JPH0497736A - Electronic endoscope apparatus - Google Patents

Abstract

PURPOSE:To obtain a still picture without color deviation immediately by a method wherein an image being photographed is discriminated between a still or animation picture at each specified cycle, a surface sequence image signal is stored in terms of color each time the image is identified as still picture to update the memory contents of a memory means to the newest surface sequence image signal and the updating of the memory contents is forbidden immediately when a freezing command is inputted. CONSTITUTION:A freezing control circuit 60 discriminates an image photographed between a still picture and an animation picture at each cycle (per 0.1sec.) based on a G image signal inputted at each 6-field period. Then, each time the picture is identified as still picture, the memory contents of field memories 42, 44 and 46 are updated to the newest RGB image signal, and when a freezing command signal is inputted, the field memories 42, 44 and 46 are latched immediately. Then, when a switch 59 is turned ON while the freezing command signal is inputted, the RGB image signal of the field memories 42, 44 and 46 is inputted into a display control circuit 57 through a changeover 48 and D/A converters 52, 54 and 56, and a still picture is displayed being enlarged on a monitor TV 58.

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 simultaneously converts the sequential image signals of each color obtained by sequentially capturing images corresponding to the illuminating light into a color image through red, green, and blue field memories. It is configured so that it can be played on a TV. Furthermore, when a freeze command is applied to freeze the monitor image, the stored images in the red, green, and blue field memories are latched, allowing the still image to be monitored. Once the command is added, the still image can be made into a hard copy.

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.

Conventionally, in order to prevent color shift in static monitor images, when a freeze command is input, it is determined whether the image currently being captured is a still image or a video, and only when it is determined to be a still image, red, An electronic endoscope device has been proposed that obtains a still image without color shift by latting the images stored in the green and blue field memories (Japanese Unexamined Patent Publications No. 2-4i131 and No. 2-41132). , Japanese Unexamined Patent Publication No. 2-55030).

[Issues that Hatmon tries to solve]

However, in the conventional electronic endoscope device described above, when a freeze command is input and the image currently being captured is determined to be a moving image, the image stored in the field memory for each color is not latched and the image is immediately stopped. There are cases where it is not possible to obtain a still image, and in this case, a time lag occurs between when a freeze command is output and when a still image without color shift is actually obtained.

The present invention was made in view of these circumstances, and it is possible to always reproduce a still image without color shift even in the frame sequential imaging method by using the freeze command, and it is also possible to always reproduce a still image without color shift even in the frame sequential imaging method. It is an object of the present invention to provide an electronic endoscope device that can be immediately stopped without causing any discomfort.

[Means to solve problems]

In order to achieve the above object, the present invention includes an imaging means for sequentially capturing images of each color in a frame-sequential method and obtaining frame-sequential image signals by this capturing, and storing the frame-sequential image signals for each color and storing them. A first storage means and a second storage means that simultaneously output one field or one frame of frame sequential image signals are input at a predetermined period, and based on the inputted one field or one frame of frame sequential image signals, determining means for determining whether the image is a still image or a moving image at predetermined intervals; each time the determining means determines that the image is a still image, the stored content of the second storage means is updated to the latest frame-sequential image signal; , when a freeze command is input, a control means for prohibiting updating of the storage contents of the second storage means, one display means, and simultaneous outputs from the first storage means and the second storage means, respectively. A first color image signal and a second color image signal of the formula are input, and when a freeze command is issued, a color image corresponding to the first color image multiplication size is displayed in a large size on the screen of the display means, and the second color image signal is inputted. A color image corresponding to the color image signal No. 2 is displayed in a small size on the same screen,
The present invention is characterized by comprising display control means for displaying at least a large color image corresponding to the second color image signal on the screen of the display means when a freeze command is input.

[Function 2] According to the present invention, a sampling check is performed at predetermined intervals to determine whether the image currently being photographed is a still image or a moving image, and each time it is determined that the image is a still image, the frame sequential image signals are memorized for each color and the images are stored. The content stored in the second storage means that simultaneously outputs the images is updated to the latest frame-sequential image signal. This results in
The second storage means always stores the latest frame sequential image signal without color shift.

Then, when a freeze command is input, the update of the memory contents of the second self-memory means is immediately prohibited, and thereby the second
The latest still image signal without any color shift is obtained from the storage means of .

Further, based on the output of the first storage means and the output of the second storage means, a moving image and a still image can be appropriately switched and displayed on one display means, and at least while displaying a moving image, A color image without color shift based on the output of the second storage means is displayed in a small size on a part of the screen.

This display of a color image without color shift can be used as a guide when selecting a desired image to be kept still.

〔Example〕

Preferred embodiments of the electronic endoscope device 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 using a frame-sequential method, converts the obtained frame-sequential image signals into a simultaneous format, and reproduces them as a color image. The light is focused on the condensing lens 1
2. The object 18 is illuminated from the end of the endoscope via the color filter disk 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 degrees, and the motor 2
0 at a predetermined rotation speed (for example, 20 rps). As a result, the light from the illumination lamp 1 (11) passes through the rotating color filter disk 14 into red (R), B (G
), each color of blue (B) is illuminated, and the light guide 1
6 to the subject 18.

The imaging lens 22 provided at the tip of the endoscope has R, G,
image the subject 18 illuminated by each illumination light of B;
This is imaged on the light receiving part of the CCD sensor 24, and the CCD sensor 24 photoelectrically converts the incident light into an RG image corresponding to each illumination light.
The B image is outputted via the amplifier 26 to the A/D converter 28 and freeze control circuit 60, respectively.

The A/D converter 28 converts the input RGB image (analog signal) into a digital signal pixel by pixel, and converts this digital signal into 2.1 R and G signals, respectively.

The data is output to field memory 32.34.36 and field memory 42.44.46 of B.

The field memories 32, 34, 36 are controlled by a field selection pulse generation circuit 38.

That is, the field sorting pulse generation circuit 38 inputs signals synchronized with each of the R, G, and B illumination lights from the color filter position detector 40, and generates an RGB image corresponding to each illumination light - that color. A write signal is sequentially output to each field memory 32, 34, and 36 to update the stored contents of the feed memo IJ'O so as to store it in the corresponding field memory. These field notes υ32.34.36
The RGB images stored in - are simultaneously read out, respectively by the changeover switch 48 and the D/A converter 52, 54, 56.
is applied to the display control circuit 57 via.

On the other hand, the field memories 42, 44, and 46 are controlled by a field selection pulse generation circuit 38 and a freeze control circuit 60.

The freeze control circuit 60 sequentially adds RGB images as described above, and also receives a freeze command signal for freezing the monitor image and a G image signal from the field selection pulse generation circuit 38 for six fields. period (0,
It is possible to input a G-EN pulse for inputting every 1 second). This freeze control circuit 60 determines whether the captured image is a still image or a moving image at each cycle (every 0.1 seconds) based on the G image signal input every 6 field periods,
Each time it is determined that it is a still image, the field memory 42, 44 .
46 is updated to the latest RGB image, and when a freeze command signal is input, each field memory 42, 44, and 46 is immediately latched.

RGB image images stored in these field memories 42, 44, 46 - simultaneously read out and each D/A
It is applied to the display control circuit 57 via converters 72, 74, and 76, and also to the changeover switch 48.

The selector switch 48 converts the RGB image signals added from the field memories 42, 44, and 46 into D/D only when the switch 59 is turned on and the freeze command signal is input.
Lead to A converter 52.54.56, otherwise field notes! The RGB image signal applied from 132.34.36 is switched to be guided to the D/A converter 52.54.56.

The display control circuit 57 receives an RGB image signal (hereinafter referred to as a first image signal) inputted from the D/A converter 52.54.56 and an RG inputted from the D/A converter 72.74.76.
It switches between a moving image and a still image based on the B image signal (hereinafter referred to as the second image signal) and displays it on one monitor TV 58. When the freeze command signal is not input, the image shown in FIG. As shown, the moving image A is displayed in a large size based on the first image signal, and the latest still image B with no color shift is displayed in a small size on the same screen based on the second image signal, and a freeze command signal is input. sometimes switch 59
The display shown in FIG. 2 (B) or (C) is performed depending on the 0N10FF of the display. That is, if the switch 59 is turned on when the freeze command signal is input, the first image signal and the second image signal are
The image signals of are exactly the same, and only the still image B' is displayed in a large size as shown in FIG. 2(B), and if the switch 59 is turned off when the freeze command signal is input,
As shown in FIG. 2(C), the still image B' is displayed in a large size (based on the second image signal), and the moving image B' is displayed in a small size on the same screen based on the first image signal. .

Next, the freeze control circuit 60 will be explained in detail with reference to FIGS. 3 and 4.

FIG. 3 is a block diagram showing one embodiment of the freeze control circuit 60. The freeze control circuit 60 includes a contour signal generation circuit 61, a comparison circuit 62, a memory 63, a counter 64, a discrimination circuit 65, an AND circuit 66, and a NAND circuit 6.
It consists of 7.

The contour signal generating circuit 61 is supplied with an oRGB plane sequential image signal (FIG. 3(B)) from an input terminal B. This image signal is an RlG, B image signal input in a frame sequential manner, and has a waveform synchronized with the period of the VD pulse (FIG. 4(A)). In FIG. 4 (Δ), 0 indicates an odd field and E indicates an even field.

The contour signal generation circuit 61 detects the contour portion (position where the contrast suddenly changes) of the image indicated by the input image signal, and outputs the contour signal to the comparison circuit 62 and the memory 63.

The memory 63 temporarily stores the contour signal and outputs it to the comparison circuit 62 after a certain period of time (0.1 seconds). G-EN pulse (Figure 4 (E))
Even field G image signal (Fig. 4(C))
It is possible to operate only during the output period of the contour signal generation circuit 6.
While writing the contour signal added from 1, 0.1
After a second, the written contour signal is read out.

The comparison circuit 62 compares the contour signal applied from the contour signal generation circuit 61 with the contour signal of the even field G image signal added from the memory and delayed by 0.1 seconds. Then, as shown in FIG. 4(G), a comparison signal indicating whether the two input signals match or do not match (a pulse signal that becomes H level when they do not match (FIG. 4(D)) is output to the discrimination circuit 65 via line D. do.

Other inputs of the discrimination circuit 65 include input terminal E or G-EN.
pulse (Fig. 4(E)) and line G from the counter 64.
An EN pulse (FIG. 4(G)) is applied via the . Here, the counter 64 is connected to the G-EN pulse and the VD pulse.
The G-EN pulse is input as shown in Figure 4.
It becomes H level in synchronization with the rise of the pulse (Fig. 4 (E)), and then the three τ lower pulses (Fig. 4 (, to)
), it outputs an EN pulse (FIG. 4 (G)) that falls to L level.

Since the discrimination circuit 65 outputs a discrimination pulse indicating whether the captured image is a still image or a moving image, this discrimination pulse is shown in FIG. 4(F).
As shown in , it goes to H level in synchronization with the comparison signal (first pulse signal), goes down to L level when the discrimination pulse is at H level, and goes down to L level in synchronization with the falling edge of the GEN pulse, and when it is at L level. This is a pulse signal that rises to H level and further falls in synchronization with the fall of the EN pulse when the discrimination pulse is at H level.

That is, when the discrimination circuit 65 discriminates that it is a still image, C, EN
It outputs a discrimination pulse that rises in synchronization with the falling edge of the pulse and falls after 3 field periods, and when it is determined that it is a moving image, it rises in synchronization with the comparison signal (first pulse signal) and falls in synchronization with the falling edge of the G-EN pulse. Outputs a discrimination pulse that falls in synchronization with the falling edge.

The discrimination pulse output from the upper 8 self discrimination circuit 65 is applied to an AND circuit 66. The EN pulse is applied from the counter 64 to the other input of the AND circuit 66, and the AND circuit 66 takes the AND condition of the two input pulses and sends the AND output (FIG. 4 (H)) through the line H. Add to NAND circuit 67.

The other input of the NAND circuit 67 is a freeze command signal (see FIG. 4 (I
)) can be input, and when the output of the AND circuit 66 is at H level and the freeze command signal is not output (when it is an H level signal),
The L level rewriting command pulse (Fig. 4 (J)) is
is outputted to the enable terminal EN of the field memory 42, 44, 46 via.

On the other hand, terminal R/ of field memory 42, 44, 46
Write signals of RGB image signals are applied to W from NAND circuits 43, 45, and 47. Here, the NAND circuits 43, 45 and 47 have RGB
Field selection pulse R- for sorting image signals for each color
R/'v\5G-R/W and B-R/W are added, and freeze command signals are added to the other inputs, respectively.
When the freeze command signal is not output (H level signal), NAND circuits 43, 45 and 47 sequentially send RGB image signal write signals (L level signal) to terminals R/W of field memo+J42, 44 and 46. Output.

The field memories 42, 44 and 46 can be rewritten only when a rewrite command pulse is applied to the enable terminal EN from the freeze control circuit 60, and R/lvV
RGB image signals are sequentially written for each color by write signals sequentially applied to the terminals from NAND circuits 43, 45 and 47. That is, field memories 42, 44 and 4
The memory contents of 6 are the tl of the rewriting command pulse in FIG. 4(J).
At t2, the image signal changes from B to B, and from R8 to R at t2 open.
4 image signal, G between t3. The image signal is rewritten from G to G. And field memory 42.
The RGB image signals stored in 44 and 46 are simultaneously read out and output to the R, G, and B output terminals 1L and M ((K), (L>, (M) in FIG. 4). Note that while an image signal is being written into the field memory, the image signal being written is simultaneously read out.

By the way, as described above, the rewrite command pulse is output from the field memory 42 when the captured image is determined to be a still image and the freeze command is not output (when the freeze command signal is an H level signal). .44 and 46
The image signal of the latest still image before the input of the freeze command is stored. On the other hand, when the freeze command is input, the rewrite command pulse is no longer output, and updating of the stored contents of the field memories 42, 44 and 46 is prohibited, resulting in a still image with a slight color shift. .

In addition, as shown by the dotted line in FIG. 4(I), the AND rotation vlr
When a freeze command is input in the middle of the H level output of 66, a rewrite command pulse having a length of three fields as shown in FIG. 4(J) cannot be obtained.

To deal with this, for example, as shown in FIG. The differential signal may be taken, the differential signal may be applied as a trigger signal to the one-shot circuit 69, and the one-shot circuit 69 may output a rewrite command pulse having a length of three fields.

FIG. 6 is a block diagram of main parts showing another embodiment of the electronic endoscope device according to the present invention. Note that the same parts as those in FIG. 1 are given the same reference numerals, and the explanation thereof will be omitted.

In FIG. 6, a freeze control circuit 80 has almost the same configuration as the freeze control circuit 60 in FIG. They differ in that they do so. Further, field memories 92, 94 and 96 are configured to input the outputs of field memories 32, 34 and 36, respectively.

Then, when a rewriting command pulse is applied from the freeze control circuit 80 to each field memo 1J92.94 and 96, the RGBii image signal stored in each field memory 92.94 and 96 is transferred to the field memory 32.34. and RGB image signals output from 36 at the same time.

According to the above configuration, the time required for rewriting is shorter than in the case of the embodiment shown in FIG. Can be rewritten.

Now, in the present invention, one monitor TV is used as shown in FIG.
58, it is possible to switch between moving image A and still image B', and display moving image A in a large size as shown in FIG. Since image B is displayed in a small size on the same screen, a desired scene without color shift can be immediately frozen by a freeze command.

That is, if a freeze command is output while watching moving image A in FIG. 2(A), if moving image A has color shift, the second
Still image B' in Figure (B) is an image without color shift that is earlier than video A, so still image B' is an image of the desired scene (video A
) may be different.

On the other hand, if the freeze command is output while looking at the latest still image B in Figure 2 (A), the latest still image B and still image B' in Figure 2 (B) at that time are matching agreement,
It is possible to freeze a desired scene without color shift.

That is, the display of the latest still image B serves as a guideline for freezing a desired scene without color shift (when a freeze command is issued).

In addition, if the still image B' is displayed in a large size and the video A is displayed in a small size on the same screen as shown in Fig. 2 (C), even during endoscopic diagnosis using the still image B', the current This allows you to see a video of the video, which allows you to extend the freeze period.

Incidentally, in this embodiment, out of color images input sequentially, images of the same color are compared with each other, but images of different colors may be compared with each other. Further, the means for determining whether it is a moving image or a still image is not limited to this embodiment, and may be based on the coincidence or mismatch between two color images, such as a method of determining based on a cross-correlation between a preceding color image and a subsequent color image. Any method may be used as long as it can be determined based on the

[Effect of ribbing]

As explained above, according to the electronic endoscope device according to the present invention, it is determined whether a still image or a moving image is present based on the coincidence or mismatch between a temporally preceding image and a subsequent image captured in a frame sequential manner. The contents of the freeze-only memory are updated to the latest frame-sequential image signal each time it is determined that the image is a still image.
As soon as a freeze command is input, updating of the above memory contents is prohibited, so it is possible to always reproduce a still image with no color shift by the freeze command, and there is no perceived time lag at the same time as the freeze command is input. can be immediately stopped.

In addition, it is possible to switch and display moving images and still images on a single monitor TV based on the output of a normal memory for converting a frame-sequential image signal into a simultaneous format and the output of a memory dedicated to freezing. In addition, when displaying a moving image, the latest still image can be displayed in a smaller size on the same screen.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an electronic endoscope device according to the present invention, and FIGS. The figure is a block diagram including details of the freeze control circuit in Figure 1, and Figure 4 (A).
(M> is a signal waveform diagram of each part used to explain Fig. 3, Fig. 5 is a block diagram showing an improved example of the freeze control circuit shown in Fig. 3, and Fig. 6 is a diagram of the present invention). It is a main part block diagram showing an example of 32.34.36.42.44.46.92.94.9
6...Field memory, 38...Pulse generation circuit for field selection, 48...
Changeover switch, 57... Display control circuit, 58...
...Monitor TV, 59...Switch, 60
．． 80... Freeze control circuit, 61... Contour signal generation circuit, 62... Comparison circuit,
63...Memory, 64...Counter, 65...Discrimination circuit, 66...AND circuit, 67...NAND circuit.

Claims (1)

[Scope of Claims] Imaging means for sequentially capturing images of each color in a frame-sequential manner and obtaining frame-sequential image signals by this imaging; and a second storage means, inputting a field sequential image signal of one field or one frame at a predetermined period, and storing a still image or a moving image based on the input sequential image signals of one field or one frame before and after the input. determining means for determining whether the image is a still image at predetermined intervals; and each time the determining means determines that the image is a still image, updating the stored content of the second storage means with the latest frame-sequential image signal and inputting a freeze command. Then, a control means for prohibiting updating of the storage contents of the second storage means, one display means, and a simultaneous first display output from the first storage means and the second storage means, respectively. A color image signal and a second color image signal are input, and when a freeze command is not input, a color image corresponding to the first color image signal is displayed in a large size on the screen of the display means, and a color image corresponding to the second color image signal is displayed. Display control means for displaying a small color image on the same screen, and displaying at least a large color image corresponding to the second color image signal on the screen of the display means when a freeze command is input. Electronic endoscope.