Display method and display system for reducing image delay by adjusting an image data clock signal

1. Field of the Invention

The present invention illustrates a display method and a display system for reducing image delay, and more particularly, a display method and a display system for reducing image delay by adjusting an image data clock signal to synchronize with a panel data clock signal.

2. Description of the Prior Art

Liquid crystal display (LCD) devices and organic light-emitting diode (OLED) devices have been widely used in our daily life because they take several advantages of thin appearance, low power consumption, and no radiation. For example, the LCD devices and OLED devices can be applied to multimedia players, mobile phones, personal digital assistants, computer monitors, or flat-screen TVs.

A conventional display device uses a pulse width modulation signal for driving a backlight source when images are displayed on a screen. The backlight source is enabled or disabled during a time interval greater than an image frame duration according to the pulse width modulation signal. Therefore, a user is easily disturbed by an unpleasant image flickering effect when the image is displayed, thereby reducing the visual quality. Specifically, images having high frequency or images including high-speed motion objects are prone to generate motion blur effects, leading to reduced image quality. Further, the user can see a transient effect of unstable pixels when the image is processed by refreshing their pixel polarities during the time interval of the enabled backlight source. Therefore, it is easy for the user to see the unpleasant image flickering effect or a double-image effect. Moreover, even if the user does not notice the image flickering effect of the screen when a high-speed image flickering effect or a high-frequency image flickering effect occurs, the user may unconsciously feel tired or suffer from permanent vision damage after watching flickering images for a long time. In order to reduce a pixel refreshing time length of the image received by human eyes, some advanced LCD devices use a pulse-type backlight technology for separating a time interval of enabling the backlight source from a time interval of refreshing pixels of the image. Theoretically, when the backlight source is enabled during a time interval of stabilized LCD pixels, the motion blur effect can be avoided.

When the time interval of enabling the backlight source is separated from the time interval of refreshing pixels of the image, a blanking interval of a vertical synchronization signal has to be increased for maintaining average brightness of the image and avoiding the motion blur effect. However, after the blanking interval of the vertical synchronization signal is increased, a time difference is present between a panel data clock signal of the display and an image data clock signal generated by a signal source. Further, when the panel data clock and the image data clock signal are asynchronous, an image input delay becomes severe, leading to the degradation of operational controllability and reducing the quality of visual interactive experience.

In an embodiment of the present invention, a display method for reducing image delay is disclosed. The display method comprises setting a transmission rate of a panel data clock signal of a display panel, setting a vertical synchronization period of a vertical synchronization signal according to at least the transmission rate of the panel data clock signal, and adjusting an image data clock signal outputted from a signal source according to the vertical synchronization period for synchronizing the panel data clock signal and the image data clock signal. The vertical synchronization period comprises a first active interval and a first blanking interval. The image data clock signal has a period comprising a second active interval and a second blanking interval. A time offset between the first active interval and the second active interval is minimized. A time offset between the first blanking interval and the second blanking interval is minimized.

In another embodiment of the present invention, a display system is disclosed. The display system comprises a display panel, a gate driving circuit, a data driving circuit, a timing controller, a backlight device, a processor, and a signal source. The display panel comprises a plurality of pixels for displaying an image. The gate driving circuit is coupled to the plurality of pixels. The data driving circuit is coupled to the plurality of pixels. The timing controller is coupled to the gate driving circuit and the data driving circuit for controlling the gate driving circuit and the data driving circuit. The backlight device is configured to provide a backlight signal. The processor is coupled to the timing controller and the backlight device for controlling the timing controller and the backlight device. The signal source is coupled to the processor and configured to generate an image data clock signal. After a transmission rate of a panel data clock signal of the display panel and a vertical synchronization period of a vertical synchronization signal are configured, the processor controls the signal source for adjusting the image data clock signal outputted from the signal source according to the vertical synchronization period. The vertical synchronization period comprises a first active interval and a first blanking interval. The image data clock signal has a period comprising a second active interval and a second blanking interval. A time offset between the first active interval and the second active interval is minimized. A time offset between the first blanking interval and the second blanking interval is minimized.

These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.

FIG. 1 is a block diagram of a display system according to an embodiment of the present invention.

FIG. 2 is an illustration of generating an image delay by adjusting a panel data clock signal of the display system in FIG. 1 .

FIG. 3 is an illustration of adjusting an image data clock signal of the display system in FIG. 1 .

FIG. 4 is an illustration of reducing the image delay by adjusting the image data clock signal of the display system in FIG. 1 .

FIG. 5 is an illustration of introducing an adjusted interval to the panel data clock signal for increasing a time length of a first blanking interval of the display system in FIG. 1 .

FIG. 6 is a flow chart of a display method for reducing image delay performed by the display system in FIG. 1 .

FIG. 1 is a block diagram of a display system 100 according to an embodiment of the present invention. The display system 100 includes a display panel 10 , a gate driving circuit 11 , a data driving circuit 12 , a timing controller 13 , a backlight device 14 , a processor 15 , and a signal source 16 . The display panel 10 can be any type of display panel, such as a display panel of a liquid crystal display (LCD) device or a display panel of an organic light-emitting diode (OLED) device. The display panel 10 includes a plurality of pixels P for displaying an image. The pixels P can be allocated in a form of a pixel array for displaying a rectangular image. The gate driving circuit 11 is coupled to the pixels P and can control a plurality of control terminals of the pixels P by using gate voltages under a row-by-row scanning process. Then, an enabling state and a disabling state of each pixel P can be controlled. The data driving circuit 12 is coupled to the pixels P and can transmit data voltages to the pixels P by using a column-by-column scanning process. Therefore, the pixels P can display different colors and different gray levels. The timing controller 13 is coupled to the gate driving circuit 11 and the data driving circuit 12 for controlling the gate driving circuit 11 and the data driving circuit 12 . The timing controller 13 can be a logic board (T-CON). It can be regarded as a core circuit for controlling various timing operations of the display panel 10 . The timing controller 13 can be used for controlling the gate driving circuit 11 and the data driving circuit 12 to scan the pixels P according to various timing clocks. The timing controller 13 can also convert an input video signal (i.e., such as a low-voltage differential signal, LVDS) into an appropriate data signal (i.e., such as a reduced swing differential signal, RSDS) used for driving internal circuits. The backlight device 14 is used for providing a backlight signal. The backlight device 14 can be any controllable light-emitting device. For example, the backlight device 14 can be a light-emitting diode array, an incandescent light bulb, an electroluminescent panel (ELP), or a cold cathode fluorescent lamp (CCFL). The processor 15 is coupled to the timing controller 13 and the backlight device 14 for controlling the timing controller 13 and the backlight device 14 . The processor 15 can be a processing chip (i.e., a scaler) disposed inside the display system 100 , or can be a microprocessor having a programmable capability. The processor 15 can save a plurality of data sets of timing control parameters. The processor 15 can use an inter-integrated circuit bus (I2C) for communicating with the timing controller 13 . The signal source 16 is coupled to the processor 15 . The processor 15 can receive an image data clock signal generated by the signal source 16 . The image data clock signal generated by the signal source 16 can be a data clock signal generated by a graphics card of an external computer, or a data clock signal generated by an audio/video player (i.e., such as a DVD player). The display system 100 can further include a memory 17 . The memory 17 is coupled to the processor 15 for saving extended display identification data (EDID) of the display panel 10 . Any reasonable hardware modification falls into the scope of the present invention.

In the display system 100 , after a transmission rate of a panel data clock signal of the display panel 10 and a vertical synchronization period of a vertical synchronization signal are configured, the processor 15 controls the signal source 16 for adjusting the image data clock signal outputted from the signal source 16 according to the vertical synchronization period. After the image data clock signal is adjusted, the image data clock signal and the panel data clock signal are synchronous. In other words, the vertical synchronization period includes a first active interval and a first blanking interval. The image data clock signal has a period including a second active interval and a second blanking interval. After the image data clock signal is adjusted, a time difference between the first active interval and the second active interval is minimized. A time difference between the first blanking interval and the second blanking interval is minimized. Further, since the panel data clock signal is synchronized with the image data clock signal, when the timing controller 13 controls the gate driving circuit 11 and the data driving circuit 12 for driving the pixels P during the first active interval to generate an image, the image delay can be avoided. Therefore, the quality of visual interactive experience can be increased. Details of the display method of the display system 100 for reducing the image delay are illustrated later.

FIG. 2 is an illustration of generating the image delay by adjusting the panel data clock signal D 1 of the display system 100 . As shown in FIG. 2 , the panel data clock signal D 1 of the display panel is a periodic signal. The period is equal to the vertical synchronization period V TOTAL of the vertical synchronization signal. The vertical synchronization period V TOTAL includes a first active interval ACT 1 and a first blanking interval BLK 1 . The pixels P of the display panel 10 are transient during the first active interval ACT 1 . The pixels P of the display panel 10 are stable during the first blank interval BLK 1 . Therefore, in order to avoid visible motion blur of the display panel 10 , the processor 15 can enable the backlight device 14 of the display panel 10 during a time period of any length within the first blanking interval BLK 1 . Further, the processor 15 can disable the backlight device 14 outside the first blanking interval BLK 1 . The first active interval ACT 1 and an interval for enabling the backlight device 14 are non-overlapped. By doing so, the “transient” pixels P of the image are invisible. Therefore, the motion blur can be avoided. In practice, the transmission rate P DATA of the panel data clock signal D 1 , a horizontal synchronization period H TOTAL of a horizontal synchronization signal, and the vertical synchronization period V TOTAL of the vertical synchronization signal satisfy an equation:

FR is a frame rate constant. For example, when the transmission rate P DATA is equal to 174.9 M per second (Hz), the horizontal synchronization period H TOTAL can be 2200 (the number of pixels), and the vertical synchronization period V TOTAL can be 1325 (the number of pixels). The frame rate FR can be 60 (Hz). The aforementioned parameters satisfy the equation of 174.9 M=2200×1325×60. In order to increase a maximum time length for enabling the backlight device 14 for enhancing supportability of image brightness, a large vertical synchronization period V TOTAL is preferable for the display system 100 . According to the equation P DATA =H TOTAL ×V TOTAL ×FR, for a constant frame rate FR and horizontal synchronization period H TOTAL , when the transmission rate P DATA of the panel data clock signal D 1 is increased, the vertical synchronization period V TOTAL of the vertical synchronization signal is increased. Since a time length of the first active interval ACT 1 is also a constant, when the vertical synchronization period V TOTAL is increased, a time length of the first blanking interval BLK 1 is increased. Since the first blanking interval BLK 1 can be regarded as a period for enabling the backlight device 14 , when the time length of the first blanking interval BLK 1 is increased, it implies that the display system 100 can display a brighter image.

However, although the motion blur can be avoided by merely enabling the backlight device 14 during the first blanking interval BLK 1 , the display system 100 requires a frame buffer since the panel data clock signal D 1 and the image data clock signal D 2 are asynchronous. Further, severe image input delay is also introduced, as illustrated below. As shown in FIG. 2 , the image data clock signal D 2 generated by the signal source 16 has an image period P IMG . The image period P IMG includes a second active interval ACT 2 and a second blanking interval BLK 2 . The end of the image period P IMG corresponds to a time point T 1 . However, as previously mentioned, in order to enhance maximum image brightness supported by the display system 100 , the first blanking interval BLK 1 of the panel data clock signal D 1 can be adjusted. Therefore, the vertical synchronization period V TOTAL is adjusted accordingly. Here, the end of the vertical synchronization period V TOTAL corresponds to a time point T 2 . A time length of the first active interval ACT 1 is equal to a time length of the second active interval ACT 2 , such as a period of scanning 1024 pixels. However, since the second blanking interval BLK 2 is different from the first blanking interval BLK 1 , a large time difference is present between the panel data clock signal D 1 and the image data clock signal D 2 , such as a time difference from the time point T 1 to the time point T 2 . For example, the time difference from the time point T 1 to the time point T 2 can be modeled as X+Y. X can be regarded as an additional time length for adjusting the second blanking interval BLK 2 to approach the first blanking interval BLK 1 . For example, X=200 denotes the additional time length of scanning additional 200 pixels in a vertical direction. Y can be regarded as an inherent time delay length. For example, Y=3 denotes the inherent time delay length of scanning 3 pixels in the vertical direction. In FIG. 2 , the time difference between the panel data clock signal D 1 and the image data clock signal D 2 is equal to |T 1 −T 2 |, such as |T 1 −T 2 |=203. Therefore, since the panel data clock signal D 1 and the image data clock signal D 2 are asynchronous, it results in significant image input delay, thereby reducing the quality of visual interactive experience. Therefore, the display system 100 can adjust the image data clock signal D 2 for reducing the image input delay. Details are illustrated later.

FIG. 3 is an illustration of adjusting the image data clock signal D 2 of the display system 100 . In FIG. 3 , for avoiding ambiguity, after the image data clock signal D 2 is adjusted, the image data clock signal D 2 is called as an image data clock signal D 2 ′ hereafter. As previously mentioned in FIG. 2 , the severe time difference is present between the panel data clock signal D 1 and the image data clock signal D 2 . A reason is that the length of the first blanking interval BLK 1 and the length of the second blanking interval BLK 2 are different. Therefore, in the display system 100 , as shown in FIG. 3 , the second blanking interval BLK 2 is adjusted to the second blanking interval BLK 2 ′. The second blanking interval BLK 2 ′ of the image data clock signal D 2 ′ includes a pre-determined blanking interval A and a user-defined blanking interval B. Particularly, the pre-determined blanking interval A can be configured by the signal source 16 . For example, a time length of the pre-determined blanking interval A can be equal to a time length of the second blanking interval BLK 2 in FIG. 2 . Therefore, the pre-determined blanking interval A can be regarded as an “initial” blanking interval. A time length of the user-defined blanking interval B can be equal to X. As previous definition, X can be regarded as the additional time length for adjusting the second blanking interval BLK 2 to approach the first blanking interval BLK 1 in FIG. 2 . For example, X=200 denotes the additional time length of scanning additional 200 pixels in the vertical direction. In other words, in the image data clock signal D 2 in FIG. 2 , the time length of the second blanking interval BLK 2 is equal to the time length of the pre-determined blanking interval A. However, the time length of the second blanking interval BLK 2 ′ of the image data clock signal D 2 ′ includes the time length of the pre-determined blanking interval A and a time length X of the user-defined blanking interval B. Since the second blanking interval BLK 2 is adjusted to the second blank interval BLK 2 ′, the image period P IMG is also adjusted to an image period P IMG ′. Further, an end time point of the image period is also adjusted from the time point T 1 to the time point T 3 . Therefore, since the time length of the second blanking interval BLK 2 ′ in FIG. 3 is longer than the time length of the second blanking interval BLK 2 in FIG. 2 (i.e., unadjusted), the image input delay can be mitigated, as illustrated below.

FIG. 4 is an illustration of reducing the image delay by adjusting the image data clock signal D 2 ′ of the display system 100 . As shown in FIG. 4 , after the image data clock signal D 2 is adjusted to the image data clock signal D 2 ′, the image period P IMG ′ of the image data clock signal D 2 ′ includes the second active interval ACT 2 and the second blanking interval BLK 2 ′. The time length of the second blanking interval BLK 2 ′ of the image data clock signal D 2 ′ includes the time length of the pre-determined blanking interval A and a time length X of a user-defined blanking interval B. As previously mentioned, for the panel data clock signal D 1 , the vertical synchronization period V TOTAL includes the first active interval ACT 1 and the first blank interval BLK 1 . The time length of the first blank interval BLK 1 includes the time length of the pre-determined blanking interval A and the time length X of the user-defined blanking interval B. For example, X is equal to 200 (i.e., the time length for scanning 200 pixels). Comparing FIG. 2 with FIG. 4 shows a reason for the reduction of the image delay time, as illustrated below. The time difference between the “original” panel data clock signal D 1 and the image data clock signal D 2 is equal to |T 1 −T 2 |, such as |T 1 −T 2 |=203. However, after the image data clock signal D 2 is adjusted to the image data clock signal D 2 ′, the time difference between the panel data clock signal D 1 and the image data clock signal D 2 ′ is equal to |T 3 −T 2 |, such as |T 3 −T 2 |=3. A reduction of the time difference between the panel data clock signal D 1 and the image data clock signal D 2 ′ implies that the image delay is mitigated. In other words, in FIG. 2 , since the time difference is severe (i.e., |T 1 −T 2 |=203), the panel data clock signal D 1 and the image data clock signal D 2 are asynchronous. However, in FIG. 4 , since the second blanking interval BLK 2 is extended to approach the second blank interval BLK 2 ′, the time length of the first blank interval BLK 1 and the time length of the second blank interval BLK 2 ′ are almost the same. Therefore, the panel data clock signal D 1 and the image data clock signal D 2 ′ are almost synchronous, leading to the reduction of the image delay. In other words, in FIG. 4 , only a short delay is present between the first blanking interval BLK 1 of the panel data clock signal D 1 and the second blank interval BLK 2 ′ of the “adjusted” image data clock signal D 2 ′, such as the delay of scanning |T 3 −T 2 |=3 pixels. Therefore, for a user, the short delay of displaying the image is imperceptible. Thus, the quality of visual interactive experience can be maintained.

FIG. 5 is an illustration of introducing an adjusted interval A to the panel data clock signal D 1 for increasing the time length of the first blanking interval BLK 1 ′ of the display system 100 . For avoiding ambiguity, after the adjusted interval A is introduced to the panel data clock signal D 1 , the panel data clock signal D 1 is called as a panel data clock signal D 1 ′ hereafter. In FIG. 5 , for enhancing design flexibility, the panel data clock signal D 1 ′ of the display system 100 can further introduce the adjusted interval A for providing a high design balance between the image brightness supportability and the image delay time. In FIG. 5 , the first blanking interval BLK 1 ′ further includes the adjusted interval Δ. A time length of the adjusted interval Δ is smaller than the time length X of the user-defined blanking interval B. For example, after the panel data clock signal D 1 uses the user-defined blanking interval B having the time length X for increasing the time length of the first blank interval BLK 1 , the panel data clock signal D 1 can further introduce the adjusted interval Δ for further increasing the time length of the first blank interval BLK 1 to generate the first blank interval BLK 1 ′ in order to maximize the supportability of the image brightness. The time length X of the user-defined blanking interval B can be equal to 200 (i.e., X=200). The time length of the adjusted interval Δ can be equal to 50. After the first blanking interval BLK 1 is adjusted to the first blanking interval BLK 1 ′, the vertical synchronization period is also adjusted from V TOTAL to V TOTAL ′. Therefore, the end time point of the vertical synchronization period V TOTAL ′ is also changed from T 2 to T 2 ′. Therefore, the time difference between the second blanking interval BLK 2 ′ and the second blanking interval BLK 1 ′ is increased to |T 3 −T 2 ′|, such as |T 3 −T 2 ′|=3+Δ=53. In other words, a total time difference between the image data clock signal D 2 ′ and the panel data clock signal D 1 ′ can be defined as a sum of the time length of the adjusted interval Δ and the inherent time delay length (i.e., 50+3=53). However, as previously mentioned, the display system 100 can introduce the adjusted interval Δ for providing the high design balance between the image brightness supportability and the image delay time. For example, when the display system 100 is operated in the word processing mode, an extremely short image delay time is not required for the user. Therefore, the time length of the adjusted interval Δ can be increased for enhancing the supportability of high image brightness. When the display system 100 is operated in a video game mode, the extremely short image delay time is required for the user. Therefore, the length of the adjusted interval Δ can be reduced to mitigate the image delay of the display system 100 . In other words, after the display system 100 introduces the adjusted interval Δ, the visual experience can be optimized according to an appropriate mode selected by the user.

In the display system 100 , any hardware modification falls into the scope of the present invention. For example, the display system 100 can further include a memory 17 . The memory 17 is coupled to the processor 15 for saving extended display identification data (EDID) of the display panel 10 . Further, data of the transmission rates of the panel data clock signals D 1 and D 2 , and data of the vertical synchronization periods V TOTAL and V TOTAL ′ of the vertical synchronization signals belong to two user-defined timing data categories of the EDID. Further, the display panel 10 can use an on-screen-display (OSD) function for displaying a mode adjustment interface. The processor 15 can set the transmission rate of the panel data clock signal and the vertical synchronization period of the vertical synchronization signal through the mode adjustment interface. Further, the EDID in the memory 17 can be set to an enabling state so as to read the EDID by the signal source 16 . In practice, the user can operate the display panel 10 by using the OSD function. Then, the display panel 10 can transmit a trigger signal to the signal source 16 . The trigger signal can be a notification signal from a low voltage to a high voltage, such as a hot-plug signal. After the signal source 16 receives the trigger signal, the signal source 16 can read the EDID for generating the image data clock signal synchronized with the panel data clock signal. However, the display system 100 is not limited to the aforementioned operational modes. For example, the memory 17 can also be integrated with the signal source 16 on a motherboard. The signal source 16 can automatically read timing data saved in the memory 17 for generating the image data clock signal synchronized with the panel data clock signal. Further, the timing data saved in the memory 17 can also be configured or adjusted by the user in a preset mode. By doing so, after the user selects the preset mode through the OSD interface of the display panel 10 , the signal source 16 can read the EDID information of the memory 17 according to the trigger signal. Then, the signal source can generate an image data clock signal having user-defined timing parameters.

Further, a definition of “synchronization” can be regarded as high time consistency between the panel data clock signal and the image data clock signal. In other words, even if an imperceptible time difference is introduced between the panel data clock signal and the image data clock signal, the two signals are still synchronous. For example, as previously mentioned in FIG. 2 , the time difference between the panel data clock signal D 1 and the image data clock signal D 2 is equal to |T 1 −T 2 |, such as |T 1 −T 2 |=203. Since a time length of scanning 203 pixels is prone to be noticed by the user, the panel data clock signal D 1 and the image data clock signal D 2 are asynchronous. However, as previously mentioned in FIG. 4 , the time difference between the panel data clock signal D 1 and the “adjusted” image data clock signal D 2 ′ is equal to |T 3 −T 2 |=3. Since a time length of scanning 3 pixels cannot be easily noticed by the user, the panel data clock signal D 1 and the “adjusted” image data clock signal D 2 ′ are substantially synchronous. In general, after reducing an noticeable time difference by more than 90%, a time difference corresponding to a time length of scanning a couple of units digits of pixels is imperceptible by the user.

FIG. 6 is a flow chart of a display method for reducing the image delay performed by the display system 100 . The display method for reducing the image delay includes step S 601 to step S 603 . Any reasonable technology modification falls into the scope of the present invention. Step S 601 to Step S 603 are illustrated below.

step S 601 : setting the transmission rate of the panel data clock signal D 1 of the display panel 10 ; step S 602 : setting the vertical synchronization period V TOTAL of the vertical synchronization signal according to at least the transmission rate of the panel data clock signal D 1 ; step S 603 : adjusting the image data clock signal D 2 ′ outputted from the signal source 16 according to the vertical synchronization period V TOTAL for synchronizing the panel data clock signal D 1 and the image data clock signal D 2 ′.

Details of step S 601 to step S 603 are previously illustrated. Thus, they are omitted here. In the present invention, correlations between the panel data clock signal D 1 and the image data clock signal D 2 may lead to the following results. (A) When the panel data clock signal D 1 and the image data clock signal D 2 are asynchronous (i.e., the time difference is equal to |T 1 −T 2 |=203), severe image delay is unavoidable. (B) After the image data clock signal D 2 is adjusted to the image data clock signal D 2 ′, the panel data clock signal D 1 and the image data clock signal D 2 ′ are substantially synchronous, such that the time difference is minimized to |T 3 −T 2 |=3. Therefore, the image delay can be greatly reduced. (C) Based on (B), when the panel data clock signal D 1 introduces the adjusted interval Δ to generate the panel data clock signal D 1 ′, the time difference between the panel data clock signal D 1 ′ and the image data clock signal D 2 ′ is slightly increased. However, the adjusted interval Δ can be used for providing the high design balance between the image brightness supportability and the image delay time. In other words, the (B) mode and the (C) mode can be regarded as two solutions for mitigating severe image delay in the (A) mode. By doing so, the quality of visual interactive experience can be increased.

To sum up, the present invention discloses a display method and a display system for reducing image delay. After the display system adjusts an image data clock signal outputted from a signal source, the image data clock signal can be substantially synchronized with a panel data clock signal. Therefore, the image delay can be reduced. Further, after the display system introduces an adjusted interval for adjusting the clock signal of the panel data, image brightness supportability and the image delay time can be customized by a user. Therefore, when the display system uses the aforementioned display method in conjunction with a pulse-type backlight technology, the display system can provide low motion blur and low display latency images. Further, the display system can provide high supportability of image brightness, thereby increasing the quality of visual interactive experience.

Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.