JPH0528949B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is an imaging device, in particular, capable of capturing an in-focus image over the entirety of an imaging target having finite dimensions in the optical axis direction. The present invention relates to an imaging device.

(Conventional technology) When taking close-up photographs of small insects, flowers, etc.
If a normal still camera or television camera is used, it is not possible to capture an image in which the entire subject is in focus. In this case, the range of focus can be expanded to some extent by narrowing down the lens and deepening the depth of focus, but this has the drawback of lowering the resolution, and objects that are quite large in the optical axis direction may still be entirely in focus. cannot be combined.

To solve these problems, an imaging device called a light scanning camera has been developed. This camera projects strong illumination light from three directions to form a thin curtain of light perpendicular to the camera's optical axis, and adjusts the camera to focus on this curtain of light. After setting like this,
When the shutter is opened and the subject is moved in the direction of the optical axis through the curtain of light, clear images of the parts of the subject that cross the curtain of light will be formed one after another on the film. . When the subject is caused to pass through the light curtain in this manner, an image in which the entire subject is in focus is captured.

Such an image is similar to a scanning electron micrograph, but it has the advantage that a color image can be obtained by using a color film as the film.

(Problem to be solved by the invention) In the light scanning camera described above, it is necessary to narrow down the illumination light to form a curtain of light, but it is extremely difficult to make the illumination light thin and the amount of light is insufficient. There are drawbacks to doing so. Because of this insufficient amount of light, there is a drawback that it takes a long time, such as one minute, to take one photograph.

Furthermore, the objects that can be imaged with a light scanning camera are limited to relatively large objects such as insects and flowers; for example, the objects that can be imaged are minute objects such as the uneven structure on the surface of a semiconductor chip on which various regions and conductors are formed. It is not possible to take an image. The reason for this is that the unevenness of such a semiconductor chip is on the order of microns, and it is actually difficult to make the light curtain thinner on the order of submicrons.

An object of the present invention is to solve the above-mentioned problems and provide an imaging device that can obtain bright illumination light and capture a focused image over the entire fine uneven structure.

(Means for Solving the Problems) The imaging device of the present invention includes a light source that emits at least one light beam, and a first deflection means that deflects the light beam emitted from the light source in the main scanning direction. , a second deflection means for deflecting the light beam in a sub-scanning direction perpendicular to the scanning direction of the first deflection means, and a second deflection means for converging the light beams deflected by the first and second deflection means onto a minute spot. a lens for projecting an image onto a scanning surface; a means for relatively displacing the scanning surface and the sample in the optical axis direction; and a plurality of light receiving elements arranged one-dimensionally in the main scanning direction; a linear image sensor that receives reflected light or transmitted light of the image via the second deflection means or a deflection means that operates in synchronization with the second deflection means; and a photoelectric sensor that is output from the linear image sensor during relative displacement by the displacement means. The apparatus is characterized in that it includes a signal processing section that performs arithmetic processing on an output signal and stores it, and a monitor section that receives the output signal of the signal processing section and reproduces an image of the sample.

(Function) According to the imaging device of the present invention, the light beam is deflected two-dimensionally and converged on the scanning plane as a minute spot, so the part of the object on the scanning plane is brightly illuminated, but the part of the object that is on the scanning plane is brightly illuminated. The darkened areas become noticeably darker. Therefore, when the object is displaced through the scanning plane, focused images of the entire object are successively formed on the linear image sensor. If the photoelectric outputs of this linear image sensor are sequentially added using memory and then the image is displayed on a monitor, an image similar to that captured by a light scanning camera will be obtained. In this case, by increasing the magnification of the lens, it is possible to capture an image of a minute object, and by increasing the magnification, the portions outside the scanning plane become even darker.

Furthermore, since the signal processing section is equipped with a frame memory, it is possible to perform calculations other than simple addition, allowing you to perform the optimal calculation depending on the purpose, which is not possible with conventional light scanning cameras. It is possible to project images that would otherwise be impossible.

(Embodiment) FIG. 1 is a diagram showing the configuration of an embodiment of a color imaging device according to the present invention. A red light source 1, a green light source 2, and a blue light source 3 are arranged to emit light beams of the three primary colors of red, green, and blue, respectively. In this example, a He-Ne laser that emits light with a wavelength of 633 nm is used as the red light source 1, and a 488 nm wavelength light is used as the green light source 2.
An Ar laser that emits light with a wavelength of m is connected to the blue light source 3.
A He-Cd laser that emits light at a wavelength of 442 nm is used. It is assumed that all the light beams emitted from each of the light sources 1 to 3 are linearly polarized. A light beam emitted from a red light source 1 is expanded into a parallel beam by an expander 4, reflected by a right-angle prism 5, and incident on a first acousto-optic element 6, which is a first polarizing element. This first acousto-optic element 6 vibrates a red light beam at high speed in the main scanning direction, and the red light beam vibrates at high speed and scans the sample surface in the X direction (perpendicular to the plane of the paper) at a scanning frequency f ₁ . do. The light beam polarized by the acousto-optic element 6 passes through relay lenses 7 and 8, passes through a first polarizing prism 9 and a quarter-wave plate 10, which act as beam splitters, respectively, and enters a first dichroic prism 11. incident. This first dichroic prism 11 reflects only green light and transmits light in other wavelength ranges. The red light beam that has passed through the first dichroic prism 11 passes through the second dichroic prism 12 that reflects only the blue light.
The beam enters a vibrating mirror 13, which is a deflection element. This vibrating mirror 13 is commonly used for red light beam, green light beam, and blue light beam,
Each light beam is deflected in the Y direction (direction of the plane of the paper) perpendicular to the X direction of the sample. The red light beam reflected by the vibrating mirror 13 passes through relay lenses 14 and 15, is converged into a minute spot by an objective lens 16, and enters a sample 17. As a result, sample 17 is
The red light beam in the form of a minute spot is scanned in the X and Y directions at a predetermined scanning frequency.
In this example, optical information about the sample is obtained by detecting reflected light from the sample 17. The reflected light from the sample 17 is again focused by the objective lens 16, passes through the relay lenses 15 and 14, enters the vibrating mirror 13 again, is reflected by the vibrating mirror 13, and then passes through the second and first dichroic prisms 12. and 11, further passes through the 1/4 wavelength plate 10, and enters the first polarizing prism 9. The light beam incident on the polarizing prism 9 passes through the quarter-wave plate 10 twice, so its polarization plane is rotated by 90 degrees, and is reflected by the polarization plane 9a, passes through the first concave lens 18, and then passes through the first concave lens 18. The linear image sensor 19 is placed at the imaging position of the relay lens 14 and the concave lens 18, and the reflected light from the sample 17 is focused in the main scanning direction. Each element is arranged one-dimensionally in a direction corresponding to the X direction of the sample (perpendicular to the plane of the paper) so that each line receives light, and the reflected light from the sample 17 is received by each element and photoelectrically converted. , the charges accumulated in each element are read out at a readout frequency _f2 . Since the linear image sensor has a charge accumulation effect, the pixels of the sample 17 and the linear image sensor 19
There is always a one-to-one correspondence with each light-receiving element constituting the sensor, and even if the scanning speed of the acousto-optic element 6 in the main scanning direction is uneven, the amount of light received changes only slightly, and photoelectric conversion is performed in a formal manner. Image distortion that differs from conventional imaging devices does not occur.

Next, scanning with green light will be explained. The light beam generated from the green light source 2 passes through an expander 20 and a rectangular prism 21, and then is converted to the same frequency as the first acousto-optic element 6 by a second acousto-optic element 22.
The sample 17 is vibrated at high speed in the X direction at _f1 , and the sample 17 is scanned at high speed in the X direction at a scanning frequency _f1 . The green light beam polarized by the second acousto-optic element 22 passes through the relay lenses 23 and 24, passes through the second polarizing prism 25, and is reflected by the right angle prism 26.
The light passes through the quarter-wave plate 27 and enters the first dichroic prism 11. Since this first dichroic prism 11 reflects only green light,
The incident green light beam is reflected and enters a common optical path, passes through the second dichroic prism 12, and enters the vibrating mirror 13. Then, it is deflected in the Y direction by the vibrating mirror 13 in the same way as the red light beam, passes through relay lenses 14 and 15, is focused into a minute spot by the objective lens 16, and enters the sample 17. As a result, the portion of the sample 17 scanned by the red beam is simultaneously scanned by the green light beam. The reflected light from the sample 17 is again focused by the objective lens 16, passes through relay lenses 15 and 14, is reflected by the vibrating mirror 13, and is further reflected by the second dichroic prism 1.
2 through the first dichroic prism 11
reflect. After that, it passes through the 1/4 wavelength plate 27 again, the polarization plane changes by 90 degrees, is reflected by the right angle prism 26, and then changes to the polarization plane 25a of the second deflection prism 25.
The light is reflected by the second concave lens 28 , converged into a minute spot, and enters the second linear image sensor 30 . Second linear image sensor 3
0 is arranged at the imaging position of the relay lens 14 and the second concave lens 28 similarly to the first linear image sensor 19, and each sensor is arranged so as to receive the reflected light from the sample 17 line by line in the main scanning direction. element as sample 1
They are arranged one-dimensionally in a direction corresponding to the X direction (perpendicular to the plane of the paper) of sample 17, and the reflected light from sample 17 is received by each light-receiving element and _{photoelectrically} converted. It is assumed that the accumulated charge is read out.

Next, scanning with blue light will be explained. The blue light beam emitted from the blue light source 3 is transmitted to the expander 32.
After passing through the right-angle prism 33, the light vibrates at high speed in the main scanning direction at a scanning frequency _f1 by the third acousto-optic element 34, passes through the relay lenses 35 and 36, passes through the third deflection prism 37, and is reflected by the right-angle prism 38. , further transmitted through the 1/4 wavelength plate 39, reflected by the second dichroic prism 12, enters a common optical path, and enters the common vibrating mirror 13, which converts the red and green light beams into Similarly, it is deflected in the Y direction. Furthermore, the relay lens 14
and 15, the light is focused into a minute spot by an objective lens 16, and enters a sample 17. As a result,
The red, green, and blue light beams are combined to form one scanning light beam, and the sample 17 is scanned in the X and Y directions by this scanning light beam. The blue reflected light from the sample 17 is again focused by the objective lens 16, passes through the relay lens 15 and the imaging lens 14, and enters the common vibrating mirror 13. Then, it is reflected by the vibrating mirror 13, reflected by the second dichroic prism 12, deviates from the common optical path, passes through the 1/4 wavelength plate 39, the deflection plane changes by 90 degrees, and the right angle prism 38 and the deflection Reflected by the prism 37, the third concave lens 40
A third linear image sensor 41 receives blue reflected light converged into a minute spot shape.
incident on . This third linear image sensor 4
1 is also placed at the imaging position of the relay lens 14 and the third concave lens 40, and similarly to the first and second linear image sensors 19 and 30, the blue reflected light from the sample 17 is reflected every line in the main scanning direction. Each element is arranged one-dimensionally in a direction corresponding to the X direction of the sample 17 so as to receive light, and the charge accumulated in each element is read out at a readout frequency _f2 .
Since the configuration is such that the vibrating mirror 13 is shared for the light beams of each color component, there is no deviation of the light beams in the vertical direction, and the occurrence of registration errors can be effectively prevented. In the present invention, the stage 42 on which the sample 17 is placed is disposed so as to be movable in the optical axis direction as shown by the arrow AB, and is displaced by the stage drive mechanism 43. This stage drive mechanism 43 is a stage drive circuit 44.
controlled by. Further, the photoelectric output signals of the linear image sensors 19, 30, and 41 are supplied to a signal processing section 45 including a frame memory, and subjected to predetermined arithmetic processing. The operations of the signal processing section 45 and the stage drive circuit 44 are controlled by a control circuit 46. Each of the appropriately processed color signals is supplied to a combining circuit 47 to create a color television signal, which can be displayed on a color monitor 48 or recorded on a video tape recorder 49.

FIG. 2 shows details of the peripheral circuit of the linear image sensor and the peripheral circuit of the signal processing section. A synchronizing circuit 50 for forming vertical and horizontal synchronizing signals V and H is connected to a clock generating circuit 51 to supply a horizontal synchronizing signal H. Clock generation circuit 51
Now, based on the supplied horizontal synchronization signal H, the first, second and third linear image sensors 19,
A clock pulse is generated to read out the charge stored in each element 30 and 41, and this read clock pulse is supplied to the first, second and third linear image sensors 19, 30 and 41, respectively. Further, the synchronization circuit 50 is connected to an acousto-optic element drive circuit 52 that controls the driving of the first, second, and third acousto-optic elements 6, 22, and 34, and is supplied with a horizontal synchronization signal H. A vibrating mirror drive circuit 53 that controls the drive of the mirror 13 is connected to supply a vertical synchronization signal V. The vertical synchronization signal V and horizontal synchronization signal H from the synchronization circuit 50 are also supplied to the control circuit. The signal processing section 45 includes amplifiers 54 to 5.
6, A/D converters 57-59, arithmetic circuits 60-6
2. Frame memories 63 to 65 are provided. First,
Second and third linear image sensors 19, 30
and 41, the amount of charge corresponding to the amount of reflected light from the sample 17 is accumulated in each element, so the amount of charge is read out synchronously based on the readout clock pulse, and
A/D converters 57, 58 are amplified through amplifiers 54, 55, and 56 connected to
After converting into a digital signal in and 59, it is sent to the frame memory 6 via arithmetic circuits 60, 61 and 62.
3, 64 and 65. With this configuration, since the amount of charge is read out synchronously from the three linear image sensors 19, 30, and 41,
Image distortion can be effectively prevented from occurring. In this example, the readout frequency _f2 of the linear image sensors 19, 30, and 41 is made to match the scanning frequency _f1 of the acousto-optic elements 6, 22, and 34, and each element of each linear image sensor is synchronized with main scanning. However, since the linear image sensor has a charge storage ability, there is a difference between the scanning frequency _f1 of the acousto-optic element and the readout frequency _f2 of each linear image sensor. Even if a shift occurs, problems such as image distortion and color shift will not occur.

In the present invention, the arithmetic circuits 60, 61 and 6
2, various operations can be performed, but in this embodiment, simple addition is performed. That is, after setting the stage 42 to the initial position, the first and second deflecting means 6, 22, 24
and 13 are driven to converge light beams of three colors onto the scanning surface to form a raster of scanning light. At the same time, the stage 42 is also moved in the optical axis direction. The moving speed of this stage is made slower than the vertical scanning speed. As the vibrating mirror 13 rotates during the vertical scanning period Tv, image signals of each color for one field are supplied from the A/D converters 57 to 59 to the calculation circuits 60 to 62, and these image signals are are stored in frame memories 63 to 65, respectively. Next, after the stage 42 moves slightly, the image signal for one field is again supplied to the calculation circuits 60 to 62. At the same time, the image signal already stored in the memory is read into the arithmetic circuit, this is added to the input image signal, and the added image signal is stored in the memory again. Thereafter, the image signals are sequentially processed while moving the stage 42 in the optical axis direction. In this way, an image signal obtained by adding a large number of field images obtained when the stage 42 is displaced in the optical axis direction by a predetermined range from the initial position is obtained in the memories 63 to 65. This image signal is supplied to a synthesis circuit 47 and displayed on a monitor 48 as a color television signal, or is displayed on a video tape recorder 4.
Record at 9. Further, when photographing on film, the color image displayed on the monitor 48 is photographed on the color film using the still camera 66.

The calculations in the calculation circuits 60 to 62 are not limited to the above-mentioned addition, and various calculations can be performed. For example, for image signals obtained while displacing the stage 42 in the optical axis direction, the maximum value of each pixel can be stored in the memory. This can be easily achieved by comparing the magnitudes of the sequentially inputted image signals and the image signals stored in the memory and updating the stored contents of the memory only when the input image signal is large.

Furthermore, various interpolations can be performed through arithmetic processing, and an optimal image can be obtained depending on the purpose.

Furthermore, the moving speed of the stage 42 does not necessarily need to be constant; for example, it can be made slower when imaging a dark part of the object, and faster when imaging a brighter part, thereby increasing the brightness. can reproduce a uniform image.

FIG. 3 is a plan view showing the relationship between the beam spot projected onto the linear image sensor and each element constituting the linear image sensor. In this embodiment, three linear image sensors 19, 30 and 4 are used.
1 have the same configuration, the first linear image sensor 19 that receives red light will be explained. The reflected light from the sample 17 is projected onto the linear image sensor 19 in the form of a minute spot, but in this example, the diameter of the projected beam spot BS is set to be slightly larger than the light receiving surface of each element 19a to 19n. Configure. The projected beam spot BS is sequentially deflected in the X direction, which is the arrangement direction of the elements 19a to 19n, so that the reflected light from the sample 17 is one-dimensionally received by each element 19a to 19n, and is reflected from the sample 17. A charge corresponding to the amount of reflected light is accumulated in each element and converted into a photoelectric output signal. If the configuration is such that the reflected light from the sample 17 is incident as a spot diameter larger than the light-receiving surface of each element of the image sensor 19 as in this example, there is a possibility that a positional error of the incident light with respect to the image sensor 19 or disturbance vibration may occur. becomes stable. In particular, when photographing with zoom, the spot diameter of the light beam is likely to change, so this is effective for an imaging apparatus equipped with a zoom photographing function.

FIG. 4 is a graph showing the relationship between the readout frequency of the linear image sensor and the amount of charge accumulated in each element. In the embodiment described above, the scanning frequency f ₁ of the acousto-optic elements 6, 22, and 34 and the readout frequency f ₂ of the linear image sensors 19, 30, and 41 were in a 1:1 relationship, but the linear image sensor has a charge storage capacity. , there is no need for synchronization, and the scanning frequency f ₁ by the acousto-optic element can be set to be higher than the readout frequency f ₂ . This example shows an example that utilizes this charge accumulation effect. Figure 4A shows the case where the readout frequency _f2 of the linear image sensor is equal to the scanning frequency _f1 in the main scanning direction of the light beam, that is, the amount of charge accumulated in the element each time the sample is scanned once with the light beam. The amount of accumulated charge is shown when the configuration is read out, and the simultaneous B is
C shows the amount of accumulated charge when f ₁ = 2f ₂ , that is, when the sample is scanned twice with a light beam and then _the amount of charge accumulated in the element is read out.
3f ₂ , that is, the amount of accumulated charge is shown in the case of a configuration in which the sample is scanned three times with a light beam and then the amount of charge accumulated in the element is read out.

In this way, if the image sensors 19, 30, and 41 are configured to receive the reflected light from the sample 17 multiple times, the main scanning frequency _f1 of the light beam can be increased.
Compared to the case where the readout frequency f ₂ of the image sensor and the readout frequency f 2 of the image sensor are set equal, the influence of the noise of the light source is averaged out, so that the S/N ratio of the photoelectric output signal can be substantially improved. Of course, in this case, the readout frequency _f2 of the image sensor is always constant, and a signal at a predetermined television rate can be obtained.

In FIG. 4, the readout frequency of the image sensor is changed, but it goes without saying that the same effect can be obtained even if the readout frequency of the image sensor is kept constant and the scanning frequency of the acousto-optic element is changed.

Next, resolution will be explained. FIG. 5A is a diagram schematically showing the scanning state on a sample by the conventional optical scanning microscope imaging device, and FIG. 5B is a diagram schematically showing the scanning state on the sample by the microscope imaging device according to the present invention. FIG. In conventional chemical scanning microscope devices, when using a light source with low output, the scanning speed must be slowed down and the scanning line density must be set low, resulting in the inconvenience that optical information existing between the scanning lines is lost. was occurring. On the other hand, if the scanning frequency f ₁ of the light beam in the main scanning direction is set to be approximately an integral multiple of the readout frequency f ₂ of the image sensors 19, 30, and 41, the main scanning speed can be increased and the scanning line density can be increased. However, it is possible to obtain a photoelectric output signal of approximately the same magnitude. As a result, the scanning line density can be set equivalently high without deteriorating the S/N ratio of the photoelectric output signal or slowing down the scanning speed of the light beam, making it possible to more accurately reproduce the optical information of the sample. . In particular, when inspecting pattern defects on photomasks and reticle patterns using conventional optical scanning microscopes, microscopic defects often exist between scanning lines and are often overlooked. Being able to set the line density to an equivalently high value is extremely effective for pattern defect inspection equipment.

Next, prevention of chromatic aberration will be explained.

In a color imaging device, a sample is irradiated with light beams of three primary colors through optical elements, so it is necessary to correct chromatic aberration caused by the optical elements. In this example, first to third concave lenses 1 are arranged movably in the optical axis direction in front of each linear image sensor 19, 30, and 41.
8, 28, and 40 in the optical axis direction, and also adjust the position of each linear image sensor in the optical axis direction to remove chromatic aberration. First, the optical system is set to be free from aberrations using green light, which is in the middle wavelength range of the three primary colors, as a reference. In this case, adjustment is facilitated by changing the position of the second concave lens 28. In this state, the reflected light from the sample 17 is transmitted to the first and third linear image sensors 19.
The first and third concave lenses 18 and 40 are appropriately moved in the optical axis direction, and the positions of the linear image sensors 19 and 41 in the optical axis direction are adjusted so as to form an image with a predetermined beam spot diameter on the linear image sensors 19 and 41. to remove chromatic aberration for red and blue.

If chromatic aberration is removed using a concave lens as in this example, there is an advantage that the deflection angle of the light beam incident on each linear image sensor can be increased. Note that chromatic aberration can also be removed by using a variable magnification lens system instead of a concave lens.

The present invention is not limited to the embodiments described above, but can be modified and changed in many ways. For example, in the above-described embodiment, the configuration was such that three light beams of red, green, and blue are projected onto the sample, but it may also be configured that two color light beams such as red and blue are projected, or one color beam may be projected onto the sample. Colored light beams may also be used.

Further, in the above-described embodiments, the configuration is such that the image is taken using the reflected light from the sample, but it is also possible to use the configuration that the image is taken using the transmitted light from the sample.

Further, as a means for deflecting the light beam, any deflecting means such as a polygon mirror can be used.

Furthermore, _the scanning frequency f ₁ by the deflection means and the readout frequency f ₂ of the linear image sensor do not necessarily have to have an integral multiple relationship. Even if it is not an integer multiple, there will be no problem with the image.

Further, in the above-described embodiment, an acousto-optic element is arranged for each of the three primary color light beams, but it is also possible to make each primary color light beam incident on a single acousto-optic element and cause it to vibrate at high speed. In this case, the optimal angle of incidence on the acousto-optic element differs depending on the wavelength of the light, so each light beam is made incident on a single acousto-optic element by changing the angle of incidence within the same plane and changed in the X direction. Alternatively, the three primary color light beams can be incident on a single acousto-optic element along different planes. In this way, when using a single acousto-optic element, an optical system is required to direct the light beams emitted from the acousto-optic element in different directions into a common vibrating mirror, but the acousto-optic element is expensive. Therefore, the price of the entire device can be reduced.

Further, in the above-described embodiment, the stage is moved in the optical axis direction, but it is also possible to keep the stage fixed and move the entire optical system including the objective lens.

Alternatively, the photoelectric output signal of the linear image sensor can be directly supplied to a monitor to display an image, and this can be photographed on film using a camera. It is preferable to perform arithmetic processing on the output signal, store it, and then display it on a monitor because various image processing can be performed through the arithmetic processing.

(Effects of the Invention) The effects of the present invention explained above are summarized as follows.

(1) A two-dimensionally deflected light beam is converged and projected onto the scanning plane, and the scanning plane and the object are displaced relative to each other in the optical axis direction. It is also possible to image objects.

(2) Since the photoelectric output signal of the linear image sensor is processed, it is possible to obtain optimal images for various uses.

(3) Since a vibrating mirror that performs sub-scanning is commonly used for each light beam, it is possible to prevent vertical color shift, that is, registration error.

(4) Since a linear image sensor with a charge accumulation effect is used as a photoelectric conversion element, and each linear image sensor is read out synchronously, even if the scanning speed of the light beam changes, image distortion and color shift will not occur. Occurrence can be completely prevented.

(5) If the scanning frequency of the light beam for each color component is set to be approximately an integer multiple of the readout frequency of the linear image sensor, the effects of noise from the light source will be averaged out, resulting in colors with a substantially high S/N ratio. An image signal can be obtained. Furthermore, the scanning line density can be equivalently increased without slowing down the scanning speed of the light beam, and loss of optical information on the sample can be avoided. In particular, a linear image sensor can obtain 1000 pixels or more, so it can form a high-resolution image signal.

(6) When observing biological samples, laser light can excite minute amounts of fluorescent components contained in living organisms, while linear image sensors are also sensitive to the fluorescent region, so they can be used to observe biological samples without using a fluorescence filter. Images can be accurately reproduced.

(7) Generally, when measuring a dimension such as line width of an uneven object, there was a drawback that the measured value varied widely depending on the focusing method. That is,
The sharpness of the edge wavelength changes depending on how you focus, so if you slice it in the same way, the measured line width will differ. Therefore, there are disadvantages in that measurement results may vary from person to person, or may vary from measurement to measurement even when performed by the same person.

On the other hand, according to the imaging device of the present invention, a focused image can be obtained over the entire surface of an uneven object, so dimensions such as line width can be measured extremely accurately, and individual differences are avoided. do not have.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an example of an imaging device according to the present invention, FIG. 2 is a circuit diagram showing the configuration of an example of a drive circuit and a signal processing section, and FIG. 3 is a beam projected onto a linear image sensor. A plan view showing the relationship between a spot and an element, FIGS. 4A to 4C are graphs showing the relationship between the readout frequency of the linear image sensor and the amount of accumulated charge, and FIGS. 5A and B show the state of the scanning line on the sample. FIG. 1... Red light source, 2... Green light source, 3... Blue light source, 4, 20, 32... Expander, 5, 2
1, 26, 33, 38...Right angle prism, 6, 2
2, 34... Acousto-optic element, 7, 8, 14, 1
5, 23, 24, 35, 36...Relay lens,
9, 25, 37...Polarizing prism, 10, 27,
39...1/4 wavelength plate, 11, 12...Dichroic prism, 13...Vibrating mirror, 16...Objective lens, 17...Sample, 18, 28, 40...
Concave lens, 19, 30, 41... linear image sensor, 42... stage, 43... stage drive mechanism, 44... stage drive circuit, 45... signal processing section, 46... control circuit, 47... synthesis circuit , 48...Monitor, 49...VTR, 50...
Synchronous circuit, 51...Clock generation circuit, 52...
Acousto-optic element drive circuit, 53... Vibrating mirror drive circuit, 54-56... Amplifier, 57-59...
A/D converter, 60-62...Arithmetic circuit, 63-
65...Frame memory, 66...Camera, BS
...beam spot.

[Claims]

1. A retransmission device that receives and retransmits television broadcasts, a plurality of modulators that modulate different carrier frequencies with video signals from a plurality of video signal regenerators or video signal generators, and the above-mentioned retransmission device. a mixer for synthesizing the general broadcasting output signal from the above, the independent broadcasting output signal from the modulator, and a signal wave for two-way data communication; and a mixer for outputting the signal wave for two-way data communication and controlling the communication according to a predetermined program. The center CPU that performs broadcasting selects a specific channel from among the general broadcast signals and independent broadcast signals that are connected to the mixer via a coaxial cable and a distributor or a branch, and selects a specific channel according to instructions from the center CPU. Multiple terminal converters that perform bidirectional data communication with the center CPU,
This terminal converter is connected to the terminal converter.

Claims (1)

a linear displacement device, which has a plurality of light-receiving elements arranged one-dimensionally in the main scanning direction, and receives transmitted light from the sample via a deflection device that operates in synchronization with the second deflection device; an image sensor; a signal processing unit that processes and stores a photoelectric output signal output from the linear image sensor during relative displacement by the displacement means; and an image of the sample upon receiving the output signal of the signal processing unit. An imaging device comprising: a monitor unit for reproducing images.