WO2013090843A1

WO2013090843A1 - Rotatable light filter assembly for camera built in a smartphone

Info

Publication number: WO2013090843A1
Application number: PCT/US2012/069940
Authority: WO
Inventors: Joel KAMERMAN; Dave Sayler; Sohrab Vossoughi; Ichaing SUN
Original assignee: Trygger Llc
Priority date: 2011-12-15
Filing date: 2012-12-14
Publication date: 2013-06-20

Abstract

A rotatable light filter assembly (210) is positioned over a camera lens (20) of a built-in camera (18) of a smartphone (14) to provide a user with selective control of light intensity and other properties of image-carrying light incident on a photosensitive image-sensor array of the camera. The rotatable light filter assembly is an integral part of a smartphone case (200) and positioned for a user to selectively cover the lens, installed in a removable back panel (230) of a smartphone, or set in an accessory case sized to fit over a camera-side smartphone panel.

Description

ROTATABLE LIGHT FILTER ASSEMBLY FOR

CAMERA BUILT IN A SMARTPHONE

Technical Field

[0001] This disclosure relates to cameras on smartphones and, in particular, to a rotatable light filter assembly for a camera built in a smartphone.

Background Information

[0002] A smartphone, such as an iPhone^®, available from Apple, Inc., Cupertino, California, contains a built-in camera for taking pictures or, in later models, capturing videos. Before a user snaps a picture, the iPhone^® camera causes a white box to appear briefly over a portion of the display screen to indicate the location where the camera will focus and calculate an overall brightness of the exposure. The camera image processing circuitry uses that portion to determine the overall white balance, exposure, and focus of the scene. The user can move the white box to cause the iPhone^® to re-compute its assessment of the white balance, exposure, and focus. When the user taps a dark spot of the scene, the entire photograph will become lighter, and when the user taps a bright part of the scene, the entire photograph will become darker.

Summary

[0003] An accessory case for a smartphone having a built-in camera with a lens substantially coplanar with a back panel of the smartphone. The accessory case has a generally rectangular frame with an open top region sized to receive the

smartphone, and a partly open bottom region that has a user-configurable slidable floor configured to confront a portion of the back panel when the smartphone is installed in the accessory case. The area of the portion is less than the area of the open top region by an amount that facilitates bidirectional sliding movement of the slidable floor along interior sidewalls of the frame for user-selectable configuration of the slideable floor in deployed and nondeployed positions.

[0004] The case has a rotatable light filter assembly including an annular disk encompassing a centrally located polarizing filter, the assembly rotatably attached to the slidable floor for spatial alignment of the polarizing filter over the lens in response to the user-selectable configuration of the slidable floor in the deployed position.

[0005] The case has a notch opening in the frame proximal a location of the camera. The opening is sized to expose a circumferential side margin of the rotatable light filter assembly while the slidable floor is positioned in the deployed position. The circumferential side margin is configured to receive tactile

manipulation for user-selectable rotational positioning of the filter via rotation of the annular disk to thereby change the polarization state of the polarizing filter about an axis normal to the slidable floor.

[0006] Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings.

Brief Description of the Drawings

[0007] Fig. 1 is a perspective view of an embodiment of an accessory case for a smartphone, in which the accessory case has a rotatable light filter assembly that holds a centrally located polarizing filter.

[0008] Fig. 2 is a perspective view of a smartphone inserted into the accessory case of Fig. 1 .

[0009] Figs. 3A and 3B are perspective views of a bottom region of the accessory case of Fig. 1 , with its slidable floor holding a first implementation of a light filter assembly and configured in, respectively, a light filter nondeployed position and a light filter deployed position; and Fig. 3C is a fragmentary sectional view taken along lines 3C— 3C of Fig. 3A.

[0010] Figs. 4A and 4B are perspective views of a bottom region of the accessory case of Fig. 1 , with its slidable floor holding a second implementation of a light filter assembly and configured in, respectively, a light filter nondeployed position and a light filter deployed position; and Fig. 4C is a fragmentary sectional view taken along lines 4C— 4C of Fig. 4A.

[0011] Figs. 5A and 5B show, respectively, rear side and front side views of the placement and fit of an annular disk of the second implementation of the light filter assembly of the accessory case of Fig. 1 to illustrate user adjustment of the polarization state of the polarizing filter.

[0012] Fig. 6 together with an enlarged detail rendering shows a volume-up button raised above the surface of the accessory case of Fig. 1 to facilitate user access when the volume-up button is operated as a camera shutter.

[0013] Figs. 7A and 7B are isometric views of, respectively, the front side and rear side of the smartphone inserted into an accessory case, according to a third embodiment. [0014] Figs. 8A, 8B, 8C, 8D, 8E, and 8F are, respectively, top plan, bottom, top, left-side elevation, right-side elevation, and bottom plan views of the third

embodiment of accessory case, into which the smartphone is inserted.

[0015] Figs. 9A and 9B are bottom plan views of a bottom region of the third embodiment of accessory case, with its slidable floor holding a light filter assembly and configured in, respectively, a light filter nondeployed position and a light filter deployed position.

[0016] Fig. 10 is an exploded view of major components of, and showing the smartphone aligned for insertion into, the third embodiment of accessory case.

[0017] Fig. 1 1A is a top plan view of the third embodiment of accessory case; and Fig. 1 1 B is a cross sectional view taken along lines 1 1 B— 1 1 B of Fig. 1 1 A, showing with its associated Detail A, the smartphone inserted into the third embodiment of accessory case and held in place by an L-shaped elastomeric retainer.

[0018] Fig. 12A is a copy of Fig. 8F (rotated 90° clockwise); Fig. 12B is a cross sectional view taken along lines 12B— 12B of Fig. 12A, showing with its Detail M, the positioning of a slidable floor; and Fig. 12C is a cross sectional view taken along lines 12C— 12C of Fig. 12A, showing with its Detail C a detent to retain the position of the slidable floor.

[0019] Figs. 13A, 13B, and 13C are top plan, perspective, and side elevation views of a light filter assembly for the third embodiment of accessory case; Fig. 13D is a cross sectional view taken along lines 13D— 13D of Fig. 13A; and Fig. 13E, together with its associated Detail E and Detail F, is a perspective view of an inner surface of the light filter assembly.

[0020] Fig. 14A and Fig. 14B, together with its associated Detail D, are plan views of an exterior surface of the slidable floor with the light filter assembly for the third embodiment of accessory case, respectively, attached to and absent from an arcuate recessed area of the slidable floor.

[0021] Fig. 15A is a fragmentary sectional view taken along lines 15A— 15A of Fig. 14; and Fig. 15B is an enlarged fragmentary perspective view of features in the arcuate recessed area of the slidable floor.

[0022] Figs. 16 and 17 are sectional views taken along lines 16— 16 and lines 17— 17, respectively, of Fig. 14A.

[0023] Fig. 18A, together with its associated Detail G, and Fig. 18B are, respectively, copies of Fig. 8F and Fig. 8E showing an elevated volume-up button. [0024] Figs. 19A and 19B are isometric views of, respectively, the front side and rear side of the smartphone inserted into an accessory case, according to a fourth embodiment.

[0025] Figs. 20A, 20B, 20C, 20D, 20E, and 20F are, respectively, top plan, bottom, top, left-side elevation, right-side elevation, and bottom plan views of the fourth embodiment of accessory case, into which the smartphone is inserted.

[0026] Figs. 21 A and 21 B are bottom plan views of a bottom region of the fourth embodiment of accessory case, with its slidable floor holding a light filter assembly and configured in, respectively, a light filter nondeployed position and a light filter deployed position.

[0027] Fig. 22 is an exploded view of major components of, and showing the smartphone aligned for insertion into, the fourth embodiment of accessory case.

[0028] Fig. 23A is a top plan view of the fourth embodiment of accessory case; and Fig. 23B is a cross sectional view taken along lines 23B— 23B of Fig. 23A, showing with its associated Detail A, the smartphone inserted into the fourth embodiment of accessory case.

[0029] Figs. 24 and its associated Detail E are side elevation views of lanyard holes; and Fig. 24A is a cross sectional view taken along lines 24A— 24A of Detail E.

[0030] Fig. 25A is a copy of Fig. 20F (rotated 90° clockwise); Fig. 25B is a cross sectional view taken along lines 25B— 25B of Fig. 25A, showing with its Detail B, the positioning of a slidable floor; and Fig. 25C is a cross sectional view taken along lines 25C— 25C of Fig. 25A, showing with its Detail C a detent to retain the position of the slidable floor.

[0031] Figs. 26A, 26B, and 26C are top plan, perspective, and side elevation views of a light filter assembly for the fourth embodiment of accessory case; Fig. 26D is a cross sectional view taken along lines 26D— 26D of Fig. 26A; and Fig. 26E, together with its associated Detail F, is a perspective view of an inner surface of the light filter assembly.

[0032] Fig. 27A and Fig. 27B, together with its associated Detail D, are plan views of an exterior surface of the slidable floor with the light filter assembly for the fourth embodiment of accessory case, respectively, attached to and absent from an arcuate recessed area of the slidable floor.

[0033] Fig. 28 is a cross sectional view taken along lines 28— 28 of Fig. 27A. [0034] Fig. 29 is an exploded view of a filter wheel for another smartphone accessory item.

[0035] Figs. 30 and 31 are cross sectional views taken along lines 30,31— 30,31 of Fig. 29, showing assembly of a filter into an elastomeric containment pocket of the filter wheel.

[0036] Fig. 32 is a cross sectional view of the smartphone and deployed filter wheel.

Detailed Description of Embodiments

[0037] Light reflected from a non-metallic surface becomes polarized; this effect is maximum at Brewster's angle, about 56° from the vertical (light reflected from metal is not polarized, due to the electromagnetic nature of light). A polarizer rotated to pass only light polarized in the direction perpendicular to the reflected light will absorb much of the light reflected from the non-metallic surface. This absorption allows reduction of glare reflected from, for example, a body of water or a road. Reflections from reflective surfaces of vegetation may also be reduced. Reflections from a window into a dark interior can be much reduced, allowing it to be seen through. (The same effects are available for vision by using polarizing sunglasses.)

[0038] In general, the sky is polarized according to the position of the sun (or at night, according to the position of the moon). For example, the maximum degree of polarization occurs in a circular band 90° from the sun. Thus, when the sun is located at its zenith, this circular band is coincident with the horizon. Consequently, an unfiltered photograph in the direction of the horizon (or in other directions) will show glare effects according to the degree of polarized light received.

[0039] Perpendicularly incident light waves tend to reduce clarity and saturation of certain colors, increasing haziness. A polarizing filter effectively absorbs these light waves, rendering outdoor scenes crisper with deeper color tones in subject matter such as blue skies, bodies of water, and foliage. For example, use of a polarizing filter, in the correct direction, removes the polarized component of skylight and therefore darkens the sky. Landscape and clouds, however, are less affected. The polarizing filter therefore produces a photographic effect having a darker and more dramatic sky, with an emphasis on the clouds.

[0040] The benefits of polarizing filters are generally not achievable by

conventional digital photography post-processing techniques. While software postprocessing can simulate many other types of filter, a photograph does not record the degree of polarization, so the optical effects of controlling polarization at the time of exposure cannot be replicated in software. A drawback of the iPhone^® and other smartphone cameras is that there is no integral lens filter available to control image brightness or reduce glare and thereby prevent overexposure arising from bright sunlight, oblique reflections from nonmetallic surfaces such as glass and water, or other external lighting conditions.

[0041] Fig. 1 is a perspective view of an accessory case 200 that fits snugly over back panel 12 of a cellular telephone in the form of a smartphone 14, such as an iPhone 4/4s^®. Smartphone 14 is shown positioned above and oriented for insertion into case 200, which includes a rotatable light filter assembly 210. Light filter assembly 210 holds a centrally located polarizing filter 32 for spatial alignment over a camera 18 (see, e.g., Fig. 4A) built in smartphone 14. As described below, light filter assembly 210 is slidably retractable to either cover or not cover a lens 20 of camera 18 (for conciseness, lens and camera are collectively, camera 18).

[0042] Filter 32 is of a linear polarizer type so its polarization state may be adjusted to reduce oblique reflections from nonmetallic surfaces and thereby promote increased image saturation. For example, filter 32 can darken blue skies and increase contrast of partly reflecting subjects, such as leaves and flowers. In other words, polarizing filter 32 has at least two applications in both color

photography and black-and-white photography: it reduces glare and surface reflection from unpolarized light, and it can darken the sky.

[0043] With reference to Fig. 1 , case 200 is in the form of a generally rectangular frame 212, with an open top region 214 and a partly open, user-configurable bottom region 216. Frame 212 includes a top side portion 220, a bottom side portion 222, an apertured side portion 224, and a notched side portion 226 that collectively form a perimeter of open top region 214. Frame 212, together with open top region 214 and bottom region 216, form a recess 228 with a slidable floor 230 defined by the interior surface of bottom region 216.

[0044] Fig. 2 is a perspective view of smartphone 14 inserted into recess 228 through open top region 214 and placed against floor 230. Smartphone 14 is inserted with its display screen 236 in a face-up position so that a user can access display screen 236 through open top region 214.

[0045] Top side portion 220 has an audio jack insertion point 250 and an On/Off button location 252. Bottom side portion 222 has a connector access and speaker opening 240. Apertured side portion 224 has a ringer button access opening 242 and a volume control button pair location 254. Notched side portion 226 has a camera-and-flash corner notch opening 244, which provides user access to rotate light filter assembly 210 while it is slidably deployed over camera 18.

[0046] Figs. 3A and 3B are perspective views of bottom region 216, showing smartphone 14 installed in accessory case 200, with its slidable floor 230 holding light filter assembly 210 and configured in, respectively, a light filter nondeployed position and a light filter deployed position. Fig. 3C is a fragmentary sectional view taken along lines 3C— 3C of Fig. 3A to show the structural components of light filter assembly 210 and its installation in slidable floor 230 and cooperative support by notched side portion 226 when in the nondeployed position of Fig. 3A.

[0047] With reference to Figs. 3A, 3B, and 3C, light filter assembly 210 includes an annular disk 260 having a beveled circumferential side margin 262 that fits inside a slot 264 of a pocket 266 formed in an arcuate notch 268 in the upper left-hand corner of slidable floor 230. Polarizing filter 32 fits inside of the central opening in annular disk 260. Slidable floor 230 fits within and is slidable along guides 270 formed near bottom region 216 and along the lengths of apertured side portion 224 and notched side portion 226. A similarly located and sized guide 272 is formed in top side portion 220. The length of slidable floor 230 is shorter than the lengths of apertured side portion 224 and notched side portion 226 by an amount 274 that facilitates bidirectional sliding movement of slidable floor 230 along guides 270 for user-selectable configuration in one of the deployed and nondeployed positions of light filter assembly 210.

[0048] With reference to Fig. 3A, setting light filter assembly 210 to the nondeployed position entails moving slidable floor 230 for placement of its bottom side margin 280 against bottom side portion 222 and thereby providing polarizing filter-free operational clearance for camera 18 and a flash lamp 282 on the back surface of smartphone 14. In the nondeployed position, guide 270 of notched side portion 226 provides lateral support for annular disk 260 by receiving its

circumferential side margin 262.

[0049] With reference to Fig. 3B, setting light filter assembly 210 to the deployed position entails moving, in the direction indicated by arrow 284, slidable floor 230 for placement of its top side margin 286 against top side portion 220 and thereby positioning polarizing filter 32 in spatial alignment with camera 18 on the back surface of smartphone 14. In the deployed position, guide 272 of top side portion 220 provides lateral support for annular disk 260 by receiving its circumferential side margin 262. Slot 264 and guide 272 are sized to permit rotation of annular disk 260, and therefore change the polarization state of polarizing filter 32, about an axis 288 (Fig. 5A) normal to floor 230.

[0050] Figs. 4A and 4B are perspective views of bottom region 216' of accessory case 200' with its slidable floor 230' holding an alternative light filter assembly 210' and configured in, respectively, a light filter nondeployed position and a light filter deployed position. Light filter assembly 210'differs from light filter assembly 210 primarily in that annular disk 260 of the latter is modified to be coplanar with the major surfaces of floor 230. Component parts and features of light filter assembly 210' corresponding to those of light filter assembly 210 have the same reference numerals followed by primes.

[0051] Figs. 4A and 4B show smartphone 14 installed in accessory case 200'. Fig. 4C is a fragmentary sectional view taken along lines 4C— 4C of Fig. 4A to show the structural components of light filter assembly 210' and its installation in slidable floor 230' and cooperative support by notched side portion 226' when in the nondeployed position of Fig. 4A. With reference to Fig. 4A, 4B, and 4C, light filter assembly 210' includes an annular disk 260' having a circumferential side margin 262' in which is routed a groove 290 that receives a tongue 292 formed in arcuate notch 268' in the upper left-hand corner of slidable floor 230'. Polarizing filter 32 fits inside of the central opening in annular disk 260'. Slidable floor 230' fits within and is slidable along guides 270' formed near bottom region 216' and along the lengths of apertured side portion 224' and notched side portion 226'. Tongues 292 are formed in guides 270'. A similarly located and sized guide 272' with tongue 292 is formed in top side portion 220'. The length of slidable floor 230' is shorter than the lengths of apertured side portion 224' and notched side portion 226' by an amount 274 that facilitates bidirectional sliding movement of slidable floor 230' along guides 270' for user-selectable configuration in one of the deployed and nondeployed positions of light filter assembly 210'.

[0052] With reference to Fig. 4A, setting light filter assembly 210' to the

nondeployed position entails moving slidable floor 230' for placement of its bottom side margin 280 against bottom side portion 222 and thereby providing polarizing filter-free operational clearance for camera 18 and flash lamp 282 on the back surface of smartphone 14. In the nondeployed position, guide 270' of notched side portion 226' provides lateral support for annular disk 260' by receiving its

circumferential side margin 262'.

[0053] With reference to Fig. 4B, setting light filter assembly 210' to the

nondeployed position entails moving slidable floor 230' for placement of its top side margin 286' against top side portion 220' and thereby positioning polarizing filter 32 in spatial alignment with camera 18 on the back surface of smartphone 14. In the deployed position, tongue 292 formed in guide 272' on top side portion 220' fits in groove 290 in side margin 262' to provide lateral support for annular disk 260'.

Tongue 292 and groove 290 are sized to permit rotation of annular disk 260', and therefore change the polarization state of polarizing filter 32, about axis 288 normal to floor 230'.

[0054] Figs. 5A and 5B show, respectively, rear side and front side views of the placement and fit of annular disk 260' of light filter assembly 210' of accessory case 200' to illustrate user adjustment of the polarization state of polarizing filter 32. A user rests his or her thumb on the portion of circumferential side margin 262' exposed by notch opening 244' and rotates annular disk 260' and perforce polarizing filter 32 as illustrated by direction arrow 296. The polarization state of polarizing filter 32 may be rotationally adjusted 360° to change a rotational position of filter 32 with respect to camera 18 while the user observes on display screen 236 image quality variations effected from filter 32. After determining a rotational position that yields a desired image quality (e.g., maximum reduction in glare or maximum enhancement in color), the user initiates image capture via touchscreen display screen 236 or a dedicated button.

[0055] Fig. 6 together with an enlarged detail rendering shows a volume-up button 298 raised above the surface of apertured side portion 224' at volume control button pair location 254 to facilitate user access when volume-up button 298 is operated as a dedicated camera shutter button. Volume-up button 298 is preferably made of hard rubber or plastic material connected by a flexible web to apertured side portion 224' to enable inward motion in response to a user pressing the button to snap a picture.

[0056] The following description of a set of drawing figures beginning with Fig. 7A and ending with Fig. 18B describes similar structural details of accessory case 200' shown in Figs. 4A, 4B, 4C, 5A, 5B, and 6. Therefore, accessory case and component parts and features of Fig. 7A through Fig. 18B use aforementioned reference numerals followed by double primes.

[0057] Figs. 7A and 7B are isometric views of, respectively, the front side and rear side of smartphone 14 inserted into accessory case 200". Figs. 8A, 8B, 8C, 8D, 8E, and 8F are, respectively, top plan, bottom, top, left-side elevation, right-side elevation, and bottom plan views of accessory case 200", into which smartphone 14 is inserted. Figs. 9A and 9B are bottom plan views of a bottom region of accessory case 200", with its slidable floor holding a light filter assembly 210" and configured in, respectively, a light filter nondeployed position and a light filter deployed position.

[0058] With reference to Fig. 10, frame 212" is of the same general design as that of frame 212 shown in Fig. 1 , except as indicated below by use of different reference numerals. A power key insert 302 and a volume keys insert 304 fit into apertures at, respectively, on/off button location 252 and volume control button pair location 254 of frame 212". A slidable floor 230" has an exterior surface 310 that includes in its upper left-hand corner an arcuate recessed area 312 into which light filter assembly 210" is inserted.

[0059] Exterior surface 310 also includes three spaced-apart grip bars 314 that facilitate a user's sliding of slidable floor 230" between the deployed and

nondeployed positions. Light filter assembly 210" includes an annular disk or filter wheel 260" into which polarizing filter 32 is inserted. An optional product label 316 may be set between filter wheel 260" and exterior surface 310 in recessed area 312. Slidable floor 230" has an interior surface 318 to which a back cover filter 142" is bonded. Back cover filter 142" is preferably a sheet of black felt having in its upper left-hand corner a semi-circular cutout portion 318 of a shape that exposes arcuate recessed area 312.

[0060] Fig. 1 1 A is a copy of Fig. 8A, with the addition of section lines 1 1 B— 1 1 B and its associated Detail A that define the cross sectional view of Fig. 1 1 B showing smartphone 14 inserted into accessory case 200" and held in place by an L-shaped elastomeric retainer 324. Detail A is an enlarged rendering showing the placement of elastomeric retainer 324 that fits in a groove 326 formed in side portions 220", 222", 224", and 226" near open top region 214 of frame 212". Elastomeric retainer 324 facilitates a snug fit of smartphone 14 inside accessory case 200".

[0061] Fig. 12A is a copy of Fig. 8F (rotated 90° clockwise), with the addition of section lines 12B— 12B and section lines 12C— 12C. Fig. 12B, together with its Detail M, defines a cross sectional view showing the positioning of slidable floor 230" with its exterior surface 310 set below the boundary of open top region 214" of rectangular frame 212". Fig. 12C, together with its Detail C, defines a cross sectional view showing a detent 328 formed in guide 270" of notched side portion 226" (and of apertured side portion 224", which is not shown in Fig. 12C) and sized to receive a tab portion 330 on the side margin of slidable floor 230" in a direction away from exterior surface 310 of slidable floor 230". Detents 328 and tab portions 330 cooperate to form a latch for slidable floor 230" in its deployed position and nondeployed (not shown in Fig. 12C) position.

[0062] Figs. 13A and 13B are top plan and perspective views of the outer surface of light filter assembly 210"; Fig. 13C is a side elevation view of light filter assembly 210". Fig. 13D is a sectional view taken along lines 13D— 13D of Fig. 13A. Fig. 13E, together with its associated Detail E and Detail F, is a perspective view of the inner surface of light filter assembly 210" (referred to collectively as "Figs. 13"). Figs. 13 show light filter assembly 210" including annular disk 260" having a centrally located aperture 332 encompassed by a circular lip 334 that receives an annular elastomeric filter retainer 336 and a circumferential edge 338 that is encompassed by an elastomeric grip edge 340. Annular disk 260" has on its inner surface an interior circular track 342 of rotation detent ramps 344 located proximal to

circumferential edge 338. Five wheel attachment snaps 346 are mutually angularly spaced apart around circular lip 334. When assembly 210" is attached and deployed, a mouth 341 (Fig. 13E) of circular lip 334 contacts back panel 12 of smartphone 14, encompasses camera 18, and forms an elastomeric light seal that suppresses ambient non-image light from reaching camera 18.

[0063] Fig. 14A and Fig. 14B, together with its associated Detail D, are plan views of exterior surface 310 of slidable floor 230" with light filter assembly 210", respectively, attached to and absent from arcuate recessed area 312. (Detail D is an enlarged fragmentary plan view of the features in arcuate recessed area 312 shown in Fig. 14B.)

[0064] Fig. 15A is a fragmentary sectional view taken along lines 15A— 15A of Fig. 14A; and Fig. 15B is an enlarged fragmentary perspective view of features in arcuate recessed area 312 of slidable floor 230". Figs. 16 and 17 are sectional views taken along lines 16— 16 and lines 17— 17, respectively, of Fig. 14A. [0065] With reference to Fig. 14B, together with its associated Detail D, and Figs. 15A, 15B, and 16, arcuate recessed area 312 includes a flash lamp aperture 348 and a central circular aperture 350 that receives circular lip 334 of annular disk 260" when light filter assembly 210" is attached to slidable floor 230". Central circular aperture 350 includes a raised rim member 352 that has on its outer surface a circumferential ridge 354 under which wheel attachment snaps 346 fit to hold annular disk 260" in place in slidable floor 230" as a user rotates filter 32. Two spaced-apart detent cantilever springs 356 each have cantilever spring rotation detent ramps 358 that mesh with rotation detent ramps 344 of annular disk 260" to produce an audible clicking sound as the user rotates filter 32 and to keep filter 32 in the desired rotational position when it is reached.

[0066] Fig. 18A, together with its associated Detail G, and Fig. 18B are, respectively, copies of Fig. 8F and Fig. 8E showing elevated volume-up button 298, which can be configured as a camera shutter button on smartphone 14. Elevating volume-up button 298 makes it easier to find by the user preparing to snap a picture.

[0067] The following set of drawing figures beginning with Fig. 19A and ending with Fig. 29B relates to an alternative accessory case 200a", which includes a slidable floor 230a" having an interior surface 318a to which a light filter assembly 210a" is attached. This differs from accessory case 200", which includes slidable floor 230" having an exterior surface 310 to which light filter assembly 210" is attached. Because of the similarity between accessory case 200" and alternative accessory case 200a", the following description provides design and assembly details of slidable floor 230a" and light filter assembly 210a", as well as any mating components.

[0068] With reference to Figs. 22 and 27B, slidable floor 230a" in its upper left- hand corner has an exterior surface 310a that includes a closed arcuate recessed area 312ae sized to receive a product label 316a in the form of an annular disk. Sidable floor 230a" also has in its upper left-hand corner an interior surface 318a that includes a partly open arcuate recessed area 312ai sized to receive light filter assembly 210a".

[0069] Figs. 24, 24A, and associated Detail E show a pair of lanyard attachment holes 320. A carrying strap (not shown) may be looped around a center section 322 formed in apertured side portion 224", and a notched side portion 226". [0070] Figs. 26A, 26B, 26C, 26D, and 26E show filter 32 removed from light filter assembly 210a" that includes annular disk 260a" having a central opening 332a that receives annular elastomeric filter retainer 336a and a circumferential edge 338a that is encompassed by an elastomer grip edge 340a. Annular disk 260a" has on its inner surface a circular recess 362 encompassing central opening 332a. A

downwardly depending circular sleeve (or barrel) 364 encompasses central opening 332a, and five wheel attachment snaps 346a positioned within circular recess 362 are mutually spaced apart around circular sleeve 364.

[0071] With reference to Fig. 27B, together with its associated Detail D, and Fig. 28, arcuate recessed area 312ai includes a flash lamp aperture 348a and a central circular aperture 350a that is encompassed by a raised rim member 352a having an annular shoulder 366. Central circular aperture 350a receives sleeve 364 of annular disk 260a" when light filter assembly 210a" is attached to slidable floor 230a". Wheel attachment snaps 346a fit against annular shoulder 366 of raised rim member 352a to hold annular disk 260a" in place in slidable floor 230a" as a user rotates filter 32. For smooth, uniform rotational adjustment, arcuate recessed area 312ai and interior circular track 342a (Fig. 26E) do not include corresponding spaced-apart detent cantilever springs and ramps, as in other embodiments.

[0072] Fig. 27A and corresponding cross section Fig. 28 show that when assembly 210a" is attached and deployed, a mouth 341 a (Fig. 26B) of retainer 336a would conform to back panel 12 of smartphone 14, encompass camera 18, and form an elastomeric light seal that suppresses ambient non-image light from reaching camera 18. Furthermore, when central opening 332a is fitted with filter 32 and light filter assembly 210a" is mated to arcuate recessed area 312ai, label 316a (Fig. 22) circumferentially encompasses downwardly depending circular sleeve 364 (Fig.

26E), and thereby provides lateral support to inhibit inadvertent dislodging of filter 32.

[0073] Fig. 29 is an exploded view of a filter wheel or annular disk 260a'" of a light filter assembly 210a'" (Fig. 32) for another type of smartphone 14"' (Fig. 32), such as an iPhone 5®. Annular disk 260a'" receives on its outer surface 402 a circular felt light seal 404 that is adhered to outer surface 402 and encompasses a central opening (also called a containment pocket) 332a'" of an annular elastomeric filter retainer 336a'" to suppress ambient light 406 (Fig. 32) from reaching a camera 18"' (when filter 32 is deployed). [0074] Figs. 30 and 31 are a sequence of cross sectional views taken along lines 30,31— 30,31 of Fig. 29, showing, respectively, filter 32 being inserted and fully installed into annular elastomeric filter retainer 336a'". Retainer 336a'" includes a flexible internal bead 410 around its inside mouth 416 defining containment pocket 332a'". Mouth 416 expands to receive filter 32 (Fig. 30), collapses around installed filter 32 (Fig. 31 ), and is laterally supported by a label 316a'" (Fig. 32) that inhibits outward flexing of mouth 416 and loss of filter 32.

[0075] Fig. 32 shows the thickness of seal 404 and felt 142a'" provides clearance 420 between a ridged mouth 418 of annular disk 260 a'" and camera 18"' so that mouth 341 a'" need not contact a back panel 12"' of smartphone 14"'. Therefore, clearance 420 facilitates sliding of a slidable floor 230a'" and eases positioning (rotational adjustment) of light filter assembly 210a'".

[0076] It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. Therefore, the scope of the present invention should be determined by the following claims and equivalents thereof.

Claims

1 . An accessory case to retain a smartphone in a mated relationship therewith, the smartphone having side margins and a built in camera with a lens that is substantially coplanar with a major surface of the smartphone, the accessory case comprising:

a frame having an open top region sized to receive the smartphone, a partly open bottom region including a floor that confronts a portion of the major surface while in the mated relationship, and interior side walls therebetween defining a recess that is sized to encompass the side margins of the smartphone while in the mated relationship;

a rotatable light filter assembly rotatably attached to the floor and including an annular disk encompassing a centrally located polarizing filter, the light filter assembly positioned on the floor at a filter location that achieves spatial alignment of the filter over the lens while in the mated relationship; and

a notch opening in the frame at a location that is proximal the camera while in the mated relationship, the notch opening sized to expose a circumferential side margin of the light filter assembly that provides a user access to perform tactile manipulation for rotational positioning of the filter via rotation of the annular disk about an axis normal to the slidable floor to thereby change the polarization state of the polarizing filter.

2. The accessory case of claim 1 , in which the floor comprises a slidable floor to confront the portion of the major surface, the area of the portion being less than the area of the open top region by an amount that facilitates bidirectional sliding movement of the slidable floor in a direction transverse to a pair of interior sidewalls for user-selectable configuration of the slideable floor and in deployed and

nondeployed positions.

3. The accessory case of claim 2, in which the notch opening is in a corner of the frame and provides user access to rotate the light filter assembly while it is in the deployed position over the lens.

4. The accessory case of claim 2, in which the slidable floor includes a bottom side margin, the interior side walls include a bottom side wall having connector and speaker openings, and in which the bottom side margin contacts the bottom side wall while in the nondeployed position to thereby provide non-polarizing filter-free operational clearance for the camera.

5. The accessory case of claim 4, in which in which the slidable floor fits within and is slidable along guides, the guides formed in the partly open bottom region and along lengths side portions of the side walls so that in the nondeployed position the guides receive the circumferential side margin and provide lateral support for the annular disk.

6. The accessory case of claim 2, in which the slidable floor fits within and is slidable along guides formed in the partly open bottom region and along lengths side portions of the interior side walls.

7. The accessory case of claim 2, in which the notch opening in the frame is sized to expose the circumferential side margin of the rotatable light filter assembly while the slidable floor is positioned in the deployed position.

8. The accessory case of claim 1 , in which the frame includes an apertured side portion including a volume control button pair location, the location

encompassing an raised volume control button configured as a shutter camera shutter button.

9. The accessory case of claim 1 , in which the polarizing filter comprises a linear or a circular polarizing filter.

10. The accessory case of claim 1 , in which light filter assembly is rotatably adjustable 360° about the axis to change a rotational position of filter with respect to lens.

1 1 . The accessory case of claim 1 , in which the floor includes an interior felt surface that confronts the major surface of the smartphone to suppress ambient light reaching the camera.

12. The accessory case of claim 1 , in which the light filter assembly includes an elastomeric filter retainer that holds the filter, the retainer including a mouth that contacts and encompasses the lens to suppress non-image ambient light from reaching the lens.

13. The accessory case of claim 1 , in which the annular disk is non-opaque and the floor includes a flash aperture for spatial alignment with a camera flash device and transmission of flash lighting via the annular disk and the flash aperture.