JP2010115341A - Electronic endoscopic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily select a wavelength range in an electronic endoscopic device which forms spectroscopic images corresponding to a selected wavelength set. <P>SOLUTION: The electronic endoscopic device images an observed object which is irradiated with white light by an imaging element 15 and forms spectroscopic images within a predetermined wavelength range selected by a user from RGB three-color image signals output from the imaging element 15 and parameters in matrix (spectral) data which is previously stored in a memory 36. It sequentially generates and indicates sweep spectroscopic images corresponding to sweep wavelength sets whose wavelengths are sequentially swept on the basis of the RGB three-color image signals and the matrix (spectral) data. The user can select a wavelength set which generates spectroscopic images in desired display colors as he or she observes spectroscopic images whose display colors change in sequence. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electronic endoscope apparatus, and more particularly, an electronic endoscope apparatus capable of forming and displaying a spectral image (video) at a specific wavelength by performing arithmetic processing on an image signal carrying a color image. About.

  In the field of electronic endoscope devices using solid-state image sensors, devices that perform spectral imaging in combination with a narrow-band bandpass filter based on the spectral reflectance of digestive organs such as the gastric mucosa, that is, have a built-in narrow-band filter. Electronic endoscope devices (Narrow Band Imaging-NBl) are attracting attention. This device is provided with a narrow-band bandpass filter instead of the surface sequential R (red), G (green), and B (blue) rotation filters, and the illumination light is transmitted through these narrow-band bandpass filters. A spectral image is formed by sequentially outputting and performing the same processing as in the case of R, G, B (RGB) signals while changing the respective weights on the signals obtained with these illumination lights. According to such a spectral image, in the digestive organs such as the stomach and the large intestine, a fine structure or the like that has not been obtained conventionally is extracted. Further, Patent Document 1 discloses that a spectral image is formed from an image obtained by using a surface sequential irradiation unit instead of a narrow-band bandpass filter.

  On the other hand, in Patent Document 2, an object to be observed irradiated with white light is not a frame sequential type using the above-described narrowband bandpass filter but a simultaneous type in which a fine mosaic color filter is arranged on a solid-state imaging device. It has been proposed that a spectral image is formed by arithmetic processing based on an image signal obtained by imaging. This Patent Document 2 obtains matrix data (spectral data) that takes into account the spectral characteristics of illumination light and the spectral characteristics of the entire imaging system including the color sensitivity characteristics of the imaging element and the transmittance of the color filter. A method of obtaining spectral reflectance data of the observed portion independent of the type of illumination light, the spectral characteristics unique to the imaging system, and the like, by calculating the RGB image signal captured by the image and the matrix data (spectral data) Is disclosed. In Patent Document 1, an estimation matrix representing the reflectance in a predetermined wavelength region (λ1, λ2, λ3) is calculated by calculating the matrix data and the RGB image signal, and a spectral image is generated based on the estimation matrix. ing. When a spectral image is formed by such an operation, it is not necessary to prepare a plurality of filters corresponding to a desired wavelength region, and replacement arrangement of these is unnecessary, so that the apparatus can be prevented from being enlarged and reduced in size. Cost can be reduced.

By the way, in an electronic endoscope apparatus capable of displaying such a spectral image, as shown in Patent Document 3, development of an apparatus that allows a user to arbitrarily set a predetermined wavelength range is underway. . In such an apparatus, the user can set a desired wavelength range in order to display a desired tissue such as a blood vessel more clearly.
JP-A-1-280448 JP 2003-93336 A JP 2007-202621 A

  However, actually, observation of the object to be observed using the electronic endoscope apparatus is preferably completed in a short time, and a preferable wavelength set cannot be searched over a sufficient time. For this reason, there is a fear that it is difficult to set an appropriate wavelength set when it is desired to display a spectral image obtained by extracting the microstructure or the like of the object to be observed.

  The present invention has been made in view of the above problems, and in an electronic endoscope apparatus that forms a spectral image corresponding to a set wavelength set, it is convenient to easily select an appropriate wavelength set. An object of the present invention is to provide an improved electronic endoscope.

An electronic endoscope apparatus according to the present invention includes: a light source that irradiates an observation object with illumination light; a color imaging element that images the observation object irradiated with the illumination light; and a wavelength set including a plurality of wavelengths. A spectral image corresponding to the wavelength set set by the wavelength setting unit is generated based on the wavelength setting unit to be set, the three-color image signal output from the color image sensor, and the spectral data stored in advance. In an electronic endoscope apparatus provided with a spectral image generating means for
The wavelength setting means sequentially sets a wavelength set in which at least one of the wavelengths is automatically swept,
The spectral image generation means sequentially generates spectral images corresponding to the wavelength sets sequentially set by the sweep wavelength set setting means.

  Note that “one of the wavelengths is automatically swept” means that one of the wavelengths is automatically increased or decreased by a predetermined wavelength.

If it is provided with a sweep start wavelength setting means for setting a first wavelength and a second wavelength different from the first wavelength as a sweep start wavelength set,
The wavelength setting means may sequentially output the first wavelength, the wavelength swept from the first wavelength to the second wavelength, and the second wavelength as a wavelength set. .

If provided with a sweep start wavelength setting means for setting the first wavelength as the sweep start wavelength set,
The wavelength setting means sequentially outputs the wavelength swept from the first wavelength to the short wavelength side, the first wavelength, and the wavelength swept from the second wavelength to the long wavelength side as a wavelength set. You may do.

A first wavelength, a second wavelength that is longer than or equal to the first wavelength, and a third wavelength that is longer than or equal to the second wavelength are set as a sweep start wavelength set. And the fourth wavelength, the fifth wavelength that is longer or the same wavelength as the fourth wavelength, and the sixth wavelength that is longer or the same wavelength as the fifth wavelength If equipped with a sweep start wavelength setting means to set as a set,
The wavelength setting means includes a wavelength swept from the first wavelength to the fourth wavelength, a wavelength swept from the second wavelength to the fifth wavelength, and the third wavelength to the sixth wavelength. The wavelength swept up to the wavelength may be sequentially output as a wavelength set.

  In the electronic endoscope apparatus according to the present invention, a light source for irradiating the observation object with illumination light, a color imaging device for imaging the observation object irradiated with illumination light, and a wavelength set including a plurality of wavelengths are set. A spectral image for generating a spectral image corresponding to the wavelength set set by the wavelength setting unit based on the wavelength setting unit to perform, the three-color image signal output from the color image sensor, and the spectral data stored in advance In the electronic endoscope apparatus including the generation unit, the wavelength setting unit sequentially sets the wavelength set in which at least one of the wavelengths is automatically swept, and the spectral image generation unit is the wavelength setting unit. Since the spectral images corresponding to the wavelength sets that are sequentially set according to the above are sequentially generated, a spectral image whose display color changes sequentially can be displayed on the monitor or the like. While observing the spectral image in which the color is sequentially changed, a spectral image of a desired display color can be selected wavelength set to generate, it is possible to easily select the appropriate wavelength set.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a basic configuration of an electronic endoscope apparatus according to an embodiment of the present invention. This endoscopic apparatus includes a normal image display mode for displaying a normal image on a monitor, a reference spectral image display mode for displaying a spectral image corresponding to a pre-stored reference wavelength set, and a swept wavelength set including a swept wavelength. The operation mode is a sweep spectral image display mode for displaying a spectral image corresponding to, and a set spectral image display mode for displaying a spectral image corresponding to a wavelength set set using the sweep spectral image display mode.

  As shown in the figure, this electronic endoscope apparatus includes a scope unit 10 inserted into a body cavity of a subject, for example, an upper digestive tract, and a processor unit 12 to which the scope unit 10 is detachably connected. A light source device 14 that emits white light is disposed in the processor unit 12. An illumination window 22 is provided at the distal end of the scope unit 10, and the other end of the light guide 23 whose one end is connected to the light source device 14 faces the illumination window 22.

  The light source device 14 includes a lamp 14a that emits white light, a lighting drive circuit 14b that lights the lamp 14a, a diaphragm 14c disposed on the front side of the lamp 14a, and a diaphragm driver 14d that opens and closes the diaphragm 14c. Has been. An optical system for allowing white light emitted from the lamp 14a to enter the light guide 23 is provided between the lamp 14a and the light guide 23, but these are not shown. In addition, this type of light source device may be configured as a separate body from other parts.

  A CCD 15 that is a solid-state imaging device is provided at the distal end of the scope unit 10. As the CCD 15, for example, a primary color filter having RGB color filters on the imaging surface is attached. Note that a complementary color filter may be used as the color filter.

  Connected to the CCD 15 is a CCD drive circuit 16 that forms a drive pulse based on a synchronizing signal, and also CDS / AGC (correlated double sampling / automatic) that samples and amplifies an image (video) signal output from the CCD 15. A gain control circuit 17 is connected. The CDS / AGC circuit 17 is connected to an A / D converter 18 for digitizing the analog output. Further, in the scope unit 10, a microcomputer 20 that controls various circuits provided therein and performs communication control with the processor unit 12 is disposed. Further, near the base of the scope unit 10, there is provided a push-type switch 19 that is connected to the microcomputer 20 and switches the display mode.

  On the other hand, the processor unit 12 is provided with a DSP (digital signal processor) 24 for performing various kinds of image processing on the digitized image signal. The DSP 24 generates a Y / C signal composed of a luminance (Y) signal and a color difference [C (R−Y, B−Y)] signal from the R, G, and B three-color image signals output from the CCD 15. A signal processing circuit 25 that performs I / P conversion and noise removal is connected to the DSP 24. The signal processing circuit 25 is connected to a signal processing circuit 26 that forms a normal color image signal for display and a first color conversion circuit 28 that generates a spectral color image signal described later.

  The signal processing circuit 26 performs various signal processing such as mirror image processing, mask generation, character generation, color adjustment, color enhancement, and structure enhancement to generate a normal color image signal for display, and this normal color image signal is displayed as a display image. The data is output to the generation unit 27. For example, a monitor 34 made of a liquid crystal display device or a CRT and an image recording device 45 made of an optical scanning recording device or the like are connected to the display image generating unit 27. In the display image generation unit 27, when the normal image display mode is selected, the normal color image signal is displayed. When the spectral reflectance image display mode is selected, the normal color image signal and the spectral reflectance data are displayed. When the spectral image display mode is selected, a spectral color image signal described later is output to the monitor 34 and the image recording device 45.

  The first color conversion circuit 28 converts the Y / C signal output from the signal processing circuit 25 into a three-color image signal of R, G, and B. The DSP 24 may be arranged on the scope unit 10 side.

  On the subsequent stage side of the first color conversion circuit 28, parameters corresponding to the reference wavelength set or the sweep wavelength set are read out from matrix (spectral) data for presumed spectral image signal generation stored in advance. A first color space conversion processing circuit 29 that performs matrix calculation on the image signals R, G, and B and outputs estimated spectral image signals λ1s, λ2s, and λ3s, and the estimated spectral image signals λ1s, λ2s, and λ3s, A second color space conversion processing circuit 30 that amplifies using a gain value for each image signal set in advance or input by the user and outputs pseudo color spectral image signals λ1t, λ2t, λ3t, and the pseudo color The spectral image signals λ1t, λ2t, and λ3t are respectively input to the R, G, and B channels for processing corresponding to the RGB signals, and the second color conversion that converts the input signals into Y / C signals. Road 32, the mirror image processing, mask generation, character generation, color adjustment, color enhancement, signal processing circuit 33 performs various signal processing such as structural enhancement and display image generating unit 27, are connected sequentially in this order.

  A reference wavelength set for performing communication with the scope unit 10 in the processor unit 12 and connected to each unit in the processor unit 12 to control the operation of each unit and form an estimated spectral image signal. Alternatively, a microcomputer 35 having a function of setting a sweep wavelength set and setting matrix data (spectral data) corresponding to the reference wavelength set or the sweep wavelength set in the color space conversion processing circuit 29 is provided. The microcomputer 35 also functions as a sweep wavelength set setting unit of the present invention. Details of the function of the microcomputer 35 will be described when the operation of the apparatus is described later. Further, the memory 35, the monitor 34, the touch panel type or keyboard type input unit 41, the image recording controller 42, and the microcomputer 20 of the scope unit 10 are connected to the microcomputer 35.

  The memory 36 stores a wavelength set, a gain set, and matrix (spectral) data for forming a spectral image. As the wavelength sets of λ1, λ2, and λ3, as shown in FIG. 2, for example, wavelength range standard set a of 400, 500, 600 (nm, the same applies hereinafter), 470, 500, 670 blood vessels for rendering blood vessels B1 set b, blood vessel B2 set c of 475, 510, 685 also for depicting blood vessels, tissue E1 set d of 440, 480, 520 for depicting specific tissues, and 480 for depicting specific tissues as well 510,580 tissue E2 set b, 400,430,475 hemoglobin set f for depicting the difference between oxyhemoglobin and deoxyhemoglobin, 415,450,500 blood for depicting the difference between blood and carotene -Carotene set g, 8 of 420, 550, 600 blood-cytoplasm set h to depict the difference between blood and cytoplasm Long set is stored. Further, gain standard sets of 1, 1, 1 are stored as gain sets of e1, e2, e3.

Matrix (spectral) data is data used when creating an estimated spectral image signal and spectral reflectance data, and is stored as a table. In the present embodiment, an example of matrix data stored in the memory 36 is as shown in Table 1 below.

The matrix data in Table 1 includes 61 wavelength range parameters (coefficient sets) p1 to p61 obtained by dividing a wavelength range of 400 nm to 700 nm at 5 nm intervals, and parameters P1 to P3 for normal image formation. Each of the parameters p1 to p61 includes coefficients k _pr , k _pg , and k _pb (p = 1 to 61) for matrix calculation.

Then, in the color space conversion processing circuit 29, a matrix operation represented by the following equation is performed by the coefficients k _pr , k _pg , k _pb and the RGB signal output from the first color conversion circuit 28, and the estimated spectral image signal λ1s. , Λ2s, λ3s are formed.

That is, when, for example, 500 nm, 620 nm, and 650 nm are selected as the wavelength ranges λ1, λ2, and λ3 constituting the spectroscopic image, the coefficients (k _pr , k _pg , k _pb ) are selected from among the 61 parameters in Table 1. , The coefficient of the parameter p21 corresponding to the center wavelength of 500 nm (−0.00119, 0.002346, 0.0016), the coefficient of the parameter p45 corresponding to the center wavelength of 620 nm (0.004022, 0.000068, −0.00097), and the coefficient of the parameter p51 corresponding to the center wavelength of 650 nm The matrix calculation is performed using a matrix composed of (0.005152, -0.00192, 0.000088).

  FIG. 3 is a diagram showing an example of a screen 47 displayed on the monitor 34 when the spectral image display mode is selected. A screen 47 of the monitor 34 displays, selects or sets a spectral image 49, a wavelength display small screen 51 for displaying, selecting or setting a wavelength set for forming the spectral image, and a gain corresponding to each wavelength. A gain display small screen 52 is displayed. A blood vessel 50 is displayed in the spectral image 49.

  The wavelength range display small screen 51 includes, for example, a set selection switch 53 for selecting a wavelength set of a to h, a sweep method selection switch 57 for selecting a wavelength sweep method in the sweep spectral image display mode, and a wavelength λ1. , Λ2, λ3, and wavelength display switches 54a to 54c for setting the sweep start wavelength set and the like by manual input.

  The gain display small screen 52 displays a set selection switch 55 for selecting a standard gain set (1, 1, 1) and gains e1, e2, e3, and is used for manual input setting. Gain display switches 56a to 56c are displayed. The switches displayed on these small screens are operated by the input unit 41.

  Hereinafter, the operation of the electronic endoscope apparatus of the present embodiment having the above configuration will be described. First, the operation in the normal image display mode will be described. In the normal image display mode, a normal color image is formed. When these images are formed, the light source device 14 shown in FIG. 1 is driven, and white light emitted from the light source device enters the light guide 23 through the stop 14c, and is disposed in the scope unit 10. The object to be observed is irradiated with white light emitted from the tip of 23. Then, the CCD 15 driven by the CCD driving circuit 16 images the object to be observed and outputs an imaging signal. This image signal is amplified by correlated double sampling and automatic gain control in the CDS / AGC circuit 17 and then A / D converted by the A / D converter 18 and input to the DSP 24 of the processor unit 12 as an RGB image signal. Is done. In the DSP 24, color conversion processing is performed on the RGB image signal, which is the three-color image signal output from the scope unit 10, and the above-described Y / C signal, that is, the normal color image signal is formed. The Y / C signal (normal color image signal) output from the DSP 24 is subjected to I / P conversion and noise removal in the signal processing circuit 25, and is input to the signal processing circuit 26 to be subjected to mirror image processing, mask generation, and character generation. Various signal processing such as color adjustment, color enhancement, and structure enhancement is performed and output to the display image generation unit 27. The display image generation unit 27 outputs the normal color image signal output from the signal processing circuit 26 to the monitor 34 and the image recording device 45.

  Next, the operation in the reference spectral image display mode will be described. When the user operates the normal image display mode and the user presses the switch 19 provided at the base of the scope unit 10, the operation mode changes from the normal image display mode to the normal image and the reference spectral image. Is switched to the reference spectral image display mode for displaying. Note that, by pressing the switch 19, the display mode is sequentially switched in the order of the normal image display mode, the reference spectral image display mode, the sweep spectral image display mode, and the set spectral image display mode.

  In the reference spectral image display mode, the spectral color image forming operation is performed in parallel with the above-described normal color image forming operation. Hereinafter, spectral color image formation will be described. As described above, the Y / C signal (normal color image signal) output from the DSP 24 is input to the signal processing circuit 26 via the signal processing circuit 25 to form a normal color image. At the same time, the Y / C signal output from the DSP 24 is input to the first color conversion circuit 28 via the signal processing circuit 25, where it is converted into an RGB signal. The RGB signals are supplied to the first color space conversion processing circuit 29, and the first color space conversion processing circuit 29 performs matrix calculation for forming an estimated spectral image based on the RGB signals and matrix data.

  Hereinafter, this calculation will be described. The color space conversion processing circuit 29 uses the matrix data stored in the memory 36 described above to perform the matrix calculation of Formula 1 for forming a spectral image on the RGB signals. Three wavelength regions λ1, λ2, and λ3 are set by operating the input unit 41, and the microcomputer 35 reads parameters corresponding to these three selected wavelength regions from the matrix data stored in the memory 36, and sets them. Input to the color space conversion processing circuit 29.

For example, when the wavelengths 500 nm, 620 nm, and 650 nm are selected as the three wavelength ranges λ1, λ2, and λ3, the coefficients of the parameters p21, p45, and p51 of Table 1 corresponding to the respective wavelengths are used, and the RGB signals are used. Estimated spectral image signals λ1s, λ2s, and λ3s are formed by the matrix calculation of the following equation (2).

  Thereafter, the estimated spectral image signals λ1s, λ2s, and λ3s are supplied to the second color space conversion processing circuit 30. The second color space conversion processing circuit 30 uses the estimated spectral image signals λ1s, λ2s, and λ3s and the matrix indicating the gain values of the estimated spectral image signals (λ1s, λ2s, and λ3s) to form a pseudo color spectral image. Matrix calculation is performed.

  Hereinafter, this calculation will be described. A gain value for each estimated spectral image signal (λ1s, λ2s, λ3s) is set by operating the input unit 43. The microcomputer 35 generates a 1 × 3 matrix corresponding to these three gain values and outputs it to the second color space conversion processing circuit 29.

For example, when e1, e2, and e3 are selected as gain values for the three wavelength regions λ1, λ2, and λ3, pseudo color spectroscopy is performed from the estimated spectral image signal (λ1s, λ2s, λ3s) by the following matrix calculation. Image signals λ1t, λ2t, and λ3t are formed.

  Thereafter, the pseudo color spectral image signals λ1t, λ2t, and λ3t are input to the second color conversion circuit 32 as three-color image signals of Rs, Gs, and Bs, respectively. In the second color conversion circuit 32, Rs, Gs, The three-color image signal of Bs is converted into a Y / C signal (Y, Rs-Y, Bs-Y), and this Y / C signal, that is, the spectral color image signal is subjected to signal processing by the signal processing circuit 33 to be displayed. Input to the image generation unit 27. In the display image generation unit 27, the normal color image signal output from the signal processing circuit 26 and the spectral color image signal output from the signal processing unit 33 are combined to generate a single color image. Output to the image recording device 45.

  In the present embodiment, when the pseudo color spectral image signals λ1t ′, λ2t ′, and λ3t ′ are input to the second color conversion circuit 32 as three-color image signals of Rs, Gs, and Bs, respectively, The image signals λ1t ′, λ2t ′, and λ3t ′ are assigned to the Rs, Gs, and Bs three-color image signals in that order. However, when the user desires a special color display, the order may be changed and assigned. Good.

  The spectral image displayed on the monitor 34 based on the spectral color image signal is composed of color components in the wavelength range as shown in FIGS. That is, FIG. 4 is a conceptual diagram in which three wavelength regions λ1, λ2, and λ3 for forming a spectral image are superimposed on the spectral sensitivity characteristics R, G, and B of the color filter of the primary color CCD 15, and FIG. 3 is a conceptual diagram in which three wavelength regions λ1, λ2, and λ3 are superimposed on the reflection spectrum of FIG. Spectral image signals λ1s, λ2s, and λ3s based on the parameters p21, p45, and p51 exemplified above are color signals in a wavelength range of about ± 10 nm with 500 nm, 620 nm, and 650 nm as center wavelengths as shown in FIG. Thus, a spectral image (moving image or still image) composed of combinations of colors in these three wavelength ranges is displayed.

  Next, display, selection, and setting of the wavelength ranges λ1, λ2, λ3 and gains e1, e2, e3 will be described. After the electronic endoscope apparatus is shipped from the factory, when the apparatus is first turned on and the apparatus is started, the above-mentioned wavelength range standard set a (400, 500, 600) and gain standard set (1, 1, 1) are set by the microcomputer 35. Selected. When the spectral image display mode is selected, the selected wavelength range (400, 500, 600) is displayed by the wavelength display switches 54a to 54c, and the gain standard set (1, 1, 1) is displayed. It is displayed on the gain display switches 56a to 56c. The first color space conversion processing circuit 29 performs the above-described matrix calculation for the wavelength range (400, 500, 600) to form estimated spectral image signals λ1s, λ2s, λ3s. Further, the second color space conversion processing circuit 30 performs the above-described calculation using the gain (1, 1, 1), and forms the pseudo color spectral image signals λ1t, λ2t, λ3t.

  A device user such as a clinician can select other wavelength sets b to h in order and arbitrarily by selecting the set selection switch 53 using the keyboard-type input unit 41. Further, the wavelength can be set to an arbitrary value by moving the positions of the wavelength display switches 54a to 54c to the left and right by operating the keyboard-type input unit 41.

  Similarly, the gain can be set to an arbitrary value by moving the positions of the gain display switches 56a to 56c to the left and right. The parameters corresponding to the wavelength ranges λ1, λ2, and λ3 of the selected wavelength set are read from the memory 36 by the microcomputer 35, and these parameters are input to the first color space conversion processing circuit 29. The first color space conversion processing circuit 29 performs the above-described matrix operation using the input parameters to form estimated spectral image signals λ1s, λ2s, and λ3s. The selected gain set is input to the second color space conversion processing circuit 30. The second color space conversion processing circuit 30 performs the above-described calculation using the input parameters to form pseudo color spectral image signals λ1t, λ2t, and λ3t.

  Thereafter, the pseudo color spectral image signals λ1t, λ2t, and λ3t are input to the second color conversion circuit 32 as three-color image signals of Rs, Gs, and Bs, respectively. In the second color conversion circuit 32, the three-color image signals of Rs, Gs, and Bs are converted into Y / C signals (Y, Rs-Y, Bs-Y), and this Y / C signal, that is, the spectral color image signal is converted. Signal processing is performed by the signal processing circuit 33 and input to the display image generation unit 27. In the display image generation unit 27, the normal color image signal output from the signal processing circuit 26 and the spectral color image signal output from the signal processing unit 33 are combined to generate a single color image. Output to the image recording device 45.

  Next, operations in the sweep spectral image display mode and the set spectral image display mode will be described. When the user operates the reference spectral image display mode and the user presses the switch 19 provided at the base of the scope unit 10, the operation mode changes from the reference spectral image display mode to the normal image and the swept spectral image. The mode is switched to the sweep spectral image display mode for displaying both images. Note that, by pressing the switch 19, the display mode is sequentially switched in the order of the normal image display mode, the reference spectral image display mode, the sweep spectral image display mode, and the set spectral image display mode.

  In the sweep spectral image display mode, the sweep spectral color image forming operation is performed in parallel with the above-described normal color image forming operation. Hereinafter, sweep spectral color image formation will be described.

  As described above, the Y / C signal (normal color image signal) output from the DSP 24 is input to the signal processing circuit 26 via the signal processing circuit 25 to form a normal color image. At the same time, the Y / C signal output from the DSP 24 is input to the first color conversion circuit 28 via the signal processing circuit 25, where it is converted into an RGB signal. The RGB signals are supplied to the first color space conversion processing circuit 29, and the first color space conversion processing circuit 29 performs matrix calculation for forming a swept spectral image based on the RGB signals and matrix data.

  Hereinafter, this calculation will be described. The color space conversion processing circuit 29 uses the matrix data stored in the memory 36 described above to perform the matrix calculation of Formula 1 for forming a spectral image on the RGB signals. In the sweep spectral image display mode, the sweep method A, the sweep method B, or the sweep method C is selected by selecting the sweep method selection switch 57 once, selecting twice, or selecting three times by operating the keyboard-type input unit 41. You can choose.

For example, when the sweep method selection switch 57 is selected once, the sweep method A in which the wavelength (Sλ2) is swept between the two wavelengths (λ1, λ3) set by the input operation is selected. For example, when the switches 54a and 54c are operated via the input unit 41 and the wavelengths 400 nm and 600 nm are selected as the two wavelengths (λ1, λ3), the wavelength Sλ2 is changed from 400 nm (λ1) to 600 nm (λ3). Are sequentially swept. That is, in the microcomputer 35, (λ1, Sλ2, λ3) is sequentially set as a wavelength set for generating a spectral image. Specifically, as shown in the following table, sweep wavelength sets that change are sequentially set. Note that the sweep wavelength set is changed 20 times per second so that it is easy to confirm the change in display color when the spectral image is displayed. Moreover, it is preferable that the user can arbitrarily set the change timing of the sweep wavelength set.

  This wavelength set sweep is repeated twice.

  Each time the wavelength set is switched, each parameter corresponding to the selected wavelength set (λ1, Sλ2, λ3) is read from the memory 36 by the microcomputer 35, and these parameters are sent to the first color space conversion processing circuit 29. Entered. The first color space conversion processing circuit 29 performs the above-described matrix operation using the input parameters to form estimated spectral image signals λ1s, Sλ2s, and λ3s. Further, the second color space conversion processing circuit 30 performs the above-described calculation using the gain (1, 1, 1) to form the pseudo color spectral image signals λ1t, Sλ2t, λ3t. Thereafter, the pseudo color spectral image signals λ1t, Sλ2t, and λ3t are input to the second color conversion circuit 32 as three-color image signals of Rs, Gs, and Bs, respectively.

  When the sweep method selection switch 57 is selected twice, one wavelength λ2 set by the input operation, the wavelength Sλ1 swept from the wavelength λ2 to the short wavelength side, and from the wavelength λ2 to the long wavelength side A sweep method B is selected in which the wavelength Sλ3 to be swept is set by setting the wavelength. For example, when the switch 54b is operated via the input unit 41 and the wavelength 550 nm is selected as one wavelength (λ2), the wavelength Sλ1 is sequentially swept from 550 nm (λ2) to 400 nm. The wavelength Sλ3 is sequentially swept from 550 nm (λ2) to 700 nm.

That is, in the microcomputer 35, sweep wavelength sets (Sλ1, λ2, Sλ3) are sequentially set as wavelength sets for generating a spectral image. Specifically, changing wavelength sets are sequentially set as shown in the following table.

  This wavelength set sweep is repeated twice.

  Each time the wavelength set is switched, each parameter corresponding to the selected wavelength set (Sλ1, λ2, Sλ3) is read from the memory 36 by the microcomputer 35, and these parameters are sent to the first color space conversion processing circuit 29. Entered. The first color space conversion processing circuit 29 performs the above-described matrix operation using the input parameters to form estimated spectral image signals Sλ1s, λ2s, and Sλ3s. Further, the second color space conversion processing circuit 30 performs the above-described calculation using the gain (1, 1, 1), and forms pseudo color spectral image signals Sλ1t, λ2t, Sλ3t. Thereafter, the pseudo color spectral image signals λ1t, Sλ2t, and λ3t are input to the second color conversion circuit 32 as three-color image signals of Rs, Gs, and Bs, respectively.

  In addition, when the sweep method selection switch 57 is selected three times, the wavelength set (Sλ1, Sλ1,..., The wavelength is swept between the two reference wavelength sets set by the input operation, the sweep start wavelength set and the sweep end wavelength set. The sweep method C for which Sλ2, Sλ3) is set is selected. For example, the switch 53 is operated via the input unit 41, the reference wavelength set a (400 nm, 500 nm, 600 nm) is selected as the sweep start wavelength set, and the reference wavelength set d (440 nm, 480, 520 nm is selected as the sweep end wavelength set. ) Is selected, the wavelength Sλ1 is sequentially swept from 400 nm to 440 nm, the wavelength Sλ2 is sequentially swept from 500 nm to 480 nm, and the wavelength Sλ3 is sequentially swept from 600 nm to 520 nm.

That is, in the microcomputer 35, sweep wavelength sets (Sλ1, Sλ2, Sλ3) are sequentially set as wavelength sets for generating a spectral image. Specifically, changing wavelength sets are sequentially set as shown in the following table.

  Each time the wavelength set is switched, each parameter corresponding to the selected wavelength set (Sλ1, Sλ2, Sλ3) is read out from the memory 36 by the microcomputer 35, and these parameters are sent to the first color space conversion processing circuit 29. Entered. The first color space conversion processing circuit 29 performs the above-described matrix operation using the input parameters to form estimated spectral image signals Sλ1sSλ2s and Sλ3s. Further, the second color space conversion processing circuit 30 performs the above-described calculation using the gain (1, 1, 1), and forms the pseudo color spectral image signals Sλ1t, Sλ2t, Sλ3t.

  In the second color conversion circuit 32, the three-color image signals of Rs, Gs, and Bs are converted into Y / C signals (Y, Rs-Y, Bs-Y), and this Y / C signal, that is, the spectral color image signal is converted. Signal processing is performed by the signal processing circuit 33 and input to the display image generation unit 27. The display image generation unit 27 combines the normal color image signal output from the signal processing circuit 26 and the swept spectral color image signal output from the signal processing unit 33 to generate a single color image, and the monitor 34. And output to the image recording device 45.

  In the present embodiment, when the pseudo color spectral image signals λ1t ′, Sλ2t ′, and λ3t ′ are respectively input to the second color conversion circuit 32 as Rs, Gs, and Bs three color image signals, the pseudo color spectral signal is input. The image signals λ1t ′, λ2t ′, and λ3t ′ are assigned to the Rs, Gs, and Bs three-color image signals in that order. However, when the user desires a special color display, the order may be changed and assigned. Good.

  As a result of the above operation, a swept spectral color image in which the display color sequentially changes is displayed on the monitor 34 simultaneously with the regular color image. The display color of the swept spectral color image changes in the same way twice. When the user desires to display in the display color during the sweep, the switch 19 provided in the scope unit 10 is pressed when the display color is changed for the second time and the display color is displayed in the desired display color. . When the switch 19 is pressed, the display mode is switched from the sweep spectral image display mode to the set spectral image display mode. Thereafter, when the switch 19 is pressed, the spectral image based on the wavelength set set by the microcomputer 35 is displayed. Is displayed.

  As is clear from the above description, in the electronic endoscope of the present invention, since the spectral image in which the display color automatically changes sequentially can be displayed on the monitor 34, the user can automatically display this display color. Accordingly, a wavelength set for generating a spectral image of a desired display color can be selected while observing a spectral image that sequentially changes, and an appropriate wavelength set can be easily selected. Furthermore, since the display color of the spectral image changes in a short time, a lesioned part that is difficult to visually recognize with the conventional spectral image display method may be easily visible, and the convenience of the electronic endoscope apparatus is further increased. improves.

  In the present embodiment, when the pseudo color spectral image signals (λ1t, λ2t, λ3t) are formed from the estimated spectral image signals (λ1s, λ2s, λ3s), the estimated spectral image signals (λ1s, λ2s, λ3s) The pseudo-color spectral image signals (λ1t, λ2t, λ3t) were formed while maintaining the wavelength order of the wavelengths, but after changing the wavelength order of the estimated spectral image signals (λ1s, λ2s, λ3s) according to the user's preference A pseudo color spectral image signal (λ1t, λ2t, λ3t) may be formed. In such a case, for example, a spectral image in which a blood vessel portion is displayed in yellow or blue is displayed.

  Furthermore, in conventional endoscopes, pigments such as indigo and pioctanin are sprayed on the object to be observed, and images of tissues colored by the pigment spraying are performed. As a wavelength set of λ1, λ2, and λ3, By selecting a wavelength range in which a tissue colored by pigment dispersion can be drawn, a spectral image equivalent to the image at the time of pigment dispersion can be obtained without performing pigment dispersion.

  In the electronic endoscope apparatus of the above embodiment, a primary color type mosaic filter having RGB color filters is used as a mosaic filter for the image sensor 15, but the present invention is not limited to this. For example, CMY (cyan, magenta, A complementary color type mosaic filter having a yellow color filter may be used.

  In the above description, an electronic endoscope system including a scope unit has been described as an embodiment of the electronic endoscope apparatus of the present invention, but the present invention is not limited to this, for example, a capsule endoscope system, It can also be applied to laparoscopes and colposcopes.

1 is a block diagram showing a configuration of an electronic endoscope apparatus according to an embodiment of the present invention. Diagram showing an example of wavelength range Figure showing an example of the screen A graph showing an example of the wavelength range of a spectral image together with the spectral sensitivity characteristics of a primary color CCD A graph showing an example of the wavelength range of a spectral image along with the reflection spectrum of a living body

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Scope part 12 Processor part 14 Light source device 14a Lamp 14b Lighting drive circuit 14c Aperture 14d Aperture drive part 15 CCD
17 CDS / AGC circuit 19 Switch 20, 35 Microcomputer 22 Lighting window 23 Light guide 24 DSP
25, 26 Signal processing circuit 28 First color conversion circuit 29 First color space conversion processing circuit 32 Second color conversion circuit 33 Signal processing circuit 34 Monitor 34s Wavelength information display area 35 Microcomputer 36 Memory 41 Input unit 47 Screen 48 Normal image 49 Spectral image 51 Wavelength display small screen 52 Gain display small screen

Claims (4)

A light source for irradiating the observation object with illumination light, a color imaging element for imaging the observation object irradiated with the illumination light, wavelength setting means for setting a wavelength set composed of a plurality of wavelengths, and the color imaging An electronic device comprising: a spectral image generating means for generating a spectral image corresponding to the wavelength set set by the wavelength setting means based on the three-color image signal output from the element and the spectral data stored in advance. In an endoscopic device,
The wavelength setting means sequentially sets a wavelength set in which at least one of the wavelengths is automatically swept,
The electronic endoscope apparatus, wherein the spectral image generation means sequentially generates spectral images corresponding to the wavelength sets sequentially set by the wavelength setting means. A sweep start wavelength setting means for setting a first wavelength and a second wavelength different from the first wavelength as a sweep start wavelength set;
The wavelength setting means sequentially outputs the first wavelength, the wavelength swept from the first wavelength to the second wavelength, and the second wavelength as a wavelength set. The electronic endoscope apparatus according to claim 1. Sweep start wavelength setting means for setting the first wavelength as a sweep start wavelength set;
The wavelength setting means sequentially outputs the wavelength swept from the first wavelength to the short wavelength side, the first wavelength, and the wavelength swept from the second wavelength to the long wavelength side as a wavelength set. The electronic endoscope apparatus according to claim 1, wherein: A first wavelength, a second wavelength that is longer than or equal to the first wavelength, and a third wavelength that is longer than or equal to the second wavelength are set as a sweep start wavelength set. And the fourth wavelength, the fifth wavelength that is longer or the same wavelength as the fourth wavelength, and the sixth wavelength that is longer or the same wavelength as the fifth wavelength It has a sweep start wavelength setting means to set as a set,
The wavelength setting means has a wavelength swept from the first wavelength to the fourth wavelength, a wavelength swept from the second wavelength to the fifth wavelength, and from the third wavelength to the sixth wavelength. The electronic endoscope apparatus according to claim 1, wherein the wavelength that is swept up to the wavelength is sequentially output as a wavelength set.

Images