JP2001007710A - Digital signal transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital signal transmission system for quickly operating signal transmission which can be applied to a digital image pickup device in a surface flaw detecting device for detecting the surface flaw of steel, which is several tens of meters long. SOLUTION: This system is provided with a digital image pickup means 1, a transmission signal processing means 2 for converting image data image picked-up by the digital image pickup means 1 into a serial signal, and for transmitting it, and a reception signal processing means 3 for receiving the serial signal transmitted from the transmission signal processing means 2, and for shaping the waveform, and for converting the serial signal into a parallel signal, and for transmitting it to an image processing means 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a digital signal transmission system. More specifically, the present invention relates to a digital signal transmission system capable of transmitting an image signal from a digital imaging device up to several tens of meters.

[0002]

2. Description of the Related Art Conventionally, as a method for detecting a surface flaw of a steel material, as shown in FIG. 6, a fluorescent magnetic powder is applied to a steel material surface S, and then the fluorescent magnetic powder is irradiated with ultraviolet rays to form the steel material surface S.
A pattern is formed on the surface of the trolley, and the pattern is imaged while moving a CCD camera (analog CCD camera) 1 ′ mounted on a trolley along the steel material W, and the imaged pattern is processed by an image processing device. Flaw detection has been performed.

In recent years, as this CCD camera, a digital C
CD cameras have been developed and put to practical use. The use of this digital CCD camera has the following advantages over the use of the analog CCD camera 1 '.

(1) Since an image can be captured by a progressive operation, a sharp image without blur can be captured when capturing a moving image.

(2) Higher-speed output is possible than with the analog CCD camera 1 '.

(3) Since the digital transmission system is used, there is little risk of deterioration of the transmission signal.

However, when image data captured by a digital CCD camera is transmitted at a high speed of 10 megabytes / second, the conventional RS-422 system can only transmit data up to several meters. Therefore, the digital CCD camera using the conventional transmission method cannot be used as an imaging device in a surface flaw flaw detection device for the steel material W which needs to take an image while moving along the steel material W having a length of several tens of meters.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is directed to a digital image pickup apparatus in a surface flaw detection apparatus for detecting a surface flaw of a steel material having a length of several tens of meters. It is a main object of the present invention to provide a digital signal transmission system which can be applied and can perform signal transmission at high speed.

[0009]

According to a first aspect of the present invention, there is provided a digital imaging unit, a transmission signal processing unit for transmitting image data captured by the digital imaging unit as a serial signal, and the transmission signal processing unit. And a reception signal processing means for receiving a serial signal transmitted from the digital signal processor, shaping the waveform thereof, and converting the signal into a parallel signal and transmitting the parallel signal to the image processing means.

In the first embodiment of the present invention, for example, the transmission signal processing means includes a parallel / serial converter for converting a parallel signal into a serial signal, and the parallel / serial converter.
A serial signal transmitter for receiving and transmitting a serial signal generated by a serial converter, wherein the reception signal processing means shapes a waveform of the serial signal transmitted from the transmission signal processing means. , A serial signal receiver for receiving and transmitting a serial signal whose waveform has been shaped by the waveform shaper, and a serial / parallel converter for converting a serial signal transmitted from the serial signal receiver into a parallel signal It has the following.

According to a second aspect of the present invention, there is provided a fluorescent magnetic particle flaw detection apparatus comprising: digital imaging means; and image processing means for performing image processing on a digital image captured by the imaging means. Transmission of image data to the image processing means is performed by the digital signal transmission method.

[0012]

Since the present invention is configured as described above, noises and the like superimposed during transmission of image data picked up by the digital image pickup means to image processing means provided at a location about 50 m away are removed. Can be entered with

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments with reference to the accompanying drawings, but the present invention is not limited to only such embodiments.

FIG. 1 is a schematic diagram of a digital signal transmission system (hereinafter, simply referred to as a signal transmission system) according to an embodiment of the present invention, and FIG. 2 is a block diagram thereof. In this embodiment, the signal transmission system of the present invention is applied to a fluorescent magnetic powder device A.

The signal transmission method according to this embodiment is based on a combination of a parallel signal transmission method and a serial signal transmission method.

That is, as shown in FIGS. 1 and 2,
A parallel / serial converter 21 for converting a parallel signal into a serial signal as transmission signal processing means 2 for processing digital image data from a digital CCD camera (digital imaging means) 1 in the traveling vehicle B; A signal processing unit having a serial signal transmitter 22 for transmitting the serial signal generated by the converter 21 to the image processing apparatus side C, and the transmission signal processing means on the image processing apparatus (image processing unit) side C. Receiving signal processing means 3 for processing a serial signal transmitted from
A signal processing means having a waveform shaper 31, a serial signal receiver 32 for receiving a serial signal shaped by the waveform shaper 31, and a serial / parallel converter 33 for converting a serial signal into a parallel signal. It is provided.

The parallel / serial converter 21, serial signal transmitter 22, serial signal receiver 32, and serial / parallel converter 33 are so-called LVDS.
(Low Voltage Differential
Signaling transmission method can be suitably used.

The waveform shaper 31 forms a waveform of a transmission signal transmitted through a transmission cable having a length of, for example, about 50 m and deteriorated by noise superimposed in the middle of the transmission signal by providing a cable security circuit. For example, as shown in FIG.
a, a servo controller 31b, and a feedback comparator 31c. Here, the adaptive filter 31a has a function of equalizing the waveform, the feedback comparator 31c has a function of shaping the DC portion, and the servo controller 3
1b has a function of restoring the sharpness of the waveform.

Next, an example of signal transmission in this embodiment will be described with reference to FIG. 4 and FIG.

The digital image data from the digital CCD camera 1 is a data group (D11 to D11) composed of two 8-bit data units according to the RS-422 transmission method.
18, D21 to D28,...) Are input to the parallel-serial converter 21. The digital image data input to the parallel / serial converter 21 is converted into a serial signal having seven data units as one series. That is, LD1 (D11 to D17) and LD2 (D18, D18
21 to D26) and LD3 (D27, 28,...),. Then, the serial data group thus converted is used as a synchronization signal (clock signal: 2).
0 MHz), that is, transmitted to the image processing apparatus side C by the serial signal transmitter 22 at 140 MHz.

The digital image data arriving at the image processing device side C is subjected to waveform shaping by a waveform shaper 31 and then received by a serial signal receiver 32 to be transmitted to a serial / parallel converter 33. 33 converts the signal into a parallel signal. That is, L
D1 (D11 to D17), LD2 (D18, D21 to D
26), LD3 (D27, 28,...),.
18, D21 to D28,...). Thereafter, this data group is processed by the image processing device 4 in the same manner as in the prior art to detect surface flaws.

As described above, according to this embodiment, the image data picked up by the digital CCD camera 1 is
The image data can be transmitted to the image processing device 4 installed at a distant place. The transmitted image data is stored in the image processing device side C.
Since the waveform shaping is performed, the influence of noise or the like superimposed during transmission can be eliminated. Therefore, the image can be restored with high accuracy, and the flaw detection accuracy is improved.

As described above, the present invention has been described based on the embodiments. However, the present invention is not limited to only the embodiments, and various modifications can be made. For example, in this embodiment, the case where the present invention is applied to the fluorescent magnetic particle flaw detector A is described, but the application of the present invention is not limited to the fluorescent magnetic particle flaw detector A, and the digital CCD camera 1 is used. Applicable to various devices.

[0024]

As described in detail above, according to the present invention,
The image data captured by the digital imaging means is
An excellent effect is obtained in that input can be made to the image processing means installed at a location about m away from the image processing means while noise or the like superimposed during transmission is removed.

[Brief description of the drawings]

FIG. 1 is a schematic view of a fluorescent magnetic particle flaw detector to which a digital signal transmission system of the present invention is applied.

FIG. 2 is the same block diagram.

FIG. 3 is a block diagram of an example of a waveform shaper used in the digital signal transmission system of the present invention.

FIG. 4 is an explanatory diagram of an example of a digital signal transmission system according to the present invention.

FIG. 5 is an explanatory diagram of an example of a serial signal in the example.

FIG. 6 is a schematic view of a conventional fluorescent magnetic particle flaw detector.

[Explanation of symbols]

 Reference Signs List 1 digital CCD camera (digital imaging means) 2 transmission signal processing means 21 parallel / serial converter 22 serial signal transmitter 3 reception signal processing means 31 waveform shaper 32 serial signal receiver 33 serial / parallel converter 4 image processing device ( Image processing means) A Fluorescent magnetic particle flaw detector B Traveling car C Image processor side S Steel surface W Steel

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G051 AA37 AB07 BA05 CA04 EA12 EA19 EA20 EA21 GA10 GB02 GC04 GC18 GD02 GE01 2G053 AA11 AB22 BA02 BA13 BB03 CB29 DC03 DC17 5C054 AA01 CC02 CH02 EA01 EA03 A05 A05 FC05 BB01 DD02 EE18 GG07 HH01 HH05

Claims (3)

[Claims] 1. A digital imaging unit, a transmission signal processing unit for transmitting image data captured by the digital imaging unit as a serial signal and transmitting the serial signal transmitted from the transmission signal processing unit, A digital signal transmission system comprising: a reception signal processing unit configured to convert a waveform into a parallel signal and transmit the parallel signal to the image processing unit. 2. A transmission system according to claim 1, wherein said transmission signal processing means converts a parallel signal into a serial signal, and a serial signal transmitter which receives and transmits a serial signal generated by said parallel-serial converter. The received signal processing means has a waveform shaper for shaping the waveform of the serial signal transmitted from the transmission signal processing means, and receives and transmits the serial signal shaped by the waveform shaper. 2. The digital signal transmission system according to claim 1, further comprising a serial signal receiver, and a serial / parallel converter for converting a serial signal transmitted from the serial signal receiver into a parallel signal. 3. A fluorescent magnetic particle inspection apparatus comprising: a digital imaging unit; and an image processing unit that performs image processing on a digital image captured by the imaging unit. 3. A fluorescent magnetic particle flaw detection apparatus, wherein image data is transmitted by the digital signal transmission method according to claim 1.