This application claims priority to Taiwanese Patent Application No. 104101604 filed on Jan. 19, 2015, the contents of which are incorporated by reference herein.
The subject matter herein generally relates to a display apparatus and a backlight driving module.
A display apparatus includes a backlight module, a driving module, and a power circuit. The driving module receives an external pulse width modulating (PWM) signal and transmits the signal to the power circuit. The power circuit outputs a working current for driving the backlight module based on the PWM signal. The driving module calculates a working cycle of the PWM signal and adjusts the PWM signal to be in a high frequency range with the constant calculated working cycle of the PWM signal to avoid audio noise being generated in the driving process and for the backlight module to remain at a predetermined brightness. Based on the calculating process, the backlight module may be lit after a certain time.
Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features. The description is not to be considered as limiting the scope of the embodiments described herein.
The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series and the like.
The present disclosure is described in relation to a display apparatus for preventing damage to a driving circuit.
The receiving module 10 receives a pulse width modulating (PWM) signal from an external component. In at least one embodiment, the PWM signal is combined by a first level signal and a second level signal in turn. The first level voltage is logic high voltage level and the second level voltage is logic low voltage level. A frequency of the PWM signal is between 100 Hz-20 kHz. The receiving module 10 receives the PWM signal from a sequence controlling chip.
The processing module 20 connects between the receiving module 10 and the selecting module 40. The processing module 20 can be configured to process the PWM signal in a predetermined time duration. The processing module 20 adjusts the PWM signal, and simultaneously outputs the adjusted signal and a selecting signal to the selecting module 40 after the predetermined time duration. The processing module 20 includes an operating unit 21, a PWM generating unit 23, and a timing unit 25.
The operating unit 21 connects the receiving module 10 and the PWM generating unit 23. The operating module 21 calculates a working cycle of the PWM signal in a first time duration, and outputs the calculated working cycle to the PWM generating unit 23.
The PWM generating unit 23 connects with the operating unit 21, the timing unit 25, and the selecting module 40. The PWM generating unit 23 outputs a timing signal to the timing unit 25 when receiving the calculated working cycle, and adjusts the PWM signal to form the adjusted signal with the calculated working cycle to the selecting module 40. In at least one embodiment, the adjusted signal is a PWM signal. A frequency of the adjusted signal is greater than the frequency of the PWM signal. In one example, and the frequency of the adjusted signal is beyond 20 kHz.
The timing unit 25 is connected to the receiving module 10, the PWM generating unit 23, and the selecting module 40. The timing unit 25 receives the PWM signal, and times a waiting duration in response to the timing signal output by the PWM generating unit 23. The timing unit 25 further generates a selecting signal to the selecting module 40 when the waiting duration exceeds a second time duration. The second time duration is a switching time of the first level signal of the received PWM signal from the receiving module 102 firstly switched into the second level signal when the timing signal is received. In at least one embodiment, the timing unit 25 is a counter.
The selecting module 40 connects with the receiving module 10, the timing unit 25, the PWM generating unit 23, and the power circuit 60. The selecting module 40 receives PWM signal from the receiving module 10, a selecting signal from the timing unit 25, and the adjusted signal from the PWM generating unit 23. When only receiving the PWM signal from the receiving module 10, the selecting module 40 outputs the unadjusted PWM signal to the power circuit 60. When simultaneously receiving the PWM signal from the receiving module 10, the adjusted signal from the PWM generating unit 23, and the selecting signal from the timing unit 25, the selecting module can be further configured to output the adjusted signal to the power circuit 60. In at least one embodiment, the predetermined time duration is a sum of the first time duration and the second time duration. The working cycle of the unadjusted PWM signal and the adjusted PWM signal are the same. The selecting module 40 is a multiplexer.
The power circuit 60 connects the selecting module 40 and the backlight module 80. The power circuit 60 outputs a first driving current based on the unadjusted PWM signal, and outputs a second driving current based on the adjusted signal. In at least one embodiment, the first driving current and the second driving current have a common working cycle.
The backlight module 80 connects with the power circuit 60. The backlight module 80 emits light with a predetermined brightness based on the first driving current or the second driving current.
The selecting module 40 outputs unadjusted PWM signal based upon input from the receiving module 10 to the power circuit 60 while the processing module 20 processing the PWM signal received from the receiving module 10. The power circuit 60 outputs a first driving signal based upon input from the selecting module 40 to the backlight module 80, thus the backlight module 80 emits lights while the processing module 20 processing the PWM signal received from the receiving module 10. Using the presented technology, the time of the backlight module 80 to be lighted is improved and the backlight module 80 remains at a constant brightness.
The operating unit 31 is connected to the receiving module 10, the DAC unit 32, and a timing unit 34. The operating module 31 calculates a working cycle of the PWM signal in a first time duration, and outputs a timing signal to the timing unit 34 after the first time duration.
The DAC unit 32 connects the operating unit 31 and the selecting module 40. The DAC unit 32 outputs an adjusted signal based on the calculated working cycle and the PWM signal to the selecting module 40. In at least one embodiment, the adjusted signal is an analog signal with a constant value.
The timing unit 34 connects with the receiving module 10, the operating unit 31, and the selecting module 40. The timing unit 34 times a waiting duration in response to the timing signals, and generates a selecting signal when the waiting duration exceeds a second time duration. The second time is a time of the first switching of the first level signal of the PWM signal to the second level signal while receiving the timing signal. In at least one embodiment, the timing unit 34 is a counter.
The selecting module 40 is connected to the receiving module 10, the timing unit 34, the DAC unit 32, and the power circuit 60. The selecting module 40 outputs the unadjusted PWM signal to the power circuit 60 in the predetermined time duration when there is no selecting signal received. After the predetermined time duration, the selecting module 40 simultaneously receives the PWM signal, the adjusted signal, and the selecting signal, and outputs the adjusted signal to the power circuit 60. In at least one embodiment, the predetermined time duration is a sum of the first time duration and the second time duration. The adjusted signal is constant value.
The power circuit 60 connects between the selecting module 40 and the backlight module 80. The power circuit 60 outputs a first driving current based on the unadjusted PWM signal, and outputs a second driving current based on the adjusted signal. In at least one embodiment, the first driving current is a PWM signal with a common working cycle, and the second driving current is a constant value.
The backlight module 80 connects with the power circuit 60. The backlight module 80 emits light with a predetermined brightness based on the first driving current or the second driving current.
The selecting module outputs unadjusted PWM signal based upon input from the receiving module to the power circuit while the processing module processing the PWM signal received from the receiving module. The power circuit outputs a first driving signal based upon input from the selecting module to the backlight module, thus the backlight module emits lights while the processing module processing the PWM signal received from the receiving module. Using the presented technology, the time of the backlight module to be lighted is improved and the backlight module remains at a constant brightness.
While various exemplary and preferred embodiments have been described, the disclosure is not limited thereto. On the contrary, various modifications and similar arrangements (as would be apparent to those skilled in the art) are intended to also be covered. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
Number | Date | Country | Kind |
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104101604 | Jan 2015 | TW | national |