JPS63146335A - Image input unit - Google Patents

Abstract

PURPOSE:To display a still picture in TV scanning speed on a TV monitor, by installing both first and second line counters, a comparator, a writing device and a memory, altogether. CONSTITUTION:With a start switch (unillustrated herein) operated, a starting signal is given to a second input terminal 26 of an image input unit 1, while a traveling contact of an electronic switch 19 is selected to the side of an output terminal 3 of the unit 1. A second line counter 10 is reset by the starting signal and its discrete value comes to zero. On the other hand, a first line counter 8 is also reset when a vertical synchronizing signal is detected by a vertical synchronizing signal detector 4 and its discrete value comes to zero as well. When discrete values of both these line counters 8 and 10 are accorded with each other, a coincident signal is given to a writing device from a comparator 9. With this constitution, a device 7 writes a still picture signal into a memory 6 at writing speed corresponding to TV scanning speed. Thus, a still picture at the TV scanning speed can be displayed on a TV monitor 25.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention is suitable for use in an analysis apparatus, such as a scanning electron microscope (SEM), which is equipped with an excitation source that is scanned two-dimensionally over an analysis sample. Regarding input devices.

(b) Prior art and its problems In general, in a scanning electron microscope, an electron beam serving as an excitation source is scanned two-dimensionally over a sample surface to detect secondary electrons, etc., and the detected signal is intensity-modulated. and T
Various images are displayed on the V monitor.

In a conventional scanning electron microscope, the obtained detection signal is once written into an image memory at a writing speed corresponding to the scanning speed of the scanning electron microscope, and read out from the image memory at a reading speed corresponding to the TV scanning speed. I am trying to display an image on the monitor. In such a scanning electron microscope, if an attempt is made to display not only a detection signal but also a still image signal at a TV scanning speed from an external TV camera, etc. on the TV monitor, the TV scanning speed is stored in the image memory. Video signals must be written at a high speed corresponding to the speed, which makes peripheral circuits complicated and increases costs.

The present invention has been made in view of the above points, and it is an object of the present invention to enable a still image at a TV scanning speed to be displayed on a TV monitor such as a scanning electron microscope with a relatively simple configuration. .

(C) Means for Solving the Problems In order to achieve the above-mentioned object, the present invention converts a still image signal at a TV scanning speed into an image at a scanning speed of an excitation source that is two-dimensionally scanned over an analysis sample. An image input device that converts into a signal and outputs the signal includes a memory into which one line of video signals is written and read out, and a readout unit that reads out the video signals from the memory at a readout speed corresponding to the scanning speed of the excitation source. a first line counter that counts a horizontal synchronizing signal corresponding to a scanning line number of the still image video signal at the TV scanning speed; and a clock that counts a horizontal synchronizing signal corresponding to a scanning line number of the excitation source output from the reading means. a second line counter; a comparison circuit that compares the counted values of both line counters and outputs the coincidence signal when they match; , a writing means for writing into the memory at a writing speed corresponding to the TV scanning speed.

(D) Effect According to the above configuration, it is possible to convert a still image video signal at a TV scanning speed into a video signal at a scanning speed of an excitation source that is two-dimensionally scanned over an analysis sample.

(e) Examples Examples of the present invention will now be described in detail with reference to the drawings. The drawing is a block diagram of one embodiment of the present invention. The image input device l of this embodiment is a scanning electron microscope (SE
M), and this image input device 1 is equipped with a TV input terminal 2, which is provided to a first input terminal 2 from, for example, a TV camera.
A still image video signal at a scanning speed is converted into a video signal at a scanning speed of a scanning electron microscope and outputted from an output terminal 3.

A still image video signal at the TV scanning speed from the first input terminal 2 (
The composite video signal) is applied to a vertical synchronization signal detection circuit 4, a horizontal synchronization signal detection circuit 5, and a writing means 7 for writing one line of still image video signals into a dual port memory 6 at a writing speed corresponding to the TV scanning speed. It will be done. Since this still image video signal at the TV scanning speed corresponds to a still image, the same video signal is repeatedly given.

Vertical synchronization signal detection circuit 4 and horizontal synchronization signal detection circuit 5
provides corresponding outputs to the first line counter 8 each time a vertical synchronization signal and a horizontal synchronization signal are detected.

The first line counter 8 counts the output of the horizontal synchronization signal detection circuit 5 and is reset by the output of the vertical synchronization signal detection circuit 4. That is, this first line counter 8
This means that the horizontal synchronization signal corresponding to the scanning line number of the still image video signal at the scanning speed is counted. The output of this first line counter 8 is given to a comparison circuit 9.

The comparison circuit 9 is supplied with the output of the first line counter 8 and the output of the second line counter 10, and when the counted values of both line counters 8.10 are compared and match, A match signal is output to the writing means 7.

The second line counter 10 counts clocks corresponding to the scanning line number of the scanning electron microscope output from the reading means 11 for reading the video signal from the dual port memory 6. That is, the count value of the second line counter 10 corresponds to the scanning line number of the video signal read out from the dual port memory 6 as described later.

In response to the match signal from the comparator circuit 9, the TV for l lines is
A writing means 7 for writing a still image video signal at a scanning speed into the dual port memory 6 at a writing speed corresponding to the TV scanning speed includes a first oscillation circuit 12 that generates a first clock corresponding to the TV scanning speed, and a coincidence signal. 1st in response to
a gate circuit I3 that outputs a clock; an A/D conversion circuit 14 that A/D converts a still image video signal at a TV scanning speed based on the first clock from the gate circuit 13;
It also consists of a dot counter 15 which generates a write address based on the first clock.

The readout means 11 that reads the video signal from the dual port memory 6 at a readout speed corresponding to the scanning speed of the scanning electron microscope includes a second oscillation circuit 16 that generates a second clock corresponding to the scanning speed of the scanning electron microscope; This second
A read counter 17 generates a read address based on a second clock from an oscillation circuit 16.

This read counter 17 is connected to the dual port memory 6
Every time reading of one line of video signal from
A carry output as a clock corresponding to the scanning line number of the scanning electron microscope is given to the second line counter IO.

That is, the count value of the second line counter 10 corresponds to the scanning line number of the video signal read out from the dual port memory 6. This second line counter lO is reset by a start signal from the second input terminal 26. This start signal is given by the user operating a start switch on the operating section in order to operate the image input device l.

The video signal read from the dual port memory 6 at a speed corresponding to the scanning speed of the scanning electron microscope is converted into an analog signal by the D/A conversion circuit 18 and output to the output terminal 3.

20 is a detector of a scanning electron microscope that detects secondary electrons from the surface of an analysis sample, and 21 is an amplifier that amplifies the detection signal. 19 is a switching circuit that selects either the detection signal from the scanning electron microscope or the video signal from the image input device 1 according to the present invention;
The output of 9 is A/D converted by the A/D conversion circuit 22 and written to the image memory 23. The image data is read out from this image memory 23 in synchronization with TV scanning and is D/A.
The signal is D/A converted by the conversion circuit 24 and is provided to the TV monitor 25 for display.

Next, the operation of the image input device 1 having the above configuration will be explained.

First, T applied to the first input terminal 2 of the image input device l
When a still image video signal at a V scanning speed is to be displayed on the TV monitor 25, a start switch of an operation section (not shown) is operated. As a result, the second
When the start signal is applied to the input terminal 26, the movable contact of the switching circuit 19 is switched to the output terminal 3 side of the image input device 1.

The second line counter lO is reset by the start signal and its count value becomes O. On the other hand, when the vertical synchronization signal detection circuit 4 detects the vertical synchronization signal, the first line counter 8 is also reset and its count value becomes zero. When the count values of both line counters 8 and 10 match, a match signal is applied from the comparison circuit 9 to the writing means 7. Thereby, the writing means 7 writes the still image video signal at the TV scanning speed corresponding to the 0th scanning line into the dual port memory 6 at the writing speed corresponding to the TV scanning speed.

The video signal of the 0th scanning line is read out from the dual port memory 6 at a low speed corresponding to the scanning speed of the scanning electron microscope by the decoding means 11, and is D/A converted and output.

When the reading of the video signal of the 0th scanning line is completed, the carry output from the reading means 11 is given to the second line counter 10, and the count value of the second line counter 10 becomes 1. On the other hand, the first line counter 8 counts horizontal synchronizing signals, and its count value becomes 1 when the horizontal synchronizing signal corresponds to the first scanning line. When the counted values of both line counters 8 and 10 match, a match signal is applied from the comparison circuit 9 to the writing means 7. In response to this coincidence signal, the writing means 7 (thus write T
V-scanning speed still image video signals are stored in dual port memory 6
will be written to. The video signal of the first scanning line is read out from the dual port memory 6 at a low speed corresponding to the scanning speed of the scanning electron microscope by the reading means 11, converted into D/A, and output.

When the reading of the video signal of the first scanning line is completed, the carry output from the reading means 11 is given to the second line counter 10, and the count value of the second line counter 10 becomes two. On the other hand, the count value of the first line counter 8 becomes 2 due to the horizontal synchronization signal corresponding to the second scanning line. Both line counters8. When the count values of lO match, a match signal is given from the comparison circuit 9 to the writing means 7. In response to this, the writing means 7 writes T
A still image video signal at a TV scanning speed corresponding to the second scanning line is written to the dual port memory 6 at a writing speed corresponding to the V scanning speed.

The video signal of this second scanning line is read out from the dual port memory 6 at a low speed corresponding to the scanning speed of the scanning electron microscope by the reading means it, converted into D/A, and output.

Thereafter, in the same way, the still image video signal at the TV scanning speed is sequentially converted into a video signal at the scanning speed of the scanning electron microscope for each line and is output. The video signal from this human-powered image device 1 is written into the image memory 23. This image memory 23 contains X.

A carry output from the reading means 11 and a second input terminal 26 as horizontal and vertical synchronizing signals for specifying the Y direction.
A start signal is given from . The video signal written in the image memory 23 is read out at the TV scanning speed and displayed on the TV monitor 25.

Although the above-mentioned embodiment describes the case where the present invention is used in a scanning electron microscope, the present invention is not limited thereto, and can of course be applied to other analytical devices such as EPMA.

(f) Effects As described above, according to the present invention, the TV can be set with a relatively simple configuration.
It is possible to convert a still image signal at a scanning speed into a video signal at a scanning speed of an excitation source that is two-dimensionally scanned over an analysis sample. This means that a scanned image and a still image at the TV scanning speed can be displayed in common.

[Brief explanation of the drawing]

The drawing is a block diagram of one embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Image input device, 6... Dual port memory, 7... Writing means, 8... First line counter, 9... Comparison circuit, lO... Second line counter,
11...Reading means.

Claims (1)

[Claims] (1) In an image input device that converts a still image video signal at a TV scanning speed into a video signal at a scanning speed of an excitation source that is two-dimensionally scanned over an analysis sample and outputs the video signal, a video signal for one line is written. a memory to be read out at the same time; a readout means for reading out a video signal from the memory at a readout speed corresponding to the scanning speed of the excitation source; and a horizontal synchronization signal corresponding to a scanning line number of the still image video signal at the TV scanning speed. a first line counter that counts the clocks corresponding to the scanning line number of the excitation source output from the readout means; and a second line counter that counts the clocks corresponding to the scanning line number of the excitation source output from the readout means. A comparison circuit outputs a coincidence signal, and in response to this coincidence signal, a still image video signal at a TV scanning speed of one line is transmitted to T.
An image input device comprising: writing means for writing into the memory at a writing speed corresponding to a V-scanning speed.