JP5245930B2 - In-vehicle display device - Google Patents

Description

  The present invention relates to an in-vehicle display device that displays various images for prompting a driver of a host vehicle to secure a required inter-vehicle distance with respect to a preceding vehicle.

  Conventionally, in order to prompt the driver of the host vehicle to secure the required inter-vehicle distance for the preceding vehicle, the inter-vehicle distance from the preceding vehicle is detected by a radar device mounted on the own vehicle, and the inter-vehicle distance There is known an in-vehicle control device that warns a driver via a display or a speaker in the host vehicle when the distance is less than a predetermined safe inter-vehicle distance (for example, see Patent Document 1).

  In addition, with this type of in-vehicle control device, it is necessary to secure a larger inter-vehicle distance than when driving in the daytime when trying to prevent a rear-end collision with a preceding vehicle during driving at night or in the evening. It has been proposed to set a safe inter-vehicle distance to a larger value when it is detected that a vehicle headlight is turned on (see, for example, Patent Document 2).

JP-A-6-191361 JP 11-34692 A

  However, in the conventional vehicle-mounted control device, when displaying a warning image on the display, the driver's line of sight is moved from the outside of the vehicle to the inside of the vehicle, and the possibility of preventing safe driving in return cannot be denied. When a warning sound is output, there is a possibility that the warning sound may be buried in the surrounding noise or the music in the vehicle, and there is a problem that it cannot always be properly notified.

  For such problems, it is conceivable to display a warning image (virtual image) superimposed on the scenery in front of the vehicle using a known head-up display, or increase the output of warning sound by a speaker. Therefore, the driver's focus is adjusted to the virtual image. In the latter case, the warning sound may be too bothersome, which may cause the driver to feel uncomfortable or uncomfortable. In particular, in the latter case, when the vehicle is traveling at night or in the evening, there is a problem in that the warning sound is output more frequently, which may give the driver more discomfort.

  In order to solve the above-described problems, an object of the present invention is to provide an in-vehicle display device capable of prompting a driver to secure a distance between vehicles safely and comfortably during traveling that requires lighting of a headlight. To do.

  The vehicle-mounted display device according to claim 1, which is an invention made to achieve the above object, wherein the projecting means projects illumination light on a road surface in front of the host vehicle, and the image display means is applied to the preceding vehicle. The gist of the invention is to display an index image representing a safe inter-vehicle distance preset as a required inter-vehicle distance in a projection area on a road surface via a projection unit. In addition, a projection area | region here means the area | region where illumination light is projected on a road surface by a projection means.

  In the vehicle-mounted display device configured as described above, for example, when illumination light using a light source of a headlight is irradiated, an index image indicating a safe inter-vehicle distance is displayed on a road (real image) in front of the vehicle. The driver's line of sight does not need to deviate from the front outside the vehicle, and the driver's focus is easily adjusted to the index image on the real image.

Therefore, according to the in-vehicle display device of the present invention, it is possible to urge the driver to secure the inter-vehicle distance safely and comfortably, for example, during traveling that requires lighting of the headlights at night or in the evening.
Also, in-vehicle display device of the present invention, the distance detection unit detects a headway distance between the host vehicle and the preceding vehicle, the display control means, based on the following distance detected by the distance detecting means, image display means to change the display mode of the index image by. The display form here refers to a form in which the index image is displayed on the road surface, and includes, for example, changing characters, colors, positions, patterns, and the like.

  In the in-vehicle display device configured as described above, for example, when the actual inter-vehicle distance is less than a predetermined safe inter-vehicle distance, the driver is warned by changing the character, color, position, pattern, etc. of the index image. Can do. Further, in this case, a projection area can be set between the host vehicle and the preceding vehicle on the road surface, so that the index image can be reliably displayed on the road surface.

Here, in the in-vehicle display device of the present invention , the own vehicle speed detecting means detects the speed of the own vehicle, and the relative speed calculating means is based on the inter-vehicle distance detected by the distance detecting means. Calculate the relative speed. Then, the distance setting means, the speed detected by the vehicle speed detecting means, and, based on the relative speed calculated by the relative velocity calculation means, to set the safe distance.

  In the vehicle-mounted display device configured as described above, by changing the safe inter-vehicle distance according to the own vehicle speed and the relative speed, for example, when the own vehicle is traveling at a high speed or when the preceding vehicle is decelerating, the indicator image display form is changed. The timing becomes earlier, and the driver can be urged to secure a safer inter-vehicle distance according to the driving situation.

Alternatively, in the in-vehicle display device of the present invention, as described in claim 2, when the environment acquisition unit acquires the traveling environment of the host vehicle, the display control unit is configured such that the traveling environment acquired by the environment acquisition unit is rainy, When indicating either an urban area or a mountain road, it is desirable to change the display position of the index image to the side approaching the host vehicle.

  In the vehicle-mounted display device configured in this way, when the driver's visibility deteriorates when driving in rainy weather, urban areas, or mountain roads, the index image indicating the safe inter-vehicle distance is positioned relatively close to the host vehicle on the road surface. As a result, the reliability of allowing the driver to visually recognize the index image can be improved.

Furthermore, in the in-vehicle display device of the present invention, as described in claim 3, when the display controller detects that the inter-vehicle distance detected by the distance detector is less than the safe inter-vehicle distance, the vehicle from the preceding vehicle side on the road surface It is desirable to move and display the index image toward the side.

  In the vehicle-mounted display device configured as described above, when the inter-vehicle distance between the preceding vehicle and the host vehicle becomes short, the index image displayed on the road surface approaches the host vehicle, so that the driver can intuitively perform the deceleration operation. Can be encouraged.

Meanwhile, vehicle display device of the present invention, the first switching means, a distance based on the inter-vehicle distance detected by the detecting means, intends row enabling or disabling of display of the index image by the image display means.

  In this case, for example, when the preceding vehicle does not exist or when the preceding vehicle is far away, the indicator image indicating the safe inter-vehicle distance is hidden to display the indicator image for a long time. Therefore, it is possible to prevent the driver from feeling annoyed or to notify the safe inter-vehicle distance only when the driver needs it.

The first switching means, the inter-vehicle distance detected by the distance detecting means is below a safe distance, and, based on the amount of change in the relative speed calculated by the relative velocity calculation means, the preceding vehicle is accelerated the vehicle The indicator image is displayed by the image display means only when the condition is met and the condition is met and the condition is met and a certain period has not passed since the condition was met. you permission.

  In the vehicle-mounted display device configured as described above, for example, when a preceding vehicle is approaching, an index image representing a safe inter-vehicle distance is displayed for a certain period only when the approach speed changes so as to be larger. Thus, it is possible to emphasize to the driver that the necessity of decelerating the host vehicle is high and notify the driver.

In the in-vehicle display device of the present invention, as described in claim 4 , the voice recognition means recognizes the voice spoken by the driver, and the second switching means recognizes the voice spoken by the voice recognition means. The display of the index image by the image display means may be permitted or prohibited based on the above.

  In this case, the display / non-display of the index image can be switched according to the driver's intention without the driver's line of sight deviating from the front outside the vehicle.

The block diagram which shows the structure of the vehicle-mounted display apparatus 1 to which this invention was applied. 7 is a flowchart showing details of display control processing executed by the CPU of the control unit 10. Explanatory drawing which shows the setting method of the safe inter-vehicle distance in a display control process. The flowchart which shows the detail of the display setting process performed in a display control process. The schematic diagram which shows the example of a display of the parameter | index image in case an actual inter-vehicle distance exceeds the safe inter-vehicle distance. The schematic diagram which shows the example of a display of the parameter | index image in case the actual inter-vehicle distance is less than the safe inter-vehicle distance. 7 is a flowchart showing details of display switching processing executed by the CPU of the control unit 10. The graph which shows the display period of a parameter | index image in a display switching process. The flowchart which shows the detail of the display setting process (2nd Embodiment) performed in a display control process. The graph which shows the display position of an index image in display setting processing. The schematic diagram which shows the display form of the parameter | index image changed according to driving | running | working environment. The flowchart which shows the detail of the display switching process (2nd Embodiment) which CPU of the control part 10 performs. The graph which shows the display period of a parameter | index image in a display switching process (2nd Embodiment).

A first embodiment of the present invention will be described below with reference to the drawings.
[First Embodiment]
<Overall configuration>
FIG. 1 is a block diagram showing a configuration of an in-vehicle display device 1 to which the present invention is applied.

  As shown in FIG. 1, the in-vehicle display device 1 includes a vehicle speed sensor 2 that detects a traveling speed of a vehicle (hereinafter referred to as the host vehicle) on which the device 1 is mounted, and a predetermined detection range on the front side of the host vehicle. A radar device 3 for detecting another vehicle (hereinafter referred to as a preceding vehicle), an in-vehicle camera 4 that generates image data that captures a landscape in front of the host vehicle, and a manual switch of the driver of the host vehicle A plurality of main body switches 5 for inputting operations, a pixel light 7 for projecting illumination light on a road surface in front of the vehicle using a light source of a headlight 6 of the host vehicle, and various images in a projection area of the pixel light 7 The image device 8 for displaying the image, the vehicle speed sensor 2, the radar device 3, the in-vehicle camera 4, the main body switch 5, the headlight 6, etc. And a control unit 10 for controlling the image device 8.

  Further, the in-vehicle display device 1 collects and publicizes a navigation device 11 that performs a well-known route guidance process based on current location information acquired using GPS, and a voice (speech voice) uttered by a driver of the own vehicle. In addition to the voice recognition device 12 that performs the voice recognition process, the wiper device 13 of the host vehicle, the ignition (IG) switch 14 and the like are connected, and various information is also input to the control unit 10 from these devices 11 to 13 and the switch 14. It is configured to be.

  The radar apparatus 3 is configured as, for example, a so-called “millimeter wave radar” of the FMCW system, and transmits and receives a frequency-modulated millimeter wave band radar wave, thereby leading vehicles and obstacles ahead of the host vehicle. An object such as an object or a pedestrian (hereinafter collectively referred to as a front obstacle) is detected (recognized), and target information relating to the front obstacle is created based on the recognition result. Output to.

  For example, the image device 8 drives an ultra-fine mirror (micromirror) spread on a semiconductor substrate to reflect or block the illumination light projected by the pixel light 7 for each pixel. The reflected light is transmitted through a rotary color wheel that can be performed several thousand times per second, and the transmitted light is displayed as an image on a projection area on the road surface.

  For example, based on map data stored in the hard disk, the navigation device 11 outputs flag information indicating the fact to the control unit 10 when the current location of the host vehicle matches an area representing an urban area or a mountain road. It is configured as follows.

  The speech recognition device 12 obtains a frequency spectrum by, for example, performing FFT (Fast Fourier Transform) on the waveform of the input speech, extracts the features of the input speech, and compares them with preregistered speech data to obtain the highest likelihood (similarity). Vocabulary data having a high frequency) is selected and an operation command corresponding to the vocabulary data is output to the control unit 10.

  The control unit 10 is configured around a well-known microcomputer comprising a CPU, ROM, RAM, I / O and a bus line connecting them, and among these, the CPU is a program stored in the ROM. Based on the RAM, the following display control process and display switching process are executed.

<Display control processing>
Next, FIG. 2 is a flowchart showing details of display control processing executed by the CPU of the control unit 10. This process starts when the power source of the in-vehicle display device 1 is turned on via the IG switch 14 or the main body switch 5, and is repeatedly executed at a predetermined cycle until the power source is turned off.

  First, when this process is started, in S110, when it is confirmed that a preceding vehicle exists based on the image data input from the in-vehicle camera 4, based on the target information input from the radar apparatus 3, The inter-vehicle distance between the preceding vehicle and the host vehicle is acquired. The inter-vehicle distance may be calculated based on input information from either the in-vehicle camera 4 or the radar device 3.

  In subsequent S120, the relative speed between the host vehicle and the preceding vehicle is calculated based on the difference (change amount) between the previous value and the current value of the inter-vehicle distance acquired in S110. The relative speed here is expressed as the speed of the preceding vehicle when the traveling speed of the host vehicle is used as a reference (zero), and shows a larger value as the preceding vehicle moves away from the host vehicle.

  In subsequent S130, based on the relative speed calculated in S120 and the traveling speed of the host vehicle input from the vehicle speed sensor 2 (hereinafter referred to as the host vehicle speed), the required inter-vehicle distance (hereinafter referred to as the following vehicle). Set a safe distance between vehicles. As shown in FIG. 3, the safe inter-vehicle distance is set so as to increase as the own vehicle speed increases or as the relative speed decreases. In addition, when flag information is input from the navigation device 11 or when an operation signal indicating that the wiper of the host vehicle is operating is input from the wiper device 13, the vehicle travels in an urban area, a mountain road, or rainy weather. Each corresponding distance is set to be longer.

  In subsequent S140, based on the inter-vehicle distance acquired in S110 and the safe inter-vehicle distance set in S130, index images (graphics, characters, symbols, colors, etc.) representing the safe inter-vehicle distance, and the display form of the index image Display setting processing for setting (display position, display pattern, etc.) is performed, and this processing is terminated.

《Display setting processing》
Here, FIG. 4 is a flowchart showing details of the display setting process executed in S140 of the above-described display control process.

  First, when this process is started, in S210, it is determined whether or not the inter-vehicle distance acquired in S110 of the display control process is equal to or greater than the safe inter-vehicle distance set in S130 of the display control process. If yes, the process proceeds to S220. If a negative determination is made, the process proceeds to S230.

  In S220, the position on the road surface corresponding to the safe inter-vehicle distance set in S130 of the display control process is set as the display position (or display area), and is initialized in advance by the driver of the own vehicle via the main body switch 5. The index image and the display pattern that have been read are read out, and this process is terminated. As shown in FIG. 5, these display forms include, for example, a line image and a character image indicating a safe inter-vehicle distance as a display position, and an area image indicating an area from the safe inter-vehicle distance to the host vehicle as a display area. Furthermore, these display forms are classified by characters, colors, contrast, moving display, and the like that the actual inter-vehicle distance is greater than the safe inter-vehicle distance, that is, the actual inter-vehicle distance is appropriate. In the present embodiment, when the actual inter-vehicle distance is appropriate, the line image can be set to move and display from the own vehicle side to the preceding vehicle side on the road surface.

  On the other hand, in S230, the position on the road surface on the own vehicle side is set as the display position (or display area) compared to the inter-vehicle distance acquired in S110 of the display control process, and the driver of the own vehicle is connected via the main body switch 5. The index image and the display pattern that are initially set in advance are read out, and the process is terminated. In addition, as shown in FIG. 6, these display forms indicate that the actual inter-vehicle distance is less than the safe inter-vehicle distance, that is, that it is necessary to secure the safe inter-vehicle distance, characters, colors, contrast, and arrow display. Emphasized by moving display. In the present embodiment, when the actual inter-vehicle distance is appropriate, the line image can be set to move and display from the preceding vehicle side toward the own vehicle side on the road surface.

<Display switching process>
Next, FIG. 7 is a flowchart showing details of display switching processing executed by the CPU of the control unit 10. In this process, a process for determining whether or not to display the index image set in the above-described display setting process according to the display form set in the same display setting process, that is, switching between display and non-display is performed. It is processing. This process is activated when the above-described display control process is started, and is repeatedly executed at a predetermined cycle until the power source of the in-vehicle display device 1 is turned off via the IG switch 14 or the main body switch 5. The

  First, when this process is started, in S310, it is determined whether or not an operation command for displaying an index image is input from the main body switch 5 or the voice recognition device 12, and if an affirmative determination is made here, The process proceeds to S350, and if a negative determination is made, the process proceeds to S320.

  In S320, it is determined whether or not an operation command for hiding the index image is input from the main body switch 5 or the voice recognition device 12. If an affirmative determination is made here, the process proceeds to S360 and a negative determination is made. In this case, the process proceeds to S330.

  In S330, it is determined whether or not the inter-vehicle distance acquired in S110 of the display control process described above exceeds the first inter-vehicle distance that is added in advance by a predetermined distance with respect to the safe inter-vehicle distance set in S130 of the display control process. If an affirmative determination is made here, the process proceeds to S350, and if a negative determination is made, the process proceeds to S340.

  In S340, it is determined whether or not the inter-vehicle distance acquired in S110 of the above-described display control process is less than the second inter-vehicle distance previously subtracted by a predetermined distance from the safe inter-vehicle distance set in S130 of the display control process. If the determination is affirmative, the process proceeds to S360. If the determination is negative, the process proceeds to S350.

  In S350, the index image set in the display setting process is displayed in the display form similarly set in the display setting process via the image device 8 and the pixel light 7, and this process ends.

In S360, a control command for hiding the index image is output to the image device 8 and the pixel light 7, and this process is terminated.
That is, in this process, as shown in FIG. 8, once the inter-vehicle distance (actual inter-vehicle distance) between the host vehicle and the preceding vehicle exceeds the first inter-vehicle distance, until the actual inter-vehicle distance falls below the second inter-vehicle distance. The index image is displayed on the road surface.

In the above embodiment, the pixel light 7 is the projecting means, the image device 8 is the image display means, the radar device 3 or the in-vehicle camera 4 is the distance detecting means, the vehicle speed sensor 2 is the own vehicle speed detecting means, and the display control process is S120. Is a relative speed calculating means, S130 is a distance setting means, S140 (display setting process) is a display control means, and among the display switching processes, S310 and S320 correspond to a second switching means.

<Effect>
As described above, in the in-vehicle display device 1 according to the present embodiment, the control unit 10 executes various processes based on the input information from each sensor and the switches 2 to 6, and automatically performs the process via the pixel light 7. Illumination light is irradiated on the road surface in front of the vehicle, and an index image representing a safe inter-vehicle distance is displayed in the projection area of the pixel light 7 via the image device 8.

  Therefore, according to the in-vehicle display device 1 of the present embodiment, since the index image representing the safe inter-vehicle distance is displayed on the road (real image) in front of the vehicle, the driver's line of sight does not have to be disengaged from the front outside the vehicle, The driver can easily focus on the index image on the real image. For example, the driver can be urged to secure the inter-vehicle distance safely and comfortably when driving the headlight 6 at night or in the evening.

  Further, in the display switching process executed by the control unit 10 of the in-vehicle display device 1, even if the actual inter-vehicle distance is around the safe inter-vehicle distance, the index image is displayed by providing hysteresis during the display period of the index image. It is possible to prevent the driver from feeling annoyed by frequently switching between display / non-display.

  Further, in the display switching process executed by the control unit 10 of the in-vehicle display device 1, when an operation command for displaying an index image is input from the main body switch 5 or the voice recognition device 12, the index image is not displayed. Even if there is, it is immediately switched to the display state, so that the driver can confirm the safe inter-vehicle distance at a desired timing.

[Second Embodiment]
Next, 2nd Embodiment of this invention is described with drawing.
The in-vehicle display device 1 of the present embodiment is the same as the first embodiment except that the display setting process and the display switching process executed by the CPU of the control unit 10 are different. The description of the points common to the first embodiment will be omitted.

《Display setting processing》
FIG. 9 is a flowchart showing details of the display setting process (second embodiment) executed in S140 of the display control process described above.

  First, when this process is started, it is determined in S410 whether or not either flag information from the navigation device 11 or an operation signal from the wiper device 13 is input. The process proceeds to S430, and if a negative determination is made, the process proceeds to S420. This step corresponds to environment acquisition means.

  In S420, as shown in FIG. 10 (a), based on the inter-vehicle distance acquired in S110 of the above-described display control process, the display position or display area is located at a position corresponding to the irradiation distance proportional to the inter-vehicle distance on the road surface. Is set, and this process ends. However, when the inter-vehicle distance here exceeds a predetermined distance A, a fixed irradiation distance is set.

  On the other hand, in S430, based on the flag information or the operation signal input in S410, the display position or the display area is approached to the host vehicle on the road surface as the position or area corresponding to driving in an urban area, a mountain road, or rainy weather. To finish the process. For example, the display position (irradiation distance) here is set to a constant distance when the actual inter-vehicle distance exceeds a short distance B as compared to the distance A, as shown in FIG. In the section where the actual inter-vehicle distance is from distance A to distance B, the distance is changed to the side closer to the host vehicle on the road surface. As shown in FIG. 11, the index image here can be highlighted by changing the display position from the normal time by combining lines, characters, figures, and the like.

  In other words, in this process, when the driver's visibility deteriorates when driving in rainy weather, urban areas, or mountain roads, an index image indicating a safe inter-vehicle distance is displayed at a position relatively close to the host vehicle on the road surface. Thus, the certainty that the driver can visually recognize the index image can be improved.

<Display switching process>
Next, FIG. 12 is a flowchart illustrating details of display switching processing (second embodiment) executed by the CPU of the control unit 10. In this process, a frequency division counter that counts the frequency division value so that the display period of the index image is constant is used. Further, the frequency division counter is initialized to zero when this processing is started.

  First, when this process is started, in S510, it is determined whether or not the inter-vehicle distance acquired in S110 of the display control process is less than the safe inter-vehicle distance set in S130 of the display control process. If an affirmative determination is made, the process proceeds to S520, and if a negative determination is made, the process proceeds to S560.

  In S520, based on the difference (change amount) between the previous value and the current value of the relative speed calculated in S120 of the display control process, it is determined whether or not the change amount exceeds zero. Therefore, it is considered that the preceding vehicle is approaching the host vehicle with acceleration, and the process proceeds to S530. If a negative determination is made, the process proceeds to S560.

In S530, the frequency division value of the frequency division counter is incremented, and the flow proceeds to S540.
In S540, it is determined whether or not the frequency division value of the frequency division counter is equal to or smaller than a preset reference value N. If an affirmative determination is made here, the process proceeds to S550, and if a negative determination is made, the process proceeds to S560. .

  In S550, the index image set in the display setting process is displayed through the image device 8 and the pixel light 7 according to the display mode set in the display setting process, and the process ends.

In S560, a control command for hiding the index image is output to the image device 8 and the pixel light 7, and the process proceeds to S570.
In S570, the frequency division value of the frequency division counter is initialized to zero, and this process is terminated.

  That is, in this process, as shown in FIG. 13, for example, when the process repetition period is 400 ms and the reference value N of the frequency dividing counter is 5, the actual inter-vehicle distance is less than the safe inter-vehicle distance, and the preceding vehicle is When it is determined that the host vehicle is approaching with acceleration, the index image is displayed for 2 seconds (400 ms × 5) from the determination.

  For this reason, for example, when the preceding vehicle is approaching, the host vehicle is decelerated by displaying the index image indicating the safe inter-vehicle distance for a certain period only when the approach speed changes so as to increase. The driver can be informed of the high necessity.

This process corresponds to the first switching means.
[Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it is possible to implement in various aspects.

  For example, the in-vehicle display device 1 of the above embodiment is configured such that the control unit 10 executes the display switching process. However, this process is not necessarily required, and the index image set by the display setting process is displayed. It may be configured to always display.

  In the display setting process of the above embodiment, the index image is displayed even when the actual inter-vehicle distance is less than the safe inter-vehicle distance. However, the present invention is not limited to this, and the actual inter-vehicle distance is safe. The index image may be displayed only when the distance is greater than the inter-vehicle distance.

  Furthermore, in the display setting process of the above embodiment, when the operation signal from the wiper device 13 is input, it is considered that the host vehicle is traveling in the rain. However, the present invention is not limited to this. For example, a well-known rain sensor Alternatively, the traveling environment (weather) of the host vehicle may be specified based on the detection result from the humidity sensor.

  The display control process of the above embodiment starts when the power source of the in-vehicle display device 1 is turned on via the IG switch 14 or the main body switch 5, but is not limited to this, for example, lighting of the headlight 6 It may be activated when it is detected.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle-mounted display apparatus, 2 ... Vehicle speed sensor, 3 ... Radar apparatus, 4 ... Vehicle-mounted camera, 5 ... Main body switch, 6 ... Headlight, 7 ... Pixel light, 8 ... Image device, 10 ... Control part, 11 ... Navigation apparatus , 12 ... voice recognition device, 13 ... wiper device, 14 ... IG switch.

Claims (4)

Projecting means for projecting illumination light on the road surface in front of the host vehicle;
An image display means for displaying an index image representing a safe inter-vehicle distance set in advance as the inter-vehicle distance required for the preceding vehicle in the projection area on the road surface via the projection means ;
Distance detecting means for detecting an inter-vehicle distance between the host vehicle and the preceding vehicle;
Display control means for changing the display form of the index image by the image display means based on the inter-vehicle distance detected by the distance detection means;
Own vehicle speed detecting means for detecting the speed of the own vehicle;
A relative speed calculating means for calculating a relative speed between the host vehicle and the preceding vehicle based on the inter-vehicle distance detected by the distance detecting means;
Distance setting means for setting the safe inter-vehicle distance based on the speed detected by the own vehicle speed detecting means and the relative speed calculated by the relative speed calculating means;
First switching means for permitting or prohibiting display of the index image by the image display means based on the inter-vehicle distance detected by the distance detection means;
With
The first switching means is configured to cause the preceding vehicle to move based on the amount of change in the relative speed calculated by the relative speed calculation means when the inter-vehicle distance detected by the distance detection means is less than the safe inter-vehicle distance. The image display is performed only when it is determined that the vehicle is approaching with acceleration and the condition is satisfied, and the condition is satisfied and a certain period has not elapsed since the satisfaction condition was satisfied. A vehicle-mounted display device that permits display of the index image by means. Comprising environment acquisition means for acquiring the traveling environment of the host vehicle,
The display control means changes the display position of the index image to the side approaching the host vehicle when the traveling environment acquired by the environment acquisition means indicates any of rainy weather, urban area, or mountain road. The on-vehicle display device according to claim 1 . The display control means moves and displays the index image from the preceding vehicle side toward the host vehicle side on the road surface when the inter-vehicle distance detected by the distance detection means is less than the safe inter-vehicle distance. The in-vehicle display device according to claim 1 or 2, wherein Comprising voice recognition means for recognizing the voice spoken by the driver;
Based on the recognized speech by the voice recognition means, of claims 1 to 3, characterized in that it comprises a second switching means for performing a permission or prohibition display of the index image by said image display means The vehicle-mounted display apparatus in any one.