JP2003281482A - Optical information recording medium and optical information reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical information recording medium from which information can be read by a reader of inexpensive constitution and by which forgery-preventing effect is obtained by improving the secrecy of information. <P>SOLUTION: An optical information recording medium 100 is provided with: a transparent code area 7 comprising a transparent cell 6 provided with a transparent reflecting layer 3; and a QR code 4 consisting of black cells 2 and bright cells 8 which have optical characteristic different from the transparent cell 6 and which can visually be recognized. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording medium in which information is recorded in an optically readable form, and an optical information recording medium for optically reading information recorded in such a medium. Information reading device.

[0002]

Problems to be Solved by the Invention For example, Japanese Patent No. 322
In Japanese Patent No. 3730, a mark such as a bar code is printed with an infrared absorbing ink (invisible ink), and the same mark is overlaid with a process ink (visible ink) to print the infrared light and the visible light. When irradiating and
An authenticity determination method is disclosed in which infrared light is absorbed and visible light is reflected to determine that the product is genuine.

Further, Japanese Patent Laid-Open No. 2000-295418 discloses a technique of increasing the amount of information recorded on a medium by printing a bar code by using a phosphor emitting infrared light. These conventional techniques are aimed at increasing the confidentiality of information and improving the amount of recorded information.

However, these conventional techniques have the following problems. First, since printing is performed with fluorescent ink or the like that cannot be visually recognized with visible light, special components such as a light source emitting infrared rays or ultraviolet rays and an infrared sensor are required, and the reading device becomes expensive. Secondly, just by invisible printing of the code as in Japanese Patent No. 3223730, the position where the code is printed on the medium cannot be known, and it is not suitable when the user manually reads the code.

Thirdly, Japanese Patent Laid-Open No. 2000-29541.
When the invisible printing and the visible printing are overlapped as in Japanese Patent No. 8 publication, a reading device equipped with both optical systems necessary for reading each of them is required, which makes the device large and expensive. There is a problem that it has to be.

The present invention has been made in view of the above circumstances, and an object of the present invention is to enable reading of information by a reading device having an inexpensive structure, enhance confidentiality of information, and prevent forgery. Another object of the present invention is to provide an optical information recording medium that can be obtained, and an optical information reading device that optically reads information recorded on such a medium.

[0007]

According to another aspect of the present invention, there is provided a transparent display unit having a transparent reflection layer which is substantially transparent to visible light and which specularly reflects visible light. A transparent code area including
The transparent display unit has a different optical characteristic from that of the transparent display unit, and includes a visible code region including a visually recognizable visible display unit. In addition, "regular reflection" means reflection performed in a state where the reflection angle is equal to the incident angle.

That is, since the transparent reflective layer is transparent to visible light and specularly reflects visible light, if invisible information is recorded by the transparent display unit, the reading device is specularly reflected by the transparent reflective layer. The information can be read by receiving the emitted light. Further, since it is possible to arrange information readable by visible light below the transparent reflection layer, it is also possible to arrange so that a part or all of the transparent code area and the visible code area overlap each other. it can. Therefore, it is possible to secure the confidentiality of information by recording invisible information, and it is also possible to increase the amount of information by recording information that can be read by visible light in duplicate. In addition, since the position of the transparent code area can be easily estimated with reference to the position of the visible code area, the user can easily read the position.

According to another aspect of the optical information recording medium, the outer shape of the transparent reflective layer is smaller than the outer shape of the transparent display unit included in the transparent code area, and the transparent display unit is transparent. The reflectance of visible light in the transparent display unit is adjusted according to the proportion of the reflective layer.

That is, if the reflectance of specular reflection in the transparent display unit becomes too high, there may be a problem in determining the brightness of the visible code area in which the amount of reflected light is lower than that of specular reflection. Therefore, with the above configuration, the contrast between the transparent display unit and the visible display area in the visible code area can be adjusted to be appropriate.

According to the optical information recording medium of the third aspect, the size and interval of the transparent reflection layer imaged on the light receiving sensor of the reading device are smaller than the resolution of the reading device for reading information. Therefore, when the reading device receives the reflected light, the reflected light by the transparent display unit can be planarly captured. Therefore, the reflected light can be stably received.

According to the optical information recording medium of the fourth aspect, in the transparent code area, the bright display unit and the dark display unit are constituted by the relative difference in the area of the transparent reflection layer. That is, since it is possible to give a difference to the reflectance of the transparent display unit depending on the area ratio of the transparent reflection layer, it is possible to give a difference to the information to be read accordingly. Therefore, it is possible to further increase the amount of information to be recorded.

According to the optical information recording medium of the fifth aspect, a bright display unit and a dark display unit are formed in the visible code area by the relative difference in diffuse reflectance with respect to visible light. Therefore, similarly to the fourth aspect, it is possible to give a difference to the information to be read according to the difference in diffuse reflectance, so that it is possible to further increase the amount of information to be recorded.

According to the optical information recording medium of the sixth aspect, since the transparent code area and the visible code area are arranged adjacent to each other, the information recorded in each area is collectively read by the reading device. Will be easier to do.

Further, according to the optical information recording medium of the seventh aspect, the transparent code area and the visible code area are arranged such that the geometric center of either one is located inside the other area. Therefore, it is possible to read both areas more easily.

According to the optical information recording medium of the eighth aspect, any one of the transparent code area and the visible code area is arranged so as to surround the outer peripheral side of the other area. According to this structure, the two areas can be arranged efficiently, and the reading performed by the reading device can be facilitated.

Further, according to the optical information recording medium of the ninth aspect, since the transparent code area and the visible code area are concentrically arranged, both areas can be arranged more efficiently. The space of the medium can be effectively used.

In addition, according to the optical information recording medium of the tenth aspect, since the transparent code area is arranged outside the visible code area, the visible code area becomes small (compact). Can be placed. Therefore, the optical information recording medium can be made as inconspicuous as possible.

According to another aspect of the optical information recording medium of the present invention, the information recorded in at least one of the transparent code area and the visible code area is read when the information is read. Place a check code to check the correctness of (error check). For example, if you put each check code in each area,
The reading device can individually read the information recorded in each area to perform an error check. If both check codes are arranged in one area, the result of the error check will be erroneous if the reading device reads only the area including the check code. Therefore, the security of information can be improved for a reading device that does not have a function of reading both areas at the same time.

According to the optical information reader of the twelfth aspect, the illumination light source has a light emitted from the illumination light which is specularly reflected by the information recording surface of the optical information recording medium and a diffusely reflected light. The light and the light are received by the light receiving sensor. Then, the decoder refers to the image signal output from the light receiving sensor to determine the lightness / darkness of the visible display unit arranged in the visible code area based on the first threshold value, and the transparent code based on the second threshold value. The lightness and darkness of the transparent display unit arranged in each area is determined, and the information recorded in each area is decoded.

That is, by configuring the optical information reading device in this way, both the information recorded in the visible code area and the information recorded in the transparent code area of the optical information recording medium are visible. By reflecting the light, it becomes possible to read by a common optical system. Therefore, it is possible to read an optical information recording medium on which more information is recorded, or an optical information recording medium with a higher security level, with a configuration that is cheaper than conventional ones.

According to the optical information reader of the thirteenth aspect, the optical axis of the illuminating light source is symmetrical with the optical axis of the light receiving sensor with respect to the normal line standing on the information recording surface of the optical information recording medium. Since it is arranged at such a position, the light specularly reflected by the information recording surface can be reliably received by the light receiving sensor. Therefore, since the entire area of the light receiving sensor can be set as the regular reflection area, the degree of freedom in code creation is further increased.

According to another aspect of the optical information reading device of the present invention, the illumination light source is the light receiving sensor, and the light emitted from the illumination light source is diffused and specularly reflected by the information recording surface of the optical information recording medium. Arranged to be received by the
The decoder determines the lightness / darkness of the visible display unit arranged in the visible code area based on the first threshold value, and determines the lightness / darkness of the transparent display unit arranged in the transparent code area based on the second threshold value. Then, the information recorded in each area is decoded.

That is, by configuring the optical information reading device in this way, both the information recorded in the visible code area and the information recorded in the transparent code area of the optical information recording medium are visible. Each can be read by reflecting the light. Therefore, similarly to the twelfth aspect, the reading of the optical information recording medium on which more information is recorded or the optical information recording medium having a higher security level can be performed with a configuration cheaper than the conventional one. it can.

According to the optical information reader of the fifteenth aspect, in the first illumination light source, only the reflected light in which the light emitted by itself is diffusely reflected by the information recording surface of the optical information recording medium is received by the light receiving sensor. The second illumination light source is arranged so as to receive light. The second illumination light source is arranged so that the light emitted from itself is both diffusely reflected and specularly reflected by the information recording surface by the light receiving sensor.

Then, the light receiving sensor outputs an image signal corresponding to the reflected light amount of the irregularly reflected light and the specularly reflected light to the decoder, and the decoder refers to the image signal,
The lightness / darkness of the visible display unit arranged in the visible code area is determined based on the first threshold value, and the lightness / darkness of the transparent display unit arranged in the transparent code area is determined based on the second threshold value. The information recorded in the area is decoded. That is, by dividing the illumination light source into the first light source and the second light source, the diffused reflection light and the regular reflection light generated on the information recording surface of the optical information recording medium are adjusted to be optimally received by the light receiving sensor. can do.

According to the optical information reader of the sixteenth aspect, in the first illumination light source, the light emitted from the first illumination light source is diffusely reflected by the information recording surface of the optical information recording medium and received by the light receiving sensor. The second illumination light source is arranged so that the light emitted from itself is specularly reflected by the information recording surface to be received by the light receiving sensor.

Then, the light receiving sensor outputs the first and second image signals to the decoder according to the received irregular reflection light amount and the regular reflection light amount, respectively, and the decoder refers to the first image signal and outputs the first image signal. The brightness of the visible display unit arranged in the visible code area is determined based on the threshold value of 1, and the transparent display unit arranged in the transparent code area is determined based on the second threshold value by referring to the second image signal. The light and dark are discriminated, and the information recorded in each area is decoded.

That is, by configuring the optical information reader in this way, both the information recorded in the visible code area and the information recorded in the transparent code area of the optical information recording medium are visible. By reflecting the light, it becomes possible to read each based on the first and second image signals. Then, it becomes easy to handle the information on each area independently.

According to the optical information reading apparatus of the seventeenth aspect, the decoder detects a portion where the visible code area and the transparent code area overlap each other as an overlapping code area, and detects the overlapping code area. Based on the above, the information recorded in either the visible code area or the transparent code area is modulated and decoded.

That is, the transparent code area having the transparent reflection layer can be arranged so as to overlap the visible code area. If the arrangement relationship between the visible code area and the transparent code area is known, these two areas can be arranged. It is possible to detect a portion where two areas are set to overlap (duplication code area). Then, if the duplicate code area can be detected, the decoder modulates the information recorded in the visible code area and the transparent code area due to the overlap (that is,
Originally, the meaning of the information recorded as an independent area is changed). Therefore, when the duplicate code area is set in the optical information recording medium, the decoding can be performed based on the information recorded in the area.

According to the optical information reading apparatus of the eighteenth aspect, when the decoder determines whether the second image signal is bright or dark based on the first threshold value, the visible display unit arranged in the visible code area. The overlapping code area is detected based on the portion where the lightness and darkness is reversed. Then, based on the detected duplicate code area, the information recorded in either the visible code area or the transparent code area is modulated and decoded.

That is, when the lightness and darkness of the second image signal obtained by receiving the specularly reflected light is discriminated by the first threshold value, the portion where the visible display unit and the transparent display unit overlap each other is the second portion. The lightness and darkness are reversed with respect to the case where the determination is made by the threshold value. Therefore, the duplicated code area can be detected by such a method, and when the duplicated code area is set in the optical information recording medium, the information recorded in the area can be detected. Can be decoded based on

According to another aspect of the optical information reading apparatus of the present invention, the light emitted from the first illumination light source is reflected by the information recording surface of the optical information recording medium to be the first reflected light. It is arranged so that it is not received by the light receiving sensor of.
According to this structure, the information recorded in the visible code area and the information recorded in the transparent code area can be accurately read by one light receiving sensor.

According to the optical information reader of the twentieth aspect, when the read information includes a check code for checking the correctness of the information, the decoder reads it based on the check code. Since it is determined whether the information is correct or incorrect, it is possible to prevent the information from being read in an incorrect state.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) The present invention is described below.
A first embodiment in which a micro QR code (registered trademark; hereinafter simply referred to as a QR code), which is a type of two-dimensional code, is used as a visible code area will be described with reference to FIGS. 1 to 8. In the present embodiment, the QR code is printed on paper or the like as usual. Then, together with the QR code, different information is recorded depending on the presence / absence of a portion printed with transparent ink.

First, the principle will be described with reference to FIG. FIG. 2 shows a portion on which a black cell (dark cell) 2 used for a QR code is printed on a sheet 1 and a portion on which it is not printed.
3 is a cross-sectional view showing a portion of transparent ink printed on the black cell 2. A transparent reflective layer 3 having substantial transparency to visible light is formed on the portion where the transparent ink is printed, and the black cell 2 under the transparent reflective layer 3 is in a visually recognizable state.

FIG. 2 (a) shows the state of reflection that occurs on the surface of each part when light (visible light) vertically incident on these parts is irradiated. At this time, light is largely diffused in the portion (W) where the black cell 2 is not printed (that is, the white portion which is the background color of the paper 1), but the light is reflected in the portion (B) where the black cell 2 is printed. Is absorbed, the reflection is small. That is, due to the difference in these reflection states, Q
The R code reader recognizes the presence / absence of the black cell 2 and Q
It is designed to read the R code.

In the portion (T) where the transparent reflection layer 3 is formed on the black cell 2, visible light almost passes through the transparent reflection layer 3, so that substantially the surface of the lower black cell 2 is exposed. Reflection takes place. That is, the reflection of light is small. Therefore,
When the vertically incident light is irradiated as described above, the QR code can be read as usual regardless of the presence or absence of the transparent reflection layer 3.

FIG. 2 (b) shows the state of reflection that occurs on the surface of each part when each part is irradiated with light having an incident angle of 45 degrees. At this time, similar to (a), the portion (W) where the black cell 2 is not printed is largely diffused (the amount of reflected light is large), and the portion (B) where the black cell 2 is printed is slightly diffused ( A small amount of reflected light).

In the portion (T) where the transparent reflection layer 3 is formed on the black cell 2, most of the light having an incident angle of 45 degrees is specularly reflected on the surface of the transparent reflection layer 3, and the incident light is very small. Part of the light passes through the transparent reflection layer 3 and is slightly diffused on the surface of the black cell 2.

That is, these three values for light with an incident angle of 45 degrees
Comparing the reflected light amounts of the two portions (W), (B), and (T), the relationship of (T)>(W)> (B) is obtained (see FIG. 3). Therefore, by irradiating the light having an incident angle of 45 degrees and receiving the reflected light, it is possible to detect the portion where the transparent reflection layer 3 is formed (of course, the incident angle is limited to 45 degrees). However, the angle can be any angle that can obtain a sufficient amount of received light by specular reflection). Specifically, the presence or absence of regular reflection can be determined by the threshold value H shown in FIG. 3, the position where the transparent reflection layer 3 is disposed can be detected, and the magnitude of the irregular reflection level can be determined by the threshold value L. The position where the black cell 2 is arranged can be detected.

As the transparent ink for forming the transparent reflection layer 3, a generally used polymer material dissolved in water or an organic solvent (no pigment or dye is added) may be used. . As the polymer material, for example, polyvinyl alcohol, methyl cellulose, ethyl cellulose, cellulose acetate, polystyrene, polyvinyl chloride, a homopolymer or copolymer of a methacrylic resin, an acrylic resin, a styrene resin, a silicon resin, a polyisobutyl resin, etc. alone or a copolymer. There is a polymer.

For example, it is better to print a thick transparent ink on a surface having a relatively large unevenness such as the paper 1, and a relatively flat surface such as a plastic sheet or a film. The transparent ink may be thinly printed on the object.

FIG. 1 shows an example of the configuration of an information code 5 in which a transparent code region 7 having a transparent reflection layer 3 is added to a QR code 4. The information code 5 has a visible code area formed by printing the QR code 4 in the central portion thereof, and the transparent cell (transparent display unit) 6 formed by the transparent reflection layer 3 in the peripheral portion has the same size as the black cell 2. The transparent code area 7 is formed by the printing arrangement. still,
In FIG. 1, the transparent cell 6 is shown by hatching.

In the information code 5, the geometric center of the QR code 4 and the geometric center of the transparent code area 7 are aligned with each other, that is, the two are arranged in a concentric positional relationship. .

The QR code 4 is formed by combining the black cell 2 and a bright cell (visible display unit) 8 which is a white square as a portion where the black cell 2 does not exist in a two-dimensional manner. Information such as kanji, kana, and symbols is encoded and formed in a rectangular shape. QR code 4
As will be described later in detail, the code reading device equipped with a CCD camera or the like optically reads and decodes the coding pattern composed of the black cells 2 and the bright cells 8. The specific pattern 4S of the QR code 4 indicates the reference position when reading the QR code 4 and also the unit data (data cell) of the QR code 4.
It shows the size of.

In the transparent code area 7, the transparent cell 6
Depending on the presence or absence of the information, the information is encoded in the same format as the QR code 4 or a unique format. That is, the transparent code area 7 also forms a two-dimensional code.

To read the QR code 4 of the information code 5, it is sufficient to determine the presence or absence of the black cell 2 by using the first threshold for the magnitude of the diffused reflection light amount. The presence or absence of the transparent cell 6 may be determined by using the second threshold value for the magnitude of the reflected light amount. The optical information recording medium 100 is formed by printing the information code 5 on the paper 1.

Next, the procedure for generating the information code 5 will be described with reference to FIG. First, data to be recorded in the visible code area, that is, as the QR code 4 is prepared (step A1), and the code size of the visible code area is determined based on the standard (of the QR code) (step A2). Subsequently, data to be recorded in the transparent code area 7 is prepared (step A3), and the code size of the transparent code area 7 is determined based on the standard (step A4). Then, a print pattern for each of the visible code area and the transparent code area 7 is created based on the data of steps A1 and A3 (step A5), and the print pattern is output to the printing device and printed (step A6).

FIG. 5 is a functional block diagram showing an electrical configuration of the code reading device (optical information reading device) 11 for reading the information code 5. The LEDs (illumination light sources) 13 to 18 of the light emitter / receiver 12 are used to illuminate the recording surface of the information code 5 with illumination light. Further, FIG. 6 shows a configuration of an optical system centering on the light emitting / receiving unit 12. LED13 ~
When the light projected by 18 is reflected by the recording surface of the information code 5, it is passed through the light receiving lens 19 to, for example, CC.
Light is received by a light receiving sensor 20 which is a D (Charge Coupled Device) area sensor. The light receiving sensor 20 uses the captured two-dimensional image as a scanning line signal in the horizontal direction, and passes through the amplifier circuit 21 to the comparison circuit 22 and A
The data is output to the / D conversion circuit 23.

The comparison circuit 22 compares the input scanning line signal with a threshold value and outputs the binarized data to the memory 24 and the specific ratio detection circuit 25. The specific ratio detection circuit 25 detects a predetermined frequency component included in the code coding pattern from the data of the binarized scanning line signal, and outputs the detection result to the memory 24. . Further, the A / D conversion circuit 23 is adapted to convert an analog scanning line signal given through the amplifier circuit 21 into digital data and output it to the memory 24.

The CPU (decoder) 26 includes LEDs 13 to
18, the amplification factor of the amplifier circuit 21, and the comparison circuit 2
It controls the threshold level given to 2 and the A / D conversion circuit 23 and the specific ratio detection circuit 25. The CPU 26 also outputs a clock signal to the synchronization signal generation circuit 27. Sync signal generation circuit 27
Generates a synchronization signal based on a clock signal provided by the CPU 26, the synchronization signal is generated by the light receiving sensor 2
0, the specific ratio detection circuit 25 and the address generation circuit 28. The address generation circuit 28 generates a write address of the memory 24 by counting the synchronization signal and outputs the write address to the memory 24.

Further, the CPU 26 is provided with an operation signal of the switch 29 for the user to perform an operation input, and the CPU 26 is adapted to output a display signal to the liquid crystal display 30 and to communicate with the communication interface. 31
It is possible to communicate with a host (not shown) via the, and to perform processing such as transmitting data stored in the memory 24. The battery 32 supplies power to each part of the code reading device 11.

In FIG. 6, LEDs 13 and 14 are arranged on both sides of the light receiving lens 19, LEDs 15 and 16 are on the left side of the LED 13, and L is on the right side of the LED 14.
EDs 17 and 18 are arranged respectively. LED15,1
The 6 and the LEDs 17 and 18 project light through the diffusion plates 33 and 34 arranged below them, and are configured as diffused light sources. LED for lighting
Are actually arranged in a larger number around the light receiving lens 19, and the LEDs 13 to 18 show some of them.

Due to such arrangement of the light sources, in the plane where the information code 5 is read, the area corresponding to the central portion of the optical system is mainly LE.
The region (Y) around which the diffuse reflection occurs (that is, the region where regular reflection does not occur) (X) due to the illumination light emitted from D13, 14 is the LED 15,
The illumination light emitted from the LED 16 and the LEDs 17 and 18 is mainly specularly reflected and enters the light receiving lens 19.

The LEDs 13 and 14 are arranged in such a positional relationship that the light emitted from the LEDs 13 and 14 is regularly reflected by the information recording surface and is not received by the light receiving sensor 20, as indicated by the broken line in FIG. Has been done. In addition, LED15 ~
The LEDs 13 and 14 may be omitted when an image with sufficient brightness can be obtained by the illumination light from the LED 18.

Next, a procedure for the code reading device 11 to read the information code 5 will be described with reference to FIG. FIG. 7 is a flowchart showing the control contents mainly performed by the CPU 26 of the code reading device 11.

First, the CPU 26 drives the LEDs 13 to 18 to emit light. Then, the light reflected by the information recording surface of the information code 5 is received by the light receiving sensor 20, and the image data of the gray value (grayscale image) is stored in the memory 24 (step B1).

Subsequently, the CPU 26 determines whether the image data stored in the memory 24 is bright or dark by the threshold L (first threshold) of the visible code area, converts it into binary image data, and stores it in a predetermined area of the memory 24. Store (Step B
2). Then, it is determined whether or not the specific pattern 4S indicating the reading reference position included in the QR code 4 exists in the binary image data (step B3). When the specific pattern 4S does not exist (step B4, “NO”)
Returning to step B1, the reading of the information code 5 is retried.

When the specific pattern 4S exists (step B4, "YES"), the CPU 26 determines the position of the data cell (black cell 2, bright cell 8) of the QR code 4 based on the position of the specific pattern 4S. (Step B5),
The array of binary data is determined from the light / dark state of the data cell (step B6). Then, the data (information) recorded in the QR code 4 is decoded (step B
7).

Next, the CPU 26 determines whether the image data of the gray value stored in the memory 24 in step B1 is bright or dark by the threshold value H (second threshold value) of the transparent code area 7, and the binary image data. And is stored in a predetermined area of the memory 24 (step B8). Then, the position of the transparent code area 7 is determined based on the position of the specific pattern 4S determined in step B3 (step B
9), the array of binary data is determined from the light and dark states depending on the presence or absence of the transparent cell 6 (step B10). Then, the data (information) recorded in the transparent code area 7 is decoded (step B11).

By the way, in the information code 5 shown in FIG. 1, the transparent code area 7 is adjacently arranged so as to surround the outer circumference of the QR code 4, which is a visible code area. When the code reading device 11 tries to read, the boundary between the two areas must match the boundary between the areas (X) and (Y) on the reading side. Therefore, it is necessary to accurately align the two. That is,
This is because if the transparent code area 7 is irradiated with irregular reflection illumination light for reading the QR code 4, strong regular reflection occurs due to the illumination, and accurate light reception is hindered.

Therefore, as shown in FIG. 8, if the visible code area 35 and the transparent code area 36 are arranged with a slight margin, the positioning at the time of reading can be performed to some extent. Can also be read.

As described above, according to the present embodiment, the optical information recording medium 100 includes the transparent code area 7 including the transparent cell 6 having the transparent reflection layer 3 and the transparent cell 6. A QR code 4 having a visually recognizable black cell 2 and a bright cell 8 having different optical characteristics.
(Visible code area). Therefore, by recording the invisible information in the transparent code area 7, it is possible to ensure the confidentiality of the information. Further, since the information readable by visible light can be redundantly recorded in the transparent code area 7, the amount of information can be increased.

Since the transparent code area 7 is arranged so as to surround the outer peripheral side of the QR code 4 and is arranged adjacent to each other so as to be concentric with each other, the two areas can be arranged efficiently. Therefore, the space of the recording medium 100 can be effectively utilized. Further, the code reading device 11 can easily read the information stored in each area. Furthermore, QR code 4
Since the visible code area is reduced by arranging the recording medium 100 on the inner side, the recording medium 100 can be made as inconspicuous as possible.

Further, according to the present embodiment, in the code reading apparatus 11, the LEDs 13 and 14 receive the light reflected by the light reflected by the information recording surface of the recording medium 100.
Arranged to receive light by LEDs 15-18
Is arranged so that the reflected light specularly reflected by the information recording surface is received by the light receiving sensor 20. Then, the light receiving sensor 20 outputs an image signal corresponding to the amount of reflected light received from each of the LEDs 13 to 18 to the CPU 26, and the CPU 2
6 is configured to decode the information recorded in each of the QR code 4 and the transparent code area 7 based on the image signal.

Therefore, the optical information recording medium 100 having the transparent code area 7 can be read by using only visible light, so that the code reading device 11 can be constructed at a lower cost than conventional ones.

Further, the LEDs 13 and 14 are arranged in such a positional relationship that the light emitted from the LEDs 13 and 14 is regularly reflected by the information recording surface of the optical information recording medium 100 so that the reflected light is not received by the light receiving sensor 20. The information recorded in the code 4 and the information recorded in the transparent code area 7 can be accurately read by one light receiving sensor 20, respectively.

(Second Embodiment) FIGS. 9 to 12 show a second embodiment of the present invention, in which the same parts as those in the first embodiment are designated by the same reference numerals and their description is omitted. Only the part will be described. Information code 41 in the second embodiment
9 is basically the same as in the first embodiment, the transparent code area 42 is formed by printing and arranging the transparent cells 6 by the peripheral transparent reflection layer 3 of the QR code 4, but FIG.
As shown in (a), a part of the transparent code area 42 is QR.
It is arranged so as to overlap with code 4.

That is, as shown in FIG. 9B, the transparent cell 6 whose hatching direction is opposite to that shown in FIG. 1B is transparent on the black cell 2. Cell 6
It is shown that they are printed on top of each other. In addition, there is a part where the transparent cell 6 is arranged even for the bright cell 8 in the area of the QR code 4. The information code 41 printed on the sheet 1 constitutes the optical information recording medium 101.

Next, a method of reading the information code 41 will be described with reference to FIG. In the information code 41, a part of the transparent code area 42 overlaps with the QR code 4, but the overlapping part is of course the black cell 2
The bright cells 8 are visible. Therefore, information code 4
The information of the QR code 4 similar to that in the first embodiment can be read by irradiating the incident light that is substantially perpendicular to 1 and receiving the diffused reflected light (see FIG. 10A).

If the information code 41 is irradiated with light obliquely incident, strong specular reflection occurs in the transparent cell 6, and in this case, the portion where the black cell 2 and the transparent cell 6 overlap is transparent. Recognized as cell 6 (Fig. 10)
(See (b)). Therefore, if the gray-valued image data received at this time is binarized by the threshold value H, the transparent cell 6
Since the position of the transparent cell 6 can be discriminated, the transparent cell 6 is represented as “white” as shown in FIG. That is, in this case, the information recorded in the transparent code area 42 can be read.

Further, the regular reflection light reception data is binarized by the threshold value L, as shown in FIG. At this time,
Since the portion where the black cell 2 and the transparent cell 6 overlap (duplication code) is recognized as the transparent cell 6, FIG.
It becomes possible to read a part of the data read as shown in (a) in a modulated format. Therefore, in this case, the data can be read in the three modes shown in FIGS. 10A, 10C, and 10D.

FIG. 11 shows a procedure for generating the information code 41. Steps C1 to C5 are exactly the same as steps A1 to A5 in the first embodiment. Then, in the following step C6, first, the print pattern of the visible code area (QR code 4) is output to the printing device for printing, and in the following step C7, the transparent code area 42 is printed.
The print pattern is output to the printing device and printed.

The information code 41 can be read by the procedure shown in FIG. 7 by using the code reading device 11 in the first embodiment, but it is read by the same device 11 by the procedure shown in FIG. You can also

That is, first, the illumination light source (LE for diffuse reflection is used.
By illuminating only D13, 14) (step B0) and executing steps B1 to B7, only the information of the QR code 4 portion is read and decoded. In this case, the data stored in the memory 24 in step B1 corresponds to the first image signal.

Next, an illumination light source for regular reflection (LED 15 to
Only 18) is turned on (step B12), the information in the transparent code area 42 is read (step B13), and steps B8 to B11 are executed and decoded. In this case, the data stored in the memory 24 in step B13 corresponds to the second image signal.

The processing up to this point corresponds to the processing of reading the information stored in the QR code 4 and the information stored in the transparent code area 42, respectively, as in the first embodiment. That is, it is the reading of the information shown in FIGS. 10A and 10C, and the process related to the reading of the information shown in FIG.

The CPU 26 performs the same processing as in step B2 on the second image signal stored in the memory 24 in step B13, determines the lightness or darkness by the threshold L (first threshold) of the visible code area, and outputs the binary value. It is converted into image data and stored in a predetermined area of the memory 24. Then, from the binarized data, the lightness and darkness are determined in the same manner as in step B6 to determine the code arrangement. Here, the code is determined as shown in FIG.

Then, the duplicate code area is detected based on the result of the step B6 (step B14). Here, the “overlapping code area” means the black cell 2 and the transparent cell 6.
This is an area in which duplicate codes are placed, where and overlap. Next, decoding is performed based on the detected duplicate code area (step B15).

For the decoding in step B15, for example, as shown in FIG. 10 (d), with respect to a part of the data of the QR code 4 decoded in step B7, the black cell 2 which is the duplicate code and the light cell 8 are duplicated. Therefore, the information originally recorded as the QR code 4 is modulated and decoded.

Alternatively, since the position of the transparent code area 42 is clear, if the transparent cell 6 serving as a duplicate code is regarded as a non-transparent cell (that is, a dark cell) and decoded, it is originally recorded as the transparent code area 42. The information that has been recorded is modulated and decoded. Any of these may be performed.

As described above, according to the second embodiment, in the optical information recording medium 101, a part of the transparent code area 42 is Q.
Since it is arranged so as to overlap with the R code 4, it is possible to separately record information in the overlapping portion. Therefore, the information recording density can be further improved.

Further, according to the second embodiment, the CPU 26 of the code reading device 11 has the threshold value L for the second image signal.
When the lightness / darkness is discriminated based on, the overlapping code area is detected based on the portion where the lightness / darkness of the black cell 2 arranged in the QR code 4 is inverted, and based on the detected overlapping code area, the QR code 4 or the transparent code area is detected. The information recorded in any of the code areas 42 is modulated and decoded. Therefore, when the optical information recording medium 101 is configured to include the duplicate code area, decoding can be performed based on the information recorded in the duplicate code area.

(Third Embodiment) FIGS. 13 and 14 show a third embodiment of the present invention. In the third embodiment, the light emitting / receiving unit 12 in the code reading device 11 is replaced by the light emitting / receiving unit 43.
The code reading device 44 is configured by replacing Note that FIG. 13 shows only the light emitting / receiving unit 43 portion.

Projector / Receiver 1 in Code Reader 11
LED 13 to 18 and the light receiving sensor 20 constituting
Are arranged in parallel above the information code 5A. On the other hand, in the code reading device 44, the light emitting / receiving unit 43 has a light emitting unit 43T and a light receiving unit 43R separated from each other.

Then, the LED 4 constituting the light projecting section 43T
5 and the diffusing plate 46 are arranged in a state of being inclined at an upper left position in FIG. 13 of the information code 5A.
The light receiving sensor 47 forming the 3R is arranged in a state of being inclined obliquely to the upper right. Further, the optical axis of the light projecting section 43T and the optical axis of the light receiving section 43R are arranged in a symmetrical positional relationship with respect to the normal line of the information code 5A on the information recording surface.

Therefore, the light projected by the LED 45 is transmitted by the diffusion plate 4.
Since the light is diffused by 6 to become a surface light source and is incident on the information code 5A from an oblique direction, the light receiving sensor 47 receives strong regular reflection light. The above constitutes the code reading device 44.

In this case, the light-receiving image of the light-receiving sensor 47 of the information code 5A is distorted and formed due to the inclination of the light-transmitting and light-receiving axes. Therefore, in order to deal with it, the information code 5A is printed in a shape corrected in advance (FIG. 14).
(See (a)). With this configuration, the light-receiving image on the light-receiving sensor 47 is the same as that seen from the front (FIG. 14).
(See (b)).

As described above, according to the third embodiment, the LED 45 (and the diffusing plate 46) which constitutes the code reading device 48.
Is arranged so that the light emitted from itself is specularly reflected by the information recording surface of the optical information recording medium 100A and the diffused and reflected light is received by the light receiving sensor 47. Therefore, the QR code 4 It is possible to read both the information recorded in 1) and the information recorded in the transparent code area 7 by a common optical system by reflecting visible light.

Therefore, when the optical information recording medium 100A is read, as compared with the code reading device 11 in the first embodiment, it is recorded in each area without the need for severe alignment during reading. Since all the existing information can be read by the specular reflection light, the user can easily read the information. In addition, the degree of freedom in creating the information code increases.

Further, since the optical axis of the illumination light source is arranged at a position symmetrical with the optical axis of the light receiving sensor 47 with respect to the normal line standing on the information recording surface of the optical information recording medium 100A, the information recording surface The light specularly reflected by is reliably received by the light receiving sensor 47.

(Fourth Embodiment) FIGS. 15 and 16 show a fourth embodiment of the present invention. The fourth embodiment adjusts the reflectance of the transparent cell when a pattern or the like is printed on the paper 48 on which the information code is printed and there is a ground color (colors other than white and black in this case). That is, FIG. 15 (a)
In the figure, the portion where the transparent cell (transparent display unit) 49 is printed and arranged is shown by hatching.

Then, in FIG. 15B, the sheet 4
The eight background colors are represented by arranging circles hatched in three different directions in correspondence with the dots of the three primary colors of RGB. A frame surrounded by a solid line in FIG. 15B is a transparent cell 49.

On the other hand, in the transparent cell (transparent display unit) 50 shown in FIG. 16, 16 small circular transparent reflection layers 51 are arranged in a matrix in the cell 50 ((b)).
Since the outer frame size is the same as that of the transparent cell 49, the reflectance of the transparent cell 50 is smaller than that of the transparent cell 49. In this way, the average reflectance of the transparent cell 50 can be set to a desired value. still,
FIG. 16A does not reflect the actual arrangement of the transparent reflection layer 51, but illustrates it conceptually.

That is, if the reflectance of the transparent cell is too high, a phenomenon similar to halation in a photograph occurs, and the QR code 4 which utilizes diffuse reflection having a smaller amount of reflected light than regular reflection.
This is because it may be difficult to read

In this case, since the dot diameter of the transparent reflection layer 51 can be reduced to about 0.01 to 0.05 mm, the dot diameter and the interval between the dots can be determined by the code reader 11 (or 44). It is better to make it sufficiently smaller than the resolution. With such a configuration, the code reading device 11 side does not individually recognize the transparent reflection layer 51, so that the reflected light of the transparent cell 50 is captured as a surface light source.

As described above, according to the fourth embodiment, the outer diameter and the interval of the transparent reflection layer 51 are made smaller than the outer diameter of the transparent cell 50 so that the transparent reflection layer 51 occupies the inside of the transparent cell 50. Since the average reflectance of the transparent cell 50 is adjusted accordingly, the contrast between the transparent cell 50 and the QR code 4 can be adjusted to be appropriate, and the QR code 4 can be read well. Like

Since the size and interval of the transparent reflective layer 51 are smaller than the resolution of the code reading device 11,
The code reading device 11 captures the reflective surface of the transparent cell 50 planarly, and can stably receive the reflected light of the transparent cell 50. Even if the background color of the paper is white,
The reflectance of the transparent cell 50 can be adjusted similarly.

(Fifth Embodiment) FIG. 17 shows a fifth embodiment of the present invention. The fifth embodiment is characterized by the arrangement of the error check code associated with the information code. FIG. 17 conceptually shows the arrangement of the check codes, in which the error check codes 52E and 53E are arranged in the visible code area 52 and the transparent code area 53 like the QR code 4. is there.
The check code used for QR code 4 is
It is a Reed-Solomon code capable of error correction. Further, FIG. 17 does not represent the actual arrangement form, but conceptually shows the arrangement form.

According to this structure, the visible code area 52 and the transparent code area 53 can be read independently, so that the conventional reading device that does not support the reading of the transparent code area 53 according to the present invention. Even if there is, only the visible code area 52 can be read.

(Sixth Embodiment) FIG. 18 shows a sixth embodiment of the present invention. The sixth embodiment is slightly different from the fifth embodiment in that the visible code area 52 and the transparent code area 53 are different from each other.
Both check code codes 52E and 53E are collectively arranged on the visible code area 52 side.

According to this structure, when only the visible code area 52 is read by the conventional reading device which is not compatible with the reading of the transparent code area 53, the check code 5
Since 3E will cause a read error,
It cannot be read. Therefore, information security can be improved. Of course, the check code may be arranged only in the transparent code area.

(Seventh Embodiment) FIG. 19 shows a seventh embodiment of the present invention. The seventh embodiment shows an example in which a code other than the QR code 4 is used as the visible code area. That is, as a visible code area, FIG. 19A shows a data matrix 54, and FIG. 19B shows a barcode (JA).
N) 55 and FIG. 19C show examples using PDF417 and 56, respectively. Then, outside the respective visible code areas, transparent code areas 57, 58 and 59 are added respectively to form information codes 60, 61 and 62.
Needless to say, these may be arranged such that the visible code area and the transparent code area partially overlap each other as in the second embodiment.

The present invention is not limited to the embodiments described above and shown in the drawings, and the following modifications or expansions are possible. The format of information recorded in the visible code area is not limited to the micro QR code 4,
Any optically readable code such as a QR code, Maxicode, or stacked barcode type two-dimensional code may be used. The specific pattern may be arranged in the transparent code area. The visible code area and the transparent code area may be arranged in other manners, for example, so that the QR code 4 and the transparent code area 7 are concentric as in the first embodiment (the geometric centers of both are It does not have to be arranged (to match).

Further, the two may be arranged vertically or horizontally. At that time, as shown in the first embodiment, both regions may be arranged adjacent to each other or may be arranged so as to have a predetermined interval. Regarding the method of detecting the duplicate code area, the decoder may be configured to detect the overlapping portion as the duplicate code area based on the positions of the visible code area and the transparent code area. That is, if the arrangement relationship between the visible code area and the transparent code area is known, the portion where these two areas are set to overlap can be detected as the overlapping code area. In the fourth embodiment, a transparent cell (bright display unit, dark display unit) having a relative area difference of the transparent reflection layer 51 may be provided in the transparent code region. That is,
Since it is possible to give a difference to the reflectance of the transparent cell depending on the area ratio of the transparent reflection layer 51, it is possible to give a difference to the information read according to the difference. Therefore, it is possible to further increase the amount of information to be recorded.

The code reading devices 11 and 44 are replaced with the error check codes 52E and 53 in the fifth or sixth embodiment.
E may be read and decoded, and error detection or error correction of information reading may be performed. The error check code may be arranged only for one of the visible code area and the transparent code area.

[Brief description of drawings]

FIG. 1 is a first example of the present invention and is a diagram showing an example of the configuration of an information code in which a transparent code area is added to a QR code.

FIG. 2A is a reflection state when visible light incident perpendicularly to an information recording surface of a recording medium is irradiated, and FIG. 2B is incident on the information recording surface with an inclination of about 45 degrees. Diagram showing the reflection state when irradiating visible light

FIG. 3 is a diagram showing a light reception level of light reflected by each part of a recording medium.

FIG. 4 is a diagram illustrating a procedure for generating an information code.

FIG. 5 is a functional block diagram showing an electrical configuration of a code reading device for reading an information code.

FIG. 6 is a diagram showing a configuration of an optical system centered on a light emitting / receiving unit.

FIG. 7 is a flowchart showing the control contents mainly performed by the CPU of the code reading device.

FIG. 8 is a diagram showing a state in which a visible code is actually printed and a transparent code area is provided with a slight margin.

FIG. 9 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 10 shows a reading state of an information code,
(A) is a reflection state when irradiating incident light that is almost perpendicular to the information code, (b) is a reflection state when irradiating obliquely incident light, and (c) is received for (b). The figure which shows the state which binarized the image signal by the threshold value H, (d) shows the state which binarized the image signal received in (b) by the threshold value L.

FIG. 11 is a view corresponding to FIG.

FIG. 12 is a view corresponding to FIG. 7.

FIG. 13 is a view corresponding to FIG. 6 showing a third embodiment of the present invention.

FIG. 14B is a diagram showing an information code whose shape is corrected, and FIG. 14A is a diagram showing an image of the information code formed on the light receiving sensor of the code reading device.

FIG. 15 is a fourth embodiment of the present invention, showing a state in which transparent cells similar to those of the first embodiment are printed on a paper having a background color, and (b) is a part of (a) enlarged. Shown as

FIG. 16 is a diagram corresponding to FIG. 15 showing a case where small transparent reflection layers are printed in a matrix on a sheet having a background color by printing to form transparent cells.

FIG. 17 is a diagram showing a layout of error check codes accompanying an information code according to a fifth embodiment of the present invention.

FIG. 18 is a view corresponding to FIG. 17, showing a sixth embodiment of the present invention.

FIG. 19 is a diagram showing a seventh embodiment of the present invention, in which (a) is a data matrix, (b) is a bar code, and (c) is an example using PDF417 as visible code areas.

[Explanation of symbols]

2 is a black cell (visible display unit), 3 is a transparent reflective layer, 4 is Q
R code (visible code area), 4S is a specific pattern, 5
Is an information code, 6 is a transparent cell (transparent display unit), 7 is a transparent code area, 8 is a bright cell (visible display unit), 13 to 1
8 is an LED (light source for illumination), 20 is a light receiving sensor, 26 is a CPU (decoder), 41 is an information code, 42 is a transparent code area, 44 is a code reading device, 45 is an LED (light source for illumination), and 47 is light receiving. Sensors, 49 and 50 are transparent cells (transparent display units), 51 is a transparent reflection layer, 52 is a visible code area, 53 is a transparent code area, 52E and 53E are error check codes, 54 is a data matrix (visible code area), 55 is a barcode (visible code area), 56
Is a PDF417 (visible code area), 57 to 59 are transparent code areas, 60 to 62 are information codes, 100, 100
Reference numerals A and 101 denote optical information recording media.

Claims (20)

[Claims] 1. A transparent display unit, which is substantially transparent to visible light and includes a transparent reflective layer that includes a transparent reflective layer that specularly reflects visible light, in which optically readable information is recorded. A code area, a visible code area having optical characteristics different from those of the transparent display unit, including a visually recognizable visible display unit, and having optically readable information recorded therein; An optical information recording medium, which is arranged in at least one of a code area and a visible code area, and is provided with a reference position for reading and a specific pattern indicating the size of the display unit. 2. An outer shape of the transparent reflective layer is configured to be smaller than an outer shape of a transparent display unit included in the transparent code area, and the transparent display unit includes the transparent reflective layer within the area. The optical information recording medium according to claim 1, wherein the reflectance of visible light is adjusted by the ratio of the area occupied by the area. 3. The size and interval of the transparent reflection layer forming the transparent pattern formed on the light receiving sensor of the reading device for reading information is configured to be smaller than the resolution of the reading device. The optical information recording medium according to claim 2, characterized in that: 4. The transparent code region is composed of a bright display unit having a relatively large area of the transparent reflection layer and a dark display unit having a relatively small area of the transparent reflection layer. The optical information recording medium according to claim 2 or 3. 5. The visible code area is composed of a bright display unit having a relatively large diffuse reflectance and a dark display unit having a relatively small diffuse reflectance. An optical information recording medium according to any one of the above. 6. The optical information recording medium according to claim 1, wherein the transparent code area and the visible code area are arranged adjacent to each other. 7. The transparent code area and the visible code area are arranged such that the geometric center of any one of them is located inside the other area. Optical information recording medium. 8. The optical information recording medium according to claim 7, wherein one of the transparent code area and the visible code area is arranged so as to surround the outer peripheral side of the other area. . 9. The optical information recording medium according to claim 8, wherein the transparent code area and the visible code area are concentrically arranged. 10. The optical information recording medium according to claim 9, wherein the transparent code area is arranged outside the visible code area. 11. A check code for checking whether the information is correct or not when information recorded in at least one of the transparent code area and the visible code area is read. The optical information recording medium according to any one of claims 1 to 10, wherein the optical information recording medium is arranged. 12. An optical information reading device comprising an illumination light source, a light receiving sensor, and a decoder, and optically reading information recorded on the optical information recording medium according to claim 1. In the device, the illumination light source receives the reflected light in which light emitted by itself is specularly reflected by the information recording surface of the optical information recording medium, and the reflected light diffusely reflected by the information recording surface. The light receiving sensor is arranged so as to receive light, and the light receiving sensor outputs an image signal according to the amount of reflected light received to the decoder, and the decoder refers to the image signal to determine the brightness of diffusely reflected light. A transparent table arranged in the transparent code area based on a second threshold for judging the lightness of the visible display unit arranged in the visible code area based on a first threshold value for judging the lightness of regular reflection light. An optical information reading device characterized by determining the lightness and darkness of a display unit and decoding the information recorded in each area. 13. The optical axis of the illumination light source is arranged at a position symmetrical to the optical axis of the light receiving sensor with respect to a normal line standing on the information recording surface of the optical information recording medium. 13. The optical information reading device according to claim 12, which is characterized in that. 14. An optical information reading device which comprises an illumination light source, a light receiving sensor, and a decoder, and optically reads information recorded on the optical information recording medium according to any one of claims 1 to 11. In the device, the illumination light source is arranged such that the light emitted by itself is diffused and regularly reflected by the information recording surface of the optical information recording medium, and is reflected by the light receiving sensor. The decoder determines the lightness / darkness of a visible display unit arranged in the visible code area based on a first threshold value for determining the lightness / darkness of diffused reflection light, and the second threshold value for determining the lightness / darkness of specular reflection light. An optical information reading device, characterized in that it is configured to determine the brightness of a transparent display unit arranged in a transparent code area and decode the information recorded in each area. 15. The illumination light source is configured such that, of the reflected light in which the light emitted from the illumination light source is diffusely reflected and specularly reflected by the information recording surface of the optical information recording medium, only the diffusely reflected light is received by the light receiving sensor. And the first illumination light source arranged as described above, and the light emitted from itself is diffused and specularly reflected by the information recording surface of the optical information recording medium, and is received by the light receiving sensor. And the second light source for illumination arranged in such a manner that the light receiving sensor receives the diffusely reflected light and the specularly reflected light and outputs an image signal according to the received reflected light amount to the decoder. The decoder may be configured to refer to the image signal to determine the lightness of a visible display unit arranged in the visible code area based on a first threshold value that determines the lightness of diffused reflection light. By referring to the image signal, the lightness / darkness of the transparent display unit arranged in the transparent code area is determined based on the second threshold value for determining the lightness / darkness of specular reflection light, and recorded in each area. 15. The optical information reader according to claim 14, wherein the optical information reader is configured to decode existing information. 16. The first illumination arranged so that the light source for illumination diffuses the light emitted from itself by the information recording surface of the optical information recording medium and is received by the light receiving sensor. Light source, and a second illumination light source arranged such that the light emitted by itself is specularly reflected by the information recording surface of the optical information recording medium and is received by the light receiving sensor. The light receiving sensor receives the diffusely reflected light, outputs a first image signal corresponding to the received reflected light amount to the decoder, and receives the specularly reflected light according to the received reflected light amount. It is configured to output a second image signal to the decoder, and the decoder refers to the first image signal to determine the visible code region based on a first threshold value that determines whether the diffuse reflection light is dark or light. Distributed to By determining the brightness of the visible display unit, and by referring to the second image signal, the transparent display unit of the transparent display unit arranged in the transparent code area based on the second threshold for determining the brightness of specular reflection light. 15. The optical information reading device according to claim 14, wherein the optical information reading device is configured to determine the lightness and darkness and decode the information recorded in each area. 17. The decoder detects a portion where the visible code area and the transparent code area overlap each other as a duplicate code area based on the positions of the visible code area and the transparent code area, and based on the duplicate code area, the visible code area. 17. The optical information reading device according to claim 12, wherein the optical information reading device is configured to modulate and decode information recorded in any of the transparent code areas. 18. The decoder, in the case where the lightness and darkness of the second image signal are discriminated based on the first threshold value, a portion in which the lightness and darkness of a visible display unit arranged in the visible code region is reversed. A redundant code area is detected based on the redundant code area, and information recorded in either the visible code area or the transparent code area is modulated and decoded based on the redundant code area. The optical information reader according to claim 16. 19. The first illumination light source is arranged such that the light emitted by itself is specularly reflected by the information recording surface of the optical information recording medium and is not received by the light receiving sensor. The optical information reading device according to any one of claims 16 to 18, characterized in that. 20. When the read information includes a check code for checking the correctness of the information, the decoder has a function of determining the correctness of the read information based on the check code. 20. The optical information reading device according to claim 12, wherein the optical information reading device is provided.