JPH05344524A - Electronic endoscope device - Google Patents

Abstract

PURPOSE:To improve the developing efficiency of the electronic endoscope device and to reduce its cost by attaining sequential color face image pickup by using a common sequential color face lighting means even when the TV system of a display device is different from that of a lighting/image pickup system of an endoscope and a light source device. CONSTITUTION:In the sequential color face image pickup type electronic endoscope device, a timing control means 10 compares a synchronizing signal from the 2nd control means 7 for executing control for the formation of a signal to be supplied to a display means 4 with the phase of the repeating period of sequential color face lighting and resets the 1st control means 8. The means 8 controls an image pickup means 5 and the sequential color face lighting based on the 1st reference TV system, but when the means 8 is reset, a deviation from a 2nd reference TV type synchronizing signal is corrected. In such constitution, the common sequential color face lighting means 11 can be used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color plane sequential imaging type electronic endoscope apparatus. In particular, the present invention relates to a configuration for enabling common use of a light source device for color field sequential illumination regardless of a standard TV (television) system such as a display device.

[0002]

2. Description of the Related Art In recent years, by inserting a set-length insertion portion into a body cavity, various organs in the body cavity can be observed, and if necessary, various therapeutic treatments can be performed using a treatment instrument inserted in a treatment instrument channel. The endoscope that can be used is widely used. This endoscope is used not only in the medical field but also in the industrial field.

Various electronic endoscopes using a solid-state image pickup device such as a charge-coupled device (CCD) as an image pickup means have been proposed.
It is being put to practical use.

In the endoscope, since the insertion portion needs to have a small diameter, the size of the solid-state image pickup device is limited, and it is difficult to increase the resolution. Therefore, the field-sequential method that sequentially emits illumination light of different wavelength bands through the color rotation filter and synthesizes color image signals captured under each illumination light to form a color image has the following advantages. Have. That is,
The frame-sequential system has an advantage that a high-resolution color image can be obtained as compared with the simultaneous system in which color imaging is performed by an image pickup unit having a color filter under white illumination.

Among the above-mentioned electronic endoscopes, an endoscope apparatus for picking up images in a frame-sequential manner is disclosed in, for example, Japanese Patent Laid-Open No. 61-
There is one disclosed in Japanese Patent No. 82731. In the light source device of this electronic endoscope device, white illumination light is converted into R (red),
A color rotation filter that sequentially switches to G (green), B (blue), etc. is required.

On the other hand, a signal processing device for converting an image pickup signal obtained by the frame sequential type image pickup device into a standard TV signal includes PAL (Phase alternation by line), NTSC.
(National Television System Comitee), SECAM
There are different methods such as. Therefore, there are monitors of each type.

Further, in the light source device, the area of the R, G, B transmission windows of the rotary filter is different and the rotation frequency of the rotary filter is different depending on each method, that is, the rotation speed of the filter, etc. There is a difference in control.

For this reason, when the video processor and the monitor of different video systems such as PAL and NTSC are provided, the rotary filter and the light source device for controlling the rotary filters according to the different TV systems such as PAL and NTSC are required as described above. Becomes That is, there is a disadvantage that a plurality of types of light source devices are required.

Therefore, the applicant of the present invention has filed Japanese Patent Application Laid-Open No. 1-2174.
Japanese Patent No. 13 proposes a light source device that solves the above point. In this light source device, a rotary color filter for generating color plane sequential light is formed in the shape of a cassette, and this can be freely inserted into and removed from the light source device. The light source device is configured to change the control speed of the rotary filter according to the type of the inserted filter cassette.

If the light source device is used, the rotary color filter cassette is exchanged, and a plurality of types of built-in synchronizing signal generating circuits are selected, so that one light source device can support a plurality of TV systems. it can.

Further, in Japanese Patent Laid-Open No. 3-68330,
A light source device is proposed in which the rotation speed and phase matching of the rotary filter can be changed according to the type of main body device combined with the light source device. According to this electronic endoscope apparatus, the rotation frequency of the rotary color filter can be changed, and highly accurate servo control can be performed. This light source device can also support a plurality of TV systems by changing the rotation frequency of the rotation color filter.

[0012]

As described above, in the color-sequential-type electronic endoscope apparatus, the frame frequency of the image signal differs depending on the TV method of the display device.
A color plane sequential illumination light source having a different repeating period according to the V method is used. For example, in the NTSC system, a light source whose RGB illumination light repetition frequency is 29.97 Hz is used, and P
The AL method used a 25 Hz light source. In these methods, since the image pickup for each color of RGB is completed for each one frame period of display, there is an advantage that the writing and reading control to the memory for synchronizing the color plane sequential signals can be simplified. However, the above-mentioned conventional light source device has a large circuit size and complexity due to the configuration including a plurality of servo circuits inside, and also has an increased number of adjustment steps, which has been a factor of high cost.

Alternatively, a plurality of TVs having monitors or recording devices
In order to prepare different video processors according to the system as described above, they were developed separately, the development efficiency was poor, and they were not standardized, so mass production could not be expected.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a common color plane even when the TV system of the display device and the like and the illumination system / imaging system of the endoscope and the light source device are different. An object of the present invention is to provide an electronic endoscope apparatus that enables sequential imaging of color planes by using a sequential light source, improves development efficiency of the apparatus, and reduces costs.

Another object of the present invention is to provide an electronic endoscope apparatus which outputs signals corresponding to different TV systems by increasing the number of common circuits to reduce the cost and improve the development efficiency. To provide.

[0016]

According to a first aspect of the present invention, there is provided an electronic endoscope apparatus which receives an image pickup means for picking up an image of a subject at a first frame frequency, and an image signal obtained by the image pickup means for picking up the subject. A signal generating means for generating a standard TV system signal having a second frame frequency that is about n / m times (n and m are natural numbers and n ≠ m) times the first frame frequency, and the signal generating means. And timing control means for synchronizing the first frame frequency of the image pickup means with the second frame frequency at a predetermined timing output from.

According to a second aspect of the present invention, there is provided an electronic endoscope apparatus in which color plane sequential illumination means for emitting color plane sequential illumination light for illuminating an object with a plurality of sequentially different color component lights at a first frame frequency is provided. A second signal which is about n / m times (n and m are natural numbers and n ≠ m) the first frame frequency when receiving an image signal imaged under the illumination light of the color plane sequential illumination means. Signal generating means for generating a standard TV system signal having a frame frequency of, and at a predetermined timing output from the signal generating means, the first frame frequency of the color plane sequential illuminating means is changed to the second frame frequency. And timing control means for synchronizing with.

An electronic endoscope apparatus according to a third aspect of the present invention is a color plane sequential system that emits color plane sequential illumination light for illuminating a subject with a plurality of sequentially different color component lights at a frame period of a first standard TV signal. Illumination means, an image pickup means for picking up an object under the illumination light of the color plane sequential illumination means, and a color plane sequential image signal picked up by the image pickup means are supplied to the first standard TV system at about n / m. And a signal generating means for generating a video signal of the second standard TV system having a frame period of double (n and m are natural numbers and n ≠ m). The electronic endoscope apparatus further generates a pseudo imaging synchronization signal having a period of about m / n times the frame period of the second standard TV system for controlling the color field sequential illumination means, and The first control means for controlling the image pickup means so as to pick up the color plane sequentially at a cycle m / n times the frame cycle of the second standard TV method, and the synchronization signal of the second standard TV method are generated. Second
Control means, detection means for detecting at least one of the repetition cycle or phase of the color plane sequential illumination means, at least one of the cycle or phase detected by the detection means, and the synchronization signal of the second control means. And based on the result, so as to synchronize with the timing control means for matching the phases of the signals generated by the first control means and the pseudo imaging synchronization signal input from the first control means, The color plane sequential illumination control means controls the phase of the color plane sequential illumination repeated in the color plane sequential illumination means.

[0019]

According to the first aspect of the invention, the signal generating means receives the image signal of the object imaged at the first frame frequency by the image pickup means, and the signal is about n / m times the first frame frequency. A standard TV system signal having a second frame frequency is generated. At this time, the timing control means synchronizes the first frame frequency of the image pickup means with the second frame frequency at a predetermined timing output from the signal generation means.

Further, in the structure according to the second aspect, the signal generating means receives the image signals picked up under the plurality of color component lights which have the first frame frequency and are sequentially different from each other, and receive the first image signal. A standard TV system signal having a second frame frequency that is approximately n / m times the frame frequency is generated.
At this time, the timing control unit synchronizes the first frame frequency of the color plane sequential illumination unit with the second frame frequency at a predetermined timing output from the signal generation unit.

Further, in the structure of claim 3, the first control means generates a pseudo imaging synchronization signal having a period of about m / n times the frame period of the second standard TV system, and the Output to the frame sequential illumination control means.

Then, the color plane sequential illumination control means controls the repeating phase of the color plane sequential illumination so as to be synchronized with the pseudo image pickup synchronizing signal inputted from the first control means. The sequential illumination means emits color plane sequential illumination light for illuminating a subject with a plurality of sequentially different color component lights at a repetition period of about m / n times the frame period of the second standard TV signal.

By the way, the timing control means compares at least one of the repetition period or phase of the color plane sequential illumination means detected by the detection means with the synchronization signal of the second control means, and based on the result. The phases of the signals generated by the first control means are matched.

The first control means controls the image pickup means so as to sequentially pick up the color planes at a cycle m / n times the frame cycle of the second standard TV system. The image pickup means is a color plane sequence for illuminating an object with a plurality of sequentially different color component lights at a repetition period of about m / n times the frame period of the second standard TV signal emitted by the frame sequential illumination means. A subject is imaged under illumination light.

Then, the signal processing means performs signal processing on the signal output from the image pickup means to become a monitor means of a second standard TV system having a frame period of about n / m times that of the first standard TV system. Output. The monitor means displays an endoscopic image.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An outline of an electronic endoscope apparatus of the present invention will be described based on the configuration example shown in FIG. 1, which is a conceptual configuration diagram of the present invention.

The electronic endoscope apparatus shown in FIG.
An endoscope 1 having an image pickup means 5 for picking up an image and outputting a signal
A signal processing device 2 having a signal processing means 6 for converting the output signal of the image pickup means 5 into a first standard TV signal; and color plane sequential illumination light, and detecting the repetition cycle and phase of the illumination light. Light source device 3 for outputting to the signal processing device 2
And monitor means 4 for displaying the signal output by the signal processing means 6.

The signal processing device 2 is based on a second control means 7 for generating a second standard TV system sync signal and a second standard TV system sync signal from the second control means 7. , A first control means 8 for generating a first standard TV system image pickup synchronization signal and a pseudo image pickup synchronization signal, and a drive means for generating and outputting a drive signal for driving the image pickup means 5 based on the image pickup synchronization signal. 9 and the phase detected by the phase detection means described later and the synchronization signal of the second control means are compared, and based on the result, the imaging synchronization signal and the pseudo imaging synchronization generated by the first control means 8 are compared. And timing control means 10 for adjusting the initial phase of the signal.

Here, the second standard TV system is about n / m times the first standard TV system (m and n are natural numbers, and m ≠).
n) frame period.

The first control means 8 sets the repetition period of m / n times the frame period of the second standard TV system on the basis of the synchronization signal of the second standard TV system to make the first standard TV system.
A system imaging synchronization signal is generated and output to the driving unit 9 and the signal processing unit 6. Together with the first control means 8
Generates a pseudo imaging synchronization signal about m / n times the frame period of the second standard TV system and outputs it to the light source device 3.

The timing control means 10 compares the second standard TV system synchronization signal from the second control means 7 with the phase signal output from the phase detection means 13 of the light source device 3 and outputs the result. The first control means 8 is reset based on

The signal processing means 6 is controlled by the image pickup synchronizing signal of the first control means until the color plane sequential image signals from the image pickup means 5 are synchronized. Further, the signal processing means 6 is controlled by the synchronizing signal of the second control means 7 from the time when the color plane sequential image signals are synchronized to the time when they are outputted to the display means 4.

The light source hand device 3 controls the repetition cycle of the illumination light based on the color surface sequential illumination means 11 for generating the color surface sequential illumination light and the pseudo imaging synchronization signal output from the first control means 8. A speed / phase control unit 12 as a color plane sequential illumination control unit and a phase detection unit 13 for detecting the repeating phase of the color plane sequential illumination light are provided.

With the above construction, the speed / phase control means 12 of the light source device 3 is input from the signal processing device 2 and repeats the color plane sequential illuminating means 11 on the basis of the pseudo image pickup synchronizing signal indicating the image pickup timing. Control the cycle. The phase detection means 13 detects the repeated phase of the color plane sequential illumination means 11 and outputs the detection signal to the timing control means 10 of the signal processing device 2.

An optical image of an object by the color plane sequential illumination light emitted from the light source device 3 is formed on the image pickup surface of the image pickup means 5 arranged at the tip of the endoscope 1.

The image pickup means 5 is m / n times (m, n times the frame period of the second standard TV system by the first control means 8).
Image pickup is driven in every cycle of (n is a natural number), and an image pickup signal of color plane sequential is output to the signal processing unit 6.

The signal processing means 6 performs predetermined signal processing, such as clamp, AGC, white balance processing, and γ correction, on the input color plane sequential image signal, and then performs A / D conversion. Then, the color plane sequential signals are synchronized with each other by using a memory means (not shown). After inputting the color plane sequential image signal and performing various signal processing,
The writing operation up to the memory means for the synchronization processing is performed by the first control means 8 in synchronization with the timing of the imaging synchronization signal. The imaging synchronization signal is the first
Of the standard TV system.

Further, the frame sequential image signal stored in the memory means is simultaneously controlled by the second control means 7 for each color.
It is read in synchronization with the second standard TV system sync signal. The read signals of the respective colors are subjected to various kinds of signal processing, and then input to the monitor means 4 together with the second standard TV system synchronizing signal and displayed as an endoscopic image.

As described above, in the face-sequential electronic endoscope apparatus, even if there is a difference in the TV system between the monitor means and the illumination system or the imaging system in the endoscope and the light source device, the observation is performed in combination. be able to.

According to the apparatus shown in FIG. 1, in the electronic endoscope apparatus of the field-sequential imaging system, the means for correcting the error between the repetition cycle of the field-sequential imaging means and the repetition cycle of the color-sequential illuminating means is a signal. Since it is configured to be provided on the processing device side,
The common color plane sequential illumination means can be used regardless of the TV system, which is highly effective in improving the development efficiency of the device and reducing the cost.

FIG. 2 shows a first embodiment of the present invention.
In this embodiment, for example, NTS is used as the first standard TV system.
An example will be described in which an image is captured under color plane sequential illumination light conforming to the C system, and the obtained color plane sequential image signal is displayed as a second standard TV system on a monitor unit such as a PAL system.

The endoscope 21 has a light distribution lens 22 at the tip of the insertion portion and a light emission end of a light guide 23 at the rear end of the light distribution lens 22. The light guide 2
The color illumination light from the light source device 26 is sequentially incident on the incident end of No. 3. Further, the endoscope 21 has an objective optical system 24 at the tip of the insertion section and a CCD 25 as an image pickup means at the rear end of the objective optical system 24. The CCD 25 forms an object image illuminated by color plane sequential illumination light on its image pickup surface and outputs an image signal obtained by photoelectric conversion to the signal processing device 34.

The light source device 26 has the following structure as color plane sequential illuminating means. That is, the light source device 26 condenses the illumination light on the single surface of the rotary color filter 27 in which three optical color filters of RGB are arranged at equal intervals on the circumference, the lamp 28 for generating white light, and the light guide. Lens 29 and motor 30 for rotating the rotary color filter
It has and. Further, the light source device 26 includes a speed detector 3 for detecting the rotation speed and phase of the rotary color filter 27.
1 and the phase detector 32, the speed / phase detection circuit, and the speed / phase servo circuit as the color plane sequential illumination control means for controlling the rotation of the motor 30 based on the pseudo imaging synchronization signal from the signal processing circuit described later. And 33.

The speed detector 31 is, for example, a motor 30.
It is composed of a frequency oscillator provided in the above, and outputs a pulse (c) according to the rotation speed of the motor. The phase detector 32 is composed of, for example, a photo sensor, and detects the rotational phase of the rotary color filter 27 by detecting the reflected light of a reflection plate (not shown) provided at a predetermined position of the rotary color filter 27. Is.

By the way, in the color field sequential illumination means,
By rotating the rotary color filter 27, there are an exposure period in which light passes and a shielding period in which light is shielded. The signal processing device 34 reads out the charges accumulated in the CCD 25 during the exposure period during the shielding period to obtain a color plane sequential image signal. Therefore, it is necessary to set the timing of rotation of the image signal and the rotation color filter 27. The speed
The phase servo circuit 33 controls the rotation of the rotary color filter 27 by the phase synchronization control combined with the speed control.

Here, the first standard TV system is NTS.
C and the second standard TV system will be described below as PAL.

In this embodiment, the rotary color filter 27 is used.
Is equivalent to 3/2 times the frame frequency of NTSC.
It is set to rotate at 9.98Hz. That is, R
The repetition frequency of the color frames of (red), G (green) and B (blue) is 59.94 Hz. This means that the color frame of color plane sequential illumination is switched for each field of NTSC. And PAL field, NT
The timing at which the three fields of the SC and the color frame of the color field sequential illumination substantially match can be used as the timing for phase matching.

The color plane sequential illumination light emitted by the light source device 3 enters the light guide 23 of the endoscope 21 at the incident end thereof, passes through the emission end thereof and the light distribution lens 22, and is irradiated onto the subject. An optical image of a subject illuminated by color plane sequential illumination passes through an objective lens 24 arranged at the tip of the endoscope and is imaged on an image pickup surface of a CCD 25.

The signal processing device 34 performs various processings on the color plane sequential image signal (f) of the subject which is picked up and output by the CCD 25 under the color plane sequential illumination light, and at the same time, the PAL system TV signal is obtained. And output to the monitor 35.
The monitor 35 inputs a PAL system TV signal and displays a subject image.

The CCD 25 is a C of the signal processing device 34.
It is driven by the CD drive circuit 36, and the color plane sequential image signals are read out at a repetition frequency of 12/5 times the frame frequency of the PAL system, that is, 60 Hz, and output to the first signal processing circuit 37. ..

The first signal processing circuit 37 includes the CCD 2
Various signal processings for the color-sequential image signal from 5 such as correlated double sampling (CDS), AGC, white balance, painting, clamp, clip, γ
Processing such as correction is performed under the control of the first control circuit 38. The signal that has undergone the various processes is supplied to the memory circuit 40 via the A / D conversion circuit 39.

The memory circuit 40 is provided corresponding to each color of the color plane sequential image signal from the CCD 25, and under the control of the first control circuit 38, the corresponding color image signals R, G, B. Are written respectively. The memory circuit 4
From 0, each color signal is simultaneously read out in synchronization with the PAL system TV signal under the control of the second control unit 41. The read color signals are input to the second signal processing circuit 43 via the D / A conversion circuit 42.

The second signal processing circuit 43 performs various signal processing on each color image signal synchronized in synchronization with the PAL system TV signal. The various kinds of signal processing include, for example, correction of variations in signal level of each color, color correction by a matrix circuit (not shown), and the like. The second signal processing circuit 43 outputs the PAL TV signal (h) to the monitor 35 after the processing. Alternatively, the second signal processing circuit 43
May encode the PAL system TV signal and output it to the monitor 35.

The second control circuit 41 generates a standard (for example, PAL system) TV synchronizing signal to read out the memory circuit 40, the D / A conversion circuit 39, and the second signal processing circuit 43. Control. At the same time, the second control circuit 41 outputs a PAL system synchronization signal (PAL-VD) to the first control circuit 38 and the timing control circuit 44.

The first control circuit 38, based on the PAL system synchronizing signal (a) from the second control means 41,
A frame sequential imaging synchronization signal (b) having a repetition frequency 12/5 times the frame frequency of the L system is generated and output to the CCD drive circuit 36. At the same time, the first control circuit 38
A first signal based on a control signal generated using the synchronization signal;
The signal processing circuit 37, the A / D conversion circuit 39, and the memory circuit 40 are controlled to be written.

Further, the first control circuit 38 is
A pseudo imaging synchronization signal (e) having a repetition frequency of 59.94 Hz, which is about 12/5 times the frame frequency of the system, is generated and output to the speed / phase servo circuit 33 which controls the motor 30. These frame sequential imaging synchronization signals
The phases of (b), the pseudo imaging synchronization signal (e), etc. are determined by the reset signal input from the timing control circuit 44.

The timing control circuit 44 is a PAL system TV synchronizing signal input from the second control circuit 41.
(a) is compared with the phase detection signal (c) input from the phase detector 32 of the light source device 26, and the first control circuit 38 is reset based on the result.

FIG. 3 shows a part of the signal waveform output from each circuit shown in FIG. The waveform (a) shown in FIG. 3 is the PAL vertical synchronization signal V generated by the second control means 41.
Shows D. "E" and "o" in the figure are odd and even numbers of the field. The waveform (b) is a frame sequential imaging synchronization signal generated by the first control circuit 38, and its repetition frequency is 60 Hz. The waveform (c) is the output of the phase detector 32, and one pulse is generated for each rotation of the rotary color filter 27, which is generated immediately before the end of the R (red) illumination.

The waveform (d) shown in FIG. 3 is a reset signal generated by the timing control circuit 44. The reset signal (d) is generated when the phase of the vertical synchronizing signal VD (a) and the phase detection signal (c) at the beginning of the odd field of the PAL system reaches a predetermined value. Further, if this reset signal (d) is generated based on the quadrature signal (÷ 4) of the phase detection signal (c), a reset signal without deviation can be obtained. Note that the two-way signal (÷ 2) is an intermediate signal for generating the four-way signal (÷ 4). This reset signal is supplied to the first control circuit 38, and each phase of the control signals such as the frame sequential imaging synchronization signal (b), the pseudo imaging synchronization signal (e), and the memory write select (g) is predetermined. The initialization is performed so that the predetermined phase is obtained. That is, the reset signal is a signal for phase matching.

The image data is read out from the memory circuit 40 simultaneously with RGB under the control of the second control means 41 in synchronization with the PAL system TV synchronizing signal. On the other hand, since the image data of the memory circuit 40 is sequentially updated as the frame-sequential image signal (f) is input, control is performed so that overwriting does not occur in writing and reading.

With the above configuration, it is possible to use a common light source for the PAL specification electronic endoscope apparatus and the NTSC specification electronic endoscope apparatus.

In this embodiment, in the frame-sequential imaging type electronic endoscope apparatus, a means for correcting an error in the repetition cycle of the field-sequential imaging means and the repetition cycle of the color-sequential illumination means is provided on the signal processing means side. It is configured to be provided. In other words, in the present embodiment, the timing control circuit can match the phase of the sync signal or the like generated by the first control circuit with the phase of the sync signal of the second standard TV system, and different TVs can be used.
A common color plane sequential illuminating means can be used between the methods, which is highly effective in improving the development efficiency of the apparatus and reducing the cost.

The present invention differs from the first embodiment in that the first
The standard TV system may be a PAL system, and the second standard TV system may be an NTSC system, in which the front and back are interchanged. Also, not limited to the PAL system and the NTSC system,
Either of them may be a SECAM system and is not limited to the system of the color television.

A second embodiment of the present invention is shown in FIG. Book second
The embodiment is provided with a timing control circuit 44A capable of stabilizing the operation even in a transient state when the power is turned on, instead of the timing control circuit 44 shown in FIG. 2 of the first embodiment. Other configurations and operations similar to those of the first embodiment are designated by the same reference numerals and description thereof will be omitted.

In the transient state, the rotary filter 27
The rotation speed of No. shows responsiveness as shown in FIG. Therefore, the PAL-VD signal (a) and the phase detection signal (c) are
, There is a possibility that a phase state that does not occur in the steady state as shown in FIG. 5 may occur, in which case the color plane sequential illuminating means and the CCD 25 cannot be synchronized and the image is disturbed. Will end up. The present embodiment has a configuration improved so that the phase initialization operation becomes unstable in a transient state when the power is turned on.

The timing control circuit 44A comprises a cycle detection circuit 45 and a reset signal generation circuit 46.

The cycle detection circuit 45 constantly detects the repetition cycle of the phase detection signal (c) input from the phase detector 32 of the light source device 3, and when the cycle is within a predetermined range, a reset signal generation circuit. The enable signal (i) is output to the output port 46 to permit the output of the reset signal. At this time, the reset signal generating circuit 46 operates in the same manner as the timing control circuit 44 described in the first embodiment, and therefore the description thereof is omitted. The reset signal generation circuit 46 does not output the reset signal unless permission is given.

With the above configuration, the timing control circuit 4
Operational instability in the transient state of 4 A can be improved. Other configurations and effects are similar to those of the first embodiment,
The description is omitted.

7 and 8 relate to the third embodiment of the present invention, FIG. 7 is a block diagram showing a concrete example of the timing control circuit, and FIG. 8 is an operation waveform diagram of the circuit shown in FIG.

The timing control circuit 50 of the third embodiment shown in FIG. 7 has a divide-by-4 circuit 51 as a dividing means for inputting the phase detection signal WSP output from the phase detector 32 shown in FIG. is doing. The timing control circuit 50 has an edge extraction circuit 52 that outputs a synchronization period signal as an edge extraction means, a cycle detection circuit 53 as a prescribed cycle detection means, and a 3-input AND gate 54 as a gate means. is doing.

The output of the AND gate 54 is input to the synchronization signal generating circuit 55 as the first control means,
The sync signal generation circuit 55 outputs a horizontal sync signal HCLK to the cycle detection circuit 53.

The divide-by-4 circuit 51 divides the phase detection signal WSP by four. The edge extraction circuit 5
Reference numeral 2 is for generating a signal obtained by extracting the edge of the divide-by-4 phase detection signal WSP4 output from the divide-by-4 circuit 51. The edge extraction circuit 52 is a quarter-division phase edge extraction signal obtained at the timing of the vertical synchronizing signal VD output from the second control circuit 41 after the input four-division phase detection signal WSP4 falls, for example. WSP4L
(Hereinafter, abbreviated as WSP4L signal) is output. The WSP4L signal is a synchronization period signal, and is, for example, “H” only between the vertical synchronization signal VD of the PAL system following the fall of the phase-divided-four phase detection signal WSP4 and the next vertical synchronization signal VD. Is a signal.

The cycle detection circuit 53 is for detecting whether or not the WSP4L signal is within a prescribed cycle range with reference to the horizontal sync signal HCLK from the sync signal generation circuit 55.

The AND gate 54 is adapted to take the logical product of the vertical synchronizing signal VD, the WSP4L signal and the output of the cycle detecting circuit 53. And AND
The gate 54 is provided with a pseudo imaging synchronization signal LS generated by the synchronization signal generation circuit 55 when the three signals are "H".
The reset signal VRESET for adjusting the phase of YN or the like is output.

With the above configuration, in the quarter frequency dividing circuit 51, the phase detection signal WSP (see FIG.
(See (a)) is divided by four to obtain the quarter divided phase detection signal WSP4 shown in FIG. 8 (b). Then, the signal WS
One vertical cycle (vertical scanning line period) immediately after the falling edge of P4 is extracted by the edge extraction circuit 52, and the result is shown in FIG.
The WSP4L signal shown in is output. In FIG. 8D, P
The vertical synchronizing signal VD of the AL system is shown.

The cycle detection circuit 53 causes the WSP4L
It is checked whether the vertical period of the signal is within a predetermined range, and if it is within the range, "H" is output.

The PAL vertical synchronizing signal VD, the WSP4L signal, and the output of the cycle detecting circuit 53 are:
The AND operation is performed by the AND gate 54, and the result is shown in FIG.
It becomes the reset signal VRESET shown in. The reset signal VR
ESET is used for resetting the synchronization signal generation circuit 55, that is, for phase matching.

As described above, by setting a predetermined range, in this embodiment, when the power source is started,
As described above, when the cycle of the phase detection signal WSP changes from the unstable state to the steady state, the phase can be adjusted.

The synchronizing signal generating circuit 55 has a predetermined timing (signal VRESET) for turning back the vertical cycle.
Then, the pseudo imaging synchronization signal LSYNC and the like shown in FIG. Then, the synchronization signal generation circuit 55 sends the pseudo imaging synchronization signal LSYNC and the like to the speed / phase servo control circuit 33 shown in FIG. 1 as the color plane sequential illumination control means.

The first standard TV signal is the NTSC system,
When the second standard TV system is explained as a PAL system,
Since the one vertical period is of the PAL system, its value is 20 msec. The pseudo imaging synchronization signal LSYN
C corresponds to an NTSC composite synchronizing signal in which the phase error is reset every 12 vertical scanning line periods with respect to the vertical period of PAL.

By the way, in the configuration in which the synchronizing signal generating circuit 54 is reset by using the edge of the signal WSP4 as it is, the servo system of the color plane sequential illuminating means, the timing control circuit and the synchronizing signal generating circuit 55. A feedback system is constructed between. Since the signal WSP is a signal that detects the rotation phase of the rotation filter 27,
The signal WSP4 including the jitter component and obtained by dividing the frequency of the signal WSP by 4 also includes the jitter component. For this reason, it is difficult to stabilize the circuit in the configuration in which the edge is used as it is.

On the other hand, in the present embodiment, since the vertical synchronizing signal VD immediately after the edge of WSP4L is used for resetting, the signal VRESET is set after the initial phase is adjusted to a predetermined timing at the time of power supply startup. Means that signals of the same phase are always input. Therefore, since the feedback circuit is not configured in the steady state, stable phase matching can be performed without being affected by the jitter component of the phase detection signal WSP in this embodiment.

With the above arrangement, in the third embodiment, it is possible to commonly use the color plane sequential illuminating means having a frame period different from that of the monitor. The present embodiment can easily generate a standard TV signal having a frame period different from that of the color field sequential illuminating means or the image pickup means, without any inconvenience such as synchronization disorder or overtaking scanning.

FIG. 9 is a block diagram of a second control circuit according to the fourth embodiment of the present invention. The second control circuit 56 according to the fourth embodiment includes a clock generator 57 that generates a reference clock CLK, a horizontal counter (hereinafter abbreviated as H counter) 58, and a horizontal ROM as horizontal storage means.
(Hereinafter, abbreviated as HROM) 59, vertical counter (hereinafter abbreviated as V counter) 60, vertical ROM (hereinafter abbreviated as VROM) 6 as vertical storage means 6
1 and a control signal generation circuit 62.

The H-count 58 counts the reference clock CLK of the clock generator 57 and outputs the count value to the address of the HROM 59. The H-count 58 is the HROM.
Load (LD) at the timing prewritten in 59.
It is supposed to be done. Therefore, the H counter 58
Can operate as a counter of a specified cycle, for example, a horizontal cycle of the second standard TV system. That is, the above H
The data (timing) written in the ROM 59 is, for example, "H" in each horizontal period, and becomes "L" in other periods according to the address designated by the count value. It is sufficient that the HROM 59 has data corresponding to one horizontal period of the second standard TV system.

The data previously written in the HROM 59 is periodically read out and becomes a horizontal synchronizing signal of the second standard TV system, which is sent to the control signal generating circuit 62.

Further, the V counter 60 is provided with the HR
Horizontal clock for loading HCL supplied from OM59
K is counted and this count value is output to the address of the VROM 61. The horizontal clock HCLK is also a signal having the horizontal cycle of the second standard TV system.

Further, the V counter 60 is provided with the VR counter.
The load (L
D). Therefore, the V counter 60
Also operates as a counter having a specified cycle. That is, the data (timing) written in the VRO 61 is, for example, “H” in each vertical cycle of the second standard TV system according to the address designated by the count value of the V counter 60, and in other periods, for example, It becomes "L". It is sufficient that the VRO 61 has data corresponding to one vertical cycle of the second standard TV system.

The data written in advance in the VROM 61 is periodically read out and becomes a vertical synchronization signal of the second standard TV system, which is output to the control signal generation circuit 62.

The control signal generation circuit 62 includes the HROM 5
9. Based on the horizontal sync signal HD and the vertical sync signal VD output from the VROM 61, a second standard TV system sync signal such as a composite sync signal C.SYNC, and a memory read control signal D / The A conversion control signal and the timing control signal of the second signal processing circuit are generated and output.

The other construction, function and effect are the same as those of the first embodiment, and the explanation thereof is omitted.

FIG. 10 is a block diagram of the first control circuit according to the fifth embodiment of the present invention. As shown in FIG. 10, the first control circuit 64 receives, for example, a reset signal VRESET output from the timing control circuit 50 shown in FIG. 7 and a V counter 6 that receives a second standard TV system horizontal synchronization signal HD.
5, a VROM 66 as vertical storage means, a D flip-flop (hereinafter, D-FF) circuit 67, an H counter 68, an HROM 69 as horizontal storage means, and a control signal generation circuit 70. There is.

With the configuration of the V counter 65 and the VROM 66, a signal is output every vertical cycle, that is, a vertical synchronizing signal is generated. The V counter 65
Is for counting the horizontal synchronizing signal HD and resetting the count value by the reset signal VRESET. This reset signal VRESET is the first standard TV
The signals are generated at the timing when the phases of the synchronization signals of the system and the second standard TV system are substantially the same.

The VROM 66 inputs the count value of the V counter 65 to an address. Further, in the VROM 66, data which is, for example, "H" is written in the vertical cycle of the first standard TV system. It suffices that the data written in the VROM 66 has the data for the repeating period (one period) of the reset signal VRESET. Alternatively, the VROM 66 may store data having an integral multiple of the repetition period.

Here, the 12 vertical periods of the NTSC system are
This is approximately equivalent to 10 vertical periods of the PAL system. When the first standard TV system is NTSC and the second standard TV system is PAL, data corresponding to 10 vertical periods of the PAL system can represent all of the NTSC system synchronization signals. That is, one cycle of the reset signal VRESET is P
This is almost equivalent to 10 vertical periods of the AL method. The difference between the periods of both equations is about 200 μs, which is negligible.

The output of the VROM 66 is the D
The signal is input to the clear terminal of the -FF circuit 67. The data input terminal of the D-FF circuit 67 is "H".
The reference clock CLK is input to the clock terminal. DF
The Q output terminal of the F circuit 67 is connected to the reset terminal of the H counter 68.

The reference clock CLK may be the same as that shown in FIG. 9 or may be different. However, in the case of different clocks, both clocks must be phase locked at the timing of the horizontal cycle.

The H counter 68 has a reference clock CL.
While counting K, the count value is reset by the Q output of the D-FF circuit 67. H
The count value of the counter 68 is supplied to the address of the HROM 69. The HROM 69 outputs a signal of, for example, "H" in each horizontal period of the first standard TV system according to the pre-written data according to the input address value, and outputs "L" in other periods. ing. The data in the HROM 61 stores data which is an integral multiple of one horizontal period.

The control signal generation circuit 70 controls the VRO.
Based on the vertical sync signal VD generated by M59 and the vertical sync signal HD generated by HROM69, the composite sync signal C.Syn is generated.
c, a CCD drive signal, a first signal processing circuit, an A / D converter, and various control signals for controlling writing to the memory are generated.

In this embodiment, for example, an endoscopic surface sequential light source having an imaging frame frequency conforming to the NTSC system is used for imaging, and a video signal conforming to the PAL system, for example, is output. In the present invention, if at least the image pickup frame period conforms to the NTSC system, the object can be achieved even if the timing of details does not completely match. Therefore, the HROM 69 has a light-shielding period (for example, a period of 1) for each field period of the NTSC system.
At 6.7 ms and a width of about 8.2 ms, data in which the horizontal timing of image pickup is set is stored so that all necessary pixels of the CCD 25 can be read. Here, for example, the reference clock CLK is 16.09375 MHz, CCD
Drive frequency 8.05MHz, CCD pixel number 200x
If it is set to 200, if the CCD is read and driven at a rate of 3 lines in 2 horizontal periods of the PAL system, data of all pixels of the CCD can be read within the light-shielding period. Therefore, in the case of the above-mentioned example, the HROM 69 has the PAL
Data for two horizontal cycles of the method are prepared. The control signal generation circuit 70 drives the CCD for three lines to read out during the period of the two horizontal periods, and generates a control signal for controlling signal processing.

With the above configuration, the signal VRESET indicating the phase coincidence between the first standard TV system and the second standard TV system is input from the timing control circuit 50, and V
The counter 65 is reset. The V counter 65
For example, counts the horizontal synchronizing signal HD input from the second control circuit 56 shown in FIG. 9 and outputs the count value as the address value of the VROM 66. VR
The OM 66 reads the prewritten data according to the input address value and outputs it as a vertical synchronization signal to the control signal generation circuit 70.

Further, the output of the VROM 66 is edge-extracted by the D-FF circuit 67 with a clear, and the H counter 68 is reset by this output.

The H counter 68 outputs the count value of the reference clock CLK supplied from the clock generator (not shown) as the address value of the HROM 69. H
The ROM 69 reads the previously written data according to the input address value, and outputs it as the horizontal synchronization signal HD.
Output to the control signal generation circuit 70. Control signal generation circuit 7
0 is a CCD drive signal based on the synchronizing signals HD and VD,
And a timing control signal of the first signal processing circuit, A / D
It generates and outputs a converter control signal and a memory write control signal.

Next, a sixth embodiment will be described. 11
The electronic endoscope apparatus 71 according to the sixth embodiment shown in FIG. 7 is an example of a configuration in which the present invention is applied to a simultaneous imaging system apparatus. still,
The same components as those of the device shown in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

The electronic endoscope device 71 of the present embodiment has an electronic endoscope 72 having a CCD 74 as an image pickup means arranged at the tip of the insertion portion, and a light source device 75 for generating white light for illumination. There is.

In addition, the electronic endoscope apparatus 71 uses the signal line 76 inserted through the endoscope 72 to transmit the CC signal.
A signal processing device 77 is provided which drives the D74, performs predetermined processing on the read signal, and outputs a TV signal according to the standard TV system of the monitor 35 or the image recording device 78 connected to the outside. There is.

In the electronic endoscope 72, as shown in FIG. 12A, a color separation filter 79 is arranged on the image pickup surface. As shown in FIG. 12B, the color separation filter array 79 has, for example, yellow (Ye), cyan (C
y), magenta (Mg), and green (G), a plurality of color mosaic filters are arranged.

Between the objective optical system 24 and the color separation filter array 79 of the CCD 74, in order from the front end side, YA
YAG cut filter 80 for cutting G laser light component
And a crystal filter 81 that cuts infrared light. That is, the image pickup system is configured to pass only the visible light component.

In the light source device 75, a diaphragm 82 is arranged between the lamp 28 and the condenser lens 29. The diaphragm 82 adjusts the amount of white light from the lamp 28 that enters the light guide 23.
The diaphragm amount is controlled by the diaphragm drive circuit 83.

An optical image of the presentation object obtained by irradiating the illumination light from the light source device 75 is formed on the image pickup surface of the CCD 74. At this time, the optical image is color-separated by a color separation filter array 79 provided in front of the CCD 74,
It is photoelectrically converted by the CCD 74 and is read out as an electric signal under the control of the CCD drive circuit 84.

The CCD drive circuit 84 has a first
Based on the output of the control circuit of the first frame frequency (for example, 29.97 frames based on the NTSC system /
The CCD 74 is driven to pick up an image in seconds.

The CCD 74 is the C of the signal processing device 77.
The CD drive circuit 84 is read and driven to generate a dot-sequential image signal at the first frame frequency and output it to the first signal processing circuit 85.

The first signal processing circuit 85 performs various signal processing on the image signal from the CCD 74 under the control of the first control circuit 86. Examples of the various signal processing include clamp, AGC (auto gain control), knee correction, clip, γ correction, filtering, color separation, automatic light control detection, and white balance correction. The first signal processing circuit 85 supplies the signal after the predetermined processing to the memory circuit 88 via the A / D conversion circuit 87.

FIG. 12 is a block diagram showing a specific example of the first signal processing circuit 85. First signal processing circuit 85
Has a pre-stage processing / detection circuit 101 for performing, for example, γ correction, AGC, automatic dimming detection, etc. as various signal processing. The detection output for automatic light control of the pre-stage processing / detection circuit 101 is output to the diaphragm drive circuit 83. The diaphragm drive circuit 83 appropriately controls the aperture amount of the diaphragm 82 according to the detection output for automatic light control.

Further, the pre-stage processing / detection circuit 101 is
Low-pass filter (hereinafter abbreviated as LPF) 102,
The image signal after the various signal processing is output to a bandpass filter 103 (hereinafter abbreviated as BPF) 103. The LPFs 102 and 103 are
Bandwidth limitation is performed on the image signal to obtain a wideband luminance signal YH and a narrowband luminance signal YL.

The output of the BPF 104 is color separation / W
It is input to the B (white balance) circuit 105. In the color separation / WB circuit 105, the output of the BPF 104 and the LPF
Predetermined calculation is performed using the output of 103 to obtain white balance and color difference signals (R-YL), (B
-YL) is obtained.

The A / D conversion circuit 87 converts the output from the first signal processing circuit 85 into a digital signal. For example, when the first signal processing circuit 85 has the configuration shown in FIG. 12, the A / D conversion circuit 87 obtains the digital luminance signal Y and the digital color difference signals (RY) and (BY).

The memory circuit 88 includes an A / D conversion circuit 8
The digital luminance signal Y and the digital color difference signals (RY) and (BY) output from No. 7 are stored. Further, each data read from the memory circuit 88 is converted into an analog signal by the D / A conversion circuit 89 and input to the second signal processing circuit 90.

Reading from the memory circuit 88 is performed under the control of the second control means 91, that is, the second frame frequency (for example, 25 frames / sec according to the PAL system).
Are read at the same timing. Further, also in the D / A conversion circuit 89, conversion is performed at the timing of the second frame frequency.

The second signal processing circuit 90 is, for example, P
Based on the timing signal from the second control circuit 91, various signal processes are performed on the luminance / color difference signals synchronized in synchronization with the AL type TV signal. As the processing in the second signal processing circuit 90, for example, clamp, masking, matrix, ridge correction, clip, P
There is signal processing such as AL coding. Then, the second signal processing circuit 90 causes the monitor 35 to perform a predetermined signal processing.
For example, a PAL TV signal that is compatible with the
Output to. Alternatively, the output of the second signal processing circuit 90 is output to the image recording device 78 such as a PAL-VTR.

The second control circuit 91 generates the TV synchronizing signal of the second frame frequency to perform the above-mentioned control and outputs the synchronizing signal to the first control circuit 86. There is.

On the other hand, the first control circuit 86 generates the synchronization signal of the first frame frequency based on the synchronization signal from the second control circuit 91 and also generates the following control signals. It is a thing. That is, the first control circuit 86 controls the signal processing timing of the first signal processing circuit 85, the conversion timing of the A / D conversion circuit 87, and the writing to the memory circuit 88. These controls are performed at the timing synchronized with the first frame frequency.

A timing control circuit 92 is provided to match the frame phases of the first control circuit 86 and the second control circuit 91. The timing control circuit 92 generates a signal for resetting the frame phase of the first control circuit 86 based on the predetermined timing of the second control circuit 91.

In this embodiment, the first frame frequency and
The phase in the first control circuit 86 is reset for each frequency of the greatest common divisor with the second frame frequency. First
And the second frame frequency are, for example, NTS
When the frame frequency is C or PAL, once every 5 frames corresponding to the frequency of the greatest common divisor (5H
The phase is reset every z).

Incidentally, the first frame frequency is
The second standard TV system does not have to conform to the second standard TV system.
It is only necessary to have an integral multiple relationship with the frame frequency of the standard TV system.

In the present embodiment, a TV signal having a frame cycle different from that of the image pickup system can be easily generated without any inconvenience such as synchronization disturbance and overtaking scanning. Then, in this embodiment, the stable TV signal can be supplied to a monitor, an image recording device, or the like.

Further, in the present embodiment, in a plurality of electronic endoscope apparatuses which output signals corresponding to different TV systems, most of the driving signal generation and driver of the CCD, the processing of the CCD reading signal, etc. can be made common. Therefore, there is an advantage that the development efficiency is high and the mass production effect is expected, and the IC can be easily formed.

Other than that, the same components and operations as those of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 13 is a block diagram of an electronic endoscope apparatus according to the seventh embodiment of the present invention.

The apparatus of this embodiment is also similar to the sixth embodiment.
This is a configuration applied to the simultaneous imaging method. In this 7th Example, about the same structure and operation as 6th Example, the same code | symbol is attached | subjected and description is abbreviate | omitted.

The endoscope apparatus 95A of the seventh embodiment is shown in FIG.
In the sixth embodiment shown in FIG. 1, a signal processing device 77 having a built-in circuit group for processing signals in accordance with the first frame frequency.
Have A. The signal processing device 77A uses the CC
The D drive circuit 84, the 1st control circuit 86, the 1st signal processing circuit 85, and the timing control circuit 92 for resetting the frame phase are collectively configured.

Further, the endoscope device 95 has a signal conversion device 77B in which a second control circuit 91A and a second signal processing circuit 90A conforming to the second frame frequency are integrated. The signal conversion device 77B is detachable from the signal processing device 77A. That is, the second control circuit 91A and the second signal processing circuit 90A are detachable from the signal processing device 77A.

In the seventh embodiment, the second signal processing circuit 9
0A includes the A / D conversion circuit 87, the memory circuit 88, and the D / A conversion circuit 89 in addition to the second signal processing circuit 90 in the embodiment shown in FIG. Also,
The second control circuit 91A controls memory writing in addition to the function of the second control circuit 91 shown in FIG. The other circuit operations are the same as those in the sixth embodiment.

With the configuration of this embodiment, it is possible to connect to a different TV type monitor device, image recording device, or hard copy device such as a video printer by simply replacing the signal conversion device. That is, the endoscope, the light source device, and the signal processing device are commonly used, and only a signal converter of a different TV system is replaced, so that the monitor can be connected to a plurality of monitors of different TV systems. Alternatively, in the present embodiment, not only the monitor but also the side receiving the signals of different TV systems is constructed as an existing system, for example.
Connection is possible only by interposing the signal conversion device.

In the electronic endoscope apparatus shown in FIG. 13, the configuration of the signal processing apparatus is such that it is surrounded by a broken line in the figure.
Configuration including timing control circuit (for example, integrated into an IC)
Also good.

The rest of the configuration, functions and effects are the same as those of the sixth embodiment, and their explanations are omitted.

In the sixth and seventh embodiments, the second control circuits 91 and 91A are the same as the second control circuit 5 shown in FIG.
6 can be configured in the same manner. Also, the sixth and seventh
In the embodiment, the first control circuit 86 can be configured similarly to the first control circuit 64 shown in FIG.

FIG. 14 is a block diagram of an electronic endoscope apparatus according to a modification of the seventh embodiment.

The electronic endoscope apparatus 96 of this modification has a structure in which an optical TV endoscope 98 detachably attached to the optical fiber endoscope 97 is provided. Other configurations and operations similar to those of the seventh embodiment are designated by the same reference numerals, and description thereof will be omitted.

The optical fiber endoscope 97 has an image guide fiber 99 arranged at the rear end of the objective optical system 24. The image guide fiber 99 is inserted from the tip of the endoscope 97 to the eyepiece. The external TV camera 98 is configured to form an optical image transmitted by the image guide fiber 99 on the image pickup surface of the CCD 98 via the image absent lens 100.

The rest of the configuration, functions and effects are the same as those of the seventh embodiment, and their explanations are omitted.

In each of the above embodiments and modifications, the first control circuit is reset via the timing control circuit with the second control circuit as a reference. Alternatively, the control circuit of may be reversed.

In each of the above embodiments, the first standard TV
Although the case where the system is the NTSC system and the second standard TV system is the PAL system has been described as an example, the system may be the reverse, or the SECAM system may be used instead of any of the systems.

By the way, when the light source device is provided with a diaphragm such as a liquid crystal, it is necessary to prevent a change in the color tone of the observed image due to a change in the aperture area of the diaphragm due to close-up observation or the like.

Therefore, for an endoscope having an automatic diaphragm mechanism in front of the CCD, a light source device for driving and controlling the automatic diaphragm mechanism is provided with a color correction filter for correcting a change in spectral transmission characteristics due to the automatic diaphragm. And on the optical axis between the light guide and the incident end of the light guide. Based on the output signal of the photometric or distance measuring means provided on the front side of the automatic diaphragm mechanism,
The color correction filter is incorporated in and out of the illumination optical path, and a diaphragm diameter determining means for giving an instruction of the diaphragm diameter to the automatic diaphragm mechanism drive control means of the light source device is incorporated.

With the above-described structure, the color correction filter moves in and out of the illumination optical path in the light source device in conjunction with the automatic diaphragm, and prevents the color tone of the observed image from changing due to the change in the aperture area of the diaphragm.

[0147]

As described above, the present invention is advantageous in that, in the electronic endoscope apparatus that outputs signals corresponding to different TV systems, the number of common circuits can be increased, and cost reduction and development efficiency can be improved. There is.

Further, according to the present invention, as described above, even if the TV system is different, the common color plane sequential illumination means can be used to perform the color plane sequential imaging, and the development efficiency of the apparatus can be improved and the cost can be reduced. There is an effect that can be achieved.

[Brief description of drawings]

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

FIG. 2 is a block diagram of the electronic endoscope apparatus according to the first embodiment.

FIG. 3 is a partial signal waveform diagram in the device shown in FIG.

FIG. 4 is a block diagram of a timing control circuit according to a second embodiment.

5 is a signal waveform diagram of the circuit shown in FIG.

FIG. 6 is an explanatory diagram showing a change in motor rotation speed when the power is turned on.

FIG. 7 is a block diagram of a timing control circuit according to a third embodiment.

8 is a signal waveform diagram of the circuit shown in FIG.

FIG. 9 is a block diagram of a second control circuit according to the fourth embodiment.

FIG. 10 is a block diagram of a first control circuit according to the fifth embodiment.

FIG. 11 is a block diagram of an electronic endoscope apparatus according to a sixth embodiment.

12 is a block diagram showing a specific example of the first signal processing circuit shown in FIG.

FIG. 13 is a block diagram of an electronic endoscope apparatus according to a seventh embodiment.

FIG. 14 is a block diagram of an electronic endoscope apparatus according to a modification of the seventh embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Endoscope 2 ... Signal processing device 3 ... Light source device 4 ... Monitoring means 5 ... Imaging means 6 ... Signal processing means 7 ... Second control means 8 ... First control means 9 ... Driving means 10 ... Timing control means 11 ... Color field sequential illumination means 12 ... Velocity / phase control means 13 ... Phase detection means

Claims (3)

[Claims] 1. An image pickup unit for picking up an image of a subject at a first frame frequency, and an image signal obtained by the image pickup unit picking up the subject to receive the image signal, and multiplying the first frame frequency by about n / m (n, m). Is a natural number and a signal generation means for generating a standard TV system signal having a second frame frequency of n ≠ m), and a predetermined timing output from the signal generation means,
An electronic endoscope apparatus, comprising: a timing control unit that synchronizes a first frame frequency of the imaging unit with the second frame frequency. 2. A color plane sequential illumination means for emitting color plane sequential illumination light for illuminating a subject with a plurality of sequentially different color component lights at a first frame frequency, and illumination light of the color plane sequential illumination means. A standard TV system signal having a second frame frequency that is approximately n / m times (n and m are natural numbers and n ≠ m) the first frame frequency after receiving the image signal originally captured. At a predetermined timing output from the signal generating means and a signal generating means,
An electronic endoscope apparatus comprising: a timing control unit that synchronizes a first frame frequency of the color field sequential illumination unit with the second frame frequency. 3. The frame period of the first standard TV signal,
A color plane sequential illumination means for emitting color plane sequential illumination light for illuminating a subject with a plurality of sequentially different color component lights; and an imaging means for imaging the subject under the illumination light of the color plane sequential illumination means. A second standard T having a frame period of the color-sequential image signal picked up by the image pickup means is about n / m times (n and m are natural numbers and n ≠ m) times that of the first standard TV system.
An electronic endoscope apparatus comprising: a signal generating means for generating a V type video signal, wherein the frame length of the second standard TV type is about m / m for controlling the color plane sequential illuminating means. A first control for controlling the image pickup means so as to generate a pseudo image pickup synchronization signal having a period of n times and to sequentially perform color plane image pickup at a period of m / n times the frame period of the second standard TV system. Means, second control means for generating a synchronization signal of the second standard TV system, detection means for detecting at least one of the repetition period and phase of the color plane sequential illumination means, and the detection means. At least one of a cycle or a phase and a synchronization signal of the second control means are compared, and based on the result, timing control means for adjusting the phase of the signal generated by the first control means; One A color plane sequential illumination control means for controlling the phase of the color plane sequential illumination repeated in the color plane sequential illumination means so as to be synchronized with the pseudo imaging synchronization signal input from the control means. Electronic endoscope device.