JP5251812B2 - Portable communication terminal - Google Patents

Description

  The present invention relates to a portable communication terminal.

  2. Description of the Related Art Conventionally, wireless tag systems have been widely provided as systems that perform wireless communication using electromagnetic waves as a medium. This system is generally composed of an RFID tag (wireless tag) and a reader / writer (wireless reader / writer), and performs radio communication with an RFID tag attached to a moving body or the like using a reader / writer using radio waves or the like. The data in the RFID tag is read or various data is written to the RFID.

JP 2006-106897 A

  The reader / writer used in the wireless tag system includes a stationary configuration or a portable configuration. When configured as a portable communication terminal, the user can easily carry it to various places. There is.

  However, when the reader / writer is configured as a portable communication terminal as described above, it is difficult to assume the actual usage environment and usage, and thus there is a problem that it is difficult to appropriately set the setting values necessary for communication processing. . For example, in an environment in which a plurality of wireless tags are read, a collision prevention process (anti-collision process) is generally performed by a reader / writer in order to appropriately recognize each wireless tag. When configured as a portable communication terminal that can be used at a place, it is difficult to set parameters used in the collision prevention process to appropriate values according to the environment.

  For example, in the case of a slotted aloha system that recognizes each wireless tag using a plurality of slots, it is required to set the number of slots to an appropriate value suitable for the environment. It is difficult to know in advance the appropriate value for the number of slots used in anti-collision processing, because it is impossible to know in advance what kind of movement will be performed, and the moving speed may change with each use. It is.

  The present invention has been made to solve the above-described problems, and in a portable communication terminal capable of performing contactless communication with a wireless tag, the number of slots used for collision prevention processing is considered in consideration of the actual usage environment. The object is to provide a configuration that can be set to an appropriate value.

The invention of claim 1 includes output means for outputting electromagnetic waves via an antenna, wireless communication means for performing wireless communication with each of the wireless tags using the electromagnetic waves, slot number setting means for setting the number of slots, As many slots as the number of slots set by the slot number setting means are prepared, each wireless tag existing within the readable range of the wireless communication means is assigned to each slot, and each wireless tag is uniquely identified. A collision preventing unit for performing a collision preventing process associated with the wireless tag, and the wireless communication unit recognizes each wireless tag based on each identification information associated with each wireless tag by the collision preventing unit, The portable communication terminal is configured to communicate with a wireless tag.
And a distribution density detecting means for detecting a distribution density of the wireless tag existing in the readable range of the wireless communication means, and a moving speed detecting means for detecting a moving speed of the portable communication terminal, The slot number setting means sets the slot number based on the distribution density detected by the distribution density detecting means and the moving speed detected by the moving speed detecting means.

Furthermore, readable range switching means for changing the readable range of the wireless communication means by switching the output level of the electromagnetic wave by the output means is provided, and the slot number setting means is provided with the readable range switching means. The number of slots is set based on the output level switched by the above, the distribution density detected by the distribution density detecting means, and the moving speed detected by the moving speed detecting means. .

Further, table data for setting an estimated processing time for reading each read number when set to each Q value based on the Q value which is a parameter for setting the number of slots and the number of read RFID tags And a reading number estimation means for estimating the number of readings of the wireless tag based on the distribution density detected by the distribution density detection means and the output level switched by the readable range switching means. It has been. The slot number setting means sets the Q value based on the read number estimated by the read number estimation means and the table data.

According to a second aspect of the present invention, calibration means for performing calibration processing of the table data is further provided, and the readable range switching means outputs the output when performing the calibration processing by the calibration means. By changing the output level of the means, the number of the wireless tags existing in the readable range at the time of the calibration process is changed, and the slot number setting means is readable at the time of the calibration process. When each readable range is set by the range switching means, the Q value is switched to a plurality of values each time the readable range is set.
Further, the calibration means estimates the number of the wireless tag in each readable range switched by the readable range switching means at the time of the calibration process, and each reading at the time of the calibration process. Reading processing time detecting means for detecting the reading processing time of the wireless tag by the wireless communication means when set to the possible range and each Q value for each combination of the readable range and the Q value; Updating means for updating the table data based on each number of the RFID tags in each readable range estimated by the number estimating means and each reading processing time detected by the reading processing time detecting means; ,have.

According to a third aspect of the present invention, when the readable range is set at the time of the calibration processing, the collision preventing means can read the partial slot among all slots set by the slot number setting means. The wireless tag existing in the readable range is assigned based on a result of assignment of the wireless tag to the partial slot by the collision preventing means. It is characterized by estimating the number of.

The invention of claim 4 further includes an upper limit of reading processing based on the readable range switched by the readable range switching means and the moving speed of the portable communication terminal detected by the moving speed detecting means. Upper limit time calculating means for calculating the time is provided.
The slot number setting means refers to the table data, and is calculated by the upper limit time calculating means within the estimated processing time for each Q value for the read number estimated by the read number estimation means. The estimated processing time satisfying the upper limit time is obtained from the table data, and the Q value is set within the satisfaction range.

According to a fifth aspect of the present invention, the moving speed detecting unit further includes an imaging unit that images the imaging target outside the apparatus at a plurality of times at different timings when the portable communication terminal is moved, and the timing varies depending on the imaging unit. The moving speed of the portable communication terminal is detected on the basis of a plurality of images of the imaging target imaged in (1).

  According to the first aspect of the present invention, the distribution density of the wireless tag existing in the readable range of the wireless communication means and the moving speed of the portable communication terminal are detected, and the slot is determined based on the detected distribution density and the moving speed. The number is set. In this way, in portable communication terminals that are used in various environments, the collision prevention processing is performed based on the distribution density of the wireless tags in the actual reading environment and the moving speed when actually operated. It becomes easy to set the number of slots to be used appropriately.

Further, there is provided a readable range switching means for changing the readable range of the wireless communication means by switching the output level of the electromagnetic wave by the output means, the output level switched by the readable range switching means, and the distribution density detecting means The number of slots is set based on the distribution density detected by the above and the moving speed detected by the moving speed detecting means. In this way, in addition to the distribution density of the wireless tag in the actual reading environment and the moving speed when actually operated, the number of slots is further considered in consideration of the readable range when actually used. It becomes possible to set. Therefore, it becomes easier to set the number of slots more appropriately.

Also, a Q value which is a parameter for setting the number of slots, based on the read number of the radio tag, the table data for setting the estimated processing time each time reading each read number when it is set in the Q value, There is provided reading number estimation means for estimating the number of readings of the wireless tag based on the distribution density detected by the distribution density detection means and the output level switched by the readable range switching means. In this way, the number of wireless tags existing in the readable range can be estimated with higher accuracy. In addition, since each estimated processing time when reading the estimated number of readings with each Q value can be grasped by referring to the table data, it is easy to select a Q value that reduces the processing time.

According to the second aspect of the present invention, the number of wireless tags existing within the readable range is changed during the calibration process by changing the output level of the output means when performing the calibration process. When each readable range is set by the readable range switching means during the processing, the Q value is switched to a plurality of values at each setting of each readable range. Further, the number of wireless tags in each readable range switched in this way is estimated, and the reading processing time of the wireless tag by the wireless communication means when set to each readable range and each Q value at the time of calibration processing , Detection is performed for each combination of each readable range and each Q value. Then, the table data is updated based on the number of wireless tags in each readable range estimated by the number estimating means and the respective reading processing times detected by the reading processing time detecting means. In this way, the number of wireless tags in the readable range can be variously changed without imposing a special effort on the user during the calibration process, and there are each number of wireless tags in the readable range. In some cases, the reading processing time when the Q value is changed to various values can be easily acquired. Since the table data is updated based on the data thus obtained, the table data can be updated to more reliable data reflecting the environment when the calibration process is performed.

According to a third aspect of the present invention, when a readable range is set at the time of calibration processing, the collision preventing means is a wireless that exists in the readable range for some of the slots set by the slot number setting means. Processing to assign tags. Then, the number estimation means estimates the number of wireless tags existing in the readable range based on the result of assignment of the wireless tags to some slots by the collision prevention means. In this way, since it is not necessary to assign all the radio tags for all slots during the calibration process, the pre-adjustment process time can be greatly reduced.

According to a fourth aspect of the present invention, the upper limit time for calculating the upper limit time of the reading process based on the readable range switched by the readable range switching means and the moving speed of the portable communication terminal detected by the moving speed detecting means. A calculating means is provided. The slot number setting means refers to the table data and satisfies the upper limit time calculated by the upper limit time calculating means among the estimated processing time for each Q value for the number of read sheets estimated by the read number estimating means. The estimated processing time is obtained from the table data, and the Q value is set within the satisfaction range. In this way, it is possible to grasp how long the reading process for the estimated number of read RFID tags should be completed (how long is the upper limit time of the reading process). Since the Q value is set within the sufficient range of the upper limit time with reference to the table data, it is difficult to cause a situation in which a part of the estimated number of read sheets is out of the readable range without being completely read.

According to the fifth aspect of the present invention, there is provided imaging means for imaging an imaging target outside the apparatus a plurality of times at different timings when the portable communication terminal moves, and the portable communication terminal is based on the images at different timings of the imaging target. Detecting the moving speed of the terminal. If it does in this way, while using an imaging means together, it will become possible to detect the movement speed of a portable communication terminal more correctly using this imaging means.

FIG. 1 is a block diagram schematically illustrating an electrical configuration of the portable communication terminal according to the first embodiment. 2A is a block diagram illustrating an information code reading unit in the portable communication terminal of FIG. 1, and FIG. 2B is a block illustrating a wireless tag processing unit in the portable communication terminal of FIG. FIG. FIG. 3 is a block diagram illustrating a specific configuration of the wireless tag processing unit of the portable communication terminal of FIG. FIG. 4 is a block diagram illustrating an electrical configuration of the wireless tag. FIG. 5 is a flowchart schematically illustrating the flow of calibration processing performed in the portable communication terminal of FIG. FIG. 6A is an explanatory diagram for explaining a normal anti-collision process, and FIG. 6B is an explanatory diagram for explaining the anti-collision process performed in the calibration process. FIG. 7A is an explanatory diagram conceptually illustrating the relationship between the readable range and the wireless tag when the output level is set to a predetermined first value, and FIG. 7B illustrates the output level. It is explanatory drawing which illustrates notionally the relationship between the readable range when set to a predetermined 2nd value, and a wireless tag. FIG. 8 is an explanatory diagram schematically illustrating table data for determining an estimated processing time according to a combination of a Q value and the number of tags. FIG. 9 is an explanatory diagram showing the number of acquired tags obtained according to the combination of the number of slots and the output level in the calibration process, and the processing time required to acquire the number of acquired tags. FIG. 10 shows data obtained by calculating a processing time corresponding to the combination of the Q value and the number of tags based on the data shown in FIG. FIG. 11 is a flowchart illustrating a Q value setting process performed prior to the non-contact communication process in the portable communication terminal of FIG. FIG. 12 is an explanatory diagram illustrating an example of detecting the moving speed V (operation speed), and (a) is an explanatory diagram illustrating a captured image obtained by capturing a predetermined object at the first timing. FIG. 6 is an explanatory diagram illustrating a captured image obtained by capturing the predetermined object at a second timing after the first timing.

[First embodiment]
Hereinafter, a first embodiment in which a portable communication terminal of the present invention is embodied will be described with reference to the drawings.
(Overall configuration of portable communication terminal)
First, with reference to FIGS. 1-4, the whole structure of the portable communication terminal which concerns on 1st Embodiment is demonstrated. FIG. 1 is a block diagram schematically illustrating an electrical configuration of the portable communication terminal according to the first embodiment. 2A is a block diagram illustrating an information code reading unit in the portable communication terminal of FIG. 1, and FIG. 2B illustrates a wireless tag processing unit in the portable communication terminal of FIG. FIG. FIG. 3 is a block diagram illustrating a specific configuration of the wireless tag processing unit of the portable communication terminal of FIG. FIG. 4 is a block diagram illustrating an electrical configuration of the wireless tag.

  The portable communication terminal 1 is carried by a user and used in various places. The portable communication terminal 1 functions as an information code reader that reads an information code such as a barcode or a two-dimensional code, and functions as a wireless tag reader that reads a wireless tag. And is configured so that reading can be performed in two ways.

  As shown in FIG. 1, the portable communication terminal 1 includes a control unit 3 that performs overall control. The control unit 3 includes a wireless tag processing unit 5, an information code reading unit 6, an LED 9, and a display unit 10. A key operation unit 11, a speaker 12, a memory 13, an external interface 17 and the like are connected.

  The control unit 3 is composed mainly of a microcomputer, has a CPU, a system bus, an input / output interface, and the like, and functions as an information processing device together with the memory 13. The LED 9, the display unit 10, and the speaker 12 are all controlled by the control unit 3, and are configured to operate in response to commands from the control unit 3. The key operation unit 11 includes a plurality of keys, and is configured to give an operation signal corresponding to a user's key operation to the control unit 3. The control unit 3 operates from the key operation unit 11. When a signal is received, an operation corresponding to the operation signal is performed.

  The external interface 17 is configured as an interface for performing data communication with the outside (for example, a host device), and is configured to perform communication processing in cooperation with the control unit 3. In addition, the portable communication terminal 1 is provided with a battery 15 and a power supply unit 16 as power sources, and power is supplied to the control unit 3 and various electric components by these.

  As shown in FIG. 2A, the information code reading unit 6 includes a light receiving sensor 33 including a solid-state imaging device such as a CCD area sensor, an imaging lens 37, and an illumination unit 31 including a plurality of LEDs and lenses. Etc., and functions to read the information code C attached to the reading object R in cooperation with the control unit 3. The information code reading unit 6 is also provided with an amplifier circuit that amplifies the signal from the light receiving sensor 33, an AD converter circuit that converts the amplified signal into a digital signal, and the like. Is omitted.

  The wireless tag processing unit 5 communicates with the wireless tag 50 (FIG. 4) in cooperation with the antenna 7 and the control unit 3 to read data stored in the wireless tag 50, or to read the wireless tag 50. It functions to write data to. The wireless tag processing unit 5 is configured as a circuit that performs transmission by a known radio wave system, and mainly includes a transmission circuit 20, a reception circuit 30, a matching circuit 26, and the like as illustrated in FIG. Has been.

  As shown in FIG. 3, the transmission circuit 20 includes a carrier oscillator 21, an amplifier 24, a transmission unit filter 25, an encoding unit 22, a modulation unit 23, and the like. The reception circuit 30 includes a reception unit filter 31, an amplifier 32, a demodulation unit 33, a binarization processing unit 34, a decoding unit 35, and the like.

  The encoding unit 22 is connected to the control unit 3, and has a configuration in which transmission data output from the CPU of the control unit 3 is encoded and output to the modulation unit 23. For example, the modulation unit 23 performs ASK on the carrier (carrier wave) having a frequency of 950 MHz output from the carrier oscillator 21 by the encoded transmission code (modulation signal) output from the encoding unit 22 when transmitting a command to the communication target. (Amplitude Shift Keying) A modulated modulated signal is generated and output to the amplifier 24. The operation / stop of the oscillation operation of the carrier oscillator 21 is controlled by the control circuit 3.

  The amplifier 24 is configured to amplify an input signal (a modulated signal modulated by the modulation unit 23) with a set gain, and outputs the amplified signal to the transmission unit filter 25. The transmission unit filter 25 outputs the filtered transmission signal to the antenna 7 via the matching circuit 26. When a transmission signal is output to the antenna 7 in this manner, the transmission signal is radiated to the outside from the antenna 7 as an electromagnetic wave.

  On the other hand, the signal received via the antenna 7 is filtered by the receiver filter 31, amplified by the amplifier 32, given to the demodulator 33, and demodulated. The demodulated signal waveform is binarized by the binarization processing unit 34 and then decoded by the decoding unit 35. The decoded received data is output to the control unit 3.

  In the present embodiment, the control unit 3 and the transmission circuit 20 correspond to an example of “output means” and function to output electromagnetic waves via the antenna 7. The control unit 3 and the wireless tag processing unit 5 correspond to an example of a “wireless communication unit” and have a function of performing wireless communication with each wireless tag using electromagnetic waves. Specifically, it functions to recognize each wireless tag based on each identification information (unique identification information) associated with each wireless tag by “collision prevention means” described later, and to communicate with each wireless tag. ing.

  The wireless tag 50 that performs non-contact communication with the wireless tag processing unit 5 is configured as a known RFID tag in hardware. As shown in FIG. 4, an antenna 51, a power supply circuit 52, a demodulation circuit 53, a control circuit 54, a memory 55, a modulation circuit 56, and the like.

  The power supply circuit 52 rectifies and smoothes a transmission signal (carrier signal) received from the communication terminal 2 received via the antenna 51 to generate an operation power supply. The operation power supply includes the control circuit 54 and the like. Supplied to each component. The demodulating circuit 53 demodulates the data superimposed on the transmission signal (carrier signal) and outputs it to the control circuit 54.

  The memory 55 includes various semiconductor memories such as a ROM and an EEPROM, and includes tag control information (tag ID) for identifying the control program, the RFID tag 50, and data set by the user according to the use of the RFID tag 50. (Product data, logistics data, etc.) are stored. The control circuit 54 is configured to read the information and data from the memory 55 and output it as transmission data to the modulation circuit 56. The modulation circuit 56 performs load modulation on the carrier signal with the transmission data and performs the antenna 51. Is transmitted as a reflected wave.

(Calibration process)
Next, the calibration process performed in the portable communication terminal of FIG. 1 will be described.
FIG. 5 is a flowchart schematically illustrating the flow of calibration processing performed in the portable communication terminal of FIG. FIG. 6A is an explanatory diagram for explaining a normal anti-collision process, and FIG. 6B is an explanatory diagram for explaining the anti-collision process performed in the calibration process. FIG. 7A is an explanatory diagram conceptually illustrating the relationship between the readable range and the wireless tag when the output level is set to a predetermined first value, and FIG. 7B illustrates the output level. It is explanatory drawing which illustrates notionally the relationship between the readable range when set to a predetermined 2nd value, and a wireless tag. FIG. 8 is an explanatory diagram schematically illustrating table data for determining an estimated processing time according to a combination of the Q value and the number of tags. FIG. 9 is an explanatory diagram showing the number of acquired tags obtained according to the combination of the number of slots and the output level in the calibration process, and the processing time required to acquire the number of acquired tags. FIG. 10 shows data obtained by calculating a processing time corresponding to the combination of the Q value and the number of tags based on the data shown in FIG.

  The calibration process shown in FIG. 5 is a process that starts when a predetermined operation is performed by a user, for example. First, a process of setting an output level of a carrier (carrier wave) output from an antenna is performed (S1). . In the present embodiment, for example, the gain of the amplifier 24 can be set and changed under the control of the control unit 3. In S1, the gain of the amplifier 24 is set to a predetermined initial value.

  Further, a Q value that is a parameter for the number of slots used in the anti-collision process (collision prevention process) is set to a predetermined initial value (S2).

Here, the anti-collision process performed at the time of normal reading in the portable information communication terminal 1 according to the present embodiment will be described first.
In the present embodiment, a known method such as a slotted aloha method is employed as the anti-collision method. In this slotted aloha system, the portable communication terminal 1 is provided with a number of time slots (number of slots) corresponding to a preset Q value, and a slot number is assigned to each time slot. In this embodiment, 2 to the power of Q (that is, 2 ^Q ) is the number of slots, and FIG. 6A conceptually illustrates the case where Q = 4, that is, the number of slots is 16. ing.

  When performing the anti-collision process, the portable communication terminal 1 first transmits a request command to the wireless tag in the readable range. On the other hand, each wireless tag present in the readable range generates a random number within the range of the number of slots set in the portable communication terminal 1 and receives a request command transmitted from the portable communication terminal 1 and randomly The numerical value is acquired. Then, as in the example of FIG. 6, the portable communication terminal 1 advances the set number of timeslots (16 in FIG. 6) in order, and each wireless tag includes a plurality of time slots that advance. A response is returned together with its own unique identification information at the time slot of the numerical value selected by itself. For example, in the example of FIG. 6, the wireless tag A acquires a numerical value “1” and responds at time slot 1 (TS1), and similarly, the wireless tag B acquires a numerical value “5”. , Responding at time slot 5 (TS5). The portable communication terminal 1 makes the responding wireless tag unique to the wireless tag for a time slot that has a response from one of the wireless tags and has no response from other tags, such as the time slots 1 and 5. Management is performed using the unique identification information. This unique identification information is returned to the portable communication terminal 1 together with a response to the time slot from the wireless tag, for example, and the wireless tag managed with the unique identification information in this way is an already selected wireless tag. Be treated.

On the other hand, if there is a response from a plurality of wireless tags in any time slot, the wireless tag is suspended without selecting any wireless tag in that time slot and proceeds to the next time slot. In the example of FIG. 6A, since the wireless tags D and F respond in the time slot 3 (TS3) and cannot be distinguished due to the collision of the wireless tags, no wireless tag is selected in the time slot 3. It will be. In this case, after completing the set number of time slots, a request command is transmitted again to the wireless tags D and F that have collided, and the same time as described above is transmitted to these wireless tags D and F. Slot assignment processing is performed. In the normal reading, the anti-collision process is performed in this way.
The control unit 3 corresponds to an example of “collision prevention means”, and prepares time slots for the number of slots set based on the Q value, and is within the readable range of the “wireless communication means”. Each wireless tag that exists is assigned to each time slot, and functions to perform anti-collision processing (collision prevention processing) that associates each wireless tag with unique identification information.

The anti-collision process as described above is performed at the time of normal reading. In the calibration process shown in FIG. 5, the slot set according to the Q value in the anti-collision process at the time of normal reading described above. Anti-collision processing is performed with a number smaller than the number (that is, 2 ^Q ). Specifically, a value obtained by dividing the number of slots normally set according to the Q value set in S2 (ie, 2 ^Q ) by a specified integer X (ie, 2 ^Q / X) is used for the calibration process. The number of slots used in anti-collision processing is used. In S3, the above-described anti-collision processing is performed, and the wireless tag is called only for the time slots of the number of slots (that is, 2 ^Q / X), and the wireless tag recognition processing for these time slots is 1 each. Anti-collision processing is stopped at the time when it is performed. Then, reading processing is performed on the wireless tag recognized until the cancellation. In the present embodiment, the calibration processing of FIG. 5 is performed with the portable communication terminal 1 stationary at an arbitrary position in a situation where a plurality of wireless tags 50 are prepared in advance as shown in FIG. In S3, anti-collision processing is performed on the plurality of prepared wireless tags 5 using time slots of 2 ^Q / X.

  In the example of FIG. 6B, when X = 4, the time slot used in S3 when Q = 4 is illustrated. In this case, in S3, the above-described anti-interval using four time slots is illustrated. Collision processing is performed.

As shown in FIG. 5, after S3, the number of wireless tags acquired by the anti-collision process of S3 (number of acquired tags) and the processing time required for acquiring the wireless tag by the reading process of S3 are stored. . Specifically, the number N of wireless tags for which the unique identification information can be acquired by the anti-collision process of S3 and the time T required for reading these N wireless tags are represented by the number of slots 2 ^{Q at} this time. Stored in association with / X. For example, as shown in FIG. 6B, when X = 4 and Q = 4, two wireless tags are acquired, and when it takes T1 time to read these two wireless tags, The number “4”, the acquired number “2”, and the processing time “T1” are stored in association with each other.

  After S4, a process for updating the table data is performed (S5). In the portable communication terminal 1 according to the present embodiment, table data as shown in FIG. 8 is stored in the memory 13 (FIG. 1) in advance. This table data includes a “Q value” that is a parameter for setting the number of time slots (number of slots) used in the above-described anti-collision processing, and the number of radio tags read (shown as “tag number” in FIG. 8). This is data for setting an estimated processing time for reading each number of read sheets when set to each Q value. In S5, a part of the table data is updated in accordance with the acquisition result in S4. Yes. In the table data of FIG. 8, for example, when five wireless tags are read when the Q value is “3” (that is, the number of slots is 8), the processing time of “115” (for example, ms) is used. It is estimated.

In the calibration process of FIG. 5, the acquired tag number N and processing time T when the number of slots is 2 ^Q / X are acquired and stored in S4. In this case, the number of slots is the same as when the number of slots is normal processing. if there was a 2 ^Q, the number of acquired tag acquired in S4 is estimated to be N × X, it takes time T × X to the recognition of the tag of the N × X is estimated. Therefore, in S5, the table data is identified by the combination of the Q value set in S2 (that is, the Q value used in the anti-collision process in S3) and the tag number N × X estimated as described above. The processing time of the portion to be processed is updated to the above time T × X. For example, when the Q value set in S2 is “3”, N × X is “20”, and T × X is “204”, the combination of the Q value “3” and the tag number “20” is used. The specified “200” is updated to “204”.

  As shown in FIG. 5, after the process of S5, it is determined whether or not the processes of S3 to S5 have been performed for all the Q values that are planned at the currently set output level (S6). If there is a value that has not been subjected to the processing of S3 to S5 within the range of the Q value that has been set, the process proceeds to No in S6, and the currently set Q value is changed to a value within the planned range. It changes to an unimplemented value (S7), and repeats the process of S3-S5 after that. On the other hand, when the processes of S3 to S5 are performed for all the planned Q values at the currently set output level, the process proceeds to Yes in S6.

  When the process proceeds to Yes in S6, it is determined whether or not calibration processing has been performed for all output levels (S8). In the portable communication terminal 1 according to the present embodiment, for example, by switching the gain of the amplifier 24 (FIG. 3), the output level of the carrier wave from the antenna 7 can be switched in a plurality of stages. Then, it is determined whether or not the processing after S2 has been carried out for all the output levels at a plurality of stages scheduled in the calibration processing. If there are any values that have not been subjected to the processing of S2 to S7 in the planned output levels of a plurality of stages, the process proceeds to No in S8, and the output level of the carrier wave from the antenna 7 is scheduled. The value is changed to an unexecuted value in the plurality of stages (S9), and then the processes after S2 are repeated. In this way, by changing the output level of the carrier wave from the antenna 7, for example, the readable range can be changed as shown in FIG. 7A to FIG. The number of existing wireless tags can be changed. On the other hand, when the processing from S2 onward is performed for all the planned output levels of a plurality of stages, the process proceeds to Yes in S8, and the calibration processing (FIG. 5) is terminated.

In this embodiment, as shown in FIG. 9, the number of slots (2 ^Q / X) is 1, 2 for each output level (shown as P1, P2, P3, P4... In FIG. 9). , 3, 4..., And in each process of S4, as shown in FIG. 9, the number N of acquisition tags and the processing time T are obtained for each combination of each output level and the number of slots. Then, based on the data obtained as shown in FIG. 9, a number of estimation processing times corresponding to the combination of the Q value and the number of tags are calculated as shown in FIG. We use for update.

In the present embodiment, the control unit 3 that performs the process of FIG. 5 corresponds to an example of “calibration means” and functions to perform the calibration process of table data as shown in FIG.
Further, the control unit 3 that performs the process of S9 corresponds to an example of “readable range switching unit”, and when the calibration process is performed by the “calibration unit”, the output level of the “output unit” is changed. As shown in FIG. 7, it functions to change the number of wireless tags existing within the readable range during the calibration process.
In the present embodiment, the control unit 3 corresponds to an example of a “slot number setting unit”, and functions to set the number of time slots used in anti-collision processing (collision prevention processing). When the calibration process is performed, the process of S9 is performed by the “readable range switching unit”, and when each readable range is set by the process of each S9, each readable range is set at S2, It functions to switch the Q value to a plurality of values by the process of S7.

  The control unit 3 that can execute the processes of S4 and S5 at each output level corresponds to an example of “number estimation means”, and each reading that is switched by the “readable range switching means” during the calibration process. It functions to estimate the number of wireless tags in the possible range.

  Further, the control unit 3 capable of executing the processes of S4 and S5 at each output level and each Q value corresponds to an example of “reading process time detecting means”, and each readable range and each Q in the calibration process. It functions to detect the reading processing time of the wireless tag by the wireless communication means when set to a value for each combination of each readable range and each Q value.

  Further, the control unit 3 capable of executing the process of S5 corresponds to an example of “update means”, and the number of wireless tags in each readable range estimated by the “number estimation means” and the “read” It functions to update the table data based on each reading processing time detected by the “processing time detecting means”.

In the present embodiment, when the readable range is set by the processing of S1 or S9 during the calibration processing, the control unit 3 corresponding to the “collision preventing means” sets based on the Q value determined in S2. For all of the slots (2 ^Q slots) to be processed, a process of assigning a radio tag existing in a readable range is performed by the process of S3 for the slot (2 ^Q / X slot). The “estimating means” estimates the number of wireless tags existing in the readable range in the processes of S4 and S5 based on the assignment result of the wireless tags to the partial slots (2 ^Q / X slots) in S3. Yes.

(Non-contact communication processing)
Next, the non-contact communication process performed with the portable communication terminal 1 of this embodiment is demonstrated. FIG. 11 is a flowchart illustrating a Q value setting process performed prior to the non-contact communication process in the portable communication terminal 1.
FIG. 11 is a process that starts when a user performs a predetermined operation for the Q value setting process. First, a process of detecting the operation speed (movement speed V) of the portable communication terminal 1 is performed. The process of S10 can be started at various timings. For example, the movement speed V (operation speed) of the portable communication terminal 1 within a predetermined time after a predetermined trigger operation is performed by the user is detected. Alternatively, the moving speed V (operation speed) within a predetermined time after a predetermined notification (for example, notification by a buzzer) may be detected for the user.

  There are various methods for detecting the moving speed V (operation speed). For example, the mobile communication terminal 1 is actually read with respect to a predetermined object placed at a certain distance from the mobile communication terminal 1. For example, a method may be used in which the predetermined object is imaged at regular time intervals by the light receiving sensor 33 (the light receiving sensor 33 corresponds to an example of “imaging unit”). In this case, as shown in FIGS. 12A and 12B, the displacement L1 within the image of the specific part Z1 (for example, a specific corner) of the predetermined object in the two images captured at a constant time interval Ta. By detecting this, the moving speed V of the portable communication terminal 1 within the time interval Ta can be detected from the displacement L1 and the imaging time interval Ta. In FIG. 12, the position in the image of the specific part Z1 in the previously captured image is indicated by the symbol Pz1, and the position in the image of the specific part Z1 in the image captured later is indicated by the symbol Pz2. ing.

  In this example, the control unit 3 and the light receiving sensor 33 correspond to an example of “moving speed detecting means” and function to detect the moving speed V of the portable communication terminal 1. When the communication terminal 1 moves, the imaging target outside the apparatus is imaged a plurality of times at different timings, and the moving speed V of the portable communication terminal 1 is detected based on a plurality of images of the imaging target imaged at different timings. It is functioning.

  Furthermore, a process of calculating the average power supply time Ta to the wireless tag based on the moving speed V (operation speed) detected in S10 and the currently set output level P is performed. In the present embodiment, the user can switch the output level of the electromagnetic wave from the antenna 7 in advance. For example, when the user designates an arbitrary output level, the output level is set to the current set level ( As the output level P) to be used for actual non-contact communication, the processes after S11 are performed. The control unit 3 corresponds to an example of a “readable range switching unit”, and changes the readable range of the “wireless communication unit” by changing the output level of the carrier wave from the antenna 7. Is functioning.

  As shown in FIGS. 7 (a) and 7 (b), when the output level of the carrier wave output from the antenna 7 is determined, the size of the readable range can be specified accordingly. In S11, the moving speed detected in S10 is determined. Average power supply time Ta of each wireless tag in the readable range set at the current output level P when the portable communication terminal 1 is moved by V (that is, each wireless tag exists in the readable range) Average time).

There are various methods for calculating the average power supply time Ta. For example, table data in which the average power supply time Ta is determined according to the combination of the output level P and the moving speed V (for example, table data obtained by experimental results). ) Is prepared in advance, and in S11, the table data is referred to and the average power supply time Ta is obtained based on the currently set output level P and the moving speed V calculated in S10. Good. Alternatively, it can be calculated by an arithmetic expression using the output level P and the moving speed V as parameters. Specifically, the diameter D1 of the readable range at a position separated from the portable communication terminal 1 by a predetermined distance can be determined by a function f (P) (for example, a proportional function) using the output level P as a parameter. For example, the power supply average time Ta (upper limit time) can be obtained by Ta = V / (D1 × 2).
In the present embodiment, the control unit 3 that executes the process of S11 corresponds to an example of an “upper limit time calculating unit”. The readable range that can be switched by the “readable range switching unit” and the “movement speed detecting unit”. The upper limit time of the reading process is calculated based on the moving speed V of the portable communication terminal 1 detected by the above.

  Thereafter, a process of acquiring the distribution density of the wireless tag is performed (S12). In the present embodiment, in the calibration process (FIG. 5), as shown in FIG. 10, the number of tags for each Q value is detected for each output, and further, although not shown in FIG. The average number of detected tags is also calculated for each output. For example, based on the number of tags detected at the output P1 (X × N12, X × N13, X × N14, X × N15... In FIG. 10), the average number of tags at the output P1 is calculated. Similarly, the average number of tags in each output is calculated for the outputs P2, P3, P4. And based on the average number of tags at each of these outputs P1, P2, P3... And each output P1, P2, P3..., It is associated with each output P1, P2, P3. The distribution density of the wireless tag is calculated and stored in the memory 13 in advance. As the “value indicating the distribution density” of each output P1, P2, P3..., As shown in FIG. 10, the average number of tags at each output (for example, ((X × N12 + X × N13 + X × N14 + X × N15... / Y1: where Y1 is the number of changes in the Q value) may be recorded in the memory 13, and the average number of acquired tags for each output as shown in FIG. A value (for example, (N12 + N13 + N14 + N15...) / Y2: where Y2 is a number obtained by changing the number of slots) may be stored in the memory 13 in the case of P1 in FIG.

In the process of S12, such a record is referred to, and the distribution density of the wireless tag corresponding to the currently set output level P is acquired. For example, if the currently set output level P is P1 shown in FIG. 10, values indicating the distribution density stored in association with P1 (for example, (X × N12, X × N13, X × N14, X × N15...) / Y: where Y is the number of changes in the Q value) is acquired as the distribution density at P1.
In the present embodiment, the control unit 3 corresponds to an example of “distribution density detection means” and functions to detect the distribution density of the wireless tag existing in the readable range of the “wireless communication means”.

Thereafter, based on the currently set output level P (the output level actually used for reading) and the distribution density obtained in S12, the number of tags within a readable range determined according to the output level. Is calculated (S13). Note that the average number of tags at each output as shown in FIG. 10 (for example, if the output is P1, ((X × N12 + X × N13 + X × N14 + X × N15...) / Y1: where Y1 is the Q value) Is stored as “value indicating distribution density”, the average value read in S12 itself is the number of tags within the readable range determined according to the current output level P. As shown in FIG. 9, the average value of the number of acquired tags for each output (for example, in the case of P1 in FIG. 9, (N12 + N13 + N14 + N15...) / Y2: Y2 is a number obtained by changing the number of slots) When stored as “value indicating distribution density”, a value obtained by multiplying the average value read in S12 by X is the number of tags within the readable range determined according to the current output level P.
In the present embodiment, the control unit 3 that executes the process of S13 corresponds to an example of the “reading number estimation unit”, and the distribution density detected by the “distribution density detection unit” and the “readable range switching unit”. It functions to estimate the number of read RFID tags based on the output level P switched by.

  And the process which calculates Q value based on the number of tags obtained by S13 and the table data obtained by the calibration process of FIG. 5 is performed (S14). Specifically, referring to the table data updated in the calibration process, the power supply in S11 within the estimated processing time for each Q value for the number of read sheets (estimated read number) calculated in S13. The estimated processing time that satisfies the average time Ta (upper limit time) is obtained from the table data, and the Q value with the shortest processing time in the satisfaction range is selected. For example, when the read number (estimated read number) calculated in S13 is “5” and the average power supply time Ta (upper limit time) in S11 is “140”, the table data in FIG. In the row of the number of tags “5”, the Q value (2, 3, 4, in FIG. 8) whose estimated processing time is less than “140” is set as a satisfactory range, and among these, “3” having the shortest processing time is set. Select as Q value. Note that after the Q value is selected in this way, actual wireless communication processing is performed, and the Q value set in S14 is used in the anti-collision processing performed in the wireless communication processing.

  In the present embodiment, the control unit 3 corresponding to the “slot number setting unit” outputs the output level switched by the “readable range switching unit”, the distribution density detected by the “distribution density detection unit”, and The number of slots is set based on the moving speed V detected by the “moving speed detecting means”. Specifically, the number of readings estimated by the “reading number estimating means”, table data, and “ Based on the upper limit time calculated by the “upper limit time calculating means”, a Q value that is a parameter for the number of slots is set.

(Main effects of this embodiment)
In the portable communication terminal 1 according to the present embodiment, the distribution density of wireless tags existing in the readable range of the “wireless communication means” and the moving speed V of the portable communication terminal 1 are detected, and the detected distributions are detected. The number of slots is set based on the density and the moving speed V. In this way, in the portable communication terminal 1 that is used in various environments, the collision prevention is performed based on the distribution density of the wireless tags in the actual reading environment and the moving speed V when actually operated. It becomes easy to set the number of slots used for processing appropriately.

  Further, by switching the output level of the electromagnetic wave by the “output unit”, a “readable range switching unit” for changing the readable range of the “wireless communication unit” is provided, and switched by this “readable range switching unit”. The number of slots is set based on the output level, the distribution density detected by the “distribution density detecting means”, and the moving speed V detected by the “moving speed detecting means”. In this way, in addition to the distribution density of the wireless tag in the actual reading environment and the moving speed V when actually operated, the number of slots is further considered in consideration of the readable range when actually used. Can be set. Therefore, it becomes easier to set the number of slots more appropriately.

  Table data for setting an estimated processing time for reading each read number when set to each Q value based on the Q value as a parameter for setting the number of slots and the read number of the RFID tag; “Reading number estimation means” for estimating the number of readings of the wireless tag based on the distribution density detected by the “distribution density detection means” and the output level switched by the “readable range switching means” is provided. Yes. In this way, the number of wireless tags existing in the readable range can be estimated with higher accuracy. In addition, since each estimated processing time when reading the estimated number of readings with each Q value can be grasped by referring to the table data, it is easy to select a Q value that reduces the processing time.

  In addition, by changing the output level of the “output means” when performing the calibration process, the number of wireless tags existing within the readable range is changed during the calibration process. When each readable range is set by the “readable range switching means”, the Q value is switched to a plurality of values at each setting of each readable range. Further, the number of wireless tags in each readable range switched in this way is estimated, and the wireless tag reading process by the “wireless communication means” when each readable range and each Q value are set during the calibration process. The time is detected for each combination of each readable range and each Q value. Then, the table data is updated based on each number of wireless tags in each readable range estimated by the “number estimation unit” and each reading processing time detected by the “reading processing time detection unit”. . In this way, the number of wireless tags in the readable range can be variously changed without imposing a special effort on the user during the calibration process, and there are each number of wireless tags in the readable range. In some cases, the reading processing time when the Q value is changed to various values can be easily acquired. Since the table data is updated based on the data thus obtained, the table data can be updated to more reliable data reflecting the environment when the calibration process is performed.

  In addition, when the readable range is set during the calibration process, the “collision prevention unit” is configured so that the wireless tag that exists in the readable range for some of the slots set by the “slot number setting unit”. The process of assigning is performed. Then, the “number estimation means” estimates the number of wireless tags existing in the readable range based on the assignment result of the wireless tags to some slots by the “collision prevention means”. In this way, since it is not necessary to assign all the radio tags for all slots during the calibration process, the pre-adjustment process time can be greatly reduced.

  Further, the upper limit time of the reading process is calculated based on the readable range switched by the “readable range switching unit” and the moving speed V of the portable communication terminal 1 detected by the “moving speed detecting unit”. An upper limit time calculation means ”is provided. The “slot number setting means” refers to the table data and is calculated by the “upper limit time calculating means” within the estimated processing time for each Q value for the read number of sheets estimated by the “read number estimation means”. The estimated processing time that satisfies the upper limit time is obtained from the table data, and the Q value is set within the satisfaction range. In this way, it is possible to grasp how long the reading process for the estimated number of read RFID tags should be completed (how long is the upper limit time of the reading process). Since the Q value is set within the sufficient range of the upper limit time with reference to the table data, it is difficult to cause a situation in which a part of the estimated number of read sheets is out of the readable range without being completely read.

  In addition, an “imaging unit” that captures an imaging target outside the apparatus a plurality of times at different timings when the portable communication terminal 1 moves is provided, and the portable communication terminal 1 is based on images of the imaging target at different timings. The moving speed V is detected. In this way, the image pickup means can be used together, and the moving speed V of the portable communication terminal 1 can be detected more accurately using this image pickup means.

[Other Embodiments]
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  In the above embodiment, an example as shown in FIG. 12 is shown as a method for detecting the moving speed V. However, the method shown in FIG. 12 is merely an example, and any method that can detect the moving speed V of the portable communication terminal 1 is used. Good. For example, a known speed sensor or acceleration sensor is provided inside the portable communication terminal 1 so that a predetermined trigger operation is performed by the user within a predetermined time or a predetermined notification (for example, by a buzzer) The movement speed V of the portable communication terminal 1 within the certain time may be grasped based on the sensor value detected within a certain time after the notification.

In the above embodiment, the Q value is set as described in S14, but further conditions may be added to the setting of the Q value. For example, at least one of the number of wireless tags read by the “wireless communication unit” during the previous reading process and the number of times the wireless tags collided in the collision prevention process performed during the previous reading process; The number of slots may be set based on the number of slots used in the previous reading process. For example, in the data of the number of readings estimated in S13 in the table data of FIG. 8, the data of the Q value in which the number of collisions between the wireless tags in the previous reading process has exceeded a certain threshold is adopted. In the previous reading process, it may not be adopted for the Q value data in which the ratio of the acquired wireless tag to the total number of slots is equal to or less than a certain threshold (that is, the empty slots are equal to or more than a certain degree). .
In this case, whether or not the previous number of slots is appropriate is determined by at least one of the number of wireless tags read during the previous reading process and the number of times the wireless tags collided during the previous reading process. And the number of slots used in the previous time can be reflected in the setting of the number of slots this time.

DESCRIPTION OF SYMBOLS 1 ... Portable communication terminal 3 ... Control part (Wireless communication means, output means, slot number setting means, collision prevention means, distribution density detection means, moving speed detection means, readable range switching means, read number estimation means, calibration Means, number estimating means, reading processing time detecting means, updating means, upper limit time calculating means)
5 ... Wireless tag processing unit (wireless communication means)
7 ... antenna 20 ... transmission circuit (output means)
33 ... Light receiving sensor (imaging means)

Claims (5)

Output means for outputting electromagnetic waves via an antenna, wireless communication means for performing wireless communication with each wireless tag using the electromagnetic waves,
Slot number setting means for setting the number of slots;
As many slots as the number of slots set by the slot number setting means are prepared, each wireless tag existing within the readable range of the wireless communication means is assigned to each slot, and each wireless tag is uniquely identified. Anti-collision means for performing anti-collision processing associated with
With
The wireless communication means is a portable communication terminal that recognizes each wireless tag based on each identification information associated with each wireless tag by the collision prevention means and communicates with each wireless tag,
A distribution density detecting means for detecting a distribution density of the wireless tag existing in the readable range of the wireless communication means;
A moving speed detecting means for detecting a moving speed of the portable communication terminal;
Readable range switching means for changing the readable range of the wireless communication means by switching the output level of the electromagnetic wave by the output means;
Table data for setting an estimated processing time for reading each read number when set to each Q value based on the Q value as a parameter for setting the number of slots and the number of read RFID tags,
A reading number estimation unit that estimates the number of readings of the wireless tag based on the distribution density detected by the distribution density detection unit and the output level switched by the readable range switching unit;
With
The slot number setting means includes the output level switched by the readable range switching means, the distribution density detected by the distribution density detection means, and the movement speed detected by the movement speed detection means. A portable communication terminal, wherein the number of slots is set based on the number of readings, and the Q value is set based on the number of readings estimated by the reading number estimating means and the table data. Calibration means for performing calibration processing of the table data;
The readable range switching unit is configured to change the output level of the output unit when the calibration unit performs the calibration process, so that the wireless tag existing in the readable range during the calibration process is changed. The number of
The slot number setting unit switches the Q value to a plurality of values at the time of setting each readable range when each readable range is set by the readable range switching unit during the calibration process. And
The calibration means includes
A number estimating means for estimating the number of the wireless tags in each readable range switched by the readable range switching means during the calibration process;
Detecting the reading process time of the wireless tag by the wireless communication means when the readable range and the Q value are set in the calibration process for each combination of the readable range and the Q value, respectively. Reading processing time detecting means for
Updating means for updating the table data based on each number of the RFID tags in each readable range estimated by the number estimating means and each reading processing time detected by the reading processing time detecting means; ,
The portable communication terminal according to claim 1 , comprising: When the readable range is set at the time of the calibration process, the collision prevention unit is configured to detect the wireless tag existing in the readable range for a part of all slots set by the slot number setting unit. Process to assign
The number estimating means, on the basis of the allocation result of the radio tag of the to some slot by the collision prevention means, according to claim 2, characterized in that to estimate the number of the radio tags present in the readable range The portable communication terminal described in 1. Upper limit time calculating means for calculating an upper limit time of reading processing based on the readable range switched by the readable range switching means and the moving speed of the portable communication terminal detected by the moving speed detecting means; Prepared,
The slot number setting means refers to the table data and is calculated by the upper limit time calculation means within the estimated processing time for each Q value for the number of read sheets estimated by the number of read sheet estimation means. obtains the estimated processing time satisfying the upper limit time from the table data, the mobile communication terminal according to any one of claims 1 to 3, characterized in that to set the Q value at that satisfy ranges . The moving speed detecting means includes
An imaging means for imaging an imaging target outside the apparatus a plurality of times at different timings when the portable communication terminal is moved;
In any one of claims 1 to 4, characterized in that to detect the moving speed of the mobile communication terminal based on a plurality of images of the imaging subject to be imaged at different timings by said image pickup means The portable communication terminal as described.

Images