design, in which the lens assembly101includes a lens barrel102and multiple lens elements103embedded within the lens barrel102. For a particular optical design for the lens assembly101, the present disclosure may include simulating a defocus rate based on thermal characteristics and using this defocus rate as a target thermal expansion rate for the lens holder106to compensate for this defocus rate.

In some embodiments, the optical thermal shift rate for the lens assembly101may be within a range of 0.5 μm/° C. to 1.0 μm/° C. In this case, the compensation rate is targeted to cancel the optical focus shift. To illustrate, an increase in temperature causes thermal expansion of the lens holder106along a characteristic dimension of the lens holder106defined with respect to the optical axis120(also referred to herein as a “length” of the lens holder106). The increase in temperature also causes thermal expansion of the lens attach adhesive104as well as the holder attach adhesive108. As such, a “total” thermal expansion rate may vary based on a particular combination of CTE of the lens holder106(the “lens holder CTE”), CTE of the lens attach adhesive104, and CTE of the holder attach adhesive108.

In some embodiments, the lens holder CTE may be within a range of 100 parts-per-million (ppm)/° C. to 140 ppm/° C., and the lens holder106may have a water absorption property of less than 0.2 percent to provide satisfactory dimensional stability of the lens holder106over moisture. In some cases, the lens holder106may be a polybutylene terephthalate (PBT) material. Alternatively, the lens holder106may be an alloy of a polycarbonate (PC) material and a PBT material. It will be appreciated that alternative plastic materials satisfying particular performance criteria may also be utilized for the lens holder106.

In some embodiments (e.g., when the lens holder106is a PBT material), the lens holder CTE may be within a range of 100 parts-per-million (ppm)/° C. to 140 ppm/° C., and the lens barrel102may be a PC material having a lens barrel CTE of about 70 ppm/° C. In this example, the lens attach adhesive104may correspond to an epoxy resin available from Dexerials or Namics having the following material properties: a CTE value within a range of 70 to 100 ppm/° C.; and an elastic modulus value in a range of 2500 to 3000 mPa.

In some embodiments (e.g., when the lens holder106is a PBT material), the lens holder CTE may be within a range of 100 parts-per-million (ppm)/° C. to 140 ppm/° C., and the substrate110may be an alumina ceramic material having a substrate CTE of about 7 ppm/° C. In this example, the holder attach adhesive104may correspond to an epoxy resin available from Namics or Henkel having the following material properties: a CTE value within a range of 150 to 180 ppm/° C.; and an elastic modulus value in a range of 300 to 800 mPa.

Thus,FIGS.1A and1Billustrate an example of a lens holder to compensate for an optical focal shift by thermo-mechanical expansion. As described further herein with respect toFIGS.6A-6B, the lens holder depicted inFIGS.1A-1Bmay be manufactured using an injection molding process that utilizes an injection mold with a symmetrical arrangement of multiple injection molding gates (e.g., four gates, with one gate for each side). The symmetrical arrangement is designed to provide substantially similar resin flow through each of the gates for substantially isotropic material properties throughout the lens holder.

FIG.2illustrates a cross-sectional view of the lens assembly101, illustrating various changes of length resulting from thermal expansion/contraction due to temperature change.

Thermal expansion may be described by the thermal expansion equation below:

In the thermal expansion equation above, L0is an initial length (e.g., a length at room temperature, such as during the component active assembly process); ΔL is the length change; α is the coefficient of thermal expansion (CTE) for the particular material; and ΔT is the temperature range.

InFIG.2, multiple length values are illustrated to show different components of a total length change for thermo-mechanical compensation of the optics thermal focal shift depicted inFIGS.1A and1B. InFIG.2, a first length value (identified as “L1”)202is designed to illustrate a length component associated with the lens attach adhesive104; a second length value (identified as “L2”) is designed to illustrate a length component associated with the lens holder106; and a third length value (identified as “L3”) is designed to illustrate a length component associated with the holder attach adhesive108. As described further herein, a thermo-mechanical compensation rate resulting from the total length of expansion (including each of the length components202,204, and206) is targeted to cancel an optical focus shift for a particular sensor/optics configuration. It will be appreciated that the second length component204may represent the most substantial component, thereby providing the largest contribution to the thermo-mechanical expansion.

With respect to image quality for user impact, studies around “just noticeable” defect (JND) metrics suggest that a defocus rate of about 0.1-0.2 μm/° C. may appear visible to a user. In other words, defocus of about 3-6 μm over a 30° C. temperature range causes sufficient loss in image sharpness to be noticeable by the user. In some embodiments, an optical shift rate associated with a particular sensor/optics configuration (e.g., the design depicted inFIGS.1A and1B) may be within a range between 0.5 μm/° C. and 1.0 μm/° C. A determination of the optical shift rate is described further herein with respect to the example depicted inFIG.3. An illustrative, non-limiting example of an optical shift rate within this range is 0.63 μm/° C. for a temperature range of 10° C. to 70° C. In this case, the lens holder106may have a CTE value within a range between 100 ppm/° C. and 140 ppm/° C. to satisfy an image quality performance metric, such as a JND metric of about 0.1-0.2 μm/° C.

As a first example, the lens holder106may be formed from a first polybutylene terephthalate (PBT) material, and the lens holder106has a first CTE value of 110 ppm/° C. An example of such a PBT material may be Crastin™ from Dupont. In this case, the expansion rate of the lens holder106may be 0.610 μm/° C., representing a total defocus rate of 0.020 μm/° C. when compared to an optical shift rate of 0.63 μm/° C. This total defocus rate would satisfy the JND metric of about 0.1-0.2 μm/° C. for image quality.

As a second example, the lens holder106may be formed from a second PBT material, and the lens holder106has a second CTE value of 120 ppm/° C. An example of such a PBT material may be Novoduran™ from Mitsubishi. In this case, the expansion rate of the lens holder106may be 0.698 μm/° C., representing a total defocus rate of −0.068 μm/° C. when compared to an optical shift rate of 0.63 μm/° C. This total defocus rate would also satisfy the JND metric of about 0.1-0.2 μm/° C. for image quality.

As a third example, the lens holder106may be formed from a mixture of a polycarbonate (PC) material and a PBT material (also referred to herein as a “PC/PBT” material or a PC/PBT alloy), and the lens holder106has a third CTE value of 100 ppm/° C. An example of such a PC/PBT material may be Duranex™ from Polyplastics. In this case, the expansion rate of the lens holder106may be 0.550 μm/° C., representing a total defocus rate of 0.080 μm/° C. when compared to an optical shift rate of 0.63 μm/° C. This total defocus rate would also satisfy the JND metric of about 0.1-0.2 μm/° C. for image quality.

It will be appreciated that the above examples are for illustrative purposes only and are not intended to limit the scope of the claimed invention. Rather, the examples serve to illustrate that selecting a lens holder material with a particular CTE value may result in the thermo-mechanical expansion rate substantially offsetting the optical focus shift, such that a total defocus rate may satisfy an image quality performance metric such as the JND metric described herein.

FIG.3illustrates a side view of the particular optical design for the lens assembly101depicted inFIG.1B(including the multiple lens elements103within the lens barrel102) to show an example of such an optical focus shift.

Optical shift over temperature is caused by three factors. The first factor is the change in the index of refraction over temperature. As the index of refraction changes, so too does the power of the lens which causes a change in focal length regardless of any mechanical changes. This is the dominant reason that the optical focus shifts. The second factor is the change in the surface figure (the physical shape of the lens) which also changes the focal length of the lens. The third factor is that any change in the mechanical length of the component that will shift the focus position.

A change in focal length (Δf), as depicted inFIG.3, may be described by Equation (I) below:
Δf=βfΔT(I)

In Equation(I), f is the focal length, and ΔT is the change in temperature from nominal. In Equation(I), β may be described by Equation (II) below:

In Equation(II), α is the material CTE; n(λ) is the index of refraction at the design wavelength; and

d⁢nr⁢e⁢ld⁢T
is the change in the relative index of refraction over temperature.

As the focus changes with respect to temperature, it can be described as a rate of change by examining the change in focus over the change in temperature. This change can be approximated by the first order equation corresponding to Equation(III) below:

This rate of change is referred to herein as “an optical shift rate over temperature” or simply “an optical shift rate.”

FIG.4is a cross-sectional perspective view of the camera module102ofFIG.1A, illustrating the lens holder106bonded to the image sensor assembly113and the lens barrel102.FIG.5is a perspective view of the lens holder106prior to the lens holder106being bonded to the image sensor assembly113and the lens barrel102, as shown inFIG.4. The perspective view depicted inFIG.5shows that the lens holder106may have multiple lens barrel ledges502a-nto receive corresponding portions of the lens barrel102. In the perspective view ofFIG.5, a first lens barrel ledge502aand a second lens barrel ledge502bare visible, with two other lens barrel ledges obscured from view. As illustrated and further described herein with respect toFIGS.6A and6B, the first lens barrel ledge502amay align with a first injection mold gate location of an injection mold used to form the lens holder106, and the second lens barrel ledge502bmay align with a second injection mold gate location of the injection mold.

FIGS.6A and6Billustrate a four gate design for injection molding to form the lens holder106depicted inFIG.5.FIG.6Ais a top view of the injection mold, illustrating four injection mold gate locations602a-darranged symmetrically with respect to a symmetry axis604.FIG.6Bis a side view of the injection mold, illustrating a side dimension of a first side610aof the inject mold corresponding to a first injection mold gate location602aof the four injection mold gate locations602a-ddepicted in the top view ofFIG.6A. In an illustrative, non-limiting example of a lens holder designed to accommodate a particular optical design (such as the lens assembly101depicted inFIGS.1A and1B), the side dimension of the first side610amay be 9.4 mm, and each side of the injection mold may have a substantially similar side dimension of 9.4 mm. In this example, each of the injection mold gate locations602a-dmay be centered on an axis located at the midpoint of the side dimension (i.e., at 4.7 mm along a 9.4 mm side dimension).

The symmetrical arrangement of the injection mold gate locations602a-dis designed to provide substantially equal flow of resin into the injection mold to provide symmetrical material properties for the lens holder106. Such symmetrical material properties are designed to provide stable/symmetric thermal expansion of the lens holder106to ensure substantially equal Z offset of the optics (to be housed within the lens holder106, such as the lens assembly101depicted inFIGS.1A and1B) to prevent a tilt that would cause loss of sharpness towards the edge of the field (blurry corners).

Thus, the four gate design depicted inFIGS.6A and6Brepresents an example of a process of forming a substantially isotropic plastic lens holder via injection molding. It will be appreciated that alternative injection mold designs may also provide substantially symmetrical material properties for the lens holder, thereby preventing tilt of the optics during temperature cycling.

FIG.7Ais a perspective view of the lens holder106ofFIG.5, which may be formed according to the injection molding process described with respect toFIGS.6A and6B.FIG.7Aillustrates the addition of the lens attach adhesive104to a first area of the lens holder106. In some embodiments, the lens attach adhesive104may be used to bond the lens barrel102of the lens assembly101to the lens holder106during a camera active alignment assembly process. In some embodiments, during the camera active alignment assembly process, corresponding features of the lens barrel102may be aligned with the lens barrel ledges (with two of the ledges502aand502bshown inFIG.7A) for proper positioning of the lens barrel102within the lens holder106, as shown in the cross-sectional perspective view depicted inFIG.4.

FIG.7Bis an inverted perspective view of the lens holder106ofFIG.5, illustrating the addition of the holder attach adhesive108to a second area of the lens holder106. In some embodiments, the holder attach adhesive104may be used to bond the substrate110of the image sensor assembly113to the lens holder106during a camera active alignment assembly process.

Multifunction Device Examples

The various applications that may be executed on the device may use one or more common physical user-interface devices, such as the touch-sensitive surface. One or more functions of the touch-sensitive surface as well as corresponding information displayed on the device may be adjusted and/or varied from one application to the next and/or within a respective application. In this way, a common physical architecture (such as the touch-sensitive surface) of the device may support the variety of applications with user interfaces that are intuitive and transparent to the user.

FIG.8A-8Cillustrate a mobile device800that may include one or more camera modules, in accordance with some embodiments. In some embodiments, the device800may include one or multiple features, components, and/or functionality of embodiments described herein with respect toFIGS.1A-1B and9.

In some embodiments of the present disclosure, the device800ofFIGS.8A-8Cmay correspond to a mobile device that may be utilized to perform various methods described further herein, such as the mobile device100depicted inFIG.1A. For example, the camera module870of the device800depicted inFIG.8Bmay correspond to the camera module102of the mobile device100depicted inFIG.1A. As another example, the sensor864of the device800depicted inFIG.8Bmay correspond to the sensor104of the mobile device100depicted inFIG.1A. As yet another example, the light source module875of the device800depicted inFIG.8Bmay correspond to the light source module106depicted inFIG.1A.

FIG.8Aillustrates that a “front” side of the device800may have a touch screen812. The touch screen812may display one or more graphics within user interface (UI)800. In this embodiment, as well as others described below, a user may select one or more of the graphics by making a gesture on the graphics, for example, with one or more fingers801(not drawn to scale in the figure) or one or more styluses807(not drawn to scale in the figure).

Device800may also include one or more physical buttons, such as “home” or menu button815, which may be used to navigate to any application836(seeFIG.8C) in a set of applications that may be executed on device800. Alternatively, in some embodiments, the menu button is implemented as a soft key in a graphics user interface (GUI) displayed on touch screen812.

In one embodiment, device800includes touch screen812, menu button815, push button805for powering the device on/off and locking the device, volume adjustment button(s)809, Subscriber Identity Module (SIM) card slot810, head set jack814, and docking/charging external port824. Push button805may be used to turn the power on/off on the device by depressing the button and holding the button in the depressed state for a predefined time interval; to lock the device by depressing the button and releasing the button before the predefined time interval has elapsed; and/or to unlock the device or initiate an unlock process. In an alternative embodiment, device800also may accept verbal input for activation or deactivation of some functions through microphone813.

FIG.8Billustrates that a “rear” side of the device800may include a camera870, in accordance with some embodiments. The camera870, which is sometimes called an “optical sensor” for convenience, may also be known as or called an optical sensor system. The camera870includes one or more camera modules, including at least one of the camera modules described herein.FIG.8Bfurther illustrates sensor864and light source module875. In some embodiments of the present disclosure, the camera870of the device800depicted inFIG.8Bincludes a fixed focus rear camera that may include the camera module102of the mobile device100depicted inFIG.1A. In some embodiments, the sensor864of device800may correspond to the sensor104depicted inFIG.1A, and the light source module875of device800may correspond to the light source module106depicted inFIG.1A.

According to some embodiments of the present disclosure, a camera module of the camera870may include a lens assembly, a lens holder, and an image sensor assembly. The lens assembly has a particular optical design and includes at least a lens barrel and multiple lens elements embedded within the lens barrel. A change of temperature causes an optical focal shift that is determined according to a particular optical thermal shift rate associated with the particular optical design. The lens holder has a lens holder CTE to compensate for the optical focal shift by thermo-mechanical expansion. The change of temperature causes a length expansion of the lens holder that is determined at least in part according to the lens holder CTE. The image sensor assembly includes at least an image sensor and a substrate coupled to the image sensor. The image sensor is configured to capture light passing through the multiple lens elements of the lens assembly and to convert the captured light into image signals. A first area of the lens holder is attached to the lens barrel of the lens assembly using a lens attach adhesive, and a second area of the lens holder is attached to the substrate of the image sensor assembly using a holder attach adhesive.

Referring toFIG.8C, a block diagram illustrates that device800may include memory802(which may include one or more computer readable storage mediums), memory controller822, one or more processing units (CPU's)820, peripherals interface818, RF circuitry808, audio circuitry810, speaker811, touch-sensitive display system812, microphone813, input/output (I/O) subsystem806, other input control devices816, and external port824. Device800may include one or more optical sensors864. These components may communicate over one or more communication buses or signal lines803.

It should be appreciated that device800is only one example of a portable multifunction device, and that device800may have more or fewer components than shown, may combine two or more components, or may have a different configuration or arrangement of the components. The various components shown inFIG.8Cmay be implemented in hardware, software, or a combination of hardware and software, including one or more signal processing and/or application specific integrated circuits.

Memory802may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state memory devices. Access to memory802by other components of device800, such as CPU820and the peripherals interface818, may be controlled by memory controller822.

Peripherals interface818can be used to couple input and output peripherals of the device to CPU820and memory802. The one or more processors820run or execute various software programs and/or sets of instructions stored in memory802to perform various functions for device800and to process data.

In some embodiments, peripherals interface818, CPU820, and memory controller822may be implemented on a single chip, such as chip804. In some other embodiments, they may be implemented on separate chips.

Audio circuitry810, speaker811, and microphone813provide an audio interface between a user and device800. Audio circuitry810receives audio data from peripherals interface818, converts the audio data to an electrical signal, and transmits the electrical signal to speaker811. Speaker811converts the electrical signal to human-audible sound waves. Audio circuitry810also receives electrical signals converted by microphone813from sound waves. Audio circuitry810converts the electrical signal to audio data and transmits the audio data to peripherals interface818for processing. Audio data may be retrieved from and/or transmitted to memory102and/or RF circuitry808by peripherals interface818. In some embodiments, audio circuitry810also includes a headset jack (e.g.,814,FIGS.8A-B). The headset jack provides an interface between audio circuitry810and removable audio input/output peripherals, such as output-only headphones or a headset with both output (e.g., a headphone for one or both ears) and input (e.g., a microphone).

I/O subsystem806couples input/output peripherals on device800, such as touch screen812and other input control devices816, to peripherals interface818. I/O subsystem806may include display controller856and one or more input controllers860for other input or control devices. The one or more input controllers816receive/send electrical signals from/to other input or control devices816. The other input control devices816may include physical buttons (e.g., push buttons, rocker buttons, etc.), dials, slider switches, joysticks, click wheels, and so forth. In some alternative embodiments, input controller(s)860may be coupled to any (or none) of the following: a keyboard, infrared port, USB port, and a pointer device such as a mouse. The one or more buttons (e.g.,809,FIGS.8A-8B) may include an up/down button for volume control of speaker811and/or microphone813. The one or more buttons may include a push button (e.g.,806,FIGS.8A-B).

Touch-sensitive display812provides an input interface and an output interface between the device and a user. Display controller856receives and/or sends electrical signals from/to touch screen812. Touch screen812displays visual output to the user. The visual output may include graphics, text, icons, video, and any combination thereof (collectively termed “graphics”). In some embodiments, some or all of the visual output may correspond to user-interface objects.

Touch screen812has a touch-sensitive surface, sensor or set of sensors that accepts input from the user based on haptic and/or tactile contact. Touch screen812and display controller856(along with any associated modules and/or sets of instructions in memory802) detect contact (and any movement or breaking of the contact) on touch screen812and converts the detected contact into interaction with user-interface objects (e.g., one or more soft keys, icons, web pages or images) that are displayed on touch screen812. In an example embodiment, a point of contact between touch screen812and the user corresponds to a finger of the user.

In some embodiments, in addition to the touch screen, device800may include a touchpad (not shown) for activating or deactivating particular functions. In some embodiments, the touchpad is a touch-sensitive area of the device that, unlike the touch screen, does not display visual output. The touchpad may be a touch-sensitive surface that is separate from touch screen812or an extension of the touch-sensitive surface formed by the touch screen.

Device800also includes power system862for powering the various components. Power system862may include a power management system, one or more power sources (e.g., battery, alternating current (AC)), a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator (e.g., a light-emitting diode (LED)) and any other components associated with the generation, management and distribution of power in portable devices.

Device800may also include one or more optical sensors864and one or more cameras870.FIG.8Cshows an optical sensor coupled to optical sensor controller858in I/O subsystem806. Optical sensor864may include charge-coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) phototransistors. Optical sensor864receives light from the environment, projected through one or more lens, and converts the light to data representing an image. In conjunction with camera(s)870, optical sensor864may capture still images or video. In some embodiments, an optical sensor is located on the back of device800, opposite touch screen display812on the front of the device, so that the touch screen display may be used as a viewfinder for still and/or video image acquisition. In some embodiments, another optical sensor is located on the front of the device so that the user's image may be obtained for videoconferencing while the user views the other videoconference participants on the touch screen display.

Device800may also include one or more proximity sensors866.FIG.8Cshows proximity sensor866coupled to peripherals interface818. Alternatively, proximity sensor866may be coupled to input controller860in I/O subsystem806. In some embodiments, the proximity sensor turns off and disables touch screen812when the multifunction device is placed near the user's ear (e.g., when the user is making a phone call).

Device800includes one or more orientation sensors868. In some embodiments, the one or more orientation sensors include one or more accelerometers (e.g., one or more linear accelerometers and/or one or more rotational accelerometers). In some embodiments, the one or more orientation sensors include one or more gyroscopes. In some embodiments, the one or more orientation sensors include one or more magnetometers. In some embodiments, the one or more orientation sensors include one or more of global positioning system (GPS), Global Navigation Satellite System (GLONASS), and/or other global navigation system receivers. The GPS, GLONASS, and/or other global navigation system receivers may be used for obtaining information concerning the location and orientation (e.g., portrait or landscape) of device800. In some embodiments, the one or more orientation sensors include any combination of orientation/rotation sensors.FIG.8Cshows the one or more orientation sensors868coupled to peripherals interface818. Alternatively, the one or more orientation sensors868may be coupled to an input controller860in I/O subsystem806. In some embodiments, information is displayed on the touch screen display in a portrait view or a landscape view based on an analysis of data received from the one or more orientation sensors.

In some embodiments, the software components stored in memory802include operating system826, communication module (or set of instructions)828, contact/motion module (or set of instructions)830, graphics module (or set of instructions)832, text input module (or set of instructions)834, Global Positioning System (GPS) module (or set of instructions)835, and applications (or sets of instructions)836. Furthermore, in some embodiments memory802stores device/global internal state857. Device/global internal state857includes one or more of: active application state, indicating which applications, if any, are currently active; display state, indicating what applications, views or other information occupy various regions of touch screen display812; sensor state, including information obtained from the device's various sensors and input control devices816; and location information concerning the device's location and/or attitude.

Communication module828facilitates communication with other devices over one or more external ports824and also includes various software components for handling data received by RF circuitry808and/or external port824. External port824(e.g., Universal Serial Bus (USB), FIREWIRE, etc.) is adapted for coupling directly to other devices or indirectly over a network (e.g., the Internet, wireless LAN, etc.).

Contact/motion module830may detect contact with touch screen812(in conjunction with display controller856) and other touch sensitive devices (e.g., a touchpad or physical click wheel). Contact/motion module830includes various software components for performing various operations related to detection of contact, such as determining if contact has occurred (e.g., detecting a finger-down event), determining if there is movement of the contact and tracking the movement across the touch-sensitive surface (e.g., detecting one or more finger-dragging events), and determining if the contact has ceased (e.g., detecting a finger-up event or a break in contact). Contact/motion module830receives contact data from the touch-sensitive surface. Determining movement of the point of contact, which is represented by a series of contact data, may include determining speed (magnitude), velocity (magnitude and direction), and/or an acceleration (a change in magnitude and/or direction) of the point of contact. These operations may be applied to single contacts (e.g., one finger contacts) or to multiple simultaneous contacts (e.g., “multitouch”/multiple finger contacts). In some embodiments, contact/motion module830and display controller856detect contact on a touchpad.

Contact/motion module830may detect a gesture input by a user. Different gestures on the touch-sensitive surface have different contact patterns. Thus, a gesture may be detected by detecting a particular contact pattern. For example, detecting a finger tap gesture includes detecting a finger-down event followed by detecting a finger-up (lift off) event at the same position (or substantially the same position) as the finger-down event (e.g., at the position of an icon). As another example, detecting a finger swipe gesture on the touch-sensitive surface includes detecting a finger-down event followed by detecting one or more finger-dragging events, and subsequently followed by detecting a finger-up (lift off) event.

Graphics module832includes various known software components for rendering and displaying graphics on touch screen812or other display, including components for changing the intensity of graphics that are displayed. As used herein, the term “graphics” includes any object that can be displayed to a user, including without limitation text, web pages, icons (such as user-interface objects including soft keys), digital images, videos, animations and the like.

In some embodiments, graphics module832stores data representing graphics to be used. Each graphic may be assigned a corresponding code. Graphics module832receives, from applications etc., one or more codes specifying graphics to be displayed along with, if necessary, coordinate data and other graphic property data, and then generates screen image data to output to display controller856.

Text input module834, which may be a component of graphics module832, provides soft keyboards for entering text in various applications (e.g., contacts837, e-mail840, IM841, browser847, and any other application that needs text input).

GPS module835determines the location of the device and provides this information for use in various applications (e.g., to telephone838for use in location-based dialing, to imaging module843as picture/video metadata, and to applications that provide location-based services such as weather widgets, local yellow page widgets, and map/navigation widgets).

Applications836may include the following modules (or sets of instructions), or a subset or superset thereof:contacts module837(sometimes called an address book or contact list);telephone module838;video conferencing module839;e-mail client module840;instant messaging (IM) module841;workout support module842;camera module843for still and/or video images;image management module844;browser module847;calendar module848;widget modules849, which may include one or more of: weather widget849-1, stocks widget849-2, calculator widget849-3, alarm clock widget849-4, dictionary widget849-5, and other widgets obtained by the user, as well as user-created widgets849-6;widget creator module850for making user-created widgets849-6;search module851;video and music player module852, which may be made up of a video playermodule and a music player module;notes module853;map module854; and/oronline video module855.

Examples of other applications836that may be stored in memory802include other word processing applications, other image editing applications, drawing applications, presentation applications, JAVA-enabled applications, encryption, digital rights management, voice recognition, and voice replication.

In conjunction with touch screen812, display controller856, contact module830, graphics module832, and text input module834, contacts module837may be used to manage an address book or contact list, including: adding name(s) to the address book; deleting name(s) from the address book; associating telephone number(s), e-mail address(es), physical address(es) or other information with a name; associating an image with a name; categorizing and sorting names; providing telephone numbers or e-mail addresses to initiate and/or facilitate communications by telephone838, video conference839, e-mail840, or IM841; and so forth.

In conjunction with RF circuitry808, audio circuitry810, speaker811, microphone813, touch screen812, display controller856, contact module830, graphics module832, and text input module834, telephone module838may be used to enter a sequence of characters corresponding to a telephone number, access one or more telephone numbers in address book837, modify a telephone number that has been entered, dial a respective telephone number, conduct a conversation and disconnect or hang up when the conversation is completed. As noted above, the wireless communication may use any of a variety of communications standards, protocols and technologies.

In conjunction with RF circuitry808, audio circuitry810, speaker811, microphone813, touch screen812, display controller856, optical sensor864, optical sensor controller858, contact module830, graphics module832, text input module834, contact list837, and telephone module838, videoconferencing module839includes executable instructions to initiate, conduct, and terminate a video conference between a user and one or more other participants in accordance with user instructions.

In conjunction with RF circuitry808, touch screen812, display controller856, contact module830, graphics module832, and text input module834, e-mail client module840includes executable instructions to create, send, receive, and manage e-mail in response to user instructions. In conjunction with image management module844, e-mail client module840makes it very easy to create and send e-mails with still or video images taken by imaging module843.

In conjunction with RF circuitry808, touch screen812, display controller856, contact module830, graphics module832, text input module834, GPS module835, map module854, and music player module846, workout support module842includes executable instructions to create workouts (e.g., with time, distance, and/or calorie burning goals); communicate with workout sensors (sports devices); receive workout sensor data; calibrate sensors used to monitor a workout; select and play music for a workout; and display, store and transmit workout data.

In conjunction with touch screen812, display controller856, optical sensor(s)864, camera(s)870, optical sensor controller858, light source module875(seeFIG.8B), contact module830, graphics module832, and image management module844, imaging module843includes executable instructions to capture still images or video (including a video stream) and store them into memory802, modify characteristics of a still image or video, or delete a still image or video from memory802.

In conjunction with touch screen812, display controller856, optical sensor(s)864, camera(s)870, contact module830, graphics module832, text input module834, light source module875(seeFIG.8B), and imaging module843, image management module844includes executable instructions to arrange, modify (e.g., edit), or otherwise manipulate, label, delete, present (e.g., in a digital slide show or album), and store still and/or video images.

In conjunction with RF circuitry808, touch screen812, display system controller856, contact module830, graphics module832, and text input module834, browser module847includes executable instructions to browse the Internet in accordance with user instructions, including searching, linking to, receiving, and displaying web pages or portions thereof, as well as attachments and other files linked to web pages.

In conjunction with RF circuitry808, touch screen812, display system controller856, contact module830, graphics module832, text input module834, e-mail client module840, and browser module847, calendar module848includes executable instructions to create, display, modify, and store calendars and data associated with calendars (e.g., calendar entries, to do lists, etc.) in accordance with user instructions.

In conjunction with RF circuitry808, touch screen812, display system controller856, contact module830, graphics module832, text input module834, and browser module847, widget modules849are mini-applications that may be downloaded and used by a user (e.g., weather widget849-1, stocks widget849-2, calculator widget849-3, alarm clock widget849-4, and dictionary widget849-5) or created by the user (e.g., user-created widget849-6). In some embodiments, a widget includes an HTML (Hypertext Markup Language) file, a CSS (Cascading Style Sheets) file, and a JavaScript file. In some embodiments, a widget includes an XML (Extensible Markup Language) file and a JavaScript file (e.g., Yahoo! Widgets).

In conjunction with RF circuitry808, touch screen812, display system controller856, contact module830, graphics module832, text input module834, and browser module847, the widget creator module850may be used by a user to create widgets (e.g., turning a user-specified portion of a web page into a widget).

In conjunction with touch screen812, display system controller856, contact module830, graphics module832, and text input module834, search module851includes executable instructions to search for text, music, sound, image, video, and/or other files in memory802that match one or more search criteria (e.g., one or more user-specified search terms) in accordance with user instructions.

In conjunction with touch screen812, display system controller856, contact module830, graphics module832, audio circuitry810, speaker811, RF circuitry808, and browser module847, video and music player module852includes executable instructions that allow the user to download and play back recorded music and other sound files stored in one or more file formats, such as MP3 or AAC files, and executable instructions to display, present or otherwise play back videos (e.g., on touch screen812or on an external, connected display via external port824). In some embodiments, device800may include the functionality of an MP3 player.

In conjunction with touch screen812, display controller856, contact module830, graphics module832, and text input module834, notes module853includes executable instructions to create and manage notes, to do lists, and the like in accordance with user instructions.

In conjunction with RF circuitry808, touch screen812, display system controller856, contact module830, graphics module832, text input module834, GPS module835, and browser module847, map module854may be used to receive, display, modify, and store maps and data associated with maps (e.g., driving directions; data on stores and other points of interest at or near a particular location; and other location-based data) in accordance with user instructions.

In conjunction with touch screen812, display system controller856, contact module830, graphics module832, audio circuitry810, speaker811, RF circuitry808, text input module834, e-mail client module840, and browser module847, online video module855includes instructions that allow the user to access, browse, receive (e.g., by streaming and/or download), play back (e.g., on the touch screen or on an external, connected display via external port824), send an e-mail with a link to a particular online video, and otherwise manage online videos in one or more file formats, such as H.264. In some embodiments, instant messaging module841, rather than e-mail client module840, is used to send a link to a particular online video.

In some embodiments, device800is a device where operation of a predefined set of functions on the device is performed exclusively through a touch screen and/or a touchpad. By using a touch screen and/or a touchpad as the primary input control device for operation of device800, the number of physical input control devices (such as push buttons, dials, and the like) on device800may be reduced.

Example Computer System

FIG.9illustrates an example computer system900that may include one or more camera modules, in accordance with some embodiments. In some embodiments, the computer system900may include one or multiple features, components, and/or implement functionality of embodiments described herein.

Various embodiments of a camera module, as described herein, may be executed in one or more computer systems900, which may interact with various other devices. Note that any component, action, or functionality described above may be implemented on one or more computers configured as computer system900ofFIG.9, according to various embodiments. In the illustrated embodiment, computer system900includes one or more processors910coupled to a system memory920via an input/output (I/O) interface930. Computer system900further includes a network interface940coupled to I/O interface930, and one or more input/output devices950, such as cursor control device960, keyboard970, and display(s)980. In some cases, it is contemplated that embodiments may be implemented using a single instance of computer system900, while in other embodiments multiple such systems, or multiple nodes making up computer system900, may be configured to host different portions or instances of embodiments. For example, in one embodiment some elements may be implemented via one or more nodes of computer system900that are distinct from those nodes implementing other elements.

In various embodiments, computer system900may be a uniprocessor system including one processor910, or a multiprocessor system including several processors910(e.g., two, four, eight, or another suitable number). Processors910may be any suitable processor capable of executing instructions. For example, in various embodiments processors910may be general-purpose or embedded processors implementing any of a variety of instruction set architectures (ISAs), such as the x8 18, PowerPC, SPARC, or MIPS ISAs, or any other suitable ISA. In multiprocessor systems, each of processors910may commonly, but not necessarily, implement the same ISA.

System memory920may be configured to store control program instructions922and/or control data accessible by processor910. In various embodiments, system memory920may be implemented using any suitable memory technology, such as static random access memory (SRAM), synchronous dynamic RAM (SDRAM), nonvolatile/Flash-type memory, or any other type of memory. In the illustrated embodiment, program instructions922may be configured to implement a control application incorporating any of the functionality described above. Additionally, existing control data of memory920may include any of the information or data structures described above. In some embodiments, program instructions and/or data may be received, sent or stored upon different types of computer-accessible media or on similar media separate from system memory920or computer system900. While computer system900is described as implementing the functionality of functional blocks of previous Figures, any of the functionality described herein may be implemented via such a computer system.

Input/output devices950may, in some embodiments, include one or more display terminals, keyboards, keypads, touchpads, scanning devices, voice or optical recognition devices, or any other devices suitable for entering or accessing data by one or more computer systems900. Multiple input/output devices950may be present in computer system900or may be distributed on various nodes of computer system900. In some embodiments, similar input/output devices may be separate from computer system900and may interact with one or more nodes of computer system900through a wired or wireless connection, such as over network interface940.

As shown inFIG.9, memory920may include program instructions922, which may be processor-executable to implement any element or action described above. In one embodiment, the program instructions may implement the methods described above. In other embodiments, different elements and data may be included. Note that data may include any data or information described above.