CN109243377B - Backlight module, display panel and display device - Google Patents
Backlight module, display panel and display device Download PDFInfo
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- CN109243377B CN109243377B CN201811249928.8A CN201811249928A CN109243377B CN 109243377 B CN109243377 B CN 109243377B CN 201811249928 A CN201811249928 A CN 201811249928A CN 109243377 B CN109243377 B CN 109243377B
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- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
- G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
- G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
- G09G3/3406—Control of illumination source
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B20/00—Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
- Y02B20/40—Control techniques providing energy savings, e.g. smart controller or presence detection
Abstract
The embodiment of the invention provides a backlight module, a display panel and a display device, wherein the backlight module comprises: backplate, light source subassembly and the printed circuit board of setting on the backplate, printed circuit board includes: and the low-level signal generating circuit is used for generating a low-level signal according to the brightness of the light emitted by the light source component. According to the embodiment of the invention, the low-level signal generating circuit arranged on the printed circuit board can adjust the generated low-level signal in real time according to the brightness of light emitted by the light source assembly, and the thin film transistor is turned off in time, so that image residue caused by leakage current is avoided, and the display effect of the display device is ensured.
Description
Technical Field
The embodiment of the invention relates to the technical field of display, in particular to a backlight module, a display panel and a display device.
Background
A Liquid Crystal Display (LCD) is one of flat panel Display devices, and a Liquid Crystal Display panel and a backlight module are important components thereof. Specifically, backlight unit includes: the backlight, the liquid crystal display panel includes: the thin film transistor is turned on when the gate voltage is in the turn-on voltage range, and turned off when the gate voltage is in the turn-off range, and the gate voltage for turning off the thin film transistor is provided by a signal of a low-level signal terminal in the gate driving circuit.
The inventor researches and finds that the liquid crystal display device has larger and larger space for adjusting the brightness of the backlight source at present. After long-term use, the thin film transistor in the liquid crystal display panel is aged due to long-term irradiation of the backlight source, so that a signal provided by the low level signal end cannot timely turn off the thin film transistor to generate leakage current, and the leakage current can cause image residue of the liquid crystal display device, thereby affecting the display effect of the display device.
Disclosure of Invention
In order to solve the above technical problems, embodiments of the present invention provide a backlight module, a display panel and a display device, which can adjust a signal at a low level signal end in real time according to the brightness of light emitted by a light source assembly, so as to avoid image sticking caused by leakage current, and ensure the display effect of the display device.
In a first aspect, an embodiment of the present invention provides a backlight module, including: backplate, light source subassembly and the printed circuit board of setting on the backplate, printed circuit board includes: a low level signal generating circuit;
and the low level signal generating circuit is used for generating a low level signal according to the brightness of the light emitted by the light source component.
Optionally, the low-level signal generating circuit includes: a rectifier sub-circuit and a generator sub-circuit;
the rectifier sub-circuit is respectively connected with the signal input end and the node and is used for rectifying the signal provided by the signal input end to generate a voltage-stabilizing signal;
and the generating sub-circuit is respectively connected with the node and the signal output end and is used for generating a low-level signal according to the voltage-stabilizing signal and the brightness of the light emitted by the light source component.
Optionally, the rectifier sub-circuit comprises: the circuit comprises a first capacitor, a second capacitor, a third capacitor, a first diode, a second diode and a load resistor;
the first end of the first capacitor is connected with the signal input end, and the second end of the first capacitor is connected with the first pole of the first diode;
the first pole of the first diode is connected with the second pole of the second diode, and the second pole is connected with the node;
a second pole of the second diode is connected with a grounding end;
the first end of the second capacitor is connected with the node, and the second end of the second capacitor is connected with the grounding end;
the first end of the load resistor is connected with the node, and the second end of the load resistor is connected with the grounding end;
and the first end of the third capacitor is connected with the node, and the second end of the third capacitor is connected with the grounding end.
Optionally, the generating sub-circuit comprises: a first load and a second load;
the first end of the first load is connected with the node, and the second end of the first load is connected with the signal output end;
and the first end of the second load is connected with the signal output end, and the second end of the second load is connected with the grounding end.
Optionally, the generating sub-circuit comprises: the first load includes: a first resistor; the second load includes: a second resistor;
at least one of the first resistor and the second resistor is a photo-resistor.
Optionally, the photoresistor is disposed on one side of the printed circuit board close to the back plate, and an orthographic projection on the back plate is a hollow area, so that light emitted by the light source assembly irradiates the photoresistor.
Optionally, the rectifier sub-circuit comprises: the circuit comprises a first capacitor, a second capacitor, a third capacitor, a first diode, a second diode and a load resistor; the generation sub-circuit includes: a first load and a second load;
the first end of the first capacitor is connected with the signal input end, and the second end of the first capacitor is connected with the first pole of the first diode;
the first pole of the first diode is connected with the second pole of the second diode, and the second pole is connected with the node;
a second pole of the second diode is connected with a grounding end;
the first end of the second capacitor is connected with the node, and the second end of the second capacitor is connected with the grounding end;
the first end of the load resistor is connected with the node, and the second end of the load resistor is connected with the grounding end;
the first end of the third capacitor is connected with the node, and the second end of the third capacitor is connected with the grounding end;
the first end of the first load is connected with the node, and the second end of the first load is connected with the signal output end;
and the first end of the second load is connected with the signal output end, and the second end of the second load is connected with the grounding end.
Optionally, the input signal of the signal input terminal is a square wave signal.
In a second aspect, an embodiment of the present invention further provides a display panel, including: the backlight module is provided.
In a third aspect, an embodiment of the present invention provides a display device, including: the display panel is provided.
The embodiment of the invention provides a backlight module, a display panel and a display device, wherein the backlight module comprises: backplate, light source subassembly and the printed circuit board of setting on the backplate, printed circuit board includes: and the low-level signal generating circuit is used for generating a low-level signal according to the brightness of the light emitted by the light source component. According to the embodiment of the invention, the low-level signal generating circuit arranged on the printed circuit board can adjust the generated low-level signal in real time according to the brightness of light emitted by the light source assembly, and the thin film transistor is turned off in time, so that image residue caused by leakage current is avoided, and the display effect of the display device is ensured.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the example serve to explain the principles of the invention and not to limit the invention.
Fig. 1 is a side view of a backlight module according to an embodiment of the invention;
fig. 2 is a top view of a backlight module according to an embodiment of the invention;
fig. 3 is a schematic structural diagram of a low-level signal generating circuit according to an embodiment of the present invention;
fig. 4 is an equivalent circuit diagram of a rectifier sub-circuit provided in an embodiment of the present invention;
FIG. 5 is an equivalent circuit diagram of a generation sub-circuit provided in an embodiment of the present invention;
FIG. 6 is a top view of a backing plate according to an embodiment of the present invention;
fig. 7 is an equivalent circuit diagram of a low-level signal generating circuit according to an embodiment of the present invention;
FIG. 8 is a diagram illustrating a first stage of a low level signal generating circuit according to an embodiment of the present invention;
FIG. 9 is a diagram illustrating a second stage of the low level signal generating circuit according to the present invention;
fig. 10 is an operation timing diagram of the low-level signal generating circuit according to the embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.
The steps illustrated in the flow charts of the figures may be performed in a computer system such as a set of computer-executable instructions. Also, while a logical order is shown in the flow diagrams, in some cases, the steps shown or described may be performed in an order different than here.
Unless defined otherwise, technical or scientific terms used in the disclosure of the embodiments of the present invention should have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. The use of "first," "second," and similar language in the embodiments of the present invention does not denote any order, quantity, or importance, but rather the terms "first," "second," and similar language are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.
Example one
Fig. 1 is a side view of a backlight module according to an embodiment of the present invention, and fig. 2 is a top view of the backlight module according to the embodiment of the present invention, as shown in fig. 1 and fig. 2, the backlight module according to the embodiment of the present invention includes: a back sheet 10, a light source assembly 20, and a printed circuit board 30 disposed on the back sheet 10, the printed circuit board 30 including: a low-level signal generation circuit 31; the low level signal generating circuit 31 generates a low level signal according to the brightness of the light emitted from the light source module.
Specifically, the backlight module further includes: a reflective sheet, a light guide plate, a diffusion sheet, and a prism sheet (not shown). Wherein, the light source subassembly is used for providing the incident light, and the reflector plate is used for reusing the partial light that reflects back, has reduced the loss of light, has improved the light utilization ratio, and the light guide plate is used for leading out the light that the light source subassembly launches, and the diffusion piece is used for diffusing the light that the light guide plate was derived, guarantees the even of light, and the prism piece is used for assembling the light of diffusion piece diffusion to improve the luminance of light.
Optionally, the back plate 10 may be made of a metal material or other materials, which is not limited in this embodiment of the invention.
Optionally, the light source assembly 20 comprises: a Light Emitting Diode (LED), or a Cold Cathode Fluorescent Lamp (CCFL).
Alternatively, the printed circuit board 30 may be a rigid printed circuit board or a flexible printed circuit board, which is not limited in this embodiment of the present invention.
The backlight module provided by the embodiment of the invention comprises: backplate, light source subassembly and the printed circuit board of setting on the backplate, printed circuit board includes: and the low-level signal generating circuit is used for generating a low-level signal according to the brightness of the light emitted by the light source component. According to the embodiment of the invention, the low-level signal generating circuit arranged on the printed circuit board can adjust the generated low-level signal in real time according to the brightness of light emitted by the light source assembly, and the thin film transistor is turned off in time, so that image residue caused by leakage current is avoided, and the display effect of the display device is ensured.
Optionally, fig. 3 is a schematic structural diagram of a low-level signal generating circuit according to an embodiment of the present invention, and as shown in fig. 3, the low-level signal generating circuit includes: a rectifier sub-circuit and a generator sub-circuit; the rectifying sub-circuit is respectively connected with the signal INPUT end INPUT and the node N and is used for rectifying the signal provided by the signal INPUT end INPUT to generate a voltage-stabilizing signal; and the generating sub-circuit is respectively connected with the node N and the signal OUTPUT end OUTPUT and is used for generating a low-level signal according to the voltage-stabilizing signal and the brightness of light emitted by the light source assembly.
Optionally, the INPUT signal of the signal INPUT is a square wave signal.
Optionally, fig. 4 is an equivalent circuit diagram of a rectifying sub-circuit provided in an embodiment of the present invention, and as shown in fig. 4, the rectifying sub-circuit includes: the circuit comprises a first capacitor C1, a second capacitor C2, a third capacitor C3, a first diode D1, a second diode D2 and a load resistor R.
Specifically, a first end of the first capacitor C1 is connected to the signal INPUT terminal INPUT, and a second end is connected to a first pole of the first diode D1; a first pole of the first diode D1 is connected to a second pole of the second diode D2, which is connected to the node N; the second diode D2 has a second pole connected to the ground GND; a first end of the second capacitor C2 is connected to the node N, and a second end thereof is connected to the ground GND; the first end of the load resistor R is connected with the node N, and the second end of the load resistor R is connected with the ground end GND; a first terminal of the third capacitor C3 is connected to the node N, and a second terminal thereof is connected to the ground GND.
It should be noted that fig. 4 specifically shows an exemplary structure of the rectifier sub-circuit. Those skilled in the art will readily appreciate that the implementation of the rectifier sub-circuits is not limited thereto, as long as their respective functions can be achieved.
Specifically, the first capacitor C1, the second capacitor C2, the first diode D1, the second diode D2 and the load resistor R are equivalent to a negative-voltage half-wave rectifier circuit, and are used for rectifying the square-wave signal to generate a regulated voltage signal, and the third capacitor C3 is used for ensuring the stability of the regulated voltage signal.
Optionally, fig. 5 is an equivalent circuit diagram of the generating sub-circuit provided in the embodiment of the present invention, and as shown in fig. 5, the generating sub-circuit includes: a first load and a second load; the first end of the first load is connected with the node N, and the second end of the first load is connected with the signal OUTPUT end OUTPUT; the first terminal of the second load is connected to the signal OUTPUT terminal OUTPUT, and the second terminal thereof is connected to the ground terminal GND.
As shown in fig. 5, the first load includes: the first resistance R1, the second load includes: and a second resistor R2.
Optionally, at least one of the first resistor R1 and the second resistor R2 is a photo resistor, where when the first resistor R1 is a photo resistor, the second resistor R2 may be a photo resistor or a fixed resistor, and when the second resistor R2 is a photo resistor, the first resistor R1 may be a photo resistor or a fixed resistor, which is not limited in this embodiment of the present invention.
Optionally, the photo-resistor is disposed on one side of the printed circuit board close to the back plate, and an orthographic projection on the back plate is a hollow area, so that light emitted by the light source assembly irradiates the photo-resistor, fig. 6 is a top view of the back plate provided in the embodiment of the present invention, and as shown in fig. 6, a position 11 on the back plate corresponding to the photo-resistor is the hollow area.
It should be noted that the shape of the hollow-out area may be a blank area, a grid, or the like, as long as the light emitted by the light source assembly can irradiate the photoresistor, and the embodiment of the present invention is not limited in this respect.
It should be noted that fig. 5 specifically shows an exemplary structure of the generation sub-circuit. Those skilled in the art will readily appreciate that the implementation of the generation sub-circuits is not so limited as long as their respective functions can be implemented.
Specifically, the photoresistor in the embodiment of the invention receives light emitted by the light source component, samples the light, converts the change of different brightness into the resistance change of the photoresistor, and further adjusts the OUTPUT signal of the signal OUTPUT terminal OUTPUT.
Assume that the voltage at node N is VNThe voltage of the OUTPUT signal of the signal OUTPUT end OUTPUT is VGL, and the resistance value of the first resistor is R1The resistance value of the second resistor is R2Wherein V isNFor a fixed value, VGL satisfies the formula VGL ═ VN/(1+R2/R1) VGL requires a voltage equal to the off signal required for the thin film transistor. The voltage of the off signal required for the thin film transistor is determined based on a thin film transistor specific curve corresponding to different light intensities stored in advance in the display device and the threshold voltage of the thin film transistor.
When V isNis-18V, when the brightness of the light source assembly is increased and the illumination intensity is E1, the voltage of the turn-off signal required by the thin film transistor can be known to be-15V according to the specific curve of the thin film transistor corresponding to different illumination intensities and the threshold voltage of the thin film transistor, and at this time, as long as the resistance ratio of the two resistors satisfies R2/R1VGL is equal to-15V at 0.2; when the brightness of the light source assembly is reduced and the illumination intensity is E2, the voltage of the turn-off signal required by the TFT can be known to be-10V according to the specific curve and the threshold voltage of the TFT corresponding to different illumination intensities, and at this time, as long as the resistance ratio of the two resistors meets R2/R1VGL is equal to-10V at 0.8.
When the display device is manufactured, the voltage of the node N and the voltage of a turn-off signal required by the thin film transistor under a certain illumination intensity are fixed values, and the corresponding relation between the illumination intensity of the photoresistor and the resistance is also determined. Specifically, the photoresistor provided in the display device needs to be determined according to the tft specific curve corresponding to different illumination intensities, the threshold voltage of the tft, and the formula VGL ═ VN/(1+R2/R1) Optionally, the selected corresponding relationship between the illumination intensity of the photoresistor and the resistance should be such that when the illumination intensity is E, the voltage of the OUTPUT signal of the signal OUTPUT terminal OUTPUT is equal to the illumination intensity of E, and the voltage of the turn-off signal required by the thin film transistor is determined according to the specific curve of the thin film transistor corresponding to different illumination intensities and the threshold voltage of the thin film transistor. For the above example, the correspondence between the light intensity of the photoresistor and the resistance needs to satisfy: when the illumination intensity is E1, the resistance value of the second resistor R2 satisfies R2＝0.2R1When the illumination intensity is E2, the resistance value R of the second resistor R2 is2＝0.8R1。
In addition, it should be noted that the resistance of the photo resistor decreases as the intensity of light increases.
Specifically, the voltage of the off signal required by the thin film transistor is-10V or-15V, which means that when the voltage of the signal applied to the gate of the thin film transistor is-10V or-15V, the thin film transistor is turned off, and the thin film transistor does not generate leakage current; on the contrary, if the voltage applied to the gate of the thin film transistor is lower than-10V or-15V, the thin film transistor cannot be turned off, that is, the thin film transistor is still turned on, and at this time, the thin film transistor may generate a leakage current.
It should be noted that, whether the tft generates a leakage current or not may affect the deflection of the liquid crystal molecules of the liquid crystal display panel, and specifically, when the tft does not generate a leakage current, the voltage of the pixel electrode connected to the drain electrode of the tft may not be affected, and the deflection state of the liquid crystal molecules in the liquid crystal display panel may not be affected, so as to achieve an optimal deflection angle for achieving a display effect, thereby ensuring the display effect. When the thin film transistor generates a leakage current, the voltage of the pixel electrode connected to the drain electrode of the thin film transistor is affected, so that the liquid crystal molecules in the liquid crystal display panel are incompletely deflected, thereby causing image sticking of the liquid crystal display device.
Specifically, the voltage of the off signal required by the tft is related to the brightness of the light source module, and the higher the brightness of the light source module is, the larger the voltage amplitude of the off signal required by the tft is, and the higher the brightness of the light source module is, the smaller the voltage amplitude of the off signal required by the tft is. It should be noted that the magnitude of the leakage current generated by the tft which cannot be turned off in time is not related to the brightness of the light source module, but is related to the signal connected to the source and drain of the tft.
In addition, fig. 7 is an equivalent circuit diagram of a low-level signal generating circuit according to an embodiment of the present invention, and as shown in fig. 7, the rectifying sub-circuit includes: the circuit comprises a first capacitor C1, a second capacitor C2, a third capacitor C3, a first diode D1, a second diode D2 and a load resistor R; the generating sub-circuit comprises: a first load and a second load.
Specifically, a first end of the first capacitor C1 is connected to the signal INPUT terminal INPUT, and a second end is connected to a first pole of the first diode D1; a first pole of the first diode D1 is connected to a second pole of the second diode D2, which is connected to the node N; the second diode D2 has a second pole connected to the ground GND; a first end of the second capacitor C2 is connected to the node N, and a second end thereof is connected to the ground GND; the first end of the load resistor R is connected with the node N, and the second end of the load resistor R is connected with the ground end GND; a first end of the third capacitor C3 is connected to the node N, and a second end thereof is connected to the ground GND; the first end of the first load is connected with the node N, and the second end of the first load is connected with the signal OUTPUT end OUTPUT; the first terminal of the second load is connected to the signal OUTPUT terminal OUTPUT, and the second terminal thereof is connected to the ground terminal GND.
The technical solution provided by the embodiment of the present invention is further explained by the working process of the low-level signal generating circuit.
Fig. 8 is an operating state diagram of a first stage of a low-level signal generating circuit according to an embodiment of the present invention, fig. 9 is an operating state diagram of a second stage of the low-level signal generating circuit according to the embodiment of the present invention, and fig. 10 is an operating timing diagram of the low-level signal generating circuit according to the embodiment of the present invention, as shown in fig. 7 to 10, the low-level signal generating circuit according to the embodiment of the present invention includes 2 diodes (D1 and D2), 3 capacitors (C1, C2 and C3), 3 resistors (R, R1 and R2), 1 signal INPUT terminal (INPUT), 1 signal OUTPUT terminal (OUTPUT) and 1 ground terminal (GND).
The INPUT signal of the signal INPUT terminal INPUT is a square wave signal with a positive amplitude.
Specifically, the method comprises the following steps:
in the first stage T1, the INPUT signal at the signal INPUT terminal INPUT is at a high level, the INPUT signal at the signal INPUT terminal INPUT is coupled to the cathode of the first diode D1 through the first capacitor C1, the first diode D1 is in a reverse bias and is turned off, the second diode D2 is in a forward bias and is turned on, the INPUT signal at the signal INPUT terminal INPUT forms a loop through the first capacitor C1 and the second diode D2, and charges the first capacitor C1, at this time, the voltage at the end of the first capacitor C1 close to the signal INPUT terminal INPUT is higher than the voltage at the end of the first capacitor C1 away from the signal INPUT terminal INPUT, and the current flows as shown in fig. 8.
In the second stage T2, the INPUT signal at the signal INPUT terminal INPUT is at low level, and cannot change abruptly due to the discharge of the first capacitor C1, and at this time, the voltage of the end of the first capacitor C1 away from the signal INPUT terminal INPUT is lower than the voltage of the end of the first capacitor C1 close to the signal INPUT terminal INPUT, the second diode D2 is under reverse bias and is turned off, the first diode D1 is under forward bias and is turned on, at this time, the first capacitor C1 is rectified by the first diode D1, and the second capacitor C2 is used for filtering, so as to obtain a regulated signal with a negative voltage, and the current flows as shown in fig. 9, at this time, the photoresistors in the first resistor R1 and the second resistor R2 receive and sample the light emitted by the light source component, and convert the change of different brightness into the resistance change of the photoresistors, and then the OUTPUT signal of the signal OUTPUT terminal OUTPUT is adjusted, so that the OUTPUT signal of the signal OUTPUT terminal OUTPUT can close the thin film transistor.
It should be noted that the output signal is sampled by the load resistor R, and processed by the internal circuit, and then the duty ratio of the pulse of the output signal is controlled to realize voltage stabilization, and the voltage stabilization signal can be obtained by repeating the above steps.
Example two
Based on the inventive concept of the above embodiments, an embodiment of the present invention further provides a display panel, including: backlight unit and display substrate.
The display panel is a liquid crystal display panel and is arranged on the light emergent side of the backlight module. Specifically, the backlight module provided by the embodiment of the invention is used for providing backlight for the display panel, and the light emitting effect of the backlight module directly influences the display effect of the display module. It should be noted that the backlight module may be of a side-in type or a direct-out type, and the embodiment of the invention is not limited thereto.
The backlight module is similar to the backlight module provided in the first embodiment, and the implementation principle and the implementation effect thereof are not described herein again.
EXAMPLE III
Based on the inventive concept of the above embodiments, an embodiment of the present invention further provides a display device, including: a display panel.
Specifically, the display device is a liquid crystal display device, and optionally, the display device may be: any product or component with a display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator and the like.
The drawings of the embodiments of the invention only relate to the structures related to the embodiments of the invention, and other structures can refer to common designs.
In the drawings used to describe embodiments of the invention, the thickness and dimensions of layers or microstructures are exaggerated for clarity. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, it can be "directly on" or "under" the other element or intervening elements may be present.
Without conflict, features of embodiments of the present invention, that is, embodiments, may be combined with each other to arrive at new embodiments.
Although the embodiments of the present invention have been described above, the above description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (8)
1. A backlight module, comprising: backplate, light source subassembly and the printed circuit board of setting on the backplate, printed circuit board includes: a low level signal generating circuit;
the low level signal generating circuit is used for generating a low level signal according to the brightness of the light emitted by the light source component;
the low-level signal generating circuit includes: a generation sub-circuit, the generation sub-circuit comprising: a first load and a second load; the first load includes: a first resistor; the second load includes: a second resistor; at least one of the first resistor and the second resistor is a photoresistor;
the photoresistor is arranged on one side, close to the back plate, of the printed circuit board, and the orthographic projection on the back plate is a hollow area, so that light emitted by the light source assembly irradiates on the photoresistor.
2. The backlight module according to claim 1, wherein the low level signal generating circuit further comprises: a rectifier sub-circuit;
the rectifier sub-circuit is respectively connected with the signal input end, the node and the grounding end and is used for rectifying the signal provided by the signal input end to generate a voltage-stabilizing signal;
and the generating sub-circuit is respectively connected with the node, the signal output end and the grounding end and is used for generating a low-level signal according to the voltage-stabilizing signal and the brightness of the light emitted by the light source component.
3. The backlight module according to claim 2, wherein the rectifying sub-circuit comprises: the circuit comprises a first capacitor, a second capacitor, a third capacitor, a first diode, a second diode and a load resistor;
the first end of the first capacitor is connected with the signal input end, and the second end of the first capacitor is connected with the first pole of the first diode;
the first pole of the first diode is connected with the second pole of the second diode, and the second pole is connected with the node;
a second pole of the second diode is connected with a grounding end;
the first end of the second capacitor is connected with the node, and the second end of the second capacitor is connected with the grounding end;
the first end of the load resistor is connected with the node, and the second end of the load resistor is connected with the grounding end;
and the first end of the third capacitor is connected with the node, and the second end of the third capacitor is connected with the grounding end.
4. The backlight module according to claim 2, wherein the first terminal of the first load is connected to the node, and the second terminal thereof is connected to the signal output terminal;
and the first end of the second load is connected with the signal output end, and the second end of the second load is connected with the grounding end.
5. The backlight module according to any one of claims 2-4, wherein the rectifier sub-circuit comprises: the circuit comprises a first capacitor, a second capacitor, a third capacitor, a first diode, a second diode and a load resistor; the generation sub-circuit includes: a first load and a second load;
the first end of the first capacitor is connected with the signal input end, and the second end of the first capacitor is connected with the first pole of the first diode;
the first pole of the first diode is connected with the second pole of the second diode, and the second pole is connected with the node;
a second pole of the second diode is connected with a grounding end;
the first end of the second capacitor is connected with the node, and the second end of the second capacitor is connected with the grounding end;
the first end of the load resistor is connected with the node, and the second end of the load resistor is connected with the grounding end;
the first end of the third capacitor is connected with the node, and the second end of the third capacitor is connected with the grounding end;
the first end of the first load is connected with the node, and the second end of the first load is connected with the signal output end;
and the first end of the second load is connected with the signal output end, and the second end of the second load is connected with the grounding end.
6. The backlight module as claimed in claim 2, wherein the input signal of the signal input terminal is a square wave signal.
7. A display panel, comprising: a backlight module according to any of claims 1 to 6.
8. A display device, comprising: the display panel of claim 7.
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| US11889600B2 (en) | 2021-12-15 | 2024-01-30 | Tcl China Star Optoelectronics Technology Co., Ltd. | Backlight module, display panel and display control method thereof, and display device |
| CN114242012B (en) * | 2021-12-15 | 2023-06-27 | Tcl华星光电技术有限公司 | Backlight module, display panel, display control method of display panel and display device |
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