RU2507549C2 - Method and apparatus for controlling colour on display - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: display has a plurality of pixels, which include red, green and blue interference modulators. Each pixel is capable of outputting higher intensity of green light than red and blue light. At least one of the interference modulators, which are capable of outputting red and blue light, is capable of outputting light having a wavelength which enables to compensate for the higher intensity of green light.

EFFECT: enhancing apparent brightness of a display.

32 cl, 21 dwg

Description

FIELD OF THE INVENTION

The technical field of the invention relates to microelectromechanical systems (MEMS).

State of the art

Microelectromechanical systems (MEMS) contain micromechanical elements, actuators and electronics. Micromechanical elements can be created using deposition, etching and / or other microprocessing methods, by which parts of the substrates and / or layers of the deposited material are etched, or by which layers are added to form electrical and electromechanical devices. One type of MEMS device is called an interference modulator. For the purposes of the present description, the term interference modulator or interference light modulator refers to a device that selectively absorbs and / or reflects light using the principles of optical interference. In some embodiments, the implementation of the interference modulator may include a pair of conductive plates, one of which or both can be transparent and / or reflective in whole or in part and capable of relative movement when a corresponding electrical signal is applied. In a particular embodiment, one plate may comprise a fixed layer deposited on a substrate, and another plate may comprise a metal membrane separated from the fixed layer by an air gap. As described in detail in the present description, the location of one wafer relative to another wafer may alter the optical interference of light incident on an interference modulator. Such devices have a wide scope, and it is useful in technology to use and / or modify the characteristics of devices of this type so that their properties can be used to improve existing products and create new products that have not yet been developed.

SUMMARY OF THE INVENTION

The system, method and devices in accordance with the invention, in each case, have their own individual characteristics, none of which, individually, is not responsible for the corresponding desired features. Below, without limiting the scope of the present invention, its most salient features are summarized. After studying the present summary and, in particular, after reading the section “Detailed Description of Preferred Embodiments”, it will become clear how the features of the present invention provide advantages over other display devices.

One embodiment includes a display. The display contains many pixels. Each of the pixels contains at least one red sub-pixel containing at least one interference modulator configured to output red light, at least one green sub-pixel containing at least one interference a modulator configured to output green light, at least one blue sub-pixel containing at least one interference modulator configured to output blue light, and at least one white sub-pixel containing at least one interference modulator configured to output colored light.

Another embodiment includes a display. The display contains many interference modulators. A plurality of interference modulators comprises at least one interference modulator configured to output red light, at least one interference modulator configured to output green light, at least one interference modulator configured to output blue light, and at least one interference modulator configured to output white light. At least one interference modulator configured to output white light outputs white light having a standardized white point.

Another embodiment includes a display. The display contains many display elements. Each of the display elements comprises a reflective surface configured to be located at a distance from the partially reflective surface. The plurality of display elements comprises at least one of a plurality of display elements configured to output colored light, and at least one of a plurality of display elements configured to interferentially output white light.

Another embodiment includes a method of manufacturing a display. The method consists in forming a plurality of display elements. Each of the plurality of display elements comprises a reflective surface configured to be located at a distance from the partially reflective surface. Each of the respective distances is selected so that at least one of the plurality of display elements is configured to output colored light, and at least one other of the plurality of display elements is configured to interferentially output white light.

Another embodiment includes a display comprising means for displaying an image. The display means comprises means for reflecting light and means for partially reflecting light. The reflective means is arranged to be located at a distance from the partially reflective means. The display means comprises first means for outputting colored light and second means for interfering outputting white light.

Another embodiment includes a display. The display contains a plurality of pixels, each of which contains red, green and blue interference modulators, which are configured to output red, green and blue light, respectively. Each of the pixels is configured to output a higher intensity of green light than red light, and is configured to output a higher intensity of green light than blue light when each of the interference modulators is configured to output red, green, and blue light.

Another embodiment includes a method of manufacturing a display. The method consists in forming a plurality of pixels. The formation of a plurality of pixels is that interference modulators configured to output red light are formed, interference modulators configured to output green light are formed, and interference modulators configured to output blue light are formed. Each of the pixels is configured to output a higher intensity of green light than red light, and is configured to output a higher intensity of green light than blue light when each of the interference modulators is configured to output red, green, and blue light.

Another embodiment includes a display. The display contains many pixels. Each of the pixels contains red, green, and blue interference modulators, which are configured to output red, green, and blue light, respectively. Each of the pixels is configured to output a higher intensity of green light than red light, and is configured to output a higher intensity of green light than blue light. At least one of the interference modulators configured to output red light, and the interference modulators configured to output blue light, is configured to output light having a wavelength selected to compensate for a higher intensity of green light.

Another embodiment includes a display comprising a plurality of means for outputting red light, a plurality of means for outputting green light, and a plurality of means for outputting blue light. The output means of red, green, and blue form a means for displaying an image pixel. Each of the pixel display means is configured to output a higher intensity of green light than blue light when the output means of red, green, and blue are configured to output red, green, and blue light.

Another embodiment includes a display comprising a plurality of display elements. The plurality of display elements comprises at least one color display element configured to output colored light, and at least one display element configured to output white light. At least one display element configured to output white light outputs white light having a standardized white point.

Another embodiment includes a display comprising means for displaying an image. The display means comprises means for outputting colored light and means for outputting white light. The white light output means outputs white light having a standardized white point.

Another embodiment includes a method of manufacturing a display, which consists in forming a plurality of display elements comprising at least one color display element configured to output colored light, and at least one display element made with the ability to output white light. At least one display element configured to output white light is intended to output white light having a standardized white point.

BRIEF DESCRIPTION OF THE DRAWINGS

In FIG. 1 is an isometric view of a portion of one embodiment of an interference modulator display in which the movable reflective layer of the first interference modulator is in the relaxed position and the movable reflective layer of the second interference modulator is in the active position.

In FIG. 2 is a block diagram of a system representing one embodiment of an electronic device including a 3 × 3 interference modulator display.

In FIG. 3 is a positional diagram of a moving mirror versus applied voltage for one exemplary embodiment of the interference modulator shown in FIG. one.

In FIG. Figure 4 shows a combination of row and column voltages that can be used to control an interference modulator display.

In FIG. 5A depicts one exemplary frame of displayed data on the 3 × 3 interference modulator display shown in FIG. 2.

In FIG. 5B shows one exemplary timing diagram for row and column signals that can be used to record the frame shown in FIG. 5A.

In FIG. 6A and 6B are system block diagrams illustrating an embodiment of a visual display device comprising a plurality of interference modulators.

In FIG. 7A is a sectional view of the device shown in FIG. one.

In FIG. 7B is a sectional view of an alternative embodiment of an interference modulator.

In FIG. 7C is a sectional view of yet another alternative embodiment of an interference modulator.

In FIG. 7D is a sectional view of yet another alternative embodiment of an interference modulator.

In FIG. 7E is a cross-sectional view of a further alternative embodiment of an interference modulator.

In FIG. 8 is a side cross-sectional view of an exemplary interference modulator, with an explanation of the spectral characteristics of the light at the output by installing a movable mirror in a number of positions.

In FIG. 9 is a graphical diagram showing a spectral characteristic of one embodiment, which contains blue and yellow interference modulators for synthesizing white light.

In FIG. 10 is a side cross-sectional view of an interference modulator, showing different optical paths through the modulator, which result in light being reflected in different colors.

In FIG. 11 is a side cross-sectional view of an interference modulator containing a layer of material for selectively transmitting light of a particular color.

In FIG. 12 is a graphical diagram showing a spectral characteristic of one embodiment, which contains green interference modulators and a purple filter layer for white light synthesis.

In FIG. 13 is a graphical diagram showing two pixels of an exemplary matrix of 30 pixels. Rows 1-4 and columns 1-4 form one pixel 120a.

In FIG. 14A is a color chart, showing colors that can be synthesized by an exemplary color display that contains red, green, and blue display elements.

In FIG. 14B is a color chart, showing colors that can be synthesized by an exemplary color display that includes red, green, blue, and white display elements.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description relates to certain specific embodiments of the invention. However, the invention can be implemented in many different ways. In the present description, reference is made to the drawings, in which similar parts are everywhere denoted by the same numeric positions. As is apparent from the following description, embodiments can be implemented in any device that is capable of displaying any image that is moving (e.g., video) or still (e.g., still image) and text or image. In particular, it is contemplated that embodiments may be implemented in or in conjunction with a variety of such diverse electronic devices as, for example, although without limitation, mobile phones, wireless devices, personal electronic assistants (PDAs), handheld or laptop computers, GPS receivers / navigators (global positioning systems), cameras, MP3 players, recording video cameras, video game consoles, watches, clocks, calculators, television monitors, flat panel displays, computer monitors, car displays (for example, mileage display, etc.), controls and / or information display devices in the cockpit, display of field of view of filming cameras (for example, rear view camera display in a vehicle), electronic photographs, electronic billboards or posters, projectors, architectural structures, packaging, and artwork (for example, displaying images on jewelry). MEMS devices that are structurally similar to the devices described in this application can also be used in non-display equipment, for example, electronic switching devices.

One embodiment is a display in which each of the pixels comprises a set of display elements, each of which may contain at least one interference modulator. The set of display elements comprises display elements configured to output red, green, blue, and white light. In one embodiment, the “white light” display element outputs white light having a wider spectral characteristic with a higher intensity than the combined spectral characteristic of “red”, “green” and “blue” display elements. In one embodiment, the display comprises a driver circuit configured to turn on a “white light” display element when data for driving a pixel is received. In addition, embodiments include color displays configured to provide most of the light output in green portions of the visible spectrum to increase the perceived brightness of the display.

One embodiment of an interference modulator display comprising an MEMS interference display element is shown in FIG. 1. In such devices, the pixels are either in a light or dark state. In the light (“on” or “open”) state, the display element reflects most of the incident visible light to the user. In the dark (“off” or “closed”) state, the display element reflects little incident light visible to the user. Depending on the embodiment, the reflective characteristics in the “on” and “off” states may be reversed. MEMS pixels can be configured to be reflected mainly in selected colors, which allows color display in addition to black and white.

In FIG. 1 is an isometric view of two adjacent pixels in a sequence of display pixels, wherein each pixel comprises an MEMS interference modulator. In some embodiments, the implementation of the interference modulator display comprises a row-column matrix of said interference modulators. Each interference modulator contains a pair of reflective layers located at a variable and controlled distance from one another to form an optical resonator with at least one variable linear size. In one embodiment, one of the reflective layers can be moved between two positions. In the first position, referred to herein as the relaxed position, the movable reflective layer is located at a relatively large distance from the stationary partially reflective layer. In the second position, referred to herein as the active position, the movable reflective layer is located much closer to the partially reflective layer. Incident light that is reflected from two layers interferes constructively or destructively, depending on the position of the moving reflective layer, with the creation of either a fully reflective or non-reflective state of each pixel.

The depicted portion of the pixel matrix in FIG. 1 contains two adjacent interference modulators 12a and 12b. In the interference modulator 12a on the left, the movable reflective layer 14a is shown in a relaxed state at a predetermined distance from the optical stack 16a, which contains a partially reflective layer. In the interference modulator 12b to the right, the movable reflective layer 14b is shown in the active state, adjacent to the optical stack 16b.

Optical stacks 16a and 16b (collectively referred to as optical stack 16), as described herein, usually consist of several fused layers, which may contain an electrode layer, such as indium and tin oxide (ITO), a partially reflective layer, such as chromium, and transparent dielectric. Thus, the optical stack 16 is conductive, partially transparent and partially reflective and can be made, for example, by depositing at least one of the aforementioned layers on a transparent substrate 20. In some embodiments, the layers are made in the form of a parallel strip pattern and can form lowercase electrodes in the display device, as further explained below. The movable reflective layers 14a, 14b can be made in the form of a sequence of parallel strips of deposited metal layer or layers (orthogonal to the line electrodes 16a, 16b) deposited on top of the uprights 18, and an intermediate removable material deposited between the uprights 18. When the material to be removed is etched, the movable reflective the layers 14a, 14b are separated from the optical feet 16a, 16b by a certain gap 19. For the reflective layers 14, a highly conductive and reflective material such as aluminum can be used, and the said strips can form column electrodes in the display device.

In the absence of applied voltage, a cavity 19 remains between the movable reflective layer 14a and the optical stack 16a, with the movable reflective layer 14a in a mechanically relaxed state, as shown for the pixel 12a on the left in FIG. 1. However, when a potential difference is applied to the assigned row and column, the capacitor formed at the intersection of the row and column electrodes at the corresponding pixel becomes charged, and the electrostatic forces are attracted to each other. If the voltage is high enough, then the movable reflective layer 14 is deformed and pressed against the optical stack 16. The dielectric layer (not shown in the figure) in the optical stack 16 can prevent short-circuiting and adjust the gap between the layers 14 and 16, as shown for the pixel 12b on the right in FIG. 1. The nature of the change is the same, regardless of the polarity of the input potential difference. At the same time, the activation of a row / column, which makes it possible to control the reflective or non-reflective states of pixels, is in many ways similar to the activation used in traditional LCDs (liquid crystal displays) and other display technologies.

In FIG. 2-5B show one example method and system for using an array of interference modulators as applied to a mapping.

In FIG. 2 is a system block diagram depicting one embodiment of an electronic device that may have features of the invention. In an exemplary embodiment, the electronic device comprises a processor 21, which can be any universal single or multi-chip microprocessor, for example, ARM, Pentium ^® , Pentium II ^® , Pentium III ^® , Pentium IV ^® , Pentium ^® Pro, 8051, MIPS ^® , Power PC ^® , ALPHA ^® or any specialized microprocessor, such as a digital signal processor, microcontroller or programmable logic array. As is customary in the art, processor 21 may be configured to execute at least one software module. In addition to executing the operating system, the processor may be configured to execute at least one application, including a web browser, a telephony application, an email program, or any other application.

In one embodiment, processor 21 is also configured to communicate with matrix former 22. In one embodiment, the matrix driver 22 comprises a row driving circuit 24 and a column driving circuit 26 that provide signals for the display matrix or panel 30. The cross section of the matrix shown in FIG. 1 taken along lines 1-1 in FIG. 2. In the case of an interference MEMS modulator, the row / column activation protocol can use the hysteresis properties of the devices in question, shown in FIG. 3. In this case, in order to cause the deformation of the moving layer from the relaxed state to the active state, a potential difference, for example, 10 Volts, may be required. However, when the voltage decreases from the above value, the movable layer maintains its state as the voltage again drops below 10 Volts. In the exemplary embodiment of FIG. 3, the moving layer does not completely relax until the voltage drops below 2 volts. Thus, in the example shown in FIG. 3, there is a change in voltage within the range of about 3 to 7 V, in which there is a window of applied voltage, inside which the device is stably in either a relaxed or an active state. Said window is referred to herein as a “hysteresis window” or “stability window”. The row / column activation protocol for a display matrix with hysteresis characteristics shown in FIG. 3, can be designed so that during gating the line, a potential difference of about 10 volts is applied to the pixels in the gated line that are to be activated, and a potential difference close to zero volts is applied to the pixels that are to be relaxed. After gating, an established potential difference of about 5 volts is applied to the pixels, so the pixels remain in any state in which the strobe pulse of the line sets the mentioned pixels. After recording, each pixel is below the potential difference within the “stability window” of 3-7 Volts in the present example. The described feature makes the pixel construction shown in FIG. 1, stable in the same mode of applied voltage, either in an active or in a relaxed previous state. Since each pixel of the interference modulator, whether in the active or relaxed state, is essentially a capacitor formed by the fixed and movable reflective layers, the aforementioned stable state can be maintained at a voltage within the hysteresis window, in fact, in the absence of power dissipation. Essentially, no current flows into the pixel if the applied potential is constant.

In typical practical cases, an image frame can be created by assigning a combination of column electrodes in accordance with the desired combination of active pixels in the first row. Then, a line pulse is applied to the electrode of row 1, activating the pixels corresponding to the assigned column conductors. Then, the assigned combination of column electrodes is changed in accordance with the desired combination of active pixels in the second row. Then, a pulse is applied to the electrode of row 2, activating the appropriate pixels in row 2, in accordance with the assigned column conductors. The pixels of line 1 are not affected by the pulse of line 2 and remain in the state in which they were set during the pulse of line 1. The described process can be repeated for the entire set of lines in a sequential way to create a frame. In general, frames are updated and / or modified with new displayed data by continuously repeating the described process at a certain desired number of frames per second. Many different protocols for controlling row and column electrodes of a pixel matrix to create image frames are also widely known and applicable in connection with the present invention.

In FIG. 4, 5A and 5B show one possible activation protocol for creating an image frame on the 3 × 3 matrix shown in FIG. 2. In FIG. 4 shows a possible combination of column and row voltage levels that can be used for pixels having hysteresis characteristics represented by the curves in FIG. 3. In the embodiment of FIG. 4, activating a pixel involves setting the voltage -V _bias and the corresponding voltage line + ΔV in the corresponding column, which can correspond to -5 Volts and +5 Volts, respectively. Pixel relaxation is performed by setting + V _bias in the corresponding column and the same + ΔV in the corresponding row, with the creation of a potential difference on the pixel equal to zero Volt. In those rows in which the row voltage is kept equal to zero volts, the pixels are stably in any state in which they were initially, regardless of whether the column is under voltage + V _bias or -V _bias . As also shown in FIG. 4, it should be understood that voltages with a polarity opposite to the voltages described above can be applied, for example, activating a pixel may involve setting + V _bias in the corresponding column and -ΔV in the corresponding row. In such an embodiment, the pixel is relaxed by setting -V _bias in the corresponding column and -ΔV in the corresponding row, creating a potential difference of zero volts on the pixel.

In FIG. 5B is a timing chart showing successive row and column signals supplied to the 3 × 3 matrix shown in FIG. 2, which results in the display circuit shown in FIG. 5A, where active pixels are non-reflective. Before recording the frame shown in FIG. 5A, the pixels can be in any state, and, in the above example, 0 volts are applied to all rows, and +5 volts is applied to all columns. When such voltages are applied, all pixels stably reside in their existing active or relaxed states.

In the frame of FIG. 5A, pixels (1,1), (1,2), (2,2), (3,2), and (3,3) are active. To achieve the mentioned states, in continuation of the “line duration” for line 1, -5 Volts are set in columns 1 and 2, and +5 Volts is set in column 3. This does not change the state of a single pixel, since all pixels remain inside the 3-7-volt stability window. Then line 1 is gated by a pulse that goes from 0 to 5 volts and back to zero. This activates the pixels (1,1) and (1,2) and relaxes the pixel (1,3). No other pixels in the matrix are changed. For the desired setting of row 2, column 2 is set to -5 Volts, and columns 1 and 3 are set to +5 Volts. Then, a similar strobe pulse applied to line 2 activates the pixel (2,2) and relaxes the pixels (2,1) and (2,3). And again, no other pixels of the matrix are changed. Similarly, row 3 is set by setting -5 Volts in columns 2 and 3 and +5 Volts in column 1. The strobe pulse of row 3 sets the pixels of row 3, as shown in FIG. 5A. After recording the frame, the row potentials are zero, and the column potentials can remain either +5 or -5 Volts, and then the display stably stores the circuit shown in FIG. 5A. Obviously, a similar procedure can be used for matrices of tens or hundreds of rows and columns. It should be understood that the distribution of time intervals, the sequence and voltage levels used to implement the activation of rows and columns can vary widely within the framework of the above general principles, and the above example is only illustrative, and it is possible to use any method of applying activation voltage in systems and methods, proposed in this application.

In FIG. 6A and 6B are system block diagrams showing an embodiment of a display device 40. The display device 40 may be, for example, a cell or mobile phone. However, similar components of the display device 40, or slightly different versions thereof, are also characteristic of display devices of various types, for example, televisions and portable media players.

The display device 40 includes a housing 41, a display 30, an antenna 43, a speaker 44, an input device 48, and a microphone 46. The housing 41 is typically made using any of a variety of different manufacturing techniques that are 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 ceramics, or combinations thereof. In one embodiment, the housing 41 comprises removable portions (not shown) that can be replaced with other removable portions of a different color, or containing different logos, patterns, or symbols.

The display 30 of an exemplary display device 40 may be any of a variety of different displays, including a bistable display of the type described herein. In other embodiments, the display 30 includes a flat panel display, such as a plasma, EL (electroluminescent), OLED (organic light emitting diode), STN LCD (color LCD with a matrix of passive supercoiled nematic elements) or TFT LCD (LCD on thin-film transistors) ) of the type described above, or a non-flat display, for example, on a CRT or device on another tube, which are widely known to specialists in this field of technology. However, to describe the present embodiment, the display 30 comprises an interference modulator display, the same as that described in this application.

The components of one embodiment of an exemplary display device 40 are depicted schematically in FIG. 6B. The illustrated exemplary display device 40 includes a housing 41 and may include additional components, at least in part, enclosed in the housing. For example, in one embodiment, an example display device 40 includes a network interface 27 that includes an antenna 43 that is coupled to a transceiver device 47. The transceiver device 47 is connected to a processor 21 that is connected to the signal conditioning apparatus 52. The signal conditioning apparatus 52 may be configured to convert a signal (e.g., filter a signal). The preliminary signal conditioning apparatus 52 is connected to the speaker 45 and the microphone 46. The processor 21 is also connected to the input device 48 and the master controller 29. The master controller 29 is connected to the frame buffer 28 and the matrix driver 22, which, in turn, is connected to the display matrix 30 The power supply 50 provides power to all components in accordance with the specific design requirements of an exemplary display device 40.

The network interface 27 includes an antenna 43 and a transceiver 47, so that an example display device 40 can communicate with at least one device on the network. In one embodiment, the network interface 27 may also include some processing means to ease the requirements of processor 21. Antenna 43 is any antenna known to those skilled in the art for transmitting and receiving signals. In one embodiment, the antenna transmits and receives radio frequency (RF) signals in the IEEE 802.11 standard, including IEEE 802.11 (a), (b) or (g). In another embodiment, the antenna transmits and receives RF signals in the BLUETOOTH standard. In the case of a cell phone, the antenna is designed to receive CDMA (Code Division Multiple Access), GSM (Global System for Moving Objects), AMPS (Advanced Mobile Phone Service), or other known signals that are used to exchange data in a wireless cellular telephone network. The transceiver 47 pre-processes the signals received from the antenna 43 so that they can be received and further processed by the processor 21. The transceiver 47 also processes the signals received from the processor 21 so that they can be transmitted from the exemplary display device 40 through the antenna 43.

In an alternative embodiment, the transceiver 47 may be replaced by a receiver. In yet another alternative embodiment, the network interface 27 may be replaced by an image source that can store or generate image data to be transmitted to the processor 21. For example, the image source may be a digital video disc (DVD) or a hard disk drive that contains data image, or a software module that generates image data.

The processor 21 typically controls the entire operation of the exemplary display device 40. The processor 21 receives data, for example, compressed image data from a network interface 27 or an image source, and processes the data into the original image data or into a format that is easily processed into the original image data. The processor 21 then sends the processed data to the master controller 29 or the frame buffer 28 for storage. The source data is usually referred to as information that identifies the characteristics of the image at each place within the image. For example, said image characteristics may include color, saturation, and brightness level.

In one embodiment, the processor 21 comprises a microcontroller, a CPU (central processing unit), or a logic unit for controlling the operation of an exemplary display device 40. The pre-signal conditioning apparatus 52 typically includes amplifiers and filters for transmitting signals to the speaker 45 and for receiving signals from the microphone 46. The pre-signal conditioning apparatus 52 may be represented by individual components as part of an exemplary display device 40 or may be part of a processor 21 or other components .

The master controller 29 receives the original image data generated by the processor 21 either directly from the processor 21 or from the frame buffer 28 and reformats the original image data in an appropriate manner for high-speed transmission to the matrix former 22. In particular, the master controller 29 reformats the original image data into a data stream having a raster-like format, so that the stream is arranged in time in a suitable manner for scanning on the display matrix 30. Then, the master controller 29 sends the formatted information to the matrix former 22. Although the master controller 29, for example, the LCD controller, is often connected to the system processor 21 in the form of an autonomous integrated circuit (IC), such controllers can be implemented in many ways. They can be embedded in the processor 21 in the form of hardware, embedded in the processor 21 in the form of software, or fully integrated in the hardware with the matrix driver 22.

Matrix shaper 22 usually receives formatted information from the master controller 29 and reformats the video data into a parallel group of signals that are fed many times per second into hundreds and sometimes thousands of conductors coming out of the two-coordinate (x-y) matrix of display pixels.

In one embodiment, the driver controller 29, the matrix driver 22, and the display matrix 30 are suitable for any type of displays described herein. For example, in one embodiment, the driver controller 29 is a conventional display controller or a bistable display controller (eg, an interference modulator controller). In another embodiment, the matrix driver 22 is a conventional driver or bistable display control device (eg, an interference modulator display). In one embodiment, the master controller 29 is integrated with the matrix driver 22. This embodiment is common in systems with a high degree of integration, for example, cell phones, watches and other displays with a small area. In yet another embodiment, the display matrix 30 is a typical display matrix or bistable display matrix (eg, a display comprising an interference modulator matrix).

The input device 48 allows the user to control the operation of an exemplary display device 40. In one embodiment, the input device 48 comprises a keyboard, for example, a QWERTY keyboard (standard English keyboard) or a telephone keypad, button, switch, touch screen, pressure or temperature sensitive membrane. In one embodiment, the input device for the sample display device 40 is a microphone 46. When a microphone 46 is used to input data into the device, voice commands can be issued by the user to control the operation of the sample display device 40.

The power source 50 may include many different energy storage devices that are widely known in the art. For example, in one embodiment, the power supply 50 is a rechargeable battery, for example, a nickel-cadmium battery or a lithium ion battery. In another embodiment, the power supply 50 is a renewable energy source, capacitor, or solar cell, including a plastic solar cell and photosensitive paint. In another embodiment, the power supply 50 is configured to receive power from a wall outlet.

In some implementation cases, control programming capability is built into the master controller, which may be located in several places on the display electronic circuit, as explained above. In some cases, the ability to program control is built into the matrix driver 22. Specialists in the art should understand that the above optimization can be performed in any number of hardware and / or software components and in a variety of configurations.

Structural elements of interference modulators that operate in accordance with the above principles can vary widely. For example, in FIG. 7A-7E show five different embodiments of the movable reflective layer 14 and its supporting structures. In FIG. 7A is a sectional view of the embodiment of FIG. 1, in which a strip of metallic material 14 is deposited on orthogonally extending support structures 18. FIG. 7B, the movable reflective layer 14 is attached to the supporting structures only at the corners of the mounts 32. In FIG. 7C, the movable reflective layer 14 is suspended from a deformable layer 34, which may contain flexible metal. The deformable layer 34 is connected, directly or indirectly, with the substrate 20 around the perimeter of the deformable layer 34. The said compounds are referred to as support columns in the present description. In the embodiment of FIG. 7D, there are support pins 42 on which the deformable layer 34 rests. The movable reflective layer 14 remains suspended above the cavity, as in FIG. 7A-7C, but the deformable layer 34 does not form support columns by filling holes between the deformable layer 34 and the optical stack 16. Instead, the support columns are formed of a leveling material that is used to form the support pins 42. The embodiment shown in FIG. 7E is based on the embodiment of FIG. 7D, but can also be configured to work with any of the embodiments shown in FIG. 7A-7C, as well as with additional embodiments not shown. In the embodiment shown in FIG. 7E, an additional layer of metal or other conductive material is used to form the busbar structure 44. This allows the signal to be directed along the back of interference modulators, which eliminates the plurality of electrodes that would otherwise have to be formed on the substrate 20.

In embodiments such as those of FIG. 7, interference modulators function as direct observation devices in which images are observed from the front of the transparent substrate 20, i.e. from the side opposite to the side on which the modulator is located. In the aforementioned embodiments, the reflection layer 14 optically shields the areas of the interference modulator on the side of the reflection layer opposite the substrate 20, including the deformable layer 34 and the busbar structure 44. This makes it possible to perform and act on the shielded areas without adversely affecting image quality. The described separate architecture of the modulator allows mutually independent selection and functioning of structural elements and materials used to solve electromechanical problems and optical problems. In addition, the embodiments shown in FIG. 7C-7E, have additional advantages due to the separation of the optical characteristics of the reflective layer 14 and its mechanical properties, which are realized by the deformable layer 34. This makes it possible to optimize the structural elements and materials used for the reflective layer 14, in terms of optical properties, and structural elements and materials used for the deformable layer 34, in terms of the desired mechanical properties.

As described above with reference to FIG. 1, a modulator 12 (i.e., both modulators 12a and 12b) comprise an optical resonator formed between mirrors 14 (i.e., mirrors 14a and 14b) and 16 (mirrors 16a and 16b, respectively). The characteristic distance or effective optical path length, d, of the optical resonator determines the resonant wavelengths, λ, of the optical resonator, and therefore of the interference modulator 12. The wavelength of the resonant maximum in visible light, λ, of the interference modulator 12 generally corresponds to the perceived color of the light reflected by modulator 12. From a mathematical point of view, the optical path length d is ½ N λ, where N is an integer. Thus, this resonant wavelength, λ, is reflected by an interference modulator 12 with optical path lengths d equal to ½ λ (N = 1), λ (N = 2), 3/2 λ (N = 3), etc. The integer N can be called the order of interference of the reflected light. For the purposes of the present description, the order of the modulator 12 is also called the order N of the light reflected by the modulator 12 when the mirror 14 is in at least one position. For example, a first-order red interference modulator 12 may have an optical path length d of about 325 nm, corresponding to a wavelength λ of about 650 nm. Accordingly, the red second-order interference modulator 12 may have an optical path length d of about 650 nm. In general, modulators 12 of higher orders reflect light in a narrower wavelength range, for example, have a higher Q (Q) value, and therefore produce colored light that is more saturated. The saturation of modulators 12 that contain a color pixel affects display properties such as color gamut and white point on the display. For example, in order for a display using a second-order modulator 12 to have the same white point or color balance as a display that contains a first-order modulator that reflects the primary color of light, a second-order modulator 12 can be selected with a different light wavelength at a central maximum.

In FIG. 8 is a side cross-sectional view of an exemplary interference modulator 12, depicting the spectral characteristics of light that would be output by installing a movable mirror 14 in a range of positions 61-65. An exemplary modulator comprises a conductive layer 52 of indium tin oxide (ITO), which acts as a column electrode. In an exemplary modulator, the movable mirror 14 comprises a line conductor.

Each of a particular group of positions 61-65 of the movable mirror 14 is indicated by an arrow extending from the fixed mirror 16. The tip of each arrow indicates one particular position from the positions 61-65 of the movable mirror. The color of the light reflected from the interference modulator is determined by the optical path length, d, between the movable and fixed mirrors 14 and 16. The distances 61-65 are chosen so as to take into account the thickness and refractive index of the dielectric layer 54 in the optical path length, d. Accordingly, the movable mirror 14, located in a different position from positions 61-65, corresponding, in each case, to a different distance d, results in a modulator 12, which produces light at the observation position 51 with a different spectral characteristic that corresponds to different colors incident light reflected by the modulator 12. In addition, at position 61, the movable mirror 14 is located close enough to the stationary mirror 16, so that interference effects are almost absent, and the modulator 12 acts as a mirror that reflects t, essentially all the colors of the incident visible light are essentially the same, for example, in the form of white light. The effect of a broadband mirror is due to the fact that the small distance d is too small for optical resonance in the visible range. Thus, the mirror 14 acts simply as a reflective surface with respect to visible light.

When the mirror 14 is set to position 62, the modulator 12 gives a shade of gray, since increasing the width of the gap between the mirrors 14 and 16 reduces the reflection coefficient of the mirror 14. At position 63, the distance d is such that the cavity functions as an interferometer, but essentially does not reflects the wavelengths of visible light, since the resonant wavelength is outside the visible range.

As the distance d increases further, the maximum spectral characteristic of the modulator 12 moves to the visible wavelength region. Therefore, when the movable mirror 14 is at position 64, the modulator 12 reflects blue light. When the movable mirror 14 is at position 65, the modulator 12 reflects green light. When the movable mirror 14 is at position 66 without deviation, the modulator 12 reflects red light.

When designing a display using interference modulators 12, modulators 12 can be designed to increase color saturation in reflected light. Saturation refers to the intensity of the color tone of the colored light. A highly saturated color tone has a vibrant, intense color, while a less saturated color tone appears more muted and gray. For example, a laser that generates in a very narrow wavelength range generates highly saturated light. In contrast, a typical incandescent lamp produces white light that may contain unsaturated red or blue. In one embodiment, the modulator 12 is made with a distance d corresponding to a higher order of interference, for example, 2nd or 3rd order, to increase the saturation of the reflected colored light.

A sample color display contains red, green, and blue display elements. In the said display, other colors are created by changing the relative intensity of the light produced by the red, green, and blue elements. Such mixtures of primary colors, for example, red, green and blue, are perceived by the human eye as other colors. The relative values of red, green, and blue in the aforementioned colorimetric system can be referred to as color coordinates in relation to the excitation of red, green, and blue photosensitive regions of the human eye. In general, the more saturated the primary colors, the wider the scale of colors that can be created by the display. In other embodiments, the display may include modulators 12 having a set of colors that form other colorimetric systems in terms of sets of primary colors other than red, green, and blue.

Another factor that is considered when designing displays containing interference modulators 12 is the synthesis of white light. “White” light is usually called light that is perceived by the human eye as light that does not have any particular color, i.e. white light does not match the tint. Then, as black is understood as the absence of color (or light), white is called light, which contains such a wide spectral range that no specific light is perceived. Under white light, we can mean light containing visible light in a wide spectral range with approximately uniform spectral intensity. However, since the human eye is sensitive to certain wavelengths of red, green, and blue light, white can be created by mixing known intensities of colored light to produce light that contains at least one spectral maximum, and which is perceived by the eye as “white” ". The color scheme of the display is the color scale that the device can reproduce, for example, by mixing red, green and blue light.

In a reflective display, white light obtained using interference modulators at the saturation level is characterized by a relatively low observed intensity due to the fact that only a small range for the synthesis of white light is reflected from incident wavelengths with relatively high intensities. On the contrary, a mirror reflecting broadband white light, for example, essentially all incident wavelengths, is characterized by a higher intensity due to the fact that a wider range of incident wavelengths is reflected. Therefore, designing reflective displays using combinations of primary colors to produce white light usually results in a trade-off between color saturation and color gamut and the brightness of the white light synthesized by the display.

In one embodiment, the movable mirror 14 is positioned so that in the first position, the modulator 12 does not reflect visible light (for example, at 63 in FIG. 8), and in the second position, the distance between the movable mirror 14 and the fixed mirror 16 is too small for interference modulating incident visible light so that the mirror 14 reflects broadband white (for example, at position 61 in FIG. 8). In such an embodiment, the movable mirror 14 reflects incident light with a broad, relatively uniform spectral characteristic over the entire visible spectrum. If the incident light contains white light, then the light reflected by the modulator 12 in the second position may be substantially the same as white light. The spectral characteristic of such a “white” reflecting state of the modulator 12 can be basically uniform over the entire visible spectrum. In one embodiment, the spectral response is tuned by the selection of modulator materials. For example, you can use different materials, for example, aluminum or copper, for the reflective surface of the movable mirror 14, to adjust the spectral characteristics of the modulator 12 when in a state of reflection of white. In another embodiment, a filter can be used to selectively absorb certain wavelengths of reflected or incident light to affect the output signal of a modulator with such broadband white.

In one embodiment of the matrix of pixels 30, each pixel contains at least one color modulator 12, for example, a modulator configured to reflect red, green and blue light, and at least one “white” modulator 12, made with the ability to reflect white light. In such an embodiment, the light from the red, green, and / or blue modulators 12 in their reflective states is added to the output of colored light. Light from white modulators 12 can be used to output white or gray light. Using white in combination with color can increase the brightness or intensity of pixels.

The white point on the display is a hue that is considered generally neutral (gray or achromatic). The point of the white display device can be characterized by comparing the white light synthesized by the device with the spectral composition of the light emitted by a completely black body at a specific temperature (“absolutely black body radiation”). A completely black emitter is a theoretical object that absorbs all the light incident on the object, and which re-emits light with a spectral characteristic depending on the temperature of a completely black body. For example, the spectral characteristic of a black body at 6500 ° K can be attributed to white light with a color temperature of 6500 ° K. Mentioned color temperatures or white dots at approximately 5000-100000 ° K are usually identified with daylight.

The International Lighting Commission (CIE) publishes standardized white dots for light sources. For example, the designation “d” of light sources refers to daylight. In particular, the standard white dots D ₅₅ , D ₆₅ and D ₇₅ , which correspond to the color temperatures 5500 ° K, 6500 ° K and 7500 ° K, are standard white dots for daylight.

The display device can be characterized by a white dot for the white light synthesized by the display. As with white light from other light sources, a person’s perception of the display is at least partially determined by the perception of white light from the display. For example, a display or a light source having a white point with a low value, for example, D ₅₅ , can give the observer a yellow feeling. A display with a higher white point temperature, for example, D _75, may give the user a “colder” or bluer tone. Users are usually more disposed towards displays with higher-temperature white dots. Therefore, controlling the white point of the display provides some suitable control of the observer's response to the display. Embodiments of the interference modulator matrix 30 may be configured to synthesize white light, at which a white point is assigned to align with a standardized white point, at least in one presumed illumination condition.

White light can be synthesized by a matrix of 30 pixels with the content of at least one interference modulator 12 in each pixel. For example, in one embodiment, the pixel matrix 30 contains pixels of a group of red, green, and blue interference modulators 12. As explained above, the colors of interference modulators 12 can be selected by assigning the optical path length d using the dependence d = ½Nλ. In addition, the balance or ratio of colors synthesized by each pixel in the matrix of 30 pixels may additionally depend on the ratio of the areas of the reflecting sections of each of the interference modulators 12, for example, red, green, and blue interference modulators 12. In addition, since the modulators 12 selectively reflect incident light, the point of white light reflected from the matrix of 30 pixels from the interference modulators 12, usually depends on the spectral characteristics of the incident light. In one embodiment, the point of white reflected light can be adjusted so that it differs from the point of white incident light. For example, in one embodiment, the pixel matrix 30 may be configured to reflect light D ₇₅ when applied to sunlight D ₆₅ .

In one embodiment, the distances d and the area of the interference modulators 12 in the pixel array 30 are selected so that the white light synthesized by the pixel array 30 corresponds to a particular standardized white point under the expected lighting conditions, for example, in sunlight, in the light of a fluorescent lamp or in light a source mounted in front to illuminate a 30 pixel matrix. For example, for a matrix of 30 pixels, a white point D ₅₅ , D _65, or D ₇₅ can be assigned in specific lighting conditions. In addition, the light reflected by a matrix of 30 pixels may have a different white point than the light of the intended or tuned light source. For example, a specific pixel matrix 30 may be configured to reflect light D ₇₅ when observed in sunlight D ₆₅ . In a more general case, the white point for the display can be selected taking into account the backlight source included in the display configuration, for example, a frontal illuminator, or taking into account specific viewing conditions. For example, the display may be configured to produce a selected white point, for example, D ₅₅ , D _65, or D ₇₅ , when observed backlit from suspected or typical sources, for example, incandescent, fluorescent, or natural light sources. In a more specific case, for example, a display for use in a hand-held device may be configured to produce a selected white point when observed under sunlight. Alternatively, a display for use in an office space may be configured to produce a selected white point, such as D ₇₅ , when illuminated with typical office fluorescent lights. In various embodiments, different distances d and areas of modulators 12 can be selected to create other standardized white point parameters for differing viewing conditions. In addition, the control of the red, green, and blue modulators 12 can also be such that they remain in reflective or non-reflective states for different time intervals to further change the relative balance of the reflected red, green, and blue light, and therefore the point of white reflected light . In one embodiment, the ratio of the areas of the reflective sections of each of the color modulators 12 can be selected so as to control the white point in different viewing conditions. In one embodiment, the optical path length d can be selected to correspond to a common multiple of at least two visible resonant wavelengths, for example, first, second, or third order maxima in red, green, and blue, so that interference modulator 12 reflects white light with three noticeable characteristic maxima on its spectral characteristic. In such an embodiment, the optical path length d can be adjusted so that the synthesized white light corresponds to a standardized white point.

In addition to the group of red, green, and blue interference modulators 12 in the pixel array 30, other embodiments include other methods for synthesizing white light. For example, one embodiment of the pixel matrix 30 includes cyan and yellow interference modulators 12, for example, interference modulators 12 that have respective separation distances d to produce blue and yellow light. The total spectral characteristic of the blue and yellow interference modulators 12 provides light with a wide spectral characteristic, which is perceived as “white”. The blue and yellow modulators are very close together, so that the observer perceives the above summarized characteristic. For example, in one embodiment, the blue modulators and the yellow modulators are located in adjacent rows of the pixel array 30. In another embodiment, blue modulators and yellow modulators are located in adjacent columns of a pixel array 30.

In FIG. 9 is a graphical diagram showing a spectral characteristic of one embodiment, which comprises blue and yellow interference modulators 12 for synthesizing white light. The horizontal axis represents the wavelength of reflected light. The vertical axis represents the reflection coefficient of the light incident on the modulators 12. Curve 80 represents the characteristic of the blue modulator, which is the only maximum concentrated within the blue part of the spectrum, for example, between blue and green. Curve 82 represents the characteristic of the yellow modulator, which is the only maximum concentrated within the yellow portion of the spectrum, for example, between red and green. Curve 84 represents the total spectral characteristic of a pair of blue and yellow modulators 12. Curve 84 contains two peaks at blue and yellow wavelengths, but is fairly uniform throughout the entire visible spectrum, so that the light reflected by such modulators 12 is perceived as white.

In general, the color of the light reflected by the interference modulator 12 is shifted when the modulator 12 is observed at different angles. In FIG. 10 is a side cross-sectional view of interference modulator 12, showing different optical paths through modulator 12. The color of light reflected from interference modulator 12 can vary for different angles of incidence (and reflection) relative to axis AA, as shown in FIG. 10. For example, in the case of interference modulator 12 shown in FIG. 10, when the light passes along an off-axis path A ₁ , the light falls on the interference modulator at a first angle, is reflected from the interference modulator, and passes to the observer. The observer perceives the first color when the light reaches the observer as a result of optical interference on a pair of mirrors in the interference modulator 12. When the observer moves or changes his position and, therefore, the viewing angle, the light perceived by the observer passes through another off-axis path A ₂ corresponding to the second different angle of incidence (and reflection). Optical interference in the interference modulator 12 depends on the optical path length d of the light transmitted in the modulator. Therefore, different optical path lengths for different optical paths A ₁ and A ₂ cause different output signals from the interference modulator 12. As the viewing angle increases, the effective optical path of the interference modulator decreases in accordance with the dependence 2d cosβ = Nλ, where β means the viewing angle (angle between the normal to the display and the incident light). With an increase in the observation angle, the wavelength of the resonant maximum of the reflected light decreases. Therefore, the user perceives different colors depending on the viewing angle. As described above, this phenomenon is called a “color shift”. Mentioned color shift is usually determined relative to the color created by the interference modulator 12, when observed along the axis AA.

In one embodiment, the pixel matrix 30 comprises a yellow first order interference modulator and a blue second order interference modulator. When such a matrix of 30 pixels is observed at increasing angles of deviation from the axis, the light reflected by the yellow first-order modulator is shifted to the blue end of the spectrum, for example, the modulator at some angle is characterized by an effective d equal to the corresponding value for the blue first order. At the same time, the light reflected by the blue second-order modulator is shifted to the corresponding light from the yellow first-order modulator. Therefore, the total aggregate spectral characteristic is wide and relatively uniform over the entire visible spectrum, even when relative spectral maxima are shifted. Thus, the described pixel matrix 30 synthesizes white light in a relatively wide range of viewing angles.

In one embodiment, a display comprising cyan and yellow modulators may be capable of synthesizing white light having a standardized white point in at least one viewing condition. For example, the spectral response of a blue modulator and a yellow modulator may be selected such that the reflected light has a white point D ₅₅ , D ₆₅ , D ₇₅ or any other suitable white point in selected lighting conditions that include light D ₅₅ , D ₆₅ or D ₇₅ , for example, sunlight for a display suitable for outdoor use. In one embodiment, the modulators may be configured to reflect light that has a different white point than the incident light under the expected or selected viewing conditions.

In FIG. 11 is a side sectional view of an interference modulator 12 comprising a material layer 102 for selectively transmitting light of a particular color. In an exemplary embodiment, layer 102 is on the side of the substrate 20 opposite from modulator 12. In one embodiment, material layer 102 comprises a magenta filter through which green interference modulators 12 are observed. In one embodiment, material layer 102 is a colored material. In one such embodiment, the material is a colored photoresist. In one embodiment, the green interference modulators 12 are first-order green interference modulators. The filter layer 102 is configured to transmit magenta light when illuminated with white light, uniform over a wide range. In an exemplary embodiment, light is incident on a layer 20 from which filtered light is transmitted to a modulator 12. Modulator 12 reflects the filtered light back through layer 102. In a similar embodiment, light passes through layer 102 twice. In a similar embodiment, the thickness of the material layer 102 can be selected to compensate for and use said double filtration. In another embodiment, the design of the frontal illuminator may be located between the layer 102 and the modulator 12. In a similar embodiment, the material layer 102 only acts on the light reflected by the modulator 12. In such embodiments, the layer 102 is suitably selected.

In FIG. 12 is a graphical diagram showing a spectral characteristic of one embodiment, which includes green interference modulators 12 and a magenta filter layer 102. The horizontal axis represents the wavelength of reflected light. The vertical axis represents the relative spectral characteristic of the light incident on the green modulator 12 and the filter layer 102 in the entire visible spectral range. Curve 110 represents the characteristic of the green modulator 12, which is the only maximum concentrated within the green part of the spectrum, for example, near the center of the visible spectrum. Curve 112 represents the characteristic of the magenta filter formed by the layer of material 102. Curve 112 contains two relatively flat portions on each side of the central horseshoe-shaped minimum. Therefore, curve 112 represents the characteristic of the magenta filter, which selectively transmits essentially all of the red and blue light and, at the same time, filters out the light from the green part of the spectrum. Curve 114 represents the total spectral response of the green modulator 12 paired with the filter layer 102. Curve 114 shows that the spectral characteristic of the combination is at a level of a lower reflection coefficient than in the case of the green modulator 12 due to the filtering of light by the filter layer 102. However, the spectral characteristic is relatively uniform across the visible portion of the spectrum, so that the filtered reflected light from the green modulator 12 and the magenta filter layer 102 is perceived as white.

In one embodiment, a display comprising a green modulator 12 with a magenta filter layer 102 may be configured to synthesize white light having a matched standardized white point in at least one viewing condition. For example, the spectral characteristic of the green modulator 12 and the magenta filter layer 102 can be selected so that the reflected light has a white point D ₅₅ , D ₆₅ , D ₇₅ or any other suitable white point in the selected backlight conditions, which contains light such as D ₅₅ , D ₆₅ or D ₇₅ , for example, sunlight, for a display suitable for outdoor use. In one embodiment, the modulator 12 and the filter layer 102 may be configured to reflect light that has a different white point than the incident light under the expected or selected observation conditions.

In FIG. 13 is a graphical diagram showing two pixels of an exemplary matrix of 30 pixels. Rows 1-4 and columns 1-4 form one pixel 120a. Rows 5-8 and columns 1-4 form a second pixel 120b. Each pixel 120a and 120b contains at least one modulator 12, configured to reflect red (column 1), green (column 2), blue (column 3) and white (column 4) light. Each pixel of the exemplary 30 pixel matrix contains 4 display elements of each color, red, green, blue and white, to form a display with “4 bits” per color, which can produce 2 ⁴ = 16 shades of each of red, green, blue or white / gray, only 2 ¹⁶ shades of color.

In FIG. 14A is a color chart that shows colors that can be synthesized by an exemplary color display that contains red, green, and blue display elements. Colors on a wide scale are synthesized in the described display by changing the relative intensity of the light synthesized by the red, green, and blue display elements. The color chart shows how the display can be controlled to create mixtures of primary colors, such as red, green and blue, which are perceived by the human eye as other colors. The horizontal and vertical axes in FIG. 14 form a coordinate chromaticity system in which color coordinates can be described. In particular, dots 130 depict the color of light reflected by exemplary red, green, and blue interference modulators. The triangular curve 133 spans an area 134 that corresponds to a color scale that can be synthesized by mixing the light received at points 130. The color scale mentioned may be called the color gamut of the display. During operation, each of the red, green, and blue pixel display elements can be controlled to synthesize different mixtures of red, green, and blue light, which are added together to form each color in a gamut of colors.

As shown in FIG. 13, in one embodiment, an example display 30 comprises pixels containing sub-pixels of red, green, blue, and white. One embodiment of a circuit for controlling such a display defines each color to be displayed by a pixel as combinations of the color coordinates (i) red, green and white, (ii) red, blue and white, and (iii) blue, green and white, which define three different color schemes. During the operation of the aforementioned embodiment, when the display controller determines that a color coordinate expressed in red, green and blue values should be set in a particular pixel, the display controller converts the color coordinate into a value expressed in the values of one of the combinations (i) of red, green and white; (ii) red, blue, and white; and (iii) blue, green, and white.

In FIG. 14B is a color chart that shows colors that can be synthesized by such a color display. The total color gamut of the display is determined by the area bounded by the curve 140, which connects each of the points 130 corresponding to the color of the primary colors of the display, red, green and blue. In addition, the point 130a corresponds to the color of the light emitted by the white sub-pixel. Mentioned point 130a may be in other places, depending on the white synthesized by the white sub-pixel. Curves 144a, 144b, and 144c connect a point 130a corresponding to a white sub-pixel with each of the points 130 corresponding to red, blue, and green, respectively. Together with curve 140, curves 144a, 144b, and 144c bound three regions 146a, 146b, and 146c within the boundaries of the display color gamut, corresponding to colors that can be synthesized (i) red, green, and white, (ii) red, blue, and white, and (iii) blue, green, and white display elements, respectively. Therefore, in principle, one embodiment of a control circuit for such a display is to determine within which of the three areas 146a, 146b or 146c is the desired color to be displayed. Then, the input color represented by the values of red, green, and blue can be converted to a new color. Such a chromaticity coordinate will be within one of the three established areas 146a, 146b or 146c. Then, the new output values can be used to control each of the three set display elements, limiting the area within which the desired color coordinate is located, namely (i) red, green and white, (ii) red, blue and white, or (iii) blue, green and white display elements, a pixel to display the desired color of light.

In one embodiment, when the chromaticity coordinate is within a selected distance (for example, on the color plot) from the point 130a of the white display element, both color and white display elements are turned on so as to synthesize a higher brightness at the pixel output for similar colors.

In another embodiment, to control such a matrix of pixels, when the total tint of the pixel data is below a threshold value, for example, the pixel data is gray or essentially gray, the driver circuit sets the white modulators in column 4 to the corresponding reflective state. In one embodiment, red, green, and blue modulators may also be in their reflective states. When the total hue for the pixel data is above a threshold value, for example, the pixel data is not essentially gray, the driver circuit sets the white modulators in column 4 to their non-reflective state, and the color modulators in columns 1-3 are set to reflective states.

In some embodiments, white display elements may be included in combination with color display elements to add additional brightness. For example, if the pixel is designed to output red light, then you can turn on all the red display elements in the pixel. In addition, you can also include at least one of the white display elements for the synthesis of other color combinations.

In some embodiments, the driver circuitry can correct the input data to compensate for the additional white surface area, so that such a display creates images with color balances that essentially do not change when the reflective white areas change (although the relative brightness of the display increases).

In one embodiment, white interference modulators are grouped with other white interference modulators, for example, in an additional column, as shown in FIG. 13. In another embodiment, the white interference modulators are evenly distributed across the pixel, for example, alternating between red, green, and blue display elements. In addition, in some embodiments, the number of white display elements in each pixel is different from the number of, for example, red, green, or blue elements.

In addition to using additional interference modulators configured to reflect white light to increase the intensity of reflected white light, it is possible to implement variants of a matrix of 30 pixels in which the overall subjective brightness of the system is increased by other means. For example, the human eye is more sensitive to green light than to other shades. Therefore, in one embodiment, the subjective brightness of the interference modulator system is increased by using an additional green interference modulator in each pixel. For example, in some embodiments, an equal number of green, red, and blue interference modulators per pixel is present. In one embodiment similar to the embodiment of FIG. 13, a second column of green interference modulators can also be included. In another embodiment, the pixel matrix 30 may comprise a 4th column, for example, shown in FIG. 13, in which some of the display elements reflect white light and some reflect green light.

In one embodiment, additional green interference modulators may be grouped with other green interference modulators, for example, in an additional column, as shown in FIG. 13. In other embodiments, the implementation of additional green interference modulators can be evenly distributed across the pixel, for example, alternating between red, green and blue display elements. In addition, in some embodiments, the number of additional green display elements in each pixel may differ from the amounts of, for example, red, green, or blue display elements. In one embodiment, the display elements are interference modulators in which the optical path lengths, d, red and blue modulators are matched to compensate for additional green pixels in the color balance of the display. In addition, in one embodiment, the optical path lengths, d, of one or both of the red and blue display elements can be selected to synthesize a more saturated color. In one such embodiment, the optical path lengths, d, of the red or blue display elements can be matched to produce higher order reflected light (2nd or higher order). The second order corresponds to the optical path length, d, equal to 1 × λ. Since interference modulators with a more saturated characteristic reflect a smaller fraction of the incoming light, such modulators have lower intensity (more dim) at the output. But, with an increase in the relative intensity of the reflected green light, such a display can be made with the possibility of providing a higher subjective brightness for the observer. In one embodiment, the ratio of the areas of red to blue is one to one, and the ratio of the areas of green to red (or blue) is greater than one to one. For example, in one embodiment, with an expression as a percentage of the total reflective area of each pixel, green is 33-50% of the pixel. In one embodiment, green is 38-44% of the pixel.

In one embodiment, the ratio of the surface area of the green interference modulators to the total reflective surface area of the pixel may be greater than the ratio of the surface area of the red and blue interference modulators to increase the subjectively perceived brightness. In another embodiment, the length of time during which the green interference modulators are in a reflective state is increased to enhance green, compared to the length of time for interference modulators generating other colors. In one embodiment, the blue and red interference modulators are tuned toward the green spectral response to enhance the visual perception of green and, therefore, to enhance the subjectively perceived brightness in the system. As is obvious to a person skilled in the art, the driver circuitry can correct the input data to compensate for additional green surface areas so that such a display creates images with color balances that essentially do not change with additional green reflective areas (but with an increase in the relative brightness of the display) . In one embodiment, additional green display elements serve in display modes when brightness is more important than color fidelity, for example, in a text display.

Although the above detailed description shows, describes and highlights the new features of the invention as applied to various embodiments, it should be understood that various exceptions, replacements and changes in the form and details of the device or method can be made by those skilled in the art without departing from the scope of the invention. Obviously, the implementation of the present invention is possible in a form that does not provide all the features and advantages set forth in the present description, since some features can be used or practically implemented separately from others. The scope of the invention is indicated by the attached claims, and not by the above description. All changes that are within the meaning and scope of equivalence of the claims are included in the scope of the attached claims.

Claims (32)

1. The display containing
a plurality of pixels, each of which includes red, green and blue interference modulators, which are configured to output red, green and blue light, respectively,
wherein each of the pixels is configured to output a higher intensity of green light than red light, and is configured to output a higher intensity of green light than blue light, and
wherein at least one of the interference modulators configured to output red light and the interference modulators configured to output blue light is configured to output light having a wavelength configured to compensate said higher green light intensity . 2. The display according to claim 1, in which the wavelength is made essentially equal to approximately one wavelength, λ, corresponding to red light, to obtain a reflection of red second order. 3. The display according to claim 1, in which the wavelength is made essentially equal to approximately one wavelength, λ corresponding to blue light, to obtain a reflection of blue second order. 4. The display of claim 1, wherein each of the plurality of pixels includes more interference modulators configured to output green light than interference modulators configured to output blue light. 5. The display of claim 1, wherein each of the plurality of pixels includes more interference modulators configured to output green light than interference modulators configured to output red light. 6. The display according to claim 1, in which each of the interference modulators of each of the plurality of pixels contains a reflective area, and the green interference modulators have a larger total reflective area than the red interference modulators and the blue interference modulators. 7. The display of claim 1, further comprising a circuit configured to drive each of the red, green, and blue interference modulators for respective time periods, and wherein the time period related to the green interference modulators is longer than the corresponding time periods, related to red and blue interference modulators. 8. A method of manufacturing a display comprising the step of:
form a lot of pixels, while the formation includes stages in which:
forming interference modulators configured to output red light;
form interference modulators configured to output green light;
form interference modulators configured to output blue light,
each of these pixels being configured to output a higher intensity of green light than red light, and
configured to output a higher intensity of green light than blue light, and
wherein at least one of the formations of interference modulators configured to output red light and the formations of interference modulators configured to output blue light includes a step of generating interference modulators configured to output light having a wavelength configured to compensate for said higher green light intensity. 9. The method of claim 8, in which the formation of interference modulators configured to output red light, includes the stage of forming interference modulators for outputting light having a wavelength made essentially equal to approximately one length waves, λ corresponding to red light, to obtain a second-order red reflection. 10. The method of claim 8, in which the formation of interference modulators configured to output blue light, includes the stage of forming interference modulators for outputting light having a wavelength made essentially equal to approximately one length waves, λ corresponding to blue light, to obtain a reflection of blue second order. 11. The method of claim 8, further comprising forming a circuit configured to excite each of the red, green, and blue interference modulators for respective time periods, and wherein the time period related to the green interference modulators is longer than the corresponding time periods related to red and blue interference modulators. 12. The method of claim 8, wherein generating the plurality of pixels includes generating a large total reflective area for the green interference modulators, which is larger than for the red interference modulators and for the blue interference modulators of each pixel. 13. A display comprising:
many means for outputting red light;
many means for outputting green light; and
a plurality of means for outputting blue light, and means for outputting red, green, and blue light form means for displaying an image pixel;
wherein each of the pixel display means is configured to output a higher intensity of green light than blue light, and
moreover, at least one of the red light output means and the blue light output means is configured to output light having a wavelength configured to compensate said higher green light intensity. 14. The display of claim 13, wherein said pixel display means comprises a pixel. 15. The display of claim 14, wherein the red, green, and blue light output means comprises red, green, and blue interference modulators configured to output red, green, and blue light, respectively. 16. The display of Claim 15, wherein each of the interference modulators of each of the plurality of pixels comprises a reflective area, and wherein the green interference modulators have a larger total reflective area than the red interference modulators and the blue interference modulators. 17. The display of claim 13, further comprising forming a circuit configured to excite each of the red, green, and blue light output means for respective time periods, and wherein the time period related to the green light output means is larger than the corresponding time periods related to red and blue light output means. 18. A display comprising:
many display elements, including:
at least one color display element configured to output colored light, and,
at least one display element configured to output white light, and at least one display element configured to output white light outputs white light having a standardized white point, so that the output white light has a different white point than the light illuminating the display. 19. The display of claim 18, wherein the at least one color display element comprises red, green, and blue display elements configured to output red, green, and blue light, respectively. 20. The display of claim 18, wherein the plurality of display elements comprises a plurality of interference modulators. 21. The display of claim 18, wherein the display is configured to correct a plurality of display elements to control a point of white output white light for various viewing conditions. 22. The display of claim 18, wherein each of the plurality of image elements includes a reflective area, and wherein the display is adapted to correct corresponding areas to control a white point of the output white light based on the observation condition. 23. The display of claim 21, wherein the display is configured to correct corresponding times at which a plurality of display elements output light to control a point of white output white light based on observation conditions. 24. The display of claim 21, wherein the various observation conditions include an office space and a sunlight environment. 25. A display comprising:
means for displaying an image, including:
means for outputting colored light; and
means for outputting white light, and means for outputting white light outputs white light having a standardized white point, so that the output white light has a different white point than the light illuminating the display. 26. The display of claim 25, wherein the display means comprises a plurality of display elements. 27. The display of claim 25, wherein the means for outputting the colored light comprises at least one display element configured to output colored light. 28. The display of claim 25, wherein the white light output means includes at least one display element configured to output white light. 29. The display of claim 26, wherein the plurality of display elements comprises a plurality of interference modulators. 30. A method of manufacturing a display comprising the step of:
form a plurality of display elements, the formation includes a stage in which: form at least one color display element configured to output colored light, and at least one display element configured to output white light wherein at least one display element configured to output white light is configured to output white light having a standardized white point, so that the output white light has another white point oh, what light, backlit display. 31. The method of claim 30, wherein generating the plurality of display elements includes generating red, green, and blue display elements configured to output red, green, and blue light, respectively. 32. The method according to p, in which the formation of many display elements includes a stage in which form a lot of interference modulators.

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