JP2001197487A - Electronic endoscope system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a still image with excellent image quality and without blurs by eliminating the mixture of image data obtained with different exposure time. SOLUTION: The whale pixel data are read from a CCD 11 by a non interlacing system at a 1/20 sec speed, e.g. and the image data are converted into image data at each 1/60 sec by an a-fold speed converting circuit 25 and outputted as a non-interlacing signal. An interlacing converting circuit 27 is provided with a frame memory 28 and a memory control circuit 29. When a freeze switch is depressed, write to the frame memory 28 is controlled. Then the odd-numbered and even-numbered field signals are generated without the mixture of image data through exposures with different timings so that the still image with satisfactory quality and without blurs is displayed.

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 the structure and processing of an electronic endoscope apparatus for forming a good still image from an image signal captured by an image sensor.

[0002]

2. Description of the Related Art An electronic endoscope apparatus is an image pickup device, for example, a CCD (Ch
arge Coupled Device)
By subjecting the video signal (image signal) obtained by the CCD to predetermined image processing, a moving image of the observed object image is displayed on the monitor. A freeze switch is arranged on the operation unit of the electronic scope. By pressing the freeze switch, a still image at that time is formed,
The still image is displayed and recorded on a recording device such as a video printer.

[0003]

By the way, recently, the number of pixels of the CCD used in the electronic scope has tended to increase, and from the conventional 410,000 pixels to the production of, for example, 850,000 pixels or more of CCDs. I have. But CC
The large number of pixels of D means that the amount of data to be read is large, which means that the time required to read data of one image (screen) is long. Processing for matching the read speed of the CCD with the display speed of the television monitor is required.

FIG. 5 shows a video signal processing circuit proposed by the present applicant in a very recent electronic endoscope apparatus using a CCD having a high number of pixels. It forms and outputs both a non-interlaced video signal and an interlaced video signal. In FIG. 5, for example, a CCD 1 of 850,000 pixels
Are driven by a non-interlace method of sequentially reading data of all pixels obtained by one exposure.
The video signals of all the pixels D1 are temporarily stored in the memory 2A of the n-times speed conversion circuit 2.

The memory 2A is controlled by a memory control circuit 2B. For example, when the reading speed of all pixel data from the CCD 1 is 1/20 second, the memory 2A is tripled (n).
The image data is obtained in 1/60 second at a reading speed of (2 ×). The output of the n-times conversion circuit 2 is used as a non-interlace video signal by a personal computer or the like, and is also supplied to the interlace conversion circuit 3. The interlace conversion circuit 3 converts the video signal into an odd field video signal and an even field video signal.
Output to the TV monitor.

FIG. 6 shows image data formed by the above configuration. The output (,...) From the CCD 1 obtained every 1/20 second shown in FIG. Is stored in the memory control circuit 2B.
As shown in FIG. 6 (B), the same image data is read out for 1/60 second and is
Each time (,,,, ...) is output.
Therefore, an image of the object to be observed is displayed on a monitor of a personal computer or the like by the non-interlace video signal. On the other hand, in the interlace conversion circuit 4, as shown in FIG. 6C, the image data (e1, o1, e2, o2, o2) of the odd field and the even field every 1/60 second.
e3, o3 ...) are generated, and the interlaced image is displayed on the television monitor.

In the electronic scope, a still image can be obtained by the freeze switch of the operation unit. When the freeze switch is pressed during the period a in FIG. ) Even field data e1
And the odd field data o1, a still image is formed. Similarly, according to the operation of the freeze switch during the period of b, c, d..., (F), (G), (H),
A still image is formed by the even and odd field data shown in (I), and this still image is displayed on a television monitor and recorded on a recording device.

However, in the above-described still image formation, the even and odd field data shown in FIGS. 6E, 6F and 6H are obtained by the same exposure (or). However, the even and odd field data shown in (G) and (I) in FIG. 6 are data obtained by mixing data obtained by different exposures, as in the case of or at least, and the time of 1/60 second is reduced. One frame image composed of the image data having a shift is displayed on the television monitor.

Therefore, if the object to be observed moves during 1/60 second, it appears in the still image as a blur of the image, and there is a disadvantage that the screen becomes hard to see. Still images require clear image quality, unlike moving images that need to capture motion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to eliminate the mixture of image data obtained by exposure at different times and to form an electronic image capable of forming a still image of good image quality. An endoscope apparatus is provided.

[0011]

According to a first aspect of the present invention, there is provided an electronic endoscope apparatus comprising: a solid-state imaging device configured to read out an image signal at a predetermined speed in a sequential scanning format; A speed conversion circuit for converting an image signal having a speed different from the reading speed of the solid-state imaging device, a frame memory for storing a frame image signal output from the solid-state imaging device, and controlling writing in the frame memory. And a signal processing circuit for interlaced scanning for forming at least a still image signal for interlaced scanning.

According to the configuration of the present invention, in the solid-state image pickup device, the image signals of all pixels are read out at a speed of, for example, 1/20 second by the sequential scanning method (non-interlace). The speed is converted into a speed at which one frame is output in 1/60 second by a speed conversion circuit, for example. Therefore, this image signal can be output to a non-interlace monitor for observation. Thereafter, the output of the speed conversion circuit is temporarily stored in a frame memory, and interlaced scanning (interlace) is performed based on the output of the frame memory.
The odd-numbered and even-numbered field image signals are formed, so that the interlaced object image (moving image) can be observed on the monitor.

When the freeze operation is performed, a still image is formed based on the data once stored in the framed memory, and the odd field data and the even field data obtained at the same exposure are used. A still image is displayed. Therefore, image data of exposures at different times are not mixed, and a still image of good image quality without image blur can be obtained.

[0014]

1 and 2 show the structure of an electronic endoscope apparatus according to an embodiment. First, the entire electronic endoscope apparatus will be described with reference to FIG. In the illustrated electronic endoscope (scope) 10, a CCD 11
The electronic scope 10 is connected to a light source device 14 and a processor device 15 via a cable. The processor device 15 is connected to, for example, a personal computer monitor 17 which is a monitor for progressive scanning (non-interlace) and a television monitor 18 which is a monitor for interlaced scanning (interlace). Further, an interlaced image signal (video signal) is supplied to various recording devices, and for example, a video printer device 20 and a hard copy device 21 are provided.

In FIG. 1, the CCD 11 has, for example, 850,000 pixels, and a non-interlaced sequential reading control is performed by a CCD driving circuit 24.
All 11 pixel data are read out at 1/20 second. At the subsequent stage of the CCD 11, an n-speed conversion circuit 25 comprising a memory 25A and a memory control circuit 25B is connected. In the n-speed conversion circuit 25, all pixel data stored in the memory 25A is read out by the CCD 11 at a reading speed (frequency). The reading is performed at 1/60 second, which is three times the speed of.

The output of the n-times speed conversion circuit 25 is output to the personal computer monitor 17 and the like as a non-interlace video signal, and is also supplied to the interlace conversion circuit 27. The interlace conversion circuit 27 includes a frame memory 28, a memory control circuit 29, and a conversion output unit 30. The interlace conversion circuit 27 temporarily stores all the pixel data in the 1/60 second period in the frame memory 28, and stores the data in the frame memory 28. By reading, odd field data and even field data are alternately formed and output every 1/60 second. The output of the interlace conversion circuit 27 is output to a recording device such as the television monitor 18 or the video printer 20 as an interlace video signal.

The embodiment has the above configuration, and its operation will be described with reference to FIGS. 3 and 4. FIG. As shown in FIG. 3A, the video signal of the object captured by the CCD 11 of the electronic scope 10 is obtained by non-interlacing every pixel data obtained by the same exposure every 1/20 second. And sequentially stored in the memory 25A. The video signal stored in the memory 25A is converted by a triple read frequency signal as shown in FIG.
As shown in (1), all pixels are read out three times at a speed of 1/60 second and output to the personal computer monitor 17. Therefore, on the personal computer monitor 17, the image data,.
,, ... are displayed as moving images by non-interlace.

On the other hand, the output of the memory 25A is supplied to an interlace conversion circuit 27.
7, the non-interlaced output of FIG. 3B is temporarily stored in the frame memory 28. Next, the data in the frame memory 28 is read out every 1/60 second and supplied to the conversion unit 30, and as shown in FIG. 3C, the image data e1, o of the odd field and the even field.
1, e2, o2, e3, o3... Are formed. This image data is supplied to the television monitor 18,
Displayed as a moving image by interlacing.

When the freeze switch 12 of the electronic scope 10 is operated, still image processing is performed. For example, when the switch 12 is pressed during the period a in FIG. 3D, FIG. Are prohibited from being written into the frame memory 28. After that, as shown in FIG.
The data of (F) is read out every 1/60 second, and based on this data, two data of o1 (odd field data) and e1 (even field data) shown in FIG. Are repeatedly formed.
These data are displayed as a still image by being output to the television monitor 18, and are output to the video printer 20.
Etc. are also recorded.

Further, when the freeze switch 12 is depressed during the period b in FIG. 3D, FIGS.
As shown in (1), write inhibition and read control of the frame memory 28 are performed, and data o1 and e1 are repeatedly formed, whereby a still image is displayed. Similarly, when the freeze switch 12 is operated during the period c in FIG. 3D, the data of o1 and e1 every / 60 seconds [FIGS. 4K to 4M] and FIG. When the freeze switch 12 is pressed during the period d, a still image is formed by the data of o1 and e1 [FIG.
(P)]. Therefore, no matter what period the freeze operation is performed, a still image is always formed by odd and even field data of a combination of the same number (circled number). That is, a still image is displayed based on the image data at the same exposure, and a high-quality still image without image blur can be obtained.

In the above-described embodiment, all the pixels are read out from the CCD 11 in 1/20 second.
The data may be read out in seconds or the like. In this case as well, the same effect as described above can be obtained by converting the data into a speed at which one frame data is output in 1/60 seconds (this speed is also arbitrary).

Also, the speed conversion of the interlace signal is not performed by the n-times speed conversion circuit 25, and 1/60
You may make it convert into speed of a second. In this case, C
The output from the CD 11 can be used as it is (or at a speed other than 1/60 seconds) as a non-interlaced video signal.

[0023]

As described above, according to the present invention,
A device that reads out image signals from a solid-state image sensor in a sequential scanning format and converts them into interlaced scanning signals. The interlaced scanning signals are temporarily stored in a field memory, and the time lag is controlled by controlling the writing of this memory. Since the odd and even field signals without the error are obtained, it is possible to eliminate the mixture of the image data obtained by the exposures at different times, and it is preferable even when the data reading speed of the solid-state imaging device and the display speed of the monitor are different. It is possible to display a high quality still image.

[Brief description of the drawings]

FIG. 1 is a block diagram showing characteristic components of an electronic endoscope apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an overall configuration of an electronic endoscope apparatus according to an embodiment.

FIG. 3 is an explanatory diagram illustrating image processing of the apparatus according to the embodiment.

FIG. 4 is an explanatory diagram illustrating image processing of the apparatus according to the embodiment and a portion that follows from FIG. 3;

FIG. 5 is a block diagram showing a configuration of an electronic endoscope apparatus proposed by the present applicant.

FIG. 6 is an explanatory diagram illustrating image processing of the apparatus in FIG. 5;

[Explanation of symbols]

 1,11 CCD, 2,25 n-speed conversion circuit, 3,27 interlace conversion circuit, 10 electronic endoscope, 12 freeze switch, 17 PC monitor, 18 TV monitor, 28 frame memory, 25B, 29 ... Memory control circuit.

Claims (1)

[Claims] 1. A solid-state imaging device for reading an image signal in a sequential scanning format at a predetermined speed, a speed conversion circuit for converting an image signal into an image signal having a speed different from a reading speed of the solid-state imaging device, and the solid-state imaging device A frame memory for storing a frame image signal output from the CPU, and a signal processing circuit for interlaced scanning for forming at least a still image signal for interlaced scanning by controlling writing in the frame memory. An electronic endoscope device.