Endoscopic imaging system in which still image-specific or motion picture-specific expansion unit can be coupled to digital video output terminal in freely uncoupled manner

Abstract

A camera control unit for processing a signal output from an imaging device incorporated in an endoscope is provided with an analog video signal output terminal through which a video signal is output to a monitor, and a digital video signal output terminal to which a still image-specific or motion picture-specific expansion unit is coupled in a freely detachable manner. By handling a release switch, a still image or motion picture can be recorded digitally. Even when the recorded image data is edited or subjected to any other processing, deterioration of image quality can be prevented. An imaging system having these advantages can be realized on a small scale.

1. An endoscopic imaging system, comprising:
 an endoscope including an elongated insertion unit having a terminal portion,  
 an illumination optical system located at the terminal portion of the elongated insertion unit for emitting illumination light,  
 an objective optical system located at the terminal portion of said insertion unit for forming an optical image of an object illuminated with the illumination light, and  
 an imaging device for photoelectrically converting the optical image either directly upon formation or after being transmitted through the insertion unit;  
 a signal processing apparatus for driving said imaging device, processing an image signal output from said imaging device, generating a digital video signal and an analog video signal, and outputting the video signals through a digital video signal output terminal and analog video signal output terminal, respectively;  
 a monitor for displaying an object image represented by the analog video signal in response to input of the analog video signal output through said analog video signal output terminal; and  
 an expansion unit to be coupled to said digital video signal output terminal in a freely detachable manner, the expansion unit being provided with at least one of a compression unit for compressing data represented by the digital video signal and a PC card slot to which a PC card on which a digital video signal representing a still image whose data has been compressed by said compression unit is stored can be coupled in the freely detachable manner.  
 
     
     
       2. An endoscopic imaging system according to  claim 1 , wherein said PC card is a small memory card selected from the group consisting of a smart medium, a compact flash memory card, A  a miniature card, a small PC card, an adapter card to be coupled to said PC card slot in a freely detachable manner with a small memory card freely detachably attached thereto, and a hard disk of type III. 
     
     
       3. An endoscopic imaging system according to  claim 1 , wherein said digital video signal output terminal is used to provide an output signal conformable to the IEEE 1394 standard. 
     
     
       4. An endoscopic imaging system according to  claim 1 , wherein said signal processing apparatus includes a communication line over which a control signal is transmitted to said expansion unit. 
     
     
       5. An endoscopic imaging system according to  claim 1 , wherein said signal processing apparatus includes a display elements  element for displaying a number of still images that have been recorded using said expansion unit. 
     
     
       6. An endoscopic imaging system according to  claim 4 , wherein said communication line has the ability to transmit information sent from said expansion unit, and the transmitted information is displayed during said signal processing. 
     
     
       7. An endoscopic imaging system according to  claim 1 , wherein said endoscope is an electronic endoscope having said imaging device located at an image formation position of said objective optical system. 
     
     
       8. An endoscopic imaging system according to  claim 1 , wherein said endoscope is an optical endoscope including an image transmitter for transmitting an optical image formed by said objective optical system, in which said imaging device is incorporated or mounted on said optical endoscope in a freely detachable manner. 
     
     
       9. An endoscopic image system according to  claim 1 , wherein said signal processing apparatus includes a frame memory into which the digital video signal is written temporarily, such that when the digital video signal is read from said frame memory, the digital video signal is output through said digital video signal output terminal. 
     
     
       10. An endoscopic imaging system according to  claim 1 , wherein said expansion unit is a still image-specific expansion unit including said compression unit and said PC card slot. 
     
     
       11. An endoscopic imaging system according to  claim 1 , wherein said expansion unit is a motion picture-specific expansion unit including said compression unit and a motion picture digital video signal output terminal. 
     
     
       12. An endoscopic imaging system according to  claim 1 , wherein said expansion unit is a still image and motion picture-specific expansion unit including said compression unit, said PC card slot, and a motion picture digital video signal output terminal. 
     
     
       13. An endoscopic imaging system according to  claim 1 , further comprising an identification unit for recognizing an expansion unit coupled to said digital video signal output terminal as either a motion picture-specific expansion unit or a still image-specific expansion unit. 
     
     
       14. An endoscopic imaging system according to  claim 13 , further comprising a release switch, wherein when said release switch is handled, said signal processing apparatus outputs either image data of a still image to said still image-specific expansion unit or image data of a motion picture to said motion picture-specific expansion unit through said digital video signal output terminal according to the result of the recognition process performed by said identification unit. 
     
     
       15. An endoscopic imaging system according to  claim 10 , wherein said still image-specific expansion unit further includes
 a first compression unit of a lossless coding type and a second compression unit of a lossy coding type, and an instruction element for instructing which of said first compression unit and said second compression unit should be selected for recording a still image.  
 
     
     
       16. An endoscopic imaging system according to  claim 1 , wherein said signal processing apparatus has a digital video output terminal to which a still image-specific expansion unit and motion picture-specific expansion unit can be coupled simultaneously. 
     
     
       17. An endoscopic imaging system according to  claim 1 , further comprising a recording elements  element for transferring and recording image data to be recorded on said PC card. 
     
     
       18. An endoscopic imaging system according to  claim 1 , further comprising a recording element for recording image data of a compressed still image on a medium other than a PC card loaded into said expansion unit. 
     
     
       19. An endoscopic imaging system according to  claim 1 , wherein a connection between said digital video signal output terminal and an input terminal of said expansion unit is configured to provide ground-level voltage, power, and data connections in the listed order. 
     
     
       20. An endoscopic image system according to claim  19    1 , wherein when power is supplied from a unit other than said signal processing apparatus to said expansion unit, a connection between said digital video signal output terminal and an input terminal of said expansion unit is configured to provide the ground-level voltage and data connections in the listed order. 
     
     
       21. An endoscopic imaging system according to  claim 19 , wherein the connection between said digital video signal output terminal and said input terminal of said expansion unit is established through pins, and wherein the length of a ground pin is the longest and the length of a power pin is shorter than the length of the ground pin and longer than the length of a data transfer pin. 
     
     
       22. An endoscopic imaging system according to  claim 20 , wherein the connection between said digital video signal output terminal and said input terminal of said expansion unit is established through pins, and wherein the length of a ground pin is longest of all the pins, and the length of a data transfer pin is shorter than the length of any other type of pin. 
     
     
       23. An endoscopic imaging system according to  claim 1 , further comprising a plurality of contact points for a ground line, a power line, and a data line, respectively, which are enclosed in a bus at said digital video signal output terminal and which are positioned such that the ground line will come into contact with said expansion unit first, the power line will come into contact therewith second, and the data line will come into contact therewith last when said bus is connected to said expansion unit. 
     
     
       24. An endoscopic imaging system, comprising:
 an endoscope including an elongated insertion unit having a terminal portion,  
 an illumination optical system located at the terminal portion of the elongated insertion unit for emitting illumination light,  
 an objective optical system located at the terminal portion of said insertion unit for forming an optical image of an object illuminated with the illumination light, and  
 an imaging device for photoelectrically converting the optical image either directly upon formation or after being transmitted through the insertion unit;  
 a signal processing apparatus for driving said imaging device, processing an image signal output from said imaging device, producing a digital video signal and an analog video signal, and outputting the video signals through a digital video signal output terminal and analog video signal output terminal, respectively;  
 a monitor for displaying an object image represented by the analog video signal in response to input of the analog video signal output through said analog video signal output terminal;  
 a digital interface unit to be coupled to said digital video signal output terminal in a freely detachable manner, the digital interface unit including  
 a memory in which said digital video signal is stored temporarily,  
 a controller for controlling a read operation and a write operation to be performed relative to said memory, and  
 a digital interface output unit for outputting the digital video signal upon being read from said memory in a form acceptable by an external device; and  
 an external storage/recording device coupled to said digital video output terminal for storing or recording said digital video signal.  
 
     
     
       25. An endoscopic imaging system according to  claim 24 , wherein said controller is incorporated in said digital interface unit. 
     
     
       26. An endoscopic imaging system according to  claim 24 , further comprising a video signal generator for generating a video signal using said digital video signal stored in said memory. 
     
     
       27. An endoscopic imaging system according to  claim 24 , further comprising
 an image synthesizer for synthesizing said digital video signal produced by said signal processing apparatus and said digital video signal stored in said memory, so as to produce synthetic image data; and  
 a synthetic video signal generator for generating a video signal using the synthetic image data produced by said image synthesizer.  
 
     
     
       28. An endoscopic image system according to  claim 1 , further comprising a light source unit of a surface sequential type which includes a white light source which emits white light, and a rotary filter which rotates to recompose the white light into sequential light rays of red, green and blue. 
     
     
       29. An image processing system for an endoscopic imaging system, comprising:
   a signal processing apparatus for driving an imaging device of a type which photoelectrically converts an optical image into an image signal, processing an image signal output from said imaging device, generating a digital video signal and an analog video signal, and outputting the video signals through a digital video signal output terminal and analog video signal output terminal, respectively; and        an expansion unit to be connected to said digital video signal output terminal in a freely detachable manner, the expans˜ 0 n unit being provided with at least one of a compression unit for compressing data represented by the digital video signal, at least one PC card slot to which a PC card for storing digital video signal data which has been compressed by said compression unit and which represents a still image can be coupled in a freely detachable manner, and a motion picture digital video signal output terminal.     
     
     
       30. An image processing system according to  claim 29 , wherein said signal processing apparatus includes a display element for displaying a number of still images that have been recorded or a time length of a motion picture that has been recorded using said expansion unit. 
     
     
       31. An image processing system according to  claim 29 , wherein the digital video signal is transferred to said expansion unit in a parallel transfer mode. 
     
     
       32. An image processing system according to  claim 29 , wherein the digital video signal is transferred to said expansion unit in a serial transfer mode. 
     
     
       33. An image processing system according to  claim 29 , wherein said expansion unit is a still image- specific expansion unit including said compression unit and said at least one PC card slot.   
     
     
       34. An image processing system according to  claim 33 , wherein said signal processing apparatus includes a modem whereby said signal processing apparatus is capable of transferring digital video signal data to an external medium while a PC card is loaded in said PC card slot. 
     
     
       35. An image processing system according to  claim 33 , wherein said compression unit compresses said data according to a lossy coding. 
     
     
       36. An image processing system according to  claim 33 , wherein said compression unit compresses said data according to a lossless coding. 
     
     
       37. An image processing system according to  claim 33 , further comprising a recording element for recording image data of a compressed still image on a medium other than a PC card loaded into said expansion unit. 
     
     
       38. An image processing system according to  claim 37 , wherein said recording element can be detachably coupled to said expansion unit. 
     
     
       39. An image processing system according to  claim 29 , wherein said expansion unit is a motion picture- specific expansion unit including said compression unit and said motion picture digital video signal output terminal.   
     
     
       40. An image processing system according to  claim 29 , wherein said expansion unit is a still image and motion picture- specific expansion unit including said compression unit, said at least one PC card slot, and a motion picture digital video signal output terminal.   
     
     
       41. An image processing system according to  claim 29 , wherein said signal processing apparatus is configured to recognize an expansion unit connected to said digital video signal output terminal and identify the same as either a motion picture- specific expansion unit or a still image - specific expansion unit.   
     
     
       42. An image processing system according to  claim 41 , further comprising a release switch operable by a user to cause said signal processing apparatus to output either image data of a still image to said still image- specific expansion unit or image data of a motion picture to said motion picture - specific expansion unit through said digital video signal output terminal according to a recognition by said signal processing apparatus of said expansion unit connected thereto.   
     
     
       43. An image processing system according to  claim 29 , wherein said signal processing apparatus has two digital video output terminals so that both of a still image- specific expansion unit and a motion picture - specific expansion unit can be coupled to said signal processing apparatus simultaneously.   
     
     
       44. An image processing system according to  claim 29 , further comprising a frame memory incorporated in one of said signal processing apparatus or said expansion unit for temporarily storing digital video signal data to facilitate recording of said data via said expansion unit. 
     
     
       45. An image processing system according to  claim 29 , further comprising a connection interface between said digital video signal output terminal of said signal processing apparatus and said expansion unit, said interface including a plurality of contact elements for a ground line, a power line, and a data line, respectively, which are positioned such that the ground line will come into contact with said expansion unit first, the power line will come into contact therewith second, and the data line will come into contact therewith last when said bus is connected to said expansion unit. 
     
     
       46. An image processing system according to  claim 29 , further comprising a connection interface between said digital video signal output terminal of said signal processing apparatus and said expansion unit, said interface including a plurality of contact elements for a ground line and a data line, respectively, which are positioned such that the ground line will come into contact with said expansion unit first and the data line will come into contact therewith last when said bus is connected to said expansion unit. 
     
     
       47. An image processing system according to  claim 46 , wherein said connection interface further comprises a control signal line over which a control signal is transmitted in parallel to data transmission over said data line. 
     
     
       48. An image processing system according to  claim 46 , wherein said connection interface further comprises two control signal lines for bi- directional transmission of control signals in parallel to data transmission over said data line.   
     
     
       49. An image processing system according to  claim 29 , further comprising a digital interface unit to be coupled in a freely detachable manner between said digital video signal output terminal of said signal processing apparatus and said expansion unit, the digital interface unit including
   a memory in which said digital video signal is stored temporarily,        a controller for controlling a read operation and a write operation to be performed relative to said memory, and        a digital interface output unit for outputting, upon being read from said memory, the digital video signal in a form acceptable to said expansion unit.     
     
     
       50. An image processing system according to  claim 49 , wherein said digital interface unit further includes a video signal generator for generating a video signal using said digital video signal stored in said memory. 
     
     
       51. An image processing system according to  claim 49 , wherein said digital interface unit further includes an image synthesizer for synthesizing said digital video signal produced by said signal processing apparatus and said digital video signal stored in said memory, so as to produce synthesized image data; and a synthetic video signal generator for generating a video signal using the synthesized image data produced by said image synthesizer. 
     
     
       52. An image processing system according to  claim 29 , wherein said PC card is a small memory card selected from the group consisting of a smart medium, a compact flash memory card, a miniature card, a small PC card, an adapter card to be coupled to said PC card slot in a freely detachable manner with a small memory card freely detachably attached thereto, and a hard disk of type III.