Backlighting for optical finger navigation

An optical finger navigation (OFN) device includes an OFN sensor module, a light source, and a vertical light guide. The OFN sensor module is coupled to a circuit substrate. The OFN sensor module generates a navigation signal in response to a movement detected at a navigation surface based on light reflected from a user's finger. The light source is also coupled to the circuit substrate. The light source generates light (which is separate from the light generated for the OFN sensor module). The vertical light guide is disposed to circumscribe a perimeter of the OFN sensor module. The vertical light guide receives the light from the light source and guides the light toward a light emission surface at a perimeter surface area circumscribing the navigation surface.

BACKGROUND

An impressive feature of optical finger navigation (OFN) devices is the ability to seamlessly integrate such devices into consumer electronics. OFN devices have many advantages over other types of navigational input devices. For example OFN devices do not have mechanical, moving parts. So there is no fear of mechanical failures. OFN devices can also be very precise, depending on the resolution of the sensor that is used for imaging the user's finger.

However, despite these advantages, it has been recognized that some implementations of OFN devices can be integrated so well that it is difficult for a user to identify the location of the OFN device. For example, the contact navigation surface for an optical finger navigation device can be finished to appear the same or very similar as surrounding finishes (i.e., black plastic, etc.). Thus, a user may have difficulty identifying the location of the OFN device relative to the surrounding components having a similar finish.

SUMMARY

Embodiments of an optical finger navigation (OFN) device are described. In one embodiment, the OFN device includes an OFN sensor module, a light source, and a vertical light guide. The OFN sensor module is coupled to a circuit substrate. The OFN sensor module generates a navigation signal in response to a movement detected at a navigation surface based on light reflected from a user's finger. The light source is also coupled to the circuit substrate. The light source generates light (which is separate from the light generated for the OFN sensor module). The vertical light guide is disposed to circumscribe a perimeter of the OFN sensor module. The vertical light guide receives the light from the light source and guides the light toward a light emission surface at a perimeter surface area circumscribing the navigation surface. Other embodiments of the OFN device are also described.

Embodiments of light guide assembly are also described. In one embodiment, the light guide assembly is configured for use with an OFN device which generates a navigation signal in response to a movement detected at a navigation surface based on light reflected from a user's finger. An embodiment of the light guide assembly includes a housing and a vertical light guide. The housing includes vertical walls formed of a substantially opaque material. The housing defines an interior space with dimensions sufficient to house an OFN sensor module. The housing also defines a navigation window for alignment between a sensor array location of the OFN sensor module and a navigation surface. The vertical light guide includes vertical walls formed of a substantially translucent material. The vertical light guide guides light from a light source approximately at a base of the vertical light guide toward a light emission surface which circumscribes at least a portion of the navigation window defined by the housing. Other embodiments of the light guide assembly are also described.

Embodiments of a computerized device are also described. In one embodiment, the computerized device is a handheld mobile phone or mobile computing device. An embodiment of the computerized device includes a screen, an OFN device, and an effect lighting apparatus. The screen provides a visual display of a graphical image. The OFN device detects user inputs based on light reflected from a user's finger at a navigation surface to manipulate at least a portion of the graphical image on the screen. The effect lighting apparatus is disposed to circumscribe the navigation surface of the OFN device. The effect lighting apparatus provides a visual indicator of a location of the navigation surface of the OFN device relative to the screen, without interfering with the functionality of the OFN device. Other embodiments of the computerized device are also described. For example, in some embodiments, the OFN device only provides visual feedback to a user via an image manipulation on the screen.

DETAILED DESCRIPTION

While many embodiments are described herein, at least some of the described embodiments relate to an optical finger navigation (OFN) device that includes one or more features to help a user identify the location of the OFN device relative to surrounding components and/or surface finishes. In general, the OFN device includes a light feature which at least partially surrounds the navigation window (e.g., the contact surface) of the corresponding OFN sensor module. During use of the OFN device, the light feature illuminates to indicate the location of the OFN device to the user. Additionally, the light feature may illuminate before an anticipated user interaction (e.g., upon waking up from a sleep mode), after an actual user interaction, or at another time.

In a specific embodiment, the OFN device includes the OFN sensor module, a light source, and a vertical light guide. The OFN sensor module is coupled to a circuit substrate (directly or indirectly). The OFN sensor module generates a navigation signal in response to a movement detected at a navigation surface based on light reflected from a user's finger. The light source is also coupled to the circuit substrate (directly or indirectly). The light source generates light (which is separate from the light generated for the OFN sensor module). The vertical light guide is disposed to circumscribe a perimeter of the OFN sensor module. The vertical light guide receives the light from the light source and guides the light toward a light emission surface at a perimeter surface area circumscribing the navigation surface.

FIG. 1depicts a schematic diagram of one embodiment of a consumer electronic device100having an optical finger navigation (OFN) device102. The consumer electronic device100may be any type of electronic device such as a mobile telephone, personal digital assistant (PDA), laptop or notebook computer, and so forth. Although not shown, embodiments of the OFN device102also may be incorporated into non-consumer electronic devices. Additionally, some devices may include multiple OFN devices102, or other quantities or configurations of OFN devices102.

The illustrated electronic device100includes a display screen104and a keypad106, in addition to the OFN device102. Conventional types of screens104and keypads106and their corresponding uses are known in the art and, hence, are not described in more detail herein. Although the electronic device100is shown and described with certain components and functionality, other embodiments of the electronic device100may include fewer or more components to implement less or more functionality.

In one embodiment, the OFN device102includes a navigation window108at which a user's finger is imaged or otherwise detected by an image sensor (refer toFIG. 11). The navigation window108generally corresponds with a surface area that is within the field of view of the image sensor.

The OFN device102also includes an effect lighting apparatus110(i.e., a light feature) that circumscribes, or surrounds, the navigation window108. In some embodiments, the effect lighting apparatus110is directly adjacent to and circumscribes the navigation window108. However, in other embodiments, the effect lighting apparatus110is need necessarily directly adjacent to the navigation window108, but is simply located within a proximity of the navigation window108so that the user can identify the location of the navigation window108. Additionally, in some embodiments, the effect lighting apparatus110does not necessarily fully circumscribe the navigation window108. In other embodiments, the effect lighting apparatus110may include multiple illuminated portions which may be collocated together. For example, the effect lighting apparatus110may include two illuminated, parallel lines interposed between the navigation window108and the keypad106(or the display104). In another example, the multiple illuminated portions may be located separately, relative to the navigation window108. For example, one illuminated portion may be located on one side of the navigation window108, and another illuminated portion may be located on another side of the navigation window108. Other embodiments may implement various quantities and/or arrangements of illuminated portions of the effect lighting apparatus110.

It should also be noted that, in certain embodiments, the effect lighting apparatus110does not interfere with the functionality of the OFN sensor. More specifically, embodiments of the effect lighting apparatus110are designed and implemented to provide location identification illumination, without providing significant amounts of illumination at the navigation surface. In this way, the OFN sensor can operate in a known manner, without requiring modifications to account for stray light from the nearby effect lighting apparatus110.

FIG. 2depicts an exploded perspective view of one embodiment of the OFN device102ofFIG. 1. The illustrated OFN device102includes an OFN sensor module112and one or more light sources114coupled to a substrate116. The substrate may be any type of suitable substrate such as a printed circuit board (PCB), flex, rigid flex, and so forth. The OFN device102also includes a mechanical switching device118such as a metal dome switch aligned with the OFN sensor module112(in this case, on a back side of the substrate116. The OFN device102also includes a vertical light guide120, an internal housing122, one or more transitional light guides124, and a navigation plate126.

A detailed description of a specific embodiment of the OFN sensor module112is provided below with reference toFIG. 11. In general, the OFN sensor module112operates to generate a navigation signal in response to a movement of a user's finger at the navigation plate126. The OFN sensor module112uses light generated by one or more internal light sources (refer toFIG. 11) which are different from the light sources114used for the vertical light guide120. More information regarding the OFN sensor module112may be obtained from U.S. patent application Ser. No. 12/464,542, entitled “Composite Package for OFN,” filed on May 12, 2009, which is incorporated herein by reference.

In one embodiment, each light source114for the vertical light guide120is a light emitting diode (LED). In a specific embodiment, the light sources114are side-firing or side-emitting LEDs. Other embodiments may use other types of LEDs (refer to the remaining figures) or other types of light sources. Although two separate light sources114are shown inFIG. 2, other embodiments may uses fewer or more light sources. For example, some embodiments use a single light source114. Other embodiments use a light source114disposed at each corner of the OFN sensor module112.

In the illustrated embodiment, each light source114emits light into the transitional light guides124, which are disposed on (or coupled to) the substrate between the light source114. In general, the transitional light guides124facilitate transmitting the light from the light sources114to the vertical light guide120. In some embodiments, the OFN device102also includes a reflective coating or substance (e.g., white paint) disposed between the transitional light guides124and the substrate116to help increase the light transmission into the vertical light guide120. In a specific embodiment, the transitional light guides124include a light guide film (LGF) to create a uniform back lighting effect. The LGF receives light from the light sources114and distributes the light along the top surface (near the vertical light guide120) of the LGF. The LGF may be attached to the substrate116with double-sided tape or another type of adhesive or connector. The use of double-sided tape, or a similar adhesive material, may facilitate the attachment of the housing122and/or the vertical light guide120to the substrate116for assembly purposes. In another embodiment, plastic light pipe also can be used to create the same effect as LGF. In further embodiments, the transitional light guides124may be integrated with the vertical light guide120for improved functionality and/or cost savings.

In one embodiment, the vertical light guide120and the housing122are placed on top of the OFN sensor module112. The vertical light guide120and the housing122may be formed together (e.g., as a two color molded part) or separately. If formed separately, the vertical light guide120and the housing122may be assembled together. In the illustrated embodiment, the housing122defines a navigation window which allows part or all of the navigation plate126to be within the field of view of the image sensor. In one embodiment, the housing122is opaque so that light within the vertical light guide120does not transmit into the field of view of the image sensor. In this way, the opaque housing122can act as a shield to prevent unwanted back light that would otherwise affect the OFN sensor module112.

The illustrated housing122also includes flanges130to cover the corresponding light sources114. The flanges130prevent some or all of the direct light emissions from the light sources114, so that bright spots at the corners of the vertical light guide are avoided.

The vertical light guide120has a light emission surface which circumscribes the navigation window108approximately at the navigation surface of the navigation plate126. In this way, the vertical light guide120provides illumination at about the navigation window108to help a user identify the location of the navigation window108and/or the navigation plate126. However, in some embodiments, the vertical light guide120does not necessarily extend all the way to the opposite surface of the navigation plate126. Rather, in some embodiment, a cover may be placed on top of the vertical light guide120, and the cover may be substantially flush with the navigation plate126. Other embodiments may use other arrangements for the vertical light guide, cover, and or similar structural components.

In some embodiments, the navigation plate126is adhered to the internal housing122by an adhesive tape128. In other embodiments, the navigation plate126may be coupled with the housing122or another component of the OFN device102by another form of adhesive (e.g., glue) or by conventional mechanical means (e.g., snap, friction, etc.). The navigation plate126may be an infrared (IR) polycarbonate (PC) cover, or another suitable type of cover, that allows light generated within and reflected back into the OFN sensor module112to be detected by the image sensor. By using IR light, the potential interference from ambient visible light may be reduced or eliminated.

FIG. 3depicts a cutaway view of an assembled embodiment of the OFN device102ofFIG. 1. As illustrated inFIG. 3, the switching device118is mounted on a back side of the substrate116, and the remaining components are mounted on a front side of the substrate116. Specifically, the light sources114are mounted at the corners of the OFN sensor module112. The housing122covers the OFN sensor module112, and the flanges130cover the light sources114. The vertical light guide120surrounds the housing122and circumscribes the navigation plate126.

The embodiment illustrated inFIG. 3specifically implements two side-firing LEDs, which are located diagonally across the OFN sensor module112. Depending on the design of the OFN device102, the transitional light guide (refer toFIG. 1) collects the light emitted by the LEDs and conveys the light to the vertical light guide120for a light distribution within the vertical light guide120. In one embodiment, the vertical light guide120provides a substantially uniform light emission around the navigation plate126and the navigation window108. In contrast to the two LED embodiment, an embodiment which uses four LEDs may have the LEDs located at each of the four corners. Accordingly, four transitional light guides124may be used—one between each pair of LEDs.

As explained above, the housing122prevents unwanted light from entering to the inner space of the housing where the OFN sensor module112is located. Consequently, even if there is a small amount of light that transmits from the vertical light guide120to edges of the navigation plate126, the top flange of the housing122may substantially block such light leakage. Alternatively, there may be an additional light barrier material (not shown) between the vertical light guide120and the navigation plate126.

To improve the visual effect and uniformity of the light emissions from the vertical light guide120, a diffusion material may be applied to the top portion or surface of the vertical light guide120. For example, translucent white paint may be applied on the top of the vertical light guide120. Alternatively, or in additional to a first material, a non-conductive vacuum metallization (NCVM) may be applied to the top portion or surface of the vertical light guide120. The paint or other diffusion material acts as a diffusion layer to smoothen the light emitted from the vertical light guide120. The use of an additional vacuum metallization coating (e.g., NCVM) with proper percentage of light transmittance may improve the visual appearance of the ring when the back lighting is turned off.

FIG. 4depicts an exploded perspective view of another embodiment of the OFN device102ofFIG. 1. The illustrated embodiment includes four light sources114coupled to the substrate116around the OFN sensor module112. In the depicted embodiment, the housing122is separate from the vertical light guide120. However, the vertical light guide120includes tabs132which extend through corresponding openings134in the housing, so that light from the LEDs can enter into the vertical light guide120. In one embodiment, the housing122includes light barriers over the LED locations, and the vertical light guide120includes angled bottom surfaces at corresponding locations in order to direct some of the light up at the corners of the vertical light guide120.

The illustrated embodiment also includes an integrated cover plate136. The integrated cover plate136includes both the navigation plate126and a diffuse transmission ring surrounding the centrally located navigation plate126. The bottom surface of the diffuse transmission ring substantially aligns with the top surface of the vertical light guide120, so that the light from the light sources114travels through the vertical light guide120and the diffuse transmission portion of the integrated cover plate136. The diffuse transmission ring may be painted and/or coated (e.g., using NCVM) as described above.

FIG. 5depicts an exploded perspective view of another embodiment of the OFN device102ofFIG. 1. The illustrated embodiment includes the mechanical switching device118, the substrate116, and the OFN sensor module112. The OFN device102also includes a single light source114and associated circuitry140(e.g., a capacitor). The OFN device102also includes the housing122, the vertical light guide120, and the integrated cover136with the navigation plate126. All of these components are similar to the embodiments described above in structure and/or function.

The illustrated OFN device102also includes a separate light pipe142that functions as a transitional light guide to transmit the light from the light source114to the vertical light guide120.FIG. 6depicts a perspective view of one embodiment of the light pipe142ofFIG. 5. The light pipe142includes a bottom surface to receive light from the light source114, which in one embodiment is a top-firing LED. The light pipe142also includes opposing protrusions (i.e., wings) which extend in a direction substantially parallel to the bottom surface. These protrusions direct the light outward in a direction that is substantially orthogonal to the direction of the light emitted from the top-firing LED.

One or more of the surfaces (shown shaded inFIG. 6) may be coated with a reflective material in order to facilitate internal reflections in the appropriate directions. Other embodiments may use other types of reflective properties and/or materials. The light exits the light pipe142through other surfaces144that are not coated with the reflective material. In some embodiments, the light pipe142also includes one or more notches146that are located to direct the internally reflected light toward the exit surfaces144. In the illustrated embodiment, the notches146are substantially V-shaped, although other embodiments may use other geometries of the light pipe142.

FIG. 7depicts a perspective view of another embodiment of the vertical light guide120and the light pipe142ofFIG. 5. As illustrated inFIG. 7, the light pipe142is shown engaged with an interior surface of the vertical light guide120.FIG. 7also illustrates the bottom surface of the light pipe142, which may be shaped with a channel, or other depression, to receive part or all of the corresponding structure of the light source114.

FIG. 8depicts a perspective view of another embodiment of the vertical light guide120ofFIG. 5. In the illustrated embodiment, the light pipe142is not shown, but a receiver indentation148is shown where the light pipe142might be engaged. The shape of the receiver indentation148may vary depending on the corresponding shape of the light pipe142. Other embodiments may omit the receiver indentation148.

FIG. 9depicts a bottom perspective view of another embodiment of the vertical light guide120.FIG. 10depicts a cutaway view of another embodiment of the OFN device102and the vertical light guide120ofFIG. 9. In the illustrated embodiments, a separate light pipe is not needed because the interior surfaces150of the vertical light guide120are shaped to perform similar functionality. In one embodiment, the interior surfaces150of the vertical light guide120are angled to reflect the light into other surfaces of the vertical light guide (as indicated by the arrows). The angled surfaces, as well as other surfaces, may be coated with a reflective material, or may be otherwise finished as a reflective surface.

FIG. 11depicts a schematic block diagram of one embodiment of the electronic device100ofFIG. 1. In one embodiment, the electronic device100is a portable electronic device. The illustrated electronic device100includes the OFN device102and the display104. The display104may display a navigation indicator160or any other type of conventional display content.

By implementing an embodiment of the OFN device102in the portable electronic system100, the OFN device102may facilitate, for example, user input to navigate content on a display device104. For example, the OFN device102may facilitate control of the navigation indicator160on the display device104. The navigation indicator160may be a cursor, a highlighter, an arrow, or another type of navigation indicator. Additionally, the user input received through the OFN device102may facilitate other types of user-controlled functionality including, but not limited to, volume controls, audio playback selections, browser controls, bio-metric identification, electronic musical instruments, actions in games, and so forth. The types of user-controlled functionality that may be implemented with embodiments of the electronic system100may depend on the type of functionality generally provided by the electronic system100. Also, althoughFIG. 11specifically illustrates a portable electronic system100, other embodiments may implement the OFN device102in electronic devices which are portable, but not necessarily held in a user's hand, or devices which are generally considered to be not portable.

The illustrated OFN device102includes an optical navigation circuit112(also referred to as the sensor module) and a microcontroller (uC)162. In general, the optical navigation circuit112generates signals representative of finger or other navigation movement at the OFN device102. The optical navigation circuit112then transmits one or more signals to the microcontroller162. Examples of types of signals transmitted from the optical navigation circuit112to the microcontroller162include channel quadrature signals based on ΔX and ΔY relative displacement values. The ΔX and ΔY displacement values may represent a specific pattern for finger print identification or a vector of displacement, direction, and magnitude. These signals, or other signals, may be indicative of a relative movement between the finger and the OFN device102. Other embodiments of the optical navigation circuit112may transmit other types of signals to the microcontroller162.

In some embodiments, the microcontroller162implements a variety of functions, including transmitting data to and receiving data from a host computer system or other electronic device (not shown) or acting on the displacement values. In one embodiment, the microcontroller162also controls the effect lighting apparatus110, which is described in various embodiments herein.

In order to generate the navigation signals, the depicted optical navigation circuit112includes a driver164, a digital signal processor (DSP)166, and an image acquisition system (IAS)168. The image acquisition system168includes the image sensor170and an analog-to-digital converter (ADC)172. Other embodiments of the optical navigation circuit112and or the image acquisition system168may include fewer or more components to implement less or more functionality.

In one embodiment, the driver164of the optical navigation circuit112controls the operation of an internal light source (not shown) to generate the light signal that illuminates the navigation surface. The driver164may control the light source to several different brightness levels, or the driver164may pulse the light source in conjunction with sending detector on/off signals to the image sensor170, thereby increasing the system response function for desirable goals. The reflected light signal is then received and detected by the image sensor170.

In one embodiment, the image sensor170generates one or more analog electrical signals corresponding to incident light on the image sensor170. The image sensor170then transmits the analog signals to the analog-to-digital converter172. The analog-to-digital converter172converts the electrical signals from analog signals to digital signals and then passes the digital signals to the digital signal processor166.

After the digital signal processor166receives the digital form of the signals from the analog-to-digital converter172of the image acquisition system168, the digital signal processor166may perform additional processing using the electrical signals. The digital signal processor166then transmits one or more signals to the microcontroller162, as described above. In some embodiments, the digital signal processor166includes a navigation engine174to generate lateral movement information based on lateral movement of the finger relative to the navigation surface of the navigation plate126. Other embodiments of the navigation engine174may generate other types of movement information.

More specifically, in one embodiment, the image sensor170may include an array of distinct photodetectors (not shown), for example, a 16×16 or 32×32 array of distinct photodetectors configured to detect light that is reflected from the illuminated spot on the navigation surface. Each of the photodetectors in the image sensor170generates light intensity information that is output as a digital value (e.g., an 8-bit digital value). Image information is captured by the image sensor170in frames, where a frame of image information includes a set of simultaneously captured values for each distinct photodetector in the image sensor170. The rate of image frame capture and tracking resolution can be programmable. In an embodiment, the image frame capture rate ranges up to 2,300 frames per second with a resolution of 800 counts per inch (CPI). Although some examples of frame capture rates and resolutions are provided, different frame capture rates and resolutions are contemplated.

The navigation engine174compares successive image frames from the image sensor170to determine the movement of image features between frames. In particular, the navigation engine174determines movement by correlating common features that exist in successive image frames from the image sensor170. The movement between image frames is expressed in terms of movement vectors in, for example, X and Y directions (e.g., ΔX and ΔY). The movement vectors are then used to determine the relative movement between a user's finger and the image sensor170. More detailed descriptions of examples of navigation sensor movement tracking techniques are provided in U.S. Pat. No. 5,644,139, entitled NAVIGATION TECHNIQUE FOR DETECTING MOVEMENT OF NAVIGATION SENSORS RELATIVE TO AN OBJECT, and U.S. Pat. No. 6,222,174, entitled METHOD OF CORRELATING IMMEDIATELY ACQUIRED AND PREVIOUSLY STORED FEATURE INFORMATION FOR MOTION SENSING, both of which are incorporated by reference herein.

FIG. 12depicts an exploded perspective view of another embodiment of the light source114, housing122, and vertical light guide120of the OFN device100. In the illustrated embodiment, the housing122includes one or more surfaces182that function to reflect light from the light source114into the vertical light guide120. In one embodiment, the surfaces182of the vertical light guide120are angled to reflect the light into other surfaces of the vertical light guide120. The angle is a non-zero angle relative to the plane of the substrate (refer toFIG. 1). In some embodiments, the housing122includes multi-faceted surfaces182on which the light from the light source114is incident. By implementing the multi-faceted surfaces182on the housing122, the light from the light source114may be reflected in various directions in order to facilitate distributing the light more evenly within the vertical light guide120.

The angled surfaces182, as well as other surfaces, may be coated with a reflective material, or may be otherwise finished as a reflective surface. In one embodiment, a NVCM coating is applied to the indicated surfaces182in order to create a mirror-like or otherwise reflective finish. In some embodiments, the angled surfaces182of the housing122also function to block or limit light from entering into the interior cavity where the image sensor is located.

The illustrated vertical light guide120also includes various light distribution features184that are integrated into the vertical light guide120. In general, the light distribution features184function to distribute the light within the vertical light guide120by way of total internal reflection (TIR) or other optical transmission effects. Various types of light distribution features184are shown, including undulating sidewalls, tiered surfaces, serration detents, and so forth. Other embodiments may include other types of light distribution features184and or other combinations of light distribution features184. Additionally, the exact locations of each type and/or quantity of light distribution features184may vary depending on the implementation of the vertical light guide. In some embodiments, a higher quantity of the light distribution features184are located at regions such as corners of the vertical light guide120, where light can be directed around the corner using TIR or upward and out of the vertical light guide120for perception by the user.

FIG. 13depicts another perspective view of the OFN device100ofFIG. 12. LikeFIG. 12, the illustrated portions of the OFN device100include the light source114, the housing122, and the vertical light guide120. This illustration also shows additional details of an embodiment of the angled surfaces182of the housing122. As depicted, the angled surfaces182include facets to reflect the light sideways (as indicated by the arrows) so that light can travel around the circumference of the vertical light guide120using TIR. Also, some examples of light distribution features184, which may further facilitate a particular distribution pattern within the vertical light guide120, are also illustrated. In some embodiments, the light distribution feature is located in approximately a corner region of the vertical light guide to direct light out of the light emission surface at the corner region of the vertical light guide. It should also be noted that the illustrated embodiment includes a single light source114, but other embodiment may include more than one light source114.

Additionally,FIG. 13illustrates the reflective surface having a protrusion with angled sidewalls to reflect at least some of the light in substantially opposing directions in the circumferential directions of the vertical light guide. In other words, the protrusion reflects some of the light to the left and some of the light to the right, within the orientation shown inFIG. 13. In this way, at least some of the light that is reflected left and right can travel around the circumference of the vertical light guide, or a portion thereof.

FIG. 14depicts a cutaway view of the OFN device100ofFIG. 12. LikeFIG. 12, the illustrated portions of the OFN device100include the light source114, the housing122, and the vertical light guide120. This illustration also shows additional details of an embodiment of the angled surfaces182of the housing122. As depicted, the angled surfaces182include facets to reflect the light outward (away from the central image sensor location) so that light can enter the vertical light guide120.

In some embodiments, the locations and configurations of the angled surfaces182on the housing122are tailored to the particular light distribution pattern of the light source114. For example, if the light source114has a very narrow beam distribution pattern, then the configuration of the angled surfaces182may be relatively concentrated in alignment with the beam pattern of the light guide182. As another example, if the light source114is a top-emitting LED, then the configuration of the angled surfaces182may be directly above the location of the LED. Alternatively, if the light source114is a side-emitting LED, then the configuration of the angled surfaces182may be distributed on one or both sides of the LED. Additionally, some of the angled surfaces182may extend down further toward the substrate in order to align the angled surfaces182more closely with the center of the side-emitting beam pattern. Other embodiments may use other configurations, depending on the size, location, intensity, beam pattern, and/or other characteristics of the light source114.

FIG. 15depicts a cutaway view of the vertical light guide120of the OFN device100ofFIG. 12. The illustrated vertical light guide120includes several different types of light distribution features184, including non-planar sidewalls, tiered sidewalls (i.e., with a step or ledge), and serration detents. In some embodiments, the ledge/slope sidewalls act as light guide to channel a substantial portion of light from the light source114to illuminate a distanced area which is at approximately the opposite side of the light guide120from the light source114. This type of feature may facilitate a design that includes a single light source114. In some embodiments, the non-planar, wavy sidewalls reduce the intensity of the light emitted from the effect lighting apparatus110at the position where the feature exist. In some embodiments, the serration detents disturb the light path and reflect a portion of light toward the corresponding emission surface area of the effect lighting apparatus110. These and other similar features may be incorporated, either individually or in various combinations, to improve uniformity of the light emitted from the effect lighting apparatus110. Additionally, some of these features also may be structural to accommodate assembly of the final device. For example, in some embodiments the step sidewalls are created to make space for the sensor112to fit in.