JPH01188178A - Picture information display device for vehicle - Google Patents

Abstract

PURPOSE:To securely prevent fascination dute the head lamp of a following vehicle, for example, by correcting a video signal to correspond to a specified area, which has luminance to be higher over a prescribed level than the luminance to be obtained by surrounding picture information. CONSTITUTION:A display 5 inputs a fascination preventing circuit output 3a from a fascination preventing circuit 3, namely, the video signal to correct a signal, which corresponds to the scenery of the luminance to be higher than the luminance of the surrounding scenery by a prescribed level, and on the basis of this inputted video signal, the scenery in a back direction of a vehicle, for example, the image of the following vehicle, etc., is displayed. When the fascination preventing circuit output 3a from the fascination preventing circuit 3 is inputted, a diaphragm adjusting circuit 7 sends a signal, which adjusts the quantity of diaphragm, to a supervising camera 1 on the basis of this inputted fascination preventing circuit output 3a. For the supervising camera 1, a diaphragm mechanism is provided to adjust the quantity of an incoming light and on the basis of the signal from the diaphragm adjusting circuit 7, the diaphragm mechanism is operated. Then, the quantity of the incoming light is adjusted. Thus, the fascination due to the head lamp of the following vehicle is prevented.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to an image information display device for a vehicle that reliably monitors the landscape behind a vehicle, such as the driving conditions of a following vehicle, etc. It is something.

(Prior Art) In recent years, various so-called image information display devices for vehicles have been proposed, in which a surveillance camera is installed in the rear of the vehicle to monitor the scenery behind the vehicle. -132224).

In such a conventional vehicle image information display device,
Video signals from a surveillance camera installed at the rear of the car are input to a display to display the scenery behind the car. In addition, the video signal from the above-mentioned surveillance camera is usually input to a throttle WA adjustment circuit, which executes throttle adjustment according to the brightness of the scenery behind the car based on this video signal, and adjusts the M of the light incident on the surveillance camera. I'm trying to adjust it.

(Problems to be Solved by the Invention) However, especially when driving at night, when strong light from the headlights of a following vehicle enters the surveillance camera, a video signal of this strong light is input to the display. Among the images projected on the display, the headlights of the following vehicles were brighter than the surrounding scenery, so this particularly bright light caused dazzling, causing problems in which the image on the display was difficult to see.

Therefore, if you increase the amount of throttle in the throttle adjustment circuit depending on the brightness of particularly strong light such as headlamps, the amount of light that enters the surveillance camera will be adjusted to decrease overall, so the display will Although the projected image of the headlights became easier to see, a new problem arose: the images of surrounding areas other than the headlights became too dark, making it impossible to reliably detect vehicles behind.

The present invention has been made in view of the above-mentioned problems, and is an image information display device for a vehicle that is capable of reliably and accurately capturing a following vehicle by preventing dazzling caused by the headlights of a following vehicle even when driving at night. The purpose is to provide

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides an image information display device for a vehicle that displays image information regarding the traveling route and the following vehicle. , a comparison means for comparing a signal value of the image information with a preset reference value, and a comparison means for setting the signal value of a specific area having a signal value exceeding the reference value to a predetermined value; and a correction means for correcting the brightness of a high brightness area.

(Function) In the image information display device for a vehicle according to the present invention, when the comparing means detects that the signal value of the image information regarding the running route and the running of the following vehicle, etc. is larger than a preset reference value. The correction means sets the signal value of the specific area having the large signal value, that is, the high brightness area, to a predetermined value to perform brightness correction.

(Example) Hereinafter, an example according to the present invention will be described in detail with reference to the drawings.

First, the configuration will be explained with reference to FIG. 1, FIG. 2, and FIGS. 4(A) and (B). A surveillance camera 1 is installed in a rear part of a vehicle inside a window glass 2 and facing rearward, and transmits video information of scenery behind the vehicle, such as a following vehicle. This surveillance camera 1 is connected to an anti-dazzle circuit 3, and the surveillance camera 1 sends video information regarding scenery such as a following vehicle to the anti-dazzle circuit 3.

When the anti-dazzle circuit 3 receives a video signal from the surveillance camera 1, it includes a correction means for correcting a video signal corresponding to a landscape whose brightness is higher than the brightness of the surrounding landscape by a predetermined level or more, among the input video signals. We are prepared. For example, among video signals of a following vehicle, a video signal of a portion where the brightness of a headlamp or the like is particularly high is corrected to approximately the same signal level as the surrounding video signal. This anti-dazzle circuit 3 is connected to a battery power source E via a switch SW1 that operates in conjunction with a switch (not shown) for turning on the headlights of the own vehicle. Therefore, switch SW1
sends switch information 21a indicating that the headlamp has been turned on to the anti-dazzle circuit 3. Further, the anti-dazzle circuit 3 is connected to each of the display 5 and the aperture adjustment circuit 7, and the anti-dazzle circuit 3 sends an anti-dazzle circuit output 3a to the display 5 and the aperture adjustment circuit 7. The display device 5 inputs a video signal corrected for a signal corresponding to a landscape whose brightness is higher than the brightness of the surrounding fence by a predetermined level or more, as described above, from the anti-dazzle circuit output 3a1 from the anti-dazzle circuit 3. Based on this input video signal, the scenery behind the car, for example, an image of a following heavy vehicle, etc., is displayed.

When the aperture adjustment circuit 7 inputs the anti-dazzle circuit output 3a from the anti-dazzle circuit 3, the human-powered anti-dazzle circuit output 3a1. : Sends a signal to the surveillance camera 1 to adjust the amount of squeezing based on the amount of squeezing.

The surveillance camera 1 is provided with an aperture mechanism for adjusting the amount of light incident through the lens, and the aperture mechanism operates based on a signal from the aforesaid aperture adjustment circuit 7.
The amount of incident light is adjusted.

Next, the internal configuration of the anti-dazzle circuit 3 will be explained.

The differentiating circuit 11 and the delay circuit 13 are connected to the surveillance camera 1, and each of the differentiating circuit 11 and the delay circuit 13 receives the video signal 1a from the surveillance camera 1. The differentiating circuit 11 is formed of, for example, a capacitor and a resistor, and when it receives a video signal 1a as shown in FIG. Send. The level shift circuit 15 is connected to the differentiation circuit 11, and when the level shift circuit 15 receives the differentiated signal 11a from the differentiation circuit 11, it shifts the entire signal level of the signal 11a, as shown in FIG. The shifted differential output 15a is sent out.

Further, the level shift circuit 15 is connected to the comparison circuit 17 and sends the above-mentioned shifted differential output 15a to the comparison circuit 17. The comparison circuit 17 includes, for example, an operational amplifier;
It is formed by a reference value signal generation circuit etc. for sending a reference value signal of a predetermined level to the reference input terminal of this operational amplifier, and a differential output 15a from the level shift circuit 15.
is input to the comparison input terminal of the operational amplifier mentioned above. Therefore, when the comparator circuit 17 receives the differential output 15a, it compares the differential output 15a with the reference value of the predetermined level described above, and sends out a signal as a result of the comparison, that is, a comparison output 17a. The pulse expansion circuit 19 is connected to the comparison circuit 17, and receives a comparison output 17a from the comparison circuit 17.

This pulse extension circuit 19 has a built-in one-shot circuit formed by, for example, a multivibrator, and when a comparison output 17a which is a pulse signal is input, a pulse with a pulse width longer than the pulse width of the input comparison output is generated. A signal 19a is sent out. The switching circuit 21 is connected to the pulse extension circuit 19, and the above-mentioned pulse signal '19
Enter a. This switching circuit 21 is connected to each of the delay circuit 13 and the hold circuit 23. When the delay circuit 13 receives the video signal 1a from the surveillance camera 1, it sends a signal obtained by delaying the input video signal 1a by a predetermined time, that is, a delayed output 13a, to the switching circuit 21. When the hold circuit 23 receives the signal 21b from the switching circuit 21, it holds the input signal 21b and sends the held signal 23b back to the switching circuit 21.

The switching circuit 21 incorporates a plurality of switching means, executes signal switching between the delay output 13a and the hold output 23b, and sends out the signal resulting from this switching as the anti-dazzle circuit output 3a.

Next, the internal structure of the switching circuit 21 will be explained in detail with reference to FIG.

As shown in FIG. 2, the switching circuit 21 is composed of an AND circuit G and two switching means SW3 and SW5. One input terminal of the AND circuit G is the switch S
W+, and inputs switching information 21a indicating that the switch SW+ has been operated. Further, the other input terminal of the AND circuit G is connected to the pulse expansion circuit 19, and receives the pulse signal 19a. The output terminal of the AND circuit G is connected to each of the switching means SW3 and SW5, and the AND output of the AND circuit G controls the switching operations of the switching means SW3 and SW5. The movable contact S3 of the switching means SW3 is connected to the display 5 and the throttle adjustment circuit 7, respectively. Further, the fixed setting S1 of the switching means SW3 is connected to the movable contact S5 of the switching means SW5.

Further, the fixed contact S2 of the switching means SW3 is connected to the output terminal of the hold circuit 23.

Furthermore, the movable contact SW5 of the switching means SWs is connected to the delay circuit 13. Moreover, the switching means S
The fixed contact S7 of Ws is connected to the input terminal of the bold circuit 23.

Next, the control operation of the switching means SW3.8W5 based on the AND output of the AND circuit G will be explained.

Figure 2 shows the state when an L-level AND output is sent out from the AND circuit G. The delayed output 13a from the delay circuit 13 is sent out as the anti-dazzle circuit output 3a via the fixed contact S1 and the movable contact S3 of the switching means SW3. Also,
When an H-level AND output is sent from the AND circuit G, the switching means SW3 and SW5 are switched off at the same time. That is, the movable contact S3 of the switching means SW3 is switched from the fixed contact SI to the fixed contact S2. Further, the movable contact S5 of the switching means SWs is the fixed contact S
7 to fixed contact S6. As a result, delay circuit 1
The delay output 13a from the hold circuit 23 is prohibited from being sent to the display 5, and the hold output 23b from the hold circuit 23 is prohibited.
is sent out as the anti-dazzle circuit output 3a via the fixed contact S2 and the movable contact S3 of the switching means SW3.

Next, the operation of the embodiment according to the present invention will be explained with reference to FIG.

First, the operation during daytime will be explained. A surveillance camera 1 attached to the rear of a vehicle sends a video signal 1a of a scene behind the vehicle, for example, a following vehicle, to a delay circuit 13. When the delay circuit 13 receives the video signal 1a, it sends a signal delayed by a predetermined time, that is, a delayed output 13a, to the switching circuit 21. On the other hand, the switch SWI is set to the open state in order to prohibit the lighting of the headlamps during the daytime. Therefore, one input terminal of the AND circuit G receives switching information 21 from the switch S W t.
Since a is not input, the AND circuit G sends out an L-level AND output. Therefore, switching circuit 2
Two switching means SW3 and SW built in 1
5 is set to the state shown in FIG. As a result, the delayed output 13a from the delay circuit 13 is directly used as the anti-dazzle circuit output 3a for the display 5 and the aperture adjustment circuit 7.
sent to. When the display device 5 receives the anti-dazzle circuit output 3a, it displays the scenery behind the car, for example, an image of a following vehicle, based on the input anti-dazzle circuit output 3a1, that is, a signal obtained by delaying the video signal 1a by a predetermined time. do. Further, when the aforementioned anti-dazzle circuit output 3a is inputted to the aperture adjustment circuit 7, the aperture adjustment of the surveillance camera 1 is performed based on the anti-dazzle circuit output 3a, and the amount of light incident on the surveillance camera 1 is adjusted.

Next, the operation at night will be explained.

When driving at night, if switch SW+ is closed to turn on the headlamp, switch SW
1 is closed, that is, H-level switching information 21a is sent to one input terminal of the AND circuit G. Furthermore, when the surveillance camera 1 captures an image of a following vehicle driving with its headlights on and sends out a video signal 1a as shown in FIG. given to each.

Among the video signals 1a shown in FIG. 3, the signals 1b and 1C are signals that are caused by the headlights of the following vehicle. Furthermore, as shown in FIG. 3, the surveillance camera 1 inserts a negative pulse horizontal synchronization signal at predetermined intervals into the video signal 1a. Such a video signal 1a
is differentiated by the differentiating circuit 11, and then the level shift circuit 15
is shifted. That is, as shown in FIG. 3, a level shift is performed such that the lowest level of the differentiated horizontal synchronizing signal is set to O volts.

Subsequently, the comparison circuit 17 compares the level of the reference value with the level of the level-shifted differential output 15a described above.

Here, as shown in FIG. 3, the level of the reference value is set to a value higher than the average level L of the differential output 15a and lower than the prominent signal level L2 caused by the headlamp or the like.

The operation when peripheral differential outputs 15a other than the first signal, that is, the prominent signal 1b from the headlamp, is input among the differential outputs 15a shown in FIG. 3 will be described.

When the comparison circuit 17 receives the differential output 15a, it compares the level L+ of the differential output 15a with a reference value set to a value larger than this level L1, and sends the L level comparison output 17a to the pulse expansion circuit 19. do. When the pulse extension circuit 19 receives the L level comparison output 17a, the L level
The level signal 19a is sent to the switching circuit 21. When the switching circuit 21 receives the L level signal 19a,
As shown in FIG. 2, the delay output 13a from the delay circuit 13
is directly sent to the display 5 and the aperture adjustment circuit 7 as the anti-dazzle circuit output 3a.

In the switching circuit 21, as shown in FIG. 2, the movable contact S5 of the switching means SW5 is connected to the fixed contact S7, and the delayed output 13a from the delay circuit 13 is held via the movable contact S5 and the fixed contact S7. It is output to the circuit 23. The hold circuit 23 holds the delayed output 13a from the delay circuit 13.

Next, as shown in FIG. 3, when the comparator circuit 17 inputs the signal 1b or 1C of the outstanding level L2 from the headlamp, the comparator circuit 17 receives the signal corresponding to the headlamp, that is, the outstanding level L2 above the level of the reference value. Differential output 1 of
5a, the comparison output 17a becomes H level only while the prominent signal corresponding to this headlamp continues.
is sent to the pulse expansion circuit 19. Pulse expansion circuit 19
When the comparison output 17a, which is a pulse signal, is input, the third
As shown by the dotted line in the figure, the pulse width of the comparison output 17a is expanded, and a pulse output 19a having a wider pulse width than the pulse width of the comparison output 17a is sent to the switching circuit 21. In the switching circuit 21, as shown in FIG.
When a high level pulse output 19a is input, only for a period corresponding to the H level signal duration of this pulse output 19a,
Switching means SW3 and S
Send to Ws. When the switching means SW3 and SW5 receive the H level signal from the AND circuit G, they each perform a switching operation, and the movable contact S3 of the switching means SW3 is switched from the fixed contact S1 to the fixed contact S2. Further, the movable contact S5 of the switching means SW5 is switched from the fixed contact S7 to S6. Therefore, the delayed output from the delay circuit 13, that is, the transmission of the high level L2 signal from the headlamp is prohibited. At this time, the hold circuit 23 also has the previous differentiated output, that is, the low level L.
The differential output 15a is held, and the movable contact S
3 switches from fixed contact S1 to 82,
Hold output 2 held in this hold circuit 23
3b is sent to the display 5 and the aperture adjustment circuit 7 as the anti-dazzling circuit output 3a via the fixed contact S2 and the movable contact S3. Therefore, the display device 5 is provided with an anti-dazzle circuit output 3a in which the high level signal from the headlamp is corrected to the same level as the surrounding signal level. Therefore, the display 5 displays an image of the following vehicle with only the headlamp image corrected. In addition, since the aperture adjustment circuit 7 inputs the dazzling circuit output 3a in which the high level signal from the headlamp has been corrected, the high level signal from the headlamp is input to the anti-dazzle circuit output 3a. Based on this, the aperture adjustment of the surveillance camera 1 is appropriately performed, and the amount of light incident on the surveillance camera 1 is appropriately adjusted.

Note that if the delay time in the delay circuit 13 is set appropriately, for example, if it is set to a time longer than the H level duration time of the H level comparison output 17a sent from the comparison circuit 17, the high level signal from the headlamp and the It is also possible to appropriately correct signals prior to such high level signals.

Furthermore, since the H level signal duration of the H level comparison output 17a from the comparator circuit 17 is extended by the pulse extension circuit 19a, the subsequent signal following a high level signal from a headlamp etc. can be adjusted appropriately. can be corrected to prevent dazzling even more reliably.

Further, the surveillance camera 1 may be constructed using a surveillance camera that transmits a video signal of a color signal.

In this way, when a surveillance camera that sends out combined color signals is used as the surveillance camera 1, a low-pass filter for removing the color signals may be inserted between the differentiating circuit 11 and the surveillance camera. good.

[Effects of the Invention] As explained above, according to the present invention, since the video signal corresponding to a specific area having a luminance higher than the luminance of the surrounding image information by more than a predetermined level is corrected, For example, it is possible to reliably prevent dazzling caused by the headlights of a following vehicle, and therefore it is possible to comfortably and accurately capture the condition of the following vehicle, thereby allowing safer driving.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing the internal configuration of the switching circuit shown in FIG. 1, and FIG. 3 is a signal waveform diagram of each part of FIG. Figure 4 (A> is the first
FIG. 4 is an explanatory diagram of a vehicle in which the embodiment shown in the figure is installed (
8) is an explanatory diagram showing an enlarged view of the light frame portion of FIG. 4(A). 1... Surveillance camera 3... Anti-dazzle circuit 5.
・・Display device 7・・1 squeeze adjustment circuit・
...Differentiating circuit 13...Delay circuit 15...Level shift circuit

Claims (2)

[Claims] (1) In a vehicular image information display device that displays image information regarding the traveling route and the driving of a following vehicle, etc., a comparison means for comparing a signal value of the image information with a preset reference value; and the reference value. a correction means for correcting the brightness of a high-brightness area of the image information by setting the signal value of a specific area having a signal value exceeding the above to a predetermined value. Device. (2) The image information display device for a vehicle according to claim 1, wherein the correction means includes a widening means for widening the area where the brightness correction is performed.