JP2003323098A - Contact type transceiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To contrive low costs by reducing the number of signal lines for communication to one. <P>SOLUTION: In a printer 1, a cartridge 3 has a memory chip 6. Contact type memory tag communication is done between the memory chip 6 and a printer engine. The signal ground of the printer engine is connected to the frame ground 24 of the cartridge 3-mounted printer 1. The frame ground 24 is connected to the drum ground 9 of the cartridge 3. The drum ground 9 is used as the reference potential of one signal line for the contact type memory tag communication. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact type transmitter / receiver for performing data communication.

[0002]

2. Description of the Related Art In recent years, for products with a huge number of individuals,
Information management such as quality and distribution is performed by storing individual information, communicating with them, and rewriting the information.

In this way, the small-sized transmitter / receiver device (element) capable of rewriting data is not limited to commercial products in the future, but may be used as an ID card of an individual in medical treatment or administration, or as securities such as electronic money. Various application developments such as the use of are expected.

Considering the number of individuals and the environment in which they are used, the device added to each individual can have a simple internal circuit configuration from the viewpoints of downsizing, cost reduction, and durability. desirable. Similarly, by simplifying the transmission / reception device that communicates with them, it is expected that the convenience of these information management systems will be improved.

Communication means between each individual and the transmitting / receiving device are classified into contact type (wired type) and non-contact type (wireless type) communication means from the viewpoint of intended use. Contact type communication means
Low cost is realized because the electromagnetic inductive coupling device used in the non-contact type communication means is not required. Further, the contact type communication means differs in the configuration of the internal circuit and the number of required communication signal lines depending on the communication method, but the configuration with two signal lines that can minimize the number of parts is the cheapest. . FIG. 6 shows an example of the configuration of a contact type transmission / reception device having two signal lines.

A contact type transceiver (referred to as a memory chip 6) attached to the cartridge 3 which does not require a power source has two
The signal line 4 and the signal line 5 which are provided with the two contact electrodes 10 corresponding to the signal lines and are connected to the driving device 2 in the printer device 1 are connected through the two contacts on the contact connector 8, that is, the contact terminal 7. The contact is made with the contact electrode 10 of the memory chip 6 to ensure continuity.

There are several communication methods in the configuration of the two signal lines, and an example thereof will be described with reference to FIGS. 7 to 9. In the drive circuit 2 of FIG. 7, the carrier signal SA (FIG. 9 (C)) is amplitude-modulated by the modulation signal generator 12 based on the data signal SB to generate the modulation signal SC (FIG. 9).
(A)) is generated and transmitted on the signal line 4. here,
The signal ground 2 which becomes the reference potential of this modulation signal SC
The signal line 5 is used as 5 (0V). The signal ground 25 is grounded to the frame ground of the printer device 1.

On the other hand, in the memory chip 6 (FIG. 8), the signal line 5 is used as the reference potential, and the modulation signal S from the signal line 4 is used.
The rectifier 14 demodulates C into a data signal SB. An example of the demodulated signal is shown in FIG. By connecting and charging the voltage holding capacitor 16 as shown in FIG. 9, it is possible to prevent the voltage from instantaneously becoming 0 V at the time of switching the carrier signal SC, so that the memory chip 6 always has VL volt (>).
0) or higher voltage is supplied (see FIG. 9B). This serves as a power supply source for the memory chip 6 having no power supply.

The memory chip 6 has the drive circuit 2
When receiving a control command for reading (that is, transmission from the memory chip 6 to the drive circuit 2) from (FIG. 7), the storage unit 1
The signal SE read from 7 is transmitted to the drive circuit 2.

To explain this operation in more detail, first,
During communication, since the drive circuit 2 is synchronized, the carrier signal S
B (FIG. 9C) is constantly transmitted to the memory chip 6. When data is transmitted from the memory chip 6 to the drive circuit 2, the transmission data SB of the drive circuit 2 is stopped in advance by a control command and the voltage is set to a constant voltage (VC). In this state, the modulator 19 (FIG. 8) transmits to the drive circuit 2. The modulator 19 is sufficiently smaller than the input impedance of the memory chip 6 (for example, 1/10).
It is composed of an impedance element 20 and a switch element 21, and is inserted between the signal line 4 and the signal line 5.

When the switch element 21 of the modulator 19 is turned on / off based on the transmission signal SG, the input impedance of the memory chip 6 changes, and the voltage amplitude of the modulation signal SC in the non-modulated state changes. As shown in FIG. 9D, binary (VC, VD: corresponding to 0 and 1 of data) changes, and this binary-changed signal is transmitted on the signal line 4.

When the receiving unit 13 of the drive circuit 2 receives a signal having the voltage amplitude shown in FIG. 9D from the signal line 4, that is, the receiving signal SH, the receiving unit 13 changes the voltage of the receiving signal SH. The detected data is transmitted to the main control unit 11 as received data SI.

[0013]

In order to perform synchronous communication while supplying electric power with the signal line 5 as the reference potential in this way, at least two signal lines are required. It was difficult to reduce the cost.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above problems and to provide a contact type transceiver which can reduce the cost by reducing the number of signal lines for communication to one. is there.

[0015]

According to a first aspect of the present invention, there is provided a contact type transmission / reception device for performing contact type memory tag communication between a storage device having a cartridge mounted in a printer and a printer engine. Is connected to the frame ground of the printer in which the cartridge is mounted, the drum ground of the cartridge is connected to the frame ground, and the drum ground is used for the contact type memory tag communication. It is characterized in that the reference potential of the signal line is used.

In claim 1, the printer engine is
The contact-type memory tag communication is not performed while the high-voltage circuit connected to the drum ground is operating, and the contact-type memory tag communication is performed when the high-voltage circuit is stopped and the discharge from the drum ground is completed. be able to.

In the storage device of the present invention, when the cartridge is detached from the printer, the cartridge coupling is detached, and the drum ground is separated from the frame ground while the photosensitive drum of the cartridge is being discharged. In this case, a filter circuit may be provided to prevent noise from flowing into the signal line.

In the third aspect, the storage device can include a coupling capacitor between the storage device and the filter circuit.

In claim 1, the frame ground is
It can be the conductive frame of the printer.

In claim 1, the storage device may not have a power source.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Construction of Contact Type Transmission / Reception Device of Embodiment> FIG. 1 shows an embodiment of the present invention. This is an example of a contact type transmission / reception device provided in the printer.

As the external device to be communicated, the memory chip 6 provided in the cartridge 3 and having no power source is used, but it is naturally applicable to the memory chip having a power source. The memory chip 6 is connected to the drive circuit 2 via the signal line 4, and data transmission / reception is performed with the drive circuit 2.

Consumables and accessory devices are removable. A contact electrode 10 is provided on the memory chip 6 on the cartridge 3 to perform contact-type transmission and reception. On the other hand, the drive circuit 2 terminates at the contact connector 8 in order to connect the signal line 4 to the memory chip 6. The contact connector 8 has a contact terminal 7 for making contact with the contact electrode 10. With the above configuration, a detachable contact type transceiver can be realized.

As shown in FIG. 2, during printing, the high voltage circuit 31 operates to charge the photosensitive drum 27 in the cartridge 3 via the charging roller 28. In order to discharge this electric charge, the drum ground 9 is connected to the frame ground 24 formed of a sheet metal (having conductivity) of the printer 1. On the other hand, also in the drive circuit 2, the signal ground 25 is grounded to the frame ground 24 of the printer 1. Therefore, the potential of the signal ground 25 of the drive circuit 2 and the potential of the drum ground 9 are the same, and by using this drum ground 9, a common reference is provided without providing a signal line between the cartridge 3 and the drive circuit 2. It becomes possible to use the electric potential.

The memory chip 6 receives a signal from the drive circuit 2 with the drum ground 9 as a reference potential. Conventionally, it has been necessary to transmit the signal ground 24 using the signal line as a reference potential, but according to the present invention, the ground signal line is not required, and the number of signal lines can be reduced.

Therefore, it is possible to reduce the number of contact terminals and signal lines associated therewith, and it is possible to reduce the size and size of the contact electrode on the memory chip 6 and the contact connector, which leads to cost reduction.

Although it has been shown that the number of signal lines can be reduced by the present invention, an example in which serial communication is performed by one signal line in the present embodiment will be described in detail below.

(Transmission of Modulation Signal from Driving Circuit) FIG. 3 shows the configuration of the driving circuit 2 shown in FIG. The main control unit 11 causes the carrier signal SA having a cycle Tclk [sec] as shown in FIG.
Is generated. On the other hand, the data signal SB transmitted from the drive circuit 2 to the memory chip 6 is 1 as shown in FIG.
/ Transfer rate is less than Tclk [bps]. The modulation signal generator 12 superimposes the data signal SB on the carrier signal SA as an amplitude component. As a result, the modulation signal SC that oscillates in the cycle Tclk
Is generated. This is transmitted using the drum ground potential as a reference potential. The example of FIG. 5A is the modulation signal SC transmitted from the drive circuit 2 to the memory chip 6.

(Signal Reception in Memory Chip 6) The modulated signal SC transmitted from the drive circuit 2 is received by the memory chip 6. FIG. 4 shows the configuration of the memory chip 6.
The amplitude component of the modulation signal SC is taken out by the rectification unit 14 built in the memory chip 6, the data signal SB shown in FIG. 5B is demodulated, and the L level signal (voltage VL) holds a certain voltage or more. Therefore, the sub control unit 1
5 can use this as a power source. Here, in order to prevent the voltage drop at the rising and falling edges of the modulation signal SC, the voltage holding capacitor 16 is inserted. The demodulated data signal SB contains the control command sent from the drive circuit 2 in addition to the write data. Based on this, the sub-control unit 15 controls the entire memory chip 6, and writes and reads to and from the storage unit 17 including a non-volatile memory or the like according to the control command. The timings of these controls and communications can be synchronized by the synchronization signal SD obtained from the modulated signal SC by the clock detector 18.

(Transmission from Memory Chip 6 to Drive Circuit 2) When a read control command is received from the drive circuit 2, the signal SE read from the storage unit 17 is applied to the drive circuit 2
Send to. This transmitting means will be described. First, since the drive circuit 2 is synchronized during communication, the carrier signal SB as shown in FIG. 5C is always transmitted to the memory chip 6. Further, when transmitting data from the memory chip 6 to the drive circuit 2, the transmission data SB of the drive circuit 2 is stopped in advance by a control command, and a constant voltage (VC) is set. In this state, the modulator 19 in the memory chip 6 transmits to the drive circuit 2.

The modulation section 19 is composed of an impedance element 20 and a switch element 21 which are sufficiently small (for example, about 1/10) with respect to the input impedance of the memory chip 6, and these are arranged between the signal line and the drum ground potential. Has been inserted. The switch element 21 based on the transmission signal SG
By turning on and off, the input impedance of the memory chip 6 changes, and as a result, the modulation signal SC in the non-modulation state changes in binary value (VC, VD) as shown in FIG. 5D. ), And they correspond to the 0s and 1s of the data. When this signal is used as a reception signal SH, the reception unit 13 of the drive circuit 2 detects a voltage change from the signal SH and transmits it as reception data SI to the main control unit 11. The above is an example of serial communication. In this way, communication is possible even with one signal line.

(Communication Timing) The drum ground 9 is
Originally, the photosensitive drum in the cartridge 3 is grounded to discharge the electric charge. In addition, other consumables of the cartridge and attached devices may also discharge noise such as static electricity through the ground potential. When the drum ground 9 is used as the reference potential, this discharge noise may make data communication unstable. In the present embodiment, the influence of discharge noise can be avoided by limiting the timing of communication during non-discharge of the photosensitive drum.

The discharge is performed during the printing operation, that is, when the high voltage circuit 31 (FIG. 2) is operating.
Even when the high-voltage circuit 31 is stopped, static electricity due to friction is discharged during rotation of the photosensitive drum, so that data communication is not performed at this time as well. Drum Earth 9
Can be used as a more stable reference potential.

(Prevention of Inflow of Electrostatic Noise into Driving Circuit 2) Next, the case where the ground of the drum ground 9 is deviated from the frame ground 24 of the printer 1 will be described. While mounting the cartridge 3 on the printer 1, the contact terminal 7 and the contact electrode 1
There is a case where the drum ground 9 is not grounded to the frame ground 24 of the printer 1 while 0 is still in contact.

As an example, the cartridge 3 is replaced by the printer 1.
Although the contact terminal 7 and the contact electrode 10 are in contact with each other when inserted into, the drum ground 9 of the cartridge 3 is not grounded until the coupling 26 of the rotary shaft shown in FIG. 2 meshes. Therefore, during that time, the photosensitive drum 27 may be charged by the operation of the high-voltage circuit 31 or static electricity may be generated by the rotation, and this charge flows into the drive circuit 2.

Even after the coupling 26 is engaged, if the cartridge 3 is pulled out from the drum ground 9 during discharging, only the ground of the drum ground 9 may be released first. As described above, only the ground of the drum ground 9 is removed, so that discharge noise may flow into the drive circuit 2 regardless of whether communication is in progress or communication is stopped, which may have an adverse effect such as damage.

In this embodiment, as shown in FIG. 1, noise inflow is prevented by providing a filter circuit 22 between the drive circuit 2 and the memory chip 6. The inflow of discharge noise can be prevented by providing a low-pass filter or a band-pass filter that passes only the communication frequency component with respect to the noise frequency band in the signal transmission path between the drive circuit 2 and the memory chip 6. .

In addition to the filter circuit 22, a coupling capacitor 23 is inserted between the drive circuit 2 and the memory chip 6 as shown in FIG.
It is possible to prevent discharge noise from flowing into the drive circuit 2.

Although the example of the contact type data communication using the drum ground of the cartridge in the printer has been described above, it can be applied to a detachable device other than the cartridge, for example, an accessory such as a paper feed cassette.

[0041]

As described above, according to the present invention,
Since it is configured as described above, the number of signal lines for communication can be reduced to one, serial communication can be performed with one signal line, and thus the number of parts such as contact terminals, contact electrodes, etc. Can be minimized, and cost reduction and space saving can be achieved.

Further, according to the present invention, when the drum ground is used as the reference potential for data communication, the communication timing is limited to the non-discharge of the drum ground, so that it is stable without being affected by the discharge noise. Data communication can be performed.

Further, according to the present invention, since the filter circuit and the coupling capacitor are inserted in the transmission path of the data signal, when the connection between the drum ground and the frame ground is broken, the discharge from the drum ground is generated. It is possible to prevent noise from flowing into the signal line side.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a cartridge 3 of FIG.

3 is a block diagram showing a configuration of a drive circuit 2 in FIG.

FIG. 4 is a block diagram showing a configuration of a memory chip 6 of FIG.

FIG. 5 is a diagram showing an example of a signal transmitted in the contact type transceiver.

FIG. 6 is a block diagram showing a configuration of a conventional contact type transceiver.

7 is a block diagram showing a configuration of a drive circuit 2 of FIG.

8 is a block diagram showing a configuration of a memory chip 6 of FIG.

9 is a diagram showing an example of a signal transmitted in the contact type transmission / reception device of FIG.

[Explanation of symbols]

4 signal lines 6 memory chips 9 drum ground 16 coupling capacitors 22 Filter circuit 24 frame ground

Claims (6)

[Claims] 1. A contact type transmission / reception device for performing contact type memory tag communication between a storage device having a cartridge attached to a printer and a printer engine, wherein the printer has the signal ground of the printer engine attached to the cartridge. And the drum ground of the cartridge is connected to the frame ground, and the drum ground is used as a reference potential of one signal line for performing the contact memory tag communication. Contact type transceiver. 2. The printer engine according to claim 1, wherein the contact-type memory tag communication is not performed while the high-voltage circuit connected to the drum ground is operating, and the high-voltage circuit is stopped from the drum ground. The contact-type transmitting / receiving device, wherein the contact-type memory tag communication is performed at the time when the discharging of the above is completed. 3. The storage device according to claim 1, wherein the cartridge coupling is disengaged when the cartridge is detached from the printer, and the drum ground is provided while the photosensitive drum of the cartridge is being discharged. A contact-type transmitting / receiving device, comprising a filter circuit for preventing noise from flowing into the signal line when separated from the signal line. 4. The contact type transmission / reception device according to claim 3, wherein the storage device has a coupling capacitor between the storage device and the filter circuit. 5. The contact type transceiver according to claim 1, wherein the frame ground is a conductive frame of the printer. 6. The contact type transmission / reception device according to claim 1, wherein the storage device has no power source.