Patent Application
20110194167
This invention relates to displays. Examples of applications in which displays may be applied include: displays which are configured to display information to operators or passengers in vehicles such as cars, trucks, airplanes, boats; displays which are configured to display information to users of electronic equipment and the like. Some embodiments provide Head UP displays (HUDs).
The following patents and applications describe some example displays:
A Head Up Display (HUD) is a display capable of projecting information directly into a human's visual field. HUDs and elements for HUDs are described, for example, in:
There remains a need for cost-effective displays for use in a wide range of applications and for displays which provide alternatives to existing display technologies.
This invention provides displays and methods for making displays. The invention has several aspects that may be applied in combination with one another or individually.
One aspect provides side-lit displays comprising at least one side-lit block or layer. The side-lit block or layer includes a barrier at which light is deflected or absorbed such that patterns on opposing sides of the barrier may be illuminated independently. The barrier may be formed by sub-surface etching.
Another aspect provides side-lit displays in which etched patterns can be selectively illuminated. The patterns are etched in such a manner that they interact primarily with light having specific polarizations. The patterns are selectively illuminated with light of appropriate polarizations.
Another aspect provides a display comprising an optically transparent block. The block has a front face and one or more sides. At least one barrier is defined in the block. The barrier divides the block into a plurality of segments. At least one light source is associated with each of the segments. The light sources are optically connected to emit light into one of the one or more sides. At least one patterned area is provided in each of the segments. The patterned areas may, for example, have the form of icons, letters, numerals, words, or the like. The patterned area is configured to scatter light so as to be visible through the front face when illuminated by the associated light source. The barrier is configured to block light from the light source associated with one of the segments from illuminating the patterned area in a different one of the segments.
Another aspect provides head-up displays which include side lighting by a plurality of multicolored light-emitting devices.
Another aspect provides side-lit displays comprising ferrofluidic display elements.
Another aspect provides methods for making displays which include etching patterns in one or more side-lit layers using polarized light.
Displays as described herein have example application in commercial, industrial and consumer visual displays, indicator lighting and other visual interfaces such as HUDs.
Other aspects of the invention and features of a range of example embodiments are described below and shown in the accompanying drawings.
The appended drawings illustrate various example embodiments of the invention. The drawings are non-limiting and are illustrative rather than restrictive.
Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure.
Patterns 14 may be made to suit an intended application of display 10. For example, patterns 14 may comprise arrows, numbers, words, letters, icons, symbols, geometric elements, or the like.
Light sources 16A, 16B, 16C (collectively or generally light sources 16) are provided adjacent one or more sides of block 12. When one of light sources 16 is operated, light from the light source 16 enters block 12 and illuminates one or more of patterns 14, thereby making the illuminated patterns 14 stand out to an observer viewing display 10. For example, as shown in
In the illustrated embodiment, light sources 16A and 16B are configured to emit light that illuminates patterns 14 at different depths (as measured, for example, from the front face 21 of block 12). In some embodiments light sources 16 emit, or can be controlled to emit, light of different colors such that different patterns 14 may be simultaneously made visible in different colors or the same pattern 14 may be displayed at different times to have different colors.
In the illustrated embodiment, a barrier 18 is etched within block 12. Barrier 18 comprises an etched surface within block 12 such that light propagating in block 12 on one side of barrier 18 tends not to propagate through barrier 18. For example, barrier 18 may scatter and attenuate light that hits it or scatter or reflect light in a direction away from the viewer. In the illustrated embodiment, barriers 18 extend substantially perpendicularly to the front surface 21 of block 12 and patterns 14 extend substantially parallel to front surface 21.
The presence of barrier 18 facilitates the independent display of patterns on either side of barrier 18. For example, in the illustrated embodiment, patterns 14A and 14C are at the same depth within block 12. Light from light source 16A would illuminate both of patterns 14A and 14C if it were not for the presence of barrier 18 between patterns 14A and 14C. Similarly, light from light source 16C would illuminate both of patterns 14A and 14C if it were not for the presence of barrier 18.
Barrier 18 and patterns 14 may be formed using the same etching processes. Preferably barrier 18 is constructed such that light from light sources 16 propagating within block 12 does not scatter off of barrier 18 toward the viewing side of display 10. In some embodiments a plurality of barriers 18 are provided to divide the volume of block 12 into a plurality of different segments 13 within which the illumination of patterns 14 can be separately controlled. In alternative embodiments, barriers 18 may be formed by depositing light scattering and/or absorbing particles within block 12, making cuts in block 12 and/or inserting or forming opaque barriers in block 12.
The provision of barriers 18 permits different regions or ‘segments’ 13 (and patterns 14 in those regions) to be illuminated or not illuminated independently of one another and/or to be illuminated with light of different colors. Thus, displays which incorporate barriers 18 may be made in a way that facilitates richer displays of information by way of patterns 14 that are packed relatively closely together and yet can be independently illuminated.
Barriers 18 may extend all of the way through block 12 from front surface 21 to back surface 23. This is not mandatory. In some embodiments barriers 18 only block the passage of light in certain layers within block 12. In some embodiments, barriers 18 are formed so as to divide a display or a display layer into two, three or more distinct segments such that patterns 14 in any one of the distinct segments may be illuminated independently of patterns 14 in others of the distinct segments.
In some embodiments, patterns 14 and/or barriers 18 are formed by laser etching of block 12. This may be achieved, for example, through the use of commercially-available sub-surface laser engraving systems (SSLE systems). Patterns 14 and barriers 18 may be defined in terms of computer generated graphics and a computer-controlled SSLE system may be used to form patterns 14 and barriers 18 within block 12.
Some embodiments are structurally similar to display 10 except that block 12 comprises a plurality of separate layers 19 stacked together. In such embodiments, patterns 14 may be formed on surfaces of the individual layers 19 by, for example, selectively sandblasting, embossing, abrading, or applying light-scattering material to form patterns 14. In addition, or in the alternative, sub-surface engraving techniques may be applied to form patterns 14 within layers 19 of block 12. The layers 19 may then be clamped and/or bonded together to form block 12. In some embodiments, layers 19 are coated or are separated by sheets of material having optical characteristics such that light tends to remain within layers 19 until it is scattered by interaction with a pattern 14 or barrier 18. An example of a block 12 made up of different layers 19 is illustrated in
In some embodiments, display layers 19 are separated from one another by optical films. The optical films may be sandwiched between layers 19.
In some embodiments there may be two or more corresponding patterns 14 that are intended to be always illuminated together. In such embodiments a single output 16 may control one or more light sources 16 that collectively illuminate the two or more corresponding patterns 14. In some embodiments, some or all of the two or more corresponding patterns 14 are in different layers from one another and/or are in different segments from one another separated by barriers 18.
Light sources 16 corresponding to one output 31 may be oriented to illuminate corresponding patterns 14 that are different from those illuminated by the light sources 16 connected to other outputs 31.
In some embodiments, light sources 16 controlled by one output 31 illuminate a particular layer within a display and/or a different segment within a layer with light of a particular color. Sufficient outputs 31 may be provided to individually control the illumination of each pattern 14 (or group of patterns 14). In some embodiments, light sources of a plurality of colors are provided to illuminate some or all patterns 14. In such embodiments the pattern 14 may be illuminated in any selected one of the plurality of colors, illuminated in a combination of the plurality of colors or not illuminated by appropriately controlling outputs 31.
A data link 35 brings external sensor input and/or control signals that indicate which features of the display should be illuminated (and in which color in some embodiments) to a main display controller 32. Display controller 32 is connected to control the individual control chips 30 by way of a communication bus 34. Communication bus 34 may have any suitable architecture. For example, bus 34 may be connected to deliver communication signals from main display controller 32 directly to each control chip 30, control chips 30 may be daisy chained such that control signals pass to some control chips 30 by way of other control chips 30, or the like.
Controller 32 may operate light sources to provide a range of visible effects. For example, controller 32 may:
In the embodiment illustrated in
Various materials and techniques may be applied to hold light sources 16 in place. For example, light sources 16 may be bonded to light guides or directly to block 12 using suitable adhesives. For example, transparent potting material or cyanoacrylate adhesives may be used to hold light sources 16 in place in some embodiments.
In the embodiment illustrated in
LEDs 41 may comprise any suitable types of LEDs including RGB, single color, round, square, large, small, standard or high-emitting, white LEDs (white with color filters for color options), standard color LEDs, etc. The type of LEDs used as light sources 16 may be suited to the application of the display. The quality and degree of light emitted by a display as described herein can depend upon the type of light sources used.
In some embodiments light sources 16 comprise laser diodes. The laser diodes may be of a type that lacks a housing or collimating optics. An aperture of the laser diode may be placed in direct optical contact with an side surface of block 12. The surface may be frosted.
In some embodiments, patterns 14 are configured to preferentially scatter light of certain polarizations. In such embodiments, light from light sources 16 corresponding to a particular pattern 14 may be polarized so as to be preferentially scattered by the corresponding pattern 14. Other nearby patterns 14 may be configured to scatter light of other polarizations preferentially. This reduces the degree to which a pattern 14 can unintentionally be made visible by light intended to illuminate an adjacent pattern 14.
Patterns 14 may be made to scatter polarized light preferentially by engraving those patterns 14 using polarized light. For example, some patterns 14 may be engraved using horizontally polarized light and some patterns 14 may be engraved using vertically polarized light. An etch made using circularly polarized light may block both horizontally-polarized and vertically-polarized light. An etch made using circularly polarized light may be applied to advantage in making barriers 18.
In a non-limiting example embodiment, an etch is polarized by slowly heating and cooling the section of block 12 to be etched using a polarized sub surface laser beam. The laser beam may be generated, for example using a frequency doubled 532 nm laser diode operating at a pulse rate of 2 kHz. The laser beam may, for example, have a power of 100 W or less. Temperature of the block prior to etching may be, for example, in the range of 15-30° C.
Ferrofluids are fluids having ferromagnetic properties. such fluids may comprise colloidal dispersions of small magnetic particles. An example of a ferrofluid that may be used as ferrofluid 53 is an optical-grade ferrofluid comprising magnetic particles carried in ethylene glycol. Such a ferrofluid may be made, for example, by preparing FeCl3 and FeCl2 in aqueous hydrochloric acid with a sodium hydroxide and trisodium citrate dehydrate solution added at 6% of the molar ratio of the Ferrous solution for optimal results. Water is then added to produce maghemite (γ-Fe2O3) which is stabilized by coating with 2-[2-(2-methoxyethoxy)ethoxy]acetic acid (MOEEAA). A ferrofluid can then be obtained by dispersion of the stabilized particles in ethylene glycol at a weight percentage of particles in the range of 10% -25% for example. Silver nanoparticles with a copper base may be sprayed on the resulting ferrofluid in order to improve its optical properties. The silver particles may, for example have dimensions on the order of 40-60 nm.
Coils 52 generate magnetic fields when energized. The magnetic fields can draw ferrofluid 53 from a reservoir 54 into a selected cavity 51 or vice versa by way of channels 55. Some embodiments have a common reservoir 54 while other embodiments have a reservoir 54 dedicated to each cavity 51. Light sources 16 the same as or similar to those described above may illuminate the ferrofluid-filled chambers 51.
For example, in the illustrated embodiment, ferrofluid 53 may be drawn from all reservoirs 51 into reservoir 54 by switching on coil 52A and switching off all other coils 52. Display 50 may be placed in an ‘inactive’ state by energizing coil 52A switching off other coils 52 and turning off light sources 16.
Ferrofluid 53 may be drawn into cavity 51B by switching on coil 52B, and so on. A ferrofluid-filled cavity 51 may be illuminated in the same manner as patterns 14.
When switch 62 is to the right, as illustrated, then circuit 60C energizes coil 52C while circuit 62B keeps coil 62B turned off. When switch 62 is to the left then circuit 60C turns coil 52C off while circuit 62B energizes coil 62B.
A display may combine one or more ferrofluid elements with one or more etched patterns 14. In some embodiments, ferrofluid elements may be configured to selectively block or reveal all or portions of certain etched patterns 14.
Displays as described herein have a wide variety of applications and configurations. The appearance of patterns 14 may be customized for specific applications. For example:
While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. By way of non-limiting example:
This application claims the benefit under 35 U.S.C. 119 of U.S. application No. 61/271,284 filed 20 Jul. 2010 and entitled LOW-COST COLOR TRANSPARENT DISPLAY USING MULTISEGMENTED MULTIPLANAR PANELS which is hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61271284 | Jul 2009 | US |
