JP2022000679A - Focal distance variable lens control method, focal distance variable lens control device, image detection method, and image detection device - Google Patents

Abstract

To provide a focal distance variable lens control method, a focal distance variable lens control device, an image detection method and an image detection device, with which, while using a sinusoidal wave as a drive signal, it is possible to obtain an appropriate image even in the intermediate region of amplitude.SOLUTION: An image detection device 1 comprises: a lens system 3 of liquid resonance type; a lens control unit 6 for outputting a drive signal Cf to the lens system 3; and an image detection unit 4 for detecting an image of an object of measurement through the lens system 3. The lens control unit 6 includes: a fundamental signal generation unit 611 for generating a sinusoidal wave fundamental signal of the same frequency as the drive signal Cf; a modulating signal generation unit 612 for generating a modulating signal of a different frequency than the drive signal Cf; and a drive signal synthesizing unit 613 for adding the modulating signal to the fundamental signal and synthesizing a signal having an imaging section a change rate of which is smaller than those of the preceding and following portions and using the synthesized signal as the drive signal Cf. The image detection unit 4 detects the image in the imaging section.SELECTED DRAWING: Figure 2

Description

The present invention relates to a focal length variable lens control method, a focal length variable lens control device, an image detection method, and an image detection device.

A liquid resonance type lens system has been developed as a variable focal length lens. An image detection device has been developed in which a pulse illumination device is combined with this lens system to detect an image focused on an arbitrary position of a subject (see Patent Document 1).
In the liquid resonance type lens system, a standing wave is generated in the internal liquid by a periodic drive signal from the control device, and the refractive index is changed concentrically to obtain a function as a lens. The focal position of is changed periodically.
The image detection device can detect an image on the imaging surface having a focal position corresponding to the phase angle by performing pulse illumination synchronized with a predetermined phase angle of the drive signal. Further, by setting a plurality of phase angles at which the pulse illumination is synchronized within one cycle, it is possible to detect a multifocal image of the subject. On the other hand, a omnifocal image can be obtained by performing continuous illumination to detect an image of the entire cycle of the drive signal, and an EDOF image (Extended Depth of Focus) can be obtained by further performing image processing.

Japanese Unexamined Patent Publication No. 2018-189702

In the lens system described above, a sine wave is used as a periodic drive signal input from the control device. By using a sine wave, it is possible to efficiently generate a signal and efficiently resonate the liquid inside the lens system.
When the drive signal is a sine wave, the rate of change of the drive signal is small (gradient) near the positive and negative peaks (phase angle is around 90 degrees or 270 degrees), and image detection at a predetermined focal position is performed. Even if the exposure time by pulsed illumination is set to be long, the deviation of the focal position between them is small, and the image can be detected with a sufficient amount of light.
However, in the middle region of the amplitude (phase angle is -50 to 50 degrees and 130 to 230 degrees, etc.), the rate of change is large, that is, the gradient is steep, and the fluctuation of the focal position is large when the exposure time by pulse illumination is long. Therefore, if the exposure time is shortened, it is difficult to obtain a sufficient amount of light.
Therefore, while using a sine wave as a drive signal, it has been required to obtain an appropriate image even in the intermediate region of amplitude, that is, an image having a sufficient amount of light and a small focal fluctuation.

An object of the present invention is to provide a focal length varifocal lens control method, a focal length varifocal lens control device, an image detection method, and an image detection device that can obtain an appropriate image even in an intermediate region of amplitude while using a sine wave as a drive signal. To do.

The focal length variable lens control method of the present invention is a focal length variable lens control method in which a drive signal is input to a liquid resonance type lens system to periodically change the refractive index of the lens system.
An image pickup in which a sine wave basic signal having the same frequency as the drive signal and a modulated signal having a frequency different from the drive signal are generated, and the modulated signal is added to the basic signal to have a smaller rate of change than the front and rear parts. It is characterized in that a signal having a section is synthesized and the synthesized signal is used as the drive signal.

The focal length variable lens control device of the present invention is a focal length variable lens control device that periodically changes the refractive index of the lens system by inputting a drive signal to the liquid resonance type lens system.
A basic signal generation unit that generates a sine wave basic signal having the same frequency as the drive signal, a modulation signal generation unit that generates a modulation signal having a frequency different from the drive signal, and the modulation signal added to the basic signal. It is characterized by having a drive signal synthesizing unit that synthesizes a signal having an imaging section having a change rate smaller than that of the front and rear portions and uses the synthesized signal as the drive signal.

The image detection method of the present invention is an image detection method for detecting an image of an object to be measured through a liquid resonance type lens system whose refractive index changes according to an input drive signal.
An image pickup in which a sine wave basic signal having the same frequency as the drive signal and a modulated signal having a frequency different from the drive signal are generated, and the modulated signal is added to the basic signal to have a smaller rate of change than the front and rear parts. A signal having a section is synthesized, and the synthesized signal is used as the drive signal, and the combined signal is used as the drive signal.
It is characterized in that the image is detected in the imaging section.

The image detection device of the present invention is a liquid resonance type lens system whose refractive index changes according to an input drive signal, a lens control unit that outputs the drive signal to the lens system, and a measurement target through the lens system. It has an image detection unit that detects an image of an object, and the lens control unit has a basic signal generation unit that generates a sine wave basic signal having the same frequency as the drive signal, and a basic signal generation unit having a frequency different from that of the drive signal. A modulation signal generation unit that generates a modulation signal and a signal having an imaging section having an imaging section having a smaller rate of change than the front and rear portions are combined by adding the modulation signal to the basic signal, and the combined signal is used as the drive signal. It has a drive signal synthesis unit, and the image detection unit detects the image in the imaging section.

In the present invention as described above, a signal synthesized by adding a modulation signal to a basic signal is used as a drive signal. At this time, by using a fundamental signal having the same frequency as the drive signal, a basic function as a drive signal that resonates the lens system can be obtained. Then, by using a modulated signal having a frequency different from that of the drive signal and adding it to the basic signal, it is possible to form an imaging section having a smaller rate of change than the front and rear parts in a part of the basic signal.
For example, when a modulated signal having a frequency twice that of the basic signal is added, one cycle of the modulated signal is superimposed on the increased section of the half cycle of the fundamental wavelength, so that the increased section of the basic signal and the modulated signal are combined. A section with a gentle slope, a flatness, or a decrease can be generated in the middle part of the fundamental wavelength by canceling out the decrease section.
By inputting a signal having an imaging section having a smaller change rate than the front and rear parts to the lens system as a drive signal, the change rate of the focal position in the image pickup section is slower than that of the front and back parts, or the change rate is almost the same. Can be constant.
Therefore, when performing image detection using a liquid resonance type lens system and pulsed illumination, even if the exposure time by pulsed illumination is long, the rate of change in the focal position is small in the imaging section, and the rate of change in the focal position is small during imaging. The deviation of the focal position can be made small, and a high-quality image can be detected with a sufficient amount of light.

In the present invention, it is preferable that the basic signal and the modulated signal are sinusoidal waves, respectively.
In the present invention as described above, the basic signal and the modulated signal can be easily and efficiently generated.

In the present invention, the modulated signal is preferably a sine wave having a frequency that is an integral multiple of the fundamental signal.
In the present invention as described above, in one cycle of the fundamental signal which is a sine wave, a modulated signal which is a sine wave having a cycle of a plurality of times thereof is superimposed, and the rate of change of the modulated signal is opposite to a part of the fundamental signal (a state in which the rate of change of the modulated signal is reversed. By setting (such as a state in which the modulation signal decreases in the portion where the basic signal increases), it is possible to easily form an imaging section in which the rate of change is smaller than before and after in the basic signal.

In the present invention, it is preferable to add a plurality of the modulated signals to the basic signal.
In the present invention as described above, it is possible to generate a waveform that cannot be obtained only by adding a single modulated signal to the fundamental signal, and it is possible to form various imaging sections.

In the present invention, when the modulated signal is added to the basic signal, at least one of the amplitude level adjustment of the modulated signal, the bias adjustment of the modulated signal, and the phase adjustment of the modulated signal with respect to the basic signal is performed. Is preferable.
In the present invention as described above, the position of the imaging section in the drive signal can be adjusted by each adjustment.

According to the present invention, there are provided a focal length varifocal lens control method, a focal length varifocal lens control device, an image detection method, and an image detection device that can obtain an appropriate image even in an intermediate region of amplitude while using a sine wave as a drive signal. can do.

The block diagram which shows the whole structure of one Embodiment of this invention. The block diagram which shows the main part of the said embodiment. The graph which shows the drive signal Cf1 synthesized in the said embodiment. The graph which shows the drive signal Cf2 synthesized in the said embodiment. The graph which shows the drive signal Cf3 synthesized in the said embodiment. The graph which shows the drive signal Cf4 synthesized in the said embodiment. The graph which shows the drive signal Cf5 synthesized in the said embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows the overall configuration of the image detection device 1 according to the embodiment of the present invention.
The image detection device 1 detects an image of the surface of the measurement object 9 placed in the imaging region while periodically changing the focal length, and is arranged on the same optical axis A intersecting the surface. It includes an objective lens 2, a lens system 3, and an image detection unit 4.
Further, the image detection device 1 operates a pulse illumination unit 5 that pulse-illuminates the surface of the object to be measured 9, a lens control unit 6 that controls the operation of the lens system 3 and the pulse illumination unit 5, and a lens control unit 6. It is equipped with a control PC 7 for the purpose.

The objective lens 2 is composed of an existing convex lens.
The lens system 3 is a liquid resonance type variable focal length lens, and the refractive index changes according to the drive signal Cf input from the lens control unit 6. The drive signal Cf is an alternating current having a frequency that causes a standing wave in the lens system 3, and is a sinusoidal alternating current signal.
In the image detection device 1, the focal length Df to the focal position Pf can be arbitrarily changed by changing the refractive index of the lens system 3 while using the focal length of the objective lens 2 as the basis.

In the image detection device 1, the drive signal Cf is a sinusoidal AC signal, and the focal position Pf and the focal length Df also periodically fluctuate in a sinusoidal manner.
At this time, if the measurement object 9 at the focal position Pf is pulse-illuminated at any time of the vibration waveform of the focal position Pf and the illuminated image is detected at that time, the image of the focal position Pf can be obtained. Become.
Although details will be described later, the drive signal Cf of the present embodiment is not a perfect sine wave, but a waveform modulated by superimposing its harmonics on a basic sine wave.

The image detection unit 4 is composed of an existing CCD (Charge Coupled Device) image sensor, a camera of another format, or the like, and can output the incident image Lg as a detection image Im of a predetermined signal format to the control PC 7. can.
The pulse illumination unit 5 is composed of a light emitting element such as an LED (Light Emitting Diode), and when a light emission signal Ci is input from the lens control unit 6, the illumination light Li is emitted for a predetermined time, and the measurement object 9 is subjected to light emission. Pulsed illumination can be applied to the surface.

In the image detection device 1, the drive of the lens system 3, the light emission of the pulse illumination unit 5, and the image detection of the image detection unit 4 are controlled by the drive signal Cf, the light emission signal Ci, and the image detection signal Cc from the lens control unit 6. ..
In the present embodiment, the lens control unit 6 is a focal length variable lens control device of the present invention, and a control PC 7 is connected to operate the setting of the lens control unit 6 and the like.

FIG. 2 shows the configuration of the lens control unit 6 and the control PC 7 of the present embodiment.
The lens control unit 6 is a dedicated unit composed of hardware that controls the operation of the lens system 3 and the pulse illumination unit 5, and is a drive control unit 61 that outputs a drive signal Cf to the lens system 3 and a pulse illumination unit 5. It has a lighting control unit 62 that outputs a light emission signal Ci, and an image detection control unit 63 that outputs an image detection signal Cc to the image detection unit 4.

The drive control unit 61 outputs the drive signal Cf to the lens system 3 and, when the lens system 3 vibrates based on the drive signal Cf, the active power or the drive current applied to the lens system 3 is used to obtain the lens system 3 from the active power or the drive current. The vibration state Vf is detected. Then, by adjusting the frequency of the drive signal Cf with reference to the vibration state Vf of the lens system 3, it is possible to lock to the current resonance frequency of the lens system 3. The vibration state Vf can also be detected by a vibration sensor installed in the lens system 3.

The drive control unit 61 includes a basic signal generation unit 611 that generates a sine wave basic signal having the same frequency as the drive signal Cf, a modulation signal generation unit 612 that generates a modulation signal having a frequency different from that of the drive signal Cf, and a basic signal. It has a drive signal synthesizing unit 613 that adds a modulation signal to the signal, synthesizes a signal having an imaging section having a smaller rate of change than the front and rear portions, and uses the synthesized signal as a drive signal Cf.

The basic signal generation unit 611 is composed of a sine wave oscillation module or an oscillation circuit, and by designating a frequency fcb (for example, about 70 KHz) suitable for driving the lens system 3, the basic signal Cb which is a sine wave of the frequency fcb is specified. (See FIG. 3) can be generated.
The modulation signal generation unit 612 is composed of a sine wave oscillation module or an oscillation circuit similar to the basic signal generation unit 611, and by designating a frequency fcm = n · fcb which is an integral multiple of the frequency of the fundamental signal Cb, the frequency fcm. It is possible to generate a modulation signal Cm1 (see FIG. 3) which is a sine wave of. As the multiple n, usually n = 2 to 4 is used. The modulation signal Cm1 may be generated by dividing the basic signal Cb.

The drive signal synthesis unit 613 is an addition module or mixer circuit that adds the modulation signal Cm1 generated by the modulation signal generation unit 612 to the basic signal Cb generated by the basic signal generation unit 611.
When the modulation signal Cm1 is added to the basic signal Cb, the drive signal synthesis unit 613 adjusts the amplitude level of the modulation signal Cm1 (increase / decrease in amplitude), adjusts the bias of the modulation signal Cm1 (increase / decrease in the amplitude center level), and modulates the signal. The phase can be adjusted with respect to the basic signal Cb of Cm1.
In the drive signal synthesis unit 613, the signal synthesized by adding the modulation signal Cm1 to the basic signal Cb is referred to as the drive signal Cf1 (see FIG. 3).

In FIG. 3, the drive signal Cf1 is generated by adding the modulation signal Cm1 = 0.5 sin (2θ) (coefficient 0.5 is the level adjustment) of the double frequency to the basic signal Cb = sin (θ). To. At this time, the output level is adjusted as in the drive signal Cf1 = (Cb + Cm1) /1.3.
In the drive signal Cf1, an imaging section S having a smaller rate of change than the portion before and after the peak is formed between the positive and negative peaks in each cycle, that is, in the middle portion of the amplitude.
The imaging section S is a modulated signal by superimposing one wavelength of the modulated signal Cm1 whose frequency is doubled on the reduced section (the section where the phase angle is 90 degrees to 270 degrees) of the basic signal Cb by half a wavelength. The decrease was offset in the increase section of Cm1 (the section where the phase angle was 135 degrees to 225 degrees), and the rate of change was reduced accordingly.

In the imaging section S, the position and shape of the drive signal Cf1 can be adjusted by adjusting the amplitude level, bias, and phase of the modulation signal Cm1 added to the basic signal Cb in the drive signal synthesis unit 613.
In FIG. 4, the basic signal Cb = sin (θ) and the modulation signal Cm1 = 0.5 sin (2θ) having a frequency twice that of the basic signal Cb are the same as those of the drive signal Cf1 in FIG. However, when the basic signal Cb and the modulation signal Cm1 are added, the drive signal Cf2 = (Cb + Cm1 + 0.5) /1.3 is set, and the bias adjustment for 0.5 minutes is performed. Due to such bias adjustment, the drive signal Cf2 has a waveform shifted upward from the drive signal Cf1 in FIG.

As shown in FIGS. 4 and 5, the drive signal synthesizing unit 613 may combine a plurality of modulated signals Cm1, Cm2, and Cm3 having different frequency multiples n with respect to the basic signal Cb.

In FIG. 5, the drive signal Cf3 has the same basic signal Cb = sin (θ) and modulation signal Cm1 = 0.5 sin (2θ) as in FIG. 3, and the modulation signal Cm2 = 0. Using 25 sin (3θ), it is synthesized as a drive signal Cf3 = (Cb + Cm1 + Cm2) /1.42.
Since the three signals are combined, the denominator for adjusting the output level is 1.42, which is larger than 1.3 in FIG.
With such a drive signal Cf3, two imaging sections S1 and S2 can be formed in one wavelength.

In FIG. 6, the drive signal Cf4 has the same basic signal Cb = sin (θ) as in FIG. 3, the modulation signal Cm1 = 0.5sin (2θ), and the modulation signal Cm2 = 0.25sin (3θ) similar to FIG. At the same time, a modulation signal Cm3 = 0.125 sin (4θ) having a frequency four times that of the basic signal Cb is used, and the drive signal Cf4 = (Cb + Cm1 + Cm2 + Cm3) /1.46 is synthesized.
Since the four signals are combined, the denominator for adjusting the output level is 1.46, which is further increased from 1.42 in FIG.
With such a drive signal Cf4, three imaging sections S1, S2, and S3 can be formed in one wavelength.

The image pickup sections S1 and S2 (see FIG. 5) in the drive signal Cf3 and the image pickup sections S1, S2 and S3 (see FIG. 6) in the drive signal Cf4 are the image pickup sections S (FIGS. 3 and 6) in the drive signals Cf1 and Cf2, respectively. Although it is not a flat shape like (see), the rate of change is small (gradient) with respect to the front and rear parts of each.

Returning to FIG. 2, the lighting control unit 62 and the image detection control unit 63 have the image pickup section S (or the image pickup section S1, S2, S3) of the drive signal Cf1 (or the drive signal Cf2 to Cf4) synthesized by the drive control unit 61. ), The image of the measurement object 9 can be detected.
The illumination control unit 62 outputs the light emission signal Ci to the pulse illumination unit 5 to execute pulse illumination on the measurement object 9. The light emission timing of the light emission signal Ci is synchronized with the drive signal Cf, the light emission is started at the start timing of the image pickup section S, and the light emission is stopped at the end timing of the image pickup section S, whereby the pulse illumination corresponding to the image pickup section S is generated. conduct.
The image detection control unit 63 outputs an image detection signal Cc to the image detection unit 4 and controls on / off of image detection. During the period from image detection on to off, pulse illumination corresponding to the image pickup section S by the pulse illumination unit 5 is performed, so that the image corresponding to the image capture section S is detected by the image detection unit 4 and detection for one frame is performed. It is sent to the control PC 7 as an image Im.

The control PC 7 performs user operations on the lens operation unit 71 that performs various setting operations on the lens control unit 6, the image processing unit 72 that captures and processes the detected image Im from the image detection unit 4, and the image detection device 1. It has an operation interface 73 for receiving.
The control PC 7 is composed of a general-purpose personal computer, and realizes the desired function by executing dedicated software. That is, by executing the lens operation software, the function of the lens operation unit 71 that controls the lens control unit 6 is realized. Further, by executing the image processing software, the function of the image processing unit 72 that processes the detected image Im from the image detection unit 4 is realized. These lens operation software and image processing software can be operated by the user via the operation interface 73 using the display screen and the input device of the control PC 7.

The lens operation unit 71 is provided with a drive signal waveform operation unit 711.
The drive signal waveform operation unit 711 operates the adjustment parameters of the basic signal Cb, the modulation signals Cm1 to Cm3, and the drive signals Cf1 to Cf4 in the basic signal generation unit 611, the modulation signal generation unit 612, and the drive signal synthesis unit 613 described above. It is displayed on 73, and the basic signal Cb, the modulation signals Cm1 to Cm3, and the drive signals Cf1 to Cf4 can be operated based on the user's operation.

According to such an embodiment, the following effects can be obtained.
In the present embodiment, the signal synthesized by adding the modulation signals Cm1 to Cm3 to the basic signal Cb is used as the drive signal Cf1 to Cf4. At this time, by using the basic signal Cb having the same frequency fcb as the original drive signal Cf suitable for driving the lens system 3, the basic function as the drive signal Cf that resonates the lens system 3 can be obtained.
Then, by using the modulated signals Cm1 to Cm3 having a frequency fcm = n · fcb different from the drive signal Cf and adding them to the basic signal Cb, the rate of change is changed in a part of the basic signal Cb more than in the front and rear parts. A small imaging section S can be formed.
By inputting the drive signals Cf1 to Cf4 having such an imaging section S into the lens system 3, the rate of change of the focal position Pf in the imaging section S is slower than that of the front and rear portions, or the rate of change is made substantially constant. Can be done.
Therefore, when performing image detection using the liquid resonance type lens system 3 and the pulse illumination unit 5, even if the exposure time by the pulse illumination unit 5 is long, the rate of change of the focal position Pf in the imaging section S is high. Is small, the deviation of the focal position Pf between imaging can be made small, and a high-quality detected image Im can be detected with a sufficient amount of light.

In the present embodiment, since the basic signal Cb and the modulated signals Cm1 to Cm3 are each made into a sine wave, each of them can be easily and efficiently generated.
Further, since the modulated signals Cm1 to Cm3 are sinusoidal waves having a frequency fcm = n · fcb, which is an integral multiple of the frequency fcb of the fundamental signal Cb, each cycle of the fundamental signal Cb, which is a sine wave, has a cycle of multiple times that of the sine wave. A state in which the modulated signals Cm1 to Cm3, which are sine waves, are superimposed, and the rate of change of the modulated signals Cm1 to Cm3 is opposite to a part of the basic signal Cb (a state in which the modulated signals Cm1 to Cm3 decrease in the portion where the basic signal Cb increases). Etc.), it is possible to easily form an imaging section S having a smaller rate of change than the front and back in the basic signal Cb.
Further, in the drive signal Cf3 of FIG. 5 and the drive signal Cf4 of FIG. 6, by adding a plurality of modulation signals Cm1 to Cm3 to the basic signal Cb, the drive signals Cf1 and Cf2 of FIGS. 3 and 4 are obtained. It is possible to generate a waveform that cannot be obtained only by adding a single modulation signal Cm1 to the basic signal Cb, and it is possible to form various imaging sections S1, S2, and S3.

In the present embodiment, when the modulation signals Cm1 to Cm3 are added to the basic signal Cb by the drive signal synthesis unit 613 and the drive signal waveform operation unit 711, the amplitude level adjustment, bias adjustment, and basic signal Cb of the modulation signals Cm1 to Cm3 are performed. The phase can be adjusted for, and the positions of the imaging sections S, S1 to S3 in the drive signals Cf1 to Cf4 can be adjusted.

In the image detection device 1 of the present embodiment and the lens control unit 6 which is a focal length variable lens control device, the imaging section S is formed between positive and negative peaks in each period of the basic signal Cb, that is, in the middle portion of the amplitude. In addition, it can be formed in the peak part.
In FIG. 7, the drive signal Cf5 uses the same basic signal Cb = sin (θ) as in FIG. 3 and the modulated signal Cm5 = 0.5 sin (3θ) having a frequency three times that of the basic signal Cb, and the drive signal Cf5. = (Cb + 0.15 · Cm5) /1.3.
In such a drive signal Cf5, the opposite peaks of the modulation signal Cm5 are superimposed on the positive and negative peaks of the basic signal Cb, and the amplitude level of the modulation signal Cm5 is adjusted so that the peaks are flat in each of the imaging sections S1 and S1. S2 can be formed.

The present invention is not limited to the above-described embodiment, and modifications to the extent that the object of the present invention can be achieved are included in the present invention.
In the above embodiment, the modulation signals Cm1 to Cm5 are sine waves, but waveforms other than sine waves may be used.
In the above embodiment, in the addition process of the basic signal Cb and the modulation signals Cm1 to Cm5 in the drive signal synthesis unit 613, the user operates from the drive signal waveform operation unit 711 to perform various adjustments of the addition process, and the imaging section S is performed. I decided to adjust the position and so on. On the other hand, by designating the focal position Pf desired by the user in the drive signal waveform operation unit 711, the basic signal Cb and the modulated signals Cmi, Cmj ... in which the imaging section S is formed at the designated focal position Pf are calculated. It may be done.

The present invention can be used for a focal length variable lens control method, a focal length variable lens control device, an image detection method, and an image detection device.

1 ... Image detection device, 2 ... Objective lens, 3 ... Lens system, 4 ... Image detection unit, 5 ... Pulse illumination unit, 6 ... Lens control unit (focus distance variable lens control device), 61 ... Drive control unit, 611 ... Basic signal generation unit, 612 ... Modulation signal generation unit, 613 ... Drive signal synthesis unit, 62 ... Illumination control unit, 63 ... Image detection control unit, 7 ... Control PC, 71 ... Lens operation unit, 711 ... Drive signal waveform operation Unit, 72 ... Image processing unit, 73 ... Operation interface, 9 ... Measurement target, Cb ... Basic signal, Cc ... Image detection signal, Cf, Cf1, Cf2, Cf3, Cf4, Cf5 ... Drive signal, Ci ... Light emission signal, Cm1, Cm2, Cm3, Cm5, Cmi ... Modulation signal, Df ... Focus distance, fcb ... Basic signal frequency, fcm ... Modulation signal frequency, Im ... Detection image, Lg ... Image, Li ... Illumination light, n ... Modulation signal Frequency multiple of, Pf ... focal position, S, S1, S2, S3 ... imaging section, Vf ... vibration state.

Claims (8)

It is a focal length variable lens control method in which a drive signal is input to a liquid resonance type lens system to periodically change the refractive index of the lens system.
An image pickup in which a sine wave basic signal having the same frequency as the drive signal and a modulated signal having a frequency different from the drive signal are generated, and the modulated signal is added to the basic signal to have a smaller rate of change than the front and rear parts. A method for controlling a variable focal distance lens, which comprises synthesizing a signal having an interval and using the synthesized signal as the driving signal. A variable focal length lens control device that periodically changes the refractive index of the lens system by inputting a drive signal to the liquid resonance type lens system.
A basic signal generation unit that generates a sine wave basic signal having the same frequency as the drive signal, a modulation signal generation unit that generates a modulation signal having a frequency different from the drive signal, and the modulation signal added to the basic signal. A focal distance variable lens control device comprising: a drive signal synthesizing unit that synthesizes a signal having an imaging section having a smaller rate of change than the front and rear portions and uses the synthesized signal as the drive signal. It is an image detection method that detects an image of an object to be measured through a liquid resonance type lens system whose refractive index changes according to an input drive signal.
An image pickup in which a sine wave basic signal having the same frequency as the drive signal and a modulated signal having a frequency different from the drive signal are generated, and the modulated signal is added to the basic signal to have a smaller rate of change than the front and rear parts. An image detection method comprising synthesizing a signal having a section, using the synthesized signal as the drive signal, and detecting the image in the imaging section. A liquid resonance type lens system whose refractive index changes according to an input drive signal, a lens control unit that outputs the drive signal to the lens system, and image detection that detects an image of an object to be measured through the lens system. With a part,
The lens control unit includes a basic signal generation unit that generates a basic signal of a sinusoidal wave having the same frequency as the drive signal, a modulation signal generation unit that generates a modulation signal having a frequency different from the drive signal, and the basic signal. It has a drive signal synthesizer that adds the modulated signals to synthesize a signal having an imaging section having a smaller rate of change than the front and rear portions, and uses the synthesized signal as the drive signal.
The image detection unit is an image detection device characterized in that the image is detected in the imaging section. In the image detection device according to claim 4,
An image detection device characterized in that the basic signal and the modulated signal are sinusoidal waves, respectively. In the image detection apparatus according to claim 4 or 5.
The image detection device, wherein the modulated signal is a sine wave having a frequency that is an integral multiple of the basic signal. The image detection device according to any one of claims 4 to 6.
An image detection device characterized by adding a plurality of the modulated signals to the basic signal. In the image detection apparatus according to any one of claims 4 to 7.
When the modulation signal is added to the basic signal, at least one of the amplitude level adjustment of the modulation signal, the bias adjustment of the modulation signal, and the phase adjustment of the modulation signal with respect to the basic signal is performed. Image detector.

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