JP2007304707A - Information code reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information code reader capable of reading an information code displayed on a liquid crystal, without being influenced by a dot pattern. <P>SOLUTION: A reflecting mirror 22 is vibrated by a piezoelectric actuator 26, and an image of the dot pattern formed as an image in an area sensor 30 is blurred by being displaced, and the information code displayed on the liquid crystal can be read without being influenced by the dot pattern. Here, the image of the dot pattern formed as an image in the area sensor 30 is blurred by vibrating the reflecting mirror 22 in a frequency of 1/F or more to exposure time F of the area sensor 30. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to an information code reader for reading two-dimensional optical information such as a QR code (registered trademark) displayed on a mobile phone or the like.

At present, as a new usage form of optical information, a QR code (registered trademark) is displayed on a mobile phone and read by a stationary scanner. For example, it is used in such a manner that a QR code is distributed to a mobile phone, and a QR code displayed on the mobile phone is read with a scanner to replace a ticket at a concert venue. Patent Documents 1 and 2 disclose optical devices that cause a mirror to vibrate with an actuator.

13A and 13B are explanatory views showing an enlarged liquid crystal surface. The liquid crystal screen is displayed in black and white in each of the openings O surrounded by the grid-like dot pattern D. 13A shows a liquid crystal surface with a high aperture ratio (for example, 70%), and FIG. 13B shows a liquid crystal surface with a low aperture ratio (for example, 30%). In the case of the high aperture ratio (70%) shown in FIG. 13A, when the dot size (DW) is 0.165 mm, the size (DB) of the non-opening portion of the dot is 0.027 mm. In the case of the low aperture ratio (30%) shown in FIG. 13B, the same dot size (DW) as that of the high aperture ratio is 0.165 mm, and the dimension (DB) of the non-opening portion is 0.076 mm.
JP 2003-29191 A JP-A-8-327927

When an information code reader tries to read a QR code displayed on the liquid crystal surface, it may be difficult to read due to the influence of the liquid crystal dot pattern. In particular, as shown in FIG. 13B, in the case of a low aperture ratio (30%), the dimension (DB) of the non-opening portion becomes relatively larger than the dot dimension (DW), and the low aperture ratio is low. It becomes difficult to distinguish between black and white of the QR code displayed in the opening O of the liquid crystal surface. Here, it is possible to make the dot pattern inconspicuous by processing on the software, but if the software processing is performed, the reading time becomes long.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an information code reader capable of reading an information code displayed on a liquid crystal without being affected by a dot pattern. There is.

In order to achieve the above object, the invention of claim 1 is an information code reader for reading an information code displayed on a liquid crystal,
A mirror 22 for reflecting light from the liquid crystal surface;
An area sensor 30 for receiving the light reflected by the mirror 22;
An imaging lens 32 for imaging the light reflected by the mirror 22 on the area sensor;
It is a technical feature that it includes image adjusting means 26, 60, 64 for blurring an image formed on the area sensor 32.

In the information code reading apparatus according to claim 1, since the imaging adjustment means blurs the image formed on the area sensor, the dot pattern is blurred, and the information code displayed on the liquid crystal is read without being affected by the dot pattern. Can do.

In the information code reader according to the second aspect, the mirror is vibrated at a frequency of 1 / F or more with respect to the exposure time F of the area sensor by the actuator. The dot pattern image formed on the area sensor is blurred, and the information code displayed on the liquid crystal can be read without being affected by the dot pattern.

In the information code reader according to claim 3, when the vibration amplitude of the mirror is a dimension DB of a non-opening portion of one dot of liquid crystal and an emission angle θ from the mirror to the imaging lens side, 2 × DB × sigθ or more By setting to, the liquid crystal surface is moved by the image of the area sensor at least twice the dimension DB of the non-opening. Therefore, it is possible to blur the dot pattern image formed on the area sensor and read the information code displayed on the liquid crystal without being affected by the dot pattern.

In the information code reading apparatus according to the fourth aspect, the actuator is composed of a plurality of piezoelectric actuators, and the plurality of piezoelectric actuators are vibrated at the same time, so that the vibration operation can be stably performed.

In the information code reader according to claim 5, since the actuator starts to vibrate when the liquid crystal is detected, the actuator is vibrated only when the information code displayed on the liquid crystal is read, thereby reducing power consumption and deterioration of the actuator. Can be prevented.

According to the information code reading device of the sixth aspect, the dot pattern image formed on the area sensor is blurred by moving the imaging lens by the actuator. For this reason, the information code displayed on the liquid crystal can be read without being influenced by the dot pattern.

According to the seventh aspect of the invention, since the image adjustment means blurs the image when the liquid crystal is detected, the image can be read quickly without being blurred when reading other than the liquid crystal.

According to the eighth aspect, since the image is blurred when the information code cannot be read, the information code that cannot be read due to the influence of the dot pattern can be read.

In claim 9, the image formed on the area sensor is blurred by a polished glass plate or a diffusing film provided between the mirror and the imaging lens, so that the dot pattern is blurred, and the liquid crystal is not affected by the dot pattern. The information code displayed on the screen can be read.

[First embodiment]
Embodiments of an information code reader according to the present invention will be described below with reference to the drawings. First, an outline of the configuration of the information code reader 10 according to the first embodiment will be described with reference to FIG. FIG. 1A is a plan view of the information code reading device 10 of the first embodiment, FIG. 1B is a view taken in the direction of arrow b in FIG. 1A, and FIG. It is c arrow line view of (A).
As shown in FIG. 1A, an information code reader 10 includes a housing 12 having a substantially rectangular box shape, and an information code such as a QR code displayed on a display of a mobile phone is displayed on the upper surface of the housing 12. A reading window 14 for reading and a detection sensor 16 including a proximity sensor for detecting a mobile phone are provided. A resin plate 14G is fitted in the reading window 14. As shown in FIG. 1A and FIG. 1B, a light guide plate 18 serving as a surface light source that emits white light to a display device of a mobile phone and light from the light guide plate 18 are disposed in the housing 12. Includes a reflecting device 20 for further reflecting the reflected light reflected on the display of the mobile phone, an imaging lens 32 for collecting the light reflected by the reflecting device 20, and an area sensor 30 comprising a CCD.

2A is a perspective view of the reflection device 20, and FIG. 2B is a side view. The reflecting device 20 includes a reflecting mirror 22, a reflecting mirror attaching resin 24, a piezoelectric actuator 26 made of a piezoelectric element for vibrating the reflecting mirror 22, and a fixing member 28 for fixing the piezoelectric actuator 26. The piezoelectric actuator 26 extends in the axial direction and vibrates the reflecting mirror 22 in the direction perpendicular to the surface.

FIG. 3 is a block diagram illustrating a circuit configuration of the information code reader according to the first embodiment.
The information code reader 10 includes an AD conversion unit 40 that performs A / D conversion on an output signal from the area sensor 30, a signal interface 44 that performs signal interface, and a control interface 46 that performs control interface. A main circuit 42 that performs decoding and control, and a buzzer 54. A signal interface 44 and a control interface 46 are connected to a host device 50 such as a personal computer or a POS terminal via a general-purpose communication interface IF including a LAN. When detecting the mobile phone, the detection sensor 16 outputs a detection signal to the control interface 46 side. The control interface 46 controls the piezoelectric actuator 26 to vibrate the reflecting mirror 22.

The information code reader 10 reads the QR code displayed on the display of the mobile phone by placing the mobile phone with the display facing downward on the reading window 14 shown in FIG. That is, the irradiation light from the light guide plate 18 illuminates the QR code displayed on the display 52 of the mobile phone. The diffuse reflection component reflected by the QR code of the specularly reflecting display 52 enters the housing 12 again, is reflected by the reflecting mirror 22 of the reflecting device 20 and enters the imaging lens 32, and the light receiving elements are in a matrix form. The QR code image is formed on the area sensors 30 arranged in the same manner. The area sensor 30 that has read and read this QR code image by photoelectric conversion outputs it to the AD conversion unit 40 as an electrical signal representing the image pattern. The main circuit 42 decodes (decodes) read data of the QR code from the signal AD-converted by the AD conversion unit 40, and obtains information represented by the QR code. Here, when the decoding of the QR code is successful, the main circuit 42 sounds the buzzer 54 and transmits the decoding result to the host device 50.

FIG. 2C is an explanatory diagram of the area sensor 30, the imaging lens 32, the reflecting mirror 22, and the best focus point BP. The reflecting mirror 22 is arranged so that the best focus point BP matches the display 52 of the mobile phone depending on the positional relationship between the area sensor 30 and the imaging lens 32.

FIG. 4 is an explanatory diagram for explaining the amount of image shake at the area sensor 30 caused by vibrating the reflecting mirror 22.
Here, in the information code reader 10 of the first embodiment, the size (DB) of the non-opening portion of the liquid crystal having the low aperture ratio (30%) described above with reference to FIG. Shake the image for more than a minute. That is, when the dimension DB of the non-opening portion of one dot of the liquid crystal and the exit angle θ from the mirror to the imaging lens side are set, the vibration amplitude BW of the reflecting mirror 22 is set to 2 × DB × sigθ or more, The reflecting mirror 22 is vibrated by the piezoelectric actuator 26 by at least twice the dimension DB of the non-opening, and the liquid crystal surface is moved on the image of the area sensor 30. The dot pattern image formed on the area sensor 30 is displaced by 2 × DB or more so that the information code displayed on the liquid crystal can be read without being affected by the dot pattern.

Next, the QR code reading process displayed on the display 52 of the mobile phone by the information code reading device 10 of the first embodiment will be described with reference to FIG.
The information code reader 10 detects a mobile phone by the detection sensor 16. Here, when the mobile phone is detected (S12: Yes), the reflection mirror 22 starts to vibrate (S14). Then, the QR code is imaged and read (S16), and the read QR code is decoded (S18). Here, until the decoding is successful (S20: No), the process returns to S16 to continue reading and decoding the QR code. On the other hand, if the decoding is successful (S20: Yes), the decoding result is output to the host device 50 (S22), and the vibration of the reflecting mirror 22 is terminated (S24).

In the first embodiment, the reflecting mirror 22 is vibrated at a frequency of 1 / F or more with respect to the exposure time F of the area sensor 30. Thereby, the image of the dot pattern formed on the area sensor 30 is blurred, and the information code displayed on the liquid crystal can be read without being affected by the dot pattern.

Further, in the first embodiment, since vibration starts when a mobile phone is detected, vibration is performed only when the QR code displayed on the liquid crystal is read, thereby reducing power consumption and preventing deterioration of the piezoelectric actuator 26. be able to.

[First Modification of First Embodiment]
Hereinafter, an information code reading device 10 according to a first modification of the first embodiment will be described with reference to FIGS. 6 and 7.
FIG. 6A is a perspective view of a reflecting device according to a first modification of the first embodiment, and FIG. 6B is a side view. In the first embodiment described above with reference to FIG. 2A, the reflecting device 20 vibrates the reflecting mirror 22 by one piezoelectric actuator 26. On the other hand, in the first modification of the first embodiment, the reflecting device 20 causes the three piezoelectric actuators 26 to synchronize and simultaneously vibrate the reflecting mirror 22. In the information code reading device 10 according to the first modification of the first embodiment, the plurality of piezoelectric actuators 26 are vibrated simultaneously, so that the vibration operation can be stably performed.

With reference to FIG. 7, the QR code reading process displayed on the display 52 of the mobile phone by the information code reading device 10 according to the first modification of the first embodiment will be described.
In the first embodiment described above with reference to FIG. 5, when the information code reader 10 detects a mobile phone, the reflection mirror 22 starts to vibrate. On the other hand, in the first modification of the first embodiment, reading of the QR code is attempted, and when the decoding cannot be performed, the reflection mirror 22 starts to vibrate.

The information code reader 10 detects a mobile phone by the detection sensor 16. When a mobile phone is detected (S12: Yes), the QR code is imaged and read (S16), and the read QR code is decoded (S18). If the decoding is successful (S20: Yes), the decoding result is output to the higher-level device 50 (S22), and the process is terminated. On the other hand, if decoding fails (S20: No), the mirror 22 starts to vibrate (S14). Then, the QR code is imaged and read (S36), and the read QR code is decoded (S38). If decoding fails (S40: No), the process returns to S36, and QR code reading and decoding continue. On the other hand, if the decoding is successful (S40: Yes), the vibration of the reflecting mirror 22 is finished (S24), and then the decoding result is output to the host device 50 (S22).

In the information code reader 10 according to the first modification of the first embodiment, the piezoelectric actuator 26 is vibrated to blur the image of the area sensor 30 when the read QR code cannot be read. The QR code displayed on the liquid crystal surface having a high aperture ratio that is not greatly affected by the dot pattern shown in FIG. 5 or the QR code printed on a product, a sticker, or the like can be read quickly without blurring the image. On the other hand, in FIG. 13B, an information code that cannot be read due to the influence of a dot pattern on a liquid crystal surface with a low aperture ratio can be read reliably.

[Second modification of the first embodiment]
The information code reading device 10 according to the second modification of the first embodiment will be described below with reference to FIG.
In the first embodiment and the first modification of the first embodiment described above, reading is started when the information code reader 10 detects a mobile phone. On the other hand, in the second modification of the first embodiment, reading is always performed, and when the decoding is impossible, it is determined whether the QR code on the liquid crystal surface is being read, and the reflection mirror 22 is vibrated. Start.

The information code reader 10 always captures and reads a QR code (S16), and decodes the read QR code (S18). If the decoding is successful (S20: Yes), the decoding result is output to the higher-level device 50 (S22), and the process is terminated. On the other hand, if decoding fails (S20: No), it is determined whether the liquid crystal surface is obscured by the reading window 14 (see FIG. 1A) by determining whether the black and white in the image has changed (S42). ). When no wrinkle on the liquid crystal surface is detected (S42: No), the process returns to S16 and continues reading. On the other hand, when wrinkles on the liquid crystal surface are detected (S42: Yes), the reflection mirror 22 starts to vibrate (S14). Then, the QR code is imaged and read (S36), and the read QR code is decoded (S38). If decoding fails (S40: No), the process returns to S36, and QR code reading and decoding continue. On the other hand, if the decoding is successful (S40: Yes), the vibration of the reflecting mirror 22 is finished (S24), and then the decoding result is output to the host device 50 (S22).

In the second modification of the first embodiment, the piezoelectric actuator 26 is vibrated to blur the image of the area sensor 30 only when the liquid crystal surface is detected. There is no, and quick reading can be performed.

[Second Embodiment]
Next, an information code reading apparatus according to the second embodiment of the present invention will be described with reference to FIGS. 9A and 9B are side views of the information code reading apparatus 10 according to the second embodiment. FIG. 9A shows the state before the imaging lens 32 is moved, and FIG. It shows after the image lens 32 has moved. In the first embodiment described above, the image of the area sensor 30 is blurred by vibrating the reflecting mirror 22. On the other hand, in the second embodiment, the image formed on the area sensor 30 is moved from the state of FIG. 9A by moving the imaging lens 32 by the solenoid 60 as shown in FIG. 9B. Blur.

FIG. 10 is a block diagram illustrating a circuit configuration of the information code reader according to the second embodiment.
The information code reader 10 of the second embodiment is the same as the configuration of the first embodiment described above with reference to FIG. However, in the second embodiment, a solenoid 60 for moving the imaging lens 32 is provided instead of the piezoelectric actuator.

With reference to FIG. 11, the QR code reading process displayed on the display of the mobile phone by the information code reading device 10 according to the second embodiment will be described. In the second embodiment, an attempt is made to read the QR code, and when the decoding is impossible, the imaging lens 32 is moved to blur the image formed on the area sensor 30.

The information code reader 10 detects a mobile phone by the detection sensor 16. When a mobile phone is detected (S12: Yes), the QR code is imaged and read (S16), and the read QR code is decoded (S18). Here, if the decoding is successful (S20: Yes), the decoding result is output to the higher-level device 50 (S22), and the process is terminated. On the other hand, if the decoding fails (S20: No), the solenoid 60 is driven to shift the focus of the imaging lens 32 as described above with reference to FIG. Blur (S14). Then, the QR code is imaged and read (S36), and the read QR code is decoded (S38). If decoding fails (S40: No), the process returns to S36, and QR code reading and decoding continue. On the other hand, if the decoding is successful (S40: Yes), the solenoid 60 is driven to return the imaging lens 32 to the position shown in FIG. 9A, and the image formed on the area sensor 30 is optimized ( (S24), the decoding result is output to the host device 50 (S22).

In the information code reader 10 of the second embodiment, the image of the dot pattern formed on the area sensor 30 is soft by moving the imaging lens 32 by the solenoid 60. For this reason, the information code displayed on the liquid crystal can be read without being influenced by the dot pattern.

[Third embodiment]
Next, an information code reader according to a third embodiment of the present invention will be described with reference to FIG.
FIG. 12A is a plan view of the information code reader according to the third embodiment, and FIG. 12B is a view taken in the direction of the arrow d in FIG. In the information code reader 10 of the third embodiment, a polished glass plate 64 is provided between the reflecting mirror 22 and the imaging lens 32 so as to blur the image formed on the area sensor 30. For this reason, the dot pattern is blurred, and the information code displayed on the liquid crystal can be read without being affected by the dot pattern. In addition, the various things which can blur an image, such as a diffusion film, can be used instead of a polished glass plate.

FIG. 1A is a plan view of an information code reader according to a first embodiment of the present invention, FIG. 1B is a view taken in the direction of arrow b in FIG. 1A, and FIG. It is c arrow line view of 1 (A). FIG. 2A is a perspective view of the reflecting device, and FIG. 2B is a side view. FIG. 2C is an explanatory diagram of the area sensor, the imaging lens, the reflecting mirror, and the best focus point BP. It is a block diagram which shows the circuit structure of the information code reader of 1st Embodiment. It is explanatory drawing for demonstrating the amount of shaking of the image in an area sensor by vibrating a reflecting mirror. It is a flowchart which shows the reading process by the information code reader which concerns on 1st Embodiment. FIG. 6A is a perspective view of a reflecting device according to a first modification of the first embodiment, and FIG. 6B is a side view. It is a flowchart which shows the reading process by the information code reading apparatus which concerns on the 1st modification of 1st Embodiment. It is a flowchart which shows the reading process by the information code reader which concerns on the 2nd modification of 1st Embodiment. FIGS. 9A and 9B are side views of the information code reader according to the second embodiment. FIG. 9A shows the state before the image forming lens moves, and FIG. 9B shows the image forming lens. Shows after moving. It is a block diagram which shows the circuit structure of the information code reader of 2nd Embodiment. It is a flowchart which shows the reading process by the information code reader which concerns on 2nd Embodiment. FIG. 12A is a plan view of the information code reader according to the third embodiment, and FIG. 12B is a view taken in the direction of the arrow d in FIG. 13A and 13B are explanatory views showing an enlarged liquid crystal surface, FIG. 13A shows a liquid crystal surface with a high aperture ratio, and FIG. 13B shows a low aperture ratio. The liquid crystal surface is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Information code reader 12 Housing 14 Reading window 18 Light guide plate 20 Reflector 22 Reflector (mirror)
26 Piezoelectric actuator (imaging adjustment means: actuator)
30 Area sensor 32 Imaging lens 60 Solenoid (imaging adjustment means: actuator)
64 Polished glass (imaging adjustment means)

Claims (9)

An information code reader for reading an information code displayed on a liquid crystal,
A mirror that reflects light from the liquid crystal surface;
An area sensor that receives light reflected by the mirror;
An imaging lens that focuses the light reflected by the mirror on the area sensor;
An information code reading device comprising: an image adjusting unit that blurs an image formed on the area sensor. 2. The information according to claim 1, wherein the imaging adjustment means is an actuator that vibrates the mirror, and vibrates the mirror at a frequency of 1 / F or more with respect to an exposure time F of the area sensor. Code reader. The vibration amplitude of the mirror by the actuator is 2 × DB × sigθ or more when the dimension DB of the one-dot non-opening portion of the liquid crystal and the exit angle θ from the mirror to the imaging lens side are set. The information code reader according to claim 2. 4. The information code reader according to claim 2, wherein the actuator comprises a plurality of piezoelectric actuators, and the plurality of piezoelectric actuators are vibrated simultaneously. 5. The information code reading device according to claim 2, wherein the actuator starts to vibrate when the liquid crystal is detected. 2. The information code reading apparatus according to claim 1, wherein the imaging adjustment means blurs an image formed on the area sensor by moving the imaging lens by an actuator. 7. The information code reading apparatus according to claim 6, wherein the imaging adjustment means blurs the image when the liquid crystal is detected. 2. The information code reading device according to claim 1, wherein the imaging adjustment means blurs an image when the information code cannot be read. 2. The information code reading device according to claim 1, wherein the imaging adjustment means is a polished glass plate or a diffusion film provided between the mirror and the imaging lens.

Images