JPH0939658A - Vehicle rearward monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately seize a distance up to an obstacle in the rear of a vehicle with a simple constitution without using a complicated operation device and an image processing device and without dazzling eyes of a person staying in the rear of the vehicle and a person of the other vehicle. SOLUTION: Two infrared light beams 20 and 22 are emitted in the rearward horizontal direction from rear left and right positions of a vehicle 10 so as to cross each other midway. An image in the vicinity of a position P where both beams 20 and 22 cross each other is picked up by an infrared ray sensitive telecamera 26 arranged in a rear part of the vehicle 10, and is displayed on a television monitor 28 in front of a driver's seat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle rear monitoring device for confirming the presence of obstacles and the like behind the vehicle,
This is a simple structure that allows the distance to an obstacle to be accurately grasped.

[0002]

2. Description of the Related Art Various devices have been proposed for informing a driver of the presence of obstacles or the like behind a vehicle when the vehicle moves backwards such as in a garage. One that has been put into practical use is, for example, a back sonar using ultrasonic waves. This is because the ultrasonic oscillator and the ultrasonic receiver are embedded in the rear bumper, etc., the ultrasonic wave is transmitted from the ultrasonic oscillator toward the rear of the vehicle, the reflected wave is received by the ultrasonic receiver, and these ultrasonic waves are emitted. The distance to the obstacle is measured from the reception time difference, and an alarm is issued when the distance exceeds a certain distance.
Further, there has been proposed a device in which the measured distance is displayed in the inner mirror (Japanese Patent Publication No. 4-25174).

As another one, a back sonar using the above-mentioned ultrasonic waves and a television camera are used together, and an image of the rear of the vehicle is taken by the television camera and disposed on the instrument panel in front of the driver's seat. The image is displayed on a TV monitor, and the information on the distance to the obstacle measured by the back sonar is superposed on a part of the TV monitor (JP-A-59-120877).
Was proposed.

Further, as another example, a bright spot matrix formed by a plurality of laser beams is projected in a square lattice pattern from the rear of the vehicle toward the ground diagonally below and rearward of the vehicle, the projected portion is imaged by a television camera, and the laser is projected by the laser. The movement of the bright spot matrix when light is projected on the obstacle is obtained by image processing to detect the presence of the obstacle, and the position and shape of the obstacle obtained by the image processing are three-dimensionally displayed on the TV monitor. A display device (Japanese Patent Laid-Open No. 5-201298) has been proposed.

[0005]

In the back sonar using the ultrasonic waves, the accuracy of detecting the distance is low depending on the shape and position of the obstacle, and the vehicle is moved backward to the position closest to the obstacle and stopped. In some cases it was not useful to get them to do it.
In addition, a calculation device for calculating the distance is required, which is expensive. Also, in the case of using a back sonar using ultrasonic waves and a TV camera together, a computing device for calculating the distance and a superimpose image for displaying the calculated distance information on the TV monitor in a superimpose manner. A production and display controller was required and again expensive. Further, in the case of using the bright spot matrix by the laser light, a light projecting device for emitting the laser light and a complicated image processing device are required, which is large and expensive. Further, since the laser light is used, there is a risk that the laser light may enter the eyes of a person behind the vehicle or a person of another vehicle to dazzle or cause a danger.

The present invention solves the problems in the prior art as described above, and eliminates the need for a complicated arithmetic unit or an image processing device, and for the eyes of a person behind the vehicle or a person of another vehicle. An object of the present invention is to provide a vehicle rear monitoring device that can accurately grasp the distance to an obstacle behind the vehicle with a simple configuration without dazzling.

[0007]

SUMMARY OF THE INVENTION According to the present invention, one or a plurality of infrared light beams emitted from an infrared light emitting diode are made into substantially parallel rays by a lens or a reflecting mirror, respectively. The image is emitted approximately horizontally or diagonally downward toward the rear of the vehicle, and an image near the position immediately behind the vehicle, through which this infrared light beam passes, is captured by an infrared-sensitive television camera located at the rear of the vehicle, and the image is captured. Is displayed on a television monitor arranged in the vehicle compartment.

According to this, when the substantially parallel infrared light beam hits an obstacle, a beam spot is formed. Since this beam spot is infrared light, it cannot be seen directly by human eyes, but it can be captured by an infrared light sensitive television camera, and its image is displayed on a television monitor. Then, when the vehicle moves back and forth, the position of the beam spot moves on the TV monitor and the intervals of the plurality of beam spots change, so the distance to the obstacle can be accurately grasped by observing the state. You can and safely retreat. Therefore, since a complicated arithmetic unit and an image processing unit are unnecessary, the structure can be easily and inexpensively constructed. In addition, since the infrared light beam is used, it is not directly visible to human eyes and does not dazzle the eyes of the person behind the vehicle or the persons of other vehicles.

As a specific arrangement pattern for arranging a plurality of infrared light beams, for example, the infrared light beams can be emitted from the rear portion of the vehicle toward the rear of the vehicle non-parallel to each other. In this way, when these multiple infrared light beams are projected onto the obstacle, the distance between the beam spots changes according to the distance to the obstacle, so the beam spot distance can be viewed on the TV monitor. Thus, the distance to the obstacle can be easily known. In particular, if the two infrared light beams are emitted non-parallel to each other in a direction in which they approach each other, and if these two infrared light beams are arranged so as to intersect or come closest to each other near the position immediately behind the vehicle, the two infrared light beams The vehicle can be safely retracted to a position where the beam spots intersect or are closest to each other, and the driver can easily make a judgment. In this case, by shaping the cross-sectional shapes of the two infrared light beams into mutually opposite arrows or triangles using an optical mask, the arrows or triangles of the two beam spots are demarcated at the position where both beams are closest. Since the orientation changes between the face-to-face state and the back-to-back state, it is possible to easily know whether the crossing or the closest position has passed.

As another arrangement pattern for arranging a plurality of infrared light beams, the infrared light beams can be emitted from the rear portion of the vehicle toward the ground at a position at a different distance from the vehicle obliquely below and behind the vehicle. With this configuration, it is possible to know the distance to the obstacle by observing on the television monitor which one of the plurality of infrared light beams hits the obstacle.

If a lens or a reflecting mirror for converting the infrared light beam into parallel light can be moved relative to the light emitting diode in the direction of its optical axis, the light from the light emitting diode will be non-parallel light. Since it can be diverged to illuminate a wide range, it can be used as illumination for a television camera, and the distance measuring function to an obstacle and the visual recognition function of the rear visual field can be switched and used. In this case, when an optical mask is arranged to make the cross section of the infrared light beam into an arrow or a triangle, the optical mask is retracted from the optical axis of the infrared light emitting diode when the rear visual field is visually recognized. .

[0012]

Embodiments of the present invention will be described below. (Embodiment 1) FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 shows an outline, and an infrared light beam emitting portion 14 is formed at a position which is apart from each other on the left and right sides of a rear bumper 12 of a vehicle 10 at substantially the same height.
Infrared beam emitting devices 16 and 18 are embedded and arranged. From the infrared beam emitting devices 16 and 18, the infrared light beams 20 and 22 emitted from the infrared light emitting diode and made into substantially parallel rays by a lens or a reflecting mirror are directed toward the vehicle rearward horizontal direction to approach each other. Are emitted non-parallel. These two infrared light beams 20, 22
Crosses at a vehicle width direction central position P near a position immediately after the vehicle rear (for example, a position within 50 cm behind the rearmost portion of the vehicle).

An infrared light-sensitive television camera 26, which is a CCD camera, is fixedly installed at a central position in the vehicle width direction above the rear door 24 of the vehicle 10 so as to face obliquely downward and rearward of the vehicle. This television camera 26 has two infrared light beams 2
A position P where 0 and 22 intersect is set as a substantially central position of the visual field, and an image of the surrounding is picked up. The image captured by the television camera 26 is displayed on the television monitor 28 provided on the instrument panel or the like in front of the driver's seat.

The structure of the infrared light beam emitting device 16 on the left side is shown in FIG. (A) is a longitudinal cross-sectional view thereof, (b) is a front view showing a mask pattern of an optical mask in a view taken along arrow A of (a),
(C) is a BB cross-sectional view of (a) showing a cross-sectional shape of the infrared light beam 20. The infrared light beam emitting device 18 on the right side has the same structure, but the mask pattern of the optical mask and the cross-sectional shape of the infrared light beam 22 are shown in FIG.
The arrow is opposite in direction to (c).

In the infrared light beam emitting device 16 of FIG. 2, an infrared light emitting diode 32 is fixedly arranged in a case 30. A lens (convex lens) 36 is disposed in front of the infrared light emitting diode 32 on the optical axis 34 and supported by a support member 38. A screw 40 is screwed into the support member 38. The screw 40 accommodates a motor, a speed reducer, etc., and is fixedly arranged in the case 30.
The lens 36 is driven to rotate by 0, so that the lens 36 is moved along the optical axis 34 of the infrared light emitting diode 32 by an arrow CC ′.
Move in the direction.

Limit switches 42 and 44 are fixedly disposed on the side of the support member 38. Limit switch 4
When the lens 36 is in the position where the lens 36 makes the infrared light beam 20 ″ generated from the infrared light emitting diode 32 parallel, the operating piece 42 a comes into contact with the side surface 38 a of the supporting member 38 to operate, and the lens 2 is in that position. The limit switch 44 is provided on the side surface 38a of the support member 38 when the lens 36 is positioned to diverge the infrared light beam 20 ″ emitted from the infrared light emitting diode 32 at a predetermined angle.
Abut and operate to detect that the position is present.

An optical mask 4 is provided in front of the lens 36 on the optical axis.
6 are provided. The optical mask 46 is shown in FIG.
As shown in the front view in FIG. 2, an arrow-shaped light transmitting portion 48 is formed, and the infrared light beam 20 'made into a parallel light beam through the lens 36 is cross-section arrowed as shown in FIG. 2 (c). The shaped infrared light beam 20 is shaped and emitted from a window 74 made of glass, plastic, or the like. The optical mask 46 is a support member 50.
Supported by. The supporting member 50 is rotated by an optical mask driving device 52 that houses a motor, a speed reducer and the like and is fixedly arranged in the case 30, as shown by D-D 'in FIG. It is displaced to a state in which it is positioned on the optical axis 34 of 32 and a state 46 'which is retracted from the optical axis 34.

Limit switches 54 and 56 are fixedly disposed near the support member 50. When the optical mask 46 is on the optical axis 34 of the infrared light emitting diode 32, the limit switch 54 comes into contact with the side surface 50a of the support member 50 to operate, and detects that the position is in that position. In the limit switch 56, the optical mask 46 is the infrared light emitting diode 3
It operates when it is at a position 46 'retracted from the second optical axis 34, and detects that it is at that position.

An example of a control device for controlling the operations of the lens driving device 70 and the optical mask driving device 52 of FIG. 2 is shown in FIG.
Shown in On the instrument panel in front of the driver's seat,
A distance measurement mode switch 60 and an illumination mode switch 62 are provided as operation mode changeover switches 58 for changing over the operation modes of the infrared light beam emitting devices 16 and 18. One of these switches 60 and 62 is selectively turned on. The control circuit 64 inputs the operation mode command output from the operation mode changeover switch 58, and the lens 3 detected by the limit switches 42 and 44.
6 and the position of the optical mask 46 detected by the limit switches 54 and 56, the driver 6
The lens driving device 70 and the optical mask driving device 52 are driven via 6, 68.

That is, when the distance measuring mode switch 60 is turned on, the lens driving device 70 is driven until the limit switch 42 is turned on, and the infrared light 20 ″ emitted from the infrared light emitting diode 32 is collimated. The lens 36 is moved to the position where the limit switch 54 is turned on.
The optical mask driving device 52 is driven until is turned on to move the optical mask 46 onto the optical axis 34 of the infrared light emitting diode. Further, when the illumination mode switch 62 is turned on, the lens driving device 70 is driven until the limit switch 44 is turned on, and the infrared light 20 ″ emitted from the infrared light emitting diode 32 is diverged at a predetermined divergence angle. The lens 36 is moved to a position where it becomes a light beam, and at the same time, the optical mask driving device 52 is driven until the limit switch 56 is turned on to move the optical mask 46 to the optical axis 34 of the infrared light emitting diode.
Evacuate from above.

The operation in the distance measuring mode is shown in FIG. FIG.
Shows the positional relationship between the vehicle 10 and the obstacle 72 (plan view) and the image displayed on the screen of the television monitor 28 at that time. Here, the position P where the two infrared light beams 20 and 22 cross each other is set to 5 from the rearmost portion 10a of the vehicle 10 to the rear.
The position is set to 0 cm. When the infrared light beams 20 and 22 are projected onto the obstacle 72 (wall or the like), the beam spots 20a and 22a are projected on the television monitor 28 as bright spots. Since the infrared light beams 20 and 22 are condensed into parallel rays by the lens 36, the intensity thereof is strong, and the beam spots 20a and 22b are displayed as sufficiently distinguishable bright spots on the television monitor 28 even in the daytime.

FIG. 4A shows the rearmost portion 10a of the vehicle and the obstacle 7.
When the distance from 2 is 1 m, the beam spots 20a, 2a
Since 2a can be located ahead of the point P where both beams 20 and 22 intersect, the images of the beam spots 20a and 22a are such that the arrows face each other. When the vehicle 10 moves backward from this state, the beam spot 2 on the screen
The distance d of 0a and 22a gradually approaches. And
When the distance between the rear part 10a of the vehicle and the obstacle 72 reaches about 50 cm, both beam spots 20a, 20a, as shown in FIG.
22a is in a state of being almost overlapped. When the vehicle 10 is further retracted, as shown in FIG.
0a and 22a are exchanged, the arrows are back to back,
The distance d between the two arrows gradually increases. In this way, the vehicle can be stopped at a desired distance from the obstacle 72 by moving backward while watching the directions of the beam spots 20a and 22a and the distance d between them on the screen 28. By displaying the distance scale on the screen of the TV monitor 28, the accurate distance between the rearmost part 10a of the vehicle and the obstacle 72 can be known in comparison with the distance d between the two arrows.

The operation in the illumination mode is shown in FIG. In the illumination mode, as shown in FIG. 5A, the lens 36 approaches the infrared light emitting diode 32 and the infrared light emitting diode 32
The infrared light 20 ″ (22 ″) emitted from the light source becomes a divergent infrared light ray 20 ′ ″ (20 ′ ″). In addition, the optical mask 46
Is retracted from the optical axis 34 of the infrared light emitting diode 32 to a position where the divergent infrared rays 20 '''(22''') are not blocked. As a result, the divergent infrared rays 20 ′ ″ (22 ′ ″) pass through the window 74 as they are and are emitted to the rear of the vehicle. FIG. 5B is a plan view showing a state in the illumination mode, in which the divergent infrared rays 20 ′ ″ and 22 ′ ″ illuminate the rear of the vehicle 10 widely,
An image of the illumination range can be captured by the infrared light sensitive television camera 26 and displayed on the television monitor 28. As a result, the lower rear part of the vehicle can be viewed through the TV monitor 28 even at night.

In this embodiment, the infrared light sensitive television camera 26 is arranged at the upper position of the rear part of the vehicle and its optical axis is arranged obliquely downward and rearward of the vehicle. (The same height position as the beam emitting part 14)
It is also possible to arrange the optical axis so that the optical axis thereof is oriented substantially horizontally toward the rear of the vehicle.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIGS. 6 to 9. FIG. 6 shows an outline thereof, and a large number of infrared light beam emitting portions 76 (in this example, 9
(Individual) infrared light beam emitting devices 81 to 89 are embedded and arranged in a grid pattern. Each infrared light beam emitting device 81
From -89, infrared light beams 91 to 99 having a substantially circular cross section, which are emitted from the infrared light emitting diode and are made into substantially parallel rays by the lens or the reflecting mirror, are emitted toward the lower rear direction of the vehicle. Of these, the upper infrared light beams 91, 92,
The emission angle θ1 of 93 is shallow, and the light is projected onto the ground 100 at a point approximately 1 m behind the rearmost part 10a of the vehicle, forming beam spots 91a, 92a, 93a in a horizontal row. The emission angle θ2 of the middle-stage infrared light beams 94, 95, 96 is deeper than the emission angle θ1 of the upper stage, and is irradiated to the ground 100 at a point about 50 cm behind the rearmost part 10a of the vehicle, and the beam spots 94a, 95a, 96a are emitted. Are formed in a horizontal row. The emission angle θ3 of the lower infrared light beams 97, 98, 99 is deeper than the emission angle θ2 of the middle stage, and is irradiated to the ground 100 at a point about 30 cm from the rearmost part 10a of the vehicle, and the beam spots 97a, 98a, 99a. Are formed in a horizontal row. In addition,
The three infrared light beams in each stage are arranged in parallel.

At the center of the rear door 24 of the vehicle 10 in the vehicle width direction, an infrared light sensitive television camera 26, which is a CCD camera, is fixedly arranged diagonally downward and rearward of the vehicle. This television camera 26 is equipped with each beam spot 91.
The visual field range includes the positions where a to 99a are formed and its periphery. The image captured by the television camera 26 is displayed on the television camera 28 arranged on the instrument panel or the like in front of the driver's seat.

The configuration of the infrared light beam emitting devices 81 to 89 is shown in a vertical sectional view in FIG. Infrared light beam emitting devices 81 to 8
In the case 9, the infrared light emitting diode 104 is fixedly arranged in the case 102. Optical axis 85 of infrared light emitting diode 104
A lens (convex lens) 106 is fixedly arranged in
The infrared light beams 91 ′ to 99 ′ emitted from the infrared light emitting diode 104 are converted into parallel rays 91 to 99 and emitted from the window 110.

FIG. 8 shows an image taken by the infrared light television camera 26 and displayed on the television monitor 28.
This is an image when there is no obstacle behind, and is displayed in a state where the bright spots by the beam spots 91a to 99a are regularly arranged.

FIG. 9 shows a state in which an obstacle 72 such as a wall exists behind. When the vehicle 10 moves backward, as shown in FIG.
As shown in (a), the upper infrared light beams 91, 92, 9
3 is projected onto the obstacle 72. At this time, the beam spots projected on the television monitor 28 are, as shown in FIG. 9B, the upper stages 91a, 92a, 93a and the middle stages 94a, 9a.
5a and 96a, the beam spots 91a, 92a, and 93a in the upper stage are projected onto the obstacle 72 (that is, from the obstacles 72 to 1).
You can see that you have approached within m. As it further moves backward, it can be seen that the beam spots 94a, 95a, 96a in the middle stage are also projected onto the obstacle 72 and approached within 50 cm from the obstacle 72. It is understood that the lower beam spots 97a, 98a, and 99a are also projected onto the obstacle 72 as it further recedes, and the beam spots 97a, 98a, and 99a approach the obstacle 72 within 30 cm.

(Third Embodiment) FIG. 10 shows a third embodiment of the present invention. This is to emit one or a plurality of infrared parallel beams 124 from the infrared light beam emitting portion 122 arranged at the rear part of the vehicle 10 toward the rear horizontal direction,
An infrared light sensitive television camera 26 is installed on the upper part of the rear part of the vehicle so as to face obliquely downward and rearward of the vehicle so that an image near the rear of the vehicle can be captured. When the obstacle is not near the rear of the vehicle, the beam spot is not formed, so that the beam spot is not displayed on the television monitor. When approaching the obstacle 72, the infrared light beam 124 is projected onto the obstacle 72 to form a beam spot 124a, and the television monitor 28
Is projected on. Since the optical axis of the television camera 26 is arranged at an angle with the optical axis of the infrared light beam 124,
As the vehicle 10 approaches the obstacle 72, the bright spot of the beam spot 124a gradually moves downward on the screen of the television monitor 28, and the distance to the obstacle 72 can be determined by looking at it.

(Other Embodiments) In each of the above-mentioned embodiments, the infrared light emitted from the infrared light emitting diode is condensed into parallel rays by using a lens, but as shown in FIG. Infrared light 1 emitted from the external light emitting diode 112
It is also possible to make 14 'into parallel rays 114 by using a reflecting mirror 116. In this case, if the infrared light emitting diode 112 and the reflecting mirror 116 are made relatively movable in the direction of the optical axis 118, a divergent ray 114 ″ when the distance between them is reduced as shown in FIG. Can be emitted as
It can be used for lighting.

In the first embodiment, the optical mask pattern is an arrow (FIG. 2B), but a triangular mask pattern like the optical mask 120 shown in FIG. 12 can be used.

[0033]

As described above, according to the present invention, there is no need to use a complicated arithmetic unit or an image processing unit, and to dazzle the eyes of a person behind the vehicle or a person in another vehicle. In addition, it is possible to accurately grasp the distance to the obstacle behind the vehicle with a simple configuration.

[Brief description of drawings]

FIG. 1 is a side view and a plan view of a vehicle showing a first embodiment of the present invention.

2 is a vertical cross-sectional view showing a specific example of the infrared light beam emitting device 16 of FIG. 1, a view taken along arrow A, and a cross-sectional view taken along line BB.

3 is a block diagram showing a specific example of a control device for the lens driving device 70 and the optical mask driving device 52 in FIG.

4A and 4B are a plan view and an image on a television monitor showing an operation of the apparatus of FIG. 1 in a distance measurement mode.

5 is a diagram showing a state of the device of FIG. 1 in an illumination mode.

FIG. 6 is a side view, a plan view, and a rear view of a vehicle showing a second embodiment of the present invention.

7 is a sectional view showing a specific example of the infrared light beam emitting devices 91 to 99 of FIG.

8 is a diagram showing an image captured by the television monitor 26 of FIG. 6, when there is no obstacle behind.

9 is a state and a television monitor image when there is an obstacle behind in FIG.

FIG. 10 is a side view, a plan view and a television monitor image of a vehicle showing a third embodiment of the present invention.

FIG. 11 is a diagram showing how an infrared light beam is converted into parallel rays or divergent rays using a reflecting mirror.

FIG. 12 is a diagram showing an optical mask having a triangular mask pattern.

[Explanation of symbols]

10 Vehicle 14,76,122 Infrared light beam emission part 20,22,91-99,114,124 Infrared light beam 26 Infrared light sensitive television camera 28 Television monitor 32,104 Infrared light emitting diode 36 Lens 46,120 Optical mask 116 Reflector

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[Procedure amendment]

[Submission date] September 11, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

The operation in the illumination mode is shown in FIG. In the illumination mode, as shown in FIG. 5A, the lens 36 approaches the infrared light emitting diode 32 and the infrared light emitting diode 32
The infrared light 20 ″ (22 ″) emitted from the light source becomes a divergent infrared light ray 20 ″ ″ (22 ″ ″). Further, the optical mask 46 is retracted from the optical axis 34 of the infrared light emitting diode 32 to a position where it does not block the divergent infrared rays 20 ″ ″ (22 ″ ″). As a result, divergent infrared rays 20 ″ ″ (22 ″ ″)
Passes through the window 74 as it is and is emitted to the rear of the vehicle. FIG. 5B is a plan view showing a state in the illumination mode. The divergent infrared rays 2 ′ ″ and 22 ″ ′ illuminate the rear of the vehicle 10 widely and the image of the illumination range is infrared light. It can be captured by the sensitive television camera 26 and displayed on the television monitor 28. As a result, the lower rear part of the vehicle can be viewed through the TV monitor 28 even at night.

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

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FIG.

[Procedure 3]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

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[Procedure amendment]

[Submission date] December 5, 1995

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG. 7

[Figure 8]

FIG.

[Fig. 2]

[Figure 3]

[Figure 9]

FIG. 4

[Figure 5]

FIG. 11

FIG.

FIG. 6

FIG. 10

Claims (6)

[Claims] 1. One or a plurality of infrared light beams emitted from an infrared light emitting diode are converted into substantially parallel rays by a lens or a reflecting mirror, respectively, from a rear portion of a vehicle to a substantially horizontal direction toward the rear of the vehicle or obliquely toward the rear of the vehicle. The infrared light beam emitting part that emits downward and the rear part of the vehicle are arranged to capture an image near the rear rear position of the vehicle through which the infrared light beam emitted from the infrared parallel beam emitting part passes. A vehicle rear monitoring device comprising an infrared light sensitive television camera and a television monitor arranged in a vehicle compartment and displaying an image captured by the infrared light sensitive television camera. 2. Infrared rays emitted from an infrared light emitting diode are converted into substantially parallel rays by a lens or a reflecting mirror and emitted in a non-parallel manner from the rear of the vehicle toward the rear of the vehicle. An infrared light-sensitive television camera, which is arranged at the light beam emitting part and at the rear part of the vehicle, and captures an image near the position immediately behind the vehicle and through which a plurality of infrared light beams emitted from the infrared light beam emitting part pass. And a television monitor arranged in the vehicle interior for displaying an image captured by the infrared-sensitive television camera. 3. The infrared light beam emitting part emits two infrared light beams non-parallel to each other in a direction of approaching each other, and these two infrared light beams cross each other near a position immediately behind the vehicle. 3. The two beams are arranged so that they are closest to each other, and the infrared light sensitive television camera captures an image of the surroundings including a position where the two infrared light beams are closest to each other. Vehicle rear monitoring device. 4. The infrared light beam emitting part is provided with an optical mask that partially transmits the plurality of infrared light beams and shapes the cross-sectional shapes of the beams into mutually opposite arrows or triangles. The vehicle rear monitoring device according to claim 3. 5. A plurality of infrared light beams emitted from an infrared light emitting diode are converted into substantially parallel rays by a lens or a reflecting mirror, respectively, and the infrared light beams are emitted from a rear portion of the vehicle at a position at different distances from the vehicle diagonally downward and rearward of the vehicle. An infrared light beam emitting part that emits toward the ground, and a plurality of infrared light beams that are arranged at the rear part of the vehicle and are emitted from the infrared light beam emitting part A vehicle rear monitoring device comprising a television camera for picking up an image of the surroundings and a television monitor arranged inside the vehicle for displaying an image picked up by the infrared-sensitive television camera. 6. The infrared light emitting diode and the lens or reflecting mirror are arranged so as to be relatively movable in the optical axis direction thereof, and the lens or reflecting mirror of the infrared diode is arranged at the moved position. The vehicle rear monitoring device according to claim 1, wherein the light is emitted as a non-parallel light beam.