JPH0415005U

JPH0415005U -

Info

Publication number: JPH0415005U
Application number: JP5427090U
Authority: JP
Priority date: 1990-05-23
Filing date: 1990-05-23
Publication date: 1992-02-06

Description

[Brief explanation of the drawing]

第１図はこの考案の一実施例による静電容量式
厚さ・枚数検出装置のブロツク図、第２図は第１
図の静電容量−電圧変換回路６の詳細を示す回路
図、第３図は第１図のハイパスフイルタ１２の詳
細を示す回路図、第４図は第３図のハイパスフイ
ルタ１２の特性を示す図、第５図は第１図のボト
ムホールド回路の詳細を示す回路図、第６図は第
１図に示す静電容量式厚さ・枚数検出装置におい
て、ボトムホールド回路８０および減算回路８２
がない場合の動作タイミングを示す図、第７図は
第１図に示す静電容量式厚さ・枚数検出装置の動
作タイミングを示す図、第８図はこの考案に係る
静電容量式厚さ・枚数検出装置を使用した枚葉印
刷機の構成図、第９図は従来の静電容量式厚さ・
枚数検出装置のブロツク図である。２……電極、６……静電容量−電圧変換回路、
８……電圧比較回路、１２……ハイパスフイルタ
、８０……ボトムホールド回路、８２……減算回
路。 Figure 1 is a block diagram of a capacitive thickness/sheet count detection device according to an embodiment of this invention, and Figure 2 is a block diagram of a capacitive thickness/number of sheets detection device according to an embodiment of this invention.
3 is a circuit diagram showing details of the high-pass filter 12 shown in FIG. 1, and FIG. 4 shows characteristics of the high-pass filter 12 shown in FIG. 3. 5 is a circuit diagram showing the details of the bottom hold circuit shown in FIG.
FIG. 7 is a diagram showing the operation timing of the capacitive thickness/number of sheets detection device shown in FIG. 1, and FIG.・A configuration diagram of a sheet-fed printing machine using a sheet number detection device, Figure 9 shows a conventional capacitive thickness printing machine.
FIG. 3 is a block diagram of a sheet number detection device. 2... Electrode, 6... Capacitance-voltage conversion circuit,
8... Voltage comparison circuit, 12... High pass filter, 80... Bottom hold circuit, 82... Subtraction circuit.

Claims

[Claims for Utility Model Registration] A pair of electrodes arranged to face each other with a detection target in between, a capacitance-to-voltage conversion circuit that changes output voltage according to changes in capacitance between the electrodes, and electrostatic capacitance. A capacitive thickness/number of sheets detection device comprising: a determination circuit that determines whether a detection target has a predetermined thickness or a predetermined number of sheets based on the output voltage of the capacitance-voltage conversion circuit; - A high-pass filter is provided between the voltage conversion circuit and the judgment circuit, and the output of the high-pass filter is given to the lower limit holding circuit, and the judgment circuit subtracts the output of the lower limit holding circuit from the output of the high-pass filter. A capacitive thickness/sheet count detection device characterized by: