Jujo Paper Co., Ltd.

Nippon Hoso' Kyokai

Japan Radio Co., Ltd.

Yutaka Kojima

Takashi Omori

Hiroyo Oshima

Koichi Nagai

Isao Kano

Yukio Kobayashi

Kazuhisa Hayeiwa

Hisashi Naka

Ken Ishiguro

Kouichi Nagai

Atsushi Ono

Takashi Ohmori

Kunio Hata

Michitoshi Minami

Kazuo Harada

Tadashi Yamagata

Takeo Konno

Michitosi Minami

Hajime Tani

Yoshihiko Shimura

Kazuaki Wakai

Tetsuroh Miyazaki

Tohru Mizokami

An amplitude modulation circuit and method. A predetermined number of (e.g., 6) drivers and differentially switched power amplifiers are provided in pairs. A program sound signal which has been quantized into a predetermined number of bits (e.g., 12 bits) is divided through a ROM into a plurality of bit groups each consisting of a predetermined number of bits (e.g., 2 bits), which are in turn distributed to the respective driver and differentially switched power amplifier pairs. In response to the value of the distributed bit group, each driver selects two different phase-shift carriers from seven different phase-shift carriers, and provides as its outputs .phi..sub.A and .phi..sub.B. With the output phase-shift carriers (.phi..sub.A and .phi..sub.B), each driver differentially switches the differentially switched power amplifier corresponding thereto. The output of each differentially switched power amplifier is weighted. The outputs of all the differentially switched power amplifiers are combined by a power combiner and then filtered through a BPF, thereby obtaining a broadcast output which has been amplitude modulated by the program sound. Thus, a digital amplitude modulation can be realized using a lower number of power amplifiers than before.

Amplitude modulation circuit and method

An amplitude modulation system. An input analog signal indicating audio, etc., is converted into a digital form and the low-order bits of the resultant digital signal are converted into analog form. The resultant analog signal is used to control a gain of an analog controlled amplifier. On the other hand, a plurality of digitally controlled amplifiers are selectively turned on/off in response to the value of the high-order bits of the digital signal. Carrier amplified by the analog controlled amplifier are combined with carriers amplified by the plurality of digitally controlled amplifiers. Comparatively rough amplitude constituents are provided by outputs of the plurality of digitally controlled amplifiers and comparatively fine amplitude constituents are provided by output of the analog controlled amplifier.

Amplitude modulation method and broadcasting apparatus for carrying out

This invention relates to a recording sheet for an ink jet printer comprising fibrous base material and a back-coating layer formed on the back surface of the base material, which characterized by that the base material contains a cationic polymer size (a), and the back-coating layer comprises a pigment, a binder and two or more of sizes (b1) and (b2), said size (b1) being alkyl ketene dimer, alkenyl succinic anhydride, or wax emulsion, and said size (b2) being a cationic polymer.

Ink-jet recording sheet

This invention concerns an ink jet recording paper characterized by comprising a base layer that contains an internal size, and an ink-receptive layer that is made out of a material having good affinity for inks, wherein the ink-receptive layer is superposed on either one or both sides of the base layer by multi-ply paper-manufacturing process; the structure of the ink jet recording paper is such that it has good ink-absorbency enough to catch up with rapid multi-color printing, and provides high optical image, vivid and uniform image definition, and almost no print through, having desirable paper-like figures and hand feeling.

Ink jet recording paper

An ink jet recording sheet providing an image by the use of an aqueous ink containing a water-soluble dye comprises a substrate having thereon a specific ink receptive layer. This ink jet recording sheet has excellent properties under maintaining the paper-like figure and feeling of an uncoated sheet.

Ink jet recording sheet

This invention relates to a recording sheet for ink jet printers which gives an image by the use of an aqueous ink containing a water-soluble dye, coated or impregnated with either of or a mixture of two kinds of water-soluble polymers: one whose polymeric unit is alkylquaternaryammonium (meth)acrylate and the other whose polymer unit is alkylquaternaryammonium (meth)acrylamide, said water-soluble polymers containing not less than 50 mol % of a monomer represented by the following formula (1), ##STR1## where R represents hydrogen or methyl group; n is an integer from 1 to 3 inclusive; R.sub.1, R.sub.2 and R.sub.3 represent hydrogen or the same or different aliphatic alkyl group with 1 to 4 carbon atoms; X.sup..crclbar. represents an anion such as halogen ion, sulfate ion, alkylsulfate ion, alkyl- or aryl-sulfonate ion and acetate ion and Y represents oxygen or imino group.

Recording sheet for ink jet printers

An ink jet recording sheet for overhead projection or blue copy comprising on a transparent or translucent support an ink-absorbing layer which is made by coating an organic solvent which contains a denatured polyethylene oxide being soluble in the organic solvent and having a water absorbing ability onto the transparent or translucent support. The ink jet recording sheet which results provides excellent ink drying ability and high optical density, and is excellent for overhead projection or blue copy.

A recording sheet for thermal dye-transfer type recording method, having a coating layer which is placed on a substrate, is contacted with a coloring material layer containing sublimable dye and on which the dye is transferred by heating. The coating layer includes as a pigment precipitated calcium carbonate of at least 25,000 cm.sup.2 /g specific-surface-area and as a binder saturated polyester or a mixture of saturated polyester with polyvinyl pyrrolidone. The sheet provides a clear record with superior color density.

Thermal dye-transfer type recording sheet

A recording sheet for thermal-dye transfer type recording having a coating layer which is placed on a substrate which is contacted with a coloring material layer containing sublimable dye and on which the dye is transferred by heating, wherein the coating layer includes both particular fine silica and particular binder, whereby the sheet provides a clear record with superior color density.

A recording sheet for thermal dye-transfer type recording having a coating layer which is placed on a substrate, which is contacted with a coloring material layer containing sublimable dye and on which the sublimable dye is transferred by heating, wherein the coating layer includes an aminoalkyd resin, whereby the recording sheet provides a record with superior color density and causes no heat-adhesion between the recording sheet and a thermal transfer substrate.

Ink jet recording paper comprising on a base sheet with a specific sizing degree a coating layer comprising a water-soluble polymeric binder and particular fine silica particles, wherein the sheet provides a superior aptitude for high speed recording with excellent optical density and improved clear image.

Thermal dye-transfer type recording sheet, having a coating layer which is placed on a base sheet, is contacted with a coloring material layer being solid or semisolid state at room temperature and on which a coloring material is transferred selectively by heating, wherein said coating layer comprises at least mixture of saturated polyester and polyvinyl pyrrolidone in a particular ratio. The sheet provides a very clear record with superior light fastness.

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Tokyo, Japan

Yutaka Kojima