JPH0680409B2 - Ink amount detection circuit - Google Patents
Ink amount detection circuitInfo
- Publication number
- JPH0680409B2 JPH0680409B2 JP60287128A JP28712885A JPH0680409B2 JP H0680409 B2 JPH0680409 B2 JP H0680409B2 JP 60287128 A JP60287128 A JP 60287128A JP 28712885 A JP28712885 A JP 28712885A JP H0680409 B2 JPH0680409 B2 JP H0680409B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- ink
- electrode
- capacitance
- ink amount
- 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 - Fee Related
Links
Landscapes
- Inking, Control Or Cleaning Of Printing Machines (AREA)
- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
Description
【発明の詳細な説明】 （技術分野） 本発明は印刷機のインキ量検知回路に関する。TECHNICAL FIELD The present invention relates to an ink amount detection circuit of a printing machine.
（従来技術） インキ量検知回路には少なくとも一方がインキ溜り部の
印刷インキに対向して設けられた検出電極に接続された
一対のコンデンサ電極を含み該一対のコンデンサ電極間
における静電容量の変化により発振周波数が変化する発
振回路と、この発振回路の出力信号が入力されてこれに
設定周波数で同調する受信回路と、この受信回路の出力
信号を直流電圧に変換して基準電圧と比較する回路とを
有するものが特開昭58−62520号公報により知られてい
る。(Prior Art) The ink amount detection circuit includes a pair of capacitor electrodes, at least one of which is connected to a detection electrode provided so as to face the printing ink in the ink reservoir, and a change in capacitance between the pair of capacitor electrodes. An oscillation circuit whose oscillation frequency changes by a signal, a receiving circuit which receives the output signal of this oscillation circuit and tunes it at a set frequency, and a circuit which converts the output signal of this receiving circuit into a DC voltage and compares it with a reference voltage. Those having the following are known from JP-A-58-62520.
しかしこのインキ量検知回路では受信回路を発振回路の
出力に設定周波数で同調させているので、発振回路の一
般に使用される発振周波数は数MHZ〜100MHZという高周
波領域になり、回路の浮遊容量による影響を抑える実装
が要求される。またインキ量と発振回路の発振周波数、
受信回路の同調強度との関係は第３図に示すようにな
り、インキ溜り部にインキが有る場合でも検出電極に付
着したインキ量によっては発振回路の発振周波数が受信
回路の設定同調周波数より低くなってインキ無しと誤検
知してしまう。However, in this ink amount detection circuit, the receiving circuit is tuned to the output of the oscillation circuit at the set frequency, so the oscillation frequency generally used in the oscillation circuit is in the high frequency range of several MHZ to 100 MHZ, and the influence of the stray capacitance of the circuit Implementation that suppresses is required. Also, the ink amount and the oscillation frequency of the oscillation circuit,
The relationship with the tuning strength of the receiving circuit is as shown in Fig. 3. Even if there is ink in the ink fountain, the oscillation frequency of the oscillation circuit is lower than the tuning frequency set by the receiving circuit depending on the amount of ink adhering to the detection electrode. And it will be falsely detected that there is no ink.
（目的） 本発明は上記欠点を改善し、浮遊容量の影響による回路
実装上の制約及び誤検知を無くすことができるインキ量
検知回路を提供することを目的とする。(Object) It is an object of the present invention to provide an ink amount detection circuit which can remedy the above-mentioned drawbacks and can eliminate restrictions on circuit mounting and erroneous detection due to the influence of stray capacitance.
（構成） 本発明はインキ量に相当する静電容量を検出する電極
と、基準信号発生回路、単安定回路及び位相比較手段を
有し、単安定回路が基準信号発生回路で発生する基準信
号に対応して始動する。この単安定回路は電極の検出し
た静電容量により出力信号のパルス幅が変化し、位相比
較手段が上記基準信号及び単安定回路の出力信号の位相
比較を行なう。(Structure) The present invention has an electrode for detecting a capacitance corresponding to the amount of ink, a reference signal generating circuit, a monostable circuit, and a phase comparison means. Correspondingly start. In this monostable circuit, the pulse width of the output signal changes depending on the electrostatic capacitance detected by the electrodes, and the phase comparison means performs phase comparison between the reference signal and the output signal of the monostable circuit.
第１図は本発明の一実施例を示す。図中１はインキ量検
出部、２は検知回路部、３はインキ量に相当する静電容
量C4を検出する電極、４は検知対象物のインキ、５はイ
ンキ送りローラ、６は接地された導電性インキ容器、７
は単安定マルチバイブレータ回路、８は無安定マルチバ
イブレータ回路からなる基準信号発生回路、９は位相比
較用フリップフロップ、10は出力端子、11,12は導体で
ある。印刷機においてインキ容器６とインキ送りローラ
５で形成されるインキ溜り部のインキはインキ送りロー
ラ５により送られてその量が変化するが、所定インキ量
に相当する静電容量、つまり電極３とインキ容器６との
間のインキによる静電容量C4が電極３により検出され
る。なお、インキ容器６とは別に電極を設けてこの電極
と上記電極３とで所定インキ量に相当する静電容量を検
出するようにしてもよい。電極３はインキ容器６の上部
に配置され、インキ容器６との間にインキ４が介在され
る。FIG. 1 shows an embodiment of the present invention. In the figure, 1 is an ink amount detection unit, 2 is a detection circuit unit, 3 is an electrode for detecting the electrostatic capacitance C 4 corresponding to the ink amount, 4 is the ink to be detected, 5 is an ink feed roller, and 6 is grounded. Conductive ink container, 7
Is a monostable multivibrator circuit, 8 is a reference signal generating circuit composed of an astable multivibrator circuit, 9 is a flip-flop for phase comparison, 10 is an output terminal, and 11 and 12 are conductors. In the printing press, the ink in the ink reservoir formed by the ink container 6 and the ink feed roller 5 is fed by the ink feed roller 5 and its amount changes, but the electrostatic capacity corresponding to a predetermined ink amount, that is, the electrode 3 and The capacitance C 4 due to the ink between the ink container 6 and the ink container 6 is detected by the electrode 3. An electrode may be provided separately from the ink container 6 and the capacitance corresponding to a predetermined ink amount may be detected by this electrode and the electrode 3. The electrode 3 is disposed above the ink container 6, and the ink 4 is interposed between the electrode 3 and the ink container 6.
無安定マルチバイブレータ回路８の発振時定数を決定す
る素子を構成するコンデンサの静電容量CAはCA＝C1＋C3
＋C5となり、無安定マルチバイブレータ回路８はその静
電容量CAに対応したパルス間隔を有するパルス信号を常
に発生する。ここにC1は検知回路部２内に実装されるコ
ンデンサの静電容量、C3はインキ量検出部１内で導体11
とインキ容器６との間に実装されたコンデンサの容量、
C5は導体11及びその接続部品の浮遊容量である。単安定
マルチバイブレータ回路７は無安定マルチバイブレータ
回路８の出力パルス信号の立下り（又は立上り）でトリ
ガーされてパルスを発生する。なお無安定マルチバイブ
レータ回路８はパルスをくり返して発生する別の発振回
路でもよく、単安定マルチバイブレータ回路７は無安定
マルチバイブレータ回路８のパルス信号の立下り時にこ
れとは別のパルス信号によりトリガーしてもよい。単安
定マルチバイブレータ回路７の発振周波数を決定する素
子を構成するコンデンサの静電容量CBはCB＝C2＋C4＋C6
となり、単安定マルチバイブレータ回路７はこの静電容
量CBに対応するパルス幅のパルス信号を出力する。ここ
にC2は検知回路部２内に実装されるコンデンサの静電容
量、C4は電極３、インキ容器６及びこれらの間に介在す
るインキにより形成されるコンデンサの静電容量、C6は
導体12及びその接続部品の浮遊容量である。フリップフ
ロップ９はデータ端子に単安定マルチバイブレータ回路
７の出力パルス信号が入力され、クロック端子に無安定
マルチバイブレータ回路８の出力パルス信号が入力され
て所定量のインキの有無に応じた２値化信号を出力す
る。The capacitance CA of the capacitor that constitutes the element that determines the oscillation time constant of the astable multivibrator circuit 8 is CA = C 1 + C 3
+ C 5 , and the astable multivibrator circuit 8 always generates a pulse signal having a pulse interval corresponding to the electrostatic capacity CA. Where C 1 is the capacitance of the capacitor mounted in the detection circuit unit 2, and C 3 is the conductor 11 in the ink amount detection unit 1.
And the capacity of the capacitor mounted between the ink container 6 and
C 5 is the stray capacitance of the conductor 11 and its connecting components. The monostable multivibrator circuit 7 is triggered by the falling edge (or rising edge) of the output pulse signal of the astable multivibrator circuit 8 to generate a pulse. The astable multivibrator circuit 8 may be another oscillator circuit which repeatedly generates pulses, and the monostable multivibrator circuit 7 is triggered by a pulse signal other than this when the pulse signal of the astable multivibrator circuit 8 falls. You may. The capacitance CB of the capacitor that constitutes the element that determines the oscillation frequency of the monostable multivibrator circuit 7 is CB = C 2 + C 4 + C 6
Therefore, the monostable multivibrator circuit 7 outputs a pulse signal having a pulse width corresponding to the electrostatic capacitance CB. Where C 2 is the capacitance of the capacitor mounted in the detection circuit unit 2, C 4 is the capacitance of the capacitor formed by the electrode 3, the ink container 6 and the ink interposed therebetween, and C 6 is It is the stray capacitance of the conductor 12 and its connecting parts. In the flip-flop 9, the output pulse signal of the monostable multivibrator circuit 7 is input to the data terminal, and the output pulse signal of the astable multivibrator circuit 8 is input to the clock terminal to binarize depending on the presence or absence of a predetermined amount of ink. Output a signal.
次にこの実施例の動作について説明する。Next, the operation of this embodiment will be described.
まずインキ容器６にインキ４が所定量入っていて電極３
がインキ４に接触している時はインキ４の高誘電率によ
る静電容量C4が電極３によって検出されて導体12を介し
て単安定マルチバイブレータ回路７の時定数を決めるコ
ンデンサ入力端子Ｃに与えられ、このコンデンサ入力端
子Ｃへの静電容量CBはCB＝C2＋C4＋C6となる。また無安
定マルチバイブレータ回路８の時定数を決めるコンデン
サ入力端子Ｃにはインキ量検出部１内に実装されたコン
デンサの静電容量C3が導体11を介して与えられ、このコ
ンデンサ入力端子Ｃへの全静電容量CAはCA＝C1＋C3＋C5
となる。無安定マルチバイブレータ回路８は第２図
（１）に示すようにその静電容量CAに対応したパルス間
隔T0のパルス信号を発生し、このパルス信号が単安定マ
ルチバイブレータ回路７のトリガー端子に入力される。
単安定マルチバイブレータ回路７はトリガー端子に入力
されたパルス信号の立下りでトリガーされて第２図
（２）に示すような静電容量CBに対応したパルス幅T1の
パルス信号を出力する。フリップフロップ９は無安定マ
ルチバイブレータ回路８からクロック端子に入力される
パルス信号の立上り（又は立下り）でデータ端子へ入力
される単安定マルチバイブレータ回路７の出力信号を読
み取ることによって無安定マルチバイブレータ回路８及
び単安定マルチバイブレータ回路７の出力信号の位相比
較を行ない、所定量のインキが有る時にはT1＞T0となっ
て第２図（３）に示すようにフリップフロップ９の出力
信号が高レベルになる。First, the ink 4 has a predetermined amount in the ink container 6 and the electrode 3
When the ink is in contact with the ink 4, the electrostatic capacitance C 4 due to the high dielectric constant of the ink 4 is detected by the electrode 3 and via the conductor 12 to the capacitor input terminal C that determines the time constant of the monostable multivibrator circuit 7. Given this, the capacitance CB to the capacitor input terminal C is CB = C 2 + C 4 + C 6 . Further, the capacitance C 3 of the capacitor mounted in the ink amount detecting portion 1 is given to the capacitor input terminal C which determines the time constant of the astable multivibrator circuit 8 through the conductor 11, and is input to the capacitor input terminal C. The total capacitance CA of is CA = C 1 + C 3 + C 5
Becomes The astable multivibrator circuit 8 generates a pulse signal with a pulse interval T 0 corresponding to its capacitance CA as shown in FIG. 2 (1), and this pulse signal is applied to the trigger terminal of the monostable multivibrator circuit 7. Is entered.
The monostable multivibrator circuit 7 is triggered by the trailing edge of the pulse signal input to the trigger terminal and outputs a pulse signal having a pulse width T 1 corresponding to the capacitance CB as shown in FIG. 2B. The flip-flop 9 reads the output signal of the monostable multivibrator circuit 7 input to the data terminal at the rising (or falling) of the pulse signal input to the clock terminal from the astable multivibrator circuit 8 to thereby obtain the astable multivibrator. The phases of the output signals of the circuit 8 and the monostable multivibrator circuit 7 are compared, and when there is a predetermined amount of ink, T 1 > T 0, and the output signal of the flip-flop 9 becomes as shown in FIG. 2 (3). High level.
またインキ容器６内のインキ４が消費されて時刻t1に電
極４がインキ４に接触しなくなった時は電極４とインキ
容器６との間に空気が入ってインキ４による静電容量C4
が電極４で検出されなくなり、単安定マルチバイブレー
タ回路７はコンデンサ入力端子への静電容量CBがCB＝C2
＋C6となってパルス幅T2のパルス信号を出力する。従っ
て所定量のインキが無くなった時（インキ４が所定量よ
り少なくなった時）はT2＜T0になり、第２図（３）に示
すようにフリップフロップ９の出力信号が低レベルにな
る。Further, when the ink 4 in the ink container 6 is consumed and the electrode 4 stops contacting the ink 4 at time t 1 , air enters between the electrode 4 and the ink container 6 and the electrostatic capacitance C 4 by the ink 4 is generated.
Is not detected by the electrode 4, and the monostable multivibrator circuit 7 has a capacitance CB to the capacitor input terminal CB = C 2
It becomes + C 6 and outputs a pulse signal of pulse width T 2 . Therefore, when the predetermined amount of ink is exhausted (when the ink 4 becomes less than the predetermined amount), T 2 <T 0 , and the output signal of the flip-flop 9 becomes low level as shown in FIG. 2 (3). Become.
この実施例は無安定マルチバイブレータ回路８のコンデ
ンサ入力端子Ｃへの静電容量CAと単安定マルチバイブレ
ータ回路７のコンデンサ入力端子Ｃへのインキを電極４
で検出している時の静電容量CB1及びインキを電極４で
検出していない時の静電容量CB2の間にCB1＞CA＞CB2の
関係を成立させることにより簡単な回路構成でインキ量
検知が可能となった。さらに導体11,12をツィストする
等の処置をしてC5≒C6とすることによりこの位相比較に
よる検知方式では浮遊容量が変動しても十分に補償でき
て回路実装上の制約を受けず、安定した検知が可能とな
った。In this embodiment, the capacitance CA to the capacitor input terminal C of the astable multivibrator circuit 8 and the ink to the capacitor input terminal C of the monostable multivibrator circuit 7 are applied to the electrode 4
A simple circuit configuration is established by establishing the relationship of CB 1 >CA> CB 2 between the electrostatic capacity CB 1 when the ink is being detected by the sensor and the electrostatic capacity CB 2 when the ink is not being detected by the electrode 4. Now it is possible to detect the amount of ink. Furthermore, by making measures such as twisting the conductors 11 and 12 so that C 5 ≈ C 6 , the detection method based on this phase comparison can sufficiently compensate even if the stray capacitance fluctuates and is not restricted by the circuit mounting. , Stable detection became possible.
（効果） 以上のように本発明によれば電極で検出したインキ量に
相当する静電容量により出力信号のパルス幅が変化する
単安定回路を基準信号に対応して始動させてこの基準信
号と単安定回路の出力信号との位相比較を行なうので、
浮遊容量の影響による回路実装上の制約を無くすことが
可能となり、かつ誤検知を無くすことができる。(Effect) As described above, according to the present invention, the monostable circuit in which the pulse width of the output signal changes due to the capacitance corresponding to the ink amount detected by the electrode is started corresponding to the reference signal and Since the phase comparison with the output signal of the monostable circuit is performed,
It is possible to eliminate restrictions on circuit mounting due to the influence of stray capacitance, and eliminate false detections.
第１図は本発明の一実施例を示すブロック図、第２図は
同実施例のタイミングチャート、第３図は従来回路の特
性曲線図である。 ２……電極、７……単安定回路、８……基準信号発生回
路、９……位相比較手段。FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a timing chart of the same embodiment, and FIG. 3 is a characteristic curve diagram of a conventional circuit. 2 ... Electrode, 7 ... Monostable circuit, 8 ... Reference signal generation circuit, 9 ... Phase comparison means.
Claims (1)
インキ量に相当する静電容量を検出する電極と、上記基
準信号に対応して始動し上記電極の検出した静電容量に
より出力信号のパルス幅が変化する単安定回路と、この
単安定回路の出力信号と上記基準信号との位相比較を行
なう位相比較手段とを備えたインキ量検知回路。1. A reference signal generating circuit for generating a reference signal,
An electrode that detects the electrostatic capacitance corresponding to the ink amount, a monostable circuit that starts in response to the reference signal and the pulse width of the output signal changes according to the electrostatic capacitance detected by the electrode, and a monostable circuit of this monostable circuit. An ink amount detection circuit including a phase comparison means for performing a phase comparison between an output signal and the reference signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60287128A JPH0680409B2 (en) | 1985-12-20 | 1985-12-20 | Ink amount detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60287128A JPH0680409B2 (en) | 1985-12-20 | 1985-12-20 | Ink amount detection circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62146632A JPS62146632A (en) | 1987-06-30 |
| JPH0680409B2 true JPH0680409B2 (en) | 1994-10-12 |
Family
ID=17713432
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60287128A Expired - Fee Related JPH0680409B2 (en) | 1985-12-20 | 1985-12-20 | Ink amount detection circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0680409B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003083795A (en) * | 2001-09-11 | 2003-03-19 | Tohoku Ricoh Co Ltd | Printing apparatus |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000190457A (en) | 1998-05-13 | 2000-07-11 | Mitsubishi Materials Corp | Detecting method of quantity of liquid in container and device thereof |
| JP2007313790A (en) * | 2006-05-26 | 2007-12-06 | Tohoku Ricoh Co Ltd | Ink level detection device/method and printing equipment |
-
1985
- 1985-12-20 JP JP60287128A patent/JPH0680409B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003083795A (en) * | 2001-09-11 | 2003-03-19 | Tohoku Ricoh Co Ltd | Printing apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62146632A (en) | 1987-06-30 |
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Legal Events
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| LAPS | Cancellation because of no payment of annual fees |