JPH06253215A - Image pickup device - Google Patents

Abstract

PURPOSE:To obtain an excellent video image by using a phase shift detection means so as to detect a phase shift of a sampling pulse from an output of a sampling means so as to adjust the phase of the pulse based on the result of detection thereby eliminating noise in the video signal. CONSTITUTION:A reference clock is generated from an oscillator 8 for image pickup at a CCD 13 and a pulse generating section 9 uses the clock to generate various pulses such as drive and signal processing. A CCD drive 12 receives the pulse to drive the CCD 13 and the image pickup signal therefrom is fed to a blanking section 14. A CCD sampling section 15 clamps a field-through part of a CCD output with a clamp pulse from a phase adjustment section 16 with respect to the CCD output and the signal part of the CCD output is sampled with a sampling pulse from the adjustment section 16. Then the signal processing section 18 receives a CCD noise elimination output from the sampling section 15 to apply required signal processing and the result is outputted as a video signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device for picking up an image of a subject by an image pickup means.

[0002]

2. Description of the Related Art Conventionally, an image pickup apparatus for obtaining an image using an image pickup element has been widely used. In these image pickup devices, the image pickup signal of the image pickup device includes unnecessary components other than the image pickup signal due to the reset pulse at the time of driving the image pickup device. In order to remove this, the image pickup signal which is an analog signal is digitally changed. A sample hold circuit is used for stabilizing a sampling point of an A / D converter used for converting a signal into a digital signal for processing. Normally, the position of the sample pulse supplied to the sample hold circuit on the time axis is fixed.

However, if the position of the sample pulse on the time axis is fixed, when the high-speed reading is performed, the most signal in the image-pickup signal is obtained as compared with the case where the image-pickup element is driven at low speed and low-speed reading is performed. The points that can stably sample and hold the part where the level increases become narrower.

Therefore, the maximum signal level may not be obtained due to deviation from the optimum sampling point due to variations in image pickup signal due to variations in chip characteristics of the image pickup element and variations in transmission delay time due to transmission line characteristics of the image pickup signal. The S / N ratio may deteriorate. Therefore, Japanese Patent Application Laid-Open No. 2-134072 proposes an image reading apparatus capable of automatically adjusting a sample pulse by appropriately selecting a delay line having a plurality of taps.

[0005]

However, in the method disclosed in Japanese Patent Laid-Open No. 2-134072, a large number of taps are required to perform delicate phase adjustment, and the scale of the select circuit for selection becomes large. There is a problem. Further, it is necessary to provide an automatic adjustment mode and compare the results of successive sampling to select the optimum delay amount, which causes a problem that the processing takes time.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an image pickup apparatus capable of stably removing noise of an image pickup signal with a simple structure and obtaining a good image. There is.

[0007]

An image pickup means for picking up an object, a driving means for driving the image pickup means, a reference signal addition means for adding a predetermined reference signal to an output of the image pickup means, and an image pickup means for the image pickup means. Pulse generation means for generating a sampling pulse for sampling the output; sampling means for sampling the output of the imaging means to which the predetermined reference signal is added by the sampling pulse; and sampling pulse from the output of the sampling means. And a phase adjustment unit that adjusts the phase of the sampling pulse based on the detection result of the phase deviation detection unit.

[0008]

[Operation] The phase shift detecting means detects the phase shift of the sampling pulse from the output of the sampling means, and the phase adjusting means adjusts the phase of the sampling pulse based on the detection result of the phase shift detecting means.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 8 relate to a first embodiment of the present invention, FIG. 1 is a conceptual configuration diagram of an image pickup apparatus, FIG. 2 is a block diagram showing the configuration of the image pickup apparatus, and FIG. 3 shows a configuration of a blanking unit. FIG. 4 is a circuit diagram showing the configuration of the OB blanking level difference detecting unit, FIG. 5 is a circuit diagram showing the configuration of the sampling pulse phase adjusting unit, and FIG. 6 is a circuit showing the configuration of the CCD signal sampling unit. 7 and 8 are first timing charts for explaining the operation of the image pickup apparatus, and FIG. 8 is a second timing chart for explaining the operation of the image pickup apparatus.

As shown in the conceptual configuration of FIG. 1, the image pickup apparatus of the first embodiment includes an image pickup element drive section 3 for driving an image pickup element 2 based on a clock generated by a pulse generation section 1,
A reference signal adding section 4 for adding the reference signal adding signal 1b from the pulse generating section 1 to the output of the image pickup element 2, an image pickup element output noise removing section 5 for removing noise of the image pickup element output by a sampling pulse, and an image pickup element output A sampling phase shift detection unit 6 that detects a phase shift of the sampling pulse from the output of the noise removal unit 5, and a sampling phase shift detection unit 6
The sampling pulse phase adjusting unit 7 that adjusts the phase of the sampling pulse according to the detection result of 1 and outputs the phase adjustment sampling pulse 7a, and automatically adjusts the phase of the sampling pulse with a simple configuration. is there.

Specifically, as shown in FIG. 2, the oscillator 8
A pulse generator 9 for generating various pulses according to a reference clock from the CPU, a CCD drive unit 12 for driving the CCD 13 by the pulse for CCD drive from the pulse generator 9, and a blanking of the output of the CCD 13 from the pulse generator 9. A blanking unit 14 that performs a blanking process with the pulse 9a; a CCD signal sampling unit 15 that performs noise removal processing on the output of the blanking unit 14 based on a sampling pulse 9b from the pulse generating unit 9;
The signal processing unit 18 which processes the output of the D signal sampling unit 15 to generate a video signal, and the CCD signal sampling unit 15 by the blanking unit sampling pulse 9c and the OB sampling pulse 9d from the pulse generating unit 9.
The OB section blanking section level difference detection section 17 for detecting the level difference between the OB section and the blanking section of the output of the OB section and the sampling pulse phase adjustment output based on the detection result of the OB section blanking section level difference detection section 17 The phase of the ranking pulse 9a is adjusted and the CCD signal sampling unit 15 is adjusted.
And a sampling pulse phase adjusting unit 16 for outputting to.

The blanking section 14 is constructed as shown in FIG. 3, and is adapted to blank the output of the CCD 13 with a blanking pulse 9a. In addition, the OB blanking section level difference detection section 1
7 is configured as shown in FIG. 4, and includes a blanking section sampling pulse 9c and an OB section sampling pulse 9c.
The level difference between the OB section and the blanking section of the output of the CCD signal sampling section 15 is detected by d, and the sampling pulse phase adjustment output is output.

The sampling pulse phase adjusting section 16
5, as shown in FIG. 5, a comparator 16a, inverters 16b, 16c and 16d, and AND circuits 16e and 1
6f and integrating circuits 16g, 16h, 16i, and generates a sampling pulse clamp pulse according to the output of the sampling pulse phase adjusting unit 16 from the sampling pulse 9b and outputs it to the CCD signal sampling unit 15. There is.

The CCD signal sampling section 15 has a correlation double sampling (CDS) as shown in FIG.
Law). Note that the present invention is not limited to this, and can also be configured by delay difference noise elimination (DDS method: FIG. 6B), integral type delay difference noise elimination (IDDS method: FIG. 6C), and other noise elimination methods. Also, a type in which a signal portion is extracted by a sampling pulse or a gate pulse can be used.

The operation of the image pickup apparatus thus configured will be described.

In order to pick up an image with the CCD 13, the oscillator 8 generates a reference clock, and the pulse generator 9 outputs a reference clock.
It generates a pulse for D drive and various pulses for signal processing. The CCD drive unit 12 receives the CCD drive pulse and drives the CCD 13. CCD1
The image pickup signal from 3 is output as a CCD to the blanking unit 1.
4 is supplied.

The CCD output has a waveform as shown in FIG. 7 (b), while the blanking section 14 supplies the blanking pulse 9a shown in FIG. 7 (c) supplied from the pulse generating section 9. Blanking with
The blanking output shown in (d) is obtained.

In the CCD signal sampling section 15, FIG.
With respect to the CCD output shown in FIG. 8A, the feedthrough portion of the CCD output is clamped by the clamp pulse shown in FIG. By sampling the signal part of the CCD output with the sample pulse shown in c), the noise-free signal is taken out and the noise-removed output shown in FIG. 7E is obtained.

Here, as shown in FIG. 7E, there is a level difference between the OB portion and the blanking portion. In the blanking output, as shown in FIGS. 8 (e) and 8 (f), originally, there should be almost no level difference between the OB portion and the blanking portion, and only the noise component due to the dark current component of the OB portion should be present. Is. Therefore, the OB blanking section level difference detection unit 17 detects the level difference between the OB sampling pulse 9d shown in FIG. 7F and the blanking sampling pulse 9c shown in FIG. Output adjustment output.

In the sampling pulse phase adjusting section 16,
By outputting the clamp pulse and the sample pulse according to the sampling pulse phase adjustment output and supplying them to the CCD signal sampling unit 15, there is almost no level difference between the OB unit and the blanking unit as shown in FIG. Not C
Obtain the CD signal sampling output. The phases of the clamp pulse and the sample pulse are now adjusted. In the signal processing unit 18, the CCD signal sampling unit 1
In response to the CCD noise elimination output from 5, the necessary signal processing is performed and the image is output.

As described above, according to the image pickup apparatus of the first embodiment, the CCD output is blanked, and O after noise removal is performed.
Since the B section and the blanking section are compared and the phase of the sampling pulse is adjusted accordingly, the phase of the sampling pulse can be easily and automatically adjusted.

Next, a second embodiment will be described. 9 and 10 relate to the second embodiment, FIG. 9 is a block diagram showing a configuration of an image pickup apparatus, and FIG. 10 is a block diagram showing a configuration of a modified example of the image pickup apparatus. The second embodiment is almost the same as the first embodiment, and since the automatic adjustment of the sampling pulse shown in the first embodiment is realized by digital signal processing, only different configurations will be described and the same configurations will be described. Are denoted by the same reference numerals and description thereof will be omitted.

In the image pickup apparatus of the second embodiment, the noise is removed by the CCD signal sampling unit 15, there is almost no level difference between the OB unit and the blanking unit, and only the dark current noise component included in the OB unit is blanked. The portion (see FIG. 8F) is clamped to the A / D reference voltage by the blank clamp unit 20 and input to the A / D converter 22. In the OB clamp section 24, the A / D converter 22
The dark current noise component is removed by detecting and clamping the level of the OB portion of the signal digitized by. The OB clamp unit 2 from which this dark current noise component is removed
The output of No. 4 is subjected to necessary digital processing by the signal processing unit 18a, and this output is converted into an analog signal by the D / A converter 26 and output as a video signal.

As shown in FIG. 10, the OB clamp section 24a detects the level of the OB section of the output of the blank clamp section 20, clamps it, and outputs it to the A / D converter 22 to detect the OB level. A / D converter 2 in section 30
The level of the OB portion of the signal digitized in 2 is detected,
OB clamp section 24a via the D / A converter 32
May be fed back to remove the dark current noise component.

As described above, according to the image pickup apparatus of the second embodiment, in addition to the effect of the first embodiment, after the level difference between the OB portion and the blanking portion is almost eliminated, the blank portion is clamped to perform A / D. It is possible to effectively use the dynamic range of the A / D converter 22 by converting and then removing the dark current noise component of the OB portion.

Next, a third embodiment will be described. Figure 11
And FIG. 12 relates to the third embodiment, FIG. 11 is a block diagram showing a configuration of an endoscope apparatus including an image pickup apparatus, and FIG. 12 is a block showing a configuration of a modified example of the endoscope apparatus including an image pickup apparatus. It is a figure. Since the third embodiment is almost the same as the first embodiment and the image pickup apparatus of the first embodiment is applied to an endoscope apparatus, only different configurations will be described and the same reference numerals will be given to the same configurations. The additional explanation is omitted.

As shown in FIG. 12, the endoscope apparatus equipped with the image pickup apparatus of the third embodiment generates a reference clock with an oscillator 8, and the pulse generator 1 (9) based on this reference clock.
The pulse for CCD drive is generated in A). The CCD drive unit 12 receives this CCD drive pulse,
The CCD 13 provided at the tip of the electronic endoscope 40 is driven via the cable 43. In the electronic endoscope 40, the illumination light from the light source 42 is applied to a subject (not shown) in front of the tip by the light guide 41, and the return light is imaged by the CCD 13.

The image pickup signal obtained by the CCD 13 is transmitted to the blanking section 14 and the cable length detecting section 44 via the cable 43. In the cable length detector 44,
The length of the cable 43 is detected, and the voltage control oscillator (VCO) 45 is controlled according to the detection result, and the VCO 4
5 generates a clock whose cable length is corrected. The pulse generator 2 (9B) generates a sampling pulse and a signal processing pulse by the reset signal detected by the reset detector 46 from this clock and the CCD output.

Since the operation of the blanking unit 14 and the subsequent circuits which receive the CCD output is the same as that of the first embodiment, the description thereof will be omitted.

As described above, in the endoscope apparatus including the image pickup apparatus of the third embodiment, in addition to the effect of the first embodiment, the cable length correction unique to the electronic endoscope 40 is combined with the sampling pulse automatic adjustment. As a result, the phase adjustment can be automatically performed even if the cable length changes. Not limited to the endoscope apparatus using the electronic endoscope, for example, as shown in FIG. 12, illumination light from the light source 42 is applied to the subject in front of the tip by the light guide 55, and return light is guided to the image guide. The same effect can be obtained even with an endoscope apparatus including an endoscope 51 that transmits to the eyepiece section by 54 and a separate external camera 52 that is connected to the eyepiece section of the endoscope 51. Obtainable.

In the first to third embodiments, the level difference between the OB section and the blanking section is detected by the OB section blanking section level difference detecting section 17 shown in FIG. 4, but the present invention is not limited to this. The pulse phase may be adjusted by obtaining the level difference by an external device such as. Alternatively, the phase may be adjusted by digital processing by a CPU or the like.

Next, a fourth embodiment will be described. FIG.
FIG. 17 relates to the fourth embodiment, FIG. 13 is a configuration diagram showing the configuration of the image pickup apparatus, FIG. 14 is a circuit diagram showing the configuration of the reference signal discrimination unit, and FIG. 15 is a timing diagram explaining the operation of the image pickup apparatus. FIG. 16 is a block diagram showing a configuration of an endoscope apparatus having an image pickup device, and FIG. 17 is a block diagram showing a configuration of a modified example of an endoscope apparatus having an image pickup device. The fourth embodiment is
Since it is almost the same as the first embodiment, only different configurations will be described, the same configurations will be assigned the same reference numerals, and description thereof will be omitted.

In the image pickup apparatus of the fourth embodiment, as shown in FIG. 13, the reference signal adding section 61 for adding a reference signal to the CCD drive pulse from the pulse generating section 9 and the noise removal by the CCD signal sampling section 15 are performed. The reference signal discriminating unit 62 shown in FIG. 14 for sampling the reference signal from the received signal to discriminate the reference signal and outputting the sampling pulse phase adjustment output to the sampling pulse phase adjustment 16 is configured. The configuration is the same as in the first embodiment.

The operation of the image pickup apparatus of this embodiment having the above structure will be described.

The oscillator 8 generates a reference clock, and the pulse generator 9 receives the reference clock to generate a CCD drive pulse, a sampling pulse, and a signal processing pulse. CCD
In order to obtain the CCD output as shown in FIG. 15 (b) in the reference signal adding section 61 in response to the drive pulse, ΦR as shown in FIG. 15 (f) in the video signal section and the OB section,
The reference signal section generates .PHI.R as shown in FIG. 15 (g), adds it to the CCD drive pulse, and outputs it to the CCD drive section 12.

The CCD drive unit 12 receives the pulse for CCD drive and drives the CCD 13 as shown in FIG.
CCD outputs as shown in (b), (c), (d) and (e) are obtained. The CCD signal sampling section 15 samples the CCD output with the clamp pulse and sampling pulse shown in FIGS. 15 (h) and 15 (i) generated by the pulse generating section 9 to obtain the sampling output shown in FIG. 15 (j).
In the reference signal discriminating unit 62 shown in FIG. 14, the reference signal portion of the CCD output is sampled by the reference signal sampling pulse from the pulse generating unit, and the sampled reference signal is compared and discriminated with the reference voltage. The sampling pulse costume adjusting unit 16 adjusts the phase of the sampling pulse and outputs the adjusted sampling pulse to the CCD signal sampling unit 15.

Thus, by adding the reference signal by driving the CCD and adjusting the phase of the sampling pulse of the CCD signal based on this, the phase of the sampling pulse can be automatically and quickly adjusted with a simple structure. it can.

The image pickup apparatus according to the fourth embodiment is an endoscope apparatus having an electronic endoscope 40 as shown in FIG. 16 or an image guide 54 as shown in FIG. 17, as in the third embodiment. It goes without saying that it can be easily applied to an endoscope apparatus in which a separate external camera 52a is attached to the eyepiece portion of the endoscope 51 equipped with.

Further, the reference signal discriminating section may be constructed in an analog manner or in a digital manner, and the CPU
Alternatively, it can be configured by an external personal computer or the like.

Further, the timing of adding the reference signal is not limited to the timing of the above-mentioned fourth embodiment, and it is also possible to add it at another timing.

Next, a fifth embodiment will be described. FIG.
FIG. 22 relates to the fifth embodiment, FIG. 18 is a configuration diagram showing a configuration of a sampling pulse phase adjustment unit of an image pickup device, FIG. 19 is a timing diagram explaining an operation of the sampling pulse phase adjustment unit, and FIG. 20 is an OB unit. FIG. 21 is a configuration diagram showing the configuration of the blanking unit level difference detection unit, and FIG. 21 is a CCD of the image pickup device.
FIG. 22 is a configuration diagram showing a configuration of a drive reset pulse ΦR generation circuit, and FIG. 22 is a CCD drive reset pulse ΦR of FIG.
FIG. 7 is a timing diagram illustrating the operation of the generation circuit. Since the fifth embodiment is almost the same as the first embodiment, only different configurations will be described, the same configurations will be denoted by the same reference numerals, and description thereof will be omitted.

The structure and operation of the sampling pulse phase adjusting unit 16 'of the image pickup apparatus of this embodiment will be described with reference to FIGS.

As shown in FIG. 18, the sampling pulse phase adjusting unit 16 'receives the sampling pulse (FIG. 19 (b)) having a phase in the CCD output (FIG. 19 (a)). The sampling pulse is integrated by the integrating circuit 72 and input to the comparator 76 (FIG. 19 (c)).
The sampling pulse inverted by the inverter 71 is integrated by the integration circuit 73 and input to the comparator 77 (FIG. 19 (e)). The outputs of the comparators 76 and 77 that are compared with the clamp pulse comparison voltage and the sample pulse comparison voltage are waveform-shaped by the differentiating circuits 78 and 80 and the diodes 79 and 81, respectively, and SR-FF.
82 set input terminal (S), reset input terminal (R)
(FIGS. 19D and 19F). SR-FF8
The output of 2 (FIG. 19 (g)) is converted into a clamp pulse shown in FIG. 19 (h) by the integrator 83, the inverter 84, and the AND circuit 85. Similarly, the integrator 86, the inverter 87, and the AND circuit 86 convert into the sample pulse shown in FIG. This clamp pulse,
A video signal from which noise has been removed can be obtained by performing CDS on the CCD output by the CCD signal sampling unit (see FIG. 2) using the sample pulse.

Here, by adjusting the clamp pulse comparison voltage and the sample pulse comparison voltage independently, the duty ratio and phase of the SR-FF 82 shown in FIG. 19B are adjusted. An output signal can be obtained. The output of the AND circuit 85 of the output signal of the SR-FF 82 whose duty ratio and phase are adjusted and the signal obtained by delaying this output signal by the integrating circuit 83 and then inverting it by the inverter 84 is shown in FIG.
It becomes the clamp pulse of. In addition, the inverter 8 outputs the output signal of the SR-FF 82 whose duty ratio and phase are adjusted.
The output of the AND circuit 88 of the signal inverted in 7 and the signal obtained by delaying the output signal of the SR-FF 82 by the integrating circuit 86 becomes the sample pulse of FIG. 19 (i).

FIG. 20 shows an example of the OB blanking section level difference detection section in this embodiment. The OB section blanking section level difference detecting section 17 'detects the level difference between the OB section and the blanking section and controls the sampling pulse phase adjusting section 16'. That is, the comparison voltage for the clamp pulse and the comparison voltage for the sample pulse are output from the OB blanking level difference detection unit 17 ′, and the two phase relationships of the clamp pulse and the sample pulse are fixed and the phase of the sampling pulse is changed. Adjustment is possible. Further, by performing the reference adjustments respectively, it is possible to adjust the two phase relationships of the clamp pulse and the sample pulse. Other configurations and operations are the same as those in the first embodiment.

Therefore, according to the image pickup apparatus of this embodiment equipped with such a sampling pulse phase adjusting unit 16 ', not only the sampling pulse phase adjustment but also the duty ratio adjustment can be easily performed.

In this embodiment, the level difference between the OB section and the blanking section is detected by the OB section blanking section level difference detection section shown in FIG. 20, but the invention is not limited to this, and an external device such as a personal computer is used. The pulse phase may be adjusted by obtaining the level difference with. Further, it may be digitally adjusted by a CPU or the like. In this case, the clamp pulse comparison voltage and the sample pulse comparison voltage are the electronic volume or D / A
It can be configured by a converter or the like, and the pulse width and phase of the pulse can be adjusted without using a trimmer resistor.
Further, a modification such as omitting the differentiating circuits 78 and 80 and the diodes 79 and 81 in FIG. 18 can be applied.

Further, the circuit configuration of the sampling pulse phase adjusting section 16 'of this embodiment is not used only for generating the clamp pulse and the sample pulse.
For example, it can be applied to a CCD drive reset pulse ΦR generation circuit. As shown in FIGS. 21 and 22,
The reset pulse ΦR generation circuit 90 for driving the CCD is SS
CCD drive horizontal transfer pulse Φ1 output from G91
(FIG. 22 (a)) and Φ2 (FIG. 22 (d)) are input to comparators 92 and 93, respectively (FIG. 22 (b),
(E)), each comparison voltage is, for example, D
By digitally controlling the signal through the A / A converters 95 and 96, the set input signal and the reset input signal as shown in FIGS.
It is possible to adjust the pulse width and phase of ΦR (FIG. 22 (g)) output from the RF-SS 82.

[0050]

As described above, according to the image pickup apparatus of the present invention, the phase shift detecting means detects the phase shift of the sampling pulse from the output of the sampling means, and the phase adjusting means detects the detection result of the phase shift detecting means. Since the phase of the sampling pulse is adjusted based on this, there is an effect that noise of the image pickup signal can be stably removed with a simple configuration and a good image can be obtained.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram of an image pickup apparatus according to a first embodiment.

FIG. 2 is a block diagram showing the configuration of the image pickup apparatus according to the first embodiment.

FIG. 3 is a circuit diagram showing a configuration of a blanking unit according to the first embodiment.

FIG. 4 is a circuit diagram showing a configuration of an OB blanking unit level difference detection unit according to the first embodiment.

FIG. 5 is a circuit diagram showing a configuration of a sampling pulse phase adjusting unit according to the first embodiment.

FIG. 6 is a circuit diagram showing a configuration of a CCD signal sampling unit according to the first embodiment.

FIG. 7 is a first timing diagram illustrating the operation of the image pickup apparatus according to the first embodiment.

FIG. 8 is a second timing chart illustrating the operation of the image pickup apparatus according to the first embodiment.

FIG. 9 is a block diagram showing a configuration of an image pickup apparatus according to a second embodiment.

FIG. 10 is a block diagram showing a configuration of a modified example of the image pickup apparatus according to the second embodiment.

FIG. 11 is a block diagram showing a configuration of an endoscope apparatus including an image pickup apparatus according to a third embodiment.

FIG. 12 is a block diagram showing a configuration of a modified example of an endoscope apparatus including the image pickup apparatus according to the third embodiment.

FIG. 13 is a configuration diagram showing a configuration of an image pickup apparatus according to a fourth embodiment.

FIG. 14 is a circuit diagram showing a configuration of a reference signal discriminating unit according to a fourth embodiment.

FIG. 15 is a timing chart illustrating the operation of the image pickup apparatus according to the fourth embodiment.

FIG. 16 is a block diagram showing a configuration of an endoscope apparatus including an image pickup apparatus according to a fourth embodiment.

FIG. 17 is a block diagram showing a configuration of a modified example of the endoscope apparatus including the image pickup apparatus according to the fourth embodiment.

FIG. 18 is a configuration diagram showing a configuration of a sampling pulse phase adjustment unit of the image pickup apparatus according to the fifth embodiment.

FIG. 19 is a timing chart for explaining the operation of the sampling pulse phase adjuster according to the fifth embodiment.

FIG. 20 is a configuration diagram showing a configuration of an OB blanking unit level difference detection unit according to a fifth embodiment.

FIG. 21 is a configuration diagram showing a configuration of a CCD drive reset pulse ΦR generation circuit of an image pickup apparatus according to a fifth embodiment.

22 is a timing chart for explaining the operation of the CCD drive reset pulse ΦR generation circuit of FIG. 21 according to the fifth embodiment.

[Explanation of symbols]

 8 ... Oscillator 9 ... Pulse generator 12 ... CCD drive 13 ... CCD 14 ... Blanking 15 ... CCD signal sampling 16 ... Sampling pulse phase adjuster 17 ... OB blanking level difference detector 18 ... Signal processor

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[Procedure amendment]

[Submission date] June 7, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction content]

As described above, in the endoscope apparatus including the image pickup apparatus of the third embodiment, in addition to the effect of the first embodiment, the cable length correction unique to the electronic endoscope 40 is combined with the sampling pulse automatic adjustment. As a result, the phase adjustment can be automatically performed even if the cable length changes. The light guide 55 is not limited to the endoscope apparatus using the electronic endoscope, and the illumination light from the light source 42 is used as shown in FIG. 12, for example.
Endoscope 51 that illuminates a subject in front of the front end by using the image guide 54 and transmits the returned light to the eyepiece portion, and a detachable external camera 52 that is connected to the eyepiece portion of the endoscope 51.
The same effect can be obtained even with an endoscope apparatus configured by.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0037

[Correction method] Change

[Correction content]

The CCD drive unit 12 receives the pulse for CCD drive and drives the CCD 13 as shown in FIG.
CCD outputs as shown in (b), (c), (d) and (e) are obtained. The CCD signal sampling section 15 samples the CCD output with the clamp pulse and sampling pulse shown in FIGS. 15 (h) and 15 (i) generated by the pulse generating section 9 to obtain the sampling output shown in FIG. 15 (j).
In the reference signal discriminating unit 62 shown in FIG. 14, the reference signal portion of the CCD output is sampled by the reference signal sampling pulse from the pulse generating unit, and the sampled reference signal is compared and discriminated with the reference voltage.
The sampling pulse phase adjusting unit 16 adjusts the phase of the sampling pulse and outputs the adjusted sampling pulse to the CCD signal sampling unit 15.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0049

[Correction method] Change

[Correction content]

Further, the circuit configuration of the sampling pulse phase adjusting section 16 'of this embodiment is not used only for generating the clamp pulse and the sample pulse.
For example, it can be applied to a CCD drive reset pulse ΦR generation circuit. As shown in FIGS. 21 and 22,
The reset pulse ΦR generation circuit 90 for driving the CCD is SS
CCD drive horizontal transfer pulse Φ1 output from G91
(FIG. 22 (a)) and Φ2 (FIG. 22 (d)) are input to comparators 92 and 93, respectively (FIG. 22 (b),
(E)), each comparison voltage is, for example, D
By digitally controlling via the A / A converters 95 and 96, the set input signal and the reset input signal as shown in FIGS. 22C and 22F are RS-FF.
The pulse width and phase of ΦR (FIG. 22 (g)) output from the RS-FF 82 can be adjusted.

Claims (1)

[Claims] 1. An image pickup unit for picking up an image of a subject, a drive unit for driving the image pickup unit, a reference signal adding unit for adding a predetermined reference signal to the output of the image pickup unit, and an output of the image pickup unit. Pulse generating means for generating a sampling pulse for, a sampling means for sampling the output of the image pickup means to which the predetermined reference signal is added by the sampling pulse, and a phase shift of the sampling pulse from the output of the sampling means. An image pickup apparatus comprising: a phase shift detecting unit that detects the phase shift; and a phase adjusting unit that adjusts the phase of the sampling pulse based on a detection result of the phase shift detecting unit.