JPS59213539A - Observation monitor for vehicle - Google Patents

Abstract

PURPOSE:To make rearward observation monitoring ever so easy in particular from a driver's seat, by providing for an objective lens sysrem plus and eyepiece system, while turning over an optical fiber bundle as far as 180 deg. at point midway, in case of an observation monitor using the optical fiber bundle. CONSTITUTION:A picture being incident from an objective lens system is led into an eyepiece system 3 inside a room by means of an optical fiber bundle 2 and watched by a driver when this car goes backward whereby it is so constituted as to make the rear view observable. The optical fiber bundle 2 are used a lot of acryl group plastic optical fibers of 0.2mm.phi or so in thickness being converged close together from point to point, and it is turned over as far as 180 deg. in a point midway whereby the picture is converted into a right standing figure. In addition, this bundle 2 disposes is projecting end face within a focal distance of the eyepiece system 3. The eyepiece system 3 is so constituted as to make an optical path bendable by means of two sheets of reflex mirrors 4 and 4' and a convex lens 31 installed between both these mirrors 4 and 4'.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a monitoring device for a vehicle such as an automobile using an optical fiber bundle. The present invention relates to a vehicle monitoring device for monitoring.

Conventionally, in vehicles such as automobiles, efforts have been made to widen the driver's field of vision to ensure safe operation, but some blind spots still remain, which is a cause 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.

For example, a proposal to use optical fiber as an image transmission medium to eliminate such a driver's blind spot was made in 1973-
8022, JP 49-135341, JP 52-38940, JP 55-85026
Although this has already been done in Japanese Utility Model Publication No. 55-25593, etc., a device with a balance between performance and price that can be put into practical use has not 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.

Second, most systems use a lens system at the output end of the optical fiber bundle to project onto a screen, resulting in an extremely dark image that cannot be put to practical use. Third, the output end of the optical fiber bundle is often placed around the driver's seat, so there is a high risk of side-to-side misunderstandings caused by viewing the image necessary for reversing from a forward-facing position. Moreover, since various instruments and operating devices are placed around the driver's seat, there is a problem that 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.
This vehicle monitoring device is characterized in that it is of a degree reversal type, the output end face of the optical fiber is placed within the focal length of an eyepiece lens system, and two reflecting mirrors are placed in combination.

The present invention will be described below with reference to drawings of embodiments.

Figures 1 and 2 show the vehicle width monitoring device of the present invention mounted on a passenger car, in which (A) is the vehicle monitoring device, (1), (2), C5. ) respectively indicate the objective lens system, optical fiber bundle, and eyepiece lens system that constitute the present invention.

In this way, the present invention allows the objective lens system (1) to be
'It is suitable for installing the eyepiece system (3) at the rear of the vehicle, or at a position diagonal to the driver at the rear of the vehicle.In this way, the length of the optical 7-eye bundle (2) can also be made relatively short. is possible and effective.

The vehicle monitoring device (A) has an objective lens system (1
) is transferred to the optical fiber bundle (2).
Indoor eyepiece system (3) VC guide, driver (M)
When reversing, etc., you can turn around and look at the car from the driver's seat (H). Therefore, the driver CM) can turn back and check the part that is generally a blind spot, which is convenient, and because the driver CM) looks through the action of turning back and forth, he does not get confused. In addition, the vehicle width monitoring device of the present invention<
A) is generally installed in the corner of the interior diagonally above the driver's seat (H) as shown in Figure 1, but it can be installed in other locations if necessary. Two units may be installed as shown by the imaginary line in the figure. In the figure, the arrow (5) indicates the inversion of the optical fiber bundle (1), and (S) indicates the cover for shielding from direct sunlight.

3 to 6 show the objective portion of the apparatus of the present invention, and as described above, (1) is the objective lens system, and (2) is the optical fiber bundle.

The objective lens system (1) includes a three-piece convex lens (11), which is fixed by a lens holder (12) so as to be in a predetermined position with the optical fiber bundle (2). Note that in this example, a wide-angle convex lens (11
) has a focal length fl of 15 and an effective aperture d! is 16
rxm, so F1=f.

/(11=0.94 bright lens is used to ensure that a sufficient amount of light is incident from the objective lens system (1).

Next, the optical system of the objective lens system (1) will be explained based on FIG. 6, in which the lens systems (11) and (31) are shown as models for convenience of explanation.

Assuming that there is an object located at a1=2g from the reference plane of the objective lens system (1), the distance b1 to the incident end surface of the optical fiber bundle (2) is set to bI==15 so as to focus on the object. By setting it to .115trrm, aI Dl f 1 is satisfied. Note that when al focuses on an object at a distance of 5 m, bl is 15. To focus on an object with Q 45rran and al of 15m, bl should be 15.464mm, but since the lens in this example has a short depth of focus, al == 2 By setting it to gH, it is possible to sufficiently monitor aI in the range of a5 to 5m.

Further, the size of the image of an object having a size of 1 m at a distance a1-'2 m at the input end face of the original fiber bundle is as follows. Note that the angle of view of the objective lens system (1) in this example is as follows. With this angle of view, a general convex lens can be used sufficiently, but when using a lens system with a wider angle than this, the numerical aperture NA of the optical fiber used will be exceeded, so the objective lens As (1), it is necessary to use the Retro 7 Orcus type. In this way, if the objective lens system (1) is a wide-angle lens with a wide angle of view, it will be possible to monitor a wide range.
If the angle is set to a slightly wide angle, the image in the peripheral areas will be distorted, so the practical angle of view seems to be about 60 to 100'. The image incident on the objective lens system (1) in this way travels through the optical fiber bundle (2) as an inverted image, so the optical fiber bundle (2) is
), it is necessary to invert 180 degrees at an appropriate position in the middle.

The optical fiber bundle (2) used in the present invention includes:
Acrylic plastic optical fibers (21) with a thickness of 0.2 mm diameter are used, and are fixed using end rings (22) so that there are 65 fibers in the vertical direction and 100 fibers in the horizontal direction. Of course, this optical fiber (21) is focused so as to have a co-V-lent relationship with the eyepiece side. The end face of the end face ring (22) is finished smoothly,
At this time, the width (Wl) in FIG. 5 is 20 cm, and the height Hl) is 13 cm. The optical fiber (21) used in the present invention is not particularly limited, but considering the price, thickness, flexibility, workability, etc., the above-mentioned plastic optical fiber such as acrylic or stainless steel is preferred. The thickness of the optical fiber (21) used in the present invention is preferably about 0.1 to 0.3 end, considering the resolving power of the human eye and considering the distance to be monitored and the magnification in this example. In addition, in the figure (2
3) is a protective tube.

Figure 7 shows the eyepiece system of the device of the present invention, where (2) is an optical fiber bundle, (3) is an eyepiece system, and (4) is two reflective mirrors. The eyepiece system (3) in this example has f2 =
200 tra, magnification m is 4x, vertical.

A convex lens (31) with a width of 100 x 150 ff1m is used, and a holder (52) is installed so that the width is 150m. A first reflecting mirror (4) is installed at an angle of 45° from the output end face of the optical fiber bundle (2) at 70 W (D), and a first reflecting mirror (4) is installed at an angle of 45° from the output end face of the optical fiber bundle (2). 2 reflection mirrors (4 of them are also installed at an angle of 45 degrees.Of course, the eyepiece system (3) is not limited to this example, and any lens system suitable for the purpose can be used. In the figure, (32) is the holder, (3
3) Tri-hood reeds, these holders (32)
and (2) (33) is preferably provided with a light-absorbing coloring on at least the inner surface, or formed from a light-absorbing colored material.

Since the eyepiece system of the present invention has the above-described configuration, the image that is transmitted by the optical fiber bundle (2) and turned 180 degrees midway to become an erect image is transmitted by the optical fiber bundle (2). (2) reaches the output end face. This erect image is then reflected by the first reflecting mirror (4
), and passes through the convex lens (31) to the second reflecting mirror (four reflecting points, and the driver observes the image. The distance a2 from this output end face to the convex lens (31) is: It is determined by the following equation depending on how much magnification m is to be set for the eyepiece lens.

m = b2 / a2 In the example of the present invention, what the driver observes is a virtual image formed at a distance of b2 behind the eyepiece, so it is visible only within the size of the lens. Therefore, it is desirable to use the eyepiece system (3) with a diameter as large as possible, so that the driver can observe even if the position of his eyes shifts slightly when he looks back. . In addition, the light emitted from the output end face of the optical fiber bundle (2) is strongest in the direction of the extension of the optical fiber, and becomes weaker as it moves away from this direction. It is advantageous to be able to observe bright images.

Figures 8 and 9 show other examples of the eyepiece part of the present invention. Figure 8 shows magnification using a convex Fresnel lens (64) constituting the eyepiece system, which is expanded by two lenses. Reflection mirrors (4) (Figure 9 shows two reflection mirrors (4), (4) that guide the image while reflecting it. (The image reflected by the four is magnified with a Fresnel lens (34). In the present invention, including the above-mentioned embodiments, two reflecting mirrors (4) and (4') are combined, so the left and right sides of the erect image are not reversed. Therefore, the optical path is set at 90° to the eyepiece system (3).
As a result, the lower half of the eyepiece V lens system (3) can be stored in the rear shelf (R), etc., as shown in Figure 7, which saves space during installation. This will not only improve the appearance, but also improve the appearance.

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 direct sunlight shielding cover (S) shown in Figure 2 is 6J, which is effective for protecting optical fibers from direct sunlight. Alternatively, it is desirable to have a lid with a tightening mechanism so that it opens only when reversing. The installation of such a cover or lid is useful for protection from dust and for vehicles following you at night.
It is also effective in preventing glare caused by book headlights.

Since the present invention has the configuration as described in detail above, a relatively short optical fiber bundle is used, and the objective lens system, eyepiece system, and reflection mirror are skillfully combined to obtain a vehicle width that provides a bright image. It has the advantage of being able to provide a surveillance device at a low price, and by providing a reflective mirror, the eyepiece V-lens system can be stored smartly in a corner of the car, saving space and improving the appearance, making it highly practical. It is something.

[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 equipped with the vehicle width monitoring device of the present invention, FIG. 2 is a side sectional view of the same, and FIG. 6 to 6 show the objective part, FIG. 3 is a perspective view thereof, FIG. 4 is a sectional view thereof, FIG. 5 is a perspective view of an optical fiber bundle used in the present invention, and FIG. 6 is an optical system. FIG. 7 is a sectional view of the eyepiece system portion, and FIGS. 8 and 9 are sectional views showing other examples of the eyepiece system portion. (A)... Vehicle monitoring device (1)... Objective lens system (11)... Convex lens (2)... Optical fiber bundle (3)...
・Eyepiece system (31)...Convex lens (4), (4...Reflection mirror #3I2] f Leather 2.50 / Base 6 figure Book 7 figure

Claims (1)

[Scope of Claims] 1. It consists of an objective lens system, an optical fiber bundle, and an eyepiece system, which inverts the optical fiber bundle by 180 degrees in the middle and
(-) (A vehicle monitoring device characterized by arranging the output end face of the lens within the focal length of the eyepiece lens system and also arranging two reflecting mirrors in combination.Z A retrofocus type objective lens system. A vehicle monitoring device according to claim 1, characterized in that a wide-angle mortar lens is used. (5) A patent claim characterized in that a lens whose focal length and effective aperture are substantially equal is used as an objective lens system. A vehicle monitoring device according to claim 1 or 2. 4. Claim 1, characterized in that a long focal length lens is used as the eyepiece system. Claim 2 or 3 5. The vehicle monitoring device according to claim 1, 2, 3, or 4, characterized in that a convex Fresnel lens is used as the eyepiece system.