Supports: cabinet structure – For particular electrical device or component
Reexamination Certificate
1999-04-20
2002-03-05
Hansen, James O. (Department: 3636)
Supports: cabinet structure
For particular electrical device or component
C312S007200, C348S794000
Reexamination Certificate
active
06352322
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a portable liquid crystal display device and, particularly, to a portable liquid crystal display device used for a portable liquid crystal television receiver, a portable liquid crystal monitor and the like devices. If described in further detail, the invention relates to the structure of a case such as a battery compartment cover or a stand for a portable liquid crystal display device.
BACKGROUND ART
Portable liquid crystal display devices for displaying image on a liquid crystal panel are light in weight, small in size, small in thickness and consume decreased amounts of electric power compared to the conventional display devices that display image on a cathode-ray tube. Because of these advantages, therefore, the portable liquid crystal display devices have, in recent years, been used in a variety of fields as multi-media equipment such as monitors, television receivers, PDAS (personal digital assistants) and the like.
In many cases, such a small portable liquid crystal display device is better watched when the image display unit is slightly tilted upward from the uprightly erected state. Therefore, the case of the portable liquid crystal display device is usually provided, on its back surface side, with a stand for standing the liquid crystal display device in a tilted state. The stand is of the swing type having a rotary shaft provided at one end thereof, and the rotary shaft is attached to a bracket provided on the back surface of the case or to a shaft hole. As required, the stand is drawn out with a swinging motion from the case, and is held in a state of being opened by a predetermined angle, so that the display device is stood in a tilted state. Furthermore, a recessed portion for holding the stand is often formed in the case on the back surface side. In such a display device, a stand that is not in use is held integrally with the case.
Batterys have been used as a power source for the portable liquid crystal display device and, hence, a battery-holding portion is formed in the case on the back surface side for holding the batterys. Usually, the battery-holding portion is covered with a battery compartment cover. At the time of renewing the batterys only, the battery compartment cover is removed from the case to open the battery-holding portion and to renew the batterys. The battery compartment cover usually slides with respect to the case.
It has been attempted to realize the portable liquid crystal display device in a small size and in a reduced weight, so that it can be easily carried. As for decreasing the size, in particular, efforts have been made to decrease the thickness as it is a tendency to increase the size of the liquid crystal display screen.
When the portable liquid crystal display device is realized in a decreased thickness, however, a problem arises in that the battery compartment cover and the stand provided in the back surface of the case interfere with each other. When there is a margin in the area on the back surface of the case, the battery compartment cover and the stand can be located on different positions in the direction of the surface as disclosed in, for example, Japanese Unexamined Utility Model Publication (Kokai) No. 63-131173. As the margin in the area on the back surface of the case decreases, however, the stand that is closed tends to overlap the battery compartment cover, making it difficult to decrease the thickness of the device.
When the liquid crystal display device is not operated for extended periods of time with the batterys loaded in the battery-holding portion, the battery-holding portion and the vicinities thereof are adversely affected by the corrosion of the batterys. When the liquid crystal display device is not used for extended periods of time, therefore, the user often removes the batterys from the battery-holding portion. However, if the user goes out carrying the liquid crystal display device with him without the batterys in the battery-holding portion, the liquid crystal display device will not work.
To prevent this, a portable liquid crystal display device has been proposed in which a window is formed in the battery compartment cover enabling the batterys in the battery-holding portion to be viewed from the external side without the need of opening the battery compartment cover (Japanese Unexamined Patent Publication (Kokai) No. 10-123488). According to this portable liquid crystal display device, furthermore, it has been attempted to decrease the thickness by overlapping the stand on the battery compartment cover.
In this portable liquid crystal display device, however, the window formed in the battery compartment cover is located at a portion where the stand and the battery compartment cover are overlapped one upon the other, and the presence of the batterys cannot be confirmed unless the stand is withdrawn from the case.
Furthermore, technology has been developed to decrease the thickness of the portable liquid crystal display device so as to approach, as much as possible, the diameter of the dry batterys which constitute the power source. This structure in which a dent is formed in the case on the back surface side thereof to hold the stand in the dent, pertains to the attempt for decreasing the thickness of the display device.
In the conventional portable liquid crystal display device, however, the battery compartment cover that slides relative to the case, as described above, makes it difficult to decrease the thickness. That is, the thickness from the outermost end surface of the stand to the side surfaces of the batterys held in the case, equals the sum of the thickness of the stand, the thickness of the battery compartment cover, and a gap to prevent an engaging hook from interfering with the batterys at the time when the battery compartment cover is slid, the engaging hook being provided on the inside of the battery compartment cover for securing the battery compartment cover to the case. This gap prevents decreasing the thickness.
Moreover, when attached to the case, the battery compartment cover may develop a play as it can be strongly depressed repetitively by finger tips during the use for extended periods of time, causing the engaging hook to be damaged or worn out, or due to dispersion in the quality of the engaging hook during the molding.
Furthermore, the above-mentioned stand is attached to the case by the rotary shafts at the ends of deflection arms formed by kerfs. When the stand is abruptly drawn out from the case or when the display device is accidentally fallen with its stand being drawn out, cracks may develop at the bottoms of the kerfs often resulting in damage.
In a practical display device, furthermore, the batterys are not, in many cases, arranged at the central portion of the display device, and the center of gravity of the device is often greatly deviated toward either the right or the left. Besides, when an antenna provided on one side on the back surface of the case of the display device is extended, the center of gravity of the display device is further greatly deviated depending upon the direction in which the antenna extends. Therefore, the position and shape of the stand attached to the case must be so contrived that the display device does not fall sideways even in the above-mentioned cases.
In the above-mentioned portable liquid crystal display device, on the other hand, a display window for viewing the image displayed on the liquid crystal panel is formed on the front surface side of the case, and a windshield (transparent dust cover) is usually arranged in the periphery of the display window to protect the liquid crystal panel. The windshield is in the form of a flat plate being made of a transparent glass or resin. The windshield is often printed to indicate display channels and the like.
In order that the windshield does not protrude beyond the case, a recessed portion is formed along the periphery of the display window for arranging the windshield, the recessed portion being lower than the surface of the case. The wind
Citizen Watch Co. Ltd.
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Hansen James O.
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