Dynamic driver IC and display panel configuration

A display device which can provide configuration information to the driver circuit and methods of manufacturing and operating the same are disclosed. In one embodiment, a display device comprises a display array and a collection of links configured to store information related to the display array.

BACKGROUND OF THE INVENTION

1. Field of the Invention

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

2. Description of the Related Technology

Microelectromechanical systems (MEMS) include micro mechanical elements, actuators, and electronics. Micromechanical elements may be created using deposition, etching, and/or other micromachining processes that etch away parts of substrates and/or deposited material layers or that add layers to form electrical and electromechanical devices. One type of MEMS device is called an interferometric modulator. As used herein, the term interferometric modulator or interferometric light modulator refers to a device that selectively absorbs and/or reflects light using the principles of optical interference. In certain embodiments, an interferometric modulator may comprise a pair of conductive plates, one or both of which may be transparent and/or reflective in whole or part and capable of relative motion upon application of an appropriate electrical signal. In a particular embodiment, one plate may comprise a stationary layer deposited on a substrate and the other plate may comprise a metallic membrane separated from the stationary layer by an air gap. As described herein in more detail, the position of one plate in relation to another can change the optical interference of light incident on the interferometric modulator. Such devices have a wide range of applications, and it would be beneficial in the art to utilize and/or modify the characteristics of these types of devices so that their features can be exploited in improving existing products and creating new products that have not yet been developed.

SUMMARY OF CERTAIN EMBODIMENTS

In one embodiment, a display device comprises a display array, and a collection of links configured to store information related to said display array.

In another embodiment, a display device comprises means for displaying image data, and means for encoding information related to said displaying means.

In another embodiment, a method of storing information related to a display array formed on a substrate comprises forming a collection of links on the substrate, wherein said information is encoded by forming each link as either an open circuit or a closed circuit between two ends of the link.

In another embodiment, a method of making a display device comprises forming a display array on a substrate, and forming a collection of links on the substrate, each link being formed as either an open circuit or a closed circuit between two ends of the link.

In another embodiment, a method of making a display device comprises forming a display array on a substrate, forming a collection of links on the substrate, the links being configured to store information related to the display array, connecting a configurable driver circuit to the collection of links, reading the information stored in the collection of links, and configuring the driver circuit based on information stored in the collection of links.

DETAILED DESCRIPTION OF THE CERTAIN EMBODIMENTS OF THE INVENTION

The following detailed description is directed to certain specific embodiments of the invention. However, the invention can be embodied in a multitude of different ways. In this description, reference is made to the drawings wherein like parts are designated with like numerals throughout. As will be apparent from the following description, the embodiments may be implemented in any device that is configured to display an image, whether in motion (e.g., video) or stationary (e.g., still image), and whether textual or pictorial. More particularly, it is contemplated that the embodiments may be implemented in or associated with a variety of electronic devices such as, but not limited to, mobile telephones, wireless devices, personal data assistants (PDAs), hand-held or portable computers, GPS receivers/navigators, cameras, MP3 players, camcorders, game consoles, wrist watches, clocks, calculators, television monitors, flat panel displays, computer monitors, auto displays (e.g., odometer display, etc.), cockpit controls and/or displays, display of camera views (e.g., display of a rear view camera in a vehicle), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., display of images on a piece of jewelry). MEMS devices of similar structure to those described herein can also be used in non-display applications such as in electronic switching devices.

One interferometric modulator display embodiment comprising an interferometric MEMS display element is illustrated inFIG. 1. In these devices, the pixels are in either a bright or dark state. In the bright (“on” or “open”) state, the display element reflects a large portion of incident visible light to a user. When in the dark (“off” or “closed”) state, the display element reflects little incident visible light to the user. Depending on the embodiment, the light reflectance properties of the “on” and “off” states may be reversed. MEMS pixels can be configured to reflect predominantly at selected colors, allowing for a color display in addition to black and white.

The depicted portion of the pixel array inFIG. 1includes two adjacent interferometric modulators12aand12b. In the interferometric modulator12aon the left, a movable reflective layer14ais illustrated in a relaxed position at a predetermined distance from an optical stack16a, which includes a partially reflective layer. In the interferometric modulator12bon the right, the movable reflective layer14bis illustrated in an actuated position adjacent to the optical stack16b.

The optical stacks16aand16b(collectively referred to as optical stack16), as referenced herein, typically comprise several fused layers, which can include an electrode layer, such as indium tin oxide (ITO), a partially reflective layer, such as chromium, and a transparent dielectric. The optical stack16is thus electrically conductive, partially transparent, and partially reflective, and may be fabricated, for example, by depositing one or more of the above layers onto a transparent substrate20. The partially reflective layer can be formed of one or more layers of materials, and each of the layers can be formed of a single material or a combination of materials.

In some embodiments, the layers of the optical stack16are patterned into parallel strips, and may form row electrodes in a display device as described further below. The movable reflective layers14a,14bmay be formed as a series of parallel strips of a deposited metal layer or layers (orthogonal to the row electrodes of16a,16b) deposited on top of posts18and an intervening sacrificial material deposited between the posts18. When the sacrificial material is etched away, the movable reflective layers14a,14bare separated from the optical stacks16a,16bby a defined gap19. A highly conductive and reflective material such as aluminum may be used for the reflective layers14, and these strips may form column electrodes in a display device.

With no applied voltage, the cavity19remains between the movable reflective layer14aand optical stack16a, with the movable reflective layer14ain a mechanically relaxed state, as illustrated by the pixel12ainFIG. 1. However, when a potential difference is applied to a selected row and column, the capacitor formed at the intersection of the row and column electrodes at the corresponding pixel becomes charged, and electrostatic forces pull the electrodes together. If the voltage is high enough, the movable reflective layer14is deformed and is forced against the optical stack16. A dielectric layer (not illustrated in this Figure) within the optical stack16may prevent shorting and control the separation distance between layers14and16, as illustrated by pixel12bon the right inFIG. 1. The behavior is the same regardless of the polarity of the applied potential difference. In this way, row/column actuation that can control the reflective vs. non-reflective pixel states is analogous in many ways to that used in conventional LCD and other display technologies.

FIGS. 2 through 5Billustrate one exemplary process and system for using an array of interferometric modulators in a display application.

FIG. 2is a system block diagram illustrating one embodiment of an electronic device that may incorporate aspects of the invention. In the exemplary embodiment, the electronic device includes a processor21which may be any general purpose single- or multi-chip microprocessor such as an ARM, Pentium®, Pentium II®, Pentium III®, Pentium IV®, Pentium® Pro, an8051, a MIPS®, a Power PC®, an ALPHA®, or any special purpose microprocessor such as a digital signal processor, microcontroller, or a programmable gate array. As is conventional in the art, the processor21may be configured to execute one or more software modules. In addition to executing 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 typical applications, a display frame may be created by asserting the set of column electrodes in accordance with the desired set of actuated pixels in the first row. A row pulse is then applied to the row1electrode, actuating the pixels corresponding to the asserted column lines. The asserted set of column electrodes is then changed to correspond to the desired set of actuated pixels in the second row. A pulse is then applied to the row2electrode, actuating the appropriate pixels in row2in accordance with the asserted column electrodes. The row1pixels are unaffected by the row2pulse, and remain in the state they were set to during the row1pulse. This may be repeated for the entire series of rows in a sequential fashion to produce the frame. Generally, the frames are refreshed and/or updated with new display data by continually repeating this process at some desired number of frames per second. A wide variety of protocols for driving row and column electrodes of pixel arrays to produce display frames are also well known and may be used in conjunction with the present invention.

FIGS. 4,5A, and5B illustrate one possible actuation protocol for creating a display frame on the 3×3 array ofFIG. 2.FIG. 4illustrates a possible set of column and row voltage levels that may be used for pixels exhibiting the hysteresis curves ofFIG. 3. In theFIG. 4embodiment, actuating a pixel involves setting the appropriate column to −Vbias, and the appropriate row to +ΔV, which may correspond to −5 volts and +5 volts, respectively Relaxing the pixel is accomplished by setting the appropriate column to +Vbias, and the appropriate row to the same +ΔV, producing a zero volt potential difference across the pixel. In those rows where the row voltage is held at zero volts, the pixels are stable in whatever state they were originally in, regardless of whether the column is at +Vbias, or −Vbias. As is also illustrated inFIG. 4, it will be appreciated that voltages of opposite polarity than those described above can be used, e.g., actuating a pixel can involve setting the appropriate column to +Vbias, and the appropriate row to −ΔV. In this embodiment, releasing the pixel is accomplished by setting the appropriate column to −Vbias, and the appropriate row to the same −ΔV, producing a zero volt potential difference across the pixel.

In theFIG. 5Aframe, pixels (1,1), (1,2), (2,2), (3,2) and (3,3) are actuated. To accomplish this, during a “line time” for row1, columns1and2are set to −5 volts, and column3is set to +5 volts. This does not change the state of any pixels, because all the pixels remain in the 3-7 volt stability window. Row1is then strobed with a pulse that goes from 0, up to 5 volts, and back to zero. This actuates the (1,1) and (1,2) pixels and relaxes the (1,3) pixel. No other pixels in the array are affected. To set row2as desired, column2is set to −5 volts, and columns1and3are set to +5 volts. The same strobe applied to row2will then actuate pixel (2,2) and relax pixels (2,1) and (2,3). Again, no other pixels of the array are affected. Row3is similarly set by setting columns2and3to −5 volts, and column1to +5 volts. The row3strobe sets the row3pixels as shown inFIG. 5A. After writing the frame, the row potentials are zero, and the column potentials can remain at either +5 or −5 volts, and the display is then stable in the arrangement ofFIG. 5A. It will be appreciated that the same procedure can be employed for arrays of dozens or hundreds of rows and columns. It will also be appreciated that the timing, sequence, and levels of voltages used to perform row and column actuation can be varied widely within the general principles outlined above, and the above example is exemplary only, and any actuation voltage method can be used with the systems and methods described herein.

FIGS. 6A and 6Bare system block diagrams illustrating an embodiment of a display device40. The display device40can be, for example, a cellular or mobile telephone. However, the same components of display device40or slight variations thereof are also illustrative of various types of display devices such as televisions and portable media players.

The display device40includes a housing41, a display30, an antenna43, a speaker45, an input device48, and a microphone46. The housing41is generally formed from any of a variety of manufacturing processes as are well known to those of skill in the art, including injection molding and vacuum forming. In addition, the housing41may be made from 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 housing41includes removable portions (not shown) that may be interchanged with other removable portions of different color, or containing different logos, pictures, or symbols.

The display30of exemplary display device40may be any of a variety of displays, including a bi-stable display, as described herein. In other embodiments, the display30includes a flat-panel display, such as plasma, EL, OLED, STN LCD, or TFT LCD as described above, or a non-flat-panel display, such as a CRT or other tube device, as is well known to those of skill in the art. However, for purposes of describing the present embodiment, the display30includes an interferometric modulator display, as described herein.

The components of one embodiment of exemplary display device40are schematically illustrated inFIG. 6B. The illustrated exemplary display device40includes a housing41and can include additional components at least partially enclosed therein. For example, in one embodiment, the exemplary display device40includes a network interface27that includes an antenna43, which is coupled to a transceiver47. The transceiver47is connected to a processor21, which is connected to conditioning hardware52. The conditioning hardware52may be configured to condition a signal (e.g., filter a signal). The conditioning hardware52is connected to a speaker45and a microphone46. The processor21is also connected to an input device48and a driver controller29. The driver controller29is coupled to a frame buffer28and to an array driver22, which in turn is coupled to a display array30. A power supply50provides power to all components as required by the particular exemplary display device40design.

The network interface27includes the antenna43and the transceiver47so that the exemplary display device40can communicate with one or more devices over a network. In one embodiment, the network interface27may also have some processing capabilities to relieve requirements of the processor21. The antenna43is any antenna known to those of skill in the art for transmitting and receiving signals. In one embodiment, the antenna transmits and receives RF signals according to the IEEE 802.11 standard, including IEEE 802.11(a), (b), or (g). In another embodiment, the antenna transmits and receives RF signals according to the BLUETOOTH standard. In the case of a cellular telephone, the antenna is designed to receive CDMA, GSM, AMPS, or other known signals that are used to communicate within a wireless cell phone network. The transceiver47pre-processes the signals received from the antenna43so that they may be received by and further manipulated by the processor21. The transceiver47also processes signals received from the processor21so that they may be transmitted from the exemplary display device40via the antenna43.

In an alternative embodiment, the transceiver47can be replaced by a receiver. In yet another alternative embodiment, network interface27can be replaced by an image source, which can store or generate image data to be sent to the processor21. For example, the image source can be a digital video disc (DVD) or a hard-disc drive that contains image data, or a software module that generates image data.

Processor21generally controls the overall operation of the exemplary display device40. The processor21receives data, such as compressed image data from the network interface27or an image source, and processes the data into raw image data or into a format that is readily processed into raw image data. The processor21then sends the processed data to the driver controller29or to frame buffer28for storage. Raw data typically refers to the information that identifies the image characteristics at each location within an image. For example, such image characteristics can include color, saturation, and gray-scale level.

In one embodiment, the processor21includes a microcontroller, CPU, or logic unit to control operation of the exemplary display device40. Conditioning hardware52generally includes amplifiers and filters for transmitting signals to the speaker45, and for receiving signals from the microphone46. Conditioning hardware52may be discrete components within the exemplary display device40, or may be incorporated within the processor21or other components.

The driver controller29takes the raw image data generated by the processor21either directly from the processor21or from the frame buffer28and reformats the raw image data appropriately for high speed transmission to the array driver22. Specifically, the driver controller29reformats the raw image data into a data flow having a raster-like format, such that it has a time order suitable for scanning across the display array30. Then the driver controller29sends the formatted information to the array driver22. Although a driver controller29, such as a LCD controller, is often associated with the system processor21as a stand-alone Integrated Circuit (IC), such controllers may be implemented in many ways. They may be embedded in the processor21as hardware, embedded in the processor21as software, or fully integrated in hardware with the array driver22.

Typically, the array driver22receives the formatted information from the driver controller29and reformats the video data into a parallel set of waveforms that are applied many times per second to the hundreds and sometimes thousands of leads coming from the display's x-y matrix of pixels.

In one embodiment, the driver controller29, array driver22, and display array30are appropriate for any of the types of displays described herein. For example, in one embodiment, driver controller29is a conventional display controller or a bi-stable display controller (e.g., an interferometric modulator controller). In another embodiment, array driver22is a conventional driver or a bi-stable display driver (e.g., an interferometric modulator display). In one embodiment, a driver controller29is integrated with the array driver22. Such an embodiment is common in highly integrated systems such as cellular phones, watches, and other small area displays. In yet another embodiment, display array30is a typical display array or a bi-stable display array (e.g., a display including an array of interferometric modulators).

The input device48allows a user to control the operation of the exemplary display device40. In one embodiment, input device48includes a keypad, such as a QWERTY keyboard or a telephone keypad, a button, a switch, a touch-sensitive screen, or a pressure- or heat-sensitive membrane. In one embodiment, the microphone46is an input device for the exemplary display device40. When the microphone46is used to input data to the device, voice commands may be provided by a user for controlling operations of the exemplary display device40.

Power supply50can include a variety of energy storage devices as are well known in the art. For example, in one embodiment, power supply50is a rechargeable battery, such as a nickel-cadmium battery or a lithium ion battery. In another embodiment, power supply50is a renewable energy source, a capacitor, or a solar cell including a plastic solar cell, and solar-cell paint. In another embodiment, power supply50is configured to receive power from a wall outlet.

In some embodiments, control programmability resides, as described above, in a driver controller which can be located in several places in the electronic display system. In some embodiments, control programmability resides in the array driver22. Those of skill in the art will recognize that the above-described optimizations may be implemented in any number of hardware and/or software components and in various configurations.

The details of the structure of interferometric modulators that operate in accordance with the principles set forth above may vary widely. For example,FIGS. 7A-7Eillustrate five different embodiments of the movable reflective layer14and its supporting structures.FIG. 7Ais a cross section of the embodiment ofFIG. 1, where a strip of metal material14is deposited on orthogonally extending supports18. InFIG. 7B, the moveable reflective layer14is attached to supports at the corners only, on tethers32. InFIG. 7C, the moveable reflective layer14is suspended from a deformable layer34, which may comprise a flexible metal. The deformable layer34connects, directly or indirectly, to the substrate20around the perimeter of the deformable layer34. These connections are herein referred to as support posts. The embodiment illustrated inFIG. 7Dhas support post plugs42upon which the deformable layer34rests. The movable reflective layer14remains suspended over the cavity, as inFIGS. 7A-7C, but the deformable layer34does not form the support posts by filling holes between the deformable layer34and the optical stack16. Rather, the support posts are formed of a planarization material, which is used to form support post plugs42. The embodiment illustrated inFIG. 7Eis based on the embodiment shown inFIG. 7D, but may also be adapted to work with any of the embodiments illustrated inFIGS. 7A-7C, as well as additional embodiments not shown. In the embodiment shown inFIG. 7E, an extra layer of metal or other conductive material has been used to form a bus structure44. This allows signal routing along the back of the interferometric modulators, eliminating a number of electrodes that may otherwise have had to be formed on the substrate20.

In embodiments such as those shown inFIG. 7, the interferometric modulators function as direct-view devices, in which images are viewed from the front side of the transparent substrate20, the side opposite to that upon which the modulator is arranged. In these embodiments, the reflective layer14optically shields the portions of the interferometric modulator on the side of the reflective layer opposite the substrate20, including the deformable layer34. This allows the shielded areas to be configured and operated upon without negatively affecting the image quality. Such shielding allows the bus structure44inFIG. 7E, which provides the ability to separate the optical properties of the modulator from the electromechanical properties of the modulator, such as addressing and the movements that result from that addressing. This separable modulator architecture allows the structural design and materials used for the electromechanical aspects and the optical aspects of the modulator to be selected and to function independently of each other. Moreover, the embodiments shown inFIGS. 7C-7Ehave additional benefits deriving from the decoupling of the optical properties of the reflective layer14from its mechanical properties, which are carried out by the deformable layer34. This allows the structural design and materials used for the reflective layer14to be optimized with respect to the optical properties, and the structural design and materials used for the deformable layer34to be optimized with respect to desired mechanical properties.

In certain display applications, there are a variety of parameters in the array driver that need to be configured before the array driver can reliably drive a display panel such as an iMoD panel. Failure to properly configure these parameters could cause a display device to fail. For example, pixels may not change state properly in response to driving signals. Such failure could appear a week, a month or a year after shipment of the display modules. To reduce the likelihood that customers or the module assembly facility improperly programs crucial parameters, a method of reliably and permanently establishing default parameters is needed.

One method of establishing default parameters may also satisfy several additional conditions. First, the display panel need not retain all of the configuration programming information required by the driver because it may be too costly to do so. Second, the method may support display panels of different types, such as display panels manufactured by different processes or manufactured with the same process under different parameters. In certain applications, the method needs only to support a small amount of information, for example, four bits of information will often be sufficient.

Certain embodiments described below provide a method of reliably and permanently encoding information which may satisfy all these requirements described.

FIG. 8is a schematic diagram illustrating one embodiment of a circuit that may be formed to store data. In the exemplary embodiment, the circuit60comprises a collection of one or more links61. Each link61can be in one of two states. In one state, a link61forms an open circuit between its two ends62and64. In the other state, a link61forms a closed circuit between both ends. The state of each link61, therefore, provides a bit of information.

Various schemes can be applied to store information in the circuit60. In one embodiment, each link61of the circuit60provides a bit of information. A circuit60comprising four links61, for example, can then provide4bits of information. In another embodiment, the number of links61in the circuit60which are open is used to provide information.

Various schemes can be applied to enable an electrical device to read the information stored in the circuit60. In one embodiment, each end of each link60is connected to a separate contact pad (not shown). An electrical device, such as a driver chip, can be mounted onto the circuit60such that contact leads of the electrical device connect to each contact pad of each link. The electrical device detects the open and closed state of each link61and therefore reads the information stored in the circuit60.

In another embodiment, one end of each link61is connected to a separate contact pad while the other end of each link61is connected to a common contact pad. Contact leads of an electrical device connect to each contact pad. The electrical device can apply a voltage signal, such as ground, to the common contact pad and sense the potential at other contact pads to detect the open and closed state of each link61.

In still another embodiment, one end of each link61is connected to a separate contact pad while the other end of each link61is connected to a constant voltage such as ground. Contact leads of the electrical device connect to each contact pad. The electrical device reads the signal at the contact pad of each link61to detect the open and closed state of that link61.

FIGS. 9A and 9Billustrate an embodiment of a method of forming the circuit60inFIG. 8to store certain information.FIG. 9Ashows a circuit60formed before the information is stored. Each link comprises a blowable fuse68connected between both ends of the link and therefore each link is in a closed circuit state.

The circuit60inFIG. 9Ais then configured to store the information by selectively blowing certain blowable fuses in the circuit60inFIG. 9A. The resulting circuit60is shown inFIG. 9B. Blowable fuses are selectively blown such that each link inFIG. 9Bencodes a bit of information.

Other methods are also available to form the circuit60inFIG. 8. In certain embodiments, each link61may comprise a circuit trace, or a highly conductive metal line such as a copper or aluminum line. In one embodiment, the metal line can be formed as a single and continuous line or a broken line segment, depending on the state of the link. In another embodiment, the circuit60is first formed wherein each link comprises a single continuous metal line. These metal lines are then selectively cut or separated corresponding to the information to be stored. The cutting or separating can be conducted through various processes including, for example, etching, cutting with a saw, and laser cutting.

The circuit60discussed above with regard toFIGS. 8,9A, and9B can be used in various applications to store information as needed. In certain embodiments, the circuit60is used to assist configuration of a driver circuit such that the driver circuit can provide proper driving signals to a display array. In these embodiments, a display array is first formed on a substrate. The circuit60is then formed on the substrate and configured to store information related to a display array, such as the type of the display array. A test device then reads information stored in the circuit60and configures an array driver based on such information. Alternatively, the circuit60may be formed in parallel with the display array. These embodiments are described in further detail below inFIGS. 10-14.

FIG. 10is a schematic block diagram illustrating one embodiment of a display panel comprising a display array and a circuit configurable to store information on the display array. The electronic device comprises a display array30, which may advantageously be a MEMS array as described above inFIGS. 2 and 6B, although the display array30may be any of a variety of displays. In one embodiment, the display array30is formed on a substrate66, such as a glass substrate.

The electronic device further comprises a circuit60similar to the circuit60discussed above with regard toFIGS. 9A and 9B. The circuit60is formed without encoding any information, but may be configured later to store certain information related to the display such as the type of the display array30. The circuit60may comprise any number of links depending on the amount of information to be stored. In the exemplary embodiment, the circuit60comprises a collection of links70,72, and74, wherein each link is in a closed circuit state. One end of the links70,72, and74is connected to contact pads82,84, and86respectively, while the other end is connected to a common contact pad80.

The circuit60may be formed on the same substrate66on which the display array30is formed. In one embodiment, the circuit60is formed on the periphery of the display array30. The circuit60and the display array30may or may not be formed in parallel.

FIG. 11is a schematic block diagram illustrating one embodiment of a display panel comprising a display array and a circuit storing information on the display array. The electronic device inFIG. 11is similar toFIG. 10, except that the circuit60here stores information related to the display array30. The link70is in an open circuit state while the links72and74are in a closed circuit state.

Various type of information can be stored in the circuit60. The information may include, for example, one or more of the following: voltage driving level, operational current level, pixel count, drive schemes, display type, color or monochrome display, shape of display (e.g. portrait vs. landscape). In another embodiment, the information forms a panel identification number which defines a set of display parameters indirectly. An electronic device mounted to the circuit60may then read this identification number and retrieve the set of parameters corresponding to the panel identification number. This embodiment may be desirable when storing configuration parameters directly in the circuit60would require an unduly large number of information bits.

As discussed above with regard toFIGS. 9A and 9B, there are various ways to form the circuit60as shown inFIG. 11. In the exemplary embodiment, the circuit60as shown inFIG. 10is first formed, wherein each link comprises a single continuous metal line. The circuit60inFIG. 10is then modified to form the circuit as shown inFIG. 11, by selectively separating or cutting these metal lines based on the information to be stored.

In another embodiment, the circuit60as shown inFIG. 10is first formed, wherein each link comprises a single continuous metal line. The circuit60inFIG. 10is then modified to form the circuit as shown inFIG. 11, by selectively blowing these blowable fuses based on the information to be stored.

In still another embodiment, the circuit60is originally formed as shown inFIG. 11. Each link is formed as a single and continuous line or a broken line segment, depending on the information to be stored.

In the exemplary embodiment, one end of the links70,72, and74is connected to a common contact pad80. Other embodiments are also available as discussed above with regard toFIG. 8. For example, one end of the links70,72, and74can be connected to a common voltage signal such as ground, instead of connecting to the contact pad80.

FIG. 12is a schematic block diagram illustrating one embodiment of an electronic device comprising an array driver connected to the display panel inFIG. 11. As discussed above, the circuit22stores information related to the display array30. In the exemplary embodiment, the circuit22stores a panel identification number representing the type of the display array30. The array driver22is as described above with regard toFIGS. 2 and 6B. The array driver22connects to the display array30to provide row and column driving signals92and94. The array driver22is also connected to the circuit60via the contact pads80,82,84, and86.

In certain embodiments, the array driver22is designed to be compatible with more than one type of display arrays. The array driver22comprises certain variable parameters. After the array driver is mounted to a display array, these parameters will be adjusted based on the type of the display array such that the array driver can reliably drive the display array. The adjustment to these parameters may or may not be permanent. In the exemplary embodiment, the array driver22comprises a configurable circuit102, the circuit comprising a collection of blowable fuses102. By selectively blowing certain blowable fuses, parameters of the array can be adjusted.

In certain embodiments, the array driver22further stores information about itself, such as an array driver identification number, in a circuit or by other means. Such information can be read by an electronic device such as a test fixture connected to the array driver. In one embodiment, such information is stored by a circuit similar to the circuit60.

In order to configure the parameters in the array driver22based on the type of the display array30, a test fixture may be connected to the array driver via an input/output interface96. The test fixture can be any electronic device suitable for configuring and testing circuit or device. The test fixture may or may not be automated. In one example, the text fixture may include a computer executing one or more software modules. Since the array driver22is connected to the circuit60, the test fixture can communicate with the circuit60via the array driver22.

The test fixture first reads the panel identification number stored in the circuit60. As discussed above with regard toFIG. 8, the test may cause the array driver to apply a voltage signal, such as +5 volts, to the common contact pad80and read the signal at the contact pads82,84, and86to detect the open circuit and closed circuit state of the links70,72, and74. The test fixture then reads the array driver identification number from the array driver22.

Both the array driver identification number and the panel identification number are in a list of pre-defined identification numbers to which the test fixture has access. For example, a list of pre-defined identification numbers may be stored at the test fixture. The test fixture then determines whether the array driver22is compatible with the display array30based on the panel identification number and the array driver identification number. If the test fixture determines that they are not compatible, it will issue a warning that an assembly error is detected.

In case the test fixture determines that the array driver22and the display array30are compatible, the test fixture then determines a set of parameters corresponding to the retrieved panel identification number. The test fixture then controls the array driver22to selectively blow certain blowable fuses in the configurable circuit98such that the set of parameters desired is loaded into the array driver22.

FIG. 13is a schematic block diagram illustrating one embodiment of an electronic device comprising an array driver connected to the display panel inFIG. 11. InFIG. 13, the array driver22is loaded with a set of parameters suitable for driving the display array30. Certain blowable fuses of the configurable circuit98are blown, after the information encoding conducted by the test fixture (seeFIG. 11).

FIG. 14is a flowchart illustrating one embodiment of a method of making a display device comprising a display array and an array driver. Depending on the embodiment, certain steps of the method may be removed, merged together, or rearranged in order. One feature of the exemplary method is that it automates the programming of a large set of configurable parameters through a small number of read-only bits stored on a display panel.

The method starts at a block1402, where a display array30is formed on a substrate. Next at a block1404, a circuit60comprising a collection of configurable links is formed on the substrate, as described above. In one embodiment, each configurable link comprises a blowable fuse. In another embodiment, each configurable links comprises a single continuous conductive metal line.

Moving to a block1406, the collection of links of the circuit60is configured to store information related to the display array30. In case each configurable link comprises a blowable fuse, the circuit60is configured by selectively blowing certain blowable fuses based on the information to be stored. In case each configurable links comprises a single continuous conductive metal line, the circuit60is configured by selective separating or cutting certain metal lines. In the exemplary embodiment, the information forms a panel identification number which defines a set of display parameters indirectly.

Next at a block1408, a configurable array driver22is connected to the collection of links of the circuit60and the display array30as described inFIG. 12. A test fixture is also connected to the configurable array driver22. Moving to a block1412, the test fixture reads the information stored in the collection of links of the circuit60as described inFIG. 12. In the exemplary embodiment, the information is the panel identification number of the display array30.

Next at a block1414, the test fixture reads from the driver circuit information identifying the type of the driver circuit, i.e., the array driver22. In the exemplary embodiment, the information is an array driver identification number. Moving to a block1416, the text fixture determines whether the driver circuit, e.g. the array driver22, is compatible with the display array30, based on the information stored in the collection of links and information identifying the type of the driver circuit. The method moves to a block1422if the test fixture determines that the array driver22is not compatible with the display array30. At a block1422, the test fixture reports an assembly error.

The method moves to a block1424if the text fixture determines that the array driver22is compatible with the display array30. At block1424, the test fixture configures the driver circuit (the array driver22) based on the information read from the collection of links of the circuit60, as described inFIG. 12. In the exemplary embodiment, the array driver22comprises a configurable circuit102, the circuit comprising a collection of blowable fuses102. The test fixture determines a set of parameters corresponding to the retrieved panel identification number. The test fixture then controls the array driver22to selectively blow certain blowable fuses in the configurable circuit98such that the set of parameters desired is permanently loaded into the array driver22. In another embodiment, the information retrieved from the collection of links may comprise a set of parameters ready to be loaded into the array driver22.

In certain embodiments, block1404may be removed. For example, a circuit60comprising a collection of links, wherein each link is initially formed as a single and continuous line or a broken line segment, depending on the information to be stored. Also, in certain embodiments, blocks1416,1418, and1422may be removed when the compatibility between the array driver22and the display array30is not at concern.