JPH0744924B2 - 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 being applied to medical electronic endoscope devices in recent years. .

Such an 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. Also, when a freeze command to freeze the monitor image is added, the stored images in the red, green, and blue field memories are latched, and the still image can be monitored.
When a hard copy command is added, the still image can be hard copied.

[Problems to be solved by the invention]

By the way, in the frame sequential method, the color image of each color 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.

When a monitor image is hard-copied by adding a hard-copy command, the color shift causes waste of copy paper. On the other hand, when hard-copying only a good still image, a still monitor image There is a problem that it is complicated because it is necessary to add a hard copy command after visually recognizing pass / fail.

The present invention has been made in view of such circumstances, and when the monitor image is statically or hard-copied by the freeze command or the hard-copy command, the static or hard-copy of the color-shifted image can be automatically prevented. An object is to provide an electronic endoscope 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 a frame 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
Discriminating means for discriminating whether or not the image is a moving image based on the color image of the frame and the color image of the subsequent one field or one frame, and the monitor image to be input is made to stand still during the period in which the discriminating means discriminates the moving image. The present invention is characterized in that a blocking means for blocking output of a freeze command or a hard copy command for hard copying a monitor image is provided.

[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 that freezes the monitor image or a hard copy command that hard copies the monitor image is input during the period when the image is determined to be a moving image, the output is blocked, which causes the color-shifted image to freeze or to be hard-coded. I try not to copy 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, and the light from the illumination lamp 10 removes near infrared rays. A subject (18) is illuminated from the tip of the endoscope through a filter (12), a color filter disc (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 °, and is rotated by a motor 20 at a predetermined rotation speed (for example, 20 rps). This causes the light from the illumination lamp 10 to move to this rotating color filter disc.
Illumination light of red, green, and blue colors that sequentially change at a cycle of 1/60 seconds is supplied via 14 and is applied to a subject 18 via a light guide 16.

The imaging lens 22 provided at the tip of the endoscope images the subject 18 illuminated by each of the red, green, and blue illumination lights, and forms an image on the light receiving portion of the CCD sensor 24. Amplifies the color image signal corresponding to each illumination light by photoelectrically converting the incident light
A / D converter 28 and freeze control circuit 5 via 26
Output to 0.

The A / D converter 28 receives a predetermined clock pulse from the motivation circuit 30, and converts the input color image signal into a digital signal pixel by pixel, and the digital signal is converted into red, green and blue fields, respectively. Output to memories 32, 34, 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 the field memory corresponding to that color. In order to do so, write signals are sequentially output to the field memories 32, 34, 36 to update the stored contents of the field memories. The color image signals stored in the field memories 32, 34 and 36 are read out at the same time and 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 is also capable of inputting a freeze command signal for stopping the monitor image. . This freeze control circuit 50
It determines whether the captured image is a moving image or a still image based on the input color image signal, and blocks the output of the freeze command signal that is input during the period when the image is determined to be a moving image. Only the input freeze command signal is output as a freeze control signal (H level signal). The freeze control signal is applied to the field memories 32, 34 and 36 respectively, and when the signal becomes H level, the respective field memories are.
Latch 32, 34, 36. 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 with reference to FIGS.
It will be described in detail with reference to the drawings.

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, a comparison circuit 52, a memory 53, a memory control circuit 54,
It is composed of a moving picture control circuit 55 and an AND circuit 56.

The contour signal generation circuit 51 receives the color image signal (third
Figure (B)) has been added. 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 FIG. 3A, O indicates an odd field and E indicates an even field.

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

The contour signal generation circuit 51 receives only the G color image signal of the odd field selected by the gate pulse in the frame sequential color image signal, and the contour portion of the image indicated by the color image signal (position where the contrast suddenly changes). Is detected and a contour signal (pulse signal) is output to the comparison circuit 54 and the memory 53.
Note that FIG. 3D shows an example of the contour signal (line D signal) generated from the contour signal generation circuit 51.

The memory 53 temporarily stores the contour signal and outputs it to the comparison circuit 52 after a certain period of time.
The signal applied from 54 through the line M enables operation only during the output period of the G-color image signal of the odd field, and the writing and reading of the contour signal are performed by the memory clock pulse applied through the line N. . Incidentally, FIG. 3 (E) shows a contour signal (line E signal) read from the memory 53. As is clear from FIGS. 3D and 3E, the memory 53 outputs the stored contour signal after the elapse of 6 field time (after 0.1 ms), and delay means for delaying the input signal by 0.1 ms. Acts as.

The comparator circuit 52 is enabled by the signal applied via line M and compares the two input signals. And
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 changed from the L level to the H level, and
It is reset in synchronization with the VD pulse and becomes L level again.

The moving image discriminating circuit 55 outputs an L level freeze prevention signal when the picked-up image is a moving image, and is similar to the gate pulse applied to the contour signal generating circuit 51 in addition to the output signal of the comparing circuit 52. A gate pulse is applied from the input terminal O. Then, the moving image discrimination circuit 55
A freeze prevention signal (FIG. 3 (G)) that is triggered by the trailing edge of the H level signal applied from the comparison circuit 52 to become the L level and is held at the L level until the end of the G color image signal of the next odd field It 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 52 while the freeze prevention signal is being output, it is retriggered.

The AND circuit 56 is adapted to receive 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, when the freeze command signal is input at time t _{1 as} shown in FIG. 3 (H), the AND condition is not satisfied by the freeze blocking signal, and then the freeze blocking signal becomes H level at time t _2. Then, the AND condition is satisfied, and the AND circuit 56 outputs the third condition.
The freeze control signal (H level signal) shown in FIG. 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. Not limited to this, 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.

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.

Although the same color images are compared with each other among the color images sequentially input in the present embodiment, different color images may be compared with each other. Further, the means for discriminating between the moving image and the still image is not limited to the present embodiment, but based on the coincidence or non-coincidence of two color images such as a method of discriminating based on the cross-correlation between the preceding color image and the subsequent color image. Any method may be used as long as it can be determined by the above method.

〔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 hard copy command are not output in the case of a moving image, it is possible to automatically prevent the still image or the hard copy of the color-shifted image when the monitor image is stopped or hard copied.

[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 ... Comparison circuit, 53 ... Memory, 55 ... Movie judging circuit, 56 ... AND circuit.

Claims (2)

[Claims] 1. A desired color image is sequentially captured by a frame 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 means for stationary the color image converted by the simultaneous method, an analog image signal of one field or one frame before the simultaneous conversion and an analog image signal of the following one field or one frame. A discriminating means for discriminating whether or not it is a moving image based on During the period, a blocking unit that blocks the output of the freeze command or the hard copy command input from the command unit to the image stationary unit, and the electronic endoscope apparatus. 2. A contour for inputting an analog image signal of one field or one frame before conversion to the simultaneous system, detecting a position where the contrast of the analog image signal suddenly changes, and outputting a pulse signal. A signal generating circuit; delay means for delaying and outputting the pulse signal output from the contour signal generating circuit by a predetermined number of fields or a predetermined number of frames; and an output signal of the contour signal generating circuit and the delay means. The electronic endoscope apparatus according to claim 1, further comprising: a comparing unit that compares the delayed output signal with each other and determines that the image is a moving image when they do not match.