1. Field of the Invention
The present invention relates to a lamp holder, a backlight device using the same, and a display using the same.
2. Description of the Related Art
For example, a liquid crystal panel used for a liquid crystal display such as a liquid crystal television additionally requires a backlight device as an external lamp because it does not spontaneously emit light. The backlight device is placed on a backside of the liquid crystal panel, and broadly includes a base made of a metal with an open surface at the side of the liquid crystal panel, a number of cold cathode tubes housed in the base as lamps, and a number of optical members (diffusion sheets and the like) which are arranged in an open portion of the base to efficiently irradiate light, which is emitted by the cold cathode tubes, to the liquid crystal panel side, and includes lamp clips for holding the cold cathode tubes, each having a slim tubular shape with respect to the base.
An example of the lamp clips as described above can be found in Japanese Patent Laid Open No. 2001-210126. The lamp clips of this invention are made of a synthetic resin, and the invention includes a mounting plate which is applied to an inner surface of the base, a locking part which is protruded to the base side from the mounting plate, is inserted into a mounting hole of the base to be capable of being locked to its peripheral edge, and a lamp holding part which is protruded to the side opposite from the locking part from the mounting plate to be capable of holding the cold cathode tube so as to surround the peripheral surface of the cold cathode tube. The lamp holding part has a C-shaped sectional configuration which is opened upward, and is elastically deformable so as to open outward during attachment and detachment of the cold cathode tube.
Incidentally, typically there is a variation in the thickness of the cold cathode tube that cannot be prevented due to a manufacturing error. Thus, setting the size of the lamp holding part which holds such a cold cathode tube can be problematic.
If the size of the lamp holding part is set with the thickest cold cathode tube in tolerance as a reference, the clearance which occurs between the lamp holding part and the cold cathode tube becomes too large when a relatively thin cold cathode tube is mounted, and large backlash occurs to the cold cathode tube.
If the size of the lamp holding part is set with the thinnest cold cathode tube in tolerance as the reference in contrast with the above-described situation, the force which is required for opening and deforming the lamp holding part becomes too large when a relatively thick cold cathode tube is mounted. Even if it is mounted, the elastic rebound force of the lamp holding part becomes too large, and therefore, there arises the problem that the cold cathode tube is urged in the detaching direction by the elastic rebound force and the cold cathode tube is easily detached, and in short, this setting method is not favorable with respect to attaching and detaching operability and holding performance. Nevertheless, there are limitations in the molding technique and strength in molding the lamp holding part to be thin in order to reduce the elastic rebound force of the lamp holding part, thus bringing about difficulties in coping with this situation.