JP4502104B2 - Image pickup apparatus having compound prism optical system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus such as a monitoring / measurement imaging apparatus or an image reading apparatus, and a composite prism optical system capable of separately capturing a visible light image and an invisible light image using a prism in an optical path of the imaging optical system. The present invention relates to an image pickup apparatus.
[0002]
[Prior art]
In an image reading device of a film scanner that uses infrared light as invisible light, a photoelectric conversion element emits light including image information of a subject via an imaging optical system by irradiating the subject with illumination light such as a film. The image information from the subject is converted into an electrical signal and read as image data by projecting and forming an image on the light receiving surface and photoelectrically converting by the photoelectric conversion element.
Also, in such an apparatus, dust adhering to the illumination optical system and imaging optical system, dust on the film, scratches, fingerprints, etc. appear as black spots on the read image data, and as a result are reproduced by a film scanner. Image defects, resulting in image quality degradation.
[0003]
On the other hand, various methods have been proposed for correcting such image defects so that they are automatically made invisible or sufficiently reduced using infrared light. Focusing on the transmittance characteristics of the film with respect to infrared light, only the dust, scratches, fingerprints, and the like that cause the above-mentioned image quality deterioration are detected by infrared light, and the detected defect data such as dust and scratches are detected. This is a method of correcting image data of a subject read with visible light.
[0004]
However, in an imaging optical system such as a lens, the optical path length shifts due to the difference in wavelength between visible light and infrared light, and the image plane formed by infrared light generally exists farther than the image plane formed by visible light. .
[0005]
Therefore, in Japanese Patent Publication No. 6-78992 (conventional example 1), the primary color image and the IR image are rotated by rotating the filter holder equipped with the red, green and blue color separation filters and the IR (infrared) filter. Although reading is sequentially performed by one photoelectric conversion element, at the time of IR image data reading by the IR filter, the image formation position is controlled by a slight change of the sensor (photoelectric conversion element) in the optical axis direction by the drive mechanism.
[0006]
In "Japanese Patent Laid-Open No. 2000-324303" (conventional example 2), a difference in image forming position due to a difference in wavelength between visible light and infrared light is corrected by changing the thickness of the filter for visible light and the filter for infrared light. is doing. Actually, the image plane formed by infrared light exists farther than the image plane formed by visible light. Therefore, in order to correct this difference in image formation position, the visible light reading is performed more than the case of infrared light reading. A thick filter is inserted to correct the position of the image plane. As a result, in the case of visible light reading and infrared light reading, it is possible to read an image with one photoelectric conversion element by controlling the optical path length to be appropriate. Further, the imaging position can be controlled by moving the imaging lens along the optical axis by the lens moving means.
[0007]
In “Japanese Patent Laid-Open No. 2001-212295” (conventional example 3), an infrared light cut filter and a visible light cut filter as an optical filter are switched by a filter motor, and at the same time, the optical filter is integrally held by a holding frame. Each optical path is formed by adjusting the focus of the imaging lens and the line sensor (imaging device) whose distances are adjusted in advance so that the visible light image and the infrared light image are in the best focus state by the focus motor. The length is corrected.
[0008]
On the other hand, in recent years, with the digitization of electronic / communication technology, there has also been the appearance of photographic film (so-called “APS film”) with a 240-size transparent magnetic layer. The image reading apparatus including the 220 size (Bronnie size) has been required to be compatible with photographic films of various sizes. Therefore, a zoom lens that can freely set an image frame has been used as an objective lens in the image reading apparatus.
[0009]
In addition, as a conventional example that uses the ultraviolet light region as invisible light, as an ultraviolet microscope apparatus capable of inspecting semiconductor integrated circuit patterns, which have been increasingly miniaturized in recent years, with high resolution and high accuracy, In "Kaihei No. 5-127096" (conventional example 4), light from a light source (mercury lamp) having a wavelength from the visible light region to the near ultraviolet region is detected by an object held on a stage through an illumination lens system and an objective lens system. The semiconductor device is irradiated. The light reflected by the semiconductor device passes through the objective lens again and is separated into an ultraviolet light path and a visible light light path by a dichroic mirror. The separated light passes through each of the two separate lens barrels, and through the variable power lens system, ultraviolet rays are guided to an ultraviolet CCD (monochrome) camera and visible light is guided to a color CCD camera. It is burned.
Therefore, the semiconductor device pattern can be displayed simultaneously with a high-resolution, high-magnification ultraviolet image and a color image in which the color of the semiconductor device pattern can be visually recognized, or by superimposing the ultraviolet image and the color image through an image processing apparatus. By displaying, an ultraviolet image can be displayed as a pseudo color image.
Here, in the zoom lens system, the chromatic aberration of the image position and the chromatic aberration of magnification are corrected for the light in the near ultraviolet region and the visible light region, respectively. In addition, a combination of a variable power lens system and an objective lens system can be selected so that the total magnification of the ultraviolet microscope is variable.
[0010]
[Problems to be solved by the invention]
However, in the image reading apparatus using infrared light as in the conventional examples 1 to 3, R, G, B filters and IR filters, infrared cut filters, visible light cut filters, etc. are used for filter switching. In the method of controlling the imaging lens and line sensor, which are switched by a motor and each time the lens focus is controlled, or the distance between the optical axes is preliminarily adjusted by the holding frame, the filter is sequentially Since the image is read while switching, the processing speed is naturally limited, and the filter switching control and the mechanism therefor tend to increase the size and complexity of the apparatus.
[0011]
Further, since the refractive index of the glass used varies depending on the wavelength of the light, the lens produces axial chromatic aberration and lateral chromatic aberration. In particular, in a zoom lens, the axial chromatic aberration fluctuates with zooming, and this fluctuation amount becomes a problem. It is said that the axial chromatic aberration is generally the largest at the telephoto end. If this axial chromatic aberration remains large, even if tracking (focusing on the R, G, and B channels) is accurately performed at the wide-angle end, a tracking error occurs on the B and R channels at the telephoto end, resulting in color bleeding. Appear.
In recent years, the design of lens optical systems has become easier with the use of computers, which can be performed precisely and at high speed. In addition, the development of glass materials such as crystals of fluorite, which is different in dispersion from ordinary optical glass, and anomalous dispersion glass Therefore, the improvement is progressing to such an extent that the longitudinal chromatic aberration in the visible light region hardly becomes a problem.
[0012]
However, it is difficult to improve axial chromatic aberration in long-wavelength regions such as near-infrared light and infrared light with respect to the visible light region, so it is difficult to improve the chromatic aberration for various sizes. Therefore, when the zoom lens is used in the image reading apparatus, it is necessary to correct the shift of the longitudinal chromatic aberration from the wide-angle end to the telephoto end in the long wavelength region due to zooming by the optical system of the image reading apparatus.
[0013]
Further, in the ultraviolet microscope apparatus of Conventional Example 4, the apparatus is complicated and tends to be large in size, such as mounting a dedicated camera in each of two separate lens barrels.
[0014]
In view of the current situation described above, R, G, B filters and IR filters in image reading devices using infrared light, etc., without using a filter disk equipped with an infrared cut filter, a visible light cut filter, etc. Invisible light focus position correction that can automatically correct axial chromatic aberration is possible even when the zoom magnification of the zoom lens changes from the wide-angle end to the telephoto end. In the ultraviolet microscope apparatus, one lens barrel and one lens unit can be corrected. An imaging apparatus having a composite prism optical system that can be used as a camera apparatus is provided.
[0015]
[Means for Solving the Problems]
  As a result of earnest research in view of the above, the present inventor has solved this problem by the following means..
[0016]
  (1) Variable imaging magnificationZoom lens and zoom lensAn imaging device for visible light and an imaging device for invisible light that photoelectrically convert an optical image of a subject formed byZoom lensAnd a reflecting surface provided with a coating that transmits a wavelength in the non-visible light region and reflects a wavelength in the visible light region, which is disposed in an optical path between the imaging device and the imaging device, and is fixed to the prism fixing base. A composite prism composed of a first prism, a second prism having a surface facing the reflecting surface of the first prism with a fixed gap, and the second prism as the first prism. Prism drive means for controlling movement along the reflecting surface and correcting a positional deviation of the imaging surface due to a difference in wavelength between visible light and invisible light due to the imaging magnification change,Zoom lensAn imaging magnification data memory in which the imaging magnification data is stored,
In order to photoelectrically convert the optical image of visible light reflected by the first prism, an imaging device for visible light is disposed at an imaging position of the optical image of visible light, transmits the first prism, and An invisible light imaging device for photoelectrically converting an invisible light optical image transmitted through a second prism is disposed at an imaging position of the invisible light optical image. An imaging apparatus having a system.
[0017]
  (2) The imaging magnification data isZoom lensThe imaging device having the composite prism optical system according to item (1), wherein the imaging magnification data of the non-visible light image corresponds to the imaging magnification of the visible light image at each of the focal lengths.
[0018]
  (3) The second prism isZoom lensWhen the image forming magnification of the first prism changes, the prism driving means drives to move along the reflecting surface of the first prism based on the image forming magnification data of the image forming magnification data memory corresponding to the image forming magnification. An imaging apparatus having the composite prism optical system according to item (1) or (2).
[0019]
  (4) The imaging device further includesCorrect image defects caused by dust, scratches, or fingerprints attached to the negative or positive film as the subject.With film defect correction means,And the same imaging deviceFilm scannerInThe imaging apparatus having the composite prism optical system according to any one of (1) to (3), which is mounted as an image reading apparatus.
[0020]
  (5) The imaging device further illuminates the subject with a wavelength including wavelengths in the visible light and invisible light regions, or illumination means for illuminating only with a wavelength in the invisible light region, and illumination control means for controlling the illumination means (1) to () characterized by comprising4An imaging device having the composite prism optical system according to any one of items 1).
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings of the embodiments.
FIG. 1 is a block diagram when an imaging apparatus having a composite prism optical system capable of correcting the invisible light focal position according to the first embodiment of the present invention is used as an image reading apparatus of a film scanner. FIG. FIG. 3 is an explanatory view of a prism driving mechanism of the embodiment, FIG. 3 is an explanatory view of invisible light focal position correction of a composite prism formed in a square shape of the embodiment of the invention, and FIG. 4 is Embodiment 2 of the invention. FIG. 5 is a block diagram when the imaging apparatus having the composite prism optical system is used as a monitoring television camera, and FIG. 5 is an image having the composite prism optical system capable of correcting the invisible light focal position according to the third embodiment of the invention. FIG. 6 is a schematic diagram when the apparatus is used as an imaging apparatus for an ultraviolet microscope apparatus, and FIG. 6 shows an imaging apparatus having a complex prism optical system capable of correcting the invisible light focal position according to Embodiment 3 of the invention. Is a block diagram of a case of using as 置用 imaging device, FIG. 7 is an explanatory view of a non-visible light focal position correction of the composite prism other than square the invention examples.
[0022]
[Example 1]
In FIG. 1, a negative film that is radiated by a light source L having a wavelength in an infrared light region and a visible light region as an illumination light source including a condensing optical system travels at a constant direction and at a constant speed by a film driving device 1. 2, and is imaged on the photoelectric conversion element surfaces of the line sensor type imaging devices 5 and 6 through the composite prism 4 by the zoom lens 3.
[0023]
The composite prism 4 is disposed in the optical path between the zoom lens 3 and the imaging devices 5 and 6, and is a film on which an interference film that transmits the wavelength in the infrared light region and reflects the wavelength in the visible light region is deposited. A first prism 4a having an isosceles right-angled triangle shape that has a surface 4c and is fixed to a prism fixing base 102a (FIG. 2), and is opposed to the coating surface 4c of the first prism 4a via a fixed gap. And the second prism 4b having an isosceles right triangle shape movable by the prism driving means 16 is formed in a regular square shape.
The second prism 4b can be moved by the prism driving means 16 in the direction indicated by the thumbprint (FIG. 3) along the coating surface 4c of the first prism 4a.
In the composite prism 4, in order to extract only the wavelength of the visible light region or the wavelength of the infrared light region, the infrared rays are respectively used as optical filters for cutting the extra wavelength region on the exit surfaces of the two prisms 4a and 4b. It is preferable to stick a trimming filter for cutting light, a trimming filter for cutting visible light, or a bandpass filter having a specific wavelength of infrared light (for example, 800 nm to 850 nm).
[0024]
A visible light imaging device 5 is disposed to photoelectrically convert an optical image of visible light reflected by the coating surface 4c of the first prism 4a, passes through the first prism 4a, and further includes a second An infrared light imaging device 6 is provided for photoelectric conversion of an optical image of infrared light transmitted through the prism 4b.
As an example of the imaging device, there is a solid-state imaging device (CCD) having sensitivity in the infrared region as well as the visible region. The imaging device also has red, green, and blue (R, G, B) light sensitivities that enable color reading of images.
In the present embodiment, a three-line sensor having three lines (R, G, B) arranged in parallel at a certain interval is used as the visible light imaging device 5. Further, as the infrared light imaging device 6, a one-line imaging device having excellent sensitivity to wavelengths in the infrared light region may be used.
[0025]
The electrical signals (hereinafter referred to as image signals) obtained by photoelectric conversion of the two imaging devices 5 and 6 that read an image line-by-line in synchronization with the film 2 traveling at a constant direction and at a constant speed are A / D. The signals are amplified by amplification circuits 7 and 8 having known image processing circuits such as conversion, automatic gain adjustment, shading correction, and gamma correction, and input to film defect correction means 9.
The output images of the amplifier circuits 7 and 8 before the film defect correction can be monitored by connecting a video monitor to the terminals 18 and 19, and the output images after the film defect correction can be connected to the terminal 20.
[0026]
In the film defect correcting means 9, as described above, black spots or the like (white dots in the case of a positive film) on the image data read by dust attached to the illumination optical system and imaging optical system, dust on the film, scratches, fingerprints, etc. Etc.), resulting in image defects that are reproduced by the image reading device, resulting in degradation of image quality. Therefore, such image defects are automatically made invisible or corrected so as to be sufficiently reduced. A known technique is used.
In other words, focusing on the infrared light transmittance characteristics of the film, only dust, scratches, fingerprints, etc. that cause the above-mentioned image quality degradation are detected by infrared light, and visible light is detected by the detected image data of dust, scratches, etc. This is a method of correcting the image data read in step 1.
The signal output of the film defect correcting means 9 is supplied via an output terminal 20 to a known photographic printing apparatus equipped with an image memory, an image processing circuit, etc. (not shown).
[0027]
As described above, the film defect correction is performed based on the image signal photoelectrically converted from the visible light imaging device 5 and the infrared light imaging device 6, but the size of the film is adjusted by the zoom lens 3 that can freely set the image frame. In order to form an appropriate optical image on the light-receiving surface of each imaging device, even if the zoom magnification is changed depending on the film size, the wavelength difference between visible light and infrared light is compatible. In the present invention, the optical path length of the infrared light can be changed using the composite prism 4 so that the positional deviation of the imaging plane due to the above can be corrected.
[0028]
In FIG. 1, the zoom lens 3 is provided with a driving means by a small motor (not shown) for each of the iris, focus, and zoom mechanisms as the lens driving means 10 to automatically or manually switch the film size, and to switch the selection between negative and positive films. The lens driving means 10 is driven through an iris control means 11, a focus control means 12, and a zoom control means 13 each having a manual or automatic control function based on a command from the control panel 17 having the above function.
Further, for each focal length value in the visible light region from the wide-angle end to the telephoto end of the zoom lens 3, the amount of focal length deviation caused by the wavelength of the infrared light region is measured in advance, and the zoom magnification data obtained thereby is obtained. Stored in the imaging magnification data memory 15.
In addition, it is preferable that each focal length of the zoom lens 3 in the visible light region is based on the center wavelength of the green channel.
In addition, the central value of the wavelength in the infrared light region takes into account the wavelength region in which dust, scratches, and the like can be efficiently detected with infrared light, and the wavelength region in which the sensitivity of the imaging device 6 for infrared light is relatively high. It is preferable to set.
[0029]
According to the film size control signal selected by the control panel 17 corresponding to the size of the film 2 loaded in the film driving device 1, the zoom magnification value of the zoom lens 3 (through the zoom control means 13 and the lens driving means 10) (Focal length) is controlled to a predetermined value so that an optical image of an appropriate size is formed on the light receiving surface of the visible light imaging device 5, and at the same time, the result is determined by the film size control signal selected by the control panel 17. The zoom magnification data by the infrared light corresponding to the predetermined zoom magnification value input to the image magnification data memory 15 is read out and added to the prism driving means 16 to drive the second prism 4b, and the infrared The optical path length of the prism 4 is corrected so that a defect image such as dust or scratches is formed on the light receiving surface of the optical imaging device 6.
[0030]
When a prism having an isosceles right triangle shape is used for the composite prism 4 disposed in the optical path between the zoom lens 3 and the imaging devices 5 and 6, as shown in FIG. The coated surface 4c is attached to the prism fixing base 102a so as to be inclined at, for example, 45 degrees with respect to the optical axis 42 (see FIG. 3), and the prism fixing base 102a is fixed to the prism mounting plate 101.
The second prism 4b is attached to the prism fixing base 102b so as to face the coating surface 4c of the first prism 4a via a fixed gap of a few tens of microns, and is marked along the coating surface 4c (see FIG. It is attached to the prism mounting plate 101 so that it can move in the direction indicated by 3).
The prism fixing base 102b is driven by a prism driving mechanism 104 having a motor 103 as a power source.
The motor 103 is controlled and driven by a drive signal sent from the imaging magnification data memory 15 via the control cable 105.
[0031]
Here, the means for correcting the optical path length will be described with reference to FIG.
For example, coins under the surface of the water appear to float up. This indicates that the apparent length is shortened in a medium having a high refractive index.
If the depth of the coin is d and the refractive index of water is n, the apparent depth of the coin is
Apparent depth = d / n
It becomes.
The same applies to a glass block. A glass block having a thickness d and a refractive index n has a thickness of d / n when converted into air.
Therefore, when a glass block having a thickness d is inserted into the optical path, the optical path length is extended by (1-1 / n) × d. That is, the optical path length can be controlled by changing the thickness d of the glass block.
[0032]
In FIG. 3, the visible light that has been reflected and refracted by the coating surface 4 c that transmits the wavelength in the infrared light region and reflects the wavelength in the visible light region forms an image on the light receiving surface of the imaging device 5 for visible light.
On the other hand, light having a wavelength in the infrared light region passes through the coating surface 4c of the first prism 4a and further passes through the second prism 4b to form an image on the light receiving surface 6b of the imaging device for infrared light.
Here, assuming that the zoom magnification (focal length) position of the zoom lens 3 is constant, the second prism 4b moves in the direction indicated by the thumb mark along the coating surface 4c and reaches the position 4bx indicated by the alternate long and short dash line. Then, the glass thickness of the composite prism 4 in the direction of the optical axis 42 is reduced, and the image formation point moves to 6x indicated by a one-dot chain line.
When the second prism 4b moves along the coating surface 4c in the direction indicated by the thumb and reaches the position of 4by indicated by the dotted line, the glass thickness in the direction of the optical axis 42 of the composite prism 4 increases and the image is formed. The point moves to 6y indicated by the dotted line.
[0033]
The above description has been made in the case where the zoom magnification of the zoom lens 3 is a constant value so that the principle can be easily understood. In practice, however, as described above, the telephoto is performed from the wide-angle end in the long wavelength region (infrared light region) by zooming. Since the axial chromatic aberration to the end changes and the imaging point moves, the optical path length of the infrared light is controlled using the composite prism 4 in the present invention so that automatic correction can be performed following the movement of the imaging point. It is possible.
[0034]
In addition, although the line sensor type imaging device was used as an Example, the system which stops the film 2 at an imaging position and images using an area sensor type imaging device may be used.
In addition, although it has been described that the infrared imaging device 6 is disposed at the optical image formation position, depending on a known film defect correction method, the infrared image pickup device 6 is disposed in advance at a position slightly deviated from the optical image formation position. You may set up.
[0035]
Although the composite prism 4 of the first embodiment has an isosceles right triangle shape because of ease of prism processing, etc., it has a different shape due to restrictions on the arrangement of the composite prism 4 and the imaging devices 5 and 6 of the imaging device 14. A composite prism 4 ′ may be configured as shown in FIG.
In particular, the first prism 4'a has a wedge-like shape, for example, like the blue channel prism of the R, G, B3 plate prism optical system for a television camera, and the coating of the first prism 4'a. The visible light optical image reflected by the surface 4 ′ c is totally reflected on the incident surface side, and then the optical image is formed on the visible light imaging device 5.
The glass thickness at the center of the optical axis of the second prism 4'b may be substantially the same as the optical path length from the coating surface 4'c to the exit surface of the first prism 4'a.
With such a configuration, the shape of the composite prism 4 ′ is complicated, but the left and right (or top and bottom) inversion of the image by the first prism 4 ′ a can be prevented. Other configurations and operations are the same as described in FIG.
[0036]
[Example 2]
FIG. 4 is a block diagram when an imaging apparatus having a square prism-shaped composite prism optical system is used as a surveillance television camera. For example, infrared light is emitted at night using an area sensor type imaging device. The present invention is suitable for application to a day / night monitoring camera that uses illumination or a subject monitoring camera that emits infrared light.
[0037]
In FIG. 4, the image processing means 21 capable of manually or automatically switching the output signals of the amplifier circuits 7 and 8, and the illumination control means 23 capable of controlling the infrared illumination lamp IRL on / off control the brightness of a subject (not shown). By detecting the sensor output to be detected or the video level, the image switching of the image processing means 21 and the blinking of the infrared illumination lamp IRL can be automatically controlled or manually controlled. If a monitoring video monitor is connected to the output terminals 18, 19 and 22, the respective images can be monitored.
In this embodiment, since a fixed focus lens is used as the objective lens 3 ′ for monitoring, the composite prism 4 is fixed by attaching the first prism 4a and the second prism 4b. Each of the imaging devices 5 and 6 is fixed to an assumed imaging position in advance.
For this reason, the image forming magnification data memory 15 and the prism driving means 16 shown in the first embodiment are not used, and the whole apparatus is simplified. Of course, a zoom lens is used as the objective lens 3 ′, and the compound prism 4 optical system capable of correcting the invisible light focal position, the imaging magnification data memory 15, the prism driving means 16 and the like are mounted, and the same as in the first embodiment. You may expect effects.
Other configurations and operations are the same as those in the first embodiment.
[0038]
[Example 3]
In this embodiment, the imaging device 14 having a composite prism optical system capable of correcting the invisible light focal position is used as a camera for an ultraviolet microscope apparatus.
In FIG. 5, an ultraviolet microscope device 39 supports a lens barrel 26 on a lens leg 24 via an arm 25, and an imaging device 14 that does not include an objective lens such as a zoom lens is mounted on the lens barrel 26 via a turret 40. ing.
Further, even during high magnification observation, for example, a mechanical stage 38 that can smoothly move the semiconductor device 36 that is a subject is mounted on the arm 25, and the mechanical stage 38 is attached to the Z stage 38Z and the Z stage 38Z. X stage 38X and Y stage 38Y (not shown). Z stage 38Z is operated by adjusting screw 37Z so that the relative position between semiconductor device 36 and objective lens system 29 can be changed for focusing. A slight movement is possible along the optical axis (Z-axis) of the lens system 29.
Further, the X stage 38X and the Y stage 38Y can be slightly moved in the vertical direction to the Z stage 38Z by operating the adjusting screw 37X and the adjusting screw 37Y (not shown).
And in order to prevent the vibration transmitted from a floor mechanically, it is preferable that the anti-vibration table 41 is installed in the lower part of the mirror leg 24.
[0039]
Light from a light source 27 such as a mercury lamp, a xenon lamp, or a mercury / xenon lamp, which emits light having a visible to near-ultraviolet wavelength, is appropriately converged by an illumination lens system 28 and reflected by a half mirror 32, and a revolver 30. Is focused by an objective lens system 29 composed of a plurality of lenses attached to the object, and enters a subject, for example, a semiconductor device 36.
The light reflected from the semiconductor device 36 is transmitted again through the objective lens system 29, the half mirror 32, the imaging lens system 31, and the half mirror 33, and is enlarged by the magnifying lens system 34 composed of a plurality of lenses accommodated in the turret 40. The image is formed on the area sensor type imaging device of the imaging apparatus 14 having the composite prism optical system capable of correcting the invisible light focal position of the present invention.
On the other hand, the light reflected by the half mirror 33 can be visually observed by an eyepiece 35 lens.
[0040]
Here, for example, a lens having a magnification of 10, 50, 100 is attached to the revolver 30 to the objective lens system 29, and a lens having a magnification of 1, 2, 4 is attached to the turret 40 as the magnifying lens system 34 to combine them. , 20, 40, 50, 100, 200, and 400 magnifications are obtained, and the pattern of the semiconductor device 36 can be switched from a low magnification to a high magnification for observation.
However, with these changes in the overall imaging magnification, axial chromatic aberration in the wavelength region of invisible light occurs in the visible light region as in the case where the zoom magnification of the zoom lens described above is changed. It is necessary to correct this.
[0041]
Therefore, correction of longitudinal chromatic aberration caused by the combination of the objective lens system 29 and the magnifying lens system 34 will be described with reference to FIG.
The ultraviolet microscope device 39 includes a lens driving unit 51 capable of driving a revolver (30) mounted with an objective lens system 29 and a turret (40) mounted with a magnifying lens system 34, and the lens driving unit 51 respectively. The image forming magnification data is converted into image forming magnification data based on the total image forming magnification value obtained by the combination of the control lens 52 and the objective lens system 29 selected by the control panel 52 and the magnifying lens system 34. Prism driving means 16 that reads out from the memory 53 and drives the second prism 4 b of the composite prism 4 is provided.
The imaging magnification data depends on the wavelength of the ultraviolet light region for each total imaging magnification value (focal length) in the visible light region for each of the total imaging magnification by the combination of the objective lens system 29 and the magnifying lens system 34. The amount of deviation of the image forming magnification that occurs is measured in advance, and the image forming magnification data obtained thereby is stored in the image forming magnification data memory 53.
[0042]
When an arbitrary combination of the objective lens system 29 and the magnifying lens system 34 is selected on the control panel 52, the revolver 30 and the turret 40 are driven by the lens driving means 51 to select the designated objective lens system 29 and the magnifying lens system 34. At the same time, predetermined imaging magnification data is read from the imaging magnification data memory 53, the second prism 4b is driven via the prism driving means 16, and the optical path length of the prism 4 is corrected.
[0043]
The subject image in which the axial chromatic aberration is corrected is output to the output terminal 19 as a color image that is formed on the visible light imaging device 5 and can confirm the color of the photoelectrically converted semiconductor device (36). A high-resolution, high-magnification ultraviolet image of the semiconductor device (36) imaged and photoelectrically converted on the device 6 is output to the output terminal 18.
Further, the ultraviolet image and the color image are superimposed and displayed by the image processing means 21, whereby the ultraviolet image can be output as a pseudo color image from the output terminal 22 and displayed on a video monitor (not shown).
[0044]
In the above description, “... Lens system” means a system including one or a plurality of optical lenses. The “eyepiece system” means a system including an eye lens, a field lens and the like for observing with the naked eye.
In this case, the half mirror 33 is a total reflection mirror, and in order to efficiently supply the total reflection light from the semiconductor device 36 to the image pickup device 14, the half mirror 33 is provided with a rotating hinge on either of the upper and lower ends, and is observed with the eyepiece system 35. 5 supplies the total reflection light from the semiconductor device 36 to the eyepiece system 35 at the position shown in FIG. 5, and when observing with the imaging device 14, the total reflection mirror may be removed from the optical path using a hinge. good.
Further, when observing and measuring a subject that is sensitive to ultraviolet rays, a mechanical shutter (not shown) is provided in any one of the optical paths of the illumination lens system 28, and the ultraviolet rays on the subject are not turned on and off. Irradiation may be prevented and damage to the subject may be minimized.
Other configurations and operations are the same as those in the first embodiment.
[0045]
【The invention's effect】
According to the present invention, the following effects are exhibited.
1. An imaging device for visible light and an imaging device for invisible light that photoelectrically convert an optical image of a subject formed by an objective lens, and invisible light that is disposed in an optical path between the objective lens and the both imaging devices A first prism having a reflective surface provided with a coating that transmits the wavelength of the region and reflects the wavelength of the visible light region; and a second prism having a surface facing the reflective surface of the first prism. Since the composite prism configured is provided, it is possible to simultaneously capture both a visible light image and a non-visible light image with a single imaging device, and it is possible to reduce the size and cost of the device.
[0046]
2. Variable imaging magnificationZoom lens and zoom lensAn imaging device for visible light and an imaging device for invisible light that photoelectrically convert an optical image of a subject formed byZoom lensAnd a reflecting surface provided with a coating that transmits a wavelength in the non-visible light region and reflects a wavelength in the visible light region, which is disposed in an optical path between the imaging device and the imaging device, and is fixed to the prism fixing base. A composite prism composed of a first prism, a second prism having a surface facing the reflecting surface of the first prism with a fixed gap, and the second prism as the first prism. Prism drive means capable of movement control along the reflecting surface, and the presetZoom lensImage magnification data memory in which image magnification data is stored,
TheLensResult ofThe axial chromatic aberration in the non-visible light region caused by changing the image magnification can be corrected continuously and automatically by controlling the glass thickness in the optical axis direction of the composite prism combining two prisms. Appropriate optical images in the light region and the invisible light region can be formed on the light receiving surfaces of the respective imaging devices, and at the same time, the imaging device can be reduced in size and cost.
[0047]
3. R, G, B filters, IR filters, infrared cut filters, visible light cut filters, etc. are not used, and the visible light region and invisible light region wavelengths are separated by a composite prism, and a visible light imaging device Since images in the respective wavelength regions are simultaneously obtained by the imaging device for invisible light, for example, when used as an image reading apparatus such as a film scanner, the processing speed is high, and the apparatus is miniaturized, simplified, and inexpensive. Can be easily achieved.
[0048]
4).Zoom lensSince the prism is disposed in the optical path between the imaging device and the imaging device, the prism can be downsized and the apparatus can be downsized.
[0049]
[Brief description of the drawings]
FIG. 1 is a block diagram when an imaging apparatus having a composite prism optical system capable of correcting the invisible light focal position according to Embodiment 1 of the present invention is used as an image reading apparatus of a film scanner.
FIG. 2 is an explanatory diagram of a prism driving mechanism according to the embodiment of the present invention.
FIG. 3 is an explanatory view of invisible light focal position correction of a composite prism formed in a square shape according to the embodiment of the present invention.
FIG. 4 is a block diagram when an imaging apparatus having a composite prism optical system according to Embodiment 2 of the present invention is used as a monitoring television camera.
FIG. 5 is a schematic diagram when an imaging apparatus having a composite prism optical system capable of correcting the invisible light focal position according to Embodiment 3 of the present invention is used as an imaging apparatus for an ultraviolet microscope apparatus.
6 is a block diagram when an imaging apparatus having a composite prism optical system capable of correcting the invisible light focal position according to Embodiment 3 of the present invention is used as an imaging apparatus for an ultraviolet microscope apparatus. FIG.
FIG. 7 is an explanatory diagram of invisible light focal position correction of a composite prism other than a quadrangle according to the embodiment of the present invention.
[Explanation of symbols]
1: Film driving device 2: Film
3: Zoom lens 3 ': Objective lens
4, 4 ': Compound prism 4a, 4'a: First prism
4b, 4'b: second prism
4bx, 4by, 4'bx, 4'by: movement position of the second prism
4c, 4'c: coating surface 5, 6: imaging device
6b, 6x, 6y: Imaging point 7, 8: Amplifier circuit
9: Film defect correcting means 10: Lens driving means
11: Iris control means 12: Focus control means
13: Zoom control means 14: Imaging device
15: Imaging magnification data memory 16: Prism driving means
17: Control panel 18, 19, 20, 22: Output terminal
21: Image processing means 23: Lighting control means
24: Mirror leg 25: Arm
26: Lens tube 27: Light source
28: Illumination lens system 29: Objective lens system
30: Revolver 31: Imaging lens system
32, 33: Half mirror 34: Magnifying lens system
35: Eyepiece type 36: Semiconductor device
37X, 37Z: Adjustment screw 38: Mechanical stage
38X: X stage 38Z: Z stage
39: Ultraviolet microscope 40: Turret
41: Anti-vibration table 42: Optical axis
51: Lens driving means 52: Control panel
53: Imaging magnification data memory
L: Light source IRL: Infrared light illumination lamp
101: Prism mounting plate 102a, 102b: Prism fixing base
103: Motor 104: Prism drive mechanism
105: Control cable

Claims (5)

A zoom lens having a variable imaging magnification, a visible light imaging device and a non-visible light imaging device that photoelectrically convert an optical image of a subject formed by the zoom lens, and the zoom lens and the both imaging devices. A first prism disposed in the optical path between the first prism and having a reflecting surface provided with a coating that transmits the wavelength of the non-visible light region and reflects the wavelength of the visible light region; A composite prism composed of a second prism having a surface facing the reflective surface of the first prism with a certain gap, and the second prism along the reflective surface of the first prism Prism driving means for controlling movement and correcting a positional deviation of the imaging plane due to a difference in wavelength between visible light and invisible light due to the imaging magnification change, and imaging magnification data of the zoom lens set in advance are stored in the memory Was And a image magnification data memory,
In order to photoelectrically convert the optical image of visible light reflected by the first prism, an imaging device for visible light is disposed at an imaging position of the optical image of visible light, transmits the first prism, and An invisible light imaging device for photoelectrically converting an invisible light optical image transmitted through a second prism is disposed at an imaging position of the invisible light optical image. An imaging apparatus having a system. 2. The composite prism according to claim 1, wherein the imaging magnification data is imaging magnification data of an invisible light image corresponding to an imaging magnification of a visible light image at each focal length of the zoom lens. An imaging apparatus having an optical system. When the image forming magnification of the zoom lens changes, the second prism causes the prism driving means to change the image of the first prism based on the image forming magnification data of the image forming magnification data memory corresponding to the image forming magnification. 3. The imaging apparatus having a composite prism optical system according to claim 1, wherein the imaging apparatus is driven so as to move along a reflecting surface. The imaging apparatus further dust adhering to the negative or positive film as the subject, scratches, or includes a film defect correcting means for correcting image defects caused by the fingerprint, and the image pickup device, an image reading apparatus in a film scanner The imaging device having the composite prism optical system according to claim 1, wherein the imaging device is mounted as a zoom lens.   The imaging device further illuminates the subject with a wavelength including wavelengths in the visible light and invisible light regions, or an illumination means for illuminating only with a wavelength in the invisible light region, and an illumination control means for controlling the illumination device. The imaging device having the composite prism optical system according to claim 1, wherein the imaging device has a composite prism optical system.

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