JPH0537720A - Pad for optical reader - Google Patents

Abstract

PURPOSE:To improve the light utilization efficiency by constituting a protective layer on a base and a film-like base with a material through which both of rays reading an original and reading a position on an original are transmitted. CONSTITUTION:Infrared rays L2 irradiating from a position sensor 28 to a reflecting film 57 at the angle of 30 deg. from a vertical direction is almost reflected on the reflecting film 57. Moreover, the infrared rays L2 irradiating from the part having no reflecting film 57 is transmitted as it is. Since the infrared rays L2 irradiating from the position sensor 28 repeat reflection and transmission depending on the part having the reflecting film 57 (diffraction grating 55) and the part having no reflecting film 57, an electric signal is extracted from the position sensor 28 and the position of the optical reader on an original is detected. On the other hand, visual rays L1 irradiating to the reflecting film 57 from the optical scanner 27 at the angle of 45 deg. from the vertical direction almost transmits through the film 57. Thus, the rays L1 transmitted through the pad 33 are reflected on the original 32 and most of the lightbeams are returned to the optical scanner 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-shaped pad used to give position information to a position sensor when an optical reading device having a position sensor attached to an optical scanner for reading characters or figures is used for reading. It is about.

[0002]

2. Description of the Related Art An optical reading apparatus of this type is equipped with an optical scanner for reading characters and figures drawn on a paper surface and a position sensor for reading positional information on the paper surface. US Patent No. 4,7
There is a structure described in Japanese Patent No. 51,380.

The position sensor optically monitors the position information on the paper surface and reproduces a character or a figure at an accurate position when printing out, displaying on a screen, or saving in a data storage device. Is what you need to do. In order to obtain this position information, a transparent film that has undergone special processing generally called a pad is used. This pad is usually formed with vertical and horizontal gratings having a certain width, and when this grating is crossed by an optical reading device, a position sensor provided in the optical reading device optically moves the grating. Position information is obtained by detecting and counting the number of crossed grids.

Here, the above-mentioned pad must satisfy the following constraint conditions.

First, the infrared rays emitted by the position sensor are reflected by a certain value or more. Secondly, a grid that can be recognized by the infrared sensitive element of the position sensor is formed,
That is, a part that reflects infrared rays and a part that does not reflect infrared rays are formed at predetermined intervals. Thirdly, the optical scanner has a transparency that can be received, that is, a high transmittance for visible light.

12 to 14 show an example of a conventional pad created to satisfy the above constraint conditions. In FIG. 12, a film-shaped pad 11 has lattices 12 extending in the vertical and horizontal directions and orthogonal to each other at a constant period. FIG. 13 shows a grid 12
FIG. 9 is an enlarged perspective view of FIG. 4, in which the grating 12 is a portion that absorbs infrared rays, and the other portion 13 reflects infrared rays.

As shown in FIG. 14, the pad 11 has an infrared reflection film 16 formed of a multilayer film of, for example, an Ag—Au alloy film and an InO ₂ film formed on the entire upper surface of a base 15 made of a polyester film, On its upper surface, for example, I
An infrared absorbing layer 17 containing a dye, such as RA-870 (manufactured by EXCITON CHEMICAL Co., Ltd.), which has a characteristic that the absorptivity to infrared rays is much higher than the absorptivity to visible light, is screen-printed in the vertical and horizontal directions at predetermined intervals to form a grid 12. Is formed. The upper surface of the grating 12 formed by the infrared absorbing layer 17 and the portion of the upper surface of the infrared reflecting film 16 where the grating 12 is not formed protect the pad 11 from damage due to contact with an optical reading device. Are covered by.

In the above structure, the infrared rays 20 emitted from the position sensor at an angle of 30 degrees from the vertical are reflected by the infrared reflecting film 16 in the portion where the grating 12 does not exist, and the grating 20 in the portion where the grating 12 exists. It is absorbed by 12. On the other hand, visible light 21 emitted from the optical scanner at an angle of 45 degrees from the vertical passes through both the infrared reflection film 16 and the infrared absorption layer 17. Therefore, the visible light 21 passes through the pad 11, reaches the original 22 below the pad 11, and is reflected by the surface of the original 22 to obtain information of characters and figures drawn on this surface, and then again. It is detected by the optical scanner through the infrared reflecting film 16 or through both the infrared reflecting film 16 and the grating 12.

In this way, the infrared rays emitted from the light source of the position sensor are repeatedly reflected and absorbed by the grating 12, so that an electric signal (binary signal) synchronized with the cycle of the grating 12 is transmitted from the infrared light receiving element of the position sensor. The position on the document of the optical reading device is detected by taking out and counting the binary signal.

[0010]

However, in the above-mentioned conventional pad 11, the visible light 21 passes through the infrared reflecting film 16 at least twice, and a part of the visible light 21 is shown in FIG.
As indicated by a broken line in FIG. 4, since the grating 12 also passes twice, light is attenuated and light utilization efficiency is reduced.

In order to screen print the infrared absorption layer 17 forming the fine grid 12 at a constant cycle, the temperature of the material of the infrared absorption layer 17, the state of the base 15 and the infrared reflection film 16, the printing speed. , It is necessary to execute printing multiple times after skillfully managing the printing direction etc.
Therefore, it is not easy to manufacture it with constant quality. Moreover, the screen printing cannot obtain the high dimensional accuracy required for the grid 12.

Further, the infrared reflecting film 16 is provided on the base 15
Since the entire upper surface of the coating is coated, the coating amount is large and the material cost is high.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pad for an optical reading device, which has high light utilization efficiency, is easy to manufacture, has stable quality, and has high dimensional accuracy, and is inexpensive.

[0014]

SUMMARY OF THE INVENTION According to the present invention, the above object is to provide an optical scanner for reading an original with a first light beam and an optical reading device with a position sensor for reading a position on the original with a second light beam. An indium tin oxide (Pd) which is arranged between the device and the original and has position information read by the position sensor, and which reflects the second light beam on the upper surface of the film-shaped base. Indium Tin Oxide (hereinafter abbreviated as ITO) layer, Ag layer and ITO layer in this order or TiO
₂ layers, SiO ₂ layer, TiO ₂ layer, SiO ₂ layer and TiO ₂
A reflective film is formed by vertically and horizontally stacking layers in order, and a protective layer is formed on the base so as to cover the reflective film. The base and the protective layer are the first and second light rays. It is achieved by providing a pad for an optical reader, characterized in that it consists of a material that is transparent to light.

The reflection film may be formed in a lattice shape, or may be located at a window portion corresponding to a gap in the lattice, and the regions through which the first and second light rays are transmitted are vertically and horizontally at predetermined intervals. It can be formed in a dot shape so as to extend in a lattice shape.

[0016]

According to the above construction, the infrared ray absorbing layer is not required, so that the first light beam emitted by the optical scanner for reading information does not pass through the infrared ray absorbing layer, and a part of the infrared ray absorbing layer is formed by the reflecting film. Only one or two passes. Therefore, the attenuation of the first light ray is suppressed.

Further, the reflection film can be formed in a predetermined lattice shape by a highly accurate photoetching method. Moreover, since the reflective film has a lattice shape, the reflective film can be saved as compared with the conventional case where the reflective film is formed on the entire upper surface of the base.

Further, from the film-shaped base to ITO
Layer, an Ag layer and an ITO layer are laminated in this order, or T
iO ₂ layer, SiO ₂ layer, TiO ₂ layer, SiO ₂ layer and Ti
The reflective film formed by stacking O ₂ layers has a high rate of transmitting the first light ray such as visible light, and the reflective film provides a high resolution to the optical reading device.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

First, the outline of the optical reading device will be described.
FIG. 1 is a bottom view of an optical reader 25, inside a case 26, one optical scanner 27 that uses a first light beam, such as visible light, and two that use a second light beam, such as infrared light. Position sensors 28, 28 are housed, and a light receiving window 29 of the optical scanner 27 is provided at the bottom of the case 26.
And a pair of lenses 30 and 31 for irradiation and focusing of the position sensor 28 are exposed. In addition, the optical scanner 2
7 and the position sensor 28 are connected to an external signal processing circuit by lead wires 23 and 24, respectively.

The optical scanner 27 and the position sensor 2
8 has an arrangement relationship as shown in FIG. 2. The original 32 is read by the optical scanner 27, and the position sensor 28
The position information of the pad 33 arranged between the optical reading device 25 and the original 32 is read.

As shown in detail in FIG. 3, the optical scanner 27 includes a pair of light sources 36 and 36 for irradiating the original 32 with visible light L1 in a scanner case 35, and the light source 36 within a fixed time axis. A light receiver 37 including a group of photoelectric sensitive light receiving elements for detecting an image reflected by the light and converting it into an electric signal.
And a lens device 38 for forming an image of the visible light L1 on the light receiver 37. The scanner case 35
Is for blocking visible light used inside the optical scanner 27 and light in the surrounding environment. The light receiver 37 is connected to an image signal processing circuit 39 provided outside for image processing, signal storage, and the like.

The position sensor 28, as shown in detail in FIG.
3, a light source 42 for irradiating 3 and an infrared light receiver 43 composed of a photoelectric sensitive light receiving element group sensitive to infrared rays, and an irradiation lens 3 for accurately irradiating the pad 33 with a constant light amount and width.
0, a condenser lens 31 for accurately condensing the reflected light from the pad 33 on the infrared receiver 43 located on a fixed focal length, and an infrared ray L2 condensed by the condenser lens 31. And a mirror 44 arranged at a position for accurately focusing on the infrared receiver 43. The sensor case 41 is also for blocking infrared rays used inside the position sensor 28 and light rays in the surrounding environment. The infrared light receiver 43 is connected to a position signal processing circuit 45 which is provided externally for performing calculation, signal storage and the like. FIG. 5 shows an infrared receiver 43 of the position sensor 28.
3 shows a pattern of the photo-sensitive light receiving element 47 of FIG. In this pattern, twelve photoelectric sensitive light receiving elements 47 are arranged, and six photoelectric light receiving elements 47 each form a pair of first divided patterns 48 and 49 in the X direction and a pair of first divided patterns 48 in the Y direction. Second
Divided patterns 50 and 51 are formed.

The relationship between this pattern and the grid 55 formed on the pad 33 is shown in FIG. The width W of the lattice 55 extending in the X direction is set to 90% to 100% of Py with respect to the interval Py between the second divided patterns 50 and 51 (FIG. 5) in the Y direction. The width of the grating 55 extending in the Y direction is also equal to the above W, and again the first division pattern 4 in the X direction.
It is set to be 90 to 100% of the interval Px of 8,49 (FIG. 5).

When the outputs of the twelve photoelectric sensitive light-receiving elements 47 are A to O as shown in FIG. 5, the position signal processing circuit 45 (FIG. 4) calculates from these outputs as shown in FIG. According to the formula, two sets of electrical signals XA, YA, XB,
By making YB and detecting the rising and falling of the electric signals XA and XB, the X coordinate of the grid 55 is detected, and by detecting the rising and falling of the electric signals YA and YB, the Y coordinate of the grid 55 is detected. To detect.

8 and 9 show a pad 33 according to the first embodiment of the present invention. As shown in FIG.
A lattice 55 extending vertically and horizontally and having predetermined intervals (cycles) D1 and D2 is formed in the.

FIG. 9 shows the details of the structure of the pad 33. In FIG. 9, a reflective film 57 is formed on the upper surface of the base 56 which transmits the visible light rays L1, the infrared rays L1 and the infrared rays L2 and extends in a grid pattern at predetermined intervals in the vertical and horizontal directions. Is formed, and the reflection film 57 forms the grating 55. On the upper surface of the base 56, which covers the reflection film 57, a protective layer made of a material that transmits the visible light L1 and the infrared light L2 is formed.

The reflective film 57 is an ITO layer from the base 56 side,
When the Ag layer and the ITO layer are laminated in this order,
The upper and lower ITO layers have a thickness of 200 to 1000 n
It is preferable that the thickness is in the range of m and the thickness of the Ag layer is in the range of 30 to 100 nm because the ratio of the first light rays such as visible light rays to be transmitted is extremely high. In addition, the reflective film 57
From the base 56 side to the TiO ₂ layer, SiO ₂ layer, TiO
_{When the two} layers, the SiO ₂ layer and the TiO ₂ layer are laminated in this order, the thickness of each layer is from the base 56 side to the TiO _{2 layer.}
Layer: λ / 4n, SiO ₂ layer: λ / 4n, TiO ₂ layer: λ /
2n, SiO ₂ layer: λ / 4n and TiO ₂ layer: λ / 4n
(However, λ represents the wavelength of the first light ray, and n represents the refractive index of each layer.) It is preferable that the ratio of the first light ray such as visible light to be transmitted is extremely high.

In the above structure, as shown in FIG. 9, the infrared ray L2 emitted from the position sensor 28 to the reflection film 57 at an angle of 30 degrees from the vertical is mostly reflected by the reflection film 57 and the rest is transmitted. To do. Further, the infrared ray L2 applied to the portion where the reflection film 57 does not exist is transmitted as it is. In this way, the infrared ray L2 emitted from the position sensor 28 is repeatedly reflected and transmitted by the portion where the reflection film 57 (grating 55) exists and the portion where the reflection film 57 does not exist, thereby synchronizing with the cycle of the position sensor 28 and the grating 55. The position of the optical reading device on the document is detected by taking out the generated electric signal (FIG. 7) and counting the binary signal.

On the other hand, the visible light L1 emitted from the optical scanner 27 to the reflection film 57 at an angle of 45 degrees from the vertical is reflected by the reflection film 57 in a very small part, and most of the rest is transmitted through the reflection film 57. To do. The visible light L1 applied to the portion where the reflection film 57 does not exist is transmitted as it is. The visible light L1 that has passed through the pad 33 in this way reaches the other original 32 and is reflected, and after reading the characters and figures drawn on the surface thereof, most of it passes through the reflective film 57 and returns to the optical scanner 27. .

10 and 11 show a pad 33 according to the second embodiment of the present invention. As shown in FIG. 10, the pad 33 reflects infrared rays in a dot shape so as to be positioned at a window portion corresponding to a gap with respect to a lattice 55 extending vertically and horizontally and having a predetermined distance D1 and D2. A reflective film 57 is formed.

FIG. 11 shows the details of the structure of the pad 33 shown in FIG. 10, in which visible light rays L1 and infrared rays L2 are shown.
The reflection film 57 that reflects the infrared ray L2 is provided on the upper surface of the base 56 that transmits the light. In a portion where the reflection film 57 does not exist, a region that transmits both the visible light ray L1 and the infrared ray L2 is vertically and horizontally. It is provided so as to extend in a lattice shape at a predetermined interval, that is, to form the lattice 55. A protective layer 58 made of a material that transmits the visible light L1 and the infrared light L2 is formed on the upper surface of the base 56 covering the reflective film 57.

Similarly, when the pad 33 shown in FIGS. 10 and 11 is used, the position on the document of the optical reading device is detected by the infrared ray L2, and the character or figure drawn on the surface of the document is read by the visible ray L1. To be

By the way, the lattice spacing D1 or D2 is
In the case of 0.33 to 0.34 mm, the width W of the reflective film 57 is
As will be described later, 0.16 to 0.17 mm is suitable, and it is not preferable to set it to 0.16 mm or less. Therefore, in the first embodiment shown in FIG. 8 and FIG. The plane area occupied by the film 57 becomes considerably large. On the other hand, in the second embodiment shown in FIGS. 10 and 11, since the reflective film forms the window of the grating 55, the plane area occupied by the reflective film 57 is relatively small. Actually, the lattice spacing D1, D2 is 0.34 mm, and the lattice width W is 0.17.
In the case of mm, the plane area occupied by the reflection film 57 is 1/3 of that of the first embodiment in the second embodiment. Therefore, the visible light L1 passing through the reflective film 57 is only a part, so that the utilization efficiency of the visible light L1 is extremely high.

In order to keep the operation accuracy of the position sensor 28 sufficiently high, the protective film 57 has a high reflectance for the infrared ray L2 and a high transmittance for the visible light ray L1. is necessary. The wavelength is 8 for the reflective film 57.
The reflectance of the reflection film 57 obtained by injecting near-infrared rays of 80 nm so that the incident angle of the reflection film 57 with respect to the vertical direction is 30 ° is preferably 20% or more,
It is preferable that the transmittance of the reflective film 57 obtained by injecting visible light having a wavelength of 570 nm or 660 nm so that the incident angle of the reflective film 57 with respect to the vertical direction is 45 ° is 40% or more.

The reflective film 57 is formed on the entire upper surface of the base 56.
The film is once formed into a uniform film by a vacuum vapor deposition method, a sputtering method, an electrodeposition method or the like, and then shaped into a predetermined shape by a photo etching method.

The base 56 and the protective layer 58 are made of, for example, polyester and have a wavelength of 570 nm or 660 n.
The visible light of m is incident on the base 56 or the protective layer 58 at an incident angle of 45 ° with respect to the vertical direction, and the near infrared ray having a wavelength of 880 nm is perpendicular to the base 56 or the protective layer 58. It is preferable that both the transmittances obtained by making the light incident at an incident angle of 30 ° with respect to the directions be 50% or more, and more preferably 70% or more.

When the lattice spacing D1 or D2 shown in FIGS. 8 and 10 is 3.33 to 0.34 mm, the reflective film 5 is used.
The width W of 7 is preferably about 0.16 to 0.17 mm,
If the thickness is 0.16 mm or less, the amount of reflection of the infrared ray L2 is small, which makes it difficult to detect the lattice by the position sensor 28, that is, the position information detection method. Therefore, the accuracy of reading an image by the optical scanner 27 is lowered.

As a combination of the first and second light rays L1 and L2, visible light rays and near infrared rays are suitable.

Further, since the reflective film 57 only needs to be formed vertically and horizontally periodically, the first and second reflective films 57 are formed.
Unlike the embodiment, for example, dots may be formed in a dot shape and vertically adjacent dots may be displaced from each other in the horizontal direction (X direction).

[0041]

As described above, according to the present invention, since the infrared ray absorbing layer is not necessary, the first light beam emitted by the optical scanner for reading information does not pass through the infrared ray absorbing layer. In addition, a part of the reflective film is used once or twice.
It just passes. Therefore, the attenuation of the first light ray is suppressed, and the light utilization efficiency is improved. In particular, when the reflective film is located in the window portion of the grating and is provided in a dot shape, the planar area of the reflective film is made smaller than that in the case where the reflective film itself is provided in a lattice shape, and the light utilization efficiency is improved. It can be further improved.

Further, since the reflecting film can be formed in a predetermined periodic shape by the photo etching method, the manufacturing is easy and the quality is stable. Further, according to the photo etching method, the dimensional accuracy of the reflective film is improved as compared with the conventional screen printing. In addition, since the reflective film is formed periodically in the vertical and horizontal directions, the reflective film can be saved compared to the conventional case where the reflective film is formed on the entire upper surface of the base, so that the cost is reduced.

Furthermore, ITO is applied from the side of the film base.
Layer, an Ag layer, and an ITO layer are laminated in this order, or a TiO ₂ layer, a SiO ₂ layer, and a TiO ₂ layer from the base side of the film form
_{Since the} reflective film is formed by laminating the _two layers, the SiO ₂ layer and the TiO ₂ layer in this order, the first light beam such as visible light has a high rate of passing therethrough, which gives the optical reader a high resolution.

[Brief description of drawings]

FIG. 1 is a bottom view showing an optical reader using the pad of the present invention.

FIG. 2 is a schematic configuration diagram showing an internal structure of the device.

FIG. 3 is a schematic configuration diagram showing an optical scanner of the apparatus.

FIG. 4 is a schematic configuration diagram showing a position sensor of the apparatus.

FIG. 5 is a plan view showing an arrangement of photoelectric sensitive light receiving elements of the same position sensor.

FIG. 6 is a plan view showing the relationship between the photoelectric-sensitive light-receiving element and the grating.

FIG. 7 is a waveform diagram of an electric signal output from the position sensor.

FIG. 8 is a plan view of the pad showing the first embodiment of the present invention.

FIG. 9 is a sectional view of the pad.

FIG. 10 is a plan view of a pad showing a second embodiment.

FIG. 11 is a cross-sectional view of the pad.

FIG. 12 is a perspective view showing a conventional pad.

FIG. 13 is an enlarged perspective view showing a grid of the pad.

FIG. 14 is a sectional view of the pad.

[Explanation of symbols]

25 Optical reader 27 Optical Scanner 29 Position sensor 32 manuscripts 33 pads 55 grid 56 base 57 Reflective film 58 Protective layer L1 first ray L2 second ray

Claims (2)

[Claims] 1. An optical reading device having an optical scanner for reading an original with a first light beam and a position sensor for reading a position on the original with a second light beam, and the position being provided between the original and the original. A pad provided with position information read by a sensor, the indium tin oxide layer, the Ag layer, and the indium tin oxide layer, which reflect the second light beam, are vertically and horizontally arranged in this order on the upper surface of the film-shaped base. A protective film is formed on the base so as to cover the reflective film, and the base and the protective layer are made of a material that transmits the first and second light rays. A pad for a featured optical reader. 2. An optical scanner having an optical scanner for reading a manuscript with a first light beam and a position sensor for reading a position on the manuscript with a second light beam, and the position being arranged between the manuscript and the position. A pad provided with position information read by a sensor, the TiO ₂ layer, S, which reflects the second light ray on the upper surface of a film-shaped base.
iO ₂ layer, TiO ₂ layer, the reflective film formed by periodically laminating vertically and horizontally in the order of the SiO ₂ layer and the TiO ₂ layer is formed, a protective layer on the base to cover the reflective film is formed, the The pad for an optical reader, wherein the base and the protective layer are made of a material that transmits the first and second light rays.