JPH0119526B2 - - Google Patents
Info
- Publication number
- JPH0119526B2 JPH0119526B2 JP56139744A JP13974481A JPH0119526B2 JP H0119526 B2 JPH0119526 B2 JP H0119526B2 JP 56139744 A JP56139744 A JP 56139744A JP 13974481 A JP13974481 A JP 13974481A JP H0119526 B2 JPH0119526 B2 JP H0119526B2
- Authority
- JP
- Japan
- Prior art keywords
- piezoelectric vibrator
- oscillation
- circuit
- frequency
- detection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000010355 oscillation Effects 0.000 claims description 43
- 238000001514 detection method Methods 0.000 claims description 37
- 239000000696 magnetic material Substances 0.000 claims 1
- 238000004804 winding Methods 0.000 description 20
- 239000006247 magnetic powder Substances 0.000 description 16
- 239000000126 substance Substances 0.000 description 7
- 239000003990 capacitor Substances 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- 239000000919 ceramic Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000005389 magnetism Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000006249 magnetic particle Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/28—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring the variations of parameters of electromagnetic or acoustic waves applied directly to the liquid or fluent solid material
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Thermal Sciences (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
- Geophysics And Detection Of Objects (AREA)
Description
【発明の詳細な説明】
本発明は、圧電振動子を用いて磁性粉体、磁性
液体、磁性粒子等の量検知を行う磁性体検知装置
に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic substance detection device that detects the amount of magnetic powder, magnetic liquid, magnetic particles, etc. using a piezoelectric vibrator.
従来、粉体、液体等の物体検知装置としては、
粉体、液体等の被検知物を収容する容器下部に圧
電振動子を配設し、その圧電振動子に被検知物が
接触して該圧電振動子にかさ及び密度に起因する
押圧力が加わり、圧電振動子の発振状態が変化す
ることを利用して物体検知を行うものがある。し
かし、これでは被検知物が圧電振動子に接触して
いるか否かの検出しかできない。 Conventionally, as an object detection device for powder, liquid, etc.
A piezoelectric vibrator is disposed at the bottom of a container containing an object to be detected such as powder or liquid, and when the object to be detected comes into contact with the piezoelectric vibrator, a pressing force due to the bulk and density is applied to the piezoelectric vibrator. There are some methods that detect objects by utilizing changes in the oscillation state of a piezoelectric vibrator. However, this method can only detect whether or not the object to be detected is in contact with the piezoelectric vibrator.
そこで、本発明は粉体、液体等が磁性を有して
いる場合、この磁性を利用して発振コイルのイン
ダクタンスを変化させるようにして、圧電振動子
を用いた発振回路の発振の有無によつて第１段階
の磁性体検知を行い、発振周波数の変化によつて
第２段階の磁性体検知が可能な磁性体検知装置を
提供するものである。 Therefore, in the case where powder, liquid, etc. have magnetism, the present invention utilizes this magnetism to change the inductance of the oscillation coil, depending on whether or not the oscillation circuit using the piezoelectric vibrator oscillates. The present invention provides a magnetic body detection device capable of performing a first stage of magnetic body detection and a second stage of magnetic body detection by changing the oscillation frequency.
以下、本発明に係る磁性体検知装置の実施例を
図面に従つて説明する。 Embodiments of the magnetic substance detection device according to the present invention will be described below with reference to the drawings.
第１図は本発明の磁性体検知装置の実施例にお
ける圧電振動子及び発振コイルの検知巻線の取付
構造の一例を示す。この図において、磁性粉体Ｐ
等を収納する容器１の下部には円筒状に突出した
支持体２が一体に形成され、この支持体２の先端
面にて圧電振動子３の周辺部が支持固定されてい
る。また、圧電振動子３の取付位置よりさらに下
方の容器１の側面には検知巻線凹部４が形成され
この検知巻線用凹部４内に発振コイルの検知巻線
５が配設される。 FIG. 1 shows an example of the mounting structure of the piezoelectric vibrator and the detection winding of the oscillation coil in an embodiment of the magnetic body detection device of the present invention. In this figure, magnetic powder P
A cylindrical protruding support body 2 is integrally formed in the lower part of the container 1 for storing the components, and the peripheral portion of the piezoelectric vibrator 3 is supported and fixed at the tip end surface of the support body 2. Further, a detection winding recess 4 is formed in the side surface of the container 1 further below the mounting position of the piezoelectric vibrator 3, and a detection winding 5 of the oscillation coil is disposed within this detection winding recess 4.
圧電振動子３は第２図及び第３図に示す如く、
銅、アルミニウム等の非磁性金属薄板のダイアフ
ラム１０上に圧電磁器１１を付着させ、この圧電
磁器１１上に電極１２Ａ，１２Ｂを形成したもの
である。ここで、ダイアフラム１０は、各電極１
２Ａ，１２Ｂに対向する共通電極として機能し、
該ダイアフラム１０及び各電極１２Ａ，１２Ｂに
は電気接続のためのリード線１３Ａ乃至１３Ｃが
接続される。このような圧電振動子３は、使用状
態において容器１内の内容物に対しダイアフラム
１０の部分にて接触し、圧電磁器１１及び電極１
２Ａ，１２Ｂは直接内容物に接触しないようにな
つており、通常ダイアフラム１０は３０乃至
500μ程度の厚みに設定されている。 As shown in FIGS. 2 and 3, the piezoelectric vibrator 3 is
A piezoelectric ceramic 11 is attached onto a diaphragm 10 made of a thin non-magnetic metal plate such as copper or aluminum, and electrodes 12A and 12B are formed on this piezoelectric ceramic 11. Here, the diaphragm 10 has each electrode 1
Functions as a common electrode facing 2A and 12B,
Lead wires 13A to 13C for electrical connection are connected to the diaphragm 10 and each electrode 12A, 12B. In use, such a piezoelectric vibrator 3 contacts the contents in the container 1 at the diaphragm 10, and the piezoelectric ceramic 11 and the electrode 1
2A and 12B are designed so that they do not come into direct contact with the contents, and the diaphragm 10 is usually
The thickness is set to about 500μ.
前記圧電振動子３を駆動する発振回路に使用さ
れる発振コイルＴは、第４図の如く、一次巻線
N1二次巻線N2及び一次巻線N1に直列接続される
前記検知巻線５とを有しており、一次巻線N1と
検知巻線５との直列接続に対しコンデンサC1が
接続されて並列共振回路が構成されている。 The oscillation coil T used in the oscillation circuit that drives the piezoelectric vibrator 3 has a primary winding as shown in FIG.
N1 has a secondary winding N2 and the detection winding 5 connected in series with the primary winding N1 , and a capacitor C1 is connected to the series connection of the primary winding N1 and the detection winding 5. are connected to form a parallel resonant circuit.
一方、磁性体検知装置の電気的構成は第５図に
示される。この図において、トランジスタ発振回
路２０は、前記圧電振動子３を帰還回路に挿入し
たものであり、トランジスタQ1のコレクタ側に
発振コイルＴが設けられ、トランジスタQ1のベ
ースには抵抗器R1，R2によりベースバイアスが
与えられ、さらにトランジスタQ1のエミツタ、
アース間には利得調整用の可変抵抗器VRが挿入
されている。前記発振コイルＴの一次巻線N1と
検知巻線５とコンデンサC1とは並列共振回路を
構成し、この並列共振回路を介して電源端子２１
に供給される直流電圧がトランジスタQ1のコレ
クタに印加される。発振コイルＴの二次巻線N2
の一端はアースされ、他端は圧電振動子３の一方
の電極（第３図における電極１２Ａ）に接続され
る。そして圧電振動子３の他方の電極（第３図の
電極１２Ｂ）はトランジスタQ1のベースに接続
される。 On the other hand, the electrical configuration of the magnetic substance detection device is shown in FIG. In this figure, the transistor oscillation circuit 20 has the piezoelectric vibrator 3 inserted into a feedback circuit, and an oscillation coil T is provided on the collector side of the transistor Q 1 , and a resistor R 1 is provided on the base of the transistor Q 1 . , R 2 provides base bias, and the emitter of transistor Q 1 ,
A variable resistor VR for gain adjustment is inserted between the ground. The primary winding N1 of the oscillation coil T, the detection winding 5, and the capacitor C1 constitute a parallel resonant circuit, and the power terminal 21 is connected to the power supply terminal 21 through this parallel resonant circuit.
is applied to the collector of transistor Q1 . Secondary winding N2 of oscillation coil T
One end is grounded, and the other end is connected to one electrode (electrode 12A in FIG. 3) of the piezoelectric vibrator 3. The other electrode of the piezoelectric vibrator 3 (electrode 12B in FIG. 3) is connected to the base of the transistor Q1 .
上記トランジスタ発振回路２０で重要なこと
は、圧電振動子３の固有の基本共振周波数で圧電
振動子３を駆動するのではなく、この基本共振周
波数をこえた圧電振動子３と支持体とによる共振
周波数の少なくとも１つにおいて圧電振動子３を
駆動するということである。この理由は、圧電振
動子固有の基本共振周波数で発振するように自励
発振回路を構成したのでは、圧電振動子の取付位
置、締付圧力、圧電振動子を支持する支持体の歪
等の外的要因によつても容易に発振の停止が生じ
るため、動作が極めて不安定であり、検出感度の
設定が難しく、ばらつきが発生し易いからであ
る。 What is important about the transistor oscillation circuit 20 is that the piezoelectric vibrator 3 is not driven at its own fundamental resonant frequency, but the piezoelectric vibrator 3 and the support resonate at a frequency that exceeds this fundamental resonant frequency. This means that the piezoelectric vibrator 3 is driven at at least one of the frequencies. The reason for this is that if the self-excited oscillation circuit is configured to oscillate at the fundamental resonant frequency unique to the piezoelectric vibrator, then the mounting position of the piezoelectric vibrator, the tightening pressure, the distortion of the support that supports the piezoelectric vibrator, etc. This is because oscillation can easily stop due to external factors, making the operation extremely unstable, making it difficult to set the detection sensitivity, and easily causing variations.
第６図は圧電振動子３として直径20mmのものを
使用した場合の基本共振周波数Bと、圧電振動子
３を支持体に装着したときの両者による共振周波
数1，2，3……と、圧電振動子３の厚み振動周
波数Tとの関係を示す。この図から判るように、
基本共振周波数Bが2500Hz位であるとすると、厚
み振動周波数Tはそれよりかなり高い4MHz前後
となり、圧電振動子３と支持体との両者による共
振周波数1，2，3……はBとTとの間の周波数
領域に位置することになる。例えば、1，2，3
……は数10KHz乃至100KHz程度の値をとる。従
つて、容器１の磁性粉体Ｐが第１図のＸレベル以
下であつて極く少量であるか無いときの発振コイ
ルＴの一次側共振周波数を2に設定し、容器１の
磁性粉体ＰがＸレベルより上でＹレベル以下のと
き、発振コイルＴの一次側共振周波数が1となる
ようにすれば、磁性粉体Ｐの量検知をトランジス
タ発振回路２０の発振周波数の変化として実行で
きることが判る。 Figure 6 shows the fundamental resonance frequency B when a piezoelectric vibrator 3 with a diameter of 20 mm is used, the resonance frequencies 1 , 2 , 3, etc. caused by both when the piezoelectric vibrator 3 is mounted on a support, and the piezoelectric The relationship between the thickness vibration frequency T of the vibrator 3 is shown. As you can see from this figure,
Assuming that the fundamental resonance frequency B is around 2500Hz, the thickness vibration frequency T is much higher than that, around 4MHz, and the resonance frequencies 1 , 2 , 3 ... due to both the piezoelectric vibrator 3 and the support body are the same as B and T. It will be located in the frequency region between . For example, 1 , 2 , 3
...takes a value of several 10KHz to 100KHz. Therefore, when the magnetic powder P in the container 1 is below the level X in FIG . If the primary resonance frequency of the oscillation coil T is set to 1 when P is above the X level and below the Y level, the amount of magnetic powder P can be detected as a change in the oscillation frequency of the transistor oscillation circuit 20. I understand.
さて、第５図のトランジスタ発振回路２０の出
力はトランジスタQ1のコレクタよりコンデンサ
C2を介して取出され、帯域フイルタFL1，FL2に
加えられる。ここで帯域フイルタFL1は周波数1
近傍の信号を通過させて出力端子３１に出すもの
であり、帯域フイルタFL2は周波数2近傍の信号
を通過させて出力端子３２に出すものである。な
お、電源端子２１に接続された電源線路２２はコ
ンデンサC3でアースされる。 Now, the output of the transistor oscillation circuit 20 in Fig. 5 is connected to the capacitor from the collector of the transistor Q1 .
It is taken out via C 2 and applied to bandpass filters FL 1 and FL 2 . Here bandpass filter FL 1 is frequency 1
The bandpass filter FL 2 allows nearby signals to pass through and outputs them to the output terminal 31, and the band filter FL 2 allows signals around frequency 2 to pass through and outputs them to the output terminal 32. Note that the power supply line 22 connected to the power supply terminal 21 is grounded through a capacitor C3 .
上記実施例の構成において、容器１内の磁性粉
体Ｐの量が充分多く、第１図のＺレベル以上であ
れば、その磁性粉体Ｐのかさと密度に起因する押
圧力が圧電振動子３に加わり、振動子３のインピ
ーダンスが変化し、予め設定された周波数1又は
2での発振条件が満たされず、トランジスタ発振
回路２０は発振しない。従つて、出力端子３１，
３２のいずれにも信号は出力されない。次に容器
１内の磁性粉体Ｐの量が少なくなり、Ｙレベル以
下となると、圧電振動子３は粉体Ｐの影響を受け
ることなく圧電振動子３と支持体とによる共振周
波数でトランジスタ発振回路２０は発振する。た
だし、この場合は発振コイルＴの検知巻線５に磁
性粉体Ｐが近接しているため低い方の共振周波数
1で発振し、このため帯域フイルタFL1の出力端
子３１に検知信号が出される。この検知信号によ
つて磁性粉体ＰがＹレベル以下でＸレベルより上
の量であることを識別できる。さらに、容器１内
の磁性粉体Ｐが極く少量となり、Ｘレベル以下と
なると、検知巻線５にも磁性粉体Ｐが近接しなく
なるため、トランジスタ発振回路２０は高い方の
共振周波数2で発振し、帯域フイルタFL2の出力
端子３２に検出信号が出される。この検知信号に
よつて磁性粉体ＰがＸレベル以下であることを識
別できる。 In the configuration of the above embodiment, if the amount of magnetic powder P in the container 1 is sufficiently large and is equal to or higher than the Z level in FIG. , the impedance of the vibrator 3 changes, and the preset frequency 1 or
The oscillation condition in step 2 is not satisfied, and the transistor oscillation circuit 20 does not oscillate. Therefore, the output terminal 31,
No signal is output to any of 32. Next, when the amount of magnetic powder P in the container 1 decreases and becomes below level Y, the piezoelectric vibrator 3 oscillates as a transistor at the resonance frequency of the piezoelectric vibrator 3 and the support without being affected by the powder P. Circuit 20 oscillates. However, in this case, since the magnetic powder P is close to the detection winding 5 of the oscillation coil T, the lower resonance frequency
1 , and therefore a detection signal is output to the output terminal 31 of the bandpass filter FL 1 . Based on this detection signal, it can be determined that the amount of magnetic powder P is below the Y level and above the X level. Furthermore, when the amount of magnetic powder P in the container 1 becomes extremely small and becomes below the X level, the magnetic powder P does not come close to the detection winding 5, so the transistor oscillation circuit 20 operates at the higher resonant frequency 2 . oscillates, and a detection signal is output to the output terminal 32 of the bandpass filter FL 2 . Based on this detection signal, it can be determined that the magnetic powder P is below the X level.
以上の如き実施例の構成によれば、次のような
効果を上げることができる。 According to the configuration of the embodiment as described above, the following effects can be achieved.
(1) トランジスタ発振回路２０における発振コイ
ルＴの一部を検知巻線５として磁性粉体Ｐに近
接可能に設けたので、圧電振動子３への磁性粉
体Ｐの接触の有無による第１段階の検知動作に
加えて、検知巻線５への磁性粉体Ｐの近接の有
無による第２段階の検知動作ができる。従つ
て、磁性粉体Ｐの量検知をより正確に実行でき
る。(1) Since a part of the oscillation coil T in the transistor oscillation circuit 20 is provided as the detection winding 5 so as to be close to the magnetic powder P, the first stage is determined by whether or not the magnetic powder P contacts the piezoelectric vibrator 3. In addition to the above detection operation, a second stage detection operation can be performed based on whether or not the magnetic powder P approaches the detection winding 5. Therefore, the amount of magnetic powder P can be detected more accurately.
(2) 圧電振動子３の基本共振周波数を利用せず
に、それよりも高い圧電振動子３とこれの支持
体とによる共振周波数を利用してトランジスタ
発振回路２０の発振回路２０の発振を行つてい
るため、圧電振動子３の取付位置、締付圧力、
支持体側の歪等の外的要因による動作の変動が
極めて小さい。従つて、検出感度のばらつきを
少なくして信頼性の向上を図ることができる。(2) The oscillation circuit 20 of the transistor oscillation circuit 20 is oscillated by using a higher resonance frequency of the piezoelectric vibrator 3 and its support without using the fundamental resonance frequency of the piezoelectric vibrator 3. Therefore, the mounting position of the piezoelectric vibrator 3, the tightening pressure,
Fluctuations in operation due to external factors such as strain on the support side are extremely small. Therefore, it is possible to reduce variations in detection sensitivity and improve reliability.
なお、帯域フイルタFL1の代りにローパスフイ
ルタを、帯域フイルタFL2の代りにハイパスフイ
ルタを使用してもよい。 Note that a low pass filter may be used instead of the band filter FL 1 , and a high pass filter may be used instead of the band filter FL 2 .
叙上のように、本発明によれば、粉体、液体等
の磁性を利用して発振コイルのインダクタンスを
変化させるようにして、圧電振動子を用いた発振
回路の発振の有無による第１段階の磁性体検知に
加えて、さらに前記インダクタンス変化に起因す
る発振周波数の変化によつて第２段階の磁性体検
知が可能な磁性体検知装置を得ることができる。 As described above, according to the present invention, the inductance of the oscillation coil is changed using the magnetism of powder, liquid, etc., and the first step is determined by the presence or absence of oscillation of the oscillation circuit using the piezoelectric vibrator. In addition to the above magnetic substance detection, it is possible to obtain a magnetic substance detection device capable of performing a second stage of magnetic substance detection by changing the oscillation frequency due to the change in inductance.
第１図は本発明の磁性体検知装置における圧電
振動子及び発振コイルの検知巻線の配置を示す断
面図、第２図は実施例で用いる圧電振動子の正面
図、第３図は同底面図、第４図は実施例で用いる
発振コイルを示す回路図、第５図は実施例の電気
的構成を示す回路図、第６図は圧電振動子と支持
体とによる共振周波数と圧電振動子固有の基本共
振周波数との関係を示す説明図である。
１……容器、２……支持体、３……圧電振動
子、４……検知巻線用凹部、５……検知巻線、１
０……ダイアフラム、１１……圧電磁器、２０…
…トランジスタ発振回路、２１……電源端子、３
１，３２……出力端子、C1乃至C3……コンデン
サ、FL1，FL2……帯域フイルタ、Ｐ……磁性粉
体、Q1……トランジスタ、Ｔ……発振コイル。
Fig. 1 is a sectional view showing the arrangement of the piezoelectric vibrator and the detection winding of the oscillation coil in the magnetic substance detection device of the present invention, Fig. 2 is a front view of the piezoelectric vibrator used in the embodiment, and Fig. 3 is the bottom view of the piezoelectric vibrator. Figure 4 is a circuit diagram showing the oscillation coil used in the example, Figure 5 is a circuit diagram showing the electrical configuration of the example, and Figure 6 is the resonance frequency of the piezoelectric vibrator and support and the piezoelectric vibrator. FIG. 3 is an explanatory diagram showing a relationship with a unique fundamental resonance frequency. DESCRIPTION OF SYMBOLS 1...Container, 2...Support, 3...Piezoelectric vibrator, 4...Recess for detection winding, 5...Detection winding, 1
0...Diaphragm, 11...Piezoelectric ceramic, 20...
...Transistor oscillation circuit, 21...Power terminal, 3
1, 32...Output terminal, C1 to C3 ...Capacitor, FL1 , FL2 ...Band filter, P...Magnetic powder, Q1 ...Transistor, T...Oscillation coil.
Claims (1)
に取付け、発振回路の帰還回路に該圧電振動子を
挿入し、該圧電振動子自体の基本共振周波数を越
えた周波数領域に存在する該圧電振動子と支持体
とによる共振周波数の少なくとも１つにおいて前
記圧電振動子を前記発振回路で駆動するととも
に、該発振回路の発振コイルの少なくとも一部を
前記磁性体に近接可能に配置し、前記発振回路の
発振の有無によつて第１段階の磁性体検知を行
い、前記発振回路の発振周波数の変化によつて第
２段階の磁性体検知を行うことを特徴とする磁性
体検知装置。1. Attach a piezoelectric vibrator to a support so that it can come into contact with a magnetic material, insert the piezoelectric vibrator into a feedback circuit of an oscillation circuit, and detect the piezoelectric vibrator existing in a frequency range exceeding the fundamental resonance frequency of the piezoelectric vibrator itself. The piezoelectric vibrator is driven by the oscillation circuit at at least one of the resonance frequencies of the vibrator and the support, and at least a part of the oscillation coil of the oscillation circuit is arranged so as to be close to the magnetic body, and the oscillation A magnetic body detection device characterized in that a first stage of magnetic body detection is performed based on the presence or absence of oscillation of a circuit, and a second stage of magnetic body detection is performed based on a change in the oscillation frequency of the oscillation circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56139744A JPS5841321A (en) | 1981-09-07 | 1981-09-07 | Detecting device of magnetic body |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56139744A JPS5841321A (en) | 1981-09-07 | 1981-09-07 | Detecting device of magnetic body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5841321A JPS5841321A (en) | 1983-03-10 |
| JPH0119526B2 true JPH0119526B2 (en) | 1989-04-12 |
Family
ID=15252361
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56139744A Granted JPS5841321A (en) | 1981-09-07 | 1981-09-07 | Detecting device of magnetic body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5841321A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4655283B2 (en) * | 2006-06-21 | 2011-03-23 | セイコーエプソン株式会社 | Liquid consumption state detector |
| JP2006343337A (en) * | 2006-06-21 | 2006-12-21 | Seiko Epson Corp | Liquid consumption state detector |
-
1981
- 1981-09-07 JP JP56139744A patent/JPS5841321A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5841321A (en) | 1983-03-10 |
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