This application claims the priority benefit of China application serial no. 201610563099.5, filed on Jul. 18, 2016. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The disclosure relates to a driving device, and particularly relates to a backlight driving device and a display device comprising the same.
In the technique field of display driving, liquid crystal displays (LCD) are gradually developed toward a trend of large size, and there are more and more researches on how to improve a resolution and image quality of the LCD. However, in recent years, backlight modules for the LCDs are gradually developed to have an adjusting technique of local dimming, so as to adjust a brightness of each light-emitting region. However, the conventional local dimming technique is to pull out a driving line from each of the light-emitting regions, and couple a plurality of drivers through a plurality of connectors to respectively adjust the brightness of the light-emitting regions. Namely, since the conventional local dimming technique requires a large number of connectors and drivers, the conventional backlight driving device having the local dimming function generally requires a large mechanical space. Therefore, it is an important issue to design a backlight driving device having a local dimming function with high efficiency, and having a low mechanical space requirement.
An embodiment of the disclosure provides a backlight driving device including a light source array, a driving circuit and a scanning circuit. The light source array includes a plurality of backlight units arranged in an array, and the backlight units are electrically connected through a plurality of scanning lines and a plurality of driving lines. The driving circuit outputs a plurality of driving signals to the backlight units through the driving lines, and the driving signals respectively include a plurality of driving pulses in different time intervals. The scanning circuit outputs a plurality of scanning signals to the backlight units through the scanning lines, and the scanning signals respectively include a start pulse in at least one of the time intervals. The start pulses of the scanning signals respectively correspond to the driving pulses in the same time interval, and drive the backlight units of the each row of the light source array in time-division.
An embodiment of the disclosure provides a display device including a display panel and a backlight driving device. The backlight driving device is disposed corresponding to the display panel. The backlight driving device includes a light source array, a driving circuit and a scanning circuit. The light source array includes a plurality of backlight units arranged in an array, and the backlight units are electrically connected through a plurality of scanning lines and a plurality of driving lines. The driving circuit outputs a plurality of driving signals to the backlight units through the driving lines, and the driving signals respectively include a plurality of driving pulses in different time intervals. The scanning circuit outputs a plurality of scanning signals to the backlight units through the scanning lines, and the scanning signals respectively include a start pulse in at least one of the time intervals. The start pulses of the scanning signals respectively correspond to the driving pulses in the same time interval, and drive the backlight units of the each row of the light source array in time-division.
In order to make the aforementioned and other features and advantages of the disclosure comprehensible, several exemplary embodiments accompanied with figures are described in detail below.
The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.
A term “couple” used in the full text of the disclosure (including the claims) refers to any direct and indirect connections. For example, if a first device is described to be coupled to a second device, it is interpreted as that the first device is directly coupled to the second device, or the first device is indirectly coupled to the second device through other devices or connection means. Moreover, wherever possible, components/members/steps using the same referential numbers in the drawings and description refer to the same or like parts. Components/members/steps using the same referential numbers or using the same terms in different embodiments may cross-refer related descriptions.
In the present embodiment, each of the backlight units 111 corresponds to a light-emitting region of the light source array 110. The driving circuit 120 is coupled to the light source array 110, and is used for outputting a plurality of same driving signals DS_1, DS_2, DS_3, DS_4 to each of the backlight units 111 in the light source array 110. The scanning circuit 130 is coupled to the light source array 110, and is used for outputting a plurality of scanning signals SS_1, SS_2, SS_3 to each of the backlight units 111 in the light source array 110.
In the present embodiment, each of the driving signals DS_1, DS_2, DS_3 and DS_4 is composed of driving pulses DP_1, DP_2 and DP_3, and the scanning signals SS_1, SS_2, SS_3 respectively include start pulses SP_1, SP_2 and SP_3, where the start pulses SP_1, SP_2 and SP_3 of the scanning signals SS_1, SS_2, SS_3 are sequentially output for respectively corresponding to the driving pulses DP_1, DP_2 and DP_3 of the same time intervals in the driving signals DS_1, DS_2, DS_3 and DS_4. Namely, each of the backlight unit 111 may receive the same driving pulses DP_1, DP_2 and DP_3. However, since the received scanning signals SS_1, SS_2 and SS_3 are different, a time that each row of the backlight units 111 sequentially receives the start pulses SP_1, SP_2 and SP_3 is different.
In the present embodiment, the backlight units of each column of the light source array 110 may respectively share a same driving line DL, such that the driving circuit 120 may respectively output the driving signals DS_1, DS_2, DS_3 and DS_4 to the backlight units 111 of each column in the light source array 110 through the driving line DL shared by each column of the backlight units 111. In the present embodiment, the backlight units of each row of the light source array 110 may respectively share a same scan line SL, such that the scanning circuit 130 may respectively output the scanning signals SS_1, SS_2 and SS_3 to the backlight units 111 of each row of the light source array 110 through the scan line SL shared by each row of the backlight units 111. To be specific, in the present embodiment, the scanning circuit 130 outputs the scanning signals SS_1, SS_2 and SS_3 to the backlight units 111 of each row of the light source array 110, and sequentially provides the start pulses SP_1, SP_2 and SP_3 to the backlight units 111 of each row of the light source array 110. In this way, the backlight units 111 of the same row may receive the scanning signal of the same scanning line SL, and the backlight units 111 of different rows sequentially receive the start pulses SP_1, SP_2 and SP_3. Therefore, in the present embodiment, when one of the backlight units 111 receives a start pulse, the light source array 110 may drive the backlight unit according to the driving pulse corresponding to the same time interval in the driving signal.
It should be noted that, in the present embodiment, the backlight units of each column of the light source array 110 are designed to share the same driving line DL, and the backlight units of each row are designed to share the same scanning line SL. Therefore, the number of overall pins of the light source array 110 can be determined according to the number of the shared driving lines DL and the number of the shared scanning lines SL, and it is unnecessary to pull out a driving line and a scanning line from each of the backlight units 111 of the light source array 110. Even more, the backlight driving device 100 may drive all of the backlight units 111 through one piece of the driving circuit 120. Namely, the backlight driving device 100 of the present embodiment may have a circuit design for sharing the driving lines DL and sharing the scanning lines SL, so as to save the number of pins of the light source array 110, and further save the number of connectors required for coupling the light source array 110 to the driving circuit 120 and the scanning circuit 130. Meanwhile, by using the scanning circuit 130, the backlight driving device 100 of the present embodiment may have an effect of saving the number of the driving circuits or a channel number the driving circuit.
For example, it is assumed that the light source array 110 has 4 columns and 3 rows of the backlight units 111, and when the backlight units of the second row of the light source array 110 receive the start pulse SP_2 in the scanning signal SS_2, each of the backlight units 111 of the second row of the light source array 110 is driven by each of the driving pulses DP_2 in the driving signals DS_1, DS_2, DS_3 and DS_4 corresponding to the same time interval. In this way, the light source array 110 may drive the backlight units of each row of the light source array 110 in time-division, and use the driving pulses in the driving signals to drive the backlight units 111 of different columns in partitions. Moreover, in the above example, the number of pins of the light source array 110 is 7 (4 shared driving lines and 3 shared scanning lines), so that the driving circuit 120 only requires 4 channels for coupling to the light source array 110, and the scanning circuit 130 only requires 3 channels for coupling to the light source array 110. Even more, the backlight driving device 100 only requires one connector having 4 pins and one connector having 3 pins for respectively coupling the driving circuit 120 and the scanning circuit 130 to the light source array 110. Namely, the circuit structure design of the backlight driving device 100 of the present embodiment may obviously decrease the number of the driving circuits, the scanning circuits or the connectors, so as to further save the mechanical space of the backlight driving device 100. Moreover, in the present embodiment, the time-division driving and partition driving refer to that all of or a part of the backlight units 111 in the light source array 110 can be driven in the same time interval or different time intervals according to a display effect required by the user or a device specification of the display device, which is not limited by the disclosure.
However, in the present embodiment, the number of the backlight units 111 (i.e. the number of the light-emitting regions) in the light source array 110 is not limited to the number shown in
Moreover, in the present embodiment, the backlight driving device 100 can be applied to display devices of any size and any type, for example, liquid crystal displays (LCD), thin-film transistor LCD (TFT-LCD) or Quantum Dot(QD) display, etc., which is not limited by the disclosure. Moreover, in the present embodiment, the driving circuit 120 may, for example, include a constant current regulator and a pulse width modulation (PWM) circuit, where the PWM circuit may modulate a constant current signal to output a plurality of consecutive and periodically varied pulses to serve as the driving signals of the disclosure. Moreover, in the present embodiment, the scanning circuit 130 is, for example, a central processing unit (CPU), a microcontroller (MCU), a timing controller, an oscillator, etc., or a combination thereof used for outputting the scanning signals of the disclosure, which is not limited by the disclosure.
Moreover, referring to
Moreover, in the present embodiment, a voltage magnitude of the driving voltage VLED are determined according to the number of the LEDs connected in series. For example, when a driving voltage required by each of the LEDs is 3V, and the driving circuit requires 0.5V, the driving voltage VLED is then 9.5V (3*3V+0.5V). However, the number of the serially connected LEDs configured in the backlight units is not limited to the number shown in
In the present embodiment, each of the backlight units 311 may include a first switch element SW and at least one LED DI. The backlight units of each column of the light source array 310 may respectively share a same driving line DL, such that the driving circuit 320 may respectively output eight driving signals DS_1, DS_2, DS_8 to the backlight units of each column of the light source array 110 through the driving line DL shared by the backlight units of each column. In the present embodiment, the eight driving signals DS_1, DS_2, DS_8 may have same waveform. In the present embodiment, the backlight units of each row of the light source array 310 may respectively share a same scanning line SL, such that the scanning circuit 330 may respectively output scanning signals SS_1, SS_2, SS_3 to the backlight units of each row of the light source array 110 through the scanning line SL shared by the backlight units of each row. In this way, the light source array 310 may drive the backlight units of each row in the light source array 310 in time-division.
In the present embodiment, the scanning signals SS_1, SS_2, SS_3 provided by the scanning circuit 330 may respectively have different start pulses SP_1, SP_2, SP_3, and the start pulses SP_1, SP_2, SP_3 may further respectively have different sub-start pulses adapted to be sequentially provided to the backlight units of each row, such that the backlight units of the same row may receive the different sub-start pulses.
To be specific,
Namely, referring to
It should be noted that, in the overall scanning signals, the number of the sub-start pulses is smaller than or equal to the number of columns of the light source array. Therefore, the number of the columns of the light source array may influence a time length occupied by the sub-start pulse in the start pulse of one cycle or a duty cycle of the sub-start pulse. For example, in the present embodiment, the light source array 310 of
Moreover, in the present embodiment, the number of the backlight units in the light source array 310 and the number of the LEDs in the backlight units are not limited to the numbers shown in
In the present embodiment, the backlight driving device 500 may also use the two scanning circuits 530_1, 530_2 to respectively implement local dimming. By increasing the scanning circuit, the number of the sub-start pulses in the start pulses respectively provided by the scanning circuits 530_1, 530_2 is only four. Namely, each row has 8 backlight units, and the scanning circuits 530_1, 530_2 are only required to provide four sub-start pulses to the backlight units of the same row. Therefore, in one start pulse, since the number of the required sub-start pulses is decreased by twice, a time length of the sub-start pulse is increased by twice, i.e. a time length of the sub-start pulse in one start pulse is increased. In other words, compared to the embodiment of applying only one scanning circuit, since the number of the sub-start pulses required to be provided by two scanning circuits in a fixed time length is decreased, the two scanning circuits may respectively provide more accurate sub-start pulses.
In the present embodiment, the backlight driving device 500 adopts two scanning circuits 530_1 and 530_2 to respectively implement local dimming. Namely, in the present embodiment, the number of pins of the light source array 510 is 14 (8 shared driving lines+3 scanning lines of the scanning zone Z1+3 scanning lines of the scanning zone Z2), so that the driving circuit 520 requires 8 channels for coupling to the light source array 510, and the scanning circuits 530_1, 530_2 respectively require 3 channels for coupling to the light source array 510. Moreover, the backlight driving device 500 only requires one connector with 8 pins and two connectors with 3 pins for respectively coupling the driving circuit 520 and the scanning circuits 530_1, 530_2 to the light source array 510.
Namely, compared to the conventional technique of pulling out a driving line from each of the backlight units for individually coupling to the driving circuit, the backlight driving device 500 of the present embodiment may obviously decrease the required driving circuits, and a performance requirement of the scanning circuit and the number of the connectors, and may support more number of the backlight units or the light-emitting regions, so as to achieve the effect of saving the mechanical space of the backlight driving device 500 and provide good resolution.
Moreover, in the present embodiment, the number of the backlight units in the light source array 510 is not limited to the number shown in
In summary, in the embodiments of the disclosure, the backlight driving device drives the backlight units in the light source array by using the driving circuit and the scanning circuit, and though the design of the driving signals and scanning signals, the backlight driving device of the disclosure may drive the backlight units of different rows of the light source array in time-division. In the embodiments of the disclosure, duty cycles of the pulses of the driving signals and the scanning signals applied to the backlight units, and distributed time intervals of the sub-start pulses in the scanning signals can be determined according to a display effect required by the user or a device specification of the display device. Moreover, the number of the connectors and the number of the driving circuits of the backlight driving device of the disclosure can be further decreased through the circuit design that the backlight units share the driving lines and the scanning lines. Moreover, the backlight driving device of the embodiments of the disclosure may implement scanning by dividing the light source array into two scanning zones, though in other embodiments of the disclosure, more scanning zones can be divided according to an actual requirement. In other embodiments of the disclosure, distribution locations of the driving signals and the scanning signals can also be exchanged, which is not limited by the disclosure.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.
Number | Date | Country | Kind |
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2016 1 0563099 | Jul 2016 | CN | national |
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20180018924 A1 | Jan 2018 | US |