JPH0646980B2 - Electronic endoscopic device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus, and more particularly to a medical electronic endoscope apparatus for imaging in a frame sequential method.

[Conventional technology]

The field-sequential method of sequentially obtaining color images corresponding to illumination light of each color from one CCD two-dimensional sensor is effective when the number of CCD two-dimensional sensors cannot be increased, and is recently being applied to a medical electronic endoscope apparatus. .

The electronic endoscope apparatus is configured so that color images sequentially captured corresponding to illumination light can be simultaneously converted via red, green, and blue field memories and reproduced as a color image on a color TV. There is. When a freeze command to freeze the monitor image is added, the stored images in the red, green, and blue field memories can be latched, and the still image can be monitored. Then, you can make a hard copy of the still image.

[Problems to be solved by the invention]

By the way, in the image sequential system, the color image of each formula channel is 1
Frames are delayed one by one, and they are simultaneously converted and reproduced as a color image. Therefore, when the conventional electronic endoscope device freezes the monitor image according to the freeze command, the subject and the endoscope are stopped. Color shift may occur in a still monitor image due to the movement between the tips.

Further, when a monitor image is hard-copied by adding a recording command, the color shift causes waste of copy paper,
On the other hand, if you want to make a hard copy of only good still images,
The recording command must be added after visually confirming whether the still monitor image is good or bad, which is complicated.

The present invention has been made in view of the above circumstances, and an electronic device that can automatically prevent a still image or a hard copy of a color-shifted image when a monitor image is stopped or hard copied by a freeze command or a recording command. An object is to provide an endoscopic device.

[Means for solving problems]

In order to achieve the above object, the present invention provides an electronic endoscope apparatus in which desired color images are sequentially captured by an image sequential method, and the color images are simultaneously converted to be reproduced as a color image. 1 field or 1 before conversion to simultaneous expression
An A / D converter for converting an analog color image of a frame or a differential value of the analog color image into a digital signal;
Delay means for delaying and outputting the digital signal output from the 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. The output of the comparing means for comparing the above and the comparing means for discriminating the moving image when they do not coincide with each other, and the freeze instruction for keeping the input monitor image stationary or the recording instruction for hard copying the monitor image during the period when the comparing means discriminates the moving image is blocked. It is characterized by having a blocking means.

[Action]

According to the present invention, in an electronic endoscope apparatus that captures images in a frame-sequential system, one field or one frame of color image before each color image is converted into a simultaneous system and the following one field or one field.
By comparing with 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 recording command to hardcopy the monitor image is input during the period when it is determined to be a moving image, the output is blocked, and thus the color-shifted image is frozen or hardcopy is performed. I try not to do it.

〔Example〕

Hereinafter, preferred embodiments of an electronic endoscope apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of the electronic endoscope apparatus according to the present invention. This electronic endoscope apparatus sequentially captures desired color images in a frame-sequential system, converts the color images into a simultaneous system, and reproduces them as a color image. Light from the illumination lamp 10 is removed by near infrared rays. The subject 18 is illuminated from the tip of the endoscope through the filter 12, the color filter disc 14, and the 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 °, and is rotated by a motor 20 at a predetermined rotation speed (for example, 20 rps). As a result, the light from the illumination lamp 10 becomes illumination light of each color of red, green, and blue that sequentially changes at a cycle of 1/60 seconds through the rotating color filter disc 14, and the subject passes through the light guide 16. 18 added.

The imaging lens 22 provided at the distal end of the endoscope includes red, green,
The subject 18 illuminated by each of the blue illumination light is imaged,
An image is formed on the light receiving portion of the CCD sensor 24, and the CCD sensor 24 photoelectrically converts the incident light to generate a color image signal corresponding to each illumination light through an amplifier 26 and an A / D converter 28.
And output to the freeze control circuit 50.

The A / D converter 28 is supplied with a predetermined clock pulse from the synchronizing circuit 30. With this, the input color image signal is converted into a digital signal pixel by pixel, and the digital signal is converted into red, green and blue fields, respectively. Memories 32, 34,
Output to 36. The field memories 32, 34 and 36 are driven and controlled by a memory control circuit 38. That is, the memory control circuit 38 inputs a signal synchronized with each illumination light of red, green, and blue from the synchronization circuit 30, and stores a color image signal corresponding to each illumination light in a field memory corresponding to that color. For each field memory 32, 34, 36
A write signal is sequentially output to and the contents stored in the field memory are updated. These field memories 32, 3
The color image signals stored in 4, 36 are read out at the same time,
It is output via the D / A converters 40, 42 and 44, respectively.

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

On the other hand, as described above, the freeze control circuit 50 is sequentially added with the color image signals before being simultaneously converted, and can input the freeze command signal for keeping the monitor image still. . This freeze control circuit 50
Determines whether the captured image is a moving image or a still image based on the input color image signal, blocks the freeze command signal that is input during the period when the image is determined to be a moving image, and determines the period as a still image. Only the freeze command signal input therein is output as a freeze control signal (H level signal). The freeze control signals are applied to the field memories 32, 34 and 36, respectively, and when the signals become H level, the field memories 32, 34 and 36 are latched. As a result, the stored contents are not updated from the respective field memories 32, 34, 36 during the preset freeze period (several seconds), and the color image signal of the same screen is output and the monitor image is stopped.

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

FIG. 2 is a block diagram showing an 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 from the input terminal B to the contour signal generating circuit 51. This color image signal is a color image signal of green (G), red (R), and blue (B) input in a frame sequential method, and has a waveform synchronized with the cycle of the VD pulse (Fig. 3 (A)). Have In addition, in FIG. 3 (A), O
Indicates an odd field and E indicates an even field.

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

The contour signal generation circuit 51 includes a gate circuit 51A, a subtractor 51B, and a delay circuit 51C.
A is a subtractor 51 for only the G color image signal of the odd field selected by the gate pulse among the field sequential color image signals.
B and output to 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 adds it to the other input of the subtractor 51B. The subtractor 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 difference signal becomes a larger signal in a portion where the contrast suddenly changes, such as the contour portion of the image.

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

Here, FIG. 3 (D) shows a contour signal (line D signal) output from the A / D converter 52, and FIG. 3 (E) shows a contour signal (line E signal) read from the memory 54. ) Is shown. As is clear from FIGS. 3D and 3E, the memory 54 outputs the stored contour signal after the lapse of 6 field time (0.1 ms), and the input signal is 0.1
Acts as a delay means to delay ms. The above A / D
Although the contour signal output from the converter 52 and the memory 54 is a digital signal, the generation position of a large contour signal is shown by a pulse in FIGS. 3D and 3E for convenience of description.

The comparison circuit 53 compares the most significant bit of the digital signal input from the A / D converter 52 with the most significant bit input from the memory 54. Then, as shown in FIG. 3 (F), when the two input signals do not match (difference signal between the two input signals), the output signal (the signal on the line F) is set to L.
The level is changed to the H level, reset in synchronization with the next VD pulse, and set to 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.
In addition to the output signal of No. 3, a gate pulse similar to the gate pulse applied to the contour signal generation circuit 51 is added. Then, the moving image discrimination circuit 55 is triggered by the trailing edge of the H level signal applied from the comparison circuit 53 to become L level, and the freeze prevention signal (L level is held until the end of the G color image signal of the next odd field ( 3 (G)) is output to the AND circuit 56 via the line G. Incidentally, when the next comparison output (signal from H level to L level) is applied from the comparison circuit 53 while the freeze prevention signal is being output, it is retriggered.

The AND circuit 56 can input the output signal of the moving image discriminating circuit 55 and the freeze command signal from the input terminal P. Then, it becomes inoperable during the input of the freeze prevention signal, and even if the freeze command signal (H level) is inputted, its output is blocked. That is,
As shown in FIG. 3 (H), when the freeze command signal is input at time t ₁ , the AND condition is not satisfied by the freeze prevention signal, and thereafter, when the freeze prevention signal becomes H level at time t _2. The condition is met, and AND circuit 5
A freeze control signal (H level signal) shown in FIG. 3 (I) is output from 6. When the freeze command signal is input at time t _{3 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). Is 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, the freeze control signal is output at that time when the AND condition is satisfied. However, the present invention is not limited to this. Instead, it may be determined whether or not 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 subsequently satisfied.

Since each field memory is latched by the freeze control signal as shown in FIG. 1, it is possible to always reproduce a still image having no color shift. Further, a hard copy device connected to the electronic endoscope device may be operated by this control signal, and in this case, an image without color misregistration can always be hard copied.

In FIG. 2, without passing through the contour signal generation circuit 51,
The color image signal may be directly input to the A / D converter 52. Although the freeze control circuit 50 inputs the analog color image signal before the simultaneous conversion, it outputs the output signal (digital color image signal) of the A / D converter 28 in FIG. You may In this case, the A / D converter 52 shown in FIG. 2 becomes unnecessary.
Further, although the same color images are compared among the sequentially input color images in the present embodiment, different color images may be compared.

〔The invention's effect〕

As described above, according to the electronic endoscope apparatus of the present invention, the preceding color image before the simultaneous conversion is matched with the subsequent color image, it is determined whether or not a moving image based on the mismatch, Since the freeze command and the recording command are not output in the case of a moving image, when the monitor image is statically or hard-copied, it is possible to automatically prevent the color-shifted image from statically or hard-copying.

[Brief description of drawings]

1 is a block diagram showing an embodiment of the electronic endoscope apparatus according to the present invention, FIG. 2 is a block diagram showing details of the freeze control circuit of FIG. 1, and FIGS. 3 (A) to 3 (K). Are timing charts used to explain FIG. 2, respectively. 32, 34, 36 ... Field memory, 50 ... Freeze control circuit, 51 ... Contour signal generating circuit, 52 ... A
/ D converter, 53 ... Comparison circuit, 54 ... Memory, 55
…… Video discrimination circuit, 56 …… AND circuit.

Claims (2)

[Claims] 1. A desired color image is sequentially captured by an image sequential method,
After converting the analog image signal showing the color image into a digital image signal, it is stored in the image memory for each color, and the digital image signals stored in the image memory for each color are simultaneously read out and converted simultaneously to produce a color image. In the electronic endoscope device adapted to reproduce as, the freeze command for outputting the freeze command for stopping the monitor image or the hard copy command for hard copying the monitor image, and the freeze command or the hard copy command from the command means are added. Then, an image stationary unit that freezes the color image converted simultaneously, an A / D converter that converts an analog image signal indicating a color image before the simultaneous conversion into a digital image signal, and One-field or one-frame digital image signal before simultaneous conversion output from the A / D converter A discriminating means for discriminating whether or not it is a moving picture based on the following and a digital image signal of one field or one frame, and a freeze command or a hardware inputted from the commanding means during the period when the judging means discriminates the moving picture. An electronic endoscope apparatus comprising: a blocking unit that blocks the output of a copy command to the image stationary unit. 2. The discriminating means delays the digital image signal output from the A / D converter by a predetermined number of fields or a predetermined number of frames, and outputs the delayed signal.
Comparing means for comparing the 1-field or 1-frame digital image signal output from the A / D conversion with the subsequent 1-field or 1-frame digital image signal delayed by the delay means, and discriminating a moving image when they do not match. The electronic endoscope apparatus according to claim 1, comprising: