JPH0249630A - Electronic endoscopic apparatus - Google Patents

Abstract

PURPOSE:To automatically prevent the stoppage of a color shift image or hard copy when a monitor image is stopped or hard copy is performed by judging whether a taken image is an animation on the basis of the coincidence and non-coincidence of a preceding color image before converted according to a simultaneous system with the succeeding color image and preventing the output of a freeze or recording order in the case of the animation. CONSTITUTION:A freeze control circuit 50 successively receives a color image signal before converted according to a simultaneous system and can input a freeze order signal for stopping a monitor image. This circuit 50 judges whether a taken image is an animation or a stationary image on the basis of the inputted color image signal and prevents the output of the freeze order signal inputted during a period judging the taken image as the animation while outputs only the freeze order signal, which is inputted during a period judging said image as the stationary image, as a freeze control signal (H-level signal). The freeze control signal is applied to respective field memories 32, 34, 36 and, when said signal becomes an H-level, the respective field memories 32, 34, 36 are latched. By this method, the color image signal of the same picture is outputted from each of the field memories 32, 34, 36 without renewing memory content for a preset freeze period (several sec) and a monitor image is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic endoscope device, and particularly to a medical electronic endoscope device that captures images in a frame-sequential manner.

[Conventional technology]

The field sequential method, which sequentially obtains color images corresponding to each color of illumination light from one CCD two-dimensional sensor, is effective when a large number of CCD two-dimensional sensors cannot be used, and has recently been applied to medical electronic endoscope devices. .

Such an electronic endoscope device is configured to simultaneously convert color images sequentially captured in response to illumination light through red, green, and blue field memories, and to reproduce the color images on a color TV. There is. Also, when a freeze command is applied to freeze the monitor image, the red, line, and blue field memories are stored! (By latching I, the still image can be monitored, and when a recording command is given to the hard copy device, the still image can be hard-copied.

[Problem that the invention seeks to solve]

By the way, in the field sequential method, each color channel has one color image.
This occurs with a frame-by-frame delay, and this is converted into a simultaneous system and reproduced as a color image. Therefore, in conventional electronic endoscope devices, when the monitor image is frozen by the freeze command, the subject and the endoscope are Movement between the tips could cause color shift in a stationary monitor image.

In addition, when making a hard copy of a monitor image by adding a recording command, the above-mentioned color shift may lead to wasted copy paper, etc.
On the other hand, if you want to make a hard copy of only good still images,
There is a problem in that the recording command must be added after visually confirming the quality of the static monitor image, which is complicated.

The present invention has been made in view of the above circumstances, and is an electronic device that can automatically prevent a color-shifted image from being frozen or hard-copied when a monitor image is frozen or hard-copied in response to a freeze command or a recording command. The purpose is to provide an endoscope device.

[Means for solving problems]

In order to achieve the above object, the present invention provides an electronic endoscope apparatus that sequentially captures desired color images in a frame-sequential manner, converts the color images simultaneously, and reproduces them as color images. 1 field or 1 before converting to simultaneous
an A/D converter that converts an analog color image of a frame or a differential value of the analog color image into a digital signal;
a delay means for delaying and outputting a digital signal output from a D converter by a predetermined number of fields or a predetermined number of frames; an output signal of the A/D converter and an output signal delayed by the delay means; a comparison means for comparing the images and determining it as a moving image when there is a discrepancy, and preventing output of a freeze command to freeze the input monitor image or a recording command to make a hard copy of the monitor image during a period when the comparing means determines it to be a moving image. It is characterized by being equipped with a blocking means.

[Effect]

According to the present invention, in an electronic endoscope device that captures images in a field-sequential manner, one field or one frame of color image before each color plane image is converted into a simultaneous system, and one field or one frame of subsequent color image.
By comparing the color image of the frame, it is determined whether or not it is a moving image. Even if a freeze command to freeze the monitor image or a record command to hard copy the monitor image is input during the period when it is determined to be a moving image,
The output is made clear, thereby preventing the color-shifted image from being frozen or hard-copied.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an electronic endoscope apparatus according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of an electronic endoscope device according to the present invention. This electronic endoscope device sequentially captures desired color images in a frame-sequential manner, converts the color images simultaneously, and reproduces them as a color image, and the light from the illumination lamp 10 is removed from near-infrared A subject 13 is illuminated from the tip of the endoscope via a filter 12, a color filter disk 14, and a light guide 16. That is, the color filter disk 14 has a red filter, a green filter, and a blue filter, each having a central angle of 120 degrees, and is rotated by a motor 20 at a predetermined rotational speed (for example, 20 rps). As a result, the light from the illumination lamp IO passes through the rotating color filter disk 14 and becomes illumination light of each color of red, green, and blue, which changes sequentially at a cycle of 1/60 seconds, and passes through the light guide 16 to the subject. Added to 18.

The imaging lens 22 provided at the tip of the endoscope has red, green,
Image the subject 18 illuminated by each blue illumination light,
This is imaged on the light receiving part of the CCD sensor 24, and the CCD sensor 24 photoelectrically converts the incident light and sends the color image signal corresponding to each illumination light to the A/D converter 28 via the amplifier 26.
and output to the freeze control circuit 50.

The A/D converter 28 is supplied with a predetermined clock pulse from the synchronization circuit 30, and thereby converts the input color image signal into a digital signal pixel by pixel, and converts this digital signal into a red, green, and blue field, respectively. Memo U32.34.
Output to 36. Field memo! 732.34.36
is driven and controlled by the memory control circuit 38. That is,
The memory control circuit 38 inputs signals synchronized with each of the red, green, and blue illumination lights from the synchronization circuit 30, and stores the color image signal corresponding to each illumination light in the field memory corresponding to that color. , each field memory 32.34.3
6 to sequentially output write signals to update the stored contents of the feed memory. These field memories 32.34
．． The color image signals stored in 36 are simultaneously read out and output via D/A converters 40, 42, and 44, respectively.

Then, red, green, converted to simultaneous expression as above,
The blue color image signal is converted into an NTSC video signal via a color encoder (not shown), etc., and is added to a color TV and reproduced as a color image.

On the other hand, to the freeze control circuit 50, as described above, the color image signals before being converted to the simultaneous type are sequentially applied, and a freeze command signal for freezing the monitor image can be input. .

The freeze control circuit 50 determines whether the captured image is a moving image or a still image based on the input color image signal, and prevents the output of the input freeze command signal during the period when the captured image is determined to be a moving image. Only the freeze command signal input during the period being determined is output as a freeze control signal (H level signal). Freeze control signals are applied to field memories 32, 34, and 36, respectively, and the signals are
When it comes to level, each field memory 32.34.36
Latch. As a result, each field memory 32
．． From 34 and 36, the stored contents are not updated for a preset freeze period (several seconds), the color image signal of the same screen is output, and the monitor image is kept still.

Next, the freeze control circuit 50 will be explained in detail with reference to FIGS. 2 and 3.

FIG. 2 is a block diagram showing one embodiment of the freeze control circuit 50. The freeze control circuit 50 includes a contour signal generation circuit 51, an A/D converter 52, a comparison circuit 53, a memory 54, a moving image control circuit 55, and an AND circuit 56.

A color image signal (FIG. 3(B)) is applied to the contour signal generating circuit 51 from an input terminal B. This color image signal is a green (G), red (R), and blue (B) color image signal that is input in a frame sequential manner, and has a waveform synchronized with the period of the VD pulse (Figure 3 (A)). have. Furthermore, in Figure 3 (A), O
indicates an odd field, and E indicates an even field.

Further, to the contour signal generating circuit 51, a gate pulse is applied from the input terminal C for selectively processing only the G color image signal of the odd field (FIG. 3(C)).

This contour signal generation circuit 51 consists of a gate circuit 51A, a subtracter 51B, and a delay circuit 51C.
A is a subtractor 51 which extracts only the G color image signal of the odd field selected by the gate pulse from among the field sequential color image signals.
B and the delay circuit 51C.

The delay circuit 51C delays the input signal by a predetermined time (for example, a time corresponding to one pixel) and applies the delayed signal to the other input of the subtracter 51B. The subtracter 51B takes the difference between the two input signals and outputs the difference signal to the AD converter 52. It should be noted that the above-mentioned difference signal becomes a very large signal at a portion where the contrast changes suddenly, such as at the outline of an image.

A/D converter 52 converts the input signal into a digital signal,
This is output to the comparison circuit 53 and memory 54. The memory 54 stores only the most significant bit of the digital signals that are sequentially input, and outputs this to the comparison circuit 64 after a certain period of time has elapsed. That is, the memory 54 is enabled to operate only during the output period of the odd field G color image signal by a memory control circuit (not shown), and at the same time the most significant bit of the input digital signal is written, the most significant bit that has already been stored is read out. I do.

Here, FIG. 3(D) shows the contour signal (line D signal) output from the A/D converter 52, and FIG. 3(E) shows the contour signal (line E signal) read out from the memory 54. ) is shown. As is clear from FIGS. 3(D) and (E), the memory 54 outputs the stored contour signal after the lapse of 6 fields (0.1 ms), and the input signal is output at 0.1+ns. It acts as a delaying means. still,
The contour signal output from the A/D converter 52 and memory 54 is a digital signal, and FIGS.
), for convenience of explanation, the generation position of a large contour signal is shown by a pulse.

Comparison circuit 53 compares the most significant bit of the digital signal input from A/D converter 52 and the most significant bit input from memory 54 . Then, as shown in Fig. 3 (F), it is triggered by the mismatch between the two input signals (difference signal between the two input signals), and the output signal (signal on line F) is
The level changes from the level to the H level, is reset in synchronization with the next VD pulse, and becomes the L level again.

The moving image discrimination circuit 55 outputs an L-level freeze prevention signal when the captured image is a moving image, and the comparing circuit 5
3 is applied, and a gate pulse similar to the gate pulse applied to the contour signal generating circuit 51 is applied. The moving image discrimination circuit 55 is triggered by the fall of the H level signal applied from the comparator circuit 53 to become an L level, and the freeze prevention signal ( 3(G)) is output to the AND circuit 56 via line G. Note that while the freeze prevention signal is being output, if the next comparison output (signal that changes from H level to L level) is applied from the comparison circuit 53, the trigger is re-triggered.

The AND circuit 56 is configured to receive the output signal of the moving image discrimination circuit 55 as well as a freeze command signal from the input terminal P. During the input period of the freeze prevention signal, it becomes inoperable, and the freeze command signal (
Even if a high level (H level) is input, its output is blocked. That is, as shown in FIG. 3(H), at time 1. When the freeze command signal is input at t2, the AND condition is not satisfied due to the freeze prevention signal, and then, when the freeze prevention signal becomes H level at time t2, the AND condition is satisfied, and the AND condition is output from the AND circuit 56 as shown in FIG. 7 reset control signal (H) shown in I)
level signal) is output. Furthermore, when the freeze command signal is input at time t as shown in FIG. 3(J), the AND condition is immediately established, and the AND circuit 56 outputs the freeze control signal shown in FIG. 3(K). Output.

In the above embodiment, even if the AND condition is not satisfied by the freeze prevention signal when the freeze command signal is input, if the AND condition is satisfied thereafter, the freeze control signal is output at that point, but the present invention is not limited to this. First, it may be determined whether the AND condition is satisfied only when the freeze command signal rises, and when the AND condition is not satisfied, the freeze control signal may not be output even if the AND condition is satisfied thereafter.

As shown in FIG. 1, since each field memory is latched by the freeze control signal, a still image without color shift can always be reproduced.

Further, a hard copy device connected to the electronic endoscope device may be operated by this control signal, and in this case, images without color shift can always be hard copied.

In addition, in FIG. 2, without going through the contour signal generation circuit 51,
The color image signal may be input directly to the A/D converter 52. Further, although the freeze control circuit 50 is configured to input an analog color image signal before simultaneous conversion, it is also configured to input an output signal (digital color image signal) of the A/D converter 28 shown in FIG. You may also do so. In this case, the A/D converter 52 shown in FIG. 2 becomes unnecessary. Furthermore, in this embodiment, out of color images that are sequentially input, images of the same color are compared, but images of different colors may be compared.

〔Effect of the invention〕

As explained above, according to the electronic endoscope device according to the present invention, it is determined whether or not it is a moving image based on the coincidence or mismatch between the preceding color image and the subsequent color image before simultaneous conversion, In the case of a moving image, since a freeze command and a recording command are not output, when a monitor image is to be frozen or hard-copied, it is possible to automatically prevent a color-shifted image from being frozen or hard-copied.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of an electronic endoscope device according to the present invention, FIG. 2 is a block diagram showing details of the freeze control circuit in FIG. 1, and FIGS. 3 (A) to (K) are timing charts used to explain FIG. 2, respectively. 32.34.36...Field memory, 50.
... Freeze control circuit, 51 ... Contour signal generation circuit, 52 ... A/D converter, 53 ... Comparison circuit,
54... Memory, 55... Video discrimination circuit, 56
...AND circuit.

Claims (2)

[Claims] (1) In an electronic endoscope device that sequentially captures desired color images in a frame-sequential method, converts the color images into a simultaneous method, and reproduces them as a color image, the first step before converting to the simultaneous method. A converting a field or one frame of an analog color image or a differential value of the analog color image into a digital signal
/D converter; a delay means for delaying and outputting the digital signal output from the A/D converter by a predetermined number of fields or a predetermined number of frames; a comparison means that compares the output signal delayed by the delay means and determines it as a moving image when there is a discrepancy; and a freeze command that freezes the input monitor image or a hard drive that freezes the input monitor image during the period in which the comparison means determines that it is a moving image. An electronic endoscope device comprising: a blocking means for blocking the output of a recording command to be copied. (2) In an electronic endoscope device that sequentially captures desired color images in a frame-sequential method, converts the color images into a simultaneous method, and reproduces them as a color image, the first step before the conversion into the simultaneous method is performed. a delay means for delaying and outputting a field or one frame of a digital color image or a differential value of the digital color image by a predetermined number of fields or a predetermined number of frames;
Compare one field or one frame of a digital color image before conversion to the simultaneous type or a differential value of the digital color image with a subsequent digital color image delayed by the delay means or a differential value of the digital color image. , a comparison means for determining that it is a moving image when there is a discrepancy, and a blocking means that prevents the output of a freeze command to freeze the input monitor image or a recording command to make a hard copy of the monitor image during the period when the comparison means determines that it is a moving image. An electronic endoscope device comprising: