JPH0478934B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention detects infrared rays periodically emitted from the object by scanning the object to be measured, and detects the infrared rays periodically emitted from the object to be measured, and detects the infrared rays emitted periodically from the object to be measured. The present invention relates to an infrared temperature distribution measuring device that sequentially samples electric signals generated during the above-mentioned periods and measures the temporal change distribution of temperature occurring within each period.

[Summary of the invention]

The present invention provides an infrared temperature distribution measuring device that includes:
By sampling with a plurality of sampling pulses corresponding to a plurality of arbitrarily set periods within each cycle, the measurement time required to create a plurality of screens can be significantly shortened.

[Conventional technology]

The applicant previously filed Japanese Patent Application No. 58-213863 (Japanese Unexamined Patent Publication No.
60-105930), the scanning of the object to be measured is synchronized with a periodic signal for causing an appropriate periodic temperature change in the object to be measured or a periodic signal obtained from a periodic temperature change caused by the object to be measured. A synchronous infrared temperature sensor that creates an image signal from a series of sample signals obtained by sampling the temperature signal (electrical signal corresponding to temperature) obtained by each cycle at any time from the beginning of each cycle. A distribution measuring device has been disclosed.

[Problem that the invention seeks to solve]

The above-mentioned prior invention considers only the creation of one screen, that is, the creation of one channel image, and cannot be used as it is in the case of multiple channels. In other words, with this synchronous measurement method, it takes time to create one screen if the period of the periodic signal is long (for example, if the period of 100 milliseconds is 100 milliseconds for a 1 mm ^2nd object, it will take about 20 minutes to make one image). Therefore, there is a problem in that it takes too much time to create multiple screens to obtain thermograms in various transient states.

Therefore, it is an object of the present invention to provide an infrared temperature distribution measuring device that can simultaneously obtain a plurality of thermograms in various transient states such as temperature rise and fall in one measurement.

[Means for solving problems]

The present invention creates and samples multiple types of sampling pulses that are generated in synchronization with each cycle corresponding to a plurality of arbitrarily set periods within each cycle, and samples the resulting multiple types of sampling pulses. Hold sample values and store them in multiple memories,
Image signals are constructed and displayed from the outputs of these memories.

[Effect]

By using multiple types of sampling pulses, multiple types of image signals can be obtained in one measurement.

〔Example〕

FIG. 1 is a block diagram showing a first embodiment of the present invention. Comparing this with the prior invention mentioned above,
When the sampling pulse generation circuit generates multiple types of sampling pulses, the difference is that there are multiple sample hold circuits, multiple memories, and display control circuits, and other aspects are almost the same.

Generally, when creating a two-dimensional thermogram, there are two methods of scanning: one is to move the object to be measured in the X and Y directions, and the other is to optically scan the surface of the object in the X and Y directions. Although either method may be used in the present invention, for convenience, the following embodiments use the former scanning method. In FIG. 1, the object to be measured is placed on a stage, and the stage is moved in the X and Y directions by horizontal and vertical drive circuits.
The detection section converts infrared energy emitted from the object to be measured during scanning into an electrical signal, and the signal processing circuit amplifies this electrical signal and adjusts its level. Periodically varying energy is supplied to the object to be measured from the energy supply means to vary its temperature. A periodic signal with a desired period, which is a source of energy fluctuation, is applied to the energy supply means from a periodic signal generating circuit. The temperature of the object to be measured periodically fluctuates up and down, and the electrical signal corresponding to the temperature detected by the detection unit also changes in the same way. A part of the periodic signal is input to a sampling pulse generation circuit and a scanning control signal generation circuit.

The sampling pulse creation circuit creates a sampling pulse delayed by a time δ set corresponding to an arbitrary desired elapsed time point from the start of each period for each period of the periodic signal. While we created sampling pulses of
In the present invention, a plurality of sampling pulses are created for each cycle. That is, in the present invention, a plurality of delay times are set within each cycle as δ ₁ , δ ₂ , ..., δn, and the number n is 2 in the case of 2 screens, 4 in the case of 4 screens, and 4 in the case of 6 screens. 6. Let's say... It goes without saying that these set periods are matched to times corresponding to various transient states to be observed (various elapsed times from temperature rise to temperature fall).
Therefore, the sampling pulse generation circuit generates n types of sampling pulse trains having the same cycle and slightly shifted phases, and drives the plurality of sample and hold circuits SH ₁ , SH ₂ , . . . , SHn.

The scanning control signal generation circuit moves the stage in the X and Y directions (object to be measured) by the required number of pixels from one pixel corresponding to the instantaneous measurement area by the detection unit in synchronization with the periodic signal from the periodic signal generation circuit. When is linear, a scan control signal is generated to move the object in the X direction only). Sampling hold circuit SH ₁ ~ SHn
holds n types of sample values (pixel signals) corresponding to the same set period within each cycle from the electric signal corresponding to the temperature from the signal processing circuit by n types of sampling pulse trains from the sampling pulse generation circuit. . Each of these pixel signals is stored in the corresponding memory M ₁ , M ₂ ,...,
The pixel signals are sequentially stored in Mn and stored in the memory, with the address of each pixel signal being shifted one by one by the scan control signal from the scan control signal generation circuit and stored in the memory. After n screens worth of image signals are stored in the memories M ₁ to Mn in this manner, the display control circuit extracts the image signals as RGB or NTSC signals and displays them as a thermogram on the display section. In this case, possible display methods include a method in which each thermogram is displayed in sequence one by one, and a method in which each thermogram is displayed simultaneously on one screen. The former is suitable for examining each thermogram in detail, and the latter is suitable for comparing and examining each thermogram, although the display surface is divided, resulting in a smaller image.

FIG. 2 is a block diagram showing a second embodiment of the invention. This example uses a sample and hold circuit
The outputs of _SH1 to SHn are input to a subtraction circuit via a switching circuit, and the outputs are stored in another memory _M0 . In this figure, the switching circuit selects any two of the sample-and-hold circuits SH ₁ to SHn and inputs them to _one subtraction circuit.
It is also possible to input two arbitrary different items selected from SHn. In this case, memory
Multiple _M0s are also required. Since the difference between two pixel signals approximately represents the change in that pixel, the image signal from memory M ₀ is displayed as a thermogram showing the temperature distribution only by the change in temperature transient phenomenon.

It is common practice to extract changes by subtracting pixel signals, but in this example, the subtracted values of pixel signals are stored in the memory _M0 , so a thermogram of changes can be obtained in one measurement. In this example, the operation when the subtraction circuit is not used is the same as that in FIG. 1.

〔Effect of the invention〕

As explained above, the effects of the present invention are as follows.

(1) Since multiple types of thermograms can be obtained at the same time in one measurement, measurement time can be significantly shortened.

(2) Similarly, changes in temperature distribution can be obtained as a thermogram in a short time with a single measurement.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a first embodiment of the invention, and FIG. 2 is a block diagram showing a second embodiment of the invention. _SH1 ~ SHn……Sample hold circuit, _M0 ,
_M1 ~Mn...Memory.

Claims (1)

[Scope of Claims] 1. The object to be measured is scanned to detect infrared rays periodically emitted from the object to be measured, and electrical signals corresponding to the temperature on the object to be measured are sequentially sampled. In an infrared temperature distribution measuring device that measures the temporal change distribution of temperature occurring within each cycle, the sampling pulse generation circuit generates multiple types of sampling pulses corresponding to any plurality of set periods within each cycle; a plurality of sample hold circuits each holding sample values corresponding to the same set period within each cycle sampled by the sampling pulse; a plurality of memories each connected to the sample hold circuit and storing the sample values; An infrared temperature distribution measuring device comprising: a display control circuit that outputs the output signals of the plurality of memories to a display section as image signals. 2. The infrared temperature distribution measuring device according to claim 1, wherein at least two of the plurality of sample and hold circuits are selected and respective sample values are subtracted and stored in a memory.