JPS6382618A - Electronic endoscope apparatus - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

(Prior Art) Conventionally, when viewing endoscopic images on a television monitor, a television camera was attached to the eyepiece of a fiberscope. However, recently, as solid-state imaging devices have become smaller, it has become possible to house them at the tip of the Uaisei t1 probe and directly display the image of the subject on a TV monitor without going through an image fiber to perform diagnosis and treatment. Now you can.

As an example of the configuration of the solid-state image sensor is shown in FIG.
, vertical transfer section (CV+) ・= (CVm),
Gate (G+ + ) - (Gmn) and horizontal transfer section (
H), photosensitive part (PI +)...(Plnn
) during the frame period is transferred from each photosensitive section (P+ + )...(Pmn) to the corresponding vertical transfer section (CV+)...(C
Gate (G+ + )...(Gm
When this transfer is completed, a new accumulation starts, and the transferred charges are sequentially sent to the horizontal transfer section (['') according to the TV method and taken out to the outside. Therefore, when a solid-state image pickup device is employed, light irradiation to a subject does not cause any inconvenience even if it is pulsed irradiation. For this reason, in the current light irradiation, a light pulse is irradiated in a period (T1) corresponding to the beginning of the field period, as shown in FIGS. 4(a) and 4(b). In addition, when extracting signals from a solid-state image sensor using an interlaced method, it is generally used to simultaneously extract signals from two vertically adjacent photosensitive sections because it is advantageous in terms of afterimage characteristics. Since signals are extracted from all photosensitive parts for each field, there is an accumulation period and a one-field period (that is, the same period as the above-mentioned period T1, generally 1/60 seconds).
Known as 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 it is also possible to perform a more objective diagnosis.
It is also necessary to record images to monitor the progress of treatment.

In this case, an endoscope device (
In electronic endoscopes (hereinafter referred to as "electronic endoscope devices"), in order to take a photograph of the image on the TV monitor, a method is used to temporarily turn the image into a still image. The video processor has a built-in frame memory in which one frame of image can be stored, and the stored image can be retrieved many times. and 1
In order to capture a frame image into a frame memory, as mentioned above, an interlaced system is used, so in a normal television system, 1/30 second of the time between two fields is required.

However, in this electronic endoscope device, the light pulse irradiation to the subject is uniformly performed during the period (T1) corresponding to the beginning of the field period, as described above, and therefore, during this period (T1), The problem was that still images were blurred by the movement of the subject, and an improvement was desperately needed.

In order to solve this problem, it is conceivable to always decide and set the time interval of light pulse irradiation during consecutive field periods to obtain continuous field image signals for generating frame images. However, with this countermeasure, the narrower the time interval, the more the two field image signals are in approximately the same state, and the field frequency is effectively halved (30 Hz), which is especially difficult when displaying moving images. Another problem occurs in that the image becomes similar to a so-called time-lapse image, and the movement of the image becomes unnatural.

The present invention has been made in view of the above, and an object of the present invention is to provide an electronic endoscope device that can suppress blurring of still images without affecting moving images.

[Configuration of the Invention (Means for Solving the Problems)] In order to achieve the above object, a solid-state image sensor in which a large number of pixels are arranged, a means for irradiating a subject with light pulses, and a light pulse from the solid-state image sensor are provided. The present invention provides an electronic endoscope device comprising means for storing one frame image generated from continuous field image signals and means for displaying this frame image as a moving image or a still image. The gist of the present invention is to provide a switching means for switching the irradiation timing to correspond to display switching of a frame image as a moving image or a still image.

(Function) In the electronic endoscope device according to the present invention, the timing of irradiation of light pulses to a subject when an image is captured by a solid-state image sensor is switched in response to switching of display of a frame image as a moving image or a still image. In this way, light pulses suitable for each display are irradiated.

(Example) Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an example of an electronic endoscope device according to the present invention. First, this device will be explained.

Reference numeral 1 denotes an endoscope probe, in which an engineering system such as an objective lens 2 and a solid-state image pickup device 3 are incorporated in its tip.

A specific example of the solid-state image sensor 3 is shown in FIG. 3, and the details are as described above. Further, an output end 12 of a light guide is arranged at the tip of the probe, and a light source lamp 9 is provided.
The light incident on the light guide light source side end 11 is emitted to the subject 13 as illumination light a.

Note that 10 is a cold mirror.

A video processor 5 inputs field image signals from the solid-state image sensor 3 through a transmission line 4, generates frame images from the field images, and includes a frame memory for storing the generated frame images.

Reference numeral 6 denotes a TV monitor which inputs a video signal from the video processor 5 and is capable of displaying frame images as moving images or still images.

Reference numeral 7 is a pulse power source, which lights the light source lamp 9 in pulses. The trigger of the pulse power supply 7 is
The first pulse phase control device 8 or the second pulse phase control device 16 performs the pulse phase control device 8.16 as described below, and the original pulses supplied to the pulse phase control device 8. The synchronizing signal is led through the switch 1-7. In addition, switching 3
17 supplies a vertical synchronization signal from the video processor 5 to the second pulse phase control device 16 when a still image imaging command signal is input from a controller (not shown);
Otherwise, the vertical synchronization signal is supplied to the first pulse phase control device @8.

Next, the operation of this embodiment will be explained using 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, and (B)
) shows a still image shadow command signal, (C) shows a pulse lighting command signal from the pulse power source 7, and (D) shows an image signal from the solid-state image sensor 3.

First, while displaying a moving image, as in the conventional case, the first The pulse phase control device 8 receives the vertical synchronization signal from the video processor 5 via the switch 17 and supplies a trigger signal to the pulse power source 7 at a predetermined timing, and the pulse power source 7 lights up the lamp 9 according to this trigger signal. It's about controlling.

Then, when a still image shooting command signal is supplied to the switch 17 during video display (FIG. 2(B)), the switch 17 switches the destination of the vertical synchronization signal from the video processor 5 to the first pulse. Switching from the phase control device 8 to the second pulse phase control 11 device 16. The second pulse phase control device 16 is
In response to this vertical synchronization signal, the continuous field images V+, V2 required to create the next one-frame image, and the light pulse irradiation to the subject for the image are applied to both images V+, V2,
A trigger signal is supplied to the pulse power source 7 to perform the triggering at the end and start of the field period of V2 (FIG. 2(C)). Strictly speaking, it is sufficient that the light pulse is not irradiated during the generation period of the vertical transfer pulse for transferring signal charges from the photosensitive section of the solid-state image sensor to the vertical transfer section.

Thereby, the pulse power source 7 controls the lighting of the lamp 9 according to this trigger signal.

In other words, the light pulse irradiation is performed during the shortest period (second) spanning two field periods.

As a result, the 2nd/TI is usually 1/13 to 1/15
Therefore, by controlling the phase of the optical pulse as described above, 1/1 of 1/60 seconds, which is one field period, can be
It is easy to capture an image in a period of about 0, and in this case, it is equivalent to setting the camera shutter speed to 1/600 second. Therefore, according to this embodiment, blurring of still images can be significantly reduced.

In addition, in the embodiment described above, the field images V+, V
Although the light pulse was lit once at the end and the end of each of the two field periods, the present invention is not limited to this.
It may be done multiple times within a short period of time.

Furthermore, in the above-described embodiment, the light pulses were turned on to obtain a still image separately at the end and start of the field period of field images V+ and V2, but the broken line in FIG. 2(C) As shown in H, it may continue for a time spanning both field periods.

Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above-mentioned embodiments, and can be modified as appropriate within the scope of the gist of the present invention.

Furthermore, in order to facilitate understanding of the invention, the term "minimum period" is used, but this does not strictly mean the period between the rear end of one field and the front end of another field; As can be seen from the meaning of the term `````````````````````````````````````````````````````````````````````````````````````````````````````````````````` such as a period with a certain degree of width within the range in which the purpose of the present invention can be achieved.

[Effects of the Invention] As described in detail above, according to the present invention, the timing of irradiation of light pulses to a subject during imaging with a solid-state image sensor is switched in response to switching of display of a frame image as a moving image or a still image. Since each displayed light pulse is irradiated, blurring of still images can be suppressed without affecting moving images, and appropriate and clear photographs can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of an electronic endoscope device according to the present invention, FIG. 2 is a timing chart for explaining the operation of the electronic endoscope device shown in FIG. 1, and FIG. 3 is a block diagram showing an example of an electronic endoscope device according to the present invention. FIG. 4, a schematic explanatory diagram showing an example of a solid-state R@ element, is a drawing showing the phase relationship between a light pulse 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.・・Switcher

Claims (3)

[Claims] (1) A solid-state image sensor in which a large number of pixels are arranged, a means for irradiating a subject with light pulses, a means for storing one frame image generated from continuous field image signals from the solid-state image sensor; In a television-type endoscope apparatus equipped with means for displaying a frame image as a moving image or a still image, the irradiation timing of the light pulse to a subject is switched in response to switching of display of the frame image as a moving image or a still image. An electronic endoscope device characterized by being provided with a switching means. (2) The switching means irradiates the light pulse at a predetermined phase within each field period when displaying a moving image, and continuously obtains the continuous field image signal for generating a frame image when displaying a still image. 2. The electronic endoscope apparatus according to claim 1, wherein the electronic endoscope apparatus performs the operation near the end of a previous field period and near the start of a subsequent field period. (3) The switching means irradiates the light pulse at a predetermined phase within each field period when displaying a moving image, and continuously obtains the continuous field image signal for generating a frame image when displaying a still image. 2. The electronic endoscope apparatus according to claim 1, wherein the electronic endoscope apparatus performs continuous operation from near the end of a previous field period to near the beginning of a subsequent field period.