JPH0332828U

JPH0332828U -

Info

Publication number: JPH0332828U
Application number: JP9162289U
Authority: JP
Priority date: 1989-08-03
Filing date: 1989-08-03
Publication date: 1991-03-29
Anticipated expiration: 2004-08-03
Also published as: JPH0753303Y2

Description

[Brief explanation of the drawing]

第１図ａおよびｂは本考案の一実施例に係る圧
電フイルタの片面側および他面側を同じ方向から
見た平面図、第２図は同圧電フイルタの各電極の
位置関係を示す模式図、第３図は同圧電フイルタ
の等価回路図、第４図は音叉型の圧電フイルタの
振動モードを示す説明模式図、第５図は第１図に
示す圧電フイルタの外装の一例を示す斜視図、第
６図ａ，ｂはそれぞれ第１電極、第２電極の電極
形成領域条件を示す模式図、第７図ａは第１図に
示す圧電フイルタの一例の特性グラフ、第７図ｂ
は従来の角板広がりモード振動型の圧電フイルタ
の一例の特性グラフ、第８図ａおよびｂは同圧電
フイルタの片面側および他面側を示す平面図、第
８図ｃは同圧電フイルタの斜視図、第９図ａ，ｂ
，ｃは同圧電フイルタの振動の状態を示す説明模
式図、第１０図は同圧電フイルタの等価回路図、
第１１図ａおよびｂは従来の音叉型の圧電フイル
タの片面側および他面側を示す平面図、第１２図
は同圧電フイルタの等価回路図、第１３図は同圧
電フイルタの各電極の位置関係を示す模式図であ
る。符号の説明、１……圧電フイルタ、２……圧電
基板、３……スリツト、４……腕部、５……音叉
部、７……第１電極、８ａ，８ｂ……第２電極、
９……第３電極。 Figures 1a and b are plan views of one side and the other side of a piezoelectric filter according to an embodiment of the present invention viewed from the same direction, and Figure 2 is a schematic diagram showing the positional relationship of each electrode of the piezoelectric filter. , FIG. 3 is an equivalent circuit diagram of the same piezoelectric filter, FIG. 4 is an explanatory schematic diagram showing the vibration mode of the tuning fork type piezoelectric filter, and FIG. 5 is a perspective view showing an example of the exterior of the piezoelectric filter shown in FIG. 1. , FIGS. 6a and 6b are schematic diagrams showing the electrode formation area conditions of the first and second electrodes, respectively, FIG. 7a is a characteristic graph of an example of the piezoelectric filter shown in FIG. 1, and FIG. 7b
8 is a characteristic graph of an example of a conventional square plate spread mode vibration type piezoelectric filter, FIGS. 8a and 8b are plan views showing one side and the other side of the same piezoelectric filter, and FIG. 8c is a perspective view of the same piezoelectric filter. Fig. 9a, b
, c is an explanatory schematic diagram showing the state of vibration of the same piezoelectric filter, FIG. 10 is an equivalent circuit diagram of the same piezoelectric filter,
Figures 11a and b are plan views showing one side and the other side of a conventional tuning fork type piezoelectric filter, Figure 12 is an equivalent circuit diagram of the same piezoelectric filter, and Figure 13 is the position of each electrode of the same piezoelectric filter. It is a schematic diagram showing a relationship. Explanation of symbols: 1... Piezoelectric filter, 2... Piezoelectric substrate, 3... Slit, 4... Arm, 5... Tuning fork, 7... First electrode, 8a, 8b... Second electrode,
9...Third electrode.

Claims

[Claims for Utility Model Registration] A piezoelectric filter comprising a plurality of electrodes formed on a piezoelectric substrate, comprising: a tuning fork portion formed by cutting at least one slit into the piezoelectric substrate and forming arms on both sides of the slit; a first electrode provided on one side of the piezoelectric substrate and formed near the periphery of the slit; and a first electrode provided on one side of the piezoelectric substrate separately from the first electrode and arranged on both arms around the slit. a second electrode formed along each outer edge of the piezoelectric substrate; and a third electrode provided on the other surface of the piezoelectric substrate, facing the first electrode and short-circuited to the second electrode. A piezoelectric filter comprising: an electrode; and a fourth electrode provided on the other surface of the piezoelectric substrate, facing the second electrode and formed separately from the third electrode.