JP5268501B2 - Wireless tag communication system and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless tag communication system, performing stable wireless tag communication without a special circuit and equipment and without changing the intensity of an electromagnetic wave to excess even when the resonance frequency of a resonance circuit of a wireless tag changes with the type and quantity of toner stored in a toner cartridge. <P>SOLUTION: When the resonance frequency of the resonance circuit of the wireless tag is f1, and the resonance frequency changed by an external factor to the wireless tag is f2, the frequency f of an electromagnetic wave used between a communication unit provided on the apparatus body and the wireless tag is f1&gt;f&ge;(f1+f2)/2. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a wireless tag communication system including a wireless tag and a communication unit provided in the apparatus body, and an image forming apparatus in which a toner cartridge to which the wireless tag is attached can be detachably mounted.

  Conventionally, an image forming apparatus using an electrophotographic method such as a laser beam printer, a digital copying machine, or a laser facsimile has been used. In such an image forming apparatus, the electrostatic latent image formed on the photosensitive drum is visualized by a developing device. Toner is supplied from the toner cartridge to the developing device, and a toner image is formed by the toner, whereby visualization is performed. A toner cartridge that supplies toner to the developing device is provided with a wireless tag that stores the type and characteristics of toner to be stored, the number of times the cartridge is used, and the like (see Patent Document 1).

Here, the distance that the communication unit provided in the image forming apparatus can wirelessly communicate with the wireless tag (hereinafter simply referred to as “communication distance”) depends on the type and amount of toner in the toner cartridge, variation in used parts, or the like. Change. For example, when the type and amount of toner change, the resonance circuit of the wireless tag is affected by the metal (magnetic material) contained in the toner, and the resonance frequency of the circuit changes. Therefore, the communication distance between the communication unit and the wireless tag also changes, causing a communication failure.
JP 2007-212698 A JP 2003-188765 A

  In order to solve the above problems, there is a method of maintaining the communication intensity by changing the communication frequency of the electromagnetic wave used between the communication unit and the wireless tag according to the resonance frequency that changes according to the amount of toner. However, in this case, a circuit for changing the communication frequency is required, and there is a possibility that the communication frequency range of RFID (Radio Frequency Identification) defined by the Radio Law is out of range.

  In Patent Document 1, the intensity of electromagnetic waves used between a wireless tag and a communication unit is set to a level at which communication with the wireless tag can be performed without any problem regardless of the type and amount of toner. Thus, a method for ensuring the stability of wireless communication is described. However, in this method, the intensity of electromagnetic waves is excessively increased, and unnecessary radiation is at a high level.

  Patent Document 2 describes a method in which a magnetic sheet is interposed so that toner contained in a toner cartridge does not affect the resonance frequency of the resonance circuit of the wireless tag. However, the magnetic sheet is expensive and expensive.

  The present invention has been made to solve the above problems, and even if the resonance frequency of the resonance circuit of the wireless tag changes depending on the type and amount of toner stored in the toner cartridge, a dedicated circuit and equipment are provided. An object of the present invention is to provide a wireless tag communication system and an image forming apparatus that perform stable wireless communication without needing to change the intensity of electromagnetic waves excessively.

The wireless tag communication system according to claim 1 includes a wireless tag and a communication unit that performs wireless communication with the wireless tag, and the wireless tag performs wireless communication with the communication unit. When the resonance frequency of the resonance circuit is f1 and the resonance frequency changed by an external factor with respect to the wireless tag is f2, the frequency f of the electromagnetic wave used between the communication unit and the wireless tag is f = (f1 + f2) / 2.

  According to this configuration, it is possible to suppress fluctuations in the intensity of the electromagnetic wave received by the resonance circuit after the resonance frequency of the resonance circuit included in the wireless tag changes and before the change due to external factors. Therefore, even when the resonance frequency of the resonance circuit of the wireless tag changes, wireless communication can be stably performed between the wireless tag and the communication means. Furthermore, since the electromagnetic wave output from the communication means is not increased, and a dedicated circuit / device is not required, stable wireless communication can be easily realized without increasing unnecessary radiation.

  According to a second aspect of the present invention, there is provided an image forming apparatus comprising: the wireless tag communication system according to the first aspect; and a toner storage body detachably attached to the apparatus main body, wherein the wireless tag is the toner. The communication means is provided in the apparatus main body, the resonance frequency f1 is a resonance frequency when no toner is stored in the toner storage body, and the resonance frequency f2 Is a resonance frequency when the amount of toner at the time of factory shipment is stored in the toner storage body.

  According to this configuration, it is possible to suppress fluctuations in the intensity of the electromagnetic wave received by the resonance circuit before and after the resonance frequency of the resonance circuit included in the wireless tag is changed by the toner stored in the toner storage body. Therefore, even when the resonance frequency of the resonance circuit of the wireless tag changes, wireless communication can be stably performed between the wireless tag and the communication means.

  Here, “the amount of toner at the time of factory shipment” means that the amount of toner stored in the toner container is sufficient, but it may be an amount that affects the resonance frequency of the resonance circuit of the wireless tag. That's fine.

A third aspect of the present invention is the image forming apparatus according to the second aspect, wherein the resonance frequency f1 of the resonance circuit when no toner is stored in the toner storage body is 13.56 [MHz]. There, the resonance frequency f2 of the resonant circuit when the toner in the toner accommodating body is accommodated are smaller frequency than f1.

  According to this configuration, the same effect as in the first aspect can be obtained.

  According to the present invention, it is possible to suppress fluctuations in the intensity of the electromagnetic wave received by the resonance circuit between after the resonance frequency of the resonance circuit of the wireless tag changes due to an external factor and before it changes. Therefore, even when the resonance frequency of the resonance circuit of the wireless tag changes, wireless communication can be stably performed between the wireless tag and the communication means. Furthermore, since the intensity of the electromagnetic wave output from the communication means is not increased, and a dedicated circuit / device is not required, stable wireless communication can be easily realized without increasing unnecessary radiation.

  A wireless tag communication system and an image forming apparatus according to an embodiment of the present invention will be described below with reference to the drawings. In this embodiment, an electrophotographic printer will be described as an example of the image forming apparatus. However, any image forming apparatus that performs printing using toner containing a magnetic material, such as a copying machine or a facsimile, may be used. .

  FIG. 1 is a cross-sectional view schematically showing an internal configuration of a printer 1 in the present embodiment. The printer 1 includes a paper feed unit 8, an image forming unit 2, a transfer unit 9, a fixing unit 11, a paper discharge tray 12, and the like.

  The image forming unit 2 includes a photosensitive drum 3, a charging unit 4, an exposure unit 5, a developing unit 6, a cleaning unit 7, and the like. The photosensitive drum 3 is an image carrier on which a toner image is formed. The charging unit 4 uniformly charges the photosensitive drum 3. The exposure unit 5 exposes the circumferential surface of the uniformly charged photoreceptor drum 3 to form an electrostatic latent image. The developing unit 6 visualizes the formed electrostatic latent image to create a toner image. The toner image produced in this way is transferred onto the recording paper by a transfer unit 9 described in detail later. The cleaning unit 7 cleans the toner remaining on the surface of the photosensitive drum 3 after the transfer is completed.

  The transfer unit 9 includes a transfer roller 91, and the toner image formed on the photosensitive drum 3 is transferred to the recording paper conveyed from the conveyance path 83 in a state where the transfer roller 91 is pressed against the photosensitive drum 3. Transfer. The paper feed unit 8 includes a paper feed cassette 81, a pickup roller 82, a transport path 83, a transport roller 84, and the like. Paper).

  The fixing unit 11 is provided on the downstream side of the image forming unit 2 and the transfer unit 9, and includes a heat roller 11a and a pressure roller 11b. The fixing unit 11 performs fixing processing of the toner image transferred to the recording paper. On the further downstream side of the fixing unit 11, a conveyance roller 86, a discharge roller 87, a conveyance path 85, and the like are provided. The paper is conveyed downstream and discharged to the paper discharge tray 12 at the top of the printer 1.

  FIG. 2 is a cross-sectional view showing a detailed configuration of the developing unit 6. The developing unit 6 includes a toner cartridge 61 including a container (container) for storing toner (developer), a developing unit 62 including a developing roller 621, and the like. Thus, the toner in the toner cartridge 61 is supplied to the agitation unit, and the toner is supplied to the agitation unit developing roller 621 by the rotational drive of the agitation roller 611 (agitating screw). A developing sleeve 6211 is provided on the outer peripheral portion of the developing roller 621, and a developing bias is applied to the developing sleeve 6211, and the toner charged positively by the agitating portion is used as the photosensitive drum 3 (FIG. 1). It is adsorbed on the exposed portion of the surface (the portion of the electrostatic latent image from which static electricity has been removed by exposure). The developing unit 6 is configured such that the toner cartridge 61 can be detachably attached to the developing unit 62.

  FIG. 3 is a partially enlarged view of a range indicated by a symbol A of the developing unit 6 in FIG. The configuration of the lower part of the mounted toner cartridge 61 is shown in detail. A wireless tag 101 is attached to one side wall portion of the toner cartridge 61, and a communication unit 102 is attached to one side wall portion of the developing unit 62. When the toner cartridge 61 is mounted, the wireless tag 101 and the communication unit 102 face each other with a predetermined distance (for example, about 5 mm).

  The wireless tag 101 performs wireless communication with the communication unit 102. The wireless tag 101 includes a semiconductor chip (wireless IC chip) that can transmit and receive data using electromagnetic waves, and generates an electromotive force by electromagnetic waves from the communication unit 102 (based on the principle of electromagnetic induction). The circuit is driven to exchange data with the communication unit 102.

  The communication unit 102 performs radio communication with the wireless tag 101 by outputting an electromagnetic wave having a predetermined communication frequency (for example, 13.56 [MHz]) with a predetermined communication output. Details of this communication frequency will be described later.

  FIG. 4 is a diagram illustrating a schematic configuration of the wireless tag 101. The wireless tag 101 includes a memory 201, a resonance capacitor 202, and a resonance inductance (antenna) 203. The memory 201 stores information unique to the toner cartridge, that is, information such as the number of times the toner cartridge is used, the characteristics of the toner in the container, and the remaining toner amount. The communication unit 102 reads this information stored in the memory 201 by wireless communication.

  The resonance inductance 203 is an antenna configured as a loop antenna, and wireless communication with the communication unit 102 is performed via the resonance inductance 203. The resonance inductance 203 and the resonance capacitor 202 constitute a resonance circuit 200. The resonance circuit 200 functions as a filter that extracts only the resonance frequency of the resonance circuit 200 and a signal having a frequency close to the resonance frequency from the signal received by the resonance inductance 203.

  Generally, in the case of an electromagnetic induction type wireless tag used for recognition of a toner cartridge in an image forming apparatus, wireless communication is performed using an electromagnetic wave having a frequency of 13.56 [MHz]. That is, the communication unit 102 outputs radio waves having a frequency of 13.56 [MHz] to transmit / receive data to / from the wireless tag 101.

On the other hand, the resonance frequency fc of the resonance circuit 200 is obtained by using the inductance L of the resonance inductance 203 and the capacitance C of the resonance capacitor 202.
fc = 1 / (2π × (L × C) ^1/2 ) (1)
Can be obtained. That is, by setting the inductance L and the capacitance C so that fc = 13.56 [MHz] in Equation (1), the electromagnetic wave output from the communication unit 102 can be stably received. .

  FIG. 5 is a graph showing the relationship between the frequency and intensity of the electromagnetic wave received by the resonance circuit 200. The graph G1 is a graph G2 when no toner is stored in the toner cartridge 61 (when the toner cartridge 61 is empty). 9 is a graph when a sufficient amount of toner is stored in the toner cartridge 61. Note that the inductance L and the capacitance C of the resonance circuit 200 are set to satisfy fc = 13.56 [MHz] using the equation (1).

  As shown in FIG. 5, when the toner cartridge 61 is empty, the resonance circuit 200 is not affected by the magnetic substance contained in the toner, so the intensity of the electromagnetic wave received by the resonance circuit 200 is a frequency of 13.56 [MHz]. It has become a peak. On the other hand, when a sufficient amount of toner is stored in the toner cartridge 61, the resonance circuit 200 is affected by the magnetic substance contained in the toner, and the intensity of the electromagnetic wave received by the resonance circuit 200 is 13.18 [MHz]. ] Peak.

  Such event differences cause the following problems. That is, the resonance frequency of the resonance circuit 200 is set to 13.56 [MHz]. When a sufficient amount of toner is stored in the toner cartridge 61, the communication unit 102 generates an electromagnetic wave of 13.56 [MHz]. When output, the resonance circuit 200 changes to the characteristics shown in the graph G2 due to the electromagnetic waves contained in the toner. Therefore, the intensity of the electromagnetic waves received by the resonance circuit 200 is about 89% compared to the intensity indicated by P1 (that is, the peak value). %). When the intensity of the electromagnetic wave received by the resonant circuit 200 decreases (that is, when the communication distance becomes long), data transmission / reception is not performed accurately. For example, since the communication unit 102 cannot recognize the wireless tag 101, information on the toner being used cannot be obtained, optimal print settings cannot be made, and maintenance information may be misrecognized. Degrades reliability and user utilities.

  As a method for solving such a problem, a method of increasing the intensity of the electromagnetic wave output from the communication unit 102 can be considered. However, an excessive electromagnetic wave intensity causes an increase in unnecessary radiation.

Therefore, in order to suppress a difference (fluctuation) in the intensity of electromagnetic waves received by the resonance circuit 200 between when the toner cartridge 61 is empty and when a sufficient amount of toner is stored, the electromagnetic waves output from the communication unit 102 are output. F = (13.18 + 13.56) /2=13.37 [MHz] (2)
And When an electromagnetic wave having a frequency of 13.37 [MHz] is output from the communication unit 102, the intensity of the electromagnetic wave received by the resonance circuit 200 is the same as when the toner cartridge 61 is empty and when a sufficient amount of toner is stored. Becomes the intensity shown in P2 (that is, about 97% of the peak value). Therefore, when a sufficient amount of toner is stored in the toner cartridge 61, the frequency of the electromagnetic wave output from the communication unit 102 is 13.37 [MHz] rather than 13.56 [MHz]. However, fluctuations in the intensity of electromagnetic waves received by the resonant circuit 200 can be suppressed. Furthermore, since there is no need to increase the intensity of the electromagnetic wave output from the communication unit 102, stable wireless communication can be easily realized without increasing unnecessary radiation and without requiring a dedicated circuit / device.

  Furthermore, as shown in FIG. 6, when the toner cartridge 61 is empty and when a sufficient amount of toner is stored in the toner cartridge 61, the peak value may increase. In such a case, assuming that the frequency of the electromagnetic wave output from the communication unit 102 is 13.56 [MHz] obtained using Equation (2), the toner cartridge 61 has a sufficient amount of toner stored therein. The intensity of the electromagnetic wave received by the resonance circuit 200 is the intensity indicated by P3 (about 98%). However, when the toner cartridge 61 is empty, the intensity indicated by P4 (about 96%) is obtained. Fluctuations in the strength. This variation can cause instability in wireless communication and cause problems.

Therefore, when the peak value of the received electromagnetic wave is different between when the toner cartridge 61 is empty and when a sufficient amount of toner is stored, in order to suppress fluctuations in the intensity of the electromagnetic wave received by the resonance circuit 200, communication is performed. The frequency f of the electromagnetic wave output from the unit 102 is 13.56> f [MHz] ≧ (13.18 + 13.56) / 2 (3)
And set.

In other words, when the resonance frequency of the resonance circuit 200 when the toner cartridge 61 is empty is f1, and the resonance frequency when a sufficient amount of toner is stored in the toner cartridge 61 is f2, the signal is output from the communication unit 102. The frequency f of the electromagnetic wave is f1> f [MHz] ≧ (f1 + f2) / 2 (4)
And set.

  In this way, by setting the frequency of the electromagnetic wave output from the communication unit 102 using the formula (3) or (4), the fluctuation of the intensity of the electromagnetic wave received by the resonance circuit 200 can be suppressed, and the communication unit Stable wireless communication can be performed between the wireless tag 102 and the wireless tag 101.

  In this embodiment, the case where the toner cartridge 61 is empty and the case where a sufficient amount of toner is stored has been described as an example. However, the “sufficient amount of toner” means, for example, the toner cartridge 61. The amount of toner at the time of shipment from the factory. However, the amount is not limited to the amount at the time of factory shipment, and any amount that affects the resonance frequency of the resonance circuit 200 may be used.

FIG. 3 is a cross-sectional view schematically showing an internal configuration of the printer. Sectional drawing which shows the detailed structure of a image development part. The elements on larger scale of the range shown with the code | symbol A of a image development part. The figure which shows schematic structure of a wireless tag. The graph which shows the relationship between the frequency and intensity of the received electromagnetic wave in a resonance circuit. The graph which shows the relationship between the frequency and intensity of the received electromagnetic wave in a resonance circuit.

Explanation of symbols

1 Printer (image forming device)
2 Image forming unit 6 Developing unit 61 Toner cartridge (toner container)
101 wireless tag 102 communication unit (communication means)
200 Resonant circuit 202 Resonant capacitor 203 Resonance inductance

Claims (3)

A wireless tag,
Communication means for performing wireless communication with the wireless tag;
The wireless tag has a resonance circuit for performing wireless communication with the communication means, and when the resonance frequency of the resonance circuit is f1, and the resonance frequency changed by an external factor with respect to the wireless tag is f2, The frequency f of the electromagnetic wave used between the communication means and the wireless tag is
f = (f1 + f2) / 2
A wireless tag communication system. The wireless tag communication system according to claim 1,
A toner container that is detachably attached to the apparatus body;
The wireless tag is attached to the toner storage body, the communication means is provided in the apparatus main body, and the resonance frequency f1 is a value when no toner is stored in the toner storage body. The image forming apparatus is a resonance frequency, and the resonance frequency f2 is a resonance frequency when the amount of toner shipped from a factory is stored in the toner storage body. The resonance frequency f1 of the resonance circuit when no toner is stored in the toner storage body is 13.56 [MHz], and the resonance frequency f2 of the resonance circuit when toner is stored in the toner storage body. the image forming apparatus according to claim 2 which is lower frequency than f1 is.

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