JPH0789049B2 - Displacement gauge - Google Patents

Description

TECHNICAL FIELD The present invention relates to a displacement meter for measuring a displacement between gauge points of a test piece in a material test.

[Prior Art] A conventional displacement meter that measures displacement between gauge marks by a contact method has a drawback that it is difficult to attach to a test piece and is easily damaged when the test piece breaks. Therefore, a non-contact type displacement meter is used. Is becoming more common. As a non-contact type displacement meter, the gauge mark displayed on the test piece was optically read by an image sensor, and the change in the gauge distance displaced by the elongation or compression of the test piece was measured. There is something.

[Problems to be Solved by the Invention] When the gauge mark displayed on the test piece is simply read by the image sensor, the output level of the video signal output from the image sensor changes according to the change of the test piece. Therefore, there is a problem that the detection of the reference point becomes inaccurate as the test progresses.

Therefore, it is an object of the present invention to provide a displacement meter in which a video signal is converted and stored so that it can be handled as a reference point identification signal and can be arithmetically processed.

[Means for Solving Problems] In order to solve the above problems, the present invention employs the following configurations.

That is, the displacement meter according to the present invention expresses brightness by comparing a video signal output from an image sensor for reading a reference point displayed with contrast of light and dark on a test piece with a preset slice signal. It is a displacement meter that binarizes a signal that represents a signal and darkness and outputs it as a bright and dark discrimination signal, and processes this signal to detect the displacement between the reference points. An up-counter for counting in synchronization with a clock signal from the sensor drive signal generating means, a memory for temporarily storing the light-dark discrimination signal for each scanning of the image sensor according to the count of the up-counter, and the memory RAM that sequentially stores the stored brightness / darkness discrimination signal
It is characterized by comprising and.

[Operation] The light-dark discrimination signal is temporarily stored in the memory for each scanning of the image sensor in accordance with the count of the up counter which counts in synchronization with the clock signal from the image sensor drive signal generating means, and is stored in the memory. The generated light / dark discrimination signal is sequentially stored in the RAM. Therefore, the video signal at an arbitrary time can be stored in the RAM, and the arithmetic processing of the video signal according to the change of the test piece becomes possible.

[Embodiment] FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.
FIG. 2 is a time chart showing the operation timing of each unit. The CCD image sensor 1 (hereinafter referred to as CCD) reads a reference mark (not shown) displayed on the test piece with bright and dark contrast. CCD1 has 2048 pixels. The CCD 1 is driven by the CCD clock driver 3. The CCD clock driver 3 receives the signal from the controller signal port P ₀ of the CPU controller 5
Output shift clock to CCD1. At this time, the up counter 6 described later is also reset by the signal from P ₀ . After receiving the shift clock, the CCD 1 outputs a video signal for each clock from the CCD clock driver 3. The video signal output from CCD1 is input to slicer 2. The slicer 2 compares the video signal with a preset slice signal, binarizes the signal representing light and the signal representing dark, and outputs a light / dark discrimination signal. The bright / dark discrimination signal is output while the output of the control signal port P ₁ of the CPU controller 5 is at the L level (second
It is written in the memory 7 during the period A shown in FIG. The address of the memory 7 is incremented by the up counter 6 which counts in synchronization with the CCD clock. After the lapse of the time A for storing the video signal from the CCD 1 in the memory 7, the signal from the signal port P ₁ becomes H level and the memory 7 becomes in the read state. The up-counter 6 is reset by the signal from the signal port P ₂ and the bright / dark discrimination signal in the memory 7 is read in synchronization with the clock signal output from the signal port P ₃ . Read data is signal port
The data is fetched from P ₄ into the CPU controller 5 and sequentially stored in the RAM 9. That is, 2048 clocks are output from the signal port P ₃ during the time B shown in FIG. 2, data is periodically taken in from the signal port P ₄ in response to this signal, and the data is transferred to a predetermined storage address of the RAM corresponding to the clock. Store in sequence. Third
The figure shows the storage state of the bright / dark discrimination signal stored in RAM. R
The bright / dark discrimination signal stored in AM9 is read out as appropriate, a change point between light and dark or a change from dark to light is detected to detect the gauge point position, and the displacement between the gauge points is measured by arithmetic processing.

When there are a plurality of CCDs, they can be simultaneously stored in the memory 7 and read into the RAM 9 as shown in FIG.

Further, by changing the cycle of the shift clock from the signal port P _0, it is possible to change the setting of the charge storage time of the CCD.

[Effects of the Invention] As is clear from the above description, according to the displacement meter of the present invention, the video signal at an arbitrary time can be stored in the RAM, and the arithmetic processing of the video signal according to the change of the test piece can be performed. I was able to do it.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG.
Figure is a time chart showing the operation timing, and Figure 3 is RA
Fig. 4 shows a state where data is stored in M. Fig. 4 shows multiple CCDs.
It is a figure which shows the case where is used. 1 …… CCD, 3 …… CCD clock driver, 5 …… CPU
Controller, 6 ... Up counter, 7 ... Memory, 9 ... RAM

Claims (1)

[Claims] 1. A video signal output from an image sensor for reading a reference point displayed with contrast of light and dark on a test piece is compared with a preset slice signal to show a signal representing light and a signal representing dark. An image sensor drive signal generating means for generating a drive signal for an image sensor, which is a displacement meter for binarizing a signal, outputting the signal as a light / dark discrimination signal, and processing the signal to detect the displacement between the reference points. An up-counter that counts in synchronization with a clock signal from the memory, a memory that temporarily stores the light-dark discrimination signal for each scan of the image sensor according to the count of the up-counter, and a light-dark discrimination stored in the memory. A displacement meter comprising a RAM for sequentially storing signals.