JP2005312718A - Light source device for electronic endoscope and electronic endoscope system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make brightness of images displayed on a TV monitor constant automatically in cases of changing the kind of electronic endoscopes connected to a processor. <P>SOLUTION: The processor 14 is connectable to a variety of electronic endoscopes and is equipped with a light source 30 and an aperture 31 or the like. The light source 30 emits light, and the aperture 31 adjusts the amount of the light. A CCD 20 captures a subject image by the light from the light source 30, converts the subject image into image signals, and outputs the image signals to the TV monitor 15 through a signal processing circuit 33. A second CPU 34 determines the type of the electronic endoscope connected to the processor 14 and sets a luminance coefficient corresponding to the determined type. The second CPU 34 acquires a correction luminance coefficient by multiplying a luminance value of the image signal by the luminance coefficient. The second CPU 34 adjusts the luminance value of the image signals by adjusting the opening γ of the aperture 31 from the correction luminance value and adjusts the brightness of the images output to the monitor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light source device for an electronic endoscope and an electronic endoscope system, and in particular, a light source device for an electronic endoscope to which a plurality of types of electronic endoscopes can be connected, and the light source device for the electronic endoscope. And an electronic endoscope system including a plurality of types of electronic endoscopes.

  An electronic endoscope (electronic scope) has a solid-state image sensor at its tip, and a subject image captured by the solid-state image sensor is converted into an image signal, and this image signal is predetermined in the electronic endoscope. After the signal processing is performed, the signal is input to the processor (light source device for electronic endoscope). In the processor, the image signal is further subjected to predetermined image processing and the like, sent to the TV monitor, and displayed as an image on the TV monitor.

Conventionally, in order to make the brightness of an image displayed on a TV monitor constant, as described in Patent Document 1, for example, by adjusting an electronic shutter speed in a solid-state imaging device having an electronic shutter function or adjusting an aperture of a light source device It is known to adjust the amount of illumination light and set the output value (luminance value) of the image signal to a reference value (a constant value).
JP-A-7-39514

  By the way, there are various types of electronic endoscopes, for example, for bronchial, lower gastrointestinal tract, duodenum, upper gastrointestinal tract, etc., and the processor is connected to such multiple types of electronic endoscopes. Is possible.

  However, depending on the type of electronic endoscope, the lens, color filter, viewing angle, observation depth, etc. differ, and the appearance of the image displayed on the TV monitor depends on the electronic endoscope connected to the light source device. May be different. That is, when the output value (luminance value) of the image signal output to the TV monitor is set to the reference value (a constant value), the apparent brightness of the video is not always the same.

  Even when the endoscope types are the same (that is, the endoscope has the same lenses, etc.) and the brightness value is set to a constant value, the brightness is perceived by each person. Depending on the user, the apparent brightness may be different.

  Therefore, when connecting a plurality of electronic endoscopes to the processor, it is necessary to manually change the reference value of the luminance value in the processor in order to make such apparent brightness the same. However, it is complicated to manually change the reference value every time the type of electronic endoscope connected to the processor is changed.

  Therefore, the present invention has been made in view of such problems, and even if the connected electronic endoscope is changed, it is not necessary to manually change the reference value of the luminance value. An object of the present invention is to provide a mirror light source device and an electronic endoscope system.

  An electronic endoscope system according to the present invention is connectable to a plurality of electronic endoscopes, and a light source device for an electronic endoscope to which one electronic endoscope is connected from the plurality of electronic endoscopes And a conversion means for converting a subject image captured by the connected electronic endoscope into an image signal, and the connected electronic endoscope are discriminated, and a correction value corresponding to the discriminated electronic endoscope is set. Correction value setting means, correction brightness value calculating means for calculating the correction brightness value by applying the correction value to the brightness value of the image signal by addition / subtraction / division / calculation, and conversion from the subject image based on the correction brightness value Brightness adjusting means for adjusting the brightness value of the image signal, and output means for outputting the image signal whose brightness value has been adjusted to a monitor.

  The converting means converts the subject image into at least first and second image signals in time series, and when the first and second image signals are sequentially output to the monitor, the corrected luminance value calculating means The correction value is applied to the luminance value of one image signal by at least one of addition / subtraction / multiplication / division calculation to obtain a correction luminance value, and the luminance adjusting means further determines the second image signal based on the correction luminance value. Adjust the brightness value. Preferably, the brightness adjusting means adjusts the brightness value of the image signal by adjusting the aperture of the light source of the light source device.

  The brightness adjusting means preferably adjusts the brightness value so that the corrected brightness value matches a predetermined reference value. When the light source device can be connected to a plurality of types of electronic endoscopes, the correction value setting means determines the type of electronic endoscope connected to the light source device, and the correction value according to the determined type Set.

  The correction value is preferably stored in a memory provided in the light source device. The correction value may be calculated by dividing a predetermined constant according to the determined electronic endoscope by a predetermined constant, and the predetermined value may be stored in a memory provided in the light source device.

  The electronic endoscope captures a subject image with a solid-state imaging device, and the luminance value of the image signal is a luminance value obtained by one method selected from at least two different methods from the luminance value of each pixel of the solid-state imaging device. In this case, the correction value is preferably different depending on the selected method.

  The electronic endoscope captures a subject image with a solid-state image sensor, and the luminance value of the image signal is an average value of luminance values of each pixel of the solid-state image sensor, an average value of luminance values of pixels near the center of the solid-state image sensor, and When the selected luminance value is one of the highest luminance values among the luminance values of each pixel of the solid-state imaging device, the correction value may be different depending on the selected luminance value.

  Each of the plurality of electronic endoscopes has specific data corresponding to each electronic endoscope, the connected electronic endoscope transmits specific data to the light source device, and the correction value setting means transmits the specific data transmitted Thus, it is preferable to determine the connected electronic endoscope.

  A second electronic endoscope system according to the present invention can be connected to a plurality of electronic endoscopes, and one electronic endoscope is connected to the plurality of electronic endoscopes. The light source device, the conversion means for converting the subject image captured by the connected electronic endoscope into an image signal, the connected electronic endoscope is discriminated, and the correction according to the discriminated electronic endoscope A correction value setting means for setting a value, a correction reference value calculation means for calculating a correction reference value by applying the correction value to a predetermined reference value by addition / subtraction / multiplication / division calculation, and a luminance value of the image signal as a correction reference value And a brightness adjusting means for adjusting the brightness value so as to match, and an output means for outputting an image signal whose brightness value has been adjusted to a monitor.

  A light source device according to the present invention is a light source device for an electronic endoscope that can be connected to a plurality of electronic endoscopes, and one electronic endoscope is connected from the plurality of electronic endoscopes. The conversion means for converting the subject image captured by the connected electronic endoscope into an image signal and the connected electronic endoscope are discriminated, and a correction value corresponding to the discriminated electronic endoscope is set. A correction value setting means, a correction brightness value calculating means for calculating a correction brightness value by applying the correction value to the brightness value of the image signal by addition / subtraction / division / calculation, and a conversion from the subject image based on the correction brightness value The image processing apparatus includes a luminance adjusting unit that adjusts a luminance value of the image signal and an output unit that outputs the image signal with the adjusted luminance value to a monitor.

  The second light source device according to the present invention is connectable to a plurality of electronic endoscopes, and the light source device for an electronic endoscope to which one electronic endoscope is connected from the plurality of electronic endoscopes. The conversion means for converting the subject image captured by the connected electronic endoscope into an image signal, the connected electronic endoscope is discriminated, and the correction value corresponding to the discriminated electronic endoscope Correction value setting means for setting the correction value, a correction reference value calculating means for calculating the correction reference value by applying the correction value to the predetermined reference value by addition / subtraction / multiplication / division calculation, and the luminance value of the image signal as the correction reference value It is characterized by comprising brightness adjusting means for adjusting the brightness value so as to match, and output means for outputting an image signal whose brightness value has been adjusted to a monitor.

  As described above, according to the present invention, even if the electronic endoscope connected to the electronic endoscope light source device is changed, the apparent brightness of the image output to the monitor can be made constant. it can.

  Embodiments according to the present invention will be described below in detail with reference to FIGS.

  FIG. 1 is a schematic diagram of an electronic endoscope system to which an embodiment of the present invention is applied. The electronic endoscope system includes an electronic endoscope (electronic scope) 10, a processor (light source device for electronic endoscope) 14, and a TV monitor 15. The electronic endoscope 10 includes an insertion unit 11 for insertion into a body cavity and an operation unit 12 for a user to hold and operate the electronic endoscope 10. A connecting tube 17 is connected to the operation unit 12, and a connecting unit 13 is provided at the tip of the connecting tube 17.

  The electronic endoscope 10 is connected to the processor 14 via the connection unit 13. The processor 14 processes the image signal sent from the electronic endoscope 10 and then functions as a video processor that outputs the image signal to the TV monitor 15, and has a light source (not shown) and a light source device. Also plays a role as. A keyboard 16 and a panel switch 18 are further connected to the processor 14. The panel switch 18 is provided with, for example, a brightness setting switch and a mode setting switch. When the brightness setting switch is operated, a reference luminance value (aer) to be described later is changed, so that the brightness of the image displayed on the TV monitor 15 is changed. Further, when the mode setting switch is operated, a luminance value calculation mode to be described later is changed.

  The processor 14 can be connected to a plurality of types of electronic endoscopes 10 via the connection unit 13. There are various types of electronic endoscopes connected to the processor 14, such as bronchial, lower gastrointestinal tract, duodenum, and upper gastrointestinal endoscopes.

  FIG. 2 shows an electrical configuration of the electronic endoscope system according to the present embodiment. The electronic endoscope 10 includes a solid-state imaging device (CCD) 20, a first CPU 23, and a light guide 21. The solid-state imaging device 20 is provided at the distal end portion of the insertion portion 11 (see FIG. 1). The light guide 21 is inserted from the connection portion 13 to the distal end portion of the insertion portion 11 through the connecting tube 17 and the operation portion 12 (see FIG. 1). The first CPU 23 transmits / receives various data to / from the second CPU 34 provided in the processor 14 by serial communication.

  The second CPU 34 provided in the processor 14 has an RTC (Real Time Clock) 35 and an EEPROM (nonvolatile memory) 36, reads the date and time from the RTC 35, and reads the date and time via a CRTC (CRT controller) 37. It is displayed on the TV monitor 15. The second CPU 34 displays various character information (patient name, age, sex, doctor name, etc.) stored in the EEPROM 36 or the like on the TV monitor 15 via the CRTC 37. A panel switch 18 and a keyboard 16 are connected to the second CPU 34.

  The processor 14 has a light source 30, and the light source 30 is optically connected to one end of the light guide 21. Illumination light from the light source 30 passes through the light guide 21 and is emitted from the other end of the light guide 21, and is irradiated, for example, to an internal organ officer. A diaphragm 31 is provided between the light source 30 and one end of the light guide 21 to adjust the amount of illumination light supplied to the light guide 21. The opening degree of the diaphragm 31 is adjusted by the diaphragm adjustment circuit 32 as will be described later, whereby the light quantity of the light source 30 is adjusted by the diaphragm 31.

The aperture of the diaphragm 31 is adjusted to γ ₁ , γ ₂ , γ ₃ ,..., Γ _n ,. Its opening _{γ 1, γ 2, γ 3} , ···, γ n, subject image captured using an adjusted light ... are sequentially depending 1 in the solid-state imaging device 20, the second, third 3,..., N,. That is, first, second, third, ..., the luminance value of the n, ... of the image signal, opening gamma ₁ respectively, gamma _2, gamma _3,..., Gamma _n, · · It is adjusted by the diaphragm 31.

  The first, second, third,..., N,... Image signals converted by the solid-state imaging device 20 are input to a signal processing circuit 33 provided in the processor 14. In the signal processing circuit 33, the input image signal is subjected to predetermined signal processing, and the processed image signal is sequentially output to the TV monitor 15 and displayed on the TV monitor 15 as an image. The signal processing circuit 33 sends the processed image signal to the TV monitor 15 and outputs the luminance signal of the processed image signal to the second CPU 34. Here, since the image signal is sequentially input to the signal processing circuit 33 for each field, the luminance signal is also sequentially output to the second CPU 34 for each field.

  The first, second, third,..., N,... Luminance signals sequentially input to the second CPU 34 for each field are based on the magnitude (luminance value (aey)). An aperture signal related to the aperture γ of the aperture 31 is output to the aperture adjustment circuit 32.

A method of adjusting the opening of the diaphragm 31 will be described in detail below by taking the (n + 1) th image signal as an example. The n-th image signal input to the signal processing circuit 33 is subjected to predetermined signal processing as described above. Of the n-th image signal that has undergone predetermined signal processing, the n-th luminance signal is input to the second CPU 34, and the second CPU 34 determines the magnitude of the n-th luminance signal (luminance value (aey _n )). ) Is calculated. The luminance value (aey _n ) is multiplied by a luminance coefficient P (correction value) and converted to a corrected luminance value (pay _n ). The corrected luminance value (paey _n ) is compared with the reference luminance value (aer), and the opening γ _{n + 1} of the diaphragm 31 when generating the (n + 1) th image signal is determined by the equation (1). Here, the opening γ is adjusted in the range of 0 to 1. When the opening γ = 1, it indicates that the throttle 31 is fully open, and when γ = 0, the throttle 31 is completely closed. It shows that.

γ _{n + 1} = γ _n × (aer / paey _n ) (1)
However, pay _n = P × aey _n
Note that payn _n = corrected luminance value in the _n -th image signal
γ _n = aperture opening when the _n -th image signal is generated

Note that the luminance value (aey _n ) is an average value of luminance values of the pixels of the solid-state imaging device 20 in the n-th image signal (hereinafter referred to as an average luminance value), or a luminance value of the pixels of the solid-state imaging device 20. It is either the highest luminance value (hereinafter referred to as peak luminance value) or the average value of the luminance values of pixels near the center of the solid-state imaging device 20 (hereinafter referred to as center weighted luminance value). Which luminance value is selected is determined by the user according to the mode selected in the panel switch 18 described above. That is, if the average luminance value calculation mode is selected, the average luminance value is selected as the luminance value (ayy). If the peak luminance value calculation mode is selected, the peak luminance value is selected as the luminance value (ayy). Calculated.

The luminance value is set with 8 bits (0 to 255). On the other hand, the reference luminance value is a value with which the corrected luminance value should be matched, and is set by 8 bits, for example, 120. Wherein if is the same as the corrected luminance value is a reference brightness value, the degree of opening of the aperture 31 as shown in equation (1) need not be particularly adjusted, opening gamma _{n + 1} is the n It remains the same as the opening degree γ _n when generating the image signal. However, for example, when the correction luminance value is smaller than the reference luminance value (120), aer / paey _n in formula (1) becomes larger than 1, the opening degree γ becomes large. On the other hand, when the corrected luminance value becomes larger than the reference luminance value, the opening degree γ decreases. That is, the light amount of the light source 30 is adjusted so that the corrected luminance value of the output value of each image signal matches the reference luminance value.

The first, second,..., N,... Image signals corresponding to the subject image are sequentially output to the monitor. Here, each image signal is originally output to a TV monitor if the diaphragm 31 is accurately adjusted and the amount of light is adjusted so that the luminance value (aey _n ) matches the reference luminance value (aer). The apparent brightness (brightness) of the image should be appropriate. That is, the opening degree of the diaphragm 31 should be adjusted by the equation (1 ′).
γ _{n + 1} = γ _n × (aer / aey _n ) (1 ′)

  However, a plurality of types of electronic endoscopes 10 are connected to the processor 14, and for example, lenses used, color filters, and the like differ depending on the types. Therefore, the apparent brightness of the video displayed on the TV monitor 15 varies depending on the type of electronic endoscope connected, and the video displayed on the TV monitor feels bright or dark. That is, even when the brightness value of each image signal is adjusted to match the reference brightness value (120), the brightness of the image displayed on the TV monitor 15 is the same for any electronic endoscope 10. It is not always visible. In addition, it is necessary to consider the difference in how the doctors who are users feel about the brightness.

Therefore, in this embodiment, and characterized by using a Paey _n instead of AEy _n as the brightness of the apparent that varies according to the type of the connected electronic endoscope to the processor 14, it can be made constant To do.

That is, in the present embodiment, the luminance coefficient P is set according to the type of electronic endoscope connected to the processor, and the luminance coefficient P is multiplied by each luminance value (ay _n ) to obtain a corrected luminance value (paey). _n ) is required. Then, the opening γ of the diaphragm 31 is adjusted so that the corrected luminance value matches the reference luminance value.

  Here, the luminance coefficient P is determined according to the apparent brightness. For example, when the apparent brightness displayed on the TV monitor is bright even though the output value of the image signal is the same as the reference brightness value, the brightness coefficient P is 1 in order to suppress the output value of the image signal. Set as above. On the other hand, when the apparent brightness is dark, the luminance coefficient P is set to 1 or less in order to increase the output value of the image signal. Thereby, in this embodiment, the apparent brightness resulting from the difference in the kind of electronic endoscope can be maintained appropriately, and the user does not operate the brightness setting switch of the panel switch 18 by himself / herself. It is possible to observe an image with appropriate brightness.

  The method for setting the luminance coefficient P will be described in further detail with reference to FIG. FIG. 3 is a diagram showing a table stored in the EEPROM 36. The EEPROM 36 stores values for luminance variables (aec) corresponding to the electronic endoscope type data, as well as the electronic endoscope type data. Here, the electronic endoscope type data is EB, EC, ED, EG, Others, and the types of electronic endoscope are bronchial, lower gastrointestinal tract, duodenum, upper gastrointestinal tract, and other electronic endoscopes, respectively. Indicates that it is an endoscope. In the present embodiment, as shown in FIG. 3, the value of the brightness variable (aec) varies depending on whether the brightness value is selected from the average brightness value, the center-weighted brightness value, or the peak brightness value.

  When the electronic endoscope 10 is connected to the processor 14, it is determined which type of electronic endoscope the connected electronic endoscope 10 is. Here, it is determined whether the electronic endoscope is for bronchial, lower digestive tract, duodenum, upper digestive tract, or other electronic endoscope. When the type of the electronic endoscope is determined, the type of the electronic endoscope and the value for the luminance variable (aec) corresponding to the luminance value calculation mode are read from the EEPROM 36. Therefore, for example, when the connected electronic endoscope is for bronchi and the luminance calculation mode is the average luminance calculation mode, 130 is read as a value for the luminance variable.

  Note that the processor 14 determines the type of the electronic endoscope 10 connected based on the serial number (specific data) transmitted from the electronic endoscope 10, for example. Here, even if the serial number is the same type, the number is different if the electronic endoscope is different. However, if the first digit of the serial number is the same, for example, the type is the same even if the serial number is different, so that the type of electronic endoscope can be determined. That is, for example, the serial number is represented as b20975. Of these, b indicates the type of electronic endoscope, and thus the processor 14 can determine the type of electronic endoscope.

  The luminance variable is set to 65 to 255 according to the characteristics of the electronic endoscope. The EEPROM 36 stores 128, which is a constant for dividing the luminance variable and is the center value of an 8-bit numerical value. Here, the luminance variable is divided by this constant 128 to become a luminance coefficient P (correction value). That is, P = aec / 128. Therefore, the luminance coefficient P is substantially stored in the EEPROM 36.

  For example, if the apparent brightness of the image displayed on the TV monitor becomes too bright even though the brightness value matches the reference brightness value (for example, 120), the brightness variable is set to be greater than 128. On the other hand, when the apparent brightness of the image displayed on the TV monitor becomes too dark even though the brightness value matches the reference brightness value, the brightness variable is set smaller than 128.

  Therefore, for example, when the apparent brightness of the video displayed on the TV monitor is too bright even though the luminance value is matched with the reference luminance value (120), the luminance coefficient P is set to 1 or more, As a result, the magnitude of the corrected luminance value becomes larger than the luminance value of the original image signal, so that the aperture of the diaphragm 31 is suppressed, the luminance value of the image signal is also suppressed, and the brightness of the image displayed on the TV monitor is also suppressed. Is done. On the other hand, when the apparent brightness is too dark, the luminance coefficient P is set to 1 or less.

  FIG. 4 shows a program executed in the second CPU 34 (see FIG. 2) provided in the processor 14. In this program, initial setting processing (step S200), endoscope connection confirmation processing (step S300), communication processing (step S400), keyboard processing (step S500), panel switch processing (step S600), and other processing (step) S700) is executed. When the other processing ends, the program returns to step S300.

  In the initial setting process, settings of registers of peripheral circuits such as the second CPU 34 and the signal processing circuit 33 and other various variables are set. In the endoscope connection confirmation process, it is confirmed whether or not the electronic endoscope 10 is connected to the processor 14. In the keyboard process, a process corresponding to the key input of the keyboard 16 is performed. In the panel switch process, a process corresponding to the input of the panel switch 18 is performed. In the other processing, processing other than the processing described above is performed, for example, processing for displaying time on the TV monitor 15 is performed. In steps S300 to S700, the automatic dimming process shown in FIG. 9 is interrupted once every time the video signal ends one field.

  The electronic endoscope connection process will be further described in detail with reference to FIG. In the electronic endoscope connection process, it is first determined in step S302 whether or not the electronic endoscope 10 is newly connected to the processor 14. If it is determined in step S302 that the electronic endoscope is not newly connected, the electronic endoscope connection process ends. If it is determined in step S302 that the electronic endoscope is newly connected, the process proceeds to step S304 where the type of the electronic endoscope connected to the processor 14 is confirmed, and the type of the connected electronic endoscope 10 is confirmed. Is determined. When the type of the electronic endoscope 10 is determined, the value of the brightness variable corresponding to the type of the electronic endoscope is read from the table (see FIG. 3) stored in the EEPROM 36 in step S306, and the value is set. The luminance variable (aec) is set, and the electronic endoscope connection process ends. Note that the processes in steps S304 and S306 are executed only once when an electronic endoscope is newly connected.

  The keyboard process will be further described in detail with reference to FIG. When the keyboard process is started, in step S502, it is determined whether or not each key of the keyboard 16 has been input. If it is determined that a key has been input, the process proceeds to the brightness variable adjustment mode in step S504. It is determined whether or not.

  Here, the brightness variable adjustment mode is a mode for changing the value for the brightness variable (aec) stored in the EEPROM 36 shown in FIG. Here, the brightness variable adjustment mode is entered by, for example, sending a predetermined instruction from the keyboard, and is canceled by inputting an enter key (step S516) as will be described later. In the brightness variable adjustment mode, the TV monitor 15 is set to the brightness variable adjustment mode, the currently selected brightness calculation mode (whether it is average brightness, peak brightness, or center-weighted brightness calculation mode), and the current The set luminance variable is displayed as aec = 128, for example.

  If it is determined in step S504 that the brightness variable adjustment mode is not set, the process proceeds to step S506, and other modes are processed. If it is determined that the adjustment mode is set, the process proceeds to step S508. In the brightness variable adjustment mode, the user sets the value of the brightness variable while viewing the display on the TV monitor 15. Therefore, in step S508, it is determined whether or not the upper key of the keyboard 16 has been pressed. If it is determined that the upper key has been pressed, 1 is added to the value of the brightness variable (aec) in step S510, and the addition is performed. The value of aec is displayed on the TV monitor 15. If it is determined in step S508 that the up key has not been pressed, the process proceeds to step S512. In step S512, it is determined whether the down key has been pressed. If it is determined that the down key has been pressed, in step S514. The value of aec is decremented by 1, and the reduced value of aec is displayed on the TV monitor.

  In step S516, it is determined whether or not the enter key on the keyboard 16 has been pressed. If it is determined that the enter key has not been pressed, the keyboard process ends. On the other hand, if it is determined that the enter key has been pressed, the value changed by the up / down key (the value displayed on the TV monitor) is determined as the value of the brightness variable in step S520 and subsequent steps, and the brightness variable adjustment mode is set. Is released. More specifically, in step S520, it is determined whether or not the currently set luminance calculation mode is the average luminance calculation mode. In the average brightness calculation mode, the value of the brightness variable determined in step S522 is the endoscope type data of the connected electronic endoscope in the table (see FIG. 3) stored in the EEPROM 36. And the changed value (aec) is stored in the term corresponding to the average luminance value, the luminance variable adjustment mode is canceled, and the keyboard processing is terminated. When it is determined in step S524 that the luminance calculation mode is the peak luminance calculation mode, in step S526, the changed value (aec) is stored in the term corresponding to the peak luminance value, as in step S522. The same applies to step S528 and step S530.

  Panel switch processing will be described with reference to FIG. In step S602, it is first determined whether or not any of the panel switches has been pressed. If it is determined that no switch has been pressed, the panel switch process ends. On the other hand, if it is determined that any switch has been pressed, it is determined in step S604 whether the pressed switch is the upper button of the brightness setting switch. If the pressed button is the up button, the reference luminance value (aer) is set in step S606. Here, each time the up button is pressed, the luminance index (asp) increases by 1, and the reference luminance value (aer) also increases as shown in FIG. Here, the luminance index (asp) is a numerical value indicating the brightness of the image, and takes a value from −5 (dark) to 0 (standard) to +5 (bright). That is, for example, when asp = 0, when the up button is pressed, asp = + 1 is set and the reference luminance value is set to 130. When the original luminance index asp = + 5, the reference luminance value is set to 170 without being changed because the reference luminance value is set to the maximum value even when the upper button is pressed.

  On the other hand, in step S608, it is determined whether or not the pressed switch is the lower button of the brightness setting switch. If it is determined that the lower button is pressed, the reference luminance value (aer) is set in step S610. Here, each time the down button is pressed, the luminance index (asp) decreases by 1, and the reference luminance value (aer) also decreases as shown in FIG. When the original luminance index asp = −5, even if the down button is pressed, the reference luminance value is set to the minimum value, so that the reference luminance value remains 70 without being changed. If the pressed switch is not a brightness setting switch, processing corresponding to the pressed switch is performed in step S612, and the panel switch processing ends.

  FIG. 9 shows the automatic dimming process in detail. As described above, the automatic light control processing is performed every time one feed elapses, and is processed by interrupting between steps S300 to S700.

In the automatic dimming process, in step S804, the luminance signal of the nth image signal is first input from the signal processing circuit 33 to the second CPU 34, and the second CPU 34 sets the luminance value (aey _n ) of the nth image signal. Is calculated. In step S806, the corrected luminance value (paey _n ) of the image signal is calculated. Here, the corrected luminance value is calculated by multiplying the luminance value of the image signal by the luminance coefficient P. That is, payn _n = P × aey _n and P = aec / 128. In step S808, based on the corrected luminance value (paey _n ) and the opening γ _n of the n th image signal stop 31, the opening of the (n + 1) th image signal stop 31 according to the above equation (1). γ _{n + 1} is calculated. In step S810, an opening signal related to the opening γ _{n + 1} is sent to the aperture adjustment circuit 32, and the aperture 31 is adjusted based on the opening γ _{n + 1} .

In the present embodiment, as described above, the brightness value aey _n is multiplied by the brightness coefficient P to calculate the corrected brightness value pay _n , and the opening γ _{n + 1} is calculated. P may be removed to obtain a corrected reference luminance value (paer), and the opening degree γ _{n + 1} may be calculated by the following equation (2). Also in this case, the luminance coefficient P = aec (luminance variable) / 128 as in the first embodiment.
γ _{n + 1} = γ _n × (paer / aey _n ) (2)
However, paer = aer / P

Further, the brightness coefficient P is multiplied to the luminance value AEy _n in the present embodiment, the correction luminance value Paey _n is calculated, moderated the predetermined correction value to the luminance value AEy _n, the correction luminance value Paey _n calculated May be. In this case, luminance variable (aec) = correction value (luminance constant) P, and the opening γ _{n + 1} of the diaphragm 31 is calculated by the following equation (3). In this case, the range of the luminance variable (aec) = P is set to −70 to +85.
γ _{n + 1} = γ _n × (aer / paey _n ) (3)
However, pay _n = aey _n + aec

Incidentally, when the addition correction value P (= aec) is the luminance value AEy _n corrected luminance value Paey _n is calculated, if the bright brightness of the apparent appearing on the TV monitor suppresses the output value of the image signal Therefore, the luminance coefficient P is set to 0 or more. On the other hand, when the apparent brightness is dark, the luminance coefficient P is set to 0 or less in order to increase the output value of the image signal.

Further, even when the corrected reference luminance value (paer) is obtained as described above, a predetermined correction value is added to or subtracted from the reference luminance value as shown in the following equation (4), and the corrected reference luminance value (paer) is calculated. ) And the opening γ _{n + 1 of the} diaphragm 31 may be calculated from this paer. In this case, luminance variable (aec) = correction value (luminance constant) P, and the range of luminance variable (aec) = P is set to −70 to +85.
γ _{n + 1} = γ _n × (paer / aey _n ) (4)
However, paer = aer + aec

  In the case of Expression (4), when the apparent brightness reflected on the TV monitor is bright, the output value of the image signal is suppressed, so that the luminance constant P is set to 0 or less. On the other hand, when the apparent brightness is dark, the luminance constant P is set to 0 or more in order to increase the output value of the image signal.

Furthermore, as shown in equation (5) instead of equation (1), AEy _n brightness coefficient P is Jose to, Paey _n may be calculated.
γ _{n + 1} = γ _n × (aer / paey _n ) (5)
However, pay _n = aey _n / P

Furthermore, as shown in equation (6) instead of equation (2), the reference luminance value may be multiplied by a luminance coefficient P to calculate paer.
γ _{n + 1} = γ _n × (paer / aey _n ) (6)
However, paer = P × aer

As described above, in the first embodiment, the luminance value AEy _n, the correction value (luminance constant or brightness coefficient), acceleration NoJo reacted by one of the calculation, to calculate the corrected luminance value Paey _n However, the corrected luminance value payey _n may be calculated by applying one or a plurality of correction values to the luminance value aey _n by calculating addition / subtraction / gradation gradually. That is, for example, the corrected luminance value may be calculated by Expression (7).
payn _n = a × (aey _n + b) −c (7)
However, a, b, and c are correction values.

Further, the above-described correction reference value paer _n may be similarly calculated by the equation (8).
paer _n = a × (aer _n + b) −c (8)
However, a, b, and c are correction values.

  In other words, in the claims, “the correction value is caused to act on the luminance value of the image signal by addition / subtraction / multiplication / division calculation” does not use all the addition / subtraction / multiplication / division calculations but the correction value by at least one addition / subtraction / multiplication / division calculation Is applied to the luminance value. There may be a plurality of correction values.

  A second embodiment will be described with reference to FIGS. In the first embodiment, as shown in FIG. 3, the electronic endoscope type data is stored in the EEPROM 36 and the value of the luminance variable is set according to the type of the electronic endoscope. The variable may be set for each electronic endoscope. That is, even if the same type of electronic endoscope (for example, for bronchi) is used, the serial number is stored in the EEPROM 36 as shown in FIG. 10 instead of the electronic endoscope type data so that the value of the brightness variable can be changed. May be stored. This is because the serial number is the same even if the type of electronic endoscope is the same, but the number is different if the electronic endoscope is different.

The electronic endoscope connection process (that is, S300 in FIG. 4) in the second embodiment will be described in detail with reference to FIG. Since other processes are the same as those in the first embodiment, description thereof will be omitted. In the following description, the opening gamma _{n + 1} by the equation (1), a description is given of a case where the calculated degree of opening gamma _{n + 1} by the equation (2) to (6), is calculated Also good.

  In the second embodiment, when the electronic endoscope connection process is started, it is first determined in step S352 whether or not the electronic endoscope 10 is newly connected to the processor 14, and the electronic endoscope is newly added. If it is determined that the connection is not established, the process ends. On the other hand, if it is determined that the electronic endoscope is newly connected, the second CPU 34 receives the serial number from the electronic endoscope 10 in step S354. In step S356, it is confirmed whether or not the table (see FIG. 10) stored in the EEPROM 36 has the same serial number as the received serial number. If it is determined that the same serial number exists in the table, in step S358, the correction value stored in the term corresponding to the serial number and the currently set luminance calculation mode in the table is the luminance variable (aec). Set as

  On the other hand, if there is no same serial number, the process proceeds to step S360, where the serial number transmitted from the electronic endoscope 10 is stored in a new item of the table (EEPROM 36) shown in FIG. In step S362, 128, which is a standard value, is stored in all mode terms of the average luminance value, peak luminance value, and center-weighted luminance value corresponding to the serial number (in the case of a luminance coefficient). In step S364, 'NEW SCOPE' is displayed on the TV monitor 15, and the user is informed that the electronic endoscope that has not been connected so far is connected to the processor 14.

  When the user sees the “NEW SCOPE”, the mode is shifted to the luminance variable adjustment mode by inputting a predetermined key from the keyboard. In the brightness variable adjustment mode, the brightness variable is adjusted with the up and down keys and the enter key of the keyboard, and the adjusted brightness variable is stored in the table of the EEPROM 36. Note that keyboard processing in the brightness variable adjustment mode is the same as that in the first embodiment, and thus description thereof is omitted. Further, the processes in steps S354 to S364 are executed only once when the electronic endoscope is newly connected.

  As described above, in the second embodiment, since the brightness variable can be set for each electronic endoscope, it is possible to set the brightness more accurately.

An electronic endoscope system is shown typically. 1 shows an electrical configuration of an electronic endoscope system. 3 shows a table stored in the memory of the processor according to the first embodiment of the present invention. The whole program which 2nd CPU provided in the processor runs is shown. An electronic endoscope connection process in the program executed by the second CPU will be described in detail. A keyboard process among the programs executed by the second CPU will be described in detail. The panel switch process in the program executed by the second CPU will be described in detail. The relationship between a brightness | luminance index and a reference | standard brightness value is shown. An automatic light control process among the programs executed by the second CPU will be described in detail. The table memorize | stored in the memory of the processor which concerns on the 2nd Embodiment of this invention is shown. The electronic endoscope connection process which concerns on the 2nd Embodiment of this invention is shown in detail.

Explanation of symbols

10 Electronic endoscope 14 Processor (light source device)
15 TV Monitor 20 Solid-State Image Sensor 23 First CPU
30 Light source 31 Aperture 32 Aperture adjustment circuit 34 Second CPU
36 EEPROM (memory)

Claims (13)

A light source device for an electronic endoscope that can be connected to a plurality of electronic endoscopes, and one electronic endoscope is connected from the plurality of electronic endoscopes;
Conversion means for converting a subject image captured by the connected electronic endoscope into an image signal;
A correction value setting means for determining the connected electronic endoscope and setting a correction value according to the determined electronic endoscope;
A correction luminance value calculating means for calculating the correction luminance value by causing the correction value to act on the luminance value of the image signal by calculation of addition / subtraction / multiplication / division;
Brightness adjusting means for adjusting a brightness value of an image signal converted from the subject image based on the corrected brightness value;
An electronic endoscope system comprising: output means for outputting the image signal whose brightness value has been adjusted to a monitor. The converting means converts the subject image into at least first and second image signals in time series, and the first and second image signals are sequentially output to the monitor,
The corrected luminance value calculating means obtains a corrected luminance value by causing the correction value to act on the luminance value of the first image signal by at least one of addition, subtraction, multiplication and division.
The electronic endoscope system according to claim 1, wherein the brightness adjustment unit adjusts a brightness value of the second image signal based on the corrected brightness value.   The electronic endoscope system according to claim 1, wherein the brightness adjusting unit adjusts a brightness value of the image signal by adjusting a diaphragm of a light source of the light source device.   The electronic endoscope system according to claim 1, wherein the brightness adjusting unit adjusts the brightness value so that the corrected brightness value matches a predetermined reference value.   The light source device can be connected to a plurality of types of electronic endoscopes, and the coefficient setting means determines the type of electronic endoscope connected to the light source device, and according to the determined type The electronic endoscope system according to claim 1, wherein a correction value is set.   The electronic endoscope system according to claim 1, wherein the correction value is stored in a memory provided in the light source device.   The correction value is calculated by dividing a predetermined value according to the determined electronic endoscope by a predetermined constant, and the predetermined value is stored in a memory provided in the light source device. The electronic endoscope system according to claim 1.   The electronic endoscope captures a subject image with a solid-state imaging device, and the luminance value of the image signal is obtained by one method selected from at least two different methods from the luminance value of each pixel of the solid-state imaging device. The electronic endoscope system according to claim 1, wherein the correction value is different depending on a selected method.   The electronic endoscope captures a subject image with a solid-state imaging device, and the luminance value of the image signal is an average value of luminance values of pixels of the solid-state imaging device, and luminance values of pixels near the center of the solid-state imaging device. The average value and the highest luminance value selected from among the luminance values of each pixel of the solid-state imaging device, wherein the correction value is different depending on the selected luminance value. Item 2. The electronic endoscope system according to Item 1.   Each of the plurality of electronic endoscopes includes specific data corresponding to each electronic endoscope, the connected electronic endoscope transmits the specific data to a light source device, and the correction value setting unit includes the correction value setting unit The electronic endoscope system according to claim 1, wherein the connected electronic endoscope is determined based on the transmitted specific data. A light source device for an electronic endoscope that can be connected to a plurality of electronic endoscopes, and one electronic endoscope is connected from the plurality of electronic endoscopes;
Conversion means for converting a subject image captured by the connected electronic endoscope into an image signal;
A correction value setting means for determining the connected electronic endoscope and setting a correction value according to the determined electronic endoscope;
A correction reference value calculating means for obtaining a correction reference value by causing the correction value to act on a predetermined reference value by addition / subtraction / multiplication / division calculation;
Brightness adjusting means for adjusting the brightness value so that the brightness value of the image signal matches the correction reference value;
An electronic endoscope system comprising: output means for outputting the image signal whose brightness value has been adjusted to a monitor. A light source device for an electronic endoscope that can be connected to a plurality of electronic endoscopes, and one electronic endoscope is connected from the plurality of electronic endoscopes,
Conversion means for converting a subject image captured by the connected electronic endoscope into an image signal;
A correction value setting means for determining the connected electronic endoscope and setting a correction value according to the determined electronic endoscope;
A correction luminance value calculating means for calculating the correction luminance value by causing the correction value to act on the luminance value of the image signal by calculation of addition / subtraction / multiplication / division;
Brightness adjusting means for adjusting a brightness value of an image signal converted from the subject image based on the corrected brightness value;
And a light source device for an electronic endoscope, comprising: an output unit configured to output an image signal having the adjusted luminance value to a monitor. A light source device for an electronic endoscope that can be connected to a plurality of electronic endoscopes, and one electronic endoscope is connected from the plurality of electronic endoscopes,
Conversion means for converting a subject image captured by the connected electronic endoscope into an image signal;
A correction value setting means for determining the connected electronic endoscope and setting a correction value according to the determined electronic endoscope;
A correction reference value calculating means for calculating the correction reference value by causing the correction value to act on a predetermined reference value by addition / subtraction / multiplication / division calculation;
Brightness adjusting means for adjusting the brightness value so that the brightness value of the image signal matches the correction reference value;
And a light source device for an electronic endoscope, comprising: an output unit configured to output an image signal whose brightness value has been adjusted to a monitor.

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