A machine for peeling and cleaning fruits and vegetables using a plurality of rotating abrasive rollers which are each driven by an electric motor. The machine has a frame with a pair of end plates that rotatively carry the rollers. Each motor is carried by an end plate and coupled to a roller solely to drive only that roller. In one preferred embodiment, the motor is coupled to a gear reducer that preferably is a cycloidal gear reducer having an output shaft coupled to one end of a roller and which has an output shaft axis of rotation generally coaxial with the axis of rotation of the roller. In another preferred embodiment, the motor can be directly coupled to the roller with its output shaft axis of rotation generally coaxial with the roller axis of rotation. To control operation and speed of the abrasive rollers, the motors are controlled by a motor controller that preferably is a variable frequency electric motor drive. Where the machine uses an auger to urge food product through the machine, the auger can be driven by an electric motor whose operation and speed preferably is controlled by a variable frequency electric motor drive. Where the machine is a rotating cage machine, the cage can be driven by an electric motor whose operation and speed preferably is controlled by a variable frequency electric motor drive. Each motor preferably is a three phase alternating current electric motor.

In the peeling and cleaning of food products that are typically vegetables and fruits, food processing machines utilizing rotating rollers that abrade the food product to peel, clean or wash the food product are commonly used. Each abrasive roller peeling and cleaning machine utilizes several abrasive elongate rollers grouped in a circle or semicircle to form a chamber for receiving the food product. Each machine also includes a drive system for rotating each roller. Abrasive roller peeling and cleaning machines are favored and have enjoyed considerable commercial success because they are versatile and use little, if any, water during operation minimizing post-processing water treatment costs.
During operation, each of the rollers of an abrasive roller food processing machine are rotated about a central longitudinal axis and food product entering the machine engages one or more of the rotating rollers. While in contact with a roller, the roller contacts and at least slightly abrades the food product. Each roller typically comprises a central core that has brush bristles which extend radially outwardly from the core which engage food product to wash or abrasively clean, peel, or clean and peel the food product. Other commonly used roller configurations include a roller having an exterior made of a relatively rough sandpaper-like material and a roller having a plurality of slightly axially spaced apart circular flexible rubber or plastic fins (flanges) or fingers carried by the roller core.
When cleaning food product, the rotating rollers abrade the food product to remove dirt and other residue on the food product to prepare the food product to be further processed or to enable the cleaned food product to be packaged and shipped to market. When peeling food product, the rotating rollers abrade the exterior of the food product typically to remove its skin thereby also washing or cleaning the food product. In some instances, while either cleaning or peeling food product, some water or another solvent can be introduced in the food product receiving chamber of the machine along with the food product.
In one type of abrasive roller peeling and cleaning machine, the machine comprises a frame with a pair of generally upstanding and spaced apart endplates that carry the rollers between them. The rollers are journalled for rotation in the end plates, both end plates remaining stationary during operation. Generally, the rollers are arranged in an upturned U-shaped semicircle (stationary U-bed) with very little space between each pair of adjacent rollers to prevent food product from passing between adjacent roller pairs and falling downwardly. To enable food product to flow from an inlet end to an outlet end of the machine, a rotating auger between the rollers urges food product axially relative to the rollers from the inlet toward the outlet.
In another type of abrasive roller peeling and cleaning machine, the abrasive rollers are arranged to form a cylindrical food product receiving chamber and are each journalled for rotation in the end plates which in turn are rotatably carried by the frame. More particularly, the rollers, struts and end plates form a cage that is rotated in addition to each abrasive roller being rotated. To enable food product to flow from the inlet to the outlet of the machine, the machine can be tilted downwardly in the desired direction of product flow or an auger can be received in the chamber with relative rotation between the cage and auger causing food product to be urged by the auger from the inlet end toward the outlet end of the machine.
To rotate the abrasive rollers, several types of drive mechanisms or drive systems are used. In one commonly used drive mechanism, the rollers are interconnected by belts with one of the rollers being connected to an electric or hydraulic motor by another belt. These belts simply transfer power between the rollers and transfer power from the motor to the rollers. The belts do not function as a gear reducing mechanism and therefore do not reduce the output speed of the motor to enable the rollers to handle more torque caused by a greater load on one or more of the rollers.
This relatively complicated drive mechanism is costly in construction and in maintenance. One known disadvantage to this type of drive mechanism is that all of the belt-interconnected rollers driven by a motor must all be driven at the same speed as the motor and cannot be varied in speed relative to another belt interconnected roller. Another known disadvantage to the belt drive mechanism is that belt wear during use can require time consuming and costly machine shutdowns to replace one or more worn belts. As a result of belt wear, one or more of the rollers can rotate at a speed less than the desired rotational speed which can result in incomplete peeling or cleaning of food product or which can cause the food product to have to remain longer in the chamber than desired to achieve the desired peeling or cleaning. Finally, these systems are bulky and use many moving parts, each of which decreases reliability while increasing maintenance.
In another kind of drive mechanism, each roller is driven by a hydraulic motor that is supplied with hydraulic fluid under pressure from a hydraulic pump. The motor is attached to an endplate of the peeling and cleaning machine and has an output shaft coupled to an abrasive roller. In a known U-bed stationary abrasive roller peeling and cleaning machine manufactured by Lyco Manufacturing Inc., 115 Commercial Drive, Columbus, Wis. 53925, the machine has two banks of rollers with the rollers of a given bank driven at the same speed and the roller speed and direction of one bank being variable relative to the roller speed and direction of the other bank. It is believed, and heretofore not known otherwise, that all of the rollers of a bank of rollers of the machine are not driven at exactly the same speed by the pump and motors because the motors are supplied in series with hydraulic fluid from the pump and fluid pressure losses downstream can cause downstream motors to run more slowly.
Unfortunately, without resort to relatively expensive hydraulic fluid throttling valves for each hydraulic motor, the speed of one roller in a bank cannot be selectively varied relative to another roller of the bank thereby at least somewhat limiting the versatility of the machine. Additionally, hydraulic drive systems are quite complicated and expensive to manufacture and can have reliability problems if hoses break or internal motor seals leak.
Another difficulty with hydraulic drive systems is that the hydraulic motor seals currently in use cannot typically withstand hydraulic fluid pressures of greater than about 1000 p.s.i. However, in many instances, to power in series as many as four or more rollers of a bank of rollers, an input pressure of as much as 1500 p.s.i. or greater is needed. To remedy this problem and prevent premature seal blowout, a flow divider is typically used. Unfortunately, using a flow divider results in pressure losses of as much as 150 p.s.i. or more in addition to pressure losses after each motor. All of these pressure losses accumulate resulting in a great deal of energy wasted as well as the rollers further downstream typically operating at a speed slightly slower than the speed of the upstream rolls.
In rotating cage type abrasive roller peeling and cleaning machines, either the inlet or outlet of the machine carries a hub that is driven through a belt by a motor that typically is an electric or hydraulic motor to cause the cage to rotate about a longitudinal axis of the cage. As the cage rotates, a ring-shaped stationary gear carried by the frame has inwardly extending teeth that engage a tooth of a gear at the end of each roller to drive the roller as the roller gears orbit interiorly the stationary gear. An example of this type of drive arrangement is found in U.S. Pat. No. 5,245,919.
This type of drive arrangement is rather elaborate and complicated because it uses so many moving parts to transfer rotary motion of the cage to each of the abrasive rollers. This complexity adds expense and increased maintenance. In addition to being more complicated and costly, this type of drive arrangement is limited because each of the drive rollers are driven by a single stationary gear as the cage rotates causing them all to rotate at about the same speed. As a result of being driven by a single stationary gear, none of the abrasive rollers can rotate at a different speed relative to any other roller. Moreover, the speed of all of the rollers is ultimately dependent upon the speed of rotation of the cage further limiting machine and processing flexibility.
What is needed is a drive system for an abrasive roller peeling and cleaning machine that enables each of the abrasive rollers to be driven independently of every other roller of the machine so that the speed of the rollers can be controlled and precisely varied. What is also needed is a more efficient abrasive roller drive system that provides more complete control over the entire peeling and cleaning process. What is further needed is a drive system for a rotating cage peeling and cleaning machine where the abrasive rollers are driven independently of the cage and auger. What is still further needed is a drive system for a rotating cage peeling and cleaning machine that enables the roller to be driven independently of the cage and independently of each other. What is also needed is a drive and control system for a peeling and cleaning machine that is more compact, more reliable, simpler and cheaper to manufacture and operate.


A position controller includes a movable member which holds the optical element and supported by a support member to be linearly movable from an anti-shake driving range in which the optical element is positioned on an optical axis to a removed position outside of the anti-shake driving range, an electromagnetic actuator including first and second coils supported by the support member and first and second magnets supported by the movable member, and an insertion/removal operational member. When the movable member is in the anti-shake driving range, the first and second magnets face the first and second coils, respectively. The first and second magnets are arranged on opposite sides of a removing-direction center line passing through a center of the optical element in a moving direction of the movable member so that a distance between magnetic-pole boundary lines of the first and second magnets increases toward the anti-shake driving position.

1. Field of the Invention
The present invention relates to a position controller for an optical element.
2. Description of the Related Art
A type of image shake correcting mechanism (shake reduction mechanism/image stabilizing mechanism) which moves an optical element such as a lens element or an image sensor (image pickup device) in a plane orthogonal to an optical axis of an optical system (this optical element is hereinafter referred to as an image-shake-correcting optical element) to reduce image shake in an optical device such as a camera has been often used in recent years. In addition, an invention devised to achieve an improvement in utilization of an optical element accommodation space when the optical device is in a non-operating state, especially to achieve a reduction in thickness of the optical system in the optical axis direction has been proposed.
The image shake correcting unit incorporated in a retractable lens disclosed in Japanese Unexamined Patent Publication 2006-146125 is provided with a lens holder which holds the first lens (designated by the reference numeral 25 in the specification) serving as an image-shake-correcting optical element and an electromagnetic actuator for driving this lens holder in orthogonal directions in a plane orthogonal to an optical axis. In addition, when the retractable lens is fully retracted, the lens holder that holds the first lens is moved to a predetermined off-axis removed (displaced) position by the electromagnetic actuator, and a reduction in length of the photographing optical system is achieved by moving the second lens (designated by the reference numeral 24 in the specification) into space that is created by the displacement of the first lens to the off-axis removed position.
In the imaging device disclosed in Japanese Unexamined Patent Publication 2006-154674 (U.S. Pat. No. 7,630,618 B2), a movable frame which supports an image sensor, which is provided as an image-shake-correcting optical element and is movable in a direction orthogonal to an optical axis of an imaging optical system, is moved by a mechanism for image shake correction within an anti-shake driving range in which the image sensor is positioned on the optical axis in a ready-to-photograph state, and the same movable frame is moved by another mechanism for displacement driving to move the image sensor from a position on the optical axis to an off-axis removed position (displaced position) away from the optical axis when the imaging device moves to the accommodated state. In a non-operating state of the imaging device, a reduction in length of the imaging optical system in the optical axis direction thereof is achieved by positioning the anti-shake correcting optical element (image sensor) that is displaced to the off-axis removed position and another optical element (e.g., a lens group) which remains on the optical axis in a plane orthogonal to the optical axis. As a specific structure therefor, a guide shaft is provided for guiding the movable frame from the anti-shake driving range to the removed position, and the aforementioned another mechanism for displacement driving is configured from a swing member which gives the movable frame a moving force in a direction along the guide shaft.
In the above-mentioned Japanese Unexamined Patent Publication 2006-146125, since the displacing movement of the first lens is performed by an electromagnetic actuator, the amount of the displacing movement of the first lens is limited within the range of the driving amount of the electromagnetic actuator. The displacing movement of the first lens by the electromagnetic actuator is determined according to various conditions such as specifications of the coils and the magnets of the electromagnetic actuator and the positional relationship therebetween; however, it is not possible to apply a large driving amount to the electromagnetic actuator which is so great that the coils and the magnets become largely displaced from each other. For instance, in the structure disclosed in the above-mentioned Japanese Unexamined Patent Publication 2006-146125, due to the limitation on the driving amount of the electromagnetic actuator, the first lens and the lens holder therefor cannot be removed from an optical axis by an amount which is large enough as to allow the whole of the second lens and the lens holder therefor to enter the space on the optical axis from which the first lens and the lens holder therefor have been removed. This limits the effect on reduction in length of the imaging optical system.
In the above-mentioned Japanese Unexamined Patent Publication 2006-154674, since the imaging device disclosed therein is equipped with a mechanism for displacement driving independently of the mechanism for image shake correction, there is no limitation on the driving amount of the electromagnetic actuator, so that an image sensor as an image-shake-correcting optical element and a holding device which holds the image sensor can be given a great amount of movement in a direction to make the image sensor and the holding device therefor removed from an optical axis.


A system for independent control of electric motors and electric lights includes a plurality of two-wire wallstations coupled in series via power wires between an alternating-current (AC) source and a light/motor control unit. The light/motor control unit is preferably located in the same enclosure as an electric motor and an electric light and has two outputs for independent control of the motor and the light. The light/motor control unit and the wallstations each include a controller and a communication circuit that is coupled to the power wiring via a communication transformer and communicate with each other using a loop current carrier technique. The light/motor control unit and the wallstations utilize pseudo random orthogonal codes and a median filter in the communication process.

1. Field of the Invention
The present invention relates to an apparatus for independently controlling a motor, such as, for example, a fan motor, together with a lighting source contained within the same enclosure as the motor and coupled to the motor. The invention also relates to a communication scheme for communicating over a power line to control the load, such as, for example, a fan motor and a light.
2. Description of the Related Art
It is often desirable to include a lamp and a fan motor in a single enclosure. Since the lamp and the fan motor are often wired in parallel, the lamp and the fan motor are generally controlled together from a switch located remotely from the lamp and the motor. FIG. 1A shows a prior art light and fan motor control system 10. The system 10 includes a maintained switch 12 coupled between an alternating-current (AC) voltage source 14 and two loads, i.e., a fan motor 16 and a lighting load 18, in an enclosure 19. The fan motor 16 and the lighting load 18 are connected in parallel such that when switch 12 is closed, the fan motor 16 and the lighting load 18 will both be on, and when the switch 12 is open, the fan motor 16 and the lighting load 18 will both be off.
There are also various schemes for independent control of a fan motor as well as a lighting load from a remote location such as a wallstation. FIG. 1B shows a prior art light and fan motor control system 20, having a dual light and fan speed control 22 coupled to the AC voltage source 14. The dual light and fan speed control 22 has two outputs: the first coupled to the fan motor 16 and the second coupled to the lighting load 18, to allow for independent control of the loads. Further, the dual light and fan speed control 22 includes a fan speed circuit for adjusting the speed at which the fan motor 16 turns and a dimmer circuit for changing the intensity of the lighting load 18. The dual light and fan speed control 22 is often mounted in a standard electrical wallbox and includes a user interface to allow a user to separately control the lighting load and the fan motor.
However, the dual light and fan speed control 22 requires two separate wires to be connected between the lamp and the fan motor. If these two connections are not provided between the wallbox and the enclosure containing the lamp and the fan motor, independent control of the lighting load 18 and the fan motor 16 will not be possible. Further, in the control system 20 of FIG. 1B, it is only possible to have one dual light and fan speed control 22, and thus, only one user interface to allow for adjustment of the intensity of the lighting load 18 and the speed of the fan motor 16. Control of the fan motor 16 and lighting load 18 from more than one location is not possible in this system.
FIG. 1C shows a prior art power-line carrier (PLC) control system 30. Power-line carrier control systems use the power system wiring to transmit control signals at high frequencies (i.e., much greater than the line frequency of 50 Hz or 60 Hz). All devices of the PLC system 30 are coupled across an AC power source 32 (from hot to neutral) to receive both power and communications from the same wiring. The system 30 includes a PLC fan motor controller 34 coupled to a fan motor 36, a PLC light controller 38 coupled to a lighting load 40, and a remote control keypad 42. The remote control keypad 42 is operable to transmit a message across the power line to the PLC fan motor controller 34 and the PLC light controller 38 to control the respective loads. One example of a communication protocol for home automation using power-line carrier technology is the industry standard X10. The X10 protocol uses a voltage carrier technique to transmit messages between devices connected to the power system. Through the voltage carrier technology, the messages are transmitted on voltages signals referenced either between the hot and neutral connections of the AC power source 32 or between the hot connection of the AC power source and an earth ground connection. The devices in an X10 system communicate using house addresses and unit addresses.
However, existing power-line carrier systems have some limitations. For example, all devices in a PLC system require a neutral connection. Also, since the X10 protocol utilizes voltage carrier technology, communication messages are transmitted throughout the power system and it is difficult to isolate the communication signals from other devices connected to the power system. Finally, the X10 protocol is not a "reliable" communication scheme since no acknowledgements are sent to a transmitting device when a receiving device has received a valid message.
Thus, it is desirable to provide a reliable means to independently control from a remote location a fan motor and a lighting load that are located in the same enclosure. Since a consumer may wish to locate the fan motor and the attached lamp in a position previously occupied by only a lamp controlled by a standard single-pole single-throw (SPST) wall switch, it is desirable to be able to control a fan motor as well as an attached lamp independently, using a two-wire control device. A two-wire device is a control device that has only two electrical connections, i.e., one for the AC source voltage and one for the fan/lamp, and does not have a neutral line connection. As shown in FIG. 1A, this kind of system typically only includes the switch 12 in series electrical connection between the AC source 14 and the loads, and no neutral connection is available in the electrical wallbox where the switch is housed. Since it is desirable to control the fan motor 16 and the lighting load 18 independently, using the existing building wiring, it is necessary to develop a means to allow independent control over the existing building wiring consisting of a single wire connecting the wall control, i.e., the dual light and fan speed control 22, to the enclosure of the fan motor 16 and the lighting load 18.
Prior art systems to accomplish this are known which provide a coding/communication scheme to independently control the fan motor and the lamp. However, many of these systems are unreliable, provide erratic, noisy operation, and require a neutral connection. It is desirable to provide a simple, reliable communication scheme for independently controlling the fan motor and lamp without a neutral connection.


A process and apparatus for treating cellulosic fiber containing fabrics to improve durable press and shrinkage resistance includes using steam as a vehicle to supply vaporized liquid cellulosic cross-linking agent and vaporized liquid catalyst to a reaction chamber in which the fabric articles are treated by cross-linking the cellulose. Normally liquid cross-linking agent and liquid catalysts are directly injected into a stream of treating steam to cause vaporization of the cross-linking agent and catalyst. Alternatively, a steam driven ejector type pump is utilized to entrain and vaporize liquid cross-linking agent and liquid catalyst in a flowing stream of steam supplied to the reaction chamber. Gaseous ammonia may also be supplied to the reaction chamber to condition the cellulosic material containing fabric before cross-linking.

1. Field of the Invention
This invention relates to the treatment of cellulosic fiber-containing fabric and articles made from such fabric with a cross-linking agent in the presence of a catalyst to improve durable press and shrinkage resistance properties of the fabric.
2. Discussion of Related Art
Treatment of cellulosic fibers (e.g., cotton, linen, hemp, rayon, etc.) and blends of fibers including cellulosic fibers with a cross-linking agent such as formaldehyde in the presence of moisture and a catalytic acid producer such as sulphur dioxide to improve the durable press (i.e., crease resistance) and shrinkage properties of fabric and articles made of such fibers is well documented in published literature and well known to those skilled in the art of fiber treatment. The physical chemistry of the process is also well documented and the effect of the cross-linking treatment on cellulosic containing fabric and articles of apparel made from such fabric has been researched and published extensively.
Exemplary prior art processes are described in the patent literature, where previous attempts have resulted in systems that are intended to solve some of the more practical problems of applying cross-linking treatment to finished articles of apparel in a low cost, high volume (i.e., commercial scale) and efficient manner, as well as cross-linking treatment systems generally for cellulosic material.
The problems intended to be solved by the prior art processes and systems are described in the various patents issued to inventors in this field, but this discussion is concerned with prior art systems for treating cellulosic and cellulosic blend fabrics that have been formed into finished articles of apparel on a high volume, continuous production basis to improve the durable press and shrinkage resistance properties of the apparel.
One approach to treating cellulosic fabrics and articles made from such fabrics described in the patent literature involves treating garments in a closed chamber using a gaseous cross-linking agent with steam and a gaseous catalyst, such as is described in U.S. Pat. Nos. 3,660,013 and 3,712,086 issued to G. Payet and J. Forg on May 2, 1972 and Jan. 23, 1973, respectively. This process involved the generation of gaseous phase cross-linking agent by heating powder of solid para-formaldehyde in a chamber containing the garments to be treated and then mixing the gas with steam and a gaseous cross-linking promoting catalyst such as sulphur dioxide in the chamber so that the mixture permeates the garments therein. The temperature in the chamber is then reduced for a period of time and the temperature in the chamber is then increased to the cross-linking temperature of the fabric and cross-linking agent. While successful, this process has drawbacks in that heated trays used to vaporize formaldehyde required constant cleaning and maintenance, the moisture content of the fabric, while critical, was difficult to control, and excess formaldehyde absorbed into the fabric weakened the fabric and required careful cleaning of residual, non-cross-linked formaldehyde from the garments after the cross-linking procedure to avoid undesirable formaldehyde odors and irritant being left on the garments.
In U.S. Pat. No. 3,837,799 issued to K. W. Wilson, R. Swidler and J. P. Gamarra on Sep. 24, 1974, a process is described for crease proofing garments made from cellulosic fiber-containing fabric using gaseous formaldehyde generated by heating para-formaldehyde in mineral oil and subjecting cellulosic fiber-containing fabric with previously applied latent catalyst to the gaseous formaldehyde in a reaction chamber at about 90.degree.-150.degree. C. In this process, two controlled procedures are required to expose the fabric to catalyst and formaldehyde, the process is both temperature and moisture sensitive, and careful cleaning of the formaldehyde and water soluble catalyst from the fabric is required.
U.S. Pat. Nos. 3,960,482 and 3,960,483 issued to G. L. Payet on Jun. 1, 1976 describe a durable press process involving a similar procedure for pre-conditioning fabric with a water soluble catalyst and then subjecting it to formaldehyde vapors and moisture before curing (cross-linking) the fabric and formaldehyde at cross-linking temperatures. The problems of the prior art systems are discussed in this patent, particularly the difficulties encountered in precisely controlling moisture content in the fabric in the presence of a toxic gas and a gaseous catalyst. In accordance with the process described in this patent, the moisture content of the cellulosic fibers is controlled so they have over 20% weight of moisture and contain a selected amount of catalyst when exposed to cross-linking formaldehyde vapor. This enables the process to be carried out at a lower temperature (i.e., room temperature) with a drastically reduced concentration of formaldehyde (6% by volume) as compared with prior art procedures. This process, as with processes previously used, required separate moisture, formaldehyde and catalyst applications to the fabric, and also was highly dependent on the moisture content of the fabric for its successful implementation. The moisture was introduced into the fabric as a spray, mist or fog, or was padded on the fabric alone or with a catalyst. This left the problem of generating the gaseous cross-linking agent and applying it to the fabric in a uniform manner as rapidly as possible. Presumably, the cross-linking formaldehyde vapor used in accordance with the process described in the patent was generated from vaporizing solid form para-formaldehyde, which entailed maintenance problems already discussed above.
U.S. Pat. No. 3,865,545 issued to J. H. Forg and G. L. Payet describes an other process for treating cellulosic fiber articles to impart a durable press thereto involving vaporizing solid para-formaldehyde in a reaction chamber and exposing the fabric articles to the formaldehyde vapors, steam and gaseous catalyst for a period of time at a temperature initially ranging from 120.degree. F. to about 145.degree. F., followed by cooling the fabric 10.degree.-30.degree. by the time of completion of the procedure. Steam and free chemicals are then purged from the chamber before the temperature in the chamber is increased to cross-linking temperature. Steam and fresh air are then circulated over the articles to clean them of residual odors. As in previously described processes, control over moisture content, cross-linking agent concentration and catalyst content in the fabric as well as temperatures are all critical to some degree; vaporization of solid para-formaldehyde is difficult to control precisely; and the formaldehyde vapor generating system is maintenance intensive.
A process for the continuous treatment of continuous fabric and/or garments for improved durable press characteristics is described in U.S. Pat. No. 3,884,632 issued to G. L. Payet and B. D. Brummet on May 20, 1975. In this patented system, the material to be treated was advanced through successive treating stations where it was sequentially moisturized, subjected to formaldehyde (generated by vaporizing solid para-formaldehyde) and catalyst, heated and cross-linked, and cleaned in a continuous process.
U.S. Pat. No. 4,032,294 issued Jun. 28, 1977 to R. D. Thompson, D. Thompson and M. A. Beeley describes a similar process for continuously treating garments using a series of workstations and chambers to process equal sized batches of garments.
U.S. Pat. No. 3,706,526 issued on Dec. 19, 1972 to R. Swidler and K. Wilson describes a durable press process using formaldehyde and sulphur dioxide to treat cellulosic fabrics. Moisture content of the fabric is described as being very important to achieve a self-limiting reaction (cross-linking) but moisture, gaseous formaldehyde and gaseous catalyst are all conveyed to the fabric by different routes and equipment, therefore requiring careful control over the system at all times to maintain proper proportioning of chemicals and moisture reaching the fabric.
U.S. Pat. No. 4,067,688 issued on Jan. 10, 1978 to G. L. Payet describes a durable press process for cellulosic fiber-containing fabrics using formaldehyde vapor and a liquid catalyst (aryl sulfonic liquid or acid) in a high moisture environment. The moisture, formaldehyde and catalyst generally are introduced to the fabric via different routes in the process, requiring careful control over operating parameters.
A known commercial process involves direct injection of a known quantity of liquid formaldehyde cross-linking agent into a stream of steam supplied at a temperature sufficient to vaporize the formaldehyde and then supplying a quantity of the steam with entrained vaporized formaldehyde into a treating chamber wherein a cellulosic containing fabric article has been placed for treatment. A gaseous cross-linking promoting catalyst such as sulfur dioxide is then introduced into the chamber and the fabric article is exposed to the mixture of steam, formaldehyde, and sulfur dioxide for a preselected time. The free steam, formaldehyde and sulfur dioxide (not retained by the fabric article) are then purged from the treating chamber and the chamber's temperature is elevated to cross-linking temperature for a sufficient time to cross-link the cellulosic material in the fabric, following which the chamber is cooled and the fabric is removed from the chamber. This process, while facilitating the delivery of formaldehyde to the fabric article to be treated by using a stream of steam as a vehicle, still required close control over the supply of gaseous catalyst, along with all of the gaseous supply tanks, conduits, valves and controls associated with the sulfur dioxide supply system. Inside the treating chamber, the gaseous catalyst moved independently of the steam and vaporized formaldehyde, so experimentation was required to ensure that the appropriate amount of sulfur dioxide gas actually reached the fabric with the cross-linking formaldehyde in a correct manner to ensure good cross-linking results for the particular fabric undergoing treatment. Achieving minimum strength loss in the treated fabric article and low residual free chemicals to be removed from the fabric after completion of the cross-linking process required careful control over the process.
Thus, while the known systems for cross-linking cellulosic containing fabric articles using steam, cross-linking agent and cross-linking promoting catalyst in a treating chamber have achieved some success, problems still remain in terms of processing cost, speed and efficiency, as well as residual chemicals left in the cross-linked fabric. Fabric strength loss resulting from cross-linking and achievement of shrinkage control with acceptable durable press quality remained to be achieved at minimum cost.

Process and apparatus for treating cellulosic fiber-containing fabric to improve durable press and shrinkage resistance


A driver device for magnetic heads for a magnetic recording and reproduction apparatus. The driver device drives at least one combined head including at least two head members, each head member having a winding coil, and the effective gap width of the combined head is changed by selectively short-circuiting at least one of the winding coils. By switching a connection between the combined head and a record amplifier or a reproduction head amplifier, the effective gap width of the combined head is changed either to a narrow effective gap width for n time speed recording or reproducing or to a wide effective gap width for standard speed recording or reproducing.

1. Field of the Invention
The present invention relates to a driver device of magnetic heads for use in a magnetic record and reproduction apparatus such as a video tape recorder (VTR) or the like.
2. Description of the Background
In FIG. 5, there is shown a rotary drum of an independent 4 head type for use in a conventional video tape recorder (VTR). A rotary drum 1 is rotated at a speed of 1800 r.p.m. in a direction shown by an arrow X, and a magnetic tape 2, a recording medium having a thickness of 19 .mu.m is wound around approximately half the rotary drum 1 and runs at a speed of 3.335 cm/sec in a direction indicated by an arrow y in the VHS system. The rotary drum 1 is provided with four rotary video heads 100a, 100b, 100c and 100d having an azimuth angle of +6.degree. or -6.degree. on its periphery. The two heads 100a and 100b having a track width of 58 .mu.m for covering a standard mode are correctly arranged in opposite positions on the rotary drum 1, and the two heads 100c and 100d having a track width of 19 .mu.m for covering a triple speed mode are arranged on the rotary drum 1 in the same manner as the heads 100a and 100b.
In FIGS. 6 and 7, there is shown another rotary drum of a combined 4 head type for use in a conventional VTR. In this case, as shown in FIG. 7, a head 300a having a track width of 58 .mu.m for standard mode record and reproduction and a head 300d having a track width of 19 .mu.m for triple speed mode record and reproduction are mounted on a head base 201 at a distance of 1 H, i.e., 370 .mu.m to constitute combined heads. Heads 300b and 300c constitute combined heads in the same manner as the heads 300a and 300d. Two pairs of combined heads 300a, 300d, 300b and 300c are arranged in opposite positions on a rotary drum 201 as shown in FIG. 6.
In the conventional rotary drum of the independent or combined 4 head type shown in FIG. 5 or 6, in the standard mode record and reproduction, heads 100a and 100b or 300a and 300b are operated, while the heads 100c and 100d or 300c and 300d are just idled in an inoperative state. In the triple speed mode record and reproduction, the heads 100c and 100d or 300c and 300d are operated, while the heads 100a and 100b or 300a and 300b are in the inoperative state. In the conventional rotary drum of the combined 4 head type, since the azimuth angle of the heads 300a and 300c is determined to an equal angle .+-.6.degree. and the azimuth angle of the heads 300b and 300d is determined to an equal angle -6.degree., in a still image reproduction, when the tape is stopped, the image can be reproduced by using the two heads 300a and 300c. That is, since one recorded video track is reproduced by the two heads having the same azimuth angle (+6.degree.) and different head widths (the head 300a=58 .mu.m and the head 300c=19 .mu.m), a clear still image can be readily reproduced without blurring. As a result, the rotary drum of the combined 4 head type is widely used for a public VTR.
In FIG. 4, there is shown a driver circuit for the video heads 300a, 300b, 300c and 300d shown in FIG. 6. A rotary transformer 315 includes four primary coils 315a, 315b, 315c and 315d and four secondary coils 315e, 315f, 315g and 315h corresponding to the respective primary coils 315a, 315b, 315c and 315d. The two video heads 300a and 300b for the standard mode are connected to the two primary coils 315a and 315b, respectively, while the two video heads 300c and 300d for the triple speed mode are connected to the two primary coils 315c and 315d, respectively. A pair of reproduction head amplifiers 309L and 309R corresponding to the respective video heads 300a and 300b are connected to one end of the secondary coils 315e and 315f, respectively. A record amplifier 312 is coupled to the other ends of the secondary coils 315e and 315f through a capacitor 316. A 2 H (2 hour) record video signal is applied to the record amplifier 312 in a 2 hour standard mode recording. A pair of reproduction head amplifiers 310L and 310R corresponding to the respective video heads 300c and 300d are connected to one end of the secondary coils 315g and 315h, respectively. Another record amplifier 313 is coupled to the other ends of the secondary coils 315g and 315h through another capacitor 317. A -6 H (6 hour) record video signal is applied to the record amplifier 313 in a 6 hour triple speed mode recording.
A pair of switches a1 and b1 are connected between the ends of the respective secondary coils 315e and 315f and ground, and a switch c1 is connected between the other ends of the secondary coils 315e and 315f and ground. A pair of switches a2 and b2 are connected between the end of the respective secondary coils 315g and 315h and ground, and a switch c2 is connected between the other ends of the secondary coils 315g and 315h and ground.
A switch d1 selects one output of the reproduction head amplifiers 309L and 309R, and a switch d2 selects one output of the reproduction head amplifiers 310L and 310R. A switch e1 selects one of 2 H and 6 H terminals connecting common terminals of the switches d1 and d2, that is, one output of the switches d1 and d2. A reproduction video signal is output from a common terminal of the switch e1.
Now, the operation of the driver circuit shown in FIG. 4 will be described in detail.
In the standard (2 hour or 2 H) mode recording, the switches a1 and b1 are closed and the switch c1 is open. The 2 H record video signal is recorded on a magnetic tape through the record amplifier 312, the rotary transformer 315 and the video head 300a or 300b. In the standard mode reproducing, the switches a1 and b1 are open and the switch c1 is closed. The switch d1 is turned over every field, and the switch e1 selects the 2 H terminal. The reproduction video signal picked up by the video head 300a or 300b is output through the rotary transformer 315, the reproduction head amplifier 309L or 309R and the switches d1 and e1.
On the other hand, in the triple speed (6 hour or 6 H) mode recording, the switches a2 and b2 are closed and the switch c2 is open. The 6 H record video signal is recorded on the magnetic tape through the record amplifier 313, the rotary transformer 315 and the video head 300c or 300d. In the triple speed mode reproducing, the switches a2 and b2 are open and the switch c2 is closed. The switch d2 is turned over every field, and the switch el selects the 6 H terminal. The reproduction video signal picked up by the video head 300c or 300d is output through the rotary transformer 315, the reproduction head amplifier 310L or 31OR and the switches d2 and el.
With the conventional magnetic heads for the magnetic record and reproduction and the driver device therefore, as described above, the tape running speed is changed depending on the standard and triple speed modes, and the track width is also changed depending on the standard and triple speed modes. Hence, the heads having the suitable different track widths are required for the standard and triple speed modes.
Further, as shown in FIGS. 5 and 6, taking note of the half periphery of the rotary drum on which the magnetic tape is loaded, when the head 100b or 300b for the standard mode is actuated, the unoperated head 100c or 300c for the triple speed mode contacts the magnetic tape. Since the head generally projects 40 .mu.m from the outer peripheral surface of the rotary drum, when the head contacts the magnetic tape, the head beats on the magnetic tape to give vibrations to the magnetic tape and to cause the vibrations in the directions of X-, Y- and Z-axes. The vibration in the tape running direction (X-axis) causes the signals on the magnetized magnetic tape to carry out a speed modulation which causes a strong jitter phenomenon and brings about jitters in the reproducted image.
Consequently, even through it is unavoidable that the operated head beats the magnetic tape, the unoperated head 100c or 300c beats the magnetic tape at a different portion to cause the vibrations, and as an inevitable result, the vibrations are transmitted to another head 200b or 300b via the magnetic tape.
In the conventional combined 4 head type, as shown in FIG. 7, since two heads are combined on one block, the beating by the adjacent head of one block largely affects the other head. Further, in order to uniformly and stably contact the magnetic tape to the gap portions ga and gd of the combined heads, a high accuracy of curvature of the tape sliding surfaces of the heads and head mounting positions on the rotary drum are required, which are difficult to accomplish. Hence, problems at the contact surface between the head and the magnetic tape constantly arise, and the surfaces of the combined heads are frequently stuffed and smudged compared with a single head.
Furthermore, as shown in FIG. 4, since the pairs of heads are each independently switched over depending on not only the standard and triple speed modes but also the record and reproduction modes, the structure of the drive circuit for the heads becomes complicated. Further, in the reproduction mode, since slight reproduction signals are transmitted through the rotary transformer 315 and various switching operations are carried out, it is difficult to remove the noise, and in order to improve the signal-to-noise ratio (S/N) of the reproduction signal, there are many limits imposed on the shielding and the ground point. Further, in the combined 4 head type, as shown in FIG. 7, accurate realization of the gap of 370 .mu.m between the combined heads as mounted brings about a manufacturing cost increase.

Driver device of magnetic heads for magnetic record and reproduction


The present invention has been made to provide a technique by which a switch unit that is disposed on the side surface of an apparatus body and shuts off, at maintenance time, power supply to predetermined electric components provided in the apparatus does not interfere with pull-out operation of a predetermined unit configured to be capable of being withdrawn from the side surface of the apparatus body without sacrificing the miniaturization of the apparatus.

1. Field of the Invention
The present invention relates to an image forming apparatus and retreat method of a switch unit of the image forming apparatus.
2. Description of the Related Art
In order to realize accurate color matching and low jitter drive in an image forming apparatus that forms a toner image on a sheet using an intermediate transfer member, it is desirable that an intermediate transfer member unit and a drive source be connected to each other via a coupling mechanism.
In general, in order to realize a configuration in which an intermediate transfer member unit and a motor serving as a drive source are connected to each other via a coupling mechanism as well as the intermediate transfer member unit is made removable for ease of maintenance, it is preferable to employ a configuration in which the intermediate transfer member unit is withdrawn from the side surface of an apparatus body. This configuration is advantageous also in terms of simplification of an apparatus structure.
For the above reason, there has been proposed a technique of employing a configuration in which an intermediate transfer member unit, a photoconductor unit, or the like can be withdrawn from the side surface of an apparatus body for the purpose of increasing maintainability and adopting a mechanism capable of realizing high quality image formation.
In a conventional image forming apparatus having the configuration described above, when the intermediate transfer member unit, a photoconductor unit, or the like is withdrawn from the side surface of an apparatus body, a front cover or side cover provided on the side surface of the apparatus body is firstly opened.
Electric components that use a high-voltage current, such as an intermediate transfer member unit and photoconductor unit, exist in an image forming apparatus. Therefore, in general, a switch unit (so-called an interlock switch unit) that shuts off power supply to the electric components such as an intermediate transfer member unit and photoconductor unit is provided when the front cover or side cover is opened for maintenance work.
In a configuration in which the switch unit as described above is provided, it is often the case that both the front cover and side cover serve as one switch unit due to space limitation or cost issues.
If the configuration in which both the front cover and side cover serve as one switch unit is employed, the switch unit is inevitably disposed on the side surface of an apparatus body. Thus, when a unit such as an intermediate transfer member unit or photoconductor unit is withdrawn from the side surface of an apparatus body, the switch unit may interfere with the withdrawal operation of the above unit.

Image forming apparatus and retreat method of switch unit of image forming apparatus

Abstract: An image forming apparatus comprising: a predetermined unit capable of being withdrawn from the side surface of the apparatus body; a switch unit that is provided on the side surface of the apparatus body and that shuts off power supply to predetermined electric components in the apparatus body at maintenance time; and a retreat mechanism that retreats the switch unit to a position that does not interfere with withdrawal operation of the predetermined unit when the predetermined unit needs to be withdrawn from the side surface of the apparatus body.


The invention relates to sun-protection formulations in solid or liquid form, containing organic and/or inorganic sunscreen filters having a prophylactic action against herpetic diseases of the skin, and to the use of said sun-screen formulations.

The present invention relates to sunscreen formulations in solid or liquid form comprising organic and/or inorganic light protection filters having prophylactic action against herpetic diseases of the skin, and to the use of these sunscreen formulations.
As is known, the skin is sensitive to solar rays, which can cause simple sunburn or an erythema, but also burns of varying severity.
However, solar rays also have other negative effects: they cause the skin to lose its elasticity and form wrinkles, thus leading to premature ageing. Dermatoses may also sometimes be observed. In extreme cases, some people can develop skin cancer.
In addition, it is known that for people who have been infected with Herpesviruses and suffer from Herpes under stress, the Herpesviruses are activated in many cases following intensive solar irradiation, leading to herpetic diseases of the skin, in particular in the mouth and lip area.
The most dangerous solar rays are the ultraviolet rays having a wavelength of less than 400 nm. The majority of the undesired effects of sunlight, such as, for example, sunburn, light-induced cell damage and skin cancer, are caused by UVB radiation (280-320 nm).
UVB radiation can cause skin reddening and damage to the cell nuclei by three different reaction paths:
sunburn as a result of the release of biological xe2x80x9cmessengersxe2x80x9d,
skin cancer as a result of direct damage to the DNA of the cell nucleus,
skin cancer as a result of the release of free radicals.
Sunburn is per se exclusively the result of an overdose of UVB radiation. This radiation releases biochemical messengers, such as, for example, histamine, which in turn cause the known effects such as itching, a feeling of pain and heat and xe2x80x9cburningxe2x80x9d of the skin. The messengers also diffuse into the blood vessels, where they cause dilation, and thus lead to an oedema. In addition, they bring about proliferation of the basal cells.
Solar radiation, including that which does not lead to sunburn, thus signifies stress for the skin cells, as the result of which the defence mechanisms against infection, or the undesired action of bacteria or viruses, are weakened. A latent herpes infection can thus be activated and manifest itself in the formation of painful blisters.
The effects of an overdose of UVB irradiation are observed at the earliest about 4 hours after irradiation, i.e. too late for any preventive measures. Sunburn is therefore not a warning signal, but an indication of skin damage which is already present.
UVA radiation having wavelengths greater than 340 nm is, in the case of healthy skin, principally responsible for the process of skin ageing. In addition, however, a carcinogenic effect is discussed for UVA radiation too.
It is also known that as a result of the presence of the ozone layer in the earth""s atmosphere, which absorbs some solar radiation, the lower limit of the ultraviolet rays which reach the surface of the earth is about 280 nm. Chronic cell damage, such as skin ageing and skin cancer, are caused by direct damage of the cell nucleus, which has specific sensitivity to UV radiation having wavelengths below 320 nm. Only at wavelengths above 340 nm does it no longer absorb radiation. Damage to the cell nucleus is based on damage to the DNA. This leads to loss of functionability of the DNA, irrespective of how the damage occurs.
However, the wavelength range of sunlight extends not only beyond the range of UVA and UVB radiation from 280 to 400 nm. The area which can be perceived by the eye extends to 800 nm and is limited by the transition to long-wave infra-red radiation, which is perceived as heat radiation. At the bottom end, the radiation crosses into the short-wave UV region, also called UVC radiation. This is the wavelength range from 100 to 280 nm.
Sunlight in the wavelength range from 400 to 800 nm (VIS region) can penetrate into the deeper layers of skin, where it can become active in a harmful manner, meaning that this very effect of light too can accelerate skin ageing processes. This is also true of IR radiation. Thus, not only UVA and UVB radiation have a harmful effect on the skin cells and cause not only immediately visible short-term damage, such as sunburn and herpes, but also long-term skin changes and skin damage, but also radiation in the wavelength range of visible light (VIS region) and in the region of infra-red radiation (IR region) contributes to skin damage and weakens its defence mechanisms.
It therefore appears desirable to provide sunscreen formulations which ensure as broad a protection as possible against the skin-damaging effect of solar irradiation. In particular, it is, however, also desirable to provide sunscreen formulations which have a prophylactic action against herpetic diseases of the skin.
The invention therefore provides sunscreen formulations comprising organic and/or inorganic light protection filters having prophylactic action against herpetic diseases of the skin, in particular of the skin in the mouth and lip area.
Sunscreen formulations according to the invention have a prophylactic action against herpetic diseases of the skin caused by viruses of the group consisting of herpes simplex and herpes labialis.
The invention therefore provides sunscreen formulations comprising one or more light protection filters or light protection filter combinations which absorb radiation in the UVA and UVB region.
Light protection filters or light protection filter combinations present can advantageously also absorb in the IR region and/or visible region.
The invention further provides for the use of sunscreen formulations which comprise organic and/or inorganic light protection filters for the prophylaxis against herpetic diseases of the skin, in particular against those diseases of the skin in the mouth and lip area which are caused by viruses of the group consisting of herpes simplex and Herpes labialis.
In particular, the use of sunscreen formulations which comprise organic and/or inorganic light protection filters and absorb in the UVA, UVB, IR and visible region of the light spectrum, for the prophylaxis against herpetic diseases of the skin caused by viruses of the group consisting of herpes simplex and Herpes labialis is provided for by the invention.
The sunscreen filters customary today in cosmetics are divided into UVA and UVB filters. For both UVA and UVB regions there are many tried and tested substances known from the specialist literature, substances here by way of example being only those such as phenylbenzimidazole-5-sulfonic acid (Eusolex(copyright) 232), benzophenone derivatives (Eusolex(copyright) 4360), benzoyl- or dibenzoylmethane derivatives (Eusolexe 9020 or Parsol(copyright) 1789, Eusolex 8020), triazone derivatives (octyltriazone, Uvinul T150(copyright)), salicylate derivatives (Eusolex HMS(copyright), Eusolex OS(copyright)), benzylidinecamphor derivatives (Eusolex(copyright) 6300), octocrylene (Eusolex(copyright) OCR), 4-aminobenzoic acid (PABA) or 2-ethyl N,N-dimethyl-4-aminobenzoate (Eusolex(copyright) 6007). Also suitable are light protection filters from the group of methoxycinnamic esters (e.g. Eusolex(copyright) 2292) or inorganic light protection filters from the group consisting of titanium dioxide and zinc oxide.
The substances of cinnamic acid derivatives, in particular octyl p-methoxycinnamate, function not only as light protection filters, but also as solvents for other UV filters and are therefore often used in combination with various filters. Since, for example, 2-ethylhexylmethoxycinnamic acid, available commercially under the name Eusolex(copyright) 2292, is a very good solvent for other UV filters, it is preferably used in combination with other UV filters, as a result of which an increased overall concentration of light protection filter present is achieved in prepared formulations.
To increase the photostability of light protection filters of the cinnamic acid class, it is also possible to use [lacuna] in the presence of the substance ethyl 3-(N-butylacetamino)propionate, as a result of which an insect-repelling action is achieved at the same time. This substance is a very polar oil which differs from traditional cosmetic oils by virtue of its miscibility with water and oils, and exhibits virtually no toxic or allergic reactions towards the skin.
The combination of ethyl 3-(N-butylacetamino)propionate with Eusolex(copyright) 2292 is therefore so highly suitable for introducing UV filters which are otherwise soluble only in low concentrations into the cosmetic preparations, in addition with increased photostability.
Light protection filters which are effective in the wavelength range from 400 to 800 nm (VIS filters) can be soluble or insoluble substances or mixtures of soluble and insoluble substances in cosmetic formulations. These may be pigments and/or dyes which reflect and/or adsorb in the visible wavelength range (VIS-reflecting). Such pigments can, in particular, be golden, red, orange, copper- or body-coloured interference pigments which resemble very closely the natural colour of the skin.
The interference pigments are preferably platelet-shaped or ground mica having a diameter of up to 15 xcexcm which is coated with SnO2 and/or TiO2. Interference pigments whose carrier material does not consist of mica are, however, also suitable. The coatings may be doped in various ways, such as, for example, by iron or cerium.
In a particular embodiment of such pigments suitable as VIS filters, the mica has a thin coating consisting of up to 1% by weight of SnO2, and a coating consisting of 50-70% by weight, preferably 54-60% by weight, of TiO2 having a rutile structure.
The mica may also have a thin coating consisting of up to 1% by weight of SnO2, and a coating consisting of 50-70% by weight, preferably 54-60% by weight, of TiO2 having an anatase structure, or may have a coating consisting of 50-70% by weight, preferably 54-60% by weight, of TiO2 having an anatase structure.
Suitable substances which can be used in cosmetic formulations and are effective as VIS filters are pearlescent pigments consisting of mica or other carrier materials which are coated with titanium dioxides or iron oxides; in particular, these are
silver pigments (mica+TiO2) having particle sizes  less than 200 xcexcm, in particular  less than 15 xcexcm, such as, for example, the commercially available Timiron MP 1005(copyright) or MP 1001(copyright), and also coarser fractions
interference pigments (mica+TiO2) having particle sizes  less than 200 xcexcm, in particular  less than 5-25 xcexcm, with golden, red, orange, copper- or body-coloured interference, such as, for example, Timiron Silk Red(copyright) or Silk Gold(copyright) or Super Red(copyright) and Super Gold(copyright) or Super Copper(copyright) or coarser fractions or other interference colours and mixtures thereof
gold pigments (mica with TiO2 and iron oxides) having particle sizes  less than 200 xcexcm, in particular  less than 5-25 xcexcm or  less than 15 xcexcm; such a gold pigment is, for example, Timiron MP 20(copyright), but coarser gold pigment fractions are also suitable
coloured pigments (mica with TiO2 and iron oxides) having particle sizes  less than 200 xcexcm, in particular  less than 5-25 xcexcm or  less than 15 xcexcm. Suitable coloured pigments are, for example, Dichrona(copyright) or Microna(copyright) matt.
Also suitable are VIS-absorbing or -reflecting fillers, such as, for example, mica coated with TiO2 and/or BaSO4. These also include, for example, Biron(copyright) (BiOCl), Low Luster(copyright) or Extender W(copyright), provided they are not 100% transparent.
Suitable inorganic UV filters are microfine ZnO and TiO2 particles which optionally also reflect or absorb in the VIS region. These are available commercially under the names Hombitec(copyright) or Sachtotec(copyright), Kemira M160(copyright), Tioveil AQ(copyright) and, to a limited extent, Eusolex T-2000(copyright), limited because it has very high transparency.
These substances have the advantage of not displaying toxic or allergic reactions towards the skin. They have a high light protection factor and therefore a long-lasting protective action. In addition to their protection action in the VIS region, they can also have a protective action in the UV or IR region.
As VIS filters, dyes approved in cosmetics can also be effective, for example those chosen from the xe2x80x9cBlaue Listexe2x80x9d (Blue List) (list of dyes approved in cosmetics) [xe2x80x9cBlaue Listexe2x80x9d Editio Cantor Verlag, editor H. P. Fiedler (1993)], which can be used individually or as a mixture. These dyes can be used as undissolved pigments. Of particular suitability here are the red, yellow and blue dyes which, individually or in a mixture with the other additives, lead to formulations which, when applied to the skin, have a natural coloration. It is therefore also possible to use dyes from this list which have colours other than those mentioned, such as, for example, orange or gold. Preference is given to using, as red dyes, those with the names DandC Red, preferably those with the numbers No. 10, C.I. 15630, No. 7, C.I. 15850 and No. 21, C.I. 45380, Acid Red, preferably Acid Red 1, C.I. 18050, Allura Red, trans-alpha, beta- or gamma-carotene, and Pigment Red. Yellow dyes in this respect are those with the names Acid Yellow, preferably Acid Yellow 1, C.I. 10316, Tartrazine, C.I. 19140, Rutin, DandC Yellow No. 7, C.I. 45350, Disperse Yellow, Food Yellow, Natural Yellow, Pigment Yellow, Solvent Yellow. Suitable blue dyes are Acid Blue, preferably Acid Blue 9, C.I. 42090, Acid Blue 80, C.I. 61585, DandC Blue No. 6, C.I. 73000, C-Blue 21, Direct Blue 86.
Apart from the dyes listed in the given list, further VIS-absorbing substances are also suitable, such as, for example, flavonoids or natural or artificial melanin.
Further inorganic UV filters which may be used are UV filters generally known to the person skilled in the art, such as, for example, those from the group consisting of titanium dioxide and zinc oxide.
Suitable VIS filters can be incorporated into cosmetic formulations in concentrations of from 0.5 to about 20% by weight. In this way, it is possible to prepare formulations in which up to 100% of the light protection filters used are VIS filters. These are substances which can be dissolved, dispersed or emulsified in a simple manner with water and oils. The formulations according to the invention, which guarantee effective protection in a very wide wavelength range, can thus be used for the preventive treatment of inflammation and allergies of the skin, for preventing certain types of cancer, optionally also for insect repellency and, in particular, for preventing herpetic diseases of the skin. Even the use of sunscreen formulations with intensive protection against UVA and UVB radiation shows here a good action against the activation of herpesviruses, which are generally known as Herpes simplex. For the mouth and lip area, in experiments which have been performed, formulations which also ensure good VIS protection and comprise light protection filters which absorb in the visible region have proven to be excellent. Said light protection filters can be inorganic filters. Suitable examples are light protection filters based on titanium dioxide and zinc oxide, as described above. The titanium dioxide may be micronized titanium dioxide which is available commercially under the name Eusolex T-2000.
Through suitable choice of light protection filters, or the combination of light protection filters and optionally other additives, the effective components of the sunscreen formulations according to the invention are distributed uniformly in the traditional cosmetic carriers and can, particularly in fatty carriers, form a continuous film; in this way they can be applied to the skin in order to form an effective protective film.
The discovery according to the invention cannot be derived from the prior art by simple inference since sunscreen formulations usually have a composition such that they absorb radiation in the UVB and, recently, also in the UVA region, and not, by contrast, in the visible wavelength range from 400 to 800 nm (VIS region) and in the IR region since the latter types of radiation have hitherto been considered harmless for the skin. However, as has been found, even irradiation in this wavelength range of light has a harmful effect. Although the actual mechanism of damage has not been unequivocally explained, it is certain that this radiation can penetrate into the deeper, thus more active, layers of the skin, where it becomes effective in a damaging manner, meaning that this very effect of light can also accelerate skin ageing processes. This means, irrespective of whether the skin is irradiated by light in the UV, visible or IR wavelength region, that damaging effects for the cells of the skin always arise. As a result, regeneration and protective reaction in the cells are required on the one hand. At the same time, the harmful effect weakens defence reactions of the skin towards bacteria and viruses. In cases of previous infection with herpesviruses or for people with a latent herpes infection, this can lead to activation of the herpesviruses and cause herpetic diseases of the skin. In particular, these diseases affect the mouth and lip area and are caused by viruses of the Herpes simplex group, the form active in the mouth and lip area being of the HSV-1 type and being referred to as Herpes labialis.
We have now found that these undesired diseases of the skin can be avoided if a sunscreen which absorbs radiation in a very wide wavelength range and thus leads to as little damage to the skin cells as possible is applied to the skin, particularly prior to intensive solar irradiation.
Depending on the wavelength range in which they absorb, the light protection filters in the sunscreen formulations according to the invention can be present individually or in combination with one or more light protection filters from other classes of substance, which can likewise be present in an amount of from 0.01 to 40% by weight, preferably from 0.5 to 20% by weight, based on the total weight of the cosmetic preparation. A further very particularly preferred embodiment comprises 3 to 10% by weight. As described, the light protection filters can be replaced by up to 100% by the VIS filters, provided they offer effective protection in a very wide wavelength range. In particular, as stated above, it is also possible to use combinations of different light protection filters which can be both inorganic and organic.
As a result of targeted selection of the individual components, the sunscreen formulations according to the invention have high chemical stability, i.e. cannot undergo hydrolysis, cannot be oxidized, have high thermal stability and high resistance to perspiration.
The sunscreen formulations according to the invention for the protection of the human epidermis against the harmful effect of solar irradiation can, depending on the use, be in various forms customarily used for this type. For example, they can, in particular, be in the form of oily, oily-aqueous, aqueous-alcoholic or oily-alcoholic lotions, emulsions, such as a cream or a milk (W/O or O/W), in the form of oily-alcoholic, oily-aqueous or aqueous-alcoholic gels, dispersions or as solid sticks or powders, or can be formulated as spray or aerosol.
The formulations according to the invention can comprise further cosmetic adjuvants which are customarily used in this type of preparation, such as, for example, thickeners, emollients, moisturizers, surfactants, preservatives, antifoams, perfumes, waxes, lanolin, propellants, dyes and/or pigments which colour the composition itself or the skin, and other ingredients customarily used in cosmetics.
The solubilizer used may be an oil, wax or other fatty substance, a low molecular weight monoalcohol or a low polyol or mixtures thereof. Particularly preferred monoalcohols or polyols include ethanol, isopropanol, propylene glycol, glycerol and sorbitol.
A preferred embodiment of the invention is an emulsion which is in the form of a protective cream or milk and, apart from one or more light protection factors, optionally ethyl 3-(N-butylacetamino)propionate, comprises at least one VIS filter, fatty alcohols, fatty acid esters, in particular triglycerides of fatty acids, fatty acids, alkyl polyglycosides, lanolin, natural or synthetic oils or waxes and emulsifiers in the presence of water.
Further preferred embodiments are oily lotions based on natural or synthetic oils and waxes, lanolin, fatty acid esters, in particular triglycerides of fatty acids, or oily-alcoholic lotions based on a low molecular weight alcohol, such as ethanol, or a glycol, such as propylene glycol, and/or a polyol, such as glycerol, and oils, waxes and fatty acid esters, such as triglycerides of fatty acids.
The sunscreen formulation according to the invention can also be in the form of an alcoholic gel which comprises one or more low molecular weight alcohols or polyols, such as ethanol, propylene glycol or glycerol, and a thickener, such as silica. The oily-alcoholic gels further comprise natural or synthetic oil or wax.
In a dispersion, the dispersant used may be an oil, wax or other fatty substance, a low molecular weight monoalcohol or a low molecular weight polyol or mixtures thereof. Particularly preferred monoalcohols or polyols include ethanol, isopropanol, propylene glycol, glycerol and sorbitol.
A particular embodiment of the present invention consists in solid sticks which consist of natural or synthetic waxes and oils, fatty alcohols, fatty acids, fatty acid esters, lanolin and other fatty substances, and, in addition to care additives, comprise, in particular, inorganic and/or organic light protection filters which absorb as broad as possible a wavelength range of sunlight.
If a sunscreen formulation is formulated as an aerosol, the customary propellants, such as alkanes, fluoroalkanes and chlorofluoroalkanes, are normally used.
If the sunscreen formulation according to the invention is formulated as a spray, aqueous/alcoholic solutions are normally used.
Optionally, one or more chemical substances having self-tanning properties can be added to the formulations. The chemical substances having self-tanning properties which may be used are all natural and synthetic substances known to the person skilled in the art which are suitable for the preparation of cosmetic formulations. These can be either vegetable extracts or synthetic self-tanning agents, such as, for example, dihydroxyacetone or xcex1-ketols.
The sunscreen formulations according to the invention can be prepared using techniques which are well known to the person skilled in the art.
It is assumed that a person skilled in the art can utilize the above description in the widest sense even without further explanation. The preferred embodiments are therefore merely to be regarded as a descriptive disclosure which is in no way limiting.

Sun-protection formulations active against herpes simplex viruses


A field shaping multi-well avalanche detector and method for fabrication thereof are disclosed. The field shaping multi-well avalanche detector provides stable avalanche multiplication gain in direct conversion amorphous selenium radiation detectors. The detector provides stable avalanche multiplication gain by eliminating field hot-spots using high-density avalanche wells with insulated wells and field-shaping within each well.

1. Field of the Invention
The present invention relates generally to solid-state imaging detectors of ionizing radiation and, in particular, to amorphous selenium radiation detectors having a field-shaping multi-well avalanche detector structure.
2. Description of the Related Art
Soon after the Nobel Prize winning invention of the gas-filled multi-wire proportional chamber by Charpak in 1968 and parallel to developments in microelectronics, micro-pattern gaseous detectors were developed for improved position resolution. However, the range of radiation induced photoelectrons is micrometer to millimeter in, with gas solid-state detectors having three-orders-of magnitude shorter photoelectron range due to their much higher density. Thus, solid-state detectors yield images with substantially higher spatial/temporal resolution. Disordered solids, which are easier and less expensive to develop than single crystalline solids, have not been utilized as photon-counting mode detection media because of low carrier mobility and transit-time-limited photo response.
Amorphous selenium (a-Se), which was previously developed for photocopying machines, has been commercially revived as a direct x-ray photoconductor for Flat-Panel Detectors (FPD) due to high x-ray sensitivity and uniform evaporation over a large area as a thick film. However, current direct conversion FPDs are limited by, inter alia, degradation of low-dose imaging performance due to electronic noise, because energy required to generate an electron-hole pair in a-Se is 50 eV at 10 V/micron. Although other photoconductive materials with higher conversion have been investigated, the other photoconductive materials suffer from charge trapping and manufacturing issues. Improved conversion of a-Se is possible by increasing the electric field above 30 V/micron, i.e., 30,000 V on a 1000 micron layer. However, this electric field increase is extremely challenging for reliable detector construction and operation, and is virtually impractical.
Amorphous solids, i.e., non-crystalline solids with disorder, have been ruled out as viable radiation imaging detectors in a photon-counting mode because of low temporal resolution due to low carrier mobilities and transit-time limited pulse response, and low conversion gain of high energy radiation to electric charge. Avalanche multiplication in selenium can be used to increase the electric charge gain. However, significant obstacles prevent practical implementation of a direct conversion a-Se layer with separate absorption and avalanche regions.
A separate localized avalanche multiplication region minimizes gain variation compared to bulk avalanche, i.e., avalanche in an entire volume of a-Se. However, a separate localized avalanche multiplication region has not been realized due to formation of field hot-spots, where F exceeds 150 V/μm, leading to irreversible material breakdown. The concept of unipolar solid-state detectors with a Frisch grid has been proposed, but such structures are not practical for direct conversion avalanche gain because the highest electric field in the well develops at the interface between the semiconductor and the pixel electrode, thereby resulting in high dark current due to large charge injection and potentially irreversible detector damage.
Therefore, provided herein is a novel radiation detector that overcomes disadvantages of conventional detectors.

Field-shaping multi-well avalanche detector for direct conversion amorphous selenium

The Research Foundation for The State University of New York


A method of treating tissue damage comprises applying a negative pressure to a wound sufficient in time and magnitude to promote tissue migration and thus facilitate closure of the wound. The method is applicable to wounds, burns, infected wounds, and live tissue attachments. A wound treatment apparatus is provided in which a fluid impermeable wound cover is sealed over a wound site. A screen in the form of an open-cell foam screen or a rigid porous screen is placed beneath the wound cover over the wound. A vacuum pump supplies suction within the wound cover over the treatment site.

The treatment of open wounds that are too large to spontaneously close has long been a troublesome area of medical practice. Closure of an open wound requires inward migration of surrounding epithelial and subcutaneous tissue. Some wounds, however, are sufficiently large or infected that they are unable to heal spontaneously. In such instances, a zone of stasis in which localized edema restricts the flow of blood to the epithelial and subcutaneous tissue forms near the surface of the wound. Without sufficient blood flow, the wound is unable to successfully fight bacterial infection and is accordingly unable to close spontaneously.
An initial stage of wound healing is characterized by the formation of granulation tissue which is a matrix of collagen, fibronectin, and hyaluronic acid carrying macrophages, fibroblasts, and neovasculature that forms the basis for subsequent epithelialization of the wound. Infection and poor vascularization hinder the formation of granulation tissue within wounded tissue, thereby inhibiting wound healing. It therefore becomes desirable to provide a technique for increasing blood circulation within wounded tissue to promote spontaneous healing and to reduce infection.
Poor blood circulation and infection at the wound may also hinder attachment of skin grafts or flaps upon wounded tissue. Skin grafts and flaps will not attach to tissue that is poorly vascularized, infected or necrotic. However, grafts and flaps can be used with much greater success on tissue that, although wounded, is able to form granulation tissue. Accordingly, a technique for promoting blood circulation at the wounded tissue would also promote successful attachment, or "take," of skin grafts or flaps to the wounded tissue as a consequence of increased blood circulation within the grafts or flaps.
Another problem encountered during the treatment of wounds is the selection of an appropriate technique for wound closure during the healing process. Sutures are often used to apply force to adjacent viable tissue in order to induce the edges of a wound to migrate together and heal. However, sutures apply a closure force to only a very small percentage of the area surrounding a wound. When there is scarring, edema, or insufficient tissue, the tension produced by the sutures can become great causing excessive pressure to be exerted by the sutures upon the tissue adjacent to each suture. As a result, the adjacent tissue often becomes ischemic thereby rendering suturing of large wounds counterproductive. If the quantity or size of the sutures is increased to reduce the tension required of any single suture, the quantity of foreign material within the wound is concomitantly increased and the wound is more apt to become infected. Additionally, the size or type of a particular wound may prevent the use of sutures to promote wound closure. It therefore becomes desirable to provide an apparatus and method for closing a large wound that distributes a closure force evenly about the periphery of the wound.
Wounds resulting from ischemia, or lack of blood flow, are also often difficult to heal since decreased blood flow to a wound may inhibit normal immune reaction to fight infection. Patients that are bedridden or otherwise non-ambulatory are susceptible to such ischemic wounds as decubitus ulcers or pressure sores. Decubitus ulcers form as a result of constant compression of the skin surface and underlying tissue thus restricting circulation. Since the patient is often unable to feel the wound or to move sufficiently to relieve the pressure, such wounds can become self-perpetuating. Although it is common to treat such wounds with flaps, the conditions that initially cause the wound may also work against successful flap attachment. Wheelchair-bound paraplegics, for example, must still remain seated after treatment of pelvic pressure sores. It therefore becomes desirable to provide a treatment procedure for ischemic wounds that can be conducted in situ upon an immobile or partially mobile patient.
Other types of wounds in which ischemia leads to progressive deterioration include partial thickness burns. A partial thickness burn is a burn in which the cell death due to thermal trauma does not extend below the deepest epidermal structures such as hair follicles, sweat glands, or sebaceous glands. The progression of partial thickness burns to deeper burns is a major problem in burn therapy. The ability to control or diminish the depth of burns greatly enhances the prognosis for burn patients and decreases morbidity resulting from burns. Partial thickness burns are formed of a zone of coagulation, which encompasses tissue killed by thermal injury, and a zone of stasis. The zone of stasis is a layer of tissue immediately beneath the zone of coagulation. Cells within the zone of stasis are viable, but the blood flow is static because of collapse of vascular structures due to localized edema. Unless blood flow is re-established within the zone of stasis soon after injury, the tissue within the zone of stasis also dies. The death of tissue within the zone of stasis is caused by lack of oxygen and nutrients, reperfusion injury (re-establishment of blood flow after prolonged ischemia), and decreased migration of white blood cells to the zone resulting in bacterial proliferation. Again, it becomes desirable to provide a technique for treating burn wounds by enhancing blood circulation to the wounded tissue to inhibit burn penetration.

This patent is subject to a terminal disclaimer.

Wound treatment employing reduced pressure


Model OPC is developed based on eigen decomposition of an aerial image expected to be produced by a mask pattern on a surface of a resist. With the eigen decomposition method the aerial image intensity distribution around a point (x, y) is accurately described in the model. A scalar approach may be used in the eigen decomposition model which treats the light wave through the mask as a scalar quantity. A eigen decomposition alternatively may use a vector approach which utilizes a vector to describe the light wave and the pupil function. A predicted SPIF may be generated from the aerial image which may be used to verify the mask modeling process by comparing the predicted SPIF to an experimentally determined SPIF. The model OPC, once calibrated, may be used to evaluate performance of a mask and refine features of the mask.

Lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, the photolithographic mask may contain a circuit pattern corresponding to an individual layer of the IC, and this pattern can be imaged onto a target portion (e.g. comprising one or more dies) on a substrate (silicon wafer) that has been coated with a layer of radiation-sensitive material (resist). In general, a single wafer will contain a whole network of adjacent target portions that are successively irradiated via the projection system, one at a time. In one type of lithographic projection apparatus, each target portion is irradiated by exposing the entire mask pattern onto the target portion in one go; such an apparatus is commonly referred to as a wafer stepper. In an alternative apparatus, commonly referred to as a step-and-scan apparatus, each target portion is irradiated by progressively scanning the mask pattern under the projection beam in a given reference direction (the "scanning" direction) while synchronously scanning the substrate table parallel or anti-parallel to this direction. Since, in general, the projection system will have a magnification factor M (generally <1), the speed V at which the substrate table is scanned will be a factor M times that at which the mask table is scanned. More information with regard to lithographic devices as described herein can be gleaned, for example, from U.S. Pat. No. 6,046,792, incorporated herein by reference.
In a manufacturing process using a lithographic projection apparatus, a mask pattern is imaged onto a substrate that is at least partially covered by a layer of radiation-sensitive material (resist). Prior to this imaging step, the substrate may undergo various procedures, such as priming, resist coating and a soft bake. After exposure, the substrate may be subjected to other procedures, such as a post-exposure bake (PEB), development, a hard bake and measurement/inspection of the imaged features. This array of procedures is used as a basis to pattern an individual layer of a device, e.g. an IC. Such a patterned layer may then undergo various processes such as etching, ion-implantation (doping), metallization, oxidation, chemo-mechanical polishing, etc., all intended to finish off an individual layer. If several layers are required, then the whole procedure, or a variant thereof, will have to be repeated for each new layer. Eventually, an array of devices will be present on the substrate (wafer). These devices are then separated from one another by a technique such as dicing or sawing, whence the individual devices can be mounted on a carrier, connected to pins, etc. Further information regarding such processes can be obtained, for example, from the book Microchip Fabrication: A Practical Guide to Semiconductor Processing, Third Edition, by Peter van Zant, McGraw Hill Publishing Co., 1997, ISBN 0-07-067250-4, incorporated herein by reference.
For the sake of simplicity, the projection system may hereinafter be referred to as the "lens"; however, this term should be broadly interpreted as encompassing various types of projection systems, including refractive optics, reflective optics, and catadioptric systems, for example. The radiation system may also include components operating according to any of these design types for directing, shaping or controlling the projection beam of radiation, and such components may also be referred to below, collectively or singularly, as a "lens". Further, the lithographic apparatus may be of a type having two or more substrate tables (and/or two or more mask tables). In such "multiple stage" devices the additional tables may be used in parallel, or preparatory steps may be carried out on one or more tables while one or more other tables are being used for exposures. Twin stage lithographic apparatus are described, for example, in U.S. Pat. No. 5,969,441 and WO 98/40791, incorporated herein by reference.
The photolithographic masks referred to above comprise geometric patterns corresponding to the circuit components to be integrated onto a silicon wafer. The patterns used to create such masks are generated utilizing CAD (computer-aided design) programs, this process is often being referred to as EDA (electronic design automation). Most CAD programs follow a set of predetermined design rules in order to create functional masks. These rules are set by processing and design limitations. For example, design rules define the space tolerance between circuit devices (such as gates, capacitors, etc.) or interconnect lines, so as to ensure that the circuit devices or lines do not interact with one another in an undesirable way. The design rule limitations are typically referred to as "critical dimensions" (CD). A critical dimension of a circuit can be defined as the smallest width of a line or hole or the smallest space between two lines or two holes. Thus, the CD determines the overall size and density of the designed circuit.
Of course, one of the goals in integrated circuit fabrication is to faithfully reproduce the original circuit design on the wafer (via the mask). Another goal is to use as much of the semiconductor wafer real estate as possible. As the size of an integrated circuit is reduced and its density increases, however, the CD of its corresponding mask pattern approaches the resolution limit of the optical exposure tool. The resolution for an exposure tool is defined as the minimum feature that the exposure tool can repeatedly expose on the wafer. The resolution value of present exposure equipment often constrains the CD for many advanced IC circuit designs.
As the technology advances in the semiconductor industry, the dimensions on a circuit have scaled down dramatically, which leads to significant deterioration in image quality and photolithography process robutstness. From a physical point of view, the ratio of the exposure wavelength over the numerical aperture of the imaging system needs to be reduced in order to improve the image fidelity. To enhance semiconductor device performance and to increase the chip functionality, the minimum feature size and minimum pitch on the chip designs have been reduced progressively in a very aggressive fashion. To meet the challenges, the semiconductor industry has developed exposure tools with shorter wavelengths and higher numerical apertures (NA). The continuous advances in photolithography exposure tools along this line have proven very successful until now. To further shorten the exposure wavelength beyond 193 nm or to further increase the numerical aperture beyond 0.9 presents enormous obstacles both economically and technically. To overcome the limitations imposed by the current photolithography exposure tool, the modification of mask data, which is commonly referred to as optical proximity correction (OPC), is gaining ever-increasing momentum in advanced photolithography. OPC usually consists of applying scattering bars (SBs), whose role is to enhance process latitude, and main feature biasing. The use of scatter bars is discussed in U.S. Pat. No. 5,242,770, herein incorporated by reference. Although scattering bar placement rules can be generated from optical imaging theory without taking the resist effect into account, the correct amount of biasing of the mask data at a given location can never be predicted accurately without considering the effect of the resist.
The original implementation of OPC is rule based, the rule set for a given process can be developed either through experiments or through a combination of optical modeling and resist modeling. The rule set thus obtained is essentially a look-up table from which the placement position of SB, if it is permitted, and the amount of correction for the main feature can be readily found, provided that the neighboring environment around the edge to be corrected can be specified. The neighboring environment considered in the rule based OPC is one-dimensional and short ranged. This character leads to its simplicity in implementation, but it also intrinsically sets the limitation of its accuracy. For 130 nm technology and beyond, the inadequacy of rule based OPC becomes evident, and new methods of OPC that can overcome the shortcomings of the rule based OPC is needed. The new method, for example, should provide a way to specify the 2-dimensional environment around the correction point on a much larger spatial scale.
For features having a pitch, where there is no room to insert SB, a typical method of optical proximity correction (OPC) is to adjust the feature edges (or apply bias) so that the printed feature width is closer to the intended width. In order for the use of the sub-resolution features and/or feature biasing to be effective for minimizing optical proximity effects, an operator having a substantial amount of knowledge regarding mask design and the printing process, as well as a substantial amount of experience, is required to modify the mask design to include the subresolution features and/or the adjustment of feature edges (biasing) if the desired goal is to be obtained. Indeed, even when an experienced operator performs this task, it is often necessary to conduct a "trial and error" process in order to properly position the subresolution features to obtain the desired corrections. This trial and error process, which can entail repeated mask revisions followed by repeated simulations, can become both a time consuming and costly process.
Current implementation for mask data biasing is commonly based on some model that has been calibrated on a specific photolithography process. Such an approach is commonly referred as to model OPC. For example, correcting for optical proximity effects (OPE) often entails attempting to "calibrate" the printing process so as to compensate for the OPEs. Currently known techniques include "correlating" so-called calibration parameters to the OPC model, which requires performing a set of detailed SEM CD measurements at various feature sites. Regardless of the actual feature shape, these are 1-dimensional width measurements. The more measurement data collected, the better the precision of the calibration parameters. However, for a reliable model parameter calibration, it is not unusual to require more than several hundreds of CD measurements at various critical feature sites under different neighboring environments. These are labor intensive and time consuming work. Worse, how the measurement CDs were taken can often become operator dependent due to the experience level, which can obviously impact the parameter calibration negatively, thereby limiting the overall effectiveness of the technique.
There are several ways to develop and implement model OPC, such as disclosed by John P. Stirniman, Michael L. Rieger, SPIE, Vol. 2197, (1994), 294 and Nick Cobb, Avideh Zakhor, and Eugene Miloslavsky, SPIE, Vol. 2726, (1996), 208. However, these models are facing ever-increasing challenges in meeting the more stringent dimension control requirements in low k1 photolithography. Those models are also very likely to fail in working with the new advanced photolithography technologies, such as Chromeless Phase Lithography (CPL) in which the topography on the mask is rather significant, and Double Dipole Lithography (DDL) in which two masks and two exposures are needed. In addition to those concerns, advanced illuminations such as customer designed illuminators using diffractive optical elements (DOE), deviations of real illuminator profiles from theoretical top-hat illuminator profiles are all presenting enormous challenges to the current available models. To tackle the difficulties, a fundamentally different model, that has more solid physical and mathematical foundations, must be developed.
Various techniques exist to achieve illumination optimization for photolithography. Various mask optimization techniques also have been known. However, currently illumination optimization and mask optimization are not generally linked. U.S. Pat. No. 6,563,566 to Rosenbluth et al. discloses to perform illumination optimization and mask optimization through a series of calculations which attempt to linearize the optimization of the mask transmission. Rosenbluth discloses to maximize the minimum NILS (normalized image log slope) and to select various constraints to be used in the calculations. Rosenbluth also recognizes that the calculations may be limited relying on the symmetry of a mask. However, the linearization of the mask transmission used by Rosenbluth requires using several approximations in the calculations, instead of the actual imaging equations themselves, which produce errors in implementing a mask to form a desired image. The linearization of the mask transmission also requires the use of a significant number of variables, which requires significant computation time to perform the calculations. Accordingly, as logic feature sizes decrease, there is a need to provide mask implementations that precisely form a desired image with minimum computational time.