JP2014177224A - On-vehicle display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an on-vehicle display device which has a good visibility of a display screen for all occupants in a vehicle and has an energy conservation effect.SOLUTION: An on-vehicle display device for displaying an image on a display screen in a vehicle comprises a sight line detector for detecting sight lines of all occupants in the vehicle on the basis of a signal from a camera mounted in the vehicle, a backlight power source for adjusting a brightness of the display screen, and a controller which instructs the backlight power source to adjust the brightness of the display screen on the basis of a signal from the sight line detector. The controller so changes instructions to the backlight power source that the brightness of the display screen differs on the basis of that the sight line detected by the sight line detector is a sight line from an occupant on a front seat or a sight line from an occupant on a rear seat, and consequently, a visibility of the display screen can be good for all occupants and an energy conservation effect can be increased.

Description

  The present invention relates to an in-vehicle display device that adjusts the brightness of a display screen (display) according to the line of sight of a passenger of a vehicle.

  Conventionally, as display screens (displays) for in-vehicle devices such as car navigation devices, liquid crystal displays and organic EL displays are generally used, but the percentage of power consumption occupied by the backlights of these displays is high, In order to reduce the power consumption of the car navigation device, various energy saving measures are taken.

As one of the energy saving measures, it is conceivable to turn off the backlight power when the driver is not looking at the display.
At this time, as a means for detecting whether or not the driver is looking at the display, a method of detecting the driver's line of sight with a camera is known.

  For example, in Patent Document 1, a camera is mounted on a car navigation device, and using the image data from the camera, it is detected whether the driver's line of sight is facing the monitor of the car navigation device. It is described that when it is determined that the user is looking at the monitor, a signal indicating that is output to the CPU.

JP 2000-322699 A

  However, in the conventional technique as shown in Patent Document 1, for example, only the driver's line of sight can be detected, and no other passenger's line of sight is taken into account. For example, if the driver's line of sight is not detected, the backlight power of the display will be turned off, and even if other passengers are looking at the display, the visibility will deteriorate (or , Cannot be visually recognized).

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an in-vehicle display device that has good visibility of a display screen for all passengers in the vehicle and has an energy saving effect. And

  In order to achieve the above object, the present invention provides an in-vehicle display device that displays an image on a display screen in a vehicle, and based on a signal from a camera mounted in the vehicle, the line of sight of all the passengers in the vehicle A line-of-sight detection unit for detecting the image, a drawing unit for generating an image to be displayed on the display screen, a backlight power source for adjusting the luminance of the display screen, and instructing the drawing unit to generate the image, A control unit that instructs the backlight power supply to adjust the brightness of the display screen based on a signal from the line-of-sight detection unit, and the control unit detects the line of sight detected by the line-of-sight detection unit Is an instruction to the backlight power source so that the brightness of the display screen is different based on whether the line of sight is from the front passenger or the rear passenger among all the passengers in the vehicle. And wherein the changing.

  According to the present invention, the line of sight of all the passengers in the vehicle is detected, and the brightness of the display screen (display) is adjusted based on which line of sight is from the passenger. The visibility of the display screen is good for everyone and the energy saving effect can be enhanced.

1 is a block diagram showing a configuration of a car navigation device in Embodiment 1. FIG. It is the schematic which looked at the car navigation apparatus carrying a camera from the front. It is an image figure which shows the vehicle interior incorporating the car navigation apparatus in Embodiment 1. FIG. 3 is a flowchart illustrating an example of processing of the in-vehicle display device in the first embodiment. 10 is a flowchart illustrating an example of processing of the in-vehicle display device in the second embodiment. 14 is a flowchart illustrating an example of processing of the in-vehicle display device in the third embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment described below, a case where the in-vehicle display device of the present invention is applied to a car navigation device will be described as an example. For example, any in-vehicle device using a display screen (display) such as an audio device may be used. It can also be applied to things.

Embodiment 1 FIG.
1 is a block diagram showing a configuration of a car navigation device according to Embodiment 1 of the present invention. The car navigation device 10 includes an in-vehicle display device 1, a navigation main body 11, an LCD monitor (display screen) 21, a backlight 22, an operation unit 23, and a camera 24.

The in-vehicle display device 1 includes a drawing unit 2, a monitor backlight power source 3, an A / D conversion unit 4, a line-of-sight detection unit 5, a control unit 6, and a memory 7, and displays an image on an LCD monitor 21 in the vehicle.
The drawing unit 2 is a block that receives an instruction from the control unit 6 and generates an image to be displayed on the LCD monitor 21.
Similarly, the monitor backlight power supply 3 is a block that adjusts the brightness (luminance) of the LCD monitor 21 by generating power to be supplied to the backlight 22 in response to an instruction from the control unit 6.

The A / D conversion unit 4 is a block that converts an analog signal into a digital signal when the camera 24 is an analog camera.
Here, the camera 24 is mounted in the vehicle, and is composed of two camera units 25 and 26. The A / D converter 4 acquires signals from the camera units 25 and 26, respectively. , Respectively, to digital signals.

  The line-of-sight detection unit 5 detects the line-of-sight of all the passengers in the vehicle based on the signal from the camera 24 mounted in the vehicle, that is, the passenger in the vehicle, the passenger in the passenger seat and the rear seat, It is a block for detecting whether or not the car navigation device is being viewed.

  The control unit 6 is a block that controls the entire in-vehicle display device 1. The control unit 6 takes in signals from the operation unit 23 and the line-of-sight detection unit 5, instructs the drawing unit 2 to generate an image, and supplies a monitor backlight power source. 3, data acquisition and writing from the memory 7, communication with the navigation main body 11, and the like are performed.

  Although details of the control of the monitor backlight power supply 3 by the control unit 6 will be described later, in order to adjust the luminance (backlight 22) of the LCD monitor 21 as a display screen based on a signal from the line-of-sight detection unit 5. The command is output to the monitor backlight power source 3, that is, the monitor backlight power source 3 is instructed to adjust the brightness of the LCD monitor 21.

In the first embodiment, the display screen is described as being the LCD monitor 21, but may be an organic EL display or the like.
The operation unit 3 may be any unit as long as it can be operated by a driver or another passenger, such as a display-integrated touch panel or an H / W key.

FIG. 2 is a schematic view of a car navigation device equipped with a camera as viewed from the front.
FIG. 2A is a view of a conventional car navigation device 10 ′ as viewed from the front, and shows a state in which only one camera 27 is provided in the center. According to this camera 27, even if the difference between the left and right seats can be recognized, it cannot be accurately detected whether the seat is the front seat or the rear seat.

  On the other hand, FIG.2 (b) is the figure which looked at the car navigation apparatus 10 in this Embodiment 1 from the front, and has shown a mode that the two camera units 25 and 26 are provided in right and left. Thus, by using a stereo camera, parallax can be acquired from the angle of line of sight from the passenger, and the left and right seats and the front seat or the rear seat can be recognized. In the first embodiment, it is assumed that two camera units are provided on the left and right of the upper part. However, as long as the seat position can be detected, the number of camera units is not limited to the left and right of the upper part. Needless to say, the number may be three or more.

  FIG. 3 is an image diagram showing the interior of the vehicle in which the car navigation device according to the first embodiment is built. Here, as shown in FIG. 3, there are four passengers in the vehicle: a driver 31, a passenger 32 in the passenger seat, a passenger 33 on the right side of the rear seat, and a passenger 34 on the left side of the rear seat. Will be described as an example.

  FIG. 4 is a flowchart showing an example of processing of the in-vehicle display device 1 in the first embodiment. The line-of-sight detection and backlight control of the LCD monitor of the driver 31 in the vehicle, the passenger 32 in the passenger seat, and the passengers 33 and 34 in the rear seat will be described with reference to FIG.

  First, when the power of the car navigation device is turned on and this process is started, the line-of-sight detection unit 5 detects the car navigation devices of the vehicle passengers 31 to 34 based on signals from the camera 24 (camera units 25 and 26). The presence or absence of a line of sight to the LCD monitor 21 is determined (step ST1).

  Here, if it is determined that there is some line of sight (in the case of YES in step ST1), the position of the passenger who is sending the line of sight (looking at the display screen of the car navigation device) is the front seat (driver's seat) Or it is determined whether it is a passenger seat) or a rear seat (step ST2).

  When there is no line of sight from the front seat passengers 31 and 32 (NO in step ST2), only the rear seat passengers 33 and 34 are looking at the LCD monitor 21, so The brightness of the display screen is not changed so that it can be easily seen from the seat, but is kept as it is (step ST3), and the process returns to step ST1.

  On the other hand, when there is a line of sight from the passengers 31 and 32 in the front seat (YES in step ST2), the timer is started if the timer is not started (step ST4). Then, until the timer expires, that is, until a certain time elapses (in the case of NO in step ST5), the check whether there is a line of sight from the front seat is repeated, and the line of sight from the front seat continues for a certain period of time. In this case (in the case of YES in step ST5), the passengers 31 and 32 in the front seat can view the display screen even if the display screen is not so bright, so the brightness of the display screen is reduced to save energy (step ST6).

In step ST4, if the timer has already been started, the process proceeds to step ST5 as it is. In addition, when a certain time has elapsed (in the case of YES in step ST5), processing for stopping and resetting the timer is also performed.
The start, stop, and reset processing of the timer is performed in the same manner in the processing (steps ST7 to ST9) in the following description, but the description is omitted.

  If it is determined in step ST1 that there is no line of sight from any seat occupant (NO in step ST1), the timer is started if the timer is not started (step ST7). Then, until the timer expires, that is, until a certain time elapses (in the case of NO in step ST8), it is repeatedly checked whether there is any line of sight, and the state where there is no line of sight from any seat is constant If the time continues (in the case of YES in step ST8), it can be determined that no one of the passengers 31 to 34 is viewing the display screen, so the display screen is turned off to save energy (step ST9).

  In this way, the line of sight of all the passengers 31 to 34 in the vehicle is detected, and when it is determined that there is no line of sight, the display screen is turned off. It is possible to prevent the power consumed by the backlight from being wasted when it is not present. Further, when only the passengers 33 and 34 in the rear seats are looking at the display screen, the brightness of the display screen is not changed. Therefore, even if the passengers 33 and 34 in the rear seats are looking at the driver 31. It is also possible to prevent a problem that the screen is turned off because the user does not watch.

  Furthermore, when there is a line of sight from the passengers 31 and 32 in the front seats, the brightness of the display screen is reduced, so that it has an energy saving effect and is easily visible to the passengers 31 and 32 in the front seats. There is also an effect.

  As described above, according to the first embodiment, the line of sight of all the passengers in the vehicle is detected, and the detected line of sight is either the line of sight from the front seat passenger or the passenger from the rear seat. Since the display screen is instructed to have different brightness based on whether it is the line of sight, that is, when the line of sight is not detected from any seat, or the line of sight only from the passenger in the rear seat is detected The display screen brightness is adjusted according to each case when the line of sight from the passenger in the front seat is detected, so that all the passengers have good visibility and display. Energy saving effect can be enhanced by reducing the power consumption of the screen backlight.

Embodiment 2. FIG.
Since the configuration of the car navigation apparatus according to the second embodiment of the present invention is the same as the block diagram of FIG. 1 shown in the first embodiment, illustration and description thereof are omitted.
In the second embodiment, the determination method in the control for giving an instruction (transmitting a brightness adjustment command) from the control unit 6 to the monitor backlight power supply 3 is different from that in the first embodiment.

Also in the second embodiment, as shown in FIG. 3, there are four passengers, a driver 31, a passenger 32 in the passenger seat, a passenger 33 on the right rear seat, and a passenger 34 on the left rear seat. Assume that there is a passenger.
FIG. 5 is a flowchart showing an example of processing of the in-vehicle display device 1 according to the second embodiment. The line-of-sight detection and LCD monitor backlight control of the driver 31 in the vehicle, the passenger 32 in the passenger seat, and the passengers 33 and 34 in the rear seat will be described with reference to FIG.

  First, when the power of the car navigation device is turned on and this process is started, the line-of-sight detection unit 5 detects the car navigation devices of the vehicle passengers 31 to 34 based on signals from the camera 24 (camera units 25 and 26). The presence or absence of a line of sight to the LCD monitor 21 is determined (step ST11).

  When it is determined that there is some line of sight (in the case of YES in step ST11), the position of the passenger who is sending the line of sight (looking at the display screen of the car navigation device) is the front seat (driver's seat or passenger's seat) ) Or rear seat (step ST12). At this time, in the first embodiment, the determination is made based on whether there is a line of sight from the front seat, but in this second embodiment, the determination is made based on whether there is a line of sight from the rear seat.

  When there is a line of sight from the passengers 33 and 34 in the rear seats (in the case of YES in step ST12), the passengers 33 and 34 in the rear seats are looking at the LCD monitor 21. In order to make it easier to see, the brightness of the display screen is not changed, but remains as it is (step ST13), and the process returns to step ST11.

  On the other hand, when there is no line of sight from the passengers 33 and 34 in the rear seats (NO in step ST12), the timer is started if the timer is not started (step ST14). Then, until the timer expires, that is, until a certain time has elapsed (in the case of NO in step ST15), the check is repeated whether or not there is a line of sight from the rear seat, and there is no line of sight from the rear seat. If the display is continued for a certain time (in the case of YES in step ST15), the passengers 31 and 32 in the front seats can view the display screen even if the display screen is not so bright. ST16).

If the timer has already been started in step ST14, the process proceeds to step ST15 as it is. In addition, when a certain time has elapsed (in the case of YES in step ST15), processing for stopping and resetting the timer is also performed.
The start, stop, and reset processes of the timer are similarly performed in the processes (steps ST17 to ST19) in the following description, but the description is omitted.

  If it is determined in step ST11 that there is no line of sight from any seat occupant (NO in step ST11), the timer is activated if the timer is not activated (step ST17). Then, until the timer expires, that is, until a certain time elapses (in the case of NO in step ST18), it is repeatedly checked whether there is any line of sight, and the state where there is no line of sight from any seat is constant If the time continues (in the case of YES in step ST18), it can be determined that no one of the passengers 31 to 34 is viewing the display screen, so the display screen is turned off to save energy (step ST19).

  In this way, the line of sight of all the passengers 31 to 34 in the vehicle is detected, and when it is determined that there is no line of sight, the display screen is turned off. It is possible to prevent the power consumed by the backlight from being wasted when it is not present. In addition, when there is a line of sight only from the passengers 31 and 32 in the front seat, the brightness of the display screen is reduced, so that it has an energy saving effect and is easily visible to the passengers 31 and 32 in the front seat. There is also an effect.

  Further, when the passengers 33 and 34 in the rear seats are looking at the display screen, the brightness of the display screen is not changed. Therefore, even if the passengers 33 and 34 in the rear seats are looking at the driver 31, The screen is turned off because it is not seen, and the brightness of the screen is reduced after the passengers 31 and 32 in the front seats are watching even if the passengers 33 and 34 in the rear seats are watching. It is also possible to prevent a problem that it becomes difficult for the passengers 33 and 34 in the seat to visually recognize.

  As described above, according to the second embodiment, the line of sight of all the passengers in the vehicle is detected, and the detected line of sight is either the line of sight from the front seat passenger or the passenger from the back seat. The display screen is instructed to have different brightness based on whether it is the line of sight, that is, when no line of sight is detected from any seat, or when the line of sight is detected only from the passenger in the front seat The display screen brightness is adjusted according to each case when the line of sight from the passenger in the rear seat is detected, so that all passengers have good visibility and display. Energy saving effect can be enhanced by reducing the power consumption of the screen backlight.

Embodiment 3 FIG.
The configuration of the car navigation apparatus according to Embodiment 3 of the present invention is also the same as the block diagram of FIG.
In the third embodiment, the determination method in the control for giving an instruction (transmitting the brightness adjustment command) from the control unit 6 to the monitor backlight power source 3 is different from those in the first and second embodiments. is there.

Also in the second embodiment, as shown in FIG. 3, there are four passengers, a driver 31, a passenger 32 in the passenger seat, a passenger 33 on the right rear seat, and a passenger 34 on the left rear seat. Assume that there is a passenger.
FIG. 6 is a flowchart showing an example of processing of the in-vehicle display device 1 according to the third embodiment. The line-of-sight detection and backlight control of the LCD monitor of the driver 31 in the vehicle, the passenger 32 in the passenger seat, and the passengers 33 and 34 in the rear seat will be described with reference to FIG.

  First, when the power of the car navigation device is turned on and this process is started, the line-of-sight detection unit 5 detects the car navigation devices of the vehicle passengers 31 to 34 based on signals from the camera 24 (camera units 25 and 26). The presence or absence of a line of sight to the LCD monitor 21 is determined (step ST21).

  Here, if it is determined that there is some line of sight (YES in step ST21), the position of the passenger who is sending the line of sight (looking at the display screen of the car navigation device) is the front seat (driver's seat). Alternatively, it is determined whether it is a passenger seat or a rear seat (step ST22). In step ST22, as in step ST12 of the second embodiment, the determination is made based on whether there is a line of sight from the rear seat.

  If there is a line of sight from the passengers 33 and 34 in the rear seat (YES in step ST22), it is further determined whether or not the line of sight is only the line of sight from the rear seat (step ST23). When the line of sight is only from the passengers 33 and 34 in the rear seats (in the case of YES in step ST23), the brightness of the display screen is changed so that the passengers 33 and 34 in the rear seats can easily see. Instead, the brightness remains as it is (step ST24), and the process returns to step ST21.

  Since the brightness can be finely adjusted in a plurality of stages (for example, 15 stages), in the third embodiment, the brightest state (brightness 15) without changing the brightness, and the state in which the brightness is reduced by one stage (brightness). The description will be made assuming that the control is performed in four steps: luminance 10), a state where the luminance is lowered by two levels (luminance 5), and a state where the backlight power is turned off (luminance 0). That is, in step ST24, the luminance is 15 (maximum bright luminance).

  On the other hand, if there is a line of sight from the passengers 33 and 34 in the rear seats but also a line of sight from the passengers 31 and 32 in the front seats (in the case of NO in step ST23), the timer is not activated. Start (step ST25). Then, until the timer expires, that is, until a certain time has elapsed (in the case of NO in step ST26), the check is repeated only from the rear seat, and there is a line of sight from both the rear seat and the front seat. Is continued for a certain time (in the case of YES in step ST26), the luminance of the display screen is reduced to one level, that is, luminance 10 (step ST27).

  This is because the brighter one is easier to see for the rear seat passengers 33 and 34, and the front seat passengers 31 and 32 may be too bright on the display screen with the maximum brightness. By reducing the brightness so that it is not so bright for the passengers 31 and 32 and visible to the passengers 33 and 34 in the rear seats, it is easy for all the passengers in the vehicle to see, and the energy saving effect is enhanced. It is processing.

If the timer has already been started in step ST25, the process proceeds to step ST26 as it is. Further, when a certain time has elapsed (in the case of YES at step ST26), processing for stopping and resetting the timer is also performed.
The start, stop, and reset processes of the timer are performed in the same manner in the processes (steps ST28 to ST33) in the following description, but the description is omitted.

  When there is no line of sight from the passengers 33 and 34 in the rear seats (NO in step ST22), the timer is started if the timer is not started (step ST28). Then, until the timer expires, that is, until a fixed time has elapsed (in the case of NO in step ST29), the check is repeated whether there is a line of sight from the rear seat, and there is no line of sight from the rear seat. If the display continues for a certain time (in the case of YES at step ST29), the passengers 31 and 32 in the front seat can view the display screen even if the display screen is not so bright. That is, the brightness is lowered to 5 (step ST30).

  If it is determined in step ST21 that there is no line of sight from any seat occupant (NO in step ST21), the timer is started if the timer is not started (step ST31). Then, until the timer expires, that is, until a certain time elapses (in the case of NO in step ST32), the check whether there is any line of sight is repeated, and the state where there is no line of sight from any seat is constant If the time continues (in the case of YES in step ST32), it can be determined that no one of the passengers 31 to 34 is viewing the display screen, so the display screen is turned off to save energy (step ST33).

  In this way, the line of sight of all the passengers 31 to 34 in the vehicle is detected, and when it is determined that there is no line of sight, the display screen is turned off. It is possible to prevent the power consumed by the backlight from being wasted when it is not present. In addition, when there is a line of sight only from the passengers 31 and 32 in the front seat, the brightness of the display screen is lowered by two stages, so that there is an energy saving effect and is visually recognized by the passengers 31 and 32 in the front seat. There is also an effect that it is easy.

  In addition, when there is a line of sight from both the front passengers 31 and 32 and the rear passengers 33 and 34, the brightness of the display screen is reduced by one level. Even if the passengers 33 and 34 in the rear seats are watching the passengers 31 and 32 in the front seats, the brightness of the screen is reduced, making it difficult for the passengers 33 and 34 in the rear seats to see. The above problem can be prevented, and it is easy for both the front passengers 31 and 32 and the rear passengers 33 and 34 to visually recognize.

  Further, when only the passengers 33 and 34 in the rear seats are looking at the display screen, the brightness of the display screen is not changed. Therefore, even if the passengers 33 and 34 in the rear seats are looking at the driver 31. It is also possible to prevent a problem that the screen is turned off because the user does not watch.

  As described above, according to the third embodiment, the line of sight of all the passengers in the vehicle is detected, and the detected line of sight is either the line of sight from the front seat passenger or the passenger from the rear seat. The display screen is instructed to have different brightness based on whether it is the line of sight, that is, when no line of sight is detected from any seat, or when the line of sight is detected only from the passenger in the front seat When the line of sight is detected only from the passenger in the rear seat, or when the line of sight from both the front seat and the rear seat is detected, the brightness of the display screen is adjusted according to each case. Therefore, the visibility is good for all the passengers, and the power consumption by the backlight of the display screen can be suppressed, and the energy saving effect can be enhanced.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  DESCRIPTION OF SYMBOLS 1 In-vehicle display apparatus, 2 Drawing part, 3 Monitor backlight power supply, 4 A / D conversion part, 5 Eye-gaze detection part, 6 Control part, 7 Memory, 10 Car navigation apparatus, 10 'Conventional car navigation apparatus, 11 Navigation main body , 21 LCD monitor (display screen), 22 backlight, 23 operation unit, 24, 27 camera, 25, 26 camera unit, 31-34 passengers.

Claims (3)

In an in-vehicle display device that displays an image on a display screen in a vehicle,
Based on a signal from a camera mounted in the vehicle, a line-of-sight detection unit that detects the line of sight of all the passengers in the vehicle;
A drawing unit for generating an image to be displayed on the display screen;
A backlight power source for adjusting the brightness of the display screen;
A control unit that instructs the drawing unit to generate the image and that instructs the backlight power source to adjust the luminance of the display screen based on a signal from the line-of-sight detection unit. ,
The control unit is configured to display the display screen based on whether the line of sight detected by the line-of-sight detection unit is a line of sight from a front seat passenger or a line of sight of a rear seat passenger among all the passengers in the vehicle. The in-vehicle display device is characterized in that an instruction to the backlight power source is changed so that the brightness of the backlight is different. The control unit, when the line of sight detected by the line of sight detection unit is a line of sight from a passenger in the front seat in the vehicle, a line of sight from a passenger in the rear seat in the vehicle, and The instruction to the backlight power source is changed so that the brightness of the display screen differs depending on the case where the line of sight is not detected from any seat in the vehicle. In-vehicle display device. When the line of sight detected by the line of sight detection unit is a line of sight only from a passenger in the front seat in the vehicle, or when the line of sight is only from a passenger in the back seat in the vehicle, The brightness of the display screen varies depending on the case where the line of sight is from both the front seat and the rear seat in the vehicle and the case where the line of sight is not detected from any seat in the vehicle. The in-vehicle display device according to claim 1, wherein an instruction for the backlight power source is changed.

Images