Display panel detection device and detection method thereof

Abstract

The invention discloses a display panel detection device and a detection method thereof. The display panel is installed on a vehicle head of a vehicle and displays a vehicle logo when the vehicle runs. The detection device comprises a current sensing circuit, an analog-to-digital converter and a judgment circuit. The current sensing circuit receives a panel total current flowing through the display panel to provide a current characteristic voltage. The analog-to-digital converter is coupled to the current sensing circuit to provide current characteristic data based on the current characteristic voltage. The judgment circuit is coupled to the analog-to-digital converter and judges whether the display panel is operated in a rated chromaticity range based on the current characteristic data so as to provide a panel state signal.

Description

Technical Field

[0001] The invention relates to a detection device, and in particular to a detection device for a display panel and a detection method thereof. Background Art

[0002] The display installed on the front of the vehicle is limited to displaying the car manufacturer's logo while the vehicle is driving. The color of the display must comply with the color gamut regulations of the headlights to ensure that it does not cause visual discomfort to the driver or road users and affect safety. Therefore, how to determine whether the color of the display is maintained within the color gamut regulations of the headlights is an important issue in the application of display devices that display car logos. Summary of the invention

[0003] The invention provides a detection device and a detection method of a display panel, which can determine the operation state of the display panel.

[0004] The display panel detection device of the present invention is installed on the front of the vehicle and displays the vehicle logo while the vehicle is driving. The detection device includes a current sensing circuit, an analog-to-digital converter (ADC), and a judgment circuit. The current sensing circuit receives the total panel current flowing through the display panel to provide a current characteristic voltage. The analog-to-digital converter is coupled to the current sensing circuit to provide current characteristic data based on the current characteristic voltage. The judgment circuit is coupled to the analog-to-digital converter and judges whether the display panel is operating in the rated chromaticity range based on the current characteristic data to provide a panel status signal.

[0005] The display panel detection method of the present invention is installed on the front of a vehicle and displays a vehicle logo while the vehicle is driving. The detection method includes the following steps: receiving the total panel current flowing through the display panel via a current sensing circuit to provide a current characteristic voltage; providing current characteristic data based on the current characteristic voltage via an analog-to-digital converter; judging whether the display panel is operating in a rated chromaticity range based on the current characteristic data via a judgment circuit to provide a panel status signal.

[0006] Based on the above, in the detection device and detection method of the display panel of the embodiment of the present invention, the detection device can detect the slight current change of the total panel current of the display panel, thereby judging the operating state of the display panel, so as to judge whether the damage of the light-emitting diode pixel in the display panel exceeds the allowable value. In addition, since the detection device converts the current waveform into a digital value for judgment, the detection device can use an analog-to-digital converter with a lower sampling rate and a judgment circuit with a lower computing power, so as to achieve the purpose of judging the operating state of the display panel at a lower hardware cost.

[0007] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 FIG. 4 is a system schematic diagram of a display panel detection device according to an embodiment of the present invention.

[0009] Figure 2 is a system diagram of a current sensing circuit of a detection device according to an embodiment of the present invention.

[0010] Figure 3 FIG. 4 is a circuit diagram of a current sensing circuit of a detection device according to an embodiment of the present invention.

[0011] 4A to 4D FIG. 4 is a schematic diagram of a voltage waveform of a current sensing circuit of a detection device according to an embodiment of the present invention.

[0012] Figure 5 is a flow chart of a display panel detection method according to an embodiment of the present invention.

[0013] Figure 6 The flowchart is a method for operating a vehicle system equipped with a display panel displaying a vehicle logo according to an embodiment of the present invention.

[0014] Wherein, the reference numerals are:

[0015] 10: Vehicles

[0016] 10a: Front

[0017] 11: Display Panel

[0018] 100: Detection device

[0019] 110, 110a: current sensing circuit

[0020] 111, 111a: Current sensing amplifier

[0021] 113, 113a: Low pass filter

[0022] 115, 115a: Current characteristic acquisition circuit

[0023] 120:Analog-to-digital converter

[0024] 130: Judgment circuit

[0025] AMP1, AMP1: differential amplifier

[0026] C1~C5: Capacitor

[0027] D1: diode

[0028] Dct: Current characteristic data

[0029] Dindex: Panel status signal

[0030] I uLED :Total panel current

[0031] R1, R2: resistor

[0032] Rsn: sensing resistor

[0033] Vcs: Current sensing voltage

[0034] Vct: Current characteristic voltage

[0035] VDD: system high voltage

[0036] Vlp: filtered voltage

[0037] Vmax: Maximum voltage

[0038] S101, S103, S105, S201, S203, S205, S207, S209: Steps DETAILED DESCRIPTION

[0039] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention.

[0040] As used herein, "about", "approximately", "essentially", or "substantially" include the stated value and the average value within an acceptable deviation range of the particular value determined by one of ordinary skill in the art, taking into account the measurement in question and the particular amount of error associated with the measurement (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within, for example, ±30%, ±20%, ±15%, ±10%, ±5%. Furthermore, as used herein, "about", "approximately", "essentially", or "substantially" can select a more acceptable deviation range or standard deviation depending on the measured property, cutting property or other property, and can apply to all properties without one standard deviation.

[0041] In the accompanying drawings, the thickness of layers, films, panels, regions, etc., is exaggerated for clarity. It should be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it may be directly on or connected to another element, or an intermediate element may also exist. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there is no intermediate element. As used herein, "connection" may refer to physical and / or electrical connection. Furthermore, "electrical connection" may be the presence of other elements between two elements.

[0042] In addition, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe the relationship of one element to another element, as shown in the figures. It should be understood that relative terms are intended to include different orientations of the device in addition to the orientation shown in the figures. For example, if the device in one figure is turned over, the elements described as being on the "lower" side of the other elements will be oriented on the "upper" side of the other elements. Therefore, the exemplary term "lower" can include both "lower" and "upper" orientations, depending on the particular orientation of the figure. Similarly, if the device in one figure is turned over, the elements described as being "below" or "below" other elements will be oriented as being "above" the other elements. Therefore, the exemplary terms "above" or "below" can include both above and below orientations.

[0043] Exemplary embodiments are described herein with reference to cross-sectional views that are schematic diagrams of idealized embodiments. Therefore, variations in the shapes of the illustrations as a result of, for example, manufacturing techniques and / or tolerances can be expected. Therefore, the embodiments described herein should not be construed as limited to the specific shapes of the regions as shown herein, but rather include shape deviations, for example, caused by manufacturing. For example, a region shown or described as flat may typically have rough and / or nonlinear features. In addition, the sharp angles shown may be rounded. Therefore, the regions shown in the figures are schematic in nature, and their shapes are not intended to illustrate the precise shapes of the regions and are not intended to limit the scope of the claims.

[0044] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals are used in the drawings and description to refer to the same or like parts.

[0045] Figure 1 is a system diagram of a display panel detection device according to an embodiment of the present invention. Figure 1 In this embodiment, the display panel 11 can be installed on the front 10a of the vehicle 10 and display the vehicle logo (such as displaying AUO) while the vehicle 10 is driving, and the detection device 100 includes a current sensing circuit 110, an analog-to-digital converter (ADC) 120, and a judgment circuit 130, wherein the display panel 11 can be a display panel with a light-emitting diode array.

[0046] The current sensing circuit 110 receives the total panel current I flowing through the display panel 11 uLED , based on the total panel current I uLED Provide a current characteristic voltage Vct, wherein based on the writing state (or screen display state) of the display panel 11, the total panel current I uLEDThe current characteristic voltage Vct may vary with time, but it maintains a single voltage level (ie, DC) in a unit time (ie, a sensing cycle).

[0047] The analog-to-digital converter 120 is coupled to the current sensing circuit 110 to provide current characteristic data Dct based on the current characteristic voltage Vct, for example, converting the analog current characteristic voltage Vct into digital current characteristic data Dct, wherein the current characteristic voltage Vct presents direct current in one unit time, and thus the analog-to-digital converter 120 can be executed once in one unit time, thereby reducing the number of executions and power consumption.

[0048] The determination circuit 130 is coupled to the analog-to-digital converter 120 and determines whether the display panel 11 operates within the rated chromaticity range (i.e., the specified color and brightness) based on the current characteristic data Dct to provide a panel status signal Dindex. Specifically, when the display panel 11 maintains the specified color and brightness, the total panel current I uLED The waveform will be roughly the same, that is, the current characteristic data Dct will be roughly the same as the factory value calculated based on the waveform measured at the factory. At this time, the panel status signal Dindex can indicate that the display panel 11 is normal; on the contrary, when the display panel 11 gradually deviates from and exceeds the specified color and brightness due to aging or failure, the total panel current I uLED The waveform will fluctuate greatly, that is, the current characteristic data Dct may have a large difference (ie, difference) from the factory value. At this time, the panel status signal Dindex may indicate that the display panel 11 is abnormal.

[0049] According to the above, in the case where the light-emitting diode pixel in the display panel 11 is damaged, the detection device 100 can detect a slight current change of the display panel 11, thereby determining the operating state of the display panel 11. In addition, since the detection device 100 can perform one detection in one unit time, the detection device 100 can use an analog-to-digital converter (ADC) 120 with a lower sampling rate and a determination circuit 130 with a lower computing power, thereby achieving the purpose of determining the operating state of the display panel 11 at a lower hardware cost.

[0050] In an embodiment of the present invention, when the difference between the current characteristic data Dct and the panel preset value set by the display panel 11 at the factory is less than a critical value, the panel status signal Dindex indicates that the display panel 11 is operating within the rated chromaticity range (i.e., a normal state); when the difference between the current characteristic data Dct and the panel preset value is greater than or equal to the critical value, the panel status signal Dindex indicates that the display panel 11 is operating outside the rated chromaticity range (i.e., an abnormal state).

[0051] In an embodiment of the present invention, the display panel 11 may be, for example, an organic light emitting diode (OLED) display panel, a sub-millimeter light emitting diode (Mini LED) display panel, a micro light emitting diode (uLED) display panel, etc., but the embodiment of the present invention is not limited thereto.

[0052] In the embodiment of the present invention, the determination circuit 130 includes, for example, a microcontroller unit (MCU) and / or a processor, but the embodiment of the present invention is not limited thereto.

[0053] Figure 2 is a system diagram of a current sensing circuit of a detection device according to an embodiment of the present invention. Figure 1 and Figure 2 In this embodiment, the current sensing circuit 110a includes a current sensing amplifier 111, a low-pass filter 113, and a current characteristic acquisition circuit 115. The current sensing amplifier 111 amplifies the sensing voltage (such as Figure 3 The current sensing voltage Vsense is used to provide a current sensing voltage Vcs. The low-pass filter 113 is coupled to the current sensing amplifier 111 to provide a filtered voltage Vlp based on the current sensing voltage Vcs. The current characteristic acquisition circuit 115 is coupled to the low-pass filter 113 to provide a current characteristic voltage Vct based on the filtered voltage Vlp.

[0054] Figure 3 FIG. 1 is a circuit diagram of a current sensing circuit of a detection device according to an embodiment of the present invention. Figure 1 , Figure 2 and Figure 3 In this embodiment, the current sensing amplifier 111a includes, for example, a differential amplifier AMP1 (corresponding to a first differential amplifier) ​​and capacitors C1 to C3 (corresponding to a first capacitor to a third capacitor). The sensing resistor Rsn is coupled in series with the display panel 11 between the system high voltage VDD and the ground voltage to provide a sensing voltage Vsense, wherein the display panel 11 is a load for the current sensing amplifier 111.

[0055] The differential amplifier AMP1 has a positive input terminal and a negative input terminal for receiving a sensing voltage, and an output terminal for providing a current sensing voltage Vcs. The capacitor C1 is coupled between the positive input terminal of the differential amplifier AMP1 and the negative input terminal of the differential amplifier AMP1. The capacitor C2 is coupled between the positive input terminal of the differential amplifier AMP1 and a ground voltage. The capacitor C3 is coupled between the negative input terminal of the differential amplifier AMP1 and a ground voltage.

[0056] In this embodiment, the low pass filter 113a includes, for example, a resistor R1 (corresponding to the first resistor) and a capacitor C4 (corresponding to the fourth capacitor). The resistor R1 is coupled between the current sensing voltage Vcs and the filtered voltage Vlp. The capacitor C4 is coupled between the filtered voltage Vlp and the ground voltage.

[0057] In this embodiment, the current characteristic acquisition circuit 115a includes, for example, a differential amplifier AMP2 (corresponding to the second differential amplifier), a diode D1 (corresponding to the first diode), a resistor R2 (corresponding to the second resistor), and a capacitor C5 (corresponding to the fifth capacitor). The differential amplifier AMP2 has a positive input terminal, a negative input terminal, and an output terminal for receiving the filtered voltage Vlp. The diode D1 has an anode coupled to the output terminal of the differential amplifier AMP2, and a cathode coupled to the negative input terminal of the differential amplifier AMP2. The resistor R2 is coupled between the negative input terminal of the differential amplifier AMP2 and the current characteristic voltage Vct. The capacitor C5 is coupled between the current characteristic voltage Vct and the ground voltage.

[0058] In the embodiment of the present invention, the resistance value of the resistor R2 and / or the capacitance value of the capacitor C5 of the current characteristic acquisition circuit 115a can be adjusted according to the characteristics of the displayed vehicle logo (such as the displayed AUO) to increase the total panel current I flowing through the display panel 11. uLED The sensitivity of the current waveform.

[0059] In the embodiment of the present invention, the current characteristic voltage Vct reflects one of the maximum voltage, the minimum voltage, and the average value of the sensing voltage Vsense generated by the total panel current IuLED passing through the sensing resistor Rsn during a sensing period (eg, at least one frame period).

[0060] 4A to 4D FIG. 1 is a schematic diagram of a voltage waveform of a current sensing circuit of a detection device according to an embodiment of the present invention. Figure 1 Referring to FIG. 4 , in this embodiment, Figure 4A is a voltage waveform showing a sense voltage Vsense, Figure 4B is a voltage waveform showing a current sensing voltage Vcs, Figure 4C is a voltage waveform showing the filtered voltage Vlp, and Figure 4D : is a voltage waveform showing the current characteristic voltage Vct. In this embodiment, the current characteristic voltage Vct reflects the maximum voltage Vmax of the sensing voltage Vsense generated by the total panel current IuLED passing through the sensing resistor Rsn during the sensing period, but the embodiment of the present invention is not limited thereto.

[0061] Figure 5 is a flow chart of a display panel detection method according to an embodiment of the present invention. Figure 5In this embodiment, the display panel is installed on the front of the vehicle and displays the vehicle logo while the vehicle is driving. The detection method includes the following method. In step S101, the total panel current flowing through the display panel is received via a current sensing circuit to provide a current characteristic voltage. In step S103, current characteristic data is provided based on the current characteristic voltage via an analog-to-digital converter (ADC). And, in step S105, a judgment circuit is used to determine whether the display panel is operating within the rated chromaticity range based on the current characteristic data to provide a panel status signal. Among them, the order of steps S101, S103, and S105 is for illustration, and the embodiments of the present invention are not limited to this. And, the details of steps S101, S103, and S105 can be referred to. Figures 1 to 3 as well as 4A to 4D As shown, no further details will be given here.

[0062] Figure 6 This is a flow chart of an operation method of a vehicle system equipped with a display panel displaying a vehicle logo according to an embodiment of the present invention. Figure 6 In this embodiment, the operation method includes the following steps. In step S201, the vehicle system drives the display panel to display the vehicle logo and switches the vehicle to the driving mode. In step S203, the detection device detects the total panel current flowing through the display panel.

[0063] In step S205, it is determined whether the difference between the total panel current and the panel preset current is greater than or equal to the current critical value. When the difference between the total panel current and the panel preset current is not greater than or equal to the current critical value, the process returns to step S203 to continuously detect the total panel current; when the difference between the total panel current and the panel preset current is greater than or equal to the current critical value, step S207 is executed.

[0064] In step S207, a panel status signal indicating an abnormality is transmitted to the vehicle system, and in step S209, the vehicle system indicates a display panel failure to prompt the user to perform inspection / repair.

[0065] In a display panel detection device and detection method of an embodiment of the present invention, the characteristics of the current waveform of the display panel 11 displaying the car logo can be found and then converted into corresponding digital values, and the difference in driving current when dozens of bad pixels are generated in the display panel 11 can be detected. Furthermore, according to the fault current range defined by the user, a panel status signal Dindex can be immediately sent back to indicate whether there is a fault, wherein the panel status signal Dindex can record a fault diagnostic code (DTC).

[0066] In the embodiment of the present invention, the current sensing amplifier 111 is used to measure and amplify the current signal flowing through the display panel 11. Its main purpose is to convert the measured current signal into a voltage signal for accurate current measurement, control or feedback control. The gain value can be adjusted for the front-end small resistor to increase the accuracy of the current measurement.

[0067] In the embodiment of the present invention, the low-pass filter 113 can be used to remove the total panel current I flowing through the display panel 11. uLED The high-frequency oscillation or noise in the current waveform is used here to reduce the interference of the high-frequency noise in the current characteristic voltage Vct on the subsequent current characteristic acquisition circuit 115.

[0068] In the embodiment of the present invention, the analog voltage originally converted into the corresponding current is converted into a digital signal by the analog-to-digital converter 120, so as to facilitate the determination circuit 130 to perform data transmission and calculation.

[0069] In the embodiment of the present invention, the purpose of the current feature acquisition circuit 115 is to find out the characteristics of the current waveform flowing through the display panel 11 displaying the car logo, and to immediately respond if there is a slight difference in the current. Basically, there are many ways to find out the characteristics of the current waveform flowing through the display panel 11 displaying the car logo, such as using an integration circuit to perform total current calculations, using the data retrieved by the ADC to perform slope and differential calculations and establish a characteristic matrix, etc., but the above methods are difficult to implement.

[0070] In the embodiment of the present invention, the detection device 100 can detect the peak value of the current waveform and increase the sensitivity to the current change by matching the RC value of the output end, so that the change between the waveforms of each current scan is less drastic, but when there is a difference in the current change, it can respond immediately. For the RC time constant of the output of the circuit, a larger RC time constant will make the output smoother, while a smaller RC time constant will make the output more sensitive.

[0071] Table 1

[0072]

[0073]

[0074] Table 1 shows the ability of the detection device 100 to identify the damage of sub-pixels. The experimental variables are: 1) the number of damaged points of the sub-pixel; 2) the color of the sub-pixel: red / green / blue.

[0075] It can be seen that the current conversion corresponds to the voltage, and has a linear decreasing relationship with the number of damage points. And the characteristics of light-emitting diodes of different colors can be observed, that is, the current consumption of light-emitting diodes is: red>green>blue.

[0076] In summary, in the detection device and detection method of the display panel of the embodiment of the present invention, the detection device can detect the slight current change of the total panel current of the display panel, thereby judging the operating state of the display panel, so as to judge whether the damage of the light-emitting diode pixel in the display panel exceeds the allowable value. In addition, since the detection device converts the current waveform into a digital value for judgment, the detection device can use an analog-to-digital converter (ADC) with a lower sampling rate and a judgment circuit with a lower computing power, so as to achieve the purpose of judging the operating state of the display panel at a lower hardware cost.

[0077] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Any person having ordinary knowledge in the technical field may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the attached patent application.

Claims

1. A detection device for a display panel, characterized in that: The display panel is installed on a front of a vehicle and displays a vehicle logo when the vehicle is running, and includes: a current sensing circuit, receiving a total panel current flowing through the display panel to provide a current characteristic voltage; an analog-to-digital converter coupled to the current sensing circuit to provide a current characteristic data based on the current characteristic voltage; and A judging circuit is coupled to the analog-to-digital converter and judges whether the display panel operates in a rated chromaticity range based on the current characteristic data to provide a panel status signal.

2. The display panel detection device according to claim 1, characterized in that: The current sensing circuit includes: a current sensing amplifier, amplifying a sensing voltage based on the total current of the panel to provide a current sensing voltage; a low pass filter coupled to the current sensing amplifier to provide a filtered voltage based on the current sensing voltage; A current characteristic acquisition circuit is coupled to the low-pass filter to provide the current characteristic voltage based on the filtered voltage.

3. The display panel detection device according to claim 2, characterized in that: The current sensing circuit includes: A sensing resistor is coupled in series with the display panel between a system high voltage and a ground voltage to provide the sensing voltage; a first differential amplifier having a positive input terminal and a negative input terminal for receiving the sensing voltage, and an output terminal for providing the current sensing voltage; a first capacitor coupled between the positive input terminal and the negative input terminal; a second capacitor coupled between the positive input terminal and the ground voltage; and A third capacitor is coupled between the negative input terminal and the ground voltage.

4. The display panel detection device according to claim 2, characterized in that: The low-pass filter comprises: a first resistor coupled between the current sensing voltage and the filtered voltage; and A fourth capacitor is coupled between the filtered voltage and the ground voltage.

5. The display panel detection device according to claim 2, characterized in that: The current characteristic acquisition circuit includes: a second differential amplifier having a positive input terminal receiving the filtered voltage, a negative input terminal, and an output terminal; a first diode having an anode coupled to the output terminal and a cathode coupled to the negative input terminal; a second resistor coupled between the negative input terminal and the current characteristic voltage; and A fifth capacitor is coupled between the current characteristic voltage and the ground voltage.

6. The display panel detection device according to claim 1, characterized in that: When the difference between the current characteristic data and a panel preset value set by the display panel at the factory is less than a critical value, the panel status signal indicates that the display panel is operating within the rated chromaticity range; when the difference between the current characteristic data and the panel preset value is greater than or equal to the critical value, the panel status signal indicates that the display panel is operating outside the rated chromaticity range.

7. The display panel detection device according to claim 1, characterized in that: The current characteristic voltage is one of a maximum voltage, a minimum voltage, and an average value of a sensing voltage generated by the total current of the panel passing through a sensing resistor in a sensing cycle.

8. A method for detecting a display panel, characterized in that: The display panel is installed on a front of a vehicle and displays a vehicle logo while the vehicle is running. The detection method includes: Receiving a total panel current flowing through the display panel via a current sensing circuit to provide a current characteristic voltage; Providing a current characteristic data based on the current characteristic voltage via an analog-to-digital converter; and A judging circuit is used to judge whether the display panel is operated in a rated chromaticity range based on the current characteristic data, so as to provide a panel status signal.

9. The display panel detection method according to claim 8, characterized in that: When the difference between the current characteristic data and a panel preset value set by the display panel at the factory is less than a critical value, the panel status signal indicates that the display panel is operating within the rated chromaticity range; when the difference between the current characteristic data and the panel preset value is greater than or equal to the critical value, the panel status signal indicates that the display panel is operating outside the rated chromaticity range.

10. The display panel detection method according to claim 8, characterized in that: The current characteristic voltage is one of a maximum voltage, a minimum voltage, and an average value of a sensing voltage generated by the total current of the panel passing through a sensing resistor in a sensing cycle.

Images