JP2004093852A - Positioning mark consisting of computer generated hologram and display body having the mark - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning mark using a computer generated hologram which is composed of dot units containing various information relating to detection of positions in the reproduced information and which functions as a sensor mark for positioning with high accuracy, and to provide a display body the base body of which can be accurately positioned by using the above positioning mark. <P>SOLUTION: In the positioning mark composed of a plurality of dots and formed on the surface of a flat base material, the dot consists of a computer generated hologram in which the information relating to the arrangement position of the dot is recorded. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an alignment mark having a computer generated hologram for deriving wavefront information of object light using a computer, and a display provided with the alignment mark.
In particular, a pattern recorded in dots or cells constituting a computer generated hologram and reproduced by coherent light such as a laser beam is used as position designating figures such as lines, arrows, and rectangles, and position designating information such as numerical values and directions. To provide a highly accurate alignment function when a pattern formed by a computer generated hologram is used as an alignment mark.
[0002]
[Prior art]
Generally, a raw material or a base material to be a material is supplied to a device for continuously transporting the material, such as a belt conveyor or a roll forward mechanism, and when manufacturing an arbitrary article (product), the raw material to be transported is precisely arranged. For this purpose, a machine-readable alignment mark (sensor mark) is used.
[0003]
For example, in order to accurately cut the printed material multi-layered on roll paper, a rectangular or arbitrary-shaped reading pattern is separately printed on the end of the unprinted roll paper of the printed material, and the printed pattern is printed using a CCD camera or the like. The process of adjusting the position of the roll paper being conveyed to the apparatus by detecting the sheet by the reading apparatus is often performed in mass production using the continuous conveying apparatus.
In the case of a medium such as roll paper or a roll film, the mark for alignment used in such a process is printed or affixed on its surface, so the roll paper or the like was conveyed at high speed. In such a case, it is difficult to detect the outer shape of the mark, or the positional accuracy becomes insufficient.
[0004]
Such an alignment mark is also used for the same purpose in an apparatus that performs processing on a sheet (sheet-by-sheet) basis. There is a problem that the accuracy becomes insufficient.
It has been proposed to use a hologram as the alignment mark.
[0005]
As a method for recording specific information as a hologram and reading the information, a method using a Fourier transform hologram or the like is known. When predetermined light enters a hologram on which such information is recorded, the recorded information is reproduced by the first-order diffracted light.
[0006]
In addition to the holograms created using the interference of the object light from the actual object (subject) and the reference light, interference fringes are converted into digital data based on data corresponding to the object on a computer. There is also known a so-called "computer hologram" in which interference fringe data is created and recorded on a medium such as a photosensitive film.
[0007]
As a computer generated hologram, an interference fringe that the above-described Fourier transform type hologram or the like has is calculated using a computer, and the interference fringe data is obtained by various methods, resulting in a function similar to that of the hologram (information due to a diffraction phenomenon). The above-mentioned specific information is recorded so as to perform (reproduce).
As a configuration of a computer generated hologram, instead of a method of arranging the computer generated hologram over the entire hologram screen, a method of configuring the entire computer generated hologram by using a minute cell formed of the computer generated hologram as a unit is also adopted.
[0008]
According to the above method, since the entire pattern is not constituted by computer holograms, it is possible to arrange computer holograms in which specific information different for each cell in the pattern is recorded, thereby allowing various information to be stored in the pattern. Can be recorded.
Generally, such a computer generated hologram is realized by a device capable of patterning in a sub-micron order with high accuracy, such as an electron beam lithography device, so that a very large amount of information can be recorded within a limited area. it can.
[0009]
In order to make light of a specific wavelength incident on a computer generated hologram realized by such a method and reproduce concealment information, a sufficient number of cells (matrix Must be present).
Since a normal computer hologram is smaller than the beam diameter (about 1 mmφ) of a laser beam for reproducing a hologram, a plurality of cells storing the computer hologram can be arranged adjacent to each other to improve the quality of a reproduced image. Done.
[0010]
[Problems to be solved by the invention]
Generally, in the process of reading the position information of the material to be conveyed by the alignment mark and correcting the misalignment between the material and the transporting device, the outer shape of the alignment mark arranged by a processing method such as printing or pasting is used by a CCD camera. Detection is performed by a reading device having a light receiver such as
At that time, the reading device only detects the outer shape of the alignment mark based on the color change between the luminance of the alignment mark and the luminance of the peripheral portion. Dependent.
That is, if the printing of the alignment mark is similar to the color of the base material, or if the outer shape of the alignment mark is unclear, there is a possibility that it will be erroneously recognized at the time of reading.
[0011]
The present invention relates to an alignment mark using a computer generated hologram that includes various information for position detection in information reproduced by a computer generated hologram configured in units of dots and functions as a sensor mark for highly accurate alignment. The purpose is to provide.
Another object of the present invention is to provide a display body capable of accurately adjusting the position of a substrate.
[0012]
[Means for Solving the Problems]
The invention according to claim 1 is an alignment mark composed of a plurality of dots on a flat base material surface,
The dot is a positioning mark, which is formed of a computer generated hologram in which arrangement position information of the dot is recorded.
[0013]
According to a second aspect of the present invention, there is provided the alignment mark according to the first aspect, wherein reproduction information from a computer generated hologram multiplexly recorded on the dots indicates different information.
[0014]
According to a fourth aspect of the present invention, there is provided the positioning mark according to the first aspect, wherein the reproduction information from the computer generated hologram multiplexly recorded on the dots indicates the same information in different areas.
[0015]
The invention according to claim 4 is the alignment mark according to any one of claims 1 to 3, wherein the computer generated hologram recorded on the dot is a Fourier transform hologram.
[0016]
The invention according to claim 5 is the alignment mark according to any one of claims 1 to 3, wherein the computer generated hologram recorded on the dot is a Fresnel hologram.
[0017]
The invention according to claim 6 is the alignment mark according to any one of claims 1 to 5, wherein a decorative image such as a picture or a character is displayed on the pattern by the computer generated hologram.
[0018]
According to a seventh aspect of the present invention, there is provided a display body provided with the alignment mark according to any one of the first to sixth aspects on a base material.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory diagram showing a state of image reproduction when a laser beam 2 is incident on a pattern 1 in which computer holograms are recorded on a plurality of dots arranged in a matrix.
As shown in FIG. 1, each dot 10 can emit the diffracted light of the reproduced image in the direction designed in advance in response to the incidence of the laser beam 1.
[0020]
The dots on which the computer generated hologram is recorded can have a small area ranging from several microns to several hundred microns, and different information can be recorded on each dot.
That is, as shown in FIG. 2, different information can be displayed as the reproduced image 11 on the pattern according to the incident position of the laser beam.
[0021]
Note that the reproduced image obtained at this time is very large compared to the size of the dot, and can be easily displayed in such a size that a human can observe it with the naked eye.
According to this principle, unique position information is recorded as computer generated hologram data for each dot arranged in the pattern, and different position information can be read depending on the location by irradiating a laser beam to the hologram data.
[0022]
FIG. 3 is an illustration showing a situation in which a base material on which an alignment mark formed by a computer hologram is placed is set in a transport device, and a stop position of the base material is controlled and determined by a reading device including a laser beam and a reproduced image receiver. FIG.
[0023]
When the reference point A on the base material and the reference point A 'on the processing device are aligned on the same line, processing can be performed accurately.
As shown in FIG. 3, the positional relationship (distance, direction, etc.) between the reference point A and each dot in the alignment mark is recorded as data of a computer generated hologram, so that the image receiving unit of the reading device can be used when a laser beam is incident. The positional relationship between the substrate and the device can be uniquely determined from the reproduced image read in step (1).
[0024]
In the case of FIG. 3, the position information projected on the image receiving portion indicates that the distance between the base point A and the apparatus reference point A ′ is 10.0 mm. It is determined that the material needs to be moved.
Based on this data, the base material is further moved, the reproduced image from the dots is continuously read, and the base material is stopped when the reproduced image reaches a point where the reproduced image indicates 0.0 mm. The device reference point A 'is matched.
[0025]
As is apparent from FIG. 3, the obtained reproduced image is larger than the area of the dot on which the reproduced image is recorded, and has a higher precision than is possible with the conventional positioning means for recognizing the outer shape of the positioning mark. Alignment can be realized.
In FIG. 3, the base material reference point A and the device reference point A 'are set for convenience of explanation, but these may not be actually displayed on the base material or the device.
[0026]
FIG. 3 shows an example in which a numerical value representing an actual distance is displayed as a reproduced image. However, a pattern suitable for reading by a machine, such as a barcode or a binary code, may be displayed.
[0027]
FIGS. 4A and 4B are explanatory diagrams showing specific examples of the alignment mark described in claim 2.
FIG. 4A shows a state of a reproduced image when a reading device having a laser beam simultaneously reads a position in the left-right direction (X direction) and a position in the transport direction (Y direction) of the base material. is there.
By recording a computer generated hologram capable of reproducing a plurality of types of data on each dot, a plurality of alignment steps can be performed from information obtained in a single reading step.
[0028]
FIG. 4 (b) shows a computer hologram having a function of reproducing different information at different positions according to the incident direction of the laser beam, and showing position detection using alignment marks recorded in each dot. It is.
In this case, the X-direction position and the Y-direction position can be processed by different types of reading devices.
[0029]
FIG. 5 is an explanatory diagram showing the characteristics of the alignment mark described in claim 3. The computer generated hologram formed for each dot is recorded so that the same reproduced image can be obtained in any case when the laser beam is incident from a plurality of directions.
By applying an alignment mark having such a function, a reading device having a laser beam can be installed in a free place to some extent. In particular, when the base material is transported to a plurality of processing devices having different functions, the same alignment is performed by recording computer holograms corresponding to the installation conditions of the reading devices in each processing device. Marks can be used in common.
[0030]
FIG. 6 is an explanatory diagram showing a state of image reproduction using the alignment mark described in claim 4.
A reconstructed image by a computer hologram recorded using the principle of the Fourier transform hologram is formed at any point in the traveling direction of the diffracted light, and similar information can be obtained.
[0031]
At this time, a small reconstructed image can be obtained by installing the image receiving device of the reading device at a distance close to the computer generated hologram, and a large reconstructed image can be obtained by installing the image receiving device at a long distance.
That is, the same information can be handled regardless of the installation position of the reading device.
[0032]
FIG. 7 is an explanatory diagram showing a state of image reproduction using the alignment mark described in claim 5.
A computer generated hologram recorded using the principle of Fresnel hologram can display a reconstructed image formed at an arbitrary point set in advance, and does not form an image at other points and is out of focus Only a reconstructed image can be obtained.
Utilizing this principle, it is possible to determine the distance between the alignment mark and the image receiving unit by installing the image receiving unit of the reading device at the point where the reproduced image is formed and evaluating the degree of image formation of the reproduced image. it can.
[0033]
This makes it possible to grasp a situation in which the base material vibrates in the vertical direction (Z direction) during transport. Based on the principle of the Fresnel hologram, information indicating the reference point on the base material and the position of the dot in the X and Y directions is recorded as a computer generated hologram, and the degree of image formation of the information is evaluated. By measuring the position, information on three directions necessary for the alignment of the base material can be obtained at once.
[0034]
FIG. 8 is an explanatory view showing an example of an external view of the alignment mark described in claim 6.
Since the alignment mark according to the present invention is composed of a plurality of dots, it is possible to change the brightness of each dot on which the computer generated hologram is recorded when observed with the naked eye, or to record the computer hologram on the recorded dot. By mixing dots that are not present, it is possible to display decorative images such as pictures and characters.
In addition, by changing the size of the dot depending on the location or arranging the alignment mark on the colored base material, the alignment mark for displaying the decorative image can be realized.
[0035]
As a result, it is possible to display information that can be recognized by the naked eye while maintaining the function of displaying a reproduced image using a computer generated hologram.
For example, displaying information such as the number of sheets and a lot number as information that can be recognized by the naked eye can be useful for production management and the like.
[0036]
As described above, as a positioning mark according to the present invention, a reflection type computer hologram is mounted on a base material such as a film or paper, and a mechanism for reading incident light of a laser beam from a reflection side is illustrated. If the computer generated hologram is mounted on a base material such as a film having transparency, the hologram can be used as information for reading transmitted light when a laser beam is incident.
[0037]
【The invention's effect】
As described above, the alignment mark according to the present invention can provide a highly accurate alignment function by being composed of the pattern of the computer generated hologram.
Further, the alignment mark according to the present invention is suitably used in a process of continuously transporting and processing a base material such as a film or paper on which a pattern recorded with a computer generated hologram can be mounted by a roll method or a sheet method. And the following effects can be obtained.
[0038]
(1) A reproduced image obtained by irradiating a laser beam or the like on a dot formed by a computer generated hologram is very large in comparison with the area of the dot, and a positioning function based on information of the reproduced image is a conventional alignment function. Higher accuracy can be achieved than alignment based on the outer shape of the alignment mark.
(2) By recording data of a plurality of computer generated holograms on each dot in a multiplex manner, different information can be obtained from fixed points on the pattern. Thereby, for example, it is possible to obtain information on the alignment in both the vertical and horizontal directions at once.
(3) By recording a computer generated hologram for reproducing different information at a plurality of observation points, it is possible to process a plurality of information simultaneously and / or separately.
(4) By recording a computer generated hologram for reproducing the same information at a plurality of observation points, it is possible to selectively use the incident direction of a laser beam or the like for reproducing the information from a plurality of candidates. .
(5) By using a Fourier transform type computer generated hologram as the computer generated hologram, a similar reproduced image can be obtained as information for positioning regardless of the distance between the positioning mark and the observation point.
In other words, the reproduction image reading device can be freely installed at an arbitrary distance.
(6) By using a Fresnel computer generated hologram as a computer generated hologram, it is possible to prevent a reproduced image from being formed at an observation point other than a preset observation point, and the base material on which the alignment mark is placed is displaced vertically. Then, the displacement can be recognized as undesired vibration at the time of conveyance.
(7) By using a computer generated hologram to realize a decorative image that can be observed with the naked eye, various types of production indicating information indicating the work order required when performing manual work, the number of sheets, a lot number, and the like. Management information and the like can be displayed together with the alignment mark.
Further, when a product itself is manufactured using a decorative image formed by a computer hologram, it is also possible to record positioning information in the product.
(8) When the Fourier transform type computer generated hologram is observed with the naked eye or a CCD camera, etc., it is recognized as a white turbid color pattern. It is possible.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an example of a computer generated hologram recorded on a plurality of dots.
FIG. 2 is an explanatory diagram showing an example of a pattern composed of a computer generated hologram that displays a different reproduced image depending on a location.
FIG. 3 is an explanatory diagram showing an example of installation of a substrate on which an alignment mark is placed, and a transfer device and a reading device.
FIG. 4A is an explanatory diagram illustrating an example of a reproduced image when a plurality of pieces of information are obtained from an arbitrary point in an alignment mark. FIG. 4B is an explanatory diagram illustrating an example of a state in which a plurality of pieces of information are obtained from an arbitrary point in an alignment mark by a plurality of image receivers that are separately arranged.
FIG. 5 is an explanatory diagram showing how information is reproduced from a computer generated hologram that reproduces the same information without depending on the incident direction of the laser beam.
FIG. 6 is an explanatory diagram showing an example of a computer generated hologram using the principle of a Fourier transform hologram that forms an image at any point in the direction of emission of diffracted light.
FIG. 7 is an explanatory diagram showing a state of Z-direction alignment control by a computer generated hologram using the principle of a Fresnel hologram.
FIG. 8 is an explanatory diagram showing an example of an alignment mark displaying a decoration image.
[Explanation of symbols]
Reference numeral 1 denotes a pattern in which computer holograms are recorded on a plurality of dots arranged in a matrix 2 ... laser beam 10 ... dots A ... substrate reference point A '... apparatus reference point

Claims (7)

In a positioning mark composed of a plurality of dots on a surface of a planar base material, the dots are formed of a computer generated hologram in which arrangement position information of the dots is recorded. 2. The alignment mark according to claim 1, wherein reproduction information from a computer generated hologram multiplexly recorded on the dots indicates different information. 2. The alignment mark according to claim 1, wherein reproduction information from a computer generated hologram multiplexed on the dots indicates the same information in different areas. The alignment mark according to any one of claims 1 to 3, wherein the computer generated hologram recorded on the dot is a Fourier transform hologram. 4. The alignment mark according to claim 1, wherein the computer generated hologram recorded on the dot is a Fresnel hologram. The alignment mark according to any one of claims 1 to 5, wherein a decorative image such as a pattern or a character is displayed on the pattern by the computer hologram. A display body comprising a base material provided with the alignment mark according to claim 1.

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