JPS63281114A - Endoscope image pickup device - Google Patents

Abstract

PURPOSE:To eliminate the need of flickering of a lamp even in case of using a face sequential scope, by providing a means for sweeping out a charge stored in a solid-state image pickup element under a white illumination which has passed through an opening. CONSTITUTION:As for an object to be photographed, illuminated by a light beam of each wavelength, an image is formed in an image area 51 of a charge coupled element by an objective lens 21, converted photoelectrically, and stores as a charge in each illumination period. Subsequently, the charge stored in a period in which a light beam has been shielded by a filter frame of a rotary filter 3 becomes a transfer mode for executing a charge transfer. This transfer mode is executed to that of an illumination of R, G and B, but a charge stored under a white illumination by an opening 2 is swept out by a sweep-out mode in its succeeding light shielding period, not inputted to a signal processing circuit 25 side but swept out and eliminated. In such a way, it is unnecessary to flicker a lamp 42, and the lamp 42 can be extended to a long service life.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an endoscope imaging device provided with means for sweeping out signals captured during an unnecessary illumination period.

[Prior Art] In recent years, by inserting an elongated insertion section, it is possible to observe the inside of a living body without requiring an incision using an observation means provided at the distal end of the insertion section, and to use treatment tools as necessary. Endoscopes, which can perform therapeutic procedures, have become widely used.

In addition, recently, the above-mentioned endoscopic l! ! (also called a fiberscope), an electronic endoscope (hereinafter referred to as "fiberscope") has an objective lens that forms an optical image on the imaging surface of a solid-state image sensor, and a photoelectrically converted video signal is guided to a signal processing means via a signal cable. electronic endoscopes or electronic scopes) are on the verge of being put into practical use.

As shown in Japanese Patent Application Laid-open No. 53-90685, conventional electronic endoscopes sequentially pass the illumination light from a light source lamp through R, G, and B color transmission filters, and sequentially capture images under three colors of illumination light. The three-color component images of R, G, and B are obtained, and the three-color component signals are combined for each pixel to generate a color image signal.

However, when using a fiberscope, white light is required, so there is a fiberscope in which the rotating filter to which the color transmission filter is attached can be retracted. In order to retract this rotating filter, a retracting mechanism is required, which complicates the structure of the light source device. For this purpose, for example, as shown in FIG. 6, in addition to a red transmission filter 102R, a green transmission filter 102G, and a blue transmission filter 102B, an aperture 103 is provided in the rotating filter 101 that is rotationally driven, so that an opening 103 is provided in the optical path when an electronic scope is used. 103, the light source lamp is turned off, and when the fiberscope is used, the rotary filter 101 is stopped, and the stop controller is controlled so that the aperture 103 is interposed in the optical path in this stopped state. It is suggested that something be done.

[Problems to be Solved by the Invention] This method eliminates the need for a retracting mechanism for the rotating filter, but when using an electronic scope, the lamp must be turned off every time the aperture 103 is inserted into the optical path. However, there are disadvantages in that a lighting/extinguishing control circuit is required, and the life of the lamp is likely to be shortened because the lamp is blinked.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide an endoscope imaging device that does not require blinking a lamp.

Means and operation for solving problem E] In the present invention, as shown in FIG. In a sequential color imager, adjacent filters (e.g. IR,
(IG) in the same figure (B) for the shading period during
As shown in a) and (b), it is also referred to as a solid state image device (SID).

) A vertical (transfer) pulse φp and a horizontal (transfer) pulse φS for charge readout are applied to the SID to perform charge transfer to the subsequent signal processing circuit. On the other hand, during the light shielding period between the frontage 2 and the adjacent red transmission filter 1R, for example, only the vertical pulse φp is applied to the SID, and no charge transfer is performed, as shown in (C) in FIG. 1(B). By sweeping out the charge imaged under the illumination light passing through the aperture 2, the lamp does not have to be turned off at the timing when the aperture 2 is interposed on the optical path.

[Actual R example] Hereinafter, the present invention will be specifically explained with reference to the drawings.

2 to 5 relate to one embodiment of the present invention, FIG. 2 is a block diagram of one embodiment, FIG. 3 is a schematic structure of a fiber path, and FIG. 4 is a block diagram of one embodiment. FIG. 5 does not show the structure of a charge coupled device used in one embodiment.

As shown in FIG. 2, the endoscopic imaging device 11 of the first embodiment uses a charge-coupled device (noted as COD) as a solid-state imaging device.

) 12, a scope control device 14 to which the electronic scope 13 can be connected, and a color monitor 15 that displays video signals output from the scope control device 14.

The scope control device 14 includes the electronic scope 13
Instead, a fiberscope 16 as shown in FIG. 3 can be attached.

The electronic scope 13 and the fiber scope 16 have an elongated insertion section 17, and an operation section is formed at the rear end of the insertion section 17, so that operations such as bending the distal end of the insertion section 17 can be performed. Yes (illustrated path).

Inside the insertion section 17 is a light guide 1 that transmits illumination light.
8 is inserted through the scope control device 14 , and by connecting it to the scope control device 14 , illumination light is supplied from the light source device 19 in the scope control device 14 to the entrance end surface of the light guide 18 . The illumination light supplied to the incident end face of the light guide 18 is emitted from the front end face of the light guide 18, and the subject is illuminated. The illuminated object is imaged on its focal plane by the objective lens 21. On this focal plane, the CCD 12 is located in the electronic scope 13, and the CCD 12 is located in the fiber scope 16.
The image guide 22 is arranged so that its distal end face faces. The optical image transmitted by this image guide 22 can be observed with the naked eye through an eyepiece 23.

On the other hand, in the electronic scope 13, the CCD 12 photoelectrically converts and stores the charge as an electric charge, which is then stored in the scope control device 14.
COD control drive circuit 2 configuring the signal processing circuit 25 in
It is read out by the ``market transfer signal'' output from 6, and 1
The signal is input to the 1G stage video processing circuit 27. This pre-stage video processing circuit 27 includes, for example, a contour enhancement circuit and a γ correction circuit, and after performing video processing on these circuits, the video is input to an A/D converter 28 and converted into a digital signal.

The control circuit 29 is included in the COD control drive circuit 26.
A control signal for generating a revision pulse φp and a horizontal pulse φS used for charge transfer is applied from . In addition, a clamp signal is applied to the control circuit 2 and the pre-stage video processing circuit 27 to output a signal that has been subjected to contour enhancement, etc.

Further, an A/D conversion clock is applied to the A/D converter 28, and A/D conversion is performed in synchronization with this clock.

The digital signal from the A/D converter 28 is stored one frame at a time in the R frame memory 31R, G frame memory 31G, and B frame memory 31B. Note that an RD/Wπ pulse is applied to these frame memories 31R, 131G, and 31B from the control circuit 29 according to the address signal and the read mode and write mode.

When video signal data for one frame is stored in each of the frame memories 31R, 31G, and 31B, they are read out at the same time. ) The signals are each converted into an analog signal by the D/A converter 32, and the harmonic components are removed through the low-pass filter 33, and the signals are input to the subsequent video processing circuit 34, respectively.

Note that a clock for performing D/Δ conversion is applied from the control circuit 25 to each D/A converter 32. Further, when performing edge enhancement, the post-stage video processing circuit 34 receives a clamp signal from the control circuit 25.

The R, G, and B color signals passed through this rear-stage video processing circuit 34 are input to the monitor 15 together with a synchronization signal (not shown).
Displayed in color.

By the way, the light source device 19 that supplies illumination light to the light guide 18 condenses the white light of the lamp 42 emitted by the power supplied from the power source 41 using the condensing lens 43, and then passes it through the rotating filter 3 to the light guide 18. Irradiates the input rA end face.

The rotary filter 3 is rotationally driven by a motor 44. A rotation drive signal is applied to this motor 44 by a rotation filter drive circuit 45 .

The rotary filter drive circuit 45 controls the rotation of the motor 44 and sends a timing signal synchronized with this rotation to the control circuit 29 to control the signal processing circuit 25 in synchronization with the rotation of the rotary filter 3. ing.

Incidentally, the position at which the motor 44 is stopped is controlled by a rotary filter stopping circuit 46. In other words, when the rotary filter 3 is in a stationary state where it has stopped rotating, the stationary position is controlled so that the aperture 2 is interposed in the optical path, and in this state, when the fiberscope 16 is connected, the aperture 2 is Can provide white illumination light.

By the way, due to the rotation of the motor 44, the rotary filter 3
When the is rotated, red transmission filters (abbreviated as R filters. The same applies to other filters) IR, G are placed in the optical path.
The filter IG, the B filter 1B, and the opening 2 will be interposed in this order, and therefore, the light guide 18 will have R, G, B, and W (white) as shown in FIG. 4(a). )
, R9... are irradiated with light of each wavelength.

The object illuminated with the light of each wavelength is
CC: D12 image area (see Figure 5) 5
1 is imaged, photoelectrically converted, and accumulated as charges during each illumination period as shown in FIG. 4(b). Therefore, during the period when light is blocked by the filter frame of the rotating filter 3,
The accumulated charges enter a transfer mode in which charges are transferred as shown in FIG. 4(C). This transfer mode is R, G,
This is carried out for the case of B illumination, but the charge accumulated under white illumination by the aperture 2 is swept out by the sweep mode as shown in FIG. 4(d) during the subsequent light-shielding period. A feature of this embodiment is that the signal is returned and removed without being input to the signal processing circuit 25 side.

The CCD 12 on which this sweeping is performed has a structure as shown in FIG. 5, for example.

The image area 51 consists of 200 pixels in the horizontal direction and 150 pixels in the vertical direction, and by applying a vertical pulse φp to this image area 51, 1 in each horizontal direction is
The 200 pixels for one line are transferred to the lower side of one line. In this case, the lowest horizontal pixel is the serial transfer register 52.
When the vertical pulse φp is applied to the serial transfer register 52, the data is transferred to the DUMP drain 53.

When the horizontal (transfer) pulse φS is applied, the serial transfer register 52 moves horizontally one pixel at a time,
The leftmost pixel is input to an amplifier 54, and this amplifier 5
After being amplified in step 4, the signal is output to the signal processing circuit 25 side.

When the R, G, B illumination period ends and the light shielding period begins, the CCD 12 stores the charges accumulated in each illumination period as shown in FIG.
The signal is output to the signal processing circuit 25 in a transfer mode as shown in C).

That is, in the transfer mode period, the vertical pulse φp becomes CC
D12 to shift one line in the vertical direction, and following this vertical pulse φp, 200 horizontal pulses φ
By applying S to the serial transfer register 52, signals of 200 pixels for one horizontal line are outputted from the CCD 12 via the amplifier 54.

When these 200 (i) horizontal pulses are applied, a vertical pulse φp is subsequently applied, and this pulse φp is followed by 200 horizontal pulses φS, which are applied to the horizontal line adjacent to the horizontal line.

Pixels are read out. In this way, by applying 150 vertical pulses φp and 200 horizontal pulses φS following each vertical pulse φp, one screen worth of image in the image area 51 is read out, and the image in the signal processing circuit 25 is read out. It is stored in one of the frame memories 31R, 31G, and 31B (31R in the case of R illumination).

On the other hand, the charge accumulated under the white (W) illumination through the aperture 2 enters the sweep mode as shown in FIG.
be swept away from

That is, only the vertical pulse φp is applied to the CCD 12 at high speed.
50 pulses are applied (the horizontal pulse φS, which is normally output following the vertical pulse φp, is not applied), and the charges for one screen of the image area 51 are discharged. (If one line remains in the serial transfer register 53, a reset pulse or a vertical pulse φp may be applied.)
In this way, during white illumination through the aperture 2, the CCD
Since the charge accumulated in 12 is discharged,
The lamp 42 does not require flashing of the lamp 42.
can have a longer lifespan.

In addition, sweeping can be done in a short time.

In the first embodiment, the image area 51 is, for example, 15
R, G for the case of 0x200 pixels.

Each illumination period of B is 5.5 ms, each charge transfer period is 4.5 ms, the illumination period by aperture 2 is 3 ms, and the n extraction period is 0.3 ms, and one frame is 33.3 m.
Although this example is for S, it can be similarly applied to other numbers of pixels.

The present invention is not limited to a field-sequential electronic scope, but can also be applied to a case where a field-sequential television camera with a built-in COD or the like is attached to the eyepiece of a fiber scope.

[Effects of the Invention] As described above, according to the present invention, since a means is provided for discharging the electric charge accumulated in the solid-state image sensor under white illumination through the aperture, it is possible to use a field sequential type scope. It is not necessary to blink the lamp even when

[Brief explanation of the drawing]

1 to 5 relate to one embodiment of the present invention, FIG. 1 is a detailed explanatory diagram of the present invention, FIG. 2 is a configuration diagram of one embodiment,
FIG. 3 is a schematic configuration diagram of a fiber scope, FIG. 4 is a timing chart for explaining the operation of the first embodiment, FIG. 5 is an explanatory diagram showing the general structure of a charge coupled device used in the first embodiment, and FIG. The figure is a front view showing a rotary filter used in a conventional example. 1R, IG, 1B...Color transmission filter 2...Aperture
3... Rotating filter 11... Endoscopy v1
Imaging device 12... CCD 13... Electronic scope 14... (scope) control device 15... Color monitor 16... Fiber scope 18... Light guide 19... Light source device 21...
...Objective lens 22...Image guide 25.
・Signal processing circuit 26 ・COD drive control circuit 51 ・Image guide 52 ・Serial transfer register procedure manual (spontaneous) January 26, 1985 1, Indication of incident 1988 patent Application No. 116407
No. 2, Name of the invention Endoscopic imaging device 3, Relationship to the case of person making corrections Patent applicant address 2-43-2, Habagaya, Shibuya-ku, Tokyo Name (037) Representative of Olympus Optical Industry Co., Ltd. Person: Satoshi Shimoyama, Department 4, Agent: 5, Date of amendment order: Voluntary) 6. Subject of amendment: Column 1 of "Detailed description of the invention" of the statement of intent, line 7 of page 13 of the specification. "...Register 53..." is replaced with "...Register 52..."
・Corrected to ``.

Claims (1)

[Claims] In an endoscope imaging device capable of capturing color images in a frame-sequential manner using an illumination means using a rotating filter provided with a plurality of filters that each pass light in a specific wavelength range and an aperture that passes incident light as is, An endoscope imaging device characterized by comprising a sweeping means for sweeping out signals imaged under illumination light passing through an aperture.