JP2009010860A - Navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that when a traveling vehicle unexpectedly enters a tunnel, even an available function for automatic flashing using an optical sensor possibly do not operates quick enough for imaging from the traveling vehicle. <P>SOLUTION: Disclosed is a navigation device 1 comprising a GPS positioning means 11 of detecting a current position, an HDD recording and reproducing means 13 of storing position information on tunnels, an imaging unit 181 which picks up images, a light emission unit 182 which emits light, a flash-ON mode in which the light emission unit 182 is made to emit the light for imaging and a flash-OFF mode in which the light emission unit 182 is not made to emit light for imaging, the optical sensor 184 which detects the lightness of light, and a control means of selecting the flash-ON mode when the lightness of light detected by the optical sensor 184 is not larger than a threshold and the flash-OFF mode when the lightness is larger than the threshold, while a control circuit 12 as the control means selecting the flash-ON mode whenever the current position is in a tunnel without reference to the lightness of light detected by the optical sensor 184. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a navigation device provided with a camera, and more particularly to a navigation device in which a flash is appropriately controlled in accordance with the environment in which the navigation device is placed during imaging by the camera.

  Conventionally, navigation devices that are standard on vehicles, portable navigation devices that are portable and can be used on any vehicle, motorcycle, or walking are commercially available. Mobile phone devices equipped with a navigation function are also commercially available.

  These navigation devices have been considered to have cameras for various purposes. For example, the following Patent Document 1 (Japanese Patent Laid-Open No. 2005-227912) discloses an invention for imaging an intersection or the like in order to provide navigation information to a partner. Patent Document 2 below (Japanese Patent Laid-Open No. 2006-4217) discloses an invention in which an oncoming vehicle is captured and displayed for traffic safety.

  Furthermore, the following Patent Document 3 (Japanese Patent Laid-Open No. 2005-106722) discloses an invention for imaging a road sign. Further, Patent Document 4 (2006-290276) below describes an invention that captures a landscape of a travel point for route guidance. Also, the following Patent Document 5 (Japanese Patent Application Laid-Open No. 2004-48427) also discloses an invention of a mobile phone device in which position information is attributed to imaging.

In such a navigation device, if the shutter is pressed to capture an image while the vehicle is running, there is a problem that the flash suddenly enters a dark tunnel or underpass from a bright place and the flash cannot be performed, resulting in insufficient exposure. As a method for solving this, the following Patent Document 6 (Japanese Patent Laid-Open No. 2005-202235) includes an optical sensor that detects ambient illuminance, and if the detected illuminance is equal to or greater than a threshold, the flash OFF mode is set. If it is less than this, the invention which makes it ON mode is disclosed.
JP 2005-227912 A JP 2006-4217 A JP-A-2005-106722 JP 2006-290276 A JP 2004-48427 A JP 2005-202235 A

  However, when the invention disclosed in Patent Document 6 is applied, the optical sensor starts detecting the illuminance in the tunnel, the relationship between the detected illuminance and the threshold is determined, and the flash mode is switched to ON. The shutter may be pushed. In addition, since the flash ON / OFF update by the optical sensor is performed intermittently, the shutter may be pushed in the tunnel without switching the flash ON / OFF in time.

  Further, the automatic flash ON / OFF mode by the optical sensor may be canceled. Some navigation devices do not have an automatic flash ON / OFF mode function using an optical sensor. In these cases, pressing the shutter to capture an image while the vehicle is running can solve the problem of sudden underexposure due to sudden entry into a dark tunnel or underpass from a bright place. There wasn't.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a navigation device that appropriately controls a flash in accordance with the environment in which the navigation device is placed when imaging with a camera. It is what.

  In order to solve the above problems, the present invention provides a current position detecting means for detecting a current position, a storage means for storing position information of a tunnel, an imaging means for taking an image, a light emitting means for emitting light, and an imaging A navigation device having a flash ON mode for causing the light emitting means to emit light sometimes and a flash OFF mode for not causing the light emitting means to emit light during imaging, wherein the current position and the position information of the tunnel coincide with each other in the flash ON / OFF mode. Control means for performing the control is provided.

  The position information of the tunnel is tunnel entrance / exit point information, and the control means sets the flash ON mode when the current position and the tunnel entrance point information match, and sets the current position and the exit point information of the tunnel. If they match, the flash OFF mode is set.

  The navigation device further includes an optical sensor for detecting ambient brightness, and the control means sets the flash ON mode if the ambient brightness detected by the optical sensor is less than a threshold, and If the brightness of the lamp is equal to or greater than a threshold value, the flash OFF mode is set.

  Further, the control means prioritizes the control of the flash ON / OFF mode based on the coincidence of the current position and the position information of the tunnel over the control of the flash ON / OFF mode based on the brightness detection by the light sensor. It is characterized by doing.

  Further, the light emitting means requires a charging time for light emission, and the control means is predetermined from the entrance point so that the charging of the light emitting means is completed when the current position reaches the entrance point of the tunnel. The flash ON mode is set at a position before the distance.

  Further, the control means stores in the storage means whether the flash mode before entering the tunnel is ON or OFF, and returns to the flash mode stored in the storage means when exiting the tunnel.

  Further, the current position detection means intermittently receives the current position, the control means obtains the current position using a moving speed calculated from past travel information, and the current position detection means does not receive the current position. Even if it is, it is determined whether or not the entrance point of the tunnel has been reached from the current position obtained using the moving speed.

  Further, the current position detection means cannot receive the current position in the tunnel, and the control means determines that the current position is determined by the virtual travel distance obtained using the tunnel approach speed calculated from the past travel information before entering the tunnel. The navigation device according to claim 1, wherein it is determined that the exit point of the vehicle has been reached.

  The image pickup device and the light emitting device may be held in a manner that the image capturing direction and the light emitting direction can be changed with respect to the mounting portion.

  It is also portable.

  In addition, it has voice generating means for outputting voice, and the control means notifies the fact that the flash ON mode is entered when entering the tunnel.

  The invention according to claim 1 has a flash ON mode in which the light emitting means emits light during imaging and a flash OFF mode in which the light emitting means does not emit light during imaging, and the current position detected by the current position detecting means is stored in the storage means. If it coincides with the location information of the tunnel, the flash ON / OFF control is performed. In the invention according to claim 2, the location information of the tunnel is the entrance / exit location information of the tunnel, and the control means is the current location and the entrance location information of the tunnel. If they match, the flash ON mode is set. If the current position matches the tunnel exit point information, the flash OFF mode is set.

  As a result, even if the automatic flash ON / OFF mode by the optical sensor is canceled or the automatic flash ON / OFF mode by the optical sensor is not provided, the shutter is pressed to capture an image while the vehicle is running. When you suddenly enter a dark tunnel from a bright place, you can avoid the problem of underexposure without being able to flash, and when you suddenly get out of a dark tunnel you need a flash. Therefore, the power consumption can be reduced by setting the flash OFF mode.

  In the invention according to claim 3, the navigation device further includes an optical sensor for detecting ambient brightness, and the control means sets the flash ON mode if the ambient brightness detected by the optical sensor is less than a threshold value. If the threshold is exceeded, the flash OFF mode is set.

  Thus, even when the current position cannot be accurately detected by the current position detection means, the flash ON / OFF control can be performed based on the ambient brightness detected by the optical sensor.

  In the invention according to claim 4, when the control means matches the position information of the tunnel stored in the storage means with the current position detected by the current position detection means rather than the flash ON / OFF mode control based on the detection by the optical sensor. Priority is given to the flash ON / OFF mode control.

  As a result, even if the vehicle enters the tunnel during the time from the start of detection by the optical sensor to the flash ON mode, the flash ON / OFF is updated intermittently by the optical sensor. Even when the vehicle enters the tunnel, the flash ON mode is set based on the coincidence between the current position and the entrance point information of the tunnel, so that it is possible to avoid insufficient exposure.

  In the invention according to claim 5, the light emitting means requires a charging time for light emission, and the flash ON mode is set before the tunnel arrival time in consideration of the charging time of the light emitting means.

  As a result, it is possible to avoid a situation in which the shutter is pressed during charging of the flash when the flash OFF mode is switched to the flash ON mode in the tunnel.

  In the invention according to claim 6, the control means stores whether the flash mode before entering the tunnel is ON or OFF, and returns to the stored flash mode when exiting the tunnel.

  Thereby, when exiting the tunnel, it is possible to return to the flash ON / OFF mode before entering the tunnel earlier than the flash ON / OFF mode control based on the detection of the optical sensor.

  In the invention according to claim 7, the current position detecting means intermittently receives the current position, the control means obtains the current position using the moving speed calculated from the past travel information, and the current position detecting means Even when the current position is not received, it is determined whether or not the tunnel entrance point has been reached from the current position obtained using the moving speed.

  As a result, even when the position information is received intermittently (for example, every second), the time when the vehicle enters the tunnel during the reception can be obtained.

  In the invention according to claim 8, the current position detecting means cannot receive the current position in the tunnel, and the control means is the virtual traveling distance obtained by using the tunnel approach speed calculated from the past traveling information before entering the tunnel. It is determined that the current position has reached the exit point of the tunnel.

  As a result, even when the current position detecting means cannot receive the current position in the tunnel, it is possible to obtain the time when the vehicle leaves the tunnel by virtual traveling.

  In the invention which concerns on Claim 9, it has an attaching part fixed to a vehicle, and an imaging means and a light emission means are hold | maintained so that an imaging direction and a light emission direction can be changed with respect to an attaching part.

  If the camera is fixed toward the front, the effect of the flash ON mode by the tunnel is weakened to capture the same direction as the headlight, but the image capturing direction and the light emitting direction can be changed with respect to the mounting part. By doing so, imaging in a direction different from the headlight can be performed, and the effect of the flash ON mode by the tunnel can be enhanced.

  In the invention according to claim 10, the navigation device is portable.

  If this navigation device is mounted on the vehicle and the camera is installed facing forward, the effect of the flash ON mode by the tunnel is weakened to capture the same direction as the headlight, but it differs from the headlight by removing it from the car Direction imaging can be performed, and the effect of the flash ON mode by the tunnel can be enhanced.

  According to an eleventh aspect of the present invention, there is provided voice generating means for outputting voice, and the control means notifies the fact that the flash ON mode is entered when entering the tunnel.

  As a result, it is possible to prevent the user from being surprised by an unexpected flash or from being unpredictable by the user.

  An embodiment of the present invention will be described with reference to the drawings, taking a navigation device as an example. However, the embodiment shown below exemplifies a navigation device for embodying the technical idea of the present invention, and is not intended to identify the present invention as this navigation device, and claims Other embodiments within the scope are equally applicable.

  FIG. 1 is a block diagram illustrating a configuration of a main part of the navigation device 1 according to the first embodiment.

  A GPS (Global Positioning System) positioning means 11 receives radio waves of position information from a plurality of GPS satellites, calculates a current position, and outputs data of the calculated position to a control circuit 12 described later.

  The control circuit 12 controls each unit by a program stored in the ROM 19.

  The HDD recording / reproducing means 13 has an HDD (hard disk drive), and records / reproduces map information and imaging.

  The map information recorded in the HDD recording / reproducing means 13 records the position information of the tunnel existing in the map, and the position information of the tunnel is composed of the entrance point information and the exit point information of the tunnel.

  The operation unit 14 includes keys (not shown) for the user to perform various operations related to navigation.

  The voice synthesis circuit 15 generates a voice corresponding to the character designated by the control circuit 12 and outputs the voice to the control circuit 12.

  The display unit 16 displays a map or the like on which a mark indicating the current position is superimposed.

  The speaker 17 outputs the voice generated by the voice synthesis circuit 15 under the control of the control circuit 12.

  The camera unit 18 that outputs an image to the control circuit 12 includes an image capturing unit 181, a light emitting unit 182, a shutter 183, an optical sensor 184, an optical sensor key 185, a forced flash key 186, and a camera power key 187.

  The imaging unit 181 captures an image based on the operation of the shutter 183.

  The light emitting unit 182 emits light based on the operation of the shutter 183 in the flash ON mode.

  The optical sensor 184 intermittently detects the illuminance under the control of the control circuit 12 and outputs the detected illuminance to the control circuit 12.

  The optical sensor key 185 performs an operation for determining whether or not to set an automatic flash mode by the optical sensor 184 (optical sensor ON mode), and the control circuit 12 sets an automatic flash mode by the optical sensor 184 by operating the optical sensor key 185. When this is done, the light emitting unit 182 is controlled based on the illuminance detected by the optical sensor 184.

  The forced flash key 186 performs an operation for determining whether or not to enter the forced flash ON mode.

  In the forced flash ON mode, the light emitting unit 182 emits light during imaging regardless of detection by the optical sensor 184.

  The camera power key 187 is used to turn on / off the camera unit.

  The RAM 20 stores information necessary for the operation of the control circuit 12.

  Next, the current position detection of the control circuit 12 will be described.

  When the navigation device is activated by turning on an ignition switch (not shown) of the vehicle, the control circuit 12 stores a map of a predetermined range centered on the current position calculated by the GPS positioning unit 11 in the HDD recording / reproducing unit 13. It is called from the map and displayed on the display unit 16.

  The time from when the GPS positioning means 11 receives the current position data until the current position is displayed takes several seconds at first, but thereafter, the current position is updated every second.

  The control circuit 12 superimposes and displays the received mark indicating the current position on the map. When superimposing the current position on the map, the current position is displayed on the road so that the current position received from the GPS positioning means 11 is on the nearest road on the map read from the HDD recording / reproducing means 13. This is called map matching.

  In the time when GPS is not received in the navigation device, or in a place where GPS cannot be received, the output from various sensors of an autonomous navigation means composed of an acceleration sensor, a snake angle sensor, etc. (not shown) is obtained to perform dead reckoning navigation. Do. For example, when you enter a tunnel and cannot receive GPS, use a gyro sensor to detect the direction change of the car and calculate the distance traveled from the number of rotations of the tire, etc. The current position is calculated.

  Also, since the GPS positioning means 11 receives intermittently every second, it is assumed that the GPS positioning means 11 continues to move at a moving speed calculated from the travel locus, time, etc. while not receiving the current position (GPS). The current position is displayed based on the virtual travel distance obtained as described above.

  FIG. 3 is a flowchart showing the flash ON / OFF control of the control circuit 12, and a program for this operation is stored in the ROM 19.

  The control circuit 12 stores in the RAM 20 whether the flash ON mode or the flash OFF mode is set. If the flash ON mode is selected, the control circuit 12 causes the light emitting unit 182 to emit light when the shutter 183 is operated to capture an image. In the flash OFF mode, the light emitting unit 182 does not emit light even when the shutter 183 is operated.

  However, when the forced flash key 186 is operated to enter the forced flash ON mode, the control circuit 12 changes to the flash ON mode.

  Further, the control circuit 12 stores in the RAM 20 whether or not it is in the optical sensor ON mode, and in the optical sensor ON mode, when the illuminance detected by the optical sensor is less than the threshold value, the flash ON mode is set as the flash ON imaging. I do.

  In FIG. 3, when the camera power key 187 is turned ON, the control circuit 12 sets the flash OFF mode as an initial state (step S1).

  If the forced flash key 186 is operated and the forced flash ON mode is selected (Yes in step S2), the control circuit 12 sets the flash ON mode (step S3). If the shutter 183 is pressed (Yes in step S4), since the flash ON mode is in effect (Yes in step S5), an imaging process with a flash is performed (step S6).

  If it is not in the forced flash ON mode (No in step S2), the current position is not in the tunnel area (No in step S8), and if it is in the optical sensor ON mode (Yes in step S11), the control circuit 12 indicates that the optical sensor is intermittent. The received illuminance is received (Yes in step S12, step S13).

  If the illuminance received from the optical sensor is less than the threshold value, the flash is necessary (Yes in step S14), and the flash ON mode is set (step S15). Then, the process proceeds to step S4, and if the shutter 183 is pressed (Yes in step S4), since it is in the flash ON mode (Yes in step S5), an imaging process with a flash is performed (step S6).

  If the illuminance received in step S14 is greater than or equal to the threshold value, the flash is unnecessary (No in step S14), and the flash OFF mode is set (step S16). Then, the process proceeds to step S4, and if the shutter 183 is pressed (Yes in step S4), since it is in the flash OFF mode at that time (No in step S5), an imaging process without flash is performed (step S7).

  If it is not the forced flash ON mode (No in step S2), the current position is in the tunnel area (Yes in step S8), and the tunnel entry point has been reached (Yes in step S9), the control circuit The voice synthesizing circuit 15 generates a voice indicating that the flash ON mode is 12 and outputs the voice from the speaker 17 (step S10). Then, the flash ON mode is set (step S3).

  As described above, when the current position is within the tunnel region, the flash is set to the ON mode. Therefore, even if the optical sensor OFF mode in which the optical sensor 184 is not used is used, the automatic flash function by the optical sensor is not provided. However, if the shutter is pushed to capture an image while the vehicle is running, the problem that the flash suddenly enters the dark tunnel and the flash cannot be performed, resulting in insufficient exposure can be avoided.

  In the process of step S9, it has been described that the control circuit 12 enters the flash ON mode when the current position reaches the tunnel entrance point. However, the present invention is not limited to this. The ON mode may be set.

  When entering the tunnel area, the optical sensor ON mode is prioritized (does not proceed to step S11), and it is checked whether or not the shutter 183 has been pressed after the flash ON mode is set. For this reason, even if the vehicle enters the tunnel area during the time from the start of detection by the optical sensor 184 to the flash ON mode, the flash ON / OFF update by the optical sensor 184 is intermittently performed. Even if the vehicle enters the tunnel area during the update, the flash ON mode is set based on the position information of the tunnel, so that the underexposure can be avoided.

  When the vehicle exits from the tunnel area, the process proceeds to step S11 to perform flash ON / OFF control based on the optical sensor 184. For this reason, if it is bright when exiting from the tunnel area, it can be switched to the flash OFF mode, and power consumption due to the flash can be prevented.

  In addition, as shown in step S10, when entering the tunnel area, the flash on mode is notified by voice. For this reason, it is avoided that the user is surprised by an unexpected flash or that the user does not expect an image.

  The voice notification may be set in advance by the user.

  Also, since the GPS positioning means 11 receives intermittently every second, it is assumed that the GPS positioning means 11 continues to move at a moving speed calculated from the travel locus, time, etc. while not receiving the current position (GPS). Since the current position is displayed based on the calculated virtual travel distance, it can be determined that the current position has entered the tunnel area even when GPS information is not received.

  In addition, in the time when the GPS is not received or the place where the GPS cannot be received, the output from various sensors of the autonomous navigation means including an acceleration sensor, a snake angle sensor, etc. (not shown) is obtained and estimated. Perform navigation. For example, when you enter a tunnel and cannot receive GPS, use a gyro sensor to detect the direction change of the car and calculate the distance traveled from the number of rotations of the tire, etc. Since the current position is calculated, even if the current position detection unit cannot receive the current position in the tunnel, the current position can be determined based on information such as the calculated moving distance and time.

  FIG. 2 is a perspective view illustrating an appearance of the navigation device according to the first embodiment. The camera unit 18 is installed in the casing 31 of the navigation device 1 that can be rotated via the support column 34 and the support unit 33 (see the arrow in the drawing). The user can take an image with the direction of the imaging unit 181 and the light emitting unit 182 in a desired direction by rotating the camera unit 18. The casing 31 of the navigation device 1 can be installed on a vehicle-mounted support base 32 so as to be rotatable (see arrows in the figure). The user can also rotate the camera unit 18 by rotating the housing 31, and can capture images with the directions of the imaging unit 181 and the light emitting unit 182 in desired directions.

  If the imaging unit 181 and the light emitting unit 182 are fixed toward the front of the vehicle, the effect of the flash ON mode by the tunnel is weakened to capture the same direction as the headlight, but as shown in FIG. In addition, since the imaging unit 181 and the light emitting unit 182 are held so that their orientations can be changed, imaging in a direction different from the headlight can be performed, and the effect of the flash ON mode by the tunnel can be enhanced.

  FIG. 4 is a flowchart showing the flash ON / OFF control of the control circuit 12 in the second embodiment. FIG. 4 is obtained by adding steps S21 to S23 to FIG. 3 which is a flowchart of the first embodiment. Since steps other than steps S21 to S23 are the same as those in the first embodiment, description thereof is omitted.

  In FIG. 4, when the current position enters the tunnel area (Yes in step S9), the control circuit 12 stores the flash mode immediately before entering the tunnel area in the RAM 20 (step S21). Then, when exiting from the tunnel area (Yes in step S22), the flash mode immediately before entering the tunnel area stored in the RAM 20 is read and set to this flash mode (step S23). For example, if the flash area is immediately before entering the tunnel area, the flash area is in the flash ON mode and returns to the flash OFF mode when exiting from the tunnel area.

  According to the second embodiment, it is possible to return to the original flash OFF mode earlier than the detection by the optical sensor 184 in this way.

  In the third embodiment, the tunnel area of the first embodiment is changed. The tunnel area of both embodiments is the tunnel area shown in step S8 of FIG. 3. When the current position enters this area, the flash ON mode is preferentially set over the optical sensor 184.

  FIG. 5 is a diagram schematically illustrating the tunnel region, FIG. 5A illustrates the tunnel region of the first embodiment, and FIG. 5B illustrates the tunnel region of the third embodiment. The tunnel region of Example 1 is the same as the length of the tunnel, and the tunnel region of Example 3 is obtained by considering the charging time of the light emitting unit in the tunnel length.

  With the exception of light emission by LEDs that are widely used in mobile phone devices, it takes time to store in a capacitor in order for the light emitting part to emit light. This time is about 3 to 5 seconds, during which the vehicle moves several tens of meters.

  Therefore, the control circuit 12 controls the flash ON mode at a point before reaching the area so that the charging is completed before reaching the tunnel area in consideration of the charging time of the light emitting unit 182.

  The point just before reaching the area may be calculated from information such as the moving speed of the vehicle, the distance from the current position to the area, the charging time, and the like, and is recorded in the HDD recording / reproducing means 13 each time. By adding the point information to be controlled to the flash ON mode as the data attached to the map information, the flash ON mode can be controlled when the current position reaches the control point.

  As described above, in the third embodiment of the present invention, the flash ON mode is set earlier by the charging time of the light emitting unit, so that the situation in which the shutter is pressed during the charging of the flash can be avoided. .

  Although the above navigation device is fixed to the vehicle, it may be a portable portable navigation device. If portable, imaging in a direction different from the headlight can be performed, and the effect of the flash ON mode by the tunnel can be enhanced.

  Further, mobile phone devices having a camera and a navigation are commercially available, and the present invention can be applied to this mobile phone.

  The present invention is applied to a vehicle-mounted or portable navigation device having a camera, a mobile phone device having a navigation function and a camera function, and a specification of the camera that captures not only a still image but also a moving image. be able to.

It is a block diagram which shows the principal part of the navigation apparatus which concerns on Example 1 of this invention. 1 is a perspective view illustrating an appearance of a navigation device according to Embodiment 1. FIG. 3 is a flowchart illustrating an operation of a control circuit of the navigation device according to the first embodiment. 7 is a flowchart illustrating an operation of a control circuit of the navigation device according to the second embodiment. FIG. 5A is a diagram schematically showing a tunnel region, FIG. 5A shows a tunnel region of Example 1, and FIG. 5B is a diagram showing a tunnel region of Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Navigation device 11 ... GPS positioning means 12 ... Control circuit 15 ... Speech synthesis circuit 17 ... Speaker 18 ... Camera part 181, ... Imaging part 182, ... Light emission part 183 ...・ Shutter 184 ・ ・ Optical sensor 185 ・ ・ Optical sensor key 34 ・ ・ ・ Flexible shaft

Claims (11)

Current position detecting means for detecting the current position, storage means for storing the position information of the tunnel, imaging means for capturing an image, light emitting means for emitting light, and a flash ON mode for causing the light emitting means to emit light during imaging A navigation device having a flash-off mode in which the light-emitting means does not emit light during imaging,
A navigation apparatus comprising control means for controlling the flash ON / OFF mode when the current position matches the position information of the tunnel.   The position information of the tunnel is tunnel entrance / exit point information, and the control means sets the flash ON mode when the current position matches the tunnel entrance point information, and the current position matches the tunnel exit point information. Then, the navigation apparatus according to claim 1, wherein the flash off mode is set.   The navigation device further includes an optical sensor that detects ambient brightness. If the ambient brightness detected by the optical sensor is less than a threshold value, the control unit sets the flash ON mode, and the ambient brightness. 2. The navigation device according to claim 1, wherein the flash OFF mode is set when the threshold is equal to or greater than a threshold value.   The control means gives priority to the control of the flash ON / OFF mode based on the coincidence of the current position and the position information of the tunnel over the control of the flash ON / OFF mode based on the brightness detection by the light sensor. The navigation device according to claim 3.   The light emitting means requires a charging time for light emission, and the control means is predetermined from the entrance point of the tunnel so that the charging of the light emitting means is completed when the current position reaches the entrance point of the tunnel. The navigation device according to claim 1, wherein the flash ON mode is set at a position before the distance.   The control means stores in the storage means whether the flash mode before entering the tunnel is ON or OFF, and returns to the flash mode stored in the storage means when exiting the tunnel. The navigation device described in 1.   The current position detecting means intermittently receives the current position, and the control means obtains the current position using a moving speed calculated from past travel information, and the current position detecting means does not receive the current position. 2. The navigation device according to claim 1, wherein it is determined whether or not the entrance point of the tunnel has been reached from the current position obtained using the moving speed.   The current position detection means cannot receive the current position in the tunnel, and the control means determines that the current position is the exit of the tunnel according to the virtual travel distance calculated using the tunnel approach speed calculated from the past travel information before entering the tunnel. The navigation device according to claim 1, wherein it is determined that the point has been reached.   The navigation apparatus according to claim 1, further comprising a mounting portion fixed to a vehicle, wherein the imaging unit and the light emitting unit are held so that an imaging direction and a light emitting direction can be changed with respect to the mounting unit. .   The navigation device according to claim 1, wherein the navigation device is portable.   2. The navigation apparatus according to claim 1, further comprising voice generating means for outputting voice, wherein the control means informs by voice that the flash ON mode is entered when entering the tunnel.

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