Canon Kabushiki Kaisha

Toshio Sakane

Tokuichi Tsunekawa

Kazuya Hosoe

Takao Kinoshita

Takashi Kawabata

Makoto Masunaga

Tetsuya Taguchi

Masahiko Ogawa

Shuichi Tamura

Isao Harigaya

Takashi Amikura

Yoshimi Kohayakawa

Junichi Takahashi

Takashi Masuda

Yasuyuki Numajiri

Haruhisa Madate

Yasuyuki Ishikawa

Yuji Itoh

Tatsuya Taguchi

A laser applying apparatus is provided with a laser source, setting means for setting the intensity of laser light applied to a portion to be irradiated, excitation means disposed in the laser source for selecting a stage of laser light intensity conforming to the set value by the setting means from among a plurality of stages of laser light intensity and causing it to be output from the laser source, and adjusting means disposed in the optical path for adjusting the intensity of the laser light output from the laser source to the intensity set by the setting means, by varying the light attenuation rate.

Laser applying apparatus

A cornea thickness measuring ultrasonic probe is provided with an ultrasonic wave propagation layer being in contact with an eye to be examined and formed substantially concentrically with the center of curvature of the cornea of the eye to be examined, a plurality of ultrasonic wave vibrators are disposed on at least one meridian, and a fixation light source is presented to the eye to be examined.

Cornea thickness measuring ultrasonic probe

An eye refractive power measuring apparatus having a unit for projecting a plurality of index images onto the fundus of an eye to be examined, a unit for detecting the eye fundus reflected light beams of the index images correspondingly to each measuring meridian direction, a unit for operating the refractive power of the eye on the basis of the output of the detecting means, a unit for moving a fixation target for fixing the eye to be examined thereto or the projection system thereof in the direction of the optic axis, and a unit for controlling the movement speed of the fixation target or the projection system thereof on the basis of the degree of variation in the result of the measurement of the operated refractive power of the eye which results from the movement.

Eye refractive power measuring apparatus

A light metering system for obtaining a light value by scanning the brightness distribution of the object space within a predetermined field of view. Of the thus-produced brightness signals, those which correspond to a particular target area in the view-field are given respective predetermined weights. The light value is derived on the basis of these weighted signals and the remaining signals.

Light metering and processing system particularly for a video camera

A distance detecting device comprising radiation projecting means for projecting a radiation beam; radiation sensing means which is disposed away from the radiation projecting means with a given length and is arranged to receive a reflected radiation beam coming from an object whose distance is to be detected as the radiation beam is projected from the projecting means; and movable means for relatively varying the incident condition of the projected radiation beam onto the sensing means. The distance to the object is found either by the position of the movable means or by the amount of displacement thereof which occurs at a time point at which the sensing means optimally receive the reflected radiation beam coming from the object in the process of relatively varying the incident condition of the projected radiation beam onto the sensing means. In the incident condition varying process, the output signal of the sensing means and a delayed signal which is obtained by delaying the output signal a predetermined period of time are compared with each other to detect a time point at which the output signal of the sensing means has reached its peak level and, accordingly, to detect when the sensing means optimally recieve the reflected radiation beam coming from the object.

Distance detecting device

In the device disclosed, an image formed by an optical system is scanned by an image sensor composed of independently arranged photoelectric transducing elements to produce an image scanning signal. A detecting circuit detects the variation of the brightness between the adjacent image elements as a measure of the sharpness of the image and the focus of the optical system. The focus detection accuracy is improved by non-linear transformation of the brightness variation signal with a non-linear transformation circuit that weighs the brightness variation signal on the basis of the signal level. A signal forming circuit detects the difference between the outputs of transducing elements and adds the differences to produce a comparator signal when a predetermined relationship is reached between the sharpness indication and the addition signal. An indicator indicates that the focusing condition cannot be discerned in response to the comparison signal and a control inhibits the output of the detection circuit to the indicator prior to the addition signal.

Focus detecting device

In the device disclosed, an image formed by an optical system is scanned by an image sensor composed of independently arranged photoelectric transducing elements to produce an image scanning signal. A detecting circuit detects the variation of the brightness between the adjacent image elements as a measure of the sharpness of the image and the focus of the optical system. The focus detection accuracy is improved by non-linear transformation of the brightness variation signal with a non-linear transformation circuit that weighs the brightness variation signal on the basis of the signal level.

An eye-fundus camera provides change-over and selection between automatic focusing and manual focusing. The eye-fundus camera includes a projector, a photo-sensor array, a focus controller and an illuminator. The projector projects a first focus mark and a second focus mark on the fundus of an eye to be examined. The photo-sensor array detects the first focus mark reflected from the fundus and the output from the sensor array is introduced into the controller to adjust the focus of the camera. The illuminator illuminates the fundus uniformly with light within a first wavelength range. The first focus mark is with light within the first wavelength range and within a second wavelength range other than the first one whereas the second focus mark is formed only of light within the first wavelength range. The eye-fundus camera further comprises a wavelength selecting mirror which cuts off light of the first wavelength range among rays of light incident upon the photo-sensor array.

Eye-fundus camera provided with automatic focusing function

A distance detecting device in which, with respect to an object whose distance is to be detected, the images of a first and a second field following different lines of sight and containing the object and different in range are scanned while, at the same time, continuous M quantized image element data regarding the first field image and continuous N (N&gt;M) quantized image element data regarding the second field image are obtained and the M image element data regarding the first field image are stored in a first circulation type shift register while the first M image element data of the N image element data regarding the second field image are stored in a second circulation type shift register and the remaining N-M image element data are stored in a third shift register, and the comparison between the stored data of the first and second shift registers during one circulation of said stored data and the relative shift of n bits each of the stored data of the second and third shift registers with respect to the stored data of the first shift register are repeatedly effected to thereby detect the distance to the object, characterized in that in the circulation circuit of the first shift register, bypass means is provided for delaying one circulation of the stored data of the first shift register by n bits relative to one circulation of the stored data of the second shift register and the stored data of the first shift register are circulated through the bypass means, whereby for each one circulation of the stored data of the first shift register, the stored data of the second shift register are shifted by n bits each relative to the stored data of the first shift register.

Distance detecting device and a focus control system utilizing the same

An eye-fundus examining instrument is provided with a phototaking system, an illumination system for illuminating the fundus of an eye, a projecting system for projecting a focus mark and a comparison mark, a finder coupled to the phototaking system for observing therethrough the fundus of the eye, the focus mark and the comparison mark, a linear photosensor array for detecting the focus mark image reflected by the fundus of the eye, a light-receiving system focused to the fundus of the eye simultaneously with the phototaking system and the projecting system, a focusing mechanism for focusing the phototaking system to the fundus of the eye, a manual adjust member for manually driving the focusing mechanism, a servomotor for driving the focusing mechanism, a control circuit for controlling the servomotor by the output of the linear photosensor array, and a switch for selecting the power supply to the control circuit.

Focusing apparatus for eye-fundus examining instrument

In the disclosed MOS-image sensor, a plurality of signal-integrating type photo-sensitive elements are set to values that depend upon the light to which they have been exposed and the time of exposure. Readout gate switches responding to a readout address arrangement sequentially read out the content of the elements. Individual reset gate switches that respond to a reset address arrangement reset each of the elements a desired time prior to the readout so as to control the signal integration time of each of the elements.

MOS-Image sensor

Disclosed is a focus detecting system in which first and second signals corresponding to image forming states at first and second positions each almost at the same distance before and behind a predetermined focal plane of an image forming optical system are obtained. A third signal corresponding to an image forming state at a third position different from the first and the second positions is also obtained. The in-focus state of the image formed by the image forming optical system is detected on the basis of a first comparison signal obtained by comparing the first and the second signals with each other, a second comparison signal obtained by comparing the first and the third signals with each other and a third comparison signal obtained by comparing the second and the third signals with each other.

Focus detection system

The present invention relates to a motion detecting device for detecting the relative motion rate or velocity between an object and an optical instrument in an exposure control system by which the exposure time, i.e. the shutter speed of the instrument is controlled in response to the relative motion rate or velocity. The motion detecting device is designed to detect the displacement ratio or speed of the position of the center of gravity of the light distribution of the object image on the imaging plane, whereby the danger for misdetection due to the periodical fluctuation of the object brightness can be profitably avoided, being possible to detect only the relative movement between the object and the instrument.

Motion detecting device in exposure control system for optical instrument

In the disclosed system, a light measuring circuit having a logarithmical amplifier, is constructed to produce pulses at a frequency corresponding to the output of the light measuring circuit. Pulses are counted during a time interval corresponding to the temperature characteristic of the light measuring circuit so as to obtain a count value corresponding to the light input free of the influence of temperature.

Growing community of inventors

Yokohama, Japan

Toshio Sakane