Display apparatus and display synchronization method for aircraft

Abstract

The present invention comprises: a plurality of display units; a plurality of processing units for receiving information regarding an image to be displayed together on the plurality of display units, generating an image signal according to the received information, and outputting it to each of the plurality of display units; and a connecting unit for connecting the plurality of processing units so that the plurality of processing units can exchange messages to synchronize the timing of outputting the image signal, thereby enabling stable display of an image on a plurality of screens.

Description

Technology Field

[0001] The present invention relates to an aircraft image display device and an aircraft image display synchronization method, and more specifically, to an aircraft image display device and an aircraft image display synchronization method capable of stably displaying images on multiple screens. Background Technology

[0002] Generally, aircraft are equipped with a Mission Computer (MC). The Mission Computer can provide aircraft pilots with the information necessary for flight operations and the execution of special missions.

[0003] At this time, information provided by the mission computer is displayed through a Multi Functional Display (MFD). For example, the mission computer may divide and display a single image across multiple panels provided in the Multi Functional Display for redundancy and fault tolerance. To this end, the Multi Functional Display may be equipped with two processors that process information provided by the mission computer, and a left panel and a right panel connected to each of the two processors to display information processed by each processor.

[0004] However, even if the mission computer provides information simultaneously to two processors, errors may occur at the time the information is finally displayed on the two panels because the two processors process the information independently. These errors can increase over time. Consequently, a problem may arise where consistent information cannot be provided to the aircraft pilot through the two panels. Prior art literature

[0005] (Patent Document 0001) KR 10-1948849 B The problem to be solved

[0006] The present invention provides an aircraft image display device and an aircraft image display synchronization method capable of stably displaying images on multiple screens.

[0007] The present invention provides an aircraft image display device and an aircraft image display synchronization method capable of providing consistent information to an aircraft pilot. means of solving the problem

[0008] The present invention comprises: a plurality of display units; a plurality of processing units for receiving information regarding an image to be displayed together on the plurality of display units, generating an image signal according to the received information, and outputting it to each of the plurality of display units; and a connecting unit for connecting the plurality of processing units so that the plurality of processing units can exchange messages to synchronize the timing of outputting the image signal.

[0009] It further includes a selection unit for selecting one of the plurality of processing units as a reference first processing unit, and selecting another processing unit as a second processing unit to correct the timing of outputting the image signal in accordance with the first processing unit.

[0010] The first processing unit comprises: a first counting unit for generating a first count value by starting a count according to a clock when power is supplied to the first processing unit; a confirmation unit for transmitting a confirmation message to the second processing unit to check whether it is operating; and a transmission unit for transmitting a count message containing information of the first count value generated by the first counting unit to the second processing unit when a response message confirming operation or a request message requesting information of the first count value is received from the second processing unit.

[0011] The second processing unit comprises: a second count unit for generating a second count value by starting a count according to a clock when power is supplied to the second processing unit; a response unit for transmitting the response message to the first processing unit when the confirmation message is received while the second processing unit is operating; a request unit for transmitting the request message to the first processing unit; and a correction unit for correcting the second count value generated by the second count unit according to the first count value included in the count message when the count message is received from the first processing unit.

[0012] The correction unit comprises: a first correction unit that calculates the difference between a first count value included in a count message received at a first time point after transmitting the response message and a second count value generated by the second count unit at the first time point, and corrects the second count value generated by the second count unit according to the difference value; and a second correction unit that calculates the delay time between a first count value included in a count message received at a second time point after transmitting the request message and a second count value generated by the second count unit at the second time point, and corrects the second count value generated by the second count unit according to the delay time.

[0013] The above-mentioned second processing unit further includes a period setting unit for setting a period to correct the timing of outputting an image signal in accordance with the first processing unit.

[0014] The present invention comprises: a process in which a plurality of processing units, each outputting a video signal to a plurality of display units, transmit and receive messages to and from each other and synchronize the timing of outputting the video signal; a process in which information regarding a video to be displayed together on the plurality of display units is received by each of the plurality of processing units, and the plurality of processing units generate a video signal according to the received information; and a process in which the plurality of processing units output a video signal to each of the plurality of display units in accordance with the synchronized timing.

[0015] The method further includes a process of selecting one of the plurality of processing units as a reference first processing unit and selecting another processing unit as a second processing unit to be corrected for the timing of the video signal output according to the first processing unit, before the plurality of processing units synchronize the timing of the video signal output.

[0016] The process of synchronizing the timing of outputting a video signal by the plurality of processing units comprises: a process in which power is supplied to the first processing unit and the first processing unit starts counting according to a clock to generate a first count value; a process in which the first processing unit transmits a confirmation message to the second processing unit to check whether it is operating; a process in which, when the second processing unit receives the confirmation message while it is operating, a process in which a response message confirming the operation is transmitted to the first processing unit; a process in which, when the first processing unit receives the response message, the first processing unit transmits a count message containing information of the first count value generated at the next time point to the second processing unit as a first step; and a process in which, when the second processing unit receives the count message as a first step, the second processing unit corrects the second count value generated by counting according to a clock as a first step according to the first count value included in the count message received as a first step.

[0017] The process of the first processing unit transmitting the confirmation message to the second processing unit is performed until the first processing unit receives the response message from the second processing unit.

[0018] The process of first correcting the second count value includes: a process of calculating the difference between a first count value included in a count message received first by the second processing unit and a second count value generated by the second processing unit starting a count according to a clock at a first time when the count message is received first; and a process of correcting by adding the difference value to the second count value generated by the second processing unit from the first time onwards.

[0019] The process of synchronizing the timing of outputting a video signal by the plurality of processing units further includes: a process of first correcting the second count value, after which the second processing unit transmits a request message requesting information of the first count value to the first processing unit; a process in which, when the first processing unit receives the request message, the first processing unit transmits a count message containing information of the first count value generated at the next time point to the second processing unit; and a process in which, when the second processing unit receives the count message, the second processing unit secondarily corrects the second count value generated by the second processing unit according to the delay time with the first count value included in the secondly received count message.

[0020] The process of correcting the second count value a second time includes: a process of calculating a delay time between a first count value included in a count message received a second time by the second processing unit and a second count value generated by the second processing unit at a second time when the count message is received a second time; and a process of correcting the second count value generated by the second processing unit by adding the value of the delay time from the second time onwards.

[0021] The process of calculating the above delay time uses the following formula.

[0022] Formula: a=(bc) / 2

[0023] (Here, a is the delay time, b is the first count value included in the count message received by the second processing unit at the second time point, and c is the second count value generated by the second processing unit at the time the request message was transmitted)

[0024] After correcting the second count value a second time, the process further includes sending a completion message to the first processing unit indicating that synchronization is complete, and the process of the plurality of processing units outputting a video signal to each of the plurality of display units is performed after the first processing unit receives the completion message. Effects of the invention

[0025] According to embodiments of the present invention, the error in the timing of image display on multiple screens can be reduced. Accordingly, images can be stably displayed on multiple screens. Therefore, an aircraft pilot can receive consistent information through multiple screens and perform missions more easily. Brief explanation of the drawing

[0026] FIG. 1 is a diagram showing the configuration of an aircraft image display device according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating an aircraft image display synchronization method according to an embodiment of the present invention. FIG. 3 is a diagram showing the frame structure of a message transmitted and received by a first processing unit and a second processing unit according to an embodiment of the present invention. FIG. 4 is a diagram showing a method of synchronizing the timing of outputting an image signal between a first processing unit and a second processing unit according to an embodiment of the present invention. Specific details for implementing the invention

[0027] Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms, and these embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. To describe the invention in detail, the drawings may be exaggerated, and like reference numerals in the drawings refer to like elements.

[0029] FIG. 1 is a diagram showing the configuration of an aircraft image display device according to an embodiment of the present invention. Below, an aircraft image display device according to an embodiment of the present invention will be described.

[0030] An aircraft image display device may be a device that displays information received from the aircraft's mission computer as an image to the aircraft pilot. For example, the aircraft image display device may be a multi-functional display device mounted on the aircraft. Referring to FIG. 1, the aircraft image display device (100) includes a plurality of display units (110), a plurality of processing units (120), and a connection unit (130).

[0031] At this time, the mission computer (200) can provide information necessary for flight and special mission execution to the aircraft pilot in the form of an image through the aircraft image display device (100). Specifically, the mission computer (200) can manage a plurality of local controllers that manage one of the control functions necessary for the flight of the aircraft, such as altitude, speed, heading, and camera. It can transmit control commands to each local controller to perform necessary control, receive information about the status from each local controller, and transmit the received information to the aircraft image display device (100) so that it can be displayed as an image. The mission computer (200) may include a plurality of generating units that generate information about an image to be displayed together on each of the plurality of display units (110). For example, when a first display unit (111) and a second display unit (112) are provided, the mission computer (200) may include a first generating unit (210) that generates information about an image to be displayed on the first display unit (111) and a second generating unit (220) that generates information about an image to be displayed on the second display unit (112) so that one image can be divided in half and displayed on each of the first display unit (111) and the second display unit (112).

[0032] The display unit (110) may be a display device (or panel) that displays information and images on a screen. The display unit (110) may be an organic light-emitting diode that forms a screen by directly applying electrical signals to each of a plurality of pixels to emit light, or an LCD (Liquid Crystal Display) that forms a screen through a backlight placed on the back of a liquid crystal layer. The display unit (110) may be provided in multiple units and installed inside an aircraft so that images can be displayed on different screens. That is, even if a failure occurs in one display unit and an image cannot be displayed normally, an image can be displayed on another display unit to allow the user to verify it. For example, a first display unit (111) that displays an image on the left side of a user on board the aircraft, and a second display unit (112) that displays an image on the right side may be provided. Accordingly, the aircraft pilot can easily check various information while viewing images in different areas displayed by the first display unit (111) and the second display unit (112). Additionally, the first display unit (111) and the second display unit (112) may be touch panels. Thus, touch signals can be received in response to the aircraft pilot's touch input. However, the number of display units (110) provided is not limited to this and may vary, and the number of generation units provided in the mission computer (200) may also vary depending on the number of display units (110).

[0033] A processing unit (120) may be connected to exchange information with a mission computer (200) and a display unit (110). A plurality of processing units (120) may be provided to receive information from the mission computer (200) regarding images to be displayed together on a plurality of display units (110), and to generate an image signal according to the received information and output it to each of the plurality of display units (110). The image signal output by the processing unit (120) may include a Vsync signal, an Hsync signal, an image enable signal, and image data, and the display unit (110) may display an image based on the output of the Vsync signal among these. Additionally, each of the processing units (120) may generate an image signal through an oscillator and output it to each of the display units (110) at regular intervals. For example, two processing units (120) may be provided, one connected to output an image signal to a first display unit (111), and the other connected to output an image signal to a second display unit (112). Each of the multiple processing units (110) can output a video signal to each of the display units (110) whenever they reach preset count values ​​while counting their own clocks. However, even if the mission computer (200) divides information about a single video in half and transmits it simultaneously to the first processing unit (121) and the second processing unit (122), the first processing unit (121) and the second processing unit (122) cannot receive the information perfectly simultaneously due to reasons such as physical delay, and thus the first processing unit (121) and the second processing unit (122) cannot output the video signal simultaneously. Therefore, it is necessary to synchronize the timing of the first processing unit (121) and the second processing unit (122) outputting the video signal so that the first display unit (111) and the second display unit (112) can display the video simultaneously.

[0034] The connection unit (130) may be a cable that connects multiple processing units (110). Accordingly, even if the multiple processing units (110) do not receive separate power inputs when generating video signals and are not ready for simultaneous operation, but operate individually, the multiple processing units (110) can synchronize the timing of video signal output by exchanging messages with each other through the connection unit (130) to synchronize the timing of video signal output. For example, since the display unit (110) displays the video based on the timing of receiving the Vsync signal among the video signals, the processing units (110) can synchronize the timing of Vsync signal output by exchanging messages with each other. The connection unit (130) may be a SerDes (serial / parallel converter) line. Accordingly, the multiple processing units (121) can transmit and receive messages to and from each other via the connection unit (130). However, the configuration of the connection unit (130) is not limited to this and may be diverse.

[0035] At this time, as shown in FIG. 1, the aircraft image display device (100) may further include a selection unit (140). The selection unit (140) may select one of the plurality of processing units (120) as a reference first processing unit (121) and select another processing unit as a second processing unit (122) to which the timing for outputting an image signal is corrected in accordance with the first processing unit (121). The selection unit (140) may arbitrarily (or randomly) select the first processing unit (121) and the second processing unit (122). For example, the selection unit (140) may select a processing unit connected to the first display unit (111) as the first processing unit (121) and select a processing unit connected to the second display unit (112) as the second processing unit (122). However, this is not limited thereto, and later, the processing unit selected as the first processing unit (121) may be selected as the second processing unit (122) by the selection unit (140), and the processing unit selected as the second processing unit (122) may be selected as the first processing unit (121) by the selection unit (140). Accordingly, each of the multiple processing units (120) may include a configuration, either in software or in hardware, to perform the role of the first processing unit (121) or the second processing unit (122).

[0036] The first processing unit (121) can provide a first count value generated by counting its own clock to the second processing unit (122). Accordingly, the second processing unit (122) can compare the second count value generated by counting its own clock with the first count value provided by the first processing unit (121) and correct the second count value so that it becomes identical to the first count value. The first processing unit (121) can be configured to output a video signal when the first count value reaches a set count value while checking the first count value. The first processing unit (121) includes a first count unit (121a), a verification unit (121b), and a transmission unit (121c).

[0037] The first count unit (121a) can start operating when power is supplied to the first processing unit (121). For example, the first count unit (121a) may be an upward counter having a function that increases by +1 whenever a signal is received. Accordingly, when power is supplied to the first processing unit (121) and it starts operating, the first count unit (121a) can start counting according to the clock of the first processing unit (121) and generate a first count value at regular intervals.

[0038] The verification unit (121b) can transmit a verification message to the second processing unit (122) to check whether it is operating through the connection unit (130). That is, since the first processing unit (121) and the second processing unit (122) operate independently and do not know whether they are operating, the verification unit (121b) transmits a verification message to the second processing unit (122), and can determine whether the second processing unit (122) is operating or not operating depending on whether a response message confirming operation is received from the second processing unit (122). That is, if the second processing unit (122) receives a verification message while it is operating, it can transmit a response message to the first processing unit (121), and if the second processing unit (122) receives a verification message while it is not operating, it cannot transmit a response message to the first processing unit (121). Accordingly, after the confirmation unit (121b) transmits a confirmation message to the second processing unit (122), if the first processing unit (121) receives a response message from the second processing unit (122), it is determined that the second processing unit (122) is in an operating state, and if the first processing unit (121) does not receive a response message from the second processing unit (122), it is determined that the second processing unit (122) is not in an operating state. Therefore, if it is determined that the second processing unit (122) is in an operating state, the first processing unit (121) and the second processing unit (122) perform a task to synchronize the timing of outputting the video signal, and if it is determined that the second processing unit (122) is not in an operating state, the confirmation unit (121b) can transmit a confirmation message to the second processing unit (122) until a response message is received from the second processing unit (122).

[0039] When the transmission unit (121c) receives a response message or a request message requesting information on the first count value from the second processing unit (122), it can generate a count message containing information on the first count value generated by the first count unit (121a) and transmit the count message to the second processing unit (122) through the connection unit (130). More specifically, the transmission unit (121c) can check the first count value generated in real time, and when the response message or the request message is received by the first processing unit (121), the transmission unit (121c) can transmit a count message containing information on the first count value generated at the time after the message is received (or the first count value generated by counting after the message is received) to the second processing unit (122).

[0040] The second processing unit (122) receives the first count value generated by the first processing unit (121), counts its own clock, and can compare it with the second count value generated to make it identical. The second processing unit (122) can be configured to output a video signal when the second count value reaches a set count value while checking the second count value. Accordingly, when the second count value becomes identical to the first count value, the first count value generated by the first processing unit (121) and the second count value generated by the second processing unit (122) reach the set count value at the same time, so the timing of the first processing unit (121) and the second processing unit (122) outputting the video signal can be synchronized. The second processing unit (122) includes a second count unit (122a), a response unit (122b), a request unit (122c), and a correction unit (122d).

[0041] The second count unit (122a) can start operating when power is supplied to the second processing unit (122). For example, the second count unit (122a) may be an upward counter that has a function of increasing by +1 whenever a signal is received. Accordingly, when power is supplied to the second processing unit (122) and it starts operating, the second count unit (122a) can start counting according to the clock of the second processing unit (122) and generate a second count value at regular intervals.

[0042] When the response unit (122b) receives a confirmation message transmitted by the confirmation unit (121b) while the second processing unit (122) is operating, it can transmit a response message to the first processing unit (121) through the connection unit (130). Accordingly, the first processing unit (121) can receive the response message and confirm that the second processing unit (122) is operating, and the first processing unit (121) can transmit a count message to the second processing unit (122) to synchronize the timing of outputting the video signal with the second processing unit (122). Specifically, it can transmit a count message containing information on a first count value generated at the time after the response message is received by the first processing unit (121) (or a first count value generated by counting after the response message is received) to the second processing unit (122).

[0043] The request unit (122c) can transmit a request message requesting information about the first count value to the first processing unit (121) through the connection unit (130). Accordingly, when the first processing unit (121) receives the request message, it can transmit a count message to the second processing unit (122). Specifically, it can transmit a count message containing information about the first count value generated at the time after the request message is received by the first processing unit (121) (or the first count value generated by counting after the request message is received) to the second processing unit (122). Therefore, the first count value included in the count message transmitted by the first processing unit (121) upon receiving the response message and the second count value included in the count message transmitted by the first processing unit (121) upon receiving the request message may be generated at different times and thus have different values.

[0044] When a count message is received from the first processing unit (121), the correction unit (122d) can correct the second count value generated by the second count unit (122a) according to the first count value included in the count message. Accordingly, the second count value generated by the second count unit (122a) can become identical to the first count value generated by the first count unit (121a) by the correction unit (122d). The correction unit (122d) includes a first correction unit and a second correction unit.

[0045] The first correction unit can calculate the difference between the first count value included in the count message received at the first time point after transmitting the response message and the second count value generated by the second count unit (122a) at the first time point. Additionally, the first correction unit can correct the second count value generated by the second count unit (122a) according to the difference value. For example, the first correction unit can calculate the difference value by subtracting the second count value generated by the second count unit (122a) at the first time point from the first count value included in the count message received at the first time point, and correct the second count value so that the calculated difference value is added to the second count value counted from the first time point point (or the next time point point). Thus, the first correction unit can eliminate the difference in magnitude that occurs between the first count value and the second count value when the first processing unit (121) and the second processing unit (122) start operating at different times.

[0046] The second correction unit can calculate the delay time between the first count value included in the count message received at the second time point after transmitting the request message and the second count value generated by the second count unit (122a) at the second time point. Additionally, the second correction unit can correct the second count value generated by the second count unit (122a) according to the delay time. That is, the difference in magnitude between the first count value and the second count value is eliminated because the first processing unit (121) and the second processing unit (122) start operating at different times, but a delay time may exist between the first count value included in the count message at the first time point and the first count value generated by the first processing unit (121) at the first time point during the process of transmitting messages through the connection unit (130). Accordingly, the second correction unit can calculate the delay time between the first count value included in the count message received at the second time and the second count value generated by the second count unit (122a) at the time of transmitting the request message from the first count value included in the count message received at the second time and by dividing the result by 2. The second correction unit can correct the value of the calculated delay time by adding it to the second count value generated by the second processing unit (122) from after the second time (or the next time). Thus, the delay time existing between the first count value generated by the first processing unit (121) and the second count value generated by the second processing unit (122) can be eliminated.

[0047] When the first count value and the second count value are synchronized, the timing at which the first processing unit (121) and the second processing unit (122) output a video signal can be synchronized. For example, both the first processing unit (121) and the second processing unit (122) can be set to output a Vsync signal at the moment when the count value reaches 1000, and since the first count value and the second count value are synchronized, the first count value and the second count value can reach 1000 at the same time. Therefore, the first processing unit (121) and the second processing unit (122) can simultaneously transmit a video signal to the first display unit (111) and the second display unit (112), respectively, so that the first display unit (111) and the second display unit (112) can simultaneously display a video.

[0048] Meanwhile, the aircraft image display device (100) may further include a period setting unit (not shown). The period setting unit may be connected to a first processing unit (121) and a second processing unit (122). The period setting unit may set a period for correcting the timing of the second processing unit (122) outputting an image signal in accordance with the first processing unit (121). Accordingly, after the first processing unit (121) and the second processing unit (122) synchronize the timing of the image signal output, even if an error occurs in the timing of the image signal output while the first processing unit (121) and the second processing unit (122) are continuously used, the operation of synchronizing the timing of the image signal output by the first processing unit (121) and the second processing unit (122) is performed repeatedly at each period set by the period setting unit, so that the first processing unit (121) and the second processing unit (122) can continue to output the image signal simultaneously.

[0049] In this way, the error in the timing of when an image is displayed on each of the multiple display units (110) can be reduced. Accordingly, an image can be stably displayed on multiple screens. Therefore, an aircraft pilot can receive consistent information through multiple screens and perform missions more easily.

[0051] FIG. 2 is a flowchart illustrating an aircraft image display synchronization method according to an embodiment of the present invention, FIG. 3 is a diagram illustrating the frame structure of a message transmitted and received by a first processing unit and a second processing unit according to an embodiment of the present invention, and FIG. 4 is a diagram illustrating a method of synchronizing the timing of outputting an image signal by a first processing unit and a second processing unit according to an embodiment of the present invention. Below, an aircraft image display synchronization method according to an embodiment of the present invention will be described.

[0052] The aircraft image display synchronization method may be a method of displaying information received from the aircraft's mission computer as an image on a plurality of synchronized screens. Referring to FIG. 2, the aircraft image display synchronization method includes a process (S110) in which a plurality of processing units that output an image signal to each of a plurality of display units transmit and receive messages to and from each other and synchronize the timing of outputting the image signal; a process (S120) in which information regarding an image to be displayed together on the plurality of display units is received by each of the plurality of processing units and the plurality of processing units generate an image signal according to the received information; and a process (S130) in which the plurality of processing units output an image signal to each of the plurality of display units in accordance with the synchronized timing.

[0053] At this time, the aircraft image display synchronization method can be performed by an aircraft image display device having a configuration as shown in FIG. 1. Accordingly, the processes of performing the aircraft image display synchronization method will be described below with reference to FIG. 1. However, the aircraft image display synchronization method is not limited thereto and can be performed by an aircraft image display device of various configurations.

[0054] Before the multiple processing units (120) synchronize the timing of outputting the video signal, the selection unit (140) may select one of the multiple processing units (120) as the reference first processing unit (121) and select another processing unit as the second processing unit (122) to which the timing of outputting the video signal is corrected in accordance with the first processing unit (121). The selection unit (140) may arbitrarily (or randomly) select the first processing unit (121) and the second processing unit (122). In the following, we will explain by example the case where the selection unit (140) selects the processing unit connected to the first display unit (111) as the first processing unit (121) and the processing unit connected to the second display unit (112) as the second processing unit (122). The first processing unit (121) and the second processing unit (122) are connected to each other through the connection unit (130) to transmit and receive messages for synchronization at the time of outputting the video signal. For example, the first processing unit (121) and the second processing unit (122) can transmit and receive messages with a frame structure as shown in FIG. 3. The first item of the message, SOF, indicates the start of the message, the next item, Command, indicates the type of message (acknowledgment message, response message, request message, etc.), the next item, Count_Tag, is a count value obtained by counting the clock of the processing unit that is counted in real time, the next item, Checksum, is the value obtained by adding Command and Count_Tag in hexadecimal, and the last item, EOF, indicates the end of the message. Each item may be 4 bytes. Accordingly, by exchanging messages, the first processing unit (121) and the second processing unit (122) can obtain information necessary to synchronize the timing of outputting the video signal, thereby synchronizing the timing of outputting the video signal. However, this is not limited thereto, and the processing unit connected to the first display unit (111) may be selected as the second processing unit, and the processing unit connected to the second display unit (112) may be selected as the first processing unit.

[0055] First, multiple processing units that output video signals to each of the multiple display units transmit and receive messages to and from each other and synchronize the timing of outputting the video signal (S110). To do this, power can be supplied to the first processing unit (121). When the first processing unit (121) receives power and starts to operate, as shown in FIG. 4, the first processing unit (121) can start counting according to its clock and generate a first count value. In addition, the first processing unit (121) can transmit a confirmation message to the second processing unit (122) to check whether it is operating through the connection unit (130). When the confirmation message is received while the second processing unit (122) is operating with power supplied, a response message confirming operation can be transmitted to the first processing unit (121); however, when the confirmation message is received while the second processing unit (122) is not operating with power not supplied, the response message cannot be transmitted to the first processing unit (121) because the second processing unit (122) is not operating. When the first processing unit (121) transmits a confirmation message to the second processing unit (122) and receives a response message from the second processing unit (122), the first processing unit (121) determines that the second processing unit (122) is in an operating state, and when it does not receive a response message from the second processing unit (122), it determines that the second processing unit (122) is not in an operating state. The process of the first processing unit (121) transmitting the confirmation message to the second processing unit (122) can be performed until the first processing unit (121) receives a response message from the second processing unit (122). When it is determined that the second processing unit (122) is in an operating state, the first processing unit (121) may first transmit a count message containing information of a first count value generated at the next time point (or next count) after receiving the response message to the second processing unit (122) in order to perform the task of synchronizing the time point of outputting the video signal with the second processing unit (122).When the second processing unit (122) receives a count message in the first step, the second processing unit (122) can first correct the second count value generated by counting according to the clock according to the first count message received in the first step. Specifically, the second processing unit (122) can calculate the difference between the first count value included in the count message received in the first step and the second count value generated by the second processing unit (122) at the first time when the count message was received in the first step, and correct the second count value generated by the second processing unit (122) from the first time step onwards by adding the difference value. For example, the second processing unit (122) can calculate the difference value by subtracting the second count value generated at the first time step from the first count value included in the count message received at the first time step. If power is supplied to the first processing unit (121) first and counts the clock before the second processing unit (122), a difference value having a positive value is calculated because the first count value counted by the first processing unit (121) is greater than the second count value counted by the second processing unit (122), and the second processing unit (122) can increase the second count value by adding the difference value to the second count value from the first time point (or the next time point). If power is supplied to the second processing unit (122) first and counts the clock before the first processing unit (121), a difference value having a negative value can be calculated because the first count value counted by the first processing unit (121) is smaller than the second count value counted by the second processing unit (122), and the second processing unit (122) can decrease the second count value by adding the difference value to the second count value from the first time point (or the next time point). Therefore, the first processing unit (121) and the second processing unit (122) can start operating at different times to first correct the difference in size between the first count value and the second count value so that it is eliminated.

[0056] At this time, a delay may occur between the first corrected second count value and the first count value due to the time required for messages to be transmitted and received between the first processing unit (121) and the second processing unit (122). Therefore, after the second count value is first corrected, a process of correcting the delay time as shown in FIG. 4 may be additionally performed. To this end, after the second processing unit (122) first corrects the second count value (or at the next time point or next count), a request message requesting information of the first count value may be transmitted to the first processing unit (121). When the first processing unit (121) receives the request message, a count message containing information of the first count value generated at the next time point (or next count) may be secondarily transmitted to the second processing unit (122). When the second processing unit (122) receives a count message a second time, the second count value generated by the second processing unit (122) can be corrected a second time according to the delay time between the first count value included in the count message received a second time. Specifically, the delay time between the first count value included in the count message received a second time by the second processing unit (122) and the second count value generated by the second processing unit (122) at the second time when the count message is received a second time can be calculated, and the second count value generated by the second processing unit (122) can be corrected by adding the value of the delay time from after the second time (or the next time or next count). For example, the following calculation formula may be used to calculate the delay time.

[0058] Formula: a=(bc) / 2

[0060] Here, a is the delay time, b is the first count value included in the count message received by the second processing unit (122) at the second time point, and c is the second count value generated by the second processing unit (122) at the time the request message is transmitted. That is, the delay time between the first count value included in the count message received at the second time point and the second count value generated by the second processing unit (122) at the time the request message is transmitted can be calculated by subtracting the second count value generated by the second processing unit (122) at the time the request message is transmitted from the first count value included in the count message received at the second time point and dividing the result by 2. The second processing unit (122) can correct the value of the calculated delay time by adding it to the second count value generated from after the second time point (or the next time point). Thus, the delay time existing between the first count value generated by the first processing unit (121) and the second count value generated by the second processing unit (122) can be eliminated. Therefore, from then on, the first count value generated by the first processing unit (121) and the second count value generated by the second processing unit (122) can be synchronized to be the same.

[0061] Meanwhile, after the second processing unit (122) corrects the second count value a second time, it can send a completion message to the first processing unit (121) indicating that synchronization is complete. That is, the second processing unit (122) can send a completion message to the first processing unit (121) at the point in time (or next count) after the second count value has been corrected a second time. Accordingly, the first processing unit (121) can confirm that the second count value generated by the second processing unit (122) is synchronized with the first count value. Therefore, the first processing unit (121) can determine that the video signal can be output to the first display unit (111) and the second display unit (112), respectively, together with the second processing unit (122).

[0062] Next, information regarding an image to be displayed together on a plurality of display units is received by each of the plurality of processing units, and the plurality of processing units generate an image signal according to the received information (S120). That is, the plurality of processing units (120) can receive information regarding an image to be displayed on each of the plurality of display units (110) from the mission computer (200) and generate an image signal according to the received information. For example, the first processing unit (121) can generate an image signal to be output to the first display unit (111), and the second processing unit (122) can generate an image signal to be output to the second display unit (112).

[0063] At this time, the process of generating a video signal by a plurality of processing units (120) may be performed simultaneously with the process of synchronizing the timing of outputting the video signal by transmitting and receiving messages to and from each other by the plurality of processing units (120), or the timing of the execution may overlap, or they may be performed sequentially. When the two processes are performed simultaneously or the timing of the execution overlaps, the plurality of processing units (120) may temporarily store the received information or the generated video signal and output the video signal to each of the plurality of display units (110) at the synchronized time.

[0064] Next, at the synchronized time, a plurality of processing units output a video signal to each of the plurality of display units (S130). In detail, the process of the plurality of processing units (120) outputting a video signal can be performed after the first processing unit (121) receives a completion message from the second processing unit (122). That is, each of the plurality of processing units (120) outputs a video signal whenever it reaches preset count values ​​while counting its own clock. Since the video signal is output simultaneously to each of the plurality of display units (110) whenever the count values ​​counted by the plurality of processing units (120) reach the preset count values, after it is confirmed that the count values ​​counted by the plurality of processing units (120) are synchronized to be identical, the video signal can be output simultaneously to each of the plurality of display units (110). For example, since the second count value counted by the second processing unit (122) is corrected to match the first count value counted by the first processing unit (121), the first count value and the second count value can reach the set count values ​​at the same time. Accordingly, based on the time when the first processing unit (121) outputs the video signal to the first display unit (111), the time when the second processing unit (122) outputs the video signal to the second display unit (112) is synchronized, so that the video signal can be transmitted simultaneously to each of the first display unit (111) and the second display unit (112). Therefore, the video can be displayed simultaneously on the screens of the first display unit (111) and the second display unit (112) without error.

[0065] Meanwhile, after the plurality of processing units (120) output a video signal to each of the plurality of display units (110) at a time synchronized with the time, the plurality of processing units (120) can synchronize the time at which the video signal is output to each of the plurality of display units (110) at each repeating cycle. Accordingly, after the plurality of processing units (120) synchronize the time at which the video signal is output, even if an error occurs at the time of outputting the video signal while the plurality of processing units (120) are continuously used, the plurality of processing units (120) can synchronize the time at which the video signal is output at each set cycle so that the plurality of display units (110) can continue to display the video simultaneously.

[0066] In this way, the error in the timing of when an image is displayed on each of the multiple display units (110) can be reduced. Accordingly, an image can be stably displayed on multiple screens. Therefore, an aircraft pilot can receive consistent information through multiple screens and perform missions more easily.

[0068] As such, although specific embodiments have been described in the detailed description of the present invention, various modifications are possible within the scope of the invention, and various combinations between embodiments are also possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims set forth below as well as equivalents thereof. Explanation of the symbols

[0069] 100: Aircraft image display device 110: Display unit 120: Processing unit 130: Connection unit 140: Selection Section 200: Mission Computer

Claims

Claim 1 An aircraft image display device comprising: a plurality of display units; a plurality of processing units for receiving information regarding an image to be displayed together on the plurality of display units, generating an image signal according to the received information, and outputting it to each of the plurality of display units; a connecting unit for connecting the plurality of processing units so that the plurality of processing units can exchange messages to synchronize the timing of outputting the image signal; and a selection unit for selecting one of the plurality of processing units as a reference first processing unit and selecting another processing unit as a second processing unit to which the timing of outputting the image signal is corrected in accordance with the first processing unit; wherein the first processing unit comprises: a first counting unit for generating a first count value by starting a count according to a clock when power is supplied to the first processing unit; a confirmation unit for transmitting a confirmation message to the second processing unit to confirm whether it is operating; and a transmission unit for transmitting a count message containing information of the first count value generated by the first counting unit to the second processing unit when a response message confirming operation or a request message requesting information of the first count value is received from the second processing unit. Claim 2 delete Claim 3 delete Claim 4 An aircraft image display device according to claim 1, wherein the second processing unit comprises: a second count unit for generating a second count value by starting a count according to a clock when power is supplied to the second processing unit; a response unit for transmitting the response message to the first processing unit when the confirmation message is received while the second processing unit is operating; a request unit for transmitting the request message to the first processing unit; and a correction unit for correcting the second count value generated by the second count unit according to the first count value included in the count message when the count message is received from the first processing unit. Claim 5 An aircraft image display device according to claim 4, wherein the correction unit comprises: a first correction unit that calculates a difference between a first count value included in a count message received at a first time point after transmitting the response message and a second count value generated by the second count unit at the first time point, and corrects the second count value generated by the second count unit according to the difference value; and a second correction unit that calculates a delay time between a first count value included in a count message received at a second time point after transmitting the request message and a second count value generated by the second count unit at the second time point, and corrects the second count value generated by the second count unit according to the delay time. Claim 6 An aircraft image display device comprising: a plurality of display units; a plurality of processing units for each receiving information regarding an image to be displayed together on the plurality of display units, generating an image signal according to the received information, and outputting it to each of the plurality of display units; a connecting unit for connecting the plurality of processing units so that the plurality of processing units can exchange messages to synchronize the timing of outputting the image signal; a selection unit for selecting one of the plurality of processing units as a reference first processing unit and selecting another processing unit as a second processing unit to which the timing of outputting the image signal is corrected in accordance with the first processing unit; and a period setting unit for setting a period for the second processing unit to correct the timing of outputting the image signal in accordance with the first processing unit. Claim 7 A process of selecting one of a plurality of processing units that output video signals to each of a plurality of display units as a reference first processing unit, and selecting another processing unit as a second processing unit to which the timing for outputting the video signal is corrected in accordance with the first processing unit; a process of the plurality of processing units transmitting and receiving messages to and from each other and synchronizing the timing for outputting the video signal; a process of receiving information regarding a video to be displayed together on the plurality of display units to each of the plurality of processing units, and the plurality of processing units generating a video signal according to the received information; The aircraft image display synchronization method comprises: a process in which the plurality of processing units output an image signal to each of the plurality of display units in accordance with a synchronized time; and a process of synchronizing the time when the plurality of processing units output an image signal, wherein the process of synchronizing the time when the plurality of processing units output the image signal includes: a process in which power is supplied to the first processing unit and the first processing unit starts counting according to a clock to generate a first count value; a process in which the first processing unit transmits a confirmation message to the second processing unit to check whether it is operating; a process in which, when the second processing unit receives the confirmation message while it is operating, a process in which a response message confirming the operation is transmitted to the first processing unit; a process in which, when the first processing unit receives the response message, the first processing unit transmits a count message including information of the first count value generated at the next time point to the second processing unit as a first step; and a process in which, when the second processing unit receives the count message as a first step, the second processing unit corrects the second count value generated by counting according to a clock as a first step according to the first count value included in the count message received as a first step. Claim 8 delete Claim 9 delete Claim 10 An aircraft image display synchronization method according to claim 7, wherein the process of the first processing unit transmitting the confirmation message to the second processing unit is performed until the first processing unit receives the response message from the second processing unit. Claim 11 The aircraft image display synchronization method according to claim 7, wherein the process of first correcting the second count value comprises: a process of calculating a difference between a first count value included in a count message received first by the second processing unit and a second count value generated by the second processing unit starting a count according to a clock at a first time when the count message is received first; and a process of correcting by adding the difference value to the second count value generated by the second processing unit from the first time onwards. Claim 12 The aircraft image display synchronization method according to claim 7, wherein the process of synchronizing the timing of outputting an image signal by the plurality of processing units further comprises: a process of, after first correcting the second count value, the second processing unit transmitting a request message requesting information of the first count value to the first processing unit; a process in which, when the first processing unit receives the request message, the first processing unit transmits a count message including information of the first count value generated at the next time point to the second processing unit; and a process in which, when the second processing unit receives the count message, the second processing unit corrects the second count value generated by the second processing unit a second time according to the delay time with respect to the first count value included in the count message received secondly. Claim 13 The aircraft image display synchronization method according to claim 12, wherein the process of secondarily correcting the second count value comprises: a process of calculating a delay time between a first count value included in a count message received secondarily by the second processing unit and a second count value generated by the second processing unit at a second time point when the count message is received secondarily; and a process of correcting the second count value generated by the second processing unit by adding the value of the delay time from the second time point onwards. Claim 14 In claim 13, the process of calculating the delay time is an aircraft image display synchronization method using the following formula: Formula: a=(bc) / 2 (wherein a is the delay time, b is a first count value included in a count message received by the second processing unit at the second time point, and c is a second count value generated by the second processing unit at the time when the request message is transmitted) Claim 15 The aircraft image display synchronization method of claim 12 further comprises, after correcting the second count value a second time, a process in which the second processing unit transmits a completion message to the first processing unit indicating that synchronization is complete, and the process in which the plurality of processing units output an image signal to each of the plurality of display units is performed after the first processing unit receives the completion message.

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