Abstract:
An endoscope system includes a processor. The processor is physically connectable to different endoscopes to receive and process signals from an endoscope that is selectively physically connected to the processor. The processor includes a database that stores pieces of endoscope data each corresponding to a different endoscope. Each piece of endoscope data is associated with ownership information. The pieces of endoscope data indicate whether usage of a physically connected endoscope is authorized. The ownership information indicates a term for which the physically connected endoscope is allowed to be utilized. An output outputs the ownership information.

Description:
[0001]     This application is a continuation of pending U.S. patent application Ser. No. 10/188,096, filed Jul. 3, 2002, the disclosure of which is expressly incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to an endoscope system adapted to manage data of a plurality of endoscopes.  
         [0003]     There are endoscopes provided with a solid state imaging device for capturing images inside a human body. Such endoscopes, so called electronic endoscopes, are normally connected to a processor that transforms the output signals from the solid state imaging device into image signals so that output devices such as monitors and video printers can display or print the image captured by the solid state imaging device.  
         [0004]     The endoscope is connected detachably to the processor so that the endoscope can be changed to a suitable type in accordance with the location of the human body to be inspected or treated with the endoscope. That is, the endoscope and the processor can be used in various combinations.  
         [0005]     The endoscope is usually provided with a memory, such as an EEPROM, into which various kinds of data related to the endoscope are stored. Data stored into the memory includes, for example, type and serial number of the endoscope, and calibration data for adjusting the white balance of the image captured by the solid state imaging device. The calibration data for adjusting the white balance includes the amount of brightness increase/decrease of red and blue colors, which will be referred hereinafter as “wb(r)” and “wb(b)”, respectively.  
         [0006]     The endoscope type and serial number are read by the processor as the endoscope is connected, and displayed on, for example, a monitor. An operator can check the information about the endoscope from the serial number by searching a database, for example, constructed in an independent computer. There is, however, information which should be checked whenever the endoscope is used. Such information requires repetitive search work which burdens the operator.  
         [0007]     Therefore, there is a need for an endoscope system that allows the operator to check information about the endoscope in use in a simpler manner.  
         [0008]     The calibration data for white balance, wb(r) and wb(b), is also read by the processor to adjust the white balance of the image generated in the processor based on the output signals from the solid state imaging device.  
         [0009]     The color balance adjusting abilities, however, are slightly different between each processor. Therefore, the processor often fails to achieve proper white balance by adjusting the colors in accordance with the calibration data obtained from the endoscope. In such case, proper white balance is achieved by performing manually a fine adjustment.  
         [0010]     Recently, processors have been developed that are provided with a memory for storing the calibration data obtained as a result of the fine adjustment mentioned above. The calibration data is stored in the memory in association with data intrinsic to the endoscope, such as serial number, to construct a database. The processor can utilize the calibration data in the database whenever the endoscope is connected and used again in the future. In this way, the processor eliminates the necessity of repetitive manual fine adjustment of the white balance.  
         [0011]     The number of endoscopes, however, of which data can be registered to the database is restricted because of the finite available memory space thereof. Thus, if there is not available memory space for storing data of a new endoscope, unimportant data such as that of old or seldom used endoscopes should be deleted manually to free up memory space. Such manual operation is a cumbersome task and may cause deletion of important data such as that of new or frequently used endoscopes if proper care is not used when manually deleting data.  
         [0012]     Therefore, there is also a need for an endoscope system that manages the database of endoscope data such that the deletion of important data is prevented.  
       SUMMARY OF THE INVENTION  
       [0013]     The present invention provides the advantage in that, in an endoscope system, important data of endoscopes in a database is prevented from being unintentionally deleted. The present invention also provides the advantage that the operator can check information about the endoscope in use in a simple manner.  
         [0014]     According to an aspect to the invention, an endoscope system including a database and a database managing device is provided. The database is configured to store a plurality of pieces of endoscope data. Each piece of the endoscope data corresponds to a different endoscope and is associated with ownership information indicating a term for which the corresponding endoscope is allowed to be utilized. The database managing device is configured to select one of the plurality of pieces of endoscope data stored in the database and replace it with a new piece of endoscope data corresponding to a new endoscope. The database managing device selects the piece of endoscope data to be replaced based on the ownership information. In this manner, the database managing device can select and replace the piece of endoscope data of the database so that, for example, the endoscope data that corresponds to the endoscopes allowed to be utilized for relatively long term remains in the database.  
         [0015]     The ownership information may include information on whether the corresponding endoscope is purchased or not. Purchased endoscopes are generally allowed to be used permanently and therefore the piece of endoscope data corresponding to purchased endoscopes should be left in the database. Accordingly, the database managing device may select and replace the piece of endoscope data related to the endoscope that is not purchased in preference to purchased endoscope data.  
         [0016]     Alternatively, the ownership information may include information on whether the corresponding endoscope is leased or not. Since the leased endoscope is allowed to be utilized for only a limited term, the database managing device may select the piece of endoscope data related to the endoscope being leased in preference to other endoscope data and replace it with the new endoscope data.  
         [0017]     In addition, the ownership information may include information on whether a term of lease of the endoscope is less than a predetermined period. In this case, the database managing device may select the piece of endoscope data related to the term of lease less than the predetermined period in preference to other endoscope data. Alternatively, the database managing device may select the piece of endoscope data related to the term of lease which has already expired since such endoscope may not be utilized in the future again.  
         [0018]     Optionally, each of the pieces of the endoscope data is associated with registration information including a date of when the piece of endoscope data is stored into the database, and the database managing device selects one piece of the endoscope data to be replaced based on the registration information among a plurality of pieces of the endoscope data selected based on the ownership information. In particular, the database managing device may select the piece of endoscope data related to the registration information including the oldest date since such old endoscope data may have less importance than those registered later.  
         [0019]     Alternatively, each of said pieces of endoscope data is associated with used date information including a date of the corresponding endoscope being used for the last time. The database managing device selects one piece of the endoscope data to be replaced based on the used date information among a plurality of pieces of the endoscope data selected based on said ownership information. In particular, the database managing device may select the endoscope data related to the used data information including the oldest date, since the endoscope not used for a long time may be seldom used also in the future.  
         [0020]     Optionally, the database and the database managing device are provided to a processor configured to be connected to the endoscope for receiving and processing signals from the endoscope.  
         [0021]     According to another aspect to the invention, an endoscope system including a processor and an output device is provided. The processor is connectable to various endoscopes to receive and process signals from the endoscopes being connected. The processor includes a database configured to store a plurality of pieces of endoscope data each corresponding to a different one of said endoscopes. Each piece of the endoscope data is associated with ownership information which indicates a term for which the corresponding endoscope is allowed to be utilized. The output device is configured to output the ownership information so that an operator of the endoscope system can confirm the ownership information.  
         [0022]     Optionally, the output device outputs the ownership information of the endoscope currently connected to the processor so that the operator can confirm the ownership information of the endoscope currently connected.  
         [0023]     Optionally, the output device is a monitor for displaying an image captured by an imaging device provided to the endoscope. In this case, the ownership information can be displayed, for example, simultaneously with the image captured by the imaging device.  
         [0024]     According to another aspect of the invention, specifications information, indicating the design specifications of the corresponding endoscope, is associated with each piece of the endoscope data in the database instead of the ownership information and outputted from the output device so that the operator can confirm the specifications of the endoscope.  
         [0025]     According to another aspect of the invention, an endoscope system including a database and a database managing device is provided. The database is configured to store a plurality of pieces of endoscope data each corresponding to a different endoscope. Each piece of the endoscope data is associated with term information which indicates a term the corresponding piece of endoscope data is valid. In order to prevent the database from being filled with invalid endoscope data, the database managing device is configured to selectively delete the piece of endoscope data in the database based on the term information.  
         [0026]     According to another aspect of the invention, an endoscope including a storage device configured to store ownership information and/or specifications information is provided. The ownership information includes a term for which the endoscope is allowed to be utilized, while the specifications information indicates design specifications of the endoscope. 
     
    
     BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS  
       [0027]      FIG. 1  schematically shows the configuration of an electronic endoscope system according to an embodiment of the invention;  
         [0028]      FIG. 2  shows an exemplary data format of a memory provided to an electronic endoscope in the electronic endoscope system of  FIG. 1 :  
         [0029]      FIG. 3  shows an example of the data stored in the memory of the electronic endoscope in  FIG. 1 ;  
         [0030]      FIG. 4  shows an exemplary structure of a database established in a memory of a processor in the electronic endoscope system of  FIG. 1 ;  
         [0031]      FIG. 5  is a flow chart showing a main routine representing the operation of the processor of the electronic endoscope system shown in  FIG. 1  according to an embodiment of the invention;  
         [0032]      FIG. 6  is a flow chart showing a subroutine DISPLAY SCOPE INFORMATION of the main routine shown in  FIG. 5 ;  
         [0033]      FIG. 7  is a flow chart showing a subroutine ENDOSCOPE REGISTRATION of the main routine in  FIG. 5 ;  
         [0034]      FIG. 8  is a flow chart showing a subroutine SELECT DATA of the subroutine ENDOSCOPE REGISTRATION in  FIG. 7 ;  
         [0035]      FIG. 9  is a flow chart showing a subroutine DISPLAY DATE &amp; TIME of the main routine shown in  FIG. 5 ;  
         [0036]      FIG. 10  is a flow chart showing a subroutine ADJUSTMENT of the main routine shown in  FIG. 5 ;  
         [0037]      FIG. 11  shows a modification of the subroutine SELECT DATA shown in  FIG. 8 ;  
         [0038]      FIG. 12  is a flow chart showing the operation of the processor when the electronic endoscope is connected according to another embodiment of the invention;  
         [0039]      FIG. 13  schematically shows a modified configuration of the electronic endoscope system of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0040]     Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings.  
         [0041]      FIG. 1  schematically shows the configuration of an electronic endoscope system  1  according to an embodiment of the invention.  
         [0042]     The electronic endoscope system  1  includes an electronic endoscope  100  and a processor  200  for processing signals from the electronic endoscope  100 .  
         [0043]     The electronic endoscope  100  includes an flexible inserting tube  110  to be inserted into a human body and an operation portion  120  connected to the proximal end of the inserting tube  110 . The electronic endoscope  100  further includes a connector  130  which is detachably connected to the processor  200 .  
         [0044]     A solid state imaging device such as a CCD  104  and an objective optical system  101  for forming an optical image on a light receiving surface of the CCD  104  are provided to the distal end portion of the inserting tube  110 .  
         [0045]     Further, one or more operation buttons  107  are provided to the operation portion  120  for controlling the operation of the processor  200 .  
         [0046]     Further, a memory such as an EEPROM  102  is provided to the electronic endoscope  100  for storing data related to the endoscope  100 , in particular, data intrinsic to each endoscope. In the present embodiment, the EEPROM  102  is located in the connector  130 .  
         [0047]     The processor  200  includes a CPU  201  which is connected to the operation buttons  107  and the EEPROM  102  via an signal cable  108 . The CPU  210  controls the operation of the processor  200  in accordance with the signals from the operation buttons  107 . The CPU  210  also accesses the EEPROM  102  to retrieve data stored therein.  
         [0048]     The CPU  201  is further connected to an input unit, such as a keyboard  400 , via an interface  212 , to control the operation of the processor  200  in accordance with the commands inputted from the keyboard  400 .  
         [0049]     The processor  200  is also provided with an operation panel  207 . A plurality of operation buttons (not shown) are arranged on the operation panel  207  such that an operator of the endoscope system  1  can press each button. Each button outputs a signal to the CPU  201 , as being pressed, to control the operation of the processor  200 .  
         [0050]     The processor includes a light source  203  optically connected to the end of a light guide  103  that is arranged throughout the electronic endoscope  100  from the connector  130  to the tip end of the inserting tube  110 . The light emitted from the light source  203  is transmitted through the light guide  103  to illuminate the area in front of the tip end of the inserting tube  110 .  
         [0051]     An diaphragm  210  is provided on the light path of the light emitted from the light source  203  to restrict the amount of light introduced into the light guide  103 . An diaphragm controller  211  controls the opening size of the diaphragm  210 , or the amount of light introduced into the light guide  103 , in accordance with signals from the CPU  201 . The operator can freely control the opening size of the diaphragm  210  by operating the keyboard  400  or the operation panel  207 .  
         [0052]     First and second signal processors  204  and  205  are provided to the processor  200  to display images captured by the CCD  104  on a monitor  300 . The first signal processor  204  receives the signal from the CCD  104  via a CCD signal cable  109  and transforms it into RGB digital image data represented in 256 levels of gray scale. The first signal processor  204  outputs the digital image data to the second signal processor  205  which generates video signal, such as NTSC, from the digital image data. The second signal processor  205  further adjusts the white balance of the video signal based on calibration data wb(r) and wb(b) received from the CPU  201  as will be described later. The second signal processor  205  outputs the video signal to the monitor  300  so that the monitor  300  displays the image captured by the CCD  104 .  
         [0053]     Note that the output device to which the second signal processor  205  may be connected is not limited to the monitor  300 , however, the second signal processor  205  may also be connected to other kinds of output devices such as a video printer, for example.  
         [0054]     A CRT controller  206  is provided to the processor to superimpose text information on the image displayed on the monitor  300 . The CRT controller  206  generates video signals representing the text information requested by the CPU  201  and output the video signals to the monitor  300  in synchronization with the video signal from the second signal processor  205 . In this way, the processor  200  superimposes arbitrary text information, such as information obtained from the CPU  201 , on the image captured by the CCD  104 .  
         [0055]     The processor  200  is also provided with a Real Time Clock (RTC)  209  and a memory  208 . The RTC  209  provides information on current date &amp; time to the CPU  201 . The memory  208  is adapted to include a database for data related to endoscopes, as will be described later.  
         [0056]      FIG. 2  shows an exemplary data format of the EEPROM  102 , and  FIG. 3  shows an example of the data stored in the EEPROM  102 .  
         [0057]     In the present embodiment, the storage capacity of the EEPROM  102  is 16 bytes and the following information are stored in the EEPROM  102  in the following order.  
         [0058]     1) “serial no.” (three bytes): the serial number of the electronic endoscope  100  which is unique for each endoscope. The “serial no.” may be set to one of values from 1 through 16777215 (0x1 through 0xffffff in hexadecimal digit).  
         [0059]     2) “scope name” (six bytes): six alphanumeric characters representing the type of the electronic endoscope  100 .  
         [0060]     3) “wb(r)” (one byte): a calibration value of the red color brightness for adjusting white balance of the image captured by the CCD  104 .  
         [0061]     4) “wb(b)” (one byte): a calibration value of the blue color brightness for adjusting white balance of the image captured by the CCD  104 . Both “wb(r)” and “wb(b)” can take a value between −128 and 127. As shown in  FIG. 3 , “wb(r)” and “wb(b)” are respectively set to −4 and 10 (0x7c and 0x8a in hexadecimal digit) in the present embodiment. This indicates the brightness of red color should be decreased by four levels in gray scale, while the brightness of blue should be increased by ten levels.  
         [0062]     5) “ownership” (one byte): a variable representing whether the endoscope is purchased or leased. “ownership”=0, 1 and 2 (0x0, 0x1, and 0x2 in hexadecimal digit) respectively represents whether the endoscope is purchased, leased for a long term (a term not less than 30 days, for example), or leased for a short term (term less than 30 days, for example).  
         [0063]     6) “spect” (one byte): a variable representing the specifications of the design of the electronic endoscope  100 . If the electronic endoscope  100  is a standard type, then “spec” is set to 0. If the electronic endoscope is a custom made one, then “spec” is set to a value corresponding to the particular design specifications. In the present embodiment, “spect” is set to 1 which indicates the optical system  101  includes a lens applied with special coatings.  
         [0064]     7) “expiration” (three bytes): the expiration date of the lease of the electronic endoscope  100 . The first one byte of “expiration” indicates the year, the next one the month, and the last one the day. In the example shown in  FIG. 3 , value 040331 is assigned to “expiration” which indicates the expiration of the lease is Mar. 31, 2004 If the electronic endoscope  100  is a purchased one, then 000000 is assigned to “expiration”. It should be noted that, in some embodiments of the invention, expiration indicates the expiration date of the service life of the endoscope instead of the expiration date of the lease.  
         [0065]     Among the items recited above, the “serial no.”, “scope name”, “ownership”, and “expiration” are examples of information for managing the endoscope, while “wb(r)”, “wb(b)”, and “spect” are examples of information representing the characteristics of the endoscope.  
         [0066]     The data of EEPROM  102  are copied to the memory  208  of the processor  200  as the electronic endoscope  100  is connected to the processor  200  for the first time to register the endoscope to the database.  
         [0067]      FIG. 4  shows an exemplary structure of the database established in the memory  208  of the processor  200 . The database includes 39 records, each record being defined for storing data related to one specific endoscope. Thus, data of 39 endoscopes can be stored in the database.  
         [0068]     Each record includes the following items in the following order,  
         [0069]     1) “register no.”,  
         [0070]     2) “scope name” 
         [0071]     3) “serial no.”,  
         [0072]     4) “wb(r)”,  
         [0073]     5) “wb(b)”,  
         [0074]     6) “ownership  
         [0075]     7) “spec”,  
         [0076]     8) “expiration”,  
         [0077]     9) “registered date &amp; time”,  
         [0078]     10) “used date &amp; time”,  
         [0079]     11) “count”.  
         [0080]     “register no.” is utilized for identifying the record. In the present embodiment, a serial number from 1 to 39 is assigned to the records.  
         [0081]     “scope name”, “serial no.”, “wb(r)” and “wb(b)”, “ownership”, “spec”, and “expiration”, are items same as that in the EEPROM  102 .  
         [0082]     “registered date &amp; time” is the date and time when the electronic endoscope  100  is connected to the processor  200  for the first time. “registered date &amp; time” includes six figures date information and four figures time information. If “registered date &amp; time” is set to “021015.1424”, for example, then it represents Oct. 15, 2002, 2:24 p.m.  
         [0083]     “used date &amp; time” is the date and time when the electronic endoscope  100  was connected to the processor  200 , or used, for the last time. The format of “used date &amp; time” is the same as that of “registered date &amp; time”.  
         [0084]     “count” is the number of times the electronic endoscope  100  is connected to the processor  200 , or used. This variable may be used as an indication of the frequency the endoscope is used.  
         [0085]      FIG. 5  is a flow chart showing a main routine of the operation of the processor  200  according to an embodiment of the invention.  
         [0086]     At first, the CPU  201  of the processor  200  initializes a variable “current_scope” to 0 (S 100 ). The variable “current_scope” is for storing the “register no.” of the record in which the data of the endoscope currently connected to the processor  200  is stored. If 0 is assigned to “current_scope”, it represents that no endoscope is currently connected to the processor  200 .  
         [0087]     After the initialization of “current_scope”, the CPU  201  remains in an idle state until the electronic endoscope  100  is connected to the processor  200 (S 102 ).  
         [0088]     When the electronic endoscope  100  is connected to the processor  200  (S 102 : Yes), the CPU  201  accesses the EEPROM  102  of the electronic endoscope  100  and obtains the data stored therein (S 104 ). Next, the first and second signal processors  204 ,  205  transform the output signal from the CCD  104  into video signal to display the image captured by the CCD on the monitor  300  (S 106 ).  
         [0089]     Then, the CPU  201  executes a subroutine DISPLAY SCOPE NAME to display the information of the electronic endoscope  100  currently connected to the processor  200  on the monitor  300  (S 108 ). Then, a subroutine ENDOSCOPE REGISTRATION is executed to store the data obtained from the EEPROM  102  into the database established in the memory  208  (S 110 ).  
         [0090]     Next, the white balance of the image captured by the CCD  104  of the electronic endoscope  100  is adjusted using the calibration value (“wb(r)”, “wb(b)”) obtained form the EEPROM  102  (S 112 ). That is, the CPU  201  sends the calibration value of “wb(r)” and “wb(b)” to the second signal processor  205  so that the second signal processor  205  adjusts the color balance of the image signals generated there.  
         [0091]     After S 112 , the processor watches whether the electronic endoscope  100  is still connected, and as long as the electronic endoscope  100  is still connected to the processor  200  (S 114 :Yes), the processor  200  displays the current date and time on the monitor  300  by executing a subroutine DISPLAY DATE &amp; TIME (S 116 ), and also performs various kinds of adjustments in accordance with manual operation by the operator by executing a subroutine ADJUSTMENT (S 118 ).  
         [0092]     If the electronic endoscope  100  is disconnected from the processor  200  (S 114 :No), the operation of the processor  200  returns to S 100 .  
         [0093]      FIG. 6  is a flow chart showing the subroutine DISPLAY SCOPE INFORMATION called in S 108  of the main routine shown in  FIG. 5 .  
         [0094]     In this routine, the CPU  201  sends the alphanumeric characters of the “scope name” obtained from the EEPROM  102  to the CRT controller  206  to superimpose the type of the electronic endoscope  100  on the image captured by the CCD  104  and displayed on the monitor  205  (S 152 ). The CPU  201  also generates a text information that corresponds to the specifications of the electronic endoscope indicated by “spec” and sends it to the CRT controller  206 . Thus, the specifications of the electronic endoscope  100  are also superimposed on the image captured by the CCD  102  (S 154 ). Note that other information obtained from the EEPROM  102  such as serial number and data on white balance may also be superimposed on the image displayed by the monitor  300  instead of or together with the scope type and specifications of the electronic endoscope  100 .  
         [0095]     Next, the CPU  201  decides whether the currently connected endoscope is a purchased one or a leased one. This is done by checking the value of “ownership” obtained from the EEPROM  102  (S 156 ).  
         [0096]     If “ownership” indicates the endoscope is leased, i.e., “ownership”=1 or 2, then the CPU  201  sends a command to the CRT controller  206  to superimpose characters “lease” on the image displayed on the monitor  300 . Thus, the operator can notice that the currently used endoscope is a leased one (S 158 ). Note that the date of expiration of the term of lease may also be displayed on the monitor  300 .  
         [0097]     If “ownership”, however, indicates that the endoscope is purchased, i.e., “ownership”=0, then S 158  is skipped, and the operation of the processor  200  returns to the main flow shown in  FIG. 5 .  
         [0098]      FIG. 7  is a flow chart showing the subroutine ENDOSCOPE REGISTRATION called in S 110  of the main routine of  FIG. 5 .  
         [0099]     In this routine, the CPU  201  decides whether or not the data related to the currently connected endoscope is already registered with the database in the memory  208  (S 202 ). This is achieved by searching within the memory  208  for a record including data that matches the “scope name” and “serial no.” obtained from the EEPROM  102 .  
         [0100]     If there is a record including the above mentioned data (S 202 :Yes), it means the data of the electronic endoscope  100  currently connected is already registered. In this case, the “register no.” of the record found is set to “current_scope” (S 204 ) and the operation of the processor  200  proceeds to S 220  which will be described later.  
         [0101]     If a record including the above mentioned data is not found (S 202 :No), it means the electronic endoscope  100  is not yet registered. In this case, the CPU  201  checks whether there is still any available memory space, or open records, within the memory  208  to store the data obtain from the EEPROM  102  (S 206 ).  
         [0102]     In the case there is still an open record (S 206 :Yes), the “register no.” of the open record is set to “current scope” (S 212 ). If there are more than one open records, the smallest “register no.” is preferably selected and set to the “current scope”. After execution of S 212 , the operation of the processor  200  proceeds to S 216  which will be described later.  
         [0103]     In the case no open record is found (S 206 :No), then the CPU  201  checks the term of lease, or “expiration”, of each record in the memory  208  (S 208 ). If CPU  201  finds any records of which term of lease has already expired (S 208 :Yes), then the CPU  201  deletes the data of that record except the register number (S 210 ), since such data are not valid and therefore should not remain in the database. Then, the record deleted at S 210  became an open record. Further, the CPU  201  sets the register number of the record to “current_scope” (S 212 ).  
         [0104]     If there is no record having an expired term of lease (S 208 :No), then a subroutine SELECT DATA is executed to select one of the records to be freed up for storing the data of the new endoscope (S 214 ). During this subroutine, the register number of the record freed up is set to “current_scope” as will be described later.  
         [0105]     After the execution of S 212  or S 214 , the CPU  201  stores the data obtained from EEPROM  102 , into the record identified by “current_scope” (S 216 ). Specifically, the CPU  201  stores “serial no.”, “scope name”, “wb(r)”, “wb(b)”, “ownership”, “spec”, and “expiration” obtained from the EEPROM  102  into the record. In this manner, the data of the new endoscope is automatically registered with the database.  
         [0106]     It should be noted that instead of data obtained from the EEPROM  102 , data manually inputted from the keyboard  400  may be stored into the record specified by “current_scope” so that, for example, data of endoscopes that do not have memories can also be registered to the processor  200 .  
         [0107]     Next, the CPU  201  obtains the current date and time information from the RTC  209  and stores it in “registered date &amp; time” of the record specified by “current_scope” (S 218 ). This is to make a record of the date and time of registration of the new electronic endoscope  100 .  
         [0108]     After the execution of S 218  or S 204 , “used date &amp; time” and “count” of the record specified by “current scope” are updated. That is, the current time information obtained from the RTC  209  is overwritten to “used date &amp; time” (S 220 ), and “count” is incremented by one (S 222 ). After S 222 , the operation of the processor  200  returns to the main flow shown in  FIG. 5 .  
         [0109]      FIG. 8  is a flow chart showing the subroutine SELECT DATA called in S 214  of the subroutine ENDOSCOPE REGISTRATION of  FIG. 7 . In this subroutine, one record is selected to free up and thereby prepare an open record for storing new data obtained from the currently connected electronic endoscope  100 . Records including data of leased endoscopes is selected in preference to other records, and records of endoscopes leased for short terms are selected in further preference to records of endoscopes leased for long terms. Thus, data of endoscopes that the user owns or can keep for a longer time tend to remain in the database.  
         [0110]     Specifically, the CPU first checks whether there are any records including data of an endoscope leased for a snort term, i.e. “ownership”=2 (S 252 ). If there are any (S 252 :Yes), then the CPU  201  select the record having the oldest “registered date &amp; time” among those records (S 254 ), since the term of lease of such endoscope expires first.  
         [0111]     If there isn&#39;t any record of which “ownership” is 2 (S 252 :No), then the CPU  201  searches for records related to endoscopes leased for long terms, i.e., “ownership”=1 (S 256 ). If there are any (S 256 :Yes), then the CPU  201  selects the record having the oldest “registered date &amp; time” among those records this time also (S 258 ).  
         [0112]     If there isn&#39;t any record of which “ownership” is 1 (S 256 :No), i.e., if there isn&#39;t any endoscopes leased, then the CPU  201  selects the record having the oldest “registered date &amp; time” among the records including data of purchased endoscope (S 260 ).  
         [0113]     After the execution of S 254 , S 258 , or S 260 , the data of the selected record is deleted except “register no.” (S 262 ). Further, the “register no.” of the selected record is set to “current_scope” (S 264 ). After S 264 , the operation of the processor  200  returns to the subroutine ENDOSCOPE REGISTRATION shown in  FIG. 7 .  
         [0114]      FIG. 9  is a flow chart showing the subroutine DISPLAY DATE &amp; TIME called in S 116  of the main routine shown in  FIG. 5 .  
         [0115]     In this subroutine, the CPU  201  checks whether or not the date and time information of a variable “date &amp; time” indicates the exact time by comparing “date &amp; time” with the date and time information from the RTC  209  (S 302 ).  
         [0116]     If the difference between the two pieces of the date and time information is less than a second, then the CPU  201  decides the two pieces of the date and time information are same (S 302 :Yes). In this case, the operation of the processor  200  immediately returns to the main flow of  FIG. 5  without updating the “date &amp; time”.  
         [0117]     If the difference between the two pieces of date and time information is not less that one second (S 302 :No), then the date and time information from the RTC  209 , or the current date and time, is set to “date &amp; time” (S 304 ). Then, the CPU  201  generates text information indicating the date and time stored in “date &amp; time” such as “May 21, 2002, 15:20:31”, for example, and sends it to the CRT controller  206  to superimpose the current date and time on the image displayed by the monitor  300  (S 306 ). In this manner, time information displayed is updated every second.  
         [0118]     After the execution of S 306 , the operation of the processor  200  returns to the main flow shown in  FIG. 5 .  
         [0119]      FIG. 10  is a flow chart showing the subroutine ADJUSTMENT called in S 118  of the main routine shown in  FIG. 5 . This routine is for allowing the operator to manually adjust the white balance of the image captured by the CCD  104 , and the opening size of the diaphragm  210 .  
         [0120]     In this routine, the CPU  201  decides whether or not the adjustment of white balance is requested by checking the signals from the keyboard  400 , the operation panel  207 , and the operation buttons  107  (S 352 ). If there is a request (S 352 :Yes), then the CPU  201  rewrites the value of the “wb(r)”, “wb(b)” in the record specified by “current scope” in accordance with the signal from the keyboard  400 , the operation panel  207 , or the operation buttons  107  (S 354 ). Further, the CPU  201  sends the value of latest “wb(r)” and “wb(b)” to the second signal processor  205  so that the second signal processor  205  re-adjusts the white balance of the image generated there (S 356 ).  
         [0121]     After the execution of S 356  or in the case there isn&#39;t any request for white balance adjustment (S 352 :No), the CPU  201  checks again the output signals from the keyboard  400 , the operation panel  207 , and the operation buttons  107  to decide whether or not the adjustment of diaphragm size is requested (S 358 ).  
         [0122]     If there is a request (S 358 :Yes), then the CPU  201  opens/closes the diaphragm  210 , via the diaphragm controller  211 , in accordance with the request from the keyboard  400 , the operation panel  207 , or the operation buttons  107  to control the amount of light introduced into the light guide  103  (S 360 ).  
         [0123]     If the execution of S 360  is completed or in the case there isn&#39;t any request (S 358 :No), the operation of the processor returns to the main flow of  FIG. 5 .  
         [0124]     It should be noted that the operation of processor  200  described in  FIG. 5  through  FIG. 10  may be modified in many ways within the scope of the invention.  
         [0125]     For example, S 254 , S 258 , and S 260  in the subroutine SELECT DATA shown in  FIG. 8  may be replaced with steps that selects the record including the oldest mused date &amp; times instead of the oldest “registered date &amp; time” as shown in  FIG. 11  (see S 254 *, S 258 *, and S 260 *). If S 254 , S 258 , and S 260  are replaced with S 254 *, S 258 *, and S 260 *, respectively, the data related to the endoscope seldom used, and may have not high possibility to be used again in the future, is deleted to free up the memory space for registering data of the new endoscope.  
         [0126]      FIG. 12  shows a flow chart of the operation of the processor  200  when the electronic endoscope is connected according to another embodiment of the invention.  
         [0127]     In this embodiment, the processor  200  first obtains the data stored in the EEPROM  102  of the electronic endoscope  100  (S 302 ). A part of or all of the data obtained are displayed on the monitor  300  if a predetermined command is inputted to the keyboard  400 , operation panel  207 , or the operation buttons  107  so that the operator can confirm the data of the electronic endoscope  100  (S 304 , S 306 ).  
         [0128]     Next, the processor  200  decides whether the currently connected electronic endoscope  100  is already registered with the database in the memory  208  by searching for a record including the “serial no.” and “scope name” that matches those obtained from the electronic endoscope  100  (S 308 ).  
         [0129]     If there is a record including the same data (S 308 :Yes), which indicates the currently connected electronic endoscope  100  is already registered, then the operation of the processor  200  proceeds to S 324  and S 326  which will be described later.  
         [0130]     If, however, there isn&#39;t any record including same data (S 308 :No), that is, the currently connected electronic endoscope  100  is a new one, the processor  200  displays a message asking the operator whether or not the new electronic endoscope  100  should be registered with the database, and accepts an instruction from the operator via the keyboard  400 , the operation panel  207 , or the operation buttons  107  (S 310 ).  
         [0131]     If the operator inputs an instruction not to register the new electronic endoscope  100   e , the processor exits the present routine. If an instruction to register the new electronic endoscope  100  is inputted, then the processor  200  checks whether the database established in the memory  208  is full or not (S 312 ). This is achieved by counting the number of endoscopes already registered with the database. If the number is less than 39, which means the database is not yet full (S 312 :No), then the processor  200  stores the endoscope data obtained in S 302  into an open record in the memory  208  (S 314 ). Note that, in S 314 , the processor  200  may display the content of the database and let the operator select the open record into which the data should be stored.  
         [0132]     In the case the database in the memory  208  is full (S 312 :Yes), that is, 39 endoscopes are already registered with the database, the processor  200  displays a message on the monitor asking whether the data of one of the registered endoscopes should be replaced with that of the new endoscope, and accepts an instruction from the operator via the keyboard  400 , operation panel  207 , or the operation button  107  (S 316 ).  
         [0133]     If an instruction not to replace data is accepted, the processor  200  exits the present routine without registering the new endoscope with the database (S 316 :No).  
         [0134]     If an instruction to replace data is accepted (S 316 :YES), then the processor  200  displays the content of the database in the memory  208  on the monitor  300  and lets the operator select the record, or the registered endoscope, of which data should be replaced (S 318 ). Thus, the operator can select the endoscope to be canceled by comparing the data, such as “ownership”. “spec”, and “expiration”, of each registered endoscope and inputting the register number of one from the keyboard  400 , for example.  
         [0135]     Next, the processor  200  deletes the data in the record corresponding to the register number inputted, except the register number itself, and stores the data obtained from the EEPROM  102  of the electronic endoscope  100  (S 320 ).  
         [0136]     After performing S 314  or S 320 , the processor  200  stores the current date and time outputted from the RTC  209  into the “registered date &amp; time” of the record into which the processor  200  has just stored the data in S 314  or S 320  (S 322 ).  
         [0137]     The processor  200  also set the current date and time obtained from the RTC  209  into the “used data &amp; time” of the record which includes the data of the currently connected endoscope  100  (S 324 ). Further, the processor  200  increments “count” of the same record (S 326 ) and exits the present routine.  
         [0138]      FIG. 13  schematically shows a modified configuration of the electronic endoscope system  1  of  FIG. 1 . Note that the electronic endoscope system of  FIG. 13  is essentially same as the system of  FIG. 1  except the points described hereinafter.  
         [0139]     The modified electronic endoscope system  1   a  of  FIG. 13  has a switch device  106  which is provided to the connector  130  of the endoscope  100 . The switch device  106  is configured to memorize, by its state, a part of the information that is stored in the EEPROM  102  in the electronic endoscope system  1  of  FIG. 1 . In the present case, the switch device  106  memorizes information related to the ownership, the specifications and the expiration of the endoscope  100 . Other information on the endoscope  100  that are recited in  FIG. 2  are stored in the EEPROM  102  as in the system of  FIG. 1 . The processor  200  obtains the information of the endoscope  100  partly from the EEPROM  102  and partly from the switch device  106 , by checking the state of the switch device  106 , and stores those data into the memory  208  if the endoscope  100  is a new one.  
         [0140]     The switch device  106  includes four switch elements  106   a ,  106   b  and  106   c  such as dip switches each having ON and OFF states. However, two or more rotary switches having many states may also be used for switch elements  106   a ,  106   b  and  106   c  instead of dip switches.  
         [0141]     The state of first and second switch elements  106   a  and  106   b  represents information related to the ownership of the endoscope  100 . For example, if the states of first and second switch elements  106   a  and  106   b  are both OFF, it indicates the endoscope is a purchased one. If the first switch element  106   a  is OFF while the second switch element  106   b  is ON, the endoscope  100  is leased for a long term. Further, if the first switch element  106   a  is ON while the second switch element  106   b  is OFF, the endoscope  100  is leased for a short term.  
         [0142]     The state of the third switch element  106   c  indicates the specifications of the endoscope. That is, the third switch element  106   c  Is set ON for the endoscope  100  of standard specifications, and OFF for the endoscope  100  having special specifications.  
         [0143]     The switch device  106  further includes a fourth switch element  106   d  for setting the expiration date of the lease of the endoscope. The fourth switch element  106   d  may be a rotary switch by which the date month and year of expiration can be set up.  
         [0144]     The switch device  106  further includes a switch state detector  105  which is connected to each of the switch elements  106   a ,  106   b ,  106   c  and  106   d  via a cable  105   a . The switch state detector  105  generates signals corresponding to the states of the switch elements and outputs it to the CPU  201  via the signal cable  108 .  
         [0145]     A watertight cover member  110  is also provided detachably to the connector  130  to prevent the switch elements  106   a - 106   d  from being operated unintentionally.  
         [0146]     It should be noted that the switch state detector  105  may be replaced with a plurality of I/O ports, each connected to different one of the switch elements  106   a - 106   d . In this case, the CPU  201  itself detects the state of each switch elements  106   a - 106   d  via the I/O ports to obtain information related to the ownership, the specifications and the expiration of the endoscope  100 .  
         [0147]     It should be also noted that the switch device  106  may be provided to the operation portion  120  of the endoscope  100  instead of to the connector  130 .  
         [0148]     The present disclosure relates to the subject matters contained in Japanese Patent Application No. P2001-206644, filed on Jul. 6, 2001, and Japanese Patent Application No P2001-263445, filed on Aug. 31, 2001, which are expressly incorporated herein by reference in their entireties.