LCD segment code screen driving display system and display method

Abstract

The invention discloses an LCD segment code screen driving display method. The method comprises the following steps: step 1, carrying out parameter configuration; step 2, scanning a single common port, specifically comprising the following steps: step 21, scanning the common port, and generating a common port scanning enable signal; step 22, the scanned common port output signal is stored in a data output register; step 23, continuing to scan all the corresponding segment selection ports, and generating a data shift enable signal; step 24, updating and storing the output data of the currently scanned segment selection port in a data shift register; 3, driving the LCD segment code screen to display according to the output levels of the public port and the segment selection port; step 4, traversing the step 2 and the step 3 for all public ports; and a complete broken code screen display process is completed. According to the invention, the shift register is used for replacing an external special data storage device, and the data is shifted in sequence in a mode of rapidly scanning the port and is output to the final control interface, so that the required data is displayed.

Description

Technical Field

[0001] The invention belongs to the field of display technology, relates to LCD driving technology, and specifically relates to an LCD segment code screen driving display system and a display method. Background Art

[0002] With the continuous development of liquid crystal (LCD) display technology, LCD has been widely used in the field of display technology. Many electronic products use LCD segment code screens as the carrier of human-computer interaction. Especially when producing electronic equipment, various display interfaces need to be designed. A certain number of digital fields are mainly set on the interface, and under a specific driving mode, various combinations of different styles are displayed to realize the transmission of digital information between machines and people.

[0003] Since the segment code screen is a low-cost, low-power display device, more and more manufacturers are using LCD segment code screens to design display interfaces. However, in the existing LCD segment code screen drive control circuit, a dedicated LCD segment code driver chip is generally used for implementation, and this dedicated driver chip can only drive one or a limited number of LCD segment code screens. In the system development process, it will not only increase the additional production cost, but also increase the design complexity of the system hardware and software. Therefore, in order to avoid the cost impact of using a dedicated LCD segment code screen driver chip, a method of directly driving the LCD screen by controlling each pin of the segment code screen is needed. Summary of the invention

[0004] In view of the defects of the above-mentioned prior art, the present invention proposes an LCD segment code screen driving display system and a display method.

[0005] The LCD segment code screen driving display method of the present invention comprises the following steps: Step 1. Perform parameter configuration and initial state settings; Step 2. Scan a single public port, specifically: Step 21. Scan the common port COM1 and generate a corresponding common port COM1 scan enable signal, so that the common port COM1 outputs a high level, while the outputs of other common ports that are not scanned are all low levels; Step 22. When scanning the common port, an output shift enable signal is generated, and the output signal of the scanned common port COM1 is stored in the data output register; Step 23. Continue to scan all the segment selection ports corresponding to the common port COM1 scanned in step 21, and generate a data shift enable signal when scanning the segment selection ports; Step 24. When the data shift enable signal is valid, the output data of the currently scanned segment selection port is updated and stored in the data shift register; Step 3. Retrieve the stored data from the data output register to generate a scan output enable signal for driving each common port; at the same time, read the data stored in the data shift register to drive each segment selection port; drive the LCD segment code screen display according to the output levels of the common port and the segment selection port; Step 4. For all common ports, traverse steps 2 and 3; complete a complete broken code screen display process.

[0006] Preferably, the parameter configuration in step 1 includes configuration of the number of ports of the common port COM and the segment selection port SEG, the bias ratio, the common port scanning time, and the segment selection port display data value parameters.

[0007] Preferably, in step 3, after driving the common port and the segment selection port, a driving analog voltage of the common port and the segment selection port is generated according to the final output level logic value of the common port and the segment selection port, and the LCD segment code screen is driven to display by the absolute value of the voltage difference between the common port and the segment selection port.

[0008] Preferably, when the common port output signal scanned in step 22 is stored in the data output register, a left shift storage method is adopted, that is, all the internally stored data is shifted one position to the left as a whole, the leftmost data is shifted out of the data shift register, and the newly stored data is stored at the rightmost position; the segment selection port output data scanned in step 24 is stored and updated in the data shift register, and a right shift storage method is adopted, that is, all the internally stored data is shifted one position to the right as a whole, the rightmost data is shifted out of the data shift register, and the newly stored data is stored at the leftmost position.

[0009] The present invention also discloses an LCD segment code screen driving display system, which is used to execute the driving display method, including an LCD control logic module, and also includes: A data configuration unit, used to configure system parameters; Data shift register, at the beginning of each scan, the configured segment selection port display data value is stored in the data shift register, and the data is shifted right when a valid data shift enable signal is collected; A data selection unit selects different data output results according to whether the scanned object is a common port or a segment selection port; A data output control module, used for controlling the output results in the data selection unit to be sequentially shifted to the left to the output shift register before the common port and all the segment selection ports corresponding to the common port are scanned, and outputting the value in the output shift register to the digital control interface after the common port and all the segment selection ports corresponding to the common port are scanned; Output shift register, when the output shift enable signal is valid, the output value of the common port is stored in the output shift register in sequence.

[0010] The present invention discloses an LCD segment code screen driving display system and a display method, which uses a shift register to replace an external dedicated data storage device, transfers data to be displayed on the LCD segment code screen to the shift register through software, shifts the data in sequence in a fast scanning port manner and outputs the data to a final control interface so that the required data is displayed.

[0011] The present invention directly controls each pin of the LCD segment code screen to replace a dedicated LCD segment code driving chip with a high cost, uses fewer resources to drive various types of LCD segment code screens, and effectively reduces the development cost of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The figure shows a schematic diagram of a specific implementation of the LCD segment code screen driving display system of the present invention; Figure 2 The figure shows a schematic diagram of a specific implementation of an LCD segment code screen in the prior art; Figure 3 The figure is a schematic flow chart of a specific implementation of the LCD segment code screen driving and displaying method of the present invention; Figure 4 FIG. 1 is a schematic diagram of logic value waveforms output by the common port and the segment selection port in the specific embodiment 1 of the present invention. Figure 4 In the figure, the horizontal axis is time and the vertical axis is the logical value; Figure 5 FIG. 1 is a schematic diagram of a simulated voltage waveform outputted from a common port in a specific embodiment 1 of the present invention; Figure 6 It is a schematic diagram of the analog voltage waveform output by the segment selection port in the specific embodiment 1 of the present invention; Figure 7 FIG. 1 is a schematic diagram of a voltage difference waveform between the common port COM2 and the segment selection port SEG1 in the specific embodiment 1 of the present invention; Figures 5 to 7 In the figure, the horizontal axis is time and the vertical axis is voltage. DETAILED DESCRIPTION

[0013] In order to more intuitively and clearly describe the specific details of the technical solution of the present invention, a detailed description will be given below in conjunction with specific embodiments and example drawings.

[0014] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the specific implementation methods of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] The purpose of the present invention is to provide an LCD segment code screen driving display system and an implementation method. By directly controlling the various pins of the LCD segment code screen and using a shift register for data transmission, there is no need to use an external dedicated data storage device, and thus various types of LCD segment code screens can be driven with fewer device resources, and the high-cost dedicated LCD segment code driver chip can be replaced, thereby reducing the system development cost and solving the cost problem brought about by the above-mentioned background technology.

[0016] The LCD segment code screen driving display system of the present invention is as follows: Figure 1 As shown, it includes an LCD control logic module and also includes: A data configuration unit is used to configure system parameters, such as the number of ports including the common port COM and the segment selection port SEG, the bias ratio, the common port scanning time, and the segment selection port display data value; Data shift register, at the beginning of each scan, the configured segment selection port display data value is stored in the data shift register, and the data is shifted right when a valid data shift enable signal is collected; A data selection unit selects different data output results according to whether the scanned object is a common port or a segment selection port; The data output control module controls the output results in the data selection unit to be shifted left to the output shift register in sequence before a common port and all the segment selection ports corresponding to the common port are scanned, and after the common port and all the segment selection ports corresponding to the common port are scanned, the value in the output shift register is output to the digital control interface.

[0017] Output shift register, when the output shift enable signal is valid, the output value of the common port is shifted left to the output shift register in sequence.

[0018] like Figure 2As shown in the figure, a typical LCD segment code screen for displaying Arabic numerals includes seven segment codes A1-A7 and a decimal point code B. There are four common ports, namely COM1 for controlling the decimal point code and segment code A1, COM2 for controlling segment codes A2 and A3, COM3 for controlling segment codes A4 and A5, and COM4 for controlling segment codes A6 and A7. Each common port corresponds to two segment selection ports SEG1 and SEG2, where SEG1 controls segment codes A1, A2, A4 and A6, and SEG2 controls segment codes A3, A5, A7 and decimal point code B. For other LCD segment code screens, there are also other control methods.

[0019] Only one common port can be scanned at a time, while multiple segment selection ports can be scanned at the same time. Applying a certain voltage between the common port and the segment selection port can light up the corresponding pixel segment in the segment code screen. The duty cycle of the LCD segment code screen represents the ratio of the effective scanning time of a single common port to the entire scanning cycle. The bias ratio of the LCD segment code screen represents the ratio of the lowest voltage to the highest voltage output by the LCD, which is generally divided into 1 / 2 and 1 / 3 bias ratios. For example, when the bias ratio of 1 / 3 is set, when the ratio of the voltage difference between the common port and the segment selection port to the LCD operating voltage is greater than 1 / 3 bias ratio, the corresponding pixel segment is lit, otherwise the corresponding pixel segment is not lit.

[0020] Each segment code or other code of the segment code screen is controlled by a common port and a segment selection port in a unique combination. The voltage of the two ports determines whether the segment code is lit or closed. For example, according to the above description, Figure 2 The middle segment code A1 is controlled by the common port COM1 and the segment selection port SEG1, and the decimal point code B is controlled by the common port COM1 and the segment selection port SEG2.

[0021] The present invention provides a method for driving and displaying an LCD segment code screen, the core point of which is to quickly transmit the data to be displayed on the LCD segment code screen to the corresponding control interface using a data shift register and an output shift register, such as Figure 3 As shown, the display method of the present invention comprises the following steps: Step 1. Perform parameter configuration and initial state settings; The required parameters are configured through the software. Depending on the application scenario requirements, the configured parameter values ​​will also be different. The configured system parameters usually include the number of ports of the common port COM and the segment selection port SEG, the bias ratio, the common port scanning time, the segment selection port display data value, etc. In the initial state, all common ports output low-level signals by default, and the data in each shift register is reset to the initial setting, for example, all are 1 or all are zero; Step 2. Scan a single public port; Step 21. Scan the common port COM1 and generate a corresponding common port COM1 scan enable signal, so that the common port COM1 outputs a high level, while the outputs of other common ports that are not scanned are all low levels; Step 22. When scanning the common port, an output shift enable signal is generated, and the output signal of the scanned common port COM1 is stored in the data output register; Since the common port COM1 outputs a high level, all the segment selection ports corresponding to the common port COM1 can output data. The LCD logic control module outputs the display signal to the data shift register according to the pre-written display driver file, and the segment selection port retrieves data from the data shift register for data output. Step 23. Continue to scan all the segment selection ports corresponding to the common port COM1 scanned in step 21, and generate a data shift enable signal when scanning the segment selection ports; Step 24. When the data shift enable signal is valid, the output data of the currently scanned segment selection port is updated and stored in the data shift register; Step 3. Retrieving the stored data from the data output register to generate a scan output enable signal for driving each common port; At the same time, the data stored in the data shift register is read to drive each segment selection port; according to the final output level logic value of the common port and the segment selection port, the driving analog voltage of the common port and the segment selection port is generated, and the display of the LCD segment code screen is driven by the absolute value of the voltage difference between the common port and the segment selection port.

[0022] Step 4. For all common ports, traverse steps 2 and 3; complete a complete broken code screen display process.

[0023] During each traversal process, in step 22 and step 24, the stored data of the data output register and the data shift register need to be updated respectively; Among them, when the common port output signal scanned in step 22 is stored in the data output register, a left shift storage method can be adopted, that is, all the internally stored data is shifted one position to the left as a whole, the leftmost data is shifted out of the data shift register, and the newly stored data is stored at the rightmost position; the segment selection port output data scanned in step 24 is stored and updated in the data shift register, and a right shift storage method can be adopted, that is, all the internally stored data is shifted one position to the right as a whole, the rightmost data is shifted out of the data shift register, and the newly stored data is stored at the leftmost position.

[0024] A specific flow chart is as follows Figure 3 As shown, the following steps are included: Specific embodiments

[0025] by Figure 2 Take the segment code screen shown as an example, there are four common ports and two segment selection ports, two of which correspond to all common ports, the bias ratio is set to 1 / 3, and the power supply voltage is VDD; After the parameter configuration and initial state setting of step 1 are completed, proceed to step 2; Step 2. The logic value waveform of the output signal of each common port in step 2 is as follows Figure 4 As shown; Step 21. First, scan the common port COM1 to generate a corresponding scan enable signal. The output of the common port COM1 is high level, while the outputs of the other common ports COM2, COM3, and COM4 that are not scanned are all low level; like Figure 4 As shown, during the time period from 0 to T1, the output of the common port COM1 is high level, and the outputs of the other common ports COM2, COM3, and COM4 are all low level; Step 22. The output level of the common port being scanned, i.e., the high level, is output to the output shift register for storage. The storage method adopted by the output shift register is left shift storage, i.e., each time storage is performed, all the data stored internally is shifted one position to the left as a whole, the leftmost data is shifted out of the data shift register, and the newly stored data is stored in the rightmost position; In the time period from step 23.0 to T1, the segment selection ports SEG1 and SEG2 corresponding to the common port COM1 are scanned at the same time, and both outputs are high level; when scanning the segment selection ports, a data shift enable signal is generated; Step 24. When the data shift enable signal is valid, the output data of the currently scanned segment selection port is stored in the data shift register, and the right shift storage method is adopted, that is, all the internally stored data is shifted one position to the right as a whole, the rightmost data is shifted out of the data shift register, and the newly stored data is stored in the leftmost position.

[0026] Step 3. Retrieving the stored data from the data output register to generate a scan output enable signal for driving each common port; At the same time, the data stored in the data shift register is read to drive each segment selection port; then, according to the final output level logic value of the common port and the segment selection port, the driving analog voltage of the common port and the segment selection port is generated; like Figure 5 and Figure 6 As shown, according to the bias ratio, power supply voltage VDD and other parameters set in step 1, the logic level is finally converted into an analog voltage through a digital-to-analog converter. At the common port COM1, the analog voltage corresponding to the high level of the logic value output in the time period from 0 to T1 is VDD, and the analog voltage corresponding to the low level of the logic value output by the common ports COM2, COM3, and COM4 is VDD / 3; In the time period from 0 to T1, the analog voltages of the corresponding logic high levels output by the segment selection ports SEG1 and SEG2 are both 0; It should be noted that, in this embodiment, whether the analog voltage difference between the common port and the segment selection port is greater than VDD / 3 is used as the judgment standard for lighting, so the analog voltage corresponding to the high level of the segment selection port representing lighting is actually a low voltage.

[0027] Thus, the output of the common port COM1 and its corresponding segment selection ports SEG1 and SEG2 in the time period from 0 to T1 is obtained; After scanning the common port COM1 and the corresponding segment selection ports SEG1 and SEG2, continue to scan the common port COM2. Figure 2 In the time period from T1 to T2 shown in FIG. 1 , steps S2 to S3 are repeated, as shown in FIG. Figure 4 As shown, during the time period from T1 to T2, the common port COM2 outputs a high level, and the outputs of the other common ports COM1, COM3, and COM4 are all low levels; the segment selection ports SEG1 and SEG2 corresponding to the common port COM2 output a high level and a low level respectively; like Figure 5 As shown, at the common port COM2, the analog voltage corresponding to the high logic value output during the time period from T1 to T2 is VDD, and the analog voltage corresponding to the low logic value output by the common ports COM1, COM3, and COM4 is VDD / 3; like Figure 6 As shown, in the time period from T1 to T2, the analog voltage corresponding to the logic value high level output by the segment selection port SEG1 is 0; the analog voltage corresponding to the logic value low level output by SEG2 is 2VDD / 3; according to Figure 4 , Figure 5 According to the above analysis, in the time period from T2 to T3 and the time period from T3 to T4, the analog voltages outputted from the common ports COM3 and COM4 and their corresponding segment selection ports are scanned respectively.

[0028] In this embodiment, the display of the LCD segment code screen is driven by the absolute value of the voltage difference between the common port and the segment selection port; the display rule set by the absolute value of the voltage difference between the COM and SEG ports is that it lights up when it is greater than VDD / 3, and it does not light up when it is less than or equal to VDD / 3, such as Figure 7 The figure shows the analog voltage difference waveform of the common port COM2 and the segment selection port SEG1. At the time T1 to T2 of the odd frame and the time T5 to T6 of the even frame, the absolute value of the voltage difference is greater than VDD / 3. At this time, the segment code A2 controlled by the common port COM2 and the segment selection port SEG1 is lit.

[0029] According to the display principle of the segment code screen, each complete full-screen display cycle includes odd frames and even frames. The voltage waveform of the even frame has a completely opposite logic value to the voltage waveform of the odd frame. From the analysis of the odd frame in the above 0 to T4 time period, it is easy to derive Figures 4 to 6 The output waveforms of each port in the even frame during the time period from T4 to T8 are shown in FIG. 1 . In the even frame, the high and low level analog voltages of the common port are defined as 2VDD / 3 and zero, respectively, and the high and low level analog voltages of the segment selection port are defined as VDD and VDD / 3, respectively.

[0030] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0031] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0032] The foregoing describes various preferred embodiments of the present invention. Unless the preferred implementation modes in various preferred embodiments are obviously self-contradictory or based on a certain preferred implementation mode, various preferred implementation modes can be arbitrarily superimposed and used in combination. The embodiments and specific parameters in the embodiments are only for clearly describing the invention verification process of the inventor, and are not used to limit the patent protection scope of the present invention. The patent protection scope of the present invention shall still be based on its claims. All equivalent structural changes made using the contents of the description and drawings of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for driving and displaying an LCD segment code screen, characterized in that , including the following steps: Step 1. Perform parameter configuration and initial state settings; Step 2. Scan a single public port, specifically: Step 21. Scan the common port COM1 and generate a corresponding common port COM1 scan enable signal, so that the common port COM1 outputs a high level, while the outputs of other common ports that are not scanned are all low levels; Step 22. When scanning the common port, an output shift enable signal is generated, and the output signal of the scanned common port COM1 is stored in the data output register; Step 23. Continue to scan all the segment selection ports corresponding to the common port COM1 scanned in step 21, and generate a data shift enable signal when scanning the segment selection ports; Step 24. When the data shift enable signal is valid, the output data of the currently scanned segment selection port is updated and stored in the data shift register; Step 3. Retrieve the stored data from the data output register to generate a scan output enable signal for driving each common port; at the same time, read the data stored in the data shift register to drive each segment selection port; drive the LCD segment code screen display according to the output levels of the common port and the segment selection port; Step 4. For all common ports, traverse steps 2 and 3; complete a complete broken code screen display process.

2. The LCD segment screen driving display method according to claim 1, characterized in that: The parameter configuration in step 1 includes the configuration of the port quantity, bias ratio, common port scanning time, and segment selection port display data value parameters of the common port COM and the segment selection port SEG.

3. The LCD segment screen driving display method according to claim 1, characterized in that: In step 3, after driving the common port and the segment selection port, the driving analog voltage of the common port and the segment selection port is generated according to the final output level logic value of the common port and the segment selection port, and the LCD segment code screen is driven to display through the absolute value of the voltage difference between the common port and the segment selection port.

4. The LCD segment screen driving display method according to claim 1, characterized in that: When the common port output signal scanned in step 22 is stored in the data output register, a left shift storage method is adopted, that is, all the internally stored data is shifted one position to the left as a whole, the leftmost data is shifted out of the data shift register, and the newly stored data is stored at the rightmost position; the segment selection port output data scanned in step 24 is stored and updated in the data shift register, and a right shift storage method is adopted, that is, all the internally stored data is shifted one position to the right as a whole, the rightmost data is shifted out of the data shift register, and the newly stored data is stored at the leftmost position.

5. An LCD segment screen driving display system, used to execute the driving display method according to any one of claims 1 to 4, comprising an LCD control logic module, characterized in that: Also includes: A data configuration unit, used to configure system parameters; Data shift register, at the beginning of each scan, the configured segment selection port display data value is stored in the data shift register, and the data is shifted right when a valid data shift enable signal is collected; A data selection unit selects different data output results according to whether the scanned object is a common port or a segment selection port; A data output control module, used for controlling the output results in the data selection unit to be sequentially shifted to the left to the output shift register before the common port and all the segment selection ports corresponding to the common port are scanned, and outputting the value in the output shift register to the digital control interface after the common port and all the segment selection ports corresponding to the common port are scanned; Output shift register, when the output shift enable signal is valid, the output value of the common port is stored in the output shift register in sequence.

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