Display control device, display control method, and display control system

Abstract

In the present invention, a first processor executes start-up processing of the first processor if a predetermined condition based on a situation of a vehicle or a situation outside the vehicle is satisfied, and executes safety display processing for displaying a safety-related image on a display unit after the start-up processing of the first processor. The start-up processing of the first processor includes reading out of data necessary for the safety display processing, and an amount of data read out for the safety display processing is smaller than an amount of data read out for normal display processing for displaying a normal display image on the display unit.

Description

Display control device, display control method, and display control system

[0001] The present invention relates to a display control device, a display control method, and a display control system.

[0002] A technology is known in which, when a specific type of data is received that is transmitted when a change in the vehicle state is detected, a second control means is activated, and a state is transitioned to in which a program is read and expanded into memory, and when an activation operation is input, the program expanded into memory is executed by the second control means (Patent Document 1).

[0003] JP 2016-91257 A

[0004] However, in the technology described in Patent Document 1, the second control means must read a large amount of data, including an image processing program, and load it into memory at startup to transition to a state where image processing can be performed, which results in a problem of a long time being required from the start of startup until the safety image is displayed.

[0005] The problem to be solved by the present invention is to provide a display control device, a display control method, and a display control system that can shorten the time from start-up until a safety-related image is displayed.

[0006] The present invention solves the above problem by executing a startup process of a first processor when predetermined conditions based on the vehicle situation or the situation outside the vehicle are met, and after the startup process of the first processor, executing a safety display process that displays a safety-related image on a display unit, the startup process of the first processor including reading of data necessary for the safety display process, and the amount of data read for the safety display process being smaller than the amount of data read for the normal display process that displays a normal display image on the display unit.

[0007] According to the present invention, it is possible to reduce the time from when the start-up begins until the safety-related image is displayed.

[0008] FIG. 1 is a block diagram showing the configuration of a display control system including a display control device according to an embodiment of the present invention. FIG. 2 is a diagram showing an example of a flowchart of control processing of a display control method executed by the display control device according to the embodiment. FIG. 3 is a diagram showing an example of a flowchart of a control procedure of battery monitoring processing executed by a microcontroller according to the embodiment. FIG. 4 is a diagram showing a timing chart of each process in the display control device according to the embodiment and a screen display on a display device. FIG. 5 is a diagram showing a timing chart of each process in the display control device according to the embodiment and a screen display on a display device. FIG. 6 is a diagram showing a timing chart of each process in the display control device according to the embodiment and a screen display on a display device. FIG. 7 is a diagram showing an example of a flowchart of control processing of a display control method executed by the display control device according to the embodiment. FIG. 8 is a diagram showing an example of a flowchart of control processing of a display control method executed by the display control device according to the embodiment.

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A display control device, a display control method, and a display control system according to embodiments of the present invention will be described below with reference to the accompanying drawings. In the present embodiment, an example in which the display control device is provided in a vehicle will be described.

[0010] A display control system including a display control device according to an embodiment of the present invention will be described using Fig. 1. The display control system is a system that performs display control to display images to a user. Fig. 1 is a block diagram showing the configuration of a display control system including a display control device according to an embodiment of the present invention. The display control system 1 includes a CAN bus 2, a display control device 3, and a display device 4. Each device is a device mounted on a vehicle. A user is a vehicle occupant, and is primarily the driver of the vehicle, but the user may also be a passenger other than the driver.

[0011] The display control device 3 is one of the onboard ECUs (Electronic Control Units) installed in the vehicle and controls the image display on the display device 4. Images displayed on the display device 4 include, for example, normal display images including vehicle information and information other than the vehicle information provided to the user. The vehicle information is information related to the vehicle's status, such as vehicle meter information. The information other than the vehicle information provided to the user is, for example, infotainment information including navigation information and entertainment information. Images displayed on the display device 4 include safety-related images. The display control device 3 is connected to an onboard network, such as a Controller Area Network (CAN), and can exchange information with other onboard ECUs (not shown) using a CAN bus 2 or the like. The other onboard ECUs include, for example, a body-related ECU, a driving-related ECU, a power supply-related ECU, and a multimedia-related ECU. The display control device 3 acquires information from the other onboard ECUs and outputs images to the display device 4 based on the acquired information. The display device 4 displays the images output from the display control device 3.

[0012] The display control device 3 includes a microcontroller 10, a system-on-chip 20, and an OSD control device 30. These devices are connected by communication means and can transmit and receive information to and from each other. The microcontroller 10, the system-on-chip 20, and the OSD control device 30 are different semiconductor devices, each with different functions. HDMI (registered trademark) is used as the image input / output interface between the system-on-chip 20 and the OSD control device 30 and between the OSD control device 30 and the display device 4. SPI communication is also used for information communication between the microcontroller 10 and the OSD control device 30. The microcontroller 10 and the system-on-chip 20 are examples of the "first processor" and the "second processor" respectively set forth in the claims.

[0013] In this embodiment, the "first processor" and the "second processor" are described as the microcontroller 10 and the system-on-chip 20, but these semiconductor devices are not limited to these as long as they have the functions to realize each process. For example, the semiconductor device may be a device that includes multiple semiconductor chips for realizing each function, with the semiconductor chips being interconnected.

[0014] The microcontroller 10 is a so-called MCU (microcontroller unit), a semiconductor device in which a CPU and peripheral circuits such as memory are integrated on a single chip. The memory includes a ROM storing programs for implementing the software of the microcontroller 10 and a RAM functioning as an accessible storage device. The CPU executes the programs stored in the ROM to perform various processes, thereby implementing the software of the microcontroller 10. The microcontroller 10 includes functional blocks including a CAN communication unit 11 that communicates with other vehicle ECUs via a CAN bus 2, a startup processing unit 12 that executes startup processing, a safety display unit 13 that executes safety display processing, and a battery monitoring unit 14 that monitors the battery voltage. The microcontroller 10 executes each function through cooperation between the software for implementing each function or each process and hardware. The programs stored in the memory include a safety display program. The safety display program causes the CPU to execute each function for implementing the safety display processing. The microcontroller 10 reads various programs, including the safety display program, from the ROM and executes the read safety display program to execute the safety display processing.

[0015] The microcontroller 10 acquires various information from other in-vehicle ECUs via the CAN bus 2 using the CAN communication unit 11. The acquired information includes startup instruction information that instructs the start of startup. The startup instruction information is output to the microcontroller 10 when a predetermined condition is satisfied. The predetermined condition is a condition based on the vehicle status or the status outside the vehicle, such as a condition that a vehicle door is in an open state or a condition that a vehicle door is estimated to be in an open state. In this embodiment, a vehicle monitoring ECU (not shown), which is different from the display control device 3, monitors whether a predetermined condition is satisfied based on the vehicle status or the status outside the vehicle, and outputs startup instruction information to the microcontroller 10 when the predetermined condition is satisfied. For example, the vehicle monitoring ECU determines that a vehicle door is in an open state when it detects a vehicle door opening control. Furthermore, the vehicle monitoring ECU estimates that a vehicle door is in an open state when it detects a user approaching the vehicle. Furthermore, the vehicle monitoring ECU estimates that a vehicle door is in an open state when it detects a door unlock. When the vehicle monitoring ECU determines that a vehicle door will be opened or when it estimates that a vehicle door will be opened, it outputs activation instruction information to the microcontroller 10. The predetermined condition may be a condition related to the state of the vehicle or the state outside the vehicle before the vehicle is started. The activation of the vehicle refers to the time when the ACC or IGN is turned on by the user.

[0016] The information acquired via the CAN bus 2 also includes vehicle information including a vehicle status and / or infotainment-related information. The vehicle information includes meter information such as vehicle speed information and vehicle energy information. The vehicle information also includes safety-related vehicle status. The safety-related vehicle status includes information regarding the status of safety devices such as brakes, ABS, airbags, and seat belts. When the system-on-chip 20 is activated, the microcontroller 10 outputs the vehicle information and / or infotainment-related information acquired from other in-vehicle ECUs to the system-on-chip 20.

[0017] The microcontroller 10 executes a startup process for the microcontroller 10 via the startup processing unit 12 when predetermined conditions based on the vehicle status or the status outside the vehicle are satisfied. Specifically, when startup instruction information is input from the CAN bus 2 due to the predetermined conditions being satisfied, the microcontroller 10 starts the startup process. The startup process includes initializing the microcontroller 10 and reading data necessary to execute each function of the microcontroller 10. The read data includes data necessary for safety display processing, such as a safety display program. By reading data, the microcontroller 10 transitions to a state in which the safety display processing can be executed. The amount of data read for the safety display processing is smaller than the amount of data read for the normal display processing, which displays a normal display image on the display device 4. Because the microcontroller 10 reads a smaller amount of data to execute the safety display processing than when the normal display processing is executed, the time required to read data is shorter than when the normal display processing is executed. Therefore, in this embodiment, the time from when the startup starts to when a safety-related image is displayed can be shortened. The normal display processing will be described later.

[0018] After the microcontroller 10 starts up, the microcontroller 10 executes a safety display process in which the safety display unit 13 displays a safety-related image (hereinafter also referred to as a safety display image) on the display device 4. The safety display process is a process for quickly displaying a safety-related image, for example, a simple OSD image on the display device 4. The safety display process has a smaller processing load than the normal display process. In the safety display process, the microcontroller 10 generates safety display information for executing the safety display process and outputs the safety display information to the OSD control device 30. For example, the microcontroller 10 generates the safety display information based on vehicle information acquired from the CAN bus 2. The safety display information includes, for example, instruction information for instructing the display device 4 to display a safety-related image from among pre-stored safety-related images. Specifically, the microcontroller 10 identifies a safety-related image to be displayed on the display device 4 based on the vehicle status indicated by the vehicle information, and generates instruction information for displaying the identified safety-related image on the display device 4. In this embodiment, a corresponding safety-related image is associated with each vehicle status. The safety-related image is an image including information related to safety. The safety-related information is information necessary for a user to make a safety decision, and is information related to the vehicle state, particularly information warning that there is an abnormality in the vehicle state. For example, a vehicle state in which there is an abnormality in the vehicle brakes is linked to a safety-related image including a warning display such as a telltale warning that there is an abnormality in the brakes. Furthermore, a vehicle state in which the vehicle door is open or the vehicle's remaining energy is low is linked to a safety-related image including a warning display warning that the vehicle door is open and a warning display warning that the vehicle's remaining energy is low, respectively. Furthermore, the vehicle state may be the vehicle speed. A safety-related image indicating the vehicle speed is linked to each vehicle speed.

[0019] In this embodiment, the instruction information may include identification information for identifying a safety-related image to be displayed on the display device 4. The identification information may be, for example, an ID number assigned to each safety-related image. Identification information for identifying a corresponding safety-related image is stored for each vehicle state. In other words, the safety display information is not the safety-related image itself, but identification information for identifying the safety-related image, and has a smaller data volume than image information such as a safety-related image and a normal display image. Therefore, the processing load of the microcontroller 10 related to the safety display processing, including the generation and output processing of the safety display information, can be reduced, and the safety display information can be output to the OSD control device 30 at a higher speed than the system-on-chip 20, which has a higher processing load. Note that in this embodiment, the microcontroller 10 may store a safety display image in its memory and output the safety display image to the OSD control device 30 as safety display information instead of the instruction information and identification information. Even in this case, the safety display image is a simple image with a smaller data volume than a normal display image. For example, the safety display image may be an image of a number such as the vehicle speed, a symbol indicating meter information, or an icon indicating a warning message.

[0020] As described above, the microcontroller 10 identifies a corresponding safety information image according to the vehicle status, and generates instruction information including identification information for identifying the identified safety information image as safety display information. For example, if there is a safety device with an abnormality, the microcontroller 10 generates instruction information for displaying a safety information image including a warning display warning that the safety device has an abnormality, based on vehicle information regarding the status of the vehicle's safety devices. The generated safety display information is output to the OSD control device 30.

[0021] Furthermore, after the microcontroller 10 has performed its startup process, the microcontroller 10 monitors the state of the vehicle's battery using the battery monitoring unit 14. The microcontroller 10 periodically acquires battery voltage information via the CAN bus 2. The voltage information is information obtained by measuring the battery voltage. The microcontroller 10 changes the timing at which it outputs startup instruction information to the system-on-chip 20 depending on the battery voltage. Specifically, the microcontroller 10 determines whether the battery voltage is equal to or higher than a first predetermined voltage based on the voltage information. If the battery voltage is equal to or higher than the first predetermined voltage, the microcontroller 10 outputs startup instruction information to the system-on-chip 20 before the vehicle starts. "Before the vehicle starts" refers to before a startup operation is input to turn on the vehicle's ACC or IGN. If the battery voltage is lower than the first predetermined voltage, the microcontroller 10 prohibits output of startup instruction information to the system-on-chip 20 before the vehicle starts, and outputs startup instruction information to the system-on-chip 20 when the vehicle starts.

[0022] Furthermore, after outputting the startup instruction information to the system-on-chip 20, the microcontroller 10 executes a display switching process when startup completion information indicating that the startup process is completed is input from the system-on-chip 20. In the display switching process, the microcontroller 10 stops output of the safety-related image by turning off an OSD line for outputting the safety-related image to the display device 4, and starts output of the normal display image by turning on a graphic line for outputting the normal display image to the display device 4.

[0023] Furthermore, the microcontroller 10 is not limited to monitoring whether the battery voltage is equal to or higher than a first predetermined voltage, but may also monitor whether the battery voltage is equal to or lower than a second predetermined voltage, which is lower than the first predetermined voltage. The first predetermined voltage is a voltage higher than the second predetermined voltage by a required voltage. The required voltage is a voltage required to continue displaying meter information until the meter information is hidden. The second predetermined voltage is a voltage minimum required to start the vehicle. When the battery voltage is equal to or lower than the second predetermined voltage, the microcontroller 10 stops supplying power to the peripheral elements until a startup operation to start the vehicle is input. The peripheral elements are elements other than the microcontroller 10 that constitute the display control system 1. The peripheral elements include the display device 4 and the system-on-chip 20. Furthermore, the microcontroller 10 may write data related to normal display processing by the system-on-chip 20 to a non-volatile memory before stopping the power supply to the peripheral elements. In other words, the system-on-chip 20 transitions to a so-called Suspend to Disk state. In this case, the second predetermined voltage may be any voltage higher than the voltage required to write data related to the normal display process into the nonvolatile memory.

[0024] Furthermore, when a condition that a vehicle door is open is satisfied, the microcontroller 10 after the startup process may control the output of startup instruction information to the system-on-chip 20 depending on whether the opened vehicle door is a door other than the driver's door. The microcontroller 10 acquires information about the opened door via the CAN bus 2. The door information is information indicating the position of the door, i.e., which seat door the door is located in the vehicle. When the opened door is the driver's door, if the battery voltage is equal to or higher than a first predetermined voltage, the microcontroller 10 outputs startup instruction information to the system-on-chip 20 before the vehicle is started. When the opened door is a door other than the driver's door, the microcontroller 10 prohibits the output of startup instruction information to the system-on-chip 20 before the vehicle is started, even if the battery voltage is equal to or higher than the first predetermined voltage, and outputs startup instruction information to the system-on-chip 20 when the vehicle is started. Doors other than the driver's door include, for example, a rear door and a back door. If the rear door or back door is open, but not the driver's door, it is assumed that the door is open not to drive the vehicle, but to allow a child to get in or out of the rear seat or to load or unload luggage.

[0025] Furthermore, the microcontroller 10 may control the output of startup instruction information to the system-on-chip 20 according to vehicle position information. After the startup process of the microcontroller 10, the microcontroller 10 acquires position information indicating the current position of the vehicle. When the current position of the vehicle is a repair shop or a car wash, the microcontroller 10 prohibits the output of startup instruction information to the system-on-chip 20 even if the battery voltage is equal to or higher than a first predetermined voltage. Furthermore, in addition to prohibiting the output of startup instruction information to the system-on-chip 20, the microcontroller 10 stops the supply of power to peripheral elements other than the microcontroller 10. When the current position of the vehicle is not a repair shop or a car wash, and the battery voltage is equal to or higher than the first predetermined voltage, the microcontroller 10 outputs startup instruction information to the second processor before the vehicle starts. When the vehicle is located in a repair shop or a car wash when the door is opened, it is assumed that the door is opened for maintenance or cleaning of the vehicle, rather than for driving the vehicle.

[0026] As described above, in this embodiment, the microcontroller 10 controls the activation state of the system-on-chip 20 based on battery voltage information. In conventional technology, the activation of the semiconductor device that executes normal display processing is initiated when there is a sign of vehicle operation, such as when a door is opened. However, even when the door is opened, the vehicle may not actually be driven, such as when the door is only opened temporarily for vehicle maintenance, cleaning, or loading and unloading. In such cases, activating the semiconductor device that executes normal display processing each time the door is opened may unnecessarily consume the vehicle's battery power and potentially result in a dead battery. In particular, when the SOC (State of Charge) falls below 60%, lead batteries deteriorate due to sulfation and other factors. In this embodiment, if the microcontroller 10 that was activated first determines that the battery voltage is low, the activation of the system-on-chip 20 is initiated only after the vehicle has actually started, thereby preventing unnecessary consumption of the vehicle's battery power.

[0027] The system-on-chip 20 is a semiconductor device (system on a chip) that includes a CPU, peripheral circuits such as memory, and is designed to function as a system that executes multiple processes on a single chip. The memory includes a ROM that stores programs for implementing the software of the system-on-chip 20, and a RAM that functions as an accessible storage device. The software of the system-on-chip 20 is implemented by the CPU executing the programs stored in the ROM to perform various processes. The system-on-chip 20 is a semiconductor device with higher processing capabilities than the microcontroller 10, and executes image processing and other processes on a larger amount of data than the data processed by the microcontroller 10.

[0028] The system-on-chip 20 has a normal display function and executes normal display processing to display a normal display image on the display device 4. The system-on-chip 20 is configured, for example, with a GPU (Graphics Processing Unit). During startup processing, the system-on-chip 20 executes initialization, reads data necessary for the normal display processing stored in memory, and loads the data into RAM. The data necessary for the normal display processing includes a normal display processing program for displaying the normal display image on the display device 4. The normal display processing program causes the system-on-chip 20 to execute various functions for realizing the normal display processing. The data necessary for the normal display processing includes an OS, a graphics library, and a display application. The system-on-chip 20 loads this data into RAM and then executes the loaded normal display processing program. During the normal display processing, the system-on-chip 20 generates a normal display image to be displayed on the display device 4 and outputs the generated normal display image to the display device 4 via the OSD control device 30.

[0029] In this embodiment, the normal display image generated by the system-on-chip 20 is an image including vehicle information and information other than the vehicle information to be provided to the user. The vehicle information includes, for example, vehicle speed information and vehicle energy information. The normal display image may also include safety information. The information other than the vehicle information to be provided to the user is, for example, so-called infotainment information including navigation information and entertainment information. The navigation information is information that provides route guidance for the vehicle. The navigation information includes, for example, map information, the current position of the vehicle, route information from the current position to the destination, and guidance information for the vehicle to travel the route. The entertainment information is information including entertainment content such as music and videos.

[0030] In the present embodiment, when startup instruction information for starting startup is input from the microcontroller 10, the system-on-chip 20 executes startup processing and transitions to a state in which normal display processing is executable. The system-on-chip 20 executes normal display processing after the startup processing of the system-on-chip 20. In the normal display processing, the system-on-chip 20 acquires information output from other in-vehicle ECUs via the microcontroller 10 and generates a normal display image including vehicle information and infotainment-related information based on the acquired information. The information output from the other in-vehicle ECUs is, for example, vehicle information including the vehicle status and infotainment-related information. The infotainment-related information is information output from a multimedia ECU that controls the vehicle's navigation system and / or content playback system. The normal display image is an image with a larger amount of data than the safety display information. For example, the normal display image is an image with a large amount of data, such as a moving image or a color image. More specifically, the normal display image is a 3D image or an animation. That is, the system-on-chip 20 performs image processing of images with a large amount of data, such as images containing entertainment content such as music and videos. The normal display image is not limited to an image including vehicle information, and may be an image including information other than vehicle information that is provided to the user without including vehicle information. When the startup process is completed, the system-on-chip 20 may output startup completion information indicating that the startup process is completed to the microcontroller 10.

[0031] The display device 4 is a display that displays images to the user. The display device 4 is configured, for example, from a liquid crystal display or an organic EL display. The display device 4 may also be equipped with a speaker that outputs audio information. In this embodiment, the display device 4 is a display that is disposed in front of the driver's seat of the vehicle, extending from the driver's seat to the passenger seat. The display device 4 is a display that includes a so-called instrument panel. Note that the display device 4 is not limited to this, and may also be another in-vehicle display or a display mounted on a portable terminal device. The display device 4 is an example of a "display unit" as defined in the claims.

[0032] The display device 4 has a normal display function that displays a normal display image generated by the system-on-chip 20 and an OSD (on-screen display) display function that displays an OSD image generated by the OSD control device 30. When the normal display image is output as an image signal from the system-on-chip 20 via the OSD control device 30, the display device 4 displays the normal display image using the normal display function. When the safety-related image generated by the OSD control device 30 is output as an image signal, the display device 4 displays the safety-related image using the OSD display function. The display device 4 may switch between displaying the safety-related image and the normal display image. For example, in this embodiment, since the microcontroller 10 starts up before the system-on-chip 20, the display device 4 may first display the safety-related image and then switch the displayed image from the safety-related image to the normal display image after the system-on-chip 20 starts up. Furthermore, after the microcontroller 10 and the system-on-chip 20 start up, the display device 4 may execute the normal display function and the OSD display function in parallel to display a composite image generated by combining the safety-related image and the normal display image.

[0033] Generally, devices that process images containing vehicle information and infotainment information are equipped with large-scale software and require loading a program from storage such as a flash memory into RAM, initializing the program, and then executing the program. Therefore, when such devices are started up, it takes time for the device to execute the startup process and transition to a state where the program can be executed, and therefore no images are displayed on the display device during the startup process. Therefore, during the startup process, the display device displays a black screen instead of displaying safety-related images such as warnings and vehicle speed. In particular, because the amount of data read during the startup process is large and it takes time to read the data, the state in which safety-related images are not displayed continues for a long time after startup begins.

[0034] In this embodiment, a semiconductor device (microcontroller 10) other than the semiconductor device (system-on-chip 20) that executes the normal display process completes the startup process first, and then executes the safety display process, thereby displaying a safety-related image on the display device 4. In particular, because the amount of data read for the safety display process is smaller than the amount of data read for the normal display process, the microcontroller 10 can execute the startup process faster than the system-on-chip 20. This reduces the time from the start of startup until the safety-related image is displayed on the display device 4. Furthermore, in this embodiment, the microcontroller 10 connects to the OSD control device 30 immediately after the startup process and can display an OSD image on the display device 4 in a short time of approximately several tens of milliseconds. This allows the microcontroller 10 to quickly display a safety-related image in approximately several tens of milliseconds before the system-on-chip 20 starts up.

[0035] The OSD control device 30 is a device that performs information processing to display an OSD image on the display device 4. In this embodiment, the OSD control device 30 is connected between the microcontroller 10 and the system-on-chip 20 and the display device 4. When safety display information is input from the microcontroller 10, the OSD control device 30 generates a safety-related image as an OSD image and outputs it to the display device 4.

[0036] The OSD control device 30 includes a processor 31 and a memory 34. The memory 34 is a storage medium that stores information for generating an OSD image. For example, the memory 34 stores safety-related images, each associated with identification information for identifying the image. The processor 31 is configured as a computer having hardware and software, and includes a ROM that stores programs, a CPU that executes the programs stored in the ROM, and a RAM that functions as an accessible storage device. The processor 31 includes at least an OSD image generation unit 32 and an output unit 33 as functional blocks. In this embodiment, the functions of the processor 31 are divided into two blocks, and the functions of each functional block are described. However, the functions of the processor 31 do not necessarily have to be divided into two blocks; they may be divided into one functional block or three or more functional blocks.

[0037] The OSD image generation unit 32 executes an OSD image generation process to generate a safety-related image as an OSD image. In the OSD image generation process, the OSD image generation unit 32 first acquires safety display information from the microcontroller 10. The safety display information is information for displaying a safety-related image. When the OSD image generation unit 32 receives safety display information from the microcontroller 10, the OSD image generation unit 32 generates a safety-related image as an OSD image based on the safety display information. For example, the OSD image generation unit 32 generates a safety-related image by reading from the memory 34 a safety-related image corresponding to the identification information included in the acquired safety display information. The safety-related image has a smaller data volume than a normal display image. For example, the safety-related image may be an image of a number such as a vehicle speed, a symbol indicating meter information, or an icon indicating a warning display. In this embodiment, the OSD image generation unit 32 reads and writes information from an SRAM, thereby enabling high-speed information processing with a low load. That is, unlike the system-on-chip 20, the OSD control device 30 does not need to start up an OS, load a library for normal image display into RAM, and prepare a display image with a large amount of data.

[0038] The output unit 33 outputs an image to the display device 4. When the output unit 33 acquires a normal display image from the system-on-chip 20, it outputs the acquired normal display image to the display device 4. When a safety-related image is generated by the OSD image generation unit 32, the output unit 33 outputs the generated safety-related image to the display device 4. In this embodiment, the output unit 33 outputs the safety-related image to the display device 4 until the startup process of the system-on-chip 20 is completed. Furthermore, when the system-on-chip 20 becomes able to execute the normal display process after the startup process, the output unit 33 outputs the normal display image to the display device 4 and stops outputting the safety-related image.

[0039] Next, an example of a control procedure for executing the display control method according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of a flowchart of control processing of the display control method executed by the display control device according to this embodiment.

[0040] In step S101, the microcontroller 10 determines whether a predetermined condition based on the vehicle status or the status outside the vehicle is satisfied. The predetermined condition is, for example, a condition that a door is in an open state. If the microcontroller 10 receives startup instruction information transmitted from the vehicle monitoring ECU when the predetermined condition is satisfied, the microcontroller 10 proceeds to step S102. If startup instruction information is not received, the microcontroller 10 returns to step S101 and repeats the subsequent steps. In step S102, the microcontroller 10 executes startup processing. The startup processing includes initialization processing and reading of data necessary for safety display processing, such as a safety display program. In step S103, the microcontroller 10 executes safety display processing. Specifically, in the safety display processing, the microcontroller 10 receives a CAN signal containing vehicle information and filters the CAN signal. The microcontroller 10 outputs safety display information to the OSD control device 30 based on the filtered CAN signal. When safety display information is input, the OSD control device 30 reads out a safety-related image based on the safety display information and outputs the read out safety-related image as an OSD image to the display device 4. When a safety-related image is input, the display device 4 displays the input safety-related image.

[0041] Next, an example of a control procedure for executing a battery monitoring process by the microcontroller 10 will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of a flowchart of the control procedure for the battery monitoring process executed by the microcontroller according to this embodiment. Steps S201 to S202, 206, and 207 are similar to steps S101 to S102 and 103 shown in Fig. 2, and therefore description thereof will be omitted.

[0042] After the startup process in step S202, in step S203, the microcontroller 10 acquires voltage information of the vehicle's battery. In step S204, the microcontroller 10 determines whether the battery voltage is equal to or higher than a first predetermined voltage. If the microcontroller 10 determines that the battery voltage is equal to or higher than the first predetermined voltage, the microcontroller 10 proceeds to step S205. If the microcontroller 10 determines that the battery voltage is not equal to or higher than the first predetermined voltage, the microcontroller 10 proceeds to step S207.

[0043] In step S205, the microcontroller 10 outputs start-up instruction information to the system-on-chip 20. As a result, the system-on-chip 20 starts the start-up process before the vehicle starts. In step S208, the microcontroller 10 determines whether the vehicle has started. For example, when the ACC or IGN is turned on, the microcontroller 10 determines that the vehicle has started. If it is determined that the vehicle has started, the microcontroller 10 proceeds to step S209. If it is determined that the vehicle has not started, the microcontroller 10 returns to step S208 and repeats the subsequent flow. In step S209, the microcontroller 10 outputs start-up instruction information to the system-on-chip 20.

[0044] When startup instruction information is input from the microcontroller 10, the system-on-chip 20 executes startup processing, and after the startup processing, executes normal display processing. Furthermore, after the startup processing, the system-on-chip 20 outputs startup completion information to the microcontroller 10. In step S210, the microcontroller 10 inputs the startup completion information. In step S211, the microcontroller 10 executes display switching processing to switch the image displayed on the display device 4 from the safety-related image to the normal display image.

[0045] Next, the transition of each process in the display control device according to this embodiment and the screen display of the display device will be described with reference to Fig. 4. Fig. 4 is a diagram showing a timing chart of each process in the display control device according to this embodiment and the screen display of the display device. Fig. 4 shows the transition of each process in the display control device 3 and the screen display of the display device 4 in the case where the timing of the vehicle startup is late after the system-on-chip 20 starts the startup process. Note that this embodiment is not limited to displaying a safety-related image before the vehicle starts as shown in Fig. 4, but may also display a safety-related image immediately upon startup of the vehicle.

[0046] In the example of FIG. 4 , an example of foreground processing is shown in the upper row, and an example of background processing is shown in the lower row. As shown in FIG. 4 , in the foreground processing, the microcontroller 10 starts a startup process P1 at time t1. During the execution of the startup process P1, the display device 4 is in a non-display state. After the microcontroller 10 finishes the startup process P1 at time t2, the microcontroller 10 starts a safety display process P2 at time t2. As a result, in the foreground processing, the display device 4 displays a safety display image S. That is, during the safety display process P2 from time t2 to time t4, the safety display image S is displayed on the display device 4. Furthermore, in the background processing, the system-on-chip 20 starts a startup process P3 at time t2 in response to startup instruction information from the microcontroller 10 after the startup process. After the system-on-chip 20 finishes the startup process P3 at time t3, the system-on-chip 20 waits in a state in which it can execute a normal display process. Then, when the vehicle is started (time t4 in FIG. 4 ), the system-on-chip 20 transitions from background processing to foreground processing and executes normal display processing. As a result, in the foreground processing, the display device 4 displays the normal display image N. That is, after time t4, in normal display processing P4, the normal display image N is displayed on the display device 4. The time when the vehicle is started is the time when the ACC or IGN is turned on.

[0047] Next, the transition of each process in the display control device according to this embodiment and the screen display of the display device will be described with reference to Fig. 5. Fig. 5 is a timing chart showing the transition of each process in the display control device according to this embodiment and the screen display of the display device. Fig. 5 shows the transition of each process in the display control device 3 and the screen display of the display device 4 in the case where the vehicle starts up early after the system-on-chip 20 starts the startup process.

[0048] In the example of FIG. 5 , an example of foreground processing is shown in the upper part, and an example of background processing is shown in the lower part. As shown in FIG. 5 , in the foreground processing, the microcontroller 10 starts a startup process P1 at time t5. During the execution of the startup process P1, the display device 4 is in a non-display state. After the microcontroller 10 finishes the startup process P1 at time t6, the microcontroller 10 starts a safety display process P2 at time t6. As a result, in the foreground processing, the display device 4 displays a safety display image S. That is, during the safety display process P2 from time t6 to time t9, the safety display image S is displayed on the display device 4. Furthermore, in the background processing, in response to startup instruction information from the microcontroller 10 after the startup process, the system-on-chip 20 starts a startup process P3 at time t6. The system-on-chip 20 finishes the startup process P3 at time t8. In the example of FIG. 5 , the vehicle starts at time t7. Therefore, when the startup process of the system-on-chip 20 is completed (time t8), the vehicle has already started up. In this case, the system-on-chip 20 starts the normal display process immediately after the startup process. The normal display process P4' in the background is a process, such as generating a normal display image, until the display device 4 is in a state where the normal display image can be displayed. When the display device 4 is in a state where the normal display image can be displayed, the system-on-chip 20 shifts from the background to the foreground and executes the normal display process P4 in the foreground. As a result, the display device 4 displays the normal display image N. In the example of FIG. 4 , the system-on-chip 20 shifts from the background process to the foreground process at time t9 and causes the display device 4 to display the normal display image N.

[0049] Next, the transition of each process in the display control device according to this embodiment and the screen display of the display device will be described with reference to Fig. 6. Fig. 6 is a timing chart showing the transition of each process in the display control device according to this embodiment and the screen display of the display device. Fig. 6 shows the transition of each process in the display control device 3 and the screen display of the display device 4 when the system-on-chip 20 starts the startup process when the vehicle is started.

[0050] In the example of FIG. 6 , an example of foreground processing is shown in the upper part, and an example of background processing is shown in the lower part. As shown in FIG. 6 , in the foreground processing, the microcontroller 10 starts a startup process P1 at time t10. During the execution of the startup process P1, the display device 4 is in a non-display state. After the microcontroller 10 finishes the startup process P1 at time t11, the microcontroller 10 starts a safety display process P2 at time t11. As a result, in the foreground processing, the display device 4 displays a safety display image S. That is, during the safety display process P2 from time t11 to time t14, the safety display image S is displayed on the display device 4. Furthermore, in the background processing, when the vehicle starts at time t12, the system-on-chip 20 starts a startup process P3 in response to startup instruction information from the microcontroller 10. The system-on-chip 20 finishes the startup process P3 at time t13. In the example of Fig. 6, the startup process of the system-on-chip 20 is started when the vehicle is started, and the system-on-chip 20 starts the normal display process immediately after the startup process. The normal display process P4' in the background is a process, such as generating a normal display image, until the display device 4 is in a state where the normal display image can be displayed. When the display device 4 is in a state where the normal display image can be displayed, the system-on-chip 20 shifts from the background to the foreground and executes the normal display process P4 in the foreground. As a result, the display device 4 displays the normal display image N. In the example of Fig. 4, the system-on-chip 20 shifts from the background process to the foreground process from time t14 and causes the display device 4 to display the normal display image N.

[0051] Next, an example of a control procedure for executing the display control method according to this embodiment will be described with reference to Fig. 7. Fig. 7 is a diagram showing an example of a flowchart of the control process of the display control method executed by the display control device according to this embodiment. In this embodiment, the microcontroller 10 starts the control flow from step S301 when activation start information is input from the vehicle monitoring ECU as a result of a predetermined condition being satisfied, that is, the door being in an open state.

[0052] In step S301, the microcontroller 10 executes a startup process. In step S302, the microcontroller 10 acquires information about the open door. In step S303, the microcontroller 10 determines whether the driver's door is open. If it is determined that the driver's door is open, the microcontroller 10 proceeds to step S304. If it is determined that the driver's door is not open, that is, if it is determined that a door other than the driver's door is open, the microcontroller 10 ends the control flow.

[0053] In step S304, the microcontroller 10 acquires voltage information of the vehicle's battery. In step S305, the microcontroller 10 determines whether the battery voltage is equal to or greater than a first predetermined voltage. If it is determined that the battery voltage is equal to or greater than the first predetermined voltage, the microcontroller 10 proceeds to step S306. If it is determined that the battery voltage is not equal to or greater than the first predetermined voltage, the microcontroller 10 proceeds to step S307. In step S306, the microcontroller 10 outputs startup instruction information to the system-on-chip 20, the OSD control device 30, the display device 4, and other peripheral elements. In step S307, the microcontroller 10 determines whether the battery voltage is equal to or greater than a second predetermined voltage. If it is determined that the battery voltage is equal to or greater than the second predetermined voltage, the microcontroller 10 proceeds to step S308. If it is determined that the battery voltage is not equal to or greater than the second predetermined voltage, the microcontroller 10 proceeds to step S310.

[0054] In step S308, the microcontroller 10 outputs start-up instruction information to peripheral elements including the OSD control device 30 and the display device 4. In step S309, the microcontroller 10 stops power to the system-on-chip 20. In step S310, the microcontroller 10 stops power to peripheral elements including the system-on-chip 20. The peripheral elements to which power is stopped include the OSD control device 30 and the display device 4.

[0055] Next, an example of a control procedure for executing the display control method according to this embodiment will be described with reference to FIG. 8. FIG. 8 is a diagram showing an example of a flowchart of the control process of the display control method executed by the display control device according to this embodiment. In this embodiment, the microcontroller 10 starts the control flow from step S401 when startup start information is input from the vehicle monitoring ECU as a result of a predetermined condition being satisfied, that is, the door being in an open state. Steps S404 to S410 are similar to steps S304 to S310, and therefore will not be described again and will be used as appropriate.

[0056] In step S401, the microcontroller 10 executes a startup process. In step S402, the microcontroller 10 acquires vehicle position information. In step S403, the microcontroller 10 determines whether the current vehicle position is a maintenance shop or a car wash. If it is determined that the current vehicle position is a maintenance shop or a car wash, the microcontroller 10 proceeds to step S404. If it is determined that the current vehicle position is not a maintenance shop or a car wash, the microcontroller 10 ends the control flow.

[0057] As described above, in the display control device, display control method, and display control system according to the present embodiment, the first processor executes a first processor startup process when a predetermined condition based on the vehicle status or the status outside the vehicle is satisfied, and after the first processor startup process, executes a safety display process that displays a safety-related image on the display unit. The first processor startup process includes reading of data necessary for the safety display process. The amount of data read for the safety display process is smaller than the amount of data read for the normal display process that displays a normal display image on the display unit. This reduces the time from when startup begins until the safety-related image is displayed.

[0058] Furthermore, in the display control device, display control method, and display control system according to this embodiment, the predetermined condition is a condition that a vehicle door is open or a condition that a vehicle door is estimated to be open. The first processor acquires vehicle battery voltage information after the startup process of the first processor, and if the battery voltage is equal to or greater than a first predetermined voltage, outputs startup instruction information to the second processor before the vehicle starts, and if the battery voltage is less than the first predetermined voltage, outputs startup instruction information to the second processor at the time of vehicle startup. The second processor, which executes the normal display process, executes the startup process of the second processor when the startup instruction information is input from the first processor, and executes the normal display process after the startup process of the second processor. This prevents unnecessary battery power consumption when the battery is low, thereby reducing the possibility of the battery running out.

[0059] In addition, in the display control device, display control method, and display control system according to the present embodiment, when the battery voltage is equal to or lower than a second predetermined voltage that is lower than the first predetermined voltage, the first processor stops supplying power to the display unit and peripheral elements including the second processor until a startup operation to start the vehicle is input. This prevents unnecessary battery power consumption when the battery is low, thereby reducing the possibility of the battery running out.

[0060] In addition, in the display control device, display control method, and display control system according to the present embodiment, if the opened vehicle door is a door other than the driver's door, the first processor outputs start-up instruction information to the second processor when starting the vehicle, even if the battery voltage is equal to or higher than the first predetermined voltage. This prevents unnecessary battery power consumption, thereby reducing the possibility of the battery running out.

[0061] In addition, in the display control device, display control method, and display control system according to the present embodiment, the first processor acquires location information indicating the current location of the vehicle after the startup process of the first processor, and if the current location of the vehicle is a repair shop or a car wash, prohibits the output of startup instruction information to the second processor and stops the supply of power to the display unit and peripheral elements including the second processor, even if the battery voltage is equal to or higher than a first predetermined voltage. This prevents unnecessary power consumption of the battery, thereby reducing the possibility of the battery running out.

[0062] In the display control device, display control method, and display control system according to the present embodiment, the first processor, in the safety display process, identifies a safety-related image to be displayed on the display unit from among pre-stored safety-related images, and generates instruction information for displaying the identified safety-related image on the display unit, the instruction information having a smaller data volume than a normal display image. This allows the safety display process, which has a smaller processing load than the normal display process that displays the normal display image, to shorten the time from startup to displaying the safety-related image.

[0063] In the display control device, the display control method, and the display control system according to the present embodiment, the display unit switches between displaying a safety image and a normal display image, thereby enabling switching of the image displayed to the user.

[0064] In the display control device, display control method, and display control system according to the present embodiment, the display unit displays a composite image generated by combining the safety-related image and the normal display image, thereby enabling the normal display image to be displayed to the user while the safety-related image is displayed.

[0065] It should be noted that the above-described embodiments have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each element disclosed in the above-described embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0066] REFERENCE SIGNS LIST 1 display control system 3 display control device 10 microcontroller 11 CAN communication unit 12 startup processing unit 13 safety display unit 14 battery monitoring unit 20 system-on-chip 30 OSD control device 31 processor 32 OSD image generation unit 33 output unit 34 memory 2 CAN bus 4 display device

Claims

1. A display control device having a first processor, wherein the first processor executes a startup process of the first processor when a predetermined condition based on a vehicle situation or a situation outside the vehicle is satisfied, and after the startup process of the first processor, executes a safety display process that displays a safety-related image on a display unit, the startup process of the first processor includes reading of data necessary for the safety display process, and the amount of data read for the safety display process is smaller than the amount of data read for normal display process that displays a normal display image on the display unit.

2. A display control device as described in claim 1, comprising a second processor which executes the normal display processing, wherein the specified condition is a condition that a door of the vehicle is in an open state or a condition that a door of the vehicle is estimated to be in an open state, wherein the first processor: acquires voltage information of the battery of the vehicle after the startup processing of the first processor; and if the voltage of the battery is equal to or higher than a first specified voltage, outputs startup instruction information to the second processor before the vehicle is started; and if the voltage of the battery is less than the first specified voltage, outputs the startup instruction information to the second processor at the time of starting the vehicle, wherein the second processor: executes the startup processing of the second processor when the startup instruction information is input from the first processor; and executes the normal display processing after the startup processing of the second processor.

3. A display control device as described in claim 2, wherein the first processor stops supplying power to the display unit and peripheral elements including the second processor when the voltage of the battery is equal to or lower than a second predetermined voltage which is lower than the first predetermined voltage, until a startup operation to start the vehicle is input.

4. A display control device as described in claim 2 or 3, wherein the first processor outputs the start-up instruction information to the second processor when the vehicle is started up, even if the voltage of the battery is equal to or higher than the first specified voltage, if the open door of the vehicle is a door other than the driver's door of the vehicle.

5. A display control device as described in any one of claims 2 to 4, wherein the first processor acquires location information indicating the current location of the vehicle after the startup process of the first processor, and when the current location of the vehicle is a maintenance shop or a car wash, prohibits the output of the startup instruction information to the second processor even when the battery voltage is equal to or higher than the first specified voltage, and stops the supply of power to the display unit and peripheral elements including the second processor.

6. A display control device as claimed in any one of claims 1 to 5, wherein the first processor, in the safety display processing, identifies a safety-related image to be displayed on the display unit from among the safety-related images stored in advance, and generates instruction information for displaying the identified safety-related image on the display unit, the instruction information having a smaller amount of data than the normal display image.

7. A display control device according to any one of claims 1 to 6, wherein the display unit switches between displaying the safety-related image and the normal display image.

8. A display control device according to any one of claims 1 to 7, wherein the display unit displays a composite image generated by combining the safety-related image and the normal display image.

9. A display control method executed by a display control device having a first processor, wherein the first processor executes a startup process of the first processor when a predetermined condition based on a vehicle situation or a situation outside the vehicle is satisfied, and after the startup process of the first processor, executes a safety display process for displaying a safety-related image on a display unit, the startup process of the first processor includes reading of data necessary for the safety display process, and the amount of data read for the safety display process is smaller than the amount of data read for normal display process for displaying a normal display image on the display unit.

10. A display control system comprising a first processor and a display unit, wherein the first processor executes a startup process of the first processor when a predetermined condition based on a vehicle situation or a situation outside the vehicle is satisfied, and after the startup process of the first processor, executes a safety display process for displaying a safety-related image on the display unit, the startup process of the first processor includes reading of data necessary for the safety display process, and the amount of data read for the safety display process is smaller than the amount of data read for normal display process for displaying a normal display image on the display unit.

Images