Abstract: A guitar belly for a guitar body including a rear or reverse plate and a side plate around and standing up from the rear plate, which are integrally formed of the same plastic material. A separate cover plate is attached over the edge of the side plate to close the guitar belly. Reinforcing ribs are integrally formed of the same material as and along with the reverse plate. These include two or three longitudinal ribs extending from at or near the top front end of the reverse plate to the bottom end thereof, two horizontal ribs, one at the narrower width part and one at the greater width part of the belly, and two oblique ribs, each extending obliquely from the center of the belly and toward the one end of the belly and respectively outward from the center of the belly in opposite directions. Some or all of the ribs also extend up the side wall of the guitar belly. The ribs cooperate to prevent distortion of the belly due to string tension or other causes including playing the guitar.

Abstract: A percussion instrument is formed from a hollow cylindrical tube which is provided with a surrounding beaded net. The net is mounted by passing net end strands into a circumferential ring of radial boreholes adjacent each end of the tube and outward through the tube ends.

Abstract: A computer system connected through appropriate analog and digital circuitry controls or monitors a piano. Solenoids connected to each piano key and to each note-sounding hammer permit a computer program to control the keys and/or the sounding of a note, as well as transmitting to the computer for storage and analysis information concerning a student's performance.

Abstract: A wind instrument is equipped with rotary valve units or keys for changing the length of vibrative air column, and a link mechanism transmits a lever action to the rotary valve unit or the key, wherein a joint incorporated in the link mechanism comprises a shaft member having an external thread and coupled with the manipulating lever, an adjustable screw member with an internal thread, a tubular member actuating the rotary valve unit or the key and retained by the adjustable screw meshed with the external thread, and an elastic member inserted between a bottom surface of the tublar member and a leading end of the external thread portion so that gaps on both sides of the tubular member are adjustable, thereby allowing the tubular member to smoothly rotate.

Abstract: A music box comprising two opposed metal combs with tuned steel teeth respectively disposed at two opposite sides relative to a pinned barrel, a driving mechanism to rotate said pinned barrel, and an adjusting device controlled to move either metal comb into the operative position, wherein rotating said adjusting device in one direction causes the tuned steel teeth of one metal comb to be struck by the pins on the outer wall of said pinned barrel in producing a certain tune or tunes; rotating said adjusting device in an opposite direction causes the tuned steel teeth of the other metal comb to be struck by the pins on the inner wall of said pinned barrel in producing a different tune or tunes.

Abstract: An optical device includes a scanning means, a first image-formation optical system, and a second image-formation optical system. A system for a device, such as the one in which images are formed by scanning with this optical device. The scanning means scans a light beam emitted from a light source. The first image-formation optical system forms the light beam, scanned by the scanning means, into an image in a first spot diameter with respect to the scanning direction, on a surface to be scanned. The second image-formation optical system utilizes the first image-formation optical system and at least part of an optical system for forming the light beam scanned, by the scanning means, into an image in a second spot diameter which is different from the first spot diameter, with respect to the scanning direction, on the surface to be scanned.

Abstract: An image recording apparatus includes a sheet feeding unit for feeding a sheet to a recording position, recording unit for recording an image on the sheet fed by the sheet feeding unit, and jam detection unit for detecting a jamming in the apparatus. Sheet holding unit is provided for holding a sheet fed by the sheet feeding unit in accordance with a detection signal from the jam detection unit to reuse the sheet, thereby using a recording sheet efficiently even after a jam has occurred.

Abstract: An image recording apparatus uses coloring photosensitive toner for a full-color copying which is in the form of a microcapsule having a shell, a photosensitive resin and a chromogenic material both encapsulated in the shell, and a developer material coated on the outer surface of the shell. To increase the monochromatic copying speed, the apparatus further uses a monochromatic toner. When a user's switch is depressed, a driver unit selects either one of the full-color and monochromatic color copying mode. When the monochromatic image is to be copied, a pressure developing unit which is used for pressure developing a color latent image is retracted, so that a recording medium on which a monochromatic toner image is deposited is free from the pressure imparted by the pressure developing unit and the pressure developing unit is not smeared with the monochromatic toner powders.

Abstract: The invention provides an image forming apparatus capable of performing an ordinary copy mode, whereby the entire surface of a document is scanned by an image reader to copy the entire surface on a copy sheet, and a serial page copy mode, whereby first and second half portions of the document are separately scanned to copy each half portion on a separate copy sheet. In the apparatus, copy sheets of different sizes are fed from a plurality of cassettes each storing a copy sheet of a predetermined size or a manual feed tray. There is provided a memory for memorizing a serial copy sheet size to be fed from the manual feed tray. When the serial page copy mode is selected in the manual feed mode, the image reader is controlled to separately scan the first and second half portions of the document on the basis of the serial copy sheet size.