JP3372307B2 - Sampling signal generator and scanning optical microscope - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in, for example, a laser printer, a bar code reader, etc., and a sampling signal generating device for generating a sampling signal from the condensing position of light from an optical deflecting means, and a scanning type using the same. Regarding an optical microscope.

[0002]

2. Description of the Related Art A means for detecting the deflection position of an optical deflector is
As disclosed in Japanese Patent Laid-Open No. 63-267991, FIG.
Reference numeral 1 shows an embodiment of the scanning laser diode 1
The laser beam 111 generated from 01 becomes parallel by the collimator lens 102 and is incident on the galvanometer mirror 103. The laser beam deflected by the galvanometer mirror 103 passes through the inverse sine lens 104 and forms an image on the photosensitive plate 105.

On the other hand, the timing laser diode 106
The laser beam emitted from the laser beam passes through the convex lens 107 and is deflected by the galvanometer mirror 103. The deflected laser beam passes through the grating 108, is collected by the condenser lens 109, and is incident on the photodetector 110. The output from the photodetector outputs a pulse each time the laser beam passes through the grating 108. In this case, by changing the pattern of the grating 108, a pulse corresponding to the position of the arbitrary galvanometer mirror 103 can be obtained.

For example, when this pulse is used as an image sampling signal, the position of the galvanometer mirror 103 can be accurately detected by the grating 108 even if the movement of the galvanometer mirror 103 is somewhat inaccurate. Therefore, if a pulse signal based on the grating 108 is used as a sampling signal, an accurate image can be obtained.

[0005]

However, as shown in FIG.
The technique disclosed in US Pat. No. 6,096,839 can only deal with the case where the deflection angle is constant. Therefore, when the image is stored in the frame memory, the vertical and horizontal sizes of the frame memory have a certain fixed value such as 512 × 512. Therefore, the number of sampling pulses of the image also has to be constant. Here, in the conventional technique, the grid 10
When the laser beam is deflected from one end to the other end of 8 and the number of pulses emitted from the photodetector 110 is N, the number of pulses emitted from the photodetector 110 is N / when the deflection angle is halved. The number is halved to 2, and the required number of sampling pulses cannot be secured. In order to set the number of sampling pulses to N, it is necessary to replace the grating 108 with a double pitch, for example.

From the above, it is conceivable to use the grating 108 having a fine pitch in advance, but when the deflection angle is continuously changed, the pitch corresponding to all the deflection angles is realized by the grating 108. Is impossible.

Further, since the conventional technique has a constant deflection angle, when this is used in a scanning optical microscope, the image cannot be enlarged or reduced unless the objective lens is changed.

According to the present invention, a sampling signal generator capable of stably and accurately obtaining a required sampling signal even if the deflection angle of the light deflecting means changes, and an image can be enlarged or reduced without changing the objective lens. An object is to provide a scanning optical microscope.

[0009]

In order to achieve the above object, the invention according to claim 1 is directed to a light deflecting means for deflecting the light of a light source, and the light reflected by the light deflecting means. The light collecting means, the light position detecting means arranged at the position where the light is collected by the light collecting means and outputting an electric signal according to the light position, and a value according to the deflection angle of the light deflecting means are set in advance. Reference signal generating means for outputting a reference electric signal,
The reference electric signal from the reference signal generating means and the electric signal from the optical position detecting means are inputted, and the comparing means for outputting a signal when both electric signals match, and the output signal from the comparing means are inputted. And a pulse generating means for outputting a pulse signal when the sampling signal generating device.

In order to achieve the above object, the invention corresponding to claim 2 is an optical deflecting means for deflecting the light of a light source, a condensing means for condensing the light radiated to the light deflecting means and condensing the reflected light. A plurality of optical position detecting means arranged at a position condensed by the condensing means and outputting an electric signal according to the optical position and having different characteristics, and the light reflected by the optical deflecting means are respectively transmitted to the optical position detecting means. Optical means for guiding, reference signal generating means for outputting a reference electric signal preset to a value according to the deflection angle of the light deflecting means, and light selected according to the inner deflection angle of each light position detecting means. Inputting the electric signal output from the position detecting means and the electric signal output from the reference signal generating means, and outputting a signal when both electric signals match, the output signal from the comparing means is input. When pulse signal A pulse generating means for outputting a sampling signal generator provided with the.

In order to achieve the above object, the invention according to claim 3 uses a plurality of lenses having different focal lengths as the light converging means according to claim 1, and according to the deflection angle of the light deflecting means. The sampling signal generating device is characterized in that an optimum lens is inserted in the optical path.

In order to achieve the above object, the invention corresponding to claim 4 is a sampling signal generating device characterized in that a zoom lens is used as the light converging means according to claim 1.

To achieve the above object, the invention according to claim 5 switches to a predetermined sampling signal when the deflection angle of the optical deflecting means according to claim 1 optically corresponds to an invalid magnification. A sampling signal generator having a configuration.

In order to achieve the above object, the invention corresponding to claim 6 is characterized by comprising the sampling signal generator according to any one of claims 1 to 5. It is a scanning optical microscope.

[0015]

According to the invention according to claim 1, since the light position detecting means outputs the position of the light incident on the light receiving surface as an electric signal , there is no problem even if the light deflecting means is continuously variable. You can Further, when the electric signal from the optical position detecting means and the reference signal from the reference signal generating means coincide with each other, the sampling pulse signal is output from the pulse generating means, so that an image without distortion can be generated.

According to the invention corresponding to claim 2, since the plurality of light position detecting means having different characteristics are provided, the light position detecting means having high sensitivity is used as the deflection angle of the light deflecting means becomes smaller. By doing so, it is possible to reliably generate the sampling signal.

According to the third aspect of the invention, the sampling signal can be reliably generated with a simpler structure than the case of the zoom lens even if the deflection angle becomes small. According to the invention corresponding to claim 4, even if the deflection angle by the light deflecting means becomes small, the scanning width of the light position detecting means can be made constant by the zoom lens.
When one optical position detecting means is used, the sampling signal can be surely generated even if the deflection angle becomes small.

According to the fifth aspect of the invention, when the deflection angle of the light deflecting means optically corresponds to the ineffective magnification,
Since the sampling signal is switched to the predetermined sampling signal, the following effects can be obtained. That is, in the region where the deflection angle of the light deflecting means is considerably small, it is considered that the light deflecting means operates in an almost ideal state. Therefore, the circuit for detecting the position of the light deflecting means is switched to the sampling signal generator which is assumed to be operating ideally,
The optical system can be simplified.

The invention corresponding to claim 6 is defined by claims 1 to 5.
Bei sampling signal generating apparatus according to any one of
Thus , it is possible to provide a scanning optical microscope capable of enlarging / reducing an image without changing the objective lens.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a first embodiment according to the present invention. The main configuration is a resonance type galvano scanner 3 which constitutes a light deflecting means for deflecting a laser beam 11 from a laser light source 10 which constitutes a light source, and a condensing means for condensing the light reflected by the galvano scanner 3. And a semiconductor position detecting element (PSD) 14 arranged at a position condensed by the condensing lens 13 and forming an optical position detecting means for outputting an analog electric signal according to the optical position. , Galvo scanner 3
Address counter 20, a memory 19, a digital-analog converter circuit (D) which constitutes a reference signal generating means for outputting a reference electric signal preset to a value corresponding to the deflection angle θ of
/ A) 21 and a variable gain amplifier 22.

Further, the reference electric signal from the reference signal generating means and the electric signal from the optical position detecting element 14 are input, and a comparison circuit 23 constituting a comparing means for outputting a signal when both electric signals match is compared with the comparison circuit 23. It comprises a one-shot timer 29 which constitutes a pulse generating means for outputting a pulse signal when the output signal from the circuit 23 is inputted.

A laser beam 2 emitted from a laser light source 1 is reflected by a surface 4A of a mirror 4 attached to a resonant galvanometer scanner 3. The laser beam 2 coincides with the optical axis 5 in a state where no deflection is performed.

The resonance type galvano scanner 3 is driven according to the magnitude of a drive signal from a drive circuit 9 described below. That is, the drive start signal output from the computer 6 is output to the waveform generation circuit 7, and the waveform generation circuit 7 generates a drive signal for driving the resonance type galvano scanner 3. This drive signal is transmitted to the resonance type galvano scanner 3 through the variable gain amplifier 8 and the drive circuit 9. In the resonance type galvano scanner 3, the mirror 4 vibrates at an angle θ according to the magnitude of the drive signal from the drive circuit 9. The laser beam 2 is deflected symmetrically about the optical axis 5 between X ₁ and X _{2 at} an angle 2θ.

Next, the function of detecting the position of the mirror 4 will be described. The laser beam 11 emitted from the laser light source 10 is collimated by the collimator lens 12. The laser beam reflected by the back surface 4B of the mirror 4 passes through the condenser lens 13 and is condensed on the semiconductor position detecting element (PSD) 14. PS
The center O of the light receiving surface 15 of D14 is arranged so as to substantially coincide with the optical axis 16. The converging point of the laser beam 11 coincides with the optical axis 16 in the state where the deflection is not performed. The condensing point moves on the light receiving surface 15 of the PSD 14 according to the rotation of the mirror 4 .

The PSD 14 is, as shown in FIG.
5 is an element that generates a signal corresponding to the position of the light incident on the light source 5. For example, it is assumed that light is incident on the light receiving surface 15 at a position apart from the optical axis 16 by Z. When the length of the light receiving surface 15 is 2L and the total current is I, the currents I ₁ and I ₂ generated at the terminals 17 and 18 at both ends are: I ₁ = (L + Z) × I / 2L I ₂ = (L−Z ) × I / 2L. The ratio of the sum of the currents I ₁ and I ₂ to the difference is (I ₁ −I ₂ ) / (I ₁ + I ₂ ) = Z / L (1), and the position of the incident light is found from the current value.

In FIG. 1, the laser beam 11 has an optical axis 1.
Deflection at an angle 2θ with 6 in between. The condensing point is PSD14
It moves on the light receiving surface 15 between 15A and 15B (length lh). Naturally, 1h is the length of the light receiving surface 15 of the PSD 14 is 2L
Since it has to be shorter, the focal length f of the condensing lens 13 is selected such that f × tan2θ ₁ = 1h <2L.

When the number of samplings is N, the sampling interval ls is ls = 1h / N. That is, a sampling signal may be generated every time the laser beam 11 moves on the light receiving surface 15 of the PSD 14 by ls. The position signal at the n-th position can be obtained by setting Z = n × ls in Expression (1).

Next, a sampling signal generating means will be described. In the memory (reference voltage RAM) 19, from the first to the Nth, Z = n × ls (n = 1 to 1) in the equation (1).
Reference voltage data corresponding to the position signal obtained in N) is stored. Prior to the start of the deflection, 1 in the memory 19
The value of the address in which the th reference voltage data is stored is set in the address counter 20 by the computer 6. When the address is output to the memory 19, the first reference voltage data is output from the memory 19 to one input terminal 23A of the comparison circuit 23 through the digital / analog conversion circuit (D / A) 21 and the variable gain amplifier 22. .

Next, when the deflection is started, the laser beam starts moving on the light receiving surface 15 of the PSD 14. PSD1
Output signals from both ends of 4 are amplified by amplifiers 24 and 25, and then a sum signal is produced by an adder circuit 26 and a difference signal is produced by a subtractor circuit 27 therefrom.

Further, the divider 28 is used to perform the equation (1).
And the output signal is input to the other input terminal 23B of the comparison circuit 23. The output of the comparison circuit 23 is LOW while the signal level of the input terminal 23B is higher than the signal level of the input terminal 23A. When the signal level of the input terminal 23B gradually decreases and becomes lower than the signal level of the input terminal 23A, the output of the comparison circuit 23 becomes HI.
Change to GH. The output of the comparison circuit 23 is transmitted as it is to the one-shot timer 29, but the output of the one-shot timer 29 becomes HIG after a certain period of time.
Change from H to LOW.

At the output of the one-shot timer 29, the rising signal when changing from LOW to HIGH becomes a sampling signal, and this sampling signal is input to the analog / digital conversion circuit (A / D) 30. The analog-digital conversion circuit 30 also outputs an analog image signal obtained by photoelectrically converting the laser beam 2 that has passed through the sample 31 by the photodiode 32, and the analog image signal is converted into digital image data by the sampling signal. .

On the other hand, at the output of the one-shot timer 29, the falling signal when changing from HIGH to LOW becomes a counter signal, and the address counter 20
Is incremented by one, and the address of the memory 19 where the second reference voltage data is stored is set. As described above, the above operation is repeated until the Nth reference voltage data of the memory 19 is output.

Next, the case where the deflection angle of the galvano scanner 3 changes will be described. PSD1 when the deflection angle is θ
The amplitude of the output signal of 4 is V. Since the number of samplings is N, the amount of change in the reference voltage output from the digital-analog conversion circuit 21 is V / N in order to obtain the next sampling signal.

When the deflection angle becomes θ / 2, PSD14
The output signal has an amplitude of V / 2. Therefore, the amount of change in the reference voltage must also be set to 1/2 of that when the deflection angle is θ. The deflection angle is set by the computer 6. The computer 6 has a variable gain amplifier 8,
Outputs the gain data according to the deflection angle set to 22 .
It The deflection angle and the amount of change in the reference voltage are set based on this data.

Here, in order to obtain the sampling signal at the same timing as when the deflection angle is θ, there is the following method in addition to the above method. (1) In the circuit of FIG. 1, a plurality of reference voltage data corresponding to all deflection angles are prepared in the memory 19 as shown in FIG. For example, in FIG. 3, when the deflection angle is θ, 0010 is set in the address counter. When the deflection angle is changed to θ / 3, 0030 is set in the address counter.

(2) In the circuit of FIG. 1, a variable gain amplifier 40 is provided between the output of the divider 28 and the comparison circuit 23 as shown in FIG. 4, and the input voltage to the input terminal 23B of the comparison circuit 23 is The voltage is always set so that the deflection angle is θ.

Next, let us consider the variable range of the deflection angle in which the sampling signal can be generated in the circuit of FIG. Of the factors related to the sampling signal, PSD14
The position resolution of will be described. Although the performance of the PSD 14 is different for each company, it will be described using the model 1L10 of SiTek. 1L10 has a light-receiving surface length of 10 mm and a positional resolution of 1.6 μm. The number of decomposition points M is: M = 10 / 1.6 × 10 ⁻³ = 6250 Approximately 1/6 at 1024/6250 when the number of samplings is N = 1024, that is, 1024 samplings up to 1/6 of the deflection angle θ. However, it becomes impossible to deal with a smaller deflection angle. Therefore, in this embodiment, the deflection angle is from θ to θ / 6.
It applies when used in the range of. Of course, if the number of samplings decreases, a deflection angle smaller than θ / 6 can be applied.

Next, a second embodiment of the present invention will be described with reference to FIG. Here, for simplicity, only the mirror position detection mechanism will be described. The same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. In the embodiment of the present invention, a plurality of PSDs 52, 5 having different characteristics are provided.
3 and 54, half mirrors 50 and 51, neutral density filters 56 and 57, and a switch 55, and the mirror 4
The optimum PSDs 52 to 54 are selected according to the change in the deflection angle of and the sampling signal is obtained from the selected PSDs.

Laser beam 11 emitted from laser light source 10
Becomes a parallel light beam by the collimator lens 12. The laser beam reflected by the back surface 4B of the mirror 4 is collected by the condenser lens 13
The light passes through the first half mirror 50 and is condensed on the first PSD 52. The laser beam reflected by the first half mirror 50 is split by the second half mirror 51. The laser beams reflected and transmitted by the second half mirror 51 are incident on the second and third PSDs 53 and 54, respectively. 5
Reference numerals 6 and 57 denote neutral density filters, which serve to equalize the amounts of light incident on the PSDs 52, 53, and 54.

The PSDs 52, 53, 54 of this embodiment have different characteristics. Specifically, SiT
A case where a product of ek company is used will be described. SiTe
The products of company k have the following different characteristics, and they correspond to PSDs 52, 53, and 54, respectively.

Model Name Photoreceptive Surface Resolution PSD 52 1L10 10 mm 1.6 μm PSD 53 1L5 5 mm 0.8 μm PSD 54 1L2.5 2.5 mm 0.4 μm The laser beam 11 is at the left end (Z = The position signal P _L when it comes to L) is obtained by converting the current into the voltage by the formula (1) (I ₁ → V ₁ , I ₂ → V ₂ ) (V ₁ −V ₂ ) / (V ₁ + V _2). ) = If ₁ V 1 + V ₂ = a 10V, the position signals P _R when came to _{P L = (V 1 -V 2} ) = 10V PSD of the right end of the light-receiving surface (Z = -L), (V 1 - _{V 2) / (V 1 +} V 2) = - 1 P R = -10V Therefore, the range R of the output signal becomes 20V (± 10V). This is the same for any PSD. The voltage change amount Δ per sampling is Δ = R / N (N is the number of samplings).

Here, it is assumed that the maximum deflection angle is θ, and the swing width of the laser beam 11 at this time matches the length of the light receiving surface of the PSD 52. When the deflection angle is changed in this state, the change amount Δ of the voltage generated by each PSD 52 to 54 is calculated as follows. (For simplicity, N = 1000.)

[0043]

[Table 1]

When the angle at the PSD 52 is θ / 4, it is possible to amplify the voltage to 20 mV. However, at the same time, the noise is also amplified and the judgment in the comparison circuit 23 becomes unstable,
A stable sampling signal cannot be obtained. Therefore, it is clear from Table 1 that it is preferable to use a PSD with a small light receiving surface as the deflection angle becomes smaller.

The output signal of each PSD is input to the switch 55 so that the optimum PSD signal can be selected according to the deflection angle. The switch 55 responds to a selection signal from the computer 6 by selecting (A1, A2), (B
1, B2) or (C1, C2) signal is selected.

In the above example, θ to θ / 2 are signals (A1, A
Use 2). θ / 2 to θ / 4 are signals (B1, B2)
To use.

Signals (C1, C2) are used for θ / 4 and above. It suffices to determine the selection conditions such as. The selected signals are amplified by the amplifiers 24 and 25, and thereafter, a sum signal is produced by the adder circuit 26 and a difference signal is produced by the subtractor circuit 27. Then, the sum signal and the difference signal are input to the divider 28,
The output signal is sent to the comparison circuit 23.

As described above, in the second embodiment of the present invention, the optimum PSD 52 to 54 signals can be selected according to the deflection angle. Therefore, compared to the first embodiment, a stable sampling signal can be obtained even with a smaller deflection angle.

Next, a third embodiment of the present invention will be described with reference to FIG. For simplicity, only the mirror position detection mechanism will be described. The same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. In the embodiment of the present invention, a plurality of condenser lenses 60, 6 having different focal lengths are used.
2 is used to make the width of the laser beam 11 on the light receiving surface of the PSD 61 constant.

Laser beam 11 emitted from laser light source 10
Becomes a parallel light beam by the collimator lens 12. The laser beam reflected by the back surface 4B of the mirror 4 passes through the condenser lens 60 and is condensed on the PSD 61. The deflection width L1 of the laser beam 11 on the PSD 61 has a deflection angle of θ and a condenser lens 60.
Let f be the focal length of, then L1 = f × tan θ. Next, it is assumed that the deflection angle decreases to θ / 2. Under this condition, the oscillation width of the laser beam is naturally halved.
As described above, when the swing width decreases, the output signal from the PSD 61 becomes small, and it becomes difficult to obtain a stable sampling signal. In this embodiment, in order to make the length on the PSD 61 the same as when the deflection angle is θ, another condenser lens 62 is inserted in the optical path instead of the condenser lens 60. Condenser lens 6
In No. 2, the focal length is twice that of the condenser lens 60. Therefore, the swing width L2 of the laser beam on the PSD 61 is L2 = 2f × tan θ / 2. If tan θ and θ are substantially equal to each other, L1 and L2 are substantially equal to each other, so that a stable sampling signal can be obtained as in the case where the deflection angle is θ. Condensing lens 60, 6
Since the focal position changes when the focal length of 2 changes, the position of the PSD 61 must also be moved in the optical axis direction in accordance with the switching of the condenser lenses 60 and 62.

Switching of the condenser lenses 60 and 62 is performed by a motor 63 as shown in FIG. Condensing lens 60, 6
2 is incorporated in a lens frame 64 fixed on a base 65. A rack 66 is attached to the bottom of the base 65.

On the other hand, the pinion 6 is attached to the rotary shaft of the motor 63.
7 is attached and is connected to the rack 66 via the pinion 67. Similarly, the movement of the PSD 61 is also performed by the rack 58 and the pinion 59.

The deflection angle is changed by the computer 6,
The computer 6 outputs a selection signal for the condenser lenses 60 and 62 that matches the deflection angle. The selection signal is the motor drive circuit 6
Sent to 8, 69. The drive signal causes the rotation shaft of the motor 63 and the pinion 67 to rotate. This rotational movement is converted into linear movement by the rack 66, and the condenser lenses 60, 6
2 and PSD 61 move in the directions of the arrows Y1 and Y2.

In the present embodiment, there are two types of condenser lenses 60 and 62, but more lenses may be used. Also, P
As for the movement of the SD 61, it is possible to carry out a method other than this embodiment. As described above, according to the third embodiment, since the optimum condenser lens is used according to the deflection angle,
A stable sampling signal can be obtained.

A fourth embodiment of the present invention will be described with reference to FIG. Here, for simplicity, only the mirror position detection mechanism will be described. The same components as those in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted. In the embodiment of the present invention, the zoom lens 70 is used as the condenser lens, and the light condensed by the zoom lens 70 is guided to the PSD 71.

Laser beam 11 emitted from laser light source 10
Becomes a parallel light beam by the collimator lens 12. The laser beam 11 reflected by the back surface 4B of the mirror 4 passes through the zoom lens 70 and is focused on the PSD 71. Zoom lens 70
The focal length continuously changes according to the deflection angle so that the width of the laser beam on the light receiving surface of the PSD 71 becomes constant. As described in the third embodiment, the positions of the zoom lens 70 and the PSD 71 must be changed when the distance changes. For this, the moving mechanism of the PSD shown in FIG. 7 may be used.

Next, a fifth embodiment of the present invention will be described with reference to FIG. Here, the same components as those in FIG. 1 are designated by the same reference numerals, the description thereof will be omitted, and a part of the configuration will be omitted for simplification.

In this embodiment, as shown in FIG.
A switch 80 is used to selectively use a sampling signal 81 generated based on the SD 14 and a sampling signal 82 generated from the computer 6.

A sampling signal 81 output from the comparison circuit 23 based on the PSD 14 and a sampling signal 82 from the computer 6 are input to the switch 80. The sampling signal 81 accurately reflects the position of the mirror.

Consider the sampling signal 82 in terms of the number of decomposition points and the image memory. Let L be the scanning width of the laser beam on the sample and δ be the resolution of the optical system at the maximum deflection angle θ. The resolution score M of this optical system is: M = L / δ On the other hand, the size of the image memory is N × N. There are the following display states depending on the relationship between M and N. When M> N, the image memory is insufficient and the sample information is decimated. When M = N, sample information is displayed without excess or deficiency. When M <N, the sample information is displayed more finely than the resolution of the optical system, that is, a so-called ineffective magnification (for example, a high magnification that has no effect on observing the details of the object).

For example, considering an optical system of a microscope, 10
When a 0 × objective lens is used, L = 160 μm, δ =
Since it is 0.25 μm, M = 640. If the image memory is N = 512, then M> N, so there is no problem.

Next, when the deflection angle is θ / 4, M = 640/4 = 160 And becomes a state of invalid magnification.

In this state, it is considered that there is no large difference in the displayed images even if sampling is performed at any position of the spot on the sample corresponding to within 3 pixels of the image memory.
That is, there is no problem even if the sampling varies a little.

Conversely speaking, for example, the mirror 4 of FIG. 1 is somewhat ideal with respect to the sampling signal generated based on the drive signal which is assumed to completely follow the drive signal from the drive circuit 9. There is no problem even if it deviates from the operating state. Further, as the deflection angle becomes smaller, the scanner operation also stabilizes and approaches the ideal operation state. Therefore, as shown in FIG. 9B, it is assumed that the mirror 4 completely follows the drive signal, and based on the drive signal. It means that there is no problem even if the created sampling signal 82 is used.

Therefore, a selection signal is output from the computer 6 to the switch 80 according to the deflection angle, and a stable sampling signal can be obtained at any deflection angle by selecting either the sampling signal 81 or the sampling signal 82.

FIG. 10 shows an example in which the sampling signal generator of the first embodiment according to the present invention is used in a scanning optical microscope. The laser beam 901 from the laser light source 900 is
The beam expander 902 expands the beam diameter to a required size. The expanded laser beam 901 passes through the polarization beam splitter 903 and the galvano scanner 9 provided at a position conjugate with the pupil position of the objective lens 911.
Incident on 04. Here, the laser beam 901 is deflected in the Y direction.

Then, the light is incident on a resonance type galvanometer scanner 907 which is also provided at a position conjugate with the pupil position of the objective lens 911 by the pupil transmission lenses 905 and 906. Here, the laser beam 901 is deflected in the X direction. The two-dimensionally scanned laser beam 901 is projected onto a pupil projection lens 908,
Passing through the imaging lens 909 and the λ / 4 wave plate 910,
It is incident on the objective lens 911. Then, a diffraction-limited spot is generated on the sample 912, and the sample 9
12 is scanned XY.

When the sample 912 is a transparent object, the laser beam 901 passes through the condenser lens 913 and is detected by the photodetector 914. On the other hand, if the sample 912 is a reflecting object, the laser beam 901 is again reflected by the objective lens 91.
1, λ / 4 wave plate 910, imaging lens 909, pupil projection lens 908, optical deflector 907, pupil transmission lenses 906, 9
05, the beam splitter 903 through the optical deflector 904
Is reflected by the condenser lens 915, condensed by the condenser lens 915, passed through the pinhole 916 arranged at the condensing position, and detected by the photodetector 917.

A signal is sent from the computer 927 to drive circuits 918 and 919 in order to perform XY scanning. Of these, the galvano scanner 904 that performs Y scanning does not require high-speed scanning (several tens Hz), so a linear operation type is used.

On the other hand, the resonance type galvano scanner 907 which performs the X scanning performs a high speed scanning (10 and several kHz), so that a non-linear (for example, sine wave) type operation type is used. Therefore, in order to obtain an image without distortion even in the non-linear scanning, the laser light source 920 (corresponding to 10 in FIG. 1) and the collimator lens 92
1 (corresponding to 12 in FIG. 1), condenser lens 922 (1 in FIG. 1)
3), a PSD 923 (corresponding to PSD 14 in FIG. 1), and a sampling signal generating circuit 924 to detect the position of the mirror and obtain a sampling signal that makes the image linear. Reference numerals 920 to 924 are a simplified version of the first embodiment shown in FIG.
The laser beam emitted from the laser beam is collimated by the collimator lens 921, is reflected on the back surface of the mirror of the resonance type galvano scanner 907, passes through the condenser lens 922, and is condensed on the PSD 923. A sampling signal is output from the sampling signal generation circuit 924 based on the signal from the PSD 923 and input to the memory 926.

On the other hand, the photodetectors 914 and 917 convert the intensity information of the sample 912 into an image signal, and the switch 9
I'm at 25. The computer 927 selects either the transmitted image signal or the reflected image signal. The selected image signal enters the memory 926 and is stored in the memory 926 based on the sampling signal from the sampling signal generation circuit 924. The stored image signal is displayed on the CRT 928 through the computer 927.

As in the embodiment of FIG. 10 described above, FIG.
Since the galvano scanner 904 is used for driving the sampling signal generator of the above embodiment, a scanning optical microscope capable of enlarging / reducing an image without changing the objective lens 911 can be obtained.

[0073]

According to the present invention, a sampling signal generator capable of stably and accurately obtaining a required sampling signal even if the deflection angle of the light deflecting means changes, and an image can be displayed without changing the objective lens. A scanning optical microscope capable of enlarging and reducing can be provided.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram for explaining a first embodiment of a sampling signal generator according to the present invention.

FIG. 2 is a view for explaining the semiconductor position detector of FIG.

FIG. 3 is a diagram for explaining the memory of FIG.

FIG. 4 is a diagram for explaining a modified example of FIG.

FIG. 5 is a schematic configuration diagram for explaining a second embodiment of the sampling signal generator according to the present invention.

FIG. 6 is a schematic configuration diagram for explaining a third embodiment of the sampling signal generator according to the present invention.

7A and 7B are views for explaining the mirror position detection mechanism of FIG.

FIG. 8 is a schematic configuration diagram for explaining a fourth embodiment of a sampling signal generator according to the present invention.

FIG. 9 is a schematic configuration diagram for explaining a fifth embodiment of the sampling signal generator according to the present invention.

FIG. 10 is a schematic configuration diagram showing an example in which a sampling signal generator according to the present invention is applied to a scanning optical microscope.

FIG. 11 is a schematic configuration diagram showing an example of means for detecting a deflection position of a conventional optical deflector.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Laser light source, 2 ... Laser beam, 3 ... Resonance type galvano scanner, 4 ... Mirror, 5 ... Optical axis, 6 ... Computer, 7 ... Waveform generating circuit, 8 ... Variable gain amplifier, 9 ... Driving circuit, 10 ... Laser Light source, 11 ... Laser beam, 12 ...
Collimator lens, 13 ... Condensing lens, 14 ... Semiconductor position detector, 15 ... Light receiving surface, 16 ... Optical axis, 17, 18 ... Terminal, 19 ... Memory, 20 ... Address counter, 21 ...
Digital-analog conversion circuit, 22 ... Variable gain amplifier,
23 ... Comparison circuit, 23A, 23B ... Input terminal, 24, 2
5 ... Amplifier, 26 ... Addition circuit, 27 ... Sum signal / subtraction circuit, 28 ... Divider, 29 ... One-shot timer, 30
... analog / digital conversion circuit, 31 ... sample, 32 ... photodiode, 40 ... variable gain amplifier, 50,51 ...
Half mirror, 52, 53, 54 ... Semiconductor position detector,
55 ... switch, 56, 57 ... neutral density filter, 60, 6
2 ... Condensing lens, 61 ... Semiconductor position detector, 63 ... Motor, 64 ... Lens frame, 65 ... Base, 58, 66 ... Rack, 59, 67 ... Pinion, 68, 69 ... Motor drive circuit, 70 ... Zoom lens , 71 ... Semiconductor position detector, 8
0 ... switch, 81, 82 ... sampling signal, 900
... light source, 901 ... laser beam, 902 ... beam expander, 903 ... beam splitter, 904 ... galvano scanner, 905, 906 ... pupil transmission lens, 907 ...
Optical deflector, 908 ... Pupil projection lens, 909 ... Imaging lens, 910 ... λ / 4 wavelength plate, 911 ... Objective lens, 91
2 ... Sample, 913 ... Condenser lens, 914 ... Photodetector, 915 ... Condenser lens, 916 ... Pinhole, 917
... Photodetector, 918, 919 ... Driving circuit, 920 ... Laser light source, 921 ... Collimator lens, 922 ... Condensing lens, 923 ... Semiconductor position detector, 924 ... Sampling signal generating circuit, 925 ... Switch, 926 ... Memory, 9
27 ... Computer, 928 ... CRT.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-5-20480 (JP, A) JP-A-61-248016 (JP, A) JP-A-4-69788 (JP, A) JP-A-4- 333013 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G06K 7/016 G02B 21/00 G02B 26/10 G06K 7/10 G06T 1/00

Claims (6)

(57) [Claims] 1. A light deflecting means for deflecting light from a light source, a condensing means for condensing light reflected by the light deflecting means, and a light position arranged at a position condensed by the condensing means. Optical position detecting means for outputting an electric signal according to the reference position, reference signal generating means for outputting a reference electric signal preset to a value according to the deflection angle of the light deflecting means, and a reference from the reference signal generating means. Comparing means for inputting an electric signal and the electric signal from the optical position detecting means and outputting a signal when both electric signals match, and pulse generation for outputting a pulse signal when the output signal from the comparing means is input A sampling signal generator comprising: 2. A light deflecting means for deflecting light of a light source, a condensing means for condensing light reflected by the light deflecting means, and a light position arranged at a position condensed by the condensing means. optical means for guiding respectively the light position detecting means of different multiple characteristics, the light reflected by the light deflecting means to the light position detecting means for outputting an electrical signal corresponding to the response to the deflection angle of the light deflecting means Reference signal generating means for outputting a reference electric signal preset to a predetermined value, an electric signal output from the light position detecting means selected according to the internal deflection angle of each light position detecting means, and the reference signal Comparing means for inputting the electric signal output from the generating means and outputting the signal when both electric signals match, and pulse generating means for outputting the pulse signal when the output signal from the comparing means is input, Equipped sump Ring signal generator. 3. The condensing unit according to claim 1, wherein the condensing unit is a plurality of lenses having different focal lengths, and an optimum lens is inserted in an optical path according to a deflection angle of the light deflecting unit. Sampling signal generator. 4. The sampling signal generating device according to claim 1, wherein the light converging means is composed of a zoom lens. 5. A sampling signal generator, wherein when the deflection angle of the light deflecting means according to claim 1 optically corresponds to an invalid magnification, the sampling signal is switched to a predetermined sampling signal. 6. A sampling signal generator according to any one of claims 1 to 5 is provided.
Scanning optical microscope that.