Abstract: A multi-function unit includes a printer engine, a logical copying machine carrying out a copying process with respect to a recording medium by the printer engine, and a plurality of logical printers carrying out printing processes with respect to the recording medium by the printer engine. The logical copying machine and the logical printers carry out apparent parallel operations.

Abstract: An image processing apparatus and method for deriving a digital watermark embedded in an image is provided which has a recognizing unit for recognizing a predetermined characteristic area in the image and a deriving unit for extracting the digital watermark from the image data in the recognized characteristic area.

Abstract: A multifunctional printing system wherein image information captured by a scanner etc., can be printed as multiple sets of copies by a printer and which is configured so that the printing operation can be stopped only at intervals from one set of copies to the next or every certain number of printouts, includes: a computing portion for calculating the time at which an interrupt can be made next, based on the designated number of print sets, the current state of printing, the information as to whether an interrupt is permissible; and a display portion for displaying the permissible interrupt time calculated by the computing portion.

Abstract: In a printing system for printing image data based on order information, a problem of disagreement between an actual quantity and a quantity described in the order information is solved. The order information transferred from an orderer is stored in a database of an order reception site and in a database of a laboratory. An operator compares the actual quantity with the quantity specified in the order information. If the two quantities do not agree, an instruction to change the order information is input from input means. Correction affirmation means receives this instruction and generates correction affirmation information. The correction affirmation means changes the order information stored in the database in the laboratory and affirms the content thereof. The correction affirmation means then transfers the correction affirmation information to the order reception site.

Abstract: An apparatus includes a communication unit which receives email through a communication line, the email having been sent by a user and including a first identifier and data. The apparatus further includes an accumulation unit which stores therein the data, a printout unit, an input unit which receives a second identifier entered by the user through direct operation thereof, and a control unit which controls the printout unit to print the data corresponding to the first identifier by reading the data from the accumulation unit if the second identifier matches the first identifier.

Abstract: Since optical communication units are provided on different faces of an outer surface of a portable printer at two or more spots thereof for effecting optical transmission and reception of data between the portable printer and a data output device such as a handy terminal and a hand-held personal computer, optical transmission and reception of data between the portable printer and the data output device (host) can be effected with ease even if it is carried on a user's belt or placed on a desk, and the optical communication units provided at two or more spots may be mounted on a single printed-circuit board.

Abstract: A camera-integrated VTR system including a printer embodying a data processing device of the invention is provided, wherein various external data supplied from an external device and internal data generated or recorded internally are enabled to be exchanged selectively, easily and directly between respective components of the system without use of any additional component therebetween so as to be printed instantaneously.

Abstract: When correction data is set, a CPU 3 reads out the correction data from an EEPROM 8 through strobe signal lines STB1-N to STB4-N and supplies it as print data signals DATA3 to DATA0 to an LED driver IC 6. When the driving of an LED array 7 according to print data is instructed, the CPU 3 supplies a group selection signal to the LED array 7 through the strobe signal lines STB1-N to STB4-N. An electrophotographic printer which can realize a high speed of the operation and contribute to the improvement of the reliability is provided.

Abstract: In an image data output apparatus for outputting image data representative of a single image through a conversion into image data representative of partial images each to be recorded, when the single image is outputted on a divisional basis into a plurality of sheets, on the associated sheet, a partial image is designated in accordance with an operation, so that only the designated partial image is outputted.

Abstract: When determining whether or not an image of an original input from an image reading device is a copy-prohibition image, a mounting position, a mounting angle or the like of the original is detected, and it is determined whether or not exact determination can be performed. If an exact determination cannot be performed, a signal instructing to again read an image of the original is output, and the operator is provided with a warning.

Abstract: A film reading image device includes a data generation device to generate index display setting field data by receiving output from an image reading device. The film reading image device further includes a size data obtaining device to obtain size data of the monitor screen of the host apparatus and a control device to set the reading resolution based on the relationship between the number of frames to be index displayed on the monitor screen of the host apparatus and the size data obtained. The image reading device executes conversion operations with the resolution set.

Abstract: A first reference image as a natural image is displayed on a display, and a first test image including the first reference image and a plurality of first modulated images each obtained by slightly modulating colors of the first reference image is printed. The first modulated image having color tones closest to the first reference image displayed on the display is selected by the operator, and global color correction in a color space is performed on the basis of the first reference image and the selected first modulated image. Further, a second reference image of a single color is also displayed on the display, a second test image including second modulated images is printed, one of the second modulated images is selected, and local color correction in the color space is performed on the basis of the second reference image and the selected second modulated image.

Abstract: A method and apparatus are hereby disclosed for a combination photonic time and wavelength-division demultiplexer. A serial photonic signal comprising sets of synchronizing pulses and “n” sets of data pulses is received at the input of the demultiplexer. A pulse separator separates the synchronization pulses from the serial photonic signal to be transmitted to “n” photonic gates. A series of “n” delay mechanisms in a parallel configuration also receive the serial photonic signal and delay the signals such that the “n” sets of data pulses coincide with the timing of the synchronization pulses. The “n” photonic gates receive the “n” sets of data signals and the synchronization pulses simultaneously, thereby passing only the “n” sets of data signals and providing parallel photonic data or the parallel electronic data may be remultiplexed.

Abstract: A method is hereby disclosed for a combination photonic time and wavelength division multiplexing method. Parallel digital inputs of quantity “n” are input into “n” modulator loaders for loading into “n” photonic modulators, each having a setup time required to provide a stable modulation state. Subsequently, a photonic pulse of a specified frequency reads the modulation state of each of the “n” photonic modulators. The “n” modulation states may then be processed by “n” delay mechanisms to time the modulation states into a serial multiplexed output comprising a series of synchronizing pulses and data digits. Several parallel digital to serial multiplexers, operating at distinct frequencies, may be used in parallel or in series to comprise a wavelength division multiplexer in accordance with the invention.

Abstract: An optical wavelength division multiplexing network which can carry out large-capacity access service with a simple constitution is provided. In an optical network comprising a plurality of layers, a highest level network comprises a ring network having a center node and remote nodes; an intermediate level network comprises a ring centered around a node belonging to the higher level network, and a lowest level network comprises a star network centered around an access node which multiplexes traffic from a plurality of ONU, the ONU and the access node being directly joined together by optical fibers; the center node belonging to the highest level network and the ONU establish a direct communication path by using lights of different wavelengths; at nodes provided therebetween, the optical signals are not electrically processed but are amplified, branched, and routed.

Abstract: An optical signaling header technique applicable to optical networks wherein packet routing information is embedded in the same channel or wavelength as the data payload so that both the single-sideband modulated header and data payload propagate through network elements with the same path and the associated delays. The header routing information has sufficiently different characteristics from the data payload so that the signaling header can be detected without being affected by the data payload, and that the signaling header can also be removed without affecting the data payload. The signal routing technique can overlaid onto the conventional network elements in a modular manner using two types of applique modules. The first type effects header encoding and decoding at the entry and exit points of the data payload into and out of the network; the second type effects header detection at each of the network elements.

Abstract: A system which improves wavelength tolerance, compensates dispersion in a simple way, reduces limitation of the fiber input power is disclosed. The operation includes receiving a clock signal from a system clock source; modulating a single mode optical signal based on the clock signal and generating an optical pulse signal having two longitudinal modes, the frequency interval thereof being n×B, n being a natural number and B being a transmission speed; generating a partial response signal by converting a binary NRZ signal from a digital signal source in synchronism with the system clock source; and modulating the optical pulse signal based on the partial response signal, and outputting a binary RZ modulated signal. The binary RZ modulated signal is input into a receiver, where two partial response components in the optical spectra of the input signal are divided, and one or both of the components are received.

Abstract: A device for deflecting a beam, having a first beam deflection unit (14) and a mirror arrangement (20) which images the deflection point (P) onto a destination point (P′). The mirror arrangement (20) is made rotationally-symmetrical over at least a certain range of deflection angles, the deflection point (P) and the destination point (P′) being located on or near the axis (24) of rotational symmetry (24) of the mirror arrangement. There can be a second deflection unit (16) at the destination point (P′). Furthermore, a process for deflecting a given beam by means of rotation of the mirror surface of a planar mirror (14, 16) from a middle position involves setting the location of the axis (12, 18) of rotation of the plane mirror with respect to the planar mirror outside the mirror surface, the location of the axis of rotation with respect to the given beam being selected by determining the point at which the minimum variation of intersection points of rearward beam extensions occurs.

Abstract: The hinge (13) should preferably be formed to have a higher resistance than ever against the pivoting of the mirror body (12) to effectively prevent the hinge (13) from being damaged. By adopting a suitable one of a variety of production steps as necessary, the hinge (13) can be formed more finely and with a higher precision and thus the micro mirror unit can be produced more easily in a shorter time. To this end, the hinge (13) is formed from a different material, such as SiNx, from the mirror substrate material from which the frame (11) and mirror body (12) are formed.

Abstract: An optical parametric amplifier pumped by ultrashort optical pulses provides time-gated image amplification or time-gated image frequency conversion, resulting in optical sectioning of an object under test and/or background rejection of improperly timed light. An ultrashort laser pulse of one frequency is used to illuminate an object under test. An ultrashort pulse light beam at a signal frequency transmitted through or scattered from the object is optically mixed with an ultrashort laser pulse at a pump frequency in a nonlinear optical medium. This mixing produces an amplified image of a particular optical section of the object at the signal frequency in addition to producing a frequency converted image of the same optical section at an idler frequency. This time-gated amplification can be used in conjunction with a confocal imaging system, or a conventional imaging system.

Abstract: An optical fiber amplifier comprises an optical fiber for light loss which is provided in a later stage than an optical fiber amplification section or midway therein, the amount of light absorption and the wavelength dependency of the absorption of the optical fiber changing according to the power of input light; whereby the optical fiber amplifier can maintain flat gain in a wide wavelength band, the gain flatness not changing over a wide dynamic range and being maintained irrespective of variation in the power of input signal light.

Abstract: An optical amplifying apparatus which includes an optical amplifier, an optical attenuator and a controller. The optical amplifier amplifies a light signal having a variable number of channels. The optical attenuator passes the amplified light signal and has a variable light transmissivity. Prior to varying the number of channels in the light signal, the controller varies the light transmissivity of the optical attenuator so that a power level of the amplified light signal is maintained at an approximately constant level that depends on the number of channels in the light signal prior to the varying the number of channels. While the number of channels in the light signal is being varied, the controller maintains the light transmissivity of the optical attenuator to be constant.

Abstract: The invention proposes a supplementary appliance (3) in order to produce an illuminated reticle (5) for telescopic sights (1), which can be fitted as required to different telescopic sights (1), to be precise to their objective end (2), and allows the user to aim at his target reliably even in twilight or moonlight.

Abstract: A see-through retroreflective structure includes a transparent polymeric film, an array of retroreflective elements attached to the polymeric film, and an array of apertures through the retroreflective structure within the array of retroreflective elements. In one embodiment, the retroreflective structure includes a metalized reflective layer formed on the transparent prism elements and a support layer, such as a fabric, is attached to the metalized reflective layer.

Abstract: An optical system comprises, in succession from the object side, a first optical element of negative optical power, a second optical element of positive optical power, and a third optical element of negative optical power, at least one of the first to third optical elements being a refracting optical element having a reflecting curved surface.

Abstract: An optical lens, has a marking entirely or partially outside an effective area of the lens to distinguish between surfaces of the lens.

Abstract: A zoom lens formed of no more than four lens groups having refractive power of, in order from the object side, positive, negative, positive, and positive. The first and third lens groups are fixed in position, whereas the position of the second lens group along the optical axis is varied to change the focal length during zooming, and the position of the fourth lens group is adjusted along the optical axis so as to compensate for what otherwise would be movement of the image surface with zooming and distance to the object. The second lens group includes a negative lens element having a concave surface or a planar surface on its object side, a combined lens which includes a biconcave lens element joined to a positive meniscus lens element with its convex surface on the object side. The third lens group consists of a single lens element with at least one surface thereof being aspherical, and the fourth lens group includes a lens element having an aspherical surface.

Abstract: A cam mechanism includes a linear guide barrel provided with a linear guide projection at one end thereof, extending radially outwards; a cam barrel fitted on the linear guide barrel, rotatable relative to the linear guide barrel and movable along the optical axis with the linear guide barrel, the cam barrel being provided with a cam groove on an inner surface thereof; a linear guide slot formed on the linear guide barrel extending parallel to the optical axis; at least one lens frame positioned inside the linear guide barrel; a projection formed on the lens frame to be slidably engaged in the linear guide slot; and a cam follower formed on the projection to be engaged in the cam groove. The linear guide projection and the linear guide slot are formed on the linear guide barrel at the same circumferential position of the linear guide barrel.

Abstract: A zoom lens includes a plurality of lens groups, and a cam barrel having a cam groove formed on an inner peripheral surface thereof. The cam barrel includes a first barrel having the cam groove on an inner peripheral surface thereof, and a second barrel which is fitted on a front part of an outer peripheral surface of the first barrel, the first barrel and second barrel being movable in the optical axis direction with a predetermined clearance provided therebetween in the optical axis direction while being rotatable together about the optical axis, so that an external force applied to the zoom lens from the outside of the zoom lens is transmitted to the first barrel via the second barrel.

Abstract: A cam barrel rotating mechanism of a zoom lens includes a plurality of lens groups guided in a direction of an optical axis without rotating about the optical axis to change a focal length of the zoom lens; a cam barrel rotatably supported to move the plurality of lens groups in the optical axis direction; a rotational barrel positioned around the cam barrel, the rotational barrel being rotatably driven; a plurality of rotation transmission grooves formed on an outer peripheral surface of the cam barrel, at an equi-angular intervals, extending parallel to the optical axis; and a plurality of inward projections formed on an inner peripheral surface of the rotational barrel to be engaged in the plurality of rotation transmission grooves, respectively.

Abstract: A selectable assembling device of a zoom lens barrel includes a stationary barrel having a female helicoid, and linear guide grooves spaced at 120 degree intervals; a cam ring including bottomed cam grooves; a linear guide barrel provided with linear guide projections and linear guide slots spaced at 120 degree intervals; and a plurality of lens frames provided with sliding projections spaced at 120 degree intervals, which are engaged in the linear guide slots of the linear guide barrel, each of the sliding projections including a cam follower which is fitted in a corresponding bottomed cam groove of the cam ring. Upon assembly, a relative angular position of assembly for the cam ring and the linear guide barrel can be selected from among three circumferential positions spaced at 120 degree intervals. A device for guiding a flexible circuit board is also provided.

Abstract: Multi-beam lithography apparatus is used for writing patterns on a substrate 14 such as a wafer for ICs. The patterns may have details of various dimensions. In order to enhance the production rate, it is attractive to write fine details with a small spot 16 and large details with a large spot. It is known to vary the spot size by varying the emissive surface of the electron source. In accordance with the invention the spot size is varied by varying the size 22 of the beam limiting aperture 20, thus enabling optimization of the beam current in dependence on the spot size. A preferred embodiment is provided with an additional (condenser) lens 24 such that the object distance remains constant when the magnification of the lens system 18, 24 is varied.

Abstract: A bayonet fixing device includes a cylindrical member; an annular member attached to one end of the cylindrical member; and a retainer ring attached to the cylindrical member to fix the annular member to the cylindrical member. The cylindrical member includes engaging lugs and insertion areas which are alternately arranged along the circumference at one end of the cylindrical member; grooves formed behind the engaging lugs; and recesses formed behind the grooves. The annular member includes a plurality of projections which are respectively fitted into the recesses via the insertion areas and the grooves. The retainer ring includes engaging blades which are fitted into the grooves via the insertion areas to be positioned between the engaging lugs and the projections in an axial direction of the cylindrical member.

Abstract: An optical low-pass filter for a solid-state image sensor of an offset sampling structure is constituted of first and second optical members. The first optical member splits an incident light ray into a rectilinear ray and a refracted ray whose propagation direction is about 45° to a horizontal direction of the solid-state image sensor. The second optical member splits an incident ray into a rectilinear ray and a refracted ray whose propagation direction is about 90° to the horizontal direction. The optical low-pass filter having this configuration splits the incident light ray into four rays whose split points are at respective corners of a parallelogram.

Abstract: A magnetic card reader for causing a magnetic card to make a move relative to a magnetic head and reproducing data on the magnetic card by the magnetic head, said magnetic card reader includes an amplifier for amplifying a magnetic signal provided by the magnetic head, a peak detection section for detecting a peak point of amplifier output from the amplifier output, a data reproduction section for reproducing digital data based on the interval between the peak points, an anomaly detection section for detecting an anomaly of the peak point interval and an output value storage section for converting the amplifier output from analog form into digital form every predetermined time and storing the provided data.

Abstract: An apparatus for recording and reproducing digital data according to the present invention, includes: a group converter; a controller; a recording converter; a recording unit; a reproducing unit; a reproducing converter; and a group reverse converter, wherein the group converter includes: a block management data generator for receiving the management data from the controller and generating block management data with respect to the corresponding blocked data, the block management data having a variable-length and containing information concerning each blocked data; a group management data generator for receiving the management data and generating group management data containing information concerning the entire grouped data; and a grouped data generator for receiving the blocked data, the block management data, and the group management data, and generating grouped data by arranging the blocked data, the block management data, and the group management data in a predetermined order.

Abstract: A hard disk drive filtering apparatus for filtering particles from flowing air generated while a hard disk installed within a housing rotates, the apparatus including a holder installed within the housing, and a filter supported by the holder, the filter having at least a pair of filter plates connected to be met at predetermined angles, wherein the flowing air is filtered while being entered into the space formed by the filter plates.

Abstract: An FD-shaped adapter for a card-shaped memory device has a base case, an electric circuit portion, a top cover, and a bottom cover. The bottom cover has a plate-shape and is provided with a bottom plate, side plates upwardly extended from side edges of the bottom plate, and flanges outwardly extended from each top edge of the side plates. The bottom cover is attached on the base case so that the flanges are sandwiched between the upper surface of the base case and an inner surface of the top cover.

Abstract: To make a soft magnetic underlayer of a double layered perpendicular magnetic recording medium thinner than heretofore while avoiding saturation. Assuming that Tb1 is the thickness of the soft magnetic underlayer of the double layered perpendicular magnetic recording medium, BS2 the saturation flux density of the same, Tm the thickness of a magnetic recording head's main pole 1 along a track direction in the vicinity of its floating surface, TWW the track width of the same, and BS1 the saturation flux density of the same, then Tb1<(BS1×Tm×TWW) / 2 (BS2×(Tm+TWW) ) is satisfied.

Abstract: A winding is wound directly on the magnetic head core formed of a single crystal of Mn—Zn ferrite. The diameter is 20-30 &mgr;m. A high-saturated magnetic flux density material (iron) having a magnetic flux density which is more than 1.3 T covers walls of the magnetic gap using sputtering. A slider including the magnetic head comprises ceramic including titanic calcium. The magnetic head is adhered to the slider with a low melting point glass. In a magnetic recording apparatus including the above-mentioned magnetic head, the slider includes air bearing surface trains arranged in the driving direction of the magnetic recording medium on a contact surface of the slider. Each bearing surface train includes protruding portions and a hollow portion direction. The hollow portion escapes the air between the protruding portion and the recording medium. The head is evacuated from the magnetic recording medium.

Abstract: A disc drive includes a spindle motor, a spindle, a disc, control circuitry, an actuator, and an armature. The spindle motor is coupled to the spindle to which the disc is also coupled. The control circuitry is coupled to the actuator and provides the actuator with control signals. The armature includes a load beam coupled to the actuator such that energization of the actuator displaces the load beam. The gimbal is coupled to the head and is also coupled to the load beam by a plurality of spaced apart. attachment points. An interconnect operably couples the head to the control circuitry.

Abstract: A suspension includes a load beam having a main body and a transducer support element which is movable relative to the main body. A sheet of dielectric material extends along the load beam and carries a plurality of transducer signal traces and a coil. A microactuator is positioned along the load beam and includes a first magnet, the coil and a lever arm. The lever arm is secured to the transducer support element and supports one of the first magnet and the coil. The other of the first magnet and the coil is secured relative to the load beam.

Abstract: A suspension supports a slider for use with a microactuator. The suspension includes a suspension arm attachment pad and a slider attachment pad, connected together by microbeams. A first plurality of microbeams run side-by-side and extend on one side of the suspension, and a second plurality of microbeams run side-by-side and extending on the other side of the suspension. The microbeams preferably include a web and at least one flange which is wider than the web, such as in an “I” shape. The suspension is fabricated out of a single crystal silicon wafer with photolithographic techniques, including doping a surface of the wafer and etching the interior of the wafer to form the “I” shaped microbeams. The microbeams of the present invention make the suspension more flexible in the lateral direction while supporting the preload force on the slider in the vertical direction.

Abstract: A second magnetic film of an inductive type electromagnetic conversion element is positioned at a trailing edge side relative to a first magnetic film of the conversion element. One edge portion of the second magnetic film is opposed to one edge portion of the first magnetic film by a given distance. The one edge portion of the second magnetic film has at least one side surface inclined at a given inclination angle not less than a maximum skew angle. The second magnetic film is extended backward, and joined with the first magnetic film. A coil film of the inductive type electromagnetic conversion element is whirled around the magnetic circuit composed of the first and second magnetic films.

Abstract: A magnetoresistive element includes a first antiferromagnetic film, a first magnetic film having a magnetization direction fixed by magnetic coupling with the first antiferromagnetic film, a second antiferromagnetic film, a second magnetic film having a magnetization direction fixed by magnetic coupling with the second antiferromagnetic film, a third magnetic film having a magnetization direction able to rotate in response to an applied magnetic field, a first nonmagnetic film disposed between the first magnetic film and the third magnetic film, and a second nonmagnetic film disposed between the second magnetic film and the third magnetic film. The third magnetic film is disposed between the first nonmagnetic film and the second nonmagnetic film, the first magnetic film is disposed between the first antiferromagnetic film and the first nonmagnetic film, and the second magnetic film is disposed between the second antiferromagnetic film and the second nonmagnetic film.

Abstract: A magnetoresistive effect film achieves sufficiently large resistance variation ratio, sufficient switch connection force from an anti-ferromagnetic layer to a fixed magnetic layer, certainly maintains head resistance at a temperature higher than or equal to 200° C. with certainly maintaining good soft magnetic characteristics of NiFe layer or NiFe layer/CoFe layer, and is superior in thermal stability and has large magnetoresistance variation ratio (MR ratio). The magnetoresistive effect film is a stacked film which is consisted of a substrate, an buffer layer, a NiFe layer, a non-magnetic layer, a fixed magnetic layer, and an anti-ferromagnetic layer. A crystal grain size of the stacked film is greater than or equal to 8 nm and less than or equal to a total layer thickness of the stacked layer excluding the substrate and the buffer layer.

Abstract: A semiconductor integrated device is provided which consists of a plurality of circuit blocks. Each circuit block is connected to a power supply terminal and a ground terminal. Signal interface sections connect signal circuits among the circuit blocks. A plurality of first diodes are serially connected to one another in a first direction between the ground terminal of a first one of the circuit blocks and the ground terminal of another of the circuit blocks. A plurality of second diodes are serially connected to one another in a second direction that is opposite to the first direction between the ground terminal of the first circuit block and the ground terminal of the another circuit block.

Abstract: The present invention is intended to prevent an element breakdown derived from an electrostatic discharge (ESD) during the handling such as packaging of an LSI chip, packing and transportation, and to divide the input protection diodes from the signal input terminal during the ordinary use of the LSI so as to prevent the inhibition of a high speed operation and a latch-up phenomenon. The first and second diodes, each connected in reverse polarity between the signal input terminal and any of a voltage supply node and a ground node inside the LSI, are divided from the signal input terminal of the LSI by controlling the first and second fuse elements, each connected between the signal input terminal and any of the first and second diodes, from the outside after the LSI is mounted to the assembly circuit board.

Abstract: A hot-line inserting and removing apparatus is capable of inserting and removing a circuit unit while the apparatus is in operation. An overcurrent protection circuit is inserted in a power supply in the hot-line inserting and removing apparatus, and has a switch which changes its resistance to prevent a rush current from flowing into a capacitive component of a connected load for protection against an overcurrent at the time the circuit unit is inserted.

Abstract: A method for fabrication of ceramic tantalum nitride and improved structures based thereon is disclosed. According to the disclosed method, an ionized metal plasma (“IMP”) tool is used to create a plasma containing tantalum ions where the plasma is sustained by a mixture of nitrogen and argon gases. The percentage of nitrogen partial flow in the mixture of gases is adjusted so as to result in a layer of tantalum nitride with a nitrogen content of at least 30%. With a nitrogen content of at least 30%, the tantalum nitride becomes ceramic. The ceramic tantalum nitride presents a number of advantages. For example, the fabrication of ceramic tantalum nitride can be easily incorporated into fabrication of semiconductor chips using copper as the interconnect metal. Also, ceramic tantalum nitride can be used as an effective etch stop layer.