JP2005326159A - On-vehicle display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle display device for displaying necessary information in an easy-to-see manner by eliminating flickering of a screen of the display device. <P>SOLUTION: This on-vehicle display device mounted on a vehicle to display predetermined information including car navigation information comprises a display device displaying predetermined information; a luminance adjusting means adjusting the luminance of the display device; a vehicle speed detection means detecting the vehicle speed; and a brightness detection means detecting the brightness of the circumference of a driver's seat of the vehicle. The luminance adjusting means adjusts the luminance of the display device based on the brightness of the circumference of the driver's seat and the vehicle speed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-vehicle display device that is mounted on an automobile and displays predetermined information including car navigation information.

  In recent years, with the development of electronic technology, the contents of information display inside automobiles have become diverse, and as the types of display contents increase, the improvement of the visibility has become one issue. As described above, as one means for improving the visibility of the display device, the brightness of the display device is adjusted according to the ambient brightness.

  All of these technologies make it difficult to see in the daytime or too dazzling at night by making the display on the display device bright when the use environment of the display device is bright, and making the display on the display device dark when the use environment is dark. Is automatically prevented.

  In the above method, the sensor is arranged to detect the ambient brightness. However, the cost for arranging the sensor is not generated, and the attached sensor operates by sensing light. Therefore, since the mounting location is limited to a predetermined position such as the vicinity of the surface of the dashboard, a large amount of cost is required to install the mounting mechanism. That is, there are problems such as the cost of a harness for transmitting an electrical signal from the sensor to the control unit for adjusting the brightness, and an increase in the dashboard unit price.

  In order to solve the above-mentioned problem, daytime and nighttime are determined based on time recognition, and a surrounding light / dark environment is determined by determining a traveling position by a car navigation device, and brightness of a display screen is determined based on these determination results. An in-vehicle display device has been devised that automatically adjusts (see Patent Document 1).

  In addition, in conventional vehicle display devices, the amount of information to be provided to passengers such as drivers increases with the advancement of advanced information, while image information processing on the side receiving information due to aging and an increase in the number of female drivers, etc. As the variability in capabilities has increased and the image information processing capabilities have changed even in driving conditions and environments, it has become possible to provide appropriate information displays that are easy to recognize in response to the situation of many people, driving, environments, etc. There is also a problem that it is difficult.

  In order to solve the above problems, it is possible to accurately control the image information display that is easy to recognize according to the situation of running, environment, etc. for many image observers including elderly people and women. There has been devised a vehicle display device that can easily acquire desired information without confusion or misunderstanding (see Patent Document 2).

Japanese Patent Laid-Open No. 11-184446 Japanese Patent Laid-Open No. 11-016091

  In the example of Patent Document 1, when the vehicle travels on a road where the shade and the sun repeat, the time recognition and the adjustment of the brightness of the display device according to the surrounding light and dark environment cannot follow and the screen is rather difficult to see. There is a problem of end.

  In the example of Patent Document 2, the brightness of the display device is adjusted according to the speed of the vehicle. This is for reducing the amount of information displayed on the screen and is necessary for the user. The problem that time information is not displayed occurs. Furthermore, it is necessary to input the user's personal information, and the operation amount is large and difficult to use.

  Against the background of the above circumstances, an object of the present invention is to provide an in-vehicle display device in which the screen of the display device blinks and is difficult to see, and necessary information is displayed.

Means for Solving the Problems and Effects of the Invention

  The present invention is to provide an in-vehicle display device for solving the above-mentioned problems. In other words, according to the first aspect, an in-vehicle display device that is mounted on a vehicle and displays predetermined information including car navigation information, the display device displaying predetermined information, and the brightness of the display device are adjusted. A brightness adjusting means; a vehicle speed detecting means for detecting the speed of the vehicle; and an illuminance detecting means for detecting the brightness around the driver's seat of the vehicle. The brightness adjusting means adjusts the brightness around the driver's seat and the speed of the vehicle. Based on this, the brightness of the display device is adjusted.

  In view of the above problems, the present invention pays attention to the fact that the change in the brightness of the side of the vehicle surrounding the vehicle is faster in proportion to the change in the vehicle speed. By adjusting the width of the screen change and the changing speed with respect to the change in the surrounding brightness, the blinking of the screen is solved. With the above configuration, it is possible to prevent the optical sensor from reacting sensitively to changes in brightness around the vehicle, causing the screen to flicker and making it difficult to see the display device.

  According to claim 2, the brightness adjusting means in the in-vehicle display device of the present invention reduces the amount of change in brightness of the display device or the speed of change in brightness of the display device when the vehicle is moving at high speed. It is possible to take a configuration that slows down. According to this configuration, for example, when the vehicle travels in the shade and in the sun, the light sensor reacts sensitively, the screen does not flicker, and the brightness of the display device becomes substantially constant, making it difficult to see the display device.

  According to claim 3, the brightness adjusting means in the in-vehicle display device of the present invention increases the amount of change in the brightness of the display device when the vehicle is moving at a low speed, or the speed of change in the brightness of the display device. Can be configured to speed up the operation. With this configuration, for example, when stopping at intersections or parking lots, it is difficult to see the display device by increasing the change to the external brightness and quickly controlling the screen brightness to an appropriate value. Can be prevented.

  In the in-vehicle display device, the screen of the display device blinks and is difficult to see, and the purpose is to display the necessary information. It was realized by adjusting the speed to be.

  Hereinafter, an in-vehicle display device according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of an in-vehicle display device according to the present invention applied to a vehicle navigation device. The range of application of the in-vehicle display device of the present invention is not limited to the vehicle navigation device.

  The navigation device 100 includes a position detector 1, a map data input device 6, an operation switch group 7, a remote control (hereinafter referred to as remote control) sensor 11, a speaker 15 for voice guidance, an external memory 9, a display device 10, and the like. Are connected to a control circuit 8 and a remote control terminal 12.

  The position detector 1 has a known geomagnetic sensor 2, a gyroscope 3, a distance sensor 4, and a GPS receiver 5 for GPS that detects the position of the vehicle based on radio waves from a satellite. Since these sensors 2, 3, 4, and 5 have errors of different properties, they are configured to be used while being complemented by a plurality of sensors. Depending on the accuracy, a part of the sensors described above may be used, and further, a steering rotation sensor, a wheel sensor of each rolling wheel, or the like may be used.

  The map data input device 6 is a device for inputting various data including so-called map matching data for improving the accuracy of position detection and road data representing road connections from the storage medium 18. As a storage medium, a CD-ROM, DVD, or hard disk drive (hereinafter referred to as HDD) is generally used because of the amount of data, but other media such as a memory card may be used.

  As the operation switch group 7, for example, a touch switch or a mechanical switch integrated with the display device 10 is used. The touch switch is composed of infrared sensors that are finely arranged vertically and horizontally on the screen of the display device 10. For example, when the infrared ray is cut off with a finger, a touch pen, or the like, the cut-off position becomes a two-dimensional coordinate value (X, Y). A pointing device such as a mouse or a cursor may be used. Various instructions can be input by the operation switch group 7 and the remote control terminal 12.

  The display device 10 is composed of a color liquid crystal display. On the screen of the display device 10, a vehicle current position mark input from the position detector 1, map data input from the map data input device 6, and a map are displayed. The additional data such as the guidance route to be displayed is superimposed and displayed, and a menu button for setting route guidance, guidance during route guidance, and a screen switching operation is displayed on this screen.

  The transceiver 13 is a device for communicating with the information center 14. Information received from the outside via the transceiver 13 is processed by the control circuit 8. Further, by connecting a mobile communication device such as a mobile phone 17 or a car phone to the communication unit 19, connection to an external network is possible and connection to the Internet or the like is possible. Furthermore, by communicating with an ETC (automatic toll collection system, ETC: Electronic Toll Collection) vehicle-mounted device 16, fee information received by the ETC vehicle-mounted device 16 from the ETC road device can be taken into the navigation device 100. Moreover, it is also possible to connect with an external network by the ETC onboard equipment 16. A configuration may be adopted in which communication with the information center 14 is performed via the mobile phone 17 or the ETC vehicle-mounted device 16.

  The control circuit 8 is configured as a normal computer, and includes a well-known CPU 81, ROM 82, RAM 83, I / O 84 which is an input / output circuit, and a bus line 85 which connects these configurations. The CPU 81 controls the program and data stored in the ROM 82 and RAM 83. The ROM 82 has a program storage area 82a and a data storage area 82b. A navigation program (hereinafter referred to as a navigation program) 82p is stored in the program storage area 82a. Data necessary for the operation of the navigation program 82p is stored in the data storage area 82b. The navigation program 82p operates on the RAM 83 in such a manner that the navigation program work memory 83w is used as a work area. When an HDD is used for the map data input device 6, the functions of the ROM 82 and the RAM 83 may be implemented by the HDD. The control circuit 8 corresponds to the brightness adjusting means in the present invention.

  Further, the external memory 9 stores information and data necessary for the operation of the navigation device. The external memory 9 is configured to retain the stored contents even when the accessory switch of the vehicle is turned off (that is, the navigation device 100 is turned off).

  With this configuration, when the navigation program 82 p is activated by the CPU 81 of the control circuit 8, the navigation device 100 operates the operation switch group 7 or the remote control terminal 12 to display the navigation device 100 on the display device 10. When the route guidance process for displaying the destination route on the display device 10 is selected from the displayed menu, the following process is performed. That is, when the driver inputs the destination based on the map on the display device 10, the current location of the vehicle is obtained based on the satellite data obtained from the GPS receiver 5, and the optimum route from the current location to the destination is obtained. Processing is performed. Then, the guidance route is displayed on the road map on the display device 10 so as to guide the driver to the appropriate route. In addition, the display device 10 and the speaker 15 which are notification means of the present invention send a message in accordance with the guidance during operation and the operating state.

  An optical sensor 20 for detecting the illuminance around the vehicle (illuminance detecting means of the present invention) includes a well-known photoconductive sensor using cadmium sulfide (CdS), and changes the electrical resistance value due to the intensity of light. It is what you use. The detected illuminance data is sent to the control circuit 8 (CPU 81).

  Reference numeral 21 denotes a vehicle speed sensor (vehicle speed detection means of the present invention) that detects the speed of the vehicle, and includes a rotation detector such as a known resolver or rotary encoder. The detected vehicle speed data is sent to the control circuit 8 (CPU 81).

  The data from the optical sensor 20 and the vehicle speed sensor 21 may be a method of receiving data taken in from another control device via an in-vehicle LAN (Local Area Network) 22 in addition to the method of taking in directly from these sensors. .

  FIG. 2 is a block diagram in which portions related to the brightness adjustment of the display device in the navigation device 100 are extracted. Data from the optical sensor 20 and the vehicle speed sensor 21 are input to the CPU 81, and the luminance of the display device 10 is calculated based on these data, and the luminance adjustment circuit 10 a included in the display device 10 (luminance adjustment means of the present invention). The instruction is sent, and the luminance adjustment circuit 10a lights the backlight 10b with the luminance based on the instruction. The luminance adjustment circuit 10a uses a known push-pull inverter circuit to turn on the cold cathode fluorescent lamp (backlight 10b) connected to the AC output side by changing the value of the input DC voltage. The DC voltage to be input is a value based on a PWM (Pulse Width Modulation) duty signal output from the CPU 81. For example, the backlight 10b is set to the maximum luminance when the duty is 100%, and the backlight 10b is set to the minimum luminance when the duty is 0%.

  The brightness adjustment process of the navigation program 82p executed in the CPU 81 will be described using the flowchart of FIG. This process is repeatedly performed together with other processes of the navigation device while the navigation device 100 is operating. First, current vehicle speed data is read from the vehicle speed sensor 21 (S1).

  Next, when the current vehicle speed exceeds a predetermined speed (for example, 60 km / h) (S2: Yes), it is determined that the vehicle is traveling at high speed, and the illuminance data read count (sampling count) from the optical sensor 20 is calculated. N3 times (S5). Further, when the current vehicle speed is within a predetermined speed range (for example, 60 km / h to 15 km / h) (S3: Yes), it is determined that the vehicle is traveling at a low speed and the number of times the illuminance data is read from the optical sensor 20 ( Sampling number) is set to N2 times (S6). Furthermore, when the current vehicle speed falls below a predetermined speed (for example, 15 km / h) (S4: Yes), it is determined that the vehicle has stopped, and the number of times of reading illuminance data (sampling number) from the optical sensor 20 is N1 times. (S7).

  When the vehicle is traveling at high speed, the illuminance data sampling interval is lengthened in order to slow down the speed at which the brightness of the display device 10 changes, and when the vehicle is traveling at low speed, the brightness of the display device 10 changes. The sampling interval of illuminance data is shortened in order to increase the speed at which it is performed. That is, if reading of illuminance data from the optical sensor is performed at regular time intervals, the sampling number N3 when the vehicle is moving at high speed is 10 times, and the sampling number N2 when the vehicle is moving at low speed is 5 times. , The number of times of sampling N1 when stopped is set to 3 times.

  Then, illuminance data is read from the optical sensor 20 (S8). When the number of readings matches the set number of samplings (S9: Yes), the process proceeds to the next step (S10).

  An adjustment value A for determining the luminance of the backlight 10b is obtained from the optical sensor 20 based on the illuminance data, and this is set as the set luminance (S10). The adjustment value A has a predetermined value according to the illuminance data, and is stored in advance as map data in the external memory 9 or the like.

When the vehicle is traveling at a high speed (S11: Yes), the set brightness is obtained by the following formula, and the brightness of the backlight 10b is determined.
Setting brightness = (Adjustment value A) × (Brightness change width B) / (Maximum value C of brightness change width) × (Brightness change speed D)
Here, the brightness change width B is a brightness change width of the backlight 10b that is changed at the vehicle speed, and the change width tends to decrease as the vehicle speed increases. The maximum width C of the luminance change sets an allowable maximum value of the luminance change width of the backlight 10b at the vehicle speed, and tends to decrease as the vehicle speed increases. The brightness change speed D is a speed at which the brightness of the backlight 10b is changed at the vehicle speed, and the change speed tends to decrease as the vehicle speed increases. The values of the luminance change width B, the maximum luminance change width C, and the luminance change speed D are stored in advance in the external memory 9 as map data. A configuration may be adopted in which the driver can change values of the adjustment value A, the luminance change width B, the maximum luminance change width C, and the luminance change speed D (parameter). That is, the driver operates the operation switch group 7 or the remote control terminal 12 and inputs values for parameters to be changed from a menu displayed on the display device 10. The input value is overwritten and stored in the external memory 9. Moreover, you may take the structure which a driver | operator can set whether to implement brightness | luminance adjustment processing. The setting method is the same as that for changing parameters.

  In this way, when the vehicle is traveling at a high speed, it is possible to realize a control that reduces the brightness change width of the backlight 10b and slows the speed of the change. It is possible to prevent the optical sensor from reacting sensitively and causing the screen to blink.

  Although the embodiments of the present invention have been described above, these are merely examples, and the present invention is not limited to these embodiments, and the knowledge of those skilled in the art can be used without departing from the spirit of the claims. Various modifications based on this are possible.

1 is a block diagram showing the overall configuration of a vehicle navigation device as one embodiment of the present invention. The block diagram which shows the detail of a brightness adjustment related part. The flowchart for demonstrating a brightness adjustment process.

Explanation of symbols

100 Navigation device 7 Operation switch group 8 Control circuit (luminance adjusting means)
9 External memory 10 Display device 10a Luminance adjustment circuit (luminance adjustment means)
10b Backlight 12 Remote control terminal 20 Optical sensor (illuminance detection means)
21 Vehicle speed sensor (vehicle speed detection means)

Claims (3)

An in-vehicle display device that is mounted on a vehicle and displays predetermined information including car navigation information,
A display device for displaying the predetermined information;
Brightness adjusting means for adjusting the brightness of the display device;
Vehicle speed detection means for detecting the speed of the vehicle;
Illuminance detection means for detecting brightness around the driver's seat of the vehicle;
With
The in-vehicle display device, wherein the brightness adjusting means adjusts the brightness of the display device based on brightness around the driver's seat and speed of the vehicle.   2. The brightness adjusting means is configured to reduce the amount of change in brightness of the display device when the vehicle is moving at high speed, or to reduce the speed of change in brightness of the display device. In-vehicle display device. 3. The brightness adjusting means increases the amount of change in brightness of the display device when the vehicle is moving at a low speed, or increases the speed of change in brightness of the display device. The on-vehicle display device described.

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