JP2008225196A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain unwanted radiation in an image forming apparatus. <P>SOLUTION: The image forming apparatus (printer 1 equipped with a communication unit 8 and a toner cartridge 21) is equipped with: a toner cartridge (toner cartridge 21) attachably/detachably attached to the image forming apparatus; a communication means (communication unit 8) communicating with a radio tag (radio tag 7) provided in the toner cartridge (toner cartridge 21); and a modulation factor changing means (setting signal generation part 871 provided in a control circuit 87) changing communication output in the communication with the radio tag (radio tag 7) by changing the modulation factor of a communication wave in communication with the radio tag (radio tag 7) by the communication means (communication unit 8). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus including a toner cartridge that is detachably mounted and a communication unit that communicates with a wireless tag provided in the toner cartridge.

  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. The image forming apparatus is provided with a developing device that develops the electrostatic latent image formed on the photoreceptor, and a toner cartridge that stores toner used for development is detachably attached to the developing device. A communication unit is provided on the image forming apparatus main body side such as a developing device in the vicinity of the toner cartridge, and a wireless tag (IC tag) is provided at a position of the toner cartridge facing the communication unit. The cartridge information such as the type and amount of toner stored in the toner cartridge and the number of times the toner cartridge is used is stored, and the stored wireless tag communicates with the communication unit on the main body side (see Patent Documents 1 and 2). ).

  Here, since the toner contained in the toner cartridge contains metal (magnetic material), when the communication unit communicates with the wireless tag of the toner cartridge, wireless communication is performed depending on the remaining amount and type of the toner. The intensity of the transmitted communication wave changes, and as a result, the limit distance (apparent communication distance, communication limit distance) at which communication is possible fluctuates.

  If the communication limit distance fluctuates in this way and the communication limit distance becomes shorter than the distance between the communication unit and the wireless tag, communication between the communication unit and the wireless tag becomes impossible.

Therefore, the communication output is set in advance so that the output after the fluctuation is large to some extent and the communication is not disabled, so that the output is somewhat large in advance. Even when the remaining toner amount is the maximum and the communication limit distance is the shortest, the communication output is set so that there is a margin that does not disable communication.
JP 2000-216715 A JP 2004-88506 A

  However, in such a conventional image forming apparatus, when the communication limit distance is not shortened due to a small amount of toner or the like, the communication output is excessively large, and unnecessary radiation is generated unnecessarily.

  SUMMARY An advantage of some aspects of the invention is that an image forming apparatus can suppress unnecessary radiation regardless of a remaining amount of toner.

  The image forming apparatus according to claim 1 includes a toner cartridge that is detachably attached to the image forming apparatus, a communication unit that communicates with a wireless tag provided on the toner cartridge, and the wireless tag by the communication unit. The image forming apparatus includes a modulation degree changing unit that changes a communication output of the communication by changing a modulation degree of the communication wave in the communication.

  According to this configuration, since the communication output can be changed by changing the modulation degree, the modulation degree of the communication wave is changed when the communication limit distance becomes short, for example, when the toner cartridge has a large amount of remaining toner. To temporarily increase the communication output to maintain a long appropriate communication limit distance so that communication is not disabled, and to reduce the communication output except when the communication limit distance is shortened. It can be made small, and unnecessary radiation can be suppressed.

  For example, when changing the communication output by changing the frequency of the communication wave, a configuration with a high cost or a large size such as a variable capacitor is required. Since the communication output is changed by changing the modulation degree of the communication wave, unnecessary radiation can be suppressed with a low cost and small configuration by applying a conventional product.

  The image forming apparatus according to claim 2, further comprising intensity detecting means for detecting the intensity of the communication wave, wherein the modulation degree changing means sets a modulation degree used for communication among a plurality of predetermined modulation degrees. The image forming apparatus according to claim 1, wherein the intensity of the communication wave detected by the intensity detecting unit is a modulation degree that is a predetermined intensity.

  According to this configuration, the intensity of the communication wave is detected, and the degree of modulation is changed based on the detected intensity. Therefore, not only the intensity variation due to the toner amount, but also, for example, variations in the characteristics of the communication means between devices, etc. Even when fluctuations occur due to various factors, it is possible to detect the fluctuation intensity and reliably change the modulation degree to an appropriate modulation degree, even when the intensity fluctuates due to various causes, Communication is not disabled and unnecessary radiation can be suppressed.

  The image forming apparatus according to claim 3, further comprising: a communicability detecting unit configured to detect whether the communication is possible, wherein the modulation degree changing unit is configured to detect the communicability among a plurality of predetermined modulation degrees. The image forming apparatus according to claim 1, wherein the modulation degree is changed to the lowest modulation degree at which communication is detected by the means.

  According to this configuration, for example, a predetermined identification signal is exchanged with the wireless tag by communication, and it is detected whether or not the communication can be properly performed, and the modulation degree at which communication is detected is detected. In addition, since the modulation degree is changed to the lowest modulation degree that can be communicated, the modulation degree is changed to an appropriate modulation degree with no excess or deficiency, and communication can be reliably performed. Thus, unnecessary radiation can be sufficiently suppressed.

  And, in this way, whether or not communication is possible is directly detected, and when the modulation degree is changed to the modulation degree according to the detected result, for example, simply detecting the intensity of the communication wave, Compared to the case where the modulation factor is changed to the modulation factor indicating that the communication can be indirectly performed based on the detected intensity, the communication can be reliably performed with the changed modulation factor.

  The image forming apparatus according to claim 4, further comprising: an information acquisition unit configured to acquire information indicating a remaining amount of toner of the toner cartridge stored in the wireless tag from the wireless tag through the communication performed by the communication unit. The image forming apparatus according to claim 1, wherein the changing unit changes the modulation degree to a lower modulation degree as the remaining amount of toner indicated by the information acquired by the information acquisition unit is smaller.

  According to this configuration, by changing the modulation degree to a lower modulation degree as the remaining amount of toner is lower, the remaining amount of toner is increased to a relatively higher modulation degree when there is a possibility that the remaining amount of toner is large and the communication limit distance may be shortened. If there is a risk that the communication output will be unnecessarily high due to a small amount of data, communication cannot be performed by changing the modulation degree to a modulation degree lower than the modulation degree and changing the modulation degree to an appropriate modulation degree. Therefore, unnecessary radiation can be reliably suppressed sufficiently.

  As described above, if information indicating the toner amount is acquired from the wireless tag and the modulation degree is changed, the intensity variation according to the toner amount is accurately determined based on the accurate toner amount indicated by the information. The modulation degree can be appropriately changed to the modulation degree corresponding to the above, and the intensity of the communication wave can be surely set to an appropriate intensity so that the communication can be reliably performed.

  6. The image forming apparatus according to claim 5, wherein a remaining toner storage unit that stores a remaining amount of toner corresponding to each modulation degree used for communication, and a remaining toner amount corresponding to the modulation degree used for communication. 2. The image forming apparatus according to claim 1, further comprising: a remaining toner amount calculating unit that reads the remaining toner amount and calculates the read remaining toner amount as the remaining toner amount of the toner cartridge.

  According to this configuration, the remaining amount of toner can be easily calculated based on the degree of modulation used for communication and the remaining amount of toner.

  According to the present invention, unnecessary radiation can be suppressed.

  Hereinafter, an image forming apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram illustrating the overall configuration of the printer 1.

  The printer 1 is an example of an “image forming apparatus” described in the claims.

  The printer 1 includes a photosensitive drum 3 on which an electrostatic latent image of an image to be copied is formed, and a developing unit 2 that develops the electrostatic latent image formed on the photosensitive drum 3.

  FIG. 2 is an enlarged view of the developing unit 2.

  The developing unit 2 is detachably attached to the developing unit 22 for developing the electrostatic latent image on the photosensitive drum 3 (FIG. 1), and is detachably attached to the developing unit 22. A toner cartridge 21 that stores toner to be used for development by the developing unit 22 and supplies the stored toner to the developing unit 22 is provided.

  The toner cartridge 21 is an example of a “toner cartridge” recited in the claims.

  FIG. 3 is a diagram showing the communication unit 8 and the wireless tag 7 provided in the developing device 22 and the toner cartridge 21, respectively. FIG. 3 is an enlarged view of the vicinity of the portion in contact with the developing device 22 at the bottom of the toner cartridge 21 in FIG.

  The wireless tag 7 is an example of a “wireless tag” described in the claims. The communication unit 8 is an example of “communication means” described in the claims.

  The wireless tag 7 is an IC tag (electronic tag, RFID tag) in which cartridge information such as the type and amount of toner stored in the toner cartridge 21 and the number of times the toner cartridge is used is stored, for example, ISO / IEC15693 or ISO / IEC14443 and other standards (ISO: International Organization for Standardization, IEC: International Electrotechnical Commission).

  On the other hand, the communication unit 8 is a communication device that communicates with the wireless tag 7. For example, the communication unit 8 is connected to the central control device of the printer 1, communicates with the central control device, and performs control through the communication from the central control device. Accordingly, communication with the wireless tag 7 is performed.

  FIG. 4 is a block diagram showing a detailed configuration of the communication unit 8.

  The communication unit 8 includes an antenna 81, a modulation circuit 82, a modulation degree setting circuit 83, a detection circuit 84, a demodulation circuit 85, an intensity detection circuit 86, and a control circuit 87.

  The antenna 81 is an antenna that transmits / receives a wireless communication wave of communication performed by the communication unit 8 to / from the wireless tag 7 to / from the wireless tag 7.

  FIG. 5 is a diagram showing a communication wave 81 w (solid line data) communicated between the communication unit 8 and the wireless tag 7. In FIG. 5, the vertical axis represents the radio wave intensity of the communication wave 81w, and the horizontal axis represents time.

  The communication wave 81w is an example of the “communication wave” described in the claims.

  The modulation circuit 82 generates and generates a communication wave 81 w for transmitting the transmission data signal to the wireless tag 7 by performing ASK modulation on a transmission data signal indicating data to be communicated to the wireless tag 7 by the communication unit 8. The communication wave 81w is transmitted to the wireless tag 7 by the antenna 81. Here, the modulation circuit 82 sets the modulation degree of the generated communication wave 81 w to the modulation degree set in the modulation degree setting circuit 83 in the process of generating the communication wave 81 w by performing such modulation.

  The modulation degree setting circuit 83 sets the modulation degree, causes the modulation circuit 82 to generate a communication wave 81w having the set modulation degree, and further causes the antenna 81 to output the communication wave 81w having the modulation degree. The communication wave 81w communicated between the unit 8 and the wireless tag 7 is changed to a communication wave having the modulation degree. If the modulation circuit 82 sets the generated communication wave 81w to a certain modulation degree, the wireless tag 7 simply performs passive communication that reflects the communication wave 81w from the communication unit 8 and returns a response. The communication wave 81w from the wireless tag 7 in the reverse direction to the communication unit 8 also has the same modulation degree.

  The detection circuit 84 performs envelope detection of the communication wave 81 w transmitted from the wireless tag 7 to the communication unit 8 and received by the antenna 81.

  In FIG. 5, the envelope signal of the communication wave 81w is shown as an envelope signal 81d. The detection circuit 84 generates the envelope signal 81d by detecting the envelope of the communication wave 81w.

  The demodulation circuit 85 demodulates the envelope signal 81d generated by the detection circuit 84, that is, generates a data signal (hereinafter, a received data signal) indicated by the envelope signal 81d. The received data signal is a signal indicating the digital signal values 0 and 1 of data transmitted from the wireless tag 7 to the communication unit 8 by, for example, 0V and 5V.

  Here, the envelope signal 81d (FIG. 5) has one of the digital signals 0 and 1 when the intensity Sa is relatively large, and the other when the intensity Sb is smaller than the intensity Sa. Respectively.

  The demodulating circuit 85 distinguishes the envelope signal 81d intensity with an appropriate threshold value between the intensity Sa and the intensity Sb, for example, and receives a 0V or 5V received data signal depending on whether the intensity exceeds the threshold value. Are generated respectively.

  The modulation degree of the communication wave 81w is determined based on the two intensities Sa and Sb corresponding to the two values indicated by the envelope signal 81d of the communication wave 81w (Sa− The degree of modulation m = {(Sa−Sb) / Sa + Sb} × 100 (%) with Sb) as the molecule.

  An example of the “modulation degree” of the “communication wave” recited in the claims is the modulation degree of the communication wave 81 w in this embodiment.

  The modulation circuit 82 changes the degree of modulation of the generated communication wave 81w within a range of 10% to 30%, for example.

  When the modulation degree set in the modulation degree setting circuit 83 (hereinafter, set modulation degree) changes, the communication output from the antenna 81 of the communication unit 8 and the communication from the communication unit 8 are changed according to the change. The communication output of the responding wireless tag 7 changes, and the intensity of the communication wave 81w in those communications, that is, the intensity Sa shown in FIG. 5 changes. Here, when the modulation degree increases, the communication output of the communication wave 81w increases, thereby increasing the intensity Sa. On the other hand, when the modulation degree decreases, the communication output of the communication wave 81w decreases and the intensity Sa decreases.

  Returning to FIG. 4, the intensity detection circuit 86 detects the intensity Sa of the communication wave 81 w based on the envelope signal 81 d generated by the detection circuit 84. The intensity detection circuit 86 inputs a communication wave intensity signal indicating the intensity Sa to the control circuit 87.

  The intensity detection circuit 86 is an example of “intensity detection means” described in the claims.

  The control circuit 87 is an information processing apparatus and is configured as a control unit of the communication unit 8. The control circuit 87 may be configured as dedicated hardware configured by wired logic, or may be configured as a computer with a built-in program including a CPU, a ROM, and a RAM.

  The control circuit 87 inputs a transmission data signal indicating data to be transmitted to the wireless tag 7 by the communication unit 8 to the modulation circuit 82, thereby transmitting the data to the wireless tag 7 and generated by the demodulation circuit 85. A reception data signal indicating data received from the wireless tag 7 to the communication unit 8 side is acquired from the demodulation circuit 85, and data received from the wireless tag 7 is acquired.

  Then, the control circuit 87 inputs the modulation degree setting signal to the modulation degree setting circuit 83, thereby setting the modulation degree indicated by the input modulation degree setting signal in the modulation degree setting circuit 83. By making such settings, the control circuit 87 changes the modulation degree of the communication wave 81w having the modulation degree to the set modulation degree by the setting, and the communication wave 81w (FIG. 5) having the set modulation degree. Communication is performed between the communication unit 8 and the wireless tag 7.

  In FIG. 4, the communication limit distance D of communication between the communication unit 8 and the wireless tag 7, which changes according to the modulation degree of the communication wave 81 w used for communication between the communication unit 8 and the wireless tag 7, by the two-dot chain line. Is illustrated.

  The communication limit distance D indicates a limit distance at which the communication unit 8 and the wireless tag 7 can communicate with each other. That is, the wireless tag 7 is at this distance with respect to the communication unit 8 or the communication unit 8 side from this distance. The wireless tag 7 can correctly recognize the data indicated by the communication wave 81w received from the communication unit 8, and the communication unit 8 also receives the communication wave 81w from the wireless tag 7 if it is in such a positional relationship. Can be recognized correctly.

  When the modulation circuit 82 changes the degree of modulation of the communication wave 81w, as described above, the communication output changes, and consequently the intensity Sa of the communication wave 81w changes. For this reason, the modulation degree is relatively large, for example, 25% or 30%. Therefore, when the intensity Sa is large, the communication limit distance D becomes long, while the modulation degree is relatively small, for example, 10% or 15%. Sometimes the strength Sa is small and the communication limit distance D is short. That is, the greater the degree of modulation, the longer the communication limit distance D in the communication wave 81w of that degree of modulation, and the shorter the degree of modulation, the shorter.

  The communication limit distance D is equal to the toner cartridge 21 (FIGS. 2, 3, and 4) attached to the developing device 22 (FIGS. 2 and 3) provided with the communication unit 8 even when the modulation degree is the same. Depending on the amount of remaining toner stored, etc., the intensity Sa of the communication wave 81w changes and changes.

  The toner stored in the toner cartridge 21 contains a metal (magnetic material). For this reason, when the amount of remaining toner changes, the degree of influence of the magnetic material changes, so that the resonance frequency of the resonance circuit (not shown) provided in the communication unit 8 or the resonance circuit provided in the wireless tag 7 By changing, those communication outputs fluctuate, the intensity Sa (FIG. 5) of the communication wave 81w changes, and the communication limit distance D fluctuates. At this time, the larger the amount of remaining toner, the lower the communication output becomes, the intensity Sa becomes weaker, and the communication limit distance D becomes shorter. On the other hand, the smaller the amount of remaining toner, the higher the communication output becomes, and the intensity Sa becomes stronger. The communication limit distance D becomes longer.

  Further, the intensity Sa of the communication wave 81w also varies depending on the distribution state of the toner in the toner cartridge 21 and the variation of the characteristics of each part of the printer 1 including the communication unit 8 and the wireless tag 7 for each apparatus. . As described above, the intensity Sa does not stop depending on the remaining toner amount, but also varies depending on other factors other than the remaining toner amount. Therefore, the communication limit distance D varies depending on various factors.

  On the other hand, in the printer 1, the positional relationship between the communication unit 8 provided in the developing device 22 and the wireless tag 7 provided in the other toner cartridge 21 is constant.

  The allowable shortest distance Dm shown in FIG. 4 is a distance between the communication unit 8 and the wireless tag 7, and is about 5 mm, for example. If the communication limit distance D fluctuates and becomes shorter than the allowable shortest distance Dm, the communication unit 8 and the wireless tag 7 cannot communicate with each other, and conversely, the communication limit distance D is the allowable shortest distance. Communication between each other can be performed only during the length of the distance Dm or more.

  FIG. 6 is a diagram illustrating a change in the communication limit distance D according to the remaining amount of toner in the toner cartridge 21.

  In FIG. 6, the remaining amount of toner in the toner cartridge 21 is plotted on the horizontal axis. The intensity Sa of the communication wave 81w changes according to the remaining amount of toner on the horizontal axis. For this reason, the communication limit distance D shown on the vertical axis also changes according to the remaining amount of toner. When the remaining amount of toner is 0%, that is, when the influence of the toner on the intensity Sa of the communication wave 81w is 0, communication is performed. The limit distance D becomes the maximum, and the communication limit distance D at this time is assumed to be 100%. As the remaining amount of toner increases, the influence on the strength Sa increases, so that the communication limit distance D varies greatly and becomes shorter. When the remaining amount of toner is 100%, the communication limit distance D is 89%.

  FIG. 7 is a functional block diagram showing functions implemented in the control circuit 87 (FIG. 4). The control circuit 87 will be described in detail with reference to FIG.

  The control circuit 87 includes functions of a setting signal generation unit 871 and a toner amount specifying unit 872.

  The setting signal generation unit 871 is an example of a “modulation degree changing unit” described in the claims. The toner amount specifying unit 872 is an example of the “toner remaining amount calculating unit” in the claims.

  When the communication unit 8 starts communication with the wireless tag 7, the setting signal generation unit 871 sets an appropriate modulation degree in the modulation degree setting circuit 83 (FIG. 4).

  FIG. 8 is a diagram illustrating a correspondence relationship between the remaining amount of toner and an appropriate degree of modulation.

  In FIG. 8, as in FIG. 6, the remaining amount of toner is taken on the horizontal axis, and for each remaining toner amount, an appropriate modulation degree is obtained when the toner amount corresponding to the remaining toner amount causes a change in intensity Sa. Shown on the axis.

  The appropriate modulation degree is the intensity Sa after the fluctuation after the intensity fluctuation as described above when the modulation degree is set in the modulation degree setting circuit 83 and the modulation degree of the communication wave 81w becomes the modulation degree. Is a modulation degree at which the communication limit distance D becomes the allowable shortest distance Dm.

  When the communication limit distance D is long, for example, in FIG. 6, the communication limit distance D is 99% when the remaining amount of toner is small and the intensity Sa is small, for example, as shown in FIG. As shown in FIG. 6, for example, when the remaining amount of toner is 90% in FIG. 6, the communication limit is increased. When the communication limit distance D becomes short, such as when the distance becomes 90%, the appropriate modulation degree becomes large, such as 24%, as shown in FIG. In other words, the appropriate modulation degree is such that the remaining amount of toner is large and the intensity Sa is low, and therefore, the higher the communication limit distance D is, the higher the modulation degree is, and the remaining amount of toner is small and the intensity Sa is not weakened. The lower the communication limit distance D, the lower the modulation degree.

  Note that how the setting signal generation unit 871 identifies the appropriate modulation degree and sets it in the modulation degree setting circuit 83 will be described later with reference to the flowchart of FIG.

  The toner amount specifying unit 872 includes a toner correspondence storage unit 872m in which a correspondence relationship between the remaining amount of toner illustrated in FIG. 8 and an appropriate modulation degree at the time of the remaining toner is stored in advance, and a setting signal generation unit The remaining amount of toner corresponding to the stored correspondence relation to the appropriate modulation degree identified by 871 is specified as the remaining amount of toner in the current toner cartridge 21. The toner amount specifying unit 872m outputs the toner remaining amount of the specified toner cartridge 21 to the central control device of the printer 1, and causes the display unit such as a setting panel to display the specified toner remaining amount on the central control device. .

  The toner correspondence storage unit 872m is an example of the “toner remaining amount storage unit” in the claims.

  Note that the appropriate degree of modulation varies depending on the remaining amount of toner and may also vary depending on other factors such as variations in the characteristics of the communication unit 8 and the wireless tag 7. Even if they are the same, the remaining amount of toner may be slightly different. The toner correspondence storage unit 872m stores a correspondence between an appropriate modulation degree and an average value of the remaining amount of toner that varies little by little when the appropriate modulation degree varies depending on other factors. It shall be. In this way, the toner amount specifying unit 872 specifies the remaining amount of toner corresponding to the appropriate degree of modulation specified by the setting signal generating unit 871, so that the toner amount specifying unit 872 is within the above-described variation range in the vicinity of the specified remaining toner amount. In addition, the current toner remaining amount can be specified.

  FIG. 9 is a flowchart showing communication processing performed by the communication unit 8 (FIG. 4).

  The communication unit 8 performs communication with the wireless tag 7 by the process shown in FIG.

  In steps Sa1 to Sa3, the control circuit 87 sets an appropriate modulation degree (see FIG. 8) in the modulation degree setting circuit 83 (FIG. 4).

  In step Sa1, the setting signal generator 871 of the control circuit 87 determines each modulation degree from the lowest modulation degree (10%) to the highest modulation degree (25%), NO is determined in step Sa3, and this is repeated. While step Sa1 is executed, each time it is executed, the modulation factor setting circuit 83 is set with a step width of a constant modulation factor sequentially from a high modulation factor.

  In step Sa2, the setting signal generator 871 similarly acquires a communication wave intensity signal (see FIG. 4) indicating the intensity Sa of the communication wave 81w from the intensity detection circuit 86 (FIG. 4).

  In step Sa3, the setting signal generator 871 indicates that the intensity Sa of the communication wave 81w having the modulation degree previously set in step Sa1 indicated by the communication wave intensity signal previously acquired in step Sa2 is allowed by the communication limit distance D. It is determined whether or not the allowable minimum strength is the shortest distance Dm. The setting signal generation unit 871 stores in advance the allowable minimum strength at which the communication limit distance D becomes the allowable shortest distance Dm. Since the communication limit distance D is determined to be a constant distance according to the strength Sa of the communication wave 81w, the setting signal generation unit 871 stores a constant single value as the allowable minimum strength.

  When the setting signal generator 871 determines that the detected intensity Sa at step Sa1 is smaller than the allowable minimum intensity (step Sa3: NO), the setting signal generator 871 returns to the process at step Sa1 to return to the current modulation degree setting circuit 83. A modulation degree smaller than the set modulation degree by a predetermined step width is set in the modulation degree setting circuit 83, and then steps Sa2 and Sa3 are repeated.

  On the other hand, when it is determined that the detected intensity Sa is the same as the allowable minimum intensity (step Sa3: YES), the setting signal generation unit 871 determines that the current setting modulation degree of the modulation degree setting circuit 83 is Since the communication limit distance D of the communication wave 81w with the modulation degree is an appropriate modulation degree that allows the allowable shortest distance Dm, the communication unit 8 is caused to execute the processes of steps Sa4 to Sa5. The setting signal generation unit 871 determines that the detection intensity Sa is the same as the allowable minimum intensity (step Sa3: YES), so that the current modulation degree setting circuit 83 has an appropriate modulation degree. Is identified.

  In step Sa4, the toner amount specifying unit 872 specifies the appropriate modulation degree by determining in step Sa3 that the setting signal generating unit 871 determines that the detected intensity Sa is the allowable minimum intensity (step Sa3: YES), the current setting modulation degree set in the modulation degree setting circuit 83 by the setting signal generation unit 871 in the last step Sa1 is acquired from the setting signal generation unit 871, and the acquired modulation degree The toner remaining amount corresponding to the toner correspondence storage unit 872m (FIG. 7) is specified as the current toner remaining amount of the toner cartridge 21. Then, the toner amount specifying unit 872 outputs a toner amount signal indicating the specified toner remaining amount to the central control device of the printer 1 to display the toner remaining amount on the setting panel.

  In step Sa5, the communication unit 8 performs communication with the wireless tag 7 using the communication wave 81w having an appropriate modulation degree set in the modulation degree setting circuit 83 as described above in steps Sa1 to Sa3. .

  Here, a conventional example will be described. In the conventional example, when the remaining amount of toner is 100% and the communication limit distance is 89% in FIG. When the communication output is set to be equal to or longer than the above-described allowable shortest distance Dm and the remaining amount of toner is less than 100%, the high modulation corresponding to the case where the remaining amount of toner in FIG. As is the case when the toner level is 10% or 30%, the communication output is unnecessarily large, excessive, and inappropriate, resulting in high unnecessary radiation. It was.

  On the other hand, in the printer 1 of the present embodiment, the modulation degree of the communication wave 81w is appropriately adjusted to an appropriate modulation degree, and the high modulation degree corresponding to the remaining amount of toner in FIG. Only when the amount is 100%, and when the remaining amount of toner is small, such as 10% or 30%, the communication limit distance D is the allowable shortest distance Dm described above using a low appropriate modulation degree such as 11% or 14%. Thus, unnecessary radiation can be suppressed while enabling communication.

  Hereinafter, other embodiments will be described.

  (A) FIG. 10 is a diagram illustrating the communication availability determination unit 871j.

  The communicable determination unit 871j is an example of “communication enable detection means” in the claims.

  The setting signal generation unit 871 may include a communication capability determination unit 871j, and may specify an appropriate modulation degree using the function of the communication capability determination unit 871j.

  In step Sa2, the communicability determination unit 871j causes the wireless tag 7 to communicate with the communication unit 8 using the communication wave 81w having the modulation degree previously set in the modulation degree setting circuit 83 in step Sa1. A predetermined identification signal is exchanged between the wireless tag and the communication unit 8. The communication determination unit 871j transmits an identification signal from the communication unit 8 to the wireless tag 7, and when the identification signal is correctly received by the wireless tag 7, the reply identification signal to which the wireless tag 7 responds is the wireless tag. 7 is received by the communication unit 8, the received reply identification signal is acquired.

  Then, in step Sa3, the communication possibility determination unit 871j determines whether or not the modulation degree set in the previous step Sa1 is an appropriate modulation degree, that is, whether the communication limit distance D is the allowable shortest distance Dm. In step Sa2, it is determined whether or not the correct identification signal is received by the communication unit 8, and the correct identification signal is received, so that communication using the communication wave 81w is possible, and the communication limit distance D is allowed. When it is the shortest distance Dm, it is specified that the current modulation degree setting of the modulation degree setting circuit 83 is an appropriate modulation degree (step Sa3: YES), and the communication unit 8 is subjected to the processing of steps Sa4 to Sa5. When the correct identification signal is not received and communication is not possible and the communication limit distance D is shorter than the allowable shortest distance Dm ( -Up Sa3: NO), the process returns to step Sa1, thereby setting the modulation degree of the modulation degree setting circuit 83 to the current modulation index constant step width as low modulation degree described above than.

  In this way, the setting signal generation unit 871 performs the processing of steps Sa1 to Sa3 using the communication enablement determination unit 871j, so that each of the minimum modulation degree (10%) to the highest modulation degree (25%) is obtained. Of the modulation degrees, the lowest modulation degree at which communication is possible, that is, the modulation degree at which the communication limit distance D becomes the allowable shortest distance Dm is set in the modulation degree setting circuit 83.

  (B) FIG. 11 is a diagram illustrating the toner amount information acquisition unit 872i.

  The toner amount information acquisition unit 872i is an example of an “information acquisition unit” in the claims.

  The toner amount information acquisition unit 872i is a functional block of functions realized by the control circuit 87, and is realized by the control circuit 87 instead of the function of the toner amount specifying unit 872 shown in FIG.

  The toner amount information acquisition unit 872i communicates with the wireless tag 7, acquires toner amount information indicating the remaining amount of toner of the toner cartridge 21 provided with the wireless tag 7 from the wireless tag 7, and acquires the acquired toner amount. Based on the information, the toner remaining amount indicated by the toner amount information is specified as the current toner remaining amount of the toner cartridge 21.

  The toner amount information acquisition unit 872i transmits the specified toner remaining amount to the central control device of the printer 1.

  The setting signal generation unit 871 includes a modulation degree storage unit 871m. Based on the storage content of the modulation degree storage unit 871m and the toner remaining amount specified by the toner amount information acquisition unit 872i, an appropriate modulation degree is obtained. Is identified.

  The modulation degree storage unit 871m has an appropriate modulation degree when the communication wave 81w is affected by the remaining amount of toner and the influence of the remaining amount of toner shown in FIG. 8, that is, the communication limit distance D is the allowable shortest distance Dm. The correspondence relationship with the degree of modulation is stored.

  In this modification, the variation in the allowable shortest distance Dm mainly occurs according to the remaining amount of toner, the variation due to factors other than the remaining amount of toner is small, and is substantially zero.

  FIG. 12 is a flowchart showing the flow of communication processing according to a modification in which the setting signal generation unit 871 includes the modulation degree storage unit 871m.

  In this modification, the communication unit 8 communicates with the wireless tag 7 not by the process shown in FIG. 9 but by the process shown in FIG.

  In step Sb1, the toner amount information acquisition unit 872i acquires the toner amount information from the wireless tag 7 and specifies the remaining amount of toner.

  In step Sb2, the setting signal generation unit 871 sets the modulation degree that the modulation degree storage unit 871m corresponds to the remaining amount of toner previously specified by the toner amount information acquisition unit 872i in step Sa1 as an appropriate modulation degree. In particular, the specified modulation degree is set in the modulation degree setting circuit 83.

  In step Sb3, the toner amount information acquisition unit 872i transmits the remaining toner amount specified in step Sb1 to the central control device of the printer 1 in the same manner as in step Sa4 in FIG.

  In step Sb4, the communication unit 8 performs communication using the communication wave 81w having the modulation degree set in the modulation degree setting circuit 83, as in step Sa5 in FIG.

  (C) The modulation circuit 82 is configured as follows, for example.

  The modulation circuit 82 includes a voltage dividing circuit that generates a voltage of the intensity Sa and the intensity Sb, and adjusts the difference in intensity between the intensity Sa and the intensity Sb by using the voltage dividing circuit, so that the modulation degree m = {(Sa−Sb ) / Sa + Sb} × 100 (%) to change the modulation factor of the communication wave 81w to the modulation factor set in the modulation factor setting circuit 83.

  Alternatively, the modulation circuit 82 adjusts the difference in intensity between the intensity Sa and the intensity Sb by changing the amplification performance of the amplifier circuit that generates the intensity Sa and the intensity Sb, and the degree of modulation m = {(Sa− By changing Sb) / Sa + Sb} × 100 (%), the modulation degree of the communication wave 81w is set to the modulation degree set in the modulation degree setting circuit 83.

  (D) The above description shows an example for carrying out the present invention, and the configuration of the printer 1 does not limit the present invention at all. Further, the numerical values such as the communication limit distance used for the description are not limited.

1 is a diagram illustrating an overall configuration of a printer. FIG. 3 is an enlarged view of a developing unit. It is a figure which shows a communication unit and a wireless tag. It is a block diagram which shows the detailed structure of a communication unit. It is the figure which showed the signal of the envelope of a communication wave and a communication wave. It is the figure which showed the fluctuation | variation of the communication limit distance. It is a functional block diagram which shows the function implement | achieved by a control circuit. FIG. 6 is a diagram illustrating a correspondence relationship between a toner remaining amount and an appropriate modulation degree. It is a flowchart which shows the communication processing which a communication unit performs. It is a figure which shows a communication possible determination part. FIG. 6 is a diagram illustrating a toner amount information acquisition unit. It is a flowchart which shows the flow of the communication process which concerns on a modification.

Explanation of symbols

D Communication limit distance (communication limit distance)
Dm Allowable shortest distance Sa Communication wave intensity (communication wave intensity)
Sb Intensity indicating digital signal value m Modulation degree (Modulation degree)
1 Printer (image forming device)
2 Development unit 3 Photosensitive drum 7 Wireless tag (wireless tag)
8 Communication unit (communication means)
21 Toner cartridge (toner cartridge)
22 Developer 81 Antenna 81d Envelope signal 81w Communication wave (communication wave)
82 modulation circuit 83 modulation degree setting circuit 84 detection circuit 85 demodulation circuit 86 intensity detection circuit (intensity detection means)
87 Control circuit 871 Setting signal generator (modulation degree changing means)
871j Communication availability determination unit (communication availability detection means)
871m Modulation degree storage unit 872 Toner amount specifying unit (toner remaining amount calculating means)
872i Toner amount information acquisition unit (information acquisition means)
872m Toner correspondence storage unit (toner remaining amount storage unit)

Claims (5)

A toner cartridge that is detachably attached to the image forming apparatus;
Communication means for communicating with a wireless tag provided on the toner cartridge;
An image forming apparatus comprising: a modulation degree changing unit that changes a communication output of the communication by changing a modulation degree of a communication wave in communication with the wireless tag by the communication unit. Comprising intensity detecting means for detecting the intensity of the communication wave;
The modulation degree changing means sets the modulation degree used for communication to a modulation degree at which the intensity of the communication wave detected by the intensity detecting means is a predetermined intensity among a plurality of predetermined modulation degrees. The image forming apparatus according to claim 1. Comprising communication enable detection means for detecting whether the communication is possible;
2. The image formation according to claim 1, wherein the modulation degree changing unit changes the modulation degree to a minimum modulation degree that is detected as being communicable by the communicability detecting unit among a plurality of predetermined modulation degrees. apparatus. Information acquisition means for acquiring information indicating the remaining amount of toner of the toner cartridge stored in the wireless tag from the wireless tag through the communication by the communication means;
The image forming apparatus according to claim 1, wherein the modulation degree changing unit changes the modulation degree to a lower modulation degree as the remaining amount of toner indicated by the information acquired by the information acquisition unit is smaller. Toner remaining amount storage means for storing the remaining amount of toner corresponding to each modulation degree used for communication;
The image according to claim 1, further comprising: a remaining toner amount calculating unit that reads out a remaining toner amount corresponding to the modulation degree used for communication from the storage unit and calculates the read remaining toner amount as a remaining toner amount of the toner cartridge. Forming equipment.

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