JPH0763446B2 - Electronic endoscopic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to an electronic endoscope apparatus using a solid-state imaging device.

(Prior Art) Conventionally, when an endoscopic image is displayed on a television monitor for viewing, a method of attaching a television camera to the eyepiece of the fiberscope has been adopted. However, recently, because the solid-state image sensor has been miniaturized, there is a method of storing it in the tip part of the endoscope probe and displaying the image of the subject directly on the TV monitor without passing through the image fiber to perform diagnosis and treatment. It came to be taken.

As shown in FIG. 3, an example of the configuration of the solid-state image pickup device is that each of the independent photosensitive parts (P ₁₁ ) ... (Pmn), vertical transfer parts (CV ₁ ) ... (CVm), and gate (GV). ₁₁ ) ... (Gmn) and a horizontal transfer section (H), the signal charges accumulated in the photosensitive sections (P ₁₁ ) ... (Pmn) during a predetermined period are stored in the photosensitive sections (P ₁₁ ). ₁₁ ) ... (Pmn) to the corresponding vertical transfer section (CV ₁ ) ... (CVm) at the gate (G ₁₁ ) ... (G
mn), new accumulation starts again when the transfer is completed, and the transferred charges are sequentially sent to the horizontal transfer unit (H) according to the television system and taken out to the outside. Therefore, when the solid-state image pickup element is adopted, light irradiation to the subject does not cause any inconvenience even if pulse irradiation is performed. For this reason, the current light irradiation is performed by irradiating the pulsed light corresponding to the start end of the field period (T ₁ ) as shown in FIGS. 4 (a) and 4 (b). Further, as a method of extracting a signal from a solid-state image sensor, when extracting by an interlace method, a method of simultaneously extracting signals from two vertically adjacent photosensitive units is generally used because it is advantageous in terms of afterimage characteristics. Since the signal is taken out from all the photosensitive parts for each field, the accumulation period is 1
It is a field period (generally 1/60 second) and is known as the field accumulation mode.

(Problems to be Solved by the Invention) By the way, diagnosis and treatment are performed by a doctor while observing images in real time, but a more objective diagnosis is made.
And it is necessary to record images to see the course of treatment.

In this case, in the endoscopic device using the solid-state imaging device described above (hereinafter referred to as “electronic endoscopic device”), since the image on the TV monitor is photographed, the normal image is temporarily taken as a still image. As a means therefor, a frame memory is built in a video processor for processing an image signal, an image of one frame is stored therein, and the stored image can be retrieved many times. There is. And to load one frame of image into the frame memory,
Since the interlace system is adopted as described above, the normal television system requires 1/30 second for two field periods.

However, in this electronic endoscope apparatus, since the light pulse irradiation to the subject is uniformly performed in correspondence with the start end portion of the field period (T ₁ ) as described above, until the irradiation of the next pulse light is performed. However, there is a problem in that the still image is blurred due to the movement of the subject, and improvement has been longed for.

In order to solve this problem, it is possible to always determine and set the time interval of light pulse irradiation in continuous field periods for obtaining continuous field image signals for generating frame images. However, with this countermeasure, as the time interval is narrower, both field image signals are in substantially the same state, and the field frequency is substantially halved (30 Hz). Another problem occurs that the image becomes the same as that of the image and the movement of the image becomes unnatural.

The present invention has been made in view of the above, and an object thereof is to provide an electronic endoscope apparatus capable of suppressing blur of a still image without affecting a moving image.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a light irradiating means for irradiating a subject with pulsed light and an image of the subject to output an image signal in an interlaced system. An electronic device including a solid-state image sensor, a storage unit for storing a frame image generated from a field image signal output from the solid-state image sensor, and a display unit for displaying the frame image as a moving image or a still image. The gist of the endoscope apparatus is to include control means for controlling the irradiation timing of the pulsed light that is irradiated for each field in response to the switching of display of a frame image as a moving image or a still image.

(Operation) In the electronic endoscope apparatus according to the present invention, the irradiation timing of the pulsed light to the subject at the time of imaging by the solid-state imaging device is switched in correspondence with the display switching as the moving image or the still image of the frame image. Thus, pulsed light suitable for each display is emitted.

(Example) Hereinafter, the Example of this invention is described, referring drawings.

FIG. 1 is a block diagram showing an example of an electronic endoscope apparatus according to the present invention. Therefore, this device will be described first.

An endoscope probe 1 has an optical system such as an objective lens 2 and a solid-state image sensor 3 incorporated in its tip.
A concrete example of the solid-state image sensor 3 is shown in FIG. 3, and the details thereof are as described above. An output end 12 of the light guide is arranged at the tip of the probe, and the light incident from the light source lamp 9 to the light guide light source side end 11 is emitted to the subject 13 as illumination light a. ing. In addition,
10 is a cold mirror.

A video processor 5 receives the field image signal from the solid-state image sensor 3 through the transmission path 4, generates a frame image from the field image, and includes a frame memory for storing the generated frame image.

Reference numeral 6 denotes a TV monitor, which can input a video signal from the video processor 5 and display a frame image as a moving image or a still image.

Reference numeral 7 is a pulse power source, which is adapted to turn on the light source lamp 9 in pulses. The trigger of the pulse power supply 7 is
The original pulse given to the pulse phase control devices 8 and 16 is performed by the first pulse phase control device 8 or the second pulse phase control device 16 as described later, and is the vertical pulse of the television camera circuit built in the video processor 5. The synchronization signal is guided through the switch 17. The switch 17 supplies the vertical synchronizing signal from the video processor 5 to the second pulse phase control device 16 when a still image capturing command signal is input from a controller (not shown), and otherwise supplies the vertical synchronizing signal to the second pulse phase controller 16. No. 1 pulse phase control device 8 is supplied.

Next, the operation of this embodiment will be described with reference to the timing chart shown in FIG. In FIG. 2, (A) is a transfer control signal of an image signal in the solid-state image sensor 3,
(B) is a still image shooting command signal, (C) is a pulse power supply 7
Pulse lighting trigger signal to, solid-state image sensor 3 (D)
3A and 3B respectively show the image signals from FIG.

First, during the display of a moving image, as in the conventional case, in order to irradiate a light pulse at a constant period (T ₁ ) corresponding to the beginning of each field period (FIG. 2 (C)), the first pulse phase The control device 8 receives the vertical synchronizing signal from the video processor 5 via the switch 17 and supplies the trigger signal to the pulse power source 7 at a predetermined timing, and the pulse power source 7 controls the lighting of the lamp 9 in accordance with this trigger signal. .

Then, while the moving image is displayed, the still image shooting command signal is sent to the switching device.
When it is supplied to 17 (FIG. 2 (B)), the switch 17 switches the supply destination of the vertical synchronizing signal from the video processor 5 from the first pulse phase controller 8 to the second pulse phase controller 16. . The second pulse phase control device 16 receives the vertical synchronizing signal and irradiates the subject with pulsed light to obtain the continuous field image signals V ₁ and V ₂ required for creating the next one-frame image. A trigger signal is supplied to the pulse power source 7 in order to perform it at the terminal end and the starting end of the field period in which the signals V ₁ and V ₂ are accumulated (FIG. 2 (C)). Strictly speaking, it is sufficient that the pulsed light is not irradiated during the generation period of the vertical transfer pulse for transferring the signal charge from the photosensitive section of the solid-state image sensor to the vertical transfer section. As a result, the pulse power supply 7 controls the lighting of the lamp 9 according to this trigger signal.

That is, the irradiation of the pulsed light is carried out for the shortest period (T ₂ ) extending over the two field periods. As a result, T ₂ / T ₁ is usually 1/13 to 1/15, so by controlling the phase of the pulsed light as above, it is about 1/10 of 1/60 seconds which is one field period. It is easy to capture the image during the period of, and this case is equivalent to the case where the camera shutter speed is cut at 1/600 seconds. Therefore,
According to this embodiment, blurring of a still image can be significantly reduced.

Incidentally, in the above-mentioned embodiment, the field image signals V ₁ , V ₂
The pulsed light is turned on once at the end portion and the start end portion of the field period in which each is accumulated, but the number of times is not limited to this, and may be plural times within a short time.

Further, in the above-described embodiment, the lighting of the pulsed light for obtaining the still image is divided into the end portion and the start end portion of the field period in which the field image signals V ₁ and V ₂ are respectively accumulated. As indicated by a broken line H in FIG. 6C, the time may be extended over both field periods.

Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above embodiments and can be appropriately modified within the scope of the gist of the present invention.

Although the term "shortest period" is used to facilitate understanding of the present invention, this does not strictly mean a period between one field rear end and another field front, and (T _As can be understood from the meaning of ₂ ), it means a period having a certain width within the range in which the object of the present invention can be achieved.

[Effects of the Invention] As described in detail above, according to the present invention, the irradiation timing of the pulsed light to the subject at the time of imaging by the solid-state imaging device is switched in correspondence with the display switching as the moving image or the still image of the frame image. Since the pulsed light suitable for each display is emitted, blurring of a still image can be suppressed without affecting a moving image, and an appropriate and clear photograph can be obtained. .

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an electronic endoscope apparatus according to the present invention, FIG. 2 is a diagram showing a timing chart for explaining the operation of the electronic endoscope apparatus shown in FIG. 1, and FIG. FIG. 4 is a schematic explanatory view showing an example of a solid-state image sensor, and FIG. 4 is a drawing showing a phase relationship between pulsed light and an image signal. 3 ... Solid-state image sensor 5 ... Video processor 6 ... TV monitor 7 ... Pulse power supply 8 ... First pulse phase control device 16 ... Second pulse phase control device 17 ... Switching device

Claims (3)

[Claims] 1. A light irradiating means for irradiating a subject with pulsed light, a solid-state image sensor for capturing an image of the subject and outputting an image signal in an interlace system, and a field image signal output from the solid-state image sensor. In an electronic endoscope apparatus including a storage unit that stores a frame image that displays a frame image and a display unit that displays the frame image as a moving image or a still image, corresponding to the display switching of the frame image as the moving image or the still image. An electronic endoscope apparatus comprising: a control unit that controls the irradiation timing of pulsed light that is irradiated for each field. 2. The control means sets the irradiation timing of the pulsed light to a predetermined phase within a field period when displaying a moving image, and obtains a field image signal for generating a frame image when displaying a still image in the field to be obtained. The electronic endoscope apparatus according to claim 1, wherein the end of the period and the start of a subsequent field period are set near the end of the period. 3. The control means sets the irradiation timing of the pulsed light to a predetermined phase within a field period when displaying a moving image, and obtains a field image signal for generating a frame image when displaying a still image in the field to be obtained. The electronic endoscope apparatus according to claim 1, wherein the pulsed light is emitted from near the end of the period to near the start of the subsequent field period.