Abstract: An automatic gain control circuit includes a power calculator for calculating power of a modulation wave supplied to a demodulator; a power comparator for comparing the power calculated by the power calculator with ideal power of a modulation scheme of the modulation signal; a first gain controller for carrying out gain control of a first AGC amplifier in response to an output of the power comparator; and a second gain controller for carrying out gain control of the second AGC amplifier in response to the output of the power comparator. The automatic gain control circuit can solve a problem of a conventional AGC circuit in that precision gain distribution cannot be achieved to the two AGC amplifiers because the two AGC amplifiers are controlled by a single control signal output from the automatic gain control circuit.

Abstract: An A-rail circuit outputs a control signal AGCOUTA whereas a B-rail circuit outputs a control signal AGCOUTB in an AGC circuit. AGCOUTA controls an AGC amplifier (A) while AGCOUTB controls an AGC amplifier (B). A difference value between a power of an input signal and (an amount of variable adjustment SWEEP+a power reference value AGCR). If an output signal of a loop filter in the A-rail circuit attains AGCARAIL>AGCATOB, AGCARAIL=AGCATOB is fixed, and AGCBRAIL is adjusted based on the difference value. If an output signal of a loop filter in the B-rail circuit attains AGCBRAIL<AGCBTOA, AGCBRAIL=AGCBTOA is fixed, and AGCARAIL is adjusted based on the difference value. A control circuit in the AGC circuit acquires a bit error rate, identifies a value of SWEEP allowing a minimum bit error rate, and fixes the value of SWEEP at the identified value.

Abstract: An image forming system is provided which includes an optical sheet and an image projector. The optical sheet is constructed by joining a plurality of sheet members with adjoining sheet members meeting to form a joint line. The image projector produces an image and projects the image to the optical sheet through a projection optical system. The relative positional relationship between the image projector and optical sheet is such that the optical axis of the projection optical system included in the image projector perpendicularly intersects the joint line in the optical sheet. Thus, reflection or scattering of light at the joint line is minimized.

Abstract: An optical prism (1) for reflecting incident light from an incidence surface (2) suited for incidence of light from an LCD (20) or the like for at least twice before emitting the reflected light as emission light from a predetermined emission surface (4). The optical prism has side surfaces (6L and 6R) crossing the incidence and emission surfaces (2 and 4) and including receded surfaces 7L and 7R) formed such as not to impede an optical path of an effective size, the incident light being led along the optical path from the incidence surface to the emission surface.

Abstract: An object is to obtain an adaptive equalizer device and an adaptive equalizer controlling method which provide an ideal output signal certainly and in a shorter time. The adaptive equalizer device includes an adaptive equalizer (4a) receiving a signal indicating a symbol, for filtering the signal indicating the symbol to adaptively remove intersymbol interference by selectively using one of a plurality of preset algorithms, and a rotation detecting circuit (19) receiving an output signal (y(n)) from the adaptive equalizer, for detecting rotation of the symbol of the output signal (y(n)), wherein the adaptive equalizer (4a) selects one of the plurality of algorithms in accordance with detected result flags (&agr;, &bgr;) from the rotation detecting circuit (19).

Abstract: An illumination apparatus which illuminates a portion to be illuminated with light from a light source comprises a plurality of light emitting members constituting the light source, a driving circuit which drives the respective light emitting members, a condenser optical system which condenses an emitted light from the light emitting member drove by the driving circuit onto the portion to be illuminated, a light control member which performs change of a light path of the light from the light emitting member to illuminate the portion to be illuminated and/or movement of the light emitting member, a movable section which operates the light control member in a predetermined period, and a light selection control section which controls the movable section and/or driving circuit so as to select the light to illuminate the portion to be illuminated from the lights of the plurality of light emitting members.

Abstract: A multi-display device synthesizes partial images, by using multiple projectors to construct one image. Each projector has an illumination device, a lattice-like lens array, a display, and a projection lens. The illumination device and lattice-like lens array form secondary light source images that are arrayed in a rectangular lattice. The display is illuminated by the plurality of secondary light source images and displays partial images. The projection lens projects the partial images. Interceptors intercept the margins of projected partial images to obtain uniform luminance. Each interceptor has an intercepting edge that is alternately concave and convex. The height of the convex parts and the pitch between adjoining concave and convex parts are selected so that projections produced by adjoining secondary light source images are displaced from each other by a half phase. Thus, a belt-shaped distribution of luminance values in the margins of the partial images are resolved nearly perfectly.

Abstract: The present invention provides an ND filter manufacturing method which makes it possible to obtain an ND filter film that has light transmittance information in respective positions by exposing and imaging image electronic data that has light transmittance information for respective positions used to form an ND filter by employing an exposure imaging device that is capable of the direct exposure imaging of the image electronic data, and developing the film. Furthermore, the light transmittance distributions of ND filters disposed in positions corresponding to the overlapping regions in a multi-display device are constructed from curves, so that the overlapping regions are hard to distinguish from the non-overlapping regions.

Abstract: In an automatic gain control circuit of a demodulating circuit, power values of pieces of symbol information I and Q of in-phase components and quadrature components of a modulated signal are calculated, a power difference between each power value and an ideal power value is detected, and an AGC control signal is produced to adjust a gain of the modulated signal according to the AGC control signal in a demodulating system including the demodulating circuit. Therefore, when an amount of noise included in the modulated signal is low, an average value of the power differences is reduced to zero, and the modulated signal can be correctly demodulated to a demodulated signal. To correctly demodulate the modulated signal including a large amount of noise, after the conversion of the AGC control signal, a sweep counter value is added to the AGC control signal so as to minimize a bit error rate of the demodulated signal.

Abstract: The aim is to improve convenience of Japanese catalogues for foreigners. Japanese catalogues are prepared and distributed to foreign purchasers in and out of Japan. On the other hand, a virtual catalogue in which the Japanese catalogues are translated to a language used by the foreigners, such as English, Chinese or Korean is put into a database and registered through an Internet server. Each foreign purchaser accesses the registered server site in the database, opens the virtual catalogue in a desired language, and selects an item of goods by associating the virtual catalogue with the catalogue e.g. by referring to item numbers. In this way, the purchaser can buy goods with better understanding. This improves convenience. On the other hand, for the mail-order sale firm, it is possible to improve the service and also to suppress the sales cost compared with when catalogues in many languages are prepared and distributed.

Abstract: The present invention provides an image forming system consisting mainly of an optical sheet and an image projector. The optical sheet is constructed by joining a plurality of sheet members with adjoining sheet members met to form a joint line. The image projector produces an image and projects the image to the optical sheet through a projection optical system. The relative positional relationship between the image projector and optical sheet is such that the optical axis of the projection optical system included in the image projector perpendicularly intersects the joint line in the optical sheet. Thus, reflection or scatterings of light at the joint line is minimized.

Abstract: The present invention is concerned with an optical sheet to be used as a screen on which an image is projected from an image projector. The optical sheet is produced by joining a plurality of optical sheet members with end surfaces thereof met each other as joint surfaces. The optical sheet members are realized with lenticular lens sheets. The lenticular lens sheet has lenses, which are elongated in a second direction, juxtaposed in a first direction orthogonal to the second direction. The optical properties of the optical sheet members that are slightly undulated vary cyclically in the first direction. Herein, the optical sheet members to be joined are a selected pair of optical sheet members whose undulations are substantially identical to each other or symmetrical to each other with respect to the joint surfaces.

Abstract: An optical prism (1) for reflecting incident light from an incidence surface (2) suited for incidence of light from an LCD (20) or the like for at least twice before emitting the reflected light as emission light from a predetermined emission surface (4). The optical prism has side surfaces (6L and 6R) crossing the incidence and emission surfaces (2 and 4) and including receded surfaces 7L and 7R) formed such as not to impede an optical path of an effective size, the incident light being led along the optical. path from the incidence surface to the emission surface.

Abstract: An optical prism (1) for reflecting incident light from an incidence surface (2) suited for incidence of light from an LCD (20) or the like for at least twice before emitting the reflected light as emission light from a predetermined emission surface (4). The optical prism has side surfaces (6L and 6R) crossing the incidence and emission surfaces (2 and 4) and including receded surfaces 7L and 7R) formed such as not to impede an optical path of an effective size, the incident light being led along the optical path from the incidence surface to the emission surface.

Abstract: The present invention provides an image display device including an LCD, a polarization switching liquid crystal cell, a birefringent plate, and an eyepiece. The LCD displays an image using a plurality of arrayed pixel locations. The polarization switching liquid crystal cell has a plurality of electrodes incorporated therein and switches the direction of polarization in which light emitted from the LCD is polarized. The birefringent plate varies the optical path of light emitted from the polarization switching liquid crystal cell depending on the direction of polarization. The eyepiece magnifies light representing an image displayed on the LCD. The LCD and polarization switching liquid crystal cell are positioned so that the distance L1 from the eyeballs to the virtual image plane of the LCD and the distance L2 from the eyeballs to the virtual image plane of the polarization switching liquid crystal cell will have the relationship of 1/L2−1/L1≧0.4 D or L2≦200 mm.

Abstract: A multi-display device synthesizes partial images, which are projected on a screen from a plurality of projectors, so as to construct one image. Each projector consists mainly of an illumination device, a lattice-like lens array, a display device, and a projection lens. The illumination device and lattice-like lens array form a plurality of secondary light source images that is arrayed in the form of a rectangular lattice or a rectangular matrix. The display device is illuminated with the plurality of secondary light source images and displays partial images. The projection lens projects the partial images. The multi-display device further includes interceptors each of which intercepts the margin of a projected partial image to be superposed on the margin of an adjoining partial image. The interceptor has an intercepting edge thereof shaped to be alternately concave and convex.

Abstract: An automatic gain control circuit includes a power calculator for calculating power of a modulation wave supplied to a demodulator; a power comparator for comparing the power calculated by the power calculator with ideal power of a modulation scheme of the modulation signal; a first gain controller for carrying out gain control of a first AGC amplifier in response to an output of the power comparator; and a second gain controller for carrying out gain control of the second AGC amplifier in response to the output of the power comparator. The automatic gain control circuit can solve a problem of a conventional AGC circuit in that precision gain distribution cannot be achieved to the two AGC amplifiers because the two AGC amplifiers are controlled by a single control signal output from the automatic gain control circuit.

Abstract: It is an object to enlarge the phase range in which a phase error can be determined. An operating block (1) calculates a power of carriers from data DI and DQ. An ideal symbol estimating block (2a) outputs a plurality of ideal symbols which correspond to the power of carriers outputted from the operating block (1). A phase error tan(.theta.) calculating block (2b) calculates prediction phase errors between the ideal symbols and the symbol given by the data DI and DQ. A phase error determining block (3) determines a phase error from among the prediction phase errors outputted from the phase error tan(.theta.) calculating block and outputs the phase error.

Abstract: It is the object of the invention to provide a compact and highly stable head-mount image display apparatus capable of always transmitting voice information of an optimal volume, irrespective of the positional relationship between the head and the ear of an observer, which is related to the shape and/or size of the head. To attain the object, speakers incorporated in the apparatus of the invention can be moved to desired positions in accordance with changes in the positional relationship between the head and the ears of observers. Further, the apparatus of the invention can be folded to reduce the area the apparatus occupies.

Abstract: A k-bit data input and a 1-bit scan input of a scan flip-flop (21.sub.i) of a multiply-accumulation operation unit (4.sub.i) respectively receive a k-bit data output and a 1-bit scan output of a scan flip-flop (21.sub.i-1) of a multiply-accumulation operation unit (4.sub.j-1) in the previous stage. A j-bit data input and a 1-bit scan input of a scan flip-flop (22.sub.i) respectively receive a j-bit data output of an adder (3.sub.i-1) of a multiply-accumulation operation unit (4.sub.i-1)) in the previous stage and a 1-bit scan output of a scan flip-flop (22.sub.j+1) in the next stage.