Scanner unit for an optical position measuring device

Abstract

A scanning unit for an optical position measuring device, which is suited for optically scanning a scale graduation, to produce positionally dependent scanning signals on the basis of scale graduation. The scanning unit includes a carrier element, at least one optoelectronic component, which is arranged on the carrier element, a radiation-sensitive or a radiation-emitting surface region of the component being oriented to face away from the carrier element. Provision is also made for at least one electrically conductive connector lead between the carrier element and a contacting region of the component. An at least semi-transparent cover element is arranged directly on the radiation-sensitive and/or radiation-emitting surface region of the component. In this case, the cover element is arranged in such a way with respect to the component that the contacting region of the component is not covered by it and, in addition, the thickness of the cover element is selected so as to ensure that the top side of the cover element exceeds the height of the connector lead in the contacting region.

1. A scanning unit for an optical position measuring device for optically
 scanning a graduation of a scale to produce positionally dependent scanning  
 signals, the scanning unit comprising:  
 a carrier element;  
 a first optoelectronic component disposed on the carrier element and having a radiation-sensitive or radiation-emitting surface region and contacting region, the surface region facing away from the carrier element;  
 an encapsulant arranged in the contacting region of the first optoelectronic component;  
 a first electrically conductive connector lead disposed between the carrier element and the contacting region, the first connector lead having a first height in the contacting region; and  
 an at least semi-transparent cover element, the cover element having the graduation and a top side, the cover element being arranged directly on the surface region so that the contacting region is not covered by the cover element, a height of the top side exceeding the first height.  
 
     
     
       2. The scanning unit as recited in  claim 1  wherein the carrier element is a board with integrated signal lines. 
     
     
       3. The scanning unit as recited in  claim 1  wherein the cover element is made of glass. 
     
     
       4. The scanning unit as recited in  claim 1  wherein the cover element is adhesively mounted on the first optoelectronic component. 
     
     
       5. The scanning unit as recited in  claim 1  wherein the first connector lead is a bonding wire. 
     
     
       6. The scanning unit as recited in  claim 1  wherein the first optoelectronic component is a light source or a detector element. 
     
     
       7. The scanning unit as recited in  claim 1  wherein the cover element has the graduation on a side facing the first optoelectronic component. 
     
     
       8. The scanning unit as recited in  claim 7  wherein the graduation is a transmitting or scanning graduation scale. 
     
     
       9. The scanning unit as recited in  claim 7  wherein the graduation includes a plurality of subregions having subregion graduations. 
     
     
       10. The scanning unit as recited in  claim 1  further comprising a second optoelectronic component disposed on the carrier element, the first and second optoelectronic components being integrated in a flat carrier substrate. 
     
     
       11. The scanning unit as recited in  claim 10  wherein the cover element is arranged over a surface region of the second optoelectronic component, the cover element having a fine subregion graduation at least in a subregion, the first and second optoelectronic components being optoelectronic detector elements. 
     
     
       12. The scanning unit as recited in  claim 1  wherein the cover element has a pocket-shaped recess in the contacting region. 
     
     
       13. The scanning unit as recited in  claim 12  comprising support elements, the cover element resting on the support elements in edge regions adjacent to the recess. 
     
     
       14. A scanning unit for an optical position measuring device for optically scanning a graduation of a scale to produce positionally dependent scanning signals, the scanning unit comprising:
 a carrier element;  
 a first optoelectronic component disposed on the carrier element and having a radiation-sensitive or radiation-emitting surface region and contacting region, the surface region facing away from the carrier element;  
 a first electrically conductive connector lead disposed between the carrier element and the contacting region, the first connector lead having a first height in the contacting region; and  
 an at least semi-transparent cover element, the cover element having the graduation, a top side, a pocket-shaped recess in the contacting region, the cover element being arranged directly on the surface region so that the contacting region is not covered by the cover element, a height of the top side exceeding the first height. wherein the cover element has .  
 
     
     
       15. The scanning unit as recited in  claim 14  further comprising support elements, the cover element resting on the support elements in edge regions adjacent to the recess. 
     
     
       16. A scanning unit for an optical position measuring device for optically scanning a graduation of a scale to produce positionally dependent scanning signals, the graduation includes a plurality of subregions having subregion graduations, the scanning unit comprising:
 a carrier element;  
 a first optoelectronic component disposed on the carrier element and having a radiation-sensitive or radiation-emitting surface region and contacting region, the surface region facing away from the carrier element;  
 a first electrically conductive connector lead disposed between the carrier element and the contacting region, the first connector lead having a first height in the contacting region;  
 an at least semi-transparent cover element, the cover element having the graduation on a side facing the first optoelectronic component, the cover element having a top side, the cover element being arranged directly on the surface region so that the contacting region is not covered by the cover element, a height of the top side exceeding the first height; and  
 an encapsulant arranged in the contacting region of the first optoelectronic component.  
 
     
     
       17. The scanning unit as recited in  claim 16  wherein the carrier element is a board with integrated signal lines. 
     
     
       18. The scanning unit as recited in  claim 16  wherein the cover element is made of glass. 
     
     
       19. The scanning unit as recited in  claim 16  wherein the cover element is adhesively mounted on the first optoelectronic component. 
     
     
       20. The scanning unit as recited in  claim 16  wherein the first connector lead is a bonding wire. 
     
     
       21. The scanning unit as recited in  claim 16  wherein the first optoelectronic component is a light source or a detector element. 
     
     
       22. The scanning unit as recited in  claim 16  wherein the graduation is a transmitting or scanning graduation scale. 
     
     
       23. A scanning unit for an optical position measuring device for optically scanning a graduation scale to produce positionally dependent scanning signals, the scanning unit comprising:
   a carrier element;        a first optoelectronic component disposed on the carrier element and having a radiation - sensitive or radiation - emitting surface region and a contacting region, the surface region facing away from the carrier element;        an encapsulant arranged in the contacting region of the first optoelectronic component;        a first electrically conductive connector lead disposed between the carrier element and the contacting region, the first connector lead having a first height in the contacting region; and        an at least semi - transparent cover element, the cover element having a graduation and a top side, the cover element being arranged directly on the surface region so that the contacting region is not covered by the cover element, a height of the top side exceeding the first height.     
     
     
       24. The scanning unit as recited in  claim 23  wherein a height of the encapsulant adjacent the cover element is substantially equal to the height of the top side. 
     
     
       25. A scanning unit for an optical position measuring device for optically scanning a graduation scale to produce positionally dependent scanning signals, the scanning unit comprising:
   a carrier element;        a first optoelectronic component disposed on the carrier element and having a radiation - sensitive or radiation - emitting surface region and a contacting region, the surface region facing away from the carrier element;        a first electrically conductive connector lead disposed between the carrier element and the contacting region, the first connector lead having a first height in the contacting region; and        an at least semi - transparent cover element, the cover element having a graduation, a top side, and a pocket - shaped recess in the contacting region, the cover element being arranged directly on the surface region so that the contacting region is not covered by the cover element, a height of the top side exceeding the first height.     
     
     
       26. A scanning unit for an optical position measuring device for optically scanning a graduation scale to produce positionally dependent scanning signals, the scanning unit comprising:
   a carrier element;        a first optoelectronic component disposed on the carrier element and having a radiation - sensitive or radiation - emitting surface region and a contacting region, the surface region facing away from the carrier element;        a first electrically conductive connector lead disposed between the carrier element and the contacting region, the first connector lead having a first height in the contacting region;        an at least semi - transparent cover element, the cover element having a graduation on a side facing the first optoelectronic component, the graduation including a plurality of subregions having subregion graduations, the cover element having a top side, the cover element being arranged directly on the surface region so that the contacting region is not covered by the cover element, a height of the top side exceeding the first height; and        an encapsulant arranged in the contacting region of the first optoelectronic component.     
     
     
       27. The scanning unit as recited in  claim 26  wherein a height of the encapsulant adjacent the cover element is substantially equal to a height of the top side. 
     
     
       28. The scanning unit as recited in  claim 1  wherein a height of the encapsulant adjacent the cover element is substantially equal to the height of the top side. 
     
     
       29. The scanning unit as recited in  claim 16  wherein a height of the encapsulant adjacent the cover element is substantially equal to the height of the top side. 
     
     
       30. A scanning unit for an optical position measuring device for optically scanning a graduation scale to produce positionally dependent scanning signals, the scanning unit comprising:
   a carrier element;        a first optoelectronic component disposed on the carrier element and having a radiation - sensitive or radiation - emitting surface region and a contacting region, the surface region facing away from the carrier element;        an encapsulant arranged in the contacting region of the first optoelectronic component;        a first electrically conductive connector lead disposed between the carrier element and the contacting region, the first connector lead having a first height in the contacting region; and        an at least semi - transparent cover element, the cover element having a top side, the cover element being arranged directly on the surface region so that the contacting region is not covered by the cover element, a height of the top side exceeding the first height.     
     
     
       31. A scanning unit for an optical position measuring device for optically scanning a graduation scale to produce positionally dependent scanning signals, the scanning unit comprising:
   a carrier element;        a first optoelectronic component disposed on the carrier element and having a radiation - sensitive or radiation - emitting surface region and at least one contacting region, the surface region facing away from the carrier element;        an encapsulant arranged at least in the at least one contacting region;        a electrically conductive connector lead disposed between the carrier element and each contacting region, each connector lead encapsulated in the encapsulant; and        an at least semi - transparent cover element, the cover element having a top side, the cover element arranged directly on the surface region, the cover element not covering any of the at least one contacting regions, a height of the encapsulant adjacent the cover element substantially equal to a height of the top side.     
     
     
       32. The scanning unit as recited in  claim 31  wherein the carrier element is a board with integrated signal lines. 
     
     
       33. The scanning unit as recited in  claim 31  wherein the cover element is made of glass. 
     
     
       34. The scanning unit as recited in  claim 31  wherein the cover element is adhesively mounted on the first optoelectronic component. 
     
     
       35. The scanning unit as recited in  claim 31  wherein each connector lead is a bonding wire. 
     
     
       36. The scanning unit as recited in  claim 31  wherein the first optoelectronic component is a light source or a detector element. 
     
     
       37. The scanning unit as recited in  claim 31  wherein the cover element has a graduation. 
     
     
       38. The scanning unit as recited in  claim 37  wherein the graduation is a transmitting or scanning graduation scale. 
     
     
       39. The scanning unit as recited in  claim 37  wherein the graduation includes a plurality of subregions having subregion graduations. 
     
     
       40. The scanning unit as recited in  claim 31  further comprising a second optoelectronic component disposed on the carrier element, the first and second optoelectronic components integrated in a flat carrier substrate. 
     
     
       41. The scanning unit as recited in  claim 40  wherein the cover element is arranged over a surface region of the second optoelectronic component, the cover element having a fine subregion graduation at least in a subregion, the first and second optoelectronic components being optoelectronic detector elements. 
     
     
       42. The scanning unit as recited in  claim 31  wherein the cover element has a pocket- shaped recess in the contacting region.   
     
     
       43. The scanning unit as recited in  claim 42  comprising support elements, the cover element resting on the support elements in edge regions adjacent to the recess. 
     
     
       44. The scanning unit as recited in  claim 37  wherein the graduation is arranged on a side of the cover element facing the first optoelectronic component. 
     
     
       45. The scanning unit as recited in  claim 37  wherein the graduation is arranged on the top side of the cover element. 
     
     
       46. The scanning unit as recited in  claim 31  wherein further electronic evaluation components to process the scanning signals are arranged on the carrier element. 
     
     
       47. The scanning unit as recited in  claim 46  wherein at least one further amplifier module is arranged on the carrier element. 
     
     
       48. The scanning unit as recited in  claim 46  wherein at least one further interpolator module is arranged on the carrier element. 
     
     
       49. The scanning unit as recited in  claim 34  wherein the cover element is adhesively mounted on the first optoelectronic component by an adhesive that is transparent to an applied wavelength. 
     
     
       50. The scanning unit as recited in  claim 49  wherein the adhesive does not contain any constituents which could diffuse into an underlying component. 
     
     
       51. The scanning unit as recited in  claim 39  wherein a plurality of optoelectronic detector elements are arranged on the carrier element and are covered with a single cover element, having four partial areas with subregion graduations arranged in front of radiation sensitive areas of the optoelectronic detector elements. 
     
     
       52. A scanning unit for an optical position measuring device for optically scanning a graduation scale to produce positionally dependent scanning signals, the scanning unit comprising:
   a carrier element;        an optoelectronic component disposed on the carrier element and having a radiation - sensitive or radiation - emitting surface region and at least one contacting region, the surface region facing away from the carrier element;        an electrically conductive connector lead disposed between the carrier element and each contacting region;        an at least semi - transparent cover element, the cover element having a graduation, the graduation including a plurality of subregions having subregion graduations, the cover element having a top side, the cover element arranged directly on the surface region, the cover element not covering any of the at least one contacting regions; and        an encapsulant arranged at least in the at least one contacting region, each connector lead encapsulated in the encapsulant, a height of the encapsulant adjacent the cover element substantially equal to a height of the top side.     
     
     
       53. The scanning unit as recited in  claim 52  wherein the carrier element is a board with integrated signal lines. 
     
     
       54. The scanning unit as recited in  claim 52  wherein the cover element is made of glass. 
     
     
       55. The scanning unit as recited in  claim 52  wherein the cover element is adhesively mounted on the optoelectronic component. 
     
     
       56. The scanning unit as recited in  claim 52  wherein each connector lead is a bonding wire. 
     
     
       57. The scanning unit as recited in  claim 52  wherein the optoelectronic component is a light source or a detector element. 
     
     
       58. The scanning unit as recited in  claim 52  wherein the graduation is a transmitting or scanning graduation scale. 
     
     
       59. The scanning unit as recited in  claim 52  wherein the graduation is arranged on a side of the cover element facing the optoelectronic component. 
     
     
       60. The scanning unit as recited in  claim 52  wherein the graduation is arranged on the top side of the cover element. 
     
     
       61. A position measuring device, comprising:
   a scale graduation; and        a scanning unit configured to optically scan the graduation scale to produce positionally dependent scanning signals, the scanning unit including:      a carrier element;        a first optoelectronic component disposed on the carrier element and having a radiation - sensitive or radiation - emitting surface region and at least one contacting region, the surface region facing away from the carrier element;        an encapsulant arranged at least in the at least one contacting region;        a electrically conductive connector lead disposed between the carrier element and each contacting region, each connector lead encapsulated in the encapsulant; and        an at least semi - transparent cover element, the cover element having a top side, the cover element arranged directly on the surface region, the cover element not covering any of the at least one contacting regions, a height of the encapsulant adjacent the cover element substantially equal to a height of the top side.