JP3416941B2 - Two-dimensional array type confocal optical device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optical device for obtaining a confocal image mainly for the purpose of three-dimensional measurement.

[0002]

2. Description of the Related Art An optical system for obtaining an image by a confocal optical system is called a confocal imaging system, and an image obtained by the confocal imaging system is called a confocal image. When performing three-dimensional measurement with a confocal imaging system, the confocal imaging system does not have a scanning mechanism such as a general laser scanning system or Nipkow disk scanning system, and confocal pinholes are arranged two-dimensionally. A two-dimensional array type confocal imaging system that simultaneously exposes each pixel of a focused image is suitable because of its high speed.
No. 8 and Japanese Patent Application Laid-Open No. 7-181023. Also, Japanese Patent Application No. 8-9 filed by the same inventor as the present invention.
Filed as 4682. See also H. J. Ti
Ziani et al .: "Three-dimensiona"
l analysis by a microlens
-Array confocalarrangemen
t ", Applied Optics, Vol. 33,
No. 4, pp. 567-572 (1994) does not arrange confocal pinholes two-dimensionally but arranges microlenses two-dimensionally to use as an objective lens.
A dimensional array type confocal imaging system has been realized. These conventional techniques will be described below.

FIG. 12 shows an apparatus according to Japanese Patent Laid-Open No. 4-265918 (hereinafter referred to as prior art A). The light emitted from the light source 1 is collimated by the collimator lens 4 and is applied to the pinhole array section 7 as parallel light. Here, the pinhole array section 7 has many pinholes arranged on the same plane. Light passing through each pinhole of the pinhole array unit 7 is regarded as a point light source, which is equivalent to the arrangement of point light sources. The light passing through the pinhole passes through the half mirror 121, and then is projected onto the object A by the objective lens 8 including the lenses 8a and 8b and the telecentric diaphragm 9. The light reflected from the object A is the objective lens 8
A pinhole array portion having a pinhole that is optically focused at the same position as the pinholes of the pinhole array portion 7 in a one-to-one correspondence with the light path deflected by the half mirror 121. A detector array 123 in which each detector is connected to each pinhole of the detector pinhole array unit 122 in a one-to-one relationship and the amount of light passing through each pinhole is detected. The above configuration is equivalent to arranging confocal optical systems in parallel. In this publication, the detector pinhole array portion, which is generally required for the detector portion, is made unnecessary by using a CCD sensor having a low aperture ratio (the ratio of photoelectric conversion elements to pixels is small). The above-mentioned configuration is referred to as a conventional technique A.

Next, an apparatus according to Japanese Patent Laid-Open No. 8-94682 (hereinafter referred to as prior art B) will be described with reference to FIG. The illumination light emitted from the light source 1 becomes a point light source at the pinhole 2 and is emitted as parallel light by the collimator lens 4. The optical path branching optical element 5 is a polarization beam splitter, and the illumination light passes as linearly polarized light. The illumination light that has passed through the optical path branching optical element 5 enters the microlens array portion 6 and is condensed at the focal point of each microlens. A pinhole array section 7 is installed at the focal position of the microlens array section 6,
Each pinhole exists in the position of the focal point of the illumination light condensed by each microlens. The illumination light that has passed through the pinhole enters the objective lens 8 and is circularly polarized by the ¼ phase plate 10 provided inside the objective lens 8 to project the image of the pinhole on the object A. Objective lens 8
Has a telecentric diaphragm 9 and lenses 8a and 8b inside.
Both-side telecentric lens with
Alternatively, the magnification does not change even if the optical system is moved in the optical axis direction. The reflected light from the object A enters the objective lens 8 again, becomes linearly polarized light orthogonal to the illumination light by the ¼ phase plate 10, is condensed, and reaches the pinhole array portion 7 again. The reflected light that has passed through the pinholes of the pinhole array unit 7 is emitted by the microlens array unit 6 as a parallel light flux. Since the reflected light is linearly polarized light which is orthogonal to the illumination light, it is deflected by the optical path branching optical element 5 which is a polarization beam splitter and enters the imaging optical section 16. The reflected light that has entered the image forming optical unit 16 is condensed by the image forming lens 12 including the lenses 12a and 12b so as to form an image on the surface of the microlens array unit 6 on the two-dimensional photoelectric sensor 15. ,
The two-dimensional photoelectric sensor 15 is reached.
As a result, a confocal image is obtained on the two-dimensional photoelectric sensor 15, photoelectrically converted by the two-dimensional photoelectric sensor 15, and output as an electric signal. The major difference from the prior art A is that the pinhole array section on the illumination side and the pinhole array section on the detector side are not separated, and one pinhole array section serves as both. In this sense, JP-A-7-181
The device disclosed in Japanese Patent No. 023 is also included in this prior art B.

Next, paper H. J. Tizani et al .:
"Three-dimensional analysis
s by a microlens-array co
nfocal arrangement ”, Appli
ed Optics, Vol. 33, No. 4, pp.
An apparatus according to 567-572 (1994) (hereinafter referred to as a conventional technique C) will be described with reference to FIG. The illumination light emitted from the light source 1 becomes a point light source by the pinhole 2 and becomes parallel light by the collimator lens 4. Then half mirror 14
After passing through 1, the microlens array 142 is irradiated. Each microlens of the microlens array 142 collects the illumination light and projects a spot on the object A. Object A
The reflected light from is collected by the same microlens as the spotted microlens, becomes parallel light, is deflected by the half mirror 141, and is subjected to the image forming action by the lens 12a and is arranged at the focal position of the lens 12a. Connect the spots on the pinhole 143. Pinhole 14
The reflected light passing through 3 becomes parallel light again by the lens 12b and enters the two-dimensional photoelectric sensor 15. Lens 12
The a and 12b and the pinhole 143 play the role of reproducing the intensity distribution of the parallel light component of the reflected light output from the upper surface of the microlens array 142 as it is on the two-dimensional photoelectric sensor 15. The difference from the prior arts A and B is that there is only one confocal pinhole on both the illumination side and the detector side, which is different from the prior arts A and B, and the objective lenses are arrayed instead. That is the point.

[0006]

What is common to these prior arts is that two-dimensional exposure is performed simultaneously in parallel.
It may be said that it is a point where a large number of spots of a two-dimensional array are formed on the object simultaneously and in parallel. Compared with the case of the most general laser scanning as a confocal imaging system, it can be said that the laser scanning uses a single beam, while the laser scanning uses a single beam. Hereinafter, such a feature will be referred to as a multi-beam confocal point.

In the case of multi-beam confocal, a problem is that spots are formed in parallel at the same time, so that an image formed by one beam is mixed with a blurred image-forming light beam of another beam. In the case of a single beam, of course, the influence of other beams cannot be considered, but in the case of multiple beams, the influence of adjacent beams cannot be ignored. If these influences are large, the confocal effect of being bright when the subject is in focus and being dark when the subject is out of focus cannot be obtained. Therefore, in the case of multi-beam confocal, it is important to devise to reduce the influence of adjacent beams. In order to reduce the influence of adjacent beams, it is common to increase the ratio between the spot diameter and the distance between spots (hereinafter referred to as spot pitch). However, if the ratio is large, if the number of beams is the same, the size of the pinhole array portion becomes significantly large in the case of the prior arts A and B, the angle of view of the objective lens becomes large, and the manufacturing of the objective lens becomes very It will be difficult. Although there is no problem in manufacturing the objective lens in the prior art C, there is no difference in that the effect of adjacent beams is as small as possible to obtain a higher confocal effect.

Therefore, an object of the present invention is to provide a two-dimensional array type confocal optical system which can reduce the influence of adjacent beams without increasing the ratio of spot diameter to spot pitch.

[0009]

In order to achieve the object, a two-dimensional confocal optical device having a pinhole array portion as in the prior arts A and B is provided with illumination light emitted from adjacent pinholes. Illumination light changing means for changing the polarization plane of the illumination light so as to have polarization planes orthogonal to each other, and selective detection for selectively transmitting the reflected light from the object so that the polarization planes are orthogonal to each other between adjacent pinholes. And a two-dimensional array type confocal optical device.

The illumination light changing means is composed of a linear polarization means for converting the illumination light into a linearly polarized light and a liquid crystal cell having a transparent electrode array of an array corresponding to each pinhole of the pinhole array section, and a selective light detecting means. Is composed of a liquid crystal cell which is common to the liquid crystal cell of the illumination light changing means, and an analyzing means which transmits only linearly polarized light in a certain direction.

Further, in the two-dimensional array type confocal optical device in which the objective lens is a microlens array as in the prior art C, the illumination lights emitted from the adjacent microlenses have polarization planes orthogonal to each other. Two-dimensional array having an illumination light changing means for changing the polarization plane of the illumination light and a selective analysis means for selectively transmitting the reflected light from the object between adjacent microlenses so that their polarization planes are orthogonal to each other. A confocal optical device.

The illumination light changing means is composed of a linear polarization means for converting the illumination light into a linearly polarized light and a liquid crystal cell having a transparent electrode array corresponding to each microlens of the microlens array. Is composed of a liquid crystal cell which is common to the liquid crystal cell of the illumination light changing means, and an analyzing means which transmits only linearly polarized light in a certain direction.

Alternatively, the illumination light changing means and the selective light detecting means are both the same polarizing plate array, and the polarizing plate array is constructed so that adjacent polarizing plates have mutually orthogonal Nicols.

Alternatively, the illumination light changing means and the selective light detecting means are both the same retardation plate array, and the retardation plate arrays are constructed such that adjacent retardation plates have a phase difference of ½ wavelength different from each other. To do.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first example of the embodiment of the present invention. The basic structure of the two-dimensional array type confocal imaging system of this example is the same as that of the prior art B. A duplicate description will be avoided and only different parts will be described. The only difference is the liquid crystal cell 2 installed below the pinhole array section 7.
0 and a power supply 21 for applying a voltage to the liquid crystal cell 20. The optical path branching optical element 5 is a polarization beam splitter, and the liquid crystal cell 20 and the optical path branching optical element 5 as a linear polarization means function as illumination light changing means for the illumination light.
With respect to the reflected light from the object, the liquid crystal cell 20 and the optical path branching optical element 5 as the light detecting means function as selective light detecting means.

First, the structure of the liquid crystal cell 20 will be described in detail, and then the operations of the illumination changing means and the selective light detecting means will be described. The structure of the liquid crystal cell 20 is shown in FIG. Figure 2
(A) is a side view. A transparent electrode (ITO film) 201 is provided under the pinhole array portion 7, and a liquid crystal 204 is sealed between the transparent electrode 202 of the transparent electrode substrate 203 below. The transparent electrode 201 has a zigzag lattice shape as shown in FIG. 2B, and one pinhole of the pinhole array portion 7 corresponds to one grid of the lattice. A voltage is applied between 201 and 202. The transparent electrode 202 is a common electrode without a pattern.

In the liquid crystal 204, liquid crystal molecules are transparent electrodes 201,
It is a twisted nematic liquid crystal (hereinafter, referred to as TN liquid crystal) in which an array is twisted by 90 degrees between 202. Transparent electrode 20
Since the voltage is not applied to the liquid crystal molecules in the areas without the patterns 1 and 202, when linearly polarized light polarized in the long axis direction of the liquid crystal molecules enters, the output light is linearly polarized with its 90 ° polarization plane rotating due to the optical rotation effect of the twisted arrangement. Becomes On the other hand, the liquid crystal portion to which a voltage is applied by the transparent electrodes 201 and 202 has no twist structure and there is no twist of the liquid crystal molecules between the electrodes, so that no optical rotation occurs at all and the light passes through in the same polarized state.

The operation of the liquid crystal cell 20 and the optical path branching optical element 5 as the linear polarization means as the illumination changing means will be described. The illumination light linearly polarized by the optical path branching optical element 5 is condensed by each microlens of the microlens array section 6, passes through the corresponding pinhole of the pinhole array section 7, and enters the liquid crystal cell 20. Illumination light emitted from the liquid crystal cell 20 is changed so as to be linearly polarized light having a 90-degree polarization plane different depending on the presence or absence of the transparent electrode in the liquid crystal cell 20. Since the pattern of the transparent electrode 201 has a zigzag pattern, the illumination lights emitted from the adjacent pinholes have polarization planes orthogonal to each other (however,
Diagonally adjacent is not considered next to).

Next, the operation of the selective light detecting means by the liquid crystal cell 20 and the optical path branching optical element 5 as the light detecting means will be described. The illumination light emitted from the liquid crystal cell 20 is circularly polarized by the ¼ phase plate 10 and is 1 when reflected by the object A.
After a phase jump of 80 degrees occurs and the reflected light passes through the ¼ phase plate 10 again, the plane of polarization is changed by 90 degrees with respect to the illumination light. The reflected light that has entered the liquid crystal cell 20 again passes through the pinhole in the polarization state as it is in the portion of the liquid crystal cell 20 where the transparent electrode 201 does not have a pattern, and the 90 ° polarization plane rotates at the portion where the pattern exists and is pinned. Pass through the hall. In any case, after passing through the pinhole, it has a polarization plane orthogonal to that of the illumination light linearly polarized by the optical path branching optical element 5, and after passing through the microlens array section 6, the optical path branching optical element. It is deflected by 5 and reaches the two-dimensional photoelectric sensor 15.

On the other hand, considering light that is blurred and is incident on an adjacent pinhole (see FIG. 3), the reflected light before entering the pinhole (to be precise, the liquid crystal cell 20) is orthogonal to each other between adjacent beams. Since the polarized light is in a polarized state, the reflected light that is blurred and is incident from the adjacent side has a polarization plane different by 90 degrees from the light that is normally incident. The polarization plane when the reflected light having different 90-degree polarization planes is incident on the optical path branching optical element 5 from the pinhole is also different from the normally incident light in the 90-degree polarization plane. Is transmitted through the optical path branching optical element 5 without being deflected by
It does not reach the dimensional photoelectric sensor 15.

By the above-described movement, the reflected light from the adjacent pinhole is not mixed and the confocal effect is not lowered. Obviously, blurry light from diagonally adjacent or next to or next to may be mixed, but it is insignificant compared to the influence of the reflected light of the next.

In this example, the conventional technique B is used as an example, but the conventional technique A does not make a great difference in principle.
Two sets of the above liquid crystal cell 20 and power source 21 are prepared and attached to both the pinhole array section 7 on the illumination side and the detector pinhole array section 122 on the detector side. A polarizing plate, which is a linear polarization means, is provided on the upper side, and a detecting means is provided between the detector pinhole array section 122 and the detector array 93 on the detector side or between the liquid crystal cell 20 and the detector pinhole array section 122 on the detector side. The polarizing plate may be arranged in parallel Nicols with the polarizing plate of the linear polarization means.

Further, in this example, in order to prevent the illumination light reflected on the surface of the microlens array portion 6 from going to the two-dimensional photoelectric sensor 15, the optical path branching optical element 5 or 1/4 which is a polarization beam splitter is provided. Although a polarizing element such as the phase plate 10 is used, the reflection on the surface of the microlens array portion 6 can be removed by coating or by tilting the microlens array portion 6. In this case, no polarizing element is needed. In such a case, as shown in FIG. 4, the desired purpose can be achieved only by providing a polarizing plate between the liquid crystal cell 20 and the pinhole array section 7. In this case, the optical path branching optical element 5 may be a non-polarization beam splitter, and the quarter wave plate 10
Is not necessary. The same thing can be realized in this way for the device according to Japanese Patent Application Laid-Open No. 7-181023.

The position of the liquid crystal cell 20 and the arrangement of the polarizing element do not necessarily have to be as in this example. For example, the liquid crystal cell 20 may be arranged on the microlens array portion 6 with the same transparent electrode arrangement as that of the microlens array portion 6, and the liquid crystal may be sandwiched between two transparent electrode substrates to arrange the liquid crystal cell alone. There are various other arrangements that are considered to be able to obtain the same effect.

The liquid crystal in the liquid crystal cell 20 is the TN liquid crystal. However, when linearly polarized illumination light passes through the liquid crystal, a voltage plane is applied and a polarization plane orthogonal to each other is applied when no voltage is applied. As long as it has the light that it has, it has a phase difference of 1/2 wavelength between the ordinary ray and the extraordinary ray by utilizing the electric field control birefringence effect in addition to the one using the optical rotatory power of the liquid crystal such as TN liquid crystal. So that the polarization plane is 90
It may be changed once.

Further, the pattern of the transparent electrode 201 is assumed to be a houndstooth pattern, but it suffices that the beam polarization planes are orthogonal to each other between adjacent pinholes, and it is not always necessary to have a houndstooth pattern. For example, even in the stripe shape, since the polarization planes of adjacent beams in at least one direction are orthogonal to each other, some effect can be obtained even if it is not as effective as the staggered lattice. Further, even when the arrangement of the microlens array section 6 is a hexagonal arrangement, the pattern shape needs to be adapted to it.

Next, FIG. 5 shows a second example of the embodiment of the present invention. The basic structure of the two-dimensional array type confocal imaging system of this example is the same as that of the conventional technique C. In this case, since the pinhole array portion is not provided, it cannot be the same as that of the first example, but the basic principle is exactly the same as that of the first example. As shown in FIG. 5, the liquid crystal cell 20 is arranged below the microlens array 142 (may be above). The transparent electrode 201 may be positioned so that one grid pattern corresponds to one microlens of the microlens array 142. The polarizing plate 51 is arranged above the liquid crystal cell 20 to serve both as the linear polarization means and the light detection means.
In this way, the same effect as the first example can be obtained. The power supply 21 is of course also necessary.

Next, FIG. 6 shows a third example of the embodiment of the present invention. The basic structure of the two-dimensional array type confocal imaging system of this example is the same as that of the prior art B. The difference from the first example is that the optical path branching optical element 5 is a non-polarization beam splitter, there is no 1/4 phase difference plate, and the microlens array section 6 is used.
The case where the reflection on the surface of the liquid crystal can be ignored, and the liquid crystal cell 2
Instead of 0, the polarizing plate array 61 has a pinhole array portion 7
It is the point installed under.

As shown in FIG. 7, the polarizing plate array 61 is formed by arranging polarizing plates whose polarization directions are orthogonal to each other in a zigzag pattern. The polarizing plates are arranged so as to correspond to the pinholes. When non-polarized illumination light (having at least two orthogonal polarization components) is emitted from the pinhole array unit 7 and enters the polarizing plate array 61, the illumination light emitted from the polarizing plate array 61 is emitted from the polarizing plate array 61. It becomes linearly polarized light according to the direction of each polarizing plate. As a result, the illumination light emitted from the polarizing plate array 61 has polarization directions in which adjacent beams are orthogonal to each other.

The polarizing plate array 61 also works as a selective light detecting means to prevent the blurred light of the adjacent beams reflected from mixing. That is, since adjacent beams have different polarization directions, even if they are mixed, they become Nicols orthogonal to the polarizing plate and cannot pass through the pinhole. Similar to the first example, even in this example, even if the base two-dimensional array type confocal imaging system is the prior art A, the polarizing plate array 61 is set to two.
It's just a matter of preparing, and it is exactly the same.

Next, FIG. 8 shows a fourth example of the embodiment of the present invention. Although the basic structure of the two-dimensional array type confocal imaging system of this example is the same as that of the conventional technique C, the difference from the second example is that the polarizing plate array 61 is below the microlens array 142 instead of the liquid crystal cell 20. It is a point installed in.

The polarizing plate array 61 is the same as that in the third example, and the same principle as in the third example prevents the reflected light from entering the microlenses of the adjacent microlens arrays 142.

Next, FIG. 9 shows a fifth example of the embodiment of the present invention. The basic structure of the two-dimensional array type confocal imaging system of this example is the same as that of the prior art B. The difference from the first example is that a retardation plate array 91 is installed below the pinhole array portion 7 instead of the liquid crystal cell 20. Unlike the third example, the optical path branching optical element 5 is a polarization beam splitter, and a 1/4 phase difference plate is also installed.

The retardation plate array 91 is formed by arranging holes (phase difference 0) and 1/2 retardation plates in a zigzag pattern as shown in FIG. Each box is arranged so as to correspond to each pinhole. Phase difference plate array 9
When linearly polarized light inclined by 45 degrees with respect to the optical axis direction of the 1/2 retardation plate in 1 is used as the illumination light, the illumination light emitted from the retardation plate array 91 has a phase difference of 0 at the hole portion. Thus, the polarization direction does not change, and the polarization direction changes by 90 degrees with the illumination light in the ½ retardation plate portion. As a result, in the illumination light emitted from the retardation plate array 91, adjacent beams have polarization directions orthogonal to each other.

The phase difference plate array 91 also serves as a selective light detecting means.
Works to prevent the blurred light of the adjacent beams that are reflected from mixing in. This principle is the same as the first example. This will be described with reference to FIG. Beams having different 90-degree polarization directions are emitted from the phase difference plate array 91, are circularly polarized by the ¼ phase difference plate 10, and are radiated to the object A. When reflected by the object A, a 180-degree phase jump occurs. After passing through the 1/4 phase plate 10 again as reflected light, the polarization direction is different by 90 degrees for each beam from that of the illumination light, and when passing through the phase plate array 91, at the hole portion. The light that passes through as it is, the polarization direction is changed by 90 degrees at the half retardation plate, and eventually the light that passes through the hole also becomes half
The light passing through the phase difference plate also has the same polarization direction (which is orthogonal to the illumination light), is deflected by the optical path branching optical element 5, and reaches the two-dimensional photoelectric sensor 15. When the reflected light of the adjacent beam is incident on the pinhole, the deflection direction is different, so that it is not deflected by the optical path branching optical element 5 and cannot reach the two-dimensional photoelectric sensor 15. Similar to the first example, even in this example, even if the base two-dimensional array type confocal imaging system is the prior art A, only two phase difference plate arrays 91 are prepared, which is exactly the same.

Next, FIG. 11 shows a sixth example of the embodiment of the present invention. Although the basic structure of the two-dimensional array type confocal imaging system of this example is the same as that of the conventional technique C, the difference from the second example is that the phase difference plate array 91 is the microlens array 142 instead of the liquid crystal cell 20. It is the point installed below.

The retardation plate array 91 is the same as that in the fifth example, and the reflected light does not mix into the microlenses of the adjacent microlens arrays 142 according to the same principle as in the fifth example.

The retardation plate arrays of the fifth and sixth examples of the present invention are an array of holes with a phase difference of 0 and retardation plates with a phase difference of ½ wavelength. Since it is sufficient that there is a difference of 1/2 wavelength, the same effect can be obtained by combining a retardation plate of 1 wavelength and a retardation plate of 1/2 wavelength.

[0039]

According to the two-dimensional array type confocal optical device of the present invention, it is possible to prevent the blurry light from admixing from the adjacent pinhole, which is always generated in the multi-beam confocal, to improve the confocal effect. . Alternatively, with the same confocal effect, the pinhole pitch can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a first example of an exemplary embodiment of the present invention.

FIG. 2A is a side view of the vicinity of the liquid crystal cell of the present invention. (B) is a figure for demonstrating the transparent electrode pattern of the liquid crystal cell of this invention.

FIG. 3 is a diagram for explaining that reflected light is mixed into an adjacent pinhole in the vicinity of the liquid crystal cell of the present invention.

FIG. 4 is a side view of the vicinity of the liquid crystal cell of the present invention.

FIG. 5 is a diagram showing a second example of the exemplary embodiment of the present invention.

FIG. 6 is a diagram showing a third example of an exemplary embodiment of the present invention.

FIG. 7 is a diagram for explaining a polarizing plate array of the present invention.

FIG. 8 is a diagram showing a fourth example of an exemplary embodiment of the present invention.

FIG. 9 is a diagram showing a fifth example of an exemplary embodiment of the present invention.

FIG. 10 is a diagram for explaining a retardation plate array of the present invention.

FIG. 11 is a diagram showing a sixth example of an exemplary embodiment of the present invention.

FIG. 12 is a diagram for explaining Prior Art A.

FIG. 13 is a diagram for explaining a conventional technique B.

FIG. 14 is a diagram for explaining a conventional technique C.

[Explanation of symbols]

1 light source 2 pinholes 4 Collimating lens 5 Optical path branching optical element 6 Microlens array part 7 pinhole array section 8a lens 8b lens 9 Telecentric diaphragm 10 1/4 phase plate 12a lens 12b lens 15 Two-dimensional photoelectric sensor 20 Liquid crystal cell 21 power supply 61 Polarizing plate array 91 Phase difference plate array

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01B 11/00-11/30 G02B 21/00-21/36

Claims (6)

(57) [Claims] 1. In a confocal optical system capable of obtaining a confocal image by aligning a large number of confocal pinholes on the same plane and performing parallel simultaneous exposure, illumination lights emitted from adjacent pinholes are orthogonal to each other. Illumination light changing means for changing the polarization plane of the illumination light so as to have a polarization plane, and selective light detecting means for selectively transmitting the reflected light from the object so that the polarization planes of adjacent pinholes are orthogonal to each other. A two-dimensional array type confocal optical device having: 2. The illumination light changing means is composed of a linear polarization means for converting the illumination light into a linearly polarized light and a liquid crystal cell having a transparent electrode array of an array corresponding to each pinhole of a pinhole array section, and selective light detection is performed. 2. The two-dimensional confocal optical system according to claim 1, wherein the means comprises a liquid crystal cell which is common to the liquid crystal cell of the illumination light changing means, and an analyzing means which transmits only linearly polarized light in a certain direction. apparatus. 3. In a confocal optical system capable of performing parallel simultaneous exposure using a microlens array as an objective lens to obtain a confocal image, illumination lights emitted from adjacent microlenses have polarization planes orthogonal to each other. Thus, the illumination light changing means for changing the polarization plane of the illumination light and the selective light detecting means for selectively transmitting the reflected light from the object between adjacent microlenses so that their polarization planes are orthogonal to each other are characterized. A two-dimensional array type confocal optical device. 4. The illumination light changing means is composed of a linear polarization means for converting the illumination light into a linearly polarized light and a liquid crystal cell having a transparent electrode array of an array corresponding to each microlens of the microlens array. 3. The two-dimensional array type confocal optical device according to claim 2, wherein the two-dimensional array type confocal optical device is constituted by a liquid crystal cell common to the liquid crystal cell of the illumination light changing means, and an analyzing means which transmits only linearly polarized light in a certain direction. . 5. The illumination light changing device and the selective light detecting device are both the same polarizing plate array, and the polarizing plate array has a structure in which adjacent polarizing plates are orthogonal Nicols. Alternatively, the two-dimensional array type confocal optical device according to claim 3. 6. The illumination light changing means and the selective light detecting means are both the same retardation plate array, and in the retardation plate array, adjacent retardation plates have a phase difference of ½ wavelength different from each other. The two-dimensional array type confocal optical device according to claim 1 or 3.