Abstract: To provide a timing generator which generates a first reference signal at a standard speed of approximately 14 MHz and a second reference signal operating at approximately 28 MHz which is double the standard speed and forms a moving image based on the first reference signal, reads, when a freeze switch is operated, an image pickup signal based on the second reference signal operating at the double speed and writes this signal into the memory 36 at the same speed. Then, by reading this still image signal from the memory at the standard speed, the still image is displayed on the monitor. Thereby, the need for setting a conventional light shielding period can be eliminated.

Abstract: With a device that connects a processor device to electronic endoscopes having CCDs with different numbers of pixels, for example, 410, 270, or 190 thousand pixels mounted thereon, all the CCDs are driven at a frequency corresponding to 410 thousand pixels. Further, an information amount converting circuit enlarges an image obtained by the CCD with 270 or 190 thousand pixels in a horizontal direction and a vertical direction by using pixel interpolation. That is, data on a pixel to be interpolated is calculated by averaging pixels around this pixel, and enlarged binary data on this target pixel is obtained. A weighting factor is applied to this binary data, and the resultant data is added to the target pixel data. This process forms an image with an aspect ratio of 4:3.

Abstract: To provide a first memory for storing an odd field data, a second memory for storing an even field data acquired in an NTSC system, a third memory for storing the same video data stored in the first and second memories, and a TV standard conversion circuit. For the data in a period for which a writing of a next data overtakes reading of the data from the first memory or the second memory, a writing into the third memory is inhibited, and the data is read from the third memory, whereby the signal of the NTSC system is converted into the signal of a PAL system. In this manner, an excellent video is displayed on a PAL monitor without any the bar noise.

Abstract: An electronic endoscopic apparatus having various sorts of electronic endoscopes mounting a CCD with a different number of pixels, for example, 410,000 pixels, 270,000 pixels or 190,000 pixels that are connectable to a processor. A CCD drive and signal processing circuit drives all the CCDs at a frequency set up for the CCD with 410,000 pixels, and an information quantity conversion circuit expands an image acquired by the CCD with 270,000 pixels or 190,000 pixels by pixel interpolation in a horizontal direction or a vertical direction to form an image with an aspect ratio of 4 to 3. Also, a video signal acquired in an NTSC system is converted into a video signal of a PAL system by using a television standard conversion circuit, thereby displaying an excellent PAL video without any bar noise.

Abstract: In an electronic endoscope using an imaging element comprising a colour filter for pixel binning, it is possible to carry out outline enhancement processing, zoom processing, and the like, to a high degree of detail. An optical chopper 36 in the form of a semi-circular plate is caused to rotate at {fraction (1/30)}th second per revolution, and images are captured in time periods of {fraction (1/60)}th second separated by light shielding intervals of {fraction (1/60)}th second. An imaging signal for the odd-numbered lines and the even-numbered lines is read out successively from the imaging element at {fraction (1/60)}th second intervals, and stored in memories 23 and 24, respectively.

Abstract: The circuit according to the present invention is a signal transmission circuit for a solid-state image pickup device which performs favorable signal transmission by suppressing heat production around an image pickup device to a minimum level. This circuit is used for transmitting video signals output from a CCD to a signal processor of a processing unit by way of a transmission line, and comprises, at a stage subsequent to the CCD, a complementary circuit composed of two current controlling diodes, a first transistor, a second transistor and a plurality of resistors. This complementary circuit operates the first transistor and the second transistor alternately, thereby outputting video signals from the CCD as positive and negative signals taking 10 V, for example, as standard. Such an operation of class B eliminates a necessity to supply a bias current, thereby preventing heat production from the transistors and resistors due to application of a bias current.

Abstract: A video signal and a control signal are converted into a radio frequency based on a radio communication method. This radio frequency is used to execute wired communications via one coaxial cable provided between a scope and a processor device. Furthermore, an electromagnetic coupling means composed of a primary coil and a secondary coil is provided between a connector and a light source device. The electromagnetic coupling means supplies power to the scope on the basis of electromagnetic induction. It is thus possible to connect the scope to both the processor device and the light source device using only two wires including a ground line. This makes it possible to prevent the inappropriate connection of or possible damage to connection pins or the like.

Abstract: In a first signal suppressing process, in cases where a signal level of a certain color signal among color signals obtained from an image sensing operation is higher than a predetermined signal level, the certain color signal is suppressed. An image sensing operation with a comparatively large exposure quantity and an image sensing operation with a comparatively small exposure quantity are performed alternately. It is detected that suppression of a certain color signal is performed in the first signal suppressing process when the image sensing operation with a comparatively large exposure quantity is performed. A calculation is made to find composition ratios of the color signals, which are obtained from the image sensing operation with a comparatively small exposure quantity. A second signal suppressing process is performed for suppressing at least one color signal other than the certain color signal such that the composition ratios become identical with the calculated composition ratios.

Abstract: There is provided a light shielding plate to shield light from a light source lamp, and this light shielding plate is rotated and driven by a light shielding plate drive circuit, and a charge stored in a CCD for a period of, for example, 20H at a start of an effective period J of a vertical scanning period, is discharged and this is set as a non-operating period and a drive control over the light shielding plate for a period of 40.5H which is a sum of this non-operating period and a blanking period B (20.5H) is performed. This provides an adequate margin of time for controlling the light shielding plate at starting and stopping times and makes the drive control easier.

Abstract: To provide a timing generator which generates a first reference signal at a standard speed of approximately 14 MHz and a second reference signal operating at approximately 28 MHz which is double the standard speed and forms a moving image based on the first reference signal, reads, when a freeze switch is operated, an image pickup signal based on the second reference signal operating at the double speed and writes this signal into the memory 36 at the same speed. Then, by reading this still image signal from the memory at the standard speed, the still image is displayed on the monitor. Thereby, the need for setting a conventional light shielding period can be eliminated.

Abstract: There is provided a light shielding plate to shield light from a light source lamp, and this light shielding plate is rotated and drived by a light shielding plate drive circuit, and a charge stored in a CCD for a period of, for example, 20H at a start of an effective period J of a vertical scanning period, is discharged and this is set as a non-operating period and a drive control over the light shielding plate for a period of 40.5H which is a sum of this non-operating period and a blanking period B (20.5H) is performed. This provides an adequate margin of time for controlling the light shielding plate at starting and stopping times and makes the drive control easier.

Abstract: An imaging device for an endoscope which can restrain the flicker of a screen caused when converting the television system, and furthermore, which makes it possible to unify processor circuits performing the processing of different systems. Having an NTSC system oscillator and a PAL oscillator with an oscillating frequency of N·fh2, and a switching device for selecting them in a scope equipped with a CCD suitable for the number of scanning lines, for example, of the NTSC system, and it drives the CCD on the basis of a timing signal formed in each of the selected oscillators. That is, when the PAL system is selected, the picture data is taken out from the CCD by a horizontal synchronization signal with a frequency of 15.

Abstract: With a device that connects a processor device to electronic endoscopes having CCDs with different numbers of pixels, for example, 410, 270, or 190 thousand pixels mounted thereon, all the CCDs are driven at a frequency corresponding to 410 thousand pixels. Further, an information amount converting circuit enlarges an image obtained by the CCD with 270 or 190 thousand pixels in a horizontal direction and a vertical direction by using pixel interpolation. That is, data on a pixel to be interpolated is calculated by averaging pixels around this pixel, and enlarged binary data on this target pixel is obtained. A weighting factor is applied to this binary data, and the resultant data is added to the target pixel data. This process forms an image with an aspect ratio of 4:3.

Abstract: An electronic endoscopic apparatus having various sorts of electronic endoscopes mounting a CCD with a different number of pixels, for example, 410,000 pixels, 270,000 pixels or 190,000 pixels that are connectable to a processor. A CCD drive and signal processing circuit drives all the CCDs at a frequency set up for the CCD with 410,000 pixels, and an information quantity conversion circuit expands an image acquired by the CCD with 270,000 pixels or 190,000 pixels by pixel interpolation in a horizontal direction or a vertical direction to form an image with an aspect ratio of 4 to 3. Also, a video signal acquired in an NTSC system is converted into a video signal of a PAL system by using a television standard conversion circuit, thereby displaying an excellent PAL video without any bar noise.

Abstract: With an electronic endoscope, a wide band video signal is output to connected instruments without giving electric shocks to a body even when the connected instruments are not insulated. The video signal V is converted to differential signals V1, V2 by a differential amp 31 and input to buffers 42, 43 via capacitors 32, 33. The clamp signal CP generated by the clamp signal output means 44 is input to the end terminals of the switches SW1, SW2 via the photocoupler 46. The differential signals V1, V2 undergo pulse clamping in the buffers 42, 43 and the DC components are restored. The video signal restoring portion 49 restores the video signal V on the basis of the differential signals V1, V2 having undergone DC restoration and outputs the video signals to the connected instruments.

Abstract: To provide a first memory for storing an odd field data, a second memory for storing an even field data acquired in an NTSC system, a third memory for storing the same video data stored in the first and second memories, and a TV standard conversion circuit. For the data in a period for which a writing of a next data overtakes reading of the data from the first memory or the second memory, a writing into the third memory is inhibited, and the data is read from the third memory, whereby the signal of the NTSC system is converted into the signal of a PAL system. In this manner, an excellent video is displayed on a PAL monitor without any the bar noise.

Abstract: An electronic endoscope system that provides, even when it uses a halogen lamp, an image having a brightness equal to that of an image obtained with a xenon lamp. The electronic endoscope system leads rays emitted from a halogen lamp to the tip of an electronic endoscope through a light guide, picks up an internal image of an object to be observed with a CCD through an objective optical system and reads out twice each of an odd field signal and an even field signal successively when a slow scan mode is selected. The odd or even field signal from each field is delayed by a delay memory in a luminance enhancement circuit, and the same field signals are added by an adder. The electronic endoscope system performs image processing of an addition signal thus obtained as a single odd or even field signal, thereby being capable of enhancing the luminance signal, for example, to a level twice as high.

Abstract: A light source device for an endoscope is capable of selecting a reading method between a method utilizing a light shading period and a method doing without a light shading period. It is possible to adopt both the new reading method and the conventional reading method. A rotary shutter is composed of, for example, a disk with a light passing portion for securing a light source path and a light shading portion formed on the outer peripheral portion, and a DC motor rotates and stops the rotary shutter. When the electronic endoscope apparatus to which the light source device is applied is of an all-pixels reading type, the rotation mode in which light is output during a predetermined light shading period at intervals of 1/30 sec is set. When the light source device is applied to a conventional electronic endoscope apparatus, for example, of a pixel mixture signal reading type system, the stop mode in which the illuminating light is not shaded is set.

Abstract: A connector guide structure for electronic endoscope systems capable of efficiently eliminating high-frequency noises which are allowed by a connector guide functioning as an antenna to mix by way of sheath members and a console. The connector guide structure comprises a connector guide for connecting a connector disposed on an electronic endoscope to a main unit, and noise eliminating capacitors are connected between the connector guide and a console of the main unit. A capacitor for eliminating noises produced by a radio knife and a plurality of capacitors for eliminating noises produced by clock-frequency signals are used as the capacitors. Feet of the capacitors are directly connected within an interval of 4 mm to 20 mm which is reserved between the connector guide and the console. Accordingly, the connector guide structure is capable of favorably eliminating not only the noises produced by the radio knife but also the noises produced by providing clock-frequency signals.

Abstract: An electronic endoscope apparatus has an illumination unit for irradiating light of red, light of green and light of blue on an object for photographing in predetermined order at a predetermined period; an image signal generation unit for receiving reflection light from the object, generating a field sequential image signal on the basis of the received reflection light and delivering the field sequential digital image signal; a first memory unit for forming a predetermined look up table; a red data memory unit for storing data of a red image signal by one field; a green data memory unit for storing data of a green image signal by one field; a blue data memory unit for storing data of a blue image signal by one field, one field from the first memory unit being stored in one of the data memory unit for red, green and blue in synchronism with the order and the predetermined period of color illumination by the illumination unit; a switching unit for reading data from one of said data memory unit in synchronism wi