JPH0140952B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic microscope, and more particularly to improvements in its scanning device.

Conventional ultrasonic microscope scanning uses a combination of reciprocating movement by a voice coil and linear movement by a motor to scan a microscopic spot of ultrasonic waves over a sample in a raster pattern, as shown in an example in Figure 1. It is. In FIG. 1, an ultrasonic transmitting/receiving element 2 consisting of a transducer and an acoustic lens is arranged above a sample 1, and connected via a drive shaft 3 to a voice coil 4, that is, an x-direction drive device consisting of the same mechanism as a loudspeaker. and set the ultrasonic transmitting/receiving element 2 to
Make it perform high-speed reciprocating movement in the direction. Also,
A sample table 5 holding the sample 1 is moved at low speed in the y direction by a y direction moving mechanism (for example, a mechanism using a lead screw, etc.) to perform two-dimensional scanning using ultrasonic waves.

During scanning, the sample must be placed at a position where the ultrasonic beam is minimized. That is, when scanning a surface, the plane created by the smallest ultrasonic beam must be parallel to the sample surface of the sample. Therefore, as the sample stage 5, 2 x, y
A member is used that can provide parallelism of the surface with respect to the direction. In order to make the surface created by the smallest ultrasonic beam parallel to the sample 1, repeat scanning and adjust the sample stage 5 to reduce the interference fringes that appear in the image, until the interference fringes no longer appear. At the point when the sample 1 was used, the planarity of the sample 1 was to be achieved for the first time. Adjusting the sample stage 5 is very time consuming, and when the sample 1 is tilted, there is a drawback that most of the observation time is spent on adjustment to achieve flatness.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks and to provide an apparatus for an ultrasonic microscope that easily makes parallel the surface where ultrasonic waves are minimized with the sample plane.

The present invention provides a sample stand that is swingable about an axis extending in a first direction and an axis extending in a second direction substantially perpendicular thereto, and and at least three gap sensors facing the surface of the sample stage, spaced apart from each other, and fixedly arranged with respect to the scanning plane of the ultrasonic beam. The apparatus is characterized in that the driving means is controlled based on the output so that the sample stage is parallel to the scanning plane of the ultrasonic beam.

The present invention will be described in detail below with reference to the drawings.

FIG. 2 is a schematic perspective view showing an embodiment of the scanning device for an ultrasound microscope according to the present invention. In this scanning device, a motor 11 is connected to a rotating drum 13 via a drive shaft 12, and inside the rotating drum 13 there is a linear reciprocating member for an ultrasonic transmitting/receiving element (not shown).
By combining the linear reciprocating movement of this member and the rotational movement of the rotary drum 13, the ultrasonic beam scans the plane of the sample 14 in a spiral manner.

In this scanning device, the bottom surface of the rotating drum 13 is parallel to the plane that the minimum spot of the ultrasonic beam from the ultrasonic transceiver element will create during scanning. Therefore, the bottom surface of this rotating drum 13 should be parallel to the surface of the sample 14 to be observed, or to the surface of the sample stage 15 if the sample 14 is not tilted. , in scanning, the minimum spot of the ultrasonic beam scans a plane parallel to the plane of the sample 14. The sample stage 15 on which the sample 14 is placed is x
A first member that swings around an axis extending in the y direction, a second member that swings around an axis that extends in the y direction, and a third member attached to the fixed part. .

In order to make the bottom surface of the rotating drum 13 parallel to the surface of the sample 14 held on the sample 15, the rotating drum 1
Four gap sensors 16, 17, 18, and 19 are arranged on the bottom surface of 3 at symmetrical positions with respect to the center of rotation. Among these, gap sensor 16,
Reference numeral 17 detects flatness in the x direction, and gap sensors 18 and 19 detect flatness in the y direction. Comparator 20 is gap sensor 16,1
The comparator 21 is connected to the gap sensors 18 and 19 and compares their outputs. The comparator 20 is attached to the third member 15c of the sample stage 15 and Similarly, the comparator 21 is attached to the second member 15b of the sample stage 15, and the comparator 21 is attached to the drive device 22 for swinging.
It is connected to a drive device 23 that swings the shaft 5a. The scanning surface where the minimum spot of the ultrasonic beam from the ultrasonic transmitting/receiving element in the rotating drum 13 will be created during scanning and the sample 14 placed on the sample stage 15
The surface of Drive device 2 in the x direction to be equal
2 can be made parallel by controlling
Similarly, for the y direction, gap sensor 1
8, 19, can be made parallel by controlling the drive device 23 in the y direction by the comparator 21.

As explained above, according to the present invention, before scanning, it is possible to make the scanning plane, which would be created by the minimum spot of the ultrasonic beam during scanning, parallel to the sample surface. In addition, the complicated labor of performing observation adjustment to make the sample surface parallel by performing multiple scans can be omitted.

Note that the present invention is not limited to the above-described embodiments, and can be modified and changed in many ways. For example, it can be used even in the case of a raster scanning device using a voice coil that does not use spiral scanning.

[Brief explanation of drawings]

FIG. 1 is a diagrammatic perspective view of an example of a conventional ultrasound microscope scanning device, and FIG. 2 is a diagrammatic perspective view of an embodiment of the ultrasound microscope scanning device of the present invention. DESCRIPTION OF SYMBOLS 11... Motor, 12... Drive shaft, 13... Rotating drum, 14... Sample, 15... Sample stand, 15a... First member of sample stand, 15b... Second member of sample stand, 15c
...Third member of sample stage, 16, 17, 18, 19...
Gap sensor, 20, 21... Comparator, 22, 2
3...Drive device.

Claims (1)

[Claims] 1. A sample stand that is swingable about an axis extending in a first direction and an axis extending in a second direction substantially perpendicular thereto; a drive means for swinging as an axis; and at least three gap sensors facing the surface of the sample stage, spaced apart from each other, and fixedly arranged with respect to the scanning plane of the ultrasonic beam; An ultrasonic microscope characterized in that the driving means is controlled so that the surface of the sample placed on the sample stage surface is parallel to the scanning plane of the ultrasonic beam.