Illumination assist device and electronic device using the same

An illumination assist device used for an electronic device having a flash lamp includes an optical plate and a cover. The optical plate is positioned between the flash lamp and the cover. The cover includes a light transmission board and a plurality of reflection sidewalls extending from a periphery of the light transmission board. The optical plate is surrounded by the plurality of reflection sidewalls. The invention also provides an electronic device using the illumination assist device.

BACKGROUND

1. Technical Field

The present disclosure relates to illumination assist devices, and particularly, to an illumination assist device used in an electronic device.

2. Description of Related Art

Electronic devices, such as cell phone and personal digital assistant (PDA), have become increasingly popular in recent years. Such electronic devices are usually carried by users at all time for them convenience and multifunction capabilities. Although the electronic devices provide many different features, other external devices may also be applied to work with the electronic devices to provide more features. For instance, the user may wish to use the electronic device to perform tasks that require an additional lighting, such as functions of a flashlight.

A typical electronic device includes a housing, a light emitting diode (LED) positioned in the housing for lighting, a battery to provide power to the LED, and a switch to control the LED. However, the LED of the electronic device has a poor brightness.

Therefore, there is room for improvement within the art.

DETAILED DESCRIPTION

FIGS. 1 and 2show an exemplary electronic device300includes an illumination assist device100and a main body200. The electronic device300includes a camera210positioned in the main body200and a flash lamp215positioned in the main body200adjacent to the camera210. The flash lamp215is used to provide flash lighting for photography. In this embodiment, the electronic device300is a mobile phone, and the flash lamp215is a xenon photoflash. The flash lamp215can also function as a flashlight, where the flash lamp215can be powered on constantly. The illumination assist device100includes an optical plate10, a cover20, a frame30, and a fixing member40.

The optical plate10is substantially a rectangular cube, and is made of transparent materials, such as polymethyl methacrylate (PMMA), polycarbonate (PC), polystyrene (PS), copolymer of methylmethacrylate and styrene (MS), and any suitable combinations thereof. The optical plate10includes a light input surface11, a light output surface12opposite to the light input surface11, and a plurality of parallel V-shaped protrusions121extending outward from the light input surface11. Each V-shaped protrusion121has a triangular cross-section taken along a line parallel to the light input surface11. Each cross-section of the protrusions121has a vertex angle in a range of about 60 degrees to 120 degrees. In this embodiment, the vertex angle is 90 degrees.

The cover20includes a substantially rectangular light transmission board21and four stepped reflective sidewalls22extending substantially perpendicularly from a periphery of the light transmission board21towards the optical plate10. The light transmission board21is made of transparent materials, and is configured to protect the V-shaped protrusions121from being damaged. Referring toFIG. 3, the light transmission board21includes a plurality of rectangular depressions211defined in an inner surface213of the light transmission board21. The rectangular depressions211are configured for guiding the light transmitted therethrough to an outside. The cover20has a high reflectivity film formed on inner surfaces223of the reflective sidewalls22, so as to increase light energy utilization rate. The cover20further includes two through holes221defined at two opposite reflective sidewalls22for being assembled with the fixing member40.

The frame30has the same shape as the reflective sidewalls22, and includes a substantially rectangular groove31defined on a periphery thereof for receiving the reflective sidewalls22. The frame30forms an opening33in a middle portion, and the opening33has a smaller dimension comparing to that of light input surface11of the optical plate10.

The fixing member40includes a first belt41, a second belt42, and a hook-and-pile fastener43. The first belt41includes a connecting end portion411for being fixed into one of the through holes221of the reflective sidewalls22. Similarly, the second belt42includes a connecting end portion421fixed into the other through hole221. The other ends of the first and second belts41,42are fixed together by the hook-and-pile fastener43. In the illustrated embodiment, the first belt41and the second belt42are made of canvas. It is to be understood that, the second belt42and the hook-and-pile fastener43may be omitted, as long as the other end of first belt41is directly connected to the other of the through holes221, such that, the fixing member40can be fixed to the main body200.

In assembling, firstly, the optical plate10is received in the cover20and surrounded by the reflective walls22, and the plurality of parallel V-shaped protrusions121face the rectangular depressions211. Secondly, the frame30is fixed to the cover20, and the reflective sidewalls22engage with the groove31. Because the dimension of the opening33is smaller than that of light input surface11, the optical plate10is not able to pass through the frame30, such that, the optical plate10is located in the cover20. Lastly, the belt41and the belt42are connected to the two through holes221of the cover20, respectively.

When a user needs a light source, the user can mount the illumination assist device100to the main body200by the first and the second belts41,42, wherein the light input surface11faces the flash lamp215. When the flash lamp215is illuminated, the light emitted from the flash lamp215enters the optical plate10via the light input surface11and is substantially reflected by the reflective sidewalls22to an inside of the optical plate10. Finally, the light is refracted at the V-shaped protrusions121and passes through the light transmission board21to provide illumination. When the user no longer desires a light source, the illumination assist device100can be unmounted from the main body200.

One of the advantages of the electronic device300is that, the flash lamp215of the main body200can generate a relatively high brightness light with the assistance of the illumination assist device100, without using any additional light sources. Another one of the advantages of the electronic device300is that it can provide an improve brightness of the flash lamp215at a specific range of viewing angles (e.g. perpendicular to the illumination assist device100).

It is to be understood that, the reflective sidewalls22may be made of materials with a high reflectivity, such as aluminum or other metals.

The V-shaped protrusions121formed on the light output surface12of the optical plate10can be replaced by a plurality of cone-shaped protrusions or arcuate-shaped protrusions or spherical protrusions.

It is to be understood that, the frame30may be omitted, as long as the optical plate10is located in the cover20by welding or conglutinating.

It is to be understood that, the fixing member40may be omitted, as long as the illumination assist device100and the main body200are fixed together by conglutinating or other mechanisms such as bolting.