JP2023015763A - Information reader - Google Patents

Abstract

To provide a configuration capable of improving a reading performance without providing any movable parts and the like.SOLUTION: An article G to which a radio tag T is attached is housed in a housing space S formed so as to suppress leakage of electric waves by a casing 20, and reading processing for reading information from the radio tag T housed in the housing space S by utilizing antennas 31, 32 disposed in the housing space S is performed by a control part 40. The control part 40 includes: output frequency changing means for changing an output frequency of electric waves outputted from each of the antennas 31, 32; and phase difference changing means for changing a phase difference by changing phase of electric waves outputted from each of the antennas 31, 32.SELECTED DRAWING: Figure 1

Description

The present invention relates to an information reader for reading information from wireless tags attached to articles housed in a housing space.

Conventionally, in order to acquire information about an article housed in a storage space such as a storage box, a wireless tag that records information about the article is attached to the article, and the wireless tag of the article is transmitted through an antenna arranged in the storage box. Many technologies are used to read information from As a technique for reading information from a wireless tag of an article stored in this way, for example, a reading device disclosed in Patent Document 1 below is known. This reading device includes a housing whose inner surface is formed of a radio wave reflecting material and an antenna housed inside the housing. When reading information from an RFID tag attached to a document housed in the housing, By adjusting the distance between the upper and lower surfaces that make up the inner surface of the housing, the influence of the area (null point) where the electric field strength is extremely weak due to the interference of the radio waves reflected inside the housing is suppressed, improving reading performance. is configured to

JP 2018-032087 A

By the way, since the null range changes depending on the storage state of the article, etc., when there are many articles in and out of the storage space, the distance between the surface and the bottom surface of the housing is adjusted as described above to suppress the effect of the null. , it is necessary to adjust the above distance each time an article is put in or taken out. Therefore, in the configuration where a movable part or the like is provided for adjusting the distance as described above, not only does the power consumption required for adjusting the distance increase, but also the manufacturing cost increases in order to ensure durability. There is

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a configuration capable of improving reading performance without providing a movable part or the like.

In order to achieve the above object, the invention described in claim 1 of the scope of claims includes:
An information reader (10) for reading information from a wireless tag (T) attached to an article (G) housed in a housing space (S),
A housing body (21) formed with an opening (21a) through which the article is put in and taken out, and a lid body (22) forming the accommodation space by closing the opening, wherein the accommodation space a housing (20) configured to suppress radio wave leakage from
a plurality of antennas (31, 32) arranged in the accommodation space;
a control unit (40) for reading information from the wireless tag accommodated in the accommodation space using the plurality of antennas;
with
The control unit includes output frequency changing means for changing output frequencies of radio waves respectively output from the plurality of antennas, and phase difference for changing phase differences by changing phases of radio waves respectively output from the plurality of antennas. a means of change;
characterized by comprising
It should be noted that the symbols in parentheses above indicate the corresponding relationship with specific means described in the embodiments to be described later.

In the first aspect of the present invention, an article with a wireless tag is stored in the storage space formed by the housing so as to suppress radio wave leakage, and a plurality of antennas arranged in the storage space are used to store the article in the storage space. A reading process for reading information from the received wireless tag is performed by the control unit. The control unit includes output frequency changing means for changing the output frequencies of the radio waves respectively output from the plurality of antennas, and phase difference changing means for changing the phase difference by changing the phases of the radio waves respectively output from the plurality of antennas. means are provided.

As a result, even if the null range changes each time an article is put in or taken out, the reading result obtained by the reading process can be changed each time the output frequency is changed or the phase difference is changed. By matching, it is possible to reduce reading failures of wireless tags due to the null range. Therefore, it is possible to suppress the influence of nulls and improve reading performance without providing a movable part or the like.

In the invention of claim 2, the output frequency changing means changes the timing of changing the output frequency according to the number of wireless tags accommodated in the accommodation space.

As the number of wireless tags accommodated in the accommodation space increases, it takes more time to read all the wireless tags in the accommodation space. It becomes easy for the radio tag to fail to be read during the above-mentioned fixed interval. On the other hand, if the fixed interval is lengthened, if the number of wireless tags is small, the reading time is lengthened because of the wasteful time after the reading is completed. Therefore, by changing the timing of changing the output frequency according to the number of wireless tags accommodated in the accommodation space, it is possible to shorten the reading time while suppressing omissions in reading.

In the third aspect of the invention, the phase difference changing means changes the timing of changing the phase difference according to the number of wireless tags accommodated in the accommodation space.

If the phase difference is changed at regular intervals, if there are a large number of wireless tags, the wireless tags are likely to be missed during the specified interval. If the number of pages is small, the reading time becomes long due to the wasteful time after the reading is completed. Therefore, by changing the timing of changing the phase difference according to the number of wireless tags accommodated in the accommodation space, it is possible to shorten the reading time while suppressing omissions in reading.

In the fourth aspect of the present invention, at least one wireless tag accommodated in the accommodation space is used as an opening/closing determination tag, and based on information obtained by intermittently performing a reading process on the opening/closing determination tag, the opening is determined. The determination unit determines whether or not the lid is opened and closed so that the lid is closed again after the is opened. Then, the reading process is intermittently performed on the open/close determination tag until the determining unit makes an affirmative determination. A reading process is performed on the tag.

From the viewpoint of reducing power consumption, the reading process for reading the wireless tags in the storage space is preferably performed not periodically but at the timing when the stored wireless tags are replaced, that is, at the timing when the lid is opened and closed. In the open state where the opening is open, radio waves leak outside the accommodation space compared to the closed state where the opening is closed. The information obtained will change. For this reason, based on the information (received signal strength, etc.) obtained by the reading process performed intermittently on the open/close judgment tag, the lid is opened and closed so that the opening is closed again after being opened. It can be determined whether or not the As a result, it is possible to determine whether or not the lid body is in the opened/closed state without using an open/close sensor or the like, and for all the wireless tags accommodated in the accommodation space for a predetermined period after the affirmative determination is made. By performing the reading process using the device, it is possible to reduce the power consumption for the reading process while improving the reading performance.

In the invention of claim 5, the information obtained by intermittently reading the second opening/closing determination tag provided outside the housing space is also taken into consideration, and after the opening is opened, The determination unit determines whether or not the lid body is opened and closed so as to be closed again. In this way, by considering the received signal strength of both the open/close determination tag inside the storage space and the second open/close determination tag outside the storage space, it is possible to improve the determination accuracy of the open/close determination of the lid. .

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing explaining the outline|summary of the information reader which concerns on 1st Embodiment. It is an explanatory view explaining an outline of an information reading device concerning a 2nd embodiment. 10 is a timing chart illustrating the relationship between switching between the tag reading mode and the low consumption mode, the open/closed state of the housing, and the received signal strength of the response wave from the open/close determination tag in the second embodiment. FIG. 11 is an explanatory diagram for explaining an overview of an information reading device that further utilizes a second opening/closing determination tag outside the housing space to determine the open/closed state of the housing in the second embodiment;

[First embodiment]
DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment embodying an information reading device of the present invention will be described below with reference to the drawings.
The information reading device 10 according to the present embodiment is a storage device that reads information about an article G stored in a storage space S provided in a housing 20 from a wireless tag (for example, an RFID tag) T attached to the article. configured as As the article G, for example, a key that requires individual management is assumed, and the wireless tag T attached to each article G records readable information about the article. Therefore, by collectively reading the wireless tags T in the accommodation space S, information on the articles G accommodated in the accommodation space S can be acquired. In addition, in FIG. 1 and the like, one of the plurality of articles G accommodated in the accommodation space S is illustrated together with the wireless tag T for convenience.

As shown in FIG. 1, the housing 20 includes a housing body 21 formed with an opening 21a through which an article G is put in and taken out, and a lid body 22 forming an accommodation space S by closing the opening 21a. The housing body 21 and the lid 22 are made of a material (for example, aluminum) that blocks radio waves or attenuates the radio wave intensity, thereby suppressing radio wave leakage from the accommodation space S. ing.

Two antennas 31 and 32 for reading the wireless tag T in the housing space S are provided at positions within the housing space S in the housing body 21 . The antennas 31 and 32 are arranged so that the transmission directions of the transmission waves are substantially orthogonal to each other. In order to prevent the items G housed in the housing space S from coming into contact with the antennas 31 and 32, the housing body 21 is provided with a housing case or the like made of a material that does not attenuate the radio wave intensity, except for the opening 21a. It can be provided so as to cover the inner surface of the main body 21 .

The information reading device 10 also includes a control unit 40 that controls the overall operation, and a first communication unit 41 and a second communication unit 42 . The first communication unit 41 is configured to perform wireless communication processing for reading the wireless tag T in the accommodation space S using the antenna 31 under the control of the control unit 40 . The second communication unit 42 is configured to perform wireless communication processing for reading the wireless tag T in the accommodation space S using the antenna 32 under the control of the control unit 40 .

The control unit 40 is configured to read information from the wireless tag T accommodated in the accommodation space S using the antennas 31 and 32 . More specifically, when performing the reading process of reading the RFID tag T in the housing space S, the control unit 40 reads the reading result using the first communication unit 41 and the antenna 31 and the second communication unit 42 and the reading result read using the antenna 32 may be used, or the result of comparing both reading results may be used in order to improve the reading accuracy.

In particular, in the present embodiment, the first communication unit 41 is controlled by the control unit 40 so as to change the output frequency of radio waves output from the antenna 31 . The second communication unit 42 is controlled by the control unit 40 so as to change the output frequency of the radio waves output from the antenna 32 .

In this embodiment, the first communication unit 41 is controlled by the control unit 40 so as to change the phase of the radio wave output from the antenna 31 . Also, the second communication unit 42 is configured to be able to change the phase of the radio wave output from the antenna 32 by being controlled by the control unit 40 . Therefore, the phase difference between the phase of the radio wave output from the antenna 31 and the phase of the radio wave output from the antenna 32 can be changed by the control by the control unit 40 .

The function of the control unit 40 that changes the output frequency of radio waves as described above corresponds to an example of "output frequency changing means", and the function of the control unit 40 that changes the phase difference of radio waves as described above is It can correspond to an example of "phase difference changing means". Therefore, the control unit 40 includes output frequency changing means for changing the output frequencies of the radio waves respectively output from the antennas 31 and 32, and phase difference by changing the phases of the radio waves respectively output from the antennas 31 and 32. and a phase difference changing means.

In the information reader 10 configured as described above, regarding the reading process performed by the control unit 40, in order to reduce the reading omission of the wireless tag due to the null range, the first reading mode for changing the output frequency of the radio wave is selected. A second read mode is employed that alters the phase difference.

In the reading process of the first reading mode, the result of collating the information obtained from each wireless tag T via the antenna 31 when the output frequency of the radio wave output from the antenna 31 is sequentially changed and the information output from the antenna 32 are compared. The read result is obtained by further collating the information obtained from each wireless tag T through the antenna 32 when the output frequency of the radio wave is sequentially changed.

In the reading process of the second reading mode, both antennas 31 , 32 from each RFID tag T and the previously obtained result of comparison are further compared to obtain a reading result.

Then, based on the reading result in the first reading mode or the reading result in the second reading mode, the article G (wireless tag T) stored in the storage space S can be specified. In order to achieve more accurate reading of the wireless tag T, the reading result in the first reading mode and the reading result in the second reading mode are further compared to obtain the articles G (wireless) stored in the storage space S. A tag T) can also be specified.

In this way, even if the null range changes each time the article G is taken in and out, the reading results obtained by the reading process each time the output frequency is changed and the reading results obtained by the reading process each time the phase difference is changed By collating the results, it is possible to reduce reading failure of the wireless tag T due to the null range. Therefore, it is possible to suppress the influence of nulls and improve reading performance without providing a movable part or the like.

As a first modification of the present embodiment, the output frequency is not limited to being changed at regular intervals, but for example, the timing of changing the output frequency according to the number of RFID tags T accommodated in the accommodation space S may be changed. That is, the interval of one reading process, which corresponds to a fixed interval, may be changed according to the number of RFID tags T accommodated in the accommodation space S.

As the number of RFID tags T accommodated in the accommodation space S increases, it takes time to read all the RFID tags T in the accommodation space S. Therefore, if the output frequency is changed at regular intervals, the number of RFID tags T If the number is large, reading failure of the wireless tag T during the above-mentioned fixed interval is more likely to occur. On the other hand, if the fixed interval is lengthened, if the number of RFID tags T is small, the reading time will be lengthened because there will be wasted time after reading is completed. For this reason, it is possible to change the timing of changing the output frequency according to the number of RFID tags T accommodated in the accommodation space S, such as increasing the interval at which the output frequency is changed as the number of RFID tags T increases. Therefore, it is possible to shorten the reading time while suppressing reading omissions.

Similarly, the phase difference is not limited to being changed at regular intervals, and the timing of changing the phase difference may be changed according to the number of RFID tags T accommodated in the accommodation space S, for example.

If the phase difference is changed at regular intervals, reading failure of the RFID tags T during the regular interval is more likely to occur if the number of RFID tags T is large. If the number of is small, the reading time becomes long due to the wasteful time after the reading is completed. Therefore, by changing the timing of changing the phase difference according to the number of RFID tags T accommodated in the accommodation space S, it is possible to shorten the reading time while suppressing omissions in reading.

The antennas for reading the wireless tag T in the accommodation space S are not limited to the antennas 31 and 32 whose transmission directions of the transmission waves are substantially orthogonal to each other. Two antennas whose directions face each other or two antennas whose transmission directions of transmission waves are parallel to each other may be adopted, or three or more antennas may be adopted.

[Second embodiment]
Next, an information reading device according to a second embodiment of the invention will be described with reference to the drawings.
The second embodiment is mainly different from the first embodiment described above in that the power consumption of the reading process is reduced by using the determination result regarding the open/closed state of the housing 20 . Therefore, the same reference numerals are assigned to substantially the same components as in the first embodiment, and the description thereof will be omitted.

From the viewpoint of reducing power consumption, the reading process for reading the plurality of RFID tags T in the accommodation space S is performed at the timing when the RFID tags T to be accommodated are replaced, that is, at the timing when the lid 22 of the housing 20 is opened and closed. preferably. For this reason, it is possible to adopt an open/close sensor or the like that can detect the open/close state of the housing 20. However, the number of parts increases, which not only increases the manufacturing cost, but also depends on restrictions such as the installation position of the open/close sensor. There is a problem that the device itself becomes large.

Therefore, in the present embodiment, as shown in FIG. 2, a wireless tag (hereinafter referred to as an open/close determination tag Tj) separately provided for open/close determination is arranged in the housing space S. FIG. In the reading process performed by the control unit 40 in the present embodiment, the lid is closed again after the opening 21a is opened, based on the received signal strength (RSSI) from the open/close determination tag Tj. 22 is in an open/closed state (hereinafter also referred to as an open/closed state of the housing 20).

In the open state in which the opening 21a is opened, radio waves leak out of the accommodation space S compared to the closed state in which the opening 21a is closed by the lid 22. Therefore, even when the same wireless tag T is read, the received signal This is because the strength becomes smaller. A control unit that determines whether or not the housing 20 is in the open/closed state based on the received signal strength (read result) when the open/close determination tag Tj is intermittently read. The function of 40 may correspond to an example of a "determination unit".

In addition, in this embodiment, a tag reading mode (continuous operation mode) for reading a plurality of RFID tags T in the accommodation space S and a low consumption mode (intermittent operation mode) for intermittently reading only the opening/closing judgment tag Tj are provided. ) are provided. In the reading process performed by the control unit 40 in this embodiment, it is determined (positive determination) that the housing 20 is in the opened/closed state based on the strength of the received signal from the open/close determination tag Tj in the low consumption mode. the low consumption mode to the tag reading mode. As a result, power consumption can be reduced as compared with the case where the reading process is always performed in the tag reading mode.

The reading process performed by the control unit 40 so as to switch between the low consumption mode and the tag reading mode will be described in detail below with reference to the timing chart shown in FIG. Note that in FIG. 3, the relationship between switching between the tag reading mode and the low consumption mode, the open/closed state (closed state or open state) of the housing 20, and the received signal strength of the response wave from the open/close determination tag Tj is shown as timing. It is shown in the chart.

At the start of the reading process (when the opening 21a is closed by the lid 22), the mode is switched to the low consumption mode, and the open/close determination tag Tj is read intermittently. Since the process of intermittently reading only the open/close determination tag Tj as a read object is performed, power saving can be achieved as compared with the process of continuously reading a plurality of wireless tags T. FIG. In the reading process in the low consumption mode, as shown in FIG. 3, if the blocked state is maintained, the received signal intensity of the tag Tj for open/close determination becomes a constant value.

Then, whether or not the housing 20 is in the open/closed state is determined based on the received signal strength of the tag Tj for open/close determination, and when the received signal strength of the tag Tj for open/close determination has hardly changed from the constant value. , it is determined that the housing 20 is not in the open/closed state, and the low consumption mode is maintained.

During this low consumption mode, when the lid 22 is opened by the user who puts in or takes out an article G and the opening 21a is opened (see time t1 in FIG. 3), radio waves leak out of the accommodation space S. The received signal strength of the received open/close determination tag Tj decreases (see time t2 in FIG. 3). Then, when the user who has finished taking in and out the article G closes the lid 22 to close the opening 21a (see time t3 in FIG. 3), radio waves are prevented from leaking out of the accommodation space S. The received signal strength of the open/close determination tag Tj received thereafter increases to the constant value (see time t4 in FIG. 3).

In this way, when the received signal intensity of the tag Tj for open/close determination decreases and then returns to the original value, it is determined that the housing 20 is open/closed (positive determination), and the loading/unloading of the article G is completed. Assuming that it is, it is switched to the tag reading mode (see time t5 in FIG. 3). As a result, processing for continuously reading a plurality of wireless tags T in the accommodation space S as reading targets is performed.

Then, when the tag reading mode continues for a predetermined period and the reading of the wireless tag T in the accommodation space S is completed (see time t6 in FIG. 3), the mode is switched to the low consumption mode again, and the opening/closing determination tag Tj is read. Until the strength of the received signal changes as described above, only the open/close determination tag Tj is intermittently read.

As described above, in the information reading device 10 according to the present embodiment, based on the received signal intensity obtained by the reading process performed intermittently on the opening/closing determination tag Tj housed in the housing space S, It is determined whether or not the housing 20 is in an open/closed state in which the lid body 22 is opened and closed so that the opening 21a is closed again after being opened. Then, the reading process is intermittently performed on the tags Tj for open/close determination until affirmative determination is made. read processing is performed.

In this way, the cover 22 is opened and closed so that the opening 21a is opened and then closed again, based on the received signal intensity and the like obtained by the reading process performed intermittently on the open/close determination tag Tj. It is possible to determine whether or not the housing 20 is in the opened/closed state. As a result, it is possible to determine whether or not the lid body 22 of the housing 20 is in the opened/closed state without using an open/close sensor or the like, and the lid body 22 is accommodated in the accommodation space S for a predetermined period after an affirmative determination is made. By performing the reading process for all the wireless tags T, it is possible to improve the reading performance and reduce the power consumption for the reading process.

For example, the open/close determination tag Tj may be attached to the inner side of the lid 22 so that the change in received signal intensity obtained when the lid 22 is opened or closed may be increased. Further, the open/close determination tag Tj is not limited to being provided separately from the RFID tag T attached to the article G to be managed, but is housed in the housing space S as a management object for each open/closed state of the housing 20. The wireless tag T attached to any one of the articles G may be used.

In addition, as shown in FIG. 4, information such as received signal strength obtained by intermittent reading processing of the second open/close determination tag Tj2 provided outside the accommodation space S is also taken into consideration. It may be determined whether or not the housing 20 is in the open/closed state. In this way, by considering the received signal intensity of both the open/close determination tag Tj inside the accommodation space S and the second open/close determination tag Tj2 outside the accommodation space S, the lid 22 of the housing 20 can be opened/closed. It is possible to improve the determination accuracy of the determination.

As a modification of the present embodiment, the antennas for reading the plurality of wireless tags T and the open/close determination tag Tj in the accommodation space S are not limited to the two antennas 31 and 32. For example, one An antenna may be employed, and in this case, the output frequency and phase of the radio wave output from the antenna may not be changeable.

The information reading device 10 according to the modification can be defined as an invention as described below.
An information reading device 10 for reading information from a wireless tag T attached to an article G housed in a housing space S,
It has a housing body 21 formed with an opening 21a through which the article is put in and taken out, and a lid body 22 that closes the opening to form the accommodation space, thereby suppressing radio wave leakage from the accommodation space. a housing 20 configured to
an antenna arranged in the accommodation space;
a control unit 40 for reading information from the wireless tag accommodated in the accommodation space by controlling the antenna;
with
The control unit
At least one wireless tag accommodated in the accommodation space is used as an open/close determination tag Tj, and the opening is opened based on the reading result when the open/close determination tag is intermittently subjected to the read processing. A determination unit that determines whether the lid is opened and closed so that it is closed again after the lid is closed,
The reading process is intermittently performed on the opening/closing determination tag until the determination unit makes an affirmative determination, and the tag is stored in the storage space for a predetermined period after the determination unit makes the affirmative determination. An information reader, wherein the reading process is performed for all the wireless tags.

The present invention is not limited to the above-described embodiments and the like, and may be embodied as follows, for example.
(1) Items G to be managed in the present invention are not limited to keys that require individual management. It may be a temporarily stored product.

(2) The housing 20 is not limited to being formed in a box shape so as to block radio waves or attenuate radio wave intensity by having a housing body 21 and a lid body 22. may be configured to be openable and closable to form a housing space that blocks radio waves or attenuates radio wave intensity.

DESCRIPTION OF SYMBOLS 10... Information reader 20... Case 21... Case main body 21a... Opening 22... Cover 31, 32... Antenna 40... Control part 41... First communication part 42... Second communication part G... Article S... Storage space T... wireless tag Tj... tag for open/close determination Tj2... second tag for open/close determination

Claims (5)

An information reading device for reading information from a wireless tag attached to an article housed in a housing space,
It has a housing body in which an opening through which the article is put in and taken out is formed, and a lid body which forms the accommodation space by closing the opening, and suppresses radio wave leakage from the accommodation space. a housing composed of
a plurality of antennas arranged in the accommodation space;
a control unit that performs reading processing to read information from the wireless tag accommodated in the accommodation space using the plurality of antennas;
with
The control unit includes output frequency changing means for changing output frequencies of radio waves respectively output from the plurality of antennas, and phase difference for changing phase differences by changing phases of radio waves respectively output from the plurality of antennas. a means of change;
An information reader comprising: 2. The information reader according to claim 1, wherein said output frequency changing means changes the timing of changing said output frequency according to the number of said wireless tags accommodated in said accommodation space. 3. The information reader according to claim 1, wherein said phase difference changing means changes the timing of changing said phase difference according to the number of said wireless tags accommodated in said accommodation space. The control unit
At least one wireless tag accommodated in the accommodation space is used as an open/close determination tag, and the opening is opened based on information obtained by the read processing performed intermittently on the open/close determination tag. A determination unit that determines whether the lid is opened and closed so that it can be closed again later,
The reading process is intermittently performed on the opening/closing determination tag until the determination unit makes an affirmative determination, and the tag is stored in the storage space for a predetermined period after the determination unit makes the affirmative determination. 4. The information reader according to claim 1, wherein the reading process is performed for all the wireless tags. The determination unit further determines whether the opening is opened by considering information obtained by the reading process performed intermittently on the second open/close determination tag provided outside the housing space. 5. The information reader according to claim 4, wherein it is determined whether or not the lid is opened and closed so that it can be closed again later.

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