JPS59204802A - Monitoring device for vehicle - Google Patents

Abstract

PURPOSE:To realize a monitoring device for a vehicle, which is inexpensive, has a bright picture and has a high practical use by connecting an objective lens system and an eyepiece system by an optical fiber bundle, and also inverting the optical bundle by 180 degrees at a middle position. CONSTITUTION:An objective lens system 1 having a view angle of 60-100 degrees is placed in the rear of a vehicle, an eyepiece system 3 having a convex Fresnel lens is placed in a driver's diagonal position of the rear in a room, and both of them are connected by an otptical fiber bundle 2. An image which is incident to the objective lens system 1 advances in the bundle 2 as an inverted image, therefore, it is made an erect image by inverting the bundle 2 by 180 degrees at a middle suitable position. When moving a vehicle backward, a driver M turns his head and looks at the eyepiece system 3, therefore, he has no illusion of the left and right. Therefore, it is possible to obtain a monitoring device for a vehicle, which is inexpensive, has a bright picture and has a high practical use.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle monitoring device such as an automobile that uses an optical fiber bundle, and in particular indirectly monitors areas that are difficult for a driver to see directly or even through a mirror. The present invention relates to a vehicle monitoring device for monitoring.

In conventional vehicles such as automobiles, efforts have been made to widen the driver's field of vision in order to ensure safe operation, but there are still considerable blind spots, which are one of the causes of accidents. For example, even in a passenger car with relatively good visibility, it is impossible to see within a few meters of the trunk when reversing.

In order to eliminate such blind spots for drivers, there was a proposal to use original fiber as an image transmitter, for example,
8022, JP 49-135341, JP 52-38940, JP 53-85026
Although this has already been done in Japanese Utility Model Publication No. 55-25595, etc., no device with a balance between performance and price that can be put to practical use has yet appeared. The first reason for this is that many devices use optical fiber bundles for quite a long time, and with the current state of the art, the brightness can be significantly reduced and the price can become extremely high.

Secondly, at the output end of the west fiber bundle, most systems use a lens system to project onto a screen, which makes the image extremely dark and impractical. Third, because the output end of the optical fiber bundle is often placed around the driver's seat, there is a high risk of misunderstandings when viewing images needed for reversing from a forward-facing position. Since various instruments and operating devices are arranged around the driver's seat, there are problems such as there is not enough room for installation.

In view of this situation, the present invention aims to provide a highly practical vehicle monitoring device that balances monitoring performance and economical efficiency. and an eyepiece system, comprising an optical fiber bundle with an intermediate diameter of 180 mm.
There is provided a vehicle monitoring device characterized in that the angle is inverted and the output end face of the optical fiber is placed within the focal length of an eyepiece lens system.

Hereinafter, the present invention'f will be explained according to the drawings of the embodiments. Figures 1 and 2 show the vehicle monitoring device of the present invention mounted on a passenger car, and (A) in the figure shows the vehicle monitoring device. In the monitoring device, (1), (2), and (3) respectively indicate the objective lens system, the nine-element fiber bundle, and the eyepiece system, which constitute the present invention. As described above, the present invention is suitable for installing the objective lens system (1) at the rear of the vehicle and the eyepiece system (3) at a position diagonal to the driver at the rear of the entire interior.
This is effective because the length of the original fiber bundle (2) can also be made relatively short. Then, this vehicle monitoring device (~) guides the image incident from the objective lens system (1) to the indoor eyepiece system (3) using the optical fiber bundle (2), and directs the image incident from the objective lens system (1) to the indoor eyepiece system (3). The driver's seat (flat) allows the driver to turn around and look at the area.Therefore, the driver (b) can turn around and check the area that is generally a blind spot, which is convenient and allows him to look through the motion of turning around. Therefore, there will be no confusion.The vehicle monitoring device (A)Fi of the present invention is generally installed in a corner of the interior diagonally from the driver's seat (as shown in Fig. 1). , it is possible to install it in another location if necessary, or two units may be installed as shown in the imaginary line in the figure. In the figure, the arrow (4) indicates the optical fiber bundle (1).
7% (8) indicated that direct sunlight was covered.

3 to 5 show the objective portion of the apparatus of the present invention, and as mentioned above, (1) is the objective lens system, and (2) is the optical fiber bundle. The objective lens system (1) is
The optical fiber bundle (2) is fixed in a predetermined position with the optical fiber bundle (2) by a lens holder (b). In this example, the focal length f1 of the wide-angle convex lens α■ is 151111%.
The effective aperture d1 is 16 times, so Fl − fl /(1
A bright lens of 1 = 0.94 is used, and a sufficient amount of light enters from the objective lens system (1).
Ru.

As the optical fiber bundle (2), an acrylic plastic optical fiber with a thickness of a2 mm is used.
The end ring (
Of course, the optical fiber 9II'i is converged so as to be correlative with the eyepiece side of the optical fiber 9II'i. The end face of the end face ring) is finished smoothly, and the width (wl) in FIG. 5 at this time is 20 m5, and the height Hl) is 13 wxi. The optical fiber 〇η used in the present invention is not particularly limited. However, in consideration of price, thickness, flexibility, processability, etc., the above-mentioned plastic optical fibers such as acrylic or styrene are preferable.

Considering the resolving power of the human eye and the distance to be monitored and the magnification in this example, the suitable thickness of the optical fiber η used in the present invention is about Q1 to α3. In addition, ) in the figure is a protective tube.

6 to 8 show the eyepiece portion of the apparatus of the present invention, in which (2) is an optical fiber bundle and (3) is an eyepiece lens system. The eyepiece system (3) in this example has a focal length (f2) of 150III, a Fresnel concentric circle pitch of α5, and an effective aperture with a width (W2) of 12
A convex Fresnel lens made of acrylic resin with a height of 80 cm and an average thickness of 2 cm is used.

Of course, the eyepiece lens system (3) Fi is not limited to this example, and any lens system can be selected as long as it is suitable for the purpose. Note that (2) in the figure is a holder that also serves as a hood, and it is recommended that at least the inner surface of this holder (A) be colored with a light-absorbing color.Next, the optical system of the device of the present invention will be explained based on Figure 9. However, in this figure, for convenience of explanation, the lens system C11,0 is shown as a model. Suppose that there is an object at a distance of a1 = 2 m from the reference plane of the objective lens system, then the distance b to the incident end face of the optical fiber optic lens (2) is
1 is bl=1 al to focus on the object
By setting the value to 13ffilK, the condition 10 = π 1 is satisfied. Note that when al focuses on an object at a distance of 5 m, bl is 15.0.
To focus on an object at a distance of 45 m and al α5, it is sufficient to set tri bx to 15.464 m, but the lens in this example has a considerable depth of focus, so I! By setting L1 = 2 m-, a
This means that it is possible to sufficiently monitor a range of l from 115 to 5 m.

Furthermore, the size of the image at the original fiber bundle input end face of an object of size 1 m at distance al = 2 m K is 1 m X-! 2! -= 1 m x 15°113
″′″! -= 7.56 mal 2m. The angle of view of the objective lens system in this example is 2 x tan-! in the lateral direction. -ηshi]-”t 67・
, 15.115 The vertical direction is 2 X tan-”-ZL≠47・15.
It is 113. With this angle of view, a general convex lens can be used sufficiently, but when using a lens system with a much wider angle, the numerical aperture NA of the optical fiber used will be exceeded, so the objective lens It is necessary to use a retrofocus system as system (1). Objective lens system (1) #'i A wide-angle lens with as wide an angle of view as possible will allow you to monitor a wider area, but if you use a too wide-angle lens, the image in the periphery will be distorted, so it is not practical. I think the angle of view is about 60 to 100 degrees.

The image that enters the objective lens system (1) in this way travels through the optical fiber bundle (2) as an inverted image, so it passes through the optical fiber bundle (2) e as shown by the arrow (4) in Figures 1 and 2. As shown above, it is necessary to perform a 180° inversion at an appropriate position between the intermediate degrees. The image thus derived is located at the optical fiber bundle (2) in the eyepiece system (3).
It reaches the end face as an erect image. Then, the distance az Fi from the output end surface to the eyepiece at 0 camera, and the magnification mtl of the eyepiece are determined by the setting n.
However, since m = b27al and 101 = τ 2, when m = 5, a2 = = 100111111% b2 = -500 + m, and although the image is slightly smaller, clear image quality can be obtained. . If m:=5 is set, a2 =120
wa.

b2=-6a, and although the image becomes larger, aberrations increase and image quality deteriorates, so care must be taken.

In the example of the present invention, what the driver observes is a virtual image formed at a distance b2 behind the eyepiece, so it is visible only within the size of the lens. therefore,
It is desirable to use the eyepiece lens system (3) with a diameter as large as possible, and by doing so, it is possible to observe even if the position of the driver's eyes is slightly different when he or she turns around. In addition, the light emitted from the output end face of the optical fiber bundle (2) is strongest in the direction of the extension line of the original fiber, and becomes weaker as the distance from this direction increases. It is more advantageous to use a focal lens because you can observe a brighter image.

Although the present invention has been described above according to the illustrated embodiment, the present invention is not limited to this example, and various other configurations can be adopted. For example, the sun protection cover (S) shown in Figure 2 is effective for protecting optical fibers from direct sunlight, and is an open/close type that opens when the transmission gear is in the reverse position. Alternatively, it is desirable to have a structure in which the lid is equipped with a constriction mechanism and is opened only when reversing. The installation of such a cover or lid is also effective for protection from dust and for preventing glare from the headlights of following vehicles at night.

Since the present invention has the configuration as described in detail above, a relatively short optical fiber bundle is used and an objective lens system and an eyepiece system are skillfully combined to provide a bright image for vehicle surveillance. It has the advantage that the device can be provided at low cost and is highly practical.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a plan sectional view showing a part of a vehicle on which the vehicle monitoring device of the present invention is mounted, FIG. 2 is a side sectional view of the same, and FIG. 3 is a sectional view of the same. 5 to 5 show the objective part, FIG. 1 is a perspective view thereof, FIG. 4 is a cross-sectional view of the image bundle, and FIG. Fig. 8 shows the eyepiece part, Fig. 6 is a perspective view thereof, Fig. 7 is a sectional view thereof, and Fig. 8 is a sectional view thereof.
The figure is a perspective view of a Fresnel lens used as an eyepiece lens system, and FIG. 9 is an explanatory diagram for explaining the optical system in the example of Ton et al. (4)...Vehicle monitoring equipment...Objective lens system Qη...Convex lens (2)...Optical fiber bundle (3)...
・Large diameter eyepiece system 0 center ・-e- ・Convex Fresnel lens (4)... (indicates reversal) Arrow 1 Hole/Figure Stem 2 Figure 3 Figure I Dojo 42 t5 Concave! 70 pages of illustrations 3/ Procedural amendment (method) 1. Indication of the case Sho SG-GODA A; No. 3 2. Name of the invention Vehicle monitoring device 3. Person making the amendment Relationship with the case Patent Applicant: 2-3-19 Kyobashi, Chuo-ku, Tokyo (603) Mitsubishi Rayon Co., Ltd. President and Director Akio Kawasaki 4th, Representative Address: 19-A, 2-chome, Kyobashi, Chuo-ku, Tokyo

Claims (1)

[Claims] 1. A system consisting of an objective lens system, an optical fiber bundle, and an eyepiece lens system, in which the optical fiber bundle is inverted 180 degrees in the middle, and the output end face of the optical fiber bundle is set in the eyepiece system. A vehicle monitoring device characterized by being placed within a focal length. 2. The vehicle monitoring device according to claim 1, characterized in that a retrofocus type wide-angle convex lens is used as the objective lens system. (5) Claims 1 and 7t are the vehicle monitoring device according to claim 2, characterized in that the objective lens system is a lens whose focal length and effective aperture are approximately equal. Azuma: Using a long focal length lens as the eyepiece system
``Claim 1, characterized in that the vehicle monitoring device according to Item 2 or 3. 5. Claim 1, characterized in that a convex Fresnel lens is used as the eyepiece system. Term, 2nd term, 3rd term
The vehicle monitoring device according to item 1 or 4.