WO2008074247A1

WO2008074247A1 - A detecting circuit and an ink cartridge

Info

Publication number: WO2008074247A1
Application number: PCT/CN2007/071088
Authority: WO
Inventors: Qingguo Xiao; Xueqian Wu; Dongnin Lin; Ligong Xie
Original assignee: Print Rite Technology Development Co Ltd of Zhuhai
Current assignee: Print Rite Technology Development Co Ltd of Zhuhai
Priority date: 2006-12-20
Filing date: 2007-11-19
Publication date: 2008-06-26
Anticipated expiration: 2009-06-20
Also published as: CN101112820A; CN100486812C

Abstract

A detecting circuit and an ink cartridge are provided. The detecting circuit comprises an electrode couple (1), a signal exchanging electrode (2), an AC signal source (8), and at least one capacitor (20) connected with the electrode couple in series. The detecting circuit has a simple structure and uses fewer elements. Therefore, the detecting circuit can be made using a simple manufacturing process and a low production cost. The circuit is not easy to be damaged and can well simulate the work characteristic of a piezoelectric element.

Description

检测电路及墨盒技术领域本发明涉及一种检测电路及墨盒，该检测电路用于检测容器中导电液体的存在或缺失，尤其是一种可检测墨盒中墨水存在或缺失的检测电路及采用该检测电路的墨盒。本发明基于申请日为 2006 年 12 月 20 日、申请号为 200610124397. 0的中国发明专利申请，该申请的内容作为参考引入本文。背景技术墨盒是一种常用的喷墨打印耗材，一般的墨盒都设置有墨水存在或缺失的检测装置，以检测墨盒中墨水的有无状况。一种现有的墨盒是使用压电元件或压电传感器对墨盒中墨水有无状况进行检测，如申请号为 200480001120. 8的中国专利申请就公开了一种使用压电元件对墨水有无状况进行检测的装置，该装置包括检测信号生成电路，用于对压电元件进行充电和放电，进而生成包含表示周期的信息的检测信号，其中所述周期是从放电结束起经过了预定的待机时间之后残留在压电元件上的残留振动的周期；和控制部，用于生成时钟信号，并且控制压电元件的充电和放电。周期值可用于确定容纳的消耗品的剩余量是否比预定量多。控制部通过对时钟信号的脉冲数进行计数来确定预定的待机时间。该方案压电元件或压电式传感器的制造工艺比较复杂，而且成本较高，批量生产时压电元件参数的一致性较差，对检测结果的稳定性有不良影响。同时，由于压电元件或压电式传感器是微电元件或微电传感器，厚度一般较小，容易损坏，因此，人们在寻找一种能代替压电元件或压电式传感器的检测电路。中国发明专利 ZL03124980. 9和中国发明专利申请 200610093869. 0公开了一种具有替代部件的检测装置及方法，该替代部件由算术逻辑运算电路构成。由于算术逻辑运算电路一般由多个放大器、与非门等组成，使用的元件较多，对减少墨水检测装置的复杂性和降低墨盒生产的成本的意义不是很大。中国发明专利 ZL03158018. 1则公开了一种液体检测电路，其由电极、电源阻抗、交流信号源和确定装置组成，该检测电路虽然比较简单，但其只有电源阻抗和交流信号源等组成，并没有很好的模仿压电元件或压电传感器的工作特性，在检测过程中，与压电元件或压电传感器有一定的差异，影响打印机对墨盒的识别。发明内容本发明的主要目的是提供一种能够较好地替代压电元件或压电传感器且结构简单的墨水检测电路；本发明的另一目的是提供一种采用该检测电路的墨盒。为实现上述目的，本发明提供的检测电路包括一对相间布置的电极对，当电极对间充满墨水时，该电极对电连通；用于与打印机交换信息的信号交换电极，其与电极对构成串联电路；产生周期性信号的交流信号源；至少有一与所述电极对串联连接的电容元件。本发明还提供墨盒，包括容纳墨水的供墨腔；把墨水排出供墨腔外的供墨口；检测电路，包括一对相间布置的电极对，当电极对间充满墨水时，该电极对电连通；用于与打印机交换信息的信号交换电极，其与电极对构成串联电路；产生周期性信号的交流信号源；至少有一与所述电极对串联连接的电容元件。附图说明图 1是本发明第一实施例的电路示意图; 图 2是本发明第二实施例的电路示意图; 图 3是本发明第三实施例的电路示意图; 图 4是本发明第四实施例的电路示意图; 图 5是本发明第五实施例的电路示意图; 图 6是本发明第六实施例的电路示意图; 图 7是本发明第一实施例的第一工作状态的等效电路示意图: 图 8是本发明第一实施例的第二工作状态的等效电路示意图以下结合图示及实施例对本发明作进一歩说明。具体实施方式图 1是本发明所述检测电路的第一实施例的电路示意图在本第一实施例中，墨水余量检测电路应用在墨盒（图未示）中，其由探针式电极对 1、信号交换电极 2、交流信号源 8和电容 20串联组成。本实施例中，探针式电极对 1是设置在墨盒中的供墨口中或供墨腔中，当探针式电极对 1间充满墨水时，探针式电极对 1的两个电极之间电连通。信号交换电极 2与设置在墨盒上的芯片（图未示）保持信号连接，当墨盒安装到打印机上时，墨盒芯片与打印机中的芯片保持信号连接，检测电路检测到的信息通过信号交换电极 2传送给墨盒芯片，然后由墨盒芯片传送到打印机上，并由打印机判断墨盒中墨水的存在或缺失。交流信号源 8 向检测电路加载一个周期性变化的信号，交流信号源 8可以是无源信号源，如晶体振荡器、无源信号发生器等；也可以是有源信号源，如有源信号发生器、周期性振荡电路或单片机、微控制器 (MCU)等。电容 20的作用是模仿压电元件或压电传感器的工作特性，让打印机检测到墨盒中有检测装置的存在。在介绍本发明所述检测电路的工作原理之前，有必要先介绍现有的打印机通过墨盒中的压电元件或压电传感器检测装置来检测墨水余量的过程，一般而言，此过程分为以下两个歩骤： BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detection circuit for detecting the presence or absence of a conductive liquid in a container, and more particularly to a detection circuit capable of detecting the presence or absence of ink in an ink cartridge and using the detection The cartridge of the circuit. The present invention is based on a Chinese patent application filed on Dec. 20, 2006, filed on Jan. 20, 2006, the content of which is hereby incorporated by reference. BACKGROUND OF THE INVENTION An ink cartridge is a commonly used inkjet printing consumable. A general ink cartridge is provided with a detecting device for the presence or absence of ink to detect the presence or absence of ink in the ink cartridge. An existing ink cartridge is a piezoelectric element or a piezoelectric sensor for detecting the presence or absence of ink in an ink cartridge. For example, the Chinese patent application No. 200480001120. 8 discloses the use of a piezoelectric element for the presence or absence of ink. And a device for detecting, comprising: a detection signal generating circuit for charging and discharging the piezoelectric element, thereby generating a detection signal including information indicating a period, wherein the period is a predetermined standby time elapsed from the end of discharging The period of residual vibration remaining on the piezoelectric element thereafter; and a control portion for generating a clock signal and controlling charging and discharging of the piezoelectric element. The period value can be used to determine if the remaining amount of consumables contained is greater than a predetermined amount. The control unit determines a predetermined standby time by counting the number of pulses of the clock signal. The manufacturing process of the piezoelectric element or the piezoelectric sensor of the solution is complicated, and the cost is high, and the consistency of the parameters of the piezoelectric element in the mass production is poor, which has an adverse effect on the stability of the detection result. At the same time, since the piezoelectric element or the piezoelectric sensor is a micro-electric element or a micro-electric sensor, the thickness is generally small and easily damaged, and therefore, a detecting circuit capable of replacing the piezoelectric element or the piezoelectric type sensor is being sought. The Chinese invention patent ZL03124980. 9 and the Chinese invention patent application 200610093869. 0 disclose a detection device and method having an alternative component which is constituted by an arithmetic logic operation circuit. Since the arithmetic logic operation circuit is generally composed of a plurality of amplifiers, NAND gates, and the like, many components are used, which is not significant for reducing the complexity of the ink detecting device and reducing the cost of the ink cartridge production. The Chinese invention patent ZL03158018. 1 discloses a liquid detecting circuit which is composed of an electrode, a power source impedance, an AC signal source and a determining device. Although the detecting circuit is relatively simple, it only has a power source impedance and intersection. The flow signal source and the like do not well simulate the working characteristics of the piezoelectric element or the piezoelectric sensor. In the detection process, there is a certain difference from the piezoelectric element or the piezoelectric sensor, which affects the recognition of the ink cartridge by the printer. SUMMARY OF THE INVENTION A primary object of the present invention is to provide an ink detecting circuit which can better replace a piezoelectric element or a piezoelectric sensor and has a simple structure. Another object of the present invention is to provide an ink cartridge using the detecting circuit. In order to achieve the above object, the detection circuit provided by the present invention comprises a pair of electrode pairs arranged between phases, the electrode pair is electrically connected when the electrode pair is filled with ink; the signal exchange electrode for exchanging information with the printer, and the pair of electrodes a series circuit; an alternating current signal source that generates a periodic signal; at least one capacitive element connected in series with the pair of electrodes. The invention also provides an ink cartridge, comprising an ink supply chamber for accommodating ink; discharging an ink to an ink supply port outside the ink supply chamber; and a detecting circuit comprising a pair of electrode pairs arranged between the electrodes, wherein the electrode is electrically charged when the electrode pair is filled with ink Connected; a signal exchange electrode for exchanging information with the printer, which constitutes a series circuit with the pair of electrodes; an AC signal source for generating a periodic signal; at least one capacitive element connected in series with the pair of electrodes. DRAWINGS 1 is a circuit diagram of a first embodiment of the present invention; FIG. 2 is a circuit diagram of a second embodiment of the present invention; FIG. 3 is a circuit diagram of a third embodiment of the present invention; Figure 5 is a circuit diagram of a fifth embodiment of the present invention; Figure 6 is a circuit diagram of a sixth embodiment of the present invention; Figure 7 is a schematic diagram of an equivalent circuit of the first operational state of the first embodiment of the present invention: Figure 8 It is an equivalent circuit diagram of the second working state of the first embodiment of the present invention. The present invention will be further described below with reference to the drawings and embodiments. 1 is a circuit diagram of a first embodiment of the detecting circuit of the present invention. In the first embodiment, an ink remaining amount detecting circuit is applied to an ink cartridge (not shown), which is composed of a probe electrode pair. 1. The signal exchange electrode 2, the AC signal source 8 and the capacitor 20 are connected in series. In this embodiment, the probe electrode pair 1 is disposed in the ink supply port or the ink supply chamber in the ink cartridge. When the probe electrode pair 1 is filled with ink, between the two electrodes of the probe electrode pair 1 Electrically connected. The signal exchange electrode 2 maintains a signal connection with a chip (not shown) disposed on the ink cartridge. When the ink cartridge is mounted on the printer, the ink cartridge chip maintains a signal connection with the chip in the printer, and the information detected by the detection circuit passes through the signal exchange electrode 2 It is sent to the cartridge chip, which is then transferred to the printer by the cartridge chip, and the printer determines the presence or absence of ink in the cartridge. The AC signal source 8 loads a periodically varying signal to the detection circuit. The AC signal source 8 can be a passive signal source, such as a crystal oscillator, a passive signal generator, etc., or an active signal source, such as an active signal. Generator, periodic oscillation circuit or microcontroller, microcontroller (MCU), etc. The function of the capacitor 20 is to mimic the operational characteristics of the piezoelectric element or the piezoelectric sensor, allowing the printer to detect the presence of a detecting device in the ink cartridge. Before introducing the working principle of the detecting circuit of the present invention, it is necessary to first introduce a process in which an existing printer detects a remaining amount of ink through a piezoelectric element or a piezoelectric sensor detecting device in an ink cartridge. Generally, this process is divided into The following two steps:

( 1 ) 检测是否存在压电元件或压电传感器； (2) 判断该压电元件或压电传感器的振荡频率是否与打印机的设定频率一致。由于压电元件或压电传感器的主要组成部分是压电晶体，故检测压电元件或压电传感器的存在实际上是检测压电晶体的存在。而压电晶体具有与电容相似的充放电特性，而打印机是通过检测压电晶体的充放电特性来判断是否存在压电晶体，因此，在上述的歩骤（1 ) 中，若检测电路中有类似压电晶体充放电特性的元件存在，则打印机就会认为检测电路中有压电元件或压电传感器存在。在上述歩骤（2) 中，打印机需要判断检测装置中的压电元件或压电传感器的振动频率是否与打印机的设定值一致时，打印机判断检测电路中是否有周期性信号，如果有周期性信号，则打印机判断此周期性信号的振荡频率是否与打印机设定的频率一致，并以此判断检测装置的正确与否。经过上述两歩检测和判断后，若打印机认为检测电路有压电元件或压电传感器的存在，并且其振荡频率与打印机设定的频率一致时，打印机就会认为墨盒中的检测装置正确，然后判断墨盒中墨水量是否足够。根据上述原理，在本实施例所述的检测电路安装到墨盒上后，若墨盒中存在有足够的墨水，探针式电极对 1的两个电极之间会电连通，其等效电路图如图 7所示。检测电路处于导通状态，打印机通过相应的电极与信号交换电极 2 信号连接，并检测此电路是否有压电元件或压电传感器的存在。此时，由于检测电路已经导通，在交流信号源 8产生的周期性信号的作用下，电容 20会反复的充放电，打印机会检测到检测电路中有具有一与压电晶体类似的充放电特性的元件存在，认为此检测电路中有压电元件或压电传感器的存在，进入下一歩的检测。此时，由交流信号源 8产生的周期性信号通过信号交换电极 2传送给打印机，打印机判断此周期性信号的振荡频率是否与设定频率一致。由于交流信号源 8产生的周期性信号的振荡频率可以设置在 10k— 200kHz范围内变化，并且可以根据打印机设定的频率进行调整，故可以根据实际情况使打印机能检测到与其设定值一致的振荡频率，因此，打印机会认为此检测电路中有压电元件或压电传感器的存在，并且其振荡频率与打印机设定的频率一致，故认为墨盒中的检测装置正确并能正确检测出墨盒中墨水的存在或缺失。此时，打印机就会通过墨盒中的检测装置对墨盒中的墨水余量是否足够进行检测。当墨盒中有足够的墨水时，探针式电极对 1电连通，检测电路也同时导通，信号交换电极 2有电压信号输出，打印机通过对应的电极检测到此输出电压信号，认为墨盒中有墨水，打印机可以正常使用。随着墨盒中的墨水被消耗，探针式电极对 1之间的墨水被耗尽，探针式电极对 1的两个电极之间失去电连接，其等效电路图如图 8所示，检测电路断开，信号交换电极 2没有电压输出，打印机不能检测到检测电路输出的电压信号，认为墨盒中的墨水即将用尽，向用户发出一个警告信号，告知用户墨盒中的墨水余量不多，需要更换新的墨盒。图 2揭示了本发明的第二实施例。与图 1中所示的第一实施例相比，图 2 中使用回路电感 4和耦合电感 5组成耦合元件，耦合元件将交流信号源 8产生的周期性信号耦合到检测电路中去，减少了交流信号源 8直接串联到检测电路时对检测电路的造成的影响。同时，由于不同种类的墨水的电阻会有一定的差异，为了使检测电路具有更广的适用性，第二实施例中在检测电路中串联一阻值可调的电阻 10，此可调电阻可根据不同墨水电阻不同而调整。本实施例中，检测电路由谐振回路和交流信号输入回路组成，其中谐振回路由探针式电极对 1、信号交换电极 2、回路电感 4、电阻 10和电容 20串联组成，交流信号输入回路由交流信号源 8与耦合电感 5串联组成。如上所述，耦合电感 5和回路电感 4组成了本实施例的耦合部分。与第一实施例相比，本实施例是通过耦合元件将交流信号源 8 产生的周期性信号耦合到谐振回路中去。同时，在谐振回路上，串联了一个阻值可调的电阻 10。本实施例中，探针式电极对 1也是设置在墨盒中的供墨口中或墨盒中的供墨腔中，当探针式电极对 1两个电极之间充满墨水时，电极对就会电连通。信号交换电极 2与打印机信号连接，并与打印机进行信息交换。交流信号源 8可以是有源信号源或无源信号源，其产生的周期性信号加载到耦合电感 5上，设置在谐振回路中的回路电感 4通过与耦合电感 5的电感耦合作用接收交流信号源 8产生的周期性信号。电阻 10与电容 20共同作用并模仿压电传感器的工作特性，让打印机检测到有检测装置的存在，此过程与上述第一实施例相同，在此不做赘述。电阻 10的阻值变化范围在 0〜10Μ Ω，可根据不同墨水的性质而进行设定，当墨水电阻较大时，可以选择使用阻值较小的电阻 10，若墨水的电阻较小时，可以选择阻止较大的电阻 10，以适应对不同种类的墨水的检测。在本实施例的检测电路安装到墨盒上后，若墨盒中存在有足够的墨水，探针式电极对 1的两个电极之间电连通，谐振回路导通，打印机通过相应的电极与信号交换电极 2 电连接，并检测此电路是否有压电元件或压电传感器的存在。此时，由于电容 20的存在，打印机会检测到谐振回路中有一具有充放电特性的元件存在，认为此检测电路中有压电元件或压电传感器的存在，进入下一歩的检测。当打印机判断检测电路中压电元件或压电传感器的振动频率是否与打印机设定的频率是否一致时，由交流信号源 8产生的周期性信号会通过耦合电感 5耦合到回路电感 4上，回路电感 4接收此周期性信号后，使整个谐振回路形成一与该周期性信号相同的振荡频率，此频率也会在信号交换电极 2 上形成，打印机检测到此周期性信号后，即判断其振荡频率是否与设定频率一致。由于信号源产生的周期性信号的振动频率可调，打印机能检测到与其设定值一致的振荡频率，打印机会认为其振荡频率与打印机设定的频率一致，故认为墨盒中的检测装置正确并能正确检测出墨盒中墨水的存在或缺失。综上所述，若墨盒中有足够的墨水，探针式电极对 1电连通并使谐振回路导通，信号交换电极 2有电压信号输出，打印机认为墨盒中有墨水；若探针式电极对 1之间的墨水耗尽，探针式电极对 1的电极之间失去电连接，谐振回路断开，信号交换电极 2没有电压输出，打印机认为墨盒中的墨水即将用尽，向用户发出一个警告信号。在本实施例中，探针式电极对 1设置在信号交换电极 2与回路电感 4的中间，在实际的应用中，探针式电极对 1也可以设置在电阻 10与电容 20的中间，还可以设置在电容 20与回路电感 4的中间，或者把本实施例中的电容 20与探针式电极对 1互换位置，探针式电极对 1位于电阻 10与回路电感 4的中间，电容 20则位于靠近信号输出端口 2的一侧。当然，在本发明实际应该过程中，耦合部分不限于本实施例中使用的电感耦合元件，图 3为本实施例第三实施方式，其使用的耦合部分为光电耦合元件。如图 3所示，本实施例中的耦合部分由发光部件和光接收部件组成，发光部件为发光二极管 6，光接收部件为光电三极管 7。本实施例中，除了耦合部分使用光电耦合元件替代电感耦合元件外，其它部件与第二实施例相同，在此不作赘述。当交流信号源 8向耦合部分的发光二极管 6传送周期性信号时，发光二极管 6会随着此周期性信号电压的有无而发光或熄灭。此时，光电三极管 7会因接收到发光二极管 6发出的光产生电流。由于发光二极管 6是随着周期性信号变化而发光或熄灭，光电三极管 7产生出的电流也会周期性的断续的。当该周期性信号为正弦波等连续变化信号时，发光二极管 6的发光强度还会随着信号绝对值的大小而增强或减弱。此时，光电三极管 7就会随着光强的强弱而产生出周期性变化的电流，电流值的大小会根据发光二级光 6发出的光强变化而变化，也就是说光电三极管 7产生的电流是根据连续变化周期性信号绝对值的大小变化而变化，其变化频率可基本保持一致。由光电三极管 7产生的电流信号在流经电阻 10时形成一电压信号，此电压信号也是一周期性变化的信号，并与交流信号源 8产生的周期性信号保持一致的变化频率。同时，此周期性变化的电压信号可以经过信号交换电极 2及对应的电极向打印机传送，打印机会检测谐振回路的振荡频率并判断墨盒中的检测装置是否正确。当装设有本实施例的检测电路的墨盒安装到打印机后，打印机会通过与上述第一、第二实施例相同的方式和过程检测和判断墨盒中的检测装置是否正确，并在确认该检测装置正确后，判断墨盒中的墨水余量是否足够。在本发明实际应该过程中，耦合部分除了可以是电感耦合、光电耦合外，还可以是电容耦合，其工作原理与上述两实施例基本一致，只是在耦合部分使用电容耦合元件，交流信号源 8向耦合电容发送周期性信号，耦合电容将该信号耦合到回路电容中，使谐振回路导通，并判断墨盒中墨水的存在或缺失。当然，本发明耦合部分不限于电感耦合、光电耦合或电容耦合这三种耦合方式，其他的耦合方式也应包含在本发明的保护范围内。参照图 4所示，图 4揭示了本发明的第四实施例。应用本发明的检测电路对墨盒中墨水余量进行检测时，为了在检测电路中得到更好的交流信号，可以在电阻 10与电容 20的支路上并联一电容元件，把回路中的直流信号分量过滤掉。在图 4所示的实施例中，其与第二实施例不同的地方在于在电阻 10与电容 20组成的支路上并联一滤波电容 21，滤波电容 21可以为 lpF— 800pF，其作用就在于可以过滤谐振回路中的直流信号分量，采用滤波电容 21的理由如下：在检测电路判断墨盒中墨水存在或缺失的过程中，由于受到打印机输送过来的检测信号和耦合元件等影响，谐振回路中可能会带有一定的直流信号分量。此直流信号分量会对打印机检测墨盒中压电元件或压电传感器的振荡频率是否与其设定频率一致时造成一定的影响，打印机有可能会误认为压电元件或压电传感器的振荡频率与其设定频率不一致，便不能正常的对墨水余量进行检测。采用滤波电容 21之后，若谐振回路中有直流信号分量存在时，当其流经电阻 10、电容 20与滤波电容 21组成的并联支路时，直流信号分量会被滤波电容 21过滤。这是因为直流信号在经过滤波电容 21时，由于直流信号没有方向的变化，其形成的电量只会停留在电容 21的一个极板上，不能到达滤波电容 21的另外一个极板上，也就是说直流信号不能通过滤波电容 21，从而滤波电容 21就能把回路中的直流信号分量过滤，避免其混入到谐振回路中的交流信号分量中，避免打印机误以为检测装置不正确情况的发生。同时，应用本发明对墨盒中墨水余量进行检测时，为了更好的模仿压电晶体的充放电特性，检测电路中可以设置多个由电阻和电容串联组成的支路。如图 5所示，为本发明的第五实施例。本实施例中，与第二实施例不同的是，在电阻 10与电容 20组成的支路上并联了一由电阻 12和电容 22组成的支路，图 5中所示电路的特性更接近压电晶体充放电特性。当打印机检测压电元件或压电传感器的存在时，检测电路可以表现出更接近于压电晶体的充放电特性，更容易让打印机认为检测电路中有压电元件或压电传感器的存在，从而进入下一歩的判断。另外，有电阻 12和电容 22组成的并联支路，除了可以使检测电路表现出更接近压电晶体的充放电特性外，电容 22还可有过滤回路中直流信号分量的作用，使检测电路表现出更接近压电晶体的充放电特性外，还得到更纯的交流信号。本实施例中并联有电阻和电容组成的支路数量有两条，在实际应用中，并联的数量可以更多。如图 6所示的第六实施例，由电阻和电容组成的支路共有 3条，分别是电阻 10、电容 20组成的第一支路、电阻 13a、电容 23a组成的第二支路和电阻 13b、电容 23b组成的第二支路。在第四到第六实施例中，耦合部分均为电感耦合，但在本发明实际应用过程中，还可以使用光电耦合元件、电容耦合元件等作为耦合部分。在实际应用中，其他的耦合方式也应该包括在本发明的保护范围内。需要强调的是，本发明所述的检测电路均可以应用到墨盒中。当然，本发明的电路组成不限于上述的实施方式，诸如耦合方式改变、电阻和电容连接方式改变等微小改变以及等效变换均应包括在权利要求所述的范围之内。工业应用性 (1) Detect whether a piezoelectric element or a piezoelectric sensor is present; (2) Determine whether the oscillation frequency of the piezoelectric element or the piezoelectric sensor coincides with the set frequency of the printer. Since the main component of the piezoelectric element or the piezoelectric sensor is a piezoelectric crystal, the presence of the detecting piezoelectric element or the piezoelectric sensor actually detects the presence of the piezoelectric crystal. The piezoelectric crystal has a charge and discharge characteristic similar to that of the capacitor, and the printer determines whether or not the piezoelectric crystal exists by detecting the charge and discharge characteristics of the piezoelectric crystal. Therefore, in the above step (1), if the detection circuit has In the presence of an element similar to the charge and discharge characteristics of a piezoelectric crystal, the printer considers that there is a piezoelectric element or a piezoelectric sensor in the detection circuit. In the above step (2), when the printer needs to determine whether the vibration frequency of the piezoelectric element or the piezoelectric sensor in the detecting device is consistent with the set value of the printer, the printer determines whether there is a periodic signal in the detecting circuit, if there is a period The sex signal, the printer determines whether the oscillation frequency of the periodic signal is consistent with the frequency set by the printer, and thereby determines whether the detection device is correct or not. After the above two detections and judgments, if the printer believes that the detection circuit has the presence of a piezoelectric element or a piezoelectric sensor, and the oscillation frequency coincides with the frequency set by the printer, the printer considers that the detection device in the ink cartridge is correct, and then Determine if the amount of ink in the cartridge is sufficient. According to the above principle, after the detecting circuit of the embodiment is mounted on the ink cartridge, if there is sufficient ink in the ink cartridge, the two electrodes of the probe electrode pair 1 are electrically connected, and the equivalent circuit diagram thereof is as shown in the figure. 7 is shown. The detection circuit is in an on state, and the printer is connected to the signal exchange electrode 2 through a corresponding electrode, and detects whether the circuit has a piezoelectric element or a piezoelectric sensor. At this time, since the detection circuit has been turned on, the capacitor 20 is repeatedly charged and discharged under the action of the periodic signal generated by the AC signal source 8, and the printer detects that the detection circuit has a charge and discharge similar to that of the piezoelectric crystal. The characteristic component exists, and it is considered that there is a piezoelectric element or a piezoelectric sensor in the detection circuit, and the next step is entered. 歩 detection. At this time, the periodic signal generated by the AC signal source 8 is transmitted to the printer through the signal exchange electrode 2, and the printer determines whether the oscillation frequency of the periodic signal coincides with the set frequency. Since the oscillation frequency of the periodic signal generated by the AC signal source 8 can be set within the range of 10k-200kHz, and can be adjusted according to the frequency set by the printer, the printer can detect the same value as the set value according to the actual situation. The oscillation frequency, therefore, the printer will consider the presence of a piezoelectric element or a piezoelectric sensor in the detection circuit, and its oscillation frequency is consistent with the frequency set by the printer, so that the detection device in the ink cartridge is considered correct and can correctly detect the ink cartridge. The presence or absence of ink. At this time, the printer detects whether the remaining amount of ink in the ink cartridge is sufficient by the detecting device in the ink cartridge. When there is enough ink in the ink cartridge, the probe electrode pair 1 is electrically connected, the detection circuit is also turned on at the same time, the signal exchange electrode 2 has a voltage signal output, and the printer detects the output voltage signal through the corresponding electrode, and the printer believes that there is Ink, the printer can be used normally. As the ink in the ink cartridge is consumed, the ink between the probe electrode pairs 1 is depleted, and the electrical connection between the two electrodes of the probe electrode pair 1 is lost. The equivalent circuit diagram is as shown in FIG. The circuit is disconnected, the signal exchange electrode 2 has no voltage output, the printer can not detect the voltage signal output by the detection circuit, and the ink in the ink cartridge is about to be exhausted, and a warning signal is sent to the user to inform the user that the ink amount in the ink cartridge is not much. A new cartridge needs to be replaced. Figure 2 discloses a second embodiment of the invention. Compared with the first embodiment shown in FIG. 1, the loop inductor 4 and the coupled inductor 5 are used in FIG. 2 to form a coupling element, which couples the periodic signal generated by the AC signal source 8 into the detecting circuit, thereby reducing The effect of the AC signal source 8 on the detection circuit when it is directly connected in series to the detection circuit. At the same time, since the resistance of different kinds of inks may have a certain difference, in order to make the detection circuit have wider applicability, in the second embodiment, a resistor 10 with adjustable resistance value is connected in series in the detection circuit, and the adjustable resistor can be Adjust according to different ink resistance. In this embodiment, the detecting circuit is composed of a resonant circuit and an alternating current signal input circuit, wherein the resonant circuit is composed of a probe electrode pair 1, a signal exchange electrode 2, a loop inductor 4, a resistor 10 and a capacitor 20 in series, and the AC signal input loop is composed of The AC signal source 8 is formed in series with the coupled inductor 5. As described above, the coupled inductor 5 and the loop inductor 4 constitute the coupling portion of the present embodiment. Compared with the first embodiment, the present embodiment couples the periodic signal generated by the alternating current signal source 8 into the resonant circuit through the coupling element. At the same time, on the resonant circuit, a resistor 10 with adjustable resistance is connected in series. In this embodiment, exploration The pin electrode pair 1 is also disposed in the ink supply port in the ink cartridge or in the ink supply chamber in the ink cartridge. When the probe electrode pair 1 is filled with ink between the electrodes, the electrode pair is electrically connected. The handshake electrode 2 is connected to the printer signal and exchanges information with the printer. The AC signal source 8 can be an active signal source or a passive signal source, and the generated periodic signal is applied to the coupled inductor 5, and the loop inductor 4 disposed in the resonant loop receives the AC signal through the inductive coupling with the coupled inductor 5. The periodic signal generated by source 8. The resistor 10 interacts with the capacitor 20 and mimics the operational characteristics of the piezoelectric sensor, so that the printer detects the presence of the detecting device. This process is the same as that of the first embodiment described above, and will not be described herein. The resistance value of the resistor 10 ranges from 0 to 10 Ω, which can be set according to the properties of different inks. When the ink resistance is large, the resistor 10 with a small resistance value can be selected. If the resistance of the ink is small, The larger resistor 10 is chosen to block the detection of different types of ink. After the detecting circuit of the embodiment is mounted on the ink cartridge, if there is enough ink in the ink cartridge, the two electrodes of the probe electrode pair 1 are electrically connected, the resonant circuit is turned on, and the printer exchanges signals through the corresponding electrodes. The electrode 2 is electrically connected and detects whether the circuit has the presence of a piezoelectric element or a piezoelectric sensor. At this time, due to the presence of the capacitor 20, the printer detects that there is a component having a charge and discharge characteristic in the resonant circuit, and it is considered that there is a piezoelectric element or a piezoelectric sensor in the detecting circuit, and the detection of the next turn is performed. When the printer determines whether the vibration frequency of the piezoelectric element or the piezoelectric sensor in the detection circuit is consistent with the frequency set by the printer, the periodic signal generated by the AC signal source 8 is coupled to the loop inductance 4 through the coupling inductor 5, the loop After receiving the periodic signal, the inductor 4 forms the same resonant frequency as the periodic signal, and the frequency is also formed on the signal exchange electrode 2. After the printer detects the periodic signal, it determines the oscillation. Whether the frequency is consistent with the set frequency. Since the vibration frequency of the periodic signal generated by the signal source is adjustable, the printer can detect the oscillation frequency that is consistent with the set value, and the printer considers that the oscillation frequency is consistent with the frequency set by the printer, so that the detection device in the ink cartridge is considered correct and It can correctly detect the presence or absence of ink in the ink cartridge. In summary, if there is enough ink in the ink cartridge, the probe electrode pair 1 is electrically connected and the resonant circuit is turned on, the signal exchange electrode 2 has a voltage signal output, and the printer considers that there is ink in the ink cartridge; if the probe electrode pair The ink between 1 is exhausted, the electrode of the probe electrode pair 1 loses electrical connection, the resonant circuit is disconnected, and the signal exchange electrode 2 has no voltage output. The printer thinks that the ink in the ink cartridge is about to run out, and issues a warning to the user. signal. In the present embodiment, the probe electrode pair 1 is disposed between the signal exchange electrode 2 and the loop inductor 4. In practical applications, the probe electrode pair 1 may also be disposed between the resistor 10 and the capacitor 20. It can be disposed between the capacitor 20 and the loop inductor 4, or the capacitor 20 in this embodiment is interchanged with the probe electrode pair 1. The probe electrode pair 1 is located between the resistor 10 and the loop inductor 4, and the capacitor 20 It is located on the side close to the signal output port 2. Of course, in the actual process of the present invention, the coupling portion is not limited to the inductive coupling element used in the embodiment, and FIG. 3 is the third embodiment of the embodiment, and the coupling portion used is a photoelectric coupling element. As shown in FIG. 3, the coupling portion in this embodiment is composed of a light-emitting member which is a light-emitting diode 6, and a light-receiving member which is a phototransistor 7. In this embodiment, except that the coupling portion uses the optoelectronic coupling element instead of the inductive coupling element, the other components are the same as those of the second embodiment, and are not described herein. When the AC signal source 8 transmits a periodic signal to the light-emitting diode 6 of the coupling portion, the light-emitting diode 6 emits or extinguishes with the presence or absence of the periodic signal voltage. At this time, the phototransistor 7 generates a current by receiving light emitted from the light emitting diode 6. Since the light-emitting diode 6 is illuminated or extinguished as the periodic signal changes, the current generated by the phototransistor 7 is also periodically interrupted. When the periodic signal is a continuous change signal such as a sine wave, the luminous intensity of the light emitting diode 6 is also increased or decreased with the absolute value of the signal. At this time, the phototransistor 7 generates a periodically varying current according to the intensity of the light intensity, and the magnitude of the current value changes according to the change of the light intensity emitted by the illuminating secondary light 6, that is, the phototransistor 7 is generated. The current is varied according to the change of the absolute value of the continuously changing periodic signal, and the frequency of change can be substantially consistent. The current signal generated by the phototransistor 7 forms a voltage signal when flowing through the resistor 10, and the voltage signal is also a periodically varying signal and maintains a constant frequency of change with the periodic signal generated by the AC signal source 8. At the same time, the periodically varying voltage signal can be transmitted to the printer via the signal exchange electrode 2 and the corresponding electrode, and the printer detects the oscillation frequency of the resonant circuit and determines whether the detection device in the ink cartridge is correct. When the ink cartridge to which the detecting circuit of the embodiment is mounted is mounted to the printer, the printer detects and judges whether the detecting device in the ink cartridge is correct by the same manner and process as the first and second embodiments described above, and confirms the detection. After the device is correct, determine if the remaining amount of ink in the ink cartridge is sufficient. In the actual process of the present invention, the coupling portion may be capacitive coupling in addition to inductive coupling and photoelectric coupling, and the working principle is basically the same as the above two embodiments, except that the capacitive coupling component is used in the coupling portion, and the AC signal source 8 is used. A periodic signal is sent to the coupling capacitor, which couples the signal into the loop capacitor, turns the resonant loop on, and determines the presence or absence of ink in the cartridge. Of course, the coupling portion of the present invention is not limited to the three coupling modes of inductive coupling, photoelectric coupling or capacitive coupling, and other coupling modes are also included in the protection scope of the present invention. Referring to Figure 4, Figure 4 discloses a fourth embodiment of the present invention. When the detection circuit of the present invention detects the ink remaining amount in the ink cartridge, in order to obtain a better AC signal in the detecting circuit, a capacitive component can be connected in parallel with the branch of the resistor 10 and the capacitor 20 to convert the DC signal component in the loop. Filtered. In the embodiment shown in FIG. 4, the difference from the second embodiment is that a filter capacitor 21 is connected in parallel with the branch formed by the resistor 10 and the capacitor 20. The filter capacitor 21 can be lpF-800pF, and the function is that Filtering the DC signal component in the resonant tank. The reason for using the filter capacitor 21 is as follows: In the process of determining the presence or absence of ink in the ink cartridge by the detecting circuit, the resonant circuit may be affected by the detection signal and the coupling component transmitted by the printer. With a certain DC signal component. The DC signal component will have a certain influence on whether the oscillation frequency of the piezoelectric element or the piezoelectric sensor in the ink cartridge is consistent with the set frequency, and the printer may mistake the oscillation frequency of the piezoelectric element or the piezoelectric sensor. If the fixed frequencies are inconsistent, the ink remaining amount cannot be detected normally. After the filter capacitor 21 is used, if a DC signal component exists in the resonant tank, when it flows through the parallel branch composed of the resistor 10, the capacitor 20 and the filter capacitor 21, the DC signal component is filtered by the filter capacitor 21. This is because when the DC signal passes through the filter capacitor 21, since the DC signal has no change in direction, the amount of electricity formed will only stay on one plate of the capacitor 21 and cannot reach the other plate of the filter capacitor 21, that is, It is said that the DC signal cannot pass through the filter capacitor 21, so that the filter capacitor 21 can filter the DC signal component in the loop to prevent it from being mixed into the AC signal component in the resonant loop, thereby preventing the printer from erroneously thinking that the detecting device is not correct. Meanwhile, when the ink amount in the ink cartridge is detected by the present invention, in order to better simulate the charge and discharge characteristics of the piezoelectric crystal, a plurality of branches composed of a resistor and a capacitor in series may be disposed in the detecting circuit. As shown in Fig. 5, it is a fifth embodiment of the present invention. In this embodiment, unlike the second embodiment, A branch composed of a resistor 12 and a capacitor 22 is connected in parallel with the branch formed by the resistor 10 and the capacitor 20. The characteristics of the circuit shown in Fig. 5 are closer to the charge and discharge characteristics of the piezoelectric crystal. When the printer detects the presence of a piezoelectric element or a piezoelectric sensor, the detection circuit can exhibit a charge and discharge characteristic closer to that of the piezoelectric crystal, making it easier for the printer to consider the presence of a piezoelectric element or a piezoelectric sensor in the detection circuit, thereby Enter the next judgment. In addition, there is a parallel branch composed of a resistor 12 and a capacitor 22, in addition to making the detection circuit appear closer to the charge and discharge characteristics of the piezoelectric crystal, the capacitor 22 can also function as a DC signal component in the filter loop to make the detection circuit behave. In addition to the charge and discharge characteristics of the piezoelectric crystal, a purer AC signal is obtained. In this embodiment, there are two branches having a resistor and a capacitor in parallel, and in practical applications, the number of parallel connections can be more. In the sixth embodiment shown in FIG. 6, a total of three branches consisting of a resistor and a capacitor are a resistor 10, a first branch composed of a capacitor 20, a resistor 13a, a second branch composed of a capacitor 23a, and a resistor. 13b, a second branch composed of a capacitor 23b. In the fourth to sixth embodiments, the coupling portions are all inductive coupling, but in the practical application of the present invention, a photoelectric coupling element, a capacitive coupling element or the like may be used as the coupling portion. In practical applications, other coupling methods should also be included in the scope of the present invention. It should be emphasized that the detection circuit of the present invention can be applied to an ink cartridge. Of course, the circuit components of the present invention are not limited to the above-described embodiments, and minor changes such as coupling mode changes, resistance and capacitance connection changes, and equivalent transformations are all included in the scope of the claims. Industrial applicability

本发明提供的检测电路简单，能减少生产墨水检测装置的复杂性，并能降低墨盒生产成本，同时检测电路又能很好的模仿压电元件或压电传感器的工作特性，能让打印机正确判断墨盒中墨水余量是否足够。 The detection circuit provided by the invention is simple, can reduce the complexity of producing the ink detecting device, and can reduce the production cost of the ink cartridge, and the detecting circuit can well imitate the working characteristics of the piezoelectric element or the piezoelectric sensor, and can make the printer correctly judge. Is the ink level in the ink cartridge sufficient?

Claims

Claim

1, detection circuit, including

a pair of electrode pairs arranged between the electrodes, when the pair of electrodes is filled with ink, the pair of electrodes is in electrical communication; a signal exchange electrode for exchanging information with the printer, which forms a series circuit with the pair of electrodes; an AC signal source for generating a periodic signal;

It is characterized by:

There is at least one capacitive element connected in series with the pair of electrodes.

2. The detection circuit of claim 1 wherein:

The alternating signal source is loaded into the series circuit by a coupling element.

3. The detection circuit of claim 2, wherein:

The coupling element is one of an inductive coupling element or a photoelectric coupling element or a capacitive coupling element.

4. The detection circuit of claim 1 wherein:

The AC signal source is one of a crystal oscillator or a periodic signal oscillating circuit or a signal generator or a microcontroller or a microcontroller.

5, ink cartridges, including

An ink supply chamber containing ink;

Discharging ink from the ink supply port outside the ink supply chamber;

Detection circuit, including

It is characterized by:

6. The ink cartridge according to claim 5, wherein:

7. The ink cartridge according to claim 6, wherein:

8. The ink cartridge according to claim 7, wherein:

The electrode pair is disposed in the ink supply chamber or disposed in the ink supply port.

9. The ink cartridge according to claim 6, wherein:

10. The ink cartridge according to claim 9, wherein: