The semiconductor device includes a plurality of semiconductor chips, and a circuit substrate having a substantially rectangular outer shape. The semiconductor device is an MCM having an MCM packaging structure in which the plurality of semiconductor chips are juxtaposed on the semiconductor chip mounting surface of the circuit substrate, and the semiconductor chip mounting surface is covered by a sealing resin along an outer edge of the circuit substrate so that the plurality of semiconductor chips are sealed. The thickness of the semiconductor chip to be mounted so as to traverse a center line has a thicker thickness in a direction perpendicular to the semiconductor chip mounting surface than the thickness of any of the other semiconductor chips which is mounted on the semiconductor chip mounting surface, the center line being defined an intersection of (i) a longitudinal cross section which divides the semiconductor chip mounting surface into two in a longitudinal direction of the semiconductor chip mounting surface and (ii) a transverse cross section which divides the semiconductor chip mounting surface into two in a transverse direction of the semiconductor chip mounting surface. This enables to suppress the warpage generated in the semiconductor device, and to reduce inadequate connection occurred due to the warpage in the semiconductor device.

In resent years, high density mounting of semiconductor devices is in need for, due to the multiple functioning, downsizing, weight reduction and reduction in the thickness of portable information devices. Consequently, an MCM structure is proposed in order to meet these demands. The MCM realizes one package in which a plurality of semiconductor devices are mounted.
An example of a semiconductor device having the MCM structure is disclosed in Japanese Unexamined Patent Publication, Tokukaihei, No. 6-89962 (published on Mar. 29, 1994). FIG. 15 is a plan view illustrating the structure of a conventional semiconductor device 100, and shows the state which has not been subjected to sealing with a resin. FIG. 16 is a side sectional view of the conventional semiconductor device 100, which has been subjected to the sealing with the resin, taken along line E-E in FIG. 15.
The semiconductor device 100 includes two semiconductor chips 101, which are juxtaposed. The two semiconductor chips 101 are directly mounted on tabs 102, respectively, and the tabs 102 are linked together by a tab joining section 103. Each of the semiconductor chips 101 receives and outputs a signal, by being wire bonded with a lead 104 via a bonding wire 105. In addition, a sealing resin 106 seals the two semiconductor chips 101 and the bonding wire 105.
By thus packing the semiconductor device including an MCM structure (MCM packaging), it is not necessary for one semiconductor device (SoC (System on Chip)) to be integrated so as to have a plurality of functions. As such, it is advantageous to cost and yield rate of fabrication of the semiconductor device.
In addition, when comparing a case where a plurality of semiconductor chips, each having a respective function, are separately packaged with a case where a plurality of semiconductor chips, each having a respective function, are MCM-packaged, the latter case can have less mounting area than the former, when mounting the semiconductor chips.
However, the conventional semiconductor device 100 has the following problem. A warpage is readily generated, if the semiconductor device 100 is of a slim package with a high aspect ratio. The aspect ratio is a ratio indicated by X/Y, where X and Y are a long side and a short side, respectively, of a two-dimensional shape.
FIG. 17 is a view illustrating a warpage which is generated in an MCM-packaged semiconductor device 110. As illustrated in FIG. 17, a warpage W1 is generated in a direction perpendicular to the mounting surface on each end part of the semiconductor device 110, when the mounting surface of the semiconductor device 110 has a size of X×Y. In addition, a bending point P emerges due to this warpage.
FIG. 18 is a view illustrating a warpage generated in a semiconductor device 120, which is of a larger size than that of the semiconductor device 110 in FIG. 17. As illustrated in FIG. 18, a warpage W2 is generated in a direction perpendicular to the mounting surface on each end part of the semiconductor device 120, when the mounting size of the semiconductor device 120 has a size of 2X×Y. In addition, a bending point P emerges due to this warpage, as similar to the semiconductor device 110.
If the semiconductor device 110 in FIG. 17 and the semiconductor device 120 in FIG. 18 warp with the same curvature, the warpage W2 of the semiconductor device 120 in FIG. 18 with a higher aspect ratio will be greater than the warpage W1 of the semiconductor device 110 in FIG. 17 (W1<W2). That is to say, the warpage greatens with a higher aspect ratio, even if the curvature is the same.
However, there is a high demand for extremely thin packages, particularly from the reduction in the thickness of portable devices itself. Thus, solving the problem of warping is demanded even more.
The following two points appear to be the cause for the warpage which is generated in the MCM-packaged semiconductor device.
The first cause is that the MCM-packaged semiconductor device tends to warp concavely as a whole from the cure shrinkage of a sealing resin. Particularly, in case of a slim semiconductor device, the cure shrinkage force of the resin is greater than the rigidity of the semiconductor device. Thus, a large concave warpage occurs. In contrast, if a resin with a lower cure shrinkage force is used, a convex warpage is generated as in an MCM-packaged semiconductor device 130, as illustrated in FIG. 19.
The second cause is that the bending point of the warpage tends to be generated particularly in an area between the semiconductor chips which are juxtaposed, as illustrated in FIG. 20. FIG. 20 is a view illustrating bending points P which emerge when a warpage is generated, in a semiconductor device 140 in which three semiconductor chips 141, 142 and 143 are juxtaposed. The bending points P emerge between the semiconductor chips 141 and 142, and between the semiconductor chip 141 and 143, respectively. The warpage W3 generates at each end part of the semiconductor device 140. The warpage starts to bend from the bending points P.
The trend of the second cause appears to be based on the fact that no semiconductor chip exists. It appears that the warpage is generated from the following reasons: (i) since the area with no semiconductor chip has a great amount of resin, a great amount of cure shrinkage occurs; and (ii) the rigidity is also insufficient since there is no semiconductor chip. In addition, a warpage (W4) at the end part of a semiconductor device 150 becomes greater as the bending points P are closer to the center of the semiconductor device 150, as illustrated in FIG. 21. Specifically, the warpage for the semiconductor device 150 satisfies W3<W4.
The generation of a large warpage is likely to cause inadequate mounting. That is, a problem of inadequate connection occurs when mounting the semiconductor device to a substrate or the like, if the warpage becomes greater.
For example, in FIG. 18, the semiconductor device 120 is mounted on a mounting substrate 125, while positioning of solder balls 121 supplied to the external terminal of the semiconductor device 120 with respect to a connection pad 126 supplied with a solder paste 127 on the mounting substrate 125. If the warpage is great in the semiconductor device 120, the solder paste 127 and the solder balls 121 cannot come into contact with each other. There is a high possibility that inadequate connection would occur if the solder is melted by a reflow furnace in this state.


An insulating sheet including resin is attached to a conductor portion composed of a wiring pattern and a columnar conductor from above. Then pressure and heat are applied to the insulating sheet using the columnar conductor as a stopper to form a layer of resin having a uniform thickness with the height of the columnar conductor being a reference to cover the conductor portion. In such method for manufacturing an electronic part, a projecting portion is formed outside a part formation area. In this substrate sheet, the amount of the resin required for forming the layer is computed based on the proportion of the volume taken up by the conductor portion in a domain including the projecting portion, and the thickness of the insulating sheet is set in accordance with the computed resin amount.

Heretofore, an electronic part and a printed wiring board that have a multilayer structure produced by forming a wiring pattern on an insulating layer and stacking wiring patterns thus formed along their thickness direction have been known.
Various methods of producing such a structure have been proposed and disclosed. FIGS. 5A and 5B are diagrams illustrating steps in a conventional process of producing each layer of an electronic part.
In the step shown in FIG. 5A, a surface of an insulating layer 1 is perforated by irradiation with a layer beam. After a hole 2 is formed by the laser processing, the hole is filled with an electrically conductive paste, or a conductor portion in the form of a film or a column is formed in the hole 2 by plating.
In the step shown in FIG. 5B, conductor portions 4 are formed by plating or etching on a surface of an insulating layer 3, which has been produced in advance. After the conductor portions 4 have been formed by the above process steps, an insulating resin 5 is applied on the surface of the conductor portions 4 by spin coating (see, for example, patent document 1).
In a different known method, a bump of an electrically conductive paste is formed on wiring on a board, then an insulating material for interlayer connection and a metal layer are provided, and the bump is caused to penetrate a molded resin by a pressing process to achieve electrical connection between said bump and the metal layer (see, for example, patent document 2).
Furthermore, a method in which a via hole conductor is formed by forming a through hole by means of a carbon dioxide gas laser or other means and filing the through hole with a paste containing powder of a low resistance metal such as gold, silver, copper and aluminum has also been disclosed (see, for example, patent document 3).
Still further, a method in which an insulating layer is formed by applying a resin around a conductor post for interlayer connection and then pressing the resin with a release film having appropriate surface roughness like an emery paper disposed between (see, for example, patent document 4).
In a different method that has been disclosed, a resin layer in the A stage on which a PET film serving as a protection film is attached is disposed in contact with a surface on which an electrically conductive projection is present, and a thermosetting insulating resin layer is formed by lamination. Then, the PET film is removed, the electrically conductive projection and wirings are brought into contact with each other to form an laminated member (see, for example, patent document 5).
Furthermore, a method of producing a wiring board in which a transfer original and a base board on which wiring is to be formed by transferring are pressed together in a state in which a spacer for keeping the film thickness of an insulating rein layer to a predetermined thickness is disposed therebetween has been disclosed (see, for example, patent document 6).    Patent Document 1: Japanese Patent Application Laid-Open No. 10-22636.    Patent Document 2: Japanese Patent Application Laid-Open No. 2002-137328.    Patent Document 3: Japanese Patent Application Laid-Open No. 2002-134881    Patent Document 4: Japanese Patent publication No. 6-57455    Patent Document 5: Japanese Patent Application Laid-Open No. 2001-177237    Patent Document 6: Japanese Patent Application Laid-Open No. 11-261198
In connection with electronic parts having a multilayer structure, incorporation of an element etc. in the interior of the electronic part has been considered in order to further increase density and functions. If an element such as a passive component is to be formed between wiring patterns stacked along the lamination direction, the distance between the aforementioned wiring patterns is an important factor that determines characteristics of the aforementioned element. Accordingly, from the viewpoint of stabilization of characteristics of the element, there has been a demand for a method for manufacturing an electronic part that enables reliable control of the distance between the aforementioned wiring patterns or the thickness of each layer in the electronic part.
Nevertheless, in the above-mentioned manufacturing method shown in FIG. 5A, a conductor portion is simply formed in a hole 2 that has been formed on an insulating layer 1 by a laser processing, but the overall thickness of the layer is not controlled.
In the manufacturing method shown in FIG. 5B, an insulating resin layer is formed to cover conductor portions by applying resin by spin coating. However, undulation is created on the surface of the insulating resin in accordance with presence/absence of the conductor portions 4, and therefore it is difficult to make the overall thickness of the layer uniform.
Furthermore, in the method in which a bump of electrically conductive paste is formed on wiring on a board and then the bump is caused to penetrate a molded resin by pressing, no consideration has been made on control of the overall thickness of the layer. Still further, Japanese Patent Application Laid-Open No. 2002-134881 only teaches to form a via hole conductor by filling paste, but no consideration is made on control of the overall thickness of the layer.
In the technology disclosed in Japanese Patent Publication 6-57455, it is necessary to remove the release film from the surface of the insulating layer after completion of the pressing process. However, there is a risk that an external force will act on the surface of the insulating layer in this removing operation and deformation etc. may occur on the surface of the insulating layer. In addition, since resin is applied to cover conductor portions as with the process shown in FIG. 5B, there is a risk that undulation will be created on the surface of the insulating resin and it will be difficult to make the overall thickness of the layer.
In the technology disclosed in Japanese Patent Application Laid-Open No. 2001-177237 also, an external force acts on the thermosetting insulating resin layer when the PET film is removed, and therefore, there is a risk that deformation may be created on the surface of the thermosetting insulating resin layer, as with the technology disclosed in the above-mentioned patent document. Accordingly, it might be difficult to make the overall thickness of the layer uniform.
In the method of setting the thickness of a layer by inserting a spacer as disclosed in Japanese Patent Application Laid-Open No. 11-261198, although it is possible to set the layer thickness, it is difficult to achieve connection between layers by a conductor portion at a predetermined position.
In such manufacturing methods, it has generally been desired, in order to reduce the manufacturing cost, to reduce the amount of the material used, namely to reduce surplus of the resin used for forming insulating layers.

Method for manufacturing an electronic part


Hot runner nozzle assembly including a mold assembly with a mold cavity therein, an inlet port in the mold assembly communicating with the mold cavity, an injection nozzle for delivering molten resin to the inlet port and an insulating sleeve positioned around the nozzle between the mold assembly and nozzle insulating the nozzle from the mold assembly.

The present invention resides in a leak proof nozzle assembly in a hot runner injection molding apparatus.
Hot runner nozzle tips may include single or multiple outlet channels for feeding molten resin to a mold cavity in an injection molding system. The hot runner nozzle tips are generally spaced from the injection gate leading to the mold cavity. The spacing is necessary to avoid direct contact between the cooled mold cavity by the heated nozzle tip in order to prevent the nozzle tip from rapidly cooling. Rapid cooling of the nozzle would cause the resin to freeze up and render the nozzle inoperable. In addition, if the nozzle tip is heated from a cold condition to its operating temperature, generally 350.degree.-450.degree. F., space must be provided for thermal expansion which results in the nozzle and the nozzle tip growing in length.
Conventional hot tip designs usually provide a bubble or resin space surrounding the tip and filled with resin. The resin in the resin space has poor thermal conductivity compared to steel and effectively insulates the hot tip from the cooled mold cavity. U.S. Pat. No. 4,312,630 is an example of this design and shows the heated tip insulated from the mold cavity by a bubble well or resin space. Since the resin in the bubble well is subjected to high injection pressure (around 20,000 psi) it must be effectively sealed. This is accomplished in U.S. Pat. No. 4,312,630 by the close fit between the nozzle shell and the sides of the well.
This method of sealing is not entirely satisfactory and was further improved by making the sealing flange of the nozzle from a separate material, generally titanium, so that less heat would be conducted from the heated nozzle body to the mold cavity. Examples of this are shown in U.S. Pat. Nos. 4,053,271, 4,557,685, 4,768,945 and 4,771,534. The sealing action is achieved while permitting the longitudinal thermal expansion of the nozzle to occur unrestricted. The sealing rings will slide within the cylinder bores of the bubbles and wilI deform inwardly to maintain the seal. Furthermore, the internal injection pressure of the resin acting on the nozzle surface of the seal tends to urge the skirt of the seal against the sides of the bubble walls to enhance the sealing action.
It was soon realized, however, that the comparatively large volume of resin contained in the bubble or resin space tended to remain there indefinitely. Some resins could tolerate this extended dwelling time at their processing temperatures, but others could not. The resins which could not tolerate the extended elevated temperature dwell are known as heat sensitive resins and soon degrade when exposed to extended periods of time at their normal processing temperatures. Typical of these heat sensitive resins are polyacetal, polyvinyl chloride and polyethylene terephthalate.
In order to solve this problem, sealing arrangements were developed to minimize and in some cases entirely eliminate the bubble or resin space while at the same time attempting to maintain good thermal insulation between the nozzle tip and the mold cavity and also to provide space for thermal expansion of the nozzle tip. Examples of these designs are shown in U.S. Pat. Nos. 4,043,740, 4,286,941, 4,344,750 and 4,981,431. In these cases, small titanium seals are used to locally contain the melt channel between the nozzle and the mold cavity gate. However, the disadvantage of these designs is that they all employ titanium alloy seals. Although titanium has almost a quarter of the thermal conductivity of steel, it does not compare as well to the insulating properties of resin or air, the other materials used for insulation in nozzle construction. Therefore, while solving the resin degradation problem, these designs required more heat energy to be provided in order to render them effectively operable. Furthermore, the small seals were usually required to deflect in order to insure an effective seal. Due to imperfect manufacturing methods, the required sizes of the seals, bubble dimensions and other variables meant that some seals were deformed beyond their elastic limit and failed while others did not make contact at all. In both cases, resin leakage would occur.
U.S. Pat. Nos. 4,662,837 and 4,682,945 show another approach to the sealing problem. In these cases, a high temperature plastic seal is used to effect the seal between the nozzle and the mold cavity. Typically, plastic has thirty times less thermal conductivity than titanium alloys. However, the high temperature seal may be subject to cracking and degradation caused by high molding pressure and high processing temperatures. Further approaches are shown in U.S. Pat. Nos. 4,161,386, 4,266,723 and 5,028,227.
Accordingly, it is a principal object of the present invention to develop an effective hot runner nozzle assembly using a heated injection nozzle and a cooled mold cavity communicating therewith. It is a further object of the present invention to develop an improved hot runner nozzle assembly as aforesaid which is leak proof, conveniently prepared and easy to use in practice.
It is a still further object of the present invention to develop an improved hot runner nozzle assembly as aforesaid which enables expansion of the nozzle, uses a resin space or bubble adjacent the nozzle tip and is not subject to resin degradation in the resin space.
Further objects and advantages of the present invention will appear hereinbelow.


A signal detector has a SQUID, a bias current supply circuit for supplying a bias current to the SQUID, and a drive circuit for detecting a magnetic flux by receiving a voltage signal of the SQUID and reading out the input signal as an output voltage. The drive circuit has two systems including a flux-locked loop system for converting a voltage signal of the SQUID into a current signal and making a magnetic flux inside the SQUID constant by feeding back a signal whereto, and an output system separate from and operating independently of the flux-locked loop system for converting a voltage signal of the SQUID and reading out the converted voltage signal without feeding back a signal to the SQUID.

The present invention relates to a signal detector for detecting weak (or small) magnetic fields, electrical currents, voltage, electromagnetic wavers, etc. using a superconducting quantum interference device, which is a highly sensitivity magnetic sensor, and to a measuring method therefor, and more particularly relates to a broadband detector for measuring a high speed signal.
FIG. 6 shows an equivalent circuit diagram of a direct-current superconducting quantum interference device (hereafter referred to as a DC-SQUID). The DC-SQUID forms a superconducting ring using a SQUID inductance 2 and a pair of Josephson junctions 1 connected to the two ends of the SQUID inductance 2. A modulation coil 3 is magnetically coupled to the superconducting ring. An input coil 4 for inputting a signal is also magnetically coupled to the superconducting ring.
The DC-SQUID is a magnetic flux-voltage transducer for periodically converting voltage Vs on both ends of the superconducting ring to a single magnetic flux quantum ("PHgr"0: 2.07xc3x9710xe2x88x92‥Wb) for a magnetic flux "PHgr" mixed inside the superconducting ring. With a constant bias current supplied to the DC-SQUID, the magnetic flux-voltage characteristic is shown in FIG. 2A. As shown in FIG. 2A the DC-SQUID has high sensitivity to magnetic flux, but this response is non-linear and the dynamic range is narrow. In the case of low frequency measurement, in order to obtain sufficient linearity and timing a Flux locked loop (FLL) method, being a type of null-balance method, is used to drive the SQUID. However, the FLL method constructs a closed loop circuit, which means that with broadband over 1 MHz stable drive is difficult due to going out of lock etc. With broadband measurement, it is also possible to utilize a method where the SQUID is driven by an open loop circuit having a simple circuit structure.
FIG. 7 is a schematic diagram of a signal detector using a superconducting quantum interference device with an open loop circuit of the related art. This detector is comprised of a bias current supply circuit 6 for applying bias current I, a broadband amplifier circuit 7 for amplifying a voltage Vs of the DC-SQUID 5, and a modulation circuit 12 for moving operation points on the magnetic flux-voltage curve to given positions. The modulation circuit 12 supplies a modulation signal Im to the SQUID through a modulation coil 3. At that time, using the magnetic flux-voltage curve of FIG. 2A, the magnetic flux-voltage conversion coefficient is adjusted so as to be fixed at point A on a rapidly changing part of the graph. Voltage Vo that has been amplified by the amplifier circuit 7 is output as output voltage Vout, and the magnetic flux-voltage conversion coefficient, as well as an input signal from the mutual inductance between the input coil and the SQUID loop, are obtained.
In the case of using an open loop circuit, the structure of a drive circuit becomes simple, and high speed signal measurement becomes easy. However, due to external causes, such as environmental magnetic noise, source noise etc., there is movement of the operating points on the magnetic flux-voltage curve. Because of this movement of the operating points, there is a problem that the magnetic flux-voltage conversion coefficient required in obtaining the input signal from the output voltage also changes.
Also, since there is no linear region in the magnetic flux-voltage characteristic of the SQUID, there is a problem that it is not possible to accurately obtain the input signal from the output voltage.
A drive circuit for magnetic flux detection for reading out an input signal as an output voltage is made up of two systems, one being a flux-locked loop system for converting a voltage signal of the superconducting quantum interference device to a current signal and making magnetic flux inside the superconducting ring constant by feeding back a feedback signal to the modulation coil, and another being an output system for converting a voltage signal of the superconducting quantum interference device to a voltage signal, and not feeding back to the modulation coil but reading out the converted voltage signal as an output voltage.
Also, the frequency band of the flux-locked loop system is narrower than the frequency band of the output system.
The frequency band of the flux-locked loop system can also be controlled to take a given value. Further, a method of using the inventive device comprises the steps of measuring a flux-voltage curve of the superconducting quantum interference device before measuring an input signal, and converting an output signal obtained from the output system of the drive circuit into an input signal by comparison with the flux-voltage curve.

Signal detector using superconducting quantum interference device and measuring method therefore


In one embodiment, an add-on pre-scanner card is removably pluggable into a local bus of a computer. The add-on pre-scanner card may be coupled to a computer network to receive network traffic. The add-on pre-scanner card may be configured to extract payloads from received packets and scan the payloads for computer viruses. The add-on pre-scanner card may pass scanned payloads and other data to the computer by way of a shared memory interface. The pre-scanner card may identify each payload as infected with a virus, virus-free, or unknown to allow the computer to distinguish payloads that do not need further scanning from those that do. The computer may further scan for viruses payloads that the pre-scanner card cannot ascertain as either virus free or virus infected.

1. Field of the Invention
The present invention relates generally to computer networks, and more particularly but not exclusively to network security apparatus.
2. Description of the Background Art
Computer viruses, worms, Trojans, and spyware are examples of malicious codes that have plagued computer systems throughout the world. Although there are technical differences between each type of malicious code, malicious codes are collectively referred to herein as "viruses" for ease of illustration and compliance with common usage.
The Internet and similar public networks enable viruses to spread quickly to infect a large number of computers. As a precautionary measure against viruses, private computer networks may deploy a virus scanner between its computers and the Internet. Currently available in-line virus scanners perform either store-scan-forward scanning or stream scanning. Store-scan-forward scanning is typically implemented in software using a complex file-based scanner. A complex file-based scanner stores received incoming data, waits to receive all of the data comprising a file, scans the file for viruses once all of its data are received, and forwards the data to its destination assuming no viruses are found in the file. Being implemented in software, store-scan-forward scanning provides great flexibility, is easily extensible, allows for high virus detection rate with relatively low false positives (i.e., erroneous detection of a virus) and low false negatives (i.e., failure to identify a virus). However, relying on a software implementation yields relatively slow performance, resulting in excessive, sometimes unacceptable, processing delays.
Stream scanning, also referred to as "cut-through" scanning, receives, scans, and forwards data on non-file data units, typically on packet levels. Scanning commences as soon as a number of data units become available, and scanned data units are immediately forwarded out to their destination assuming no viruses are found. This way, data receiving, scanning, and forwarding occur concurrently, allowing for faster throughput compared to store-scan-forward scanning. Stream scanning, whether implemented in hardware or software, provides performance advantage that is noticeable by the end-user. However, stream scanning has relatively low virus detection capability because only forward scanning is possible, and has higher rates of false positives and false negatives. In addition, hardware based implementations often rely on less sophisticated scanning algorithms that open up the network to virus attacks.

Pre-scanner for inspecting network traffic for computer viruses


A spacer for a windshield wiper includes an anchoring member, a cylindrical shaft, a biasing device, a bracing stand, and a retaining device. The anchoring member is to be mounted on the wiper blade seat and has a shaft accommodation hole. The shaft is inserted into the hole and is rotatable relative thereto but is not movable in an axial direction. The shaft includes an enlarged head exposed outwardly of the hole and is formed with a radially and outwardly projecting pivot pin that extends into a bearing hole in the bracing stand, thereby mounting the bracing stand on the shaft. The biasing device is sleeved on the shaft to bias the latter to rotate in a clockwise direction. The retaining device retains the bracing stand against rotation by the biasing device once the lower portion of the bracing stand is moved toward the windshield wiper to abut against the windshield so as to space the windshield wiper from the windshield against the urging action of the wiper arm.

1. Field of the Invention
The invention relates to a spacer, more particularly to a spacer which is adapted to be mounted on a windshield wiper so as to position and space apart the windshield wiper from a windshield of a car when the windshield wiper is not in use.
2. Description of the Related Art
A conventional windshield wiper is usually mounted on the windshield of a car and is urged by a wiper arm to abut against the windshield for wiping rain water therefrom. The windshield wiper includes a wiper blade seat mounted pivotally on the wiper arm, and an elongated wiper blade disposed on and attached to the wiper blade seat. The wiper blade is formed with an elongated wiper blade rubber element which abuts against the windshield such that when left unattended or unused for a relatively long period of time, dirt may accumulate on the windshield and the rubber element. When actuated, the rubber element may cause scratches on the windshield, thereby resulting in poor visibility through the windshield.


A multi-function care bed is disclosed including a flatbed having a plurality of panels foldable between a first configuration in which the plurality of panels are adapted to support a person in a horizontal position, and a second configuration in which the plurality of panels are adapted to form a chair to support the person in a seated position. The multi-function care bed also includes a bed frame configured to support the person on a mattress, the bed frame being movable between a first position in which the bed frame substantially overlies the flatbed, and a second position in which the plurality of panels of the flatbed are exposed so as to allow transfer of the person between the bed frame and the flatbed. The multi-function care bed also includes a body movement system in which a group of arms lift, lower, roll, or massage the person.

For bedridden people, toileting, showering, and avoiding bedsores are some of the most difficult tasks to accomplish independently. Solutions for these issues differ depending on the level of the physical impairment of the bedridden person. It is understandable that someone who loses almost all movement capability must get a nurse's help.
Care beds are known that have showering envelopes, water collectors, or hoses, in which the bedridden person can remain in bed to accomplish these activities. Although these known care beds provide help to the bedridden person and to the nurse caring for that person, such care beds are still inconvenient in practice.
In some care beds, the mattresses or beds have openings for patients to do toileting. This type of bed needs to be customized. In addition, bedding on top of the mattress often gets contaminated during the toileting process. With the opening and contamination, patients often feel uncomfortable compared to a normal sleeping environment.
In another known care bed system, a shower bath uses a mattress that is put into a tub. The mattress can move vertically to help the patient get into and out of the water.
Another type of shower bath tub is known which contains a toilet seat inside the tub. The water closet function is provided without increasing the space requirement relative to conventional shower-bathtubs, and feces cannot block the shower water discharge. However, transferring the patient to the bath tub in the above two cases is still significant work for the nursing staff.
In some other systems, showering/bathing envelopes are provided in which a person can be laid down while the caretaker washes the person's body. Issues with such a device include: 1) the person must be transferred to the bathing envelope; and 2) watching and contacting the cared person's body during the bathing process are necessary, which makes some people uncomfortable.
A three-section mattress or platform is included in other systems, in which the mattress or platform can turn into a chair for showering or using a toilet. Such mattresses or platforms, however, have a waterproof surface which is good for showering or toileting, but is not good for long-term sleeping as comfortably as on a common mattress or a bed with dry and soft bedding.
Bedsores are another issue for many bedridden patients. One way to reduce bedsores is to use a mattress that has one or both sides which can rise under mechanical or electrical drive, as seen on today's market, which rolls the patient to the left or right, but nursing help is also sometimes needed.

Multi-function multi-configuration care bed for enhanced patient comfort and caregiver convenience


A zoom lens includes, in order from its object side, a first lens unit having a negative refracting power, a second lens unit having a positive refracting power, a third lens unit having a negative refracting power, and a fourth lens unit having a positive refracting power. The zoom lens further includes an aperture stop disposed between the first lens unit and the third lens unit. During zooming from the wide angle end to the telephoto end, distances between the lens units change, the first lens unit moves first toward the image side and thereafter toward the object side, the second lens unit moves in such a way as to be located closer to the object side at the telephoto end than at the wide angle end, the distance between the second lens unit and the third lens unit is larger at the telephoto end than at the wide angle end, and the aperture stop moves in such a way as to be located closer to the object side at the telephoto end than at the wide angle end. The second lens unit and the third lens unit satisfy certain conditions.

1. Field of the Invention
The present invention relates to a zoom lens. The present invention further relates to an image pickup apparatus, such as a digital camera and video camera, equipped with a zoom lens and an image pickup element.
2. Description of the Related Art
In recent years, digital cameras have replaced film cameras to become the mainstream in the technical field of the image pickup apparatus. Digital cameras have image pickup areas that are generally smaller in size than those of film cameras, and therefore a reduction in the size of digital cameras can be achieved more easily. Nowadays, since there is the trend that a higher importance is placed on the portability as compared to the past, the sizes of digital cameras have been made smaller. Furthermore, since consumers wish to enjoy easy shooting in both indoor and outdoor shooting situations, increases in the angle of view and increases in the zoom ratio of zoom lenses used as the optical systems of digital cameras are needed.
Various zoom lenses have been developed in the past with a view to achieve a smallness in size, a wide angle of view, and a high zoom ratio. For example, Japanese Patent Application Laid-Open Nos. 2006-208889 and 11-84242 disclose negative-front type zoom lenses in which the lens unit located closest to the object side has a negative refracting power. The negative front type zoom lens like this has a retro-focus type overall refracting power arrangement, which is more advantageous in achieving a large angle of view at the wide angle end as compared to the positive-front type zoom lens, and also advantageous in achieving smallness in the overall size of the zoom lens by virtue of a reduction in the size of the lens unit closest to the object side.
The zoom lenses disclosed in Japanese Patent Application Laid-Open Nos. 2006-208889 and 11-84242, mentioned above byway of example, include, in order from the object side thereof, a first lens unit having a negative refracting power, a second lens unit having a positive refracting power, a third lens unit having a negative refracting power, and a fourth lens unit having a positive refracting power, wherein during zooming from the wide angle end to the telephoto end, the second lens unit and the third lens unit are moved toward the object side.


A thermal image transfer recording medium is composed of a support, a thermal image transfer ink layer formed thereon, and a heat resistant protective layer which is composed of a cellulose-modified polymer with a backbone polymer thereof being cellulose and/or a cellulose derivative and a branch polymer thereof being a copolymer of a reactive silicone oil and a vinyl monomer, and which is formed on the back side of the support opposite to the thermal image transfer ink layer with respect to the support.

1. Field of the Invention
The present invention relates to a thermal image transfer recording medium, which is free from sticking phenomenon and blocking phenomenon, and has excellent preservability and printing performance.
2. Discussion of Background
In a conventional thermal image transfer recording system, an image receiving sheet is superimposed on a thermal image transfer recording medium which comprises a support and a thermal image transfer ink layer formed thereon in such a manner that the image receiving sheet is brought into pressure contact with the thermal transfer ink layer, a thermal head is brought into contact with the back side of the support which is opposite to the thermal image transfer ink layer, and the thermal head is heated with the application of a pulse-shaped signal current thereto, whereby the thermal image transfer ink layer is imagewise fused or sublimated to form images on the image receiving sheet.
In a thermal fusing image transfer system, in particular when black color printing is performed, a thermal image transfer recording medium with an ink layer which contains carbon black is employed.
Furthermore, in the case of color printing, three separate thermal transfer recording media with primaries, yellow, magenta and cyan, are prepared and colored images are printed by successively superimposing these thermal transfer recording media on an image receiving sheet.
In a thermal sublimation image transfer system, the amount of a sublimable ink to be sublimated is controlled by the amount of thermal energy applied thereto by a thermal head, so that image density gradation printing can easily be performed. Specifically, images with high density can be printed by increasing the voltage to be applied to the thermal head or the length of the application time of the current pulses applied thereto, and images with low density are printed by decreasing the voltage to be applied to the thermal head or the length of the application time of current pulses. Color printing can be performed in the same manner as by the thermal fusing image transfer system, and color printing with image density gradation can be performed by changing the amount of thermal energy applied by the thermal head.
As the material for the support of a thermal fusing image transfer medium and a sublimation type thermal image transfer medium, plastics films such as a polyethylene terephthalate (PET) film are in general use. However, when plastics films such as a PET film are employed as the support, a portion of the film with which a thermal head comes into contact is fused by the heat applied thereto through the thermal head, and is stuck on the thermal head during an image transfer step. The result is that the recording medium cannot be transferred at a stable speed. When this sticking phenomenon takes place, not only the printing quality is considerably degraded, but also the fused film makes a big noise when it is peeled away from the thermal head, or the transportation of the recording medium is stopped by the thermal head to which the fused film adheres, or the recording medium is broken by the thermal head.
In order to prevent this sticking phenomenon, there have been proposed various methods of providing a heat resistant protective layer on one side of the support of the recording medium with which a thermal head comes into contact, that is, on the side opposite to the thermal image transfer ink layer.
For example, Japanese Laid-Open Patent Applications 55-7467 and 63-172688 propose the provision of a heat resistant protective layer comprising silicone resin, epoxy resin, melamine resin, phenolic resin, fluorine plastics, polyimide resin, polyamide resin, or cellulose resin, on one side of the support.
Furthermore, Japanese Laid-Open Patent Application 60-201989 proposes the provision of a heat resistant protective layer comprising an aromatic polyamide; and Japanese Laid-Open Patent Application 63-203387 proposes the provision of a heat resistant protective layer comprising an aromatic polysulfone resin.
These heat resistant protective layers, however, cannot prevent the occurrence of the sticking phenomenon sufficiently for use in practice, and when a thermal image transfer recording medium with such a heat resistant protective layer is preserved in the form of a roll, the heat resistant protective layer and the thermal image transfer ink layer of the thermal image transfer recording medium stick together, that is, the so-called blocking phenomenon takes place.
When such a blocking phenomenon takes place, the thermal image transfer recording medium in the form of a roll cannot be transferred smoothly, and ink components from the ink layer are transferred to the heat resistant protective layer and fixed thereon, and are then transferred to, deposited on, or fixed on a heating element portion of a thermal head and its vicinity, so that printing quality obtained is significantly degraded.
Japanese Laid-Open Patent Application 61-143195 proposes the provision of a back coat layer (i.e. a heat resistant protective layer) which comprises a silicone graft copolymer or a block acrylic copolymer. The back coat layer comprises a silicone graft copolymer or a block acrylic copolymer and has excellent slip properties, and therefore an ant-sticking performance, and excellent heat resistant performance and anti-blocking performance. However, the silicone graft copolymer and block acrylic copolymer are poor in film formation properties, so that when continuous printing is performed, the surface portion of the back coat layer comprising such a copolymer is scraped therefrom by a thermal head, and scraped components from the back coat layer are fused and adhere to a heating element of the thermal head and its vicinity. As a result, the printing quality obtained is significantly degraded in the same manner as when the blocking phenomenon takes place. In order to obtain excellent printing quality, the thermal head must be cleaned very frequently, but this is troublesome.
Furthermore, Japanese Laid-Open Application 1-221281 proposes a thermal image transfer recording medium with the provision of a heat resistant protective layer comprising an ethyl cellulose resin with the addition of silicone oil and/or additives such as a surfactant on an ink layer. This method, however, has the shortcoming that the silicone oil and/or additives such as a surfactant are transferred to the ink layer while the recording medium is allowed to stand at high temperatures or preserved for a long period of time, and the transferred silicone oil and/or additives to the ink layer cause non-uniform image transfer and imperfect image transfer with the formation of non-printed portions, so that obtained printing quality is significantly degraded. This shortcoming is the same as that of a method of providing a resin layer which contains, for instance, a solid or semi-solid surfactant, which is disclosed in Japanese Laid-Open Patent Application 57-129789.
Japanese Laid-Open Patent Application 1-234292 discloses the provision of a heat resistant protective layer comprising an acetate-group-containing cellulose ester resin or this cellulose ester resin with the addition of silicone oil thereto. This protective layer, however, still has the same shortcomings as in the heat resistant protective layers disclosed in Japanese Laid-Open Patent Applications 55-7467 and 63-172688, and Japanese Laid-Open Patent Application 1-221281.
As mentioned above, varieties of a heat resistant protective layer for a thermal image transfer recording medium have been proposed, but most of them still have the shortcomings that transfer performance becomes poor, a thermal head is abraded, the support of the recording medium is broken, which degrades printing quality, when printing is carried out continuously for an extended period of time; and the anti-blocking performance and prevention of the formation of thermal head dust are insufficient for use in practice.