PATENT DOCUMENT

Publication Number: US-10126850-B2
Application Number: US-201314106283-A
Country: US
Kind Code: B2

Title: Active integrated touch/display

Abstract:
An integrated touch sensitive display is provided. The integrated touch sensitive display can include rows and columns of touch electrodes. Various modulation techniques can be applied to one or more of the touch electrodes to allow sense circuitry to individually measure a capacitance associated with each of the touch electrodes. The capacitances can be used to determine a location and/or amount of touch or hover events at or near the integrated touch sensitive display.

Claims:
What is claimed is: 
     
       1. A touch sensor panel comprising
 a plurality of touch electrodes located in a plurality of regions of the touch sensor panel, wherein:
 each of the plurality of touch electrodes is:
 located in a respective region of the plurality of regions that corresponds to the respective touch electrode, and 
 associated with respective circuitry located in the respective region of the touch sensor panel, 
 
 the respective circuitry is configured to, in response to receiving at the respective circuitry a code sequence signal, couple in the respective region of the touch sensor panel an associated touch electrode to one of a first voltage source and a second voltage source, different from the first voltage source, based on the code sequence signal, and 
 each respective circuitry is configured to receive a different code sequence signal, wherein sense circuitry is operable to generate a current sense signal based on a difference between a first current through the first voltage source and a second current through the second voltage source. 
 
 
     
     
       2. The touch sensor panel of  claim 1 , further comprising demodulation circuitry operable to demodulate the current sense signal to determine a capacitance at a touch electrode of the plurality of touch electrodes based on a code sequence signal received by respective circuitry associated with the touch electrode of the plurality of touch electrodes. 
     
     
       3. The touch sensor panel of  claim 1 , wherein code sequence signals received by respective circuitry associated with each of the plurality of touch electrodes comprise the same sequence of values, and wherein each of the code sequence signals received by respective circuitry associated with the plurality of touch electrodes has a different phase offset. 
     
     
       4. The touch sensor panel of  claim 1 , wherein code sequence signals received by respective circuitry associated with the plurality of touch electrodes each comprise a pseudo inverse code or a Kasami code. 
     
     
       5. The touch sensor panel of  claim 1 , wherein a length each of the code sequence signals received by respective circuitry associated with the plurality of touch electrodes is greater than or equal to a number of touch electrodes in the plurality of touch electrodes. 
     
     
       6. The touch sensor panel of  claim 1 , wherein respective circuitry associated with each of the plurality of touch electrodes comprises a latch coupled to receive a code sequence signal associated with the touch electrode. 
     
     
       7. The touch sensor panel of  claim 6 , wherein the touch electrodes are arranged in rows and columns, and wherein latches of respective circuitry associated with touch electrodes in the same column are coupled in series. 
     
     
       8. The touch sensor panel of  claim 1 , wherein:
 the respective circuitry associated with a touch electrode of the plurality of touch electrodes comprises a transmission gate, 
 the plurality of touch electrodes, including other touch electrodes, are arranged in rows and columns, 
 transmission gates of respective circuitry associated with touch electrodes in the same row are operable to couple their associated touch electrode to receive either a first stimulation signal from a first bus, coupled to the first voltage source, of the row or a second stimulation signal from a second bus, coupled to the second voltage source, of the row based on the code sequence signal, 
 transmission gates of respective circuitry associated with touch electrodes in the same column are coupled to receive the same code sequence signal; and 
 transmission gates of respective circuitry associated with touch electrodes in each row are coupled to receive a different code sequence signal. 
 
     
     
       9. The touch sensor panel of  claim 8 , further comprising sense and demodulation circuitry operable to detect a touch or hover event at a touch electrode in a particular row and in a particular column based at least on a code sequence signal received by respective circuitry associated with the touch electrode in the particular row and in the particular column and a difference between a first current through a first bus for the particular row and a second current through a second bus for the particular row. 
     
     
       10. The touch sensor panel of  claim 9 , wherein detecting a touch or hover event at the touch electrode in the particular row and in the particular column comprises multiplying the code sequence signal received by respective circuitry associated with the touch electrode in the particular row and in the particular column by the difference between the first current and the second current. 
     
     
       11. The touch sensor panel of  claim 8 , wherein a length of each of the code sequence signals is greater than or equal to a number of columns of touch electrodes. 
     
     
       12. The touch sensor panel of  claim 8 , wherein a first stimulation signal for a row is generated by a first stimulation signal generator, and wherein a second stimulation signal for the row is generated by a second stimulation signal generator. 
     
     
       13. The touch sensor panel of  claim 12 , wherein the first stimulation signal for the row and the second stimulation signal for the row are 180-degrees out of phase from each other. 
     
     
       14. The touch sensor panel of  claim 8 , wherein a first stimulation signal for a row is generated by a stimulation signal generator, and wherein a second stimulation signal for the row is generated by the stimulation signal generator. 
     
     
       15. A method comprising:
 receiving, at a respective circuitry, a code sequence signal, wherein:
 the respective circuitry is located in a respective region of a plurality of regions of the touch sensor panel that corresponds to a respective touch electrode of a plurality of touch electrodes of the touch sensor panel, and 
 the respective touch electrode is located in the respective region of the plurality of regions that corresponds to the respective touch electrode and is associated with the respective circuitry; 
 
 in response to receiving the code sequence signal, coupling in the respective region of the touch sensor panel the respective touch electrode to one of a first voltage source and a second voltage source, different from the first voltage source, based on the code sequence signal; and 
 generating a current sense signal based on a difference between a first current through the first voltage source and a second current through the second voltage source. 
 
     
     
       16. An electronic device comprising:
 a touch sensor panel having a plurality of touch electrodes located in a plurality of regions of the touch sensor panel, wherein:
 each of the plurality of touch electrodes is:
 located in a respective region of the plurality of regions that corresponds to the respective touch electrode, and 
 associated with respective circuitry located in the respective region of the touch sensor panel, 
 
 the respective circuitry is configured to, in response to receiving at the respective circuitry a code sequence signal, couple in the respective region of the touch sensor panel an associated touch electrode to one of a first voltage source and a second voltage source, different from the first voltage source, based on the code sequence signal, and 
 each respective circuitry is configured to receive a different code sequence signal; and 
 
 
       sense circuitry operable to generate a current sense signal based on a difference between a first current through the first voltage source and a second current through the second voltage source.

Description:
FIELD 
     This relates generally to touch sensitive devices and, more specifically, to touch sensitive devices having an integrated touch sensor and display. 
     BACKGROUND 
     Touch sensitive devices have become popular as input devices to computing systems due to their ease and versatility of operation as well as their declining price. A touch sensitive device can include a touch sensor panel, which can be a clear panel with a touch sensitive surface, and a display device, such as a liquid crystal display (LCD), that can be positioned partially or fully behind the panel or integrated with the panel so that the touch sensitive surface can cover at least a portion of the viewable area of the display device. The touch sensitive device can allow a user to perform various functions by touching the touch sensor panel using a finger, stylus, or other object at a location often dictated by a user interface (UI) being displayed by the display device. In general, the touch sensitive device can recognize a touch event and the position of the touch event on the touch sensor panel, and the computing system can then interpret the touch event in accordance with the display appearing at the time of the touch event, and thereafter can perform one or more actions based on the touch event. 
     In some applications, the touch sensor panel and the display device can be integrated into a single unit to reduce the space needed by these devices. However, when a touch sensor panel is integrated with a display, crosstalk can occur between the touch sensor stimulation signals and the display signals used to control the display panel. 
     SUMMARY 
     An integrated touch sensitive display is provided. The integrated touch sensitive display can include rows and columns of touch electrodes. Various modulation techniques can be applied to one or more of the touch electrodes to allow sense circuitry to individually measure a capacitance associated with each of the touch electrodes. The capacitances can be used to determine a location and/or amount of touch or hover events at or near the integrated touch sensitive display. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a cross-sectional view of an exemplary integrated touch sensitive display according to various examples. 
         FIG. 2  illustrates a top view of an exemplary integrated touch sensitive display according to various examples. 
         FIG. 3  illustrates a block diagram of an exemplary touch electrode that can be included within an integrated touch sensitive display according to various examples. 
         FIG. 4  illustrates a block diagram of a portion of an integrated touch sensitive display having the touch electrode of  FIG. 3  according to various examples. 
         FIG. 5  illustrates a block diagram of another exemplary touch electrode that can be included within an integrated touch sensitive display according to various examples. 
         FIG. 6  illustrates a block diagram of a portion of an integrated touch sensitive display having the touch electrode of  FIG. 5  according to various examples. 
         FIG. 7  illustrates a block diagram of a portion of another integrated touch sensitive display having the touch electrode of  FIG. 5  according to various examples. 
         FIG. 8  illustrates a block diagram of a portion of an integrated touch sensitive display having circuitry separate from the touch electrodes according to various examples. 
         FIG. 9  illustrates a block diagram of a portion of another integrated touch sensitive display having circuitry separate from the touch electrodes according to various examples. 
         FIG. 10A  illustrates a block diagram of a portion of an integrated touch sensitive display having combined display data and touch detection integrated circuits (ICs) according to various examples. 
         FIG. 10B  illustrates an exemplary stackup of the integrated touch sensitive display of  FIG. 10A  according to various examples. 
         FIG. 11  illustrates a block diagram of a portion of another integrated touch sensitive display having separate display data and touch detection ICs according to various examples. 
         FIG. 12  illustrates an exemplary system for operating an integrated touch sensitive display according to various examples. 
         FIGS. 13-16  illustrate exemplary personal devices that can include an integrated touch sensitive display s according to various examples. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description of examples, reference is made to the accompanying drawings in which it is shown by way of illustration specific examples that can be practiced. It is to be understood that other examples can be used and structural changes can be made without departing from the scope of the various examples. 
     This relates to an integrated touch sensitive display. The integrated touch sensitive display can include rows and columns of touch electrodes. Various modulation techniques can be applied to one or more of the touch electrodes to allow sense circuitry to individually measure a capacitance associated with each of the touch electrodes. The capacitances can be used to determine a location and/or amount of touch or hover events at or near the integrated touch sensitive display. 
       FIG. 1  illustrates a cross-sectional view of an exemplary integrated touch sensitive display  100  according to various examples. Touch sensitive display  100  can be integrated into a variety of touch sensitive devices, such as mobile phones, tablets, touchpads, portable or desktop computers, portable media players, or the like. Display  100  can include a stack of metal layers and pixel elements  101  as shown in  FIG. 1 . Pixel elements  101  can be operable to display one or more colors. For example, pixel element  101  can include red, green, and blue subpixels that can be selectively activated to produce a desired color. 
     Display  100  can further include a display driver (not shown) operable generate a data signal for controlling the operation of pixel element  101 . The data signal can be sent to pixel element  101  via metal 2 layer (M2)  105  and transmission gate  111 . Transmission gate can be coupled to receive a gate signal  109  from a gate driver (not shown) via metal 1 layer (M1)  107 . Gate signal  109  can be used to select display pixels that are to receive display data from the gate driver by selectively opening and closing transmission gate  111 . 
     Display  100  can further include Vcom and metal 3 layer (VCOM+M3)  103  for providing a supply voltage to various circuit elements within display  100 . As will be discussed in greater detail below, VCOM+M3  103  can be patterned into touch electrodes that can be used to detect touch and hover events on or near display  100 . VCOM+M3  103  can be further patterned to allow transmission gate  111  to be coupled to pixel element(s)  101  through VCOM+M3  103 , as shown in  FIG. 1 . 
       FIG. 2  illustrates a top view of display  200  that can be used to detect touch events on a touch sensitive device, such as a mobile phone, tablet, touchpad, portable or desktop computer, portable media player, or the like. Display  200  can be similar or identical to display  100  and can include a single layer of multiple touch electrodes  201  that are arranged in a grid or other configuration. In some examples, touch electrodes  201  can be formed by patterning VCOM+M3  103  of display  100  into rectangular or other desired shapes. As will be discussed in greater detail below with respect to various examples, each touch electrode  201  can be driven with a stimulation signal and sense circuitry can be used to monitor changes in capacitance that can occur at each touch electrode  201 . These changes can typically occur at a touch electrode  201  when an object (e.g., finger or passive stylus) is placed in close proximity to the touch electrode. Based on the monitored changes in capacitance, a location of a touch or hover event on or near display  200  can be determined. 
       FIG. 3  illustrates a block diagram of an exemplary touch electrode  301  that can be used as touch electrode  201  of display  200  according to various examples. The body of touch electrode  301  can be formed by patterning VCOM+M3  103  of display  100  into a rectangular or other desired shape. As shown, touch electrode  301  can include buffer  303  coupled between voltage sources VDD and VSS. Buffer  303  can include an inverter coupled between the voltage sources VDD and VSS and having an output coupled to VCOM+M3  103  and an input coupled to receive code sequence  307 . In this way, code sequence  307  can be used to selectively cause touch electrode  301  to be coupled to either VDD or VSS. For example, a high value (e.g., a voltage corresponding to a logic high) in code sequence  307  can cause the inverter of buffer  303  to couple voltage source VSS to touch electrode  301 , while a low value (e.g., a voltage corresponding to a logic low) in code sequence  307  can cause the inverter of buffer  303  to coupled voltage source VDD to touch electrode  301 . 
     Code sequence  307  can include any sequence of binary values that have a relatively low autocorrelation. For example, code sequence  307  can include a pseudo inverse code, Kasami code, or the like. Additionally, as described in greater detail below, code sequence  307  can be used as a modulation signal to uniquely modulate and demodulate each touch electrode  301  of display  400  and, as such, can have a length that is greater than or equal to the number of touch electrodes of display  400 . 
     Touch electrode  301  can further include latch  305  coupled to receive a clock signal and code sequence  307  as inputs. Latch  305  can be operable to store and output the value of code sequence  307  at its input at a rising (or falling) edge of the clock signal. 
       FIG. 4  illustrates a block diagram of a portion of display  400  according to various examples. Display  400  can be an implementation of display  200  made using touch electrodes  301  shown in  FIG. 3 . In the illustrated example, display  400  can include two columns and three rows of touch electrodes  401 ,  403 ,  405 ,  407 ,  409 , and  411  that can be similar or identical to touch electrode  301 . Each touch electrode of display  400  can include a latch  305  coupled to receive a clock signal from clock  421  and a buffer  303  coupled between voltages VSS and VDD provided by constant voltage sources VSS  413  and VDD  415 . 
     As shown in  FIG. 4 , the touch electrodes in each column of display  400  can be coupled together in a cascaded fashion such that the input of latch  305  and buffer  303  of one touch electrode can be coupled to receive the output of latch  305  of an adjacent touch electrode. For example, buffer  303  and latch  305  of touch electrode  403  can be coupled to receive the output of latch  305  of touch electrode  401  as an input. Similarly, buffer  303  and latch  305  of touch electrode  405  can be coupled to receive the output of latch  305  of touch electrode  403  as an input. All touch electrodes in each column can be coupled together in a similar manner. 
     A touch electrode in each column of touch electrodes can be coupled to receive a code sequence. For example, touch electrode  401  in the first column of touch electrodes can be coupled to receive code sequence  307 . This code sequence can be received as an input to both buffer  303  and latch  305  of touch electrode  401 . In response to the received code sequence  307 , buffer  303  can couple touch electrode  401  to either voltage VDD or VSS. Additionally, latch  305  store and output a value of code sequence  307  at each rising (or falling) edge of the clock signal received from clock  421 . In this way, code sequence  307  can be provided to the first touch electrode in a column and can be propagated through each touch electrode in the column at each clock cycle. For example, in the first clock cycle, touch electrode  401  can receive the first bit of code sequence  307 . At the second clock cycle, touch electrode  403  can receive the first bit of code sequence  307  while touch electrode  401  can receive the second bit of code sequence  307 . This process can be repeated while touch detection is being performed. At the end of code sequence  307 , the code can begin again at the first bit. 
     The code sequence received by each column of touch electrodes can include the same repeating sequence of values, but the sequence can be delayed by an amount to prevent any two touch electrodes from receiving the same portion of the sequence at the same time. For example, the first touch electrode  407  of the second column of touch electrodes can be coupled to receive offset code sequence  419 . Offset code sequence  419  can include the same repeating code sequence of code sequence  307 , but code sequence  419  can be delayed relative to code sequence  307 . For example, in a touch sensor having two columns and three rows, the code sequence of code sequence  307  can include a total of six bits (e.g., bit  1 , bit  2 , bit  3 , bit  4 , bit  5 , and bit  6 ). In this example, offset code sequence  419  can be delayed by three bits to prevent any bit from being received by two touch electrodes at the same time. For instance, as touch electrode  401  receives bit  1 , touch electrode  407  can receive bit  4 . During the next clock cycle, touch electrode  403  can receive bit  1 , touch electrode  409  can receive bit  4 , touch electrode  401  can receive bit  2 , and touch electrode  407  can receive bit  5 . In the following clock cycle, touch electrode  405  can receive bit  1 , touch electrode  411  can receive bit  4 , touch electrode  403  can receive bit  2 , touch electrode  409  can receive bit  5 , touch electrode  401  can receive bit  3 , and touch electrode  407  can receive bit  6 . This process can be repeated any number of times. In this way, each touch electrode can be uniquely modulated by being selectively coupled between voltages VSS and VDD according to its received code sequence. 
     As illustrated by this example, code sequence  307  can have a length that is greater than or equal to the number of touch electrodes in display  400  in order to uniquely modulate each touch electrode. Additionally, the minimum offset between code sequences applied to any two columns can be equal to the number of rows in the touch sensor. In other words, code sequence  307  can have a length greater than or equal to the total number of touch electrodes in display  400  and can be barrel shifted across all touch electrodes such that in time, each touch electrode can have a unique bit of code. 
     Display  400  can further include sense circuitry  417  coupled to voltage sources VSS  413  and VDD  415 . Sense circuitry  417  can include current sensors operable to determine an amount of current drawn by the touch electrodes of display  400  from each voltage source. A current sense signal representing the difference between the sensed amount of current drawn from each voltage source can be output by sense circuitry  417 . The current sense signal can be provided to demodulation circuitry that can be operable to demodulate the current sense signal using a code sequence for a particular electrode. For example, since the modulation of each touch electrode is known for a given time (e.g., the code sequence applied to the touch electrode), a multiplier  423  can be used to demodulate the current sense signal by multiplying the current sense signal by the code sequence for a particular touch electrode to determine the contribution of that touch electrode to the current sense signal. For example, to determine the current contribution of touch electrode at position (X, Y) (e.g., position (1, 2)) of display  400 , the code being applied to the touch electrode at position (X, Y) (e.g., position (1, 2)) can be multiplied with the current sense signal from sense circuitry  417 . The determined current from the touch electrode at position (X, Y) (e.g., position (1, 2)) can be representative of the capacitance at or near the touch electrode at position (X, Y) (e.g., position (1, 2)). This capacitance can be used to detect the location and amount of touch or hover events at or near the touch electrode. This process can be repeated for each touch electrode. 
     While the example shown in  FIG. 4  includes two columns and three rows of touch electrodes, it should be appreciated that display  400  can include any number of rows and columns of touch electrodes. These additional rows and columns can be coupled together in a manner similar to that shown in  FIG. 4 . For example, the touch electrodes in each column can be coupled together in a cascaded fashion such that the latch output of one touch electrode is coupled to the input of the next touch electrode. Additionally, the code sequence applied to the columns of display  400  can have a length greater than or equal to the number of touch electrodes of display  400 . The code sequence applied to each column can be offset by an amount that prevents any two touch electrodes of display  400  from receiving the same portion of the code segment. This can include offsetting the code segment by at least the number of rows in each column. However, larger offsets can be used if the length of the code sequence is greater than the number of touch electrodes in display  400 . Additionally, while the touch electrodes are shown in  FIG. 4  in a grid configuration, it should be appreciated that other configurations are also possible to form the desired touch region pattern. Moreover, while specific configurations have been described with reference to the rows and columns of display  400 , it should be appreciated that the orientation of display  400  can be changed such that the described configurations for the rows and columns can be similarly applied to the columns and rows of display  400 , respectively. Furthermore, while various examples describe a sensed touch, it should be appreciated that the display  400  can also sense a hovering object and generate hover signals therefrom. 
       FIG. 5  illustrates a block diagram of an exemplary touch electrode  501  that can be used as touch electrode  201  of display  200  according to various examples. The body of touch electrode  501  can be formed by patterning VCOM+M3  103  of display  100  into a rectangular or other desired shape. As shown, touch electrode  501  can include buffer  503  coupled to receive code sequence  507  and stimulation signals Stim A, Stim B as inputs. Stimulation signals Stim A and Stim B can include any desired signal, such as a sinusoidal signal, square wave signal, or the like. Buffer  503  can include a transmission gate coupled between the stimulation signals Stim A and Stim B and can be operable to selectively allow one of the received stimulation signals to be transmitted to the output of the transmission gate, which can be coupled to VCOM+M3  103 , in response to the code sequence  507  input. For example, a high value (e.g., a voltage corresponding to a logic high) in code sequence  507  can cause the transmission gate of buffer  503  to allow stimulation signal Stim B to be transmitted to touch electrode  501 , while a low value (e.g., a voltage corresponding to a logic low) in code sequence  507  can cause the transmission gate of buffer  503  to allow stimulation signal Stim A to be transmitted to touch electrode  501 . Similar to code sequence  307 , code sequence  507  can include any sequence of binary values that has a relatively low autocorrelation. For example, code sequence  507  can include a pseudo inverse code, Kasami code, or the like. Additionally, as described in further detail below, code sequence  507  can be used to uniquely modulate and demodulate each touch electrode of each row of display  600  and, as such, can have a length that is greater than or equal to the number of touch electrodes in each row of display  600 . 
       FIG. 6  illustrates a block diagram of a portion of display  600  according to various examples. Display  600  can be an implementation of display  200  made using touch electrodes  501  shown in  FIG. 5 . In the illustrated example, display  600  can include two columns and three rows of touch electrodes  601 ,  603 ,  605 ,  607 ,  609 , and  611  that can be similar or identical to touch electrode  501 . As shown, each touch electrode can include a buffer  503  coupled to receive a pair of stimulation signals and a code sequence. Touch electrodes in the same row can be coupled to receive the same pair of stimulation signals. For example, touch electrodes  601  and  607  in the first row can be coupled to receive stimulation signals Stim A and Stim B, while touch electrodes  603  and  609  in the second row can be coupled to receive a second set of stimulation signals Stim A+1 and Stim B+1. Similarly, touch electrodes  605  and  611  in the third row can be coupled to receive a third set of stimulation signals Stim A+2 and Stim B+2. In some examples, each pair of stimulation signals (e.g., Stim A and Stim B) can include the same signal, but the stimulation signals can be 180-degrees out of phase from each other. Additionally, stimulation signals from each pair of stimulation signals can have low cross correlation values. For example, stimulation signal Stim A can have low cross correlation with stimulation signals Stim A+1 and Stim A+2. Similarly, stimulation signal Stim B can have low cross correlation with stimulation signals Stim B+1 and Stim B+2. 
     Each touch electrode in the same column can be coupled to receive the same code sequence. For example touch electrodes  601 ,  603 , and  605  in the first column can be coupled to receive code sequence  507 , while touch electrodes  607 ,  609 , and  611  in the second column can be coupled to receive offset code sequence  619 . As mentioned above, code sequence  507  can include any sequence of binary values that have a relatively low autocorrelation. For example, code sequence  507  can include a pseudo inverse code, Kasami code, or the like. Offset code sequence  619  can include the same code sequence of code sequence  507 , but can be offset by an amount that prevents any touch electrode in the same row of display  600  from receiving the same portion of the code at any time. For example, in a touch sensor having two columns with three rows each, the code sequence of code sequence  507  can have a total of two bits (e.g., bit  1  and bit  2 ). In this example, offset code sequence  619  can be delayed by 1 bit to prevent any bit being received by two touch electrodes in the same row at the same time. For instance, as touch electrodes  601 ,  603 , and  605  receive bit  1 , touch electrodes  607 ,  609 , and  611  can receive bit  2 . During the next clock cycle, touch electrodes  601 ,  603 , and  605  can receive bit  2 , while touch electrodes  607 ,  609 , and  611  can receive bit  1 . In this way, each touch electrode in a row can be uniquely modulated by selectively coupling it to either of a pair of stimulation signals (e.g., between stimulation signals Stim A and Stim B). 
     Display  600  can further include sense circuitry  621 ,  623 , and  625  coupled between pairs of stimulation signals. Sense circuitry  621 ,  623 , and  625  can each include current sensors operable to determine an amount of current drawn by the touch electrodes of display  600  from each stimulation signal source. A current sense signal representing the difference between the sensed amount of current drawn from each stimulation signal source can be output by each of sense circuitry  621 ,  623 , and  625 . The current sense signal can be provided to demodulation circuitry that can be operable to demodulate the current sense signal using a code sequence for a particular electrode. For example, since sense circuitry  621  is coupled to measure the current drawn by a known row of touch electrodes  601  and  607 , and because the modulation for a particular touch electrode within the row the modulation of each touch electrode is known for a given time (e.g., the code sequence applied to the touch electrode), a multiplier  627  can be used to demodulate the current sense signal by multiplying the current sense signal by the code sequence for a particular touch electrode to determine the contribution of that touch electrode to the current sense signal. For example, to determine the current contribution of touch electrode at position (X) (e.g., position 2) of the first row of display  600 , the code being applied to touch electrode  607  (e.g., offset code sequence  619 ) can be multiplied with the current sense signal from sense circuitry  621 . The determined current from the touch electrode  607  can be representative of the capacitance at or near touch electrode  607 . This capacitance can be used to detect the location and amount of touch or hover events at or near the touch electrode. While not shown, it should be appreciated that additional multipliers can be coupled to sense circuitry  623  and  625  to demodulate the current sense signals in a similar manner. 
     Using a configuration similar or identical to that of  FIG. 6  allows the use of M stimulation signals and a code sequence having a length of N for a display having M rows and N columns of touch electrodes. This advantageously reduces the length of the code sequence (e.g., code sequence  505  and offset code sequence  619 ) needed, thereby reducing the integration time for the display. Additionally, the amount of circuitry located on each touch electrode can be reduced since a latch is no longer needed. 
     While the example shown in  FIG. 6  includes two columns and three rows of touch electrodes, it should be appreciated that display  600  can include any number of rows and columns of touch electrodes. These additional rows and columns can be coupled together in a manner similar to that shown in  FIG. 6 . For example, the touch electrodes in each column can be coupled to receive the same code sequence, while touch electrodes in each row can be coupled to receive the same pair of stimulation signals. The code sequence applied to the columns of display  600  can have a length greater than or equal to the number of columns of display  600 . Each pair of stimulation signals can include the same signal, but the stimulation signals can be 180-degrees out of phase from each other. Additionally, each pair of stimulation signals can have low cross correlation values with other pairs of stimulation signals. The code sequence applied to each column can be offset by an amount that prevents any two touch electrodes in the same row of display  600  from receiving the same portion of the code segment. This can include offsetting the code segment for each column by 1. However, other offsets can be used if the length of the code sequence is greater than the number of touch electrodes in each row of display  600 . Additionally, while the touch electrodes are shown in  FIG. 6  in a grid configuration, it should be appreciated that other configurations are also possible to form the desired touch region pattern. Moreover, while specific configurations have been described with reference to the rows and columns of display  600 , it should be appreciated that the orientation of display  600  can be changed such that the described configurations for the rows and columns can be similarly applied to the columns and rows of display  600 , respectively. Furthermore, while various examples describe a sensed touch, it should be appreciated that the display  600  can also sense a hovering object and generate hover signals therefrom. 
       FIG. 7  illustrates a block diagram of a portion of display  700  according to various examples. Display  700  can be another implementation of display  200  made using touch electrodes  501  shown in  FIG. 5 . In the illustrated example, display  700  can include two columns and three rows of touch electrodes  701 ,  703 ,  705 ,  707 ,  709 , and  711  that can be similar or identical to touch electrode  501 . Similar to the display  600 , each touch electrode can include a buffer  503  coupled to receive a pair of stimulation signals and a code sequence. However, unlike the implementation shown in  FIG. 6 , buffers  503  of display  700  can be coupled to receive the same stimulation signal input generated from stimulation signal generator  713 . The stimulation signal generated by signal generator can be similar to the stimulation signals used in display  600 . For example, the stimulation signal can include a sinusoidal or square wave signal. Since the same stimulation signal is applied to both inputs of each buffer  503  in each row, display  700  can include sense circuitry  715 ,  717 , and  719  coupled to each pair of inputs of each row of display  700 . In this way, the amount of current being drawn by each row of touch electrodes can be determined. Additionally, by globally applying the stimulation signal to all supply lines and electrodes of display  700  (e.g., Gate Line High, low voltage supplies, etc.), as well as the display back plane shielding, the level of undesired current sensed by sense circuitry  715 ,  717 , and  719  can be reduced, thereby improving the dynamic range requirement of the analog front end circuitry. 
     Similar to display  600 , each touch electrode in the same column can be coupled to receive the same code sequence. For example touch electrodes  701 ,  703 , and  705  in the first column can be coupled to receive code sequence  507 , while touch electrodes  707 ,  709 , and  711  in the second column can be coupled to receive offset code sequence  619 . Code sequence  507  and offset code sequence  619  can be similar or identical to those used in display  600 . In this way, each touch electrode in a row can be selectively coupled it to either of stimulation signal inputs in a unique way. 
     By including sense circuitry for pair of stimulation inputs for each row of display  700  and by uniquely coding each column of touch electrodes, the capacitance of each touch electrode of display  700  can be determined. For example, a multiplier  727  can be coupled to receive a current sense signal representative of the difference between the sensed amount of current drawn from each stimulation signal source from sense circuitry  715 . To determine the amount of current drawn by a particular touch electrode X in the row of touch electrodes coupled to sense circuitry  715 , multiplier  727  can multiply the received current sense signal by the code sequence for column X. For example, to determine the current drawn by touch electrode  707  (the touch electrode in the second column), the sense signal from sense circuitry  715  can be multiplied by offset code sequence  619 . The result can be a signal representative of the current from touch electrode  707 . While not shown, it should be appreciated that additional multipliers can be included and coupled to receive current sense signals from each of the sense circuits. 
     While the example shown in  FIG. 7  includes two columns and three rows of touch electrodes, it should be appreciated that display  700  can include any number of rows and columns of touch electrodes. These additional rows and columns can be coupled together in a manner similar to that shown in  FIG. 7 . For example, the touch electrodes in each column can be coupled to receive the same code sequence, while all touch electrodes in all rows can be coupled to receive the same stimulation signal. The code sequence applied to each column can be offset by an amount that prevents any two touch electrodes in the same row of display  700  from receiving the same portion of the code segment. This can include offsetting the code segment for each column by 1. However, other offsets can be used if the length of the code sequence is greater than the number of touch electrodes in each row of display  700 . Additionally, while the touch electrodes are shown in  FIG. 7  in a grid configuration, it should be appreciated that other configurations are also possible to form the desired touch region pattern. Moreover, while specific configurations have been described with reference to the rows and columns of display  700 , it should be appreciated that the orientation of display  700  can be changed such that the described configurations for the rows and columns can be similarly applied to the columns and rows of display  700 , respectively. Furthermore, while various examples describe a sensed touch, it should be appreciated that the display  700  can also sense a hovering object and generate hover signals therefrom. 
     In other examples, each of sense circuitry  715 ,  717 , and  719  can be coupled to sense the current drawn by blocks of touch electrodes rather than rows or columns of electrodes. For example, sense circuitry  719  can instead be coupled to sense the current drawn by a first block of electrodes formed by touch electrodes  703 ,  705 ,  709 , and  711  (or any other rectangular block of electrodes containing any number of electrodes), sense circuitry  717  can be coupled to sense the current drawn by a second block of electrodes formed by touch electrodes  701 ,  707 , and the two electrodes located above touch electrodes  701  and  707  (not shown), and sense circuitry  715  can be coupled to sense the current drawn by a third block of electrodes (not shown). 
       FIG. 8  illustrates a block diagram of a display  800  according to various examples. Display  800  can include rows and columns of touch electrodes  801 , which can be formed by patterning VCOM+M3  03  of display  100  into rectangular or other desired shapes. Display  800  can further include buffers  807 ,  809 ,  811 , and  813  coupled to touch electrodes  801  on the left half of the first row of touch electrodes by traces  802 . In some examples, traces  802  can be formed by patterning the M1  107  of display  100  and can be coupled to VCOM+M3  103  of touch electrodes  801  by vias. Buffers  807 ,  809 ,  811 , and  813  can each include a transmission gate for selectively coupling touch electrodes  801  to buses DS 0 -DS 3 . Display  800  can be coupled to receive code sequence  815  to control buffers  807 ,  809 ,  811 , and  813  to selectively couple touch electrodes  801  to buses DS 0 -DS 3 . Code sequence  815  can have a length equal to the number of rows of display  800  and can be configured to cause only one row of touch electrodes  801  to be coupled to buses DS 0 -DS 3  at the same time. For example, code sequence can have one high bit (e.g., corresponding to logic 1) followed by low bits (e.g., corresponding to logic 0) for a total number of bits equal to the number of rows of touch display  800 . 
     Display  800  can further include latch  817  coupled to receive code sequence  815  and a clock signal from clock  819 . Latch  817  can be operable to store and output the value at its input at a rising (or falling) edge of the clock signal. 
     Display  800  can further include shift register  805  and gate driver  803  coupled to receive an output of shift register  805  and modulated signal  823 . In some examples, modulated signal  823  can include a modulated VGL and VGH bias voltages of display  800 . Gate driver  803  can apply modulated signal  823  to each of the touch electrodes  801  in the left half of the top row of display  800 . This can effectively bootstrap the majority of the undesired parasitic capacitances of display  800  and prevent sense circuitry  821  from being overloaded, thereby reducing the dynamic range requirement of the receiver front end circuitry. 
     While not shown, additional buffers, latches, shift registers, gate drivers, and traces can be included for each half of each row of display  800  and can be coupled to touch electrodes  801  in a manner similar to that shown for the left half of the first row of display  800 . For example, four buffers can be coupled between buses DS 0 -DS 3  and the touch electrodes  801  on the left half of the second row of display  800  by traces patterned into M1  107 . An additional shift register can be included and can be coupled to an additional gate driver. The additional gate driver can also be coupled to receive modulated signal  817  and can be coupled to apply modulated signal  817  to each of the touch electrodes  801  on the left half of the second row of display  800 . Similar circuitry can be included for the remaining rows on the left half of display  800 . Additionally, similar circuitry can be included for each row on the right half of display  800  and additional buses DS 4 -DS 7  (not shown) can be included for the right half of display  800 . 
     Similar to the example shown in  FIG. 4 , the circuitry for each row of touch electrodes  801  can be coupled together in a cascaded fashion such that the code sequence received by the buffers and latch of one row can be received from the output of a latch from an adjacent row. For example, the circuitry for the left half of the second row of touch electrodes (not shown) can include four buffers and a latch coupled to receive the code sequence output of latch  817 . The output of the second row&#39;s latch can similarly be provided to the buffers and latch of the circuitry for the left half of the third row of touch electrodes  801  and so on. In this way, code sequence  815  can be propagated through the circuitry associated with each row touch electrodes  801  to selectively couple and decouple each row of touch electrodes  801  from buses D 0 -D 3 . 
     Display  800  can further include sense circuitry  821  to perform self-capacitance measurements by measuring the current drawn by the touch electrodes  801  currently coupled to each of buses DS 0 -DS 3 . Since code sequence  815  can be configured to cause only one row of touch electrodes  801  to be coupled to buses DS 0 -DS 3  at any time, sense circuitry  821  can simply measure the current drawn on each bus to measure the current drawn by a particular touch electrode  801  in a particular row. For example, during a first clock cycle, buffers  807 ,  809 ,  811 , and  813  can couple the touch electrodes  801  in the first row of display  800  to buses DS 0 -DS 3  and sense circuitry  821 . During this clock cycle, all other touch electrodes  801  can be uncoupled from buses DS 0 -DS 3 . Sense circuitry  821  can then measure the current drawn from each bus to determine the capacitance at each touch electrode  801  in the row (e.g., the current drawn from bus DS 0  corresponds to the capacitance of the touch electrode  801  in the first row and the first column). At a second clock cycle, buffers  807 ,  809 ,  811 , and  813  can uncouple the touch electrodes  801  in the first row from buses DS 0 -DS 3 . In this clock cycle, buffers associated with the second row of touch electrodes  801  can couple the second row of touch electrodes  801  to buses DS 0 -DS 3  while all other touch electrodes are uncoupled from buses DS 0 -DS 3 . Sense circuitry  821  can then measure the current drawn from each bus to determine the capacitance at each touch electrode  801  in the second row (e.g., the current drawn from bus DS 3  corresponds to the capacitance of the touch electrode  801  in the second row and the fourth column). This process can be repeated for each row of display  800 . 
     Using a configuration similar or identical to that shown in  FIG. 8  advantageously reduces the circuitry located within each touch electrode. For example, no buffers, latches, or other circuitry is located on touch electrodes  801 . 
     While display  800  is shown having one bus for each touch electrode  801  on each half row, it should be appreciated that a greater number of buses can be included. For example, eight buses can be included on the left side of display  800  and can be coupled to touch electrodes  801  on the left side of the first two rows. In this example, latch  817  can be omitted and a single latch can be placed between the circuitry for the second and third rows. This advantageously shortens the code sequence  815  needed to modulate display  800  (e.g., the minimum length of code sequence  815  can be (number of rows)/2), thereby reducing the integration time for touch/hover detection. However, a greater amount of space on the side of display  800  can be needed for the additional buses. Other numbers of buses, up to the number of touch electrodes  801  in each half of display  800 , can be used. 
       FIG. 9  illustrates a block diagram of a display  900  according to various examples. Display  900  can include rows and columns of touch electrodes  901 , which can be formed by patterning VCOM+M3  103  of display  100  into rectangular or other desired shapes. Display  900  can further include buffers  907 ,  909 ,  911 , and  913  coupled to touch electrodes  901  on the left half of the first row of touch electrodes by traces  902 . In some examples, traces  902  can be formed by patterning the M1  107  of display  100  and can be coupled to VCOM+M3  103  of touch electrodes  901  by vias. Buffers  907 ,  909 ,  911 , and  913  can each include a transmission gate similar or identical to that of buffer  503 , described above. 
     Display  900  can further include latches  917 ,  919 ,  921 , and  923  coupled to receive a clock signal from clock  925  and coupled together in a cascaded fashion such that the input of one latch is coupled to the output of another. Latches  917 ,  919 ,  921 , and  923  can be operable to store and output the value at its input at a rising (or falling) edge of the clock signal. Additionally, the input to each latch can be coupled to control one of buffers  907 ,  909 ,  911 , and  913  to selectively couple touch electrodes  901  to one of a pair of buses (e.g., couple touch electrode  901  in the first row and first column between buses DS 0  and DS 1 ). A first latch can be coupled to receive code sequence  927 . In this way, code sequence  927  can be provided to the first buffer and can be propagated through each buffer for each row at each clock cycle. For example, in the first clock cycle, touch buffer  909  can receive the first bit of code sequence  927 . At the second clock cycle, buffer  911  can receive the first bit of code sequence  927  while buffer  907  can receive the second bit of code sequence  927 . This process can be continuously repeated while touch detection is being performed. At the end of code sequence  927 , the code can begin again at the first bit. 
     Similar to code sequence  307 , code sequence  927  can include any sequence of binary values that has a relatively low autocorrelation. For example, code sequence  927  can include a pseudo inverse code, Kasami code, or the like. Additionally, as described in further detail below, code sequence  927  can be used to uniquely modulate and demodulate each touch electrode of each row of display  900  and, as such, can have a length that is greater than or equal to the number of touch electrodes in each row of display  900 . 
     Display  900  can further include shift register  905  and gate driver  903  coupled to receive an output of shift register  905  and modulated signal  917 . In some examples, modulated signal  917  can include a modulated VGL and VGH bias voltages of display  900 . Gate driver  903  can apply modulated signal  917  to each of the touch electrodes  901  in the left half of the top row of display  900 . 
     Display  900  can further include shift register  905  and gate driver  903  coupled to receive an output of shift register  905  and modulated signal  929 . In some examples, modulated signal  929  can include a modulated VGL and VGH bias voltages of display  900 . Gate driver  903  can apply modulated signal  929  to each of the touch electrodes  901  in the left half of the top row of display  900 . 
     While not shown, additional buffers, latches, shift registers, gate drivers, and traces can be included for each half of each row of display  900  that can be coupled to touch electrodes  901  in a manner similar to that shown for the left half of the first row of display  900 . For example, four buffers can be coupled between buses DS 0 -DS 7  and the touch electrodes  901  on the left half of the second row of display  900  by traces patterned into M1  107 . Four additional cascaded latches can also be coupled to the additional buffers. The additional buffers and additional latches can be coupled to receive the code sequence output by latch  923 . An additional shift register can be included and can be coupled to an additional gate driver. The additional gate driver can also be coupled to receive modulated signal  929  and can be coupled to apply modulated signal  929  to each of the touch electrodes  901  on the left half of the second row of display  900 . Similar circuitry can be included for the remaining rows on the left half of display  900  and can be coupled together in a cascaded fashion as described above. Similar circuitry can also be included for each row on the right half of display  900  and additional buses DS 8 -DS 15  (not shown) can be included for the right half of display  900 . 
     Similar to display  800 , the circuitry for each row of touch electrodes  901  can be coupled together in a cascaded fashion such that the code sequence received by the buffers and latch of one row can be received from the output of the last latch from an adjacent row. For example, the circuitry for the left half of the second row of touch electrodes (not shown) can include four buffers and four latches coupled to receive the code sequence output. The output of the second row&#39;s last latch can similarly be provided to the buffers and latches of the circuitry for the left half of the third row of touch electrodes  901  and so on. In this way, code sequence  927  can be propagated through the circuitry associated with each row touch electrodes  901  to selectively modulate each touch electrode  901  of display  900 . 
     Display  900  can include sense circuitry  915  coupled to buses DS 0 -DS 7 . Sense circuitry  915  can include current sensors operable to determine an amount of current drawn by the touch electrodes of display  900  from each bus. A current sense signal representing the difference between the sensed amount of current drawn from each pair of buses can be output by the current sensors (e.g., current sensor  916 ). The current sense signal can be provided to demodulation circuitry that can be operable to demodulate the current sense signal using a code sequence for a particular electrode. For example, since sense circuitry  916  is coupled to measure the current drawn by a known row of touch electrodes (the first row), and since the modulation of each touch electrode within the row is known for a given time (e.g., the code sequence applied to the touch electrode), a multiplier can be used to demodulate the current sense signal by multiplying the current sense signal by the code sequence for a particular touch electrode to determine the contribution of that touch electrode to the current sense signal. For example, to determine the current contribution of touch electrode at position (X) (e.g., position 2) of the first row of display  900 , the code being applied to the second touch electrode of row one can be multiplied with the current sense signal from sense circuitry  916 . The determined current from the touch electrode can be representative of the capacitance at or near the touch electrode. This capacitance can be used to detect the location and amount of touch or hover events at or near the touch electrode. While not shown, it should be appreciated that additional current sensors and multipliers can be coupled to buses DS 2 -DS 7  to demodulate the current sense signals in a similar manner. 
     While display  900  is shown having one pair of buses for each touch electrode  901  on each half row, it should be appreciated that a greater number of buses can be included. For example, 16 buses can be included on the left side of display  900  and can be coupled to touch electrodes  901  on the left side of the first two rows. 
       FIG. 10A  illustrates a block diagram of display  1000  according to various examples. Display  1000  can be an implementation of display  200  made using combined display data and touch detection ICs  1003 . Display  1000  can include rows and columns of touch electrodes  1001 , which can be formed by patterning VCOM+M3  103  of display  100  into rectangular or other desired shapes. Display  1000  can further include combined display data and touch detection ICs  1003  coupled to touch electrodes  1001  by traces  1002 . In some examples, traces  1002  can be formed by patterning the M1  107  of display  100  and can be coupled to VCOM+M3  103  of touch electrodes  1001  by vias. 
     In other examples, as shown in  FIG. 10B , the stackup of display  1000  can include a back ITO layer  1011 , glass dielectric  1013 , dielectric  1015 , metal 1 layer  1017 , dielectric  1019 , metal 2 layer  1021 , dielectric  1023 , metal 3 layer  1025 , dielectric  1027 , VCOM ITO layer  1029 , dielectric  1031 , pixel ITO layer  1033 , and via  1035 . In these examples, touch electrodes  1001  of display  1000  can be formed by patterning VCOM ITO layer  1029 , metal 3 layer  1025  can be separated from VCOM ITO layer by dielectric  1027 , and each electrode formed from VCOM ITO layer  1029  pixel can be coupled to metal 3 layer  1025  by a via  1035 . 
     Referring back to  FIG. 10A , display  1000  can include a touch sensor similar to touch sensors  800  and  900 , except that combined display data and touch detection ICs  1003  can be used to perform the functions of the circuitries attached to each row of displays  800  or  900 . For instance, in some examples, data/touch IC  1003  can be used to perform the gate driving functions of gate driver  803  and shift register  805 , the modulating function of clock  819 , latch  817 , and buffers  807 / 809 / 811 / 813 , and the touch/hover detection of sense circuitry  821 . Similarly, in other examples, data/touch IC  1003  can be used to perform the gate driving functions of gate driver  903  and shift register  905 ; the modulating function of clock  925 , latches  917 / 919 / 921 / 923 , and buffers  907 / 909 / 911 / 913 ; and the touch/hover detection of sense circuitry  915 . 
     In some examples, display  1000  can be separated into two halves across line  1005 . In these examples, data/touch ICs  1003  on one half of the display can be configured to update its associated half of the display while data/touch ICs  1003  on the other half of the display can be configured to perform touch detection on its associated half. Data/touch ICs  1003  can be configured to repeatedly switch between display updating and touch detection. For example, the data/touch ICs  1003  on the top half of the display  1000  can update the display for 8 ms while the data/touch ICs  1003  on the bottom half of the display  1000  can perform touch detection. After the 8 ms, the data/touch ICs  1003  on the top half of the display  1000  can perform touch detection for 8 ms while the data/touch ICs  1003  on the bottom half of the display  1000  can update the display. This process can be repeated to simultaneously update the display and perform touch detection. In other examples, both halves of display  1000  can be updated during the same 8 ms (or other amount) segment of time. This can be done through the use of two active gate lines—one for the top half of display  1000  and one for the bottom half of display  1000 , where each half of display  1000  has independent display data lines and sources. Once the display is updated, touch sensing can be performed for both halves of display  1000  during the next 8 ms (or other amount) segment of time. 
     In other examples, display  1000  can be further separated into smaller sections. For example, display  1000  can be separated into four sections as defined by lines  1005  and  1007 . In these examples, data/source ICs  1003  for half of the sections can be configured to update the display while the remaining data/source ICs  1003  can be configured to perform touch detection. The data/source ICs  1003  can be further configured to switch between touch detection and updating the display as discussed above. It should be appreciated that display  1000  can be separated into any desired number of sections. 
       FIG. 11  illustrates a block diagram of another touch sensitive display  1100  according to various examples. Display  1100  can be an implementation of display  200  made using separate display data IC  1105  and touch detection IC  1003 . Display  1100  can include rows and columns of touch electrodes  1101 , which can be formed by patterning VCOM+M3  103  of display  1100  into rectangular or other desired shapes. Display  1100  can further include touch IC  1103  coupled to touch electrodes  1101  by traces  1102 . In some examples, traces  1102  can be formed by patterning the M1  107  of display  100  and can be coupled to VCOM+M3  103  of touch electrodes  1101  by vias. One set of eight traces  1102  has been shown in  FIG. 11  coupling touch electrodes  1101  to touch IC  1103 . However, it should be appreciated that additional sets of eight traces can be included for each column of touch electrodes  1101  and that they have been omitted from  FIG. 11  to avoid cluttering the figure. Display  1100  can further include display IC  1105  for updating the display. 
     Display  1100  can include a touch sensor similar to touch sensors  800  and  900 , except that touch IC  1103  and display IC  1105  can be used to perform the functions of the circuitries attached to each row in either display  800  or  900 . For instance, in some examples, touch IC  1103  can be used to perform the modulating function of clock  819 , latch  817 , and buffers  807 / 809 / 811 / 813 , and the touch/hover detection of sense circuitry  821 . Additionally, display IC  1105  can be used to perform the gate driving functions of gate driver  803  and shift register  805 . Similarly, in other examples, touch IC  1103  can be used to perform the modulating function of clock  925 , latches  917 / 919 / 921 / 923 , and buffers  907 / 909 / 911 / 913 ; and the touch/hover detection of sense circuitry  915 . Additionally, display IC  1105  can be used to perform the gate driving functions of gate driver  903  and shift register  905 . 
     Using a configuration similar or identical to that shown in  FIG. 11 , the amount of space on the sides of display  1100  can be reduced. This can be beneficial when display  1100  is included in devices with smaller form factors that need smaller widths. 
     One or more of the functions relating to the operation of an integrated touch sensitive display described above can be performed by a system similar or identical to system  1200  shown in  FIG. 12 . System  1200  can include instructions stored in a non-transitory computer readable storage medium, such as memory  1203  or storage device  1201 , and executed by processor  1205 . The instructions can also be stored and/or transported within any non-transitory computer readable storage medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “non-transitory computer readable storage medium” can be any medium that can contain or store the program for use by or in connection with the instruction execution system, apparatus, or device. The non-transitory computer readable storage medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, a portable computer diskette (magnetic), a random access memory (RAM) (magnetic), a read-only memory (ROM) (magnetic), an erasable programmable read-only memory (EPROM) (magnetic), a portable optical disc such a CD, CD-R, CD-RW, DVD, DVD-R, or DVD-RW, or flash memory such as compact flash cards, secured digital cards, USB memory devices, memory sticks, and the like. 
     The instructions can also be propagated within any transport medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “transport medium” can be any medium that can communicate, propagate or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The transport medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic or infrared wired or wireless propagation medium. 
     It is to be understood that the system is not limited to the components and configuration of  FIG. 12 , but can include other or additional components in multiple configurations according to various examples. Additionally, the components of system  1200  can be included within a single device, or can be distributed between multiple devices. 
       FIGS. 13-16  show example systems in which an integrated touch sensitive display according to examples of the disclosure may be implemented.  FIG. 13  illustrates an exemplary personal device  1300 , such as a tablet, that can be used with a an integrated touch sensitive display according to various examples.  FIG. 14  illustrates another exemplary personal device  1400 , such as a mobile phone, that can be used with an integrated touch sensitive display according to various examples.  FIG. 15  illustrates yet another exemplary personal device  1500 , such as a portable media player, that can be used with an integrated touch sensitive display according to various examples.  FIG. 16  illustrates another exemplary personal device  1600 , such as a laptop computer, that can be used with an integrated touch sensitive display according to various examples. 
     Therefore, according to the above, some examples of the disclosure are directed to an integrated touch sensitive display comprising: a first voltage source; a second voltage source; a plurality of touch electrodes, wherein each of the plurality of touch electrodes comprises an inverter operable to couple an associated touch electrode to either the first voltage source or the second voltage source based on a code sequence signal, and wherein each of the plurality of touch electrodes is coupled to receive a different code sequence signal; and sense circuitry operable to generate a current sense signal based on a difference between a first current through the first voltage source and a second current through the second voltage source. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the display can further include demodulation circuitry operable to demodulate the current sense signal to determine a capacitance at a touch electrode of the plurality of touch electrodes based on a code sequence signal received by the touch electrode of the plurality of touch electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the code sequence signals received by each of the plurality of touch electrodes comprise the same sequence of values, and wherein each of the code sequence signals received by the plurality of touch electrodes has a different phase offset. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the code sequence signals received by the plurality of touch electrodes each comprise a pseudo inverse code or a Kasami code. Additionally or alternatively to one or more of the examples disclosed above, in some examples, a length each of the code sequence signals received by the plurality of touch electrodes is greater than or equal to a number of touch electrodes in the plurality of touch electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, each of the plurality of touch electrodes further comprises a latch coupled to receive a code sequence signal associated with the touch electrode. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the touch electrodes are arranged in rows and columns, and wherein latches of touch electrodes in the same column are coupled in series. 
     Some examples of the disclosure are directed to an integrated display touch screen comprising: a plurality of touch electrodes arranged in rows and columns, each touch electrode comprising a transmission gate formed thereon, wherein: transmission gates of touch electrodes in the same row are operable to couple their associated touch electrode to receive either a first stimulation signal from a first bus of the row or a second stimulation signal from a second bus of the row based on a code sequence signal, transmission gates of touch electrodes in the same column are coupled to receive the same code sequence signal; and transmission gates of touch electrodes in each row are coupled to receive a different code sequence signal. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the display further includes sense and demodulation circuitry operable to detect a touch or hover event at a touch electrode in a particular row and in a particular column based at least on a code sequence signal received by the touch electrode in the particular row and in the particular column and a difference between a first current through a first bus for the particular row and a second current through a second bus for the particular row. Additionally or alternatively to one or more of the examples disclosed above, in some examples, detecting a touch or hover event at the touch electrode in the particular row and in the particular column comprises multiplying the code sequence signal received by the touch electrode in the particular row and in the particular column by the difference between the first current and the second current. Additionally or alternatively to one or more of the examples disclosed above, in some examples, a length of each of the code sequence signals is greater than or equal to a number of columns of touch electrodes. Additionally or alternatively to one or more of the examples disclosed above, in some examples, a first stimulation signal for a row is generated by a first stimulation signal generator, and wherein a second stimulation signal for the row is generated by a second stimulation signal generator. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the first stimulation signal for the row and the second stimulation signal for the row are 180-degrees out of phase from each other. Additionally or alternatively to one or more of the examples disclosed above, in some examples, a first stimulation signal for a row is generated by a stimulation signal generator, and wherein a second stimulation signal for the row is generated by the stimulation signal generator. 
     Some examples of the disclosure are directed to an integrated touch sensitive display comprising: a plurality of touch electrodes arranged in rows and columns; a plurality of buses; and a plurality of transmission gates operable to couple only a portion of the plurality of touch electrodes to the plurality of buses at the same time, wherein the portion of the plurality of touch electrodes includes a number of touch electrodes equal to a number of buses in the plurality of buses. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the plurality of transmission gates are operable to sequentially couple portions of the plurality of touch electrodes to the plurality of buses. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the plurality of transmission gates are operable to sequentially couple portions of the plurality of touch electrodes to the plurality of buses. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the plurality of touch electrodes are formed from a first metal layer of the integrated touch sensitive display, and wherein the plurality of transmission gates are coupled to the plurality of touch electrodes by a plurality of traces formed in a second metal layer of the integrated touch sensitive display. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the display can further include sense circuitry coupled to the plurality of buses, wherein the plurality of transmission gates and the sense circuitry are included within a plurality of integrated circuits. Additionally or alternatively to one or more of the examples disclosed above, in some examples, each of the plurality of integrated circuits further comprises display driver circuitry for updating a display of the integrated touch sensitive display. Additionally or alternatively to one or more of the examples disclosed above, in some examples, the display can further include sense circuitry coupled to the plurality of buses, wherein the plurality of transmission gates and the sense circuitry are included within a first integrated circuit, and wherein the integrated touch sensitive display further comprises a second integrated circuit operable to update a display of the integrated touch sensitive display. 
     Although examples have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the various examples as defined by the appended claims.

Metadata:
Filing Date: 20131213
Publication Date: 20181113
Grant Date: 20181113
Priority Date: 20130816
Inventors: YOUSEFPOR, MARDUKE
Assignee: APPLE INC
CPC Classifications: [{"code": "G06F3/0416", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/13452", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/044", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04166", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0446", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0445", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/04166", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0446", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0445", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/13452", "inventive": true, "first": false, "tree": "[]"}, {"code": "G02F1/13452", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": true, "tree": "[]"}, {"code": "G06F3/0412", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 52466499