JP2004090639A - Container for print material and its detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To generate a sufficient resonant oscillation by applying a high voltage to a piezoelectric element even when only a weak power can be fed in a cartridge communicating with a printer. <P>SOLUTION: A cartridge 100 utilizes the carrier of a signal transmitted from a printer PT for generating a power and generates driving power of each element including a sensor SS. Power thus generated is fed to a sensor driving voltage generating section 220 thence to the sensor SS. The sensor driving voltage generating section 220 supplies power to the sensor SS through a supply circuit having a high impedance. Power is discharged through a circuit having a low impedance (r2<r1). Even if the power supply capacity from a power supply is limited, the sensor SS can release a large energy in a unit time thus ensuring displacement of oscillation in the sensor SS. <P>COPYRIGHT: (C)2004,JPO

Description

{Circle over (1)} The present invention relates to a storage container that stores a printing material and is mounted on a printing apparatus and a detection method for detecting a state of the printing material stored in the storage container.

Various known containers, for example, ink cartridges for ink jet printers and toner cartridges for laser printers and copiers, are known as containers for storing printing materials of printing apparatuses. In such a storage container, there is a demand for detecting the state of the stored printing material and performing appropriate management. For example, the state of the ink remaining in the container (remaining amount, temperature, viscosity, pressure, etc.) is measured to control the amount of ink in the cartridge or to control the size of ink droplets. . Various detecting elements can be used for such a detecting unit. As an example, a technique using a piezoelectric element as a sensor for measuring the amount of ink can be cited (Patent Document 1 below). The piezoelectric element has a property of being distorted when a voltage is applied, and generates vibration using the distortion. In this technique, a piezoelectric element is made to face a cavity, and the amount of ink is detected from a difference in resonance frequency of a resonance phenomenon caused by vibration generated by distortion of the piezoelectric element. The printing apparatus can acquire the ink amount detected by the sensor by performing predetermined communication with such a cartridge. Communication is performed by making the printing apparatus and the cartridge electrically contact with each other, and by non-contact type using electromagnetic waves.

JP 2001-147146 A

た め Since the magnitude of the generated vibration depends on the degree of distortion of the piezoelectric element, when the applied voltage is small and the distortion is small, sufficient vibration does not occur and the sensor may not function properly. In addition, since the cartridge that performs non-contact communication with the printing apparatus is not supplied with power directly from the printing apparatus, it is necessary to generate power for driving the above-described sensor by electromagnetic induction using received electromagnetic waves. there were. However, in the conventional cartridge, the electric power generated by electromagnetic induction is weak, and it has been difficult to drive a sensor that needs to apply a high voltage. Such a problem of power supply also occurs when a battery is housed in a container and the battery is used as a power source, provided that the power used by the sensor exceeds the power supplied from the battery.

課題 Such a problem is not limited to the ink cartridge containing the ink, but also applies to other printing materials, for example, a cartridge (container) containing toner. The present invention has been made in view of such a problem, and an object of the present invention is to detect a state of a printing material using a phenomenon accompanying release of energy due to discharge from a detection element.

In order to solve at least a part of the above-described problems, the present invention uses a detection element provided in a storage container that stores a printing material, and when detecting the state of the printing material, the detection element has a predetermined impedance. An electric energy is supplied through a supply circuit, and the electric energy stored in the detection element is discharged through a discharge circuit having an impedance lower than the impedance of the supply circuit. Utilizing this, the state of the printing material is detected.

According to the present invention, since the impedance of the supply circuit for supplying energy to the detection element is made larger than the impedance of the supply circuit for supplying electric energy, the power per unit time required for driving the detection unit is reduced. At the same time, the energy released per unit time during discharge can be increased. Therefore, large energy can be released at the time of discharge from the detection element, and the detection accuracy of the state of the printing material can be improved. The container may be detachable from the printing apparatus, or may be non-removably attached. Further, the container may be of a type in which replenishment of printing material is not possible, or may be of a type in which replenishment is possible.

The invention of a printing material storage container to which such a detection technique is applied,
Utilizing a phenomenon associated with release of energy due to discharge from the detection element, a detection unit that detects the state of the printing material,
A drive circuit for driving the detection unit, comprising: a discharge circuit for performing the discharge from the piezoelectric element; and a supply circuit having an impedance greater than that of the discharge circuit and supplying energy used for the discharge to the detection element. And a driving circuit including the following.

Hereinafter, embodiments of the present invention will be described in the following order based on examples.
A. Schematic configuration of cartridge:
B. Cartridge electrical configuration:
C. Circuit configuration of ink remaining amount detector:
D. Ink remaining amount measurement routine:
E. FIG. effect:
F. Modification:

A. Schematic configuration of cartridge:
FIG. 1 is an external perspective view of the cartridge 100. An ink supply port 110 for supplying ink to a print head of the printer is provided at a lower portion of the cartridge 100, and an antenna 120 for communicating with the printer by radio waves and a sensor for measuring the remaining ink amount are provided at an upper portion. SS and a logic circuit 130 are provided.

In this example, a piezoelectric element was used for the sensor SS. The cartridge 100 measures the amount of ink by emitting an elastic wave generated by vibrating the piezoelectric element of the sensor SS to the ink liquid surface, and measuring the back electromotive force by combining the reflected wave and the residual vibration.

B. Cartridge electrical configuration:
FIG. 2 is a block diagram of the logic circuit 130 provided in the cartridge 100. The logic circuit 130 includes an RF circuit 200, a control unit 210, a sensor drive voltage generation unit 220, an ink remaining amount detection unit 230, and a power generation unit 240.

The RF circuit 200 includes a demodulation unit 201 that demodulates a radio wave received from the printer PT via the antenna 120, and a modulation unit 202 that modulates a signal input from the control unit 210 and transmits the signal to the printer PT. The printer PT oscillates a carrier wave of 27.12 MHz, and transmits a control signal to the cartridge 100 by ASK modulating the carrier wave. ASK modulation is a method of changing the amplitude of a carrier wave in accordance with a digital signal.

On the other hand, commands and data returned from the control unit 210 to the printer PT are modulated by the modulator 202 and transmitted. PSK modulation is a method of changing the phase of a carrier wave in accordance with a digital signal. The printer PT and the cartridge 100 communicate with each other by such a method. Note that the modulation scheme described here is merely an example, and it goes without saying that other modulation schemes can be used.

The control unit 210 performs various controls according to the control signal demodulated by the demodulation unit 201. This control is, for example, control for transmitting a signal for detecting the amount of ink using the remaining ink amount detection unit 230 to the remaining ink amount detection unit 230.

(4) The power generation unit 240 generates power by rectifying the carrier received by the RF circuit 200. Here, the generated power is 5V. Although the connection is omitted in the figure, the power generation unit 240 is connected to the RF circuit 200, the control unit 210, and the like, and is used as a power source for driving each of them. Further, as shown by a thick line in the figure, the sensor drive voltage generation section 220 is connected to the power generation section 240.

On the other hand, the sensor drive voltage generator 220 generates a voltage required to drive the sensor SS. Regardless of the magnitude of the voltage, the piezoelectric element is distorted by the electrostriction effect when a voltage is applied and accumulates electric charge, and when the electric charge is released by discharge, the distortion is released and released, causing free vibration. The sensor SS uses the free vibration of the piezoelectric element to detect the amount of remaining ink, but the magnitude of the vibration is proportional to the magnitude of the applied voltage. In the embodiment, a high voltage of about 18 V is used. Therefore, the sensor drive voltage generation unit 220 is configured by a boost type charge pump. Note that the sensor drive voltage generation unit 220 may use a combination of charge pumps in multiple stages when the output voltage is low with one charge pump. Further, various step-up DC / DC converters such as a switching regulator may be used.

C. Circuit configuration of ink remaining amount detector:
FIG. 3 is a circuit configuration of the ink remaining amount detection unit 230. As shown, the remaining ink amount detection unit 230 includes two transistors Tr1 and Tr2, two resistors R1 and R2, an amplifier 232, a comparator 234, a count control unit 236, a counter 238, and an oscillator (not shown). And In addition, the remaining ink amount detection unit 230 transmits a signal to the terminal TA for inputting the charge signal from the control unit 210 to the transistor Tr1, a terminal TB for inputting a discharge signal to the transistor Tr2, and a signal to the count control unit 236. It has an input terminal TC for inputting, a terminal TD for inputting the count clock from the oscillator to the counter 238, and a terminal TE for outputting the output value of the counter 238 to the control unit 210.

The transistor Tr1 is a PNP transistor, the base is connected to the terminal TA, and the emitter is connected to the sensor drive voltage generator 220. The collector is connected to the sensor SS via the resistor R1. On the other hand, the transistor Tr2 is an NPN transistor, the base is connected to the terminal TB, and the collector is connected to the sensor SS via the resistor R2. The emitter is grounded. Since the two transistors Tr1 and Tr2 are of the PNP type and the NPN type, when the terminal TA is dropped, the transistor Tr1 is turned on, and when the terminal TB is raised, the transistor Tr2 is turned on. For convenience of description, TA and TB may be referred to as a charge signal TA and a discharge signal TB using signals input to those terminals.

一端 One end of the sensor SS is connected to a connection point between the resistor R1 and the resistor R2, and the other end is grounded. One end of the sensor SS is also connected to the amplifier 232. The resistors R1 and R2 are connected to the sensor drive voltage generator 220 and the ground line via the transistors Tr1 and Tr2. Accordingly, the sensor SS is charged by receiving the supply of electric energy by the supply circuit including the sensor drive voltage generation unit 220, the transistor Tr1, and the resistor R1, and is charged by the discharge circuit including the resistor R2, the transistor Tr2, and the ground line. , So that the charge can be discharged. The amplifier 232 is further connected to the comparator 234, and the output terminal of the comparator 234 is connected to the count control unit 236. The output terminal of the count control unit 236 is connected to the counter 238. The output terminal of the counter 238 is connected to the terminal TE.

The resistor R1 used at the time of charging is a resistor having a larger resistance value than the resistor R2 used at the time of discharging. The resistance value r1 of the resistor R1 and the resistance value r2 of the resistor R2 were determined as follows. In the sensor SS using a piezoelectric element, when electric charges are accumulated in the sensor SS, mechanical distortion occurs in the sensor SS due to an electrostrictive effect. When the accumulated charge is discharged from this state, the strain is released in proportion to the amount of energy released per unit time, and the sensor SS vibrates. Since detection is performed using this vibration, it is desired to increase the energy released per unit time, so that the resistance value r2 is set as small as possible. Since the on-resistance of the transistor Tr2 is also present, the impedance rd of the discharge circuit cannot be 0, so that the resistor R2 may not be actually provided (r2 = 0). On the other hand, the supply of electric energy to the sensor SS (actually, charging via the transistor Tr1) is ultimately limited by the energy that the sensor drive voltage generation unit 220 can output per unit time. Even if the circuit resistance of the supply circuit is reduced, the current supplied by the internal resistance of the sensor drive voltage generation unit 220 is actually limited. Therefore, the resistance value r1 of the resistor R1 is determined by using the output voltage V of the sensor drive voltage generator 220 and the upper limit value imax of the current that can be taken out of the generator 220 without difficulty. rc is
rc = V / imax
Determined to be. Specifically, using the ON resistance rON of the transistor Tr1 and the wiring resistance rr of the circuit, r1 = rc−rON−rr
It may be determined as In the present embodiment, the impedance rc of the supply circuit and the impedance rd of the discharge circuit are expressed by:
rc> rd
Therefore, the energy supplied per unit time from the sensor drive voltage generation unit 220 can be considerably smaller than the energy released per unit time during discharging. Therefore, the energy required for detection by the sensor SS is accumulated over time and released in a short period of time, so that the sensor drive voltage generation unit 220 having a small energy supply capability can be used and sufficient resonance for detection can be achieved. The phenomenon is generated in the sensor SS.

Hereinafter, the operation of the above circuit will be described with reference to the timing chart shown in FIG. In the initial state, both the charge signal TA and the discharge signal TB are high, the transistor Tr1 is turned off, and the transistor Tr2 is turned on. Therefore, the sensor SS is grounded via the transistor Tr2, and no charge is accumulated. When the measurement using the sensor SS is started, first, the discharge signal TB is set to low, and the transistor Tr2 is turned off. Subsequently, when the charging signal TA from the control unit 210 goes low, the transistor Tr1 is turned on (time t1). Therefore, in the interval t1 to t2, the voltage generated by the sensor drive voltage generation unit 220 is applied to the sensor SS via the resistor R1, and charge is accumulated in the sensor SS. The voltage gradually increases to the voltage generated by the drive voltage generation unit 220. At this time, since the charging is performed via the resistor R1, the energy stored per unit time is smaller than the energy per unit time of the discharge performed via the resistor R2. Therefore, as shown in FIG. 4, the gradient at the time of charging has a waveform that is gentler than the gradient at the time of discharging. The sensor SS accumulates electric energy by charging, and accumulates mechanical distortion inside due to the electrostriction effect. That is, the sensor SS is deformed.

Next, when the control unit 210 makes the charging signal TA high at time t2, the transistor Tr1 turns off. When the control unit 210 makes the discharging signal TB high at time t3, the transistor Tr2 turns on. As a result, in the section t3 to t4, the transistor Tr2 is turned on, and the electric charge accumulated in the sensor SS is discharged via the resistor R2. In this embodiment, in order to avoid that both of the transistors Tr1 and Tr2 are turned on, a section t2 to t3 where both are turned off is provided. Due to this discharge, the sensor SS emits the strain accumulated inside by charging at a stretch and is deformed. Then, a voltage is not applied, so that the sensor SS is in a state where free vibration is possible. When used, it will vibrate freely at the resonant frequency of the cavity. Since the sensor SS is still deformed even with free vibration, a voltage is generated at both ends of the sensor SS due to the deformation. The change in the voltage is amplified by the amplifier 232 and output to the comparator 234. The comparator 234 compares the change in the amplified voltage with a predetermined comparison voltage Vref, converts the signal into two high / low signals, and outputs the two signals to the count control unit 236. The count control unit 236 generates a count control signal for enabling the operation of the counter 238 during a period corresponding to five pulses of the output signal from the comparator 234 after the resonance of the piezoelectric element starts according to the signal input from the terminal TC. . The counter 238 counts the number of pulses using the count clock input from the terminal TD while the count control signal is high (count enable). The count value of the counter 238 is sent to the control unit 210 and sent to the printer PT. The printer PT calculates the vibration frequency of the sensor SS from the count value of the counter 238, and measures the amount of ink in the cartridge 100.

D. Ink remaining amount measurement routine:
FIG. 5 is a flowchart of the ink amount measurement routine. This processing is performed by processing in the ink cartridge 100 and processing in the printer PT. First, on the ink cartridge side, when the control unit 210 inputs an ink amount measurement command from the printer PT via the RF circuit 200 (step S100), it outputs a charging signal to the ink remaining amount detection unit 230 (step S101). After a lapse of a predetermined time, a discharge signal is output (step S102). Then, the count clock is counted by the counter 238 of the remaining ink amount detection unit 230 (step S103), and the control unit 210 outputs the count value to the printer PT via the RF circuit 200 (step S104). On the printer PT side, the oscillation frequency of the oscillator included in the remaining ink amount detection unit 230 is known, the oscillation frequency of the sensor SS is calculated from this count value, and the state of the remaining ink amount is determined according to the frequency (step S105). The printer PT determines that there is sufficient ink when the frequency is 90 KHz (step S106), and determines that there is no ink when the frequency is 110 KHz (step S107). By the above processing, the amount of ink remaining in the cartridge can be measured.

E. FIG. effect:
As described above, in the present embodiment, the resistance value of the resistor used at the time of charging is set high, and the resistance value of the resistor used at the time of discharging is set low. With such a configuration, it is possible to supply sufficient power for causing a resonance phenomenon while suppressing the power per unit time that can be supplied to the sensor. In addition, since a large amount of energy can be released in a short time at the time of discharging, a large vibration can be generated in the sensor SS, and the remaining amount of the ink can be accurately detected using the vibration of the sensor SS.

F. Modification:
In the cartridge 100 of the present embodiment, the ROM 12 of FIG. 2 may be a memory unit for storing various information related to the cartridge 100. In the memory unit, information such as the serial number and date of manufacture of the cartridge 100, the type of the filled ink, and the like are recorded in advance. An example of the memory unit is an EEPROM. In the above-described ink amount measurement routine of the present embodiment, the data indicating the remaining ink state is transmitted to the printer in step S107. However, the data may be written to the memory unit simultaneously or alternatively. . In this way, when the cartridge is removed from the printer and mounted on another printer, the remaining state of the ink can be immediately known without measuring the ink amount again.

In addition, the cartridge 100 of the present embodiment may include a memory voltage generation unit that supplies power to the above-described memory unit using the power of the power generation unit 240, separately from the sensor drive voltage generation unit 220. . By doing so, even when the voltage required to write data to the memory unit and the voltage required to drive the sensor are different, it is possible to efficiently generate the power required for each.

The sensor drive voltage generator may be used also as a second power generator for supplying power to the memory. By doing so, the circuit configuration of the ink cartridge can be simplified.

In the above embodiment, the example in which the present invention is applied to the ink cartridge containing ink has been described, but the present invention is not limited to this. The present invention may be applied to other printing materials, for example, a toner cartridge containing toner.

In the above embodiment, the control unit 210 is configured as hardware, but may be configured as software. For example, instead of the control unit 210, a microcomputer including a CPU, a ROM, a RAM, and the like may be used. Further, the measurement of the remaining amount of ink is performed by processing on the ink cartridge 100 side and the printer PT side, but all the processing may be performed on the ink cartridge 100 side.

In the above embodiment, the power on the cartridge 100 side is generated from the electromagnetic wave for communication. However, a small button battery or the like is housed in the cartridge 100, and the sensor SS is driven using the power of this battery. It is good. Even in this case, by making the impedance of the supply circuit for supplying power larger than the impedance of the discharge circuit, the power per unit time at the time of charging can be suppressed low, and a small battery can be used. Further, the usable period of the battery can be extended.

Further, in the above embodiment, the remaining amount of ink is detected as the state of the printing material. However, the detection target is not limited to this, and the temperature, humidity, density, mass, viscosity, or pressure of the printing material may be detected. And the like may be detected. This is because changes in the properties of the printing material, such as temperature, humidity, and density, can be taken out as changes in the resonance frequency in some form.

In the above embodiment, the impedance of the circuit is adjusted by the resistors R1 and R2, but the impedance may be adjusted by another method. For example, it may be adjusted by the on-resistance of the transistors Tr1 and Tr2. Alternatively, the impedance may be adjusted by providing a coil component in consideration of the charging / discharging time (frequency) of the sensor SS.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and it is needless to say that the present invention can be implemented in various modes without departing from the gist of the present invention. . For example, the whole or a part of the antenna 120 and the logic circuit 130 may be configured as a single-chip system LSI.

FIG. 3 is an external perspective view of the cartridge 100. FIG. 3 is a block diagram of a logic circuit of the cartridge 100. 4 is a circuit configuration of an ink remaining amount detection unit 230. 5 is a timing chart of a circuit configuring an ink remaining amount detection unit 230. 4 is a flowchart of an ink amount measurement routine executed by a control unit 210.

Explanation of reference numerals

Reference Signs List 100 cartridge 110 ink supply port 120 antenna 130 logic circuit 200 RF circuit 201 demodulation unit 202 modulation unit 210 control unit 220 sensor drive voltage generation unit 230 ink remaining amount detection unit 232 amplifier 234 Comparator 236 ... Count control unit 238 ... Counter 240 ... Power generation unit SS ... Sensor

Claims (13)

A storage container that stores the printing material and is mounted on the printing device,
Utilizing a phenomenon associated with release of energy due to discharge from the detection element, a detection unit that detects the state of the printing material,
A drive circuit for driving the detection unit, the discharge circuit performing the discharge from the detection element, and a supply circuit having an impedance greater than the discharge circuit and supplying the detection element with electric energy used for the discharge. And a driving circuit having a circuit. (4) The container according to claim 1, wherein the detection element is a piezoelectric element. It is a container of the printing material of Claim 2, Comprising:
The driving unit generates a resonance phenomenon by the discharge performed after the supply of the electric energy to the piezoelectric element,
The container, wherein the detection unit detects a state of the printing material from a resonance frequency obtained by the resonance phenomenon. The container according to claim 2,
A storage container comprising a power supply unit for driving the detection unit, wherein the power that the power supply unit can supply per unit time is smaller than the power that the piezoelectric element can discharge per unit time by the discharge circuit. The container according to claim 4, wherein
With a receiving unit that receives electromagnetic waves from outside,
The power supply unit includes:
A storage container comprising: a power generation unit configured to generate power from electromagnetic waves received by the reception unit; and a power supply unit configured to supply the generated power as a power supply of the drive circuit. The container according to claim 5, wherein
The receiving container, wherein the receiving unit is provided as a part of a communication unit that exchanges data including a state of the printing material with the printing device. The container according to claim 4, wherein the power supply unit is a battery stored in a part of the container. The container according to claim 4, wherein the driving unit includes a booster circuit that boosts the voltage of the supplied power and uses the boosted voltage as the power of the supply circuit. The container according to claim 1, wherein the detected state of the printing material is a remaining amount of the printing material. The container according to claim 1, wherein the detected state of the printing material is one of temperature, humidity, density, mass, viscosity, and pressure of the printing material. A storage container that stores the printing material and is mounted on the printing device,
Utilizing a phenomenon associated with release of energy due to discharge from the detection element, a detection unit that detects the state of the printing material,
A driving circuit for driving the detection unit, comprising: a charging circuit for charging the detection element; and a discharging circuit for discharging electric energy stored in the detection element, wherein a period of charging by the charging circuit is And a drive circuit set longer than the discharge period of the discharge circuit. An apparatus that detects a state of the printing material using a detection element provided in a container that stores the printing material,
A supply circuit having a predetermined impedance for supplying electric energy to the detection element;
A circuit for discharging the electric energy stored in the detection element, a discharge circuit having a lower impedance than the supply circuit,
A detection unit for detecting a state of the printing material by utilizing a phenomenon associated with release of energy by the discharge. A method for detecting the state of the printing material using a detection element provided in a storage container containing the printing material,
Supplying electrical energy to the detection element through a supply circuit having a predetermined impedance;
Discharging the electric energy stored in the detection element through a discharge circuit having a lower impedance than the impedance of the supply circuit;
A method for detecting a printing material, wherein the state of the printing material is detected using a phenomenon associated with release of energy by the discharge.

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