KR20110057197A - Light turning device with prismatic light turning features - Google Patents

Abstract

The light guide device includes a light guide 182 and two or more spaced apart slits 100. The slits 100 are formed by cutouts in the light guide 182. Sidewalls of the slits form facets to redirect light impinging on the facets. In some embodiments, the light guide is attached to the light source 192. The light source 192 emits light and the light is introduced into the light guide 182, and the slits 100 redirect the light from the light guide 182 to the desired target. In some embodiments, the target is a display, and the first plurality of slits 100 direct light from the light source 192 across the light guide 182 onto the face of the display. The second plurality of slits 100 direct light from the light guide 182 towards the display.

Description

LIGHT TURNING DEVICE WITH PRISMATIC LIGHT TURNING FEATURES}

Reference to Related Application

This application claims the benefit of priority under 35 U. S. C. § 119 (e) of US provisional patent application 61 / 093,695 (filed September 2, 2008).

Technical Field of the Invention

The present invention generally relates to a light turning device. In particular, the present invention relates to a light turning device using a prism-like structure for guiding light to illuminate a display, for example. In addition, the present invention relates to a method of use and manufacturing method of the device.

Microelectromechanical systems (MEMS) include micromechanical elements, micro actuators and microelectronic devices. The micromechanical element may be formed using deposition, etching and / or other micromachining processes that etch a portion of the substrate and / or the deposited material layer or add layers to form an electromechanical device. have. One type of MEMS device is called an interferometric modulator. As used herein, the term interferometric modulator or interferometric light modulator means an apparatus that selectively absorbs and / or reflects light using the principles of optical interference. In certain embodiments, the interferometric modulator may comprise a pair of conductive plates, wherein either or both of the pair of conductive plates may be transmissive and / or reflective in whole or in part and may be suitable for If you do, you can do relative exercises. In certain embodiments, one conductive plate may comprise a pinned layer deposited on a substrate, and the other conductive plate may comprise a metal film separated by an air gap from the pinned layer. As will be explained in more detail herein, the optical interference of light incident on the interferometric modulator can be varied by the relative position of the conductive plate. The scope of application of these devices is extensive, and using and / or modifying the features of this type of device is such that these properties can be used to improve existing products and to create new products that have not yet been developed. It will be useful in the art.

In some embodiments, a light guide apparatus is provided. The device comprises the light guide formed of a light propagating material that supports the propagation of light through the length of the light guide body. The light guide is defined by a plurality of outer surfaces. A first outer surface of the outer surfaces includes a plurality of spaced apart first slits configured to redirect light incident on the light guide, wherein each slit is cut out in the first outer surface It is formed by an undercut. A second outer surface of the outer surfaces includes a plurality of spaced apart second slits configured to redirect the light incident on the light guide, wherein each slit is formed by a cutout portion in the second outer surface.

In some other embodiments, an illumination device is provided. The apparatus comprises first means for generating light and guiding the light to propagate through a light turning body; Second means for redirecting light propagating through the light turning body; And third means for redirecting light propagating through the light turning body.

In yet another embodiment, an illumination method is provided. The method includes propagating light through the light turning body. Light propagating through the light guide is redirected by impinging light on facets of the first and second plurality of slits. The plurality of slits are formed by cutouts in two surfaces of the light turning body.

In some other embodiments, a method of manufacturing a lighting device is provided. The method includes providing a body of light propagating material that supports propagation of light through the length of the body of light propagating material. First and second plural spaced cut out portions are formed on different sides of the body. In some other embodiments, an illumination device formed by this method is provided.

1 is an isometric view of a portion of an embodiment of an interferometric modulator display with a movable reflective layer of a first interferometric modulator in a relaxed position and a movable reflective layer of a second interferometric modulator in an operating position;
2 is a system block diagram illustrating one embodiment of an electronic device incorporating a 3x3 interferometric modulator display.
3 is a diagram showing the position of the movable mirror versus the applied voltage for one exemplary embodiment of the interferometric modulator of FIG. 1;
4 shows a set of row and column voltages that can be used to drive an interferometric modulator display;
5A illustrates one exemplary frame of display data in the 3x3 interferometric modulator display of FIG. 2;
FIG. 5B illustrates one exemplary timing diagram of the row and column signals that may be used to write the frame of FIG. 5A; FIG.
6A and 6B are system block diagrams illustrating one embodiment of a visual display device including a plurality of interferometric modulators.
7A is a cross-sectional view of the device of FIG. 1;
7B is a cross-sectional view of an alternative embodiment of an interferometric modulator;
7C is a cross-sectional view of another alternative embodiment of an interferometric modulator;
7D is a cross-sectional view of another alternative embodiment of an interferometric modulator;
7E is a sectional view of a further alternative embodiment of an interferometric modulator;
8 is a sectional view of a display device;
9 is an enlarged view of a portion of the cross-sectional view of FIG. 8;
10A is a cross-sectional view of one embodiment of a light turning feature.
10B is a cross-sectional view of another embodiment of a light turning structure.
10C is a cross-sectional view of another embodiment of a light turning structure.
11A is a plan view of one embodiment of a display device;
11B is a cross-sectional view of the display device of FIG. 11A;
11C-11E are plan views of embodiments of the display device;
12A and 12B are cross-sectional views of embodiments of the display device;
13A-13C are plan views of embodiments of the display device.

Although the following detailed description is directed to certain specific embodiments of the present invention, the present invention may be implemented in various ways. In this description, the same parts will be described with reference to the drawings denoted by the same reference numerals. Each embodiment may be any device that is configured to display an image depending on whether it is a moving image (e.g. video) or a still image (e.g. still image) and a character or a picture. Can be implemented. More specifically, each embodiment is a mobile phone, a wireless device, a personal data assistant (PDA), a mini or portable computer, a GPS receiver / navigator, a camera, an MP3 player, a camcorder, a game console, a wrist watch, a clock, Calculators, television monitors, flat panel displays, computer monitors, automotive displays (e.g. odometer displays, etc.), cockpit controls and / or displays, camera view displays (e.g. rear views of vehicles view) a variety of electronic devices, including but not limited to displays of cameras), electronic photographs, electronic billboards or signs, projectors, architectural structures, packages and art structures (e.g., display of images for jewelry). It is contemplated that this may be implemented or associated with the various electronic devices. MEMS devices of structures similar to those described herein may also be used for non-display applications such as in electronic switching (ie, switching) devices and the like.

Some embodiments disclosed herein include a light guide having portions cut into the body. The cutouts form prismatic structures, also called slits, which redirect or redirect light propagating through the light guide. For example, the walls of the cutouts redirect light in the desired direction. In some embodiments, the light source is connected to the light guide. Light from the light source is introduced into the light guide, propagates through the light guide and contacts the facets of the cut out portions. The facet of the slit, for example, redirects light from the light guide to a display, for example an interferometric modulator. In some embodiments, the first and second plurality of slits are formed on opposing major surfaces (main surface or major side) of the light guide. The slit is configured to redirect light from a common main surface.

In some other embodiments, the plurality of slits are formed in a line light source. For example, the slits are positioned and tilted to redirect light introduced into the line light source from a point light emitter at the end of the line light source. The redirected light may be emitted, for example, from a line light source along the length of the light source, or in some other embodiments to an area comprising a second plurality of slits. The second plurality of slits redirect the light towards the display.

One embodiment of one reflective interferometric modulator display comprising an interferometer MEMS indicator is illustrated in FIG. 1. In these devices, the pixels are in a bright state (or bright state) or a dark state (dark state). In the bright ("relaxed" or "open") state, the display element reflects a large portion of the incident visible light to the user. When in the dark ("activated" or "closed") state, the display element reflects little incident visible light to the user. The light reflection characteristics of the "on" and "off" states may be reversed depending on the embodiment. MEMS pixels are configured to reflect preferentially in the selected color to enable color display in addition to black and white.

1 is an isometric view showing two adjacent pixels in a series of pixels of a visual display, where each pixel comprises a MEMS interferometric modulator. In some embodiments, the interferometric modulator display includes a row / column array of these interferometric modulators. Each interferometric modulator includes a pair of reflective layers located at variable and controllable distances from each other to form a resonant optical cavity having at least one variable dimension. In one embodiment, one of the reflective layers may move between two positions. In a first position, also referred to herein as a relaxed position, the movable reflective layer is located relatively far from the fixed partial reflective layer. In a second position, also referred to herein as an operating position, the movable reflective layer is located closer to the stationary partially reflective layer. Incident light reflected from these two layers constructively or destructively interferes depending on the position of the movable reflective layer to produce an overall reflective state or non-reflective state for each pixel.

The illustrated portion of the pixel array in FIG. 1 includes two adjacent interferometric modulators 12a and 12b. In the interferometric modulator 12a located on the left side, the movable reflective layer 14a is illustrated at a relaxed position away from the optical stack 16a including the partial reflective layer. The interferometric modulator 12b located on the right side illustrates the movable reflective layer 14b in an operating position adjacent to the optical stack 16b.

The optical stacks 16a, 16b (collectively referred to as "optical stacks 16") referred to herein typically comprise several fused layers, which are indium tin oxide ( an electrode layer such as indium tin oxide (ITO), a partially reflective layer such as chromium, and a transparent dielectric. Thus, the optical stack 16 is electrically conductive, partially reflective, and can be manufactured, for example, by depositing one or more of the layers onto the transparent substrate 20. The partially reflective layer (ie, partially reflective layer) may be formed of various partially reflective materials such as various metals, semiconductors and dielectrics. The partially reflective layer may be formed of one or more layers of material, each of which may be formed of a single material or a combination of materials.

In some embodiments, as will be described further below, the layers of the optical stack 16 are patterned into parallel strips, and within a display device (ie, display) as further described below. Row electrodes may also be formed. The movable reflective layers 14a, 14b are the intervening sacrificial material deposited between the pillar portions 18 and the deposited metal layer or deposited metal layers deposited on the top surface of the pillar portion 18 (optical laminations 16a, 16b). May be formed as a series of parallel strips) orthogonal to the row electrodes). When the sacrificial material is etched away, the movable reflective layers 14a, 14b are separated from the optical stacks 16b, 16b by a predetermined gap 19. A highly conductive and reflective material such as aluminum can be used for the reflective layer 14, and these strips may form columnar electrodes in the display. 1 is not to scale. In some embodiments, the spacing between the pillars 18 may be on the order of 10 to 100 μm, while the gap 19 may be on the order of <1000 mm 3.

As illustrated by the pixel 12a in FIG. 1, when no voltage is applied, the gap between the movable reflective layer 14a and the optical stack 16a in a state where the movable reflective layer 14a is mechanically relaxed. 19) is maintained. However, when a potential (voltage) difference is applied to the selected row and column, the capacitor formed at the intersection of the row electrode and the column electrode in the corresponding pixel is charged, and the electrostatic force pulls the electrodes together. If the voltage is high enough, the movable reflective layer 14 deforms and exerts a force on the optical stack 16. The dielectric layer (not shown in this figure) in the optical stack 16 is short-circuited to prevent the separation distance between layers 14 and 16, as indicated by the working pixels 12b on the right side of FIG. Adjust. This behavior is the same regardless of the polarity of the applied potential difference.

2-5B illustrate one exemplary process and system for using an array of interferometric modulators in display applications.

2 is a system block diagram illustrating one embodiment of an electronic device that may contain interferometric modulators. The electronic device includes a processor 21, which is an ARM (registered trademark), Pentium (registered trademark), 8051, MIPS (registered trademark), Power PC (registered trademark), ALPHA (registered trademark) A general purpose single chip processor or a multi chip microprocessor, or any special purpose microprocessor such as a digital signal processor, a microcontroller, or a programmable gate array. As is conventional in the art, the processor 21 may be configured to execute one or more software modules. In addition to the execution of an operating system, the processor may be configured to execute one or more software applications, including a web browser, a telephone application, an email program, or any other software application.

In one embodiment, the processor 21 is also configured to communicate with the array driver 22. In one embodiment, the array driver 22 includes a row driver circuit 24 and a column driver circuit 26 that provide signals to the display array or panel 30. The cross section of the array illustrated in FIG. 1 is indicated by line 1-1 of FIG. 2. However, while FIG. 2 illustrates a 3x3 array of interferometric modulators for clarity, the display array 30 may include a vast number of interferometric modulators and may differ in a row direction rather than in a column direction (e.g., 300 pixels per row x 190 pixels per column).

3 is a diagram of movable mirror position versus applied voltage for one exemplary embodiment of the interferometric modulator of FIG. 1. For MEMS interferometric modulators, the row / column operation protocol may utilize the hysteresis characteristics of these devices as illustrated in FIG. 3. The interferometric modulator may, for example, require a potential difference of 10 volts to deform the movable layer from a relaxed state to an operating state. However, if the voltage decreases from this value, the movable layer remains in that state when the voltage drops back below 10 volts. In the illustrated embodiment of FIG. 3, the movable layer does not fully relax until the voltage drops below 2 volts. As such, in the example illustrated in FIG. 3 there is a voltage range of about 3 to 7 V, where there is a window of applied voltage in which the device is stable in a relaxed or operating state. This is referred to herein as a "hysteresis window" or "stability window." For the display array with the hysteresis characteristics of FIG. 3, the pixels to be operated in the strobe row during row strobing are exposed to a voltage difference of about 10 volts, and the pixels to be relaxed are close to zero volts. Row / column operating protocols can be designed to be exposed to After strobing, the pixels are exposed to a steady state or bias voltage difference of about 5 volts to maintain the state in which the row strobeing placed the pixels. In this example, each pixel, after being written, exhibits a potential difference within a "stable window" of 3 to 7 volts. This characteristic stabilizes the pixel design illustrated in FIG. 1 under the same applied voltage conditions in the existing state of operation or relaxation. Since each pixel of the interferometric modulator is essentially a capacitor formed by the fixed reflective layer and the movable reflective layer depending on whether it is operating or relaxed, this stable state can be maintained at the voltage in the hysteresis window with little power loss. If the applied potential is fixed, no current flows into the pixel.

As described further below, in a typical application, an image is transmitted by transmitting a set of data signals (each having a predetermined voltage level) across a set of column electrodes according to the desired set of operating pixels in the first row. It can also form a frame. Next, a row pulse is applied to the electrodes of the first row to operate the pixels corresponding to the set of data signals. The set of data signals is then changed to correspond to the desired set of working pixels in the second row. A pulse is then applied to the electrodes of the second row to actuate the appropriate pixels in the second row in accordance with the data signal. The pixels in the first row remain unaffected by the pulses in the second row and remain as they were set during the pulses in the first row. This may be repeated sequentially for a whole series of rows to create a frame. In general, by repeating this process by the desired number of frames per second, the frames are refreshed and / or updated with new display data. In addition, a wide variety of protocols for driving the row electrodes and column electrodes of the pixel array for creating the image frame may be used.

4, 5A and 5B illustrate one possible operating protocol for generating display frames on the 3x3 array of FIG. FIG. 4 illustrates a possible set of row voltage levels and column voltage levels that may be used for the pixel representing the hysteresis curve of FIG. 3. In the embodiment of Figure 4, to operate the pixel it is necessary to set the appropriate column to -V _bias and the appropriate row to + ΔV, where -V _bias And + ΔV correspond to −5 volts and +5 volts, respectively. Pixel relaxation is accomplished by setting the appropriate rows with the same + ΔV, where the volt potential difference for the pixels is zero, and setting the appropriate columns with + V _bias . In these rows where the row voltage remains at zero volts, the pixels are stable whatever their original state, regardless of whether the column is a -V _bias or a + V _bias . As also illustrated in FIG. 4, it will be appreciated that voltages of opposite polarity to those described above may be used. For example, turning on a pixel sets the appropriate column to + V _bias This may involve setting the appropriate row to -ΔV. In this embodiment, pixel relaxation is performed by setting the appropriate row with the same -ΔV and the appropriate column with -V _bias , which produce a zero volt potential difference for the pixel.

FIG. 5B is a timing diagram illustrating a series of row and column signals applied to the 3x3 array of FIG. 2 in the display configuration illustrated in FIG. 5A, wherein the operational pixels are non-reflective. Prior to writing the frame illustrated in FIG. 5A, the pixels may be in any state, in this example, all rows are initially zero volts and all columns are +5 volts. According to these applied voltages, the pixels are all stable in their existing operating or relaxed state.

In the frame of Fig. 5A, (1,1), (1,2), (2,2), (3,2) and (3,3) pixels are operated. To accomplish this, the first and second columns are set to -5 volts and the third column is set to +5 volts during the "line time" for the first row. This does not change the state of any pixels because all the pixels remain in the 3 to 7 volt stability window. Next, the first row is strobe with pulses going from zero to five volts and back to zero volts. This operates the (1,1) pixel and the (1,2) pixel and relaxes the (1,3) pixel. Other pixels in the array are not affected. To set the second row as desired, set the second column to -5 volts and the first and third columns to +5 volts. Next, the same strobe applied to the second row will activate the (2,2) pixels and relax the (2,1) and (2,3) pixels. Again, other pixels of the array are not affected. The third row is similarly set by setting the second column and the third column to -5 volts and the first column to +5 volts. The strobe of the third row sets the pixels of the third row as shown in FIG. 5A. After writing the frame, the row potentials can be zero and the column potentials can be held at +5 volts or -5 volts, so that the display is stable in the configuration of FIG. 5A. It will be appreciated that the same process can be used for arrays with tens or hundreds of rows and columns. In addition, the timing, procedure, and voltage levels used to perform the row and column operations can vary widely within the general principles of the foregoing, the examples are merely illustrative, and other operating voltage methods are described herein. It will also be appreciated that it can be used with systems and methods.

6A and 6B are system block diagrams illustrating one embodiment of the display device 40. For example, the display device 40 may be a mobile phone or a mobile phone. However, the same components of the display device 40 or some variations thereof may also include various types of displays, such as televisions, portable media players.

The display device 40 includes a housing 41, a display 30, an antenna 43, a speaker 45, an input device 48, and a microphone 46. The housing 41 is generally formed by any of a variety of manufacturing processes well known to those skilled in the art, including injection molding and vacuum molding. In addition, the housing 41 may be made of any of a variety of materials including, but not limited to, plastic, metal, glass, rubber and ceramic, or a combination thereof. In one embodiment, the housing 41 includes detachable portions (not shown) that may be compatible with the detachable portions having different colors or including different logos, pictures or symbols.

The display 30 of the exemplary display device 40 may be any of a variety of displays, including bistable displays, as described herein. In another embodiment, the display 30 may be a flat panel display, such as a plasma, EL, OLED, STN LCD or TFT LCD, as described above, or non-flat, such as a CRT or other type of tube device. flat-panel) display. However, for the purpose of describing this embodiment, the display 30 includes an interferometric modulator display as described herein.

Components of one embodiment of exemplary display device 40 are schematically illustrated in FIG. 6B. The exemplary display device 40 shown may include a housing 41 and may include additional components at least partially housed therein. For example, in one embodiment, exemplary display device 40 includes a network interface 27 that includes an antenna 43 coupled to a transceiver 47. The transceiver 47 is connected to the processor 21, which is connected to conditioning hardware 52. Conditioning hardware 52 may be configured to adjust the signal (eg, filter the signal). Conditioning hardware 52 is connected to a speaker 45 and a microphone 46. The processor 21 is also connected to the input device 48 and the driver controller 29. The driver controller 29 is coupled to the frame buffer 28 and to the array driver 22, which is then coupled to the display array 30. The power supply (ie, power supply) 50 provides power to all components as required for a particular exemplary display 40 design.

The network interface 27 includes an antenna 43 and a transceiver 47 so that the exemplary display device 40 can communicate with one or more devices over a network. In one embodiment, network interface 27 may also have some processing power that can mitigate the requirements of processor 21. The antenna 43 may be any antenna for transmitting and receiving signals. In one embodiment, the antenna transmits and receives RF signals in accordance with IEEE 802.11 standards, including IEEE 802.11 (a), (b), or (g). In another embodiment, the antenna transmits and receives RF signals in accordance with the BLUETOOTH standard. In the case of a mobile phone, the antenna is designed to receive CDMA, GSM, AMPS or other known signals used for communication within a wireless mobile telephone network. The transceiver 47 may process the signal received from the antenna 43 in advance so that the signal may be received by the processor 21 and further manipulated. The transceiver 47 also processes the signal received from the processor 21 so that the signal can be transmitted from the exemplary display device 40 via the antenna 43.

In alternative embodiments, the transceiver 47 may be replaced with a receiver. In yet another alternative embodiment, network interface 27 may be replaced with an image source (ie, an image source) capable of storing or generating image data to be sent to processor 21. For example, the image source may be a digital video disc (DVD) or hard disk drive containing image data, or a software module for generating image data.

The processor 21 generally controls the overall operation of the exemplary display device 40. The processor 21 receives data such as compressed image data from the network interface 27 or the image source, and in a format capable of immediately processing the data as raw image data or as source image data. Process. Processor 21 then sends the processed data to driver controller 29 or to frame buffer 28 for storage. Source data typically refers to information that identifies image characteristics at each location within an image. For example, such image characteristics may include color, saturation and gray-scale levels.

In one embodiment, processor 21 includes a microcontroller, CPU or logic unit that controls the operation of exemplary display device 40. Conditioning hardware 52 generally includes amplifiers and filters to send a signal to speaker 45 and to receive a signal from microphone 46. The conditioning hardware 52 may be a separate component within the exemplary display device 40 or may be embedded within the processor 21 or other components.

The driver controller 29 appropriately reformats the original image data for high speed transfer to the array driver 22 by taking the original image data generated by the processor 21 directly from the processor 21 or from the frame buffer 28. . In particular, the driver controller 29 has a time sequence suitable for reformatting the source image data into a data flow with a raster like format to scan across the display array 30. The driver controller 29 then sends the formatted information to the array driver 22. Although driver controller 29, such as an LCD controller, is often associated with system processor 21 as a stand-alone integrated circuit (IC), such controllers may be implemented in various ways. They may be inserted as hardware into the processor 21, may be inserted into the processor 21 as software, or may be fully integrated into the hardware with the array driver 22.

Typically, array driver 22 receives formatted information from driver controller 29 and outputs video data in parallel sets of waveforms that are applied multiple times per second to hundreds, sometimes thousands, of lead lines from the xy matrix pixels of the display. Reformat the.

In one embodiment, driver controller 29, array driver 22, and display array 30 are suitable for any of the types of displays described herein. For example, in one embodiment, driver controller 29 is a conventional display controller or bistable display controller (eg, interferometric modulator controller). In another embodiment, the array driver 22 is a conventional driver or bistable display driver (eg, interferometric modulator display). In one embodiment, the driver controller 29 is integral with the array driver 22. Such embodiments are common in highly integrated systems such as mobile phones, watches and other small displays. In another embodiment, display array 30 is a typical display array or bistable display array (eg, a display comprising an array of interferometric modulators).

The input device 48 allows a user to control the operation of the exemplary display device 40. In one embodiment, the input device 48 includes a keypad, a button, a switch, a touch sense screen, a pressure sensitive film or a thermal film, such as a QWERTY keyboard or a telephone keypad. In one embodiment, the microphone 46 is an input device for the exemplary display device 40. When the microphone 46 is used to input data to the device, voice commands may be provided by the user to control the operations of the exemplary display device 40.

Power supply 50 may include various energy storage devices that are well known in the art. For example, in one embodiment, the power supply 50 is a rechargeable battery such as a nickel-cadmium battery or a lithium ion battery. In another embodiment, power supply 50 is a renewable energy source, capacitor, or solar cell, including plastic solar cells, solar cell paints. In another embodiment, the power supply 50 is configured to receive power from a wall outlet.

In some embodiments, the control program resides in a driver controller that can be located at some point in the electronic display system as described above. In some cases, the control program is in the array driver 22. The foregoing optimization may be implemented in a number of hardware and / or software components and in various forms.

The detailed structure of the interferometric modulator operated in accordance with the principles described above can vary widely. For example, FIGS. 7A-7E (hereinafter sometimes referred to collectively simply as "FIG. 7") represent five different embodiments of the movable reflective layer 14 and its supporting structure. FIG. 7A is a cross-sectional view of the embodiment of FIG. 1, in which a strip of metal material 14 is deposited on a support 18 extending in an orthogonal direction. In FIG. 7B, the movable reflective layer 14 is attached to the support at the corner only on the tether 32. In FIG. 7C, the movable reflective layer 14 is square or rectangular and is suspended from a deformable layer 34, which may also include a flexible metal. This deformable layer 34 is connected directly or indirectly to the substrate 20 around the deformable layer 34. These connecting portions (or connecting portions) are also referred to herein as support pillars. The embodiment shown in FIG. 7D has a support pillar plug 42 on which the deformable layer 34 rests. The movable reflective layer 14 remains suspended over the gap as in FIGS. 7A-7C, but the deformable layer 34 fills the holes between the deformable layer 34 and the optical stack 16. Does not form a support column Rather, the support column is formed of a flattening material, which is used to form the support column plug 42. The embodiment shown in FIG. 7E is an embodiment based on FIG. 7D, but can be adapted to work with any of the embodiments shown in FIGS. 7A-7C as well as additional embodiments not shown. In the embodiment shown in FIG. 7E, an extra layer of metal or other conductive material has been used to form the bus structure 44. This allows the signal to be transmitted along the backside of the interferometric modulator, eliminating a number of electrodes that may otherwise be formed on the substrate 20.

In an embodiment as shown in FIG. 7, the interferometric modulator functions as a direct-view device, wherein the images are seen from the front side of the transparent substrate 20 and the modulators are arranged opposite. In these embodiments, the reflective layer 14 optically blocks a portion of the interferometric modulator on the side of the reflective layer opposite the substrate 20, including the deformable layer 34. This allows the blocked area to be constructed and operated without adversely affecting the image quality. For example, this blocking allows the bus structure 44 in FIG. 7E, which provides the ability to separate the optical properties of the modulator from the electromechanical properties of the modulator, such as addressing and movement resulting from the addressing. . This separable modulator structure selects the materials and structural designs used for the optical and electromechanical aspects of the modulator to function independently of each other. Moreover, the embodiment shown in FIGS. 7C-7E has additional advantages obtained by separating the optical properties of the reflective layer 14 from the mechanical properties performed by the deformable layer 34. This optimizes the structural design and materials used for the reflective layer 14 with respect to the optical properties and the structural designs and materials used for the deformable layer 34 with respect to the desired mechanical properties.

Light incident on the interferometric modulator is reflected or absorbed due to constructive or destructive interference depending on the distance between the optical stack 16 and the reflective layer 14. The perceived brightness and quality of a display using an interferometric modulator depends on the light incident on the display because the light is reflected to form an image on the display. In some situations, such as in low ambient light conditions, an illumination system may be used to illuminate the display to form an image.

8 is a cross-sectional view of a display device including a lighting system including a light guide panel 80 disposed adjacent to display 81. The light guide panel 80 includes a light turning film 89 having light turning structures 82. The light source 92 introduces light into the light guide panel 80. The light turning structures 82 direct the light propagating through the light guide panel 80 onto the display 81.

Referring to FIG. 9, it has been found that the light turning structures 82 are susceptible to light loss, which can reduce the amount of light redirected to the display 81. The light turning structures 82 are formed by surfaces 83a and 83b and facets 82a and 82b which form angles θ ₁ and θ ₂ greater than 90 °, respectively. . Typically, light incident on the facet 82a may be reflected toward the display 81 or may continue to propagate into the light guide panel 80 by total internal reflection. However, light incident on the facet 82a close to the angle at right angles to the surface thereof is not reflected, but can propagate from the light guide panel 80, thereby causing light loss. In display light applications, this light loss can cause a reduction in display brightness and / or uniformity.

Referring to FIG. 10A, some embodiments of the present invention provide slits 100 for redirecting light propagating through the light guide 180, which may be a panel of optically transmissive material. . Advantageously, the slit 100 reduces light loss by recycling light propagating from the panel (ie, light guide) 180. For example, light ray 103 propagates from panel 180 but is then reintroduced into panel 180 to be redirected from panel 180 by contact with facet 104 as needed. It continues to propagate until

It will be appreciated that the slit 100 is a cut out portion in the light guide 180 and is defined by facets 104 and 106. The volume defined by the “cut out portion” extends at least partially directly over the light guide 180 when the surface 108 is positioned face down. In some embodiments, facet 106 and surface 108 define an angle 110 of 90 ° or less and are in contact through that angle. It will be appreciated that if no material forms the light guide 180, the slit 100 may be filled with other materials within the light guide 180 to facilitate total internal reflection. In another embodiment, the slit 100 may have an open space and may be free of solid material at all.

The facets 104 are tilted to direct or reflect light propagating through the panel 180 in a predetermined direction. In some embodiments, light is introduced into the light guide by the light source 192 and impinges on the facet 104 and is redirected towards the display 81.

Referring to FIG. 10B, the slit 100 is lined with an antireflective coating 112 in some embodiments. The antireflective coating 112 has the advantage of reducing unwanted light reflections. For example, for light exiting facet 104, the coating 112 may minimize reflection of light from facet 106, thereby facilitating reintroduction of light into panel 180. Let's do it. Examples of antireflective coatings include, but are not limited to, silicon oxide (SiO ₂ ) coatings, silicon silicide (SiN ₄ ) coatings and aluminum oxide (Al ₂ O ₃ ) coatings.

In some embodiments, the slit 100 forms an open volume relative to the surface 108. In some other embodiments, referring to FIG. 10C, the slit 100 may be fully disposed within the light guide 180. For example, the slits 100 may be formed below the surface 108, and the narrow connections 114 at the ends of each slit 100 may be formed of, for example, natural materials of the panel 180. It may be sealed by elasticity or by application of a sealant or adhesive on these parts. The sealing of the connection portion 114 is protected against external objects that may come into contact with the edges or surfaces of the facets 104 and 106 of the slit 100, thereby reducing contamination or damage of the slit 100. have. In some other embodiments, the narrow connection 114 is not sealed and the opening defined by the connection is relatively narrow relative to the illustrated cross sectional area of the slit 100, thereby providing protection for the slit 100. to provide.

It will be appreciated that the illustrated slits 100 do not necessarily have to be drawn to scale, and their relative sizes may be different. Also, the relative angles of the facets 104 and 106 may differ from those illustrated. For example, the cross-sectional area of the slit 100 may vary, and the relative orientation and angle defined by the facets 104 and 106 may vary from slit to each other.

10A-10C, in some embodiments, the facets 104, 106 may be substantially parallel to one another and also parallel to the surface 108 with a single slit sidewall 105. Can be joined by. The slit 100 can thus define a volume having the shape of a parallelogram. The parallel orientation of the slit sidewalls 105 advantageously facilitates total internal reflection of the light within the body 102, because the parallel sidewalls 105 draw light at an angle similar to the surface 108. Because it reflects.

The slit 100 may be used in various devices that require light turning or direction change. In some embodiments, the slit 100 is used as a light turning structure in the lighting device. Such lighting devices may include a large area of light for indoor or outdoor use. For example, lighting devices can provide overhead lighting for rooms and other interior spaces.

FIG. 11A is a plan view of a display system including a light guide 180 and a lighting system including a light bar 190 utilizing the slit 100 as a light turning structure. 11B is a cross-sectional view of the display device. The light bar 190 and the light guide 180 are formed of a substantially optically transmissive material capable of supporting the propagation of light through the length of these structures. For example, the light bar 190 and the light guide 180 may be formed of glass, plastic, or other highly transparent material.

11A and 11B, the light guide 180 is disposed adjacent to the display 181 to face the display. Slit 100 is configured to redirect light from light bar 190 toward display 181. In some embodiments, the lighting system acts as front light. The light reflected from the display 181 is transmitted back through the light guide 180 and out of the light guide toward the viewer. The display 181 may include various display elements, for example, a plurality of spatial light modulators, interferometric modulators, liquid crystal elements, electrophoretic elements, and the like, which may be arranged in parallel with the main surface of the panel 180. Display 181 is display 30 (FIGS. 6A and 6B) in some embodiments.

With continued reference to FIG. 11A, light bar 190 has a first end 190a for receiving light from light emitter 192. The light bar 190 and the light emitter 192 together form a line light source. The light emitter 192 may include a light emitting diode (LED), but other light emitting devices are also possible. Light emitted from the light emitter 192 propagates into the light bar 190. This light is guided therein, for example, at its sidewalls through total internal reflection, forming an interface with air or some other surrounding fluid or solid medium. For example, if the light bar 190 is formed of a material having a refractive index similar to that of the light guide 180, the light bar 190 may be air, fluid, or solid to facilitate total internal reflection within the light bar 190. It may be separated from the light guide 180 by the medium.

The light bar 190 includes a slit 100 on at least one side, for example, a side 190b that substantially faces the light guide 180. The slit 100 reverberates light incident on the side surface 190b of the light bar 190 and directs the light from the light bar 190 (eg, from the side surface 190c). It is configured to face inward. It will be appreciated that the slit 100 shown in FIG. 11A is schematic. The size, shape, density, position, etc. of the slit 100 may be different from that shown to achieve the desired light turning effect. For example, in some embodiments, slit 100 extends further into the body of light bar 190 as the distance from side 190a increases.

In certain embodiments, the illumination device further includes a coupling optic (not shown) between the light bar 190 and the light guide 180. For example, the coupling optical device may change or parallelize, enlarge, or diffuse the color of light propagating from the light bar 190.

Accordingly, the light travels from the first end 190a in the direction of the second end 190d of the light bar 190 and may be reflected back toward the first end 190a. In this way, light impinging on the slit 100 is diverted towards the adjacent light guide 180. The light guide 180 is disposed relative to the light bar 190 to receive light redirected by the slit. The light guide 180 then redirects light from the light guide 180 toward the display 181.

Although only one side of the light bar 190 is shown for ease of discussion and illustration (FIG. 11A), in some embodiments, the slit 100 is formed on multiple faces of the light bar 190. Referring to FIG. 11C, the slit 100 is formed along side surfaces 190b and 190c of the light bar 190. Forming the slit 100 on multiple surfaces may have the advantage of more efficiently redirecting light per unit length of the light bar 190. In addition, the spacing between the slits 100 on each side 190b, 190c can increase the given density of the slit 100 per unit length of the light bar 190, which facilitates the manufacture of dense slit patterns. It can have an advantage. It will be appreciated that the slits in surfaces 108, 109 may differ in one or more of the total number, cross-sectional shape, dimensions, and angle formed between the slits and the major surface.

Referring to FIG. 11D, light bars such as light bar 190 and the like may be integrated within the light guide, thereby forming a single light guide / light bar structure 182. This integrated light guide / light bar structure 182 has the advantage of manufacturing by reducing the number of components in the display. It will be appreciated that the light turning structure may take various forms, including prismatic shaped structures, such as slits 100 (discussed further herein), holographic structures, or various other light turning structures known in the art. will be.

It will be appreciated that the light guide 182 or 180 (FIGS. 10A-11C) is defined by opposing first and second edge portions. As illustrated, the slit 100 can be formed on one of these edges to redirect the light in a direction toward the opposite edge. The third and fourth edges further define the light guide 182, where light enters the light guide by, for example, colliding with the third edge (lower edge in FIG. 11E). The light guide 182 also includes an upper and lower major surface (main side or major surface) (which extends from the first edge to the second edge and from the third edge to the fourth edge).

Light enters the light guide 182 from the light emitter 192. The light can be paralleled and also redirected by the slit 100 towards the display area 183, where the light redirecting structure redirects the light towards the display (not shown).

With continued reference to FIG. 11D, the slit 100 closer to the emitter 192 may block light from reaching the surface of another slit 100 further away from the emitter 192. As the distance from the light emitter 192 along the Y axis increases, the slit 100 further extends along the X axis to come into contact with light from the light emitter 192. In some embodiments, the slit 100 furthest from the emitter 192 may extend substantially the entire length of the emitter 192 along the X axis.

It will be appreciated that the pitch or density of the slit 100 along the Y axis, the length of the slit 100 along the X axis and the angle of the slit 100 may be uniform or may be varied to achieve the desired light turning effect. Could be. For example, in some embodiments, the exposed surface area of the slit 100 for contacting and redirecting light is substantially the same per unit length along the Y axis, thus the direction of uniform flux per unit length along the Y axis Facilitate the converted light.

In order to further increase the efficiency of light extraction (i.e., increase the rate at which light is diverted towards the display area 183), the light from the light emitter 192 is applied to the edges of the illustrated light guide 182. Inclined toward 184, whereby slit 100 is formed. The light can be inclined, for example, by attaching the light emitter 192 to the light guide 182 at a predetermined angle to direct the light in a desired direction, or by using an appropriate optical component or film. Advantageously, the undirected light is recycled, thereby increasing the light extraction efficiency compared to the configuration where the light is not directed along the edge where the slit 100 is formed.

Referring to FIG. 11E, as described above, in some embodiments, additional slits 100 are formed in the area 182 corresponding to the display. Light is emitted from the emitter 192, and the light is then redirected by the slit 100 on the edge 184, which is redirected to the slit 100 in the display area 182. Thereby turning towards the display (not shown).

In some other embodiments, the slit 100 may be formed in the light guide without the slit 100 forming the light turning structure of the light bar. 12A illustrates a cross-sectional view of a display device including a light guide 180 having a slit 100. The light bar 190 enters light into the first end 180a of the light guide 180. The light may travel from the first end 180a in the direction of the second end 180d of the light guide 180, and may be reflected back toward the first end 180a by total internal reflection. As propagated through the light guide 180, some of the light impinges on the slit 100 and is redirected towards the display 181.

With continued reference to FIG. 12A, the slit 100 is formed along a major surface (major side or major surface) 180b, with the major surface facing the display 181. In some other embodiments, referring to FIG. 12B, the slit 100 may be disposed along both major surfaces of the light guide 180, eg, along both major surfaces 180b and 180c. As mentioned above, forming the slit 100 along a plurality of surfaces is directed to light for ease of manufacture and efficiently when high density slit is desired for the unit length of the light guide 180. Has the advantage to switch. 12A and 12B are shown as separated from the cross section 180a for ease of illustration, it will be understood that the light bar 190 may form or may be separated from the light guide body 180 in an integrated structure. Could be. For example, the light bar 190 of FIGS. 12A and 12B may form a single light guide having slits in the light bar 190 and the main surface of the light guide.

The slit 100 may be distributed in the light bar 190, the light turning light guide 180, and the integrated light guide / light bar structure 182 in various patterns to achieve a desired light turning characteristic. have. It will be appreciated that the uniformity of power per area is desirable in many applications for uniformly illuminating the display 181 (FIGS. 11B, 12A and 12B). The slits 100 may be arranged to achieve good uniformity of power per area.

13A, 13B and 13C, the density of the slit 100 is determined by the light bar 190 (FIG. 13A), the point light emitter (or point light source) 192 (FIG. 13B), or the edge 184 ( Increases with increasing distance from FIG. 13C). Referring to FIG. 13A, the number of slits 100 per unit area (either or both of the upper and lower main surfaces of the light guide 180) is an edge of the light guide 180 directly adjacent to the light bar 190. Increases with increasing distance from. The slit 100 extends in a substantially straight light parallel to the light bar 190.

Referring to FIG. 13B, the number of slits 100 per unit area (either or both of the upper and lower main surfaces of the light guide 180) increases with distance from the point light source 192. The slit 100 for the semicircular segment is concentrated in the point light source 192.

Referring to FIG. 13C, the number of slits 100 per unit area (in one or both of the upper and lower main surfaces of the light guide 180) increases with distance from the edge 184. An additional slit 100 along its edge redirects the light to allow its side of the light guide 182 to function as a line light source.

In some embodiments, the various densities of the slit 100 allow the flux of redirected light per unit area to be highly uniform with respect to the area of the light turning light guides 180, 182 corresponding to the display 181. . Since light propagates through the light turning light guides 180 and 182, a predetermined amount of light comes into contact with the slit 100 and is redirected from the light guides 180 and 182. In this way, as more light is redirected by contact with the slit 100, the remaining light propagating through the light guides 180, 182 is reduced with distance from the light source. In order to compensate for the reduction in the amount of light propagating through the light guides 180, 182, the density of the slit 100 increases with distance from the point or line light source.

The density of the slit refers to the area occupied by the slit 100 per unit area of the body of material in which the slit is formed. A single large slit 100 or a plurality of small slits 100 within a given area may have the same density. In this way, the density can change due to, for example, a change in the size and / or number of slits 100 per area.

The slit 100 can be formed by various methods. In some embodiments, the slit 100 is formed as a body of light propagating material, such as a light guide or a light bar. For example, the body of light propagating material may be formed by extrusion through a die having an opening corresponding to the cross-sectional shape of the light guide or light bar and having a protrusion in the die corresponding to the slit 100. The material forming the body is expanded and / or stretched through the die in the direction in which the slit 100 extends, thereby forming the length of the material having the slit 100 while having a desired cross-sectional shape. The length of the material is then cut into the desired dimensions for the light guide or light bar.

In another embodiment, the body of light propagating material may be formed by casting, where the material is placed in a mold and cured. The mold includes an extension corresponding to the slit. The body of light propagating material, once cured, is removed from the mold. Since the mold may correspond to a single light guide or light bar, the body of the removed light propagating material may be used as a single light redirecting light guide or light bar. In another embodiment, the mold produces large sheet material, which is cut to the desired size for one or more light redirecting light guides and / or light bars.

In another embodiment, the body of light propagating material is formed by injection molding, wherein the fluid material is injected into the mold and then released from the mold after curing. If the mold corresponds to a single light guide or light bar, the body of removed light propagating material may be used as a single light redirecting light guide or light bar. The mold also produces a large sheet material, which sheet is cut to the desired size for one or more light redirecting light guides and / or light bars.

In some other embodiments, the slit 100 is formed after the formation of the light turning body. For example, the slit 100 may be formed by embossing, wherein a die having a protrusion corresponding to the slit 100 is pressed against a body of light propagating material to press the slit 100 into the body. To form. The body may be heated to be flexible enough for the body to take the shape of the slit 100.

In another embodiment, the material is removed from the body of light propagating material to form the slit 100. For example, the slit 100 may be formed by heating or cutting in the body. In another embodiment, material is removed from the body by laser ablating.

It will be appreciated that the methods disclosed herein may be used to form light bars and / or light guides. In some embodiments, the light bar can be formed after the formation of the light guide. For example, after forming a sheet of material having a slit (e.g., by extrusion, casting, injection molding or removal of the material from the body of the light propagating material), the sheet material is cut or stamped into the desired shape. Can be processed. In this cutting or stamping process, the slit 100 may be formed at the edge of the light guide.

In some other embodiments, the light guide is formed in zones that are later compounded. Such zones can be formed using the methods disclosed herein. The zones are bonded or otherwise attached together with the refractive index matching material to form a single light guide. Consecutive zone formation of the light guide enables the formation of curved slits 100 that may make it difficult to form as a single continuous structure for a particular method.

In some embodiments, the light guide is attached to the display after formation. The light guide is also attached to the light source to form a display with an illumination system.

Those skilled in the art will recognize that the present invention is disclosed in the context of certain preferred embodiments and examples, but that the present invention extends beyond the specifically disclosed embodiments to other embodiments and / or uses of the present invention and obvious variations and equivalents thereof. I will understand. In addition, while several variations of the invention have been shown and described in detail, other variations that fall within the scope of the invention will be readily apparent to those skilled in the art based on the present disclosure. In addition, various combinations or sub-combinations of the specific forms or aspects of the above embodiments may be made and these are also contemplated as being within the scope of the present invention. It is to be understood that various features and aspects of the disclosed embodiments can be combined or replaced with one another to form various modes of the disclosed invention. Therefore, it is intended that the scope of the invention disclosed herein is not limited by the specifically disclosed embodiment described above but of course only determined by the following claims.

Claims (39)

A light guide material formed of a light propagating material that supports propagation of light through the length of the light guide body,
The light guide is defined by a plurality of outer surfaces,
A first outer surface of the outer surfaces includes a plurality of spaced apart first slits configured to redirect light incident on the light guide, wherein each slit is cut out in the first outer surface Formed by an undercut,
A second one of said outer surfaces includes a plurality of spaced apart second slits configured to redirect light incident on said light guide, wherein each slit is formed by a cutout in said second outer surface Light guide apparatus. The light guide of claim 1, wherein the light guide extends between opposing first and second edge portions, opposing third and fourth edge portions, and between the first and second edge portions and the third and fourth edge portions. A light guide device defined by opposing first and second major surfaces. The light guide device according to claim 2, wherein the first outer surface is a surface of the first main surface, and the first plurality of slits are formed by cutouts in the first main surface. The light guide device according to claim 3, wherein the second outer surface is a surface of the first edge portion, and the second plurality of slits are formed by cutouts in the first edge portion. 5. The method of claim 4, wherein the second plurality of slits are configured to redirect light propagating from the third edge portion across the light guide toward the second edge portion, wherein the first plurality of slits Is configured to change the direction changed by the second plurality of slits toward the second main surface. The light emitting device of claim 3, wherein the second plurality of slits are formed by cut portions in the second main surface, and the first and second plurality of slits are configured to remove light propagating from a direction of the first edge portion. A light guiding device configured to change direction toward two principal surfaces. The light guide device according to claim 2, wherein the density of the slits increases as the density from the first edge portion increases. The light guide device of claim 2 wherein the surface area of the slits increases as the density from the first edge portion increases. The light guide device of claim 1, wherein an angle formed between one slit and the first outer surface is different between the first plurality of slits or between the first and second plurality of slits. The light guide device according to claim 1, wherein the surface area of the slit is different between the first plurality of slits or between the first and second plurality of slits. The light guide device of claim 1 further comprising an antireflective coating on surfaces of the first and second plurality of slits. The light guide device of claim 1 wherein the slits define spaced concentric semicircles. The method of claim 1,
Display;
A processor configured to communicate with the display and configured to process image data; And
And a memory device configured to communicate with the processor. The light guide device of claim 13, further comprising a driver circuit configured to transmit at least one signal to the display. 15. The light guiding device of claim 14, further comprising a controller configured to transmit at least a portion of the image data to the driver circuit. The light guide device of claim 13 further comprising an image source module configured to transmit the image data to the processor. The light guide device of claim 16 wherein the image source module comprises at least one of a receiver, transceiver, and transmitter. 14. The light guide device of claim 13, further comprising an input device configured to receive input data and to transmit the input data to the processor. 14. The light emitting device of claim 13, wherein the light guide comprises a front light for the display, the front light comprising a light source configured to propagate light through the light guide, The slit is configured to redirect light towards the display. 20. The light guide of claim 19, wherein the display comprises a plurality of interferometric modulators, the interferometric modulators forming pixel elements. First means for generating light and guiding the light to propagate through a light turning body;
Second means for redirecting light propagating through the light turning body; And
And third means for redirecting light propagating through the light turning body. 22. A lighting device as claimed in claim 21, wherein said second and third means comprise a plurality of slits formed by cutouts in the surface of said light turning body. 22. The lighting device of claim 21, wherein said first means comprises a light emitting diode. 24. The light emitting device of claim 23, wherein the second means comprises a plurality of slits formed by cutouts in the edge portion of the light turning body, the light emitting diode being located at an edge portion of a light bar, And said second means is adapted to redirect light from said light emitting diode across the length of said light turning body. The lighting apparatus according to claim 21, further comprising a fourth means for displaying an image through the light turning body. 27. The lighting apparatus of claim 25, wherein said fourth means comprises a plurality of interferometric modulators, said interferometric modulators forming pixel elements. Propagating light through the light redirector; And
Redirecting the light by impinging the light on facets of the first and second plurality of slits,
And said plurality of slits are formed by cutouts in two surfaces of said light turning body. 28. The device of claim 27, wherein the light guide extends between opposing first and second edge portions, opposing third and fourth edge portions, and between the first and second edge portions and the third and fourth edge portions. Defined by opposing first and second major surfaces, the first plurality of slits being disposed in the first edge portion,
Propagating the light includes directing light into the third edge of the light turning body;
Redirecting the light includes redirecting light coming from the third edge portion toward the second edge portion in a direction crossing the light guide. 29. The method of claim 28, wherein the second plurality of slits are disposed on the first major surface, and wherein redirecting the light comprises redirecting the light towards the second major surface. Providing a body of light propagating material; And
Forming first and second plurality of separated cutout portions on different sides of the body,
And the material supports propagation of light through the length of the body. 31. The method of claim 30, wherein the different sides comprise an edge and a major surface of the body. 31. The method of claim 30, further comprising disposing an antireflective coating on the surfaces of the cut out portions. 31. The method of claim 30, wherein forming the plurality of spaced apart cuts comprises extruding the light propagating material through a die. 31. The method of claim 30, wherein forming the plurality of spaced apart cuts comprises casting the light propagating material in a mold. 31. The method of claim 30, wherein forming the plurality of spaced apart cuts comprises injection molding a light propagating material through a mold. 31. The method of claim 30, wherein forming the plurality of separated cutouts comprises embossing the body of light propagating material. 31. The method of claim 30, wherein forming the plurality of spaced apart cuts comprises machining or laser ablating the body of light propagating material. 31. The method of claim 30, further comprising attaching a display comprising a plurality of pixels to the body of light propagating material. A lighting device manufactured by the method of claim 30.

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