JP2008278290A - Inter-unit communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inter-unit communication device which wireless connects units while reducing electromagnetic interference between them. <P>SOLUTION: The inter-unit communication device 100 has a first unit 1 which is provided with first band-shaped differential transmission lines 12A and 12B that have a specified length and are arranged parallel to each other, and a differential signal transmission element 11 that outputs differential signals to the first differential transmission lines 12A and 12B. In addition, the inter-unit communication device 100 also has a second unit 2 which is provided with second differential transmission lines 22A and 22B that are overlapped with the first differential transmission lines 12A and 12B, and arranged so as to face each other, and a differential signal receiving element 21 that is connected to their edges. The first unit 1 and the second unit 2 are placed through a dielectric medium 4 or a space. If a differential signal flows on the first differential transmission lines 12A and 12B, it is transmitted to the second differential transmission lines 22A and 22B through capacitive coupling and inductive coupling. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inter-unit communication apparatus.

  In recent years, wireless tags using RFID (Radio Frequency-IDentification) as described in Non-Patent Document 1 have been used for identification of various articles, and the frequency band is also in the microwave range from the VHF band and the UHF band. It extends to the 2.4 GHz band.

  In these short-distance communications, an efficient antenna such as a microstrip antenna (commonly referred to as a patch antenna) described in Patent Document 1 is used in order to communicate with a radio tag having a large power restriction, in particular, with sufficient quality. In addition, the host device must use sufficient antenna power. For this reason, many apparatuses are subject to various managements related to radio wave law and electromagnetic environment compatibility as radio equipment.

  However, for example, RFID tags attached to products and their packaging and used for logistics traceability, inventory management, destination designation, etc. have a communication distance of several mm to several cm with the host device. There are many things that can only be done.

  This also applies to management performed by communication with a removable unit in the apparatus. For example, there are several RFID tags attached to replacement parts that are responsible for a part of the image forming process of a process cartridge such as a toner cartridge and a photosensitive drum used in an image forming apparatus such as a copying machine or a printer disclosed in Patent Document 2. Communication is performed at a distance of about mm.

In non-contact transmission with a short communication distance, a communication device that is generally regarded as a wireless device in accordance with radio wave regulations is used. That is, a part that performs non-contact electromagnetic coupling in communication between these units and devices generally has an antenna structure that generates a large radiated electromagnetic field.
Sandip LaHiri “RFID Sourcebook” IBM Press, Aug. 31, 2005 Japanese Patent No. 3223594 JP 2006-30472 A

  An object of the present invention is to provide an inter-unit communication apparatus that enables wireless connection while suppressing electromagnetic interference between units.

  In order to achieve the above object, one aspect of the present invention provides the following inter-unit communication apparatus.

[1] A differential signal transmitting element, a first unit that transmits a signal from the differential signal transmitting element and includes a pair of first differential transmission lines disposed on the same plane, and the pair A pair of the first differential transmission lines arranged opposite to each other in parallel with a predetermined distance so as to form a coupled line system based on capacitive coupling and inductive coupling with the first differential transmission line. Differential signal reception connected to the end of the pair of second differential transmission lines, and a current flowing in the same direction as the current flowing in the pair of first differential transmission lines And a second unit stacked on the first semiconductor integrated circuit element.

[2] The first and second differential transmission lines are arranged to face each other in a non-contact manner in a dielectric or space interposed between the first unit and the second unit. The inter-unit communication device according to [1], which is characterized in that

[3] The inter-unit communication apparatus according to [1], wherein at least one of the first and second differential transmission lines is a differential transmission line arranged in a meander shape.

[4] The first and second differential transmission lines are terminated or terminated at a connection end of the differential signal receiving element with a resistor having a value equal to the characteristic impedance of the first and second differential transmission lines. The inter-unit communication apparatus according to [1], characterized in that

[5] In the first and second differential transmission lines, the distance between the first differential transmission line and the second differential transmission line in the parallel and opposed portions is set to The inter-unit communication apparatus according to [1], wherein the distance is smaller than an interval between two lines of each differential transmission line.

[6] The inter-unit communication according to [1], wherein one of the first and second units has a tag structure including a differential signal transmission element and a film-like differential transmission line. apparatus.

[7] In the above [1], one of the first and second units is a main body of the image forming apparatus, and the other is a replacement part installed in contact with the main body. Inter-unit communication device.

[8] The first unit includes oscillating means for applying a high-frequency current to the first differential transmission line, and the second unit is a rectifier circuit connected to the second differential transmission line. The inter-unit communication device according to [1], further comprising:

  According to the inter-unit communication apparatus of the first aspect, it is possible to perform wireless connection while suppressing electromagnetic interference between the units.

  According to the inter-unit communication apparatus of the second aspect, signal transmission can be performed between the units without contact.

  According to the inter-unit communication apparatus of the third aspect, the wiring length of the straight portion of the differential transmission line can be shortened.

  According to the inter-unit communication device of the fourth aspect, the characteristic impedances of the entire differential transmission line system become equal, and the waveform deterioration of the transmission signal can be reduced.

  According to the inter-unit communication device of the fifth aspect, a signal transmitted from one of the first and second differential transmission lines can be received with high reliability and stability in the other differential transmission line.

  According to the inter-unit communication apparatus of the sixth aspect, a wireless tag can be constructed.

  According to the inter-unit communication apparatus of the seventh aspect, the present invention can be applied to the image forming apparatus and its replacement parts.

  According to the inter-unit communication apparatus of the eighth aspect, the signal receiving semiconductor element can be operated without providing a power source to the semiconductor integrated circuit element on which the signal receiving semiconductor element is mounted.

[First Embodiment]
FIG. 1 is a perspective view showing an inter-unit communication apparatus according to the first embodiment of the present invention.
(Configuration of inter-unit communication device)
The inter-unit communication apparatus 100 includes a first unit 1 on which a differential signal transmitting element 11 for transmitting data is mounted, a differential signal receiving element 21 for receiving data, and a silicon having a small uniform thickness. And a second unit 2 stacked on the first unit 1 via a dielectric 4 made of, for example. The dielectric 4 may be a space such as an air layer.

  For example, one of the first and second units 1 and 2 is an apparatus main body, and the other is a replacement part of the apparatus main body.

  The first unit 1 is connected to a differential output terminal of the differential signal transmission element 11 and is a pair of first differential transmission lines 12A having a predetermined length disposed in parallel in a dielectric 4 made of silicon or the like. , 12B and a termination resistor 13 connected between the terminations of the first differential transmission lines 12A, 12B.

  The termination resistor 13 is a resistor having a value equal to the characteristic impedance of the first differential transmission lines 12A and 12B. As a result, the differential transmission lines 12A and 12B of the first unit are matched and terminated in the same manner as the dummy load of the pseudo antenna, and the electromagnetic field is closed in the near field and no radiated electromagnetic field is generated.

  The second unit 2 has the same length as the first differential transmission lines 12A and 12B, and faces the first differential transmission lines 12A and 12B, and is disposed in the dielectric 4 with a predetermined gap. The pair of second differential transmission lines 22 </ b> A and 22 </ b> B and a termination resistor 23 connected between the differential input terminals of the differential signal receiving element 21 are configured.

  The termination resistor 23 is a resistor having a value equal to the characteristic impedance of the second differential transmission lines 22A and 22B. As a result, the differential transmission lines 22A and 22B of the second unit are matched and terminated in the same manner as the dummy load of the pseudo antenna, and the electromagnetic field is closed in the near field and no radiated electromagnetic field is generated.

  In addition, the first unit 1 or the second unit 2 has the first differential transmission lines 12A and 12B or the second differential transmission lines 22A and 22B in a film shape, and the differential signal transmission elements 11 and 24, A tag structure combined with the differential signal receiving elements 14 and 21 may be used. Thereby, a wireless tag can be easily constructed.

  In the second differential transmission lines 22A and 22B, the differential input terminal of the differential signal receiving element 21 is connected to the end corresponding to the end of the first differential transmission lines 12A and 12B.

  The second differential transmission lines 22A and 22B are disposed to face the first differential transmission lines 12A and 12B with the dielectric 4 interposed therebetween. Further, the first differential transmission lines 12A, 12B, 22A and 22B are Since the first differential transmission lines 12A and 12B and the second differential transmission lines 22A and 22B are arranged at a minute interval, a sufficient capacity is provided between them. It has a configuration that causes sexual coupling.

(Configuration of data demodulation circuit)
FIG. 2 is a circuit diagram of a data demodulating circuit connected to the differential signal receiving element. The data demodulating circuit 30 includes comparators 31 and 32 having one input terminal connected to the output terminal of the differential signal receiving element 21, and RS flip-flops (RS FFs) connected to both output terminals of the comparators 31 and 32. ) Circuit 33.

The comparators 31 and 32 are configured using differential operational amplifiers. A threshold value V _TH1 from a threshold setting circuit (not shown) is input to the − input terminal of the comparator 31, and a threshold value (not shown) is _supplied to the + input terminal of the comparator 32. The threshold value V _TH2 from the setting circuit is input. The output signal of the comparator 31 is input to the S input terminal of the RS flip-flop circuit 33, and the output signal of the comparator 32 is input to the R input terminal of the RS flip-flop circuit 33.

(Operation of inter-unit communication device and data demodulation circuit)
FIG. 3 is a waveform diagram showing the operation of the differential signal receiving element. The operation of the first embodiment will be described with reference to FIGS.

  When a differential data signal is output from the differential signal transmission element 11, this differential data signal is output to the first differential transmission lines 12A and 12B, proceeds toward the terminal thereof, and a terminating resistor serving as a load. 13 is reached.

  At the same time, the capacitance of the differential data signal is mainly present between the second differential transmission lines 22A and 22B by the dielectric 4 in the process of transmitting the first differential transmission lines 12A and 12B. Is transmitted to the second differential transmission lines 22A and 22B through the terminal, and is input to the differential signal receiving element 21 and terminated by the termination resistor 23.

The differential data signal input to the differential signal receiving element 21 is amplified by the differential signal receiving element 21 and then input to the + input terminal of the comparator 31 and the − input terminal of the comparator 32. In addition, threshold _values V _TH1 and V _TH2 are input from the threshold setting circuit to the − input terminal of the comparator 31 and the + input terminal of the comparator 32.

  The signal received by the differential signal receiving element 21 is obtained by differentiating the trapezoidal wave from the transmission side as shown in FIG. 3 from the characteristics of the differential transmission lines 12A, 12B, 22A, and 22B that couple the units 1 and 2. The shape becomes. Therefore, the change point from the logic L to the logic H is detected by the comparator 31, the change point from the logic H to the logic L is detected by the comparator 32, and the output of the RS flip-flop circuit 33 is changed from the logic L to the logic H. The binary logic (transmission signal) of the transmission source is demodulated by changing to H at the change point to, and changing to L at the change point from logic H to logic L.

  Since the differential signal propagating through the first differential transmission lines 12A and 12B is a baseband of a digital signal that is not limited by the band of the carrier wave, broadband communication can be performed. That is, it is the differential signal amplitude shown in FIG. 3 that determines the reception characteristics, and it is sufficient that the rise / fall is fast regardless of the operating frequency.

  Therefore, it is possible to perform transmission over a wide band from the frequency of the signal zero, and it is possible to transmit the digital signal as it is without performing special coding. Further, since the communication according to the present invention is based on current-driven differential transmission, it is suitable for application to an LSI or the like where there is a great demand for low-voltage driving.

[Second Embodiment]
FIG. 4 is a cross-sectional view showing an inter-unit communication apparatus according to the second embodiment of the present invention.
(Configuration of inter-unit communication device)
In this embodiment, in the first embodiment, each of the first and second units 1 and 2 is provided with a differential signal transmitting element and a differential signal receiving element. Is the same as in the first embodiment.

  The first unit 1 includes first differential transmission lines 12A and 12B disposed so as to be exposed in the space 5 of the first and second units 1 and 2, and first differential transmission lines 12A and 12A. Connection electrodes 16 </ b> A to 16 </ b> D that connect 12 </ b> B to the differential signal transmitting element 11 and the differential signal receiving element 14, and an electronic circuit 15 are configured.

  The electronic circuit 15 includes a differential signal transmission element 11 connected to one end of the first differential transmission lines 12A and 12B, a termination resistor 13 connected to the other ends of the first differential transmission lines 12A and 12B, and A differential signal receiving element 14 is mounted.

  Further, the second unit 2 is exposed to the space 5 so as to face the first differential transmission lines 12A and 12B, and the second differential transmission line 22A and the second differential transmission line 22A. , 22B are connected to the differential signal receiving element 21 and the differential signal transmitting element 24, and the connection electrodes 26A to 26D and the electronic circuit 25 are provided.

  The first differential transmission lines 12A and 12B and the second differential transmission lines 22A and 22B have a length of 10 cm, for example.

  The electronic circuit 25 includes a differential signal receiving element 21 and a terminating resistor 23 connected to the other ends of the differential transmission lines 22A and 22B, and a differential signal connected to one end of the second differential transmission lines 22A and 22B. A transmission element 24 is mounted. A data demodulating circuit similar to the data demodulating circuit 30 shown in FIG. 2 is connected to the differential signal transmitting element 24.

(Operation of inter-unit communication device)
Next, the operation of the inter-unit communication device in the second embodiment will be described.
(Transmission from the differential signal transmitting element 11 to the differential signal receiving element 21)
When a differential data signal is output from the differential signal transmission element 11, the differential data signal is output to the first differential transmission lines 12A and 12B via the connection electrodes 16A and 16B, and toward the terminal. Then, the terminal resistor 13 is terminated via the connection electrodes 16C and 16D.

  At the same time, the differential data signal from the differential signal transmission element 11 is transmitted between the second differential transmission lines 22A and 22B via the space 5 in the process of transmitting the first differential transmission lines 12A and 12B. Are transmitted to the second differential transmission lines 22A and 22B via the electrostatic capacitance mainly present in the first and second signals, and input to the differential signal receiving element 21 via the connection electrodes 26C and 26D.

  The differential data signal input to the differential signal receiving element 21 is amplified by the differential signal receiving element 21, and then the processing described in the first embodiment is performed by the data demodulation circuit 30 shown in FIG. .

(Transmission from the differential signal transmitting element 24 to the differential signal receiving element 14)
Next, when a differential data signal is output from the differential signal transmitting element 24, the differential data signal is connected to the connection electrodes 26A and 26B, the second differential transmission lines 22A and 22B, and the connection electrodes 26C, A terminal resistor 23 is terminated through 26D.

  At the same time, the differential data signal from the differential signal transmission element 24 is transmitted between the first differential transmission lines 12A and 12B via the space 5 in the process of transmitting the second differential transmission lines 22A and 22B. Are transmitted to the first differential transmission lines 12A and 12B via the electrostatic capacitance mainly present in the first and second signals and input to the differential signal receiving element 14 via the connection electrodes 16C and 16D.

  The differential data signal input to the differential signal receiving element 14 is amplified by the differential signal receiving element 14, and then the data demodulating circuit similar to the data demodulating circuit 30 shown in FIG. The processing described in the above is performed.

  In the second embodiment, the first unit 1 or the second unit 2 uses the first differential transmission line 12A, 12B or the second differential transmission line 22A, 22B as a film, A tag structure may be formed together with the dynamic signal transmitting elements 11 and 24 and the differential signal receiving elements 14 and 21. Thereby, a wireless tag can be easily constructed.

[Third Embodiment]
FIG. 5 is a plan view showing a first unit of the inter-unit communication apparatus according to the third embodiment of the present invention. FIG. 5 shows the configuration of the first unit 1, but the second unit 2 is configured in the same manner.

  In the first unit 1, the differential signal transmitting element 11 and the differential signal receiving element 14 are arranged close to each other in the electronic circuit 15, and the connection between the differential signal transmitting element 11 and the differential signal receiving element 14 is a meander ( The first differential transmission lines 12A and 12B arranged in the form of a meander) are sufficient between the differential transmission lines 12A and 12B and the second differential transmission lines 22A and 22B even if the unit is downsized. An electrostatic coupling or an inductive coupling is formed. In addition, the length of the meander-shaped portion of the first differential transmission lines 12A and 12B is 10 cm as an example.

  In FIG. 5, the entire first differential transmission lines 12A and 12B are horizontally long, but may be square, for example.

[Fourth Embodiment]
FIG. 6 is a perspective view showing a unit according to the fourth embodiment of the present invention.

  The unit according to this embodiment is applied to an image forming apparatus such as a color printer, and includes an image forming processing unit 41, an image forming processing unit 42, an image forming processing unit 43, and an image forming processing unit 44. Yes. The image forming processing units 41 to 44 are provided with communication devices 45A to 45D used for communication with a communication device provided in the main body of the image forming device (not shown).

  The image forming processing units 41 to 44 are, for example, toner-type developing processing units that are replacement parts, and correspond to yellow, magenta, cyan, and black colors.

  The communication devices 45A to 45D have the same configuration. For example, the differential signal transmission element 11, the first differential transmission lines 12A and 12B, the termination resistor 13, and the differential signal reception element 14 described in the first embodiment. And an electronic circuit 15.

  Further, in the main body of the image forming apparatus, the differential signal receiving element 21, the second differential transmission lines 22 </ b> A and 22 </ b> B shown in the second embodiment, and the terminal are located at positions facing the communication devices 45 </ b> A to 45 </ b> D. A resistor 23, a differential signal transmission element 24, and an electronic circuit 25 are provided.

  In the present embodiment, for example, when data such as toner completion is transmitted from the image forming processing units 41 to 44 to the main body of the image forming apparatus, the first differential transmission line 12A, Data is output to 12B.

  This data is a capacitance that exists mainly between the dielectric 4 and the second differential transmission lines 22A and 22B in the process of proceeding toward the ends of the first differential transmission lines 12A and 12B. To the second differential transmission lines 22A and 22B, and input to the differential signal receiving element 21 on the image forming apparatus side via the second differential transmission lines 22A and 22B.

  In the image forming apparatus, information on the image forming processing units 41 to 44 can be acquired by processing the output signal of the differential signal receiving element 21.

[Fifth Embodiment]
FIG. 7 is a connection diagram showing an inter-unit communication apparatus according to the fifth embodiment of the present invention.
In the present embodiment, a power supply circuit for supplying power from the transmission side to the reception side is added to the first embodiment.

  The power supply circuit 70 is installed in the first unit 1 to generate a continuous wave of a predetermined frequency and output an oscillation circuit 71 as an oscillating means for outputting the continuous wave to one end of the first differential transmission lines 12A and 12B. The second differential transmission lines 22A and 22B of the second unit 2 are connected to the other ends of the second unit 2 and guided from the first differential transmission lines 12A and 12B to the second differential transmission lines 22A and 22B. And a rectifier circuit 72 that rectifies a high-frequency signal to obtain a DC voltage.

  The oscillation circuit 71 is configured using, for example, a CMOS (Complementary Metal Oxcide Semiconductor) device, a resistor (R), and a capacitor (C), and oscillates a signal having a frequency of f = 1 / (2.2CR). Note that the oscillation circuit 71 can substitute the output of the clock circuit mounted in the first unit 1.

  The rectifier circuit 72 includes four diodes 721A to 721D made of diodes having the same specifications, and a smoothing capacitor 722 connected between the rectified outputs.

  The diodes 721A to 721D constitute a bridge rectifier circuit, and the connection point of the diodes 721A and 721B and the connection point of the diodes 721A and 721B connected in series in the same direction are the second differential transmission lines 22A and 22B. Connected to the other end.

(Power supply operation)
In FIG. 7, when the oscillation circuit 71 oscillates at a high frequency, the oscillation signal is applied to one end of the first differential transmission lines 12A and 12B. Since the second differential transmission lines 22A and 22B are coupled to the first differential transmission lines 12A and 12B by capacitive coupling and inductive coupling, the high-frequency signal from the oscillation circuit 71 is transmitted to the second differential transmission line 12A and 12B. The signals are transmitted to the transmission lines 22A and 22B and input to the rectifier circuit 72.

  The rectifier circuit 72 applies a high-frequency signal from the second differential transmission lines 22A and 22B, that is, a DC voltage obtained by rectifying an AC wave by the diodes 721A to 721D to the smoothing capacitor 722. The smoothing capacitor 722 smoothes the pulsating wave from the diodes 721A to 721D and removes the ripple. The terminal voltage of the smoothing capacitor 722 is applied as a power supply to the power supply terminal of the differential signal receiving element 21.

Next, examples of the present invention will be described.
FIG. 8 is a transfer characteristic diagram according to the embodiment of the present invention. The inventor configured the inter-unit communication apparatus 100 shown in the first embodiment with the following parameters and analyzed the characteristics thereof. In FIG. 8, the vertical axis is represented by 20 log (out / in).

  That is, the first differential transmission lines 12A and 12B and the second differential transmission lines 22A and 22B have a line width of 1 mm and a thickness of 100 μm.

  The upper and lower intervals between the first differential transmission lines 12A and 12B and the second differential transmission lines 22A and 22B are 1 mm, and the first differential transmission line in a portion where the currents flowing through both transmission lines are parallel to each other. The distance between 12A and 12B and the second differential transmission lines 22A and 22B (up and down distance) was set to 1 mm.

  Furthermore, the length of the portion where the first differential transmission lines 12A and 12B and the second differential transmission lines 22A and 22B are parallel is set to 100 mm.

  As is apparent from FIG. 8, if the length of the coupling portion between the first differential transmission lines 12A and 12B and the second differential transmission lines 22A and 22B is 100 mm, a component of 100 MHz or more is practical. It can be seen that transmission is possible at −12 dB or more.

  According to the analysis of the present inventor, if the length of the portion where the first differential transmission lines 12A and 12B and the second differential transmission lines 22A and 22B are combined is increased, transmission to a lower band is possible. Even if the distance between the differential wiring pair (differential transmission lines 12A and 12B) is reduced, the transmission characteristics can be improved.

  Also, the wiring widths of the first and second differential transmission lines 12A, 12B, 22A, and 22B may be increased, and the distance between the wirings in the differential pair may be increased accordingly. As a result, the distance between the differential pairs that can obtain the same frequency characteristics can be increased, the margin of positional accuracy can be increased, the application range can be expanded, and the mounting can be facilitated.

  From the above, a part of the image forming process of a toner cartridge or a process cartridge (photosensitive drum, etc.) used in an image forming apparatus such as a copier or printer whose communication distance with the host device is only about several mm to several cm. It can be seen that it is suitable for a replacement part that bears.

[Other embodiments]
The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, the combination of the components between the embodiments can be arbitrarily performed.

  For example, in each of the above embodiments, the differential transmission structure is configured by the differential signal transmission element, the differential transmission line, and the differential signal reception element. It may be.

1 is a perspective view showing a semiconductor integrated circuit device according to a first embodiment of the present invention. It is a circuit diagram of the data demodulation circuit connected to a differential signal receiving element. It is a wave form diagram which shows operation | movement of a differential signal receiving element. It is sectional drawing which shows the semiconductor integrated circuit device based on the 2nd Embodiment of this invention. It is a top view which shows the 1st unit of the inter-unit communication apparatus which concerns on the 3rd Embodiment of this invention. It is a perspective view which shows the inter-unit communication apparatus which concerns on the 4th Embodiment of this invention. It is a connection diagram which shows the inter-unit communication apparatus which concerns on the 5th Embodiment of this invention. It is a transmission characteristic figure concerning the example of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st unit 2 2nd unit 4 Dielectric 5 Space 11, 24 Differential signal transmission element 12A, 12B 1st differential transmission line 13, 23 Termination resistance 14, 21 Differential signal receiving element 15, 25 Electron Circuits 16A-16D, 26A-26D Connection electrodes 22A, 22B Second differential transmission line 30 Data demodulating circuit 31, 32 Comparator 33 RS flip-flop circuits 41-44 Image forming processing units 45A-45D Communication device 70 Power supply circuit 71 Oscillation circuit 72 Rectifier circuit 100 Inter-unit communication device 721A to 721D Diode 722 Smoothing capacitor V _TH1 , V _TH2 threshold

Claims (8)

A first unit comprising a differential signal transmitting element and a pair of first differential transmission lines that transmit signals from the differential signal transmitting element and are disposed on the same plane;
The pair of first differential transmission lines are arranged opposite to each other in parallel with a predetermined distance so as to form a coupled line system by capacitive coupling and inductive coupling with the pair of first differential transmission lines. A pair of second differential transmission lines, and a differential connected to the ends of the pair of second differential transmission lines in which current flows in the same direction as the current flowing in the pair of first differential transmission lines. A second unit including a signal receiving element and stacked on the first semiconductor integrated circuit element;
An inter-unit communication apparatus comprising:   The first and second differential transmission lines are disposed so as to face each other in a non-contact manner in a dielectric or space interposed between the first unit and the second unit. The inter-unit communication apparatus according to claim 1.   2. The inter-unit communication apparatus according to claim 1, wherein at least one of the first and second differential transmission lines is a differential transmission line arranged in a meander shape.   The first and second differential transmission lines are terminated or terminated at a connection end of the differential signal receiving element with a resistor having a value equal to the characteristic impedance of the first and second differential transmission lines. The inter-unit communication apparatus according to claim 1.   In the first and second differential transmission lines, the distance between the first differential transmission line and the second differential transmission line in the parallel and opposed portions is different from each other. The inter-unit communication apparatus according to claim 1, wherein the distance is smaller than the interval between the two lines of the dynamic transmission line.   The inter-unit communication apparatus according to claim 1, wherein one of the first and second units has a tag structure including a differential signal transmission element and a film-like differential transmission line.   2. The inter-unit communication according to claim 1, wherein one of the first and second units is a main body of an image forming apparatus, and the other is a replacement part installed in contact with the main body. apparatus. The first unit includes oscillating means for applying a high-frequency current to the first differential transmission line,
The inter-unit communication apparatus according to claim 1, wherein the second unit includes a rectifier circuit connected to the second differential transmission line.

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