CN100428085C - image capturing method and related device - Google Patents

Abstract

The present invention provides a method for capturing a pattern on a printing medium, wherein the pattern includes a holographic pattern. The method includes the following steps: (a) providing an image capturing device, which includes a light source and a photosensitive component, wherein the light source emits a light beam which is reflected by the pattern and then received by the photosensitive component; (b) adjusting the relative positions of the printing medium, the light source and the photosensitive component so that the photosensitive component falls in a blind area after the light beam is imaged by the holographic pattern on the printing medium; and (c) using the light source and the photosensitive component to capture the pattern on the printing medium.

Description

Image capture method and related device

technical field

The present invention relates to holography, in particular to a method and related device for capturing an image on a printing medium, the image including a holographic image.

Background technique

Holography (holography) has been developed for more than 50 years. The application range of holography is quite wide, such as holography data access for accessing data in three dimensions, and for certificates, valuables, etc. Anti-counterfeiting of special scratch film on securities and lottery tickets.

Holography is a method of recording a holographic image of an object by using the unique interference and diffraction characteristics of light. Please refer to FIG. 1 . FIG. 1 is a schematic diagram of a conventional holographic system 10 . The holographic system 10 can make a holographic pattern of an object 12 on a film 14 . The holographic system 10 includes a light source 16 and a semi-transmissive lens group 18 for dividing the light emitted by the light source 16 .

The semi-transmissive lens set 18 splits the light emitted by the light source 16 into a reference ray L _ref directly incident on the film 14 and an object ray L _obj reflected on the film 14 through the object 12 . Since the optical path difference between the reference ray L _ref and the object ray L _obj is different, an interference pattern like a grating with different light and shade will be formed on the film 14 . In detail, if the optical path difference between the reference ray L _ref and the object ray L _obj received by a point A on the film 14 is an integral multiple of the wavelength of the light emitted by the light source 16, a "constructive interference" will be formed at point A. On the contrary, if the optical path difference between the reference ray L _ref received by another point B on the film 14 and the object ray L _obj is (an integer+1/2) times the wavelength of the light emitted by the light source 16 , a dark spot of “destructive interference” will be formed at point B, and all the bright spots and dark spots on the negative film 14 are collected to form the holographic image pattern formed by the object 12 on the negative film 14 .

In the holographic system 10 shown in Fig. 1, the relative positions between the light source 16, the object 12 and the negative film 14 are fixed during the imaging process of the object 12 onto the negative film 14, and any point on the negative film 14 can receive The light reflected from any point on the part of the object 12 illuminated by the light, that is, any point on the film 14 includes the pattern of all points in the part of the object 12 illuminated by the light. However, the light source 16 can also inject light onto the film 14 from various angles through the reflection of the object 12 , so as to expose the patterns presented by the object 12 at various angles on the film 14 . In this way, due to the reversibility of the light, the patterns presented by the object 12 at the different angles can be seen when viewing the negative film 14 from the different angles.

Due to the characteristic that different patterns will appear when viewed from different angles, holographic patterns can be used for anti-counterfeiting of certificates. For example, an authentic document printed on a printing medium includes a first holographic image pattern, and the first holographic image pattern is formed by the light source 16 reflecting light from a plurality of specific angles to the printing medium through the object 12 Yes, if a fake document containing a second hologram pattern is attempted to be fake, because in the process of making the second hologram pattern, the angles at which the light source 16 is incident on the film 14 will not be as accurate as the first hologram pattern. During the process, the light source 16 is incident on various angles of the film 14, therefore, the false photocopy document captured by an image capture device for the fake document will not be the same as the real document captured by the image capture device The true photocopied document can be used to determine the authenticity of the false document.

Although the setting of the first hologram pattern on the genuine document can prevent the genuine document from being forged, yet, just because the setting of the first holographic pattern on the genuine document makes the real photocopy document appear on the first The data displayed at the hologram pattern cannot be easily read due to the interference of the first hologram pattern.

Contents of the invention

Therefore, the main purpose of the present invention is to provide a method for capturing a pattern on a printing medium, the pattern including a hologram pattern, and the pattern captured by the method does not include the hologram pattern.

To achieve the above purpose, the present invention discloses a method for capturing a pattern on a printing medium, the pattern comprising a hologram pattern, the method comprising the following steps: (a) providing an image capturing device, which comprises a a light source and a photosensitive component, the light source emits a light that is reflected by the pattern, and is received by the photosensitive component; In the blind area after the hologram pattern on the printing medium is imaged, and (c) using the light source and the photosensitive component to capture the pattern on the printing medium.

In step (b), the relative position among the light source, the photosensitive element and the printing medium can be changed by changing the photosensitive element, changing the position of the light source and setting a transparent plate between the printing medium and the image capture device way to adjust.

Since the method of the present invention is to change the relative positions among the light source, the printing medium and the photosensitive component when the pattern of the printing medium includes the holographic image pattern, so that the photosensitive component will not receive the holographic image from the pattern. The light reflected from the holographic pattern, that is, the photosensitive element will not capture the holographic pattern, so the photosensitive element can clearly capture the pattern printed on the printing medium.

Description of drawings

FIG. 1 is a schematic diagram of an existing holographic imaging system;

2 is a schematic diagram of a hologram pattern reflecting light from a light source in a preferred embodiment of the present invention;

3 is a schematic diagram of a hologram pattern reflecting another light from a light source in a preferred embodiment of the present invention;

4 is a flow chart of a method for capturing a pattern on a printing medium in a preferred embodiment of the present invention;

5 is a schematic diagram of an image capture device in a preferred embodiment of the present invention;

FIG. 6 is a schematic diagram of the image capture device shown in FIG. 5 in a first state;

FIG. 7 is a schematic diagram of the image capture device shown in FIG. 5 in a second state;

FIG. 8 is a schematic diagram of the image capture device shown in FIG. 5 in a third state;

9 and 10 are side views of an image capture device in the second embodiment of the present invention.

Detailed ways

Please refer to FIG. 2 and FIG. 3. FIG. 2 is a schematic diagram of a hologram pattern 30 reflecting a light _L1 transmitted from a light source 32 at an initial position in a preferred embodiment of the present invention, and FIG. 3 is a hologram pattern 30 is a schematic diagram of reflecting light L ₂ from the light source 32 moving to a predetermined position. As mentioned above, since the holographic pattern 30 is being imaged onto the negative film 14 (see FIG. 1 ), the light source 16 injects light into the negative film 14 from various angles through the reflection of objects corresponding to the holographic pattern 30 to form the holographic image pattern 30, therefore, the holographic image pattern 30 can reflect the light _L1 emitted by the light source 32 shown in FIG. Different patterns are formed in the first area 34 and the second area 36 respectively, and the holographic pattern 30 can also reflect the light L ₂ emitted by the light source 32 shown in FIG. 3 to the third area 44 and the fourth area. 46 and other different areas to form different patterns in the third area 44 and the fourth area 46 respectively, and the hologram pattern 30 is a collection of these patterns presented in different areas. In other words, from the first region 34, the second region 36, the third region 44 and the fourth region 46, the different patterns included in the holographic image pattern 30 can be observed respectively. Therefore, in FIG. The photosensitive element 40 in the first area 34) can receive the light reflected from the hologram pattern 30 .

In FIG. 2, a first blind zone (blind zone) 38 will be formed between the first area 34 and the second area 36. Similarly, a second blind zone 48 will be formed between the third area 44 and the fourth area 46. between. The holographic image pattern 30 will not reflect the light L ₁ emitted by the light source 32 to the first blind area 38, that is, for the light L ₁ emitted by the light source 32 at the initial position, from the initial position (the first area 34 ) to the photosensitive element 40 at the first blind area 38 (a predetermined position) will not receive the light reflected from the holographic pattern 30 . The holographic image pattern 30 will not reflect the light L ₂ emitted by the light source 32 to the second blind area 48, that is, for the light L ₂ emitted by the light source 32 that moves from the initial position to the predetermined position, it is located at the The photosensitive element 40 at the predetermined position changes from receiving the light reflected from the holographic pattern 30 to not receiving the light reflected from the holographic pattern 30 . To sum up, an image capture device can capture the patterns or blind spots presented at different angles in the holographic pattern by adjusting the position of the photosensitive element or adjusting the position of the light source therein. Therefore, the pattern captured by the image capture device may only be the pattern on the printing medium.

The method of the present invention is to guide the light emitted by the light source 32 into the patterns presented in the hologram pattern 30 at various angles (the hologram pattern 30 is included in an image, and the image is printed on a printing medium). To an area (blind area) that does not include the photosensitive component 40, so that the photosensitive component 40 will not receive the light transmitted on the pattern presented at various angles in the holographic image pattern 30, equivalently, the photosensitive component 40 captures the pattern printed on the printing medium, as if the pattern does not include the hologram pattern 30 .

Please refer to FIG. 4 and FIG. 5. FIG. 4 is a flowchart of a method 100 for capturing a pattern PATTERN on a printing medium 54 (shown in FIG. 5) in a preferred embodiment of the present invention. The pattern PATTERN includes a hologram image pattern HG, and Fig. 5 is a schematic diagram of an image capture device 50 in a preferred embodiment of the present invention, the image capture device 50 includes an image capture module 70, a transparent platform 56 for placing a printing medium 54 , and a logic unit 60 . The image capture module 70 includes a movable light source 52 for emitting light and a movable photosensitive component 58 for receiving light reflected by the printing medium 54 , and the logic unit 60 is used to control the operation of the light source 52 and the photosensitive component 58 . The image capturing device 50 can be a scanner or a copier, the photosensitive element 58 can be a charge coupled diode (CCD), and the logic unit 60 can be a logic circuit or a program code stored in a memory. Method 100 includes the following steps:

Step 102: start;

(the print medium 54 has been placed on the transparent platform 56 of the image capture device 50, and an initial relative position is configured between the light source 52, the photosensitive component 58 and the print medium 54 of the image capture device 50, so that the print medium 54 is positioned on the photosensitive In the depth of field (DoF) of the component 58, the light source 52 and the photosensitive component 58 are located at an initial position respectively)

Step 104: Adjust the relative positions among the printing medium 54, the light source 52 and the photosensitive element 58, so that the photosensitive element 58 falls in the blind area corresponding to the holographic pattern HG;

(As shown in Figure 2, if the photosensitive element 58 is not required to pick up the holographic image pattern HG on the printing medium 54, only the position of the photosensitive element 58 or the light source 52 needs to be adjusted so that the photosensitive element 58 is located at the corresponding position of the holographic image pattern HG within the blind area, that is, the logic unit 60 can control the light source 52 and/or control the photosensitive element 58 to move to a predetermined position)

Step 106: Use the light source 52 and the photosensitive element 58 to capture the pattern PATTERN on the printing medium 54 according to the changed relative positions between the light source 52, the photosensitive element 58 and the printing medium 54, so that the photosensitive element 58 only captures the pattern PATTERN;

(So far, the pattern PATTERN captured by the photosensitive element 58 will not include the pattern presented by the holographic pattern HG, so the photosensitive element 58 can capture a very clear pattern PATTERN)

Step 108: end.

(The logic unit 60 can also selectively control the light source 52 and the photosensitive element 58 to return to the initial position)

Please refer to FIG. 6 to FIG. 8 and also refer to FIG. 2 and FIG. 3 . The photosensitive elements 58 are all located in the initial position), the side view of the image capture device 50; FIG. (the light source 52 is still at the initial position, but the photosensitive element 58 has moved to the predetermined position), the side view of the image capture device 50; and FIG. And the side view of the image capture device 50 when the printing medium 54 is arranged in the changed relative position (the light source 52 has moved to the predetermined position, but the photosensitive element 58 remains at the predetermined position). The photosensitive element 58 in FIG. 7 and FIG. 8 is located in the blind area corresponding to the hologram pattern HG.

In FIG. 7 , the method 100 of the present invention is to move the photosensitive element 58 from the initial position to the predetermined position, so that the photosensitive element 58 will not receive the light reflected from the hologram pattern HG. In FIG. 8 , the method 100 of the present invention is to move the light source 52 from the initial position to the predetermined position, so that the photosensitive element 58 will not receive light reflected from the holographic pattern HG.

In the above embodiment, the light source 52 and photosensitive element 58 included in the image capture device 50 are relatively movable. However, the image capture device of the present invention may also include a relatively fixed light source and photosensitive element. Please refer to FIG. 9 and FIG. 10. FIG. 9 and FIG. 10 are side views of an image capture device 80 in a second embodiment of the present invention. The image capture device 80 includes a light source 82, a transparent platform 56, and a photosensitive component 88 , and logic unit 60. What is different from the image capture device 50 shown in FIG. ) 90 (adapter 96 among Fig. 10), is used for changing the relative position between light source 82, photosensitive assembly 88 and printing medium 54, and adapter 90,96 can be a transparent plate that length and width are 160 millimeters and 130 millimeters respectively. The first side 92 of the transparent plate 90 shown in FIG. 9 is used to place the printing medium 54 , while the second side 94 is parallel to the first side 92 . The first side 98 of the transparent plate 96 shown in FIG. In the second embodiment of the present invention, the transparent plate 90 shown in FIG. 9 has a thickness of 6 mm, and the transparent plate 96 shown in FIG. 10 has a thickness of 3 mm at one end and a thickness of 8 mm at the other end. mm.

Compared with the existing method of capturing an image on a printing medium, the method of the present invention changes the light source 52, printing medium according to the angle corresponding to a specific pattern among all the patterns included in the holographic pattern HG to be printed on the printing medium 54. 54 and the photosensitive element 58, so that the photosensitive element 58 will not receive the light reflected by the holographic image pattern HG, that is, the photosensitive element 58 will not pick up the holographic image pattern HG. Therefore, the photosensitive element 58 The pattern PATTERN printed on the printing medium 54 can be clearly captured.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the patent of the present invention.

Claims (24)

1. method of patterning that captures on the print media, this pattern comprises a holographic images pattern, this method comprises the following steps:

(a) provide an image capture unit, it comprises a light source and a photosensory assembly, and this light source sends a light after this pattern reflection, is received by this photosensory assembly;

(b) adjust relative position between this print media, this light source and this photosensory assembly, so that this photosensory assembly falls within the blind area after the holographic images pattern imaging of this light on this print media; And

(c) use this light source and this photosensory assembly to capture pattern on this print media.

2. the method for claim 1, it is in step (b), and the relative position between this light source, this photosensory assembly and this print media is adjusted by the position of adjusting this photosensory assembly.

3. the method for claim 1, it is in step (b), and the relative position between this light source, this photosensory assembly and this print media is adjusted by the position of adjusting this light source.

4. the method for claim 1, it is in step (b), and the relative position between this light source, this photosensory assembly and this print media is adjusted by the mode that a transparent panel is arranged between this print media and this image capture unit.

5. method as claimed in claim 4, wherein this transparent panel comprises that one is used for placing first of this print media, and one is parallel to this first second.

6. method as claimed in claim 4, wherein this transparent panel comprises that one is used for placing first of this print media, and one is not parallel to this first second.

7. the method for claim 1, it comprises in addition:

This image capture unit one logical block is provided, is used for adjusting the relative position between this light source and this photosensory assembly.

8. method as claimed in claim 7, wherein this logical block is a logical circuit.

9. method as claimed in claim 7, wherein this logical block is one to be stored in the program code in the internal memory.

10. method as claimed in claim 7, wherein this photosensory assembly is a packaged type, and this this photosensory assembly of logical block may command moves to a precalculated position.

11. method as claimed in claim 7, wherein this light source is a packaged type, and this this light source of logical block may command moves to a precalculated position.

12. the device of the pattern on the fechtable print media, this pattern comprises a holographic images pattern, and this device comprises:

One transparent platform is in order to put this print media;

One image acquisition module is arranged at a side of this transparent platform, and this image acquisition module comprises a light source and a photo-sensitive cell; And

One logical block, this logical block are in order to controlling the running of this light source and this photo-sensitive cell, and the relative position between this light source and this photo-sensitive cell is adjusted in control;

Wherein this light source sends a light after this pattern reflection, receive by this photo-sensitive cell, this logical block and adjust this light source and this photo-sensitive cell between relative position so that this photo-sensitive cell is arranged in the blind area of this light after the holographic images pattern imaging on this print media.

13. an image capture unit is used for capturing a pattern of printing on the medium, this pattern includes a holographic images pattern, and it comprises:

One transparent platform is used for placing this print media;

One light source is used for launching a light to this print media;

One photosensory assembly is used for receiving this light and reflects and next reflection ray from this print media; And

One adapter (adaptor), be arranged between this transparent platform and this print media, be used for changing the relative position between this light source, this photosensory assembly and this print media, so that this photosensory assembly falls within the blind area after the holographic images pattern imaging of this light on this print media.

14. device as claimed in claim 13, wherein this adapter is a transparent panel.

15. device as claimed in claim 14, wherein this transparent panel comprises that one is used for placing first of this print media, and one is parallel to this first second.

16. device as claimed in claim 15, wherein the thickness of this transparent panel is 6 millimeters.

17. device as claimed in claim 14, wherein this transparent panel comprises that one is used for placing first of this print media, and one is not parallel to this first second.

18. device as claimed in claim 17, wherein the thickness of an end of this transparent panel is 3 millimeters, and the thickness of the other end is 8 millimeters.

19. an adapter that is used for an image capture unit, this image capture unit has a printing medium of a pattern in order to capture one, and can comprise a holographic images pattern in this pattern, and this image capture unit comprises:

One transparent platform;

One light source; And

One photosensory assembly;

This adapter comprises:

One first, be used for placing this print media; And

One second, be arranged at one of this first side with a predetermined way, be used for being placed on this transparent platform;

By the setting of this adapter, make the light that this light source is launched, after this print media reflection, wherein this photosensory assembly falls within the blind area of this holographic images video imaging.

20. adapter as claimed in claim 19 is a transparent panel.

21. adapter as claimed in claim 20, wherein first face of this transparent panel is parallel to this second.

22. adapter as claimed in claim 21, wherein the thickness of this transparent panel is 6 millimeters.

23. adapter as claimed in claim 19, wherein first face of this transparent panel is not parallel to this second.

24. adapter as claimed in claim 23, wherein the thickness of an end of this transparent panel is 3 millimeters, and the thickness of the other end is 8 millimeters.

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