JPS59187211A - Photoelectric distance measuring device - Google Patents

Abstract

PURPOSE:To obtain a photoelectric distance measuring device, whose handling is very easy and accuracy is high, by providing a circuit, which individually takes out the outputs of photoelectric conversions from photoelectric converter elements, and further providing a light source for lighting. CONSTITUTION:A diode array 3 for receiving light comprising a plurality of photoelectric conversion elements is arranged along an optical axis 2 on the side of image formation with respect to a lens 1. The array 3 is constituted of the group of minute light receiving diodes. The light receiving surfaces of the diodes are aligned in a straight-line state along the optical axis on the image forming side. A pair of a light source P for lighting and a mirror 10 is arranged. In this way, the focal point of the lens 1 is controlled based on the output of the photoelectric conversion of the light receiving diodes 31-3n. Then, the automatic focal point adjustment, which is sufficiently accurate in actual use, can be performed. Since the very compact linear optical converter can be incorporated into an optical system, the device can be made compact, and the handling can be extremely simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a photoelectric distance measuring device suitable for various cameras and the like.

(Prior art and its problems) Conventionally, the distance from a reference point to an object has been measured using a tape measure for short distances, and by optical triangulation for long distances.

Projects ultrasonic waves to the target object and uses the reflected waves to supplement the target.

A method of determining the distance based on the time required from transmission to reception of ultrasonic waves and a method of similarly determining the distance using reflection of light such as a laser beam are used.

However, these devices have drawbacks such as the devices are generally large in size and the distance measurement operation requires time and effort.

All of these methods were inappropriate for simply determining the distance to an object.

(Purpose) The present invention fundamentally eliminates the drawbacks of the conventional technology, and
with the purpose of fully satisfying the aforementioned requirements.

By combining a lens and a plurality of photoelectric conversion elements, and by providing a circuit that extracts the photoelectric conversion output of each photoelectric conversion element individually, it is also equipped with a light source for irradiation, making it compact, highly accurate, and easy to handle. This provides an extremely simple photoelectric distance measuring device.

(Example) FIG. 1 is a configuration diagram of an optical system, in which a plurality of light receiving diode arrays 3 as photoelectric conversion elements are arranged along the optical axis 2 on the imaging side of the lens element.
is composed of a group of minute light-receiving diodes, and since these light-receiving surfaces are arranged linearly along the imaging side optical axis 2, the photoelectric conversion output changes depending on the position of the imaging side Fl + F2. The resulting light-receiving diodes are different. Further, a light source P for illumination is arranged in a pair with a mirror 10.

This light source is placed on the optical axis 2' equivalent to 2.

Note that 4 is a light-shielding mask, which does not need to be provided, but
This can prevent light rays near the optical axis 2 from entering parallel to the surface of the light receiving diode array 3 and deteriorating the signal-to-noise ratio of the photoelectric conversion output.

Therefore, if the distance from the lens 1 to the object Tt is a, the distance between the lens 1 and the image forming F is 1, and the focal length of the lens is 1, then the following relationship holds true using the general convex lens formula. .

That is, if b in equation (1) is found, the value of a is also found,
As a result, the distance to the object T is measured using the lens 1 as a reference point.

In this method, the light emitted from the illumination light source P located approximately at the focal length f of the lens 1 becomes a substantially parallel light beam after passing through the lens 1 and is irradiated onto the subject T.

As shown in Figure 1, based on the relationship of equation (1), the imaging FI+F
2 changes, and if the distance to the object TI is al, the reflected light becomes the image F1, and the lens 1 and the image F
1, whereas if the distance to the object T2 is al, the reflected light becomes the image F2, and the distance between the lens 1 and the image F2 becomes b2.

From each light receiving diode of the light receiving diode array 3.

By extracting the photoelectric conversion output for each individual, the image forming Fl
+ The position of F2 is detected, which makes the distance al+a
2 is required.

Figure 2 shows a photodiode array 3 and a circuit for extracting photoelectric conversion output from each individual diode array.

2 is a plan view of an integrated circuit in which a switching element section 5 and a shift register 6 are formed together with a light receiving diode array 3 on the same substrate, forming a -dimensional photoelectric converter 7. FIG.

FIG. 3 is an equivalent circuit of the one-dimensional C/C converter shown in FIG. 2, in which the output of the shift register 6 is repeatedly shifted to the IIIQ order by the clock pulse 8.

This output 0 (from this, F
Switches 51 to 5 such as ET (IW effect transistor)
．． 1 is turned on next, the light receiving diodes 31 to 3n of the light receiving diode array 3 are sequentially connected to the output 9, and the 9' conversion outputs of the light receiving diodes 31 to 3n are individually and sequentially taken out.

Furthermore, when the dimension L1 of the -dimensional y6 electrical converter 70 is 4mm and L2 is 27nm, the arrangement pitch of the light receiving diodes 31 to 3n can be set to 15μm, so the focal position adjustment accuracy of various cameras is about 60μm. Distance measurement is performed with sufficient accuracy.

Therefore, a separate control circuit and drive device (not shown)]
By j'η, the focus of the lens 1 is controlled based on the photoelectric conversion outputs of the light receiving diodes 31 to 3n.

In addition to realizing automatic focus adjustment with sufficient precision for practical use, it is only necessary to incorporate an extremely small one-dimensional nine' jump converter into the optical system, making it extremely suitable for implementation in various cameras.

In addition, any photoelectric conversion element such as a light receiving diode and a light receiving transistor as 31 to 3n may be used.

The same effect can be achieved by using other circuits with similar functions in the peripheral circuits that take out each of the C electric conversion outputs, and there are other variations, such as separating the nine conversion elements from the seven peripheral circuits. It's white f.

(Effects) As is clear from the above explanation, according to the present invention, a distance measuring device that does not require any particular distance measuring operation is realized with a simple configuration that does not require a movable mechanism, and can be used for automatic focusing and adjustment of various cameras. , it can be used to prevent collisions of various vehicles, etc., and a great effect can be obtained. Furthermore, distance measurement in a dark place is also possible using the illumination light source.

[Brief explanation of the drawing]

1 to 3 show embodiments of the present invention, FIG. 1 is a configuration diagram of an optical system, FIG. 2 is a plan view of a one-dimensional nine-density converter integrated into an integrated circuit, and FIG. There is an equivalent number of times as shown in the figure. 1: Lens, 2: Imaging side optical axis, 3. Light-receiving diode array (a plurality of photoelectric conversion elements), 31 to 3n light-receiving diodes, 4 light-shielding mask, 5: switch row. 51 to 5n: switch, 6: shift register, 8: cloth pulse, 9 output, 0゛ mirror, P: irradiation light source.

Claims (1)

[Claims] A rechargeable distance measuring device comprising a plurality of photoelectric conversion elements arranged along the optical axis on the imaging side of a lens, and a circuit for extracting a photoelectric conversion output from each of the photoelectric conversion elements. A distance measuring device characterized by being equipped with a light source.