JP2009132333A - Navigation device and display control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate user's work at dark environment. <P>SOLUTION: The navigation device can be mounted on a vehicle, and includes: a secondary cell; LCD for displaying an image; a detection means (S03) for detecting that feeding of electric power from the outside is shut off; an environment detection means (S13) for detecting that it is a night mode; and a display form switching means (S15) for brightening the display form of the image displayed by the LCD when it is detected that feeding of electric power from the outside is shut off (YES at S13) when the night mode is detected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a navigation device and a display control method, and more particularly to a navigation device that can be mounted on a vehicle and a display control method executed by the navigation device.

In recent years, navigation devices are often installed in vehicles and often stolen. As a technique for preventing theft, Japanese Patent Application Laid-Open No. 5-1666075 discloses that when the engine key switch is turned off with the operation unit removed from the main body, the light emitting diode blinks to indicate that the mode is theft prevention mode. In addition, when the engine key switch is on, the light emitting diode is turned on (continuously lit), and an electronic device with an anti-theft device that displays the remounting position display or the remounting position illumination of the operation unit is described. However, if the navigation device can be seen from outside the vehicle, it may be stolen. For this reason, there are users who take it out of the car and hide it or hide it from the outside of the car. However, at night, etc., there is a problem that it is necessary to carry out the removal work in the dark and the removal work is difficult.
Japanese Patent Laid-Open No. 5-166075

  The present invention has been made to solve the above-described problems, and one of the objects of the present invention is to provide a navigation device that facilitates the work of the user in a dark environment.

  Another object of the present invention is to provide a display control method that facilitates a user's work in a dark environment.

  In order to achieve the above object, according to one aspect of the present invention, a navigation device is a navigation device that can be mounted on a vehicle, and includes a secondary battery, display means for displaying an image, and external power supply. Detecting means for detecting that the power supply has been shut off, environment detecting means for detecting whether the surrounding environment is a predetermined environment, and when the predetermined environment is detected, external power supply is cut off by the detecting means Display mode switching means for brightening the display mode of the image displayed by the display means.

  According to this aspect, when a predetermined environment is detected and the external power supply is interrupted, the display mode of the displayed image becomes bright. If a bright image is displayed, a lot of light is emitted, so that the environment can be brightened. As a result, it is possible to provide a navigation device that facilitates the user's work in a dark environment.

  According to another aspect of the present invention, the navigation device is a navigation device that can be mounted on a vehicle, and detects that the secondary battery, the display means for displaying an image, and the external power supply are cut off. Detecting means for detecting whether the surrounding environment is a predetermined environment, and when the predetermined environment is detected, it is detected that the power supply from the outside is cut off by the detecting means. The image display means for displaying a predetermined image on the display means.

  According to this aspect, when a predetermined environment is detected, a predetermined image is displayed when the external power supply is cut off. If the predetermined image is a bright image, a lot of light is emitted, so that the environment can be brightened. As a result, it is possible to provide a navigation device that facilitates the user's work in a dark environment.

  Preferably, when a predetermined environment is detected, when the detection unit detects that the external power supply is cut off, the display unit further includes a luminance control unit that improves the luminance of the image displayed by the display unit.

  If this situation is followed, since the brightness | luminance will increase and the irradiated light quantity will increase, an environment can be further brightened.

  Preferably, the apparatus further includes a stopping unit that stops the driving of the display unit when a predetermined time elapses after the detection unit detects that the external power supply is cut off.

  According to still another aspect of the present invention, a display control method is a display control method for a navigation device that can be mounted on a vehicle, and the navigation device includes a secondary battery and display means for displaying an image. A step of detecting that the external power supply is cut off, a step of detecting whether the surrounding environment is a predetermined environment, and an external power supply is cut off when the predetermined environment is detected If it is detected that the display has been performed, a step of brightening a display mode of an image displayed by the display means is included.

  According to this aspect, it is possible to provide a display control method that facilitates the user's work in a dark environment.

  According to still another aspect of the present invention, a display control method is a display control method for a navigation device that can be mounted on a vehicle, and the navigation device includes a secondary battery and display means for displaying an image. A step of detecting that the external power supply is cut off, a step of detecting whether the surrounding environment is a predetermined environment, and an external power supply when the predetermined environment is detected If it is detected that is blocked, the display means displays a predetermined image.

  According to this aspect, it is possible to provide a display control method that facilitates the user's work in a dark environment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
FIG. 1 is a perspective view showing an example of a portable navigation device according to one embodiment of the present invention. Referring to FIG. 1, the portable navigation device 10 is coupled with the supporting stand 50 as the support device, to be integrated is coupled to a support stand. The support stand 50 includes a base 51, a rotary bearing 53, a rotary shaft 55 rotatably supported by the rotary bearing 53, a stand arm 57 having one end connected to the rotary shaft 55, An attachment stay 59 coupled to the other end and a cigarette lighter connection cable 73 are included.

  The back surface of the base 51 is bonded to the upper surface of the dashboard of the vehicle with an adhesive, for example. The rotary bearing 53 is fixed substantially at the center of the base 51 and supports the rotary shaft 55 in a rotatable manner. The rotary bearing 53 has a stopper that suppresses free rotation of the rotary shaft 55 so that the rotary shaft 55 does not rotate easily.

  A stand arm 57 is coupled to the other end coupled to the rotary bearing 53 of the rotary shaft 55. Further, an attachment stay 59 is coupled to the end of the stand arm 57 opposite to the end coupled to the rotating shaft 55. The attachment stay 59 holds the portable navigation device 10 in a detachable manner. Further, the attachment stay 59 has a claw 60 that engages with a recess of the portable navigation device 10 so that the portable navigation device 10 is not easily separated when coupled to the portable navigation device 10.

  The cigarette lighter connection cable 73 extending from the inside of the base 51 has a plug 71 that can be inserted into a cigarette lighter socket provided in the vehicle at one end thereof. The cigarette lighter connection cable 73 passes through the inside of the rotary bearing 53, the rotary shaft 55, and the stand arm 57, and the other end is connected to the terminals 61 </ b> A and 61 </ b> B of the mounting stay 59.

  FIG. 2 is a functional block diagram showing an outline of the hardware configuration of the portable navigation device in the present embodiment. Referring to FIG. 2, the portable navigation device 10 includes a central processing unit (CPU) 11 for controlling the entire portable navigation device 10 and a ROM (Read Only Memory) that stores programs executed by the CPU 11. 19, a RAM (Random Access Memory) 21 used as a work area of the CPU 11, a GPS receiver 13, a TV receiver 14, a liquid crystal display (LCD) 23, a touch screen 25, operation keys 27, Audio codec 29, backlight 31, amplifier 33 connected to audio codec 29, speaker 35 connected to amplifier 33, video decoder 37, secondary battery 39, power supply circuit 41, memory interface ( I / F) 15 and serial communication I / F It includes a 7, a.

  The GPS receiver 13 receives radio waves transmitted from GPS satellites in the global positioning system (GPS), and measures the current position on the map. Then, the measured position is output to the CPU 11. A removable memory card 15A is attached to the memory I / F 15. The CPU 11 reads the map data stored in the memory card 15 </ b> A and displays on the LCD 23 an image in which the current position input from the GPS receiver 13 is written on the map. Note that a display such as an organic ELD (Electro Luminescence Display) may be used instead of the LCD 23.

  The backlight 31 is disposed on the back side of the LCD 23 and irradiates light toward the LCD 23. The LCD 23 has a plurality of pixels, and displays an image by transmitting or blocking light emitted from the backlight 31 for each pixel. That is, pixels that transmit light emitted from the backlight 31 become brighter, and pixels that do not transmit light become darker. When the LCD 23 displays a color image, the LCD 23 reproduces a color with a set of three pixels of red (R), green (G), and blue (B), and all three pixels transmit light. , White is reproduced. For this reason, when the LCD 23 reproduces an image having a white screen as a whole, the light emitted from the backlight 31 is transmitted through the LCD 23 the most and is irradiated on the front surface of the LCD 23.

  Note that an organic EL (Electro-Luminescence) display can be used in place of the LCD 23, and the backlight 31 is not necessary when an organic EL display is used. In the organic EL display, as in the case of the LCD 23, the bright image displayed on the organic EL display has a larger amount of light to irradiate than the dark image. Furthermore, when the amount of light emitted by white is the largest among the colors displayed on the organic EL display and the entire screen displays a white image, the front of the organic EL display is irradiated with the most light.

  The CPU 11 determines whether or not the portable navigation device 10 is moving based on the two positions measured by the GPS receiver 13 at two different times. If the two positions are different, it is determined that they are moving. If the two positions are the same, it is determined that they are not moving.

  The TV receiver 14 receives a television broadcast signal, converts it into a video signal, and outputs it to the CPU 11. The television broadcast signal is not limited to an analog television broadcast signal, but includes a digital television broadcast signal. The CPU 11 outputs a video signal to the LCD 23, whereby a television broadcast video is displayed on the LCD 23.

  The touch screen 25 is made of a transparent member and is provided on the display surface of the LCD 23. The touch screen 25 detects the position on the display surface of the LCD 23 designated by the user with a finger or the like, and outputs it to the CPU 11. The CPU 11 displays various buttons on the LCD 23 and receives various operation instructions in combination with the instructed position detected by the touch screen. The operation screen displayed on the LCD 23 by the CPU 11 includes an operation screen for operating the portable navigation device 10. The operation key 27 is a button switch and includes a power key for switching the main power source on and off.

  The audio codec 29 includes a circuit that converts an analog audio signal into digital data and a circuit that converts the digital data into an analog audio signal, and processes the sound data. When the audio data that has been compression-encoded is input, the audio codec 29 converts it into an analog audio signal and outputs it to the amplifier 33.

  If the memory card 15A stores sound data compressed and encoded in accordance with a standard such as MP3 (MPEG Audio Layer-3), the CPU 11 can read the sound data and output it to the audio codec 29. it can. Thereby, sound such as music stored in the memory card 15 </ b> A is output from the speaker 35.

  The video decoder 37 includes a decoding circuit that converts input digital data into an analog video signal. The video decoder 37, which is controlled by the CPU 11 and receives compressed and encoded video data, converts it into an analog video signal and outputs it to the LCD 23. If the memory card 15A stores video data compressed and encoded in accordance with a standard such as MPEG (Moving Picture Experts Group), the CPU 11 reads the video data and outputs it to the video decoder. Thereby, an image is displayed on the LCD 23.

  Power supply circuit 41 has its input terminal connected to terminals 43A and 43B. When the portable navigation device 10 is mounted on the support stand 50, the terminals 43A and 43B are electrically connected to the terminals 61A and 61B included in the mounting stay 59, respectively. Terminals 61A and 61B are respectively connected to a vehicle battery if plug 71 is inserted into a cigarette lighter socket provided in the vehicle. Therefore, when the portable navigation device 10 is mounted on the support stand 50, power is supplied to the power supply circuit 41 from the vehicle battery. The power supply circuit 41 supplies power supplied from the vehicle battery to the entire portable navigation device 10 while the portable navigation device 10 is mounted on the support stand 50.

  Here, by attaching the portable navigation device 10 to the instruction stand 50, the input terminals 43A and 43B are electrically connected to the terminals 61A and 61B of the mounting stay 59, and the portable navigation device 10 is Although the example connected with the cigarette lighter connection cable 73 was shown, the insertion port of the cigarette lighter connection cable 73 is provided in the portable navigation device 10, and the cigarette lighter connection cable 73 is inserted into the insertion port of the portable navigation device 10. Thus, the cigarette lighter connection cable 73 may be connected to the portable navigation device 10.

  The secondary battery 39 is connected in parallel with the power supply circuit 41. When the amount of stored power is reduced, the secondary battery 39 is charged with electric power supplied from the vehicle battery while the portable navigation device 10 is mounted on the support stand 50. The secondary battery 39 is discharged when the portable navigation device 10 is disconnected from the support stand 50, and supplies power to the entire portable navigation device 10 instead of the power supply circuit 41. Therefore, even if the portable navigation device 10 is not attached to the support stand 50, it can be driven by receiving power from the secondary battery 39.

  The CPU 11 has an input terminal connected to the terminal 43A. When the portable navigation device 10 is attached to the support stand 50, the terminal 43A is electrically connected to the terminal 61A included in the attachment stay 59. Terminal 61A is connected to the ground (GND) of the vehicle battery. Therefore, the CPU 11 can detect whether or not it is electrically connected to the vehicle battery (external power source) by detecting the high / low voltage of the terminal 43A. In other words, it can be detected that the power supplied from the vehicle battery has been cut off.

  FIG. 3 is a flowchart illustrating an example of the flow of display control processing. The display control process is a process executed by the CPU 11 when the CPU 11 executes a display control program.

  Referring to FIG. 3, in step S01, CPU 11 executes a display mode switching process. Although details of the display mode switching process will be described later, this is a process of determining the mode of the portable navigation device 10 and switching the display mode of the image displayed on the LCD 23 to a display mode corresponding to the determined mode. The mode refers to a state that the portable navigation device 10 can take, and here, there are a day mode and a night mode. The portable navigation device 10 is switched to either the day mode or the night mode. The portable navigation device 10 is switched to the day mode when the periphery is bright, and is switched to the night mode when the periphery is not bright.

  The display mode includes a first display mode and a second display mode. The second display mode is brighter than the first display mode. For example, the image displayed in the second display mode is an image obtained by inverting the bright and dark portions of the image displayed in the first display mode. For this reason, when the portable navigation device 10 is switched to the day mode, the image is displayed brighter than when the portable navigation device 10 is switched to the night mode. Conversely, when the portable navigation device 10 is switched to the night mode, the image is displayed darker than when the portable navigation device 10 is switched to the day mode. For example, when an image in the second display mode is displayed, a bright image is displayed on the LCD 23. Therefore, in an environment where the periphery is dark, light emitted from the backlight 31 is transmitted through the LCD 23 and emitted to the front. For this reason, since the light irradiated from the backlight 31 is irradiated to the driver, the driving operation is hindered. For this reason, when the portable navigation device 23 is switched to the night mode, an image of the first display mode darker than the image of the second display mode is displayed. In an environment where the surroundings are bright, the light emitted from the backlight 31 passes through the LCD 23 and is emitted to the front. However, since the light emitted from the periphery of the vehicle to the driver has more light, Will not interfere with the operation. Conversely, displaying a bright image makes it easier to see the image. For this reason, when the portable navigation device 10 is switched to the daytime mode, an image in the second display mode brighter than the image in the first display mode is displayed.

  In step S02, the navigation operation is performed in the display mode set by the CPU 11 in step S01. The navigation operation is a process of displaying a map specifying the current car position specified by the GPS receiver 13, searching a route from the current car position to the destination, and displaying the route on the specified map. Processing for displaying video received by the TV receiver 14, processing for playing back music data stored in the memory card 15A attached to the memory I / F 14, and the like.

  Thereafter, in step S03, it is determined whether or not the external power supply is turned off. If it is detected that the external power supply has been turned off, the process proceeds to step S04; otherwise, the process returns to step S01. The detection of the change in the external power supply from ON to OFF is detection that the external power supply is cut off. Here, the external power source is a battery mounted on the vehicle. Specifically, the CPU 11 determines that the external power supply is OFF if the voltage of the terminal connected to the terminal 43A is high, and determines that the external power supply is ON if the voltage is low. The external electronic application is judged to be ON because the plug 71 is connected to a cigar socket connected to the vehicle battery, the accessory power supply of the vehicle is ON, and the portable navigation device 10 is used as a support stand. The external power supply is determined to be OFF when the plug 71 is not connected to the cigar socket, when the accessory power supply of the vehicle is OFF, or the portable navigation device 10 is used for support. This is one of the cases where the stand 50 is not attached.

  In step S04, the display time is set to 20 seconds. In the next step S05, an inquiry screen is displayed on the LCD, and the process proceeds to step S06. The inquiry screen is a screen for inquiring whether or not to continue the navigation operation. The inquiry screen includes, for example, a message “Do you want to continue the navigation operation?”, A button with a character “Yes”, and a button with a character “No”. In step S08, the CPU 11 determines whether or not the display time set in step S04 has elapsed. If it is determined that the time has elapsed, the process proceeds to step S12; otherwise, the process returns to step S05. For this reason, the inquiry screen displayed in step S05 is displayed until 20 seconds elapse or until the user inputs an instruction. Although the display time is set to 20 seconds here, the display time is not limited to this. It is sufficient that the time is sufficient for the user to instruct after the inquiry screen is displayed in step S05.

  In step S06, it is determined whether an instruction to continue the navigation operation or not to continue is accepted. If any instruction is accepted, the process proceeds to step S07; otherwise, the process proceeds to step S08. Specifically, an instruction input by the user to the operation key 27 is received. If the user points to a button with the word “Yes” included in the inquiry screen, the instruction to continue the navigation operation is accepted, but if the user points to the button with the character “No”, the navigation operation An instruction not to continue is accepted.

  In step S07, it is determined whether or not the instruction received in step S06 is an instruction to continue the navigation operation. If the accepted instruction is an instruction to continue the navigation operation, the process proceeds to step S09. If the accepted instruction is an instruction not to continue the navigation operation, the process proceeds to step S13.

  When the process proceeds to step S09, the display mode switching process is performed in the same manner as in steps S01 and S02 (step S09), the navigation operation is performed (step S10), and the process proceeds to step S11. In step S11, it is determined whether an instruction to turn off the internal power supply is accepted. If an instruction to turn off the internal power supply is received, the process proceeds to step S12; otherwise, the process returns to step S09. The operation of turning off the internal power supply is an operation of turning off the main power switch, for example. In step S12, the internal power is turned off and the process is terminated. Specifically, the power supplied from the secondary battery 39 is cut off.

  On the other hand, the process proceeds to step S13 when the instruction accepted in step S07 is an instruction not to continue the navigation operation. In step S13, it is determined whether the portable navigation device 10 is switched to the night mode or the day mode. If it is determined that the mode is switched to the night mode, the process proceeds to step S14; otherwise, the process proceeds to step S12. This is because when the mode is switched to the daytime mode, the surrounding environment is bright, and even if the internal power supply is turned off as it is, there is no problem in the work for preventing the portable navigation device 10 from being stolen.

  In step S14, the irradiation time is set to 90 seconds, and the process proceeds to step S15. In step S15, the display mode of the image displayed on the LCD 23 is switched to the second display mode. The image displayed on the LCD 23 is brighter in the second display mode than in the first display mode. Since the amount of light transmitted through the LCD 23 out of the light emitted from the backlight 31 is large, more light is emitted after switching to the second display mode than before switching. When an organic EL display is used instead of the LCD 23, the image of the first display mode displayed on the organic EL display is brighter than the image of the second display mode and has a larger amount of light to be irradiated. After switching, more light is emitted than before switching.

  In step S16, the luminance of the backlight 31 is improved. When the brightness of the backlight is improved, the amount of light emitted from the backlight 31 is increased, so that the surroundings can be illuminated more brightly. When an organic EL display is used instead of the LCD 23, the luminance of the organic EL display is improved. As the brightness increases, the amount of light to be irradiated increases, so that the surroundings can be illuminated more brightly.

  In the next step S17, it is determined whether or not the display time set in step S14 has elapsed. If the display time has elapsed, the process proceeds to step S18; otherwise, the process returns to step S15. Thereby, the image is displayed for 90 seconds in the second display mode brighter than the image displayed in the first display mode. Therefore, the dark surroundings can be illuminated brightly for 90 seconds with the light emitted from the backlight 31. When an organic EL display is used instead of the LCD 23, a dark periphery can be illuminated brightly for 90 seconds with light emitted from the organic EL display. For this reason, the portable navigation apparatus 10 can be used as a flashlight for 90 seconds.

  Since step S01 is not executed after step S15 is executed, the process of switching to the first display mode is prohibited when the mode is switched to the night mode, and after switching to the second display mode. The first display mode cannot be switched. Here, the irradiation time is set to 90 seconds. However, the present invention is not limited to this, and an operation for preventing the portable navigation device 10 from being stolen after the external power supply is turned off. It is sufficient that the time is sufficient for the user to perform.

  In step S18, image display is stopped, and the process proceeds to step S12. Specifically, the driving of the LCD 23 and the backlight 31 is stopped. Thereby, no light is emitted from the backlight 31, and the LCD 23 stops displaying an image. When an organic EL display is used instead of the LCD 23, driving of the organic EL display is stopped, and the organic EL display is stopped from displaying an image. In step S12, the internal power is turned off and the process is terminated.

  FIG. 4 is a flowchart illustrating an example of the flow of the display mode switching process. The display mode switching process is a process executed in step S01 in FIG. Referring to FIG. 4, in step S21, CPU 11 obtains the current time. And the time table memorize | stored in ROM19 is read (step S22). In the next step S23, the mode in which the portable navigation device is set is determined based on the current time and the time table read in step S22. The time table is a table that defines time zones respectively corresponding to the night mode and the day mode. Here, the time table associates the time zone from 7:00 to 19:00 with the daytime mode, and associates 19:01 to 6:59 with the night mode. The surrounding environment (second environment) in the time zone associated with the day mode is brighter than the surrounding environment (first environment) in the time zone associated with the night mode.

  In the next step S23, it is determined whether or not the time zone including the current time acquired in step S21 is associated with the night mode by the time table. If it is associated with the night mode, the process proceeds to step S24, and if it is the day mode, the process proceeds to step S25.

  In step S24, the image displayed on LCD 23 is set to the first display mode, and the process returns to the display control process. On the other hand, in step S25, the image displayed on the LCD 23 is set to the second display mode, and the process returns to the display control process.

  Here, it is determined whether the mode is the day mode or the night mode from the current time and the time table. However, an optical sensor is provided, and the amount of light detected by the optical sensor is a threshold value. If it exceeds the threshold value, it may be determined as the day mode, and if it is less than the threshold value, it may be determined as the night mode. In this case, for example, even in the daytime period, it is possible to facilitate the work for preventing the portable navigation device from being stolen in a dark place such as an indoor parking lot.

<Second Embodiment>
Although the portable navigation device in the first embodiment switches the display mode of the image displayed on the LCD 23, the portable navigation device in the second embodiment changes the image displayed on the LCD 23. It is a thing. Hereinafter, differences from the portable navigation device 10 according to the first embodiment will be described.

  FIG. 5 is another flowchart illustrating an example of the flow of the display control process. Referring to FIG. 5, the difference from the display control process shown in FIG. 3 is that step S15A is changed. Other processing is the same as the processing shown in FIG. 3, and therefore description thereof will not be repeated here.

  Referring to FIG. 5, in step S <b> 15 </ b> A, CPU 11 displays a predetermined image on LCD 23. The predetermined image is, for example, a white image that is entirely white. In the white image, each pixel of RGB transmits light from the backlight 31, so that the entire surface of the LCD 31 transmits light emitted from the backlight 31. That is, the white image is an image that transmits the most light among the images displayed on the LCD 31. The predetermined image only needs to be an image that transmits the light of the backlight 31, and the entire surface does not need to be white, and a part thereof may be white. In the present embodiment, the white image is displayed. However, for example, a yellow or blue-white image may be used as long as the image transmits a lot of light.

  Even when an organic EL display is used in place of the LCD 23, the predetermined image is, for example, a white image that is entirely white. The white image is irradiated with a lot of light because each pixel of RGB emits light. That is, the white image is an image that emits the most light among the images displayed on the organic EL display. Note that the predetermined image only needs to be an image with a large amount of light to be irradiated, and the entire surface does not need to be white, and a part thereof may be white. Note that the image is not limited to a white image, and may be a yellow or blue-white image, for example, as long as the image emits a lot of light.

  In step S14, since 90 seconds is set as the irradiation time, a white image is displayed for 90 seconds. Therefore, the dark surroundings can be illuminated brightly for 90 seconds with the light emitted from the backlight 31. When an organic EL display is used instead of the LCD 23, a dark periphery can be illuminated brightly for 90 seconds with light emitted from the organic EL display. For this reason, the portable navigation device 10 can be used as a flashlight for 90 seconds, and the portable navigation device can be easily removed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a perspective view which shows an example of the portable navigation apparatus in one of embodiment of this invention. It is a functional block diagram which shows the outline | summary of the hardware constitutions of the portable navigation apparatus in this Embodiment. It is a flowchart which shows an example of the flow of a display control process. It is a flowchart which shows an example of the flow of a display mode switching process. It is another flowchart which shows an example of the flow of a display control process.

Explanation of symbols

  10 portable navigation device, 11 CPU, 13 GPS receiver, 14 TV receiver, 15 memory I / F, 15A memory card, 17 serial communication I / F, 23 LCD, 25 touch screen, 27 operation keys, 29 audio codec , 31 Backlight, 33 Amplifier, 35 Speaker, 37 Video decoder, 39 Secondary battery, 41 Power supply circuit, 43A, 43B terminal, 50 Support stand, 51 Base, 53 Rotating bearing, 55 Rotating shaft, 57 Stand arm, 59 Mounting stay, 60 claws, 61A, 61B terminal, 71 plug, 73 cigarette lighter connection cable.

Claims (6)

A navigation device that can be mounted on a vehicle,
A secondary battery,
Display means for displaying an image;
Detecting means for detecting that the external power supply is cut off;
Environment detection means for detecting whether the surrounding environment is a predetermined environment;
A display mode switching unit for brightening a display mode of an image displayed by the display unit when the detection unit detects that the external power supply is cut off when the predetermined environment is detected; A navigation device comprising: A navigation device that can be mounted on a vehicle,
A secondary battery,
Display means for displaying an image;
Detecting means for detecting that the external power supply is cut off;
Environment detection means for detecting whether the surrounding environment is a predetermined environment;
An image display means for displaying a predetermined image on the display means when the detection means detects that the external power supply is cut off when the predetermined environment is detected. Navigation device.   When the predetermined environment is detected, when the detection unit detects that the external power supply is cut off, the display unit further includes a luminance control unit that improves the luminance of the image displayed by the display unit. The navigation device according to claim 1 or 2.   The navigation according to claim 1, further comprising a stopping unit that stops driving of the display unit when a predetermined time has elapsed after the detection unit detects that the external power supply is cut off. apparatus. A display control method for a navigation device that can be mounted on a vehicle,
The navigation device
A secondary battery,
Display means for displaying an image,
Detecting that the external power supply is cut off;
Detecting whether the surrounding environment is a predetermined environment;
A display control method comprising: brightening a display mode of an image displayed by the display unit when it is detected that the external power supply is cut off when the predetermined environment is detected. A display control method for a navigation device that can be mounted on a vehicle,
The navigation device
A secondary battery,
Display means for displaying an image,
Detecting to detect that the external power supply is cut off;
Detecting whether the surrounding environment is a predetermined environment;
A step of displaying a predetermined image on the display means when it is detected that the external power supply is cut off when the predetermined environment is detected.

Images