JPH06137947A - High amplification measuring equipment of intensity of specific received pulse light - Google Patents

Abstract

PURPOSE:To provide a high amplification measuring equipment for measuring the intensity of specific received pulse light while tuning and amplifying and employed in means for detecting position, traveling direction or traveling speed of a specific pulse light source. CONSTITUTION:The high amplification measuring equipment of the intensity of specific received pulse light comprises a photoelectric converting element 1 which produces current upon receiving light, a tuning amplifier 2 for tuning/amplifying an output from the photoelectric converting element 1 produced upon receiving a pulse light of specific period, a comparator 3 for comparing an amplified output from the tuning amplifier 2 with a preset decision reference value and producing an ON output when the output from the tuning amplifier 2 is higher than the decision reference value otherwise producing an OFF output, and a unit for calculating the rate of ON output for a predetermined time as the intensity of received pulse light having specific period. This equipment alloxys great amplification of pulse light having specific period and high sensitivity catching of light emitting source and thereby employed generally in photometer, distance measuring equipment, direction measuring equipment, and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention receives a specific pulsed light with high sensitivity and also measures the intensity of the received light. For example, a target position of a moving body (specific pulsed light source) and a traveling direction, The present invention relates to a high-amplification measuring device for the received light intensity of a specific pulsed light, which is used as a means for detecting the traveling speed.

[0002]

2. Description of the Related Art In order to track a target object, it is necessary to measure the direction of the target object and the distance to the target object. Therefore, conventionally, as a means for grasping the direction and distance of a target, for example, with respect to the distance, a technique in which the reflection time of an ultrasonic wave or a laser beam from the object is mainly used. Further, as a means for determining the direction of the target object, it is mainly used to set a specific pulse light source on the target object and measure it with a PSD (positioning sensor) or a CCD (charge coupled device).

[0003]

A distance measuring device using ultrasonic waves or laser light is high in cost, cannot distinguish reflected waves for different target objects, and specifies a target object. Have difficulty. Further, since the direction measuring device using PSD cannot increase the amplification factor so much and has low sensitivity, it is against the demand for high sensitivity of light reception.

Therefore, an object of the present invention is to enable a high amplification of a pulse light having a specific period in order to catch a light emitting source with high sensitivity, and can be widely used in photometers, distance measuring devices, direction measuring devices, etc. An object of the present invention is to provide a high-amplification measuring device for the received light intensity of pulsed light.

[0005]

As means for solving the above-mentioned problems, a measuring apparatus for highly amplifying received light intensity of a specific pulsed light according to the present invention comprises a photoelectric conversion element 1 which outputs a current by receiving light. Tuning amplifier 2 for tuning / amplifying the output from the photoelectric conversion element 1 by pulsed light of a specific cycle
And the output Vo (voltage) amplified by the tuning amplifier 2 and a preset determination reference Vc (voltage) are compared, and the output Vo of the tuning amplifier 2 is determined as the determination reference value Vc.
It is composed of a comparator 3 that outputs ON when it is larger, and outputs OFF when it is smaller, and a device (pulse counter) 5 that calculates the ratio of the ON output state of the ON / OFF output in a certain period of time as the received light intensity of pulse light of a specific cycle. It is characterized by being.

[0006]

The photoelectric conversion element 1 outputs a current having a magnitude corresponding to the amount of received light, and the tuning amplifier 2 amplifies the output of the pulse light having a specific period from the output of the photoelectric conversion element 1 to obtain a response voltage (or Current). The comparator 3 compares the amplified light reception response voltage Vo with the determination reference voltage Vc, and outputs ON when the light reception response voltage Vo exceeds the determination reference voltage Vc, and outputs OFF when it is less than that. The pulse counter 5 calculates the ratio of the ON output and digitally outputs it.

[0007]

EXAMPLE An example of the present invention shown in the drawings will be described below.
The photodiode 1 which is one of the photoelectric conversion elements constituting the high-amplification measuring device shown in FIG. 1 generates (photoelectric conversion) a current having a magnitude (proportional) corresponding to the amount of received light.
The tuned amplifier 2 tunes and amplifies the output of the pulse light having the specific period generated in the photodiode 1, and outputs the amplified output as a light reception response voltage Vo. The comparator 3 compares the light reception response voltage Vo output from the tuning amplifier 2 with the determination reference voltage Vc supplied from the determination reference voltage power supply 4, and is turned on (Vcc) when the light reception response voltage Vo is higher. Volt), and if it is small, it is output as off (zero volt). The judgment reference voltage power supply 4 is configured as a variable type capable of setting the judgment reference voltage Vc to an arbitrary voltage value. The pulse counter 5 reads a certain number of times from the above-mentioned on / off output converted and output from the comparator 3 in a certain period of time to calculate the on-state ratio,
The ratio of this ON state is used as a digital output of the received light intensity of the specific cycle pulsed light.

Next, an example of the operating state of the above-mentioned high amplification measuring apparatus will be described with reference to FIGS. 2 and 3. For example, in the case of performing high amplification such that the voltage gain exceeds 80 dB, after the output of the photodiode 1 is resonance-amplified by the tuning amplifier 2 even if the intensity of the incident light is stable, as shown in FIG. Fluctuates wildly over time. Light reception response voltage Vo
As an example, the graph shown in FIG. 3A is obtained. The saturation voltage of the tuning amplifier 2 of this embodiment is set to 5V. Those that exceed the line of the judgment reference voltage value Vc shown in FIG. 3A by the comparison operation of the comparator 3 output Vcc = 5V (ON state) as an ON output and are below the line of the judgment reference voltage value Vc. Outputs 0 V (off state) as an off output. As a result,
The light reception response voltage Vo of A is output-converted as in the ON / OFF state conversion diagram shown in FIG. 3B. In response to this output conversion, the pulse counter 5 outputs 1000
Assuming that the ON state (ratio) is counted 650 times by going through the reading, the digital output will be output as the received light intensity of "650" in this case.

When the digital output output as described above is used for a photometer, an arithmetic unit (not shown) can express a percentage of the ON state within a certain fixed time as a percentage. For example, the calibration curve shown in FIG. 4 is obtained based on the number of times the 100% light receiving state is turned on. If this calibration curve is read and the received light intensity is displayed by the display device,
The entire high-amplification measuring device described above is used as a photometer. The natural space is usually filled with ambient light, but since the measuring device of the present invention responds only to pulsed light of a specific period,
It is possible to measure the received light intensity with a sufficiently high sensitivity even under ambient light such as sunlight. Further, a distance measuring device, a direction measuring device, and the like, which will be described later, can similarly increase the sensitivity of light reception.

Next, when used as a distance measuring device,
Generally, the intensity of light decreases as the distance from the light source increases. As an example, if the relationship between the received light intensity and the distance is obtained in advance as shown in the graph of FIG.
The distance from the light source to the light source can be estimated and it can be used as a distance measuring device. Further, as a direction measuring device, FIG.
As shown in A, it can consist of a sensor 6 with a photodiode 1 and a focused lens 7 directly behind it. Alternatively, as shown in FIG. 6B,
The sensor 6 may be configured as a bottomed cylindrical cover 8 installed on the bottom surface. In both cases, when the incident area of the incident light B incident on the sensor 6 with respect to the incident light A is compared with the incident area of the incident light A on the sensor 6, in FIG. In 6B, since the cover 8 is a cylinder, the incident area of the incident light B on the sensor 6 is smaller. Since the incident area is small, the amount of incident light is also small, and an inverse proportional relationship is established between the incident angle and the incident light amount. Therefore, the azimuth angle can be measured by digitally outputting the received light intensity from a certain direction with the measuring device of the present invention and performing calculation,
It can be used as a direction measuring device.

[0011]

In the highly amplified measuring apparatus for the received light intensity of the specific pulsed light according to the present invention, the output (current) having a magnitude corresponding to the amount of light received by the photodiode 1 is highly amplified,
Since the intensity is further digitally output, it is possible to measure the intensity of highly amplified specific period pulsed light, the light emission source can be caught with high sensitivity, and it can be widely used in photometers, distance measuring devices, direction measuring devices, and the like.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a high-amplification measuring device for a received light intensity of specific pulsed light according to the present embodiment.

FIG. 2 is a graph showing a change with time of a light reception response output after tuning and amplifying the output of the photodiode of the above.

FIG. 3A is a graph showing a light reception response voltage after being amplified by the above tuning amplifier, and B is a graph showing a relationship in which the light reception response voltage is converted into an ON / OFF output by a comparator.

FIG. 4 is a calibration curve showing the relationship between the percentage of ON output of the comparator and the received light intensity.

FIG. 5 is a curve diagram showing the relationship between the distance between the photodiode and the light source and the count percentage of the pulse counter.

FIG. 6A is a schematic configuration diagram when a lens is used,
B is a schematic block diagram when a cover is used.

[Explanation of symbols]

 1 Photodiode 2 Tuning amplifier 3 Comparator 4 Judgment reference voltage power supply 5 Pulse counter

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location // G01P 3/36 Z 9010-2F

Claims (1)

[Claims] 1. A photoelectric conversion element that outputs a current by receiving light, a tuning amplifier that tunes and amplifies the output from the photoelectric conversion element by pulsed light of a specific period, and an output amplified by the tuning amplifier. A comparator that compares a preset judgment reference value, outputs ON when the output of the tuning amplifier is larger than the judgment reference value, and outputs OFF when the output is smaller than the judgment reference value, and an ON output during a certain time of the ON / OFF output. An apparatus for highly amplifying the received light intensity of a specific pulsed light, comprising: a device for calculating a ratio of states as a received light intensity of a specific cycled pulsed light.