Patent Publication Number: US-11035890-B2

Title: Abnormality detection data recording device

Description:
TECHNICAL FIELD 
     The present disclosure relates to a technique of processing an abnormality detected by, for example, an overcurrent protection function, an overvoltage protection function, or the like. 
     BACKGROUND 
     A liquid crystal display device is used not only as an output part of a television receiver or as a monitor of a personal computer but also as an in-vehicle monitor or the like. 
     For example, when a liquid crystal display device is used as an in-vehicle monitor, the abnormality detection of the liquid crystal display device is particularly important in order to secure the safety of the vehicle. 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     [Patent Document 1] Japanese Patent Laid-Open No. 2011-70282 
     [Patent Document 2] Japanese Patent Laid-Open No. 2011-34507 
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     However, the conventional liquid crystal display device has a protection function of protecting it when an abnormality is detected, but it has a configuration in which the history does not remain even when the abnormality is detected. 
     Further, the related art discloses a technique of processing a communication abnormality, but does not disclose a configuration capable of detecting an abnormality and leaving its history. 
     The present disclosure provides some embodiments of an abnormality detection data recording device capable of detecting an abnormality and leaving its history. 
     Means for Solving Problem 
     According to one embodiment of the present disclosure, there is provided an abnormality detection data recording device including a first semiconductor integrated circuit device and a second semiconductor integrated circuit device. The first semiconductor integrated circuit device includes an abnormality detection part configured to detect an abnormality of an electronic device in which the abnormality detection data recording device is installed, and a transmission part configured to transmit abnormality detection data indicative of the abnormality detected by the abnormality detection part. The second semiconductor integrated circuit device includes a reception part configured to receive the abnormality detection data by wired communication with the transmission part, and a storage part configured to nonvolatilely store the abnormality detection data received by the reception part (first configuration). 
     In the first configuration of the abnormality detection data recording device, the wired communication is 1-wire serial communication (second configuration). 
     In the second configuration of the abnormality detection data recording device, the abnormality detection data is a plurality of pulse signals, a number of the pulse signals corresponding to a type of the abnormality detected by the abnormality detection part (third configuration). 
     In the third configuration of the abnormality detection data recording device, the second semiconductor integrated circuit device includes a mask part between the reception part and the storage part, which is configured to mask a pulse whose pulse width is equal to or less than a predetermined value with respect to the abnormality detection data received by the reception part (fourth configuration). 
     In any one of the first to fourth configurations of the abnormality detection data recording device, the first semiconductor integrated circuit device further includes: an output abnormality detection part configured to detect an output abnormality of the first semiconductor integrated circuit device; and a first terminal kept at a predetermined level when an output abnormality of the first semiconductor integrated circuit device is detected by the output abnormality detection part. The second semiconductor integrated circuit device further includes: a second terminal kept at the predetermined level when an abnormality of the electronic device, in which the abnormality detection data recording device is installed, is detected by the abnormality detection part. The abnormality detection data recording device includes a signal line that connects the first terminal and the second terminal (fifth configuration). 
     In any one of the first to fifth configurations of the abnormality detection data recording device, the electronic device is a liquid crystal display device, the first semiconductor integrated circuit device is a level shifter IC, and the second semiconductor integrated circuit device is a system power supply IC configured to supply a power supply voltage to at least the level shifter IC (six configuration). 
     According to another embodiment of the present disclosure, there is provided a semiconductor integrated circuit device including: an abnormality detection part, and a transmission part. The abnormality detection part is configured to detect an abnormality of an electronic device mounted with the semiconductor integrated circuit device, and the transmission part is configured to transmit abnormality detection data indicative of the abnormality detected by the abnormality detection part to a reception part of another semiconductor integrated circuit device by wired communication (seventh configuration). 
     According to another embodiment of the present disclosure, there is provided a semiconductor integrated circuit device including a reception part and a storage part. The reception part is configured to receive abnormality detection data transmitted from a transmission part of another semiconductor integrated circuit device by wired communication, and the storage part is configured to nonvolatilely store the abnormality detection data received by the reception part (eight configuration) 
     According to another embodiment of the present disclosure, there is provided a liquid crystal display device including the abnormality detection data recording device of any one of the first to sixth configurations (ninth configuration). 
     According to another embodiment of the present disclosure, there is provided a liquid crystal display device including the abnormality detection data recording device of any one of the first to seventh configurations (tenth configuration). 
     Effect of the Invention 
     According to the present disclosure in some embodiments, it is possible to detect an abnormality and to leave its history by the abnormality detection data recording device disclosed herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a configuration of a liquid crystal display device according to one embodiment of the present disclosure. 
         FIG. 2  is a diagram illustrating a configuration example of a pixel array. 
         FIG. 3  is a diagram illustrating a configuration example of an abnormality detection data recording device. 
         FIGS. 4A to 4D  are diagrams illustrating examples of abnormality detection data. 
         FIG. 5  is a diagram illustrating an exemplary modification of the abnormality detection data recording device. 
         FIG. 6  is a diagram illustrating another exemplary modification of the abnormality detection data recording device. 
         FIG. 7  is a diagram illustrating still another exemplary modification of the abnormality detection data recording device. 
         FIG. 8  is an exterior view of a vehicle. 
         FIG. 9  is a view illustrating an interior of the vehicle. 
     
    
    
     EMBODIMENT FOR THE INVENTION 
     &lt;Configuration of Liquid Crystal Display Device&gt; 
     First, a configuration example of a liquid crystal display device  1  will be described.  FIG. 1  is a block diagram illustrating a configuration of the liquid crystal display device  1 . The liquid crystal display device  1  includes a pixel array  11 , a system power supply IC  12 , a timing control IC  13 , a level shifter IC  14 , a gate driver  15 , a source driver  16 , a gamma correction IC  17 , and a backlight (not shown). 
     As illustrated in  FIG. 2 , the pixel array  11  includes a plurality of pixel circuits  11 A arranged in a plurality of rows and a plurality of columns, a plurality of gate lines GL, which is installed to correspond to the plurality of rows, respectively, and a plurality of source lines SL, which is installed to correspond to the plurality of columns, respectively. One end of each of the gate lines GL is connected to the gate driver  15 . One end of each of the source lines SL is connected to the source driver  16 . 
     Each of the pixel circuits  11 A has a thin film transistor (TFT)  11 B and a liquid crystal cell  11 C. Unlike the present embodiment, a switch other than the TFT, which may be controlled to be turned on and off depending on a voltage applied to the gate line GL, may also be used instead of the TFT. A gate of each TFT  11 B is connected to a corresponding gate line GL. A source of each TFT  11 B is connected to a corresponding source line SL. A drain of each TFT  11 B is connected to a common line (not shown) to which a common voltage is applied via a corresponding liquid crystal cell  11 C. The liquid crystal cell  11 C has two transparent electrodes facing each other and a liquid crystal sealed between the two transparent electrodes. 
     When the gate line GL has a low level, i.e., when a negative power source voltage VOFF as described hereinbelow is applied to the gate line GL, the TFF  11 B is turned off. On the other hand, when the gate line GL has a high level, i.e., a positive power supply voltage VON to be described later is applied to the gate line GL, the TFF  11 B is turned on. When the TFF  11 B is in an ON state, a voltage of the source line SL is written in a storage node N between the drain of the TFF  11 B and the liquid crystal cell  11 C, and the voltage written in the storage node N 1  is held in the storage node N 1  by switching the TFF  11 B from the ON state to the OFF state. The light transmittance of the liquid crystal cell  11 C varies depending on the voltage written in the storage node N 1 . 
     Returning to  FIG. 1 , the system power supply IC  12  operates in response to the supply of an input voltage VIN, and generates an analog power supply voltage AVDD, a logic power supply voltage VDD, a positive power supply voltage VON and a negative voltage VOFF, respectively, for supplying to each part of the device. 
     The timing control IC  13  operates in response to the supply of the logic power supply voltage VDD, and controls timing of operation of the gate driver  15  and the source driver  16 , for example, based on a video signal V-SIG supplied from a GPU (not shown) in  FIG. 1 . 
     The level shifter IC  14  operates in response to the supply of the positive power supply voltage VON and the negative power supply voltage VOFF, shifts the level of a control signal supplied from the timing control IC  13  and then transfers it to the gate driver  15 . 
     The gate driver  15  sequentially selects the plurality of gate lines GL of the pixel array  1  at predetermined time intervals. The gate driver  15  sets the selected gate line GL to a high level. 
     In the present embodiment, the gate driver  15  has a plurality of gate drivers ICs. A plurality of gate lines GL is allocated to the respective gate drivers ICs, and each gate line GL is connected to one of the gate drivers ICs. Unlike the present embodiment, the gate driver  15  may also be configured by a single gate driver IC. 
     Furthermore, in the present embodiment, each gate driver IC is mounted on a glass substrate on which the pixel array is formed, by chip on glass (COG). Unlike the present embodiment, each gate driver IC may not be mounted on the glass substrate and may be mounted on a substrate (e.g., a printed circuit board or the like) other than the glass substrate. 
     The source driver  16  writes a voltage of a level corresponding to the video signal V-SIG to the storage node N 1  of each pixel circuit  11 A corresponding to the gate line GL selected by the gate driver  15  via each source line SL. 
     In the present embodiment, the source driver  16  has a plurality of source driver ICs. A plurality of source lines SL is allocated to the respective source drivers ICs, and each source line SL is connected to one of the source drivers ICs. Unlike the present embodiment, the source driver  16  may also be configured by a single source driver IC. 
     Furthermore, in the present embodiment, each source driver IC is mounted on a glass substrate on which the pixel array is formed, by chip on glass (COG). Unlike the present embodiment, each source driver IC may not be mounted on the glass substrate and may be mounted on a substrate (e.g., a printed circuit board or the like) other than the glass substrate. 
     The gamma correction IC  17  generates a gamma correction voltage in response to the supply of the analog power supply voltage AVDD from the system power supply IC  12 , and supplies the gamma correction voltage to the source driver  16 . 
     The backlight (not shown) irradiates the rear surface of the pixel array  11  with light. The light incident from the rear surface of the pixel array  11  is adjusted in luminance according to the light transmittance of each liquid crystal cell  11 C in each pixel of the pixel array  11  and then emitted from the front of the pixel array  11 . 
     &lt;Configuration of Abnormality Detection Data Recording Device&gt; 
     The aforementioned liquid crystal display device  1  includes an abnormality detection data recording device illustrated in  FIG. 3 . The abnormality detection data recording device illustrated in  FIG. 3  includes the level shifter IC  14  and the system power supply IC  12 . A voltage VL in  FIG. 3  may be, for example, a voltage having the same value as the input voltage VIN in  FIG. 1 . 
     The level shifter IC  14  includes a protection part  14 A, a logic part  14 B, negative-channel metal oxide semiconductor (NMOS) transistors  14 C and  14 D, a pull-up resistor  14 E, and external terminals T 1  to T 4 . 
     The system power supply IC  12  includes a pull-up resistor  12 A, an inverter part  12 B, a logic part  12 C, an electrically erasable programmable read-only memory (EEPROM)  12 D, an NMOS transistor  12 E, a pull-up resistor  12 F, and external terminals T 5  to T 8 . The logic part  12 C includes a mask part  12 G. 
     When an abnormality of the liquid crystal display device  1  is detected, the protection part  14 A protects the liquid crystal display device  1  by stopping or limiting the output of the level shifter IC  14 , or the like. Examples of the abnormality of the liquid crystal display device  1  detected by the protection part  14 A may include an overcurrent, an abnormality of the pixel array  11 , a poor connection between the liquid crystal display panel including the pixel array  11  and the level shifter IC  14 , and the like. 
     The logic part  14 B generates a plurality of pulse signals (abnormality detection data), the number of the pulse signals corresponding to the type of abnormality of the liquid crystal display device  1  detected by the protection part  14 A. For example, when using  1  to  4  pulse signals as illustrated in  FIGS. 4A to 4D , four types of abnormalities may be expressed. It is desirable that all pulse widths W 1  of the pulse signals be substantially the same, and it is also desirable that a predetermined period T 1  in which no pulse exists at the end of the pulse signals be provided. The value of the pulse width W 1  and the value of the predetermined period T 1  are not particularly limited, but for example, the pulse width W 1  may be set to 6 μs and the value of the predetermined period T 1  may be set to 25 μs. Itis also desirable that the interval between adjacent pulses be equal to the pulse width W 1 . In the present embodiment, the period during which no pulse is generated is set to a high level, but conversely, the period during which no pulse is generated may be set to a low level. 
     In the case where the level shifter IC  14  is a level shifter IC having outputs of a plurality of channels, for example, the outputs of the plurality (m) of channels are divided into a plurality (n, where n&lt;m) groups according to the magnitude of the output current capability, and if there is a channel that may be in an overcurrent in any group, the overcurrent of the corresponding group may be detected. That is, the type of abnormality of the liquid crystal display device  1  may be classified for each group. On the other hand, an overcurrent of each channel may be detected. That is, the type of abnormality of the liquid crystal display device  1  may be classified for each channel. 
     The logic part  14 B outputs the generated pulse signal (abnormality detection data) to a gate of the NMOS transistor  14 C. A source of the NMOS transistor  14 C is connected to a ground potential, and a drain of the NMOS transistor  14 C is connected to the external terminal T 1 . 
     The external terminal T 1  is pulled up by an external resistor R 1  and also connected to the external terminal T 5  of the system power supply IC  12  by an external wiring. The external terminal T 5  is pulled up by the pull-up resistor  12 A and also connected to an input terminal of the inverter  12 B. An output terminal of the inverter  12 B is connected to the logic part  12 C. 
     Therefore, the pulse signal (abnormality detection data) is sent from the level shifter IC  14  to the system power supply IC  12  by 1-wire serial communication, and is supplied to the logic part  12 C in an inverted form. 
     The mask part  12 G of the logic part  12 C masks a pulse whose pulse width is equal to or less than a predetermined value V 1  with respect to the pulse signal (abnormality detection data). The predetermined value V 1  may be set to a value slightly smaller than the pulse width W 1 . This makes it possible to remove a noise when the pulse-shaped noise having a narrow width is superimposed on the pulse signal (abnormality detection data). 
     The logic part  12 C writes the pulse signal (abnormality detection data) masked by the mask part  12 G in the EEPROM  12 D. Accordingly, the abnormality detection data recording device illustrated in  FIG. 3  can detect an abnormality and leave its history. The data written in the EEPROM  12 D may be the same logic as the pulse signal (abnormality detection data) or may be an inverted logic of the pulse signal (abnormality detection data). 
     The logic part  12 C is connected to the external terminals T 6  and T 7 . The external terminals T 6  and T 7  are connected to the timing control IC  13  by respective external wirings. Therefore, the timing control IC  13  can read out the abnormality detection data written in the EEPROM  12 D. It may also be configured such that an IC other than the timing control IC  13  reads out the abnormality detection data written in the EEPROM  12 D. The abnormality detection data read out from the EEPROM  12 D may be used for, for example, processing of the entire liquid crystal display device  1  in the event of occurrence of abnormality, analysis of a portion where an abnormality occurs, or the like. 
     Furthermore, the logic part  14 B is connected to the external terminals T 2  and T 3 . The external terminals T 2  and T 3  are connected to the timing control IC  13  by respective external wirings. 
     A gate of the NMOS transistor  14 D is connected to the logic part  14 B and a source of the NMOS transistor  14 D is connected to the ground potential. A drain of the NMOS transistor  14 D is connected to the external terminal T 4  and also connected to the pull-up resistor  14 E. Furthermore, a gate of the NMOS transistor  12 E is connected to the logic part  12 C and a source of the NMOS transistor  12 E is connected to the ground potential. A drain of the NMOS transistor  12 E is connected to the external terminal T 8  and also connected to the pull-up resistor  14 F. The external terminal T 4  and the external terminal T 8  are connected by an external wiring. 
     When an output abnormality of the system power supply IC  12  is detected by an output abnormality detection part (not shown) which is installed in the system power supply IC  12  and detects an output abnormality of the system power supply IC  12 , the logic part  12 C turns on the NMOS transistor  12 E to set the external terminals T 8  and T 4  to a low level. In addition, when an abnormality of the liquid crystal display device  1  is detected by the protection part  14 A, the logic part  14 B turns on the NMOS transistor  14 D to set the external terminals T 4  and T 8  to a low level. 
     The logic part  14 B recognizes an abnormality of the system power supply IC  12  based on the voltage level of the external terminal T 4 , and performs a necessary protection operation when there is an output abnormality in the system power supply IC  12 . Likewise, the logic part  12 C recognizes an abnormality of the level shifter IC  14  based on the voltage level of the external terminal T 8 , and performs a necessary protection operation when there is an abnormality in the liquid crystal display device  1 . This makes it possible to perform appropriate protection when an abnormality occurs in both the system power supply IC  12  and the level shifter IC  14 . 
     In the present embodiment, there is one IC that transmits the abnormality detection data, but a plurality of ICs that transmits the abnormality detection data may be used. For example, when ICs that transmit the abnormality detection data are two ICs  1 A and  1 B, the configurations as illustrated in  FIGS. 5 to 7  are considered. 
     In the configuration illustrated in  FIG. 5 , the abnormality detection data transmission line of IC  1 A and the abnormality detection data transmission line of IC  1 B are separated from each other. In this case, it is necessary to install two external terminals for receiving the abnormality detection data in the IC that receives the abnormality detection data. 
     In the configuration illustrated in  FIG. 6 , the abnormality detection data transmission line of IC  1 A and the abnormality detection data transmission line of IC  1 B are common to each other. In this case, only one external terminal is required to receive the abnormality detection data in the IC that receives the abnormality detection data, but it is necessary to include a flag or the like for identifying whether it is data derived from IC  1 A or IC  1 B in the abnormality detection data. 
     In the configuration illustrated in  FIG. 7 , IC  1 A also transmits the abnormality detection data of IC  1 B. In this case, only one external terminal is required to receive the abnormality detection data in the IC that receives the abnormality detection data, but it is necessary to include a flag or the like for identifying whether it is data derived from IC  1 A or IC  1 B in the abnormality detection data. 
     &lt;Applications of Liquid Crystal Display Device&gt; 
     The aforementioned liquid crystal display device  1  is mounted on, for example, a vehicle  101  illustrated in  FIG. 8 . The liquid crystal display device  1  may be used as, for example, at least one of a center information display (CID)  102  for performing a map display of car navigation or the like, an instrument cluster  103 , display devices  104 L and  104 R of an electronic side mirror system, and a display device  105  of an electronic rear-view mirror system (see  FIG. 9 ). When the liquid crystal display device is applied to the instrument cluster  103 , it may be configured by one liquid crystal display device for performing display of a plurality of instruments, or configured by a plurality of liquid crystal displays, each performing display of at least one instrument. 
     Notes 
     Various technical features disclosed herein may be differently modified, as well as the aforementioned embodiment, without departing from the spirit of the present disclosure. 
     For example, in the aforementioned embodiment, the abnormality detection data recording device is mounted on the liquid crystal display device, but it may be mounted on an electronic device other than the liquid crystal display device. 
     Furthermore, in the aforementioned embodiment, the abnormality detection data recording device transmits and receives the abnormality detection data by 1-wire serial communication, but it may transmit and receive the abnormality detection data by wired communication other than the 1-wire serial communication. 
     That is, the aforementioned embodiments are merely illustrative in all aspects and should not be understood as limiting, and the technical scope of the present disclosure is not the description of the aforementioned embodiments but presented by the accompanying claims. Therefore, it is to be understood that it includes all modifications that fall within the meaning and scope of the accompanying claims and their equivalents. 
     EXPLANATION OF REFERENCE NUMERAL 
     
         
           10  liquid crystal display device 
           12  system power supply IC 
           13  timing control IC 
           14  level shifter IC 
           101  vehicle