This invention provides a clock generator which is capable of improving modulation accuracy without accompanying an increase in consumption current by steady current when spectrum spread of a clock signal is executed. The phase balanced voltage Vf to be inputted to the voltage control oscillator (VCO) 9 is modulated within a dead band region in which no difference signals Pr, Pr are outputted from the charge pump circuit 7 when a difference in oscillation frequency between an output clock signal fo and a reference clock signal fr is detected. Consequently, the output clock signal fo is changed within the range of a lock frequency in a PLL circuit, so as to execute the spectrum spread of the output clock signal fo while maintaining the lock state of the oscillation frequency in the PLL circuit.

1. Field of the Invention
The present invention relates to a clock generator which generates a clock signal of which oscillation frequency is diffused with spectrum to reduce electromagnetic wave radiation due to high-speed oscillation operation.
2. Description of Related Art
As higher performance in electric appliances has conventionally been advanced, operation of appliance has been sped up further more and higher integration design of semiconductor devices for those appliances and theirs packaging substrates has been developed. An oscillation period of a clock signal and the like is shortened to meet with the level same as wiring length of signal wirings on a packaging substrates and its semiconductor device, which results in that signal wiring functions as an antenna and electromagnetic wave radiation, unnecessary radiation, increases.
Furthermore, portable electric appliances have become popular for recent years and suppression of electromagnetic waves radiation is demanded for those portable electric appliances. Since miniaturization and weight saving are required for portable electric appliances, conventional countermeasure such as improvement of circuit arrangement design, insertion of shielding material against electromagnetic wave and the like are restricted before such necessity.
As countermeasure, there has been suggested so-called spectrum diffusion technology for changing oscillation frequency of a clock signal. As an example for such case that a clock signal to which spectrum diffusion is applied is outputted in a PLL circuit, JP Laid-open Patent publication No. 2000-101424 discloses related technology.
First technology is such that an integrated clock signal is obtained by integrating a to-be-inputted clock signal with an integrator, and in a limiter, an integrated clock signal is modulated by a frequency control signal of which voltage level changes with frequency lower than that of a clock signal, whereby there is obtained an output clock signal of which cycle continuously changes. To be more specific, voltage level of an integrated clock signal and that of a frequency control signal are compared, whereby cycle of an integrated clock signal is modulated with changed frequency responsive to voltage level of a frequency control signal and an output clock is obtained. Oscillation frequency is changed by inputting an output clock signal of which frequency changes to a PLL circuit.
Second technology is such that there is provided a direct current amplifier between a low pass filter (LPF) and a voltage control oscillator (VCO) and a frequency control signal of which voltage level changes is inputted to the direct current amplifier.
Third technology is such that, in a charge pump, bias current which generates in response to a frequency control signal is added to charge current which generates in response to an output signal from a phase comparator and voltage level of a capacitor charged/discharged depending on current is controlled, whereby voltage level of a control signal to be inputted to a voltage control oscillator (VCO) is controlled so as to control oscillation frequency.


A common interface and communication methodology are provided for interaction between the components of a storage area network for them to activate “triggers” that cause actions to be taken by the devices to utilize copy service functions to create additional copies of data, and to potentially route load to other resources. The actions can be taken by any of the elements of the storage area network to mitigate the impact of the pending failure. The advantage of this system over current methods is that it can detect both failure and impending failure in any component in the system and use resources in any other component to mitigate the failure. This creates a much more comprehensive recovery strategy and the potential to save more data than in current systems.

1. Technical Field
The present application relates generally to an improved data processing system and method. More specifically, the present application is directed to a preemptive data protection for copy services in storage systems, service systems, and application architecture.
2. Description of Related Art
A storage area network (SAN) is a network of storage disks. In large enterprises, a SAN connects multiple servers to a centralized pool of storage systems. Compared to managing hundreds of servers, each with its own disks, SANs improve system administration. By treating all of a company's storage as a single resource, disk maintenance and routine backups are easier to schedule and control.
Storage area networks, as well as other network data processing systems, include multiple layers, such as applications, database applications, file systems, host server systems, network infrastructure, and storage systems. Current implementations keep these layers abstract, but include redundancy within each layer for fault tolerance.
In some SANs, the storage systems themselves can copy data to other storage systems for backup without any processing overhead at the host systems. In computer systems with two or more storage systems, peer to peer remote copy (PPRC) allows one storage system to mirror a volume on a second storage system. Synchronous PPRC causes each write to the primary volume to be performed to the secondary volume as well. The input/output (I/O) operation is only considered complete when update to both the primary and the secondary volumes have completed. Asynchronous PPRC flags tracks on the primary volume to be duplicated to the secondary volume when time permits.

Preemptive data protection for copy services in storage systems and applications

International Business Machines Corporation


An optical pickup apparatus comprising: a laser-light source that selectively emits first and second laser lights parallel with each other; a diffraction grating that includes a plurality of periodic structures joined to be different in phase from each other in a direction optically corresponding to an optical-disc-tracking direction, and generates 0th-order and ±1st-order-diffracted lights by diffracting the first or second laser light; an objective lens that focuses the 0th-order and ±1st-order-diffracted lights generated from the diffraction grating on the same track of the disc; and a photodetector to which reflected light of the 0th-order and ±1st-order-diffracted lights focused on an optical disc is applied through the objective lens, and which generates a differential-push-pull signal, a direction of a straight line connecting light-emitting points of the first and second laser lights in the laser-light source being inclined relative to the direction optically corresponding to the optical-disc-tracking direction in the diffraction grating.

1. Field of the Invention
The present invention relates to an optical pickup apparatus.
2. Description of the Related Art
There is known an optical pickup apparatus including a laser light source that can selectively emit laser light having a wavelength for DVD (Digital Versatile Disc) and laser light having a wavelength for CD (Compact Disc), for example. The laser light source has two light emitting points respectively emitting these two laser lights, with a predetermined space between the points.
This optical pickup apparatus including two types of diffraction gratings that generate 0th order light and ±1st order diffracted lights for generating tracking error signals for each of the two laser lights. Specifically, the two types of the diffraction gratings are assembled so that grating surfaces thereof having different configurations are arranged back to back (See Japanese Patent Laid-Open Publication No. 2007-164962, for example) or assembled so that they are opposed to each other (See Japanese Patent Laid-Open Publication No. 2007-149249, for example).
For example, a diffraction grating provided for laser light having a wavelength for DVD has a configuration for generating the 0th order light and ±1st order diffracted lights suitable for an in-line differential push-pull method by which a tracking error signal is generated, while a diffraction grating provided for laser light having a wavelength for CD has a configuration for generating the 0th order light and ±1st order diffracted lights suitable for a three-beam differential push-pull method by which a tracking error signal is generated (See Japanese Patent Laid-Open Publication No. 2004-145915, for example).
That is, since these two types of the diffraction gratings have the configurations different from each other, they are assembled so that the two grating surfaces are arranged back to back or so that they are opposed to each other as mentioned above, to be incorporated as a single diffraction grating in an optical pickup apparatus for both DVD and CD.
In the above-mentioned optical pickup apparatus, since the laser light having a wavelength for DVD, for example, from the laser light source is applied to both of the above-mentioned diffraction gratings for DVD and CD, the laser light is affected by the diffraction grating for CD.
For example, when performing tracking error control in reproduction, etc., of DVD, in order to generate a differential push-pull signal, it is necessary to diffract the laser light having a wavelength for DVD with the diffraction grating for DVD, to generate the ±1st order diffracted lights (±1st order diffracted lights for DVD). At the same time, the 0th order light is generated from the laser light having a wavelength for DVD by the diffraction grating for DVD, however, the ±1st order diffracted lights (noise) generated by diffracting this 0th order light with the diffraction grating for CD have the same levels in intensity as those of the above-mentioned ±1st order diffracted lights for DVD. This leads to a drop in accuracy of the tracking error signal.


A network print system includes a host having the function to generate print data, a printer that processes printing on the basis of a specified print data, and a communication network that connect the printer and the host so that they can communicate with each other. The printer of the network print system carries out send request of desired print data to the host, and receives print data corresponding to the send request, and thereby executes print processing in accordance with the print data. Further, the host includes a memory to store the print data, and sends the print data stored in the memory to the printer that has carried out a send request of print data when the send request of the print data is carried out in the printer through the communication network.

1. Field of the Invention
The present invention relates to a network print system to output images including documents and the like prepared by a computer connected on a network such as LAN or so by use of an optional printer connected on the same network.
2. Description of the Related Art
Recently there are many network print systems to output images made by computers in a configuration of a network environment such as LAN involving plural computers and plural printers.
In the network print systems in the prior art, at the event of image data created (a print job) by a certain computer so as to be printed by a printer, the print job was immediately sent to the printer designated on the network or a print server to store and control the print job.
In each printer or print server, the received print job is stored initially into a First-In First-Out (FIFO) print queue consisting of a buffer memory and the like, and a print job that has come first into the print queue is printed first.
In this manner, in the print job management methods by the conventional network print systems, at the event of a print job on a computer, the print job is sent to a printer or a print server set on the network as print data. Accordingly, there were many cases where many print jobs were accumulated in a certain printer or print server designated on the network, even though print queues of other printers were empty.
Furthermore, in each printer or print server, print jobs were executed in the sequence of coming into the print queue, therefore, even a print job of one sheet had to wait in the case when another print job of numerous sheets had come into the print queue of the printer just before it. Namely, printing was executed always by a predetermined printer, so even when there were other printers ready for printing, a user who wanted to print out only one sheet had to wait for a long time, which was one of the negative effects in the prior art.
Still further, since printing was executed in the sequence of print jobs coming into a print queue of the printer or print server, when plural users utilized a single printer, they may have left their own printed matters in that printer. Namely, the information of printed matters may have been accessed by other persons, as a result, it was difficult to keep secrecy, which was another problem in the prior art.
Also, print jobs were controlled at the printer side, and the contents of the print queue were printed at once, therefore, if printed matters were output by mistake, unnecessary printed matters were output automatically. Moreover, it was very difficult to completely delete a print job created by mistake from the computer side, which was another problem in the prior art.
And further, when plural copies of an identical document were necessary, for instance, in a conference or so, in the conventional network print system, it was necessary to copy the printed matter output by the printer by use of a photoelectric copying machine or to execute the same print job many times.

Network print system for allowing a printer or printers to select a host


A power conversion apparatus for converting direct current from a power source to polyphase alternating current includes a plurality of carrier signal generators, a plurality of gate signal generators, and a plurality of legs. The carrier signal generators are configured and arranged to independently generate and transmit a plurality of carrier signals, respectively. The gate signal generators are operatively coupled to the carrier signal generators, respectively, to receive the carrier signals, each of the gate signal generators being configured and arranged to generate an on/off signal by comparing a command value of each phase of the polyphase alternating current and corresponding one of the carrier signals. The legs are connected to the gate signal generators. Each of the legs is operated based on the on/off signal transmitted from corresponding one of the gate signal generators to convert the direct current to each phase of the polyphase alternating current.

1. Field of the Invention
The present invention relates to a power conversion apparatus. More specifically, the present invention relates to the power conversion apparatus for generating on/off signals using pulse width modulation (PWM).
2. Background Information
Several types of voltage-type inverters used to drive alternating current motors are currently known. In these inverters, three of single-phase half-bridge circuits are connected in parallel with each of the single-phase half-bridge circuits having two electrical switches connected in series, and the on/off signals of the switches are generated by pulse width modulation (PWM). When the switches are switched on and off, a ripple current will be generated according to the frequency of the PWM modulating signal (the carrier) and according to the motor inductance. Thus, a smoothing capacitor inserted into the circuit to smooth out the ripple current.
Japanese Laid-Open Patent Application Publication No. 2000-78850 discloses one example of an inverter device and a method for controlling the inverter device that reduces the ripple current and the capacity of the smoothing capacitor. In the inverter device disclosed in this reference, two inverters shares a common smoothing capacitor. Moreover, countermeasures are adopted such as synchronizing the carriers of each inverter, switching the peaks and troughs (valleys) of the triangular waves of the inverters used for modulation, and synchronizing the on state of one with the off state of the other. As a result, the ripple currents flow alternately into the smoothing capacitor to cancel each other.
Moreover, Japanese Laid-Open Patent Application Publication No. 05-56653 discloses another example of an inverter apparatus in which a converter is placed between an alternating current source and a direct current bus, and an inverter is placed between the direct current bus and the alternating current load. In the inverter apparatus disclosed in this reference, the two modulation signals are synchronized, and the flow of current into a smoothing capacitor attached to the direct current bus is reduced. Thus, the inverter apparatus disclosed in this reference performs synchronization control of two power conversion devices (the converter and the inverter) that are connected to the shared smoothing capacitor.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved power conversion system. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.

Power conversion apparatus for converting direct current to polyphase alternating current


A method for determining where in time to schedule a project in a computerized system for scheduling multiple projects operates in conjunction with a database composed of schedules for individual projects with resources assigned to some tasks. A user specifies the resources to be used for a new project, the loading caused by projects whose dates are already determined, the earliest possible start times for the new project, and the maximum amount of expansion in flow time (start to finish time) allowed for the new project, with considering inter-project resource contention. The new project is delayed only long enough to allow contention for the selected resources to be resolved, while not violating the flow time expansion restriction.

Project management and resource scheduling are important functions that can be applied to a variety of enterprises and business concerns. There are many variables and dependencies that are involved in a project management effort. These variables and dependencies must be managed and resolved in an organized and effective manner to achieve desired and optimal results.
In general, there are three main elements that should be addressed in scheduling a project. First, the project requirements are determined and quantified. These requirements, for example, can include resource availability, manufacturing schedules, engineering milestones and other tasks that must be performed to achieve an end result. These project requirements are then represented in a model or framework to organize and track all of the requirements. There are many types of models that can be used to represent and manipulate these project requirements. For example, these models can take into account factors such as tasks, task interrelationships, precedence relationships, resources and various restrictions on the tasks and resources that make up a project.
The second main element in scheduling a project is an objective function. This objective function determines the relative quality and comparative advantages and disadvantages between various schedule alternatives at different decision points. The objective function can determine which schedule is a "better" schedule and which schedule is a "worse" schedule. Often included in this objective function is what-if analysis to evaluate amongst an array of possible outcomes and scenarios and provide decision support to management and other interested members of an organization. As the name suggests, the objective function expresses the "objectives" of the schedule, usually in mathematical terms and quantities that can be more easily managed and compared to each other.
The third main element in scheduling a project is the actual process for determining task sequences and times. Many processes exist in the prior art for scheduling one or more projects. These processes can support various kinds of modeling capabilities and objective functions. Some of these are heuristically based and some are designed to produce optimal results. Objective functions normally focus on bottom-line results predicted by a schedule. These bottom-line results are typically based on due dates, predicted completion dates, milestone completions and resource productivity. Optimization techniques may also be applied to quantities such as weighted values, a sum or a maximum value in order to arrive at an optimal solution. Another technique used is phase-gate processes. Phase-gate processes establish different project phases. Each phase ends with a gate that may or may not be passed through, depending upon the satisfaction of specific entry or exit criteria.
There are limitations associated with many of these existing techniques. Although the theories underlying these techniques may be sound, in a practical implementation it is often very difficult, if not impossible, to produce a truly optimal schedule. There are numerous reasons for this difficulty. A schedule is at best an imperfect model or representative approximation of reality. Reality is a constantly changing and evolving entity, which often requires constant attention and changes to schedules and their management, further complicating the modeling activity. Furthermore, most practical scheduling problems are "NP-hard", i.e., nondeterministic polynomial, meaning that they are most likely very difficult to solve optimally using a mathematical analysis.
Another complication in project scheduling is that it is quite common for organizations is to have more active projects in place than their resources can easily or effectively accommodate. This can quickly turn into an overload condition where there are insufficient resources available at the necessary or opportune time to have the intended effect. One reason that this problem can occur is that management wants to take advantage of most, if not all, of the new opportunities that currently exist or will exist shortly. Problems can also arise when front-end organizations, like marketing, may have sufficient capacity and resources to propose and define projects. At the same time, however, other organizations, such as new product development and manufacturing, may be currently operating at capacity and/or over-subscribed with work, and cannot handle the new work that marketing is committing them to do. Further in this regard, Little's Law says that work in a system or work-in-process (WIP) is proportional to flow time. In other words, the more work that exists in the organization at a given point in time, the longer the average start-to-finish time for any of the given projects.
There are other, less obvious penalties to having too many active projects occurring simultaneously in an organization. Probably the most significant penalty is the one attributed to multitasking inefficiencies. This occurs when personnel move back and forth between tasks and/or projects without completing any of them. The end result of these multitasking inefficiencies is that the time required to complete any given task can be extended arbitrarily. In a competitive environment where time to market is critical, this arbitrary task extension can be a significant liability and put an organization at a severe competitive disadvantage in the marketplace.
Finally, it is almost a universal truth that all projects will encounter some type of delay, both foreseen and unforeseen. These delays can arise from known or unknown origins and can extend projects significantly.
Once launched, projects progress in ways that may not have been envisioned or planned for in the initial project stages. There are known and unknown events that can introduce all manners of perturbations into the system with correspondingly different results and outcomes. Projects can take on a life of their own, and it becomes difficult to make a decision to terminate them before completion. This usually happens only after significant time, energy and resources have been expended. The termination of a project can be a very stressful, wasteful and time-consuming process. There is a strong need for better control and insight into how and why projects are launched or introduced into an organization to begin with.
There are various quantitative methods that can be used to limit the introduction of new projects into organizations. One method compares the estimates of aggregate resource consumption versus availability, over a given time period. In certain simpler and less complex applications, this method can be very effective. However, there can be surprises and unforeseen results due to its approximate nature and dependency upon estimates.
Another approach is to create detailed schedules for all of the projects. Resource contention is resolved within and between the various project schedules, at least for some of the resources. The objective function attempts to optimize a combination of parameters in order to complete projects as quickly and efficiently as possible. This approach can be reliable, given reasonable project schedules. However, there is a common, practical problem encountered when scheduling projects: how much earlier should a project be started, in order to produce some minimal additional efficiency? For example, it might be possible to begin work on a project a month earlier and, by taking advantage of temporary availability of some resources, thereby advance its completion date by a week. However, this approach may create other disadvantages, due to the fact that there are more concurrent projects in the system. A scheduling system should enable a manager to evaluate the various tradeoffs associated with such an approach.
Therefore, it is desirable to provide a practical and controllable mechanism for limiting the starts of new projects and a method that allows organizations to deal with both capacity issues and work-in-process issues. Given the common real world limitations and operational scenarios that are frequently encountered, such as project opportunities that can arrive at arbitrary times and projects that are hard to control and hard to stop, a very effective way of controlling work-in-process is to control the induction or commencement of new projects in an organization. The present invention achieves this objective through a practical, quantitative means of controlling project starts based on a combination of capacity and project flow times.


An automated warehouse includes an apparatus main body a transfer device. The apparatus main body includes a plurality of stationary shelves arranged horizontally and vertically, and having upper surfaces on which cassettes can be placed. The transfer device transfers the cassette by holding a flange of the cassette. The transfer device includes a vertical rail and a transfer head. The vertical rail includes an upper end adjacent to a supporting surface of a top stationary shelf. The transfer head is a member vertically movable along the vertical rail. The transfer head includes a vertical arm having a length such that the vertical arm can hold the flange of the cassette placed on the top stationary shelf.

1. Field of the Invention
The present invention relates to an automated warehouse, and more specifically to an automated warehouse which stores articles adjacent to a processing apparatus.
2. Description of the Related Art
In a manufacturing plant for semiconductors or liquid crystal products, a substrate, such as a silicon wafer or a glass plate, undergoes various processing formations, such as film forming, oxidation, and etching, so that a semiconductor device or a liquid crystal device is formed on the substrate. Between the processing apparatuses of these kinds, cassettes, which contain substrates, are conveyed by an overhead conveying vehicle in units of cassettes. At the delivery location of the cassettes between the processing apparatus and the overhead conveying vehicle, there is disposed a buffer, which is referred to as an apparatus front automated warehouse, for adjusting processing time between the overhead conveying vehicle and the processing apparatus (for example, refer to Japanese Patent Application Laid-Open No. 2001-298069).
A conventional apparatus front automated warehouse is provided with a plurality of stationary shelves for storing cassettes which are vertically arranged at intervals, and a transfer device which can transfer an article among the respective stationary shelves. The stationary shelves are vertically disposed at intervals, and the top stationary shelf is the cassette delivery location between the overhead conveying vehicle and the stationary shelves. A cassette delivery port between the processing apparatus and the stationary shelves is disposed below the bottom stationary shelf. The processing apparatus takes out a substrate from the cassette placed on this delivery port, and then processes the substrate.
The transfer device is disposed so as to face the side of the stationary shelves opposite to the processing apparatus side, and transfers the cassette among the respective stationary shelves and between the respective stationary shelves and the delivery port. By disposing such an apparatus front automated warehouse, even when a supply or carrying-out of the cassette is stagnated due to trouble in processing apparatuses and conveying apparatuses, carrying-in and carrying-out of the cassette can be continued without causing system down time.
When transporting an automated warehouse like the one disclosed in Japanese Patent Application Laid-Open No. 2001-298069, the apparatus height is restricted in the case of air transportation, and the like. Therefore, conventionally, the automated warehouse is divided into upper and lower portions so as to be individually transported. However, in this case, assembling and disassembling the automated warehouse require a lot of effort, and further, after assembling the warehouse, the transfer position of the transfer head of the transfer device may deviate from the original transfer position, i.e., the position where it was before the warehouse was divided into two portions. When the transfer position is deviated, an on-site operation for re-teaching the transfer position is required.


The present invention provides a main nozzle of a combustor, a plurality of the main nozzles are to be installed on an outer peripheral side of a pilot nozzle of the combustor at an interval in a circumferential direction of the pilot nozzle, the main nozzle includes a main nozzle body extending in an axial line; a swirl vane protruded from an outer peripheral surface of the main nozzle body in a radial direction of the axial line, and is configured to allow a fluid flowing downstream in a direction of the axial line to swirl around the axial line; and temperature sensors installed on the main nozzle body so as to be disposed on a tangential line to a mean line of the swirl vane drawn between a vane ventral surface and a vane dorsal surface of the swirl vane, at a downstream end portion of the swirl vane.

In recent years, as a combustor of a gas turbine, a premixed combustion type in which fuel is mixed in advance with compressed air (combustion air) sent from the compressor to generate an air-fuel premixture, and the air-fuel premixture is combusted has been widely used.
As this type of combustor, a combustor including a pilot nozzle provided on a central axis of the combustor, and a plurality of main nozzles disposed parallel to the pilot nozzle is known.
It is necessary to raise a temperature of a turbine inlet to improve the efficiency of the gas turbine, but there is a problem that NOx increases exponentially as the temperature increases. As a countermeasure for the NOx increase, for example, a combustor disclosed in the following Patent Document 1 includes a main nozzle that forms a homogeneous air-fuel mixture by swirling flow and thereby limits formation of a local high-temperature region.
The main nozzle of this combustor has a main nozzle body that is a shaft body extending in an axial line of the main nozzle, and a swirl vane swiling compressed air sent from the compressor.
Incidentally, a phenomenon in which fire flames move upwards at the center of swirling flow (flashback) is known to occur often when the air-fuel premixture formed by swirling is combusted. When anomalous combustion such as flashback occurs, there is concern of firing at the main nozzle and causing thermal damage, and therefore this is desired to be limited.
In order to prevent such a phenomenon, a technique in which a temperature sensor such as a thermocouple is provided at a distal end of the main nozzle, and compressed air in a casing of a turbine is injected on the basis of detection results by the temperature sensor, thereby avoiding damage to the main nozzle, is known.

Main nozzle, combustor, and method for manufacturing main nozzle


A press cage may include pairs of opposing wall plates, each of the pairs of wall plates being orthogonal with respect to the other pairs, with corresponding machined indentations located at predetermined locations on broad faces of the wall plates which are adjacent to each other. The press cage may also include coupler assemblies made of coupler parts, each of the parts fixed to machined indentation of the corresponding machined indentations at one of the predetermined locations, the coupler parts locked together.

A press machine (hereinafter referred to as "press") typically includes large and heavy drums that are made to roll during the printing process and transfer an image onto a substrate that is pressed by and made to travel between the drums. Old presses typically include frames made of assembled planar plates forming the walls of the frame. Assembly procedures of such frames are typically prone to adjustment problems and the alignment between rear and front walls is many times not satisfactory. Features are added to walls in order to address these problems, but machining these features requires machining of walls at their narrow lateral facet. In order to accomplish this special adaptors ("knees") on CNC machines are used, which affect precision and increase cost. On the other hand, handling, shipment and storage of machined plates in any stage of production is fairly easy. Recent frame designs are based on a "monolithic" cage. In producing a monolithic cage both rear and front sides of the cage are machined at once using a very large and precise milling machine, thus bypassing a long chain of tolerances that would have otherwise been needed, and eliminating assembly. First the cage is cast, then runners are removed and then the cage is subjected to machining in two stages—rough and final. Connecting and stabilizing beams connect the front wall to the rear wall, and bestow rigidity, stiffness and dimensional stability to the cage. In a monolithic cage those beams are cast along with the rear and front walls. Since outside dimensions of the cage determine the type and size of the milling machine capable of machining it, all connecting beams are designed to remain within the outermost perimeter of the cage. Machining requirements, especially part size and accuracy, impose a "size barrier" on the cage and there are only few machines available with such combinations of part size and accuracy.
The number and size of beams in a monolithic cage of a press are limited since the printing press is densely populated and a connecting beam may interfere with mounting and dismounting procedures of sub units of the cage. Size barrier and components density within the cage result in fewer beams, and the remaining beams have thin cross section. This consequently lowers the natural frequency of the cage. Loosing rigidity in this design also affects machining accuracy and dimensional stability of the cage, since fixing the cage on a CNC machine is more difficult. Logistics, too, is complex with monolithic cage design.

Method and system for the production of frame structure for printing presses

Hewlett-Packard Development Company, L.P.


A light source module including an optical film and at least one light source unit is provided. The light source unit and the optical film enclose a space. The light source unit includes a reflecting device, at least one light bar, and a collimated unit. The reflecting device is disposed under the optical film. The light bar includes a plurality of light-emitting elements arranged along a third direction. The collimated unit extends along a direction parallel to the third direction and includes an upper reflective portion and a lower reflective portion. A shortest distance between one end of the lower reflective portion located adjacent to the reflecting device and the optical axis of the light-emitting elements along a second direction is defined as a first half light-emitting width, which is gradually increased along the third direction from a center portion of the collimated unit towards two sides thereof.

1. Technical Field
The invention relates to a light source module, and particularly relates to a light source module adapted for a display device.
2. Related Art
In recent years, along with enhancement of light-emitting efficiency and prolonging of service life of light-emitting diodes (LEDs), and due to characteristics and advantages of low power consumption, low pollution, high efficiency, high response speed, small volume, light weight and capable of being disposed on various surfaces, the LEDs are widely applied in various optical fields. Generally, the LEDs can be applied to various illumination devices and various planar displays in daily life, for example, liquid crystal displays (LCDs).
Taking the application of the LED in the LCD domain as an example, a backlight module of the LCD is a planar light source, and a basic operation principle thereof is to convert valid light of a linear light source or a point light source into a planar light source with high brightness and good uniformity. Generally, based on different light source positions, the light source modules are grouped into side incident type light source modules and direct type light source modules, wherein since a structure of the direct type backlight module is simple and a plurality sets of light sources can be adopted, the direct type backlight module may provide higher brightness and luminance, so that it is generally used in electronic products having a large size LCD.
Further, in the current direct type backlight module, the number of the used LEDs is decreased or a height of light cavity is decreased by configuring a secondary optical lens; however a product cost is increased. On the other hand, regarding a direct type backlight module without using the secondary optical lens, it has a thicker light cavity, or more LEDs have to be configured, so that system reliability is decreased. Moreover, regarding another direct type backlight module without using the secondary optical lens, it is mainly composed of LEDs, a reflective lampshade, a diffusion plate, and a bottom reflective sheet, in which the reflective lampshade reflects a light beam come from the LEDs to the bottom reflective sheet, and the bottom reflective sheet reflects the light beam to the diffusion plate for emitting light, such that the above direct type backlight module may have a lower cost and thinner thickness to achieve a great advantage. However, a brightness of the backlight module is determined by a brightness of a center point thereof, so that under a premise that a limited number of the LEDs are used, it is important to improve the brightness of the center point while considering light-emitting uniformity and front of screen (FOS) performance.
Taiwan Patent No. I410714B discloses a side incident type light source module including a light guide plate and a plurality of LED light sources. Taiwan Patent No. M444487U1 discloses a bar-shape lampshade, where one side of the bar-shape lampshade is recessed to form a reflective trough. Taiwan Patent Publication No. 200907229A discloses an LED device disposed in a reflective lampshade. Taiwan Patent No. I386685B discloses a casing including an extending reflective portion. China Patent No. CN100389349C discloses a reflective plate disposed on a substrate of a casing.


Radiated light with a specified wavelength from a material is detected and a first parameter corresponding to the emissivity ratio is obtained from the plurality of detection signals. Since the emissivity takes on different values according to the condition of the surface of the material, the first parameter changes depending on the surface condition of the material. There is a correlation between a physical value indicating a condition of the material surface and the first parameter. The correlation remains equivalent even if a second parameter corresponding to the physical value is used instead of the physical value itself (for example, an optical physical value such as reflectivity and absorptivity, the thickness of a film formed on the material surface, the surface roughness, and the degree of galvannealing). As an example of the parameter corresponding to the physical value, there is the logarithmic ratio between emissivities (ln .epsilon..sub.a /ln .epsilon..sub.b) corresponding to the temperature in the vicinity of the surface. Therefore, a second parameter can be obtained on the basis of the correlation and a physical value can be obtained. When the emissivity or logarithmic emissivity ratio is used as the second parameter, the temperature in the vicinity of the material surface can be obtained from the second parameter and the plurality of detection signals.

1. Field of the Invention
The present invention relates to a measurement technique for measuring physical values on the surface (optical physical values such as refractive index, reflectivity, and absorptivity, and values indicating surface shape such as surface roughness, surface temperature, thickness of thin film, etc.) of a material in the process of manufacture by detection of thermal radiation energy having two or more different wavelengths.
2. Prior Art
In the process of manufacturing semiconductor material, metallic material, and the like, various reactions such as oxidation, galvannealing, and vapor deposition occur on the surface of the material in process either artificially or naturally and thereby vary physical properties of the material surface greatly on account of such reactions. However, the sensing of the interior of the material is very difficult. It is not preferred from a practical point of view to attach many sensors to the material in order to obtain various data. Therefore, the surface temperature is selected as the most influential parameter from the physical, values or state values, and the surface temperature is utilized for process control as the value for predicting changing status in on-line sensing or in theoretical calculation. For example, in a process of forming oxide film on a silicon wafer, correlative data between the heat pattern of the oxidation process furnace and physical properties of oxide film are measured off-line to obtain many off-line data in advance. The furnace temperature is controlled based on such data. (Although it is desirable to execute control of the surface temperature, indirect control according to the furnace temperature is executed because of difficulty in the on-line sensing.)
For the on-line material surface temperature sensing, there are two temperature sensing techniques: contact method and non-contact method. In the contact temperature sensing method using a thermocouple, thermistor, etc., many problems occur such as: the measurable temperature range is limited, the position where temperature can be measured is limited to the point of sensing, and contamination of the material occurs (addition of impurities thereto) by the contact. Therefore, the processes to which this method is applicable are limited. In the non-contact temperature measuring method, there is "radiation thermometry". This is a practical technique in the process line of metallic materials such as iron, steel and aluminum, and there is a radiation thermometer as a product on the market.
For the process line of a metallic material as described above, there already is developed a technique to measure the surface temperature in a non-contact manner. However, for the process of manufacturing a semiconductor or a new material, such a measuring technique is still in the studying stage. Although various efforts are being made to develop surface temperature measuring techniques, there has not yet been developed any effective technique.
It is reported, for example, in Watanabe, et. al., "Measurement of Wafer Temperature within Semiconductor Heat Treatment Apparatus by Radiation Thermometer", The Transactions of the Japanese Institute of Measurement and Automatic Control Engineers, Vol. 25, No. 9, pp. 925-931 (1989), that it has at last been made possible to apply radiation thermometry to a manufacturing process, to which furnace temperature control has hitherto been applied, by using fiber optics and prisms. From the fact that studies recently made public are on such a stage, it is the present state that there has not been developed any effective technique of on-line radiation thermometry in the field of processing semiconductors.
On the other hand, there are widely used radiation thermometers with the radiation thermometry technique applied thereto for measuring the surface temperature of hot matters. There are two types of such radiation thermometers, i.e., single-color thermometers using a single wavelength for the measurement and two-color thermometers using two wavelengths. Even the two-color thermometer using two wavelengths, not to mention the single-color thermometer, produces a great measurement error when the emissivity of the object of measurement changes.
More specifically, there is no problem with the temperature measurement accuracy of the two-color thermometer when spectral emissivities for two wavelengths are virtually equal or have constant proportionality therebetween. However, the surface condition of a hot matter suddenly changes due to oxidation reaction caused thereon, and when the spectral emissivities deviate from the aforesaid relationship, the measurement accuracy decreases extremely. The error in the single-color radiation thermometer becomes much greater. Therefore, there is a demand for a temperature calculation method for the two-color thermometer responding to changes in the spectral emissivity. Studies for providing such a method are being made, and an improved two-color thermometer is being contemplated for use even where the emissivity changes.
There is a method disclosed in Japanese Patent Publication No. 3-4855 and a TRACE (Thermometry Reestablished by Automatic Compensation of Emissivity) method disclosed in Tanaka and D. P. Dewitt, "Theory of a New Radiation Thermometry Method and an Experimental Study Using Galvannealed Steel Specimens", The Transactions of the Japanese Institute of Measurement and Automatic Control Engineers, Vol. 25, No. 10, pp. 1031-1037 (October 1989). Since both of the above calculation methods are substantially the same, the former will be described below. The spectral emissivity for radiation energy (light wave) emitted from a material in process is obtained by using Wien's approximation law. When wavelengths are .lambda..sub.1 and .lambda..sub.2, the emissivities are given by the following expressions (1) and (2). By eliminating temperature T from these expressions, expression (3) can be obtained. (Symbols used in these expressions will be mentioned below.)
Measurement wavelength: .lambda..sub.1 [.mu.m] PA1 Spectral emissivity for a measurement PA1 wavelength: .epsilon..sub.i [.mu.m] PA1 True temperature of the hot matter surface: T [K] PA1 Brightness temperature of the hot matter surface at a wavelength .lambda..sub.i : Si [K) PA1 Planck's second radiation constant: C2 (1.4388.times.10.sup.4) [.mu.M.multidot.K] EQU .epsilon..sub.1 =exp[(C2/.lambda..sub.1){(1/T)-(1/S1)}] (1) EQU .epsilon..sub.2 =exp[(C2/.lambda..sub.2){(1/T)-(1/S2)}] (2) EQU .epsilon..sub.1.sup..lambda.1 /.epsilon..sub.2 =exp[(C2{(1/S2)-(1/S1)}](3)
The left side of the expression (3) is the ratio between "the wavelength power, or involution, of spectral emissivities", which, will hereinafter be called "emissivity involution ratio" for simplicity. The old two-color radiation thermometer measures temperature on the assumption that the ratio between spectral emissivities (.epsilon..sub.1 /.epsilon..sub.2) is "1" or a constant. Because it does not respond to changes in the spectral emissivities, it produces a great measurement error. (The ratio between emissivities will hereinafter be called "emissivity ratio".)
In Japanese Patent Publication No. 3-4855, the correlative function "f" of the spectral emissivity ratio (.epsilon..sub.1 /.epsilon..sub.2) to the emissivity involution ratio is decided in advance by measurement. To be concrete, if radiation thermometry and true temperature measurement are performed at the same time by using, for example, a thermocouple, the spectral emissivity is obtained. By using such data, the spectral emissivity ratio and the emissivity involution ratio can be obtained. Hence, the correlative function f can be obtained from them. Further, since the brightness temperatures S1 and S2 can be obtained as outputs of the two-wavelength detector, the value of the above emissivity involution ratio can be obtained by calculating the right side of expression (3). Accordingly, in the temperature measurement, the brightness temperatures are measured and the emissivity ratio is obtained according to the following expression (4) from the emissivity involution ratio calculated according to the above expression (3) by using the correlative function f. The temperature T is obtained by making calculations according to the following expression (5). EQU .epsilon..sub.1 /.epsilon..sub.2 =f(.epsilon..sub.1.sup..lambda.1 /.epsilon..sub.2.sup..lambda.2) (4) EQU T=(.lambda..sub.2 -.lambda..sub.1)/{(.lambda..sub.1 .lambda..sub.2 /c2)1n(.epsilon..sub.1 /.epsilon..sub.2)+(.lambda..sub.2 /s1)-(.lambda..sub.1 /s2).} (5)
However, when the above described prior art is applied to surface temperature measurement in surface processing of silicon semiconductors, such as the formation of a surface thin film, problems arise such that the function "f" in expression (4) becomes very complicated and the calculation becomes difficult or, if it is simplified by approximation, an error is produced. In the surface process of the silicon semiconductor, the thin film of the surface changes. Therefore, when attempting to measure the surface temperature, the emissivity varies greatly because of optical interference in the thin film. This makes practical radiation thermometry difficult.
In the manufacturing process of semiconductor materials, metallic materials, and the like, although it has been desired that the surface physical properties of the materials in process are measured and on-line process control is thereby executed, such control is not practiced in reality. Further, since surface physical properties change with time and also are closely related with the temperature of the material, it becomes necessary that the surface physical properties and the surface temperature are measured at the same time on an on-line basis. However, it has hitherto been impossible to simultaneously measure the surface physical properties and the surface temperature in the same position of the material.
Further, when the measurement method by the two-color thermometer using the above expressions (1) to (5) is applied to thermometry of a hot matter whose surface condition changes with the progress of oxidation reaction or the like, temperature measurement with high accuracy can be attained provided that the measurement wavelengths used are "insensitive" to changes of the surface status. However, when the spectral emissivities of the selected wavelengths are sensitive to the change in the surface condition, a problem arises that greatly decreases the measurement accuracy.
More specifically, as a concrete example, when the spectral emissivities of selected wavelengths sensitively change responding to changes in the surface status of a hot matter, in one case, the surface oxidizes and forms a translucent (to the measurement wavelength) oxide film on the surface. In such a case, optical interference takes place in the translucent film formed on the surface and the spectral emissivity is thereby greatly reduced.
Makino et. al. gives account of such a phenomenon of a sudden change of emissivity in, for example, "Heat Transfer 1986", Vol. 2, Hemisphere (1986) pp. 577-582, on the basis of experiments and model calculations based on optical interference theories, that a drop (valley) appears in the spectral emissivity (reflectivity) spectrum at a short-wavelength zone when surface oxidation occurs and the sudden change is confirmed to be a characteristic change of the valley moving toward the longer-wavelength side as the oxidation progresses.
FIG. 65 to FIG. 69 are diagrams schematically showing an example of such a characteristic change in a spectral emissivity spectrum. Referring to the diagrams, the axis of abscissas represents the spectral wavelength .lambda. and the axis of ordinates represents the emissivity .epsilon.. Further, the portion indicated by "valley" is the valley in the spectral emissivity spectrum.
FIG. 65 to FIG. 69 show changes in the spectral emissivity spectrum of the surface as an oxide film is progressively formed on a surface of a metal such as stainless steel.
FIG. 65 shows a spectrum in a low temperature state when no oxide film is formed. FIG. 66 shows a spectrum in an intermediate temperature state when an oxide film is not yet formed. FIG. 67 shows a spectrum in an intermediate temperature state when an oxide film has started to form. FIG. 68 shows a spectrum in a state of the material at the same temperature and having the oxide film developed thereon, and FIG. 69 shows a spectrum in a state of the material heated to a high temperature and having a thick oxide film formed thereon.
The occurrence of the valley is considered chiefly attributable to optical interference caused by an oxide film, and the above introduced Makino et. al. obtained spectral emissivity spectra through model calculation based on interference theories and report that results of the calculation and the experimental results concur well with each other.
Accordingly, the change in the spectral emissivity spectrum occurs because radiation energy of a spectral wavelength band on the order below the thickness of the oxide film is selectively trapped in the oxide film. More specifically, remarkable energy attenuation is produced because radiation of a uniquely selected wavelength band produces interference or multiple reflection in the oxide film and the valley moves from a short wavelength side to a long wavelength side because the uniquely selected wavelength band moves as the oxide film becomes thicker.
Since the emissivity ratios change as the spectral emissivity spectra change with the passage of time as described above, it is natural that measurement errors are produced in the old type two-color radiation thermometer. Measurement errors are equally produced even in the above described improved type two-color thermometer because of difficulty in the calculation of expressions used therein.
The calculation in the improved type two-color thermometer using nearby two wavelengths .lambda..sub.1 and .lambda..sub.1x (.lambda..sub.1 <.lambda..sub.1x) requires that correlation of the two spectral emissivities .epsilon..sub.1 and .epsilon..sub.1x is determined as a regression function in advance from experimental data on an off-line basis. Therefore, the regression procedure falls into difficulty that will be briefly described below.
Supposing that actual measured data of spectral emissivities .epsilon..sub.1 and .epsilon..sub.1x are obtained while the movement of the valley from the short wavelength side to the long wavelength side is taking place as in the spectral emissivity spectrum described above, the correlation of the emissivity .epsilon..sub.1 and the .epsilon..sub.1X changes as "positive correlation".fwdarw."negative correlation".fwdarw."positive correlation".
This will be understood easily if the changes in the values of the emissivities .epsilon..sub.1 and .epsilon..sub.1x corresponding to the nearby two wavelengths .lambda..sub.1 and .lambda..sub.1x are traced in FIG. 65 through FIG. 69. More specifically, when the low wavelength portion of the "valley" in the diagrams (the portion where the spectral gradient is negative) comes between the wavelengths .lambda..sub.1 and .lambda..sub.1x, the relative magnitude between the spectral emissivities .epsilon..sub.1 and .epsilon..sub.1x is reversed and the positiveness and the negativeness of the correlation are reversed.
The situation will be concretely shown in FIG. 70 and FIG. 71. The correlation before passing the valley (FIG. 70) and after passing the valley (FIG. 71) is obviously completely reverse.
Tanaka et. al., "Studies on Iron Manufacture", No. 339 (1990) pg. 63-67, shows the graph .epsilon..sub.1 vs. .epsilon..sub.2 is not one-valued, but rather forms a loop, as schematically shown in FIG. 72. This loop is supposedly due to radiation interference occurring in the oxide film.
Thus, the occurrence of some measurement error is unavoidable even in the improved type two-color thermometer because the correlative regression graph between the emissivities .epsilon..sub.1 and .epsilon..sub.1x cannot be simply determined.
When temperatures of stainless steel plate (SUS 304) were actually measured with the above-described improved type two-color thermometer while surface oxidation was in progress, the maximum measurement error in the domain of galvannealing temperature around 600.degree. C. was approximately 15.degree. C. and the standard deviation was approximately 5.degree. C.
In the course of the development of surface oxidation or surface galvannealing and the change in surface physical properties as described above, the temperature is an influential process parameter in the steel manufacturing process control. Therefore, it is a serious problem that there is an error in the measurement value obtained by radiation thermometry and hence there are demands for a more accurate thermometer. The desired measurement accuracy is a temperature measurement error of .+-.5.degree. C. (maximum error is within 5.degree. C.).
Accordingly, there are demands for the development of a radiation thermometer having higher measurement accuracy than the above improved type two-color thermometer.
Therefore, in order to overcome the above described difficulties in the improved type two-color thermometer, it is contemplated to use three or more wavelengths for the measurement so as to form a number of combinations of two wavelengths out of them. Then, the same process as with the improved type two-color thermometer is performed for each combination of two wavelengths to measure temperature.
However, in such methods using three or more measurement wavelengths and increasing the number of combinations of two wavelengths, there still are the following problems.
To simplify the explanation, an example will be considered where the measurement wavelengths are three (i.e., .lambda..sub.1,.lambda..sub.2, and .lambda..sub.3 when .lambda..sub.1 <.lambda..sub.2 <.lambda..sub.3), and the combinations of the two wavelengths are made for convenience to be (.lambda..sub.2, .lambda..sub.3) and (.lambda..sub.1,.lambda..sub.2).
From brightness temperatures S1, S2, and S3 measured for the wavelengths .lambda..sub.1, .lambda..sub.2, and .lambda..sub.3, two combinations (S2, S3) and (S1, S2) corresponding to the above combinations of wavelengths are made. Emissivity involution ratios and .epsilon..sub.3.sup..lambda.3 /.epsilon..sub.2.sup..lambda.2 and .epsilon..sub.2.sup..lambda.2 /.epsilon..sub.1.sup..lambda.1 are calculated using expressions corresponding to the above-mentioned expression (3). Correlative functions f1 and f2 corresponding to the above-mentioned expression (4) are applied to the above emissivity involution ratios to obtain emissivity ratios .epsilon..sub.3 /.epsilon..sub.2 and .epsilon..sub.2 /.epsilon..sub.1.
However, if it is assumed that the function f1 is given according to the graph shown in FIG. 73 because an oxide film is formed on the surface of the object of measurement, the emissivity ratio takes on two values A1 and A2 when the value of the emissivity involution ratio obtained from the expression corresponding to the expression (3) is AO. On the other hand, if it is assumed that the function f2 is given according to the graph shown in FIG. 74, three values B1, B2, and B3 are obtained as the emissivity ratios corresponding to the calculated value B0 of the emissivity involution ratio.
Therefore, when the number of measurement wavelengths is simply increased and applied to the above described improved-type two-color thermometer, an expression corresponding to the above-mentioned expression (5) must be used to calculate temperatures for the five points (i.e., the two emissivity ratios A1 and A2 and the three emissivity ratios B1 to B3). A search must be made for those temperatures agreeing with each other from the temperatures obtained from A1 and A2 and the temperatures obtained from B1 to B3, to thereby determine the agreeing temperature as the true surface temperature. Accordingly, there is a problem that the calculation process for the search is complex.
As an example of prior art radiation thermometry, there is disclosed in U.S. Pat. No. 4,417,822, a laser additionally used. The reflectivity for the laser beam from the surface of the object of measurement is used for compensating for the emissivity. This method has a disadvantage in that the apparatus becomes complex and expensive because it employs a laser. Further, it is required to obtain off-line data for the measurement of the reflectivity for the laser beam. However, the data involves intricate factors related to an optical scattering phenomenon taking place on the surface. It is therefore questionable whether the off-line data can be used in the on-line measurement. Besides, since an error is produced in the on-line measurement value of the reflectivity, the error in the temperature measurement becomes great.
In U.S. Pat. No. 4,561,786, a radiation thermometrical art is disclosed using an apparatus as shown in FIG. 75.
In this art, a radiation wave is converged by a lens 813 and separated by a rotating filter 815 to obtain two-color measurement wavelengths. Outputs for the two-color wavelengths are detected by a detector 811 and secondary calculation is performed on the outputs to obtain "ratio" and "difference" therebetween. By utilizing such calculation values, the temperature calculation is performed for practical use.
Referring to FIG. 75, reference numeral 851 denotes a division block for performing a division between outputs W1 and W2 of sample and holding circuits 845 and 847. Namely, its output constitutes the "ratio". Reference numeral 859 denotes a differential amplifier for performing a subtraction between outputs of sample and holding circuits 855 and 857. The output constitutes the "difference". Reference numerals S1 to S4 denote timing signals for synchronizing the rotational position of the rotating filter 815 with the controlling system. 817 denotes a spectroscopic filter for the first wavelength and 819 denotes a spectroscopic filter for the second wavelength 841 and 843 denote amplifiers.
For the outputs from the division block 851 and the differential amplifier 859, linearizing networks 853 and 861 and resistance values R1, R2, R3, and R4 are set up after adjusting them in accordance with each object of measurement. The calculation temperature value is displayed on a meter 875.
In this method, adjustments of the linearizers 853 and 861, and resistors R1 to R4 are determined in a trial and error manner. Accordingly, the calculation method that has come into existence as a result of trial and error is not based upon theories. In fact, there is no theoretical description given.
According to this method, it is stated that temperature measurement on aluminum with surface change progressing thereon can be made with high accuracy (.+-.5.degree. C.). However, to obtain such high accuracy, a long trial and error period is required (data for setting up are not disclosed).
Because the apparatus using the above-described method has no theoretical foundation, a long period of trial and error will be required for measuring materials other than aluminum. It therefore has no general applicability.
From the standpoint of those who control manufacturing processes, such a system is preferable when not only the surface temperature is measured but also the changes in other surface physical properties are monitored (sensed) and process control is executed through feedback control with such monitored values. Surface physical properties of materials are not only directly affected by such factors as surface roughness, surface reflectivity (emissivity), surface absorptivity, and refractive index, but also greatly affected indirectly by such physical properties within the material such as oxide film thickness, galvannealed film thickness, evaporation-deposited film thickness, electric conductivity, and boundary (inter-film) refractive index. More specifically, surface physical properties are determined by the physical properties of the substance produced after reactions have taken place in the vicinity of the surface and the physical properties related to the interface between the produced substance and the base material. It may safely be said that the surface properties cannot be assumed from the direct physical properties of the surface itself. Of course, the surface properties are greatly affected by conditions of the material in process such as surface temperature, internal temperature, and their distribution.
Thus, in accurately obtaining surface physical properties of a material in process, it is preferred that not only the surface physical properties but also changes in the physical property and changes in the state within the material are sensed. For example, in the above described oxide film forming process on a silicon wafer, control of the surface physical property is only executed indirectly by controlling the furnace temperature, while blind control (without any on-line sensor) is executed as to the actual condition of the physical property of the oxide film. Naturally, statistical process errors occur. Because of difficulty of the sensing, such "blind" control is prevalent throughout general semiconductor processes and is responsible for low yield rate of semiconductors. Such situations are present not only in the field of processing semiconductors but also in the fields of processing high tech materials such as ceramics and superconductive materials. In order to improve such "blind" control, which executes indirect control of physical properties by temperature to increase the yield rate in the process, it is desired that on-line monitoring (sensing) capable of measuring changes in surface physical property of material in process is realized.


A controller for use in a vibratory mechanism includes an amplitude control circuit that generates an amplitude control signal that varies from a minimum value to a maximum value. The vibratory mechanism is adapted to vibrate at an amplitude based on an amplitude control signal characteristic. Additionally, the controller includes a frequency control circuit that is operatively coupled to the amplitude control-circuit to produce a frequency control signal that varies based on the amplitude control signal characteristic.

Vibratory work machines such as, for example, vibratory compactors are well known. Typically, vibratory work machines such as compactors for soil, gravel, asphalt, etc. include vibratory mechanisms that are configured to provide one or more frequency settings as well as one or more amplitude settings. In operation, the vibration amplitude and vibration frequency of a vibratory compactor may be varied by a user to suit a particular application. For example, the vibration amplitude and frequency suitable for compacting gravel for a road may be different from the vibration amplitude and frequency suitable for compacting soil for a footpath.
Typically, vibratory compactors include vibratory mechanisms that produce vibrations using two or more weights that rotate about a common axis. The weights are eccentrically positioned with respect to the common axis and are typically movable with respect to each other about the common axis to produce varying degrees of imbalance during rotation of the weights. As is commonly known, the amplitude of the vibrations produced by such an arrangement of eccentric rotating weights may be varied by positioning the eccentric weights with respect to each other about their common axis to vary the average distribution of mass (i.e., the centroid) with respect to the axis of rotation of the weights. As is generally understood, vibration amplitude in such a system increases as the centroid moves away from the axis of rotation of the weights and decreases toward zero as the centroid moves toward the axis of rotation. It is also well known that varying the rotational speed of the weights about their common axis may change the frequency of the vibrations produced by such an arrangement of rotating eccentric weights.
Known vibratory mechanisms, such as that disclosed by U.S. Pat. No. 3,656,419 to Boone, typically enable users to select a desired vibration frequency from one or more possible frequencies independent of the selection of a desired vibration amplitude. In some cases, the vibratory mechanism may enable a user to adjust only vibration amplitude while vibration frequency remains fixed or uncontrolled, or may enable the user to adjust only vibration frequency while vibration amplitude remains fixed or uncontrolled. Unfortunately, these known vibratory mechanisms do not establish any relationship or dependency between vibration frequency and vibration amplitude. As a result, a user may be permitted to inadvertently select a vibration frequency and amplitude combination that results in a decoupling between a vibratory mechanism and a surface being compacted by the vibratory mechanism. Further, some vibratory mechanisms may permit the user to select an operating condition in which the vibratory mechanism vibrates at a high frequency and a high amplitude, which may result in a vibratory overload (e.g., a bearing overload) within the vibratory mechanism and/or a device, machine, etc. to which the vibratory mechanism is operatively coupled. Still further, some vibratory mechanisms permit users to select one or more vibration frequencies that are coincident with natural resonant frequencies of the vibratory mechanism and/or a device, machine, etc. to which the vibratory mechanism is coupled.
The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art.


A method and device comprising an easily reworkable alpha particle barrier is provided. The easily reworkable alpha particle barrier is applied in the space between the surface of the chip and the surface of the substrate, and reduces soft error rate (SER). Further, the easily reworkable alpha particle barrier material is chosen from the group of an organic material, a hydrocarbon, more specifically a polyalphaolefin (PAO) oil, and a polymer or filled polymer; wherein the polyalphaolefin oil has a viscosity below 1000 cSt (at 100° C.). The easily reworkable alpha particle barrier material can be used with multichip modules (MCM's) allowing easy device rework of one or more dies without affecting other dies on the same substrate.

Electronic components utilizing integrated circuit chips are used in a number of applications. Controlled Collapse Chip Connection (C4 or "flip chip") is an interconnect technology developed by IBM that provides a large chip to package I/O capability. Typically, one or more integrated circuit chips are mounted above a single or multiple layer substrate and pads on the chip are electrically connected to corresponding pads on the substrate by a plurality of electrical connections such as solder bumps.
The die-attached flip chip package typically includes a gap or space between the integrated circuit chip and the substrate resulting from the overall height of the solder bump connection between the chip and the substrate or adjacent carrier. The substrate material and/or the interconnect solder can emit alpha particles. Alpha particle emissions result from the radioactive decay of impurity elements such as polonium, thorium and uranium in the substrate or the interconnect solder. The alpha particles can cause changes in both logic and memory functions of the device in close proximity to the alpha particle source. Such a disruption of the normal operation of the semiconductor devices is commonly referred to as a soft error upset (SEU) and the overall contribution to the performance of the device is described as the soft error rate (SER).
The C4 joints are susceptible to cyclic fatigue cracking due to the expansion mis-match between the chip and the underlying substrate, or carrier. In order to improve the reliability of the solder joints under cyclic field operating conditions of the package (on/off), the gap is often filled with an underfill material. The underfill material is often a particle-filled epoxy compound that enhances the fatigue life of the C4. The underfill material also helps to absorb the alpha particle radiation. The fillers in the epoxy underfills should be of high purity to assure that the underfill itself is not a source of alpha particles.
There are, however, packages that do not contain the traditional epoxy underfill and hence are susceptible to SER. These packages are typically large multi chip modules (MCMs) that require chip reworkabilty for upgrades or defective chip replacement. Removing the hardened, or cured underfill (such as the conventional epoxy underfills) for chip rework is complicated, if not impractical. There are also other packages which do not contain the epoxy underfill such as those that do not suffer from the expansion mis-match between the chip and the carrier, or those that are not subjected to large cyclic temperature excursions in field operation.
Earlier MCM packages contained thin film technology, a thin film of metal and/or a polymer such as a polyimide on the substrate, which provided the unintended benefit of absorbing the alpha radiation from the substrate. However, thin film technology tends to be very expensive. As described earlier, the use of hardened, or cured epoxy underfill makes device rework extremely difficult and economically unfeasible. Therefore, there is a need to provide an effective alpha particle barrier that is easily reworkable and cost efficient, and which minimizes or eliminates SER.

Method and device including reworkable alpha particle barrier and corrosion barrier


An optical pickup apparatus and method are provided. The apparatus and method include a light source unit having a holder in which an optical module having first and second light sources for emitting light having different wavelengths and a grating are installed, an optical path changer for changing a path of the light emitted from the first or second light sources, an object lens for focusing light passing through the optical path changer on a relatively thin disc or a relatively thick disc, and a photodetector unit. The photodetector unit includes a first photodetector having a first main photodetector, a first sub-photodetector, and a second sub-photodetector for receiving light diffracted into three beams by the grating and reflected by the relatively thin disc and converting the received light into an electrical signal, and a second photodetector having a second main photodetector, a third sub-photodetector, and a fourth sub-photodetector for receiving light diffracted into three beams by the grating and reflected by the relatively thick disc and converting the received light into an electrical signal.

1. Field of the Invention
The present invention relates to a compatible optical pickup apparatus and a method for controlling the phases of three beams. More particularly, the present invention relates to a compatible optical pickup apparatus which can simultaneously control focus offset and phases of three beams with respect to discs having different thicknesses, and a method for controlling the phases of the three beams.
2. Description of the Related Art
An optical pickup is used to record or reproduce data with respect to an optical disc and includes a light emitting portion and a light receiving portion. The light emitting portion allows light emitted from a light source to be incident on the disc. The light receiving portion allows light reflected from the disc to be received by a photodetector so that data is reproduced or a servo is performed.
Referring to FIG. 1A, a conventional compatible optical pickup apparatus includes an optical module 103 having a first light source 101 emitting light having a wavelength of about 650 nm and a second light source 102 emitting light having a wavelength of about 780 nm, a light source unit 100 having a grating 104 supported by a holder 105 and dividing light emitted from the first and second light sources 101 and 102 into three beams for performing a tracking servo or focusing servo function, a beam splitter 107 for changing a proceeding path of the light emitted from the first and second light sources 101 and 102, an object lens 113 for focusing light reflected from the beam splitter 107 on first and second discs 110 and 111, and a photodetector unit 115 for detecting light by receiving the light reflected from the first and second discs 110 and 111. A collimating lens 112 for converting incident light into a parallel beam is provided between the beam splitter 107 and the object lens 113.
The first light source 101 is used for the first disc 110 which is relatively thin while the second light source 102 is used for the second disc 111 which is relatively thick. The light emitted from the first and second light sources 101 and 102 is reflected by the beam splitter 107 and proceeds toward the first and second discs 110 and 111. After being reflected from the firs and second discs 110 and 111, the light passes through the beam splitter 107 and is received by the photodetector unit 115. The photodetector unit 115, as shown in FIG. 1B, includes a first photodetector 117 for detecting the light reflected from the first disc 110 and a second photodetector 118 for detecting the light reflected from the second disc 111. The first photodetector 117 has a four-section structure. The second photodetector 118 includes a main photodetector 118a having a four-section structure and a pair of sub-photodetectors 118b and 118c arranged on both sides of the main photodetector 118a.
The light emitted from the first and second light sources 101 and 102 are diffracted into three beams by the grating 104. A tracking error is detected using the three beams in a differential phase detecting method with respect to the first disc 110 and a three beam method or a push-pull method with respect to the second disc 111. The first photodetector 117 used for the differential phase detector comprises a four-section photodetector. Among a +1st order beam 121, a −1st order beam 122, a 0th order beam 123, which are diffracted by the grating 104, only the 0th order beam 123 is formed on the first photodetector 117. Thus, the +1st order beam 121 and the −1st order beam 122 are not used in detecting track errors of the first disc 110. Since the differential phase method, the three beam method, and the push-pull method are widely known techniques, detailed descriptions thereof are omitted.
According to the above structure, a compact disk (CD) and a digital video disk (DVD) can be compatibly recorded and reproduced using a pickup apparatus. However, during setting for the compatible optical pickup apparatus, an operation to satisfy conditions for reproducing and recording data for both CD and DVD is required. Since the CD and DVD have different data recording properties or are different in physical structure, satisfying all of the respective conditions is needed.
For this purpose, it is common to first set the conditions for the DVD and then the conditions for the CD. To obtain a recording/reproducing performance with respect to a disc, conditions such as photodetector balance (PDB), RF level, focus offset, tracking offset, and phase must be satisfied. The PDB is used to adjust the light reflected from the disc for focusing at the center portion of the photodetector. FIG. 2A shows an S curve which indicates the occurrence of a focus error signal. Preferable focusing is obtained when the S curve passes the zero point 0 such as for a curve S1. When the S curve is shifted and does not pass the zero point 0 such as for the curve S2, a focus offset is generated. Since focusing is not normally performed when the focusing offset is generated, the S curve must be adjusted to pass the zero point 0.
Since the PDB and the focus offset are the most important conditions to meet, the following descriptions will focus on these conditions only. The photodetector is moved in x and y directions to adjust the PDB of the DVD while the light source unit 100 is moved in a z direction to adjust the focus offset. Thus, the positions of the light source unit 100 and the photodetector unit 115 for meeting the optimal conditions are fixed. After the setting for the DVD is complete, the conditions for the CD need to be met. However, since the optical conditions for the DVD are already met, the conditions for the CD need to be met without changing the present state of the DVD parameters. Thus, to meet the PDB for the CD, the positions of the light source unit 100 or the photodetector unit 115 must not be changed. Considering the above, to meet the PDB for the CD, the photodetector unit 115 is rotated without changing the position of the photodetector unit 115. Since the first photodetector 117 of the photodetector unit 115 is set to be optimal for the DVD, the photodetector unit 115 is rotated by a predetermined angle θ1 with respect to the first photodetector 117 so as not to change the position of the first photodetector 117.
Next, for the tracking of the CD, a tracking error detection is performed using the three beam method. To accurately detect a tracking error, the phases of three beams must satisfy a predetermined angle, for example, 180°. The grating 104 is rotated to control the phases of three beams. The grating 104 is rotated so as not to change the position of the light source 100. In other words, since the first light source 101 is presently set to satisfy the optimal conditions for the DVD, the holder 105 is rotated by a predetermined angle θ2 with respect to the first light source 101 without changing the position of the first light source 101. When the grating 104 is rotated, as shown in FIGS. 2B and 2C, the phases of the three beams e, f, and g focused on a track 123 of the CD are controlled. In the graph of FIG. 2C, a tracking error signal by the beams e and g is shown and the phase difference between the beams e and g is 180°.
In adjusting the PDB with respect to the CD, although in the above description the photodetector unit 115 is rotated without changing the position of the first photodetector 117, the position of the first photodetector 117 practically changes. Thus, to readjust the PDB with respect to the DVD, an operation to adjust the position of the photodetector unit 115 needs to be performed. After the PDBs with respect to the DVD and the CD are repeated, an optimal PDB for both the DVD and CD can be obtained.
Also, in controlling the phases of three beams with respect to the CD, although in the above description the first light source 101 is not to be moved in the z direction when the holder 105 is rotated, the position of the first light source 101 is practically changed. Thus, to readjust the focus offset for the DVD, an operation to adjust the position of the light source unit 100 must be performed. After the focus offset for the DVD and the phases of three beams for the CD are repeatedly adjusted, optimal conditions can be obtained for both the DVD and CD.
However, in adjusting the PDB of the CD, since the effect by the rotation of the photodetector unit 115 on the PDB of the DVD is small, it is unnecessary to readjust the PDB of the DVD after adjusting the PDB of the CD, or the number of repeated adjustments is small. In contrast, when the holder 105 is rotated to control the phases of three beams for the CD, the rotation of the holder 105 greatly affects the focus offset of the DVD. Thus, since the adjustments need to be repeated to control the focusing offset of the DVD, a lot of time is required and labor efficiency is reduced.

Optical pickup apparatus and method for controlling phases of three beams