JP2004033334A - Electronic endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To conveniently realize a white balance adjustment in an electronic endoscope. <P>SOLUTION: In an electronic scope 10, a light guide L is branched to light guides La and Lb. The light guide La is arranged to the tip of an insertion portion and used as lighting for an imaging element S1 for endoscopic observation. The tip of the light guide Lb is arranged in a white balance adjustment section 15. A white subject W and an imaging element S2 are provided in the white balance adjustment section 15. The subject W is illuminated by the light of the light guide Lb and the image can be taken by the imaging element S2. During a white balance adjustment, the imaging element S2 is selected by a switching circuit 16. The output ratio of the RGB signal of the imaging element S2 is obtained in an image signal processing section 17. The proper gain of the RGB signal is obtained by a control section 18 and the RGB gain of a DSP 174 is adjusted. The switching circuit 16 is switched to the imaging element S1 to take an image for an endoscopic observation. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to white balance adjustment in an electronic endoscope device.
[0002]
[Prior art]
In medical treatment using an electronic endoscope (electronic scope), a different electronic scope is used for each application. Therefore, in a facility such as a hospital, a plurality of electronic scopes must be constantly provided. Meanwhile, since the electronic scope is used in a lumen where external light is blocked, a light source for illuminating the inside of the lumen is required. However, providing a light source for each electronic scope is wasteful both locally and economically. Therefore, the light source unit is configured as a unit independent of the electronic scope, and each electronic scope is mounted on the light source unit according to the application. At this time, the light source unit is configured as, for example, an independent light source device or an integrated video signal processing unit (processor unit) together with a video signal processing circuit and the like.
[0003]
Various types of lamps are used for the light source unit according to use conditions. The spectrum of a lamp differs for each type of lamp, and even for the same type of lamp, the spectrum varies from product to product. Even with the same lamp, the spectrum changes over time. Similarly, the spectral sensitivity characteristics of the imaging device mounted on the electronic scope are also affected by differences in types, variations among products that occur during the manufacturing process, changes over time in the color filter array, and the like. The light from the light source is transmitted to the tip of the electronic scope via the optical fiber. However, since the spectral transmittance characteristics of the optical fiber are not uniform for all wavelengths, the length of the insertion part of the electronic scope is long. However, if the length of the optical fiber is different, the spectrum of the illumination light emitted from the tip of the electronic scope will also be different. Further, the amount of light supplied from the lamp to the optical fiber is adjusted by a diaphragm device, but the spectrum of the light supplied to the optical fiber is affected by the driving state of the diaphragm.
[0004]
Since the spectral sensitivity characteristics of the electronic scope and the spectrum of the illuminating light are affected by the various factors described above, the color tone of the image obtained by the electronic scope is affected by the combination of the electronic scope and the light source unit and the usage time of the lamp. . In order to adjust the deviation of the color tone of the captured image due to these, it is necessary to perform white balance adjustment with the electronic scope mounted on the light source unit.
[0005]
[Problems to be solved by the invention]
The adjustment of the white balance is performed by inserting the tip of the electronic scope into a cylindrical jig whose inside is colored white and operating switches such as a keyboard connected to the processor unit and the like. The user (user) himself / herself must perform these white balance adjustments each time, but it is extremely troublesome for the user to perform such operations every time the electronic scope is mounted on the light source unit.
[0006]
An object of the present invention is to provide an electronic endoscope that can easily perform white balance adjustment.
[0007]
[Means for Solving the Problems]
An electronic endoscope according to the present invention is an electronic endoscope that includes an optical transmission unit that transmits illumination light to a distal end of an insertion section, and a first imaging device that captures an image of the distal end of the insertion section using the illumination light. A white member as a reference for white balance adjustment, and a color signal for irradiating the white member with a part of the light transmitted by the light transmission unit and detecting a color signal corresponding to a spectrum of light reflected from the white member. It is characterized by comprising a detecting means and a white balance adjusting means for adjusting a first gain corresponding to each color component of an image signal detected by the first image sensor based on the color signal.
[0008]
For example, the white balance adjustment unit adjusts the first gain so that the output ratio of the image signal for each color component becomes uniform. For more accurate white balance adjustment, the color signal detection means preferably includes a second image sensor for white balance adjustment, and the color signal is preferably generated from an image signal of the second image sensor.
[0009]
In addition, the electronic endoscope includes, for example, an image signal processing unit that can process an image signal of the first or second image sensor, and an image signal by selectively selecting one of the first and second image sensors. Switching means connected to the processing means. At this time, the color signal is generated by the image signal processing means, and the first gain is adjusted by the image signal processing means. According to such a configuration, since the image signal processing means can be shared by the first and second image pickup devices, it is possible to manufacture at a lower cost.
[0010]
Further, in such a configuration, when the power of the electronic endoscope is turned on, the second image pickup device is connected to the image signal processing means by the switching means, and the white balance adjustment means is driven. If the first image pickup device is connected to the image signal processing means by the switching means when the gain adjustment of 1 is completed, the white balance adjustment is automatically performed without making the user aware of the white balance adjustment work. Can do it.
[0011]
Further, for example, the electronic endoscope includes a first image signal processing unit that processes an image signal of the first image sensor, and a second image signal that processes the image signal of the second image sensor and generates the color signal. An image signal processing unit; and a gain adjusting unit that adjusts a second gain of each color signal in the second image signal processing unit such that an output ratio of each color signal becomes a predetermined value. At this time, the white balance adjusting means adjusts the first gain based on the second gain. According to such a configuration, white balance adjustment can be performed independently of the imaging operation for endoscopic observation by the first imaging element, and even while the observation image is displayed on the monitor. And white balance adjustment.
[0012]
At this time, while the first image processing unit is being driven, the second image processing unit, the gain adjustment unit, and the white balance adjustment unit may be repeatedly driven at predetermined intervals. According to such a configuration, white balance adjustment can be performed in parallel during the endoscope observation, and the spectrum fluctuation until the light source becomes stable at the time of lighting and the spectrum of the illumination light due to the aperture stop. White balance adjustment according to the fluctuation of.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 schematically shows a configuration of an electronic endoscope apparatus according to a first embodiment of the present invention.
[0014]
The electronic endoscope device according to the present embodiment generally includes an electronic endoscope (electronic scope) 10, a video signal processing device (processor unit) 20, a keyboard 30, and a monitor TV31. The processor unit 20, the keyboard 30, and the monitor TV 31 are provided on each stage of the cart 32, and the electronic scope 10 is mounted on the processor unit 20.
[0015]
The electronic scope 10 includes a flexible tubular insertion part 11 inserted into the body, an operation part 12 for an operator to operate the movement of the electronic scope 10, and a tubular flexible member. The communication pipe 13 is configured to connect the communication pipe 13 to the processor unit 20 in a flexible manner. Note that the processor unit 20 may further be connected to peripheral devices such as a video printer, a video cassette recorder (VCR), a computer, and a storage device (for example, an MO, a hard disk, etc.).
[0016]
FIG. 2 is a block diagram showing an electrical and optical configuration of the electronic endoscope apparatus of FIG. The electrical and optical configuration of the electronic endoscope device according to the present embodiment will be described with reference to FIG.
[0017]
In the electronic scope 10, a light guide L formed of a bundle of ultra-fine optical fibers is provided. One end of the light guide L is connected to a light source unit in the processor unit 20 when the connector unit 14 is connected to the processor unit 20. The bundle of optical fibers of the light guide L is divided into two in the connector section 14 into an illumination light guide section La and a white balance adjustment light guide section Lb. The illumination light guide section La reaches the distal end of the insertion section 11 through the communication pipe 13 and the operation section 12, and irradiates illumination light for photography. On the other hand, the light guide part Lb for white balance adjustment supplies light to a white balance adjustment part 15 provided in the connector part 14.
[0018]
An imaging device S1 such as a MOS image sensor or a CCD is provided at the tip of the insertion section 11 of the electronic scope 10. The image sensor S1 is connected to an image signal processing unit 17 via a switch circuit 16, and its driving is controlled by the image signal processing unit 17. The image signal obtained by the image sensor S1 is subjected to a camera process process or the like in the image signal processing unit 17, and then transmitted as a digital image signal to a video signal processing circuit in the processor unit 20.
[0019]
The switch circuit 16 is a switch for selectively switching the connection between the image sensor S1 and the image signal processing unit 17 to the connection between the white balance adjustment unit 15 and the image signal processing unit 17, and the switching is performed by the control unit. 18. The control unit 18 is also connected to a microcomputer in the processor unit 20 and the image signal processing unit 17, performs communication with the processor unit 20, and controls driving of the image signal processing unit 17. Although not shown in the figure, the control unit 18 is connected to various operation switches provided on the operation unit 12, and can perform various controls in response to switch operations on the operation unit 12.
[0020]
In the present embodiment, the white balance adjustment unit 15, the switch circuit 16, the image signal processing unit 17, and the control unit 18 are provided in the connector unit 14 of the electronic scope 10, and FIG. Will be described later.
[0021]
The image signal from the image signal processing unit 17 of the electronic scope 10 is subjected to signal processing such as gain adjustment in a video signal processing circuit 21 in the processor unit 20 and then a luminance signal (Y) and a color difference signal (RY). ) And (BY), and are output to the memory (Y) 22, the memory (RY) 23, and the memory (BY) 24, respectively. The respective image signals via the memories 22 to 24 are synchronized and input to the video processing circuit 25. The operations of the memories 22 to 24 are controlled by the microcomputer 28, and the timing is controlled based on a synchronization signal from the timing circuit 27. That is, the microcomputer 28 is connected to the timing circuit 27, and a built-in memory control circuit for controlling the driving of the memories 22 to 24 based on the synchronization signal from the timing circuit 27.
[0022]
When a freeze button (not shown) of the operation unit 12 is operated, the image data stored in the memories 22 to 24 is held, and the image data stored in the memories 22 to 24 is repeatedly output to the video processing circuit 25. Is done. As a result, the images held in the memories 22 to 24 are displayed on the monitor TV 31 as still images. When the image signal processing unit 17 of the electronic scope 10 outputs an analog image signal, the video signal processing circuit 21 performs a decoding process and an A / D conversion process, and thereafter performs the same process.
[0023]
In the video processing circuit 25, the image signal is converted into an analog signal, subjected to process processing such as amplification processing, clamping processing, blanking processing, etc., and output as an RGB signal, a Y / C signal, or a composite video signal (compensation terminal circuit). Circuit) 26a, 26b. The output terminal circuit 26a is connected to, for example, a monitor TV 31 via a video signal cable (not shown), and the output terminal circuit 26b is connected to a device other than the monitor TV 31, such as a video printer or a VCR. Video signals are transmitted to the output terminal circuits 26a and 26b by a predetermined method, and impedance matching and the like are performed in the output terminal circuits 26a and 26b.
[0024]
The timing of processing in the video processing circuit 25 is controlled based on a synchronization signal from the timing circuit 27. The video processing circuit 25 is also connected to the microcomputer 28, and is controlled based on a control signal from the microcomputer 28. A keyboard 30 is connected to the microcomputer 28.
[0025]
The video signal processing circuit 21 is further connected to a microcomputer 28 and an aperture adjustment circuit 29. The aperture adjustment circuit 29 controls the drive of the aperture A based on the luminance signal (Y) from the video signal processing circuit 21 and adjusts the amount of light incident on the light guide L from the light source Ls. Note that the light from the light source Ls passes through the converging lens (not shown) and is condensed at the incident end of the light guide L across the stop A.
[0026]
Next, the electrical configuration inside the electronic scope 10 will be described in more detail with reference to FIG. FIG. 3 is a block diagram showing the configuration of each block (white balance adjustment unit 15, switch circuit 16, image signal processing unit 17, control unit 18) shown in the connector unit 14 of FIG. 2 in more detail.
[0027]
A white balance adjustment subject (white member) W and a white balance adjustment image sensor S2 are arranged in the white balance adjustment unit 15 and a white balance adjustment light guide Lb. A tip (injection end) is provided. The light transmitted from the light source Ls is emitted toward the subject W from the emission end of the light guide Lb. The image sensor S2 is arranged to face the subject W, and can capture an image of the subject W illuminated by light from the white balance adjustment light guide Lb.
[0028]
The switch circuit 16 includes, for example, three switches 161, 162, and 163. One of two selectable contacts provided on each of the switches 161 to 163 is connected to a power supply terminal, a drive signal input terminal, and a video signal output terminal of the image sensor S1 provided at the tip of the insertion portion 11, respectively. Have been. On the other hand, the other selectable contacts of the switches 161 to 163 are respectively connected to a power supply terminal, a drive signal input terminal, and a video signal output terminal of the image sensor S2 provided in the white balance adjustment unit 15. The common electrodes of the switches 161 to 163 are connected to a power supply circuit 171, an image sensor driving circuit 172, and an A / D conversion IC 173 in the image signal processing unit 17, respectively. The switching operation of each of the switches 161 to 163 is controlled by the microcomputer 181 in the control unit 18. The microcomputer 181 selects one of the image sensors S1 and S2, and each contact of the switches 161 to 163 is connected to a contact connected to the selected image sensor.
[0029]
The power supply circuit 171 is a circuit for supplying power to the selected imaging elements S1 and S2, and is connected to a power supply unit in the processor unit 20 (in FIG. 2, the power supply unit in the processor unit 20 is Omitted). The image sensor drive circuit 172 is a circuit that supplies a drive signal to the image sensor S1 or S2, and is controlled by a DSP (digital signal processor) 174 in the image signal processing unit 17. The A / D conversion IC 173 samples and holds the image signal from the image sensor S1 or S2, converts the analog signal into a digital signal, and sends it to the DSP 174. In the DSP 174, camera processing such as blanking, clamping, white balance, and γ correction is performed on the image signal, and the image signal is sent to the video signal processing circuit 21 of the processor unit 20.
[0030]
The DSP 174 of the image signal processing unit 17 is controlled by the microcomputer 181 of the control unit 18. On the other hand, the microcomputer 181 performs white balance calculation, exposure calculation and the like based on data from the DSP 174, and performs white balance adjustment in the DSP 174 and control of the electronic shutter in the image sensor S1. The microcomputer 181 is connected to the microcomputer 28 in the processor unit 20 and the nonvolatile memory 182 in the control unit 18. The microcomputer 28 detects an operation of an operation switch (not shown) such as a freeze button provided on the operation unit 12 (see FIG. 1), and notifies the microcomputer 28 of the processor unit 20 of the operation. Further, for example, the memory 182 stores a serial number for identifying each electronic scope, setting values specific to each electronic scope, and the like. These data are also transmitted to the microcomputer 28 via the microcomputer 181. Can be.
[0031]
Next, a white balance adjustment processing operation in the first embodiment will be described with reference to FIG. FIG. 5 is a flowchart of a white balance adjustment process according to the first embodiment.
[0032]
When the power of the processor unit 20 is turned on while the connector unit 14 of the electronic scope 10 is mounted on the processor unit 20 and power is supplied to the electronic scope 10, the microcomputer 181 first selects the switch circuit 16 by using the image sensor. The process is switched to S2 to start the white balance adjustment processing of FIG.
[0033]
In step S101, an image of the white subject W illuminated with light from the light guide Lb is captured by the image sensor S2, and, for example, one frame of RGB image signals are integrated (or averaged) in the DSP 174, respectively. The value is notified to the microcomputer 181. In step S102, the integrated RGB output ratios are compared. In the present embodiment, it is determined whether or not the output values of R and B are equal to the output value of G. If it is determined that either the value of R or B is not equal to the value of G, in step S103, the gains of R, G, and B in the DSP 174 are adjusted. For example, if the ratio of the detected RGB signals is r _R : R _G : R _B , The gains of R, G, and B are respectively 1 / r of the currently set values. _R Times, 1 / r _G Times, 1 / r _B Set to double. When the gain of the G signal is kept constant, each of the R and B gains is set to r. _G / R _R Times, r _G / R _B Set to double. When the change of the gain of each signal is completed, the output ratio of RGB amplified by each gain changed in step S102 is compared. The processes in steps S102 and S103 are repeated until it is determined in step S102 that the output value of G is equal to the output values of R and B.
[0034]
If it is determined in step S102 that G = R and G = B (or R: G: B = 1: 1: 1), the process proceeds to step S104, and the adjusted RGB is stored in the memory 182 in the electronic scope 10. The gain value is stored. As a result, the white balance adjustment processing of the first embodiment ends, and the microcomputer 181 switches the selection of the switch circuit 16 to the image sensor S1. That is, the normal photographing operation of the electronic scope 10 is started, and the image signal of the image taken by the image sensor S1 is sent to the processor unit 20 and displayed on the monitor TV31.
[0035]
In the above description, it is assumed that the imaging device S1 and the imaging device S2 have the same spectral sensitivity characteristics, and that the light emitted from the light guide La and the light emitted from the light guide Lb have the same spectrum. Are not equal. In such a case, for example, a filter may be provided in front of the image sensor so that the spectral sensitivity characteristics of the image sensor S1 are equal to the spectral sensitivity characteristics of the image sensor S2, or the light emitted from the light guide La may be provided. A filter may be provided in front of the light emitting end of the light guide Lb such that the spectrum of the light emitted from the light emitting end of the light guide Lb is equal to the spectrum of the light emitted from the light emitting end. Further, as another method, a white subject illuminated by light from the light guide La is imaged by the image sensor S1 using a predetermined light source in advance, and the ratio of the RGB image signal by the image sensor S1 at this time is calculated. The relationship between the ratio of the RGB image signals by the image sensor S2 when the white object illuminated by the light from the light guide Lb is captured by the image sensor S2 is obtained, and the gain of the image signal for each of RGB is weighted. It is also possible to keep For example, if the spectral sensitivity characteristics of the imaging elements S1 and S2 are equal, but the light from the light guide Lb is 1.2 times stronger than the light from the light guide La, only the blue component is 1.2 times stronger than the other color components. The gain of the image signal for each of RGB is set to be 1: 1: 1.2.
[0036]
As described above, according to the first embodiment, since the white balance adjustment is automatically performed, the user is not bothered by the white balance adjustment work. Further, in this embodiment, since a jig or the like for adjusting the white balance is not required, there is no trouble in storing and preparing the jig. Further, in the present embodiment, since the white balance adjustment is automatically performed when the power is turned on, the user does not need to be conscious of the white balance adjustment itself.
[0037]
In the first embodiment, the white balance adjustment process is automatically performed when the power is turned on. However, when the user feels that the adjustment is necessary, a predetermined switch, for example, a keyboard connected to the processor unit is used. The white balance adjustment processing may be started by performing an operation.
[0038]
Next, an electronic endoscope apparatus according to a second embodiment of the present invention will be described with reference to FIGS. In the electronic endoscope apparatus according to the second embodiment, the configuration of the electronic scope is different from that of the first embodiment, but the configuration of the processor unit is the same as that of the first embodiment. Hereinafter, only a portion different from the first embodiment will be described. Further, the same reference numerals are used for configurations common to the first embodiment.
[0039]
FIG. 5 is a block diagram illustrating a configuration of an electronic scope 10 ′ according to the second embodiment. The image signal processing unit 17 'in FIG. 5 is a combination of the image signal processing unit 17 and the control unit 18 in the first embodiment, and includes a power supply circuit 171, an image sensor driving circuit 172, an A / D converter. It comprises an IC 173, a DSP 174, a microcomputer 181, and a memory 182. In the first embodiment, the image signal processing unit 17 is shared by the image sensor S1 of the electronic scope 10 and the image sensor S2 of the white balance adjustment unit 15, and the selection is performed using the switch circuit 16. On the other hand, the white balance adjustment unit 15 ′ of the second embodiment includes an image processing circuit 151, an RGB gain adjustment circuit 152, and a memory 153 independently of the image signal processing unit 17.
[0040]
The image sensor S2 captures an image of a white subject (white member) W irradiated with light from the light guide Lb. At this time, the image processing circuit 151 of the white balance adjustment unit 15 ′ samples and holds the image signal from the image sensor S2, performs A / D conversion, and separates the image signal into RGB image signals. Further, the image processing circuit 151 controls the driving of the image sensor S2. The RGB gain adjustment circuit 152 integrates (or averages) image signals for one field for each of RGB, calculates an appropriate RGB gain based on the integrated image signal value for each of RGB, and calculates the calculated RGB. The RGB gain in the image processing circuit 151 is adjusted based on the value of the gain. The calculated RGB gain values are stored in the readable and writable nonvolatile memory 153 and output to the microcomputer 181 of the image signal processing unit 17 ′. The RGB gain adjustment circuit can control the drive timing of the image processing circuit 151 and the like based on a signal from the microcomputer 181. Further, in the present embodiment, the integration is performed for one field, but may be performed for one frame, or may be performed for a partial area of a one-field image.
[0041]
FIG. 6 is a flowchart of the white balance adjustment processing according to the second embodiment. In the second embodiment, the white balance adjustment processing is performed in parallel with the normal image processing for endoscopic observation in the image signal processing unit 17 ′. In other words, while the image of the observation region captured by the image sensor S1 is displayed on the monitor TV 31, the white balance adjustment processing of FIG. 6 is executed at predetermined intervals. Note that the execution of the white balance adjustment process is performed using, for example, an interrupt process.
[0042]
In the white balance adjustment processing of the second embodiment, first, in step S201, an image of a white subject W illuminated with light from the light guide Lb is captured by the image sensor S2, and is stored in the memory 153 in the image processing circuit 152. The RGB image signals amplified based on the recorded RGB gain values are respectively integrated (or averaged) for one frame.
[0043]
In step S202, the integrated RGB output ratio is compared in the RGB gain adjustment circuit 152. That is, it is determined whether the values of R and B are equal to the value of G. If it is determined that either the value of R or B is not equal to the value of G, the gains of R, G, and B in the image processing circuit 151 are adjusted in step S203. For example, if the ratio of the detected RGB signals is r _R : R _G : R _B , The gains of R, G, and B are respectively 1 / r of the currently set values. _R Times, 1 / r _G Times, 1 / r _B Set to double. When the gain of the G signal is kept constant, each of the R and B gains is set to r. _G / R _R Times, r _G / R _B Set to double. When the gain of the RGB signal is changed, the process returns to step S202, and the output ratio of the RGB image signal amplified by the changed gain is compared. The processes of steps S202 and S203 are repeated until it is determined that G = R and G = B in step S202.
[0044]
If it is determined in step S202 that G = R and G = B (or R: G: B = 1: 1: 1), in step S204, the adjusted RGB is stored in the memory 153 in the white balance adjustment unit 15 ′. The gain value is recorded, and the RGB gain value is output to the microcomputer 181 of the image signal processing unit 17 '. In step S205, the microcomputer 181 sets the RGB gain in the DSP 174 based on the input RGB gain value. Thus, the white balance adjustment processing of the second embodiment ends.
[0045]
If the spectral sensitivity characteristics of the imaging elements S1 and S2 and the spectrum of light emitted from the light guides La and Lb are different, a filter is provided or calibration is performed in advance as in the first embodiment. In this way, RGB weighting is performed.
[0046]
As described above, also in the second embodiment of the present invention, the same effects as in the first embodiment can be obtained. In the second embodiment, since the white balance adjustment unit includes an independent image signal processing system, it is possible to perform white balance adjustment while performing shooting for endoscopic observation with an electronic scope. Furthermore, in the second embodiment, since the white balance adjustment is repeatedly performed at a predetermined interval, even if the spectrum of the light source fluctuates from the time the light source is turned on until the output becomes stable, it follows the fluctuation. To adjust the white balance. In addition, since the spectrum of the illumination light is also affected by the aperture, if the light amount is changed during endoscopic observation, the white balance may be lost. In the second embodiment, the white balance is repeatedly adjusted. Since this is done, this can be handled.
[0047]
In the present embodiment, the single-chip simultaneous imaging system equipped with an on-chip color filter has been described as an example. However, the present invention can be applied to a frame sequential imaging system. In the present embodiment, the image sensor is used for the white balance adjustment unit. However, any sensor (light receiving element) capable of detecting the spectrum of light from the light guide for performing gain adjustment may be used. It is not something to be done. For example, a color sensor including a set of three or more photodiodes having RGB filters may be used.
[0048]
【The invention's effect】
As described above, according to the present invention, white balance adjustment in an electronic endoscope can be easily performed.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a configuration of an electronic endoscope apparatus according to a first embodiment to which the present invention has been applied.
FIG. 2 is a block diagram schematically showing a circuit configuration of the electronic endoscope apparatus according to the first embodiment shown in FIG.
FIG. 3 is a block diagram illustrating a circuit configuration of the electronic scope according to the first embodiment.
FIG. 4 is a flowchart of a white balance adjustment process according to the first embodiment.
FIG. 5 is a block diagram illustrating a circuit configuration of an electronic scope according to a second embodiment.
FIG. 6 is a flowchart of a white balance adjustment process according to the second embodiment.
[Explanation of symbols]
10 Electronic scope
11 Insertion section
15 White balance adjustment unit
16 Switch circuit
17 Image signal processing unit
151 Image processing circuit
152 RGB gain adjustment circuit
174 DSP
S1, S2 imaging device
W White subject
L, La, Lb Light guide
Ls lamp

Claims (7)

An electronic endoscope comprising: a light transmission unit configured to transmit illumination light to a distal end of an insertion unit; and a first imaging device configured to capture an image of the distal end of the insertion unit using the illumination light.
A white member as a reference for white balance adjustment;
A color signal detection unit that irradiates a part of the light transmitted by the light transmission unit to the white member and detects a color signal corresponding to a spectrum of light reflected from the white member,
An electronic endoscope comprising: a white balance adjustment unit that adjusts a first gain corresponding to each color component of an image signal detected by the first image sensor based on the color signal. 2. The electronic endoscope according to claim 1, wherein the white balance adjustment unit adjusts the first gain so that an output ratio of an image signal for each color component becomes uniform. The electronic endoscope according to claim 1, wherein the color signal detection unit includes a second image sensor for white balance adjustment, and the color signal is generated from an image signal of the second image sensor. mirror. Image signal processing means capable of processing an image signal of the first or second image sensor;
Switching means for selectively selecting one of the first and second imaging elements and connecting to the image signal processing means,
The electronic endoscope according to claim 3, wherein the color signal is generated by the image signal processing means, and the first gain is adjusted in the image signal processing means. When the power of the electronic endoscope is turned on, the switching means connects the second image pickup device to the image signal processing means, drives the white balance adjustment means, and controls the first balance by the white balance adjustment means. 5. The electronic endoscope according to claim 4, wherein when the adjustment of the gain is completed, the first imaging device is connected to the image signal processing unit by the switching unit. 6. First image signal processing means for processing an image signal of the first image sensor;
Second image signal processing means for processing the image signal of the second image sensor and generating the color signal;
Gain adjustment means for adjusting a second gain of each color signal in the second image signal processing means so that an output ratio of each color signal becomes a predetermined value,
The electronic endoscope according to claim 3, wherein the white balance adjustment unit adjusts the first gain based on the second gain. 7. The apparatus according to claim 6, wherein the second image processing unit, the gain adjustment unit, and the white balance adjustment unit are repeatedly driven at predetermined intervals while the first image processing unit is being driven. An electronic endoscope according to item 1.

Images