JP2014217001A - Image quality control device, image display system and image quality control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image quality control device capable of controlling an image quality of a display device in accordance with an ambient environmental change while suppressing the number of required illuminance sensors when installing a plurality of display devices in an internal space of a mobile.SOLUTION: An image quality control device 40 comprises: an illuminance selection section 42 which inputs detection outputs L1, L2 and L3 of illuminance sensors for detecting brightness in an internal space of a mobile and selects an illuminance sensor to be utilized from among the illuminance sensors for each of a plurality of display devices 21-26 on the basis of movement detection information MD of the mobile; and an image quality control section 45 for individually controlling a display image quality on the basis of detection output from the selected illuminance sensor for each display device.

Description

  The present invention relates to an image display technique, and more particularly to a technique for displaying an image on each of a plurality of display devices installed in an internal space of a moving body such as a vehicle, a ship, or an aircraft.

  In recent years, display devices such as liquid crystal displays and organic EL displays have been used in various places for various applications. For example, for personal use, display devices are used in television broadcast receivers, personal computers, and portable information terminals (for example, mobile phones and smartphones). Also, in public places and commercial facilities, display devices are used for public displays or digital signage (digital signage) for the purpose of advertising or providing information, and display devices with touch panel functions of vending machines are also equipped with display devices. It is used. Furthermore, some transportation vehicles and private passenger vehicles have a display device as a component of an in-vehicle navigation system or RSE (Rear Seat Entertainment). Here, the RSE system refers to an audiovisual system configured so that a passenger can spend time traveling in the vehicle without being bored with a seat other than the frontmost seat in the vehicle.

  2. Description of the Related Art In recent years, a brightness control technique that uses an illuminance sensor that detects brightness information of a surrounding environment and controls the brightness of a display device according to a detection value of the illuminance sensor is known. Such brightness control technology has already been applied to personal display devices such as television broadcast receivers, liquid crystal displays, and portable information terminals. In addition, the application of luminance control technology to a display device installed in a public place or a display device installed inside a moving body such as a passenger vehicle is also being promoted.

  However, in a display device installed in a moving body such as a vehicle, the range in which the brightness (illuminance) of the surrounding environment changes is larger than in a display device installed in a home, and the frequency of the change Therefore, it is difficult to appropriately control the display brightness.

  For example, in the case of a display device such as a television broadcast receiver and a liquid crystal display installed in a home, a user usually installs the display device in a place where direct sunlight is not irradiated. In this case, it is common to assume an illuminance of about 1000 lux (1 lux is a lumen per square meter) as the upper limit of the range that the illuminance can take, and it is rare that the display device in use moves. Therefore, it is unlikely that the illuminance around the display device will change continuously in a short time. On the other hand, in the case of a display device installed inside a moving body, it is assumed that the moving body moves in various time zones such as nighttime and daytime. Also, various places such as a dark place in the building and a bright place outdoors during the day are assumed as the destination of the moving body. For this reason, it is necessary to assume an environment where the illuminance around the display device continuously changes greatly within a short time.

  For example, Japanese Patent Laying-Open No. 2011-203342 (Patent Document 1) discloses a technique for controlling the display luminance of a display device installed inside a vehicle. The in-vehicle display device disclosed in Patent Document 1 includes a light receiving unit that measures the brightness of a display screen and brightness of a driver's line of sight in order to grasp the influence of environmental light in different directions. Display luminance control according to the driving environment can be performed using illuminance values obtained from two types of illuminance sensors called light receiving units that measure the brightness outside the vehicle.

Japanese Patent Laying-Open No. 2011-203342 (for example, FIG. 1 and paragraphs 0009 to 0015)

  However, when a plurality of display devices are installed inside a mobile body and an attempt is made to construct a system for appropriately individually controlling the display brightness of the plurality of display devices using conventional brightness control technology, the need for an illuminance sensor is required. There is a problem that the number increases and the cost increases. For example, the brightness control technique disclosed in Patent Document 1 requires two types of illuminance sensors per display device. For this reason, as the number of installed display devices increases, the required number of illuminance sensors increases, and the cost required to construct the system also increases.

  In view of the above, the object of the present invention is to appropriately control the display image quality of these display devices according to changes in the surrounding environment when a plurality of display devices are installed in the internal space of the moving body. To provide an image quality control device, an image display system, and an image quality control method capable of suppressing the required number of illuminance sensors.

  An image quality control apparatus according to a first aspect of the present invention includes an original image signal supplied from a signal source, a detection output of at least one illuminance sensor that detects the brightness of the internal space of the moving body, The display image quality of N display devices (N is an integer of 2 or more) arranged in the internal space of the moving body is input using movement detection information indicating a moving state or position detection information indicating the position of the moving body as an input. An illuminance selection unit that selects an illuminance sensor to be used from among the at least one illuminance sensor for each display device based on the movement detection information; and And an image quality control unit for individually controlling the display image quality based on the detection output of the selected illuminance sensor.

  An image display system according to a second aspect of the present invention includes the at least one illuminance sensor and the image quality control device.

  An image quality control method according to a third aspect of the present invention includes an original image signal supplied from a signal source, a detection output of at least one illuminance sensor that detects the brightness of at least one location in the internal space of the moving body, N display devices (N is an integer equal to or greater than 2) arranged in the internal space of the moving body with movement detection information indicating the moving state of the moving body or position detection information indicating the position of the moving body as inputs. An image quality control method for controlling the display image quality of the display device, the step of selecting an illuminance sensor to be used from the at least one illuminance sensor for each display device based on the movement detection information; and the display device And individually controlling the display image quality based on the detection output of the selected illuminance sensor.

  According to the present invention, an illuminance sensor to be used is selected from at least one illuminance sensor for each display device based on movement detection information or position detection information of a moving body, and detection of the selected illuminance sensor is performed. The display image quality is individually controlled based on the output. For this reason, when a plurality of display devices are installed in the internal space of the moving body, the display image quality of these display devices can be appropriately controlled according to changes in the surrounding environment, and the required number of illuminance sensors is suppressed. You can also.

It is a block diagram which shows schematic structure of the image display system of Embodiment 1 which concerns on this invention. 1 is a block diagram illustrating a schematic configuration of an image quality control apparatus according to Embodiment 1. FIG. 3 is a flowchart schematically showing a processing procedure by an illuminance selection unit according to the first embodiment. (A), (B) is a graph which shows the example of the relationship between average brightness | luminance and display brightness | luminance. It is a figure which shows roughly the structural example at the time of applying the image display system of Embodiment 1 to a passenger vehicle. It is a figure which shows an example of the look-up table referred by the illumination intensity selection part. It is a figure which shows roughly the structural example at the time of applying the image display system of Embodiment 1 to a rail vehicle. It is a block diagram which shows schematic structure of the image display system of Embodiment 2 which concerns on this invention. 6 is a block diagram illustrating a schematic configuration of an image quality control apparatus according to Embodiment 2. FIG. 6 is a flowchart schematically showing a processing procedure by an illuminance selection unit according to the second embodiment. It is a figure which shows roughly the structural example at the time of applying the image display system of Embodiment 2 to a railway vehicle. It is a figure which shows an example of the look-up table referred by the illumination intensity selection part. It is a figure which shows the other example of the look-up table referred by the illumination intensity selection part. It is a figure which shows roughly the other structural example at the time of applying the image display system of Embodiment 2 to a rail vehicle. It is a block diagram which shows schematic structure of the image display system of Embodiment 3 which concerns on this invention. 6 is a block diagram illustrating a schematic configuration of an image quality control apparatus according to Embodiment 3. FIG. 10 is a flowchart schematically showing a processing procedure by an illuminance selection unit of the third embodiment.

  Hereinafter, various embodiments according to the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a schematic configuration of an image display system 10 according to the first embodiment of the present invention. The image display system 10 is disposed in the internal space of the moving body 1. Examples of the mobile body 1 include, but are not limited to, a passenger vehicle traveling on a road, a railway vehicle traveling on a track, a ship navigating in a sea area, or an aircraft flying in an air area.

  Inside the moving body 1, there are a signal source 11 for supplying the original image signal So to the image display system 10, and the speed (unit: meters / second), acceleration (time change rate of speed) or angular velocity (unit) of the moving body 1. : A movement detecting unit 12 having a sensor for detecting (radians / second).

  The movement detection unit 12 supplies the image display system 10 with movement detection information MD indicating the speed, acceleration, angular velocity, or a combination of one or more of these. A gyro sensor may be used as the angular velocity detection sensor. When the moving body 1 moves at an angle with respect to the ground surface, it is effective to use a gyro sensor.

  In addition, in this Embodiment, although the movement detection part 12 is integrated in the inside of the mobile body 1, it is not limited to this. The movement detection unit 12 may be brought into the mobile body 1 from the outside. For example, the image quality control device 40 establishes a communication link with a mobile information terminal (such as a smartphone) equipped with an acceleration sensor and a gyro sensor, and acquires the detection output of the acceleration sensor or the gyro sensor from the mobile information terminal. It is also possible.

  As the signal source 11, for example, an information reproducing device that reads an image signal from a recording medium such as an HDD (Hard Disk Drive), a DVD (Digital Versatile Disc), or a Blu-ray Disc (registered trademark), a broadcast such as a digital television broadcast receiver Examples include a receiving device, a device that reads an image signal stored in a recording medium built in a portable information terminal (such as a smartphone), or a communication device that receives an image signal distributed from a specific information distribution system. When the moving body 1 is a railway vehicle, image data is received from a base station of an information distribution system installed at a specific point such as a station and stored in a recording medium, or old image data is stored in the received image data. A communication device to be updated can be used as the signal source 11.

  As shown in FIG. 1, the image display system 10 is disposed at a position different from each other with a plurality of display devices 21, 22, 23, 24, 25, and 26 installed in the internal space of the moving body 1. Illuminance sensors 31, 32, and 33, and an image quality control device 40 that individually controls display image quality of the display devices 21 to 26 are provided.

  The illuminance sensors 31, 32, 33 detect illuminance values as the brightness of the installation locations of the illuminance sensors 31, 32, 33 and supply detection outputs L 1, L 2, L 3 indicating these illuminance values to the image quality control device 40. . The illuminance sensors 31, 32, and 33 may include, for example, a phototransistor or a photodiode that converts an optical signal into an electric signal. Moreover, it is desirable that the illuminance sensors 31, 32, and 33 are not installed in locations that are close to each other. For example, when the moving body 1 is a passenger vehicle, the illuminance sensors 31 and 32 are located in the vicinity of the window in the vicinity of the vehicle interior wall provided with a window through which external light is inserted, or in the vicinity of any one of the display devices 21 to 26. , 33 are effective.

  The illuminance sensors 31, 32, 33 and the image quality control device 40 can be connected by wire. Illuminance sensors 31, 32, 33 using a short-range wireless communication technology such as a wireless local area network (WiFi) such as WiFi (registered trademark) or a Bluetooth (registered trademark) instead of the wired connection. And the image quality control device 40 can be connected wirelessly.

  For example, when an imaging device such as a camera is installed in the moving body 1 in advance for a videophone or monitoring application, the imaging is performed instead of the detection outputs L1 to L3 of the illuminance sensors 31, 32, and 33. It is also possible to convert the illuminance value from the pixel value of the image captured by the device and use it.

  The image quality control device 40 receives the original image signal So supplied from the signal source 11, the movement detection information MD, and the detection outputs L1, L2, and L3 of the illuminance sensors 31 to 33, and inputs to the display devices 21 to 26, respectively. In addition to generating image signals S1 to S6 to be supplied, a control signal for individually controlling the display image quality (display brightness, contrast, color, and / or sharpness, etc.) of the display devices 21 to 26 is generated as will be described later. be able to.

  FIG. 2 is a block diagram showing a schematic configuration of the image quality control device 40 of the present embodiment. As shown in FIG. 2, the image quality control device 40 performs an image processing such as image quality enhancement on the original image signal So to generate an image signal Sa, and an image represented by the image signal Sa. And a feature analysis unit 44 that detects a feature amount of a (still image or moving image).

  As described above, the input signal processing unit 43 has a function of generating an image signal Sa by performing image processing such as high image quality on the original image signal So, but instead, performs image processing on the original image signal So. Instead, the original image signal So can be output as it is as the image signal Sa.

  Here, the input signal processing unit 43 needs to have a configuration corresponding to the type of the signal source 11. For example, when the original image signal So supplied from the signal source 11 is modulated or encoded, the input signal processing unit 43 has a function of demodulating or decoding the modulated or encoded original image signal So. It is necessary to have. When the signal source 11 is a communication device that receives image data from a base station of an information distribution system installed at a specific point such as a station, the input signal processing unit 43 stores the received image data. You may have a recording medium.

  When the image represented by the image signal Sa is a moving image, the feature analysis unit 44, for example, an average luminance value (average value of pixel values in a single frame) of a single frame constituting the moving image or An average luminance value of a plurality of consecutive frames (a value obtained by averaging the average luminance value of each frame over a plurality of frames) can be calculated as a feature amount.

  Alternatively, the feature analysis unit 44 may calculate a luminance histogram of an image represented by the image signal Sa, and use a representative value of the luminance histogram as a feature amount of the luminance distribution. For example, the value indicating the luminance deviation of the high luminance side, the low luminance side, or the intermediate gradation can be used as the representative value of the luminance histogram. Alternatively, the Nth quantile (N is an integer of 3 or more) or the mode value of the luminance histogram can be used as the representative value. Here, the Nth quantile means a score when the relative cumulative frequency obtained from the luminance histogram is equally divided into N. In the case of the decile, the point where the relative cumulative frequency becomes the number of pixels exceeding N / 10 of the total number of pixels is referred to as the Nth decile.

  The feature analysis unit 44 supplies the data FD indicating the feature amount to the image quality control unit 45 and also supplies the image signal Sa as it is to the image quality control unit 45 as the image signal Sb. Here, the feature analysis unit 44 can generate an image signal Sb different from the image signal Sa by performing image processing corresponding to the feature amount on the image signal Sa.

  On the other hand, as shown in FIG. 2, the image quality control device 40 analyzes the movement detection information MD and outputs the analysis information MA that is the analysis result, and the display device based on the analysis information MA. An illuminance selection unit 42 that selects an illuminance sensor to be used from among the illuminance sensors 31 to 33, and an image quality for individually controlling the display image quality of the display devices 21 to 26 based on the detection output of the selected illuminance sensor And a control unit 45.

  The movement analysis unit 41 analyzes the movement detection information MD to generate analysis information MA indicating a state related to the movement of the moving body 1, and supplies the analysis information MA to the illuminance selection unit 42. The movement analysis unit 41 includes, for example, a stationary state indicating that the moving body 1 is not moving, a high speed moving state indicating that the moving body 1 is moving quickly, and a low speed moving state indicating that the moving body 1 is moving slowly. Information indicating one of the types of states (information indicating the intensity of speed) can be generated as analysis information MA. The analysis information MA should be determined according to the type and structure of the mobile body 1 and is not limited to information indicating these three types of states.

  Next, the illuminance selection unit 42 will be described with reference to FIG. FIG. 3 is a flowchart schematically showing a processing procedure by the illuminance selection unit 42. The illuminance selection unit 42 first acquires the detection outputs L1 to L3 of the illuminance sensors 31 to 33 (step S10), and then acquires the analysis information MA from the movement analysis unit 41 (step S11).

  Thereafter, the illuminance selection unit 42 refers to a lookup table (LUT) 47 stored in the data storage unit 46 that is a nonvolatile memory, and the illuminance sensor to be used from among the illuminance sensors 31 to 33 for each display device. Is selected (step S12). The look-up table 47 stores data that defines usage conditions of the illuminance sensors 31 to 33 according to the analysis information MA. For example, as described above, when the analysis information MA is information indicating any of three types of states (stationary state, low-speed movement state, and high-speed movement state), the illuminance to be selected according to each of the three types of states Data specifying the sensor can be stored in the lookup table 47. The person who builds the image display system 10 is, for example, the installation status of the display devices 21 to 26 and the illuminance sensors 31 to 33, the performance of the display devices 21 to 26 and the illuminance sensors 31 to 33, and the traveling path of the moving body 1 or The contents of the data stored in the lookup table 47 can be appropriately determined according to the assumed situation of the navigation route.

Here, the illuminance selection unit 42 weights the detection outputs L1, L2, and L3 of the illuminance sensors 31, 32, and 33 with the coefficients α ₁ , α ₂ , and α ₃ , respectively, so that the illuminance sensor to be used for each display device is used. May be selected. For example, the coefficient alpha ₁ is when zero, the detection output L1 × alpha ₁ weighted becomes zero, the illuminance sensor 31 is not selected. On the other hand, when the coefficient α ₁ is non-zero (for example, α ₁ = 1), the illuminance sensor 31 is selected.

  After the illuminance sensor is selected in step S12, the illuminance selection unit 42 corresponds to each of the display devices 21, 22, 23, 24, 25, and 26 based on the detection output of the illuminance sensor selected for each display device. The estimated illuminance values Lin (1), Lin (2), Lin (3), Lin (4), Lin (5), and Lin (6) are calculated (step S13). For example, the average value, maximum value, minimum value, or intermediate value of the detection outputs of the illuminance sensors selected for each display device can be calculated as the estimated illuminance values Lin (1) to Lin (6). Here, “maximum value” means the maximum value among the detection output values of the plurality of selected illuminance sensors, and “minimum value” means the value of the detection output of the plurality of selected illuminance sensors. Means the minimum value. In addition, “intermediate value” means a value located in the center when the detection output values of these illuminance sensors are arranged in ascending order when the selected plurality of illuminance sensors is an odd number. An even number of a plurality of illuminance sensors means an arithmetic average value of two values close to the center when the detection output values of these illuminance sensors are arranged in ascending order.

  Next, the illuminance selection unit 42 outputs the control information Ct specifying the display devices 21 to 26 and the estimated illuminance values Lin (1) to Lin (6) to the image quality control unit 45 (step S14). As the control information Ct, for example, a unique number (MAC address or the like) assigned to each of the display devices 21 to 26 is cited. Thereafter, the illuminance selection unit 42 repeatedly executes the above steps S10 to S14 (NO in step S15) until it is determined that the process is ended (YES in step S15).

  Next, the image quality control unit 45 will be described. The image quality control unit 45 operates with the estimated illuminance values Lin (1) to Lin (6), the data FD representing the feature amount, and the image signal Sb as inputs. The image quality control unit 45 generates six systems of image signals S1 to S6 based on the image signal Sb, and supplies these image signals S1 to S6 to the display devices 21 to 26, respectively. The display devices 21 to 26 display images represented by the image signals S1 to S6, respectively.

  The image quality control unit 45 also displays the display image quality (display brightness, contrast, color, sharpness, etc.) of the display devices 21 to 26 based on the estimated illuminance values Lin (1) to Lin (6) and the data FD. ) To generate control signals QC1 to QC6. The display devices 21 to 26 have a function of adjusting the image quality of the display image so that the display image quality specified by the control signals QC1 to QC6 is obtained.

  For example, FIGS. 4A and 4B are graphs showing examples of the relationship between the average luminance and the display luminance when the feature amount indicated by the data FD is average luminance (256 gradation values). . 4A and 4B, the horizontal axis represents the average luminance of the image, and the vertical axis represents the display luminance of any of the display devices 21 to 26. As illustrated in FIG. 4A, the image quality control unit 45 controls the control signals QC1 to QC1 to set the display brightness to 100% when the average brightness is low and set the display brightness to C1% when the average brightness is high. QC6 is generated. For example, in the case of a bright image, the visibility can be improved by reducing the display luminance.

  In addition, the image quality control unit 45 controls the control signals QC1 to QC6 to decrease the overall display luminance as indicated by the arrows in FIG. 4B as the illuminance estimation values Lin (1) to Lin (6) are lower. Is generated. Conversely, the image quality control unit 45 can generate the control signals QC1 to QC6 that increase the overall display luminance as the estimated illuminance values Lin (1) to Lin (6) are higher. For example, in a high illuminance environment such as in fine weather, the values of the detection outputs L1 to L3 of the illuminance sensors 31 to 33 are large. In this case, it is necessary to set the display luminance high. Thereby, it can suppress that a display image feels dark by the brightness of external light.

  When the display devices 21 to 26 are liquid crystal display devices having a backlight, the characteristics of the backlight are grasped in advance in order to control the display brightness, and the drive current or drive voltage to be supplied to the backlight and the display brightness It is desirable to know the relationship between the two. For example, the light emission intensity of the backlight can be controlled by using a PWM signal (Pulse Width Modulated signal). Further, the controllable range of the light emission luminance differs depending on the characteristics of the backlight. In this embodiment, since it is assumed that the illuminance range of the surrounding environment of the moving body 1 is wide, it is desirable to use a liquid crystal display device provided with a backlight with high luminance output.

  In addition, some backlights of liquid crystal display devices can be subjected to local dimming control. The light emission area of the backlight capable of local dimming control is divided into a plurality of divided areas, and the light emission luminance can be locally controlled for each divided area. In the local dimming control, the contrast of the display image can be improved by locally reducing the light emission luminance of the divided region corresponding to the dark image region with reference to the maximum light emission luminance value of the backlight. When a liquid crystal display device having a backlight subjected to local dimming control is used as the display devices 21 to 26, the image quality control unit 45 controls a control signal for local dimming control with respect to the backlights of the display devices 21 to 26. It is preferable to generate QC1 to QC6.

  In addition, when the display devices 21 to 26 include a plurality of types of display devices having different display characteristics, the image quality control unit 45 desirably performs different image quality control for each type of display device. As a specific example, the display devices 21 and 22 are 12-inch size liquid crystal display devices, and the display devices 23 to 26 are 20-inch size organic EL panels. Such an example is, for example, a display device used in a car navigation system in which the display devices 21 and 22 are provided for the driver's seat FL, and the display devices 23 to 26 are display devices for RSE (rear seat entertainment) applications. It is assumed when

  Also, for example, when different types of display devices display images with the same display brightness, a difference occurs in the feeling of glare that viewers feel from these display devices. Specifically, if the display sizes of the display devices are different from each other, a display device having a large display size tends to make the viewer feel dazzled because the area of the display image in the viewer's field of view increases. Under such circumstances, it is appropriate to lower the display luminance of a display device having a larger display size than a display device having a smaller display size.

  The image quality control unit 45 can generate six systems of image signals S1 to S6 having the same contents as the image signal Sb. It is also possible to perform image quality correction such as resolution improvement on the image signal Sb to generate the image signals S1 to S6.

  Next, the example which applied the said image display system 10 to the passenger vehicle 2 which is 1 type of the mobile body 1 is demonstrated.

  FIG. 5 is a diagram schematically illustrating an internal space of the passenger vehicle 2 including the display devices 21 to 26 and the illuminance sensors 31 to 33 of the image display system 10. Usually, since the passenger vehicle 2 is equipped with a speedometer, this speedometer can be used as the movement detector 12. In this case, the movement analysis unit 41 uses the speed information obtained from the speedometer as the movement detection information MD.

  For example, the front seat FR on the right side with respect to the front in the traveling direction of the passenger vehicle 2 can be the driver seat, and the front seat FL on the left side can be the passenger seat. The display devices 21 and 22 are disposed in front of the internal space of the passenger vehicle 2, and a person seated on the front seats FL and FR can view the display devices 21 and 22. The display devices 21 and 22 can be used mainly as a display device of a car navigation system. An illuminance sensor 31 is disposed in the vicinity of the window in the forward direction of the passenger vehicle 2.

  On the other hand, display devices 23 and 24 for RSE are arranged on the back of the front seats FL and FR of the passenger vehicle 2, respectively, and a person seated in the middle seat ML can see the display device 23. A person sitting in the middle seat MR can view the display device 24. On the other hand, display devices 25 and 26 for RSE are also arranged on the backs of the middle seats ML and MR, respectively, so that a person seated in the rear seat BL can see the display device 25 and sit in the rear seat BR. Those who do can view the display device 26. An illuminance sensor 32 is disposed in the vicinity of the left window behind the passenger vehicle 2, and an illuminance sensor 33 is disposed in the vicinity of the right window behind the passenger vehicle 2.

  As described above, the installation location of the illuminance sensors 31, 32, and 33 is effective to be in the vicinity of the window or in the vicinity of any one of the display devices 21 to 26 in the vicinity of the vehicle interior wall provided with the window through which the external light is inserted. is there. In the example of FIG. 5, no illuminance sensor is installed near the rear window. The reason is that light incident from the rear window is blocked by the rear seats BL and BR, so that the influence on the display screens of the display devices 25 and 26 is considered to be weak. In this way, it is possible to eliminate the arrangement of the illuminance sensor in a place where the influence of external light is considered to be small due to the design reasons of the structure around the display device.

  Since the illuminance sensor is intended to measure the brightness received by the viewer's vision, the direction in which the light-receiving surface of the illuminance sensor faces (hereinafter also referred to as “light-receiving surface direction”) is as much as possible for the viewer. It is desirable to match with the direction close to the line of sight. For example, the direction of the light receiving surface of the illuminance sensor 32 can be made to coincide with the direction close to the viewer's line of sight sitting on the rear seat BL (the direction from the rear seat BL to the display device 25). The direction can be made to coincide with the direction (the direction from the rear seat BR to the display device 26) close to the viewing direction of the viewer seated in the rear seat BR.

  Further, due to the internal structure of the passenger vehicle 2, the light receiving surface direction of the illuminance sensor may not be matched with the viewer's line-of-sight direction (for example, the direction from the rear seat BR to the display device 26). In such a case, as a next candidate for the light receiving surface direction of the illuminance sensor, the illuminance sensor is arranged at a position near the display device, and the light receiving surface direction of the illuminance sensor is set to the direction from the display device toward the viewer. be able to. For example, the direction of the light receiving surface of the illuminance sensor 32 can be made to coincide with the direction opposite to the viewer's line of sight seated on the rear seat BL (the direction from the display device 25 to the rear seat BL). Can be made to coincide with the direction opposite to the line of sight of the viewer seated in the rear seat BR (direction from the display device 26 to the rear seat BR). By installing the illuminance sensors 32 and 33 in this way, the brightness of light incident on the vicinity of the display device to which the viewer's line of sight is directed can be measured. It is possible to estimate.

FIG. 6 is a diagram illustrating an example of the lookup table 47 referred to by the illuminance selection unit 42 of the image quality control device 40 mounted on the passenger vehicle 2. The analysis information AD includes information indicating any of a stationary state, a low-speed movement state, and a high-speed movement state of the moving body 1. The look-up table 47 stores data for specifying an illuminance sensor to be selected for each of the display devices 21 to 26 when the passenger vehicle 2 is in a stationary state, a low-speed movement state, or a high-speed movement state. Here, “static state”, “low-speed movement state”, and “high-speed movement state” are the following three types using threshold values th1 and th2 (th1 <th2) when the speed of the passenger vehicle 2 is v. It shall be determined according to the speed range.
Still state: 0 ≦ v <th1,
Low speed movement state: th1 ≦ v <th2,
High-speed movement state: th2 ≦ v.

  Here, the threshold value th1 is a value close to zero, and is set to a value that can absorb fluctuations in numerical values due to vibration or the like.

  In the present embodiment, the speed v of the passenger vehicle 2 is a scalar amount (absolute value) having no direction. Instead, the speed v of the passenger vehicle 2 may be detected as a vector quantity indicating the traveling direction of the passenger vehicle 2. In this case, the movement analysis unit 41 can generate an analysis result based on the traveling direction of the passenger vehicle 2, and the illuminance selection unit 42 can use analysis information MA indicating the analysis result.

When the passenger vehicle 2 is in a stationary state, it is desirable to select an illuminance sensor arranged in an environment closest to the illuminance environment as the illuminance sensor to be used for controlling the display luminance. Therefore, according to the lookup table of FIG. 6, the illuminance sensor 31 closest to the display devices 21 and 22 is selected, and the illuminance sensor is used for the display devices 23 and 25 arranged on the left side of the passenger vehicle 2. 32 is selected, and the illuminance sensor 33 is selected for the display devices 24 and 26 arranged on the right side of the passenger vehicle 2. The estimated illuminance values Lin (1) to Lin (6) at this time are calculated according to the following formula, for example.
Lin (1) = Lin (2) = L1,
Lin (3) = Lin (5) = L2,
Lin (4) = Lin (6) = L3.

Next, when the passenger vehicle 2 is in a low-speed movement state, the illuminance sensor 31 is selected for the display devices 21 and 22 according to the look-up table in FIG. 6, and the display devices 23, 24, 25, and 26 are selected. Is selected from the illuminance sensors 32 and 33. The reason for selecting in this way is that when the moving body 1 moves at a relatively low speed, the illuminance value in the vicinity of the illuminance sensor 31 disposed in front of the traveling direction is compared with the illuminance values in the vicinity of the illuminance sensors 32 and 33 behind. This is because the values tend to be stable. The estimated illuminance values Lin (1) to Lin (6) at this time are calculated according to the following formula, for example.
Lin (1) = Lin (2) = L1,
Lin (3) = Lin (4) = Lin (5) = Lin (6) = (L2 + L3) / 2.

  Next, when the passenger vehicle 2 is in a high-speed movement state, the front illuminance sensor 31 is selected for all the display devices 21 to 26 according to the lookup table of FIG. At this time, for example, in an urban area where buildings are densely populated, the change in brightness of the surrounding environment of the passenger vehicle 2 that moves at a relatively high speed tends to become severe, and an illuminance value with sufficient accuracy for fine control is obtained. Difficult to get. Therefore, it is desirable to select only the illuminance sensor 31 that outputs a value that most reflects the illuminance at the front position in the traveling direction of the passenger vehicle 2. The estimated illuminance values Lin (1) to Lin (6) at this time are all the values of the detection output L1 of the illuminance sensor 31.

  As described above, when the passenger vehicle 2 is in a high-speed movement state, only the front illuminance sensor 31 is selected, and the other illuminance sensors 32 and 33 are not selected. At this time, it is possible to temporarily stop the power supply to the illuminance sensors 32 and 33 and not operate the illuminance sensors 32 and 33. At this time, the illuminance selection unit 42 may acquire only the detection output L1 of the illuminance sensor 31 and may not acquire the detection outputs L2 and L3 of the illuminance sensors 32 and 33. Thereby, the power consumption of the image display system 10 can be suppressed.

  Further, as described above, the illuminance selection unit 42 estimates that the brightness change in the surrounding environment of the passenger vehicle 2 becomes more severe as the speed v of the passenger vehicle 2 increases, and determines the number of illuminance sensors to be used. Can be reduced. On the other hand, in a depopulated area where there are almost no buildings in the vicinity, even if the passenger vehicle 2 moves through the depopulated area at a high speed, there may be a situation in which the change in brightness of the surrounding environment does not become severe. In order to cope with such a situation, the movement analysis unit 41 monitors the values (illuminance values) of the detection outputs L1 to L3 of the illuminance sensors 31, 32, and 33, and the fluctuations of those values are all within a certain range. , It can be determined that the change in the brightness of the surrounding environment of the passenger vehicle 2 is moderate, and the determination result can be included in the analysis information MA and output to the illuminance selection unit 42. In this case, the illuminance selection unit 42 selects all the illuminance sensors 31, 32, and 33 for all the display devices 21 to 26 even when the passenger vehicle 2 is in a high-speed movement state, and these illuminance sensors. The arithmetic average value (= (L1 + L2 + L3) / 3) of the detection outputs 31, 32, and 33 can be calculated as the estimated illuminance values Lin (1) to Lin (6).

  If it is difficult to install the illuminance sensors 31 to 33 as shown in FIG. 5 due to the internal structure of the passenger vehicle 2, the installation position is changed as appropriate, and lookup is performed in accordance with the change. Data stored in the table 47 may be changed. In this case, it is desirable to install an illuminance sensor having a light receiving surface directed at a position where external light enters the passenger vehicle 2 regardless of the position at which the illuminance sensor is disposed. At this time, an illuminance sensor may be arranged near the window of the passenger vehicle 2 in consideration of the influence of sunlight.

  Further, the design reasons of the image display system 10 (for example, the distances from the windows of the installation locations of the display devices 25 and 26 are the same, but the distances from the wall surfaces of the illuminance sensors 32 and 33 are different from each other, The values of the detection outputs L2 and L3 of the illuminance sensors 32 and 33 may be different from each other even under an external light environment under similar conditions due to the presence of a shield. In such a case, the values of the detection outputs L2 and L3 may be individually adjusted by weighting the values of the detection outputs L2 and L3 of the illuminance sensors 32 and 33 with a weighting factor for correction.

  The image display system 10 of the present embodiment can be applied to vehicles other than the passenger vehicle 2. FIG. 7A is a diagram schematically illustrating an example of the internal space of a railway vehicle including the display devices 21 to 24 and the two illuminance sensors 31 and 32 of the image display system 10. As shown in FIG. 7A, a pair of display devices 21 and 22 are provided on the wall surface directly above the pair of open / close doors 51 and 52 of the railway vehicle. The other pair of display devices 21 and 22 are also provided on the wall surface directly above the pair of open / close doors 53 and 54 of the railway vehicle. Here, the pair of display devices 21 and 22 are disposed at positions adjacent to each other, and the other pair of display devices 23 and 24 are also disposed at positions adjacent to each other. Furthermore, one illuminance sensor 31 is provided on the wall surface between the display devices 21 and 22 and the open / close doors 51 and 52, and one wall surface between the display devices 23 and 24 and the open / close doors 53 and 54 is also provided. Illuminance sensor 32 is provided. The open / close doors 51, 52, 53, and 54 have windows 51w, 52w, 53w, and 53w, respectively, and the railcar itself has windows 55 and 56 having a large area. For this reason, the degree of change in the brightness of the surrounding environment varies depending on the moving speed of the railway vehicle. For example, when the railway vehicle is in a low-speed movement state or a stationary state, the illuminance selection unit 42 selects only the illuminance sensor 32 for the display devices 21 and 22, and the illuminance sensor for the display devices 23 and 24. Only 33 can be selected (assigned). On the other hand, when the railway vehicle is in a high-speed movement state, the illuminance selection unit 42 can select (assign) the illuminance sensors 31 and 32 to the display devices 21, 22, 23, and 24.

  On the other hand, FIG. 7B is a diagram schematically showing another example of the interior space of the railway vehicle having the display devices 21 to 24 of the image display system 10 and the four illuminance sensors 31, 32, 33, 34. is there. The configuration of the internal space shown in FIG. 7B is the same as the configuration of the internal space shown in FIG. 7A except for the arrangement of the illuminance sensors 31, 32, 33, and 34. In FIG. 7B, the illuminance sensor 31 is provided on the wall surface between the display device 21 and the open / close door 51, the illuminance sensor 32 is provided on the wall surface between the display device 22 and the open / close door 52, and the display device 23 and the open / close door 53. The illuminance sensor 33 is provided on the wall surface between the display device 24 and the illuminance sensor 34 on the wall surface between the display device 24 and the open / close door 54. For this reason, the number of the illuminance sensors 31 to 34 is the same as the number of the display devices 21 to 24.

  In the configuration shown in FIG. 7B, only the illuminance sensor 31 closest to the display device 21 is always selected for the display device 21 and the illuminance closest to the display device 22 for the display device 22 is selected. If only the sensor 32 is always selected, the amount of light irradiated to the display devices 21 and 22 is different from each other. When an imbalance in display luminance occurs between the display devices 21 and 22, both display devices 21 are displayed. , 22 at the same time, the viewer feels uncomfortable. In order to avoid such a problem, the illuminance selection unit 42 of the present embodiment selects the two illuminance sensors 31 and 32 for the display devices 21 and 22 according to the change in the brightness of the surrounding environment, What is necessary is just to utilize the output of these illumination intensity sensors 31 and 32 (for example, utilization of the average of the outputs of illumination intensity sensors 31 and 32). Further, it is not always necessary to provide the four illuminance sensors 31 to 34, and it is sufficient to provide only the illuminance sensors 21 and 22 which are half the number of the display devices 21 to 24 as shown in FIG. .

  As described above, the image display system 10 according to the first embodiment selects an illuminance sensor to be used from the illuminance sensors 31 to 33 for each display device based on the movement detection information MD of the moving body 1. The display image quality of the display devices 21 to 26 is individually controlled based on the detection output of the selected illuminance sensor. For this reason, even when a plurality of display devices 21 to 26 are installed in the internal space of the moving body 1, the display image quality of the plurality of display devices 21 to 26 can be appropriately controlled in accordance with changes in the surrounding environment. It is also possible to suppress the required number of illuminance sensors.

  In particular, when the movement analysis unit 41 analyzes the velocity information of the moving body 1 as the movement detection information MD, an analysis result corresponding to the frequency of change in the brightness of the surrounding environment of the moving body 1 can be obtained (estimated). Therefore, fine image quality control can be performed.

  In addition, since the required number of illuminance sensors can be suppressed, the cost of the illuminance sensors is reduced, and the number of places where the illuminance sensors are installed is reduced. For this reason, the overall cost required for constructing the image display system 10 in the moving body 1 can be reduced.

  Moreover, since the display brightness | luminance of the display apparatuses 21-26 can be made appropriate according to the brightness of a surrounding environment, power consumption can be suppressed with an improvement in visibility.

  In addition, the number of illuminance sensors 31 to 33 and installation locations are not limited to three and three locations. What is necessary is just to determine suitably the number of illuminance sensors, and an installation location according to the shape and area of the mobile body 1 (passenger vehicle or a rail vehicle). In the example of FIG. 5, the illuminance sensors 32 and 33 are installed in the space between the middle seats ML and MR and the rear seats BL and BR, but are not limited thereto. For example, the illuminance sensors 32 and 33 may be installed in the space between the front seats FL and FR and the middle seats ML and MR, or the illuminance sensors 32 and 33 are installed behind the rear seats BL and BR. It is also possible. Furthermore, an illuminance sensor can be additionally installed at an intermediate point between the seats FL, FR, ML, and MR.

Embodiment 2. FIG.
Next, a second embodiment according to the present invention will be described. FIG. 8 is a block diagram illustrating a schematic configuration of the image display system 10B according to the second embodiment. This image display system 10B is arranged in the internal space of the moving body 1B. Examples of the moving body 1B include a passenger vehicle, a railway vehicle, a ship, and an aircraft, but are not limited thereto.

  Inside the moving body 1B, a signal source 11 that supplies the original image signal So to the image display system 10B and a movement detection unit 12B that supplies position detection information PD indicating the current position of the moving body 1 are arranged. Yes. The configuration of the signal source 11 shown in FIG. 8 is the same as that of the signal source 11 shown in FIG. The movement detection unit 12B according to the present embodiment uses the global positioning system (GPS) that is a satellite positioning system, and the current position (latitude, longitude, and altitude) of the moving body 1B on the earth. It is equipped with a GPS receiver that detects within a certain error range. In addition, the movement detection unit 12B can acquire highly accurate time information from a received signal from a GPS satellite.

  In addition, in this Embodiment, although the movement detection part 12B is equipped in the inside of the mobile body 1B, it is not limited to this. The movement detection unit 12B may be brought into the mobile body 1B from the outside. For example, the image quality control device 40B can establish a communication link with a portable information terminal (smartphone or the like) equipped with a GPS receiver, and acquire the output of the GPS receiver from the portable information terminal.

  As shown in FIG. 8, the image display system 10 </ b> B includes a plurality of display devices 210 to 260 installed in the internal space of the moving body 1 </ b> B, and illuminance sensors 31, 32, and 33 disposed at different positions. The image quality control device 40B for individually controlling the display image quality of the display devices 210 to 260 is provided.

  The configuration of the illuminance sensors 31, 32, and 33 shown in FIG. 8 is the same as that of the illuminance sensors 31, 32, and 33 shown in FIG. The illuminance sensors 31, 32, and 33 supply detection outputs L1, L2, and L3 indicating illuminance values to the image quality control device 40B. As in the case of the first embodiment, the illuminance sensors 31, 32, 33 and the image quality control device 40B can be connected by wire or wirelessly.

  The image quality control device 40B receives the original image signal So supplied from the signal source 11, the position detection information PD, and the detection outputs L1, L2, and L3 of the illuminance sensors 31 to 33, and inputs to the display devices 210 to 260, respectively. In addition to generating image signals S1 to S6 to be supplied, control signals for individually controlling display image quality (display brightness, contrast, color, and / or sharpness) of the display devices 210 to 260 are generated.

  FIG. 9 is a block diagram showing a schematic configuration of the image quality control device 40B of the present embodiment. As shown in FIG. 9, the image quality control device 40B includes an input signal processing unit 43, a feature analysis unit 44, and an image quality control unit 45, similarly to the image quality control device 40 of the first embodiment. The configuration and operation of the input signal processing unit 43, feature analysis unit 44, and image quality control unit 45 shown in FIG. 9 are the same as the configuration and operation of the input signal processing unit 43, feature analysis unit 44, and image quality control unit 45 shown in FIG. Is the same.

  The image quality control device 40B according to the present embodiment analyzes the position detection information PD and outputs the analysis information PA that is the analysis result, and the illuminance sensor 31 for each display device based on the analysis information PA. To an illuminance selection unit 42 </ b> B that selects an illuminance sensor to be used.

  The movement analysis unit 41B analyzes the position detection information PD to generate analysis information PA, and supplies the analysis information PA to the illuminance selection unit 42B. The analysis information PA includes position information indicating the current position of the moving body 1B, speed information indicating the time change of the position of the moving body 1B, direction information indicating the direction of travel of the moving body 1B, and the current date. Time information indicating the date and time. It is possible to acquire speed information from a speedometer mounted on the mobile body 1B, and it is also possible to acquire time information from a clock mounted on the mobile body 1B. As for the azimuth information, when the mobile body 1B is equipped with a geomagnetic sensor, the azimuth information can be obtained based on the detection output of the geomagnetic sensor.

  Next, the illuminance selection unit 42B will be described with reference to FIG. FIG. 10 is a flowchart schematically showing a processing procedure by the illuminance selection unit 42B. The illuminance selection unit 42B first acquires the detection outputs L1 to L3 of the illuminance sensors 31 to 33 (step S10), and then acquires the analysis information PA from the movement analysis unit 41 (step S11B).

  Thereafter, the illuminance selection unit 42B uses the analysis information PA and refers to a look-up table (LUT) 47B stored in the data storage unit 46, which is a non-volatile memory. The illuminance sensor to be used is selected from (Step S12B). The look-up table 47B stores data that defines usage conditions of the illuminance sensors 31 to 33 according to the analysis information PA. The person who builds the image display system 10B, for example, the installation status of the display devices 210 to 260 and the illuminance sensors 31 to 33, the performance of the display devices 210 to 260 and the illuminance sensors 31 to 33, and the traveling path of the moving body 1B or The contents of the data stored in the lookup table 47B can be appropriately determined according to the assumed situation of the navigation route.

  In addition, the illuminance selection unit 42B, like the illuminance selection unit 42 of the first embodiment, based on the detection output of the illuminance sensor selected for each display device, the display devices 210, 220, 230, 240, 250, The estimated illuminance values Lin (1), Lin (2), Lin (3), Lin (4), Lin (5), and Lin (6) respectively corresponding to 260 are calculated (step S13).

  Then, the illuminance selection unit 42B outputs the control information Ct specifying the display devices 210 to 260 and the estimated illuminance values Lin (1) to Lin (6) to the image quality control unit 45 (step S14). As the control information Ct, for example, a unique number (MAC address or the like) assigned to each of the display devices 210 to 260 can be cited. Thereafter, the illuminance selection unit 42B repeatedly executes the above steps S10, S11B, S12B, S13, and S14B (NO in step S15) until it is determined that the process is ended (YES in step S15).

  Similar to the image quality control unit 45 of the first embodiment, the image quality control unit 45 of the present embodiment generates six systems of image signals S1 to S6 based on the image signal Sb, and these image signals S1 to S6 are generated. It supplies to the display devices 210-260, respectively. Display devices 210 to 260 display images represented by image signals S1 to S6, respectively. The image quality control unit 45 also displays the display image quality (display brightness, contrast, color) of the display devices 210 to 260 based on the estimated illuminance values Lin (1) to Lin (6) and the data FD indicating the image feature amount. , And / or sharpness, etc.) are generated. The display devices 210 to 260 have a function of adjusting the image quality of the display image so that the display image quality specified by the control signals QC1 to QC6 is obtained.

  Next, the example which applied the said image display system 10B to the rail vehicle which is a kind of mobile body 1B is demonstrated.

  FIG. 11 is a diagram schematically showing an internal space of a railway vehicle (leading vehicle) 3F including the display devices 210 to 260 and the illuminance sensors 31 to 33 of the image display system 10B. In the example of FIG. 11, only one leading vehicle 3F is shown, but in reality, the following train is connected to the leading vehicle 3F.

  As shown in FIG. 11, in the interior space of the leading vehicle 3F, an illuminance sensor 31 is installed in front of the traveling direction, an illuminance sensor 32 is installed on the rear left side, and an illuminance sensor 33 is installed on the rear right side. Further, on the inner wall on the right side of the leading vehicle 3F, a display device 220 having a pair of display screens 22A and 22B, a display device 240 having a pair of display screens 24A and 24B, and a display having a pair of display screens 26A and 26B. A device 260 is installed. A passenger whose line of sight is directed to the right side can view the images displayed on the display devices 220, 240, and 260. On the other hand, on the left inner wall of the leading vehicle 3F, a display device 210 having a pair of display screens 21A and 21B, a display device 230 having a pair of display screens 23A and 23B, and a display having a pair of display screens 25A and 25B. A device 250 is installed. A passenger whose line of sight is directed to the left side can view the images displayed on the display devices 210, 230, and 250.

  Here, the line of sight of the passenger of the leading vehicle 3F is mainly directed outward from the center of the leading vehicle 3F. On the other hand, the light receiving surfaces of the illuminance sensors 32 and 33 are directed to the inside of the leading vehicle 3F so that the illuminance inside the leading vehicle 3F can be detected.

FIG. 12 is a diagram illustrating an example of a lookup table 47B referred to by the illuminance selection unit 42B of the image quality control device 40B mounted on the leading vehicle 3F. The look-up table 47B stores data for specifying an illuminance sensor to be selected for each of the display devices 210 to 260 when the leading vehicle 3F is in a stationary state, a low-speed movement state, or a high-speed movement state. Here, “static state”, “low-speed movement state”, and “high-speed movement state” are the following three types using threshold values Th1 and Th2 (Th1 <Th2) when the speed of the leading vehicle 3F is V. It shall be determined according to the speed range.
Resting state: 0 ≦ V <Th1,
Low speed movement state: Th1 ≦ V <Th2.
High-speed movement state: Th2 ≦ V.

  Here, the threshold value Th1 is a value close to zero, and is set to a value that can absorb the fluctuation of the numerical value due to the detection accuracy of the GPS receiver.

When the leading vehicle 3F is in a stationary state, it is desirable to select an illuminance sensor arranged in an environment most similar to the illuminance environment as the illuminance sensor to be used for controlling the display luminance. Therefore, according to the look-up table in FIG. 12, the illuminance sensor 32 is selected for the display devices 210, 230, 250 arranged on the left side of the leading vehicle 3F, and the display device arranged on the right side of the leading vehicle 3F. For 220, 240 and 260, the illuminance sensor 33 is selected. The estimated illuminance values Lin (1) to Lin (6) at this time are calculated according to the following formula, for example.
Lin (1) = Lin (3) = Lin (5) = L2,
Lin (2) = Lin (4) = Lin (6) = L3.

  Next, when the leading vehicle 3F is in a low-speed movement state or a high-speed movement state, the front illuminance sensor 31 is selected for all the display devices 21-26. At this time, the change in the brightness of the surrounding environment of the moving passenger vehicle 2 tends to be intense, and it is difficult to obtain an illuminance value with sufficient accuracy for fine control. Therefore, it is desirable to select only the illuminance sensor 31 that outputs a value that most reflects the illuminance at the front position in the traveling direction of the leading vehicle 3F. The estimated illuminance values Lin (1) to Lin (6) at this time are all the values of the detection output L1 of the illuminance sensor 31.

  In the system environment shown in FIG. 11, there are few shielding objects such as seats. Further, due to the characteristic that the leading vehicle 3F is a railway vehicle, the internal space of the leading vehicle 3F is wide in the height direction, and the interval between the left and right inner walls of the internal space is narrow compared to the length of the leading vehicle 3F in the longitudinal direction. In such a structure, when the leading vehicle 3F is stationary, the illuminance sensor 33 installed on the opposite side (right side) is selected for the display devices 210, 230, 250 installed on the left side, and the right side is selected. For the display devices 220, 240, and 260 installed in, it may be preferable to select the illuminance sensor 32 installed on the opposite side (left side). For example, when a situation is assumed in which direct sunlight is incident on the inside of the leading vehicle 3F from the right side, the illuminance sensor that receives the direct sunlight is an illuminance that is installed with the light receiving surface facing the inside of the leading vehicle 3F. It is not the sensor 33 but the illuminance sensor 32 installed with the light receiving surface facing inside the vehicle. At this time, the display devices 210, 230, and 250 are also irradiated with the direct sunlight.

  In such a case, it is preferable to use the lookup table shown in FIG. 13 instead of the lookup table shown in FIG. Therefore, the illuminance selection unit 42B estimates the distribution of light to be inserted into the interior of the leading vehicle 3F based on the detection outputs L1 to L3 of the illuminance sensors 31 to 33, and FIG. 12 and FIG. 12 according to the estimated distribution of light. It is preferable to use the lookup table shown in FIG.

  As described above, when the leading vehicle 3F is in the moving state (low speed moving state or high speed moving state), only the front illuminance sensor 31 is selected, and the other illuminance sensors 32 and 33 are not selected. At this time, it is possible to temporarily stop the power supply to the illuminance sensors 32 and 33 and not operate the illuminance sensors 32 and 33. At this time, the illuminance selection unit 42B can acquire only the detection output L1 of the illuminance sensor 31 and can not acquire the detection outputs L2 and L3 of the illuminance sensors 32 and 33. Thereby, the power consumption of the image display system 10B can be suppressed.

  In addition, in the example of FIG. 11, although the illumination intensity sensors 31-33 are installed in three places, it is not limited to this. The number of illuminance sensors may be four or more. It is desirable to provide an illuminance sensor at regular intervals in the longitudinal direction of a vehicle that is elongated in the traveling direction such as a railway vehicle.

  The image display system 10B of the present embodiment can also be incorporated into a railway vehicle (following vehicle) that follows the leading vehicle 3F. FIG. 14 is a diagram schematically showing the internal space of the following vehicle 3N having the display devices 210 to 260 and the illuminance sensors 32 and 33 of the image display system 10B. Unlike the leading vehicle 3F, the illuminance sensor 31 is not installed in front of the following vehicle 3N in the traveling direction. The reason is that no window is provided in front of the following vehicle 3N and it is connected to the leading vehicle 3F, and it is difficult to use this illuminance even if the illuminance in the front area of the following vehicle 3N is obtained. is there.

  In general, the railway vehicles 3F and 3N stop near the platform of the station building at intervals of several minutes to several tens of minutes. When the railcars 3F and 3N are blocked in the station building, the surrounding illuminance environment is greatly different from that when the railcars 3F and 3N are moving. In addition, when a large number of connected railway vehicles are in operation, the vehicle that stops at the center of the station building is blocked by sunlight, so the illuminance in the interior space of the vehicle is about the room illuminance. On the other hand, the vehicle that stops at a place away from the central portion is directly irradiated with sunlight, and the illuminance of the interior space of the vehicle may be close to the illuminance during sunny weather. Even in such a case, the display image quality of the display device in each vehicle can be appropriately adjusted according to the brightness of the surrounding environment by incorporating the image display system 10B in each vehicle.

  By the way, the illuminance selection unit 42B may acquire and use azimuth information and time information indicating the azimuth in which the front ends of the railcars 3F and 3N are facing from the analysis information PA. Specifically, the illuminance selection unit 42B estimates the position of the sun based on the azimuth information and time information, and further from the sun based on the arrangement information such as the windows of the railway vehicles 3F, 3N, It is also possible to estimate the incident direction of sunlight inserted into 3N. The illuminance selection unit 42B can calculate the illuminance estimation values Lin (1) to Lin (6) with higher accuracy by selecting the illuminance sensor using the estimation result.

  In the configuration example shown in FIG. 11, when the railway vehicle 3F is in a high-speed movement state, the illuminance selection unit 42B can select only the illuminance sensor 31 in front of the railway vehicle 3F for all the display devices 210-260. Explained. In this example, when the direction of a light source that has a very strong influence such as sunlight can be detected using the azimuth information and the time information, the illuminance selection unit 42 </ b> B uses the illuminance sensor 31 for all the display devices 210 to 250. Instead of selecting only, data for selecting the illuminance sensor can be stored in the lookup table 47B in the same manner as when the railway vehicle 3F is stationary (FIG. 12 or FIG. 13).

  In addition, the illuminance selection unit 42B that has detected such a case adds an estimated illuminance value so that a certain value is added to the display brightness of the display device that is expected to be affected by sunlight among the display devices 210 to 260. Lin (1) to Lin (6) may be generated. Thus, bright display on the display device is possible.

  Moreover, it is preferable that the display devices 210 to 260 be installed at a place where the influence of external light is not as much as possible. However, for example, when the sunlight is expected to be inserted into the inside of the railway vehicle 3F from the right side, the right display devices 220, 240, and 260 receive the backlight and receive an image without receiving direct sunlight irradiation. On the other hand, any one of the display devices 210, 230, and 250 on the left side is expected to display an image upon receiving direct sunlight irradiation. The illuminance selection unit 42 </ b> B that has detected such a case has an estimated illuminance value Lin such that the display brightness of the display device that receives direct sunlight irradiation and the display brightness of the display device that receives backlight are relatively high. A correction value may be added to (1) to Lin (6) or multiplied by a correction coefficient. These correction values or correction coefficients can be obtained by using an arithmetic expression, a reference table, or parameter values prepared in advance.

  Furthermore, the illuminance selection unit 42B can select an illuminance sensor to be used from the illuminance sensors 31 to 33 based on the time information. For example, when the time zone in which the moving body 1B is moving is nighttime, the illuminance selection unit 42B estimates that the amount of external light incident on the inside of the moving body 1B from the outside is extremely small, and the display devices 210 to 210 Only a specific illuminance sensor can be selected for all 260. In the configuration example illustrated in FIG. 11, when the time zone during which the railcar 3F travels is nighttime, the illuminance selection unit 42B can select only the illuminance sensor 31 for all of the display devices 210 to 260.

  As described above, the image display system 10B according to the second embodiment selects an illuminance sensor to be used from the illuminance sensors 31 to 33 for each display device, based on the position detection information PD of the moving body 1B. The display image quality of the display devices 21 to 26 is individually controlled based on the detection output of the selected illuminance sensor. For this reason, even when a plurality of display devices 21 to 26 are installed in the internal space of the moving body 1B, it is possible to appropriately control the display image quality of the plurality of display devices 21 to 26 according to changes in the surrounding environment. It is also possible to suppress the required number of illuminance sensors.

  Moreover, since the display brightness | luminance of the display apparatuses 21-26 can be made appropriate according to the brightness of a surrounding environment, power consumption can be suppressed with an improvement in visibility.

  As in the case of the first embodiment, the number and installation locations of the illuminance sensors 31 to 33 are not limited to three and three.

Embodiment 3 FIG.
Next, a third embodiment according to the present invention will be described. FIG. 15 is a block diagram illustrating a schematic configuration of an image display system 10C according to the third embodiment. This image display system 10C is arranged in the internal space of the moving body 1C. Examples of the moving body 1C include a passenger vehicle, a railway vehicle, a ship, and an aircraft, but are not limited thereto.

  Inside the moving body 1B, a signal source 11 that supplies the original image signal So to the image display system 10C, a movement detection unit 12B that supplies position detection information PD indicating the current position of the moving body 1, and an external communication system And an information supply unit 14 for acquiring weather information MD and map information TD. The configuration of the signal source 11 and the movement detection unit 12B illustrated in FIG. 15 is the same as the configuration of the signal source 11 and the movement detection unit 12B illustrated in FIG. Similar to the second embodiment, the movement detection unit 12B is provided inside the moving body 1C. However, the movement detecting section 12B is not limited to this, and may be brought into the moving body 1C from the outside.

  As shown in FIG. 15, the image display system 10 </ b> C includes a plurality of display devices 210 to 260 installed in the internal space of the moving body 1 </ b> C, and illuminance sensors 31, 32, and 33 disposed at different positions. The image quality control device 40C for individually controlling the display image quality of the display devices 210 to 260 is provided.

  The configuration of the illuminance sensors 31, 32, and 33 shown in FIG. 15 is the same as that of the illuminance sensors 31, 32, and 33 shown in FIG. The illuminance sensors 31, 32, and 33 supply detection outputs L1, L2, and L3 indicating illuminance values to the image quality control device 40C. As in the case of the first embodiment, the illuminance sensors 31, 32, 33 and the image quality control device 40C can be connected by wire or wirelessly.

  The image quality control device 40C receives the original image signal So supplied from the signal source 11, the position detection information PD, and the detection outputs L1, L2, and L3 of the illuminance sensors 31 to 33, and inputs to the display devices 210 to 260, respectively. In addition to generating image signals S1 to S6 to be supplied, control signals for individually controlling display image quality (display brightness, contrast, color, and / or sharpness) of the display devices 210 to 260 are generated.

  FIG. 16 is a block diagram illustrating a schematic configuration of an image quality control device 40C according to the present embodiment. As shown in FIG. 16, the configuration of the image quality control device 40C includes an illuminance selection unit 42C instead of the illuminance selection unit 42B of the second embodiment, and includes a lookup table 47C instead of the lookup table 47B. Except for this point and the point having the information acquisition unit 48, the configuration is the same as that of the image quality control device 40B of the second embodiment.

  The movement analysis unit 41B in FIG. 16 supplies the analysis information PA to the illuminance selection unit 42B. As in the second embodiment, the analysis information PA includes position information indicating the current position of the moving body 1C, speed information indicating the time change of the position of the moving body 1C, and the direction of travel of the moving body 1C. Azimuth information indicating the current date and time information indicating the current date and time. It is possible to acquire speed information from a speedometer mounted on the moving body 1C, and it is also possible to acquire time information from a clock mounted on the moving body 1C. As for the azimuth information, when the mobile body 1C is equipped with a geomagnetic sensor, the azimuth information can be obtained based on the detection output of the geomagnetic sensor.

  When the information acquisition unit 48 receives the supply of the analysis information PA from the movement analysis unit 41B, the information acquisition unit 48 requests the information supply unit 14 for the map information of the area including the current position of the mobile body 1C indicated by the analysis information PA, and The information supply unit 14 is also requested for the weather information of the position.

  The information supply unit 14 has a communication function, acquires weather information MD and map information TD from an external communication system in response to a request from the information acquisition unit 48, and acquires the weather information MD and map information TD as an information acquisition unit. 48. Examples of the external communication system include a traffic control system, a railway vehicle control system, or a computer network.

  Next, the illuminance selection unit 42C will be described with reference to FIG. FIG. 17 is a flowchart schematically showing a processing procedure by the illuminance selection unit 42C. The illuminance selection unit 42C first acquires the detection outputs L1 to L3 of the illuminance sensors 31 to 33 (step S10), and then analyzes information from the movement analysis unit 41, similarly to the illuminance selection unit 42B of the second embodiment. PA is acquired (step S11B).

  Next, the illuminance selection unit 42C acquires at least one of the weather information MD and the map information TD from the information acquisition unit 48 (step S11C). Thereafter, the illuminance selection unit 42C uses at least one of the weather information MD and the map information TD and the analysis information PA, and refers to a lookup table (LUT) 47C stored in the data storage unit 46 that is a nonvolatile memory. Then, the illuminance sensor to be used is selected from the illuminance sensors 31 to 33 for each display device (step S12C). The look-up table 47C stores data that defines usage conditions of the illuminance sensors 31 to 33 according to the combination of the weather information MD, the map information TD, and the analysis information PA. The person who builds the image display system 10C, for example, the installation status of the display devices 210 to 260 and the illuminance sensors 31 to 33, the performance of the display devices 210 to 260 and the illuminance sensors 31 to 33, and the traveling path of the moving body 1C or The contents of the data stored in the lookup table 47C can be appropriately determined according to the assumed situation of the navigation route.

  Similarly to the illuminance selection unit 42B of the second embodiment, the illuminance selection unit 42C is based on the detection output of the illuminance sensor selected for each display device 210, 220, 230, 240, 250, The estimated illuminance values Lin (1), Lin (2), Lin (3), Lin (4), Lin (5), and Lin (6) respectively corresponding to 260 are calculated (step S13).

  Then, similarly to the illuminance selection unit 42B of the second embodiment, the illuminance selection unit 42C controls the image quality control information Ct specifying the display devices 210 to 260 and the estimated illuminance values Lin (1) to Lin (6). It outputs to the part 45 (step S14). Thereafter, the illuminance selection unit 42C repeatedly executes the above steps S10, S11B, S11C, S12C, S13, and S14 (NO in step S15) until it is determined that the process is completed (YES in step S15).

  Similar to the image quality control unit 45 of the second embodiment, the image quality control unit 45 of the present embodiment generates six systems of image signals S1 to S6 based on the image signal Sb, and these image signals S1 to S6 are generated. It supplies to the display devices 210-260, respectively. Display devices 210 to 260 display images represented by image signals S1 to S6, respectively. The image quality control unit 45 also displays the display image quality (display brightness, contrast, color) of the display devices 210 to 260 based on the estimated illuminance values Lin (1) to Lin (6) and the data FD indicating the image feature amount. , And / or sharpness, etc.) are generated. The display devices 210 to 260 have a function of adjusting the image quality of the display image so that the display image quality specified by the control signals QC1 to QC6 is obtained.

  In the image display system 10C described above, the illuminance selection unit 42C is based on at least one of the weather information MD and the map information TD in addition to the analysis information PA (including position information and time information). It is possible to select an illuminance sensor to be used every time. As a result, the image quality control unit 45 can perform finer display image quality control according to the surrounding environment of the moving body 1C.

  For example, when the weather state at the current position of the moving body 1C is rainy or cloudy, the illuminance selection unit 42C estimates that the amount of external light incident on the inside of the moving body 1C from the outside is small, and the display devices 210-260. Only a specific illuminance sensor can be selected. For example, in the configuration example illustrated in FIG. 11, when the weather condition at the current position of the railcar 3F is rainy or cloudy, the illuminance selection unit 42C selects only the illuminance sensor 31 for all the display devices 210 to 260. be able to.

  In addition, when it is possible to determine that the current position of the moving body 1C is underground or in a tunnel based on the map information TD, the illuminance selection unit 42C is configured to transmit the external light incident on the inside of the moving body 1C from the outside. It is estimated that the amount is always constant, and only a specific illuminance sensor can be selected for all of the display devices 210-260. For example, in the configuration example illustrated in FIG. 11, the illuminance selection unit 42 </ b> C can select only the illuminance sensor 31 for all of the display devices 210 to 260. Alternatively, in this case, the illuminance selection unit 42 </ b> C can select none of the illuminance sensors 31 to 33.

  The illuminance selection unit 42C may estimate the incident direction of sunlight and the amount of light based on the combination of the weather information MD, the direction information, and the time information. For example, when the weather condition at the current position of the moving body 1C is sunny, it can be estimated that the amount of incident sunlight is high. Therefore, the illuminance selection unit 42C includes the illuminance selection unit 42B according to the second embodiment. Similarly, it is possible to estimate the incident direction of sunlight to be inserted into the moving body 1C from the sun, and to select an illuminance sensor using the estimation result. On the other hand, when the weather condition at the current position of the moving body 1C is rainy or cloudy, it can be estimated that the amount of incident sunlight is low. In this case, according to the estimation result, the illuminance selection unit 42C can select any one of the illuminance sensors 31 to 33 or deselect all the illuminance sensors 31 to 33.

  Although various embodiments according to the present invention have been described above with reference to the drawings, these are examples of the present invention, and various forms other than the above can be adopted.

  1, 1B, 1C mobile body, 2 passenger vehicle, 3F, 3N railway vehicle, 10, 10B, 10C image display system, 11 signal source, 12, 12B movement detection unit, 14 information supply unit, 21-26, 210-260 Display device, 31-33 Illuminance sensor, 40, 40B, 40C Image quality control device, 41, 41B Movement analysis unit, 42, 42B, 42C Illuminance selection unit, 43 Input signal processing unit, 44 Feature analysis unit, 45 Image quality control unit, 46 Data storage unit, 47, 47B, 47C Look-up table (LUT), 48 Information acquisition unit.

Claims (20)

With the original image signal supplied from the signal source, the detection output of at least one illuminance sensor for detecting the brightness of the internal space of the moving body, and the movement detection information indicating the moving state of the moving body as inputs, An image quality control device for controlling the display image quality of N display devices (N is an integer of 2 or more) arranged in an internal space of a moving body,
An illuminance selection unit that selects an illuminance sensor to be used from among the at least one illuminance sensor for each display device based on the movement detection information;
An image quality control device comprising: an image quality control unit that individually controls the display image quality based on a detection output of the selected illuminance sensor for each display device.   The image quality control apparatus according to claim 1, wherein the movement detection information is information indicating at least one selected from speed, acceleration, and angular velocity of the moving body. . The movement using the original image signal supplied from the signal source, the detection output of at least one illuminance sensor for detecting the brightness of the internal space of the moving body, and position detection information indicating the position of the moving body as inputs. An image quality control device for controlling the display image quality of N display devices (N is an integer of 2 or more) arranged in an internal space of a body,
An illuminance selection unit that selects an illuminance sensor to be used from among the at least one illuminance sensor for each display device based on the position detection information;
An image quality control device comprising: an image quality control unit that individually controls the display image quality based on a detection output of the selected illuminance sensor for each display device. The image quality control device according to claim 3,
The mobile body is equipped with a GPS receiver that detects the current position of the mobile body on the earth using a global positioning system,
The image quality control apparatus, wherein the position detection information is information indicating a current position detected by the GPS receiver.   5. The image quality control device according to claim 1, wherein the number of the at least one illuminance sensor is smaller than the number of the display devices. 6.   6. The image quality control device according to claim 5, wherein the at least one illuminance sensor includes M (M is an integer of 2 or more) illuminance sensors arranged at different positions in the internal space of the moving body. An image quality control device. The image quality control device according to any one of claims 1 to 6,
Further comprising a look-up table for determining usage conditions of the illuminance sensor;
The image quality control device, wherein the illuminance selection unit selects the illuminance sensor to be used with reference to the lookup table.   8. The image quality control apparatus according to claim 7, wherein the look-up table defines an illuminance sensor to be used according to a speed range of the moving body.   9. The image quality control device according to claim 1, wherein the illuminance selection unit acquires azimuth information indicating a azimuth in which one end of the traveling direction of the moving body is directed, and the azimuth is selected. An image quality control apparatus that selects an illuminance sensor to be used based on information. The image quality control device according to claim 3 or 4,
It further includes an information acquisition unit that acquires weather information of the current position indicated by the position detection information,
The illuminance selection unit selects an illuminance sensor to be used based on the weather information. The image quality control device according to claim 3 or 4,
An information acquisition unit that acquires map information of a region including the current position indicated by the position detection information;
The illuminance selection unit selects the illuminance sensor to be used based on the map information. The image quality control device according to any one of claims 1 to 11,
An information acquisition unit that acquires time information indicating the current time;
The illuminance selection unit selects an illuminance sensor to be used based on the time information. The image quality control device according to any one of claims 1 to 12,
A feature analysis unit for detecting a feature amount of the image represented by the original image signal;
The image quality control device, wherein the image quality control unit controls the display image quality based on the feature amount. The image quality control device according to claim 13,
The feature amount is an average luminance of an image represented by the original image signal,
The image quality control apparatus, wherein the display image quality includes display brightness. Using the original image signal supplied from the signal source and the movement detection information indicating the movement state of the moving body as inputs, N display devices (N is an integer of 2 or more) arranged in the internal space of the moving body. An image display system for displaying images,
At least one illuminance sensor for detecting the brightness of the internal space of the moving body;
An image quality control device that controls display image quality of the N display devices based on a detection output of the at least one illuminance sensor;
The image quality control device includes:
An illuminance selection unit that selects an illuminance sensor to be used from among the at least one illuminance sensor for each display device based on the movement detection information;
An image display system comprising: an image quality control unit for individually controlling the display image quality based on a detection output of the selected illuminance sensor for each display device. With the original image signal supplied from the signal source and position detection information indicating the position of the moving body as inputs, each of N display devices (N is an integer of 2 or more) arranged in the internal space of the moving body. An image display system for displaying an image,
At least one illuminance sensor for detecting the brightness of the internal space of the moving body;
An image quality control device that controls display image quality of the N display devices based on a detection output of the at least one illuminance sensor;
The image quality control device includes:
An illuminance selection unit that selects an illuminance sensor to be used from among the at least one illuminance sensor for each display device based on the movement detection information;
An image display system comprising: an image quality control unit for individually controlling the display image quality based on a detection output of the selected illuminance sensor for each display device. The image display system according to claim 16 or 17,
The image quality control device further includes a look-up table that defines usage conditions of the illuminance sensor,
The illuminance selection unit selects the illuminance sensor to be used with reference to the lookup table. An original image signal supplied from a signal source, a detection output of at least one illuminance sensor that detects the brightness of at least one location in the internal space of the moving body, and movement detection information indicating the moving state of the moving body. As an input, an image quality control method for controlling the display image quality of N display devices (N is an integer of 2 or more) arranged in the internal space of the moving body,
Selecting an illuminance sensor to be used from the at least one illuminance sensor for each display device based on the movement detection information;
And a step of individually controlling the display image quality based on the detection output of the selected illuminance sensor for each display device. The original image signal supplied from the signal source, the detection output of at least one illuminance sensor that detects the brightness of at least one location in the internal space of the moving body, and position detection information indicating the position of the moving body are input. As an image quality control method for controlling the display image quality of N display devices (N is an integer of 2 or more) arranged in the internal space of the moving body,
Selecting an illuminance sensor to be used from the at least one illuminance sensor for each display device based on the position detection information; and
And a step of individually controlling the display image quality based on the detection output of the selected illuminance sensor for each display device.   20. The image quality control method according to claim 18, wherein the illuminance sensor to be used is selected with reference to a look-up table that defines use conditions of the illuminance sensor.

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