Abstract: A light-source driver for a light-source unit detachable from an endoscope body of a portable endoscope is provided. The light-source driver includes a first switch, a pilot lamp, a warning lamp, a second switch, and a light-switching block. The first switch switches its status between the On-state and Off-state in connection with the attachment and detachment of the light-source unit to the endoscope body. The pilot lamp indicates that the illumination light source is being energized. The warning lamp indicates that the output voltage of a battery has dropped below a predetermined value. The second switch switches the status of the warning lamp between the On-state and Off-state in connection with the On-state and the Off-state of the first switch. The light-switching block switches the pilot lamp to the Off-state and further enables the second switch when the second switch is set to the On-state and the output voltage has declined to or below the predetermined value.

Abstract: An autofluorescence endoscope system including first and second exciting light sources, an exciting-light cut-off filter, an imaging device, a light-source controller, and an imaging device driver, is provided. The first and second exciting light sources emit first and second exciting light, respectively. The wavelengths of the first and second exciting lights range in a first and second band, respectively. The first and second exciting lights make an organ autofluoresce. The wavelength in the second band is longer than that of the first band. The exciting-light cut-off filter attenuates a light component at least of the first or second band from an optical image. The imaging device captures an optical image of the subject passing the exciting-light cut-off filter. The light-source controller controls the first and second exciting light sources.

Abstract: An endoscopic system includes an endoscopic device having a light guide passing therethrough to a distal end thereof, a light source in communication with the endoscopic device, the light source transmitting illumination light to the light guide, a light source controller in communication with the light source, the light source controller controlling an intensity of the illumination light transmitted to the light guide, and at least one temperature sensor, at least a portion of which is carried by the endoscopic device. The temperature sensor senses a temperature of at least a portion of the endoscopic device and produces a signal indicative of the sensed temperature, the signal being transmitted to the light source controller. The light source controller varies the intensity of the illumination light transmitted to the light guide based at least in part upon the signal indicative of the sensed temperature.

Abstract: A lighting device for an electronic endoscope system, includes a light source; a set of rotary shutters having at least two rotary shutters, having a rotational axis parallel to an optical axis of the light source, the rotary shutters alternately intercepting incident illuminating light emitted from the light source and allowing the incident illuminating light to pass through the set of rotary shutters to proceed toward a light guide, wherein the rotary shutters are associated with each other to be capable of integrally rotating about the rotational axis, each of the rotary shutters having at least one light-shielding portion and at least one opening; and an adjusting device which rotates one of the rotary shutters relative to the other to change an opening angle of each opening to adjust an amount of illuminating light which passes through the set of rotary shutters.

Abstract: An endoscopic apparatus having an image pickup system operating as follows. Before picking up a still image in a body cavity that almost no light can reach, the system extinguishes LED and resets charges accumulated in respective pixels in a CMOS image sensor. In this reset state, the system illuminates LED and allows the CMOS image sensor to pick up a still image. While the charges are being read from the pixels, the system extinguishes LED and prevents further charges from being accumulated in the pixels from which the charges have not been read yet.

Abstract: An endoscope system of the present invention has a video processor and a light source device, and an endoscope can be connected thereto. And a control portion of the light source device detects connection with the endoscope and the video processor, detects connection with the video processor and the light source device and detects the type of the endoscope by an endoscope detection portion. And when non-connection of the endoscope and the video processor is detected, or non-connection of the video processor and the light source device is detected, the control portion controls so that the light amount of illumination light supplied from the light source device to the endoscope becomes a predetermined light amount according the detected type of the endoscope.

Abstract: An adjusting method for endoscope systems comprises a first adjusting step, a second light adjusting step and a storing step. The first adjusting step compares video signals, which are produced from illumination light rays that are reflected from an object and whose wavelengths fall within first, second, and third ranges, with one another, and regulates a lamp current that flows into a light source lamp. The second light adjusting step adjusts a diaphragm that controls an amount of light which is emitted from the light source lamp and which is irradiated to the object. The storing step stores the lamp current regulated at the first adjusting step and a light limiting level adjusted at the second adjusting step.

Abstract: A light source apparatus for an endoscope including a main light source; a light guide member whose incident end face is opposed to the main light source and which guides light incident thereon to an emission end face thereof; an auxiliary light source which is activated to emit light when no light is emitted from the main light source and which is supported to move between a stand-by position in which the auxiliary light source is located out of a main light path between the main light source and the incident end face and an operative position in which the auxiliary light source is located in the main light path and is opposed to the incident end face when the main light source is inoperative; and an auxiliary light source emission control device for driving the auxiliary light source at a continuous emission mode to emit light of a predetermined intensity or at an intermittent emission mode to emit light of an intensity higher than the predetermined intensity.

Abstract: A light source device enables manual and automatic light regulation performed on illumination light that is irradiated to an object. A set value of a light regulation level for light emanating from a light source which is determined for use of an endoscope 11 is stored in a memory. When the driving power supply of the endoscope 11 is turned on again in order to reuse the endoscope, the stored and previously determined set value of the light regulation level is compared with a threshold value. When the previously determined set value of the light regulation level is equal to or larger than the threshold value, a diaphragm 26 is adjusted so that the light regulation level is set to a predetermined value. When the previously determined set value of the light regulation level is equal to or smaller than the threshold value, the diaphragm 26 is adjusted so that the light regulation level will be set to the previous determined set value.

Abstract: A fluorescence image display apparatus is provided; wherein, when a pseudo color image representing the tissue state of a target subject is obtained, based on a fluorescence image emitted from the target subject upon the irradiation thereof by an excitation light, the tissue state can be recognized regardless of the intensity of the fluorescent light. Based upon the statistical quantity of a wide band fluorescence image computed by a statistical quantity computing means, a gain that the wide band and narrow band fluorescence image data are to be multiplied by is computed by a gain computing means. A gain multiplying means multiplies the wide band and narrow band fluorescence image data by the gain, whereby a green gradation is assigned to the wide band fluorescence image and a red gradation is assigned to the narrow band fluorescence image, and a composite image data is obtained by an image composing means.

Abstract: An electronic endoscope apparatus has a light source, a pixel luminance detector, a division setter, an average block luminance calculator, a peak-luminance determiner, a representative luminance calculator, and a brightness adjuster. The division setter divides the subject image into a plurality of blocks composed of given pixels. The average block luminance calculator calculates a plurality of average block-luminance-levels. The peak-luminance determiner compares the average block-luminance-levels with each other in order to determine a substantially maximum average block-luminance-level from the plurality of average block-luminance-levels as a peak luminance level. The representative luminance calculator calculates a representative luminance level indicating a brightness of the subject image. The brightness adjuster adjusts the brightness of the subject image in accordance with the representative luminance level.

Abstract: An illumination control system comprises a rotation detecting section, an abnormality determination section, and a filter removing section. The rotation detecting section detects the rotational driving of a filter which is located on a path of illumination light emitted from a light source, which irradiates color light rays having different wavelengths to an object, and which is driven by a rotational driver. The abnormality determination section determines whether status of filter rotation is normal or abnormal based on the detected rotation of the filter by the rotation detecting section. The filter removing section removes the filter from the path of the illumination light when the abnormality determination section determines that the status of filter rotation is abnormal.

Abstract: An aperture mechanism of this apparatus is provided with an aperture blade which has, for example, an outline converging toward the front end with a shielding width of the front-end blade section smaller than the diameter of a ray bundle transmitted into a light guide to achieve desired dimming by shielding the light in proximity of the central region in the ray bundle earlier than that in the outer regions. Thus, a relatively narrow distribution of light will be radiated onto an observed object for a long-distance examination of smaller aperture quantities and a wide distribution of illumination light will be radiated for a short-distance examination of larger aperture quantities. In addition, the aperture mechanism may be configured to move a small-circle aperture blade which is smaller than the cross-sectional area of the ray bundle disposed on the optical axis in the direction of optical axis to shield the light in proximity of the central region in the ray bundle earlier than that in the outer regions.

Abstract: An endoscope system comprising an endoscope which incorporates an imaging element together with an element for determining the type of the imaging element; a light source apparatus, which includes a DMD in a light path from a light source lamp, for determining incidence or non-incidence of the illuminating light from the light source lamp on a mirror; a CPU which determines the type of imaging element based on the information provided by the type determining element and detects a time required by the imaging element for charge reading based on the determination result; and a DMD control circuit which controls the DMD at a charge reading timing of the imaging element corresponding to the charge reading time detected by the CPU, the endoscope system making it possible to extend the exposure time to a maximum regardless of the type of the endoscope, by controlling the light shielding time of illuminating light in accordance with the type of the imaging element.

Abstract: An object of the present invention is to make the light distribution by a light guide even. In the light guide, an amount of light emitted from the central region in the light emission end face is relatively small in comparison with an amount of light emitted from a peripheral region in the light emission end face. For example, a mask for shielding light is provided near the light emission end face of the light guide. The mask is, for example, circular, and is aligned with an optical axis Z0 as the center. By providing the mask, the light emitted from the central region in the light emission end face is shielded around the optical axis Z0.

Abstract: A lighting system for an endoscope includes a lamp positioned so that an optical axis thereof is oriented horizontally; a light guide having an incident end upon which the illuminating light from the lamp is incident; a diaphragm plate rotated about a pivot so as to advance into and retract from an optical path of the illuminating light, the pivot extending parallel to the optical axis of the lamp and positioned above or below the optical path. The diaphragm plate includes a notch which is formed at one end of the diaphragm plate, the notch being positioned along an arc which is centered about the pivot and which intersects a center of the light guide when the diaphragm plate rotates about the pivot; and a large number of minute perforations formed along and below the arc.

Abstract: A light source apparatus for an endoscope including a main light source; a light guide member whose incident end face is opposed to the main light source and which guides light incident thereon to an emission end face thereof; an auxiliary light source which is activated to emit light when no light is emitted from the main light source and which is supported to move between a stand-by position in which the auxiliary light source is located out of a main light path between the main light source and the incident end face and an operative position in which the auxiliary light source is located in the main light path and is opposed to the incident end face when the main light source is inoperative; and an auxiliary light source emission control device for driving the auxiliary light source at a continuous emission mode to emit light of a predetermined intensity or at an intermittent emission mode to emit light of an intensity higher than the predetermined intensity.

Abstract: An electronic endoscope having an illuminating section in which an LED for illumination that emits illuminating light to illuminate an observed site is provided and a C-MOS image sensor which has an image pickup surface on which an optical image is formed and outputs a video signal.

Abstract: Disclosed is a diagnosis supporting device that acquires a reference image signal of a subject that is illuminated with reference light and a fluorescent image signal of the subject that is excited by irradiation with excitation light, calculates a first intensity coefficient based on the maximum brightness level of the fluorescent image data and calculates a second intensity coefficient corresponding to the maximum brightness level of the reference image data, and controls the intensities of the excitation light and the reference light according to the first and second intensity coefficients. The coefficients are determined such that the intensities of the excitation light and the reference light increase as the maximum brightness levels of the fluorescent image data and the reference image data decrease.

Abstract: An adjusting method for endoscope systems comprises a first adjusting step, a second light adjusting step and a storing step. The first adjusting step compares video signals, which are produced from illumination light rays that are reflected from an object and whose wavelengths fall within first, second, and third ranges, with one another, and regulates a lamp current that flows into a light source lamp. The second light adjusting step adjusts a diaphragm that controls an amount of light which is emitted from the light source lamp and which is irradiated to the object. The storing step stores the lamp current regulated at the first adjusting step and a light limiting level adjusted at the second adjusting step.

Abstract: The present invention is an electronic-endoscope apparatus for compensating for lack of light quantity caused by a delayed response from a light shielding mechanism when an all-pixel reading system is used. In the case of, for example, a moving image, this apparatus reads pixel mix data out from a CCD to reproduce motions faithfully. For a still image, this apparatus reads out all pixels obtained by the CCD during a single exposure period using a light shielding period set by a light shielding plate, and outputs this data to a mixing circuit via memories to form a pixel mix signal. This configuration enables a high-quality still image to be obtained. In this case, however, the light quantity may be insufficient due to a delayed response from the light shielding plate. Thus, during the exposure period for still-image formation, the lamp voltage is increased above a normal amount or the diaphragm aperture is increased in order to compensate for the shortage of light quantity.

Abstract: An electronic endoscope of the present invention includes a video-scope, video-processor, a light source, a luminance value calculator, a light-adjuster, and a determiner. The luminance value calculator successively calculates a luminance value indicating brightness of the object image, on the basis of said image-pixel signals. The light-adjuster adjusts a quantity of light radiating from the distal end of the video-scope on the basis of a difference between the luminance value and a reference value indicating a proper brightness of the object image at regular-time-intervals, such that the brightness of said object image displayed on the monitor is maintained at a constant level. The determiner determines whether halation occurs on the object image displayed on the monitor, on the basis of the luminance value. The light-adjuster includes a light-reducer.

Abstract: An endoscope assembly consisting of an endoscope 622, a light source, 626 and a camera 552 with display 558. The endoscope contains a memory 670 with data that describes the endoscope and its operating characteristics. When the light source is connected to the endoscope with a fiber optic cable 628, the data in the memory are read into a control processor 538a internal to the light source. The control processor, based on the endoscope data configures the light source so that it emits an appropriate amount of light for that endoscope. The light source also sends a control unit 556 of the camera data indicating the type of endoscope to which the camera is attached. Based on this endoscope type data, the control unit processes the image signals generated by the camera head in an appropriate form for the attached endoscope so as to produce appropriate signals for presenting an image on the display.

Abstract: A light source device comprises a pair of aperture blades, which opens and closes an optical path through which illumination light radiated from a light source passes so that the amount of the illumination light entering a light guide fiber bundle of the endoscope is adjusted. A guide slot is formed in each of the aperture blades, and an engaging pin is engaged with each of the guide slots. A tension coil spring connects the aperture blades to urge the aperture blades always in a direction in which the aperture blades opens or closes, so that the engaging pin is always engaged with an edge of the guide slot.

Abstract: Excitation light for normal light observation with wavelengths in the visible spectrum, which is output from a lamp, and excitation light with wavelengths in the infrared spectrum for exciting a fluorescent substance characteristic of being accumulated readily in a lesion are irradiated simultaneously to a living tissue, to which the fluorescent substance has been administered, through an endoscope. Fluorescence components are separated from light stemming from the living tissue by means of a separator such as a dichroic mirror, introduced to a first imaging device, and then imaged. Light components with wavelengths in the visible spectrum are introduced to a second imaging device and then imaged. Signals representing the images are subjected to signal processing, whereby a video signal is produced. For better diagnosis, two images are displayed while, for example, one of the images is superimposed on the other.

Abstract: When a new processor is connected to an old electronic endoscope provided with a memory storing B data for image processing specific to the scope, white balance control is carried out by a microcomputer. That is, at the time when power is turned on, this microcomputer determines whether or not image processing data compatible with the new processor is present in the old electronic endoscope. If the compatible data are not present, the microcomputer carries out white balance control based on the image of white board picked up by the user, and additionally writes new C data for image processing at the time of white balance control in a memory of the old electronic endoscope together with data identification information. Thereby, the compatibility with an old type of electronic endoscope is maintained.

Abstract: An aperture mechanism of this apparatus is provided with an aperture blade which has, for example, an outline converging toward the front end with a shielding width of the front-end blade section smaller than the diameter of a ray bundle transmitted into a light guide to achieve desired dimming by shielding the light in proximity of the central region in the ray bundle earlier than that in the outer regions. Thus, a relatively narrow distribution of light will be radiated onto an observed object for a long-distance examination of smaller aperture quantities and a wide distribution of illumination light will be radiated for a short-distance examination of larger aperture quantities. In addition, the aperture mechanism may be configured to move a small-circle aperture blade which is smaller than the cross-sectional area of the ray bundle disposed on the optical axis in the direction of optical axis to shield the light in proximity of the central region in the ray bundle earlier than that in the outer regions.

Abstract: A light source device comprises an aperture mechanism having a pair of aperture blades in an optical path formed between a light source and an incident end surface of a light guide on which an illuminating light is made incident. The first and second aperture blades are rotated, in a plane perpendicular to the optical axis of the optical path, about a movable shaft, which is parallel to the optical axis. The first and second aperture blades shade the luminous flux of the illuminating light, to adjust the amount of illuminating light, from the outer peripheries of the section of the luminous flux. A protruding plate is formed on an inside periphery of the first aperture blade. When the first aperture blade closes a half of the section, the protruding plate shades a swinging region above the center of the section of the luminous flux.

Abstract: In an electronic endoscope apparatus according to the present invention, a micromirror device reflects light from a light source to allow it to enter a light guide. A light blocking period is set by driving the polarization angles of micromirrors of the micromirror device to a light guide non-incident angle &thgr;s. This light blocking period is utilized to read signals for all pixels for one frame stored in a CCD by the same exposure. Thus, the light blocking period can be promptly set to obtain a stably bright motion picture not affected by any motions, or the like. Further, the quantity of light can be controlled by controlling the polarization angles in the micromirror device. Furthermore, desired white light is obtained.

Abstract: A lighting system for an endoscope includes a lamp positioned so that an optical axis thereof is oriented horizontally; a light guide having an incident end upon which the illuminating light from the lamp is incident; a diaphragm plate rotated about a pivot so as to advance into and retract from an optical path of the illuminating light, the pivot extending parallel to the optical axis of the lamp and positioned above or below the optical path. The diaphragm plate includes a notch which is formed at one end of the diaphragm plate, the notch being positioned along an arc which is centered about the pivot and which intersects a center of the light guide when the diaphragm plate rotates about the pivot; and a large number of minute perforations formed along and below the arc.

Abstract: In a device for detecting transmission losses of optical light guide means (2) of an endoscope (3) by means of measurements, said optical light guide means (2) having an optical inlet portion (4) through which light from a light source (6) is transmitted to an optical outlet portion (8) of the means to be checked, said device comprising at least one light sensor (10) measuring the light intensity emerging from the optical outlet portion (8) of the means (2) to be checked, and an evaluation means (14) for the signal of the at least one light sensor (10), said evaluation means (14) having a display means (18) for displaying the measurement result, it is provided that the at least one light sensor (10) is arranged in a chamber (20), that the optical outlet portion (8) of the light guide means (2) to be checked is adapted to be introduced through an opening (22) of the chamber (20) into the chamber (20), and that the inner surface (24) defining the chamber (20) diffusely reflects the light emerging from the optic

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: 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: A light source device for endoscopes capable of preventing an incident end-face of a lightguide from generating heat due to infrared light emitted from a light source, and capable of radiating sufficient ultraviolet light and visible light. A light source emits at least ultraviolet light, visible light and infrared light. A condenser lens condenses the light emitted from the light source at the incident end-face of a light guide. A wavelength control filter and another selected filter are arranged between the light source and the condenser lens. Each optical axis of the light source, the wavelength control filter, the selected filter, the condenser lens, and the lightguide is linearly aligned, thereby providing a simplified alignment operation in manufacturing processes.

Abstract: A device for controlling an amount of light of a lighting unit for use in an endoscope that is used to view an image of an object. A light shielding system shields light generated by a light source and transmitted to the endoscope and a stepping motor drives the light shielding system for a plurality of predetermined time intervals. A system detects a brightness of the image during each of the plurality of predetermined time intervals and an input system inputs one of a plurality of desired brightnesses of the image. A generating system generates a predetermined number of pulses during each of the plurality of predetermined time intervals, the predetermined number of pulses being transmitted to the stepping motor and a system determines an angular position of the light shielding system.

Abstract: A method and apparatus where the output from a high intensity light source is controlled so that whenever the output is not directed at a surface, the light source output intensity is automatically reduced to a safe level. This is achieved by monitoring the reflected light from a surface and when this reflection indicates that the light source is not directed at a surface, the light intensity is reduced to a safe level.

Abstract: In an electronic endoscope, and a memory which contains image pickup area information including size and light distribution characteristics are provided, and in a processor device to which this electronic endoscope is connected, a photometric part for measuring the light receiving state by using separated photometric areas, and a microcomputer are provided, and this microcomputer reads the above described image pickup area information on the electronic endoscope side, and sets a photometric areas (EA to EC) whose size is approximately the same corresponding to the size of the image pickup area in the above described photometric part, and in the meantime, gives weightings A to C to each separated area of these photometric areas (EA to EC). Consequently, even in the case where the sizes and the light distribution characteristics of the actual image pickup areas (FA to FC) determined by the objective optical system are changed, it is possible to realize fine photometry and brightness control.

Abstract: A larger number of micromirrors arranged on an illumination optical path of a lamp in a light source device for supplying an illumination light to an endoscope and by using a silicon chip as a base are arranged the micromirrors in a two-dimensional are set at two angles. When the micromirrors are set at one of the two angles, a reflected light is supplied to the light guide. When the micromirrors are set at the other angle, the micromirrors are driven such that the reflected light is not supplied to the light guide. An intensity of illumination light supplied to the light guide or the like is adjusted at a high speed by using a brightness level by selected the micromirrors at the two angles respectively, so that an endoscope image which can be easily observed is obtained.

Abstract: The present invention provides an electronic endoscope apparatus which prevents a picked up image from being blurred utilizing an optical magnification change mechanism. A viewing distance is changed by moving a movable lens with an actuator, magnification changing location of the movable lens is detected with an encoder and a shutter speed for a CCD which is shorter than an exposure time while the optical magnification changing mechanism is not operating is set with a CPU dependently on the magnification changing location. It is possible to prevent an image from being blurred, for example, by storing various patterns which provide higher electronic shutter speeds as an image magnification ratio is enhanced in a ROM and controlling an electronic shutter speed with these patterns.

Abstract: In an electronic endoscope, a flexible scope has an image sensor provided at a distal end thereof, and an optical light guide extending therethrough. The scope is detachably connectable, at a proximal end thereof, to a processing unit, which processes image-pixel signals successively read from the image sensor. A light source is provided in the processing unit such that light, emitted from the light source, is guided through the guide and radiates from the distal end of the scope. An aperture-stop is associated with the source that regulates the radiation of light from the distal end of the scope. A histogram generator generates a luminance-signal-histogram based on the processed signals. An average luminance level-value is approximately calculated based on luminance signals exhibiting thinned luminance levels extracted from the histogram.

Abstract: The present invention is a unit for eliminating the fluctuation of luminous energy reduction by keeping the response time of a shading mechanism constant even if a diaphragm opening degree differs when reading every pixel by setting a shading period. This unit is provided with a shading mask having a quadrangular or V-shaped opening and moves a shading shutter in the horizontal direction perpendicular to the vertically moving direction of a diaphragm plate. Therefore, a shading period is set in accordance with the constant response time of the shading shutter and the rate of luminous energy reduction becomes constant. Moreover, a high-quality static image having a stable brightness can be obtained by reading the signal of every pixel obtained by a CCD through one-time exposure while using the shading period and then pixel-mixing signals. Furthermore, it is possible to use the Archimedean spiral for the outer periphery of the diaphragm plate or the shading shutter.

Abstract: A light source device comprises an aperture mechanism having a pair of aperture blades in an optical path formed between a light source and an incident end surface of a light guide on which an illuminating light is made incident. The first and second aperture blades are rotated, in a plane perpendicular to the optical axis of the optical path, about a movable shaft, which is parallel to the optical axis. The first and second aperture blades shade the luminous flux of the illuminating light, to adjust the amount of illuminating light, from the outer peripheries of the section of the luminous flux. A protruding plate is formed on an inside periphery of the first aperture blade. When the first aperture blade closes a half of the section, the protruding plate shades a swinging region above the center of the section of the luminous flux.

Abstract: A device for controlling an amount of light of a lighting unit for use in an endoscope, used to view an image of an object. The device includes a light shield for shielding light generated by a light source and transmitted to the endoscope. A stepping motor drives the light shield for a series of predetermined time intervals. Brightness of the image is detected during each of the time intervals and pulses are generated during each of the time intervals. A desired brightness of the image is input. The number of pulses generated is determined in accordance with the input desired brightness of the image. The pulses generated are used to drive the stepping motor in each of the plurality of time intervals.

Abstract: In an electronic endoscope, a video-scope has an image sensor for photographing an object image and a light guide for guiding light toward an object. A video-processor has a light source, a stop, a signal conversion circuit, a histogram processing circuit, and a CPU. When the video-scope is connected to the video-processor, light emitted from the light source is guided by the light guide and radiates from a distal end of the light guide, so that an object image is formed on the image sensor. The object image is then converted into the image-pixel signals. Further, a representative value, which relates to a brightness of the object image, is calculated on the basis of the image-pixel signals through the signal conversion circuit, the histogram processing circuit, and the CPU. Then, a control of light radiating from the distal end of the light guide is performed at regular time-intervals. Namely, the stop is controlled such that the brightness of the object image is proper.

Abstract: A light source apparatus is used in a video endoscope system having a charge coupled device (CCD) image sensor and a monitor. The light source apparatus provides illumination to a scene to be imaged by the CCD image sensor and displayed on the monitor. The light source apparatus includes a discharge lamp serving as a light source. The lamp is subject to progressive degradation during use so that its output light intensity achievable with a given level of input current gradually decreases through its lifetime. The current supplied to the lamp is controlled using a feedback control technique so as to maintain the output light intensity of the lamp at a substantially fixed, desired intensity level. In order to allow the operator to timely replace the discharge lamp with a new one, the input current to the discharge lamp is detected and compared to a threshold level. The threshold level may be selected to a level corresponding to the rated power of the lamp designated by the manufacturer.

Abstract: The present invention is a unit for eliminating the fluctuation of luminous energy reduction by keeping the response time of a shading mechanism constant even if a diaphragm opening degree differs when reading every pixel by setting a shading period. This unit is provided with a shading mask having a quadrangular or V-shaped opening and moves a shading shutter in the horizontal direction perpendicular to the vertically moving direction of a diaphragm plate. Therefore, a shading period is set in accordance with the constant response time of the shading shutter and the rate of luminous energy reduction becomes constant. Moreover, a high-quality static image having a stable brightness can be obtained by reading the signal of every pixel obtained by a CCD through one-time exposure while using the shading period and then pixel-mixing signals. Furthermore, it is possible to use the Archimedean spiral for the outer periphery of the diaphragm plate or the shading shutter.

Abstract: A device for controlling an amount of light of a lighting unit for use in an endoscope that is used to view an image of an object. A light shielding system shields light generated by a light source and transmitted to the endoscope and a stepping motor drives the light shielding system for a plurality of predetermined time intervals. A system detects a brightness of the image during each of the plurality of predetermined time intervals and an input system inputs one of a plurality of desired brightnesses of the image. A generating system generates a predetermined number of pulses during each of the plurality of predetermined time intervals, the predetermined number of pulses being transmitted to the stepping motor and a system determines an angular position of the light shielding system.

Abstract: A device for controlling an amount of light of a lighting unit for use in an endoscope, used to view an image of an object. The device includes a plurality of light shields for shielding light generated by a light source and transmitted to the endoscope. A plurality of stepping motors drive the light shield for a series of predetermined time intervals. Brightness of the image is detected during each of the time intervals and pulses are generated during each of the time intervals. The number of pulses generated is determined in accordance with a difference between the brightness of the image detected during each of the time intervals and a desired brightness of the image. The pulses generated are used to control the drive of the plurality of stepping motors in each of the plurality of time intervals.

Abstract: A device for controlling an amount of light of a lighting unit for use in an endoscope, used to view an image of an object. The device includes a light shield system for shielding light generated by a light source and transmitted to the endoscope. A stepping motor drives the light shield for a series of predetermined time intervals. Brightness of the image is detected during each of the time intervals and pulses are generated during each of the time intervals. One of a plurality of brightness ranges is set in accord with desired brightness of image. A determination is made as to whether the detected brightness is within one of the ranges. The pulses generated are used to drive the stepping motor in each of the plurality of time intervals.

Abstract: The present invention is an electronic endoscope apparatus that can appropriately compensate for the lack of light quantity caused by a delayed response from a shielding mechanism in using the all-pixel reading system to form a high-quality image. In this apparatus, for a moving image, a pixel mix signal is read out from a CCD to reproduce motions faithfully. For a still image, to improve the image quality, a shielding period set by the shielding plate is used to read out all the pixels obtained by the CCD during a single exposure in order to form a pixel mix signal using a mixing circuit. A lamp characteristic memory stores table data indicating the characteristic between the lamp voltage of the current lamp and the quantity of outgoing light so that based on this data, a lamp voltage higher than in moving images is supplied to the lamp during the exposure for still-image formation.