Driving apparatus

Abstract

A driving apparatus capable of suppressing operation noise, the apparatus comprising a piezoelectric element expanding and contracting in accordance with a driving signal; a supporting shaft connected to said piezoelectric element; a movable body frictionally engaged with said supporting shaft and capable of moving along said supporting shaft; and a driving portion applying said driving signal including a first driving signal which moves said movable body towards a first direction to said piezoelectric element, wherein said driving portion can repeatedly apply said first driving signal against said piezoelectric element by taking a first time in between, and said first driving signal comprises a main driving waveform group which moves said movable body to said first direction, and a sub driving waveform group which is placed after said main driving waveform group by having the a second rest time shorter than said first time in between.

1 . A driving apparatus comprising;
 a piezoelectric element expanding and contracting in accordance with a driving signal;   a supporting shaft connected to said piezoelectric element;   a movable body frictionally engaged with said supporting shaft and capable of moving along said supporting shaft; and   a driving portion applying said driving signal including a first driving signal which moves said movable body towards a first direction to said piezoelectric element, wherein   said driving portion can repeatedly apply said first driving signal against said piezoelectric element by taking a first time in between, and   said first driving signal comprises a main driving waveform group which moves said movable body to said first direction, and a sub driving waveform group which is placed after said main driving waveform group by having the a second rest time shorter than said first time in between.   
     
     
         2 . The driving apparatus as set forth in  claim 1  wherein said movable body has an engagement portion formed at one end part of a second direction which is approximately perpendicular to said first direction, and frictionally engaging with said supporting shaft, and
 said movable body has one handed supporting structure supported by said supporting shaft via said engagement portion. 
 
     
     
         3 . The driving apparatus as set forth in  claim 1  wherein said sub driving waveform group includes a waveform which moves said movable body toward said first direction, and when a vibration period caused in said movable body is T while said movable body is stopped, then said second rest time is shorter than T/4. 
     
     
         4 . The driving apparatus as set forth in any one of  claims 1 , wherein said sub driving waveform group includes a waveform which moves said movable body to an opposite direction against said first direction, and when the vibration period caused in said movable body is T while said movable body is stopped, then said second rest time is longer than T/ 4  and shorter than 3T/4. 
     
     
         5 . The driving apparatus as set forth in any one of  claims 1  wherein said sub driving waveform has a first sub driving waveform group being placed by having said second rest time in between with respect to said main driving waveform group, and
 a second sub driving waveform group being placed after said sub driving waveform group by having a third rest time shorter than said first time in between with respect to said first sub driving waveform group. 
 
     
     
         6 . The driving apparatus as set forth in  claim 5  wherein said second sub driving waveform group includes a waveform which moves said movable body in a same direction that said first sub driving waveform group moves said movable body, and
 when a vibration period T caused in said movable body is T while said movable body is stopped, then said third rest time is shorter than T/ 4 . 
 
     
     
         7 . The driving apparatus as set forth in  claim 5  wherein said second sub driving waveform group includes a waveform which moves said movable body to an opposite direction that said first sub driving waveform group moves said movable body, and
 when a vibration period T caused in said movable body is T while said movable body is stopped, then said third rest time is longer than T/ 4  and shorter than  3 T/ 4 . 
 
     
     
         8 . A driving apparatus comprising;
 a piezoelectric element expanding and contracting in accordance with a driving signal;   a supporting shaft connected to said piezoelectric element;   a movable body frictionally engaged with said supporting shaft and capable of moving along said supporting shaft; and   a driving portion applying said driving signal including a first driving signal which moves said movable body towards a first direction to said piezoelectric element, wherein   said driving portion can repeatedly apply said first driving signal against said piezoelectric element by taking a first time in between,   said first driving signal comprises a main driving waveform group which moves said movable body to said first direction, and a sub driving waveform group which is placed after said main driving waveform group by having the a second rest time shorter than said first time in between,   said sub driving waveform group includes a waveform which moves said movable body toward said first direction, and when a vibration period caused in said movable body is T while said movable body is stopped, then said second rest time is shorter than T/4.   said sub driving waveform has a first sub driving waveform group being placed by having said second rest time in between with respect to said main driving waveform group, and   a second sub driving waveform group being placed after said sub driving waveform group by having a third rest time shorter than said first time in between with respect to said first sub driving waveform group.   
     
     
         9 . The driving apparatus as set forth in  claim 8 , wherein said second sub driving waveform group includes a waveform which moves said movable body in a same direction that said first sub driving waveform group moves said movable body, and
 when a vibration period T caused in said movable body is T while said movable body is stopped, then said third rest time is shorter than T/4.   
     
     
         10 . The driving apparatus as set forth in  claim 9 , wherein said second sub driving waveform group includes a waveform which moves said movable body to an opposite direction that said first sub driving waveform group moves said movable body, and
 when a vibration period T caused in said movable body is T while said movable body is stopped, then said third rest time is longer than T/4 and shorter than 3T/4.   
     
     
         11 . A driving apparatus comprising;
 a piezoelectric element expanding and contracting in accordance with a driving signal;   a supporting shaft connected to said piezoelectric element;   a movable body frictionally engaged with said supporting shaft and capable of moving along said supporting shaft; and   a driving portion applying said driving signal including a first driving signal which moves said movable body towards a first direction to said piezoelectric element, wherein   said driving portion can repeatedly apply said first driving signal against said piezoelectric element by taking a first time in between,   said first driving signal comprises a main driving waveform group which moves said movable body to said first direction, and a sub driving waveform group which is placed after said main driving waveform group by having the a second rest time shorter than said first time in between,   said sub driving waveform group includes a waveform which moves said movable body to an opposite direction against said first direction,   when the vibration period caused in said movable body is T while said movable body is stopped, then said second rest time is longer than T/4 and shorter than 3T/4,   said sub driving waveform has a first sub driving waveform group being placed by having said second rest time in between with respect to said main driving waveform group, and   a second sub driving waveform group being placed after said sub driving waveform group by having a third rest time shorter than said first time in between with respect to said first sub driving waveform group.   
     
     
         12 . The driving apparatus as set forth in  claim 11 , wherein said second sub driving waveform group includes a waveform which moves said movable body in a same direction that said first sub driving waveform group moves said movable body, and
 when a vibration period T caused in said movable body is T while said movable body is stopped, then said third rest time is shorter than T/4.   
     
     
         13 . The driving apparatus as set forth in  claim 11 , wherein said second sub driving waveform group includes a waveform which moves said movable body to an opposite direction that said first sub driving waveform group moves said movable body, and
 when a vibration period T caused in said movable body is T while said movable body is stopped, then said third rest time is longer than T/4 and shorter than 3T/4.