JPH07190727A - Image pick up device and image pick up method - Google Patents

Abstract

PURPOSE:To minimize an effect of vibration caused by circumferential environment to a photographed image by releasing the shutter of a camera as soon as the primary differential quotient of the wave form of measured vibration becomes zero, and storing an image signal obtained at that time in a memory. CONSTITUTION:The vibration wave form of a photographing object 10 for a photographing device is measured by a vibration meter 5, it is converted into digital signals by an input step processing section 6, a differential wave form is produced by a processing section 7, and pulses are outputted when the aforesaid form is copied. In an output step processing section 8, the aforesaid pulse output is amplified so as to be inputted to a drive circuit, a shutter 9 is released, the surface shape of an object 10 is formed into an image over a two dimensional plane by an image forming means 1, and the image is then transformed into electric signals by a photographing section 2. The transformed electric signals are transformed into numerical values so as to be temporarily stored in a frame memory 4. By this constitution, there is no need for providing a vibration proof system, and an effect of vibration caused by circumferential environment to a photographed image can thereby be minimized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device and an image pickup method for picking up an image of an image pickup object in a vibration environment.

[0002]

2. Description of the Related Art Conventionally, when a fine dimension of a surface of a liquid crystal substrate or a semiconductor chip is reproduced, evaluation of a finished dimension has been performed by a picked-up image obtained by picking up an image of an object to be measured.

When the picked-up image is picked up in a vibrating environment and the picked-up image is affected by vibration,
A phenomenon such as blurring of the entire image appears, and details of the image obtained by imaging become ambiguous. For this reason, when detailed information of an image is required, such as in the case of measurement using an image in which a minute size is imaged as described above, it becomes a serious problem.

Conventionally, when an image is picked up in a vibrating environment, in order to reduce the influence of the vibration of the picked-up image, a method of eliminating the influence (sway) of the ambient vibration of the image pickup system itself has been adopted. It was For example, a method of inserting a vibration damping material such as anti-vibration rubber between the image pickup system and the vibration source to soften the vibration of the vibration system itself and thereby reduce the influence of the vibration of the image captured It was taken. This method is a method of reducing the influence of vibration of a captured image by positively removing the shake itself of the entire imaging system.

[0005]

In such a conventional method, it is impossible to eliminate all vibrations by the vibration absorbing material. This is because even though various vibration damping materials are inserted into the vibration in the actual vibration environment, the vibration damping material of the vibration damping material can be removed even though the frequency band of the vibration that the vibration damping material can remove is limited. Vibration outside the frequency band that can be removed reaches the entire imaging system and affects the captured image.

The present invention has been made based on the above circumstances, and when an image is taken for measurement of a minute dimension or the like, the taken image is minimally affected by vibration caused by the surrounding environment. An object of the present invention is to provide an image pickup device and an image pickup method which can be limited.

[0007]

In order to achieve the above object, the invention corresponding to claim 1 is an image pickup means having a shutter for taking an image of an image pickup object and opening and closing an optical path, and the image pickup object. Vibration detection means capable of grasping the state of vibration, timing detection means for detecting the timing at which the first differential value of the vibration waveform measured by this vibration detection means becomes zero, and zero timing detected by this timing detection means At this time, the image pickup device is provided with a processing unit that opens the shutter and stores an image signal obtained from the image pickup unit in a frame memory.

In order to achieve the above object, the invention according to claim 2 can grasp the state of vibration of the image pickup object when the image pickup means for picking up an image of the image pickup object is taken in a vibrating environment. This is an image pickup method in which a vibration waveform is measured by a vibrometer, and when the first derivative value of the measured vibration waveform becomes zero, the image pickup means takes an image of the image pickup target.

[0009]

According to the inventions according to claims 1 and 2, when an image is taken for measurement of a minute dimension or the like, it is possible to minimize the influence of the imaged image due to vibration caused by the surrounding environment. .

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of the present invention, which is configured as follows.

The image pickup device 11 comprises an image forming means 1, an image pickup section 2, a vibrometer 5 and a shutter 9. The image forming means 1 forms an image of the surface shape of an image pickup object 10 on a two-dimensional plane. The image pickup unit 2 converts the image formed by the image forming unit 1 into an electric signal. The shutter 9 is arranged between the image pickup section 2 and the image forming means 1 and opens and closes the optical path.

The input stage processing section 3 amplifies the electric signal from the image pickup section 2 and converts it into an image of numerical data which is multi-valued according to the signal level. The frame memory 4 temporarily stores an image of numerical data obtained by the input stage processing unit 3. The vibrometer 5 measures the vibration state of the imaging target 10, that is, the vibration waveform.

The input stage processing unit 6 converts the vibration waveform (analog) from the vibrometer 5 into digital. The processing unit 7 differentiates the digital signal from the input stage processing unit 6 and outputs a pulse signal at the zero crossing. The output stage processing unit 8
The pulse signal from the processing unit 7 is amplified.

An embodiment of the present invention thus constructed will be described below with reference to FIG.

First, the vibration waveform of the image pickup object 10 with respect to the image pickup device 11 shown in FIG. 2A is measured by the vibrometer 5 installed in the image pickup device 11 (step S1: hereinafter referred to as S1). This vibration waveform is converted into a digital signal by the input stage processing unit 6 (S2). Then, the processing section 7 generates the differential waveform shown in FIG. 2 (2) (S3), and outputs the pulse shown in FIG. 2 (3) at the zero crossing (S4).

This pulse output is amplified by the output stage processing unit 8, and the amplified signal is input to a drive circuit (not shown) that drives the shutter 9 to open and close. Then, the shutter 9 opens. By opening the shutter 9, the surface shape of the object 10 to be imaged is changed by the image forming means 1.
An image is formed on the dimensional plane, and this image formation is converted into an electric signal by the image pickup unit 2. The converted electric signal is converted into numerical data in the input stage processing unit 3, and the image converted into numerical data is temporarily stored in the frame memory 4 (S).
5). In FIG. 2, a, b, c, d, e, and f all represent time.

According to the embodiment described above, the vibration waveform (combination of fluctuations of many frequencies) is measured by the vibrometer 5, and the peak point of the waveform is detected. At this time, the fluctuation amount is changed. Is zero, that is, the vibration is temporarily stopped. Therefore, when the vibration is stopped, the timing for imaging the imaging target object 10 of the imaging device 11 is set. Therefore, a vibration isolation system having a complicated structure is used. When the image is taken for measurement of a minute dimension without the provision, it is possible to minimize the influence of the imaged image due to the vibration caused by the surrounding environment.

[0019]

As described above, according to the present invention, when an image is picked up for measurement of a minute dimension without a vibration isolation system having a complicated structure, the picked-up image shows the surrounding environment. It is possible to provide an image capturing apparatus and an image capturing method that can minimize the influence of vibration caused by the above.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a first embodiment according to the present invention.

FIG. 2 is a diagram for explaining the operation of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image forming means, 2 ... Imaging part, 3 ... Input stage processing part, 4 ... Frame memory, 5 ... Vibrometer, 6 ... Input stage processing part, 7 ... Processing part, 8 ... Output stage processing part, 9 ... Shutter 10 ... Object to be imaged.

Claims (2)

[Claims] 1. An image pickup unit having a shutter that opens and closes an optical path by picking up an image of an image pickup target, a vibration detection unit capable of grasping a state of vibration of the image pickup target, and a vibration detection unit measured by the vibration detection unit. Timing detection means for detecting the timing when the first-order differential value of the vibration waveform becomes zero, and at the timing of zero detected by the timing detection means, the shutter is opened and the image signal obtained from the imaging means is stored in the frame memory. An image pickup device comprising: 2. When picking up an image of an image of an imaged object under a vibration environment, the vibration waveform is measured by a vibrometer capable of grasping the state of vibration of the imaged object, and the measured vibration is measured. An image pickup method for picking up an image of the image pickup object by the image pickup means when the first differential value of the waveform becomes zero.