Display control circuit and display
By introducing a current compensation module and a judgment module into the display control circuit to detect and compensate the leakage current phenomenon of the dual-gate transistor, the problems of high strobe adjustment and high quality requirements in the prior art are solved, and a better display effect is achieved.
Patent Information
- Application Number
- CN202420584113.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-25
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2034-03-25
AI Technical Summary
The existing adjustment method to reduce strobes requires precise control of the level value of a certain node. It is difficult to fine-tune control, and the quality of circuit components is high, making it difficult to achieve.
A control circuit for a display is designed, including a current compensation module, a judgment module, a light emitting module, a dual gate transistor, a buffer module and a driving transistor. By comparing the common node voltage of the dual gate transistor with the standard voltage, a current compensation signal is generated when the threshold value exceeds, and a compensation current is introduced to reduce strobes.
By accurately compensating for the working defects of the dual-gate transistor, the video flashable phenomenon of the display device in specific situations is significantly reduced and the display effect is improved.
Smart Images
Figure CN222507133U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of displays, and in particular relates to a control circuit of a display and a display. Background Art
[0002] The display control circuit is an electronic circuit used to control and drive the operation of various display devices (such as LEDs, liquid crystal displays, etc.). The display control circuit usually includes an input port, an output port, and a control logic unit. The input port receives the control signal from the external device, and the control logic unit controls the brightness, color, scanning and other parameters of the display device through the output port according to the requirements of the input signal, thereby realizing the control of the display effect.
[0003] The design of the display control circuit usually takes into account the operating characteristics of the display device, such as operating voltage, current, refresh rate, etc., to ensure that each pixel unit in the display device achieves the expected display effect. For each pixel unit, the corresponding transistor can be driven based on the voltage provided by the driving circuit. However, when the display driving circuit operates at a low frequency, the transistor may have leakage current and other phenomena. The leakage current will cause the brightness of the display to change. When too many transistors have leakage current, visible flicker will occur.
[0004] Existing methods to eliminate visible flicker include, for example, improving the voltage holding capacity of the storage capacitor to stabilize its voltage under long-term operation; or adjusting the size of the common voltage Vcom of the TFT substrate to improve the symmetry between the positive and negative voltages and Vcom, reduce the brightness difference between the positive and negative polarities, and thus reduce flicker. However, existing adjustment methods often require precise control of the level value of a certain node, which is difficult to fine-tune and has high requirements on the quality of circuit components, making it difficult to achieve. Utility Model Content
[0005] The purpose of the embodiments of the present application is to provide a display driving circuit, aiming to solve the problem that the existing adjustment method for reducing flicker often requires precise control of the level value of a certain node, which makes fine-tuning control difficult, has high requirements on the quality of circuit components, and is difficult to implement.
[0006] The embodiment of the present application is implemented by providing a control circuit of a display, the control circuit comprising:
[0007] Current compensation module, judgment module, light emitting module, dual-gate transistor, cache module and driving transistor;
[0008] The dual gate end of the dual gate transistor is connected to the signal source, the first end of the dual gate transistor is connected to the first end of the driving transistor, the second end of the dual gate transistor is connected to the gate of the driving transistor, the second end of the driving transistor is connected to the second end of the cache module, the first end of the cache module is connected to the voltage source, and the second end of the cache module is also connected to the data source, the common node of the two transistors in the dual gate transistor is connected to the first end of the judgment module, the second end of the judgment module is connected to the gate of the driving transistor, the third end of the judgment module is connected to the first end of the current compensation module, the second end of the current compensation module is connected to the light emitting module, and the second end of the judgment module is connected to the light emitting module.
[0009] Preferably, the current compensation module is further provided with a third terminal, and the third terminal of the current compensation module is connected to a current source for introducing a compensation current into the light-emitting module.
[0010] Preferably, the judgment module includes at least a voltage comparison unit and a PWM signal control unit, the voltage comparison unit is used to compare the voltage value of the common node of the two transistors in the dual-gate transistor with a standard voltage value, and when the comparison result exceeds a threshold value, the PWM signal control unit is controlled to generate a current compensation signal for the current compensation module to introduce a compensation current into the light-emitting module.
[0011] Preferably, the control circuit includes at least two working states, namely a reading state and an output state. The reading state is used to read the voltage signal input by the voltage source, and the output state is used to control the light-emitting module to emit light.
[0012] Preferably, the control circuit changes its own working state based on the timing characteristics of the signal source, the data source and the voltage source input signal.
[0013] Preferably, the light emitting module comprises at least one light emitting diode.
[0014] Preferably, the signal source is used to input a scan control signal to control the on-off status of the dual-gate transistor.
[0015] Another object of an embodiment of the present application is to provide a display, wherein a light emitting module of the display is controlled based on the control circuit as described above.
[0016] Preferably, the display further includes a communication module, a RAM module, a ROM module, a sound / image decoding module, an I / O interface, a liquid crystal screen component, an audio module and a processing unit; and the control circuit is arranged in the processing unit.
[0017] A display driving circuit provided in an embodiment of the present application has the advantages of: through coordinated control of a current compensation unit, a voltage comparison unit, etc., the working defects of the dual-gate transistor are accurately compensated and regulated, which greatly reduces the visible flicker that may occur in the display device under certain circumstances, so that the display device has a better display effect. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 A schematic diagram of a display provided in an embodiment of the present application;
[0019] Figure 2 A simplified circuit diagram of a control circuit of a display provided in an embodiment of the present application;
[0020] Figure 3 A schematic diagram of a judgment module provided in an embodiment of the present application;
[0021] Figure 4 A signal timing diagram provided for an embodiment of the present application. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.
[0023] As used herein, "coupled" or "connected" may refer to two or more elements making direct physical or electrical contact with each other, or making indirect physical or electrical contact with each other, or may refer to two or more elements operating or acting on each other. The term "circuit" generally refers to an object composed of one or more transistors and / or one or more active and passive components connected in a certain manner to process signals.
[0024] However, those skilled in the art will appreciate that the same element may be referred to by different names. This application does not distinguish elements by name, but by functional differences.
[0025] In addition, the embodiments of the present application include features of multiple specific embodiments and method steps and their sequences for constructing and operating these specific embodiments. However, other specific embodiments may also be used to achieve the same or equivalent functions and step sequences. Unless otherwise defined in this specification, the meanings of scientific and technical terms used herein are the same as those understood and used by technicians in the field to which this application belongs. In addition, singular nouns used in this specification include plural forms of the nouns, and plural nouns used also include singular forms of the nouns, unless otherwise conflicting with the context.
[0026] The specific implementation of the present application is described in detail below in conjunction with specific embodiments.
[0027] like Figure 1 As shown, it is a structural diagram of a display provided by an embodiment of the present application, including a processing unit, a liquid crystal screen component and other structures, wherein the processing unit can be a single-chip microcomputer or a dedicated control chip, etc. The control circuit of the display of this solution can be set in the processing unit, or in the logic board in the liquid crystal screen component, and connected to the processing unit through a bus to control the liquid crystal screen display. The specific location of the circuit setting is not limited here.
[0028] like Figure 2 As shown, a control circuit of a display is provided, the control circuit comprising:
[0029] A current compensation module, a judgment module, a light-emitting module, a dual-gate transistor, a cache module and a driving transistor; the dual-gate end of the dual-gate transistor is connected to a signal source, the first end of the dual-gate transistor is connected to the first end of the driving transistor, the second end of the dual-gate transistor is connected to the gate of the driving transistor, the second end of the driving transistor is connected to the second end of the cache module, the first end of the cache module is connected to a voltage source, the second end of the cache module is also connected to a data source, the common node of the two transistors in the dual-gate transistor is connected to the first end of the judgment module, the second end of the judgment module is connected to the gate of the driving transistor, the third end of the judgment module is connected to the first end of the current compensation module, the second end of the current compensation module is connected to the light-emitting module, and the second end of the judgment module is connected to the light-emitting module.
[0030] The display device is imaged by several pixel units, and a signal and / or voltage can be provided to the display to display the corresponding image, and the signal of the image is provided by the display drive / control circuit. By controlling the frame output from the display control circuit, a data voltage or current corresponding to the brightness and / or color of the image to be displayed is provided to multiple pixels simultaneously or successively. For each pixel unit, a driving transistor can be driven based on the data voltage or current provided from the display control circuit. When driving a display unit, such as some light-emitting diodes, the light-emitting diode can emit light with a specific brightness specification. The value of its luminous brightness can be determined by the voltage difference between the source electrode of the driving transistor and the gate electrode of the driving transistor.
[0031] Those skilled in the art will know that Figure 2Only the core components of the present application are shown in the figure. Each branch in the figure may be provided with components such as capacitors and resistors, which are not all shown here. In the embodiment of the present application, the voltage source is VDD, the data source is DATA, the signal source is SS, Vs can be a standard voltage for providing a reference value of the comparison voltage, M1 is a driving transistor, and M2 is a dual-gate transistor, which is used to control light emission. Since the signal source is connected to the input end of the dual-gate transistor to control its conduction, the data source can be written into the gate of the driving transistor through its connection method.
[0032] In the embodiment of the present application, the potential value of the gate of the driving transistor and the common end of the two transistors in the dual-gate transistor are first judged against the standard voltage value through a judgment module. When the difference exceeds a preset threshold value, it indicates that a more obvious leakage current or offset phenomenon has occurred, that is, a compensation current is introduced into the current compensation module to change the power supply to the light-emitting module, thereby achieving the effect of reducing visible flicker.
[0033] Since the current value output by the gate of the driving transistor may drift due to its operating temperature or inaccurate input voltage value, and the dual-gate transistor may have leakage current, the present solution detects and compensates for them separately through the set current compensation unit, thereby achieving the reduction of the flicker phenomenon and improving the display effect of the display.
[0034] As a preferred embodiment of the present application, the current compensation module is further provided with a third terminal, and the third terminal of the current compensation module is connected to a current source for introducing a compensation current into the light-emitting module.
[0035] In the embodiment of the present application, the compensation current is introduced by a separate current source, which does not affect the working state of the original circuit structure. The introduced current may also include a number of filter units for removing clutter.
[0036] As another preferred embodiment of the present application, the judgment module is used to compare the voltage value of the common node of the two transistors in the dual-gate transistor with the standard voltage value, and when the comparison result exceeds a threshold, control the current compensation module to generate a compensation current, and introduce the compensation current into the light-emitting module.
[0037] In the embodiment of the present application, an additional standard voltage input is used to improve the accuracy of detection comparison.
[0038] like Figure 3As shown, as another preferred embodiment of the present application, the judgment module includes at least a voltage comparison unit and a PWM signal control unit, and the voltage comparison unit is used to perform the voltage comparison and control the PWM signal control unit to generate a current compensation signal for the current compensation module based on the comparison result.
[0039] In the embodiment of the present application, the judgment module may compare the voltage value or the current value. Preferably, the voltage is compared to reduce the cost.
[0040] As another preferred embodiment of the present application, the control circuit includes at least two working states, namely a reading state and an output state. The reading state is used to read the voltage signal input by the voltage source, and the output state is used to control the light-emitting module to emit light.
[0041] In the embodiment of the present application, the control circuit can use the mainstream two-state control method to control the specific on and off conditions of the light-emitting module.
[0042] As another preferred embodiment of the present application, the control circuit changes its own working state based on the timing characteristics of the signal source, the data source and the voltage source input signal.
[0043] In the embodiments of the present application, Figure 4 As shown, a timing control schematic diagram of the signal source, the data source and the voltage source input signal is provided, and the emission timings of the high level and the low level need to match each other.
[0044] As another preferred embodiment of the present application, the light emitting module may include one or more light emitting diodes.
[0045] In the embodiment of the present application, since the circuit adopts a current compensation unit, the current output capability is strong and several diodes can be controlled simultaneously.
[0046] As another preferred embodiment of the present application, the signal source is used to input a scan control signal to control the on-off state of the dual-gate transistor. In the embodiment of the present application, the on-off state of the dual-gate transistor is controlled by changing the emission timing of the signal source signal.
[0047] like Figure 4As shown, an embodiment of the present application also provides a display, wherein the light-emitting module of the display is controlled based on the control circuit as described above. The control circuit includes: a current compensation module, a judgment module, a light-emitting module, a dual-gate transistor, a cache module and a driving transistor; the dual-gate end of the dual-gate transistor is connected to a signal source, the first end of the dual-gate transistor is connected to the first end of the driving transistor, the second end of the dual-gate transistor is connected to the gate of the driving transistor, the second end of the driving transistor is connected to the second end of the cache module, the first end of the cache module is connected to a voltage source, and the second end of the cache module is also connected to a data source, the common node of the two transistors in the dual-gate transistor is connected to the first end of the judgment module, the second end of the judgment module is connected to the gate of the driving transistor, the third end of the judgment module is connected to the first end of the current compensation module, the second end of the current compensation module is connected to the light-emitting module, and the second end of the judgment module is connected to the light-emitting module.
[0048] In the embodiment of the present application, the potential value of the gate of the driving transistor and the common end of the two transistors in the dual-gate transistor are first judged against the standard voltage value through a judgment module. When the difference exceeds a preset threshold value, it indicates that a more obvious leakage current or offset phenomenon has occurred, that is, a compensation current is introduced into the current compensation module to change the power supply to the light-emitting module, thereby achieving the effect of reducing visible flicker.
[0049] Since the current value output by the gate of the driving transistor may drift due to its operating temperature or inaccurate input voltage value, and the dual-gate transistor may have leakage current, the present solution detects and compensates for them separately through the set current compensation unit, thereby achieving the reduction of the flicker phenomenon and improving the display effect of the display.
[0050] like Figure 1 As shown, as a preferred embodiment of the present application, the display also includes a communication module, a RAM module, a ROM module, a sound / image decoding module, an I / O interface, a LCD screen component, an audio module and a processing unit; the control circuit is arranged in the processing unit.
[0051] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, a first end may be referred to as a second end, and similarly, a second resistor may be referred to as a first resistor and a second end may be referred to as a first end. Both the first resistor and the second resistor are resistors, but they are not the same resistor. The first end and the second end represent that the element has at least two different terminals.
[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A control circuit for a display, characterized in that: The control circuit comprises: Current compensation module, judgment module, light emitting module, dual-gate transistor, cache module and driving transistor; The dual gate end of the dual gate transistor is connected to the signal source, the first end of the dual gate transistor is connected to the first end of the driving transistor, the second end of the dual gate transistor is connected to the gate of the driving transistor, the second end of the driving transistor is connected to the second end of the cache module, the first end of the cache module is connected to the voltage source, and the second end of the cache module is also connected to the data source, the common node of the two transistors in the dual gate transistor is connected to the first end of the judgment module, the second end of the judgment module is connected to the gate of the driving transistor, the third end of the judgment module is connected to the first end of the current compensation module, the second end of the current compensation module is connected to the light emitting module, and the second end of the judgment module is connected to the light emitting module.
2. The control circuit of the display according to claim 1, characterized in that: The current compensation module is further provided with a third terminal, and the third terminal of the current compensation module is connected to a current source for introducing a compensation current into the light emitting module.
3. The control circuit of the display according to claim 1, characterized in that: The judgment module includes at least a voltage comparison unit and a PWM signal control unit, wherein the voltage comparison unit is used to compare the voltage value of the common node of the two transistors in the dual-gate transistor with a standard voltage value, and when the comparison result exceeds a threshold value, the PWM signal control unit is controlled to generate a current compensation signal for the current compensation module to introduce a compensation current into the light-emitting module.
4. The control circuit of the display according to claim 1, characterized in that: The control circuit includes at least two working states, namely a reading state and an output state. The reading state is used to read the voltage signal input by the voltage source, and the output state is used to control the light-emitting module to emit light.
5. The control circuit of the display according to claim 4, characterized in that: The control circuit changes its own working state based on the timing characteristics of the signal source, the data source and the voltage source input signal.
6. The control circuit of the display according to claim 1, characterized in that: The light emitting module includes at least one light emitting diode.
7. The control circuit of the display according to claim 1, characterized in that: The signal source is used to input a scan control signal to control the on-off status of the dual-gate transistor.
8. A display, characterized in that: The light-emitting module of the display is controlled based on the control circuit according to any one of claims 1 to 7.
9. The display according to claim 8, characterized in that The display also includes a communication module, a RAM module, a ROM module, a sound / image decoding module, an I / O interface, a liquid crystal screen component, an audio module and a processing unit; the control circuit is arranged in the processing unit.