JPH0534436A - Distance measuring apparatus for automobile - Google Patents

Abstract

PURPOSE:To miniaturize a distance measuring apparatus for an automobile without increasing its cost. CONSTITUTION:A light-emitting element 1 is driven by a pulse from a pulse modulator 2 to generate pulse light and this pulse light is collected by a light transfer lens 3 and trasferred to a reflector. The light reflected from the reflector has its wavelengths harmful to distance measurement cut by the filter 4 of a light-receiving portion 2 and is collected by a plurality of short-focus light- receiving lenses 5 and the light is guided to a light-receiving element 7 by flexible optical fiber 6 and this photoelectric transfer signal is guided to a signal processing circuit 9 and the distance is measured from the delay time of propagation taken from the emission of the pulse light to the reception of the light reflected at the reflector. Therefore, the distance measuring apparatus can be miniaturized without increasing its cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention receives the reflected light of a reflector of the outgoing light that is sent in a predetermined direction, and determines the distance to the reflector based on the propagation delay time from the sending of the light to the reception of the light. The present invention relates to a distance measuring device for an automobile for measuring.

[0002]

2. Description of the Related Art FIG. 2 shows, for example, Japanese Utility Model Laid-Open No. 62-180784.
And FIG. 2 is a view showing a conventional distance measuring apparatus for automobiles disclosed in Japanese Patent Publication No. JP-A-2003-264, in which 1 is a light emitting element which is provided in a transmitter 11 and which generates pulsed light for distance measurement, and 2 is a light emitting element. It is a pulse modulator that drives 1.

Reference numeral 3 denotes a light-transmitting lens for condensing pulsed light toward a reflector, 4 a filter provided on the front surface of the light-receiving portion 12 for cutting harmful light, and 5 a provided behind the filter 4 for reflecting light. Light receiving lens for condensing, 7 is a light receiving element provided at the rear of the light receiving section 12, 8 is a wide band amplifier for inputting and amplifying the output of the light receiving element 7, 9 is output of the pulse modulator 2 and output of the wide band amplifier 8. Is a signal processing circuit that measures the distance to the reflector based on the propagation delay time from the transmission of light to the reception of light. Reference numeral 10 is a control unit including a pulse modulator 2, a signal processing circuit 9, and a wideband amplifier 8. is there.

Next, the operation will be described. The light emitting element 1 is driven by the pulse modulator 2 to generate pulsed light L _t for distance measurement. This pulsed light L _t is condensed by the light transmitting lens 3, becomes a beam of light having a width of one lane at the maximum measurable distance of the present apparatus, and is emitted in a predetermined direction.

The reflected light L _r from the reflector passes through the filter 4 of the light receiving section 12 to cut harmful light other than the wavelength used for the distance measurement which interferes with the distance measurement, and then is received by the light receiving lens 5a. It is focused on the light receiving element 7.

The light receiving element 7 converts the condensed light into an electric signal by photoelectric conversion, and amplifies the electric signal to a level at which the wide band amplifier 8 can process the signal.

The signal processing circuit 9 measures the distance to the reflector on the basis of the propagation delay time from the transmission of light to the reception of light by the signals from the pulse modulator 2 and the wide band amplifier 8 and outputs it to the outside.

[0008]

Since the conventional automobile distance measuring device is constructed as described above, it is safe when the performance of the light emitting element 1 and the reflector irradiated with the emitted light are humans or animals. The output power of the light emitting element 1 is limited due to the problem of the property, and it is necessary to increase the light receiving aperture area in order to increase the detection sensitivity with the limited power.

For this reason, because of the lens efficiency, it is unavoidable to use a lens having a large diameter and a long focus as the light receiving lens 5a, and it becomes a large device with a large depth, which makes it difficult to mount it on an automobile. There was a problem of becoming.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to reduce the size of the device without increasing the cost, and to provide a compact vehicle ranging device which can be easily mounted on an automobile. The purpose is to get.

[0011]

SUMMARY OF THE INVENTION A vehicle distance measuring apparatus according to the present invention includes a light receiving lens for arranging a plurality of short focus lenses and condensing the light and a light receiving element for collecting the light condensed by the light receiving lens. And a flexible optical fiber for guiding.

[0012]

Since the light-receiving lens of the present invention has a short focal length, the distance between the light-receiving element and the light-receiving element is reduced and the light collected by this light-receiving element is guided to a single light-receiving element.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a distance measuring device for an automobile according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration explanatory view showing the configuration of the embodiment.

In FIG. 1, reference numerals 1 to 4 and 7 to
The part denoted by 12 is exactly the same as the above-mentioned conventional distance measuring device for an automobile, and its duplicated description will be omitted.

Reference numeral 5 is a short-focused light-receiving lens arranged to collect the reflected light, and 6 is a flexible optical fiber for guiding the light collected by the light-receiving lens 5 to the light-receiving element 7.

The light receiving lens 5, the optical fiber 6 and the filter 4 are housed in the light receiving section 12, the filter 4 is arranged on the front side of the light receiving section 12, and the light receiving element 7 is attached on the rear side. Other configurations are the same as those in FIG.

Next, the operation will be described. The light L _t is sent out from the light sending unit 11 in a predetermined direction, and the light L reflected by the reflector is reflected.
_The light receiving unit 12 receives _r .

The light receiving section 12 cuts off harmful light having a wavelength not used for distance measurement out of the reflected light L _r by the filter 4 and then condenses it by a plurality of short-focused light receiving lenses 5 to provide a flexible light. The fiber 6 guides the light to a single light receiving element 7, and the light receiving element 7 converts the electric signal into an electric signal to control the unit 1.
Output to 0.

The control unit 10 outputs the electric signal input from the light receiving element 7 to the signal processing circuit 9 to a level at which the wide band amplifier 8 can perform signal processing.

In this signal processing circuit, the signal from the pulse modulator 2 and the broadband amplifier 8 is used to measure the distance to the reflector based on the propagation delay time from the transmission of light to the reception of light, and the signal is output to the outside.

In the above embodiment, the light receiving lens 5 having a circular aperture shape is used. However, when a plurality of light receiving lenses 5 are arranged, a square shape or a square shape is used so that the effective area of the lens becomes as large as possible. A hexagonal lens or the like may be used.

In the above embodiment, the description has been given assuming that the light receiving lens 5 is a glass lens, but it may be a Fresnel lens in order to integrate a plurality of light receiving lenses.

[0023]

As described above, according to the present invention, since a plurality of short focus lenses are arranged, the depth of the light receiving portion can be made small, and the number of light receiving elements is not increased, so that the device can be miniaturized without increasing the cost. There is an effect that can be converted.

[Brief description of drawings]

FIG. 1 is a structural explanatory view of a distance measuring device for a vehicle according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration of a conventional automobile distance measuring device.

[Explanation of symbols]

 1 light emitting element 2 pulse modulator 3 light transmitting lens 4 filter 5 light receiving lens 6 optical fiber 7 light receiving element 8 wide band amplifier 9 signal processing circuit 10 control unit 11 light transmitting unit 12 light receiving unit

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[Procedure amendment]

[Submission date] January 17, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction content]

[0001]

BACKGROUND OF THE INVENTION This invention, by receiving the light reflected by the reflector of the delivery light transmitted in the direction of Jo Tokoro, the distance from the light delivery to the reflector on the basis of the propagation delay time to the light receiving The present invention relates to an automobile distance measuring device.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0019

[Correction method] Change

[Correction content]

The control unit 10 amplifies the electric signal input from the light receiving element 7 to a level capable of signal processing by the wide band amplifier 8 and outputs it to the signal processing circuit 9.

Claims (1)

Claim: What is claimed is: 1. A light emitting element which is driven by a pulse modulator and generates pulsed light for distance measurement, and a light receiving element which receives reflected light from a reflector of the pulsed light and condenses the reflected light. A plurality of short-focused light receiving lenses, a flexible optical fiber that guides the light collected by the light receiving lenses to the light receiving element, the output of the light receiving element and the output of the pulse modulator, and the pulse A distance measuring device for an automobile, comprising: a signal processing circuit that measures a distance to the reflector based on a propagation delay time from generation of light to reception of light by the light receiving element.