JP3182415B2 - Imaging device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus of a field sequential image pickup method with improved color shift and resolution.

[Prior art] In recent years, by inserting an elongated insertion portion into a body cavity,
2. Description of the Related Art Endoscopes (scopes or fiberscopes) capable of diagnosing and examining internal organs and the like are widely used. In addition to being used for medical purposes, it is also used for observing and inspecting an object in a pipe of a boiler, a machine, a chemical plant, or the like, or in a machine, for industrial use.

Further, various types of electronic endoscopes using a solid-state imaging device such as a charge-coupled device (CCD) as an imaging unit have been used.

An electronic endoscope apparatus using the electronic endoscope includes an electronic endoscope 101 as shown in FIG. The electronic endoscope 101 has an elongated, for example, flexible insertion section 102, and a large-diameter operation section 103 is connected to the rear end of the insertion section 102. A flexible universal cord 104 extends laterally from the rear end of the operation section 103, and a connector 105 is provided at the tip of the universal cord 104. The electronic endoscope 101 is connected via the connector 105 to a video processor 106 in which a light source device and a signal processing circuit are provided. Further, a monitor 107 is connected to the video processor 106.

On the distal end side of the insertion portion 102, a rigid distal end portion 109 and a bending portion 110 that can bend up and down / left and right, for example, are sequentially provided on the rear side adjacent to the distal end portion 109. By rotating a bending operation knob 111 provided on the operation section 103, the bending section 110 can be bent in the left-right direction or the up-down direction. Further, the operation unit 10
3 is provided with an insertion port 112 which communicates with a treatment instrument channel (not shown) provided in the insertion section.

As shown in FIG. 12, a light guide 114 for transmitting illumination light is inserted into the insertion section 102 of the electronic endoscope 101. The distal end portion of the light guide 114 is provided with the distal end portion 109 of the insertion section 102 so that illumination light can be emitted from the distal end portion 109. In addition, the entrance end face side of the light guide 114 is
And is connected to the connector 105. Further, an objective lens system 115 is provided at the distal end portion 109, and a solid-state imaging device 116, which is, for example, a charge-coupled device (CCD), is provided at an image forming position of the objective lens system 115. The solid-state imaging device 116 has sensitivity in a wide wavelength range from the visible region to the ultraviolet region and the infrared region. The solid-state imaging device 116
Are connected to signal lines 126 and 127, and these signal lines 126 and 127
Is internally provided in the insertion portion 102 and the universal cord 104 and is connected to the connector 105.

On the other hand, in the video processor 106, a lamp 121 that emits light in a wide band from ultraviolet light to infrared light is provided. As the lamp 121, a general xenon lamp, a strobe lamp, or the like can be used. The xenon lamp and the strobe lamp can emit not only visible light but also a large amount of ultraviolet light and infrared light. The lamp 121 is supplied with power from a power supply 122. A rotary filter 150 driven by a motor 123 is provided in front of the lamp 121. In the rotary filter 150, filters for transmitting light in the red (R), green (G), and blue (B) wavelength regions for normal observation are arranged along the circumferential direction.

Further, the rotation of the motor 123 is controlled and driven by a motor driver 125.

The light transmitted through the rotary filter 150 and separated in time series into light of each wavelength region of R, G, and B is further divided into the light guides.
The light is incident on the incident end face 114, is guided to the distal end portion 109 via the light guide 114, is emitted from the distal end portion 109, and illuminates an observation site as a subject.

The return light from the observation site due to the illumination light, that is, the subject image is formed on the photoelectric conversion surface of the solid-state imaging device 116 by the objective lens system 115, and is photoelectrically converted. The solid-state imaging device 116 includes the signal line 126
Via the driver circuit 1 in the video processor 106
A drive pulse from 31 is applied, and reading and transfer are performed by this drive pulse. A video signal read from the solid-state imaging device 116 is input to a preamplifier 132 provided in the video processor 106 or the electronic endoscope 101 via the signal line 127. . The video signal amplified by the preamplifier 132 is input to a process circuit 133, subjected to signal processing such as γ correction and white balance, and
According to 34, it is converted into a digital signal. The digital video signal is supplied by the select circuit 135 to three memories (1) 136a, memory (2) 136b, and memory (3) 136c corresponding to, for example, each color of red (R), green (G), and (B). Is selectively stored. The memory (1) 136a, the memory (2) 136b, and the memory (3) 13
6c are read out at the same time, and by the D / A converter 137,
The signal is converted to an analog signal, output as R, G, B color signals, and input to the encoder 138.
From 38 is output as an NTSC composite signal.

Then, the R, G, and B color signals or the NTSC composite signal are input to the monitor 107, and the monitor 107 displays the observation region in color.

In the video processor 106, a timing generator 142 for generating the timing of the entire system is provided, and the timing generator 142 synchronizes the motor driver 125, the driver circuit 131, and the select circuit 135 with each other. Is to be taken.

Therefore, one image is created using time-series signals of three colors of R, G, and B.

[Problems to be Solved by the Invention] However, in the above-described electronic endoscope apparatus, in order to improve the vertical resolution, when the solid-state imaging device is driven in a field accumulation mode and two-line simultaneous reading, an odd field and an even field are used. In order to capture two images of the field and to display them on the monitor 107 after the completion of the imaging, a time-series signal of three colors of R, G, and B is required for two periods. That is, as shown in FIG. 13, column A is read in the first cycle of R, G, B, and column B is read in the next cycle of R, G, B. For example, assuming that the accumulation period of an image of one color is a field period (1/60 second) equal to the vertical synchronization, it takes twice as long as three colors, that is, 1/10 second, in order to capture one image. Is required, which causes a problem that color shift is increased.

If the time required to capture one image is reduced to reduce the aforementioned color shift, the accumulation period of one color image is reduced to 1/6 of the time required to capture one image, resulting in reduced sensitivity. However, there is a problem that a dark subject cannot be projected.

On the other hand, in the case of imaging in the frame accumulation mode, since the columns A and B shown in FIG. 13 are alternately read, the cells in the columns not read continue to store optical information. Therefore, it is necessary to prevent interference by adjacent colors, and a light-blocking period during which illumination light is not applied must be provided. As a result, there is a problem that the time required to capture one image becomes longer as in the above-described field accumulation mode.

In the case where the time for capturing one image is set to be short, at least one of the columns A and B is read during one field period shown in FIG. Even fields are displayed on the monitor 107 by using an interpolation signal using captured information, and therefore, there is a problem that regular images are arranged every other row and the vertical resolution is reduced.

The present invention has been made in view of the above points, and shortens the time required to capture one image,
It is an object of the present invention to provide an imaging device with improved vertical resolution.

[Means for Solving the Problems] An image pickup apparatus according to the present invention provides a subject with at least first and second illumination lights in a predetermined wavelength range and different wavelengths from the first and second illumination lights. Illuminating means for sequentially irradiating a third illuminating light of a region and a fourth illuminating light of a wavelength region different from the first to third illuminating lights in chronological order; An imaging unit that sequentially captures a subject image irradiated in a time series with the fourth illumination light in each of the first to fourth illumination light irradiation periods and accumulates charges; (1) a first transfer unit for transferring the charge accumulated during the irradiation period of the second illumination light from the imaging unit during the irradiation period of the third illumination light; The charge accumulated during the irradiation period of the above is transferred from the imaging means during the irradiation period of the fourth illumination light. A second transfer unit, a third transfer unit configured to transfer the charge accumulated by the imaging unit during the third and fourth illumination light irradiation periods during the first illumination light irradiation period from the imaging unit; A fourth transfer unit configured to transfer charges accumulated by the imaging unit during the fourth and first illumination light irradiation periods during the second illumination light irradiation period from the imaging unit; and the first and third transfer operations. First luminance signal generating means for generating a predetermined luminance signal based on the electric charges transferred from the means, and a first luminance signal generating means for generating a predetermined color signal based on the electric charges transferred from the first and third transfer means. A second color signal generation unit, a second luminance signal generation unit that generates a predetermined luminance signal based on the electric charges transferred from the second and fourth transfer units, and the second and fourth transfer units. Second color signal generating means for generating a predetermined color signal based on the transferred electric charges; Video signal generating means for generating a predetermined video signal based on the luminance signal generated by the first and second luminance signal generating means and the color signal generated by the first and second color signal generating means And characterized in that:

In addition, an image pickup device according to the present invention includes an image pickup element for picking up an image of a subject, in which first and second pixel columns each having a plurality of pixels for accumulating electric charges are alternately arranged, and picks up an image using the image pickup element. The first and second illumination light at least in a predetermined wavelength region, the third illumination light in a wavelength region different from the first and second illumination light,
An illumination unit for sequentially irradiating and illuminating the fourth illumination light in a wavelength region different from the third illumination light in a time series, and the first pixel row of the imaging unit includes the first and second illumination lights. The charge accumulated during the irradiation period of the illumination light is transferred from the first pixel column to the third
A first transfer unit for transferring the illumination light during the irradiation period, and the second pixel column of the imaging unit stores the charge accumulated during the second and third illumination light irradiation periods in the second pixel column. A second transfer unit for transferring from the column during the irradiation period of the fourth illumination light, and an electric charge accumulated by the first pixel column of the imaging unit during the third and fourth illumination light irradiation periods, Third transfer means for transferring the light from the first pixel column during the irradiation period of the first illumination light;
A fourth transfer in which the charges accumulated in the second pixel column of the imaging unit during the irradiation periods of the fourth and first illumination lights are transferred from the second pixel column during the irradiation period of the second illumination light. Means, and electric charges transferred from the first and third transfer means,
First luminance signal generating means for generating a predetermined luminance signal;
First color signal generation means for generating a predetermined color signal based on the charges transferred from the first and third transfer means;
A second luminance signal generating means for generating a predetermined luminance signal based on the electric charges transferred from the second and fourth transfer means, and a charge transferred from the second and fourth transfer means, A second color signal generating means for generating a predetermined color signal, a luminance signal generated by the first and second luminance signal generating means, and a color generated by the first and second color signal generating means. Video signal generation means for generating a predetermined video signal based on the signal.

[Operation] With the above-described configuration, the illumination light of a plurality of colors is radiated in a time series, and the transfer of the electric charge from the image sequence of the image sensor is performed in a time series when a plurality of colors are combined. A luminance signal and a color signal are generated from each of the obtained charges for a plurality of colors to generate a video signal.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 to 4 relate to a first embodiment of the present invention,
FIG. 1 is a block diagram of an electronic endoscope device, FIG. 2 is an explanatory diagram of a rotation filter, FIG. 3 is an explanatory diagram of video signal processing, and FIG. 4 is an explanatory diagram of a solid-state imaging device.

In the imaging device, as shown in FIG. 1, a light guide 14 for transmitting illumination light is inserted through an insertion portion (not shown) of the electronic endoscope, as shown in FIG. The distal end surface of the light guide 14 is provided at the distal end 9 of the insertion section, and the illumination light can be emitted from the distal end 9.
Further, the incident end face side of the light guide 14 is provided inside a universal cord (not shown) and connected to a connector (not shown). Also, an objective lens system is provided at the tip 9.
A solid-state imaging device 16 which is, for example, a charge-coupled device (CCD) is provided at an image forming position of the objective lens system 15. The solid-state imaging device 16 has sensitivity in a wide wavelength range from the visible region to the ultraviolet region and the infrared region. Signal lines 26 and 27 are connected to the solid-state imaging device 16, and these signal lines 26 and 27 are provided inside the insertion portion and the universal cord, and are connected to the connector.

On the other hand, a lamp 21 that emits light in a wide band from ultraviolet light to infrared light is provided in the video processor.
As the lamp 21, a general xenon lamp, a strobe lamp, or the like can be used. The xenon lamp and the strobe lamp can emit not only visible light but also a large amount of ultraviolet light and infrared light. The lamp 21 is supplied with power from a power supply 22. A rotary filter 51 that is driven to rotate by a motor 23 is provided in front of the lamp 21. As shown in FIG. 2, the rotary filter 51 includes a filter 6 that passes light in the magenta (Mg) wavelength region for normal observation.
0, a filter 61 that transmits light in the yellow (Ye) wavelength region, a filter 62 that transmits light in the green (G) wavelength region, and a cyan (C
A filter 63 that transmits light in the wavelength range of y) is provided along the circumferential direction.

The rotation of the motor 23 is controlled and driven by a motor driver 25, as shown in FIG.

The light that has passed through the rotary filter 51 and is separated in time series into light in the respective wavelength regions of Mg, Ye, G, and Cy is further incident on the incident end face of the light guide 14 and passes through the light guide 14. The light is guided to the distal end portion 9, emitted from the distal end portion 9, and illuminates an observation site as a subject.

The return light from the observation site due to the illumination light, that is, the subject image is transmitted by the objective lens system 15 to the solid-state imaging device.
An image is formed on 16 photoelectric conversion surfaces, and the photoelectric conversion is performed. A driving pulse from a driver circuit 31 in the video processor is applied to the solid-state imaging device 16 via the signal line 26, and reading and transferring are performed by the driving pulse. The video signal read from the solid-state imaging device 16 is input to a preamplifier 32 provided in the video processor or the electronic endoscope via the signal line 27.
The video signal amplified by the preamplifier 32 is input to a process circuit 33, subjected to signal processing such as γ correction and white balance, and converted into a digital signal by an A / D converter. This digital video signal is supplied to, for example, magenta (M
g), four memories (1) 36a, memory (2) 36b, memory (3) 36c, and memory (4) 36d corresponding to each color of yellow (Ye), green (G), and cyan (Cy) Is stored. The memory (1) 36a, the memory (2) 36b,
The memory (3) 36c and the memory (4) 36d are read out simultaneously, and the output of the memory (1) 36a is input to the arithmetic circuit 55a and the arithmetic circuit 55c of the arithmetic unit 55, and the memory (2) 36d
The output of b is calculated by the arithmetic circuits 55b and 55d of the arithmetic unit 55.
The output of the memory (3) 36c is input to the arithmetic circuit 55a and the arithmetic circuit 55c of the arithmetic unit 55, and the output of the memory (4) 36d is The signals are input to the arithmetic circuit 55b and the arithmetic circuit 55d.

The output of the arithmetic circuit 55a and the output of the arithmetic circuit 55b are alternately switched by the switch 40 and output to the matrix circuit 41 as a luminance signal (Y).

The matrix circuit 41 further includes the arithmetic circuit 55c
Is output as a color difference signal (RY) by the arithmetic circuit 55d.
Are input as color difference signals (BY).

The matrix circuit 41 converts the luminance signal (Y) and the color difference signals (RY) and (BY) from R (red), G (green), and B (blue).
And outputs the color signal to the D / A converter 37.
The signal is converted into an analog signal by the converter 37, and R, G,
The signal is output as a B color signal, is input to an encoder 38, and is output from the encoder 38 as an NTSC composite signal.

Then, the R, G, B color signals or the NTSC composite signals are input to a monitor (not shown), and the monitor displays the observed part in color.

Further, a timing generator 42 for generating the timing of the entire system is provided in the video processor, and the timing generator 42 synchronizes the motor driver 25, the driver circuit 31, and the select circuit 35. It is supposed to be.

The operation of the imaging device configured as described above will be described.

The rotation of the motor 23 is controlled and driven by a motor driver 25. Accordingly, the rotation filter 51 is driven to rotate, and the light transmitted through the rotation filter 51 and separated in time series into light in the respective wavelength regions of Mg, Ye, G, and Cy is incident on the incident end face of the light guide 14. The light is guided to the distal end portion 9 via the light guide 14, and is emitted from the distal end portion 9 to illuminate an observation site as a subject.

The return light from the observation site due to the illumination light, that is, the subject image is formed on the photoelectric conversion surface of the solid-state imaging device 16 by the objective lens system 15 and is photoelectrically converted.

The solid-state imaging device 16 is driven in a frame accumulation mode by a driver 31, and is divided into an odd column A and an even column B, for example, as shown in FIG. The odd-numbered column A is read at timings A and C, which are the timings at which 62 and 63 change, and the even-numbered column B is read at timings B and D.

When the rotation filter 51 disperses the illumination light in the order of the filters 60, 61, 62, and 63, that is, when the illumination light is applied to the subject in the order of Mg, Ye, G, and Cy, at the time of the timing A, From the odd-numbered column A of the solid-state imaging device 16, from timing C to timing A
The read signal is a signal of a subject image sequentially irradiated with the illumination light of G and Cy, and at the timing B, the even-numbered column B of the solid-state imaging device 16 is read. From the timing D to the timing B, the read signal is a signal of a subject image sequentially irradiated with the illumination light of Cy and Mg. Signals accumulated from timing A to timing C are read from the odd column A of the image sensor 16, and the read signals are signals of a subject image sequentially irradiated with Mg and Ye illumination light. In the case of D,
From the even-numbered column B of the solid-state imaging device 16, signals accumulated from timing B to timing D are read, and the read signals are signals of a subject image sequentially irradiated with Ye, G illumination light. .

When the color information of the subject image at the timings A to D described above is arranged, A: G + Cy = 2G + B (1) B: Mg + Cy = R + G + 2B (2) C: Mg + Ye = 2R + G + B (3) D: Ye + G = R + 2G (4) The above-mentioned color information, that is, the signal from the solid-state imaging device 16 is pre-amplified by the preamplifier 32, and the process circuit
The signal is subjected to signal processing such as γ correction and white balance by 33, and is converted into a digital signal by an A / D converter 34. For example, a selector circuit is provided as a signal shown in FIG.
Entered into 35.

The selector circuit 35 is the solid-state imaging device converted into a digital signal by the A / D converter 34 as described above.
The signal from the memory 16 is sequentially output to the memory (1) 36a, the memory (2) 36b, the memory (3) 36c, and the memory (4) 36d in synchronization with the timings A to D described above.

Thus, the memory (1) 36a stores the color information of G + Cy at the timing A, for example, as shown in FIG. 3B, and the memory (2) 36b stores, for example, FIG. As shown in FIG. 3, the color information of Mg + Cy at the timing B is stored. The memory (3) 36c stores, for example, the color information of Mg + Ye at the timing C as shown in FIG. (4) In 36d, for example, color information of Ye + G at the timing D is stored as shown in FIG. 3 (E).

The following is a summary of the color information of the subject image at the timings A to D described above.

A: G + Cy = 2G + B (1) B: Mg + Cy = R + G + 2B (2) C: Mg + Ye = 2R + G + B (3) D: Ye + G = R + 2G (4) The aforementioned memory (1) 36a , Memory (2) 36b, memory (3)
The color information stored in the memory 36c and the memory (4) 36d are read out at the same time and output to the arithmetic unit 55 shown in FIG.

In the arithmetic unit 55, from the above-described equations (1) to (4),
The operation of the expression (5) described later is performed by the operation unit 55a, the operation of the expression (6) described later is performed by the operation circuit 55b, and the operation of the expression (7) described later is performed by the operation circuit 55c. The operation of Expression (8) is performed by the operation circuit 55d.

(1) + (3): (2G + B) + (2R + G + B) = 2R + 3G + 2B = Y (even) (5) (2) + (4): (R + G + 2B) + (R + 2G) = 2R + 3G + 2B = Y (odd) (6) (3)-(1): (2R + G + B)-(2G + B) = 2R-G = RY (7) (2)-(4): (R + G + 2B)-(2G + R) =-G + 2B = BY (8) Equation (5) described above is obtained from a signal obtained when the odd columns of the solid-state imaging device 16 are read, and becomes a luminance signal (Y) of an odd field. 6) is obtained from a signal when the even-numbered column B of the solid-state imaging device 16 is read out, and becomes a luminance signal (Y) of an even-numbered field. The above-described equations (7) and (8) are used for the solid-state imaging device 16. Are obtained from signals when the odd-numbered column A and the even-numbered column B are read out, and become color difference signals of both fields.

The outputs of the arithmetic circuits 55a and 55b are output to the matrix circuit 41 by the switch 40 as a luminance signal (Y) corresponding to the field. The outputs of the arithmetic circuits 55c and 55d are output to the matrix circuit 41 as color difference signals (RY) and (BY).

The matrix circuit 41 converts the input luminance signal and color difference signal into R, G, B original signals as described above, and the R, G, B original signals are converted into analog signals by the D / A converter 37. , And output as R, G, B color signals, as well as input to an encoder 38, which outputs an NTSC composite signal.

Accordingly, the luminance signals (Y) obtained by the above-described equations (5) and (6) become different luminance signals (Y) in the odd column A and the even column B shown in FIG. Since all the columns of all 16 imaging cells are used, the vertical resolution is improved. Further, the color difference signal (RY) obtained by the above-described equation (7) is a signal using an odd number of imaging cell columns of the solid-state imaging device 16, and the color difference signal (RY) obtained by the above-described equation (8) is obtained. (BY) uses an even number of imaging cell columns of the solid-state imaging device 16. However, the color information has less influence on the visual sense than the luminance information, and the influence on the vertical resolution is small even if the information of the odd-numbered column A and the even-numbered column B is the same.

Further, the horizontal resolution is the odd-numbered row A of the solid-state imaging device 16.
And all the even-numbered rows B, that is, all the imaging cells of the solid-state imaging device 16 are used.

That is, there is an effect that the vertical resolution and the horizontal resolution of one screen can be improved.

Further, one image can be captured by the four-color filters, the time required to capture one image can be reduced, and since the four-color filters have a complementary color relationship, the luminance signal ( For Y), the filter accumulated over the entire circumference of the filter 51 can be used, and there is an effect that the imaging sensitivity can be improved.

5 to 7 relate to a second embodiment of the present invention.
FIG. 5 is a block diagram of an electronic endoscope apparatus, FIG. 6 is an explanatory diagram of a rotation filter, and FIG. 7 is an explanatory diagram of video signal processing. Note that the same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

The imaging device of the present embodiment is different from the rotation filter of the electronic endoscope device described in the first embodiment in that the rotation filter 52 includes:
An arithmetic unit 56 is provided instead of the arithmetic unit.

As shown in FIG. 6, the rotary filter 52 is a filter 64, 64, which transmits light in the green (G) wavelength region for normal observation.
A filter 65 that transmits light in the wavelength region of yellow (Ye) and a filter 66 that transmits light in the wavelength region of cyan (Cy) are arranged along the circumferential direction.

Memory (1) 36a, memory (2) 36b, memory (3) 36c,
As shown in FIG. 5, the memory (4) 36d is read simultaneously, and the output of the memory (1) 36a is input to the arithmetic circuits 56a, 56c and 56d of the arithmetic unit 56,
The output of the memory (2) 36b is input to the arithmetic circuit 56b, the arithmetic circuit 56c, and the arithmetic circuit 56d of the arithmetic unit 56, and the output of the memory (3) 36c is the arithmetic circuit of the arithmetic unit 56. 56a, the arithmetic circuit 56c, and the arithmetic circuit 56d, and the output of the memory (4) 36d is
The arithmetic circuit 56b, the arithmetic circuit 56c, and the arithmetic circuit 56
d and are to be entered.

The output of the arithmetic circuit 56a and the output of the arithmetic circuit 56b are alternately switched by the switch 40 and output to the matrix circuit 41 as a luminance signal (Y).

The matrix circuit 41 further includes the arithmetic circuit 56c
Is input as a color signal (2R), and the output of the arithmetic circuit 56d is input as a color signal (2B).

The matrix circuit 41 generates R (red), G (green), and B (blue) color signals from the luminance signal (Y) and the color signals (2R) and (2B).

The operation of the thus configured electronic endoscope apparatus will be described.

The selector circuit 35 converts the signals from the solid-state imaging device 16 shown in FIG. 7A converted into digital signals by the A / D converter 34 into timings A to 64 at which the filters 64, 65, 66, 64 of the rotary filter 52 are switched. In synchronization with D, memory (1) 36a,
The data is sequentially output to the memory (2) 36b, the memory (3) 36c, and the memory (4) 36d.

Thus, the memory (1) 36a stores the color information of G + Cy at the timing A, for example, as shown in FIG. 7B, and the memory (2) 36b stores, for example, FIG. As shown in FIG. 7, G + G color information at the timing B is stored, and the memory (3) 36c stores G + Ye color information at the timing C as shown in FIG. (4) The color information of Ye + Cy at the timing D is stored in 36d, for example, as shown in FIG. 7 (E).

The color information of the subject image at the timings A to D described above is arranged as follows.

A: G + Cy = 2G + B (9) B: G + G = 2G (10) C: G + Ye = R + 2G (11) D: Ye + Cy = R + 2G + B (12) The memory (1) 36a , Memory (2) 36b, memory (3)
The color information stored in the memory 36c and the memory (4) 36d are read out at the same time and output to the arithmetic unit 56 shown in FIG.

In the arithmetic unit 56, from the equations (9) to (12) described above,
The operation of the expression (13) described later is performed by the operation unit 56a, the operation of the expression (14) described later is performed by the operation circuit 56b, and the operation of the expression (15) described later is performed by the operation circuit 56c. The operation of Expression (16) is performed by the operation circuit 56d.

(9) + (11): (2G + B) + (R + 2G) = R + 4G + B = Y (even) (13) (10) + (12): (2G) + (R + 2G + B) = R + 4G + B = Y (odd) ( 14) {(11)-(9)} + {(10)-(12)}: (RB) + (R + B) = 2R (15) {(10)-(12)}-｝ (11) − (9)｝: (R + B) − (R−B) = 2B (16) The above-described equation (13) indicates that the odd-numbered row A of the solid-state imaging device 16 is obtained.
Is obtained from the signal when reading out, and becomes the luminance signal (Y) of the odd-numbered field. The above-mentioned equation (14) is obtained from the signal when reading out the even-numbered column B of the solid-state imaging device 16,
The luminance signal (Y) of the even field is obtained, and the above-described equations (15) and (16) are obtained from the signal obtained when the odd column A and the even column B of the solid-state imaging device 16 are read out. Becomes

The outputs of the arithmetic circuits 56a and 56b are output to the matrix circuit 41 by the switch 40 as a luminance signal (Y) corresponding to the field. The outputs of the arithmetic circuits 56c and 56d are output to the matrix circuit 41 as color signals (2R) and (2B).

The matrix circuit 41 converts the input luminance signal and chrominance signal into R, G, B original signals as described above.
The R, G, and B original signals are converted to analog signals by a D / A converter 37, output as R, G, and B color signals, and input to an encoder 38, and output from the encoder 38 as an NTSC composite signal. You.

That is, in this embodiment, a filter that transmits the same wavelength region is used.
64, 64 can be used, and there is an effect that the number of types of filters can be reduced.

Other configurations, operations and effects are the same as those of the above-described embodiment.

8 to 10 relate to a third embodiment of the present invention.
FIG. 8 is a block diagram of the electronic endoscope device, FIG. 9 is an explanatory diagram of a rotation filter, and FIG. 10 is an explanatory diagram of video signal processing. Note that the same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

The imaging device according to the present embodiment includes a rotation filter 53 instead of the rotation filter of the electronic endoscope apparatus described in the first embodiment.
An arithmetic unit 57 is provided in place of the arithmetic unit.

As shown in FIG. 9, the rotary filter 53 includes filters 67 and 67 that transmit light (W) in the entire wavelength range for normal observation, a filter 68 that transmits light in the yellow (Ye) wavelength range, and cyan ( C
A filter 69 that transmits light in the wavelength region of y) is provided along the circumferential direction.

Memory (1) 36a, memory (2) 36b, memory (3) 36c,
As shown in FIG. 8, the memory (4) 36d is read simultaneously, and the output of the memory (1) 36a is input to the arithmetic circuit 57a, the arithmetic circuit 57c, and the arithmetic circuit 57d of the arithmetic unit 57,
The output of the memory (2) 36b is input to the arithmetic circuit 57 of the arithmetic unit 57, the arithmetic circuit 57c, and the arithmetic circuit 57d, and the output of the memory (3) 36c is the arithmetic circuit of the arithmetic unit 57. 57a, the arithmetic circuit 57c, and the arithmetic circuit 57d, and the output of the memory (4) 36d is
The arithmetic circuit 57b, the arithmetic circuit 57c, and the arithmetic circuit 57
d and are to be entered.

The output of the arithmetic circuit 57a and the output of the arithmetic circuit 57b are alternately switched by the switch 40 and output to the matrix circuit 41 as a luminance signal (Y).

The matrix circuit 41 further includes the arithmetic circuit 57c
Is input as a color signal (2R), and the output of the arithmetic circuit 57d is input as a color signal (2B).

The matrix circuit 41 generates R (red), G (green), and B (blue) color signals from the luminance signal (Y) and the color signals (2R) and (2B).

The operation of the thus configured electronic endoscope apparatus will be described.

The selector circuit 35 converts the signals from the solid-state imaging device 16 shown in FIG. 10A converted into digital signals by the A / D converter 34 into timings A to 67 at which the filters 67, 68, 69, 67 of the rotary filter 53 are switched. In synchronization with D, memory (1) 36a,
The data is sequentially output to the memory (2) 36b, the memory (3) 36c, and the memory (4) 36d.

Thus, the memory (1) 36a stores the color information of W + Cy at the timing A, for example, as shown in FIG. 10 (B), and the memory (2) 36b, for example, as shown in FIG. 10 (C). As shown in FIG. 10, the color information of W + W at the timing B is stored. The memory (3) 36c stores the color information of W + Ye at the timing C as shown in FIG. (4) In 36d, for example, as shown in FIG. 10 (E), color information of Ye + Cy at timing D is stored.

The color information of the subject image at the timings A to D described above is arranged as follows.

A: W + Cy = R + 2G + 2B (17) B: W + W = 2R + 2G + 2B (18) C: W + Ye = 2R + 2G + B (19) D: Ye + Cy = R + 2G + B (20) The memory (1) 36a , Memory (2) 36b, memory (3)
The color information stored in the memory 36c and the memory (4) 36d is read out at the same time and output to the arithmetic unit 57 shown in FIG.

In the arithmetic unit 57, from the above equations (17) to (20),
The operation of the expression (21) described later is performed by the operation unit 57a, the operation of the expression (22) described later is performed by the operation circuit 57b, and the operation of the expression (23) described later is performed by the operation circuit 57c. The operation of Expression (24) is performed by the operation circuit 57d.

(17) + (19): (R + 2G + 2B) = (2R + 2G + B) = 3R + 4G + 3B = Y (even) (21) (18) + (20): (2R + 2G + B) + (R + 2G + B) = 3R + 4G + 3B = Y (odd) ... ( 22) {(19)-(17)}-{(18)-(20)}: (RB) + (R + B) = 2R ... (23) {(18)-(20)}-｛ (19) − (17)｝: (R + B) − (R−B) = 2B (24) Equation (21) is obtained by calculating the odd-numbered row A of the solid-state imaging device 16.
Is obtained from the signal when reading out, and becomes the luminance signal (Y) of the odd-numbered field. The above-mentioned equation (22) is obtained from the signal when reading out the even-numbered column B of the solid-state imaging device 16,
The luminance signal (Y) of the even field is obtained, and the above-mentioned equations (23) and (24) are obtained from the signal obtained when the odd column A and the even column B of the solid-state imaging device 16 are read out. Becomes

The outputs of the arithmetic circuits 57a and 57b are output to the matrix circuit 41 by the switch 40 as a luminance signal (Y) corresponding to the field. The outputs of the arithmetic circuits 57c and 57d are output to the matrix circuit 41 as color signals (2R) and (2B).

The matrix circuit 41 converts the input luminance signal and chrominance signal into R, G, B original signals as described above.
The R, G, and B original signals are converted to analog signals by a D / A converter 37, output as R, G, and B color signals, and input to an encoder 38, and output from the encoder 38 as an NTSC composite signal. You.

That is, in this embodiment, there is an effect that the filters 67, 67 that transmit all the wavelength regions can be used.

Other configurations, operations and effects are the same as those of the above-described embodiment.

The rotation cycle of the rotation filter is preferably one frame cycle, but may be an appropriate cycle depending on the control of the memory and the method of reading the solid-state imaging device.

Further, the operation unit and the matrix circuit may be provided at the subsequent stage of the D / A converter, and the operation may be performed by an analog signal.

Further, even when the position of the filter disposed in the rotary filter and the rotation direction of the rotary filter are changed, the same operation is obtained by changing the calculation circuit of the calculation unit and the calculation formula of the calculation circuit. It may be.

Further, the R and B color signals input to the matrix circuit may be obtained by an arithmetic circuit using another equation.

[Effects of the Invention] As described above, according to the present invention, a plurality of colors of illumination light are radiated in a time series, and the transfer of charges from the pixel columns of the image sensor is performed in a time series To improve the vertical resolution without affecting sensitivity and color shift by generating a luminance signal color signal from each of the electric charges for a plurality of colors obtained in the time series and generating a video signal. And an effect that one image can be created in a short time can be obtained.

[Brief description of the drawings]

1 to 4 relate to a first embodiment of the present invention, FIG. 1 is a block diagram of an electronic endoscope apparatus, FIG. 2 is an explanatory view of a rotary filter, and FIG. 3 is an explanation of video signal processing. Figure,
FIG. 4 is an explanatory view of a solid-state image sensor, FIGS. 5 to 7 relate to a second embodiment of the present invention, FIG. 5 is a block diagram of an electronic endoscope apparatus, and FIG. FIGS. 7 and 8 are explanatory diagrams relating to video signal processing, FIGS. 8 to 10 relate to a third embodiment of the present invention, FIG. 8 is a block diagram of an electronic endoscope apparatus, and FIG. FIG. 10 is an explanatory diagram relating to video signal processing, FIGS. 11 to 13 are related to the prior art, FIG. 11 is a configuration diagram of an electronic endoscope device, FIG.
FIG. 12 is a block diagram of an electronic endoscope apparatus, and FIG. 13 is an explanatory diagram of a solid-state imaging device. 16 ... Solid-state image sensor 31 ... Driver 51 ... Rotating filter

Claims (2)

(57) [Claims] A first illumination light having at least a predetermined wavelength region, a third illumination light having a wavelength region different from the first and second illumination light, and Illuminating means for sequentially and chronologically irradiating fourth illumination light of a wavelength region different from the first to third illumination lights, and the first to fourth illumination lights from the illumination means are sequentially
Imaging means for capturing an image of a subject illuminated in time series during each of the first to fourth illumination light irradiation periods and accumulating electric charges; and wherein the imaging means irradiates the first and second illumination light. A first transfer unit that transfers the charge accumulated in the period during the irradiation period of the third illumination light from the imaging unit; and a charge that the imaging unit accumulates during the irradiation period of the second and third illumination light, A second transfer unit for transferring during the irradiation period of the fourth illumination light from the imaging unit; and a charge accumulated by the imaging unit during the irradiation periods of the third and fourth illumination lights from the imaging unit to the first transfer unit. A third transfer unit that transfers the illumination light during the irradiation period; and an image pickup unit that transfers the charges accumulated during the fourth and first illumination light irradiation periods from the imaging unit during the second illumination light irradiation period. A fourth transfer unit that transfers the charges based on the charges transferred from the first and third transfer units. First luminance signal generating means for generating a predetermined luminance signal; first color signal generating means for generating a predetermined color signal based on the electric charges transferred from the first and third transfer means; A second luminance signal generation unit that generates a predetermined luminance signal based on the electric charges transferred from the second and fourth transfer units; and a second luminance signal generation unit based on the electric charges transferred from the second and fourth transfer units. A second color signal generation unit for generating a predetermined color signal; a luminance signal generated by the first and second luminance signal generation units; and a color generated by the first and second color signal generation units. An image pickup apparatus comprising: a video signal generation unit configured to generate a predetermined video signal based on a signal. 2. An image pickup device for picking up an image of a subject, wherein first and second pixel columns each having a plurality of pixels for accumulating electric charges are alternately arranged, and an image pickup device for picking up an image by the image pickup device. On the other hand, at least first and second illumination lights in a predetermined wavelength region, third illumination light in a wavelength region different from the first and second illumination lights, and the first to third illumination lights Illuminating means for sequentially irradiating and illuminating a fourth illumination light in a wavelength region different from that in the time series, and wherein the first pixel column of the imaging means is in the irradiation period of the first and second illumination light A first transfer unit that transfers the electric charge accumulated in the first pixel column during the irradiation period of the third illumination light from the first pixel column, and the second pixel column of the imaging unit performs the second and third illumination. The second step of transferring the charge accumulated during the light irradiation period from the second pixel column during the fourth irradiation light irradiation period. Transfer means; and transferring, from the first pixel row, the charge accumulated by the first pixel row of the imaging means during the third and fourth illumination light irradiation periods during the first illumination light irradiation period. A third transfer unit that irradiates the second pixel row of the imaging unit with the charge accumulated during the irradiation period of the fourth and first illumination light from the second pixel row by the second illumination light A fourth transfer unit that transfers the data in a period, a first brightness signal generation unit that generates a predetermined brightness signal based on the charge transferred from the first and third transfer units, A first color signal generating means for generating a predetermined color signal based on the charges transferred from the transfer means, and a predetermined luminance signal based on the charges transferred from the second and fourth transfer means A second luminance signal generating unit that performs the operation based on the charges transferred from the second and fourth transfer units. A second color signal generating means for generating a predetermined color signal; a luminance signal generated by the first and second luminance signal generating means; and a luminance signal generated by the first and second color signal generating means. And a video signal generating means for generating a predetermined video signal based on the color signal.