JP3112487B2 - Signal processing device for image freeze - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image freeze signal processor for obtaining a freeze image with less image blur.

[0002]

2. Description of the Related Art In recent years, with the advance of solid-state imaging technology, the density of pixels and the size of chips have been reduced, and an endoscope having a solid-state imaging element mounted at the tip, that is, an electronic endoscope device has been developed. ing. These devices have the function of observing the part to be inspected by inserting it into the body cavity, and also have the function of recording an observation image of the same part. The quality of the recorded image as well as the observation function is very important. This has a great effect on the diagnosis of the part to be inspected. Therefore, at the time of recording, the operator of the endoscope, after stopping the patient, freeze-displays the image of the region to be inspected several times, selects the most desirable image as the recorded image, and, for example, selects the monitor image. Still images are recorded on a photographing device, a video printer, a still video proppy device, or the like. However, even if the patient is stationary, there is considerable movement of the inspected part as long as the patient is observing the inside of the living body, and it may be necessary to freeze again many times to eliminate image blurring due to this movement. There was a defect.

As described above, the deterioration of the recorded image due to the movement of the subject differs depending on the type of the image pickup device and the image pickup method. For example, when a frame transfer type CCD (hereinafter, referred to as an FT type CCD) is used as an image sensor, the movement of a subject during an exposure period causes image blur, and an interline type CCD (hereinafter, referred to as an FT type CCD). IT
When skipped scanning is performed using a type CCD, image flickering due to the movement of the subject during the exposure period and flickering due to the difference in image between fields occur. In addition, for the purpose of reducing the diameter of the endoscope, a monochrome CCD is mounted at the tip of the endoscope, and the illumination light is, for example, RGB.
In the so-called color plane sequential method using sequential light, since each primary color image of RGB sequentially captured in chronological order is displayed simultaneously, so-called color shift in which the movement of the subject is displayed as a color shift. It becomes a problem.

In order to solve the above-mentioned problem, the applicant of the present invention disclosed in Japanese Patent Application No. 63-209677 does not display a still image on a monitor or the like at the same time when the freeze function is activated. Proposed a device that detects image blurring (color misregistration, etc.) from an image signal input to a monitor and displays the image signal with the least amount of detection as a still image on a monitor or the like.

[0005]

SUMMARY OF THE INVENTION However, in the proposal of Japanese Patent Application No. 63-209677, after a freeze operation is performed to obtain a still image, a certain time is required until a still image is actually obtained. Because of the time lag, the operator may feel uncomfortable or freeze on a screen that is not intended by the operator.

Incidentally, as shown in Japanese Patent Application No. 63-109187, a plurality of continuous image frames are recorded,
It is also considered to select and display an image having no color shift from among them, but it is disadvantageous in cost and size because a large amount of memory is required.

The present invention has been made in view of the above points, and provides an image freeze signal processing apparatus capable of obtaining a still image with less time lag and less image blur without using a large amount of memory. The purpose is to:

[0008]

Means for Solving the Problems and Functions The present invention, as shown in the conceptual diagram of FIG.
First memory 2 for synchronization etc. via D converter 1
And a still image memory which becomes the second memory from the first memory with the least amount of motion within a fixed time from a freeze signal input to the motion detection / control circuit 3 and output by the freeze operation. Write to 4. The first memory 2 and the still image memory 4 control image read / write by the R / W controller 5. The changeover switch 6 is switched by the freeze signal so that the image in the first memory 2 is output to the image in the still image memory 4, and the image is output via the D / A converter 7.

When the motion detection / control circuit 3 stores an image with a small amount of motion in the still image memory 4, the motion detection operation is stopped, and the update of the image in the still image memory 4 is prohibited. Is output as a still image. On the other hand, when an image with a small amount of motion is not stored, an image with the least amount of motion within a fixed time is output as a still image.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. 2 to 4 relate to a first embodiment of the present invention, FIG. 2 shows an endoscope apparatus having the first embodiment, FIG. 3 shows a configuration of a motion detection / control circuit, and FIG. 4 shows a timing chart for explaining the operation of one embodiment.

An endoscope apparatus 11 shown in FIG. 2 includes an electronic scope 12 having a built-in field-sequential imaging means, and a field-sequential light source unit 13 for supplying illumination light to the electronic scope 12.
And an image processor 14 that performs signal processing on the electronic scope 12 and constitutes the first embodiment, and a display device (not shown). In the electronic scope 12, a light guide 15 for transmitting illumination light is inserted into an elongated insertion portion. By connecting the rear end of the light guide 15 to the light source unit 13, light is sequentially supplied from the light source unit 13. Is done.

That is, the white light of the lamp 16 is
The red, green, and blue color transmitting filters that form the rotating color filter 18 are rotated by the color filter 18 to convert the light into red, green, and blue light in sequence, and are condensed and irradiated on the rear end face of the light guide 15 by the condenser lens 19. . The light guide 15 transmits the light in a sequential manner, and irradiates the light forward from the end face of the distal end of the insertion portion toward the subject in front. The illuminated subject is imaged by the objective lens 21 attached to the distal end of the insertion section on the CCD 22 disposed on the focal plane.
The optical image is photoelectrically converted by the CCD 22. The data is read out by a drive signal output from the CCD driver 23 and is converted into a digital color sequential signal by the A / D converter 24.
The data is stored in the G memory and the B memory corresponding to each color. For example, a signal captured under red illumination light is stored in the R memory.

From the image signals stored in the R, G, and B memories, each color signal is read out at the same time, applied to the contact a of the changeover switch 26 as a color plane synchronization signal, and holds a still image. It is input to the still image memory unit 27. The signal that has passed through the changeover switch 26 becomes an analog color signal through each D / A converter of the D / A converter unit 28, and is output to a display device (not shown).

The output of the A / D converter 24 is input to a motion detection / control circuit 31 which further detects a color shift and controls the storage of a still image in the still image memory 27. The still image memory 27 is used for motion detection /
In response to a control signal from the control circuit 31, the color plane synchronizing signal output from the synchronizing memory
7 are stored in R, G, and B memories. The still image memory unit 27 reads out a signal stored in synchronization with the synchronization memory unit 25 in response to a signal from an R / W (read / write) controller 32, and switches the changeover switch 26.
Is applied to the contact b.

The changeover switch 26 is switched to a contact (that is, b) on the side of the still picture memory 27 in response to a freeze instruction signal from a freeze instruction means 33 for giving a freeze instruction. Therefore, the freeze instruction means 33 is operated. Then, the image read from the still image memory unit 27 is displayed on the display device.

FIG. 3 shows the configuration of the motion detection / control circuit 31. The input color sequential signal is input to the motion amount detection circuit 34, and the motion amount (or color shift amount) of each image is detected. As a method of detecting the amount of motion, Japanese Patent Application No. 63-20694
9. A method as disclosed in Japanese Patent Application No. 63-272830 can be employed. The output of the motion amount detection circuit 34, that is, the detected motion amount is input to the minimum value detection circuit 35.

This minimum value detection circuit 35 is
Among the motion amounts input to the first gate circuit 36, the minimum motion amount is held over time, and every time the minimum value is updated, an update pulse is output to the first gate circuit 36 constituted by an AND circuit. The first gate circuit 36 outputs a write pulse to the still image memory unit 27 and activates the first timer 37 in a retriggerable manner. When the timer operation is started, the first timer 37 outputs a pulse which becomes "H" for a predetermined period of time, and becomes "L" after this predetermined period of time.
To the maximum value (of the amount of motion). This fixed time is a time during which a past image is held in the still image memory unit 27.

The minimum value detection circuit 35 outputs an "L" freeze enable signal to the second gate circuit 38 if the amount of motion being held is equal to or less than a preset freeze level. A freeze signal is also input to the second gate circuit 38, and an output of the second gate circuit 38 is input to a second timer 39. Input terminal of the second gate circuit 38
Of the input terminals on the minimum value detection circuit 35 side invert the input value
The freeze enable signal is applied to this input.
It is. That is, the freezing signal from the minimum value detection circuit 35
Freeze signal is input when no signal is input
Sometimes output occurs. The second timer 39, when a freeze-friendly signal is not output, when the freeze signal is input, the timer operation is started the predetermined time T2 "L". With this timer operation, an operation time until a freeze image is generated after the freeze signal is input is determined. The second timer 39 inverts the output,
While the timer 39 is running, that is, the timer is "H"
"L" is output to the third gate 40 during the period of
During the period when it is not moving, “H” is output.
You .

The output of the second timer 39, together with the freeze signal, is input to a first gate 36 to which an update pulse is input via a third gate 40 formed of a NAND gate. Since the third gate 40 is a NAND circuit, it has two inputs.
It becomes "L" when both force ends are "H". That is, when the freeze signal is output, the timer 39 is set to “L”.
After the predetermined time T2 becomes “H”, the output of the third gate 40 also becomes “H”, so that an update pulse can be output through the first gate 36. In the meantime, the image with the minimum motion amount detected by the minimum value detection circuit 35 is stored in the still image memory unit 27.

The operation of the first embodiment will be described below with reference to the timing chart of FIG. The color sequential signal is input to a motion amount detection circuit 34, and the motion amount is detected. As shown in FIG. 4 (a), N indicated by 1, 2, 3,.
For the image o., the amount of movement is sequentially detected, for example, as shown in FIG. In FIG. 4B, the freeze level is set as the upper limit of the amount of motion allowed as a still image.

With respect to the amount of motion as shown in FIG. 4B, the minimum value detection circuit 35 determines that the amount of motion of the input image is smaller than the amount of motion held before that. An update pulse is output as shown in ()). In this case, if the output of the first timer 37 is “H” as shown in FIG. 4D and the freeze signal is “L” as shown in FIG.
The update pulse is output to the still image memory 27 as a write pulse through the first gate 36 as shown in FIG.
The still image memory 27 stores an image with a small amount of motion. FIG. 4 (i) shows the number of the freeze image held in the still image memory unit 27.

When the amount of movement becomes smaller than the freeze level, the minimum value detection circuit 31 outputs a freeze enable signal to the second gate 38 as shown in FIG. Then, in this state, when the freeze signal shown in FIG. 4 (f) is output at the time A shown by the reference symbol A in the figure, from the last update pulse before this (indicated by P3 in FIG. 4 (h)), If the time is within the time set by the first timer 37, the image written by the writing pulse P3 is output to the display device as a frozen image via the changeover switch 26 shown in FIG.

That is, in this case, an image having the minimum amount of motion is displayed as a freeze image within the time set by the first timer 37 from the time of the freeze operation. On the other hand, when the freeze signal is output by the freeze operation in a state where the freeze enable signal is not output as at the time indicated by the symbol B in FIG.
, The second timer 39 is started, and becomes "L" for a fixed time T2 as shown in FIG. 4 (g). This fixed time T2
When it becomes "H" later, the image with the minimum amount of motion during this time T2 is written into the still image memory unit 27 by a write pulse,
Hold, and this image is displayed on the display device.

That is, in this case, after the freeze signal,
The smallest still image within the time T2 is held and displayed. In the first embodiment, the time lag can be reduced by dividing the process of generating a freeze image in the motion detection period before and after the freeze operation. Also, it does not require much memory. FIG. 5 shows a configuration of the motion detection / control circuit 41 according to the second embodiment of the present invention. In the second embodiment,
A motion detection period after a freeze signal is input is not provided.

In this motion detection / control circuit, in FIG. 3, the update pulse output from the minimum value detection circuit 35 is input to a gate circuit 42, and a signal obtained by inverting a freeze signal is input to the gate circuit 42. This gate circuit 4
2 is output to the still image memory unit 27 as a write pulse and is also input to the first timer 37. Other configurations are the same as in the first embodiment.

Accordingly, the time of the freeze operation is set to, for example, FIG.
In the state indicated by reference numeral A, the operation is the same as in the first embodiment, and in the state indicated by reference numeral B, the image at that time is displayed as a frozen image. Therefore, the response to the freeze request (operation) is better than in the first embodiment. On the other hand, the function of preventing color misregistration or image blurring is slightly inferior. However, since a freeze request is generally made after an operator recognizes a clear image, in practice, color There is no problem with the slip prevention ability.

FIG. 6 shows a simultaneous endoscope apparatus 51 having a third embodiment of the present invention. The apparatus 51 includes an electronic scope 12 'having a built-in simultaneous imaging means, a light source unit (not shown) for emitting white light, a simultaneous image processor 14' of the third embodiment, and a display device (not shown). It is composed of

The electronic scope 12 'is the same as the electronic scope shown in FIG. 2, except that a color filter 22a for color separation is provided on the front surface of the CCD 22. The above C
When a drive signal from the CCD driver 23 is applied to the CD 22, the photoelectrically converted signal is read out and input to the signal processing circuit 52. The signal processing circuit 52 separates the signals into a luminance signal Y and a chrominance signal C. The signals are converted into digital signals by A / D converters 53Y and 53C, respectively, and then stored in the Y memory and the C memory of the first memory unit 54. You.

The output of the first memory section 54 is passed through a changeover switch 26 'having a two-circuit configuration, and is output to the D / A converter section 2.
8 'and input to the still image memory 27'. Both memory units 54, 27 '
The read / write is controlled by the R / W controller 32. The output signal of the A / D converter 53Y is input to the motion detection / control circuit 31, which detects the amount of motion from a luminance signal different from one field / frame, and stores a still image in the still image memory 27 '. Generate a write pulse.

The motion detection / control circuit 31 is connected to, for example, a foot switch 55 held in the image processor 14 'via a cable, and receives a freeze signal output when the foot switch 5 is turned on. You. The freeze signal also serves as a signal for performing switching control on the changeover switch 26 'so that the contact point a is turned on from the contact point a.

The motion detection / control circuit 31 of the third embodiment
5 may be used. The operation and effect of the third embodiment are substantially the same as those of the first and second embodiments.

FIG. 7 shows a configuration of a color misalignment prevention freeze circuit 43 according to a fourth embodiment of the present invention, FIG. 8 shows a period during which the circuit 43 operates, and FIG. 9 performs writing and reading to and from a frame memory. FIG. 10 is a timing chart for explaining the operation of this embodiment. In this embodiment, as shown in FIG. 8, fixed periods before and after the input of the freeze trigger, that is, Ta, Tb
Is a circuit that freezes the image with the least color shift in the period including.

In FIG. 7, terminal A is set to 1 every 1/60 second.
R, G, B plane sequential signals for frames are input. This signal is sent to a frame memory set (hereinafter abbreviated as FMS) 44. This FMS 44 has four frame memories of R, G, and B each (R1, R2,.
Shown at 4. ), Writing to each frame memory is controlled by the write chip select controller 45A, and reading is controlled by the read chip select controller 45B. The write and read chip select controllers 45A and 45B generate chip select signals for writing and reading in synchronization with the synchronization signal output from the synchronization signal generation circuit 46. This synchronization signal is transmitted to the FMS address decoder 47A.
The address signal for the FMS 44 generated by the FMS address decoder 47A is
4 is input. Note that the synchronization signal is also output to other circuits.

The FMS 44 has two output ports, one output port is connected to the input terminal of a D / A converter at the subsequent stage (for example, reference numeral 28 in FIG. 2), and the other output port detects motion. The input terminal of the correlation detecting circuit 48 is connected to the input terminal. The FMS 44 is controlled by the read data bus select controller 47B so that the same data is output from the two output ports during a moving image. As for the address of the FMS 44, the write address and the read address are multiplexed as shown in FIG. 9, and the address is fetched by an address fetch signal in response to writing and reading to the frame memory. ing. Therefore, it is possible to read data from an arbitrary frame memory to the two output ports from a frame memory other than the currently written frame memory.

At the time of a normal moving image, as shown in FIG. 10, the image data input to the terminal A is a single-color frame of R, G, and B every one vertical synchronizing signal (hereinafter, referred to as 1VD). Image) data and an odd field (Od
d) and the even field (Even) are time-divided. And the write chip select controller 45A
Selects the image data of Rn, Gn, and Bn for each 1 VD in ascending order of the subscript n, and cyclically repeats the selection so that the R, G, and B monochromatic plane-sequential image data are respectively R, G, and The data is distributed to the B memory bank and written to the frame memory.

Reading from the frame memory is controlled by the read chip select controller 45B so as to read out field data in synchronization with the vertical synchronization signal VD immediately after writing. At this time, the field read out matches the field information of the video synchronization signal. For example, in FIG. 10, after writing data of R2, even data of R2 is written in the next field, and R2 is written in the next field.
Odd data is further added to the next field by the Ev of R2.
en data will be read. Similar operations are performed on the G and B data with a delay of one field each.

At the time of such a moving image, the image data input to the correlation detection circuit 48 is
Thus, the degree of correlation between the R, G, and B image data is detected and quantified. The digitized data is input to the memory 49A, and a period of writing cycle to the FMS 44,
That is, it is held for 12 fields. Therefore, as shown in the table, the combination of frame memories to be read is 1
There are two ways.

Table
field
R Read R1 R2 R2 R2 R3 R3 R3 R4 R4 R4 R1 R1 R1 G Read G1 G1 G2 G2 G2 G3 G3 G3 G4 G4 G4 G1 G1 B Read B1 B1 B1 B2 B2 B2 B3 B3 B3 B4 B4 B4 R1 These 12 combinations (However, in the combination of R, G, and B, data up to the immediately preceding or succeeding image data is taken into account) Data indicating the degree of correlation is written to the memory 49A and held. And F
When one cycle of writing to the MS 44 is completed, the old (R,
G, B) shows the new degree of correlation (R,
G, B) can be rewritten to data representing the degree of correlation corresponding to (G, B). In this case, for example, the frame memory G2
When data is written to the RG
In the combination of B, (R2, G2,
B1), (R2, G2, B2), (R3, G2, B2)
Since these three types cannot be read, nine types of data excluding these three types and data indicating the degree of correlation are effective as combinations of R, G, and B.

The encoder 49B and the sorter 49C rank the correlation amounts for the data indicating the above nine degrees of correlation (that is, order the RGB images from the smaller motion amount). Then, as shown in FIG. 7, when the freeze trigger is input to the CPU 50, the CPU 50 controls the encoder 49B or the read chip select controller 45B to which the output of the encoder 49B is input, thereby obtaining The combination of (R, G, B) corresponding to the data indicating the strongest correlation among the data indicating the degree of correlation is selected immediately, and the (R, G, B) of the selected combination is selected.
G, B) Image data is output to a D / A converter connected to an output port and displayed on a monitor, for example.

In this way, an image having the strongest RGB correlation, that is, an image with the least color shift, is selected from the images before the input of the freeze trigger and is output. what if,
Assuming that the combination of (R4, G3, B3) is selected, R4, G3, and
Writing of B3 to the frame memory is prohibited, and writing to other frame memories becomes possible. Therefore, in the memory bank of R, R1, R2, and R3 are:
Cyclic writing is performed, and G1, G2, and G4 are performed in the memory bank of G, and B1, B, and B are performed in the memory bank of B.
2 and B4 are written.

At this time, if the degree of correlation for the new combination of R, G, B is stronger than the degree of correlation of (R4, G3, B3), the new combination of R, G, B is converted to D / A. Output to the output port connected to the converter, writing to these frame memories is prohibited,
Writing to other frame memories is possible,
In this case, writing of R4, G3 and B3 to the frame memory is permitted. This operation is performed for a certain period T shown in FIG.
b, the color shift prevention freeze after the input of the freeze trigger becomes possible, and the periods Ta and Tb before and after the timing of the input of the freeze trigger (total period Ta + T)
In b), a frozen image with the least color shift can be displayed or recorded.

According to this embodiment, there is a merit that the time lag from the input of the freeze trigger to the display of the freeze image with little color shift is reduced, and the freeze image with little color shift can be displayed without increasing the capacity of the frame memory. Having.

By the way, monochrome observation may be performed in an apparatus having a color shift prevention freeze function for displaying a still image with a small color shift. In the case of this monochrome image, color misregistration does not originally occur, but if the same function of preventing color misregistration as in the case of a color image is activated, a freeze operation will be delayed for a certain period of time. With the configuration shown in FIG. 11, in the case of a monochrome image, a freeze image may be displayed immediately without delay.

In the image freeze signal processing device 60 of the fifth embodiment shown in FIG. 11, an RGB plane sequential image signal captured by, for example, the electronic scope 12 shown in FIG. , AD conversion means 6
2. The image is inputted to the color shift prevention freeze means 61 constituted by the (image) memory means 63, the DA conversion means 64 and the color shift prevention freeze control means 65. The color shift prevention freeze means 61 stores the RGB plane sequential input signal in the sequential memory means 63 at the time of displaying a moving image, and reads out and outputs the RGB synchronized image signal from the memory means 63 so as to conform to the standard TV signal. At the time of display, updating of the read data in the memory means 63 is prohibited by the color shift prevention freeze means 61, and as a result, a still image signal is output.

The color shift prevention freeze control means 65 detects the amount of movement of the subject for a certain period of time after the freeze instruction, and controls the memory means 63 to store an image in which the amount of movement of the subject is minimized. It has a color shift prevention freeze mode and an immediate freeze mode in which the image is frozen as soon as a freeze instruction is given, and is controlled by a signal from the freeze operation control means 67.

The output of the monochrome display instruction means 69 and the instruction signal from the freeze instruction means 68 are input to the freeze operation control means 67. When a freeze instruction is issued during the monochrome display, the freeze mode is immediately changed to the normal freeze mode. If so, the color shift prevention freeze control unit 65 is controlled to select the color shift prevention freeze mode. The monochrome display means 66 normally outputs the RGB signals input from the color shift prevention freeze means 61 to a monitor means (not shown) as it is, and when an instruction signal from the monochrome display instruction means 69 is input, a specific signal is output from the RGB signals. , For example, a G signal is output to each output terminal of RGB.

FIG. 12 shows a specific embodiment of the color shift prevention freeze means 61. The output signal of the A / D converter 62 is
The image data is input to the first memory unit 70 constituting the image memory unit 63. The first memory means 70 synchronizes the image data and inputs it to the second memory means 71 which becomes a still image memory means. The output signal of the first memory means 71 is D /
It is input to the A conversion means 64. The first memory means 7
The output of 0 is input to the motion detecting means 72 to detect the amount of motion, and the amount of motion is input to the minimum value holding means 73 and the freeze control means 74.

The minimum value holding means 73 holds the minimum value of the movement amount, and stores the held movement amount in the freeze control means 7.
Output to 3. The freeze control means 74 includes a timer means 75
And controls whether or not the second memory means 71 is write-protected by a signal from the freeze operation control means 67. For example, when the freeze instruction means 68 is operated, a signal for generating a freeze image for preventing color misregistration is input to the freeze control means 74 via the freeze operation control means 67. Then, within the time set by the timer means 75, an image with a small amount of motion is written from the first memory means 70 to the second memory means 71, and the second memory means 71
Is controlled so that the image with the minimum amount of motion is held.

On the other hand, when the monochrome display instructing means 69 is operated, the freeze control means 74 immediately sets the second memory means 71 in a write-protected state, and before the write-protection, the second memory means 71 Is repeatedly read out as a frozen image.

FIG. 13 shows a specific configuration of the monochrome display means 66. The R, G, and B signals output from the color shift prevention freeze unit 61 are output by the monochrome display instruction unit 69.
The signals are input to signal switching means 76 and 77 each composed of two analog switches or the like whose switching is controlled. The R and B signals are applied to the contact points a of the signal switching means 76 and 77, respectively.
The G and B signals are applied to the contact b of both signal switching means 76 and 77. The common contact is connected to the input terminals of buffer means 78 and 80, and the G signal is connected to the input terminal of buffer means 79 through the monochrome display means 66.

When a monochrome freeze instruction is issued from the monochrome display instructing means 69, the contact b is switched on so that the image stored in the second memory means is displayed in monochrome. I have. As described above, in the fifth embodiment, the color shift prevention freeze mode and the immediate freeze mode are provided, and both modes are switched in synchronization with the monochrome display instruction. In the monochrome display, a freeze operation without delay is possible, and the operability of the freeze is improved.

Next, a modification of the fifth embodiment will be described. FIG. 14 shows a modification of FIG. In FIG.
The output signal of the freeze operation control means 67 is
5, the output control signal controls the freeze control means 74 and the timer means 75, so that both the color shift prevention freeze mode and the immediate freeze mode can be appropriately switched, and at the same time, the timer means 75 prevents the color shift. In the freeze mode, the time for detecting the movement of the subject can be varied. The other configuration is the same as that of FIG.

FIG. 15 shows a modification of FIG. FIG.
In 5, the R, G, B signals are input to the color component extraction means 81, applied to the contact a of each switch constituting the switching means 82, and extracted to the contact b by the color component extraction means 81. A common extracted color signal is applied. The switching means 82 is switched by the monochrome display instruction means 69 so that the contact b is turned on.

Referring to FIG. 15, the outline of the monochrome frozen image is displayed by the output signal of the color component extracting means 81. By the way, in the electronic endoscope apparatus provided with the automatic iris mechanism, if the freeze operation is performed during the operation of the automatic iris, the amount of light applied to the subject changes with each of the R, G, and B color lights. The color of the image may change. Further, in the simultaneous type electronic endoscope apparatus, particularly when imaging is performed in a frame mode in which one image is obtained from two field images, the difference in brightness between the two field images flickers ( Flicker).

Second, when water is supplied from the tip of the endoscope body to clean the objective lens, the automatic aperture responds to the reflected light of water, and the brightness changes drastically. Third, when light other than illumination light is incident on the image pickup device, such as when laser irradiation is performed for treatment in a body cavity, the automatic aperture malfunctions and proper brightness cannot be obtained.

These disadvantages can be solved by using the configuration of the endoscope device 84 having the sixth embodiment shown in FIG. The endoscope device 84 of FIG.
, Light source unit 86, and image processor unit 87 of the fifth embodiment.
And a monitor (not shown). The electronic scope 85 is, for example, the one shown in FIG. 6 and further provided with a freeze switch 88.

The CCD driver 2 of the image processor 87
The image signal read from the CCD 22 in response to the drive signal from 3 is input to the signal processing circuit 89, where the image signal is processed to generate a standard video signal, which is output from the video output terminal to the monitor. For example, a luminance signal of the signal processing circuit 89 is input to a detection circuit 90, where the luminance signal is detected and an average level is detected.
1 is input. The aperture control circuit 91 compares the input signal level with a standard level in an appropriate lighting state, and outputs a difference signal to a motor drive circuit 93 via a hold circuit 92.

The current is amplified by the (motor) drive circuit 93 and the rotation angle of the aperture control motor 94 is controlled. An aperture plate 95 is attached to the rotation shaft of the aperture motor 94,
This diaphragm plate 95 is driven by a motor 94,
By controlling insertion / removal (amount) from the illumination optical path, the illumination light amount of the illumination light of the lamp 96 supplied to the incident side end face of the light guide 15 via the condenser lens 97 can be controlled.

A freeze instruction signal output when the freeze switch 88 is turned on is input to the CPU 98, and the CPU 98 outputs a hold signal for stopping the aperture operation to the hold circuit 92 for at least one frame period thereafter. I do. The CPU 98 outputs a freeze signal to the signal processing circuit 89 so that the freeze is performed after the stop operation is actually stopped. When the hold signal is supplied from the CPU 98, the hold circuit 92 stops the aperture operation by holding the aperture signal obtained by the aperture control circuit 91 for a predetermined period or while the hold signal is being applied.

As described above, by stopping the automatic aperture operation for at least one frame immediately after the freeze instruction, a change in the color tone due to the aperture operation at the time of freeze (plane sequential method) and the occurrence of flicker (simultaneous method) are prevented. In addition, the image quality during freeze can be improved.
The signal processing circuit 89 is provided with a means for generating a freeze image with a configuration similar to that shown in FIG. 6 (not shown).

FIG. 17 shows a specific configuration of the hold circuit 92 of FIG. An output signal (indicated by ei in FIG. 17) of the aperture control circuit 91 is input to the capacitor 102 via the analog switch 101, and the signal held by the capacitor 101 is output to the drive circuit 93 via the buffer 103 ( In FIG. 17, it is indicated by e0).

FIG. 18 shows a schematic configuration of a main part of the sixth embodiment. That is, the diaphragm means 1 for changing the irradiation light amount
05, aperture control means 106 for calculating the optimal aperture amount from the image signal and controlling the aperture amount, and aperture control means 106
Control means 107 for holding the aperture signal output from the camera for a certain period and fixing the aperture, and aperture control means 107
Control instruction means 1 for instructing the aperture to fix the aperture
08, the aperture is fixed when the image quality is degraded when the automatic aperture is operated.

FIG. 19 shows the structure of the main part of an electronic endoscope device 111 having the seventh embodiment. For example, a frame-sequential image signal output from the CCD 22 in the electronic scope 12 shown in FIG.
After signal processing such as D conversion, the signal is input to a D / A & subsequent signal processing circuit 116 via a delay circuit 114 and a freeze memory 115 in a color shift prevention freeze circuit 113, and a standard video signal is output from a video output terminal. Is output.

For example, the luminance signal of the signal processing circuit 112 is input to the detection circuit 90 as in FIG. The output signal of the detection circuit 90 is output to an aperture control motor 94 via an aperture control circuit 91, an (aperture signal) hold circuit 92, and a drive circuit 93. The delay circuit 114 delays a signal by, for example, one image, and image signals constituting two images appearing at the input / output terminals of the delay circuit 114 are input to the motion detection circuit 121, Is detected, and the detected amount of motion is input to the minimum value detection circuit 122, and the minimum amount of motion is detected.

The operation of the minimum value detection circuit 122 is started by the freeze instruction circuit 123 (the operation may be as in the first embodiment), and the detection time setting circuit 12
4 to perform the operation of detecting the minimum amount of motion within the detection time set by
Is held in a write-protected state. If a motion amount smaller than the previously held motion amount is detected within this detection time, a signal for canceling the write prohibition is sent to the write prohibition gate circuit 125, and the memory write signal from the memory R / W controller 126 is sent to the freeze memory. The image is supplied to the freeze memory 115 and is written into the freeze memory 115.

After the end of the detection time, the image having the smallest motion amount within the detection time is stored in the freeze memory 11.
5 and the image is repeatedly read out and displayed as a freeze image. The detection time setting circuit 124 sends a control signal for causing the color misregistration prevention freeze circuit 113 to operate for a certain period of time, and at the same time, sends a hold signal to the hold circuit 92 to stop the automatic aperture. The operation of the hold circuit 92 is the same as that of FIG.

With the configuration shown in FIG. 19, malfunction of the motion detection circuit due to the operation of the automatic aperture circuit can be prevented, and a more accurate color shift prevention freeze function can be realized. FIG.
Shows a main part of an electronic endoscope apparatus provided with an eighth embodiment of the present invention.

In the endoscope apparatus, the objective lens surface becomes dirty with mucus or the like due to the insertion of the distal end portion into the body.
Many have an air / water supply mechanism to clean it. In the electronic endoscope apparatus, the observation screen changes drastically due to the reflected light of the scattered water droplets at the time of water supply. In the conventional electronic endoscope apparatus, there is a problem that the brightness of the screen becomes abnormal for a moment when the water supply ends, because the automatic diaphragm operates even when the water is supplied. FIG. 20 solves this.

In FIG. 20, when an original water supply button (not shown) is pressed, an electric switch is opened / closed in conjunction with the pressing, and the water supply detection circuit 131 detects water supply.
At this time, the CPU 98 generates a hold signal to the (aperture signal) hold circuit to fix the automatic aperture. Thereby, it is possible to prevent the brightness abnormality due to the automatic throttle operation at the time of water supply.

The other points are the same as those of the embodiment shown in FIG. In this embodiment, the water supply detection is performed by the switch. However, since the screen during water supply varies greatly, the motion detection circuit 121 shown in FIG.
It is also conceivable that the water supply operation is detected from the amount of motion of the image by using such a method. FIG. 21 shows a ninth embodiment of the present invention.
It is a block diagram showing a part of composition of an electronic endoscope apparatus provided with an example.

In many endoscope devices, a tube called a channel is provided inside the scope, and various treatments are performed using the tube. One of these procedures is laser irradiation. In this method, laser light is guided into a body through a channel by a device called a probe, and cauterization of an affected part is performed. As another procedure, a transendoscopic electric scalpel is also known. In these devices, since light is emitted during treatment, the automatic aperture responds to this light, and there is a problem that the brightness becomes abnormal. FIG. 17 solves this.

FIG. 21 shows an operation signal input from a laser device 141 or an electric scalpel device 142 outside the electronic endoscope apparatus instead of the water supply detection signal in FIG.
The automatic aperture operation is stopped during these operations. That is, a signal output from the laser irradiation switch 143 of the laser device 141 is input to the irradiation detection circuit 144, and the laser irradiation is detected. This detection signal is
The signal is input to a CPU 98 provided in the image processor 87 via a connector 147 via a cable 146 connected to a connector 145 of the laser device 141, for example.

When the CPU 98 receives this signal,
As in FIG. 20, a hold signal is output to a hold circuit (not shown) to fix the aperture amount and prevent a malfunction of the automatic aperture.

[0074]

As described above, according to the present invention, timer means for setting the time for operating the minimum value detection circuit,
The image corresponding to the minimum amount of motion can be updated and written into the still image storage memory while the timer is activated, and if a freeze instruction signal is output while the timer is activated, the memory is write-inhibited. Is provided, when a freeze instruction operation is performed, a frozen image can be obtained with a smaller time lag than when the minimum value is detected from the freeze instruction time. Also, a large amount of memory is not required.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram of the present invention.

FIG. 2 is a configuration diagram of an endoscope apparatus including the first embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a motion detection / control circuit.

FIG. 4 is a timing chart for explaining the operation of the first embodiment.

FIG. 5 is a block diagram showing a configuration of a motion detection / control circuit according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram of an endoscope apparatus including a third embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a fourth embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a period during which the fourth embodiment operates.

FIG. 9 is an explanatory diagram of address fetching for writing and reading data to and from a frame memory.

FIG. 10 is a timing chart for explaining the operation of the fourth embodiment.

FIG. 11 is a block diagram showing a configuration of a fifth embodiment of the present invention.

FIG. 12 is a block diagram illustrating a configuration of a color shift prevention freeze unit according to a fifth embodiment.

FIG. 13 is a circuit diagram showing a configuration of a monochrome display unit in FIG. 10;

FIG. 14 is a block diagram illustrating a configuration of a color misregistration prevention freeze unit according to a modification of the fifth embodiment.

FIG. 15 is a configuration diagram of a monochrome display unit in FIG. 12;

FIG. 16 is a configuration diagram of an endoscope apparatus including a sixth embodiment of the present invention.

FIG. 17 is a circuit diagram of a hold circuit in FIG. 15;

FIG. 18 is a schematic configuration diagram of a main part of a sixth embodiment.

FIG. 19 is a block diagram showing a main part of an electronic endoscope apparatus according to a seventh embodiment of the present invention.

FIG. 20 is a block diagram showing a main part of an eighth embodiment of the present invention.

FIG. 21 is a block diagram showing a main part of a ninth embodiment of the present invention.

[Explanation of symbols]

 2 First memory 3 Motion detection / control circuit 4 Still image memory 5 R / W controller 6 Changeover switch

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akinobu Uchikubo 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside O-limpus Optical Industry Co., Ltd. (72) Yudai Nakagawa 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Within Olympus Optical Co., Ltd. (72) Inventor Akihiro Miyashita 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Masahiko Sasaki 2-43-2, Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Kogyo Co., Ltd. (72) Inventor Shoichi Ieoka 2-43-2 Hatagaya, Shibuya-ku, Tokyo In Olympus Optical Kogyo Co., Ltd. (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 5/91-5/956 H04N 9/79-9/898 A61B 1/04 372 G06T 1/00

Claims (2)

(57) [Claims] An image obtained by imaging an object by an imaging means.
Input means for inputting an image signal, an image based on a video signal inputted to the input means stationary
A still image memory means for storing the still image as an image, and a predetermined output of the still image stored in the still image memory means.
Output instructing means for giving an instruction to output earlier, based on the video signal input from the input means,
The amount of motion that continuously detects the amount of motion of the subject at predetermined intervals
Detecting means, and among the motion amounts detected by the motion amount detecting means,
Minimum value holding means for sequentially detecting small values and holding the minimum value
If, each time a new minimum value by the minimum value holding means is held
Update signal output means for outputting a predetermined update signal to the update signal output means from the update signal output means
Writing a still image in the still image memory means
Control means, and the update signal is output from the update signal output means.
A timer that starts when it stops and stops after a predetermined period of time
Means and the output instruction during a period in which the timer means is running.
When an instruction to output a still image is given by means
The still image stored in the still image memory means is
An image freeze signal processing device, comprising: output control means for outputting to an output destination . 2. An input unit for continuously inputting a video signal obtained by imaging an object by an imaging unit in a time series, and an image based on a video signal continuously input to the input unit is sequentially updated. A still image memory unit for storing a plurality of still images as still images, a determining unit for determining a still image in which a moving amount of a subject is smallest among a plurality of still images stored in the still image memory unit, and the still image memory unit Among the still images stored in
Output instruction means for issuing an instruction to output a specific still image to a predetermined output destination; and when an output instruction signal is output from the output instruction means
The still image having the smallest moving amount of the subject determined by the determining unit and the moving amount of the subject determined by the determining unit after a lapse of a predetermined period since the output instruction signal is output from the output instructing unit. Detecting means for comparing the still image with the smallest still image and detecting the still image with the smallest moving amount of the subject; and outputting the still image detected by the detecting means from the still image memory means to a predetermined output destination. A signal processing device for image freeze, comprising: control means.