JPH05111459A - Electronic endoscope device - Google Patents

Abstract

PURPOSE:To provide the electronic endoscope device which is less degraded in sensitivity, can decrease color slurring and can improve a vertical resolution. CONSTITUTION:The electronic endoscope device which obtains an endoscopic image by picking up the image of a testee body by a solid-state image pickup element 16 provided in the electronic endoscope has an illuminating means for irradiation the testee body with plural rays of illuminating light varying in wavelength regions and memories 41 to 46 for storing the signals read out by interlace scanning of the solid-state image pickup element 6 according to the illuminating light. The device is also constituted to have an interpolation circuit 48 which forms pseudo signals in a vertical direction based on the plural signals corresponding to the illuminating light read out by the interlace scanning and a video signal forming means which forms video signals by the signals outputted after being made simultaneous by the memories 41 to 46 and the interpolation circuit 48.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic endoscope apparatus having means for improving vertical resolution.

[0002]

2. Description of the Related Art In recent years, by inserting an elongated insertion portion into a body cavity, it is possible to observe internal organs in the body cavity and, if necessary, perform various medical treatments using a treatment instrument inserted in a treatment instrument channel. Mirrors are widely used. Further, various electronic endoscopes of a type in which a solid-state image pickup device such as a charge-coupled device (hereinafter abbreviated as CCD) is provided as an image pickup means on the distal end side of the insertion portion and image information is taken out as a photoelectrically converted electric signal have been proposed. ing.

A conventional endoscope apparatus includes an electronic endoscope 1 as shown in FIG. The electronic endoscope 1 has an elongated and flexible insertion portion 2, for example, and a large-diameter operation portion 3 is connected to the rear end of the insertion portion 2. A flexible cable 4 extends laterally from the rear end of the operation section 3, and a connector 5 is provided at the tip of the cable 4.
The electronic endoscope 1 is connected via the connector 5 to a video processor 6 including a light source device and a signal processing circuit. Further, a monitor 7 is connected to the video processor 6.

On the distal end side of the insertion portion 2, a hard distal end portion 9 and a bending portion 10 adjacent to the distal end portion 9 and capable of bending to the rear side are sequentially provided. Further, by rotating the bending operation knob 11 provided on the operation portion 3, the bending portion 10 can be bent in the horizontal direction or the vertical direction. Further, the operation section 3 is provided with an insertion opening 12 that communicates with a treatment tool channel provided in the insertion section 2.

As shown in FIG. 28, a light guide 14 for transmitting illumination light is inserted into the insertion portion 2 of the electronic endoscope 1 which constitutes the conventional endoscope apparatus. The tip surface of the light guide 14 is arranged at the tip portion 9 of the insertion portion 2,
Illumination light can be emitted from the tip portion 9. Further, the incident end side of the light guide 14 is inserted into the universal cord 4 and connected to the connector 5. An objective lens system 15 is provided at the tip portion 9, and a solid-state image pickup device 16 ″ is provided at an image forming position of the objective lens system 15.

The solid-state image pickup device 16 "has sensitivity in a wide wavelength range from the ultraviolet region to the infrared region including the visible region. The solid-state image pickup device 16" has signal lines 26, 2
7, the signal lines 26 and 27 are inserted into the insertion portion 2 and the universal cord 4 and connected to the connector 5.

On the other hand, in the video processor 6, there is provided a lamp 21 which emits a wide band light from ultraviolet light to infrared light. As the lamp 21, a general xenon lamp, a strobe lamp, or the like can be used.
The xenon lamp and strobe lamp emit a large amount of not only visible light but also ultraviolet light and infrared light. This lamp 2
1, the power source 22 supplies electric power. A rotary filter 50, which is driven to rotate by a motor 23, is arranged in front of the lamp 21.

The rotating filter 50 is provided with filters for transmitting light in the red (R), green (G), and blue (B) wavelength regions for normal observation, which are arranged along the circumferential direction. Further, the motor 23 is controlled in rotation by a motor driver 25 and driven.

After passing through the rotary filter 50, R, G,
The light that is time-sequentially separated into the lights of the respective wavelength regions of B is further incident on the incident end of the light guide 14, is guided to the tip portion 9 through the light guide 14, and from the tip portion 9. The light is emitted to illuminate the observation site. The return light from the observation site due to the illumination light is formed into an image on the solid-state image pickup device 16 ″ by the objective lens system 15 and photoelectrically converted.

A drive pulse from a driver circuit 31 in the video processor 6 is applied to the solid-state image pickup device 16 "via the signal line 26, and the drive pulse is used for reading and transfer. The video signal read from the solid-state image sensor 16 ″ is input to the preamplifier 32 provided in the video processor 6 or the electronic endoscope 1 through the signal line 27. Is becoming The video signal amplified by the preamplifier 32 is input to the process circuit 33, subjected to signal processing such as γ correction and white balance, and converted into a digital signal by the A / D converter 34.

This digital video signal is selected by the select circuit 35, for example, three memories (1) 36a, memory (2) 36b, and memories corresponding to respective colors of red (R), green (G), and blue (B). (3) It is adapted to be selectively stored in 36c. The memory (1) 36a, the memory (2) 36b, and the memory (3) 36c are read at the same time, converted into analog signals by the D / A converter 37, and output as R, G, B color signals. , Is input to the encoder 38, and from this encoder 38 NT
It is output as an SC composite signal.

The R, G, B color signals or N
The TSC composite signal is input to the color monitor 7, and the color monitor 7 displays the observed region in color. Further, in the video processor 6, a timing generator 40 for generating the timing of the entire system is provided, and the timing generator 40 synchronizes the respective circuits of the motor driver 25 and the driver circuit 31.

[0013]

SUMMARY OF THE INVENTION In the above-mentioned conventional electronic endoscope apparatus, the R,
The G and B signals are read out without interlacing. Therefore, when read out (and displayed on a monitor) as a field image (from the memory that stores the signal read out in non-interlace), the horizontal resolution can be made good, but the vertical resolution becomes poor. Was there.

When normal interlaced reading is performed to increase the vertical resolution, and when one information is read at the same cycle (for example, 1/60 second), R, G, and B Since there are odd and even fields, time for 6 fields is required, and the color shift increases in the case of a moving subject. In addition, when the read cycle is increased to reduce color misregistration, the charge storage time becomes short, and the sensitivity decreases.

Now, consider a conventional example, for example, a case where interlaced read signals are synchronized in FIG.
From the solid-state image sensor 16 ″, RODD → GEVEN → BODD → R
When the video signals are read in the order of EVEN → GODD → BEVEN (where IODD or IEVEN (I represents R, G, B))
Represents an odd field or an even field in the frame color signal I. ), R, G, B written in memory
The signals include an odd number field and an even number field, and if these signals are synchronized at the same time, vertical flicker and false colors occur.

The present invention has been made in view of the above points, and an object of the present invention is to provide an electronic endoscope apparatus capable of reducing the sensitivity deterioration, reducing the color shift, and further improving the vertical resolution.

[0017]

SUMMARY OF THE INVENTION The present invention relates to an electronic endoscope apparatus for obtaining an endoscopic image by picking up an image of a subject with an image pickup device provided in the endoscope. Illuminating means for irradiating the subject with light, storage means for storing a signal read by interlaced scanning of the image sensor according to the illuminating light, and illuminating light read by the interlaced scanning Pseudo signal generating means for generating a pseudo signal in the vertical direction based on a plurality of signals, and video signal generating means for generating a video signal by a signal output by being synchronized by the storage means and the pseudo signal generating means. With the configuration provided, a video signal representing one color image is generated by using the pseudo field image generated by the pseudo signal generating means. Enabling Rukoto, and generates a video signal comprising a high resolution in the vertical direction than the field image by normal interlace scan. Therefore, by performing the normal interlaced scanning at high speed, the sensitivity can be made higher than that in the case where the video signal is generated, and further, the image with less flicker and the high resolution can be held. Further, the resolution in the vertical direction can be improved as compared with the case where the field image is generated from the non-interlaced scanning.

[0018]

Embodiments of the present invention will be specifically described below with reference to the drawings. 1 to 11 relate to a first embodiment of the present invention, FIG. 1 shows a configuration of an electronic endoscope apparatus of the first embodiment, and FIG. 2 shows an interlaced structure from a solid-state imaging device used in the first embodiment. 3 shows how signals are read out by scanning, FIG. 3 shows signals at various portions of FIG. 1, FIG. 4 shows the configuration of an image pickup apparatus according to the driving method 2, and FIG. 5 shows a solid-state image pickup element on a part of the screen of an HDTV. 6 shows a state in which a character imaged in is displayed, FIG. 6 shows a state in which a character imaged by a solid-state image sensor is displayed on a part of the screen of an HDTV driven by driving method 2, and FIG. 7 is an explanatory diagram of FIG. FIG. 8 shows a state in which a character imaged by the solid-state image sensor is displayed on a part of the screen of the HDTV by driving by the driving method 3, FIG. 9 is an operation explanatory diagram of the driving method 3, and FIG. FIG. 11 shows a block configuration for performing interpolation with high accuracy. Shows an example of the result.

In the first embodiment shown in FIG. 1, the same components as those shown in FIG. 28 are designated by the same reference numerals. The subject image illuminated by the illumination light transmitted by the light guide 14 is formed on the solid-state image sensor 16. The subject image is photoelectrically converted by the solid-state image sensor 16 and read out at a predetermined timing by a drive signal from the driver 31.
The timing of the drive signal of the driver 31 is controlled by the timing generator 40.

A method of driving the solid-state image pickup device 16 will be described. (A) Driving method example 1: In an NTSC standard TV, the aspect ratio is 3: 4, 525 lines / 60 fields, and interlaced scanning is performed. Even in the case of an image pickup apparatus using a solid-state image pickup element having an aspect ratio of 3: 4 which is usually used, or even in the case of an image pickup apparatus using a solid-state image pickup element having an aspect ratio of 1: 1 such as an electronic endoscope. Even in the case, the frequency of reading the video signal from the solid-state image sensor was the same as the frequency of displaying the video in both the horizontal and vertical directions.

In HDTV, the aspect ratio is 9:16, 1
125 lines / 60 fields, interlaced scanning display is performed, and the solid-state image sensor used in a normal image pickup device in HDTV has a horizontal pixel as compared with the solid-state image pickup device used in a conventional NTSC image pickup device. ,
The number of vertical pixels increases. For this reason, the drive frequency of the solid-state image sensor in HDTV is higher than the drive frequency of the solid-state image sensor in the conventional NTSC standard, and a high-speed circuit is required for the subsequent stage for processing it. In this driving method example 1, the frequency for reading the video signal from the solid-state image sensor is the same as the frequency for displaying the video in both the horizontal and vertical directions.

(B) Driving Method Example 2: FIG. 4 is a block diagram of an image pickup apparatus according to this driving method example 2. In the solid-state image pickup device 16 'for converting an image into an electronic signal, a driving signal generating circuit 31' is provided. A signal necessary for driving the solid-state image pickup device 16 'is applied. The video signal output from the solid-state image pickup device 16 'is converted into a digital signal by the A / D converter 34' via the output amplifier 32 'and then stored in the memory 53'. The video signal output stored in the memory 53 'is read from the memory 53' by the memory control signal generation circuit 53a and output to a monitor or a processing device.

FIG. 5 considers a solid-state image pickup device having a pixel number such that the character "A" is output in the area indicated by Pa in FIG. 5 on the HDTV screen. As shown in the driving method example 1, in the driving method example 1, the frequency for reading the video signal from the solid-state image sensor is the same as the frequency for displaying the video in the 1 horizontal direction and the 1 vertical direction, and the solid-state image sensor has a different aspect ratio. When an image is picked up using the image pickup device, there is an area on the screen where an image is not output as shown by Pb in FIG.

FIG. 7A shows the video signal output of the solid-state image pickup device in the vicinity of a in FIG. Figure 7
In (a), there is an invalid signal portion in which the video output signal of the solid-state image sensor is not read out or is being read in a blank during one horizontal period. The area indicated by Pb in FIG. 5 corresponds to this invalid signal portion. Here, as shown in FIG. 5, the ratio of the horizontal effective period of the solid-state image sensor output to the horizontal period of the output signal is m: M.

In order to simplify the explanation, the horizontal blanking period will be ignored in the explanation. In this driving method example 2,
As shown in FIG. 7B, by using the invalid signal portion and reading the video output signal in one horizontal direction of the solid-state image sensor for the entire one horizontal period and performing the above-mentioned driving, the horizontal direction of the solid-state image sensor is obtained. It becomes possible to perform the read operation of the direction pixels in a time M / m times as long as the time required for the read operation of the driving method example 1, and lower the driving frequency of the solid-state imaging device to m / M of the driving method example 1. Is possible. Driving method example 2
FIG. 6 shows the signal read out in step (1) as it is.

This horizontal video signal output is subjected to processing such as scan conversion by the memory 53 'and the memory control signal generating circuit 53a in FIG. 4 and then output, so that the original video is displayed on the screen. It becomes possible to obtain. Figure 5
In the above, there is a period in which the video signal output of the solid-state image sensor is not read out even in one vertical period. As shown in the figure, the ratio between the vertical effective period of the output of the solid-state image sensor and the vertical period of the output signal is n: N.

The driving method in the horizontal direction is applied in the vertical direction. In order to simplify the explanation, the vertical blanking period will be ignored in the explanation. As in the case of reading in the horizontal direction, the invalid signal portion is used to read the video output signal in one vertical direction of the solid-state image sensor over the entire one vertical period, thereby performing the read operation of the vertical pixels of the solid-state image sensor. It is possible to perform the read operation in a time N / n times as long as the time required for the conventional read operation, and it is possible to reduce the drive frequency of the solid-state image sensor to the conventional n / N.

The vertical video signal output is subjected to processing such as scanning conversion by the memory 53 'and the memory control signal generating circuit 53a in FIG. 4 and output to obtain the original video on the screen. Is possible. By simultaneously performing the horizontal and vertical driving methods described above,
It is possible to lower the driving frequency. In the case of the solid-state imaging device in the imaging area shown in FIG. 5, the driving frequency is (m × n) by using the driving method example 2 shown in this embodiment.
/ (M × N). Although the horizontal and vertical blanking periods are omitted in the above description, the same description can be made when the horizontal and vertical blanking periods exist.

As described above, according to the driving method example 2, the driving frequency of the solid-state image pickup device can be made lower than usual.
As a result, the band of the video signal output becomes low, low-speed output amplifiers, A / D converters, etc. can be used, and the cost can be reduced. Further, it is possible to suppress heat generation around the solid-state image sensor.

In the driving method example 2, the HDT
Although the description has been made based on V, Method 2 is not limited to HDTV, but an example in which a read operation of a solid-state image sensor has a pause period like an electronic endoscope in a normal NTSC standard. Can also be applied.

(C) Simple driving example: Next, another driving method different from the driving method example 2 will be described. The configuration of the imaging device in this case is the same as that of the driving method example 2. In FIG. 7, the character "A" is photographed and output by the normal driving method. Here, one horizontal period is divided into k as shown in FIG. 8, and reading of the video signal output within the divided 1 / k horizontal period is performed as shown in FIGS. 9 (a) and 9 (b). Perform in one horizontal period. That is, the drive frequency of the solid-state imaging device can be set to 1 / k of the conventional drive frequency by reading out the video output signal of the entire one screen in k fields.

In addition to the above example, h division is also performed within one vertical period, and reading of the video output signal within the divided 1 / h vertical period is performed within one conventional vertical period.
In other words, by dividing the video output signal of the entire screen into (h × k) fields and reading out, the drive frequency is
It can be (h × k). The original image can be obtained on the screen by synthesizing the video output signals read over these several fields using a memory or the like.

According to such a driving example, a driving method example 2
Similarly to the above, the frequency of the solid-state image sensor can be made lower than usual. As a result, the band of the video signal output becomes low, low-speed output amplifiers, A / D converters, etc. can be used, and the cost can be reduced. Further, it is possible to suppress heat generation around the solid-state image sensor. It should be noted that this driving example is applicable not only to the case of a still image, but also to a moving image by performing processing such as field interpolation.

According to the driving method example 2 or the driving example described above, the solid-state image sensor is driven at high speed by reading out the video signal output of the solid-state image sensor for at least one screen period and then performing processing such as scan conversion. It becomes possible to obtain a high-bandwidth video signal without any need. As a result, a low-speed output amplifier 32 ', an A / D converter 34', or the like that handles the video signal output of the solid-state image sensor can be used, and it is possible to reduce the cost and perform a reliable operation. .. It is also possible to suppress heat generation from the solid-state image sensor and these circuits.

By the way, it is assumed that the solid-state image pickup device 16 of the first embodiment shown in FIG. 1 is read in the field storage 2-line simultaneous read interlace mode. That is, as shown in FIG. 2, in the odd field, two horizontal lines indicated by A are added and read, and in the even field, 2 indicated by B.
The horizontal lines of the book are added and read. This interlaced scanning is performed by the solid-state image sensor 1 by each interlaced reading.
All 6 pixels are read.

Here, the rotary filter 50 is in synchronism with the reading of the solid-state image pickup device 16, and in the field cycle,
The solid-state imaging device 16 is rotated in order of R, G, and B so as to illuminate the subject, and the solid-state image pickup device 16 includes RODD, GEVEN, REVEN, GODD, and B.
A video signal (corresponding to each field image formed by adding one plane information of the solid-state image sensor 16) is output in each field cycle in the order of EVEN. Where ODD
Indicates an odd field and EVEN indicates an even field.

The frame-sequential video signal is pre-processed in the pre-processing circuit 33 and converted into a digital signal by the A / D converter 34. The video signal converted into a digital signal is input to the memories 41 to 46 that constitute the memory unit 47 according to the read field.
The memories 41, 42, 43, 44, 45, and 46 are memories for RODD REVEN, GODD, GEVEN, BODD, and BEVEN, respectively. In FIG. 1, RODD is abbreviated as RO and REVEN is abbreviated as RE.

The outputs of the memories 41 to 46 are input to an interpolation circuit 48 as a means for generating a pseudo signal, and
Post-process circuit 49 via switches SW1 to SW3
The synchronized signal is input to. The output of the post-process circuit 49 is converted into analog R, G, B signals by the D / A converter 37 and output to a color monitor (not shown).

As shown in FIG. 1, in the memory section 47, the contact a of the switch SW1 is the output of the interpolation circuit 48, the contact b is the output signal of the memory 41, and the contact c is the output signal of the memory 42. Are respectively applied. The output of the interpolation circuit 48 is applied to the contact a of the switch SW2,
To the contact c, and the output signal of the memory 44 is applied to the contact c. In addition, switch SW
The output of the interpolation circuit 48 is applied to the contact point a of 3, the output signal of the memory 45 is applied to the contact point b, and the output signal of the memory 46 is applied to the contact point c.

Input signals to the memory section 47, respective memory output signals, signals calculated by the interpolation circuit 48 (interpolation calculation input), selection of switches SW1 to SW3 and switches SW1 to SW1.
The timing of the output from 3 is shown in FIG. In FIG. 3, when the solid-state image sensor read signal and the memory read signal are the same, the solid-state image sensor output is read in the field in time with the memory read signal. In FIG. 3, R1O, G1O, and B1O are read for a certain odd field, R1E, G1E, and B.
1E corresponds to the reading of a certain even-numbered field, and R0O to B0E are information of one round before R1O to B1O.

In the field in which RODD is read from the solid-state image sensor 16, the REVE stored in advance is stored in the memory.
N, GODD, BEVEN and RODD stored in that field are read out. RODD and GODD are output as they are, and the interpolation circuit 4 is used by REVEN, RODD, and BEVEN.
An interpolation signal BOC which is a pseudo signal of B ODD is formed and output by 8.

Similarly, in the next field, the previously stored RODD, BEVEN, and GODD, and the GEVEN stored in that field are read out. GEVEN, BEVEN
Is output as it is, and an R-even EVEN interpolation signal REC is formed and output by RODD, GODD, and GEVEN. After that, SW1 to SW3 similarly read and output as shown in FIG. As shown in FIG. 3, the interpolation signal is also calculated by the signal selected from the memories 41 to 46 in a timely manner.

Here, an interpolation method when the aforementioned RODD is read will be described. (1) Method of interpolating with the same color signal: This is B
This is a method of forming OC from BEVEN. BOC (n) = BEVEN (n) + BEVEN (n + 1) Here, n means a scanning line number.

(2) Interpolation method based on the correlation between RODD and REVEN: This is a method for obtaining BOC from BEVEN based on the correlation between RODD and REVEN. If k = (REVEN (n) -RODD (n + 1)) / (RODD (n + 1) -RODD (n + 1)), then BOC (n) = kBEVEN (n + 1) + (1-k ) Beven (n).

(3) Interpolation by correlation of three lines of REVEN: This is a method of obtaining BOC by correlation of three lines of RODD. If h = (RODD (n) -RODD (n + 1) / (RODD (n-1) -RODD (n + 1)), then BOC (n) = hBEVEN (n + 1) + (1-h) Beven (n).

In the case of this method (3), h may be obtained by using GEVEN, or hb and GEV obtained by BEVEN
You may obtain h by calculating hE obtained by EN. For example, h = (hb + hE) / 2. Interpolation is performed by one or a combination of the above three methods. Further, an example of a calculation method for making the interpolation highly accurate will be described below.

Conventionally, in an image processing circuit that involves interpolation such as image enlargement or reduction, the interpolation count is p / q, (q
-P) / q (q, p is an integer q ≠ 0) is used, and in order to obtain the interpolation data from the input data d1 and d2, the operation of d1 × p / q + d2 × (q−p) / q is performed. ing.

FIG. 10 shows a block diagram of this example.
It is (a). The input data d1 and d2 are input to the arithmetic units 93 and 94 via the input terminals 91 and 92, respectively. The data d1 is subjected to a calculation of × p / q by the coefficient p / q from the interpolation coefficient input terminal 96 in the calculator 93, and is output to the adder 95. Similarly, the data d2 is multiplied by the coefficient (q-p) / q from the interpolation coefficient input terminal 97 in the calculator 94.
The calculation of (q-p) / q is performed and the result is output to the adder 95. The adder 95 adds these to obtain a desired value. A memory look-up table (hereinafter abbreviated as LUT) is often used as the computing units 93 and 94.

However, in the circuit configuration as shown in FIG. 10A, if the data word length cannot be sufficiently long due to the cost speed circuit scale or the like, a calculation error due to rounding will occur. Then, this error becomes a noise and deteriorates the image quality.

Therefore, by using the configuration shown in FIG. 10B, the calculation error can be reduced without increasing the circuit scale. The description will be given below. The input data d1 and d2 are input to the subtractor 98 via the input terminals 91 and 92, respectively, and are normally subtracted in the subtractor 98. When d1 ≧ d2, the sign bit becomes “1”,
When d1 <d2, the sign bit becomes “0”, and d1,
It is input to the LUT 93 'together with the result of d2. This LU
T93 'is a coefficient selection signal from the coefficient selection terminal 96' and is p / q
You can select the table.

When the sign bit is "1", the data of d1-d2 is directly calculated by the xp / q table of the LUT 93 'and input to the adder 95. Further, the adder 95 uses the delay circuit 9 for adjusting the d2 data for time adjustment.
A desired value can be obtained by inputting through 9 and adding.

When the sign bit is "0", the data of d1-d2 is calculated in the complement format by the table of xp / q and output in the complement format. At this time, the sign bit is L
It may be used to select the table of the UT93 '(d1-d
2) and (d1−d2) × p / q data does not need to have a sign bit. The complement format data without the sign bit (d1-d2) × p / q and the delay circuit 9
The d2 that has passed 9 is input to the adder 95 and added to obtain a desired value.

The results obtained by performing the 12/5 times interpolation enlargement on the following data are as follows: 1: conventional example of FIG. 10 (a), 2: embodiment of FIG. 10 (b) and 3: data error. FIG. 11 shows a case where the length is calculated sufficiently long and the value is rounded off at the end to obtain an integer. Here, the original data is 25, 30,
35, 19 ...

As described above, according to the method shown in FIG. 10B, the data error length is calculated with a sufficiently long length, and the result is rounded off at the end, so that the result agrees with the effective data length.
I understand from. In other words, without increasing the circuit scale,
The calculation error can be reduced.

In the read processing method described with reference to FIGS. 1 to 3, the output signal required for one color plane is 4
Since it is obtained by the signal within the field (less than the signal of 6 fields required for a normal color 1 plane, therefore, the color shift is reduced.

The R, G, B signals switched by the switches SW1 to SW3 shown in FIG. 1 pass through the post process circuit 49, are converted into analog signals by the D / A converter 37, and are output.

In the first embodiment, there is little movement,
That is, when the color shift is small, a higher resolution image can be obtained by reading the signal obtained from the solid-state image sensor 16 and stored in the memories 41 to 46 without using the interpolation signal and using it as it is according to the field. .. (In this case, one frame image can be obtained with 6 fields.) The block diagram at that time does not include the interpolation circuit 48. The user may switch it with a selection switch (not shown). According to this embodiment, the output signal required for the color 1 plane can be obtained from the signals within 4 fields, so that the color shift can be reduced as compared with the conventional example.

Further, since the field image generated by the normal non-interlaced reading is temporarily stored in the memory and is generated from the memory by the interlaced reading, only the image information of three fields is used, so that the vertical resolution becomes low. In this embodiment, since the signals of almost 4 fields are used, the vertical resolution can be increased. Further, this embodiment can make the color shift smaller than that of the field image generated by the normal non-interlaced reading. (The field image generated by the normal non-interlaced readout is the one captured in the 6-field period. On the other hand, in this embodiment, the field image is captured in the 4-field period. If the period is shortened, the color shift can be reduced, but in that case, the S / N is lowered.) Next, the second embodiment will be described.

This is a case where the output timing of the solid-state image sensor 16 and the timing of the video signal output from the processor are close to each other, and a line for outputting the signal output from the solid-state image sensor 16 without passing through the memory is provided. Is reduced. A block diagram of this second embodiment is shown in FIG. The block configuration up to the input of the memory unit 47 is the same as that of the first embodiment shown in FIG.

The memory section 47 of this embodiment has four memories a to d (51 to 54) and direct switches SW1 to SW3.
Consists of a line connecting to. In addition, memories a to d (51
~ 54) The output and the output of the preprocessing circuit 33 are input to the interpolation circuit 48.

FIG. 13 shows an input signal to the memory section 47, each memory output signal, interpolation calculation input, and switches SW1 to SW3.
The timing of is shown. A read-modify-write mode for writing in the memory may be used. The method of generating the interpolation signal is the same as in the first embodiment. The output signal is also the same as in the first embodiment.

Also in the case of the second embodiment, when the motion is small, the interpolation circuit 48 is not used, and signals of 6 fields are used as in the first embodiment to obtain a video output with a higher resolution. .. Each memory output in this case, switch SW1
Timings of SW3 to SW3 are shown in FIG. In this case, each memory OUT for the input of the memory unit 47 is the same as that in FIG. 13, and no interpolation calculation is performed.

The output signal of the memory section 47 is processed in the same manner as in the first embodiment. In the case of the second embodiment, as can be seen from FIG. 13, the information stored in each memory is not a dedicated memory for RGB information, but the information stored so as to cycle.

In the above description of the second embodiment, the case where the output timing of the solid-state image pickup device 16 and the output timing of the video signal from the processor are close to each other has been explained. By putting in, it becomes possible to deal with the case where the above timing is separated.

Next, the third embodiment will be described. FIG. 15 is a block diagram showing the configuration of the main part of the third embodiment.
The blocks other than the memory unit 47 shown in FIG. 15 are the same as those in the first embodiment, and thus the description thereof will be omitted. The input video signal of the memory unit 47 is input to the time adjustment memory 55 and the R, G, B memories 56 to 58. The time adjustment memory 55 is a memory for time-correcting the input signal of the memory unit 47 so that the interpolation circuit 48 can calculate it.

The R, G, B memories 56-58 store the input signals according to the R, G, B memories and output the signals to the interpolation circuit 48 and the switches SW1-SW3 at appropriate times. In the interpolation circuit 48, the time adjustment memory 55 is used as in the first embodiment.
An interpolation signal is created from the output video signals of the R, G, B memories 56 to 58.

FIG. 16 shows the timing of the memory section 47 input signal, each memory output signal, switch contact selection, and memory section 47 output signal. If the output timing of the solid-state image sensor 16 is close to the output timing of the video signal from the processor, the time adjustment memory 55 can be omitted.

The switches SW1 to SW3 are the RGB memory 5
6 to 58 outputs and the output of the interpolation circuit 48 are selected and output at appropriate times. The output of the memory unit 47 is processed in the same manner as in the above-described embodiment to become an output video signal.

Next, a fourth embodiment will be described. A block diagram of the fourth embodiment is shown in FIG. Preprocessing circuit 3
The blocks up to 3 are the same as in the first embodiment. The output video signal of the preprocessing circuit 33 is an R, G, B memory 56-5.
Enter in 8.

The R, G, B memories 56-58 store according to the input signals R, G, B, and interpolate circuit 48 and SW1.
~ Output a signal to SW3 in a timely manner. The first in the interpolation circuit 48
Similar to the embodiment, an interpolation signal is created from the R, G, B memories 56 to 58 output video signals. However, in the case of this embodiment, the interpolation method (2) cannot be performed.

FIG. 18 shows the timing of the memory section 47 input signal, each memory output signal, switch contact selection, and memory section 58 output signal. The switches SW1 to SW3 select and output the outputs of the RGB memories 56 to 58 and the interpolation circuit 48 at appropriate times. The output of the memory unit 47 is processed in the same manner as in the above-described embodiment to become an output video signal.

When the output timing of the solid-state image pickup device 16 is close to the output timing of the video signal from the processor, one of the RGB memories 56 to 58 can be omitted. The configuration in this case is shown in FIG. in this case,
Similar to the second embodiment, the memories 59 and 60 are not dedicated memories for the respective RGB information, but the stored information changes so as to cycle.

Output signals of the memories 59 and 60 and the memory section 4
The input signal 7 is switched by the switches SW1 to SW3 at appropriate times and is output. These timings are shown in FIG. The writing / reading of the memory may be performed, for example, in a read-modify-write mode in which new data is written while reading the previous data. Here, in the case of the fourth embodiment, when an interpolating circuit is not necessary, such as when interlacing is not performed, the switches SW1 to SW are set as shown in FIG.
By switching W3, the memory can be reduced as compared with the conventional example (FIG. 28).

In the above embodiment, the scanning line interpolation method is not limited to the three methods shown in the first embodiment, but the three
The combination of the three methods or the method that detects the motion and interpolates the
Any method may be used as long as it can be interpolated from the information of 4 fields.

Next, a fifth embodiment of the present invention will be described. The present embodiment is a system in which only G is interlaced. A block diagram of this embodiment is shown in FIG. In the rotary filter 60 used here, the aperture ratio of the G, R and B filters is 2: 1: 1 as shown in FIG.

The solid-state image sensor 16 obtains information on the odd field GODD and the even field GEVEN with respect to the timing G of the G filter. In the case of R and B filters, odd field information RODD and BODD are obtained respectively. The read GODD, GEVEN, RODD, and BODD are selectively input to and stored in the memory GODD 61, the memory GEVEN62, the memory R63, and the memory B64 through the preprocessing circuit 33 and the A / D converter 34, respectively. ..

Here, when the output is in the odd field, the signals of GODD, RODD and BODD are read out from the memory GODD 61, the memory R63 and the memory B64, respectively. These three signals are input to the Y matrix circuit 65 and YOD
D signal is generated. The YODD signal is input to subtractors 67 and 68, and subtracted from the RDDD signal and the BODD signal, respectively, and R-YODD and B-YODD signals are generated.
The YODD, R-YODD, and B-YODD signals are converted into RGB signals by the matrix circuit 70.

On the other hand, when the output is an even field, the signals GEVEN, RODD and BODD are read from the memory GEVEN61, the memory R63 and the memory B64, respectively. These three signals are input to the Y matrix circuit 66, and the YEVEN signal is generated. At the same time, as in the odd field, R-YODD,
A B-YODD signal is generated. This R-YODD, BY
The ODD signal and the YEVEN signal are input to the interpolation circuit 69, and R-YEVEN and B-YEVEN are generated.

This interpolation method may be performed in the same manner as the method shown in the first embodiment, for example. Y matrix circuit 66 output YEVEN signal and interpolation circuit 69 output R-YEVEN, BY
The EVEN signal is input to the matrix circuit 70 and output as an RGB signal. Also, SW4,5,6 is an odd field,
The signal input to the matrix circuit 70 is switched according to the even field.

In this embodiment, since the RY and BY signals are formed by RGB signals in the same field, vertical false colors and the like are improved. Although the present embodiment has been described by using the RGB filter as the filter 60, G
An all-color transmissive filter (W) may be used instead of the filter. This filter is shown in FIG. in this case,
Instead of GODD and GEVEN in this embodiment, YODD and YEV are directly used.
Since the EN is obtained, the Y matrix circuits 65 and 66 are not necessary. Other operations are the same.

Next, a sixth embodiment of the present invention will be described. A block diagram of this embodiment is shown in FIG. here,
As the rotary filter 60, the same W, R, and B filters as in FIG. 24 are used. The solid-state image sensor 16 obtains the information of the odd field YODD and the even field YEVEN with respect to W at the timing of the W filter. In the case of the R filter, the information RODD of the odd field is obtained, and in the case of the B filter, the information BODD of the even field is obtained.

The read YODD, YEVEN, and RODD
, BEVEN pass through the pre-process circuit 33 and the A / D converter 34, and are respectively passed through the memory YODD 71 and the memory YEV.
The data is selectively input to and stored in the EN72, the memory R63, and the memory B64.

Here, when the output is in the odd field, the signals YODD, RODD and BEVEN are read from the memory YODD 71, the memory R63 and the memory B64.
This YODD signal is input to the subtractor 75, and the subtractor 7
Subtracting from the RODD signal at 5 produces R-YODD. On the other hand, the BEVEN signal is B along with the YODD and RODD signals.
It is input to the -Y interpolation calculation circuit 73 to generate a B-YODD signal. The YODD, R-YODD, and B-YODD signals are converted into RGB signals by the matrix circuit 70.

Here, for the calculation in the BY interpolation calculation circuit 73, for example, YODD, RDDD, and NEVEN signals may be used to obtain BODD by the method shown in the first embodiment and then subtract YODD. On the other hand, when the output is an even field, the memory Y
The signals of YEVEN, RODD, and BEVEN are read from the EVEN 72, the memory R63, and the memory B64. This Y
The EVEN signal is input to the subtractor 76, and the subtractor 76 outputs B
By subtracting from the EVEN signal, B-YEVEN is generated.

On the other hand, the RODD signal is input to the RY interpolation calculation circuit 74 together with the YEVEN and BEVEN signals to generate the R-YEVEN signal. This R-YEVEN signal is the above-mentioned B-YOD.
It can be obtained in the same way as the D signal. These, YEVEN, RY
The EVEN and B-YEVEN signals are converted into RGB signals by the matrix circuit 70. In this embodiment, the Y signal is obtained as an interline signal in the odd field and the even field, and the color difference signal is optimally interpolated using the Y signal, so that an image with high resolution can be obtained.

Next, a seventh embodiment of the present invention will be described. A block diagram of the seventh embodiment is shown in FIG. The rotary filter 60 of this embodiment is the same as that shown in FIG. The solid-state image pickup device 16 obtains information on the odd field GODD and the even field GEVEN for G at the timing of the G filter. In case of R filter, odd field information RODD,
In the case of the B filter, the even field BEVEN is obtained.

The read GODD, GEVEN, and RODD
, BEVEN pass through the pre-processing circuit 33 and the A / D converter 34, and are respectively passed through the memory GODD 61 and the memory GEV.
The data is selectively input to and stored in the EN 62, the memory R63, and the memory B64.

Here, when the output is an odd field, the signals GODD, RODD and BEVEN are read from the memory GODD 61, the memory R63 and the memory B64, respectively.
These three signals are input to the B interpolation circuit 77 and a BODD signal is generated. This interpolation method may be performed in the same manner as the method shown in the first embodiment, for example. These, GODD, RODD, B
The ODD signal is post-processed as an RGB signal.

On the other hand, when the output is an even field, the signals GEVEN, RODD, and BEVEN are read from the memory GEVEN61, the memory R63, and the memory B64. These three signals are input to the R interpolation circuit 78, and the REVEN signal is generated. These GEVEN signal, REVEN and BEVEN signals are R
It is post-processed as a GB signal. Since the present embodiment processes as RGB signals, the circuit can be simplified as compared with the fifth and sixth embodiments.

In the embodiment described above, the solid-state image pickup device 1
When the image signal (video signal) is read out from the image sensor 6 in the interlace mode, the pixels of two horizontally adjacent lines are added in each interlace read-out to read all the pixels of the solid-state image sensor 16 in each interlace read-out period. ing. The present invention is not limited to this,
For example, a signal read out by a normal non-interlaced read or a normal interlaced read in which pixels on two adjacent lines are not added is temporarily stored in a memory means, and an image signal stored in the memory means is stored in the solid-state image sensor 1
6) in the interlaced mode), the video signal of the even field or the odd field is generated by the addition process, and the interpolation circuit process is performed to similarly reduce the field period (from the 6 field period). A video signal for one color frame may be generated from the image signal for a short period.

[0091]

As described above, according to the present invention,
Sensitivity is not reduced in frame sequential imaging, color shift is small,
Interlaced imaging with few false signals in the vertical direction can be performed, the vertical resolution is improved, and a high-quality image can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an electronic endoscope apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing how signals are read by interlaced scanning from the solid-state imaging device used in the first embodiment.

FIG. 3 is an operation explanatory view showing signals of respective parts in FIG.

FIG. 4 is a block diagram showing a configuration of an imaging device according to driving method 2.

FIG. 5 is an explanatory diagram showing a state in which a character imaged by a solid-state image sensor is displayed on a part of the screen of an HDTV.

FIG. 6 is a diagram showing a state in which a character imaged by a solid-state image sensor is displayed on a part of a screen of an HDTV by driving by a driving method 2.

FIG. 7 is an explanatory diagram of a driving method 2.

FIG. 8 is a diagram showing a state in which a character imaged by a solid-state image sensor is displayed on a part of a screen of an HDTV by driving by driving method 3;

FIG. 9 is an operation explanatory diagram of driving method 3.

FIG. 10 is a block diagram showing a configuration for performing interpolation with high accuracy.

11 is a diagram showing an example of the calculation result of FIG.

FIG. 12 is a block diagram showing the configuration of an electronic endoscope apparatus according to a second embodiment of the present invention.

FIG. 13 is an operation explanatory view showing signals of respective parts of the second embodiment.

FIG. 14 is an operation explanatory diagram showing signals of respective portions when an interpolation circuit is not used in the second embodiment.

FIG. 15 is a block diagram showing the configuration of a memory unit according to the third embodiment of the present invention.

FIG. 16 is an operation explanatory diagram showing signals of respective parts in the third embodiment.

FIG. 17 is a block diagram showing the configuration of a memory unit according to the fourth embodiment of the present invention.

FIG. 18 is an operation explanatory diagram showing signals of respective parts in the fourth embodiment.

FIG. 19 is a block diagram showing the configuration of a memory unit according to a modification of the fourth embodiment.

FIG. 20 is an operation explanatory view showing signals of respective parts in the modification of the fourth embodiment.

FIG. 21 is an explanatory diagram of the operation when the interpolation circuit is not used in the fourth embodiment.

FIG. 22 is a block diagram showing the configuration of an electronic endoscope apparatus according to a fifth embodiment of the present invention.

FIG. 23 is an explanatory view showing a filter used in the fifth embodiment.

FIG. 24 is an explanatory diagram showing a filter used in a modification of the fifth embodiment.

FIG. 25 is a block diagram showing the configuration of an electronic endoscope apparatus according to a sixth embodiment of the present invention.

FIG. 26 is a block diagram showing the configuration of an electronic endoscope apparatus according to a seventh embodiment of the present invention.

FIG. 27 is a side view of a conventional electronic endoscope apparatus.

FIG. 28 is a block diagram showing the configuration of a conventional electronic endoscope apparatus.

[Explanation of symbols]

 14 ... Light guide 16 ... Solid-state imaging device 23 ... Motor 31 ... Driver 32 ... Preamplifier 33 ... Process circuit 34 ... A / D converter 37 ... D / A converter 41-46 ... Memory 47 ... Memory part 48 ... Interpolation circuit 49 ... Post Process circuit SW1-SW3 ... Switch

[Procedure amendment]

[Submission date] July 10, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

A method of driving the solid-state image pickup device 16 will be described. (A) Driving method example 1: In the NTSC standard TV, the aspect ratio is 3: 4, 525 lines / 60 fields, and interlaced scanning is performed. This driving method is used even in the case of an image pickup apparatus which uses a solid-state image pickup device with an aspect ratio of 3: 4 which is usually used, or with a solid-state image pickup device with an aspect ratio of 1: 1 like an electronic endoscope. Even in the case of such an image pickup apparatus , the driving method is such that the frequency of reading the video signal from the solid-state image pickup device is the same as the frequency of displaying the image in both horizontal and vertical directions.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

(B) Driving Method Example 2: HDTV displays an aspect ratio of 9:16, 1125 lines / 60 fields, and interlaced scanning, and a solid-state image pickup element used in a normal image pickup apparatus in HDTV is Both the number of horizontal pixels and the number of vertical pixels are larger than those of the solid-state image sensor used in the conventional NTSC standard image pickup device. For this reason, the drive frequency of the solid-state image sensor in the HDTV is higher than the drive frequency of the conventional solid-state image sensor in the NTSC standard, and a high-speed circuit for processing the latter is required. This drive method requires a high drive frequency
The driving method facilitates driving of the solid-state imaging device.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

[0022] Figure 4 shows a block diagram of an imaging apparatus according to the driving method example 2, the video from 'the drive signal generating circuit 31 in the' solid-state image pickup device 16 for converting the electric signal, the solid-state imaging device 16 ' The signals required to drive the are applied. The video signal output from the solid-state image pickup device 16 'is converted into a digital signal by the A / D converter 34' via the output amplifier 32 'and then stored in the memory 53'.
The video signal output stored in the memory 53 'is read from the memory 53' by the memory control signal generation circuit 53a and output to a monitor or a processing device.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

In the driving method example 2, the HDT
Although the description has been given based on V, Method 2 is not limited to HDTV, but an example in which a read operation of a solid-state image sensor has a pause period like an electronic endoscope in a normal NTSC standard. there is also so can also be applied.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Delete

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Delete

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Delete

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Delete

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

Here, the rotary filter 50 is in synchronism with the reading of the solid-state image pickup device 16, and in the field cycle,
The solid-state imaging device 16 is rotated in order of R, G, and B so as to illuminate the subject, and the solid-state image pickup device 16 includes RODD, GEVEN, BODD, REVEN, G
A video signal (corresponding to each field image formed by processing one plane information of the solid-state image sensor 16) is output in the order of ODD and BEVEN in each field cycle. Here, ODD indicates an odd field and EVEN indicates an even field.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0090

[Correction method] Change

[Correction content]

In the embodiment described above, the solid-state image pickup device 1
When an image signal (video signal) is read out from 6 in the interlaced mode, pixels of two lines that are horizontally adjacent in each interlaced reading are added to read all the pixels of the solid-state image sensor 16 in each interlaced reading period. ing. The present invention is not limited to this,
For example, a signal read by a normal non-interlaced read or a normal interlaced read in which pixels of two adjacent lines are not added is temporarily stored in a memory means, and the image signal stored in the memory means is stored in the solid-state image sensor 1
6) in the interlaced mode), the video signal of the even field or the odd field is generated by the addition process, and the interpolation circuit process is performed to reduce the field period (from the 6 field period). A video signal for one color frame may be generated from the image signal for a short period. Next driving method
There is another driving method different from the method example 2. In this case
The configuration of the image pickup apparatus is the same as that of the driving method example 2. Figure 7
The character "A" is photographed and output by the usual driving method.
It is a thing. Here, as shown in FIG. 8, one horizontal period
Video is divided into k parts, and the video is divided into 1 / k horizontal periods.
The signal output is read as shown in FIGS. 9 (a) and 9 (b).
In the conventional 1 horizontal period. In other words, the video output of the entire screen
By reading out the force signal by dividing it into k fields, solid-state imaging is possible.
Set the drive frequency of the image element to 1 / k of the conventional drive frequency
be able to. In addition to the above example, within one vertical period
Also, h division is performed and the divided 1 / h vertical period
Read out the video output signal in the conventional one vertical period.
U In other words, the video output signal for the entire screen is (h × k)
The drive frequency is set to 1
It may be / (h × k). These number fields
Using the memory etc., the video output signal read over
Obtaining the original image on the screen by performing composition, etc.
You can According to such a driving method, driving method example 2
Same as above, lower the frequency of the solid-state image sensor than usual
You can As a result, the bandwidth of the video signal output is low
, Low speed output amplifier, A / D converter, etc. are used.
It can be configured at low cost. In addition, the peripheral part of the solid-state image sensor
It is possible to suppress heat generation. This driving method is stationary
Fields, not just those that apply in the case of images
You can also use it for moving images if you perform processing such as interpolation.
is there. According to the above driving method, the video signal output of the solid-state image sensor
Force is read for at least one screen period before scanning
Drive the solid-state image sensor at high speed by
It is possible to obtain a high-bandwidth video signal without moving it.
Become. This makes it possible to handle the video signal output of the solid-state image sensor.
Output amplifier 32 ', A / D converter 34', etc.
Things that can be used, inexpensive and reliable operation
It is possible to In addition, solid-state image sensors and
It is also possible to suppress heat generation from the road.

[Procedure Amendment 11]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shinji Yamashita Shinji Yamashita 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Akinobu Uchikubo 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Co., Ltd. (72) Inventor Katsuyuki Saito 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd. (72) Masahito Goto 2-43-2 Hatagaya, Shibuya-ku, Tokyo No. Olympus Optical Co., Ltd. (72) Inventor Akihiro Miyashita 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Co., Ltd.

Claims (1)

[Claims] 1. An electronic endoscope apparatus for obtaining an endoscopic image by picking up an image of the subject with an imaging device provided in the endoscope, and irradiating the subject with a plurality of illumination lights having different wavelength ranges. Illumination means, storage means for storing a signal read by interlaced scanning of the image sensor according to the illumination light, and vertical direction based on a plurality of signals corresponding to the illumination light read by the interlaced scanning. An electronic device comprising: a pseudo signal generating unit that generates a pseudo signal; and a video signal generating unit that generates a video signal from a signal that is synchronized and output by the storage unit and the pseudo signal generating unit. Endoscopic device.