A magnetoresistance effect film including a magnetically pinned layer, a non-magnetic intermediate layer and a magnetically free layer has sidewall layers covering at least side surfaces of the magnetically pinned layer and the non-magnetic intermediate layer. The sidewall layers are made of a high-resistance oxide, nitride, fluoride, boride, sulfide or carbide having a specular reflection effect against conduction electrons, thereby to prevent non-elastic scattering of electrons and missing of spin information on side surfaces of the magnetoresistance effect film.

This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2003-099360, filed on Mar. 30, 2001; the entire contents of which are incorporated herein by reference.
This invention relates to a magnetoresistance effect element; magnetic head and magnetic reproducing apparatus. More particularly, the invention relates to a magnetoresistance effect element configured to carry a sense current perpendicular to the film plane of a magnetoresistance effect film, and also to a magnetic head and a magnetic reproducing apparatus using the magnetoresistance effect element.
Discovery of giant magnetoresistance effect in a multi-layered structure of magnetic layers has triggered remarkable improvement of the function of magnetic devices, especially the function of magnetic heads. Especially, discovery of the giant magnetoresistance effect (GMR) by a spin valve (SV) film has brought about great technical development in the field of magnetic devices. A spin valve film includes a non-magnetic layer (called a spacer layer or non-magnetic intermediate layer) interposed between two metallic ferromagnetic layers to fix magnetization of one of the ferromagnetic layers (called a pinned layer or magnetically pinned layer) in one direction under a bias magnetic field from an anti-ferromagnetic layer or hard magnetic layer and to permit the other ferromagnetic layer (called a free layer of magnetically free layer) to incline its magnetization direction relative to the pinned layer in response to an external magnetic field such that a giant magnetoresistance can be obtained.
Among SV films of this type, a CPP (current-perpendicular-in-plane) type SV element configured to carry a current approximately perpendicular to the SV film plane exhibits a larger giant magnetoresistance effect than CIP (current-in-plane) type SV elements.
As one type of CPP elements, a TMR element using a tunneling magnetoresistance effect) film has been developed as well. Such a TMR film includes an insulating layer of Al2O3 as the spacer layer. The TMR film has the same layer configuration as that of the SV film from the viewpoint of the function.
The CPP magnetoresistance effect element using a magnetoresistance effect film (both a SV film and a magnetoresistance effect film are regarded herein to include a GMR film and a TMR film) not only exhibits a larger rate of MR change than CIP elements but also has the advantage that miniaturization of the element contributes to increasing the quantity of MR change because the resistance of the element relies on the element area.
This advantage is very useful in this era where magnetic devices are progressively miniaturized. For example, also regarding magnetic heads using SV films, which are under improvement of the recording density by approximately 60% a year, those using CPP magnetoresistance effect elements are regarded to be more and more hopeful along with progressive miniaturization of the reproducing head portions in accordance with improvements of the recording density.
Although, however, those CPP magnetoresistance effect elements have the above-mentioned advantages, they involve the problem about the scaling rule, which is peculiar to CPP elements, because the rate of MR change decreases when the element size approaches the mean free path of electrons. This phenomenon is not large as far as the element size is sufficiently large relative to the mean free path of electrons, but becomes serious together with onward miniaturization of the element.
That is, although conventional CPP magnetoresistance effect elements can cope with miniaturization to a certain extent, they are not readily applicable to superfine magnetic devices that will be desired in future, and could not perform their full function.
The present invention has been made taking those problems into account. It is therefore an object of the invention to provide a CPP magnetoresistance effect element that ensures a high rate of MR change and a large quantity of MR change without departing from the scaling rule even when its size is near the mean free path of electrons. A further object of the invention is to provide a magnetic device, especially a magnetoresistance type magnetic head, using the CPP magnetoresistance effect element, and a magnetic reproducing apparatus and a magnetic storage device using the magnetic device.
To accomplish the objects, a magnetoresistance effect element according to the first embodiment of the invention comprises:
a magnetoresistance effect film having a magnetically pinned layer which includes a ferromagnetic film whose magnetization direction is pinned substantially in one direction, a magnetically free layer which includes a ferromagnetic film whose magnetization direction varies with an external magnetic field, and a non-magnetic intermediate layer interposed between the magnetically pinned layer and the magnetically free layer;
a pair of electrodes electrically connected to the magnetoresistance effect film to carry a current in a direction approximately perpendicular to the film plane of the magnetoresistance effect film; and
sidewall layers formed at least on side surfaces of the magnetically pinned layer, the non-magnetic intermediate layer and the magnetically free layer of the magnetoresistance effect film.
The sidewall layer may be formed by, for example, oxidizing, nitrifying, fluoridating, carbonizing, sulfurating or boronizing the side surface of the magnetoresistance effect film.
Since the sidewall layer is stabilized more when crystallized, the above-summarized configuration produces the effect that oxygen, nitrogen, fluorine, carbon, sulfur or boron contained in the sidewall layer is unlikely to spread into the magnetoresistance effect film. Additionally, since the crystallized portion clearly defines the boundary between the sidewall layer and the magnetoresistance effect film and thereby makes a sharp potential profile at the boundary, there is also the effect that the specular reflection effect of conduction electrons of the sense current further increases. Since the increase of the specular reflection effect results in making the best use of the mean free path of electrons, degradation of the MR-changing rate is prevented.
That is, the sidewall layer made of a compound of an oxide, nitride, fluoride, carbide, boride or sulfide on the side surface of the magnetoresistance effect film produces the specular reflection effect of electrons. Additionally, it is possible to prevent a decrease of the MR-changing amount.
If the sidewall layer is in form of a compound phase containing, as a major component thereof, an oxide, fluoride, nitride, boride, carbide or sulfide of any one selected from the group consisting of B, Al, Si, Ge, W, Nb, Mo, P, V, Sb, Zr, Hf, Y, Ti, Ta, Zn, Pb, Cr, Sn, Ga, Cu and rare earth elements, then the potential profile at the boundary can be sharpened, and the specular reflection effect of electrons on the side surface of the magnetoresistance effect film can be enhanced.
If the side wall layer contains at least one kind of element selected from the group consisting of Fe, Co and Ni, and at least one kind of element selected from the group consisting of B, Al, Si, Ge, W, Nb, Mo, P, V, Sb, Hf, Zr, Y, Ti, Ta, Zn, Pb, Cr, Sn, Ga, N, O, F, S, C, Cu and rare earth elements, then the potential profile at the boundary can be sharpened, and the specular reflection effect of electrons on the side surface of the magnetoresistance effect film can be enhanced.
If the sidewall layer is in form of a mixture phase mixing an amorphous phase and a crystalline structure containing Fe, Co or Ni as a major component, its resistance can be increased, and simultaneously, spontaneous magnetization thereof by Fe, Co or Ni in the crystalline structure enhances the bias effect from the hard bias film and the anti-ferromagnetic bias film. For the purpose of enhancing the resistance of the sidewall layer, the crystal grain side of the crystalline portion had better be small, and the maximum grain size is preferably not larger than 20 nm. The ratio the crystalline structure occupies in the sidewall layer is preferably not more than 50% to ensure a high resistance. Therefore, the content of Fe, Co or Ni in the sidewall layer is preferably not more than 70 atomic %, and more preferably, not more than 50 atomic %. That content may be otherwise determined in case the crystalline structure is made of an oxide, fluoride, nitride, boride, carbide or sulfide.
If the sidewall layer includes an amorphous phase containing as its major component an oxide, fluoride, nitride, boride, carbide or sulfide of at least one kind of element selected from the group consisting of B, Al, Si, Ge, W, Nb, Mo, P, V, Sb, Hf, Y, Zr, Ti, Ta Zn, Pb, Cr, Sn, Ga and rare earth metals, diversion of the sense current from the side surface of the magnetoresistance effect film can be prevented.
In case the sidewall layer contains, as its major component, an oxide, fluoride, nitride, boride, carbide or sulfide of at least one kind of element selected from the group consisting of B, Al, Si, Ge, W, Nb, Mo, P, V, Sb, Hf, Y, Zr, Ti, Ta Zn, Pb, Cr, Sn, Ga and rare earth metals, the specular reflection effect at the side surface of the magnetoresistance effect film can be enhanced. In this case, if the sidewall layer is in form of a mixture of a crystalline structure and an amorphous phase, both an increase of the specular reflection effect by the crystalline phase and an increase of the resistance by the amorphous structure can be realized simultaneously.
The sidewall layer may contain as its major component an oxide, fluoride, nitride, boride, carbide or sulfide of at least one kind of element selected from the group consisting of Fe, Co., Ni, Mn, B, Al, Si, Ge, W, Nb, Mo, P, V, Sb, Hf, Zr, Ti, Ta, Zn, Pb, Cr, Sn, Ga and rare earth metals, and may be in form of a substantially amorphous phase.
Crystallization of the sidewall layer produces the effect that oxygen, nitrogen, fluorine, carbon, sulfur or boron contained in the sidewall layer is unlikely to spread into the magnetoresistance effect film. Additionally, since the crystallized portion clearly defines the boundary between the sidewall layer and the magnetoresistance effect film and thereby makes a sharp potential profile at the boundary, there is also the effect that the specular reflection effect of conduction electrons of the sense current further increases.
As a method of identifying a xe2x80x9ccrystalline phase,xe2x80x9d electron diffraction, for example, may be used. For example, if a diffraction spot having an orderly arrangement is observed in an electron diffraction image obtained through a transmission type electron microscope (TEM), the structure can be confirmed to be crystalline. More precisely, if a period suggesting an orderly arrangement is found in the diffraction intensity of the electron diffraction image, the structure can be confirmed to be crystalline. If equally spaced interstitial images, i.e. lattice images, derived from a certain plane orientation, or moire images caused by the overlap of lattices, are observed, then the structure is determined to be crystalline.
The xe2x80x9camorphous phasexe2x80x9d can be identified, for example, by the fact that no such periodicity is found in the electron diffraction, or the like.
Whether a structure is a xe2x80x9cmixture of an amorphous phase and a crystalline phasexe2x80x9d can be confirmed if both properties of a crystalline phase and an amorphous phase are observed depending on the location of the sample.
Whether it is magnetic or not can be confirmed by measuring magnetization of a thin film sample of the sidewall layer prepared by the same method. Alternatively, it can be known by measuring magnetization of a bulk sample or thin film sample of the same composition, based on a result of chemical composition analysis by EDX (energy dispersive X-ray spectroscopy), for example.
In any version of the magnetoresistance effect element according to the invention summarized above, thickness of the sidewall layer is preferably in the range from 0.5 nm to 10 nm. If the thickness is less than 0.5 nm, the sidewall layer cannot make a sharp potential profile at the boundary, and a sufficient effect of specular reflection cannot be obtained. Additionally, the sidewall layer is too thin to prevent diversion of the sense current.
On the other hand, if the thickness of the sidewall layer is 10 nm or more, effects of the use of the hard bias film and anti-ferromagnetic bias film for exerting a biasing effect to the free layer are seriously diluted due to magnetic decoupling, and it may result in deterioration of S/N ratio of the magnetoresistance head.
The magnetoresistance effect element according to the embodiment of the invention summarized above can be incorporated into a reproducing magnetic head to obtain a highly sensitive magnetic head.
The magnetoresistance head, thus obtained, can be mounted in a magnetic reproducing apparatus to enable stable reproduction of super-densely recorded information.
A magnetic storage device having a plurality of magnetoresistance effect elements according to any one of the above-summarized types is useful as MRAM (magnetic random access memory) that can magnetically rewrite information. That is, when the magnetoresistance effect element according to the embodiment of the invention is used in MRAM having no hard bias film or anti-ferromagnetic bias film, the sidewall layer having the specular reflection effect shows its effect.
As summarized above, according to the embodiment of the invention, since a CCP type magnetoresistance effect element has formed a sidewall layer on a side surface of the magnetoresistance effect film, high MR-changing rate and large MR-changing amount can be obtained even in a magnetoresistance effect element of a submicron size or a smaller size without departing from the scaling rule.
In addition to that, it is also possible to provide a magnetic head having high output power and high S/N, magnetic reproducing apparatus using same, and magnetic storage device using same. Thus the invention has remarkable industrial advantages.

Magnetoresistance effect element, magnetic head and magnetic reproducing apparatus


The present invention provides an analog buffer and a liquid crystal display apparatus using the same and a driving method thereof capable of reducing power consumption. An analog buffer according to the present invention includes: a comparator including an inverter connected in series to the input line; a feedback switch connected between the input line and the output line; and an output inverter, connected between the comparator and the output line, for pre-charging any one of driving voltages of a first driving voltage and a second driving voltage into the output line for a reset interval, and for cutting-off the first and second driving voltages when the pre-charged voltage is fed back via the feedback switch to the input line so that it is converged to the input voltage for a feedback interval.

1. Field of the Invention
The present invention relates to an analog buffer, and more particularly, to an analog buffer and a liquid crystal display apparatus using the same and a driving method thereof capable of reducing power consumption.
2. Discussion of the Related Art
A liquid crystal display device displays a picture by way of controlling a light transmittance of liquid crystal materials having a dielectric anisotropy using an electric field. To this end, the liquid crystal display device includes a liquid crystal panel having a pixel matrix and a drive circuit for driving the liquid crystal panel.
As illustrated in FIG. 1, the liquid crystal display device of the related art includes a liquid crystal panel 2r having a pixel matrix, a gate driver 4r for driving gate lines GL1 to GLn of the liquid crystal panel 2r, a data driver 6r for driving data lines DL1 to DLm of the liquid crystal panel 2r and a timing controller 8r for controlling a driving timing of the gate driver 4r and the data driver 6r.
The liquid crystal panel 2r includes the pixel matrix having pixels 12r formed at each area defined by each intersection of gate lines GL and data lines DL. Each of the pixels 12r has a liquid crystal cell Clc that controls a light transmittance depending on the electric field generated by a pixel signal and a thin film transistor TFT that drives the liquid crystal cell Clc.
When the thin film transistor TFT receives a gate driving signal from a gate line GL, i.e., a gate high voltage VGH, the thin film transistor TFT is turned on to supply a video signal from the data line DL to the liquid crystal cell Clc. Moreover, when the thin film transistor TFT receives a gate low voltage VGL from the gate line GL, the thin film transistor TFT is turned off, thereby maintaining a video signal charged to the liquid crystal cell Clc.
The liquid crystal cell Clc can be equivalently represented as a capacitor. The liquid crystal cell Clc includes a common electrode and a pixel electrode connected to the TFT wherein a liquid crystal material is inserted between the common electrode and the pixel electrode. The liquid crystal cell Clc further includes a storage capacitor (not illustrated) for stably maintaining the video signal charged thereto until a next video signal is charged. The liquid crystal cell Clc varies the arrangement of liquid crystal materials with a dielectric anisotropy in accordance with the video signal charged through the TFT, thereby controlling the light transmittance. Accordingly, the liquid crystal cell Clc represents gray levels.
The liquid crystal panel 2r is driven by an inversion system in which a polarity of the liquid crystal cell Clc is inverted in a designated unit by a certain unit using a data signal, to prevent a deterioration of the liquid crystal materials and to improve display quality. The inversion system uses a frame inversion in which a polarity of a liquid crystal cell is inverted by units of one frame, a line inversion in which a polarity of a liquid crystal cell is inverted in units of horizontal lines, a column inversion in which a polarity of a liquid crystal cell is inverted in units of vertical lines, and a dot inversion in which a polarity of a liquid crystal cell is inverted in units of liquid crystal cells.
Among these inversion systems, the line inversion system has reduced power consumption compared to the column inversion and the dot inversion systems. It is because the column inversion and the dot inversion systems invert a polarity of a liquid crystal cell by using only a data signal, and thus a range of their driving voltages is relatively large, whereas, because the line inversion system alternates a common voltage Vcom supplied as a reference voltage, the range of a driving voltage can be lowered.
The gate driver 4r shifts a gate start pulse (GSP) from a timing controller 8r in accordance with a gate shift clock (GSC) to sequentially supply a scan pulse of the gate high voltage VGH to the gate lines GL1 to GLm. Moreover, the gate driver 4r supplies the gate low voltage VGL during a scan pulse of the gate high voltage VGH is not supplied to the gate lines GL1 to GLm.
The data driver 6r shifts a source start pulse (SSP) from the timing controller 8r in accordance with a source shift clock (SSC) to generate a sampling signal. Further, the data driver 6r latches a video data RGB provided by the signal SSC in accordance with the sampling signal, and then supplies the latched video data by a line unit in response to a source output enable (SOE) signal. Then, the data driver 6r converts digital video data RGB supplied by the line unit to analog video signals using gamma voltages, supplied from a gamma voltage, to thereby supply the analog video signals to the data lines DL1 to DLm. At this time, the data driver 6r determines the polarity of the video signals, in response to the polarity controlling signal (POL) from the timing controller 8r at the time of the conversion of the digital video data to the analog video signals.
The timing controller 8r generates the signals GSP and GSC for controlling the gate driver 4r, and also generates a source start signal SSP, a source shift clock SSC, a source output enable signal SOE and the signal POL signals for controlling the data driver 6r. More specifically, the timing controller 8r generates a variety of control signals such as the GSP, GSC, GOE, SSP, SSC, SOE, POL and the like by using a data enable DE signal representing an effective data interval, a horizontal synchronizing signal Hsync, a vertical synchronizing signal Vsync and a dot clock (DCLK) to determine the transmission timing of the pixel data RGB.
In the liquid crystal display device configured as described above, the data driver 6r includes an analog buffer for preventing a distortion of the video signal supplied to the data line, in accordance with an amount of RC load on the data line. The gate driver 4r also includes an analog buffer for preventing a distortion of the gate driving signal supplied to the gate line, in accordance with an amount of RC load on the gate line. In general, an amplifier (OP-AMP) is mainly used for the analog buffer. However, a scheme having a simplified circuit configuration using an inverter has been recently proposed.
For instance, a paper "AMLCD '02", pp. 21-24, published by Toshiba describes an analog buffer, which employs three inverters as illustrated in FIG. 2. The analog buffer illustrated in FIG. 2 includes: first to third inverters 3, 5 and 7 which are connected in series between an input line and an output line; first to third capacitors 2, 4 and 6 which are connected in series to input terminals of the first to the third inverter 3, 5 and 7, respectively; a first switch 1 connected between the input line and the first capacitor 2; second to fourth switches 8, 9 and 10 which are connected between input terminals and output terminals of the first to the third inverters 3, 5 and 7, respectively; and a fifth switch 11 connected between the input line and the output line.
First, for a reset interval RESET supplied by a first control signal CS1 as illustrated in FIG. 3, first to fourth switches 1, 8, 9 and 10 are turned on. Accordingly, an input terminal and an output terminal of the first to the third inverters 3, 5 and 7, respectively, are shorted, so that the first to third inverters 3, 5 and 7, respectively, are initialized to an inverter logic threshold voltage (VTH) at an intermediate voltage of a power voltage. Thus, the first to the third capacitors 2, 4 and 6, respectively, connected to each input terminal of the first to the third inverters 3, 5 and 7, are charged by a difference voltage of the input voltage Vin and the inverter logic threshold voltage VTH.
Next, for a feedback interval FEEDBACK, by a second control signal CS2 supplied as illustrated in FIG. 3, a fifth switch 5 for feedback is turned on, so that an output voltage Vout corresponding to the input voltage Vin is monitored in an output line. In other words, if a fed-back output voltage Vout is higher than the input voltage Vin when the fifth switch 11 is turned on, then the input voltage becomes higher than the threshold voltage VTH. As a result, the first to the third inverters 3, 5 and 7 drop the output voltage. If the fed-back output voltage Vout is lower than the input voltage Vin, then the input voltage Vin becomes lower than the threshold voltage VTH. As a result, the first to the third inverters 3, 5 and 7 raise the output voltage Vout. As described above, the output voltage Vout in the first to the third inverters 3, 5 and 7 is subject to an oscillation at an early stage of the feedback interval FEEDBACK, and ultimately converges to the input voltage Vin.
Because the analog buffer is organized with only the inverters, its configuration is simple compared to the related art analog buffer implemented using the amplifier OPAMP. However, in the analog buffer illustrated in FIG. 2, since the third inverter 7 in the output terminal should drive a data line DL with a large capacitance C, it has a drawback that its size should be large. Also, since the third inverter 7 in the output terminal should always maintain the threshold voltage VTH after the output voltage has been converged to the input voltage Vin, it has a drawback that its power consumption becomes large.

Analog buffer and liquid crystal display apparatus using the same and driving method thereof


Apply heat to thermoplastic resin film, which is eventually to become an insulating resin layer, and press the film against a mold for forming grooves on a surface of the film. Next, press-fit an electronic component into the resin film from a back-face of the film, thereby exposing electrodes of the component from a bottom of the grooves. Then cool the film for curing. Peel the film off the mold, then fill the grooves with conductive paste, and cure the paste for forming circuit patterns. The foregoing procedure allows bringing the electrodes positively into conduction with the circuit patterns of a circuit board incorporating the electronic component, and achieving a narrower pitch between routings of the circuit patterns.

In recent years, narrower pitches of circuit patterns of circuit boards have been required in the market in order to increase a board density. In parallel with this tendency, a circuit board incorporating electronic components therein is proposed. The circuit board incorporating electronic components, in particular, is required to have a further narrower pitch in circuit patterns.
Japanese Utility Model Publication No. S62-70473 discloses a method of avoiding short circuits in a circuit having a narrow pitch: forming grooves on an insulated board, and then filling the grooves with conductive paste for forming a circuit, thereby avoiding short-circuits. However, this utility model does not teach at all about incorporating electronic components in the board per se.
On the other hand, Japanese Patent Application Non-Examined Publication No. 2001-93934 discloses a method of manufacturing a circuit board incorporating electronic components as follows: First, press-fit an electronic component into insulating resin, and expose electrodes of the component from a flat surface of the opposite side of the resin. Next, print a circuit pattern on the flat surface, thereby coupling the component with the pattern. However, since circuit patterns with narrow pitches are formed on the flat face of the circuit board manufactured by this method, a short circuit tends to occur between the circuit patterns.

Circuit board and method of manufacturing the same

Matsushita Electric Industrial Co., Ltd.


A SIM card adaptor for allowing use of a smaller format SIM card in an electronic device using a larger format SIM card is provided. The SIM card adaptor may include, an adaptor body having a cutout region defined by walls in the adaptor, the cutout region preferably shaped to receive the smaller format SIM card therein; and the adaptor body may be sized and shaped for use in the electronic device using the larger format SIM card, and wherein the adaptor body includes plastic and/or nylon, carbon fiber, aluminum, or similar material capable of withstanding heat levels up to at least about 200° Fahrenheit without degradation.

With the recent evolution of smaller format SIM cards, such as micro and nano, and in particular, as a result of their adoption by a number of cellular phone manufacturers, it has become apparent that an SIM card adaptor device is required to allow use of such smaller SIM cards with electronic devices capable of receiving only the larger SIM cards.
More specifically, it is pretty easy to trim a mini or micro SIM card down to fit into a current technology electronic device, such as an iPhone 5, by just simply trimming away excess plastic from around the chip until it fits inside the iPad or iPhone SIM tray. However, what happens if one wishes to go the other way? There may be circumstances where one wishes to use an iPhone 5's nano SIM in a different electronic device. If one was to need to have an iPhone 5 serviced for any reason, they may wish to retain their nano SIM during time of servicing, and use in a device utilizing a micro or mini SIM card.
One solution has been suggested by a micro SIM card adaptor such as that described in an article available at: http://www.wired.com/gadgetlab/2010/05/fingers-on-with-the-microsim-card-adaptor/. Such a device is a piece of plastic cut to hold the micro SIM card and allow loading it back into a regular mini SIM slot. However, such a device still suffers from a number of disadvantages.
More specifically, many electronic device, such as, cellular phones generate a lot of internal heat particularly adjacent to their SIM card tray as a result of operation with the battery. More particularly, such SIM cards are located adjacent or below the battery resulting in very high levels of heat generation. As is well known to those of ordinary skill in the art such levels of heat are damaging to circuits, and often cause the circuits to malfunction, such as may occur with an adaptor such as previously described in the article above, in which it is left open and exposed to high heat levels.
In accordance with the invention, the problems of the prior art with an adaptor enabling use of a SIM card having a smaller format, such as a nano SIM card, with an electronic device, such as a cellular phone, capable of receiving a SIM card having a larger format are avoided as is discussed further hereafter.

This patent is subject to a terminal disclaimer.


A radio communication apparatus comprises an analog I/Q signal generator, a digital demodulator, and an interference wave suppression control block. The interference wave suppression block detects a gain difference between an in-phase component and a double quadrature component, based on an input and output signals of a low pass filter in the digital demodulator and the output of the double quadrature mixer, and controls a reference voltage of an A/D converter in the digital demodulator. Therefore, it is possible to reduce the gain difference of the in-phase component and the quadrature component, and to effectively eliminate an interference wave mixed in a base band signal. Furthermore, a radio communication apparatus according to the present invention comprises an antenna input block, a reception block, a transmission block, and an in/out block. Because a frequency when sending data is equal to the frequency when receiving data, it is possible to quickly change transmission and reception. Accordingly, it is possible to effectively use time-slots and transfer data at high speed.

1. Field of the Invention
The present invention relates to a radio communication apparatus used for a radio receiver such as a cellular phone. Especially, the present invention relates to a circuit system which suppresses an interference wave automatically and is able to transfer data at high speed.
2. Related Background Art
The cellular phone has prevailed rapidly. There are an analog system and a digital system for the cellular phone. The digital system can use frequency band more efficiently than the analog system, and the digital system surpasses the analog system in capability for security. Because of this, it is predicted that the digital system becomes predominant in future.
The digital system converts a voice signal into code information and transfers the information by radio frequency. Because of this, the digital system has a feature in that it hardly suffers the influence of noise. On the other hand, in order to increase the number of channels available for the cellular phone, frequency band per a channel has to be narrowed. However, when the frequency band per a channel is narrowed, each channel easily suffers the influence of the noise. Because of this, a conventional circuit which suppresses an image interference wave by using a quadrature mixer and a .+-.45.degree. phase shifter has been known.
In order to suppress the image interference wave, it is necessary to control a gain difference and a phase difference between an I signal as an in-phase component and a Q signal as a quadrature component. However, the conventional circuit has initially set the gain difference and the phase difference only by hand. The reason is because differential signals of the gain difference and the phase difference is very little, for example, less than 1 dB or 2.degree., and because a technique which detects such a micro signal with high precision and controls the gain difference and the phase difference has not been established. Because of this, the gain difference and the phase difference had to be controlled by hand. Accordingly, it has taken a long time to control the gain difference and the phase difference, and the conventional circuit could not suppress the image interference wave at will.
On the other hand, FIG. 17 is a diagram which explains TDMA (time-division multiple access) in a mobile communication system called a GSM system which is prevailing in Europe. As shown in FIG. 17, the GSM system transfers data at each time-slot. A sending timing fRX of a mobile station (MS) which communicates with a base station and a receiving timing fTX is being shown in FIG. 17.
The mobile station receives the data at a time R1 and sends data at a time T1. The mobile station receives the next data at a time R2 after 8 time-slot of the time R1. Between times R6 and R7, a period which monitors another channel is provided.
The mobile station has to perform both of a voice communication and a data transfer within one time-slot. Because of this, the capability of transferring data is inevitably limited by a time length per one time-slot.
Accordingly, in order to transfer a large amount of data at high speed, a bit rate in a time-slot has to be raised, or data transfer has to be performed by using a plurality of slots. It is difficult to realize the former because of restriction of the conventional system. In the case of the latter, because an interval between the sending period and the receiving period becomes narrow inevitably, a frequency synthesizer used in the radio communication apparatus has to be changed quickly. That is, it is necessary to use an expensive frequency synthesizer.


An image forming apparatus comprises: an operation part having a display area and operable to receive an input from a user; a first display part operable to display, in a part of the display area, (i) a first image to be visible only from a range of a first viewing angle and (ii) a second image to be visible only from a range of a second viewing angle that does not overlap with the range of the first viewing angle; an audio output part operable to output an audio explaining the first image; and a second display part operable, while the audio explaining the first image is being output, to display, in a remaining part of the display area, a notification indicating that the audio explaining the first image does not correspond to the second image, such that the notification is visible from the range of the second viewing angle.

(1) Field of the Invention
The present invention relates to an image forming apparatus having an operation part for receiving an input from a user.
(2) Description of the Related Art
An image forming apparatus such as a copier includes a user-friendly function to enhance the usability of the apparatus. For example, Japanese Patent Application Publication No. 2006-218637 discloses an image forming apparatus that includes a display on an operation part (e.g., operation panel) so as to display a state of the apparatus (e.g., the occurrence of a paper jam or an execution state of a job) on the screen. Also, the image forming apparatus outputs an audio guide explaining how to make a copy or how to clear a paper jam. The above-described functions enable the user to seta copy mode as desired or to clear a paper jam while looking at a displayed image on the screen and listening to the audio guide.
Also, Japanese Patent Application Publication No. 2007-322480 discloses an image forming apparatus that has a so-called "multi-view function". In the multi-view function, a display of an operation panel shows first and second images where the first image is only visible from the range of a first viewing angle and the second image is only visible from the range of a second viewing angle that does not overlap with the first viewing angle.
The multi-view function enables simultaneous display of different images and is convenient to the user for the following reasons. With the multi-view function, the user does not need to manually switch between images to look at each of the images. Instead, the user can look at the images by simply tilting his/her face to the right and left in front of the operation panel to adjust to each viewing angle.
In view of improving operability for a user, it is conceivable to have a structure that includes an operation part having the above-described multi-view function, and that outputs an audio guide.
However, operability for a user may not be improved if an audio guide is simply introduced to the operation part having the multi-view function.
For example, assume that a first image is an image for selecting a copy mode and is only visible from the front of an operation panel, and that a second image is an image for showing an execution state of a job and is only visible from a diagonally left direction with respect to the operation panel. Also assume that a user A is listening to an audio guide for the first image in front of the operation panel, and, while the user A is still listening to the audio guide, a user B approaches the copier and attempts to check the execution state of a job by looking at the second image from the diagonally left direction. In this case, the user B may be confused whether or not the audio guide that is being output corresponds to an image that he/she is looking at.
Also, assume that a structure is adopted in which different audio guides are provided for different images, and the audio guides are output by means of manual operations such as pressing keys. This structure, however, requires an operation for switching between the audio guides and complicates the operations of the copier. For example, consider the following case: at the time of paper jams, a first image shows how to clear a paper jam in front of the copier, a second image shows how to clear a paper jam at the left side of the copier, and a user performs operations to clear the paper jams while listening to a first audio guide for the first image and a second audio guide for the second image in sequence. In this case, the user performs operations to clear the paper jam in front of the copier while looking at the first image and listening to the first audio guide. Then, after the paper jam in front of the copier is cleared, the user moves to the left side of the copier to perform different operations to clear the paper jam on the left side.
Therefore, if the user forgets to perform a key input operation for switching to the second audio guide, the user cannot listen to the second audio guide even though he/she can look at the second image from the left direction. As a result, the user is forced to go back to the front of the copier to perform the key input operation for switching.

Image forming apparatus with multi-view display

Konica Minolta Business Technologies, Inc.


Methods and apparatus are provided that permit downhole tools to be run into a well along with logging tools that can log the downhole tools into place by real time transmission of the data to a surface location. In one aspect, an apparatus includes a telemetry tool, a logging tool in communication with the telemetry tool and a downhole tool.

1. Field of the Invention
The present invention generally relates to well completion. More specifically, the invention relates to placement of downhole tools in a wellbore using logging equipment run into the wellbore on a tubular string with the tools. Still more particularly, the invention relates to the use of wireless, real time communication between logging components run into well on a tubular string and the surface of the well.
2. Background of the Related Art
Hydrocarbon wells are formed by drilling an initial borehole in the earth and then lining the borehole with pipe or casing to form a wellbore. The casing prevents the walls of the wellbore from caving in and facilitates the isolation of certain parts of the wellbore. Subsequently, at least one area of the wellbore casing is perforated to permit communication with an oil bearing formation therearound. As the oil enters the perforated casing, it is typically collected in a separate tubular string used as a conduit to move the oil to the surface of the well.
In one example of well completion, a borehole is formed and casing is then run into the borehole. The casing is initially suspended from the surface of the well but is thereafter cemented into place with cement deposited in the annular area formed between the outer surface of the casing and the walls of the borehole. In order to access a formation of interest around the wellbore, a bridge plug may be installed in the wellbore below the area of interest. The bridge plug is run into the well on a tubular string and includes an outward radially extendable sealing element to contact and seal an area between the bridge plug and the casing wall. Bridge plugs can be set hydraulically or mechanically and their use is well known in the art. With the bridge plug set, a tubular string with a packer, a screened portion and a perforating gun are run into the well. When the perforating gun is adjacent the formation of interest, the packer is set. Packers, like bridge plugs include a radially extendable sealing element. Additionally, packers include a central bore with a sealing member therein to seal the area between the inner bore and the production tubing extending therethough. With the packer set and the area of the wellbore isolated, the perforating guns are fired and the casing and cement therearound are perforated. With the perforation, fluid communication is established between the formation fluids and the surface of the well via the production tubing. Additionally, the producing area of the wellbore is isolated from other areas.
The foregoing example is simplified. More typically, various areas of a wellbore are isolated and perforated in order to access different formations that are present at different depths in the wellbore. More importantly, lateral wellbores are now routinely formed from a central wellbore to reach and to follow formations extending from the central wellbore. The lateral wellbores are drilled from the central wellbore and are initiated with the use of a whipstock or some other diverter that can be run into the wellbore in a tubular string and anchored therein. The whipstock includes a slanted or concave area which can guide a cutting tool though the wall of the casing to form a xe2x80x9cwindowxe2x80x9d though which a lateral wellbore can be formed. In other instances, casing is run into the central wellbore with a preformed window therein. With the window in place, a new borehole can be formed and with directional drilling techniques, the new wellbore can reach or follow a particular sand or other hydrocarbon bearing formation.
Prior to the well completion techniques described above, wellbores are routinely the subject of a variety of testing designed to determine the characteristics of surrounding formations. The characteristics are indicative of the types of fluids present in formations. One type of testing is performed with a gamma ray tool. A gamma ray tool includes a radiation detector for detecting naturally occurring gamma radiation from a formation. An electrical signal is produced corresponding to each detected gamma ray and the signal has an amplitude representative of the energy of the gamma ray. The detector includes a scintillation crystal or scintillator which is optically coupled to a photomultiplier tube. The scintillator may comprise a gadolinium-containing material, such as gadolinium orthosilicate that is suitably doped, for example with cerium, to activate for use as a scintillator. The quantity of cerium in terms of number of atoms is typically of the order of about 0.1% to about 1% of the quantity of gadolinium. The scintillator may comprise other materials, such as sodium iodide doped with thalium (Nal)(Tl), bismuth germanate, cesium iodide, and other materials.
Another type of logging tool is a neutron tool. Neutron tools are used to analyze fluids in a formation to determine their characteristics. This is especially important where water or some other non-hydrocarbon fluid has migrated into an area adjacent a perforated wellbore. Production of water creates additional expense and necessarily reduces the production of oil at the surface of the well. In order to identify and eliminate water entering a wellbore, the formations around the wellbore are tested using a logging tool such as a neutron tool. The neutron tool emits neutrons into the formation and subsequently recovers the neutrons after they have been deflected by the formation. By counting the number of neutrons returning, the makeup of the fluid can be determined and water, oil and gas can be identified and distinguished. Thereafter, elimination packers can be installed in the wellbore to contain the water. The neutron tool is conventionally run into a well on wireline and the isolation packers are subsequently run in on a tubular string to a location corresponding to the depth at which the logging tool indicated the presence of water.
In the examples above, tubular strings with tools are inserted into a wellbore and lowered to a position of interest based upon previously measured information related to depth and information about formations and fluids therein. The previous measurements are typically performed in an open hole with the logging tools conveyed on wireline. However, during the subsequent process of conveying the tools with tubing or drill-pipe, improper or inaccurate measurements of the length of the drill string may take place due to inconsistent lengths of collars and drill-pipes, pipe stretch, pipe tabulation errors, etc., resulting in erroneous placement of the tools. Thus, the tools may be positioned in the wrong area of the wellbore and the surrounding formations may not be effectively accessed. Repeating the insertion of the tool string may be very costly both in expenses and time.
There is a need therefore, for a method and apparatus to combine some aspects of well logging with some aspect of well completion. There is a further need for methods and apparatus to utilize well logging and downhole tools in a single trip. There is yet a further need for methods and apparatus permitting downhole well completion tools to logged into a wellbore on a run-in string of tubulars along with logging tools to ensure that the downhole tools are positioned at the optimum location in the wellbore. There is yet a further need for methods and apparatus to locate wellbore completion tools in a cased wellbore that more completely utilizes logging data from prior, open hole tests. There is yet a further need for apparatus and methods that includes the run-in of various downhole tools along with various logging tools capable of operating in a cased wellbore in order to locate a zone of interest in real time and place the tools in the optimum place in the wellbore in a single run with no separate power lines extending from the apparatus to the surface of the well.
Methods and apparatus are provided that permit downhole tools to be run into a well along with logging tools that can log the downhole tools into place by real time transmission of the data to a surface location. In one aspect, an apparatus includes an electromagnetic telemetry tool, a logging tool in communication with the telemetry tool and a downhole tool. In another aspect, the apparatus includes a telemetry tool, a gamma ray tool, and a whipstock and anchor assembly. In yet another aspect, the invention includes a telemetry tool, a gamma ray tool, and at least one packer constructed and arranged to isolate an area of the wellbore. In yet another aspect, a method and apparatus are provided to utilize a telemetry tool, a well logging tool and a perforating gun assembly on a tubular string. In another aspect of the invention a method is provided to log at least one wellbore component into a well using a telemetry tool and a gamma ray tool wherein the real time information from the gamma ray tool is transmitted to the surface of the well where it is compared to a prior log. By comparing the real time information with the historical data, an operator at the surface of the well can identify a moment when the wellbore component is adjacent a particular area of interest. In another aspect of the invention, a neutron tool is run into a cased wellbore along with a telemetry tool and at least one wellbore component like an isolation packer. The neutron tool identifies specific fluids, like water and the packers are used to isolate the area of water.

Apparatus and methods for placing downhole tools in a wellbore