JPH05241493A - Production of information code-containing rainbow hologram for invisible type mechanical reading - Google Patents

Abstract

PURPOSE:To improve hiding property, higher density and security of information codes for mechanical reading, by disposing a second photosensitive material in a real image reconstruction position and photographing a white light reconstruction type hologram by interference with reference light. CONSTITUTION:The master hologram 1 is illuminated with the reference light 8 to reconstruct the real image of the object to be photographed. Interference fringes are recorded by the interference of luminous bodies (real image reconstruction) 14 from the master hologram 1 with the reference eight 13 on a second photosensitive material 12 disposed in the reconstruction position of this real image, by which the white light reconstruction type hologram (rainbow hologram) is photographed. A slit 2 for photographing the hologram recorded with the information codes 2A for mechanical reading at both ends is held in the state of bringing the slit in tight contact with the master hologram 1, by which the information codes 2A are eventually simultaneously recorded on the photosensitive material 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rainbow hologram containing a machine-readable information code capable of reading information by a machine, and particularly to a machine-readable information code without impairing the hologram display effect. The concealment of information, increase the density of information codes for machine reading, and security (anti-counterfeiting effect)
The present invention relates to a method for manufacturing a rainbow hologram containing an invisible type machine-readable information code, which can be improved.

[0002]

2. Description of the Related Art Conventionally, a rainbow hologram whose information can be read by a machine has no effect of a display (for example, a dog is shown), and it only looks like 7 colors.

On the other hand, recently, a so-called machine-readable rainbow hologram has been proposed in which the rainbow hologram also has an effect as a display. Furthermore, for the purpose of sticking to security-requiring securities such as credit cards, prepaid cards, gift certificates, etc., the security as well as the security (anti-counterfeiting effect)
A machine-readable rainbow hologram with a mark has also been proposed.

Now, in a machine-readable rainbow hologram which has an effect as a display of this kind and an anti-counterfeiting effect, when some information is added to the rainbow hologram, it is necessary to record the information separately from the photographed object.

In this case, as a method of adding information,
For example, when photographing a rainbow hologram containing a machine-readable information code, a method has been already proposed in which the machine-readable information code is scattered and recorded in the entire hologram photographing slit.

However, in such a method, since the machine-readable information code is recorded in the entire hologram photographing slit, the following various problems are caused by this.

That is, first, when the hologram is observed using a high-performance white light source or a monochromatic light source such as a laser, the brightness of the machine-readable information code recorded on the hologram photographing slit is Since the size is larger than the observer's pupil, the observer feels a difference in brightness between the opening portion and the non-opening portion of the slit. Then, due to such a phenomenon, there is a possibility that the existence of the machine reading information code recorded in the slit may be known, and further, if the observation conditions are adjusted, the recorded machine reading information code may be read. is there.

Secondly, when the area of the black portion of the machine reading information code is increased in order to process the hologram photographing slit itself, the hologram itself becomes dark. In order to increase the density, there are restrictions on the type and shape of the information code.

[0009]

As described above, in the conventional method for producing a rainbow hologram containing a machine-readable information code, the effect of the hologram as a display is impaired, the security is low, and the machine There is a problem that it is difficult to increase the density of the read information code.

The present invention has been made to solve the above problems, and an object thereof is to improve the concealability of a machine-readable information code without impairing the effect of a hologram as a display. And a method for producing a rainbow hologram containing an invisible type machine-readable information code, which is highly reliable and is capable of increasing the density of the machine-readable information code and improving security.

[0011]

In order to achieve the above object, the present invention provides a method for producing a two-step type white light reproducing hologram (rainbow hologram),
First, a master hologram is imaged on a first photosensitive material by interference between a reference light and an object light emitted from an object to be imaged.
The process of, and the master hologram, the slit for hologram recording in which the information code for machine reading is recorded at the end is overlaid, and the master hologram is illuminated with the light conjugate with the reference light to reproduce the real image of the object to be captured, The second step comprises disposing a second photosensitive material at the reproduction position of the real image and photographing the white light reproduction hologram by interference with the reference light.

Here, in particular, the machine reading information code is recorded at one end portion or both end portions of the hologram photographing slit.

As the machine-readable information code, an information-coded figure is recorded.

[0014]

Therefore, in the method of manufacturing a rainbow hologram containing an invisible machine-readable information code of the present invention,
When incorporating an information code for machine reading that is invisible in normal reproduction with white light into a rainbow hologram,
By recording a machine-readable information code at the end of the hologram shooting slit and shooting it, even when the hologram is visually observed using a high-performance white light source or a monochromatic light source such as a laser, the slit Since there are no optical obstacles in the opening, no difference in light and shade due to the machine-readable information code occurs. Therefore, the observer cannot recognize the machine-readable information code at all under normal observation,
Security can be improved.

Further, since the machine reading information code is recorded at the end of the hologram photographing slit, the recorded machine reading information code is located at a position outside the observer's visual field. Is not related to the brightness of the information code, and the type and shape of the information code do not hinder the high density of the machine-readable information code.

Further, since the virtual image of the object to be photographed can be seen,
The effect of the hologram as a display is not impaired.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an example of the overall configuration of an optical system for producing a rainbow hologram containing an invisible machine-readable information code according to the present invention. The rainbow hologram containing the invisible type machine-readable information code of the present embodiment is manufactured as follows.

That is, first, as a first step, a hologram of the object to be photographed (master hologram of the second step) is caused by interference between the reference light and the object light emitted from the object to be photographed on a first photosensitive material (not shown). 1) will be taken.

Next, as a second step, as shown in FIG. 1, hologram recording slits 2 having machine reading information codes 2A recorded at both ends are superposed on the master hologram 1 obtained above. In this case, the machine reading information code 2 is provided at both ends of the hologram photographing slit 2.
As A, for example, an information coded figure as shown in FIG. 2A, 2B, or 2C is recorded.

On the other hand, a laser beam 3A generated from the laser device 3 is reflected by a mirror 4 and split into two directions by a beam splitter 5. Then, one of the laser beams 3A1 is reflected by the mirror 6 and enters the master hologram 1 holding the hologram photographing slit 2 as the reference beam 8 through the lens 7. Further, the other laser beam 3A2 is reflected by the mirror 9 and further reflected by the mirror 10.
Then, the light is reflected as the reference light 13 through the lens 11 into the second photosensitive material 12 for hologram photographing.

As a result, the master hologram 1 is illuminated with the reference light 8 to reproduce a real image of the object to be photographed, and the object from the master hologram 1 is recorded on the second photosensitive material 12 arranged at the reproduction position of this real image. Light (real image reproduction) 14 and reference light 1
Interference with 3 causes interference fringes to be recorded to photograph a white light reproduction hologram (rainbow hologram). Further, in this case, by holding the hologram photographing slit 2 in which the machine reading information code 2A is recorded at both ends in a state of being in close contact with the master hologram 1, the machine reading information code 2A is also at the same time. 2 photosensitive material 12
Will be recorded in.

Next, in the rainbow hologram containing the invisible type machine reading information code of the present embodiment manufactured as described above, when illuminated with white light, the object to be photographed is reproduced as shown in FIG. .. That is, in FIG. 3, at the viewpoint A, only the object to be imaged, which is imaged in the same manner as a normal rainbow hologram, is observed. Also, viewpoint B
In C and C, the object to be photographed appears to be slightly darker than in the viewpoint A, but since the machine reading information code 2A is small, most or all of the machine reading information code 2A enters the observer's eyes. It is difficult to determine if it is a machine-readable information code. Therefore, the observer cannot recognize that the coded information is recorded at all, and can improve the security. Moreover, since the virtual image of the object to be photographed is visible, the effect of the hologram display is not impaired.

On the other hand, when the machine reading information code 2A recorded in the photographed rainbow hologram is read out, as shown in FIG. 4, for example, the rainbow hologram 12 is irradiated with light conjugate with the reference light 13 of FIG. By doing so, the machine reading information code 2A is reproduced as a real image, so that the information can be read by disposing the optical sensor 15 including a light receiving element or the like at this real image reproducing position.

As described above, in the present embodiment, when a two-step type rainbow hologram is produced, the first step is to first illuminate the first light-sensitive material with the reference light and the object light. The master hologram 1 is photographed by interference with the first hologram, and then, as a second step, the master hologram 1 is overlapped with the hologram photographing slits 2 having the machine reading information code 2A recorded on both ends thereof in a closely contacted state. The master hologram 1 is illuminated with light (reference light 8) conjugate with the reference light of the step to reproduce the real image of the object to be photographed, and then the second photosensitive material 12 is disposed at the reproduction position of this real image, The rainbow hologram is photographed by the interference with the reference light 13.

Therefore, the following various effects can be obtained.

(A) When incorporating a machine reading information code invisible in normal reproduction with white light into a rainbow hologram, record the machine reading information code 2A at both ends of the hologram photographing slit 2. Since the image is taken, even when the hologram is visually observed using a high-performance white light source or a monochromatic light source such as a laser, there is no optical obstacle in the opening of the slit. There is no difference between bright and dark due to the information code 2A.

Therefore, the observer cannot recognize the machine reading information code 2A at all in normal observation, and can improve the security (counterfeit prevention effect).

(B) Since the machine reading information code 2A is recorded on both ends of the hologram photographing slit 2, the recorded machine reading information code 2A is:
Since it is located outside the observer's field of view, it has nothing to do with the brightness at the time of observing the hologram, and the type and shape of the information code 2A impede the densification of the machine reading information code 2A. It never becomes.

That is, the restriction of the machine reading information code 2A itself can be reduced as compared with the conventional method, so that the machine reading information code 2A of higher density can be recorded.

(C) Since the virtual image of the object to be photographed is visible, the effect of the hologram as a display is not impaired.
As a result, when it is attached to an item requiring security, such as a credit card or a prepaid card, it is possible to have not only an effect as a display but also an extremely high security (forgery prevention effect).

(D) Since the entire hologram photographing slit 2 is not processed, the hologram itself does not become dark, and the concealing property of the machine reading information code 2A can be improved.

(E) Reference beams 8 and 13 for hologram recording
As described above, the reading condition can be changed by using light other than the parallel light, and the machine reading information code 2
It is possible to further improve the hiding property of A.

The present invention is not limited to the above embodiments, but can be implemented in the same manner as described below.

(A) In the above embodiment, the machine reading information code 2A is not limited to the one shown in FIG. 2, but a bar code, a carla code, a number, a character, etc. can be applied.

(B) In the above embodiment, the case where the machine reading information code 2A is recorded at both ends of the hologram photographing slit 2 has been described, but the invention is not limited to this, and the machine reading information code 2A is recorded in the hologram photographing slit. A rainbow hologram may be produced by recording only one end of 2 and photographing.

[0037]

As described above, according to the present invention, 2
In a method of manufacturing a step-type white light reproduction hologram (rainbow hologram), a first step of photographing a master hologram on a first photosensitive material by interference between a reference light and an object light that illuminates an object to be photographed. And a hologram recording slit with a machine-readable information code recorded at the end on the master hologram, and illuminates the master hologram with light that is conjugate to the reference light to reproduce the real image of the object to be imaged. The second step of arranging the second photosensitive material at the reproducing position and photographing the white light reproducing hologram by interference with the reference light, without impairing the effect of the hologram as a display, It is possible to improve the concealment of the machine reading information code, increase the density of the machine reading information code, and improve the security. Umate reliable invisible type machine-readable information cords rainbow manufacturing method of a hologram can be provided.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a method for producing a rainbow hologram with an invisible machine-readable information code according to the present invention.

FIG. 2 is an external view showing an example of a machine reading information code of a hologram photographing slit applied to the same embodiment.

FIG. 3 is a schematic diagram for explaining a reproduction state of a rainbow hologram containing an invisible machine reading information code obtained in the same example.

FIG. 4 is a schematic diagram for explaining a method of reading a machine reading information code recorded in a rainbow hologram containing an invisible machine reading information code obtained in the same example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Master hologram, 2 ... Hologram photographing slit, 2A ... Machine reading information code, 3 ... Laser device, 3A ... Laser light, 3A1, 3A2 ... Laser light,
4 ... Mirror, 5 ... Beam splitter, 6 ... Mirror, 7
... Lens, 8 ... Reference light, 9 ... Mirror, 10 ... Mirror, 1
1 ... Lens, 12 ... Second photosensitive material, 13 ... Reference light, 1
4 ... Object light, 15 ... Optical sensor.

Claims (3)

[Claims] 1. A method for producing a two-step type white light reproduction hologram (rainbow hologram), wherein a master hologram is formed on a first photosensitive material by interference between a reference light and an object light emitted from an object to be photographed. First to shoot
And the master hologram, a hologram reading slit having a machine-readable information code recorded at the end is overlaid,
The master hologram is illuminated with light conjugate with the reference light to reproduce a real image of the object to be photographed, and a second photosensitive material is provided at a reproduction position of the real image, and a white light reproduction type by interference with the reference light. A second step of photographing a hologram, and a method for producing a rainbow hologram with an invisible type machine-readable information code, comprising: 2. The information code for machine reading includes:
The method for producing a rainbow hologram containing an invisible machine-readable information code according to claim 1, wherein the hologram recording slit is recorded at one end portion or both end portions. 3. The machine-readable information code comprises:
The method for producing a rainbow hologram containing an invisible machine-readable information code according to claim 1, wherein an information-coded figure is recorded.