An optical pickup head device includes a diffraction grating for generating zero-order diffracted light and at least first-order diffracted light and provides a tracking error signal with a DPP method. The diffraction grating includes grating patterns with a nonuniform period or phase. The size of the first-order diffracted light converged on an optical recording medium is larger in the direction parallel to a tangent to the track than in the direction perpendicular to the tangent. P1/P0>PW2/PW1 is established, where PW1 represents the power that is required to record information on the optical recording medium, PW2 represents the maximum power that allows information recorded on the optical recording medium to be reproduced without being erased, P0 represents the light amount of the zero-order diffracted light converged on the optical recording medium, and P1 represents the light amount of the at least first-order diffracted light converged on the optical recording medium. This configuration makes it possible to detect a tracking error signal with reduced offset, even if a recordable optical recording medium having two information recording planes is used.

1. Field of the Invention
The present invention relates to an optical pickup head device that is used in an apparatus for recording, reproducing or erasing information on an optical recording medium and an information recording/reproducing apparatus. The present invention also relates to an information recording method that employs the optical pickup head device.
2. Description of the Related Art
An optical memory technique that uses optical disks having pit patterns as high-density large-capacity recording media is finding wide application, e.g., to digital audio disks, video disks, document file disks, and data files. In recent years, high-density large-capacity optical disks, called DVD, have been put to practical use and attracted considerable attention as information media that can handle mass information like animation. The DVD optical disks are recorded/reproduced with a so-called red semiconductor laser that emits a laser beam having a wavelength of about 650 nm.
FIG. 10 shows the configuration of a general optical system used in an optical pickup head device of an optical disk system that can perform recording and reproduction. A semiconductor laser source 1, i.e., a light source, emits a linearly polarized divergent beam 700 having a wavelength λ1 of 650 nm. The beam 700 emitted from the semiconductor laser 1 enters a diffraction grating 60. The diffraction grating 60 divides the beam 700 into three beams: a zero-order diffracted light beam and ±first-order diffracted light beams. The zero-order diffracted light beam is a main beam 700a for recording/reproducing information. The ±first-order diffracted light beams are two sub-beams 700b, 700c used for differential push-pull (DPP), with which a tracking error signal can be detected stably. To avoid unnecessary recording by the sub-beams, the ratio of diffraction efficiency of the zero-order diffracted light beam 700a to each of the first-order diffracted light beams 700b, 700c is generally about 20:1. The three beams 700a to 700c generated in the diffraction grating 60 pass through a polarizing beam splitter 52 and enter a collimator lens 53 having a focal length of 20 mm. The collimator lens 53 converts the beams into parallel light. The beams 700a to 700c thus collimated pass through a quarter-wave plate 54, where the beams are converted into circularly polarized light. Then, the beams are converted into convergent beams with an objective lens 56 having a focal length of 3 mm, pass through a transparent substrate 41a of an optical recording medium 41, and are focused on an information recording plane 41b. The aperture of the objective lens 56 is limited by an aperture 55 so that the NA is 0.6. The transparent substrate 41a has a thickness of 0.6 mm.
FIG. 11A is a front view schematically showing the diffraction grating 60, and FIG. 11B is a cross-sectional side view of the diffraction grating 60. A Y-direction is parallel to a tangent to the track on the optical recording medium 41 and an X-direction is perpendicular thereto. Straight grating patterns are formed on the diffraction grating 60 at an equal period of Pt. The grating depth d0 is set so that the ratio of light amount of the beam 700a to each of the beams 700b, 700c is 20:1. An angle θ between a spatial frequency axis 60d of the diffraction grating 60 and the Y-axis is determined by the positional relationship between the tracks on the information recording plane 41b and the focused beams 700a to 700c, and generally is in the range of about 1 to 2 degrees.
FIG. 12 shows the relationship between the beams 700a to 700c on the information recording plane 41b and the tracks. The optical recording medium 41 is provided with continuous grooves that serve as the tracks. The track period Tp is 0.74 μm. The beams are arranged so that when the main beam 700a is positioned on a track, each of the sub-beams 700b, 700c is positioned between tracks. In other words, a distance L between the main beam 700a and the sub-beam 700b or 700c in the direction perpendicular to the tracks is 0.37 μm.
The beams 700a to 700c reflected from the information recording plane 41b pass through the objective lens 56 and enter the quarter-wave plate 54, where the beams are converted into linearly polarized light that differs by 90 degrees from the light traveling from the semiconductor laser 1 to the optical recording medium 41. Then, the beams are converted into convergent beams by passing through the collimator lens 53 and reflected from the polarizing beam splitter 52. The beams 700a to 700c reflected from the polarizing beam splitter 52 pass through a cylindrical lens 57 and enter a photodetector 31. The transmission of beams 700a to 700c through the cylindrical lens 57 imparts astigmatism to the beams. The photodetector 31 includes eight light receiving portions 31a to 31h. The light receiving portions 31a to 31d receive the beam 700a, the light receiving portions 31e, 31f receive the beam 700b, and the light receiving portions 31g, 31h receive the beam 700c. Each of the light receiving portions 31a to 31h outputs a current signal that corresponds to the amount of light received.
The output signals of the light receiving portions 31a to 31d for receiving the main beam 700a are used to generate a focusing error signal with an astigmatism method, a tracking error signal with a phase-difference method, and a tracking error signal with a push-pull method. When a disk having continuous grooves such as DVD-RW (registered trademark) is recorded/reproduced, the output signals of the light receiving portions 31e to 31h for receiving the sub-beams 700b, 700c are used together with the output signals of the light receiving portions 31a to 31d so as to generate a tracking error signal with a DPP method. The focusing error signal and the tracking error signal are amplified to a desired level and phase-compensated, and then sent to actuators 91, 92, thereby performing focusing control and tracking control.
In DVD, a two-layer disk that includes two information recording planes is standardized for read-only ROM disks. A conventional optical pickup head device can read information from the read-only two-layer disk without any problems by detecting a tracking error signal with the phase-difference method.
Research and development of an optical recording medium having two recordable information recording planes (hereinafter, referred to as a two-layer recording disk) has yielded significant results. Since no information is written in the two-layer recording disk in its initial state, a tracking error signal cannot be detected with the phase-difference method. Accordingly, like an optical recording medium having a single recordable information recording plane (hereinafter, referred to as a single-layer recording disk), the tracking error signal should be detected with the DPP method.
However, there is a problem of using the two-layer recording disk in a conventional device having the above configuration. Even if a tracking error signal is detected by the DPP method, it causes uncorrectable offset fluctuations when the objective lens follows tracking or the optical recording medium tilts. The reason for this is as follows. When information is recorded on one of the information recording planes (hereinafter, this information recording plane is referred to as a focusing plane), the beam focused on the focusing plane is partly reflected and partly transmitted by the focusing plane. The transmitted beam reaches the other information recording plane (hereinafter, this information recording plane is referred to as a non-focusing plane) in a defocused manner. The beam reflected from the non-focusing plane also enters the photodetector. However, this beam cannot be cancelled completely by the DPP method for detecting a tracking error signal because of aberration, a nonuniform light amount of the beam, or the like. Therefore, the amount of beam that is not cancelled varies when the objective lens follows tracking or the optical recording medium tilts, causing offset fluctuations in the tracking error signal. As a result, off-track occurs and erases some of the information recorded on the adjacent tracks during recording, so that information recorded on the optical recording medium cannot be read faithfully.

Optical pickup head device, information recording/reproducing apparatus, and method for recording information


A power tong 10 rotates a tubular during makeup or breakout of the threaded connection. A tong frame 12, a rotatable ring 20, and a cage plate assembly may each have an open throat for receiving the tubular. A plurality of dies 32 are preferentially manufactured from aluminum, and each have a knurled surface for engaging the tubular. A fluid powered cylinder 54 increases tension between the brake band 50 and the cage plate assembly. Neutral cam portions of the cam surface one positioned radially outward substantially from the makeup and breakout cam portions.

Hundreds of patents have been granted for power tongs designed to make up and break out oilfield tubulars. Most commercially successful power tongs have an open throat so that the power tong can be moved laterally on or off the tubular. Power tongs with closed throats have utility for certain applications, but generally are not as widely used as rig power tongs for connecting and disconnecting tubulars as they are run into and out of the well.
Chrome plated tubulars are being increasingly popular due to the increased protection provided by highly corrosive downhole environments. The advantage of plating the tubular is substantially sacrificed, however, if the tong dies which make up the connection "mark" the OD of the tubular to the extent that the chrome plating is pierced. When the tubular is then placed downhole, corrosive fluids may act on this damaged area, thereby corroding the steel tubular, and may spread as the corrosive fluids get under the chrome layer.
In an attempt to minimize marking of chrome plated tubulars, some power tongs have employed aluminum dies. Aluminum substantially reduces markings since the aluminum material is softer than both the chrome and the oilfield tubular. The problem with this practice is that the aluminum dies, which reduce marking by providing relatively smooth biting surface, do not adequately grip the tubular to perform the makeup or breakout operation. Accordingly, aluminum dies in power tongs commonly slide on the tubular surface during the makeup or breakout operation, which then further scrapes and damages the chrome plating on the oilfield tubular.
U.S. Pat. No. 4,084,453 discloses a power tong with a rotary cage plate and a rotary gear with a relatively low cam angle for cooperation with gripping heads. This tong, which performs satisfactory for many applications, does not provide the minimum marking necessary for use on chrome plated oilfield tubulars.
The disadvantages of the prior art are overcome by the present invention, and an improved power tong as hereinafter disclosed, which is particularly suitable for taking up and breaking out chrome plated oilfield tubulars.


A current regulator controls the electron emission from a cold cathode using closed-loop feedback from a current sensor in the cathode connection. The regulator circuit includes a cold cathode, a current-sensing element, a current-limiting element, and current-control element. Additionally, the closed-loop current regulator may comprise a reference element for generating the reference level, a circuit power supply and a cathode bias supply. The regulator and cathode may be assembled from separate components, or the entire circuit may be integrated onto a single substrate. In one embodiment, the current level is set by adjusting the reference element directly. In a second embodiment, the current level is set by adjusting the circuit power supply, so that the current level can be set remotely without the need to adjust the reference element directly. The second embodiment is preferably suited for the regulation of beam current in analytical instrumentation. In a third embodiment, the fixed reference element is replaced with a time-varying voltage signal. The current from the cathode then becomes a linear function of the time-varying reference signal. The third embodiment is preferably suited for application as an amplifying element or as the electron source in an emissive display.

The present invention relates generally to cold cathode devices and associated applications and, more particularly, to a closed-loop circuit that can stabilize the emission of the cold cathode.
A cold cathode is an electron emitter whose emission mechanism is field-based rather than temperature-based. Field-based electron emission occurs when a high electric field is applied to the surface of the cathode""s emitter material residing in a vacuum environment. A tunneling effect allows electrons to pass from the emitter into the vacuum, producing a flow of electrons as defined by the Fowler-Nordheim equation. This tunneling effect is strongly dependent on the surface work function of the emitter material. The surface work function is an inherent property of the emitter material that is affected by surface contamination. Since no vacuum environment can be contamination-free, there is a continuous flux of surface contaminants being carried onto and off of the emitter surface, resulting in wide fluctuations of the emission current on both short and long time scales.
The surface contamination effect is especially problematic in cold cathode applications. Unlike thermal cathodes, which operate at temperatures above 1 000xc2x0 C., the cold cathode is incapable of boiling off impurities on the surface of the emitter. In devices utilizing cold cathodes water vapor and other background gasses are constantly being absorbed and desorbed on the surface of the cathode which changes the surface work function and causes fluctuations in the emission. Thermionic cathodes, which are commonly used in many applications, such as CRT displays, vacuum tubes for audio amplification, vacuum tubes for microwave power amplification, and cathodes for analytical instrumentation and the like, characteristically differ from cold cathodes in that they employ temperature-based electron emission. The electron emission from thermionic cathodes is a function of the power applied to the cathode that determines the operating temperature of the cathode through Joule heating. Thus, the thermionic cathode is considered a power-controlled current source. When the cathode is emitting the maximum current possible for a given temperature, it is said to be operating in emission-limited mode. This mode produces the highest operating current for a given temperature, but can produce unstable emission since the emission from the thermionic cathode is also a strong function of the surface work function. However, since these cathodes are typically operated at above 100020  C. adsorption of contaminants is minimized, so thermionic cathodes typically operate at much lower noise levels than cold cathodes and thus stabilization concerns are not as prevalent. Further stabilization of the emission current of a thermionic cathode can be achieved by operating the cathode in space-charge-limited mode, where the anode voltage and geometry limit the maximum allowed current density as defined by the Langmuir-Child relation.
Since the emission from cold cathodes is field-based, and fields are generally a function of applied voltage, cold cathodes are considered voltage-controlled current sources. When the cathode is operating at the maximum emission current possible for a given control voltage, the cold cathode is said to be operating in emission-limited mode. This mode maximizes the output current from the cathode, but, as described above, produces unstable or noisy emission current. Stability of the cold cathode is a paramount concern in most electron-beam devices that employ a cold cathode, such as audio, video or radar applications. In radar applications noise translates into a degraded signal that reduces the overall detection efficiency. In video applications, noise translates into visual artifacts or uneven brightness present on the monitor.
Several schemes to minimize emission current noise in cold cathodes have recently been developed. See for example, U.S. Pat. Nos. 5,847,408, entitled xe2x80x9cField Emission Devicexe2x80x9d, issued Dec. 8, 1998 in the name of inventors Kanemaru, et. al. and 5,173,634, entitled xe2x80x9cCurrent Regulated Field-Emission Devicexe2x80x9d, issued Dec. 22, 1192 in the name of inventor Kane. Of these schemes, the most prevalent are passive stabilization, most often embodied by incorporation of a resistor or resistive layer into the cathode, and active stabilization, most often embodied by incorporation of a MOSFET or other type of transistor in the cathode circuit. Both of these schemes are open-loop control schemes; that is, they attempt to control emission current without incorporating any measurement of the actual emission current for corrective feedback. Additionally, material changes to the cathode, in the form of changes to the emitter material and the use of coatings on the emitter, have been proposed as means of limiting noise and increasing cathode stabilization.
Passive stabilization seeks to control the emission current by reducing the applied voltage as the emitted current increases. This open-loop scheme is only partially successful, because the emitted current tends to be an exponential function of the applied voltage, while the resistor can provide only a linear reduction in voltage as a function of the emission current. In other words, it is mathematically impossible for the linear passive stabilization scheme to keep up with the exponential fluctuations in emission.
Active stabilization represents an improvement over passive stabilization, in that the transistor element is used as a current-limiting element in the circuit. In this open-loop scheme, the transistor limits the supply of electrons to the cathode, which in turn limits the emission current. In other words, the cathode can only emit electrons if electrons are available. Under these conditions, the cathode is said to be operating in supply-limited mode. This operating mode for cold cathodes is analogous to space-charge-limited mode for thermionic cathodes. In this mode, the stability of the emitted current is directly dependent on the stability of the current-limiting element, which can vary greatly depending on external factors such as temperature, supply voltage variations, and others. Thus, in active stabilization schemes if the current-limiting element is unstable, the resulting emitted current will also be unstable. This is apparent because of the open-loop circuitry which provides for no measurement of the actual emission current for corrective feedback.
Additionally, attempts have been made to address cold cathode stabilization problems by using different emitter materials or coatings on the cathode. Coatings have been used to make the surface of the emitter more inert and thereby raise the surface work function. Alternately, cathodes have been fabricated out of highly resistive materials to allow for a negative feedback mechanism to be built into the cathode""s structure. Implementation of these material changes to the cold cathode has proven to have minimal positive effect on the stabilization concerns.
A desired cold cathode stabilization scheme would depart from these open-loop circuit methods in that the stabilization scheme would control emission current by providing corrective feedback to a measured emission current. It would be desirable to provide for a cold cathode circuit that regulates the emission current using closed-loop feedback. Additionally, the emission current of the cold cathode would benefit from regulation that can be provided remotely, without direct adjustment of the circuit.
The present invention provides for improved stability for the emission current of cold cathode technologies. Addition of a closed-loop current regulating circuit enables practical application of cold cathode technology in areas where cathode noise and instability have historically been insurmountable limiting factors.
A closed-loop, cold cathode current regulator in accordance with the present invention comprises a cold cathode having an emitter and an electrode that cooperates to extract electrons from the emitter, a current limiting element that controls the flow of electrons to the emitter in response to a control signal, a current sensing element that produces an output signal that is a function of the current flowing from the emitter and a current control element that based upon the output signal of the current sensing element and a reference level produces the control signal.
In one embodiment of the invention the reference level is produced by a reference element that provides a fixed set point input to the current control element. The reference element may comprise a resistive voltage divider that derives a voltage output signal from the circuit power supply. In an additional embodiment of the invention the reference element may include a resistive voltage divider and a non-inverting gain element. In this embodiment the voltage output signal is derived from the circuit power supply, but with a rate of change that differs from that of the circuit power supply.
In an alternate embodiment of the invention the reference level is produced by a time-varying input source. The time variation may represent the transmission of analog or digital information that can be intended for aural, visual or data processing interpretation.
Additionally, the current regulator circuit of the present invention may include a circuit power supply, which may provide power to the circuit at a fixed direct-current (DC) voltage. Alternatively, the circuit power may be derived from an alternating-current (AC) source, transformer-coupled, with rectifier and filter circuitry that can allow the voltage applied to the circuit to vary in proportion to the magnitude of the AC source at the input. The regulator circuit also may include, if required for the particular cold cathode of interest, a cathode bias supply that can draw power either from the supply for the current regulating circuit or from an external source.
Additionally the present invention is embodied in a method for regulating current in a cold cathode using a closed-loop circuit. The method comprises producing a reference level based upon a set point current for a cold cathode emitter, producing a sensing output that is a function of the current flowing from the emitter, comparing the sensing output and the reference level to produce a control signal and regulating the flow of electrons to a cold cathode in response to the control signal.
As such, the present invention is capable of providing for a closed-loop regulator circuit that provides field-based, cold cathodes with markedly improved current stabilization. Additionally, further embodiments of the invention allow the emission current to be controlled remotely, without direct adjustment of the circuit. These benefits have wide spread applicability to numerous cathode devices, including but not limited to, analytical devices (e.g. scanning electron microscopes), CRT monitors and the like.

Closed-loop cold cathode current regulator


A teleconverter includes a master lens apparatus-side mount on which a master lens apparatus is mounted, a camera body-side mount on which a camera body is mounted, and a converter lens unit that has a negative refracting power for mounting the master lens apparatus thereon to obtain a lens system having a focal length longer than that of the master lens apparatus, the converter lens unit including a first lens group on the master lens apparatus side and a second lens group on the camera body side with an on longest air separation interposed between them, the first lens group has positive refracting power, and the second lens group has negative refracting power, with satisfaction of the following condition (1):−1.53<f1/f<−0.66  (1)where f is the focal length of a whole system of the converter lens unit, and f1 is the focal length of the first lens group.

The present invention relates to a tele-converter that is mounted on a master lens apparatus to obtain a lens system having a focal length longer than that of the master lens apparatus, and an imaging system comprising the same.
So far, there has been a rear teleconverter known in the art that comprises mounts corresponding to the mount of a master lens apparatus and the mount of a camera body, wherein a converter lens is interposed between the master lens apparatus and the camera body via those mounts to extend or elongate the focal length of the whole lens system.
Such rear teleconverters are convenient to and preferably used by those who use single-lens reflex cameras with interchangeable lenses in general and those who carry out telephotography, because of capable of making the focal length longer simply. Such rear teleconverter lenses, for instance, are set forth in Patent Publications 1 to 6.
Patent Publication 1: JP(A) 2004-226648
Patent Publication 2: JP(A) 2005-043788
Patent Publication 3: JP(A) 2005-107261
Patent Publication 4: JP(A) 2009-080176
Patent Publication 5: JP(A) 2010-191211
Patent Publication 6: JP(A) 2011-081111

This patent is subject to a terminal disclaimer.

Teleconverter mounted on a master lens apparatus to obtain a lens system having a focal length longer than that of the master lens apparatus, and imaging system comprising the same


A color video camera having an automatic white balance adjusting function and operating with selection of modes including a negative-to-positive reversal mode of shooting the color negative film to obtain the positive picture, wherein in the negative-to-positive reversal mode, the color signals output from the image sensor are amplified by the amplifiers whose gains have been changed from the values for an ordinary object shooting mode to values suited for shooting the negative film.

1. Field of the Invention
This invention relates to color video cameras and, more particularly, to such cameras which have the function of automatically adjusting the white balance in TTL mode and are capable of obtaining a positive picture from the negative film.
2. Description of the Related Art
The conventional automatic white balance adjusting methods for color video cameras may be divided into two large groups employing (i) the external colorimetry and (ii) the TTL colorimetry. Of these, the automatic white balance adjustment of the TTL type the output signal of the image sensor, based on which the white balance is controlled and, therefore, produces no errors, from which the external colorimetry type suffers, due to the difference in the spectral characteristic between the colorimeter and the image sensor and, in the case of the interchangeable-lens type camera, the change of the spectral characteristic as the lens is interchanged with another one. Accordingly, the latter has widely been utilized.
FIG. 1 is a block diagram illustrating the construction of the conventional automatic white balance adjusting circuit of the TTL type in the color video camera. An image sensor using a CCD or the like produces three output signals of the three primary colors R (red), G (green) and B (blue). Of these, the R and B signals are amplified by white balance control amplifiers 2 and 3, respectively. The color signal G and the outputs of the amplifiers 2 and 3 all are supplied to each of a Y processing circuit 4 for producing a luminance signal (Y signal) and a C processing circuit 5 for producing color-difference signals. The color-difference signals output from the C processing circuit 5 are supplied to a balanced modulator 6 which receives other inputs of color subcarrier signals f.sub.SC1 and f.sub.SC2 of 90.degree. phase difference. The output of the .modulator 6, or the chrominance signal (C signal), and the output of the Y processing circuit 4, or the luminance signal (Y signal), are added in an adding circuit 7. A detecting circuit 8 detects a high-luminance portion (peak value) of the luminance signal output from the Y processing circuit 4. The color-difference signals output from the C processing circuit 5 are also supplied to sample-and-hold (S/H) circuits 9 and 10 and integration circuits 11 and 12. A white balance control circuit 13 controls the gains of the amplifiers 2 and 3 individually through a control voltage conversion circuit 14.
With the camera of such construction, light coming from an object to be photographed forms an image on the image sensor 1 where it is photoelectrically converted into electrical signals. From this image sensor 1, the electrical signals are output for each of the colors R, G and B. Of these, the R signal and the B signal, after their amplitudes have been controlled by the amplifiers 2 and 3 for white balance control respectively, are supplied to each of the Y processing circuit 4 and the C processing circuit 5. The G signal is supplied without further alteration to the Y processing circuit 4 and the C processing circuit 5. And, the luminance signal (Y signal) is output from the Y processing circuit 4, while the color-difference signals R-Y and B-Y are output from the C processing circuit 5.
The aforesaid color-difference signals R-Y and B-Y are supplied to the balanced modulator 6, where they are subjected to balanced modulation by using the color subcarrier signals f.sub.SC1 and f.sub.SC2 of 90.degree. phase difference, and are output as a chrominance signals (C signal). Then, this chrominance signal and the above-described luminance signal (Y signal) are mixed in the adding circuit 7, and therefrom a composite video signal is output, which is supplied to a reproduction circuit (not shown).
Here, the above-described composite video signal is of such a form that the white balance has been adjusted by the amplifiers 2 and 3 for white balance control. That is, in order to adjust the white balance, the high-luminance portion of the luminance signal output from the Y processing circuit 4 is first detected. By using that detection signal, the sample-and-hold circuits 9 and 10 carry out sampling of the color-difference signals R-Y and B-Y. At the same time, the integration circuits 11 and 12 carry out the integration of the color-difference signals R-Y and B-Y. Then, the white balance control circuit 13 controls the gains of the amplifiers 2 and 3 in such a manner that the values R-Y.sub.peak and B-Y.sub.peak of the color-difference signals obtained by the aforesaid sampling in the peak (high-luminance portion) of the luminance signal, or the average values R-Y.sub.Ave and B-Y.sub.Ave of the color-difference signals obtained by integrating them for one picture. Thus, the adjustment is made so as to obtain always optimum white balance. In this connection, it should be pointed out that each of the amplifiers 2 and 3 is controlled through the control voltage conversion circuit 14, and that these amplifiers 2 and 3 are in the form of voltage-controlled amplifiers. Hence, the gain is controlled by the DC voltage applied to the control terminal.
FIG. 2 shows the details of the conventional control voltage conversion circuit 14. The output terminals (ROUT, BOUT) 13a and 13b of a D/A converter in the white balance control circuit 13 are connected respectively through resistors R.sub.1 and R.sub.2 to bleeders of resistors R3 and R4 and resistors R5 and R6 connected across a D.C. electric power source of 5 volts.
From one of the output terminals of the D/A converter in the white balance control circuit 13, say, 13a, a D.C. voltage which takes a value in the range of from 0 to 5 volts depending on the above-mentioned values R-Y.sub.peak and B-Y.sub.peak of the color-difference signals is output. For this D.C. voltage, the width of variation is changed according to the impedance ratio of the resistor R.sub.1 and the bleeder of resistors R.sub.3 and R.sub.4, and the value of the center of the width of variation is determined by the ratio of the resistance R.sub.3 and R.sub.4 of the bleeder, before it is applied to the control terminal (RCONT) 2a of the amplifier 2 for white balance control. Likewise, at the other output terminal 13b of the D/A converter in the white balance control circuit 13, there also appears a D.C. voltage, which, after the width of variation and its central value have been determined by the values of the resistor R2 and the bleeder resistors R.sub.5 and R.sub.6, is applied to the control terminal (BCONT) 3a of the amplifier 3 for white balance control. And, the values of the resistors R.sub.1 to R.sub.6 are previously set so that the central values and the variation widths of these D.C. voltages become optimum in a prescribed color temperature range (usually 3000.degree. K. to 7000.degree. K.).
Because, in such a conventional color video camera as described above, however, the gain of the amplifier for white balance control is fixed, if, as the color negative film is shot to obtain a positive picture, the picture is inverted, the gain of the amplifier for white balance control does not become a proper value. This leads to a problem in that the optimum white balance adjustment cannot be assured.
Also, in the conventional color video camera described above, the luminance signal output from the Y processing circuit 4 is supplied as it stands to the above-described detecting circuit 8 so that the high-luminance portion is detected. When the color negative film is shot to obtain a positive picture, therefore, the high-luminance portion of the luminance signal cannot reliably be detected. This contributes to a problem of failing to attain an optimum white balance adjustment.
Furthermore, in the conventional color video camera described above, the color signals output from the image sensor 1 are supplied directly to the amplifiers 2, 3 and the processing circuits 4, 5. When a color negative film is shot to obtain the positive picture, the influence of the film base which is a colored orange system cannot be removed. This contributes to a problem in that the white balance cannot accurately be adjusted.

Color video camera using common white balance control circuitry in negative and postive image photoimaging modes


Improved aluminum substrates suitable for use in the production of lithographic printing plates. A surfactant surface treatment for such aluminum substrates improves the quality of radiation sensitive coatings subsequently applied to the substrate. The surfactant may be in a layer comprising a mixture of a hydrophilizing composition and a surfactant on the aluminum alloy surface; or a hydrophilizing layer comprising a hydrophilizing composition may be on the aluminum alloy surface and a surfactant layer comprising a surfactant on the hydrophilizing layer.

1. Field of the Invention
The present invention relates to aluminum substrates suitable for use in the production of lithographic printing plates. More particularly, the invention pertains to a surfactant surface treatment for such aluminum substrates which improves the quality of radiation sensitive coatings subsequently applied to the substrate.
2. Description of the Prior Art
It has long been known to form printing plates by coating a lithographically suitable radiation sensitive composition onto the surface of an aluminum sheet substrate with subsequent imagewise exposure to radiation and development. Oleophilic image areas which remain after development accept and transfer ink during the printing process and the hydrophilic non-image areas accept water or aqueous solutions during printing to repel such greasy inks.
Typically the substrate comprises an aluminum alloy and the surface of the substrate has been pretreated before coating the radiation sensitive composition with one or more processes such as cleaning, degreasing, chemical etching, mechanical graining, electrochemical graining, anodizing and/or hydrophilizing. Each of these pretreatment steps contributes to forming a high quality printing plate by providing advantageous surface characteristics such as surface uniformity, adhesion to image areas, removal of non-image areas, length of printing run, surface hardness and differentiation between ink accepting and ink repelling areas.
In order to prepare a high quality printing plate, it is important that a very uniform radiation sensitive coating be applied to an underlying hydrophilic surface. Achieving such a uniform coating has been somewhat of a problem in the art and the resulting plates may show a somewhat irregular mottled or non-heterogeneous appearance. It has been found that this is a result of poor wetting of the radiation sensitive coating to the underlying hydrophilic surface. It has now been unexpectedly found that when a surfactant is included in the composition of an underlying layer, the applied radiation sensitive coating is substantially uniform and non-mottled in appearance.

Surfactant in precoat for lithographic plates


A device for simultaneously dispensing a solution containing a sample to a test device and aspirating the sample from the device. In one embodiment the device is hand-held and includes a control mechanism, e.g., button for activating the dispensing and aspiration of the sample. The testing device may take the form of a multi-well plate with a plurality of wells arranged in rows and columns, with the bottom of the wells formed as a photonic crystal biosensor. The device can be configured with dispense and aspirate manifolds and associated dispense and aspirate ports which are positioned in all the wells along a row or column of wells so as to simultaneously aspirate and dispense solution to all the wells in a row or column of the multi-well plate.

This disclosure relates to the art of devices used for aspirating and dispensing small quantities of fluids. More particularly, the disclosure relates to a combination aspirating and dispensing device suitable for use with test devices having a sample containment region in the form of one or more wells or columns of wells, for example in the form of a multi-well plate.
Test devices in the field of biology and biochemistry can take a variety of forms, including devices arranged in an array of wells, such as an 8×12 array of wells arranged in rows and columns. In order to conduct a test on the sample the sample must be loaded into the well. A variety of dispensing devices are known in the art, and described in the patent literature. See, for example, U.S. Pat. Nos. 5,578,270; 6,374,683; 6,325,114; 6,537,505 and 6,983,636. Some of these dispensing devices are automated, while others require a human operator to manually dispense a sample into a well of a test device.
The assignee of this invention has developed a grating-based biosensor which can be affixed to the bottom of a bottom-less multiwell plate whereby the multiwell plate forms a receptacle for holding a biochemical sample to be tested. Grating-based sensors represent a new class of optical devices that have been enabled by recent advances in semiconductor fabrication tools with the ability to accurately deposit and etch materials with precision less than 100 nm.
Several properties of photonic crystals make them ideal candidates for application as grating-type optical biosensors. First, the reflectance/transmittance behavior of a photonic crystal can be readily manipulated by the adsorption of biological material such as proteins, DNA, cells, virus particles, and bacteria on the crystal. Other types of biological entities which can be detected include small and smaller molecular weight molecules (i.e., substances of molecular weight <1000 Daltons (Da) and between 1000 Da to 10,000 Da), amino acids, nucleic acids, lipids, carbohydrates, nucleic acid polymers, viral particles, viral components and cellular components such as but not limited to vesicles, mitochondria, membranes, structural features, periplasm, or any extracts thereof. These types of materials have demonstrated the ability to alter the optical path length of light passing through them by virtue of their finite dielectric permittivity. Second, the reflected/transmitted spectra of photonic crystals can be extremely narrow, enabling high-resolution determination of shifts in their optical properties due to biochemical binding on the surface of the grating while using simple illumination and detection apparatus. Third, photonic crystal structures can be designed to highly localize electromagnetic field propagation, so that a single photonic crystal surface can be used to support, in parallel, the measurement of a large number of biochemical binding events without optical interference between neighboring regions within <3-5 microns. Finally, a wide range of materials and fabrication methods can be employed to build practical photonic crystal devices with high surface/volume ratios, and the capability for concentrating the electromagnetic field intensity in regions in contact with a biochemical test sample. The materials and fabrication methods can be selected to optimize high-volume manufacturing using plastic-based materials or high-sensitivity performance using semiconductor materials.
Representative examples of grating-type biosensors in the prior art are disclosed in Cunningham, B. T., P. Li, B. Lin, and J. Pepper, Colorimetric resonant reflection as a direct biochemical assay technique. Sensors and Actuators B, 2002. 81: p. 316-328; Cunningham, B. T., J. Qiu, P. Li, J. Pepper, and B. Hugh, A plastic calorimetric resonant optical biosensor for multiparallel detection of label-free biochemical interactions, Sensors and Actuators B, 2002. 85: p. 219-226; Haes, A. J. and R. P. V. Duyne, A Nanoscale Optical Biosensor: Sensitivity and Selectivity of an Approach Based on the Localized Surface Plasmon Resonance Spectroscopy of Triangular Silver Nanoparticles. Journal of the American Chemical Society, 2002. 124: p. 10596-10604.
The photonic crystal biosensors of the assignee and associated detection instruments for label-free binding detection are also described in the patent literature; see U.S. patent application publications U.S. 2003/0027327; 2002/0127565, 2003/0059855 and 2003/0032039. Methods for detection of a shift in the resonant peak wavelength are taught in U.S. Patent application publication 2003/0077660. The above-references patent applications and articles are hereby incorporated by reference in their entirety.
There is currently a need in the art for simple, easy to use device which allows for simultaneous dispensing and aspirating of a solution containing a test sample onto a testing device, e.g., one configured in an array of wells. This invention meets that need.

Simultaneous aspirator and dispenser for multiwell plates and similar devices


In one embodiment of the present description, a copy relationship is established between a storage location at a first site and a storage location at a second site in a data storage system, wherein a dynamically assignable bitmap preset to one of a plurality of different predetermined bit patterns is selected as a function of both the availability of the selected bitmap and the type of predetermined bit pattern identified for the selected bitmap. The selected bitmap may be assigned as an out-of-sync bitmap wherein updates to the storage location at one site, which are to be copied to the storage location at the other site, are indicated in the selected bitmap, and data writes being written to the storage location at the one site, are copied to the storage location at the other site, using the selected bitmap as an out-of-sync bitmap. Other aspects are described.

1. Field of the Invention
The present invention relates to a method, system, and program for copying data between primary and secondary storage locations subject to a copy relationship.
2. Description of the Related Art
Data backup systems can provide continuous availability of production data in the event of a sudden catastrophic failure at a single point in time or data loss over a period of time. In one such system, production data is mirrored from a local site to a remote which may be separated geographically by several miles from the local site. Such dual, mirror or shadow copies are typically made in a secondary storage device at the remote site, as the application system is writing new data to a primary storage device usually located at the local site. Different copy technologies may be used for maintaining remote copies of data at a secondary site, such as International Business Machine Corporation's ("IBM") Metro Mirror Peer to Peer Remote Copy (PPRC), Extended Remote Copy (XRC), Coupled XRC (CXRC), Global Copy, and Global Mirror Copy.
In data mirroring systems, data is typically maintained in volume pairs, comprising a primary volume in a primary storage device and a corresponding secondary volume in a secondary storage device that includes an identical copy of the data maintained in the primary volume. The primary and secondary volumes are identified by a copy relationship. Primary and secondary storage controllers may be used to control access to the primary and secondary storage devices.
Geographically Dispersed Parallel Sysplex (GDPS) is an example of an application that customers may use to manage planned and unplanned outages. The GDPS application can detect failures at the primary storage system which may be at a local site, for example. Such failures may include a problem writing or accessing primary storage volumes at the local site. When the GDPS recovery application detects that a failure has occurred, it can invoke a swapping function referred to as the "HyperSwap" function. This function may be used to swap processing for all volumes in the mirrored configuration from the local site to the remote site. As a consequence of the swap, the storage volumes at the remote site which were originally configured as the secondary volumes of the original copy relationship, are reconfigured as the primary volumes of a new copy relationship. Similarly, the storage volumes at the local site which were originally configured as the primary volumes of the original copy relationship, may be reconfigured as the secondary volumes of the new copy relationship, once the volumes at the local site are operational again.
In connection with the swapping function, a failover function may be invoked. In the GDPS recovery application, the failover function can in some instances, obviate performing a full copy when re-establishing data replication in the opposite direction, that is, from the remote site back to the local site. More specifically, the failover processing resets or reconfigures the remote storage devices (which were originally configured as the secondary storage devices) to be the primary storage devices which are placed in a "suspended" status pending resumption of the mirroring operation but in the opposite direction. In the meantime, the failover processing starts change recording for any subsequent data updates made by the host to the remote site.
Once the local site is operational, failback processing may be invoked to reset the storage devices at the local site (which were originally configured as the primary storage devices) to be the secondary storage devices. Mirroring may then be resumed (but in the opposite direction, that is remote to local rather than local to remote) to resynchronize the secondary storage devices (originally the primary storage devices) at the local site to the data updates being stored at the primary storage devices (originally the secondary storage devices) at the remote site.
Copy services such as PPRC and data recovery programs which use copy services such as PPRC, frequently use various types of bitmaps stored in metadata. For example, bitmaps may be "static" bitmaps which are reserved for a particular function. Other bitmaps, often referred to as "dynamic" bitmaps, may be available for use by different functions and thus may be dynamically assigned to a function requesting a bitmap.
In general, the contents of static bitmaps are not known until they are initialized by the function reserved for that static bitmap. Dynamic bitmaps available for use by different functions, are typically initialized when created so that all bits of the bitmaps are initialized to a zero value. Once a function has completed use of a bitmap, the bitmap is considered to be "dirty" and thus is typically reinitialized (cleaned) before being used again.
The static and dynamic bitmaps are typically set up at the time the volumes are created. When a function requires a dynamic bitmap, it is assigned a bitmap index to an available dynamic bitmap. The value of this index which identifies the dynamic bitmap being assigned to the function, is typically kept in separate metadata until the bitmap is no longer in use.
In known copy services such as PPRC, an out-of-synch (OOS) bitmap is an example of a static bitmap reserved for the OOS function. An OOS bitmap includes a bit for each track of a primary storage location that storage controllers are to copy over to a corresponding track of a secondary storage location of a copy relationship. Thus, the out-of-synch bitmap indicates a backlog of tracks waiting to be copied. During normal copy operations, any writes to a storage controller for the primary storage location, are recorded in the out-of-synch bitmap (OOS) and then copied over to the secondary storage location.
Previously, processing of the swapping operation of failover commands such as the PPRC Failover command typically included initialization of the Out-Of-Sync (OOS) bitmap for all original remote volumes being reconfigured as primary volumes for the replacement copy relationship. The OOS bitmap is frequently stored as a data structure in metadata within the primary storage locations of the copy relationship. In a typical OOS bitmap, a zero bit indicates that no update has occurred for the data track of the primary storage location represented by that bit of the OOS bitmap. Hence, in many prior data recovery programs, the OOS bitmap is typically initialized to all zeros by accessing the metadata of the primary storage location and writing zeros to every bit position of the bitmap.

Bitmap selection for remote copying of updates

INTERNATIONAL BUSINESS MACHINES CORPORATION


An electric heater for ceilings which emits radiant heat includes a radiant plate having heating elements which radiate in a downward direction. The radiant plate is mounted to a top part by a number of elastic/flexible brackets, including pivotable and non-pivotable brackets. The brackets allow the radiant plate to move laterally outward in a horizontal plane when the radiant plate is heated to prevent twisting or other deformation of the radiant plate. The pivotable brackets are mounted near the ends of the heater on all four sides to accommodate expansion of the radiant plate in a horizontal plane. The non-pivotable brackets are mounted at the midpoints of the ends of the heater.

The present invention relates to a heater based on a hot radiant plate which radiates heat, and comprising a heating element which produces and distributes heat across the radiant plate, a thermal insulation layer which also supports the radiant plate and ensures good heat contact between the heating element and the radiant plate, a cold plate where the electrical and mechanical fastening means are mounted, and fastening means between the hot plate and the cold plate which, with minimal heat contact, ensure free horizontal movement between the two plates while keeping them locked together about a center point.
A radiant panel heater is in principle based on heating a plate to a desired temperature so that heat waves are emitted to the surroundings as direct radiation from the plate. As a rule it is desirable to direct the heat waves in particular directions, for example downward from a ceiling heater, this being achieved by thermal insulation in other directions or by shielding against radiation in those directions where it is unwanted.
Electric radiant heaters for ceilings are previously known, comprising a relatively elongate radiant heating element consisting of an extruded aluminum profile which is heated to about 300.degree. C. The radiant heat profile is mounted in a steel box and insulation is placed on the top side so that there is a significant temperature difference between the radiating plate and the surface of the radiant element facing other directions.
Because of the various types of requirements set for such electric radiant heaters for ceilings, the design thereof involves considerable difficulties, inter alia, caused by uneven thermal expansion of the materials contained in the structure, an expansion which may lead to undesirable sounds, torsion and deformations. Furthermore, in the previously known examples there is considerable heat contact and thereby heat transfer to those parts of the heater which shall not emit radiant heat, this heat thus being unavailable for heating those areas which are meant to be heated. It is only the radiant heat energy emitted in the desired direction that can be regarded as effective energy; all other radiated energy is to be considered a heat loss.
A ceiling heater is always highly visible in a room and should therefore be as discreet in its design and selection of materials as possible so as not to become a disturbing element in the ceiling, this being particularly important in buildings such as churches, for example. It may often be desirable to design the ceiling heater as a part of the ceiling, a task rendered difficult with the existing structures which are fixedly locked to one or more aluminum profiles positioned side by side in a steel box.
For space heating it is generally these types of heaters that are used:
Wall radiators, the main purpose of which is to heat the air in the room. These are well suited to low-ceilinged rooms used for extended periods of time. This type of heating is not suited to high-ceilinged rooms because a great deal of air circulation will occur in the room, at the same time as the hot air will accumulate on top, next to the ceiling.
Ceiling heat and floor heat, both of which are a low-temperature radiant heat having a surface temperature 5.degree.-25.degree. C. above the air temperature. Here the purpose is to give a low temperature radiant heat to the whole room from the heating elements built into the ceiling or floor. The weakness of the system is that it has a great deal of thermo-technical inertia, and that it does not concentrate the heat in those areas of the room where it is wanted. The effect delivered is about 150 watt/m.sup.2.
Reflector heaters, which have incandescent heating elements of 600.degree.-800.degree. C. These are heaters which have high heat output in relation to size. They emit a short-wave heat radiation which after an extended period of time may often feel uncomfortable. The reflector is easily soiled, preventing the heat waves from being reflected down into the room and resulting in the heater changing character by approaching a convector heater, the heat thereby remaining on top right next to the ceiling.
Medium-temperature radiant panel heaters, which may be ceiling heater cassettes, either free-hanging or built into dropped ceiling systems, and having a radiant plate temperature in the range of 50.degree.-100.degree. C. above air temperature. For higher temperatures (up to 330.degree. C.) the radiant plate is commonly an extruded aluminum profile having the heating element positioned in a track in the aluminum profile which is mounted in an outer housing, so that the heat expansion in the longitudinal direction can occur as unobstructed as possible (Norwegian Patent Application No. 873830). These heaters have little thermo-technical inertia, function equally well if they become soiled, and are particularly well suited to high-ceilinged rooms which have poor thermal insulation in the walls and are not in continuous use. They provide a comfortable long-wave radiant heat which can be concentrated over those areas in the room where heating is desired, and they do not produce much air circulation in the room. These are heaters yielding an effect of 500-5000 watt/.sup.2.

Ceiling mounted electrical heater with flexible mounting structure


The present invention provides a food preparation board with multiple and distinct measurement zones. The food preparation board comprises a work surface that is provided for preparation of a food item thereon, and is sized to receive at least a portion of the food item. A rest surface is located opposite the work surface. A first measurement zone is defined by a first portion of the work surface. The first measurement zone is comprised of a first plurality of measurement indicia corresponding to a first measurement scale. A second measurement zone is defined by a distinct second portion of the work surface, the second measurement zone is comprised of a second plurality of measurement indicia corresponding to a second measurement scale. The second measurement scale is different than the first measurement scale.

Food preparation boards are generally used in combination with kitchen utensils to facilitate the preparation of food-related items. There is often a need to cut or otherwise form food items to predetermined sizes while cooking. The present invention seeks to overcome certain of the limitations and other drawbacks of the prior art, and to provide new aspects and advantages not heretofore available.


Methods, systems, and apparatus, including computer programs encoded on computer storage media, for determining a suitable building layout for a property. One of the operations is performed by optionally, receiving building module parameters for section of qualifying building modules. displaying, via a user interface, a graphical representation of two or more building modules. A user may customize a building layout from the two or more building modules. The system displays an assembled building layout including two or more building modules. The system receives a confirmation of the assembled building layout for 3D printing. Based on the assembled building layout, instructions are generated and transmitted to one or more 3D printers to manufacture one or more building structures based on the selected building layout.

Traditional building planning and building construction processes are often complicated and inefficient. Building planning may require hiring an architect to design a building, creating a floor plan, hiring a lead contractor or multiple contractors to construct the building, obtaining permits from local agencies to begin the construction, and incurring inspections of the structure at various times during construction. As to building a structure often a foundation must first be poured and then framing, plumbing, electrical systems and drywall must be constructed or installed. Construction of a new structure on a property often takes many months to complete and requires multiple workers and inspections as the construction proceeds.

Custom assembly of 3D printed building modules


A separator contains thermoplastic synthetic fiber, and acid-resisting oxidation-resisting inorganic filler, wherein the cumulative volume of pores having a pore size not smaller than 1 .mu.m is not larger than 20% of the cumulative volume of all pores, and the maximum pore size is not larger than 10 .mu.m.

1. Field of the Invention
The present invention relates to a lead-acid battery separator.
2. Description of the Related Art
The method for producing a separator mainly used in a lead-acid battery is classified into two groups, namely, a method using an extrusion molding apparatus to form a sheet-like separator (U.S. Pat. Nos. 3,351,495 and 5,336,573), and a method using paper making process to form a sheet-like separator (U.S. Pat. No. 4,367,271). In the former, after ultra-high-molecular-weight polyethylene powder, silica and petroleum oil are heated, melted and kneaded and the mixture is extruded in the form of a sheet by an extrusion molding apparatus, a major part of petroleum oil is extracted with an organic solvent to obtain porosity to thereby form a so-called polyethylene separator. In the latter, binder is mixed with thermo plastic synthetic fiber and inorganic filler as main components and sheet-making is performed by paper making process to thereby form a so-called synthetic pulp separator. The synthetic pulp separator is generally stuck to a glass mat in use.
In recent years, the separator for a lead-acid battery, especially for a SLI battery has been required (1) to be lower in electrical resistance, (2) to have excellent oxidation resistance at a high temperature, (3) to prevent penetration and short-circuiting with an active material, (4) to have structures such as a more reliable shape (for example, the shape of a envelope), etc., because of a countermeasure against Products Liability and (5) to be inexpensive.
(1) As the separator low in electrical resistance, a separator more excellent in cold start characteristic of the battery has been required with the advance of down sizing of the battery.
(2) Oxidation resistance has been required not only with the increase in the frequency of use of the battery under a high temperature with the advance of reduction in space of underhood but also with the advance of motorization in tropical regions such as Southeast Asia, etc.
(3) With respect to the penetration and short-circuiting, electric power consumption due to the key off current in apparatuses with the increase of electric equipments, etc. has become to be hardly ignored. Accordingly, named hydrous short circuit has been actualized.
(4) A structure in which a sense of security is given by means of enveloping electrode plates or has a tendency to be welcomed with a favorable impression.
(5) The polyethylene separator requires a long time for petroleum oil extraction with an organic solvent and, further, a high expense is required for equipment and as a running cost because an apparatus for recovering the organic solvent and petroleum oil is needed. On the other hand, the synthetic pulp separator is made expensive because the synthetic pulp separator needs a stuck glass mat.
The polyethylene separator is apt to be oxidized because a network constituting pores is a polyethylene thin film. Particularly under a high temperature, deterioration is accelerated so that many cracks give rise in the separator, thereby causing to short the lifetime of the battery.
Further, it is generally considered that a separator having a smaller pore size is better to prevent the penetration of an active material causing short-circuiting. The aforementioned separator is however poor in diffusion of the electrolyte because the pores are too small. Accordingly, a stratification of electrolyte occurs to cause shortening of lifetime.
The polyethylene separator has the following defects. A great deal of care and a large equipment cost are required for prevention of the risk of a fire and for prevention of the pollution of the environment in a production process because of use of petroleum oil and an organic solvent. Further, the electrolyte in the battery will be contaminated with oil remaining in the separator, which oil is necessary for improvement of acid resistance of the separator.
In the synthetic pulp separator, the cumulative volume of pores having a pore size not smaller than 1 .mu.m is 40-60% of the cumulative volume of all pores. Because the pore size is too large to prevent the penetration of an active material, penetration short-circuiting occurs when discharge is deep. Further, to prolong the lifetime of the battery, the synthetic pulp separator must be generally used in combination with a glass mat. In that case, there is a defect that cold start characteristics can be obtained with much difficulty because evolved gas from electrodes will remain in the glass mat as bubbles (so-called bubble holding phenomenon).

Lead-acid battery separator and method for producing thereof


An electrostatic discharge (ESD) protection circuit, suitable for an input stage circuit including a first N channel metal oxide semiconductor (NMOS) transistor, is provided. The ESD protection circuit includes an P channel metal oxide semiconductor (PMOS) transistor and an impedance device, in which the PMOS transistor has a source coupled to a gate of the first NMOS transistor, and a drain coupled to a source of the first NMOS transistor, and the impedance device is coupled between a gate of the PMOS transistor and a first power rail to perform a initial-on ESD protection circuit. The ESD protection circuit formed by the PMOS transistor and the resistor is capable of increasing the turn-on speed of the ESD protection circuit and preventing the input stage circuit from a CDM ESD event.

1. Field of the Invention
The present invention generally relates to an electrostatic discharge (ESD) protection circuit, in particular, to a Charged-Device Model (CDM) ESD protection circuit.
2. Description of Related Art
An ESD event refers to a phenomenon of electrical discharge of a current for a short duration during which a large amount of current is provided to a semiconductor integrated circuit (IC). ICs are generally susceptible to ESD events, which may damage or destroy the integrated circuit. Thus, ESD protection of ICs is a critical factor in obtaining higher yield and stable IC characteristics. The susceptibility of a device to ESD can be determined by testing each one of three models which include Human Body Model (HBM), Machines Model (MM) and Charged-Device Model (CDM).
With regard to a CDM ESD event, electrostatic charge could be stored within the body of an IC product due to induction or tribocharging and most of the charge is accumulated in a substrate, including a base, a body or a well of the devices disposed on the IC, and is uniformly distributed in the substrate. Once a certain pin of the IC is suddenly grounded, the electrostatic charge originally stored within the IC will be discharged through the grounded pin. This is called the CDM ESD event. The CDM ESD event delivers a large amount of current in a very short period of time, and in general, the entire ESD event can take place in less than 2 nanoseconds (ns). Current levels can reach several tens of amperes during discharge of the electrostastic charge, which are remarkably greater than those of the HBM and MM models.
Additionally, there are many situations where the pins of an IC may become grounded; for example, the pin may touch grounded metallic surface or the pin may be touched by grounded metallic tools. Different ICs have different die sizes, so their equivalent parasitic capacitances are totally different from one another. Thus, different ICs have different peak current and different CDM ESD levels. When a device under test (DUT) with the equivalent capacitance of 4 pF is put under a 1-kV CDM ESD test, the CDM ESD current can rise to more than 15 A within several nanoseconds. Compared with HBM and MM ESD events, the discharging current in a CDM ESD event is not only larger, but faster. Since the duration of CDM ESD events is much shorter than HBM and MM ESD events, the internal circuit may be damaged during CDM ESD events before the ESD protection circuit is turned on.

Electrostatic discharge protection circuit


A device configured to monitor a voltage at a voltage rail for driving a motor includes processing circuitry configured to receive an indication of a switching signal for a phase of a plurality of phases of the motor. Inverter circuitry associated with the device is configured to electrically couple the phase to the voltage rail or to a reference rail associated with the voltage rail based on a driving signal that is generated based on the switching signal. The processing circuitry is further configured to determine a measurement time to measure the voltage at the voltage rail based on the switching signal and generate, using an analog-to-digital converter (ADC), a set of measured voltage values based on the voltage at the voltage rail during the measurement time.

Operation of a motor may be performed by a controller. The controller controls a rotor rotation of the motor based on a position of the rotor relative to stator coils of the motor. For example, the controller may control inverter circuitry to provide power from a voltage rail to each phase of the motor based on the rotor position to provide a desired rotor speed and/or torque.

Voltage monitor using switching signal for motor


A stud type track roller bearing includes a stud having an inner ring portion, a threaded portion and an intermediate portion therebetween. A flange formed with an inclined surface is provided at an end of the inner ring portion. An intermediate ring formed with a pair of oppositely inclined surfaces is fitted onto the inner ring portion in abutment with the flange and a side ring formed with an inclined surface is also fitted onto the inner ring portion in abutment with the intermediate ring so that a pair of inner guide grooves is provided on the stud. An outer ring formed with a pair of outer guide grooves is fitted onto the inner ring portion with a gap therebetween to define a pair of annular guide channels which are spaced apart from each other axially and provided with a plurality of rollers.

1. Field of the Invention
This invention generally relates to a stud type track roller bearing for use in various linear motion mechanisms and cam mechanisms in industrial robots, machining tools, and office automation machines and in particular to a stud type track roller bearing having a double roller channel structure.
2. Description of the Prior Art
A stud type track roller bearing is well known in the art and its typical structure is illustrated in FIG. 3. As shown, it includes a stud A including a head portion B which is somewhat larger in diameter an which defines an inner ring portion. An outer ring C is fitted onto the inner ring portion B with a predetermined gap therebetween to define an annular roller channel in which a plurality of cylindrical rollers D are arranged to provide a rolling contact between the inner ring portion B and the outer ring C. This structure is effective in sustaining a radial load, but it is not suitable for sustaining other loads such as axial and moment loads.


To provide a photomask capable of preventing a foreign matter generation in using the photomask, and an exposure method using this photomask. The photomask includes a transparent substrate 2; a transfer pattern 4 formed in a main region 3 of a center portion of the transparent substrate 2; a light-shading band region 5 provided adjacent to the main region 3 in the outer peripheral region of the main region 3; and a pellicle 6 formed by adhering a pellicle film 6a to a pellicle frame 6b by an adhesive 8a, wherein this pellicle 6 is adhered onto a light-shading region 7 consisting of a light-shading film formed in the outer peripheral region of the main region 3, through an adhesive 8b.

Irradiation of exposure light is performed through a photomask (reticle), for example, to form a transfer pattern in a manufacture of the semiconductor device.
A photomask formed with a light-shading film pattern on a transparent substrate composed of a rectangular quartz glass is conventionally used, and as a material of a light-shading film, a chromium-based material (elementary chromium, or chromium containing nitrogen, oxygen, and carbon, etc, or a lamination film of these material films) is generally used.
Further, in recent years, a phase shift mask has been developed for practical use, to improve a resolution of the transfer pattern. Various types (for instance, a Levenson-type, an assist-pattern-type, and a self-matching type, etc) are known as the phase shift mask, and as one of them, a halftone phase shift mask suitable for the pattern transfer of a hole and a dot with high resolution is known.
This halftone type phase shift mask is obtained by forming a light translucent film pattern having a phase shift amount of about 180 deg, wherein the light translucent film is sometimes formed of a single layer or sometimes formed of multi-layers. For example, patent document 1 discloses the light translucent film pattern formed of a thin film composed of a substance containing metal such as molybdenum, silicon, and nitrogen as main constituent elements.
The light translucent film with such materials is excellent in acid resistance and resistance to light, in addition to having an advantage capable of controlling a prescribed phase shift amount and transmittance by a single layer.
When manufacturing these photomasks, it is necessary to form a fine pattern and therefore a pattern forming method of the photomask generally includes the steps of forming a resist pattern by exposing the resist to light by performing pattern drawing by an electron beam exposure apparatus; and thereafter forming the pattern by dry etching.
Note that as the kinds of the resist, there are a positive resist and a negative resist.
The positive resist is the resist having a property that a part irradiated with electron beam is removed by a resist developer, and the negative resist is the resist having a property that a part excluding the part irradiated with the electron beam is removed by the resist developer.
The choice as to which of the positive resist and the negative resist is used is made, to select more preferable one in terms of forming the pattern or shortening of drawing time of the electron beam exposure apparatus.
In addition, the aforementioned transfer pattern is formed in a rectangular main region located in a center portion of the rectangular transparent substrate, and during using the photomask, outer peripheral part of this main region is shield by a masking blind provided in the exposure apparatus, and the pattern of the main region is transferred to the resist on the transfer substrate.
In addition, in order to prevent the transfer to the outer peripheral part of this main region by leaked light, the photomask generally has a light shading band region adjacent to the main region.
In addition, in the photomask, a mark pattern, etc. of an alignment mark, etc, generally used for aligning with each kind of devices for photomask exists mainly in the peripheral part of the main region depending on specifications of each exposure apparatus manufacturer, a photomask user, and a photomask manufacturer.
Conventionally, when the pattern transferring is made using the positive resist, the peripheral region of the main region, excluding a desired mark pattern, is made, as a non-drawing region, where a light-shading film is formed.
On the other hand, when the pattern transferring is made with the negative resist, the peripheral region of the main region, excluding desired mark pattern and light-shading band, is made as, the non-drawing region, where the transparent substrate is exposed.
Namely, exposing patterns on the resist are performed by scanning a substrate surface based on pattern data.
Therefore, it is general to shorten a drawing time to avoid drawing, patterns on an unnecessary region.
Further, in order to prevent adhesion of foreign matters to the formed pattern, it is general to use the photomask by mounting a protective film called a pellicle.
The pellicle is formed by adhering a pellicle film consisting of a transparent polymer membrane to a pellicle frame usually consisting of metal, and this pellicle frame is attached to a surface of the photomask by using an adhesive.
More specifically, the pellicle frame is adhered to an outside of the light-shading band by using the adhesive, to cover the main region and the light-shading band.
In addition, in order to prevent the foreign matters from adhering onto the photomask, the adhesive is sometimes provided to an inner surface of the pellicle frame.
Note that the aforementioned each kind of mark pattern could exists not only in the pellicle but also outside the pellicle.
Incidentally, it is known that when the pattern transfer is performed by using the photomask, with pellicle mounted thereon, the pellicle is irradiated with laser beams, thereby accelerating reaction of ammonium ions that exist in the pellicle (in the air) and sulfate ions which are used for cleaning the photomask and are remained on the photomask, then, ammonium sulfate is deposited, and such the foreign matters are adhered onto the photomask (for example, patent document 1).    (Patent document 1) Japanese Patent Laid Open No. 2000-352812
However, in the photomask, with the transfer pattern formed thereon by using the negative resist, namely, the photomask, with the non-drawing region, namely the transparent substrate exposed in the peripheral region of the main region excluding the desired mark pattern and the light-shading band, there occurs a problem that a plurality of foreign matters are found in the photomask after use.
In addition, it is found that above problem is more remarkable in the photomask with the transfer pattern formed thereon by using the negative resist than in the photomask with the transfer pattern formed thereon by using the positive resist.
Accordingly, regarding the photomask with the transfer pattern formed thereon by using the negative resist, namely, the photomask, with the non-drawing region, namely, the transparent substrate exposed in the peripheral region of the main region excluding a desired mark pattern and the light-shading band, there is a problem that the photomask becomes unusable with a few using times.
As a cause of generating the aforementioned problem, there is given such a case that when the adhesive used for adhering the pellicle frame to the photomask is directly adhered to the transparent substrate, a stray light by a multiple reflection of the exposure light in the exposure apparatus during using the photomask transmits from a rear surface side of the transparent substrate to the transparent substrate, whereby the adhesive used for adhering the pellicle frame to the photomask, or the adhesive used for adhering the pellicle film to the pellicle frame, and further the adhesive inside of the pellicle frame if the adhesive is given thereto are irradiated with this stray light, and as a result, gas generated from the adhesive, being an organic substance, becomes a deposited substance, and would be adhered onto the photomask.
In addition, when the adhesive is not applied to the inside of the pellicle frame, it can be considered that components remained by an alumite treatment of the pellicle frame (including a coloring process) or the component remained by coating processing, etc, of the pellicle frame are deposited by irradiating the pellicle frame with the stray light which is caused by the multiple reflection, etc, of the exposure light in the exposure apparatus when using the photomask, and this stray light transmits the transparent substrate from the rear surface side to emit onto the pellicle frame, thereby adhering a deposit onto the photomask.
In addition, it is confirmed that the aforementioned problem becomes more remarkable, as a light source wavelength of the used exposure apparatus becomes shorter from the present KrF excimer laser (wavelength of 248 nm) to an ArF excimer laser (wavelength of 193 nm) and a F2 excimer laser (wavelength of 157 nm).
Therefore, there is a problem that even more foreign matters could be generated, as the exposure light wavelength applied by the exposure apparatus becomes shorter, accompanied by applying finer LSI pattern in recent years.
FIG. 5 shows an example of energy possessed by the light source wavelength of the exposure apparatus and a bonding energy of organic substances coming from matters such as the adhesive, etc.
In this way, as the wavelength of the light source of the exposure apparatus becomes shorter, it can be considered that the bonding energy possessed by molecules of the adhesive is more liable to be cut, and simultaneously a polymerization reaction or a radical reaction could occur, and as a result, generation of gas or generation of deposits become even remarkable.

Matsushita Electric Industrial Co., Ltd.


A light source unit includes a light emitting element supporter to support a plurality of light emitting elements disposed with a dispersed pattern in a two-dimensional direction as a light emitting element assembly, and light emitted from the light emitting element assembly exits to a target; a light return member disposed at a position facing a light emitting side of the light emitting element assembly while setting a space with the light emitting element supporter, the light return member returning light emitted from the light emitting element assembly toward at an inner side of two dimensional direction of the light emitting element assembly, and a flow path of the cooling air to pass through cooling air supplied from an air supply unit into the space.

1. Technical Field
The present invention relates to a light source unit and image projection apparatus to emit light to a target.
2. Background Art
Screen images of personal computers, video images, and image data stored in memory cards can be transmitted to image projection apparatuses known as projectors that can project images onto a screen. In the projector, light emitted from a light source is focused on a micro mirror display device known as a digital micro mirror device (DMD), or a liquid crystal plate, and then images are displayed as images such as color images on the screen.
In the projector, a high intensity discharge lamp is conventionally used as the light source, but other light sources have been developed. For example, as a light emitting element for light source units, semiconductor elements such as a light emitting diode (LED), a laser diode (LD), or organic electroluminescence (OEL) have been developed as the light source. The laser diode can be used as the light source for the image projection apparatuses to enhance, for example, color reproduction performance, light emission efficiency, and light use efficiency. Further, because the laser diode is a point light source or projects parallel beams, a lighting system can be designed easily, color lights can be synthesized using a simple configuration, and a projection lens having a small numerical aperture (NA) can be used.
When the light emitting element such as the laser diode (LD) is employed as the light source for the image projection apparatuses, light quantity of one single light emitting element is not enough for light quantity required for the image projection apparatuses.
In view of such issue, a semiconductor light source apparatus of JP-2011-197593-A is devised, in which a number of light emitting elements are packed two dimensionally on a plane, and light quantity required for an image projection apparatus can be obtained by adding light quantity of a number of light emitting elements. In this semiconductor light source apparatus, a number of light emitting elements are supported by a light emitting element supporter in a matrix pattern while setting the light axis of each of semiconductor light emitting elements is substantially parallel to each other. Light emitted from the semiconductor light emitting elements are condensed by using a collimator lens retained at a lens holder of each of the semiconductor light emitting elements to obtain light quantity required for the image projection apparatus.
As for image projection apparatuses using a light emitting element assembly arranging a number of light emitting elements with a dispersed pattern on two dimensional direction as a light source, efficient cooling of the light emitting elements becomes an issue because if the cooling is not enough, light emitting quantity may not be stabilized, and lifetime of the light emitting elements becomes short.
The light emitting element assembly can be cooled by disposing a heat dissipater such as a heat sink on a rear side of a light emitting element supporter that supports the light emitting element assembly, in which air is supplied to the heat dissipater to cool the light emitting element assembly using a cooling fan.
However, cooling effect may not be enough just by cooling the rear side of the light emitting element supporter. Especially, when a large number of light emitting elements are densely disposed on a plane to achieve a small-sized light source, or when a large number of light emitting elements are used to increase light quantity, cooling effect may not be enough.

Light source unit and image projection apparatus including light source unit


The present invention provides a method for protecting against UV radiation-induced skin damage. Specifically, compositions including dapsone are administered to provide UV protection. The dapsone compositions may be administered orally, or by other parenteral routes, such as topically, transdermally, by inhalation, and the like.

Human skin is a-primary target of nonionizing electromagnetic radiation in the ultraviolet, visible, and infrared ranges, and consists of three distinct layers: the stratum corneum, the epidermis, and the dermis. The epidermis and dermis contain several molecules known as chromophores, that are capable of absorbing light or UV radiation (UVR). The main chromophores in human skin include such molecules as nucleic acids, aromatic amino acids, proteins, porphyrins, carotenoids, steroids, and quinones (Mary S. Matsui and Vincent A. DeLeo, Skin Cancer: Mechanisms and Human Relevance Chp. 4, 22 (Hasan Mukhtar ed., 1995)).
The UV spectrum is divided into A, B, and C ranges. The UVC range extends from wavelengths between 200 and 290 nm. The UVB spectrum includes wavelengths between 290 and 320 nm, and is generally known as the sunburn spectrum because it produces erythema in human skin. UVA radiation includes wavelengths between 320 to 400 nm. Atmospheric ozone absorbs all UVC and much of the UVB, so that the spectrum of UV radiation at the earth's surface consists primarily of UVA. The depth to which a photon penetrates in vivo is related to its wavelength. Thus, most UVB radiation transmitted through the ozone layer is absorbed within the first 0.03 mm of the epidermis, whereas one third of UVA radiation penetrates to a depth of 0.1 mm (Hardie et al., Surgery 87:177 (1980)).
When the skin is exposed to UVR, energy transferred to chromophores from the absorbed radiation may result in molecular reorganization and/or interaction with nearby biomolecules. For example, after UVR absorption, DNA may form dipyrimidine lesions, such as cyclobutane pyrimidine dimers. In turn, characteristic mutations result, e.g., mutations in p53, that have been shown to be important in producing non-melanoma skin cancer. (A. Ziegler et al., Nature 372:773-776 (1994)). Furthermore, the UV-induced conversion of urocanic acid from the trans to cis isomer has been linked to the subsequent development of non-melanoma skin cancers (Craig A. Elmets et al., Skin Cancer: Mechanisms and Human Relevance Chp. 18, 230 (Hasan Mukhtar ed., 1995)).
Further insight into UV-induced skin tumor formation has been gained from studies in rodents. UV-induced skin tumors stimulate a strong immune response. If UV-induced tumors are implanted into normal, genetically identical mice, they are promptly rejected by the host immune-system and the animals survive. If the same tumor is implanted into mice that have been exposed to subcarcinogenic doses of UVR, immunological destruction of the tumor does not occur. These results indicate that UVR produces mutations in skin cells and facilitates tumor growth by impairing immune surveillance. The presence of both deficiencies is necessary for clinically apparent skin cancers to develop (J. T. Krutmann and C. A. Elmets eds. (1995). Photoimmunology. Oxford: Blackwell Scientific).
Currently marketed sunscreens function either as ultraviolet (UV) filters or UV blocks. UV blocks, such as TiO2 and ZnO, as well as derivatives of other metal-oxides, form a physical barrier that scatters UV light. These UV blocks offer the most comprehensive sunscreen protection, blocking the full spectrum of UVA and UVB light. However, the most commonly used sunscreens are UV filters, which are typically organic compounds. A disadvantage of UV filters is that each organic compound has a limited range of maximum UV absorptivity, rendering each reagent better suited for either UVA protection or UVB protection, but not both.
The UV-induced mouse tumor model has proven very useful not only in gaining mechanistic understanding of skin tumor formation, but also in determining if topical products promote or inhibit the formation of UV-induced tumors. A standard UV carcinogenicity model accepted for the testing of topical pharmaceuticals employs the albino hairless Crl:SKH1-hr BR mouse (P. D. Forbes et al., Photobiology. 663-669 (E. Riklis ed., 1991)).
After administration of a topical formulation, experimental protocols typically instruct that mice be irradiated once daily, five days per week, for 40 weeks. Intensity and cumulative UV radiation dose is measured in Robertson-Bergen Units (RBU). The RBU is a measure of biological effectiveness for UVR, with 400 RBU being approximately one minimal erythema dose in previously untanned human skin, i.e., about 30 mJ/cm2 in a sun-sensitive skin type I or II. Mouse carcinogenicity studies are completed at 600 RBU per week because this produces an appropriate tumor mean latent period for comparison with test article treated and untreated controls. At this radiation level, about half of the untreated animals will have a first perceptible tumor by week forty-one. A higher control UVR level of 1200 RBU per week results in a significant reduction in the median tumor latent period. At this radiation dose, about half of the untreated animals will have a first perceptible tumor by week twenty-four. Animals continue to be observed for 12 weeks after 40 weeks of product application to provide a total of 52 weeks of tumor data.
At least two common topical therapies promote tumor formation in this UV induced mouse carcinogenicity model. Benzoyl peroxide and retinoids such as tretinoin, which are commonly used to treat acne, promote the formation of skin tumors compared to untreated or vehicle controls. (Physicians Desk Reference, 56th Edition, Medical Economics Company, Inc., Montvale N.J., (2002)). While many topical products containing these actives are currently in use, the patients who use them are strongly encouraged to avoid sun exposure on their face after using the product. However, significantly shielding the face from sun exposure, especially for young adults, is virtually impossible for products that are often used twice daily.
U.S. Pat. Nos. 6,113,888 to Castro et al.; U.S. Pat. No. 6,200,964 to Singleton et al.; and U.S. Pat. No. 6,231,837 to Stroud et al. describe topical compositions that contain therapeutics. However, the therapeutic is not included to provide protection from ultraviolet radiation. If UVR protection is desired, sunscreens are added to the formulations.
Topical compositions including dapsone have been described in U.S. Pat. Nos. 5,863,560 and 6,060,085 to Osborne, and U.S. application Ser. No. 10/081,050 to Osborne, which are herein incorporated by reference in their entirety. However, these compositions were formulated to treat acne, not to prevent skin damage from UV radiation.
Therefore, new compositions that protect against UV-induced skin damage are needed.