JP2018030309A - Mounted article detection means and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide mounted article detection means capable of stably detecting presence/absence of mounting of a mounted article with a simple configuration.SOLUTION: Mounted article detection means comprises: a mounted article detection terminal connected to a mounted article; a switch element having one end connected to predetermined high potential and the other end connected to the mounted article detection terminal via a resistance element; a capacitive element having one end connected to a connection point between the mounted article detection terminal and the resistance element and the other end connected to low potential having a voltage lower than that of the high potential; a potential detector detecting potential of a connection point between the switch element and the resistance element; and a connection mechanism connecting the mounted article detection terminal to the low potential when the mounted article is mounted. By turning ON the switch element, the mounted article detection means charges the capacitive element via the resistance element by the high potential, and, in a state of turning OFF the switch element, detects the potential of the connection point by the potential detector.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a mounted product detection unit that detects whether or not a removable mounted product is mounted, and a printing apparatus including the mounted product detection unit.

Conventionally, patent document 1 is known as this kind of technique. Patent Document 1 discloses a technique for detecting lens mounting by a lens mounting state detection unit in a camera with interchangeable lenses. In the technique of Patent Document 1, when the lens mounting state detection means does not detect the lens mounting, the resistance value of the pull-up resistor is lowered, the lens mounting is detected, and it is determined that the interchangeable lens is correctly mounted. In this case, the resistance value of the pull-up resistor is increased. This is intended to prevent an increase in current flowing through the pull-up resistor when the lens is mounted, and to suppress current consumption of the lens mounting state detecting means.
In addition, it is necessary to detect whether or not an ink cartridge, a waste ink tank, or the like as an attachment in the printing apparatus is attached to the printing apparatus, for example, as well as replacement of a lens as an attachment in the camera. There is a case.

Japanese Patent Laid-Open No. 7-114087

  According to the technique of Patent Document 1, resistance value variable means for increasing the resistance value of the pull-up resistor is provided, whereby the resistance value of the pull-up resistor is switched according to the detection result of the lens mounting state detection means. For this reason, it is necessary to newly provide a resistance value variable means, and it is necessary to detect whether or not a lens is mounted and feed back the result to the resistance value variable means. As a result, the control system has become complicated, causing a cost increase.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

(Application example 1)
The attachment detection means according to the present invention is an attachment detection means for detecting whether or not a detachable attachment is attached, wherein the attachment detection terminal connected to the attachment and one end connected to a predetermined high potential A switching element whose other end is connected to the attachment detection terminal via a resistance element, one end connected to the attachment detection terminal and the resistance element, and the other end having a low potential lower than the high potential A capacitive element connected to the switch, a potential detector for detecting a potential at a connection point between the switch element and the resistance element based on a reference potential, and when the mounted product is mounted, the mounted product detection terminal is A connection mechanism for connecting to a low potential, and by turning on the switch element, the capacitor element is charged via the resistance element by the high potential, and the potential detection is performed with the switch element turned off. vessel Thus detecting the potential of the connection point.

  According to this application example, a simple charge / discharge circuit using a switching element, a resistance element, and a capacitive element, and a potential detector are provided, and the presence / absence of a mounted product is detected with a circuit configuration that does not require complicated feedback control. be able to. Therefore, it is possible to realize a mounted product detection means that causes little cost increase. Furthermore, a capacitive element is connected to the fitted product detection terminal connected to the fitted product, and the capacitive element is charged with a high potential by turning on the switch element. As a result, when the attached product is not connected, the attached product detection terminal is in a floating state (open state), but the charged potential state is stably maintained by the capacitor element. Therefore, the potential of the mounted product detection terminal does not fluctuate due to disturbance or the like, and it is possible to stably detect whether the mounted product is mounted.

(Application example 2)
In the above application example, it is desirable that the time during which the switch element is turned on is longer than the time during which the capacitive element is charged to a potential higher than the reference potential by the high potential via the resistance element.

  According to this application example, the time for which the switch element is turned on is set longer than the time for which the capacitive element is charged to a potential higher than the reference potential. As a result, the charging potential of the capacitive element is reliably higher than the reference potential, so that the mounted product is reliably detected.

(Application example 3)
In the above application example, it is preferable that the mounted product detection unit repeats ON and OFF of the switch element at a predetermined cycle.

  According to this application example, the switch element is intermittently turned on / off, and an operating current does not always flow for detection. Therefore, current consumption can be reduced.

(Application example 4)
In the above application example, the potential detector is preferably a comparator that compares the potential at the connection point with the reference potential.

  According to this application example, since the potential detector is a comparator, the reference potential can be easily set, changed, and adjusted.

(Application example 5)
In the application example, it is preferable that the attached product is an ink cartridge that is attached to a printing apparatus including a printing mechanism that performs printing on a printing medium.

  According to this application example, when the ink cartridge is attached to or detached from the printing apparatus, the mounting state can be reliably detected.

(Application example 6)
In the above application example, it is preferable that the attached product is a waste ink tank that is attached to a printing apparatus including a printing mechanism that performs printing on a printing medium.

  According to this application example, when the waste ink tank is attached to or detached from the printing apparatus, it is possible to reliably detect the mounting state.

(Application example 7)
A printing apparatus according to the present invention is a printing apparatus that includes a printing mechanism that performs printing on a printing medium, and has a mounted product detection terminal connected to the mounted product, one end connected to a predetermined high potential, and the other end A switching element connected to the attachment detection terminal via a resistance element, and a capacitance element having one end connected to the attachment detection terminal and the resistance element and the other end connected to a low potential lower than the high potential A potential detector that detects a potential at a connection point between the switch element and the resistance element based on a reference potential; and a connection mechanism that connects the mounted product detection terminal to the low potential when the mounted product is mounted. The capacitor element is charged via the resistance element with the high potential by turning on the switch element, and the potential at the connection point is detected by the potential detector with the switch element turned off. That.

  According to this application example, a printing apparatus including a printing mechanism that performs printing on a printing medium includes a simple charge / discharge circuit using a switching element, a resistance element, and a capacitive element, and a potential detector, and performs complex feedback control. The presence / absence of a mounted product can be detected with a circuit configuration that is not required. Therefore, it is possible to realize a printing apparatus with little cost increase factor.

The figure which shows an example of the internal structure of an inkjet printer. The block diagram of a mounting article detection means. The circuit diagram which shows the specific example of a switch element and an electric potential detector. The timing chart figure of a mounted article detection means. The timing chart figure of a mounted article detection means. The circuit diagram which shows the other specific example of a switch element and an electric potential detector.

(Embodiment)
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of a mounted product detection unit 1 to which the present invention is applied and a printing apparatus including the mounted product detection unit will be described with reference to the drawings. In the present embodiment, an inkjet printer 10 will be described as an example of a printing apparatus to which the present invention is applied.
In the drawings referred to in the following description, the vertical and horizontal scales of members or parts may be shown differently from the actual ones for convenience of description and illustration. In addition, illustrations of components other than those necessary for the description may be omitted.

(Printer)
First, the inkjet printer 10 will be outlined.
FIG. 1 is a diagram illustrating an internal configuration of the ink jet printer 10. The carriage 12 is slidably held on the carriage shaft 14 and is fixed to a part of the belt 16. The belt 16 is stretched around the main pulley 18 and the driven pulley 20.

  The main pulley 18 is driven to reciprocate by a carriage motor 22, and in conjunction with this, the belt 16 reciprocates in the direction of arrow X in FIG. As the belt 16 reciprocates, the carriage 12 also reciprocates in the direction of arrow X in FIG. 1 while being guided by the carriage shaft 14.

  The printing paper (printing medium) 24 is sandwiched between a paper feed roller (not shown) and a counter roller (not shown). When the paper feed roller is driven to rotate by the paper feed motor 26, the counter roller also rotates. In this way, the printing paper 24 moves in the arrow Y direction in FIG. 1 as the paper feed roller and the counter roller rotate.

  A print head 30 serving as a liquid ejection unit is mounted on the carriage 12 so as to face the printing paper 24. Also, an ink cartridge (mounted product) 34 of black ink and color ink such as cyan, magenta, and yellow is detachably mounted on the carriage 12. Each color ink is supplied from the ink cartridge 34 to the print head 30 via an ink flow path (not shown). When the stored ink is used up, the ink cartridge 34 is removed from the carriage 12 and a new ink cartridge 34 is mounted on the carriage 12 and used.

  The print head 30 forms dots on the print paper 24 by ejecting ink as droplets toward the print paper 24 moving in the arrow Y direction in FIG. 1 while reciprocating in the arrow X direction in FIG. That is, printing is performed on the printing paper 24.

  A capping mechanism 36 and a flushing mechanism 37 are provided in an area where the printing paper 24 does not pass inside the inkjet printer 10, that is, in a non-printing area.

  The capping mechanism 36 sucks the clogged ink in the ink solidified body or the ink discharge port in the print head 30 when the ink in the print head 30 is solidified or when the ink discharge port of the print head 30 is clogged. Used for suction cleaning (purging).

  The outer peripheral portion of the capping mechanism 36 is formed of an elastic body 39 such as rubber, and is configured so that the inside of the capping mechanism 36 is airtight when in contact with the print head 30. In the vicinity of the capping mechanism 36, a suction pump (not shown) for applying a negative pressure to the internal space of the capping mechanism 36 is disposed. A waste ink tank (attached product) 50 for collecting ink discharged from the suction pump as waste ink is disposed vertically below the suction pump (in the direction of arrow Z).

  The flushing mechanism 37 is provided in a non-printing area on both sides of the printing paper 24 in the arrow X direction so that a part of the paper edge of the printing paper 24 overlaps. The flushing mechanism 37 is a mechanism provided for the print head 30 to perform flushing. Flushing is an operation of ejecting ink from the nozzles of the print head 30 in a non-printing region in order to prevent the nozzles of the print head 30 from being thirsty. Therefore, when flushing is performed, ink is ejected and collected by the flushing mechanism 37 serving as a liquid receiving portion.

  Further, since the flushing mechanism 37 is partially overlapped with the paper edges on both sides of the printing paper 24, when the borderless printing is performed on the printing paper 24, the flushing mechanism 37 is ejected from the paper edge of the printing paper 24. Ink is picked up by the flushing mechanism 37. Borderless printing is a printing function that prints the entire printing paper 24 so that there is no margin at the edge of the paper during printing. In the case of borderless printing, an image to be printed is printed on the printing paper 24. Set it to a slightly larger size. For this reason, ink may be ejected in areas protruding from the paper edges on both sides of the printing paper 24.

  The waste ink tank 50 is detachably stored in the tank storage unit 40 of the inkjet printer 10. Waste ink collected by the capping mechanism 36 and the flushing mechanism 37 flows into the waste ink tank 50 via the waste ink tube 44 and is stored. Before the waste ink overflows from the waste ink tank 50, the user removes the waste ink tank 50 from the inkjet printer 10 and discards the waste ink to the outside. Thereafter, a waste ink tank 50 capable of storing waste ink is attached to the inkjet printer 10.

  As described above, the ink cartridge 34 and the waste ink tank 50 are detachably attached to the inkjet printer 10. If the ink cartridge 34 is not attached, the ink jet printer 10 cannot supply ink to the print head 30 and cannot perform printing. Further, if the waste ink tank 50 is not attached, the inkjet printer 10 cannot perform printing because the interior of the inkjet printer 10 is stained with waste ink. Therefore, it is important to detect whether the ink cartridge 34 and the waste ink tank 50 are installed in order for the ink jet printer 10 to perform a normal printing operation. Further, it is not known when the ink cartridge 34 or the waste ink tank 50 is attached or detached (attached or removed irregularly), and the detection of the presence / absence of attachment is performed correspondingly so that the use of the inkjet printer 10 is not hindered. Need to be done.

(Configuration of installed product detection means)
Next, the mounted product detection means 1 will be described.
FIG. 2 is a configuration diagram of the mounted product detection means 1. The mounted product detection means 1 includes a controller 60 provided in the inkjet printer 10, an ink cartridge 34 or a waste ink tank 50 (hereinafter collectively referred to as mounted products 34 and 50) as a mounted product, and a connector unit 68.

  The controller 60 includes a CPU (Central Processing Unit) 61 that operates by receiving supply of a positive power source (predetermined high potential) VDD and a negative power source (low potential) VSS from a power source 62. The CPU 61 controls the operation of each functional unit (not shown) in the CPU 61 based on a program stored in a ROM (Read Only Memory) 63. Further, the CPU 61 performs various arithmetic processes using a RAM (Random Access Memory) 64.

  The CPU 61 includes a plurality of input / output ports. For example, an output port CVDD that outputs a high potential VDD, an output port CRST that outputs a reset signal, an output port CSCK that outputs a clock signal, and an input / output port CSDA that transmits and receives data. Further, the CPU 61 includes a detection input / output port CO for detecting whether or not the mounted products 34 and 50 are mounted.

The output ports CVDD, CRST, CSCK, and the input / output port CSDA are drawn out to the connector portion 68 by wiring. A resistance (resistive element) 65 is connected to the detection input / output port CO, and the detection input / output port CO is pulled out to the connector portion 68 as a mounted product detection terminal COI. That is, the resistor 65 is connected in series between the detection input / output port CO and the mounted product detection terminal COI. Further, one end of a capacitor (capacitance element) 66 is connected to the wiring connecting the mounted product detection terminal COI and the resistor 65, and the other end of the capacitor 66 is connected to the low potential VSS.
Both the terminal CVSS and the terminal COO of the controller 60 are connected to the low potential VSS, and the low potential VSS is pulled out to the connector portion 68.

  The attachments 34 and 50 include terminals corresponding to the respective terminals on the controller 60 side that are pulled out to the connector portion 68. Specifically, an input port (input terminal) CVDD to which a high potential VDD is input, an input port (input terminal) CRST to which a reset signal is input, an input port (input terminal) CSCK to which a clock signal is input, These are an input / output port CSDA (input / output terminal) for performing transmission / reception, an input port (input terminal) CVSS to which a low potential VSS is input, and a terminal COI and a terminal COO used for detection of the mounted products 34 and 50. In the present embodiment, the terminal COI and the terminal COO are connected by wiring inside the attachments 34 and 50.

  The attachments 34 and 50 include a memory 55 that stores information related to the attachments 34 and 50. The information regarding the mounted products 34 and 50 is, for example, the ID data (type, date of manufacture, serial number, etc.) of the mounted products 34 and 50, and in the case of the ink cartridge 34, the color type, the remaining ink amount, etc. In this case, it is free space. The mounted products 34 and 50 transmit ID data to the CPU 61 via the various input / output ports described above, and receive data from the CPU 61 to update the ink remaining amount of the ink cartridge 34, the empty capacity of the waste ink tank 50, and the like. And remember.

  When the attachments 34 and 50 are attached to the inkjet printer 10, each terminal on the controller 60 side and each corresponding terminal on the attachment product 34 and 50 side are connected to each other at the connector portion 68, and the CPU 61 and the attachments 34 and 50 are connected. Can communicate with each other. In addition, since the terminal COI and the terminal COO on the attachments 34 and 50 side are connected by the wiring included in the attachments 34 and 50, the terminal COI on the controller 60 side is the terminal COI and the terminal on the attachments 34 and 50 side. Via the COO, it is connected to the terminal COO on the controller 60 side and is connected to the low potential VSS. In other words, when the attachments 34 and 50 are attached by the connector 60 with the wiring connecting the terminal COI and the terminal COO on the controller 60 side, the terminal COI and the terminal COO on the attachments 34 and 50 side, and the connector portion 68, A connection mechanism for connecting the product detection terminal COI to the low potential VSS is configured.

(Circuit of attached product detection means)
Next, the circuit configuration of the mounted product detection means 1 will be described.
FIG. 3 is a circuit diagram showing a specific example of the switch element and the potential detector. Specifically, a circuit diagram of the detection input / output port CO portion of the CPU 61 is shown. The circuit of the mounted product detection means 1 includes a semiconductor relay (switch element) 71, an inverter (potential detector) 72, a NOR gate 73, and an inverter 74.

  The semiconductor relay 71 functions as a switch for connecting the high potential VDD to the output side terminal OUT by connecting the input side terminal IN to the high potential VDD and connecting the output side terminal OUT to the detection input / output port CO. The semiconductor relay 71 is, for example, a transmission gate, a photocoupler, a field effect transistor (FET), or the like. The semiconductor relay 71 is controlled by the switching signal S. When the switching signal S is at the logic level “H (High)”, the semiconductor relay 71 is turned on, the output terminal OUT becomes the high potential VDD, and the switching signal S is at the logic level “L ( When “Low”, the output terminal OUT is in a high impedance state.

  The inverter 72 functions as a potential detector that detects the potential of the detection input / output port CO. That is, the inverter 72 is a potential detector that operates using the threshold voltage (inverted voltage) as the reference potential Vref (see FIG. 4A), and is a detection input / output port CO (semiconductor relay (switch element) 71) connected to the input terminal. "L" level is output to the output terminal when the potential at the connection point between the resistor and the resistor (resistive element) 65 is higher than the reference potential Vref, and to the output terminal when the potential of the detection input / output port CO is lower than the reference potential Vref. Outputs “H” level.

  The output terminal of the inverter 72 is connected to one input terminal of the 2-input NOR gate 73. A detection signal D for taking in the potential of the detection input / output port CO (a result of the mounted product detection) to the CPU 61 is input to the other input terminal of the NOR gate 73 via the inverter 74. Specifically, when the detection signal D is at “H” level, the detection output of the inverter 72 as a potential detector is output to the output terminal of the NOR gate 73, and the detection result R of whether or not the mounted products 34 and 50 are mounted. It becomes.

(Operation of attached product detection means)
Next, the operation of the mounted product detection means 1 having the above-described circuit configuration will be described.
4A and 4B are timing charts of the mounted product detection means 1. FIG. FIG. 4A is a timing chart when the mounted products 34 and 50 are not mounted, and FIG. 4B is a timing chart when the mounted products 34 and 50 are mounted.

  4A shows the switching signal S, the detection signal D, the potential of the detection input / output port CO, the potential of the mounted product detection terminal COI, and the detection result R when the mounted products 34 and 50 are not mounted.

The switching signal S is a signal that changes from the “L” level to the “H” level at the time t1 and changes from the “H” level to the “L” level at the time t2 in the detection cycle (n). The detection cycle is repeated at a predetermined period (detection period) (detection cycle (n) and detection cycle (n + 1)), and accordingly, the switching signal S becomes “H” level or “L” level. When the switching signal S becomes “H” level at time t1, the semiconductor relay 71 is turned ON, the output side terminal OUT (detection input / output port CO) becomes the high potential VDD, and the capacitor 66 is charged through the resistor 65. The Thereafter, when the switching signal S becomes “L” level at time t2, the semiconductor relay 71 is turned OFF, the output side terminal OUT becomes in a high impedance state, and charging is stopped. That is, the semiconductor relay (switch element) 71 repeats ON and OFF at a predetermined cycle (detection cycle).
When the attachments 34 and 50 are attached and detached irregularly, the interval (detection cycle) between the detection cycle (n) and the detection cycle (n + 1) is set so as not to hinder the use of the inkjet printer 10. Specifically, for example, it is determined by the maximum permissible time from when the mounted items 34 and 50 are mounted in the actual use state to when the mounted product 34 is put into operation, and is set at an interval of 2 seconds (2-second cycle).

  The detection signal D is a detection signal for fetching the detection result by the potential detector (inverter 72) into the CPU 61, and the time t3 after the switching signal S changes from the “H” level to the “L” level at the time t2. From then on, it remains at the “H” level for a certain period. The time t3 is set to a time after the time t2 and before the voltage charged in the capacitor 66 equal to or higher than the reference potential Vref (dashed line) drops below the reference potential Vref due to a leakage current of the circuit system. Is done. When the detection signal D is at “H” level, the detection result by the inverter 72 is taken into the CPU 61.

  Since the semiconductor relay 71 is turned on, the potential of the detection input / output port CO becomes the high potential VDD at time t1. At this time, the capacitor 66 is charged by the high potential VDD via the resistor 65. Thereafter, the semiconductor relay 71 is turned off at time t2 to be in a high impedance state, so that the potential of the detection input / output port CO becomes equal to the potential of the mounted product detection terminal COI via the resistor 65.

  The potential of the mounted product detection terminal COI approaches the high potential VDD as the capacitor 66 is gradually charged with the high potential VDD via the resistor 65 after time t1. The time from time t1 to time t2 (time when the switch element is turned on) is set longer than the time during which the capacitor 66 is charged to a potential higher than the reference potential Vref. If the time is sufficiently long, the potential of the mounted product detection terminal COI reaches the high potential VDD. After that, when the semiconductor relay 71 is turned off at time t2 and the detection input / output port CO is in a high impedance state, the mounted products 34 and 50 are not mounted, and the mounted product detection terminal COI is in an open state. The potential of the detection terminal COI does not change abruptly and gradually decreases due to a leakage current of the circuit system.

  In this way, the capacitor (capacitor element) 66 is connected to the mounted product detection terminal COI connected to the mounted product, and the semiconductor relay (switch device) 71 is turned on, so that the capacitor 66 is set to, for example, the high potential VDD. Charged. As a result, when the attachments 34 and 50 are not connected, the attachment detection terminal COI is in a floating state (open state), but is stably in a high potential VDD state by the capacitor 66 charged to the high potential VDD. Keep. Therefore, the potential of the mounted product detection terminal COI does not fluctuate due to disturbance or the like, and it is possible to reliably detect whether the mounted products 34 and 50 are mounted.

  As described above, when the mounted products 34 and 50 are not mounted, as shown in FIG. 4A, when the detection signal D becomes “H” level at time t3, the potential of the detection input / output port CO is It is higher than the reference potential Vref. Therefore, the output of the inverter (potential detector) 72 becomes “L” level, and as a result, the detection result R that is the output of the NOR gate 73 becomes “H” level. Thereby, it is detected that the attachments 34 and 50 are not attached. That is, in the present embodiment, when the detection signal D is “H” level and the detection result R is “H” level, the CPU 61 determines that the mounted products 34 and 50 are not mounted.

  Next, referring to FIG. 4B, the switching signal S, the detection signal D, the potential of the detection input / output port CO, the potential of the mounted product detection terminal COI, and the detection result when the mounted products 34 and 50 are mounted. R will be described. The switching signal S and the detection signal D are the same as those in FIG. 4A, and the interval between the detection cycle (m) and the detection cycle (m + 1) is the same as the interval between the detection cycle (n) and the detection cycle (n + 1).

Since the semiconductor relay 71 is turned on, the potential of the detection input / output port CO becomes the high potential VDD at time t1. Thereafter, at time t2, the semiconductor relay 71 is turned off and enters a high impedance state. Therefore, the potential of the detection input / output port CO becomes the same as that of the mounted product detection terminal COI via the resistor 65 when the semiconductor relay 71 is turned OFF at time t2.
Here, since the attachments 34 and 50 are attached, the attachment detection terminal COI is set to the low potential VSS via the terminal COI and the terminal COO on the attachments 34 and 50 side and the terminal COO on the controller 60 side. It is connected. Therefore, the potential of the detection input / output port CO becomes the low potential VSS.

  Therefore, when the detection signal D becomes “H” level at time t3, the potential of the detection input / output port CO is lower than the reference potential Vref. Therefore, the output of the inverter (potential detector) 72 becomes “H” level, and as a result, the detection result R that is the output of the NOR gate 73 becomes “L” level. Thereby, it is detected that the attachments 34 and 50 are attached. That is, in the present embodiment, when the detection signal D is “H” level and the detection result R is “L” level, the CPU 61 determines that the mounted products 34 and 50 are mounted.

(Function and effect)
As described above, according to the present embodiment, it is possible to reliably detect whether or not the mounted products 34 and 50 are mounted with a simple circuit configuration that does not require complicated feedback control. For this reason, it is possible to realize the mounted product detection means 1 with little cost increase factor.

Further, since the detection can be performed intermittently, an operation current does not always flow for detection, and a reduction in current consumption is possible. The detection cycle can be appropriately set according to the maximum permissible time from when the mounted products 34 and 50 are mounted to when the mounted product 34 is put into operation. For example, when the detection cycle can be set long, the value of the resistor 65 Can be increased to reduce the current flowing into the capacitor 66 to reduce the current consumption.
Further, when the value of the resistor 65 is increased in this way, even when the mounted products 34 and 50 are mounted, the mounted product detection terminal COI → the mounted product 34 and 50 side terminal COI → the mounted product 34 and 50 side terminal. Since the current flowing through the path of COO → controller 60 side terminal COO → low potential VSS can be reduced, current consumption can be reduced.

As a specific example, if the high potential VDD is 3.3 V, the resistor 65 is 1 kΩ, and the capacitor 66 is 1000 pF, the maximum current flowing into the capacitor 66 is 3.3 mA, and the time for which the capacitor 66 is charged to 3.3 V is about 6 mS. Become. Therefore, the shortest detection period can be set to about 6 mS. Further, when the mounted products 34 and 50 are mounted, the current flowing through the mounted products 34 and 50 when the semiconductor relay 71 is turned on is 3.3 mA.
Here, when the shortest cycle can be set to 10 times or 100 times, for example, the resistance 65 is set to 10 kΩ and 100 kΩ, and the maximum current flowing into the capacitor 66 and the current flowing when the attachments 34 and 50 are attached Can be reduced to 1/10 and 1/100, and the current consumption can be further reduced.

  Further, for example, a capacitor 66 charged to a high potential VDD is connected to the mounted product detection terminal COI connected to the mounted product. As a result, when the attachments 34 and 50 are not connected, the attachment detection terminal COI is stably charged by the capacitor 66 and maintains the charged potential. Therefore, the potential of the mounted product detection terminal COI does not fluctuate due to disturbance or the like, and it is possible to detect whether the mounted products 34 and 50 are mounted stably.

  The present invention is particularly effective for detecting whether or not an ink cartridge or a waste ink tank is installed in an ink jet printer that is a printing apparatus including a printing mechanism that discharges ink and prints on printing paper. The apparatus can also be applied to detecting whether or not a mounted product is mounted. Further, in the present embodiment, the present invention has been described by taking the inkjet printer 10 as an example, and therefore, the ink cartridge 34 or the waste ink tank 50 for liquid ink is assumed as the attachment, but the attachment is a leather printer or the like. It may be a toner cartridge (ink cartridge) or a waste toner tank (waste ink tank) for toner, which is powdered ink used in the above.

(Modification)
The embodiment of the present invention has been described above, but various modifications can be made, for example, as described below, without departing from the spirit of the present invention.

(Modification 1)
FIG. 5 is a circuit diagram showing another specific example of the switch element and the potential detector. Specifically, a circuit diagram of the detection input / output port CO portion of the CPU 61 is shown. The circuit of the mounted article detection means 1 includes a clocked buffer (switch element) 75, an inverter 76, an operational amplifier (potential detector) 77, and an AND gate 78.

  The output state of the clocked buffer 75 is controlled by a signal input to the control terminal CNTL. Specifically, when the signal input to the control terminal CNTL is at the “L” level, the logic level of the input terminal IN of the clocked buffer 75 is output to the output terminal OUT and the signal input to the control terminal CNTL. Is at the “H” level, the output terminal OUT is in a high impedance state. In the first modification, the clocked buffer 75 operates with the voltage of the power source 62 (see FIG. 2), and the switching signal S is input to the control terminal CNTL via the inverter 76. Therefore, when the switching signal S becomes “H” level at time t1, the output side terminal OUT (detection input / output port CO) of the clocked buffer 75 becomes “H” level (high potential VDD), and the capacitor 66 has the resistance 65. Is charged through. After that, when the switching signal S becomes “L” level at time t2, the output side terminal OUT of the clocked buffer 75 becomes in a high impedance state, and charging is stopped.

The operational amplifier 77 is a comparator that compares the potential input to the non-inverting input terminal (+ terminal) with the potential input to the inverting input terminal (− terminal) and outputs the result. In the first modification, the potential of the detection input / output port CO is input to the non-inverting input terminal, and the reference potential Vref is input to the inverting input terminal. Here, when the potential of the detection input / output port CO is higher than the reference potential Vref, the output of the operational amplifier 77 becomes the “H” level.
Therefore, if the potential of the detection input / output port CO (+ terminal) is higher than the reference potential Vref (−terminal) when the detection signal D becomes “H” level, the output of the operational amplifier 77 becomes “H” level, and AND The detection result R is outputted as “H” level from the gate 78. That is, also in the first modification, as in the above-described embodiment, when the detection result R is “H” level, the CPU 61 can determine that the attachments 34 and 50 are not attached, and the detection result R is “L”. In the case of the “level”, the CPU 61 can determine that the mounted products 34 and 50 are mounted.

  As apparent from the circuit diagram of FIG. 5, the clocked buffer 75 in which the output side terminal OUT is connected to the detection input / output port CO and the input line connected from the detection input / output port CO to the non-inverting input terminal of the operational amplifier 77 are known. This is a circuit configuration of a general input / output port included in the CPU. Therefore, when the CPU 61 is used as a controller of a system in which the mounted product detection unit 1 is mounted, the switch element can be realized by the existing input / output port of the CPU 61, so that the cost is not increased.

(Modification 2)
In the above-described embodiment, the example in which the inverter 72 whose threshold voltage is the reference potential Vref is used as the potential detector has been described. However, the inverter 72 may be a Schmitt trigger inverter. The Schmitt trigger inverter has a hysteresis characteristic in which the threshold voltage when the input voltage increases and the threshold voltage when the input voltage decreases are different. Therefore, by using the Schmitt trigger inverter, the short-circuit current in the inverter 72 when the input voltage (the potential of the detection input / output port CO) is in the vicinity of the reference potential Vref can be reduced, and the input voltage can be changed minutely. It is possible to suppress the output fluctuation of the inverter 72 caused by.

(Modification 3)
In the circuit shown in FIG. 3 or FIG. 5, the capacitor 66 and the mounted product detection terminal COI are directly connected, but the capacitor 66 and the mounted product detection terminal COI may be connected via a resistance element. As a result, it is possible to suppress the maximum current when the mounted products 34 and 50 are connected and the current starts to flow from the charged capacitor 66 to the low potential VSS. Therefore, it is possible to suppress a steep current from flowing when the attachments 34 and 50 are connected, and the reliability of the attachment detection means 1 is improved.

(Modification 4)
The detection period of the presence / absence of attachment may be changed as appropriate according to the operating state of the system including the attachment detection unit 1. Thereby, for example, in the inkjet printer 10, when the cover for storing the mounted products 34 and 50 is open (during replacement), the detection cycle is short, and when the cover is closed and operating, the detection cycle is long. It is possible to stop the detection and stop detection when it is sleeping.

(Modification 5)
In the above-described embodiment, the terminal 60 includes the terminal COI (attachment detection terminal COI) and the terminal COO on the controller 60 side, the wiring connecting the terminal COI and the terminal COO on the attachments 34 and 50 side, and the connector portion 68. Although the connection mechanism comprised was illustrated, a connection mechanism is not restricted to this.
For example, the ink jet printer 10 is provided with a momentary switch that is turned on by being pressed by the mounting products 34 and 50 when the mounting products 34 and 50 are mounted. The momentary switch is connected so as to short-circuit the terminal COI on the controller 60 side and the terminal COO on the controller 60 side when turned on. Thus, a connection mechanism is configured to connect the terminal COI on the controller 60 side (attachment detection terminal COI) to the low potential VSS when the attachments 34 and 50 are attached.

  The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit of the present invention. For example, the technical features in the embodiments and modifications may be replaced or combined as appropriate to solve part or all of the above-described problems or to achieve part or all of the above-described effects. Can be done. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

  DESCRIPTION OF SYMBOLS 1 ... Installed article detection means, 10 ... Inkjet printer, 12 ... Carriage, 24 ... Print medium, 30 ... Print head, 34 ... Ink cartridge (installed article), 50 ... Waste ink tank (installed article), 65 ... Resistance (resistance) Element), 66 ... capacitor (capacitance element), 68 ... connector part, 71 ... semiconductor relay (switch element), 72 ... inverter (potential detector), 75 ... clocked buffer (switch element), 77 ... operational amplifier (potential detection) vessel).

Claims (7)

A wearing product detecting means for detecting whether or not a detachable wearing product is mounted,
An attachment detection terminal connected to the attachment;
A switching element having one end connected to a predetermined high potential and the other end connected to the wearing article detection terminal via a resistance element;
One end is connected to the mounted product detection terminal and the resistance element, and the other end is connected to a low potential lower than the high potential, and a capacitive element;
A potential detector that detects a potential at a connection point between the switch element and the resistance element based on a reference potential;
A connection mechanism for connecting the attachment detection terminal to the low potential when the attachment is attached, and
By turning on the switch element, the capacitive element is charged through the resistance element by the high potential,
The mounted article detection means, wherein the potential at the connection point is detected by the potential detector with the switch element turned off. In claim 1,
The wearing article detection means characterized in that the time for which the switch element is turned on is longer than the time during which the capacitive element is charged to a potential higher than the reference potential by the high potential via the resistance element. In claim 1 or 2,
A wearing article detecting means characterized by repeating ON and OFF of the switch element at a predetermined cycle. In any one of Claim 1 to 3,
The mounted product detection means, wherein the potential detector is a comparator for comparing the potential at the connection point with the reference potential. In any one of Claims 1-4,
The mounted product detecting means, wherein the mounted product is an ink cartridge mounted on a printing apparatus having a printing mechanism for printing on a print medium. In any one of Claims 1-4,
The mounted product detecting means, wherein the mounted product is a waste ink tank mounted on a printing apparatus having a printing mechanism for printing on a print medium. A printing apparatus having a printing mechanism for printing on a print medium,
A mounted product detection terminal connected to the mounted product, one end connected to a predetermined high potential, the other end connected to the mounted product detection terminal via a resistance element, and one end detected the mounted product A capacitance element connected to the terminal and the resistance element and having the other end connected to a low potential lower than the high potential, and a potential for detecting a potential at a connection point between the switch element and the resistance element based on a reference potential A detector and a connection mechanism for connecting the mounted product detection terminal to the low potential when the mounted product is mounted, and the switch element is turned on and the capacitor via the resistance element by the high potential. A printing apparatus, wherein an element is charged and the potential at the connection point is detected by the potential detector in a state where the switch element is turned off.

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