Abstract: An image sensing system is provided with a fluorescent lamp which performs AC lighting to irradiate an object, an inverter power source which supplies currents to the fluorescent lamp, a lighting frequency changing circuit which changes the frequency of the current supply, a lens which images an image onto a film, and a CCD image sensing device which is capable of changing the period of exposure by the formed image and which outputs the image of the object as an electric signal through photoelectric conversion. The exposure period of the CCD image sensing device is controlled by a microcomputer and a timing generator. The lighting frequency changing circuit is controlled so that the phase of the exposure period and the phase of the current supply to the fluorescent lamp are in synchronism with each other.

Abstract: The present invention is a film housing device comprising a film housing member that houses developed film; a driving mechanism that feeds the film housed in said housing member to a position outside the housing member where the film may be visually observed by the naked eye; and an operating member to operate said drive mechanism. Using said construction, when the operating member of the film housing device is operated, the drive mechanism operates and the developed film is fed to a position outside the housing member where the film may be visually observed by the naked eye. Therefore, the photographic content of the film may be confirmed with the naked eye using only the film housing device where it is not necessary to connect the device to a film reading device such as film scanner.

Abstract: A still video adapter is attached to the body of a standard photographic camera, in place of the back cover of the camera, to enable picture taking on a magnetic disk, being provided with a deck portion extending from one side to the front of the adapter to hold a magnetic disk in parallel with the side of the adapter.

Abstract: A cover accessory for a still camera permits the replacement of the film with an electronic recording of the video image. An optical system is provided with the cover for re-forming an image of an object, an image having been formed by an objective lens in a predetermined film plane, and providing the image to a photo taking device for electronically recording image data. A relay viewfinder optical system is connected optically to the viewfinder of the camera, and indicates at least one viewfinder indication that is proper to the video accessory through the relay viewfinder.

Abstract: A still video adapter device is detachably mounted to a back portion of a camera body, in place of a rear cover. The light passing through an objective lens of the camera body is relayed by a relay optical system and split into two groups, one being directed to an image sensor for the still video photography, the other to a light measuring element for the exposure control. The output of the light measuring element is integrated and compared with a given value, thereby generating a signal for interrupting the flash light emission when the integrated value reaches the given value.

Abstract: The present invention relates to an optical system of a radiation thermometer in which the measuring optical system and the finder optical system can be focused. The central portion of the sub-mirror in Cassegrainian type optical system is used as a finder lens of the finder optical system. The third mirror is located between the main and sub-mirrors in order to reflect the light passed through the central portion of the sub-mirror. The light reflected on the third mirror is used for finder observation.

Abstract: There is disclosed a bi-level focusing plate of phase grating type in which micro unit patterns, each of which is comprised of one or more projections and one or more recessions, are arranged regularly and repeatedly at a pitch of 10 to 30 .mu.m. The phase difference between each of projections and each of recessions is set at .pi. radian against a light having a wavelength of 400 to 700 nm and the ratio in area of total area of projections or recessions in one unit pattern to the area of said one unit pattern is set so as to fall into a range of 0.3 to 0.5. The focusing plate is characterized in that the boundaries in each unit pattern each defined between the projection and the recession adjacent to each other therein are comprised of straight-lined portions and curved portions.

Abstract: The present invention relates to an optical system of a radiation thermometer in which the measuring optical system and the finder optical system can be focused. The central portion of the sub-mirror in Cassegrainian type optical system is used as a finder lens of the finder optical system. The third mirror is located between the main and sub-mirrors in order to reflect the light passed through the central portion of the sub-mirror. The light reflected on the third mirror is used for finder observation.

Abstract: A light source device for a color enlarger, in which at least three linear light sources are used in order to served as a red light source, a green light source, and a blue light source, respectively, are disclosed. In the device, the linear light source serving as a red light source is arranged perpendicularly to an optical axis of a projection lens in the color enlarger. The other linear light sources serving as green and blue light sources respectively, are arranged perpendicularly to the optical axis and are symmetrical with respect to the optical axis.