JPH01272929A - Optical measuring instrument - Google Patents

Abstract

PURPOSE:To facilitate switching between AC measurement and DC measurement by switching and connecting a pulse generating circuit to a pulse motor driving circuit directly at the time of the AC measurement and through a gate circuit to a pulse motor driving circuit at the time of the DC measurement. CONSTITUTION:The output of the pulse generating circuit 4 is supplied to the pulse motor driving circuit 5 through a changeover switch S1 to drive a pulse motor M, and a rotary sector 1 rotates. A position signal corresponding to the cut part of the rotary sector 1 is detected by a position detecting means 6 which utilizes the reflection of light, etc., and inputted to the gate circuit 7 like an AND circuit together with the output of the pulse generating circuit 4. The changeover switch S1 connects a common C to an AC contact at the time of the AC measurement to connect the pulse motor driving circuit 5 to the pulse generating circuit 4 directly. Further, the changeover switch S1 connects the common C to a DC contact at the time of the DC measurement to supply the output of the gate circuit 7 to the pulse motor driving circuit 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an optical measuring device capable of direct current measurement and alternating current measurement of incident light.

[Prior Art] A photovoltaic element (for example, 3i SQe photodiode, 11IAS, 11ISb) is a detection element that detects incident light by utilizing a photovoltaic effect that generates an electromotive force when infrared rays are incident.

As a circuit using this element, as shown in FIG. 4, there is a circuit in which incident light is intermittently made incident on a detector 2 by a rotating sector 1 rotated by a motor M, and is amplified by an amplifier A for measurement.

[Problem to be solved by this invention] In the case of this signal processing, there are DC measurement and AC measurement.In the case of DC measurement, there is no driving part such as a rotating sector (chopper), so signal processing is easy and the response speed is fast. , it is necessary to perform direct current correction such as the drift of the dark current of the device. Further, in AC measurement, DC correction is not necessary, but the response is slow because it depends on the rotational frequency of the rotating sector, and the apparatus and circuitry become complicated. For this reason, it is necessary to use both separately.

If an AC measurement device having a rotating sector as shown in FIG. 4 is simply switched from AC measurement to DC measurement, there is a problem that the incident light may not reach the detection element depending on the stopping position of the rotating sector.

In view of the above points, an object of the present invention is to provide a switching switch = 2
- To provide an optical measuring device that can easily switch between AC measurement and DC measurement by providing a switch.

[Means for Solving the Problem 1] This defense allows the output of the pulse generation circuit to pass when the output of the position signal detection means that generates the position signal corresponding to the notch of the rotating sector rotated by the pulse motor is not generated. Goo 1~ Optical measuring device equipped with a circuit and a changeover switch for directly connecting the pulse generation circuit to the pulse motor drive circuit during AC measurement and connecting the gate circuit to the pulse motor drive circuit during DC measurement f) It is.

[Embodiment] FIG. 1 is an explanatory diagram of the configuration of an embodiment of the present invention.

In the figure, incident light 1- is interrupted by a rotating sector 1 rotated by a pulse motor M, detected by a detector 2, and signal-processed by a measuring means 3 to measure the temperature of the object to be measured. In addition, the output of the pulse generation circuit 4 or the selector switch S1
The signal is supplied to the pulse motor driving circuit 5 via the pulse motor M, and the pulse motor M is driven to rotate the rotation sector 1. A position signal corresponding to the notch of the rotating sector 1 is detected by a position detection means 6 that uses reflection of light, etc., and is input to circuits 1 to 7 such as an AND circuit together with the output of the pulse generation circuit 4. , is supplied to the pulse motor drive circuit 5 via the changeover switch S1, and the check means 8 controls the pulse generation of the pulse generation circuit 4 via the switch S2. During AC measurement, the changeover switch S1 connects the common C to the AC contact, and connects the pulse motor drive circuit 5 and the pulse generation circuit 4.
During DC measurement, the common C is connected to the DC contact and the output of the goo 1-circuit 7 is switched and connected so that it is supplied to the pulse motor drive circuit 5.

Further, as shown in FIG. 2, the rotating sector 1 has a plurality of flexible parts 1a and notches 1b on its outer periphery, and is located approximately at the center of each notch 1b. It has a detection hole 1C, and the position detection means 6 emits and receives light,
If the reflected light is reflected, a detection signal for the right side of the notch 1b is generated.

= 4 - Next, the operation will be explained with reference to FIG.

When measuring an AC signal, the common of the changeover switch S1 is connected to the AC contact, and the switch S2 is connected to the AC contact. Pulse generation circuit 4
The pulse output is supplied to the pulse motor drive circuit 5 via the changeover switch S1, the pulse motor M rotates, and the rotation sector 1 rotates.

As a result, the incident light is intermittently converted into alternating current and enters the detector 2, and an alternating current signal enters the measuring circuit 3. At this point, the output J of the position detection means 6 is the pulse Jfi raw circuit 4.
does not affect.

When measuring a DC signal, the common C of the changeover switch S1 is connected to the DC contact, and the switch S2 is closed.

Then, the pulse output of the pulse generation circuit 4 as shown in FIG. , the rotation also rotates the lid 1.

The output of the position detection means 6 for detecting the position of the notch 1b is supplied to the gate circuit 7 at 1 level when the hole 1C is not detected, thereby avoiding the pulse output of the pulse generation circuit 4. This pulse is checked by the checking means 8, and the pulse generation of the pulse generating circuit 4 is stopped.

The position signal detecting means 6 rotates sequentially, and the position signal detecting means 6 detects the notch 11 . When the hole 1C corresponding to 1 is detected, an L level signal is supplied to the gate circuit 7, and at this time the gate circuit 7 does not allow the pulse from the pulse generating circuit 4 to pass through.

The check means 8 detects that this pulse does not come, and generates a stop signal to the pulse generating circuit 4 to stop pulse generation. In this state, switch $1 is opened.

When the pulse motor M is stopped at such a position, the hole ic is located at the center of the notch 1b between the shield parts 1a and the shield part 1a, as shown in FIG. Therefore, the shielding part 1a does not come to the detector 2, but the notch part 1b comes to the detector 2, and direct current measurement can be performed. Although not shown, the measuring means 3 may include an alternating current circuit and a direct current circuit, and may be used by switching between them. Also, check means 8
A visual light-emitting element is provided to allow a human to press the switch S2.
You can leave it blank.

[Effects of the Invention] As described above, the present invention utilizes a position detection means etc. to correctly position the detector in the notch of the rotating sector, so even if the device is for AC measurement, The incident light enters the detector without being obstructed by the rotating sector, making it possible to easily perform not only AC but also DC measurements.

[Brief explanation of the drawing]

1 and 2 are configuration explanatory diagrams showing one embodiment of the present invention, FIG. 3 is a signal explanatory diagram, and FIG. 4 is a configuration explanatory diagram showing a conventional example. DESCRIPTION OF SYMBOLS 1... Rotating sector, 2... Detector, 3... Measuring means, 4... Pulse generating circuit, 5... Pulse motor drive circuit, 6... Position detecting means, 7... gate circuit,
8... Check means, Sl... Changeover switch, S2
...Switch, M...Pulse motor

Claims (1)

[Claims] 1. A rotating sector that is rotated by a pulse motor and has a plurality of notches for intermittent incident light, a position detecting means that generates a signal corresponding to the position of the notch of this rotating sector, and this position detecting means. A gate circuit that allows the output pulses of the pulse generation circuit to pass through when the output signal does not generate a detection signal, and a gate circuit that connects the pulse generation circuit and pulse motor drive circuit when measuring AC, and connects the gate circuit to the pulse motor drive circuit when measuring DC. Optical measurement device equipped with a changeover switch for