JP2009139484A - Microscope apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microscope that acquires an observation image with optimum sampling frequency at any time. <P>SOLUTION: This scanning microscope apparatus includes: a sample information acquisition means for generating an analog signal that changes in accordance with the sample information; an acquired condition storage means for storing the acquired condition acquired by the sample information acquisition means; a sampling frequency determination means for calculating the apparatus resolution from the acquired condition and determining the sampling frequency required for generating image data having pixel resolution satisfying the apparatus resolution from the analog signal; an image data generating means for sampling with the determined sampling frequency and generating the image data from the analog signal; an image data storage means; and an observation image outputting means for generating the observation image of an optional image size from the image data and outputting the observation image to a display device. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a microscope capable of displaying sample information such as surface shape information of a fine sample on a display means such as a monitor.

When observing surface shape information of a fine sample with a monitor, a scanning optical microscope, a scanning probe microscope, or the like is widely used.
For example, in Patent Document 1, light emitted from a light source is collected on the surface of a sample by an objective lens, the collected light is scanned in a plane direction, the reflected light is received by a light receiving element, and sampling is performed. A scanning optical microscope is disclosed that observes shape information on a sample surface by digitally converting a received light signal by an analog-to-digital converter by a sampling clock generated by a clock generator and displaying the converted information on a monitor. ing.

Conventionally, in the case of a scanning optical microscope, the frequency of the sampling clock used for the above-described analog-digital conversion (hereinafter simply referred to as “sampling frequency”) is a combination of the NA (numerical aperture) of the objective lens and the light source wavelength. Regardless of the resolution of the monitor, the same sampling frequency was always used. In the case of a scanning probe microscope, the same sampling frequency is always used regardless of the tip diameter of the scanning probe.
Japanese Patent Laid-Open No. 10-311949

However, when the sampling frequency is used in accordance with the resolution of the monitor, an observation image may not be acquired with a sampling period optimum for the visual field to be observed.
For example, when the sampling frequency is lower than the optical resolution or the mechanical resolution (hereinafter referred to as “undersampling”), the microscope cannot effectively use its own optical performance.

  Further, when a sampling frequency that is excessively higher than the optical resolution is used (hereinafter referred to as “oversampling”), the microscope acquires data more than necessary, and consumes resources such as memory.

  The present invention has been made in view of the above-described problems, and a problem to be solved is to provide a microscope apparatus that acquires an observation image at a sampling frequency optimum for a visual field that is always desired to be observed.

  In order to solve the above-described problem, the present scanning microscope apparatus obtains the sample information in a microscope apparatus that obtains an analog signal that changes in accordance with sample information to be observed and generates image data of the sample. A sample information acquisition unit that generates an analog signal that changes according to the sample information, an acquisition condition storage unit that stores an acquisition condition for acquiring the sample information by the sample information acquisition unit, and the acquisition A sampling frequency determining means for calculating an apparatus resolution that is a resolution inherent to the sample information acquisition means from conditions, and determining a sampling frequency necessary for generating the image data satisfying the apparatus resolution from the analog signal; and By sampling the analog signal using the sampling frequency determined by the sampling frequency determining means. Image data generation means for converting the analog signal into a digital signal to generate the image data, image data storage means for storing the image data generated by the image data generation means, and storage from the image data storage means Observation image output means for acquiring the image data and generating an observation image of an arbitrary image size from the image data and outputting the observation image to a display device.

  According to the present invention, it is possible to provide a microscope apparatus that acquires an observation image at a sampling frequency optimum for a visual field that is always desired to be observed.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
(First embodiment)
FIG. 1 is a diagram illustrating a configuration example of a confocal scanning laser microscope 100 according to the present embodiment.

  A confocal scanning laser microscope 100 according to the present embodiment includes a laser microscope main body 101 having an optical system that irradiates a sample with laser light and acquires an observation image, and controls the laser microscope main body 101 to monitor an image on the monitor 103. , And a monitor 103 that displays the output observation image.

  Here, the laser microscope main body 101 includes a laser light source 110, a PBS (Polarization Beam Splitter) 111, a two-dimensional scanning unit 112, a 1 / 4λ plate 113, a revolver 114, an objective lens 115, an imaging lens 116, a pinhole 117, and light detection. 118 and AD converter 119 at least.

  The light emitted from the laser light source 110 passes through the PBS 111. Then, the light enters the two-dimensional scanning unit 112. The two-dimensional scanning unit 112 two-dimensionally scans the light beam applied to the sample 120 through the objective lens 115 attached to the revolver 114. At this time, the light beam is converted from linearly polarized light to circularly polarized light by the ¼λ plate 113.

  Since the two-dimensional scanning unit 112 is disposed at a position conjugate with the pupil of the objective lens 115, the light beam incident on the pupil of the objective lens 115 becomes a convergent light and scans the surface on the sample 120 in focus. To do.

  Here, the two-dimensional scanning unit 112 and the revolver 114 are controlled by the controller 102. In the two-dimensional scanning unit 112 according to the present embodiment, scanning is performed using a commonly used method called raster scan, but the present invention is not limited to this.

  On the other hand, the light beam reflected by the surface of the sample 120 is again introduced into the PBS 111 via the objective lens 115, the 1 / 4λ plate 113, and the two-dimensional scanning means 112. Then, the luminous flux is reflected by the PBS 111 and condensed on the pinhole 117 by the imaging lens 116.

  Here, the condensing position by the objective lens 115 is an optically conjugate position with the pinhole 117. That is, when an arbitrary surface on the sample 120 is at a position where light is collected by the objective lens 115, the reflected light from the sample 120 is collected on the pinhole 117, so that the reflected light passes through the pinhole 117. In addition, when an arbitrary surface of the sample 120 is deviated from the condensing position by the objective lens 115, the reflected light from the sample 120 is not condensed on the pinhole 117, and thus the reflected light passes through the pinhole 117. do not do.

As described above, the photodetector 118 receives only the reflected light in the region where the surface of the sample 120 is located at the condensing position of the objective lens 115.
A detection signal from the photodetector 118 is analog-digital converted by the AD converter 119 and output to the controller 102. The controller 102 generates an observation image from the detection signal and outputs the observation image to the monitor 103. As a result, the user of the confocal scanning laser microscope 100 can observe the observation image of the sample 120 on the monitor 103.

  In the configuration described above, for example, the sample information acquisition unit corresponds to the laser microscope main body 101 (excluding the AD converter 119). The acquisition condition storage means corresponds to the condition input unit 206 and the photon wavelength storage unit 204. The sampling frequency determination unit corresponds to the sampling frequency calculation unit 203. The image data generation means corresponds to the AD converter 119 and the sampling clock generation unit 209. The image data storage means corresponds to the detection signal receiving unit 200 and the detection signal storage unit 202. An observation image output unit corresponds to the display image construction unit 207 and the display image storage unit 208.

FIG. 2 is a block diagram illustrating the configuration of the controller 102 according to the present embodiment.
The controller 102 according to this embodiment includes a detection signal receiving unit 200 that receives a detection signal from the AD converter 119, a condition setting unit 201 that sets conditions for the two-dimensional scanning unit 112, and the like, and the received detection signal A detection signal storage unit 202 that stores the sampling frequency, a sampling frequency calculation unit 203 that calculates an optimal sampling frequency, a light source wavelength storage unit 204 that stores the wavelength of the laser light source 110 to be used, and an I / F (Inter / Face), an image transfer I / F 205, a condition input unit 206 that acquires and stores various conditions from a condition input screen, a display image construction unit 207 that generates an observation image to be displayed from a detection signal, A display image storage unit 208 that stores the observation image, and a sample that generates a sampling clock having an arbitrary sampling frequency It includes a Gukurokku generator 209, a.

  The detection signal receiving unit 200 receives the detection signal output from the AD converter 119 and transfers it to the detection signal storage unit 202. On the other hand, the detection signal storage unit 202 stores the transferred detection signal.

  The condition setting unit 201 transfers the conditions (for example, NA of the objective lens to be selected, scanning width, etc.) acquired by the condition input unit 206 to the two-dimensional scanning unit 112 and the revolver 114. In this embodiment, the scanning width is transferred to the two-dimensional scanning unit 112, and the selected objective lens type is transferred to the revolver 114. In addition, the condition setting unit 201 supplies the sampling clock obtained from the sampling clock generation unit 209 to the AD converter 119.

  The sampling frequency calculation unit 203 obtains various conditions (for example, NA of the objective lens) for calculating the optimum sampling frequency by the condition input unit 206 and sets the wavelength of the laser light source 110 being used as the light source wavelength. Obtained from the storage unit 204. Then, an optimum sampling frequency is calculated in the combination of the acquired NA of the objective lens 115 and the wavelength of the laser light source 110.

The image transfer I / F 205 outputs the observation image stored in the display image storage unit 208 to the monitor 103 and displays the observation image on the monitor 103.
The display image construction unit 207 acquires a detection signal from the detection signal storage unit 202 and generates an observation image in accordance with the image size displayed on the monitor 103. Note that the image size to be displayed is acquired from the condition input unit 206.

  The sampling clock generator 209 generates a sampling clock according to the sampling frequency calculated by the sampling frequency calculator 203. For example, it can be realized using a PLL circuit or the like.

The controller 102 described above can be realized by, for example, an information processing apparatus including a volatile / nonvolatile storage device and a CPU.
For example, the detection signal storage unit 202, the light source wavelength storage unit 204, and the display image storage unit 208 can be realized using a volatile / nonvolatile storage device (RAM, flash memory, magnetic storage device, etc.). The sampling frequency calculation unit 203 and the condition input unit 206 can be realized by causing the CPU to execute instructions according to a program stored in advance in a nonvolatile storage device.

  Similar to the sampling frequency calculation unit 203, the display image construction unit 207 may be realized by causing the CPU to execute an instruction according to a program stored in advance in a non-volatile storage device, or may include a dedicated hardware or FPGA ( (Field Programmable Gate Array) or the like. For the sampling clock generator 209, for example, a PLL circuit may be used.

FIG. 3 is a diagram illustrating an example of condition acquisition processing by the condition input unit 206 according to the present embodiment.
In the condition acquisition process according to the present embodiment, the CPU included in the controller 102 displays a GUI (hereinafter referred to as “condition input screen 300”) on the monitor 103 in accordance with a predetermined program command. When the user designates various conditions on the condition input screen 300 using a mouse or the like, the condition input unit 206 acquires and stores the conditions. The acquired conditions may be appropriately stored in a volatile / nonvolatile storage device (not shown).

  The condition input screen 300 according to the present embodiment includes an objective lens setting unit 301, a zoom condition setting unit 302, a display image size setting unit 303 for setting an image size to be displayed on the monitor 103, and an image acquisition button 304. Prepare.

  The objective lens setting unit 301 is a screen for selecting the objective lens 115 connected to the revolver 114. FIG. 3 shows an example of a screen when the objective lens 115 of 5 times, 10 times, 20 times, 50 times, 100 times, and 150 times can be selected.

The zoom condition setting unit 302 is a screen for setting the scanning width of the two-dimensional scanning unit 112.
The display image size setting unit 303 is a screen for setting the image size of the observation image output to the monitor 103.

When the above settings are made and the image acquisition button 304 is pressed, acquisition of an observation image and output of the observation image to the monitor 103 are started.
FIG. 4 is a flowchart showing the process of the confocal scanning laser microscope 100 according to the present embodiment.

  In step S400, when the user presses the image acquisition button 304, the confocal scanning laser microscope 100 starts an observation image acquisition process. Then, in the confocal scanning laser microscope 100, the process proceeds to step S401.

  In step S401, the condition input unit 206 acquires various conditions set on the condition input screen 300 (for example, NA of the objective lens, zoom condition, display image size, etc.). Then, the process proceeds to step S402.

  In step S <b> 402, the sampling frequency calculation unit 203 calculates the confocal scanning type according to the present embodiment from the NA of the objective lens 115 acquired from the condition input unit 206 and the light source wavelength value λ stored in the light source wavelength storage unit 204. The optical resolution δ of the laser microscope 100 is obtained, and the optimum sampling frequency fsp in the AD converter 119 is calculated.

Specifically, the sampling frequency calculation unit 203 performs the following calculation.
(1) The sampling frequency calculation unit 203 substitutes the spatial frequency CTF (Contrast Transfer Function) by substituting the NA of the objective lens 115 being used and the wavelength λ of the laser light source 110 being used into the following equation. calculate.

CTF = 2 * NA / λ (Line pair / mm) (1)
(2) The sampling frequency calculation unit 203 calculates the optical resolution δ by substituting the CTF calculated in Expression (1) into the following expression.

δ = 1000 * {1 / (2 * CTF)} (μm) (2)
Here, the optimum sampling frequency is defined as the frequency at which the resolution of the image data obtained by sampling satisfies the optical resolution δ. In this case, from the sampling theorem, the frequency at which the resolution of the image data is at least twice the optical resolution δ is the optimum sampling frequency.

  In the present embodiment described below, an example is shown in which the frequency at which the resolution of the image data is twice the optical resolution δ is calculated as the optimum sampling frequency, but the present invention is not limited to this. For example, if necessary, the frequency at which the image resolution is three times, four times,... Relative to the optical resolution δ may be set as the optimum sampling frequency. At this time, it is natural that it is not limited to an integer multiple.

  (3) The sampling frequency calculation unit 203 is a visual field region determined by the optical resolution δ calculated by the equation (2), the scanning width of the two-dimensional scanning unit 112 determined by the zoom setting of the zoom condition setting unit 302, and the scanning angle at that time. The number of sampling clocks N is calculated by substituting the horizontal real field of view X into the following equation.

N = 2 * (X / δ) (3)
In addition, when the frequency at which the image resolution is three times, four times,... Relative to the optical resolution δ is set as the optimum sampling frequency, any N satisfying the following equation may be used.

N ′ ≧ 2 * (X / δ) (3) ′
(4) Since the two-dimensional scanning unit 112 according to the present embodiment uses a linearly driven galvano scanner, the sampling frequency calculation unit 203 uses the sampling clock number N calculated by the equation (3) and the galvano scanner. The optimum sampling frequency fsp is calculated by substituting the following drive frequency f into the following equation.

fsp = 2 * N * f (Hz) (4)
When the optimum sampling frequency fsp is calculated by the processes (1) to (4) described above, the sampling frequency calculation unit 203 transfers the sampling frequency to the sampling clock generation unit 209, and the process proceeds to step S403.

  In step S <b> 404, the condition setting unit 201 transfers the type of the objective lens 115 acquired from the condition input unit 206 and the scanning width of the two-dimensional scanning unit 112 to the revolver 114 and the two-dimensional scanning unit 112, respectively. Further, the condition setting unit 201 supplies the AD converter 119 with the sampling clock having the optimum sampling frequency fsp obtained from the sampling clock generation unit 209.

  On the other hand, the revolver 114 switches the objective lens to the type of the transferred objective lens 115, and the two-dimensional scanning unit 112 starts scanning with the transferred scanning width. In addition, the AD converter 119 starts analog-digital conversion at the optimum sampling frequency fsp for the detection signal.

  In step S <b> 405, the detection signal receiving unit 200 receives the detection signal output from the AD converter 119 and stores it in the detection signal storage unit 202. In step S406, the display image construction unit 207 generates an observation image that matches the display image size acquired from the condition input unit 206 from the detection signal stored in the detection signal storage unit 202, and the display image storage unit 208. To remember.

  In step S <b> 407, the image transfer I / F 205 reads the observation image stored in the display image storage unit 208 and outputs it to the monitor 103. As a result, the observation image is displayed on the monitor 103.

FIG. 5 is a diagram illustrating a specific example of the calculation result of the optimum sampling frequency fsp in step S403.
For example, when the setting (zoom) of the zoom condition setting unit 302 is 1 × and 3 ×, the actual field of view X (μm) with respect to the field of view 500 is different. The calculation result 501 at the time of 3 and the calculation result 502 at the time of 3 times are shown.

  When the wavelength λ of the laser light source 110 is 407 (μm) and the NA of the objective lens 115 is 0.15 (5 times), the optical resolution δ is 0.68 from the equations (1) and (2). Calculated. Further, since the real field of view X is 2560 (μm) when the zoom is 1 ×, the optimum sampling frequency fsp is calculated as 60.4 (MHz) from the equations (3) and (4).

  As described above, the sampling clock generation unit 209 generates a sampling clock using the optimum sampling frequency fsp calculated by the sampling frequency calculation unit 203. Then, since the condition setting unit 201 supplies the sampling clock to the AD converter 119, the AD converter 119 performs analog-to-digital conversion on the detection signal using the sampling clock having the optimum sampling frequency fsp. The converted detection signal is stored in the detection signal storage unit 202 via the detection signal receiving unit 200.

  Here, the data (detection signal) stored in the detection signal storage unit 202 is always sampled using the optimum sampling frequency fsp that satisfies the resolution (for example, the optical resolution δ in the first embodiment) of the apparatus. Data. Therefore, even if output to the monitor 103 as it is, the resolution of the monitor 103 may be insufficient compared to the resolution of data stored in the detection signal storage unit 202.

  Therefore, in this embodiment, when the observation image is output to the monitor 103, the data stored in the detection signal storage unit 202 is constructed so as to satisfy the image size specified by the display image size setting unit 303. The image is reconstructed by the unit 207 and output to the monitor 103 via the image transfer I / F 205.

  Further, when the user of the confocal scanning laser microscope 100 analyzes and measures the observation image, the data (observation image) stored in the display image storage unit 208 is not used and is stored in the detection signal storage unit 202. Use the image data that has been saved. When analysis and measurement are performed using the image data stored in the detection signal storage unit 202, the analysis, the position of measurement, and the like are determined by the image size specified by the display image size setting unit 303. The data stored in the detection signal storage unit 202 is reconstructed so as to satisfy the condition, and is performed on the observation image output to the monitor 103.

As described above, the confocal scanning laser microscope 100 described above includes one path from the laser light source 110 to the AD converter 119, but may include a plurality of paths.
In the present embodiment, the process until the confocal scanning laser microscope 100 outputs the still image (observation image) to the monitor 103 has been described. For example, the user observes the observation image on the monitor 103 in real time. In the case where the observation image is continuously displayed on the monitor 103, for example, when the measurement site is specified, the frequency lower than the optimum sampling frequency fsp (for example, the optimum sampling frequency fsp) is continuously displayed. May be used as a sampling frequency, and the optimum sampling frequency fsp may be used only when a still image (observed image) is acquired.

  Thereby, for example, when observing in real time and searching for a portion of the sample 120 to be measured while displaying on the monitor 103, it is possible to prevent the memory consumption from increasing and the system operation from slowing down.

  Further, the confocal scanning laser microscope 100 according to the present embodiment calculates the optimum sampling frequency fsp using the equations (1) to (4). For example, the NA and the actual value of the objective lens 115 are calculated. The optimum sampling frequency for the combination of the fields of view X may be prepared as a table in advance. As a result, the load on the sampling frequency calculation unit 203 is reduced.

In step S402, the sampling frequency calculation unit 203 sets the sampling frequency necessary for generating an observation image having a pixel resolution satisfying the optical resolution δ from the detection signal as the optimum sampling frequency fsp. The sampling frequency necessary to generate an observation image having the pixel resolution of the observation image having an image size that can be displayed on the monitor 103 from the detection signal may be calculated, and this may be used as the optimum sampling frequency fsp.
(Second embodiment)
FIG. 6 is a diagram illustrating a configuration example of a scanning probe microscope (SPM) 600 according to the present embodiment.

  The scanning probe microscope 600 according to this embodiment includes a probe microscope main body 601 that acquires an observation image (hereinafter referred to as “SPM image”) from the displacement of the probe, and controls the probe microscope main body 601 to display the SPM image on the monitor 603. A controller 602 for outputting and a monitor 603 for displaying the SPM image to be outputted are provided.

  Here, the probe microscope main body 601 includes at least a scanner management unit 611, an XYZ scanner 612, a stage 613, a probe 614, a holder 615, a displacement detector 616, a Z scanner driver 617, an XY scanner driver 618, and an AD converter 619.

  The XYZ scanner 612 is a cylindrical piezoelectric body having electrodes in the XYZ directions. A stage 613 is fixed to the XYZ scanner 612, and a sample 620 is placed on the stage 613.

  In the vicinity of the sample 620, a probe 614 fixed to the holder 615 is disposed. When the probe 614 is displaced by the interaction acting between the sample 620 and the probe 614, the displacement detector 616 detects the displacement and outputs an output signal corresponding to the displacement. In the present embodiment, the probe 614 and the displacement detector 616 constitute a sensor system.

  The output signal of the displacement detector 616 is input to the Z scanner driver 617. Then, the Z scanner driver 617 outputs a Z drive signal to the XYZ scanner 612. As a result, the voltage applied to the XYZ scanner 612 changes and the XYZ scanner 612 is driven in the Z direction.

At this time, feedback control is performed to move the stage 613 in the Z direction so that the displacement of the probe 614 is always constant.
On the other hand, the scanner management unit 611 that manages the scanning width of the XYZ scanner 612 outputs an XY trigger signal for obtaining an SPM image to the XY scanner driver 618. The XY scanner driver 618 outputs an XY drive signal. Then, the applied voltage of the XY scanner driver 618 changes and XY scanning is performed. The XY scanning according to the present embodiment uses a method called raster scanning that is generally used, but the present invention is not limited to this.

  The AD converter 619 receives the sampling clock in the X direction from the controller 602, and converts the output signal of the Z scanner driver 617, that is, the Z displacement signal from analog to digital. Then, the data is output to the controller 602. The controller 602 generates an SPM image from the displacement signal and outputs it to the monitor 603. As a result, the SPM image is displayed on the monitor 603. Based on this SPM image, the shape of the sample is measured.

  In the configuration described above, for example, the sample information acquisition unit corresponds to the probe microscope main body 601 (excluding the AD converter 619). The acquisition condition storage unit corresponds to the condition input unit 706 and the probe information storage unit 704. The sampling frequency determination calculation means corresponds to the sampling frequency calculation unit 703. The image data generation means corresponds to the AD converter 619 and the sampling clock generation unit 709. Further, the image data storage unit corresponds to the detection signal receiving unit 700 and the detection signal storage unit 702. An observation image output unit corresponds to the display image construction unit 707 and the display image storage unit 708.

FIG. 7 is a block diagram showing the configuration of the controller 602 according to the embodiment of the present invention.
The controller 602 according to this embodiment stores a detection signal receiving unit 700 that receives a detection signal from the AD converter 619, a condition setting unit 701 that sets conditions for the scanner management unit 611, and the received detection signal. Detection signal storage unit 702, sampling frequency calculation unit 703 that calculates an optimal sampling frequency, probe information storage unit 704 that stores information (for example, tip diameter) about the probe 614 to be used, and I / O of the monitor 603 Image transfer I / F 705 that is F (Inter / Face), a condition input unit 706 that acquires and stores various conditions from a condition input screen and the like, and a display image construction unit that generates an SPM image for display from a detection signal 707, a display image storage unit 708 for storing the SPM image, and a sampler having an arbitrary sampling frequency Includes a sampling clock generating unit 709 for generating a clock, a.

  The detection signal receiving unit 700 receives the detection signal output from the AD converter 619 and transfers it to the detection signal storage unit 702. On the other hand, the detection signal storage unit 702 stores the transferred detection signal.

  The condition setting unit 701 transfers the conditions acquired by the condition input unit 706 (for example, the XY scanning width of the XYZ scanner 612) to the scanner management unit 611. In addition, the sampling clock obtained from the sampling clock generator 709 is supplied to the AD converter 619.

  The sampling frequency calculation unit 703 obtains various conditions (for example, the XY scanning width of the XYZ scanner 612) for calculating the optimum sampling frequency by the condition input unit 706, and the tip diameter of the probe 614 used. Is acquired from the probe information storage unit 704. Then, an optimum sampling frequency is calculated in the combination of the acquired XY scanning width of the XYZ scanner 612 and the tip diameter of the probe 614.

  Here, regarding the image transfer I / F 705, the display image construction unit 707, the display image storage unit 708, and the sampling clock generation unit 709, the image transfer I / F 205, the display image construction unit 207, and the display image storage unit shown in FIG. Since it is the same as 208 and the sampling clock generator 209, a detailed description is omitted.

The controller 602 described above can be realized by, for example, an information processing device including a volatile / nonvolatile storage device or a CPU.
For example, the detection signal storage unit 702, the probe information storage unit 704, and the display image storage unit 208 can be realized by a volatile / nonvolatile storage device. Further, the sampling frequency calculation unit 703 and the condition input unit 706 can be realized by causing the CPU to execute instructions according to a program stored in advance in a nonvolatile storage device.

  Similar to the sampling frequency calculation unit 703, the display image construction unit 707 may be realized by causing the CPU to execute an instruction according to a program stored in advance in a non-volatile storage device, or may include dedicated hardware, FPGA, or the like. It may be realized by. The sampling frequency calculation unit 703 may use a PLL circuit, for example.

FIG. 8 is a diagram illustrating an example of condition acquisition processing by the condition input unit 706 according to the present embodiment.
In the condition acquisition process according to the present embodiment, the CPU provided in the controller 602 displays a GUI (hereinafter referred to as “condition input screen 800”) on the monitor 603 in accordance with a predetermined program instruction. When the user specifies various conditions on the condition input screen 800 using a mouse or the like, the condition input unit 706 acquires and stores the conditions. The acquired conditions may be appropriately stored in a volatile / nonvolatile storage device (not shown).

  The condition input screen 800 according to this embodiment includes a scanning width setting unit 801 that sets the XY scanning width of the XYZ scanner 612, a display image size setting unit 802 that sets an image size to be displayed on the monitor 603, and an image acquisition button 803. And comprising.

When the above settings are made and the image acquisition button 803 is pressed, the acquisition of the SPM image and the output of the SPM image to the monitor 603 are performed.
When the user presses the image acquisition button 803, the sampling frequency calculation unit 703 performs AD conversion using the XY scanning width of the XYZ scanner 612 input by the condition input unit 706 and the probe tip diameter φ shown in FIG. The optimum sampling frequency fsp in the unit 619 is calculated.

Specifically, the sampling frequency calculation unit 703 performs the following calculation.
Here, it is generally known that the spatial resolution of the scanning probe microscope is about the tip diameter of the probe 614 used. Therefore, the optimum sampling frequency satisfying the in-plane resolution can be obtained from the tip diameter of the probe 614 as follows.

  From the sampling theorem, the frequency at which the resolution of the image data is at least twice the in-plane resolution is the optimum sampling frequency. In this embodiment, the resolution of the image data is twice the in-plane resolution. The example which calculates the frequency used as an optimal sampling frequency is shown. However, the present invention is not limited to this. For example, the frequency at which the resolution of the image data is three times, four times,... At this time, it is natural that it is not limited to an integer multiple.

  (5) The sampling frequency calculation unit 703 calculates the probe tip diameter φ (nm) of the probe 614 being used and the X-direction scanning width L (nm) of the XYZ scanner 612 being used as follows: By substituting, the number N of sampling clocks satisfying the in-plane resolution is calculated.

N = 2 * (L / φ) (5)
If the frequency at which the image resolution is three times, four times,... Relative to the in-plane resolution is the optimum sampling frequency, any N satisfying the following equation may be used.

N ≧ 2 * (L / φ) (5) ′
(6) The sampling frequency calculation unit 703 calculates the scan time T (ms) per line in the X direction by substituting the movement speed V (nm / ms) in the X direction of the XYZ scanner 612 into the following equation. .

T = L / V (ms) (6)
(7) The sampling frequency calculation unit 703 substitutes the optimum sampling frequency fsp by substituting the sampling clock number N calculated from the equation (5) and the scan time T calculated from the equation (6) into the following equation. calculate.

fsp = N / T (kHz) (7)
As described above, the sampling clock generation unit 709 generates a sampling clock using the optimum sampling frequency fsp calculated by the sampling frequency calculation unit 703. Since the condition setting unit 701 supplies the sampling clock to the AD converter 619, the AD converter 619 uses the sampling clock having the optimum sampling frequency fsp as a detection signal from the displacement signal from the Z scanner driver 617. Analog-to-digital conversion will be performed. The converted detection signal is stored in the detection signal storage unit 702 via the detection signal receiving unit 700.

  Here, the data (detection signal) stored in the detection signal storage unit 702 is always sampled using an optimal sampling frequency that satisfies the resolution of the apparatus (for example, the in-plane resolution in the second embodiment). Data. Therefore, even if output to the monitor 603 as it is, the resolution of the monitor 603 may be insufficient compared to the resolution of data stored in the detection signal storage unit 702.

  Therefore, in this embodiment as well, as in the first embodiment, when outputting an SPM image to the monitor 603, the detection signal storage unit 702 satisfies the image size specified by the display image size setting unit 802. Is reconstructed by the display image construction unit 707 and is output to the monitor 603 via the image transfer I / F 705.

  Further, when the user of the scanning probe microscope 600 analyzes and measures the SPM image, the data (SPM image) stored in the display image storage unit 208 is not used, but is stored in the detection signal storage unit 702. Use image data. When analysis and measurement are performed using the image data stored in the detection signal storage unit 702, the analysis, an indication of the position to be measured, and the like are specified by the display image size setting unit 802. The data stored in the detection signal storage unit 702 is reconstructed so as to satisfy the above condition, and is performed on the observation image output to the monitor 603.

  Further, the scanning probe microscope 600 according to the present embodiment calculates the optimum sampling frequency fsp using the equations (5) to (7). For example, the tip diameter φ of the probe 614 and the XYZ scanner An optimum sampling frequency for a combination of 612 XY scan widths may be prepared as a table in advance. Thereby, the load on the sampling frequency calculation unit 703 is reduced.

The sampling frequency calculation unit 703 sets the sampling frequency necessary to generate a detection signal having a pixel resolution satisfying the in-plane resolution from the analog signal as the optimum sampling frequency fsp. It is also possible to calculate a sampling frequency necessary for generating an observation image having a pixel resolution of an observation image having an image size that can be displayed from the detection signal, and use this as the optimum sampling frequency fsp.
(Modification)
In the first and second embodiments described above, the clock frequency of the sampling clock used for the AD converter 119 (AD converter 619) is calculated by the sampling frequency calculation unit 203 (sampling frequency calculation unit 703). As shown in FIG. 10, a sampling frequency setting unit 1001 that allows the user to arbitrarily set a desired sampling frequency may be provided on the condition input screen 1000.

  In this case, the sampling frequency set by the user may be undersampling (or oversampling). Therefore, for example, as shown in FIG. 11, a sampling frequency determination unit 1101 is additionally provided in the controller 1100 to determine whether the sampling frequency set by the user is undersampling (or oversampling). Alternatively, for example, a pop-up display 1300 shown in FIG. 13 may be displayed.

  FIG. 12 is a flowchart showing specific processing of the sampling frequency determination unit 1101 shown in FIG. Hereinafter, a controller including the sampling frequency determination unit 1101 is referred to as a controller 1100.

  When the user sets the conditions displayed on the condition input screen 1000 and presses the image acquisition button 304, the controller 1100 moves the process to step S1201.

  In step S1201, the condition input unit 206 acquires various settings (for example, objective lens NA, zoom, sampling frequency, display image size, etc.) from the condition input screen 1000 and stores them. Then, the condition input unit 206 moves the process to step S1202.

  In step S1202, the sampling frequency determination unit 1101 calculates the optimum sampling frequency fsp using Expressions (1) to (4). Alternatively, the optimum sampling frequency fsp is acquired from a table of optimum sampling frequencies for the combination of the NA of the objective lens 115 and the real field X prepared in advance.

  Then, the sampling frequency determination unit 1101 compares the sampling frequency acquired in step S1201 (hereinafter referred to as “set sampling frequency”) with the optimum sampling frequency fsp for the combination of the NA of the objective lens 115 and the real field X. To do.

  If the set sampling frequency is substantially equal to the optimum sampling frequency fsp, the sampling frequency determining unit 1101 determines that the set sampling frequency is not undersampling (or oversampling), and the process proceeds to step S1204. For example, when the set sampling frequency is within a range of 5% before and after the optimum sampling frequency fsp, it may be determined that they are substantially coincident. Note that the range for determining the optimum sampling frequency fsp is not limited to 5%, and can be set arbitrarily.

  If the set sampling frequency is not substantially equal to the optimum sampling frequency fsp, the sampling frequency determining unit 1101 determines that the set sampling frequency is undersampling (or oversampling), and the process proceeds to step S1203.

  In step S1203, the sampling frequency determination unit 1101 displays a pop-up display 1300 shown in FIG. 13 on the monitor 103 as a warning message, and informs the user that undersampling (or oversampling) has occurred. Then, the sampling frequency determination unit 1101 moves the process to step S1204. Thereafter, the processing of steps S404 to S408 shown in FIG. 4 is performed.

  10 to 12, the case where the sampling frequency determination unit 1101 is added to the controller 102 of the confocal scanning laser microscope 100 has been described as the controller 1100, but the sampling frequency determination is performed by the controller 602 of the scanning probe microscope 400. The same applies to the case where the unit 1101 is added.

  As described above, according to the embodiment of the present invention, the sampling frequency calculation unit 203 (or the sampling frequency calculation unit 703) always calculates the optimum sampling frequency fsp (step S403) or prepared in advance. The optimum sampling frequency fsp is obtained from the table. Then, the AD converter 119 (or AD converter 619) performs analog-digital conversion of the detection signal in accordance with the sampling frequency fsp.

  As a result, the observation always satisfies the resolution (for example, the optical resolution δ in the first embodiment, the in-plane resolution in the second embodiment) included in the apparatus without being limited to the resolution of the monitor 103 (monitor 603). It is possible to obtain a measurement result (SPM image) sampled at the sampling frequency fsp optimum for the desired visual field.

  Further, since sampling is always performed at the optimum sampling frequency fsp, oversampling can be prevented. As a result, it is possible to eliminate wasteful memory consumption caused by oversampling.

It is a figure which shows the structural example of the confocal scanning laser microscope which concerns on a 1st Example. It is a block diagram which shows the structure of the controller which concerns on a 1st Example. It is a figure which shows the example of the condition acquisition process by the condition input part which concerns on a 1st Example. It is a flowchart which shows the process of the confocal scanning laser microscope which concerns on a 1st Example. It is a figure which shows the specific example of the calculation result of the optimal sampling frequency fsp by step S403. It is a figure which shows the structural example of the scanning probe microscope which concerns on a 2nd Example. It is a block diagram which shows the structure of the controller which concerns on the Example of 2nd invention. It is a figure which shows the example of the condition acquisition process by the condition input part which concerns on a 2nd Example. It is a figure which shows the outline | summary of the probe which concerns on a 2nd Example. It is a figure which shows the modification of the condition input screen which concerns on a 1st Example. It is a figure which shows the modification of the confocal scanning laser microscope which concerns on a 1st Example. It is a flowchart which shows the process of the confocal scanning laser microscope shown in FIG. It is a figure which shows the example of the pop-up display screen which concerns on this modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Confocal scanning laser microscope 101 ... Laser microscope main body 102 ... Controller 103 ... Monitor 200 ... Detection signal receiving part 201 ... Condition setting part 202 ... Detection signal storage part 203 ... Sampling frequency calculation unit 204 ... Light source wavelength storage unit 205 ... Image transfer I / F
206 ... Condition input unit 207 ... Display image construction unit 208 ... Display image storage unit 209 ... Sampling clock generation unit 300 ... Condition input screen 600 ... Scanning probe microscope 601 ... Probe microscope main body 602... Controller 603... Monitor 700... Detection signal receiving unit 701 .. condition setting unit 702 .. detection signal storage unit 703 .. sampling frequency calculation unit 704. Storage unit 705 Image transfer I / F
706 ... Condition input unit 707 ... Display image construction unit 708 ... Display image storage unit 709 ... Sampling clock generation unit 800 ... Condition input screen

Claims (13)

In a microscope apparatus that obtains an analog signal that changes according to sample information to be observed and generates image data of the sample,
Means for acquiring the sample information, sample information acquiring means for generating an analog signal that changes in accordance with the sample information;
An acquisition condition storage means for storing an acquisition condition for acquiring the sample information by the sample information acquisition means;
Sampling frequency determining means for calculating an apparatus resolution that is a resolution specific to the sample information acquiring means from the acquisition conditions, and determining a sampling frequency necessary for generating the image data satisfying the apparatus resolution from the analog signal; ,
Image data generating means for converting the analog signal into a digital signal to generate the image data by sampling the analog signal using the sampling frequency determined by the sampling frequency determining means;
Image data storage means for storing the image data generated by the image data generation means;
Obtaining the image data stored from the image data storage means, generating an observation image of an arbitrary image size from the image data, and outputting the observation image to a display device;
A scanning microscope apparatus comprising: An image size designating means capable of arbitrarily designating the image size,
The scanning microscope apparatus according to claim 1, further comprising: The observation image output means generates an observation image having an image size designated by the image size designation means;
The scanning microscope apparatus according to claim 2. The sampling frequency determining means is a sampling frequency necessary for generating the image data satisfying the apparatus resolution from the analog signal, and an arbitrary sampling frequency is selected from the sampling frequencies prepared in advance for each of the acquisition conditions. select,
The scanning microscope apparatus according to claim 1. The image data generation means performs sampling of the analog signal using a frequency smaller than the sampling frequency determined by the sampling frequency determination means when continuously generating the observation image.
The scanning microscope apparatus according to claim 1. The sampling frequency determining means determines the sampling frequency so that the image data having a pixel resolution of an observation image having an image size that can be displayed by the display device can be acquired.
The scanning microscope apparatus according to claim 1. Sampling frequency input means that allows the user to specify an arbitrary sampling frequency,
The first sampling frequency specified by the sampling frequency input means is compared with the second sampling frequency determined by the sampling frequency determination means, and the first sampling frequency is set to the second sampling frequency. On the other hand, if it is not within a certain range, sampling frequency determination means for displaying a warning to that effect on the display device, and
The scanning microscope apparatus according to claim 1, further comprising: The sample information acquisition means includes a laser microscope that has an optical system that detects the reflected light by irradiating the sample with laser light, and generates an analog signal that changes in accordance with the intensity of the reflected light. The
The scanning microscope apparatus according to claim 1. The apparatus resolution is the optical resolution of the laser microscope.
The scanning microscope apparatus according to claim 8. The acquisition conditions include the objective lens, field size, laser light wavelength and scanning speed of the laser microscope.
The scanning microscope apparatus according to claim 8. The sample information acquisition means includes a probe that is displaced by interaction with the sample, and includes a probe microscope that generates an analog signal that changes in accordance with the displacement.
The scanning microscope apparatus according to claim 1. The apparatus resolution is an in-plane resolution of the probe microscope.
The scanning microscope apparatus according to claim 11. The acquisition conditions include the tip diameter, field size, and scanning speed of the scanning probe of the probe microscope.
The scanning microscope apparatus according to claim 11.