Display System

Abstract

To provide a display system in which one display shows a plurality of screens and a screen in which a related abnormality is happening alone is displayed in black without fail.SOLUTION: The display unit 42 synthesizes a first screen, a second screen, and a third screen generated by a drawing unit 41 so that the screens are lined side by side, and displays the screens in a display unit 5. A timer counter circuit 44 sets a black picture layer-on for a screen that an abnormality monitor unit 43 has become unable to detect a normal operation of each part related to a screen at shorter intervals than specific intervals, and the display unit 42 overlaps black picture layers on the screen that is set to the black picture layer-on, thereby displaying the screen in black.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a display system mounted on an automobile. [Background technology]

[0002] 2. Description of the Related Art A known display system mounted on an automobile is one that displays a plurality of screens arranged horizontally on a landscape display (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-292812 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a display system mounted on an automobile, it is preferable to achieve functional safety by displaying a black screen on a screen related to an abnormality such as a breakdown when the abnormality occurs.

[0005] However, in a display system that displays multiple screens on a single display, turning off the backlight of the display and displaying a black screen on the entire display screen is undesirable because it causes screens that are not related to anomalies or that are not subject to functional safety to be displayed as black screens.

[0006] If the processing unit performing the drawing process of the screen related to the abnormality is made to draw a black image as that screen, it is possible to make only the screen related to the abnormality a black image; however, since the screen drawing process is usually realized by software processing, this is not necessarily sufficient in terms of ensuring functional safety.

[0007] Furthermore, in a process in which a screen relating to an abnormality is displayed as a black screen when an abnormality is detected, if a malfunction or other problem occurs in the processing unit itself which detects the abnormality, it becomes impossible to reliably display the screen relating to the abnormality as a black screen.

[0008] Therefore, an object of the present invention is to reliably display only the screen related to an abnormality such as a breakdown in a display system that displays a plurality of screens on a single display device in the event of the occurrence of the abnormality in the display system. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a display system for displaying a plurality of different screens on one display, the display system comprising: a drawing means for drawing each of the plurality of screens; a display means for arranging and displaying the screens drawn by the drawing means on the display; a black-screen display control means; and an abnormality monitoring means for repeatedly detecting an abnormality relating to at least one of the target screens as a target screen and outputting a normal detection to the black-screen display control means when no abnormality is detected. The black-screen display control means sets a black-screen ON to the display means for a target screen for which the abnormality monitoring means no longer outputs a normal detection at a time interval shorter than a predetermined time, and the display means displays a black screen for the target screen for which the black-screen ON has been set.

[0010] Here, this display system may be configured such that the black screen display control means sets black screen off for a target screen for which a normal detection has been output from the abnormality monitoring means in the display means, and for a target screen for which black screen off has been set in the display means, the target screen is displayed on the display without displaying a black screen for that target screen.

[0011] In this case, the display system may be configured such that black screen ON is set as an initial value on each of the target screens when the display system starts operating. Also, in this case, the display system may be configured so that the black-screen display control means is provided with a timer counter corresponding to each target screen, and each timer counter is reset when normal detection of the corresponding target screen is output and when it counts up to a predetermined value, and when normal detection of the corresponding target screen is output, black-screen OFF of the corresponding target screen is set in the display means, and when it counts up to the predetermined value, black-screen ON of the corresponding target screen is set in the display means, and the abnormality monitoring means repeatedly detects abnormalities related to each target screen at time intervals shorter than the time required for the timer counter to count from 0 to the predetermined value, and when no abnormality is detected, outputs normal detection to the black-screen display control means.

[0012] Alternatively, in this case, the display system may provide an abnormality flag corresponding to each target screen, and the abnormality monitoring means may set the abnormality flag corresponding to a target screen for which no abnormality has been detected to a first value, thereby outputting normal detection of the target screen to the black-screen display control means, and the black-screen display control means may execute a task corresponding to each target screen. Here, each task checks the value of the abnormality flag corresponding to the corresponding target screen, and when the abnormality flag is the first value, sets the black-screen off of the corresponding target screen to the display means and sets the abnormality flag to a second value, and when the abnormality flag is the second value, sets the black-screen on of the corresponding target screen to the display means, repeating this process at predetermined time intervals. Also, the abnormality monitoring means repeatedly detects abnormalities related to each target screen at time intervals shorter than the predetermined time, and sets the abnormality flag corresponding to a target screen for which no abnormality has been detected to a first value.

[0013] Here, the above display system may be configured so that, for a target screen for which black screen on is set in the display means, a black screen layer is overlaid on the target screen and displayed on the display, thereby displaying the target screen as a black screen. In the above display system, it is preferable that the black screen display control means operates on an operating platform different from that on which at least the drawing means and the abnormality monitoring means operate. Furthermore, the above display system may be an on-board display system installed in an automobile.

[0014] According to such a display system, in a display system in which a plurality of screens are arranged and displayed on a single display, a black screen can be displayed for each screen. In addition, since the black screen is displayed not when an abnormality is detected but when normality cannot be detected at a time interval shorter than a predetermined time, the black screen is displayed even if a failure occurs in the abnormality detection function itself, thereby improving the reliability of functional safety. Effect of the Invention

[0015] As described above, according to the present invention, in a display system that displays multiple screens on a single display, when an abnormality such as a breakdown occurs, it is possible to reliably display only the screen related to the abnormality as a black screen. [Brief description of the drawings]

[0016] [Figure 1] 1 is a block diagram showing a configuration of a display system according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing the arrangement of displays according to the first embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram illustrating functions of a rendering unit and a display unit according to the first embodiment of the present invention. [Figure 4] FIG. 4 is a diagram illustrating a control operation for black screen display according to the first embodiment of the present invention. [Diagram 5] 1 is a block diagram showing a configuration of a display system according to a second embodiment of the present invention; [Figure 6] FIG. 11 is a diagram illustrating a control operation for black screen display according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described. First, the first embodiment will be described. FIG. 1 shows the configuration of a display system according to the first embodiment. As shown in the figure, the display system includes a first video source device 1, a second video source device 2, a data device 3, a display control system 4, and a display unit 5. The display control system 4 is, for example, a system configured as an SoC (System on a Chip), and includes a drawing unit 41, a display unit 42, an abnormality monitoring unit 43, and a timer counter circuit 44.

[0018] The display unit 5 is a display device having a large, horizontally elongated display surface, and is placed, for example, on the dashboard of an automobile as shown in FIG. The first video source device 1 is, for example, a video player, and the rendering unit 41 of the display control system 4 generates a first screen representing the video output from the first video source device 1, as shown in, for example, FIG. 3a1. The second video source device 2 is, for example, a camera that captures the rear of a car, and the rendering unit 41 of the display control system 4 generates a second screen representing the image output from the second video source device 2, as shown, for example, in FIG. 3a2.

[0019] The data device 3 outputs data representing various conditions such as the vehicle speed and engine RPM to the display control system 4, and the drawing unit 41 of the display control system 4 generates a third screen simulating a meter cluster, for example, as shown in FIG. 3a3, from the data output from the data device 1.

[0020] Then, the display unit 42 of the display control system 4 composites the first screen, the second screen, and the third screen generated by the rendering unit so that they are aligned horizontally, and displays the composite on the display unit 5, as shown in FIG. 3b.

[0021] Here, the second screen and the third screen are screens subject to functional safety, which display a black screen when an abnormality such as a failure related to the screen occurs. Next, the display unit 42 has a function of overlaying and displaying a black image layer BL on the second screen generated by the drawing unit 41, as shown in Figure 3c1. By overlaying and displaying the black image layer BL, the second screen is displayed as a black image, as shown in Figure 3c2.

[0022] Similarly, the display unit 42 has a function of overlaying and displaying a black-image layer BL on the third screen generated by the drawing unit 41, as shown in Figure 3d1, independently of the function of overlaying and displaying a black-image layer BL on the second screen, and by overlaying and displaying the black-image layer BL, the third screen is displayed as a black screen, as shown in Figure 3d2.

[0023] Next, the display control system 4 includes a timer counter circuit 44 corresponding to the second screen, and a timer counter circuit 44 corresponding to the third screen. The abnormality monitoring unit 43 repeatedly detects whether the second video source device 2 and the drawing unit 41 related to the second screen are abnormal / normal, and when normality is detected, notifies the timer counter circuit 44 corresponding to the second screen of the normal detection.

[0024] Furthermore, the abnormality monitoring unit 43 repeatedly detects the abnormality / normality of the data device 3 and the drawing unit 41 related to the third screen, and when normality is detected, notifies the timer counter circuit 44 corresponding to the third screen of the detection of normality.

[0025] The operation of black screen control in such a display system will now be described. In the default state when the display system is started up, the black screen layer of the second screen is set to ON in the display unit 42, and when the black screen layer of the second screen is set to ON, the display unit 42 displays the black screen layer BL superimposed on the second screen on the display unit 5. When the black screen layer of the second screen is set to OFF, the display unit 42 displays the second screen generated by the drawing unit as is on the display unit 5.

[0026] Similarly, in the default state when the display system is started up, the display unit 42 has the black screen layer of the third screen set to ON, and when the black screen layer of the third screen is set to ON, the display unit 42 displays the third screen with a black screen layer BL superimposed on it on the display unit 5. When the black screen layer of the third screen is set to OFF, the display unit 42 displays the third screen generated by the drawing unit as is on the display unit 5.

[0027] Next, the operation of each timer counter circuit 44 will be described. The timer counter circuit 44 is a counter that counts up a count value TCNT with a clock of a fixed period, and the count value TCNT is reset when a normal detection is notified from the abnormality monitoring unit 43 and when the count value TCNT reaches a value Th.

[0028] Furthermore, when the timer counter circuit 44 is reset by notification of normal detection before the count value TCNT reaches the value Th, it sets the black screen layer of the corresponding screen to OFF in the display unit 42. Furthermore, when the timer counter circuit 44 is reset after the count value TCNT reaches the value Th, it sets the black screen layer of the corresponding screen to ON in the display unit 42.

[0029] Here, the abnormality monitoring unit 43 is configured to repeatedly detect abnormality / normality regarding the corresponding screen at time intervals shorter than the time required for the timer counter circuit 44 to count the count value TCNT from 0 to the value Th.

[0030] The control procedures for black screen display for the second and third screens, which are functional safety target screens, are the same, so a specific example of the above-mentioned operation of the timer counter circuit 44 will be shown in FIG. 4, taking the second screen as a representative example.

[0031] As shown in FIG. 4, the second screen is displayed as a black screen by default with the black screen layer turned on at the time of start-up, and the count value TCNT of the timer counter circuit 44 corresponding to the second screen starts to count up.

[0032] Then, if a normal detection is notified from the abnormality monitoring unit 43 at time t1 before the count value TCNT of the timer counter circuit 44 corresponding to the second screen reaches the value Th, the count value TCNT of the timer counter circuit 44 corresponding to the second screen is reset to 0, the black screen layer of the second screen is set to off, the black screen display is cancelled and the second screen generated by the drawing unit 41 is displayed on the display unit 5.

[0033] Then, the timer counter circuit 44 corresponding to the second screen starts counting up the count value TCNT from 0, and if a normal detection is notified from the abnormality monitoring unit 43 at time t2 before the count value TCNT reaches the value Th, the count value TCNT of the timer counter circuit 44 corresponding to the second screen is reset to 0, the black screen layer of the second screen is set to off, and the display of the second screen generated by the drawing unit 41 on the display unit 5 is maintained.

[0034] Then, the timer counter circuit 44 corresponding to the second screen starts counting up the count value TCNT from 0, and if at time t3 the count value TCNT reaches a value Th without receiving a normal detection notification from the abnormality monitoring unit 43, the count value TCNT of the timer counter circuit 44 is reset to 0, the black screen layer of the second screen is set to ON, and the second screen displays a black screen.

[0035] Then, the timer counter circuit 44 corresponding to the second screen starts counting up the count value TCNT from 0, and if at time t4 the count value TCNT reaches the value Th again without receiving a normal detection notification from the abnormality monitoring unit 43, the count value TCNT of the timer counter circuit 44 is reset to 0, the black screen layer of the second screen is set to ON, and the black screen display of the second screen is maintained.

[0036] Then, the timer counter circuit 44 corresponding to the second screen starts counting up the count value TCNT from 0, and if a normal detection is notified from the abnormality monitoring unit 43 at time t5 before the count value TCNT of the timer counter circuit 44 corresponding to the second screen reaches the value Th, the count value TCNT of the timer counter circuit 44 corresponding to the second screen is reset to 0, the black screen layer of the second screen is set to off, the black screen display is canceled, and the second screen generated by the drawing unit 41 is displayed on the display unit 5.

[0037] As a result, after the display system is started, the second screen is maintained in a black screen state until the abnormality monitoring unit 43 detects that each part related to the second screen is normal, and after the abnormality monitoring unit 43 detects that each part related to the second screen is normal, the drawing unit 41 starts displaying the second screen generated by the drawing unit 41 on the display unit 5. Thereafter, while the abnormality monitoring unit 43 detects that each part related to the second screen is normal at intervals shorter than the predetermined time required for the timer counter circuit 44 to count up from 0 to the count value TCNT, the second screen generated by the drawing unit 41 continues to be displayed on the display unit 5, and if the abnormality monitoring unit 43 is no longer able to detect that each part related to the second screen is normal at intervals shorter than the predetermined time, the display of the second screen transitions to a black screen, and the black screen display is maintained until the abnormality monitoring unit 43 detects that each part related to the second screen is normal.

[0038] The first embodiment of the present invention has been described above. As described above, according to the first embodiment, in a display system in which a plurality of screens are displayed side by side on a single display unit 5, a black screen can be displayed for each screen. In addition, since the black screen is displayed not when an abnormality is detected but when normality cannot be detected at a time interval shorter than a predetermined time, the black screen is displayed even if a failure occurs in the abnormality detection function itself, thereby improving the reliability of functional safety.

[0039] Furthermore, the timer counter circuit 44 can be mounted in the display control system 4 as hardware capable of operating independently, thereby making it possible to achieve more reliable functional safety.

[0040] A second embodiment of the present invention will now be described. FIG. 5 shows the configuration of a display system according to the second embodiment. The display system according to the second embodiment differs from the display system according to the first embodiment shown in FIG. 1 only in the configuration of the display control system. As shown in the figure, the display system 4 according to the second embodiment includes a first subsystem 410 and a second subsystem 420. The first subsystem 410 and the second subsystem 420 are systems constructed on different virtual machines on a hypervisor or different CPUs. The first subsystem 410 includes the rendering unit 41 and the display unit 42 shown in the first embodiment. The first subsystem 410 also executes an abnormality monitoring task 4101 corresponding to the second screen and an abnormality monitoring task 4101 corresponding to the third screen.

[0041] Then, as in the first embodiment, assuming that the second screen and the third screen are screens that are subject to functional safety, the second subsystem 421 executes a black screen layer control task 4201 corresponding to the second screen and a black screen layer control task 4201 corresponding to the third screen.

[0042] The control procedures for black screen display on the second and third screens, which are the screens subject to functional safety, are the same, so below, the operation of black screen display will be explained using the second screen as a representative example. The abnormality monitoring task 4101 corresponding to the second screen, while the display system is in operation, repeatedly detects the abnormality / normality of the second video source device 2 and the rendering unit 41 related to the second screen (step 602), as shown in FIG. 6a, and repeatedly performs the process of setting the abnormality flag to 0 when normality is detected (step 604).

[0043] 6B, when the display system is started, the black screen layer control task 4201 corresponding to the second screen sets the abnormality flag to 1 (step 652), and then checks whether the abnormality flag is 0 (step 654).

[0044] If the abnormal flag is 0, the black screen layer of the second screen is set to OFF (step 656), and the abnormal flag is set to 1 (step 658). If the abnormal flag is not 0 but 1, the black screen layer of the second screen is set to ON (step 660), and the abnormal flag is set to 1 (step 658).

[0045] Then, if the abnormality flag is set to 1 in step 658, the process waits for a predetermined time (for example, 15 ms) to elapse (step 662) and returns to the process from step 654. Here, the abnormality monitoring task 4101 is configured to repeatedly detect abnormality / normality regarding the corresponding screen at time intervals shorter than the predetermined time awaited in step 662 of the black image layer control task 4201 .

[0046] According to such an operation of the black screen layer control task 4201, the black screen display on the second screen is controlled as follows. That is, the second screen is displayed as a black screen by default when the screen is started up, with the black screen layer being on. Also, since the black screen layer control task 4201 sets the abnormality flag to 1 when the screen is started up (step 652), the black screen layer remains on (step 660) until the abnormality monitoring task 4101 detects that each part related to the second screen is normal and sets the abnormality flag to 0, and the black screen display of the second screen is maintained.

[0047] On the other hand, when the abnormality monitoring task 4101 detects that each part related to the second screen is normal and sets the abnormality flag to 0 (step 654), the black screen layer is set to off (step 656), the black screen display is cancelled, and the second screen generated by the drawing unit 41 is displayed on the display unit 5.

[0048] After the black-image layer is set to OFF (step 658), the abnormal flag is reset to 1 (step 658), and after a predetermined time has elapsed (step 662), the black-image layer is set to OFF (step 656) and the black-image layer is set to ON (step 660) again according to the value of the abnormal flag.

[0049] Therefore, if the abnormality monitoring task 4101 detects that each part related to the second screen is normal and the abnormality flag is not set to 0 during the lapse of a predetermined time (step 662), the black screen layer is set to ON (step 660) and the second screen is displayed as a black screen.

[0050] On the other hand, if the abnormality monitoring task 4101 detects that each part related to the second screen is normal during the lapse of a predetermined time (step 662) and sets the abnormality flag to 0, the black screen layer is set to off (step 656), and the display of the second screen generated by the drawing unit 41 on the display unit 5 is maintained.

[0051] As a result, after the display system is started, the second screen is maintained in a black screen display until the abnormality monitoring task 4101 detects that each part related to the second screen is normal, and after normality is detected, the second screen generated by the drawing unit 41 starts to be displayed on the display unit 5. Thereafter, while the abnormality monitoring task 4101 detects that each part related to the second screen is normal at time intervals shorter than the predetermined time, the second screen generated by the drawing unit 41 continues to be displayed on the display unit 5, and if the abnormality monitoring task 4101 is no longer able to detect that each part related to the second screen is normal at time intervals shorter than the predetermined time, the display of the second screen transitions to a black screen display, and is maintained until the abnormality monitoring task 4101 detects that each part related to the second screen is normal.

[0052] As described above, according to the second embodiment, in a display system in which screens of a single number of display units are arranged and displayed, a black screen can be displayed for each screen. In addition, since the black screen is displayed not when an abnormality is detected but when normality cannot be detected at a time interval shorter than a predetermined time, the black screen is displayed even if a failure occurs in the abnormality detection function itself, thereby improving the reliability of functional safety. Also, since the abnormality monitoring task 4101 that detects abnormalities and the black screen layer control task 4201 that controls the black screen display are mounted on different virtual machines on a hypervisor or different subsystems constructed on different CPUs, more reliable functional safety can be realized.

[0053] The embodiment of the present invention has been described above. In the above embodiment, the display unit 42 displays a black screen by overlaying a black screen layer on the screen, but the black screen display may be performed by other methods. For example, the display unit 42 may display a black screen by masking pixel data representing the colors, such as RGB, of the pixels constituting the screen output from the drawing unit 41 and outputting black pixel data. Moreover, the above embodiment can also be applied to the case where the display control system 4 performs display on a plurality of display units 5 in the same manner. [Explanation of symbols]

[0054] 1...first image source device, 2...second image source device, 3...data device, 4...display control system, 5...display unit, 41...drawing unit, 42...display unit, 43...abnormality monitoring unit, 44...timer counter circuit, 410...first subsystem, 420...second subsystem, 4101...abnormality monitoring task, 4201...black screen layer control task.

Claims

1. A display system that displays a plurality of different screens on a single display, a drawing means for drawing each of the plurality of screens; a display means for arranging the images drawn by the drawing means and displaying them on the display; A black screen display control means; an abnormality monitoring means for repeatedly detecting an abnormality relating to at least one screen as a target screen and outputting a normal detection to said black screen display control means when no abnormality is detected, The black screen display control means sets a black screen ON state to the display means for a target screen for which a normal detection signal is no longer output at a time interval shorter than a predetermined time from the abnormality monitoring means; The display means displays a black screen on a target screen for which a black screen ON is set, The black screen display control means sets the black screen off of the target screen for which a normal detection is output from the abnormality monitoring means to the display means, the display means displays the target screen on the display without displaying the black screen of the target screen for which the black screen off is set, And the display system is Equipped with an abnormality flag corresponding to each target screen, the abnormality monitoring means sets an abnormality flag corresponding to a target screen in which no abnormality has been detected to a first value, thereby outputting normal detection of the target screen to the black screen display control means; the black screen display control means executes a task corresponding to each target screen, each task checks the value of an abnormality flag corresponding to a corresponding target screen, and when the abnormality flag is a first value, sets the corresponding target screen to a black screen OFF state in said display means and sets the abnormality flag to a second value, and when the abnormality flag is the second value, sets the corresponding target screen to a black screen ON state in said display means, repeating this process at predetermined time intervals; a display system characterized in that the abnormality monitoring means repeatedly detects abnormalities related to each target screen at time intervals shorter than the predetermined time, and sets an abnormality flag corresponding to a target screen in which no abnormality has been detected to a first value.

2. The display system according to claim 1, A display system, characterized in that, when the display system starts operating, a black screen ON is set as an initial value on each of the target screens.

3. A display system according to claim 1 or 2, The display system is characterized in that the display means displays a black screen on a target screen for which black screen on is set by overlaying a black screen layer on the target screen and displaying it on the display.

4. A display system according to claim 1, 2 or 3, A display system, wherein said black screen display control means operates on an operating platform different from that of at least said drawing means and said abnormality monitoring means.

5. A display system according to claim 1, 2, 3 or 4, The display system is an on-board display system installed in an automobile.

Images