JP2003325444A - Electronic endoscopic equipment and image signal processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To alter a visual field without operating an electronic endoscope. <P>SOLUTION: A memory 42 is provided to an electronic scope 10 and the mask position data peculiar to the individual electronic scope 10 are stored in the memory 42. When the electronic scope 10 is mounted in a processor 100, the processor 100 reads the mask position data from the memory 42. A memory control circuit 120 applies mask processing to the image signal read from an image memory 106 on the basis of the mask position data and the mask data read from an ROM 122. By altering the mask position data arbitrarily by the operation of the specific switch of a front panel switch 114, the visual field of the image to be displayed on a monitor 200 is altered. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus, and more particularly to signal processing for a video signal obtained from an image sensor.

[0002]

2. Description of the Related Art Electronic endoscopes have been widely used in recent years as an effective means for observing an object, for example, the inner wall of the digestive organ in an instant. The electronic endoscope includes an insertion part that is inserted into a body organ or the like, and an imaging element combined with an objective lens is embedded at the tip of the insertion part. The image sensor transmits a video signal corresponding to the subject image to a dedicated video signal processing device called a processor, and the processor reproduces a color image of the subject on the monitor screen based on the video signal.

Conventionally, the area of the image pickup device from which the video signal is to be read is predetermined, and it has been necessary to change the orientation of the insertion portion in order to change the visual field on the monitor screen.

[0004]

However, when there are a plurality of objects of interest such as the affected area and the forceps, such as when treating the affected area with forceps or the like, one of the objects of interest is brought into focus. It is preferable to form an image in the center of the matching imaging surface, but changing the field of view requires changing the orientation of the insertion part, that is, the operation of the electronic endoscope itself, which not only complicates the operation but also inserts it during treatment. There is a problem that the movement of the part causes a treatment error.

Further, when observing a narrow tubular inner wall such as the duodenum, it is practically impossible to change the direction of the insertion section, and in order to change the visual field, the insertion direction of the insertion section is changed. Therefore, it is necessary to switch and use a plurality of electronic endoscopes having different visual field directions, which requires a long time for observation and treatment, resulting in a heavy burden on the patient.

The present invention has been made in view of the above problems, and an object thereof is to provide an electronic endoscope apparatus and a video signal processing apparatus which can easily change the field of view without operating the electronic endoscope. I am trying.

[0007]

An electronic endoscope apparatus of the present invention selects an arbitrary part from an image pickup device for photoelectrically converting an optical image of a subject into a video signal and a video signal obtained from the image pickup device. And a display unit for reproducing the optical image of the subject in a specific display area of the monitor screen based on the video signal extracted by the extraction unit, and the video signal to be extracted is selected by the extraction unit. Therefore, the main feature is to arbitrarily change the field of view in the display area.

It is preferable that the electronic endoscope apparatus further comprises masking means for converting the remaining video signals excluding the video signal selected by the extracting means into color signals of a specific level.

Further, the video signal processing device of the present invention is attachable to and detachable from an electronic endoscope equipped with an image pickup device for photoelectrically converting an optical image of a subject into a video signal, and a video signal obtained from the image pickup device is used. Extraction means for selecting and extracting an arbitrary part, and display means for reproducing an optical image of the subject in a specific display area of the monitor screen based on the video signal extracted by the extraction means are extracted by the extraction means. It is characterized in that the visual field in the display area is arbitrarily changed by selecting the video signal to be displayed.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an electronic endoscope system to which the electronic endoscope apparatus of this embodiment is applied. The electronic endoscope apparatus according to the first embodiment converts an optical subject image into a video signal and displays the video signal on a monitor screen. The simultaneous imaging system is adopted to reproduce a color image. The NTSC system is adopted as the standard.

The electronic endoscope apparatus includes a scope (electronic endoscope) 10 which is a side-viewing type electronic endoscope, a processor 100 to which the scope 10 is connected, and a monitor device 200 connected to the processor 100. Prepare

The scope 10 includes a flexible tube 20. The scope 10 includes a light guide member 12 including an optical fiber bundle.
(Shown by hatching in the figure) is the tip portion 2 of the flexible tube 20.
0a, and the base end side of the light guide member 12 is optically connected to the light source unit 102 provided in the processor 100 when the scope 10 is attached to the processor 100. As a result, the illumination light from the light source unit 102 is guided to the flexible tube distal end portion 20a by the light guide member 12, and the subject on the side of the distal end portion, for example, the visceral organ 500 is illuminated.

An image sensor 14 having a solid-state image sensor, such as a CCD, is provided at the flexible tube tip portion 20a. As shown in the partially enlarged sectional view of FIG. 2, the image sensor 14 includes an objective lens system 16 combined with a CCD 18, and an optical mask 22 is integrally formed on the image pickup surface side of the CCD 18, that is, the objective lens side. It is provided in. An optical image of the subject illuminated by the white illumination light is formed on the image pickup surface of the CCD 18 by the objective lens system 16, and converted into light of each color by a complementary color chip filter (not shown) on the image pickup surface. The optical object image formed on the CCD 18 is photoelectrically converted into an analog image pickup signal for one frame by the image pickup sensor 14, and sequentially read out from the CCD 18 by the CCD drive signal generated by the timing control circuit 112 of the processor 100. The optical mask 22 blocks the light to the area that is not imaged by the objective lens system 16.

The analog image pickup signal read from the image pickup sensor 14 is transmitted to the first stage video signal processing circuit 104.
The first-stage video signal processing circuit 104 has a preamplifier, a video filter, a sample hold circuit, a γ circuit, and the like.
In (1), image processing is performed according to the characteristics of the image sensor 14 and the optical characteristics of the scope 10, and further converted into a component digital signal composed of a luminance signal Y and color difference signals Cb and Cr, which are sequentially stored in the image memory 106.

The component digital signal for one frame is read from the image memory 106 and sent to the subsequent video signal processing circuit 108. Rear video signal processing circuit 10
Reference numeral 8 includes a video filter, a white balance correction circuit, a clamp circuit, a γ correction circuit, a contour enhancement circuit, a character imposing circuit, and the like. The component digital signal is output to the monitor device 200 in the subsequent video signal processing circuit 108.
The image processing is performed according to the characteristics of, and further converted into an analog color video signal such as an NTSC composite video signal in which a color difference signal and a decoding synchronization signal are multiplexed on a luminance signal.

The analog color video signal is processed by the processor 1.
00 to the monitor device 200, and the monitor device 20
A subject image is reproduced on the screen of 0 based on this analog color video signal. The analog color video signal is output from the processor 100 to a recording device 300 such as a VTR or VCR and recorded on a video tape or the like. Further, the analog color video signal is output to a medical image filing device 350 such as a personal computer via an interface (not shown) and is written therein as a still image or moving image data in a recording medium such as a hard disk.

A keyboard 400 is connected to the system control circuit 110 as an external input device, and character information such as a patient name input from the keyboard 400 and an observation date and time obtained from a timer circuit (not shown) is used by the system control circuit 110 to form a character pattern. It is converted into a signal and output to the character imposing circuit of the subsequent video signal processing circuit 108, where it is added to the component digital signal. As a result, the character information is displayed on the screen of the monitor device 200 together with the reproduced color image of the optical subject image.

The system control circuit 110 is a microcomputer that controls all operations of the processor 100, and is provided with a CPU, a ROM that stores programs and parameters for executing various routines, and a RAM that temporarily stores data and the like. . The timing control circuit 112 generates a timing signal such as a synchronization signal for synchronizing the operation of each circuit.

The processor 100 is provided with a front panel 114 having a plurality of switches for manually adjusting the image quality, the amount of illumination light, etc., and setting various modes, and each circuit of the processor 100 and A power supply unit 116 that supplies electric power to the light source unit 102, and a power supply unit 1
A main power button 118 for switching ON / OFF of 16 is provided.

The scope 10 has a grip portion 30 which is integral with the flexible tube 20, and the grip portion 30 is provided with various buttons for mechanically operating the flexible tube 20. Further, the connector section 40 provided at the end of the connected flexible tube integrally extending from the grip section 30 has various connectors for optically and electrically connecting to the processor 100 and a connector unique to the electronic endoscope. A memory 42 is provided for storing the mask position data. The memory 42 is, for example, a rewritable EEPR.
OM.

The processor 100 has a mask processing function of applying an electronic mask to the outer edge of the subject image obtained from the scope 10 and displaying only the focused region on the monitor screen by the objective lens system 16 (FIG. 2). ing.
The processor 100 includes a memory control circuit 120 that controls a writing operation and a reading operation of a component digital signal with respect to the image memory 106, and outputs an electronic masked image by adjusting a read address generated by the memory control circuit 120. is doing.

More specifically, the memory control circuit 12
0 is a mask position data indicating the relative position of the electronic mask when the scope 10 is connected, by reading from the ROM 122 mask data indicating the size and shape of the electronic mask to be applied to the reproduced color image when the main power of the processor 100 is turned on. Is read from the memory 42 built in the scope 10, and when the scope 10 is operated, a series of read addresses is generated based on the mask data and the mask position data. When a series of read address data is output to the image memory 106, a predetermined component digital signal, that is, a luminance signal Y and color difference signals Cb, C are output from the image memory 106 according to the read address data.
r is output to the subsequent video signal processing circuit 108.

The masking process will be described with reference to FIGS. 3 and 4. FIG. 3 is a diagram conceptually showing the relative positional relationship between the pixel region and the image pickup region of the CCD 18, the image formation region of the objective lens system on the image pickup surface of the CCD 18, the light shield region by the optical mask, and the electronic mask region. FIG. 4 is a front view of the monitor device 200.

The CCD 18 is composed of a large number of pixels which are two-dimensionally arranged, and M pixels are arranged in the horizontal direction (indicated by arrow X in the drawing) and N pixels are arranged in the vertical direction (indicated by arrow Y in the drawing). There is. The relative position of an arbitrary pixel G in the pixel area of the CCD 18 is determined by setting the pixel at the upper left corner of the CCD as the origin (0,
It is represented by the relative position (i, j) from the origin when the value is set to 0). Parameter i is the origin Go (0,0) in the X direction
And the condition 0 ≦ i ≦ M is satisfied. Also,
The parameter j is the number of pixels from the origin Go (0,0) in the Y direction and satisfies the condition 0 ≦ j ≦ N.

In the CCD 18, not all pixels are used for image pickup, but m × n pixels (m ≦ M, n included in a rectangular image pickup area KR surrounded by a dashed line in the figure).
Only ≦ N) can output the image pickup signal corresponding to the subject image, and the pixels included in the region surrounding the outside output the signal for determining the black level. The relative position of the imaging region KR in the pixel region is represented by the distance (Sx, Sy) from the origin to the read start pixel Gs at the upper left corner of the imaging region KR. The image memory 106 of the processor 100 has a C
Although component digital signals for all pixels of the CD 18, that is, M × N pixels, are written, only m × n pixels included in the imaging region KR are read.

An area where the objective lens system 16 can form a clear image on the image pickup surface is defined as an imaging area FR (a circular area surrounded by a broken line in the drawing). Objective lens system 16
Is provided so that the imaging region FR covers almost the entire imaging region KR and the imaging center Cf thereof coincides with the center Ck of the imaging region KR. Since the optical mask 22 is provided so as to cover the outside of the image formation region FR, it has a substantially triangular shape inside the image pickup region KR and outside the image formation region FR, that is, at the four corners of the image pickup region KR in the figure. Optical mask area MR
1 to MR4 (indicated by hatching to the right) output black level signals based on the dark current because they are covered by the optical mask 22.

When reading the component digital signal from the image memory 106, the processor 100 reads only the component digital signal corresponding to the rectangular area surrounded by the chain double-dashed line, and the latter stage video signal processing circuit 108.
Give to. This rectangular area is an area that can be displayed as a subject image on the screen 202 of the monitor device 200, and is defined here as a video area PR. This image area PR
Are smaller than the horizontal direction pixel number m and the vertical direction pixel number n of the imaging region KR, respectively, and the video region PR is inside the imaging region KR.
Strictly speaking, it is arranged inside the four optical mask regions MR1 to MR4.

The square-shaped region surrounding the outside of the image region PR is defined as the electronic mask region ME, and is shown by hatching in the upper left direction in the drawing. As is apparent from the figure, the optical mask regions MR1 to MR4 are included in the electronic mask region ME. When reading the component digital signal from the image memory 106, the processor 100 does not read the component digital signal corresponding to the electronic mask region ME, and outputs a mask color signal (for example, a black level signal) to the subsequent video signal processing circuit 108. give. That is, by converting the component digital signal corresponding to the electronic mask area ME into a mask color (background color) signal,
An electronic mask is applied to the electronic mask region ME including R1 to MR4. The shape of the electronic mask is not limited to the square shape, and the size thereof is not limited to that of the present embodiment as long as it has an area and a shape enough to cover the optical mask region.

As shown in FIG. 4, a video display area WPR is set at a predetermined position on the screen 202 of the monitor device 200, and the video display area WPR is included in the video area PR read from the image memory 106. A subject image corresponding to α × β pixels is displayed. An area surrounding the outside of the video display area WPR is represented by a background color (for example, a black level color).

Information on the image region PR, that is, mask data indicating the size and shape of the region where the image signal is to be output, is stored in the ROM 122. Further, the mask position data indicating the relative position of the image area PR in the image pickup area is stored in the memory 42. In the present embodiment, the operator can arbitrarily change the mask position data, that is, the relative position of the image region PR, so that the visual field on the monitor screen can be changed without operating the electronic endoscope.

FIG. 5 is a front view showing the appearance of the processor 100. A front panel 114 and a main power button 118 are provided on the surface of the processor 100. The front panel 114 is arranged in a region surrounded by a broken line in the drawing, and a visual field changing switch group 130, specifically, an upward moving switch 132, a downward moving switch 134, a rightward moving switch 136, and a leftward direction. A movement switch 138, a center movement switch 140, and first to third preset switches 142, 144, 146 are provided.

FIG. 6 is a diagram showing a change in the relative position of the image area PR by the manual operation of the switch group 130, and FIGS. 7 and 8 are displayed on the monitor screen when the relative position of the image area PR is changed. It is a schematic diagram which shows a to-be-photographed image.

The image area PR is the image pickup area K as an initial position.
It is defined at the center of R, and its initial position is shown by a chain double-dashed line in FIG. The image area PR is relatively movable within the imaging area KR, and when the upward movement switch 132 is pressed, the image area PR moves in the negative direction (upward in the figure) along the Y axis, and similarly, the downward movement switch 134. Is pressed in the positive direction along the Y axis (downward in the figure), and when the rightward movement switch 136 is pressed, it is moved in the positive direction along the X axis (rightward in the figure) and the leftward movement switch 138. When is pressed, it moves in the negative direction (left in the figure) along the X axis,
Move relative to each other. When the center movement switch 140 is pressed, it is returned to the initial position in any position.

For example, in a state where the subject image S, which is shown as a hatched substantially circular shape in FIG. 6, is formed in the image pickup region KR, the image region PR is moved from the initial position to the upper left in the diagram by pressing the switches 132 and 138. When it is moved to a position deviated in the direction (position shown by a dotted line in the figure), the image area P
The relative position of the subject image S in R moves in the lower right direction. Therefore, although the insertion section 20 is not actually operated, the tip of the insertion section 20 is moved to the CCD 18 as if the subject image S moves in the lower right direction on the monitor screen 202 as shown in FIG. An image as if moved in the direction corresponding to the upper left direction of FIGS. 1 and 2 is displayed. Also,
By pressing the switches 134 and 136, the image area PR
Is moved to a position deviating from the initial position to the lower right direction in the figure (position indicated by a broken line in the figure), the subject image S in the image region PR relatively moves to the upper left direction, and as shown in FIG. On the monitor screen 202, an image is obtained in which the tip of the insertion section 20 is moved in a direction corresponding to the lower right direction of the CCD 18 as if the subject image S were moved in the upper left direction. 7 and 8, the position of the subject image S when the video region PR is set to the initial position is shown by a broken line.

The first to third preset switches 142, 1
44 and 146 are respectively assigned the relative positions of the set video regions PR, and the video regions PR are moved to the corresponding relative positions simply by pressing the first to third preset switches 142, 144 and 146. Can be made. The data of the image area PR corresponding to the preset switches 142, 144 and 146, that is, the mask position data can be changed according to the preference of the operator.

The mask position data changed by the switch group 130 is associated with the information unique to each scope 10 such as the product name and product number of the scope 10 and the operator name by the memory control circuit 120, and is incorporated in the scope 10. The recorded data is recorded in the memory 42. Therefore, when the same scope 10 is connected to the processor 100 again, the previous mask position data is read out by the memory control circuit 120, and the operator can observe and treat in a visual field according to his / her preference without being aware of it. .

The switch group 130 is incorporated in the front panel 114 of the processor 100, but the function of the switch group 130 may be provided in a dedicated input device separate from the processor 100, or a keyboard may be used. The configuration may be such that it is assigned to a specific key of 400, a configuration in which a combination of a plurality of keys is provided, or a configuration in which the relative position of the image region PR is changed by voice input using a microphone.

FIG. 9 shows a video signal processing program executed in the system control circuit 110. This program is started when the main power is turned on, and when the connection of the scope 10 is detected in step S102, the mask position data is read from the memory 42 of the connected scope 10 in the next step S104. In the following step S106, the image memory 1 is read based on the read mask position data and the mask data in the ROM 122.
The video signal read from 06 is masked and transmitted to the monitor device 200.

In step S108, it is detected whether or not the position change of the image area PR is instructed by the operation of the switch group 130. If the position change of the image area PR is instructed, the mask position data is updated in step S110. , Mask processing is performed based on the mask position data updated in step S112, and step S11
At 4, the mask position data is written in the memory 42. Then, in step S116, it is detected whether or not the scope 10 is pulled out. If it is pulled out, this program is ended, and if it is determined that it is connected, the process returns to step S108. If it is determined in step S108 that the switch group 130 is not operated, steps S110 to S114 are not executed and step S11 is executed.
Go to 6.

Further, an image recognition circuit for recognizing a particular target object such as forceps from the video signal read out from the image memory 106 is further provided at the subsequent stage of the image memory 106, and the target object on the video region PR is provided by the image recognition circuit. When the relative movement is detected, the data of the movement direction and the movement amount are sent to the system control circuit 110, and the electronic mask position, that is, the position of the image area PR is automatically adjusted so that the object of interest is always in the center of the screen. You may adjust. In this case, it is not necessary to operate the switch group 130 at the same time when the forceps are operated, and the operability is extremely improved.

In the present embodiment, the electronic endoscope is a side-view type in which the optical axis of the objective optical system is perpendicular to the true axis of the insertion portion. It may be a direct-viewing type electronic endoscope whose optical axis is parallel to, or a perspective-type electronic endoscope in which the optical axis of the objective optical system is inclined with respect to the axis of the insertion portion.

[0043]

As described above, the electronic endoscope apparatus of the present invention has the advantage of being excellent in operability because the field of view can be changed without operating the scope.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an electronic endoscope apparatus according to the present invention, and is a schematic block diagram of an electronic endoscope system.

FIG. 2 is a partially enlarged cross-sectional view schematically showing a configuration of a flexible tube tip of the electronic endoscope shown in FIG.

FIG. 3 is a schematic diagram showing a relative positional relationship among an image pickup surface of the CCD shown in FIG. 1, an image forming area, an optical mask area, and an electronic mask area.

FIG. 4 is a diagram showing a video display area set on a screen of a monitor device.

FIG. 5 is a front view of the processor.

FIG. 6 is a schematic diagram showing a change in relative position of an image area on an image pickup surface of a CCD.

FIG. 7 is a schematic diagram showing a relative position change of a subject image on a monitor screen when a video area relatively moves.

8 is a schematic diagram showing a change in relative position of a subject image on the monitor screen when the image area relatively moves in a direction different from that in FIG. 7.

FIG. 9 is a flowchart showing a video signal processing program executed by a system control circuit.

[Explanation of symbols]

10 electronic endoscope 18 CCD (imaging device) 42 memory 100 processor (video signal processor) 106 image memory 120 memory control circuit 122 ROM 200 monitor

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Claims (3)

[Claims] 1. An image pickup device for photoelectrically converting an optical image of a subject into a video signal, an extracting unit for selecting and extracting an arbitrary part from a video signal obtained from the image pickup device, and an extracting unit for extracting the image signal. Display means for reproducing an optical image of a subject in a specific display area of the monitor screen based on the video signal, and by selecting the video signal to be extracted by the extraction means, the visual field in the display area can be arbitrarily set. An electronic endoscope device characterized by being changed. 2. The electronic endoscope according to claim 1, further comprising masking means for converting the remaining video signals excluding the video signal selected by the extracting means into color signals of a specific level. Mirror device. 3. An electronic endoscope having an image pickup device for photoelectrically converting an optical image of a subject into a video signal, wherein the electronic endoscope is detachable, and an arbitrary part is selected from the video signal obtained from the image pickup device. An extraction unit for extracting and a display unit for reproducing an optical image of the subject in a specific display area of the monitor screen based on the video signal extracted by the extraction unit are selected, and the video signal to be extracted by the extraction unit is selected. By so doing, the visual field in the display area can be arbitrarily changed.