JPS63205505A - Area measuring method by ccd area image sensor - Google Patents

Abstract

PURPOSE:To perform fast, high-efficiency measurement by drawing a measured graphic with an added illuminance ratio on the sensor of a photographic camera, binarizing the signals in element units when those signals are led out, and integrating and converting the number of the signals into area and displaying it. CONSTITUTION:A background figure and a graphic 2 to be measured which is given contrast are set opposite the image pickup camera 1. The lens system 4 of this camera 1 is adjusted and its position is also adjusted so that the whole of the graphic 2 is projected on the photodetection surface of the CCD area image sensor 3 in the camera. This sensor 3 detects the illuminance of an image part 6 with the quantity of light projected on the photodetection surface and separates charges from respective picture elements into binarization data according to a light-shade border based upon constant illuminance. The output of this sensor 3 is counted by a integrating counter 13 and an arithmetic circuit 14 calculates the area value, which is displayed on a digital indicator 15 and also sent to an output control part 16 for using the data. Thus, the area of the graphic, etc., is measured.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for measuring the area of an arbitrary shape, and particularly to a CCD area image sensor that instantaneously measures and digitally calculates using a CCD area image sensor. Regarding the area measurement method by.

[Conventional technology]

Conventionally, to measure the area of this type of figure, two arms are connected at their free rotation ends, the other end of one arm is fixed outside the measurement figure, and the other end of the arm traces the circumference of the figure. Amsler area meter, in which a small wheel attached to the free end rotates and the number of revolutions indicates the area, and an object to be measured is placed between a parallel ultraviolet light source and a light receiving part (phototube) placed opposite it to shield it. A photoelectric area meter, which calculates the area from the current change in the light-receiving part caused by the size of the shadow, or another type of figure is set on the side of a cylinder, and while the cylinder is rotated at a constant speed, the point light source is rotated by a small amount in the axial direction. There is a method using a photomultiplier tube, which uses a phototube to detect the change in one reflected light beam depending on the contrast of the measured figure by transporting it in synchronization with the speed, and then integrates the detection time and converts it into area.

[Problem that the invention seeks to solve]

The conventional Amsler area meter described above has the disadvantage that it requires manual tracing around the figure and is not suitable for complex figures. In addition, since the method using a phototube or photomultiplier tube requires the generation of secondary electrons, a considerable amount of energy is required for the reflected light, which has the drawback of lowering detection accuracy and taking more time.

SUMMARY OF THE INVENTION An object of the present invention is to provide an area measurement method using a CCD area image sensor that measures the area of figures, etc. at high speed and with optical efficiency in order to solve the above-mentioned problems.

[Means for solving problems]

In general, advances in electronic device technology and television technology have led to the development of CCD line sensors and CCD area image sensors that perform light-to-electrical conversion as image input elements, and improvements in the sensitivity of photography cameras that use CCD area image sensors as light-receiving elements. As progress has progressed, the value of use for general industrial purposes is being reconsidered.

The present invention provides an optical image formed by such a CCD area image sensor on a light receiving surface through an optical meter of a photographing camera.
Focusing on the fact that the opposing light-receiving elements generate electrical signals according to the illuminance of their optical images, and the electrical signals of each element are sequentially extracted via the storage section, the illuminance ratio was added to the measurement figure. A digital area measurement method in which an object is depicted on the CCD area image sensor of a photographing camera, and at the stage of extracting a signal for each element, it is binarized by a shaping circuit, the number of signals is integrated, converted to area, and displayed. It is.

That is, the area measurement method using the CCD area image sensor of the present invention projects an optical image of the figure to be measured with contrast against the back shadow onto the light receiving surface of a photographing camera incorporating an optical system and a CCD area image sensor. The area of the figure to be measured is obtained by converting the output signal of the image of the figure to be measured obtained from the CCD area image sensor into a binary pulse signal using a waveform shaping circuit and repeatedly integrating the operation of counting the number of pulse signals. It is composed of

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an area measuring device for explaining one embodiment of the present invention.

FIGS. 2(a) and 2(b) are a measurement diagram and a signal waveform diagram, respectively, during figure scanning according to the present invention.

As shown in FIG. 1, a measurement figure 2 is set facing the imaging camera 1 and contrasted with the back surface. The photographing camera 1 has a lens system 4 so that the entire measurement figure is projected onto the light-receiving surface of the CCD area image sensor 3 installed inside the machine.
and the position of the lens system 4. However, when using online as part of the process, measurement figure 2
The size for photographing, that is, the effective area 5, is determined, and the positions of the photographing camera 1 and the measurement figure 2 are fixed. Further, depending on the measurement figure size and measurement accuracy, the relative position between the photographing camera 1 and the effective area 5 of the measurement figure 2 is shifted stepwise in the left and right and up and down directions on the hardware and scans the entire position.

On the other hand, this CCD area image sensor 3 is shown in FIG.
As shown in a), there are 5 pixels 20 with a square size of 50 μm.
There are 60 pixels, and the charge of each pixel changes depending on the illuminance detected by the image section 6 depending on the amount of light irradiated on the light receiving surface, and the brightness and darkness with a constant illuminance as a boundary are binarized and separated into ON and OFF states.

The binarized state detected by the image section 6 is transferred to the storage section 7 by a clock signal and recorded therein. The state of the storage section 7 can be read out at the timing required by the subsequent processing block, and the detection operation of the image section 6 and the readout operation of the previously detected image are processed in parallel. Therefore, due to the difference in illuminance of the optical image formed on the light receiving surface of the CCD area image sensor 3, a charge image corresponding to the brightness of the optical image is formed in the image section 6, and this is sequentially read out via the storage section 7. At this stage of readout, when the measurement figure 2 divided by contrast is scanned, the pixels 20 shown in FIG. 2(a) existing in the optical image are shown in FIG. 2(b). “1
When scanning an area other than the measurement figure 2, the corresponding pixel 20 outputs a signal 21 of 0 as shown in FIG. 2(b).

The accuracy of the above-mentioned measurement is almost determined by the size of the measurement figure 2 projected on the pixel 20 of the CCD area image sensor 3, so if higher performance is required, the magnification of the lens system 4 of the photographing camera 1 should be adjusted. The size that the pixel 2-0 occupies on the measurement figure 2 is made smaller by increasing the number of pixels or by employing a zoom mechanism. At this time, if the entire measurement figure 2 cannot be projected onto the CCD area image sensor 3, the table 8 for fixing the measurement figure 2 should be a numerically controllable XY table.
Considering the effective area 5 on the measurement figure 2 that can be projected in - times, each time the - time measurement operation is completed, the projection position is shifted in the X and Y directions by an amount equivalent to the size of the effective area 5, and the next measurement operation is performed. The entire surface of the measurement figure 2 is scanned. Since the projection magnification and the operation of the table 8 need to be synchronized, the system control unit 10 controls the camera control unit 11 and the table drive unit 12 to set the photographing camera magnification and table drive step size corresponding to measurement accuracy. do.

Further, the output signal of the CCD area image sensor 3 is sent to an integration counter 13 via a waveform shaping circuit 9 for the purpose of noise reduction.

The integration counter 13 continues to count randomly input pulse signals until the measurement operation for one figure is completed, and upon completion, sends the pulse signals to the arithmetic circuit 14 as a digital signal. As a result, the arithmetic circuit 14 allows the system control section 10 to control the camera control section 11 and the table drive section 1.
The number of counts counted by the integrating counter 13 is converted into an actual area using the projection magnification that is controlled by the device as a constant, and distortion correction of the CCD area sensor image sensor 3 for photographing is performed sequentially, and the area value is converted into an area value. The calculated value is displayed on the digital indicator 15 or meter, and the area of a figure or the like can be easily measured by transmitting it to the output control section 16 for use with a digital printer or online.

In this way, the present embodiment can realize high-speed and highly efficient area measurement. However, regarding sending the digital signal from the waveform shaping circuit 9 to the arithmetic circuit 14, the output signal of the waveform shaping circuit 9 is directly sent to the integrating circuit. This can also be realized by inputting the data and performing A/D conversion upon completion of the measurement operation for one figure and sending the result to the arithmetic circuit 14.

〔Effect of the invention〕

As explained above, the present invention depicts a measurement figure with an illuminance ratio on the CCD area image sensor of a photographing camera, and at the stage of extracting a signal for each element, converts it into a binary value using a shaping circuit and calculates the number of signals. By integrating and converting to area and displaying it, there is an effect that area measurement can be performed efficiently in a short time.

For example, area measurement as a pre-process to set the plating current in the plating process, area measurement in the production department such as maps or layouts, area measurement of inspection objects observed with microscopes and other optical instruments, etc. Especially highly efficient area measurement. This is particularly effective when data is collected or analyzed using a computer or the like.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an area measuring device for explaining an embodiment of the present invention, and FIGS. 2(a) and 2(b) are measurement diagrams and signal waveform diagrams, respectively, during figure scanning in the present invention. 1... Photographing camera, 2... Measurement figure, 3... CC
D area image sensor, 4...lens system, 5...
Effective area, 6... Image section, 7... Storage section, 8... Table, 9... Waveform shaping circuit, 10.
... System control section, 11... Camera control section, 12.
...Table drive unit, 13...Integration counter, 14
...Arithmetic circuit, 15...Digital indicator,
16... Output control unit, 20... Pixel, 21... C
CD area sensor output signal.

Claims (1)

[Claims] An optical image of the figure to be measured with contrast against the back shadow is projected onto the light receiving surface of a photographing camera incorporating an optical system and a CCD area image sensor, and an output signal of the image of the figure to be measured obtained from this CCD area image sensor is generated. A method for measuring an area using a CCD area image sensor, characterized in that the area of a figure to be measured is obtained by repeatedly integrating the operation of converting into a binary pulse signal by a waveform shaping circuit and counting the number of pulse signals;