Patent Publication Number: US-2011063822-A1

Title: Method for adjusting focus of flash light

Description:
BACKGROUND OF THE PRESENT INVENTION 
     1. Field of Invention 
     The present invention relates to a method of adjusting a focus between a lens and a light source of the flash light, and more particularly to a method for selectively adjusting a focal distance between a lens and a light source of the flash light without altering a fixed length of the housing of the flash light, so as to selectively adjust an illumination angle of a light beam generated from the light source. 
     2. Description of Related Arts 
     Flash light is commonly used in many emergency situations or dark environments. It is portable and can be used in many different places for many reasons. For examples, when the police man is on duty at night and passing through a sparsely populated area, he/she needs temporarily illuminate the area for searching; when people go camping or hiking, the flash light device is one of the indispensable equipments to assist them find a way out under the weak or dark light. 
     Traditionally, the flash light has a fix light intensity and specific patent, so that the user has to choose one flash light for one purpose, such as the flash light which is able to gather the light for focus on a relatively smaller area for higher light intensity. The user may choose another flash light which is able to illuminate a longer distance and wider range of the environment. It is inconvenient if the flash light has only one illuminating patent. For instance, a hiker carrying the fixed light patent flash light can not efficiently adjust the flash light to focus on the near sight object to prevent being tripped by the object, or adjust the flash light to illuminate the far sight to check out the environment for safety purpose. 
     Therefore, in order to meet the requirement for using the flash light in variety situations, an adjustably focus between the lens and the light source of the flash light is invented for providing a plurality of light patent, so that the flash light is able to selectively illuminate both of the near and far sight, or choose light emitting angle projected through the lens of the flash light. The most common flash light with selectively adjustable light patent is through adjusting the distance between the lens and the light source, so as to provide a variety of focus. The light patents of the flash light are generated in responsive to the distances between the lens and the light source. Thus, the distance between the lens and the light source are normally adjusted via rotating a front end portion of the flash light to rotatably move the lens away from or closer to the light source, so as to generate the variety of light patents. 
     However, the overall length of the flash light is longer after the lens at the front end portion of the flash light is movably rotated away from the light source, so that the flash light may not be able to fit into the original pocket or compartment for storing the flash light, such as packing up the flash light into the compartment of a gun set worn by the policemen. In order to store the flash light into the bag or compartment and minimize the overall size of the flash light, the front end portion of the flash light usually has to be rotated to a minimized distance between the lens and the light source, so that the flash light can be stored. When the user, such as hiker, policemen, or solider takes out the flash light for illumination, the user has to rotatably re-adjust the focus of the lens and the light source to a predetermined distance, so as to select the light patent the user desired or needed. 
     SUMMARY OF THE PRESENT INVENTION 
     An object of the present invention is provide a method for adjusting a focus between a lens and a light source of a flash light, which is able to selectively adjust the illumination angle via adjusting a focal distance between a lens and a light source without altering a fixed length of flash light. 
     Another object of the present invention is provide a method for adjusting a focus between a lens and a light source of a flash light, wherein the adjustor is able to drive the light source or the lens to move reciprocatingly without altering the fixed length of the housing. 
     Another object of the present invention is provide a method for adjusting a focus between a lens and a light source of a flash light, wherein the illumination angle of the light beam can be selectively adjusted via adjusting the focus of the lens and the light source through moving the light source toward or away from the lens, so as to minimize the overall length of the flash light. 
     Another object of the present invention is provide a method for adjusting a focus between a lens and a light source of a flash light, wherein the lens is a convex lens, so that the light beam projected from the light source through the lens is able to have a maximized projecting angle. 
     Another object of the present invention is provide a method for adjusting a focus between a lens and a light source of a flash light, wherein the conductive holder and tubular conductor effectively ensure the light source electrically contacting with the power source when the light source is being reciprocatingly moved toward or away from the light source. 
     Another object of the present invention is provide a method for adjusting a focus between a lens and a light source of a flash light, wherein the lens is affixed at the front end portion of the flash light, so that the lens may be able to completely seal the housing of the flash light apparatus, so as to provide the water proof function. 
     Accordingly, in order to accomplish the above objects, the present invention provides a method for adjusting a focus of a flash light, comprising the steps of: 
     (a) providing a hollow housing, which has an open front end, a closed rear end defining a fixed length between the front end and the rear end, wherein the housing further has a light cavity formed within the front end of the housing and a power cavity formed at the rear end for receiving a power source; 
     (b) coaxially supporting a lens of a light arrangement at the front end of the housing, and a light source, which is embodied as LED, within the light cavity of the housing at a position behind the lens for generating a light beam alignedly towards the lens; and 
     (c) movably actuate a light adjustor of the light arrangement at the housing between the front and rear ends thereof to selectively adjust a distance between the lens and the light source along a longitudinal axis of the housing for adjusting the focus between the lens and the light source without altering the fixed length the housing, so as to adjust an illumination angle of the light beam. 
     These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a flash light apparatus according to a preferred embodiment of the present invention. 
         FIG. 2  is a side sectional view of the flash light apparatus according to the preferred embodiment of the present invention. 
         FIG. 3  is a partially sectional view of the flash light apparatus according to the preferred embodiment of the present invention, illustrating the light source moving toward the lens. 
         FIG. 4  is another partially sectional view of the flash light apparatus according to the preferred embodiment of the present invention, illustrating the light source moving away from the lens. 
         FIG. 5  is a flow diagram illustrating the method of adjusting the focus of the flash light according to the preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 and 2  of the drawings, a flash light according to a preferred embodiment of the present invention is illustrated, wherein the flash light is adapted to selectively adjust its focus by a method, as shown in  FIG. 5 , comprising the following steps. 
     (a) Provide a hollow housing  100  which has an open front end  102  and a closed rear end  104  defining a fixed length L between the front end  102  and the rear end  104 . The housing  100  further has a light cavity  106  formed within the front end  102  of the housing  100  and a power cavity  108  formed at the rear end  104  for receiving a power source  300 . 
     (b) Coaxially support a lens  202  of a light arrangement  200  at the front end  102  of the housing  100 , and a light source  204  within the light cavity  106  of the housing  100  at a position behind the lens  202  for generating a light beam alignedly towards the lens  202 . Accordingly, the light source  204  is embodied as LED according to the preferred embodiment. 
     (c) Movably actuate a light adjustor  206  of the light arrangement  200  at the housing  100  between the front and rear ends  102 ,  104  thereof to selectively adjust a focal distance between the lens  202  and the light source  204  along a longitudinal axis of the housing  100  for adjusting the focus between the lens  202  and the light source  204  without altering the fixed length the housing  100 , so as to adjust an illumination angle of the light beam. 
     More specifically, the housing  100  comprises a housing body  11  to define the light cavity  106  and the power cavity  108  therewithin, and a front cover  12  provided at the open front end  102  of the housing  100 , preferably provided at a peripheral edge of the lens  202  for reinforcing the lens  202  being supported at the front end  102 . Therefore, when the adjustor  206  is being rotatably moved to adjust the distance between the lens  202  and the light source  204 , the length from the rear end  104  of the housing body  11  of the housing  100  to the front cover  12  is remaining the same. In other words, the housing  100  has the fixed length while the distance between the lens  202  and the light source  204  is changing. 
     Accordingly, the step (c) further comprises a step of rotatably and coaxially coupling a sleeve actuator  210  with an outer circumferential surface of the housing  100  within the light cavity  106  thereof to drive the light source reciprocatingly moving along the longitudinal axis of the housing  100  so as to selectively adjust the distance between the lens  202  and the light source  204 . 
     According to the preferred embodiment, when the sleeve actuator  210  is freely rotated at one direction with respect to the longitudinal axis of the housing  100 , the focal distance between the lens  202  and the light source  204  is prolonged. Likewise, when the sleeve actuator  210  is freely rotated at the opposed direction with respect to the longitudinal axis of the housing  100 , the focal distance between the lens  202  and the light source  204  is reduced. 
     In the step (c), a step of supporting a light supporter  208  is further provided with the light cavity  106 , such that the light source  204  is supported to align with the lens  202  and to engage with the sleeve actuator  210 . Therefore, when the sleeve actuator  210  is rotated, the light supporter  208  is driven to reciprocatingly move along the longitudinal axis of the housing  100 . 
     As shown in  FIGS. 2 ,  3  and  4 , the light supporter  208  further has a supporting platform  2081  operatively supporting the light source  204  thereat to coaxially align with the lens  202 . Furthermore, the sleeve actuator  210  is arranged to drive the light supporter  208  to reciprocatingly move along the longitudinal axis of the housing  100 , so as to adjust the distance between the light source  204  and the lens  202 . 
     Accordingly, the illumination angle of the light beam generated from the light source  204  projecting through the lens  202  is able to be selectively adjusted through driving the light supporter  208 , which is supporting the light source  204  thereat, to move frontwardly and backwardly. In other words, a focus between the lens  202  and the light source  204  is adjustable via adjusting the distance therebetween through driving the light supporter  208  by the sleeve actuator  210 , so as to adjust the illuminating angles of the light beam to select variety of light patents, such as a narrower illuminating range as shown in  FIG. 4  or a wider illuminating range as shown in  FIG. 3 . 
     As mentioned above, the light supporter  208  preferably has an outer threaded portion  209  and the sleeve actuator  210  preferably has an inner threaded portion  211  for engaging with the outer threaded portion  209  of the light supporter  208 , so that when the sleeve actuator is rotatably moved to drive the light supporter  208  moving reciprocatingly, the light source  204  is driven to reciprocatingly move toward and away from the lens  202 , so as to generate variety of illuminating angles of the light beam. Therefore, through the inner threaded portion  211  of the sleeve actuator  210  driving the outer threaded portion  209  of the light supporter  208  of the light adjustor  206 , the focal distance between the lens  202  and the light source  204  is adjustable without altering the fixed length L of the housing  100 . 
     In other words, the sleeve actuator  210  is rotatably moving only in radial direction to drive the light supporter  208  moving in both radial direction and the longitudinal axis direction of the housing  100  through the inner and outer threaded portion  209 ,  211  of the light supporter  208  and sleeve actuator  211  respectively, so as to adjust the illumination angles in the manner of fixed length of the housing  100 . 
     It will be readily appreciated by one skilled in the art that the sleeve actuator  210  may also be engaging with the lens  202  or both of the lens  202  and the light supporter  208  supporting the light source  204  thereat for adjusting the distance between the lens  202  and the light source  204 . It is worth to mention that the sleeve actuator  210  rotatably engaging with the light supporter  208  not only provide the adjustable illumination angles without altering the fixed length L of the housing  100 , but also minimize the total fixed length L of the housing  100  while maximizing the range of variety of illumination angles. The lens  202  may be replaceable or interchangeable with another lens which has different protruding arc of a convex or concave lens for different lighting purposes, such as wide angle illuminating or focused spot light effect. An extra lens may be provided within the light cavity  106  to incorporate with the original lens  202 , such that the flash light apparatus may be able to selectively adjust more illuminating effects, such as light projecting angle or color via a dyeing lens. 
     It is worth to mention that the fixed length L of the housing  100  while adjusting the focal distance between the lens  202  and the light source  204  enables the flash light being stored into the original compartment or bag fittedly for receiving the flash light without adjusting to a minimized distance between the lens  202  and the light source  204 , so that a user does not have to re-adjust the distance between the lens  202  and the light source  204  every time they take it out from the flash light bag or compartment. 
     In the present preferred embodiment, a front blocker  212  is preferably provided to dispose within the light cavity  106  at a rear side of the lens  202  to limit the light supporter  208  being moved forward to the lens  202 , so as to prevent the lens  202  being hit by the light source  204 . More particularly, the front blocker  212  is preferred to radially and inwardly protruded from a surrounding wall of the light cavity  106  at a front end of the inner threaded portion  211  of the sleeve actuator  210 , so that when the light supporter  208  is driven to forwardly move toward the lens, the front blocker  212  is acting as a stopper to prevent the light supporter  208  moving forward to directly contact the light source  204 , such as LED, with the lens  202 , as best shown in  FIG. 3 . 
     In the presently preferred embodiment, the step (a) further comprises a step of providing a tubular conductive holder  214  within the power cavity  108  to electrically contact with the light supporter  208  so as to ensure the light source  204  being electrically connected with the power source  300  when the light source  204  is moved. 
     In order to affix the conductive holder  214  within the power cavity  108  of the housing  100  to electrically contact with the light supporter  208  while contacting with the power source  300  via contacting to a terminal  216  preferably affixed to the conductive holder  214  within power cavity  108  of the housing  100 , the step (b) further comprises the steps of followings to ensure the light source  204  being electrically connected with the power source  300  when the light source  204  is moving. 
     In other words, the step (b) further comprises the following steps. 
     (b.1) Provide the front cover  12  of the housing  100  for the lens  202  being coaxially sealed and affixed therewithin, wherein the sleeve actuator  210  is detachably coupled with the front cover  12 . 
     (b.2) Provide the housing body  11  for the conductive holder  214  being coaxially coupled thereto. 
     (b.3) Coaxially couple the front cover  12  with the housing body  11  by coupling the sleeve actuator  210  with the conductive holder  214 . 
     Accordingly, the step (a) further comprise a step of rearwardly extending a tubular conductor  218  from the light supporter  208  toward the power cavity  108  to slidably contact with the conductive holder  214 , so that the tubular conductor  218  is able to slidably contact with the tubular conductive holder  214 , so as to ensure the light source  204  supported at the light supporter  208  is electrically connecting with the power source  300 . In other words, the tubular conductor  218  extended from the rear side of the light supporter  208  has a predetermined length to ensure that the tubular conductor  218  is able to contact with the conductive holder  214  while the sleeve actuator  210  is being rotatably driven to drive the light supporter  208  moving reciprocatingly for adjusting the illumination angles of the light beam. 
     Specifically, when the light source  204  is reciprocatingly moved along the longitudinal axis of the housing  100 , an outer circumferential surface of the tubular conductor  218  is slidably contacted with an inner circumferential surface of the conductive holder  214  to ensure light source  204  being electrically connected with the power source  300 . 
     In order to ensure the conductive holder  214  and the tubular conductor  218  being slidably and stably contacted with each other, the conductive holder  214  may further has an inner threaded portion  215  formed at the inner circumferential surface thereof to engage with an outer threaded portion  219  of the tubular conductor  218  at the outer circumferential surface thereof, such that when the light supporter  208  is moving reciprocatingly, the tubular conductor  218  is guided to reciprocatingly slide to contact with the conductive holder  214  via the inner and outer threaded portion  215 ,  219  of the conductive holder  214  and tubular conductor  218  respectively. 
     It will be appreciated that the conductive holder  214  not only ensures the light supporter  208  being electrically conducted but also stably guides the light supporter  208  to reciprocatingly move along the longitudinal axis of the housing  100  via the threaded portion. 
     As will be appreciated by one skilled in the art, the inner and outer threaded portion of the conductive holder  214  and the tubular conductor  218  respectively may be interchangeable. In other words, the conductive holder  214  may be engaged with the tubular conductor  218  via an outer threaded portion of the conductive holder  214  engaging with an inner threaded portion of the tubular conductor  218 . 
     As described above, the sleeve actuator  210  of the light adjustor  206  is able to drive the light source  204  reciprocatingly moving within the light cavity  106  with the fixed total length of the housing  100 , such that the arrangement of the light adjustor  206 , light source  204 , and the lens  202  is able to relatively more easily to provide the waterproof structure and function of the light cavity  106  and the power cavity  108 . A resilient ring may further provided between the reinforcing ring  220  and the sleeve actuator  210 , between the front cover  12  and the lens  202 , and/or between the front cover and an interior wall of the sleeve actuator  210  to conceal the light cavity  106 , so as to provide a waterproof flush light apparatus. 
     Accordingly, a reinforcing ring  220  may be further provided for the conductive holder  214  reinforcingly and stably guiding the tubular conductor  218  moving along the axis direction of the housing  100  to electrically connect with the power source  300 . The reinforcing ring  200  is preferably affixed at the surrounding wall of the light cavity  106  at a position protruding inwardly and radially therefrom, wherein the reinforcing ring  220  is located between the surrounding wall of the light cavity  106  and the conductive holder  214 , such that conductive holder  214  is being held stably in position for guiding the reciprocating movement of the tubular conductor  218 , so as to keep contacting therewith. 
     As best shown in  FIGS. 3 and 4 , the conductive holder  214  further has a front blocking edge  222  located at a very front end of the conductive holder  214 , so that when the light supporter  208  is driven to rearwardly move away from the lens, the front blocking edge  222  is able to limit the light supporter  208  being moved backwardly to the power cavity  108  of the housing  100 . 
     Therefore, the method further comprises the steps of providing the front blocking edge  222  at the conductive holder  214  to limit the light supporter  208  being moved backward to the power cavity  108 , and radially and inwardly forming the front blocker  212  from a surrounding wall of the light cavity  106  at a front end of the inner threaded portion  211  of the sleeve actuator  210  to limit the light supporter  208  being moved forward to the lens  202  so as to prevent the lens  202  being hit by the light source  204 . 
     As shown in  FIGS. 1 and 2  of the drawings, a switch  224  is further provided for controlling the power of the flash light preferably in an on-and-off manner, wherein the switch  224  is preferably provided at the closed rear end  104  of the housing  100  and electrically connecting with the power source  300  to controllably switching the power of the flash light. A rear panel  226  may further provided at the rear end  104  of the housing  100  to seal the power cavity  108 , so as for accessing the power source  300  within the power cavity  108 . 
     As embodied in the present invention, the power source  300  is preferably one or more replaceable batteries being received within the power cavity  108  of the housing  100 , so that the batteries are able to be accessed via removing the rear panel  226  to access the power cavity  108 . 
     Accordingly, the switch  224  is preferably provided on the rear panel  226  for being conveniently controlling the switch  224  while holding a rear portion of the housing body  11  of the housing  100 . Therefore, when the switch  224  is being pressed to electrically connect with the power source  300  to form a closed circuit between the light source  204 , power source  300  and the switch  224 , the light beam is generated from the light source  204 . Likewise, when the switch  224  is being pressed again, the circuit is disconnected to turn off the power supplied to the light source  204  embodied as LED. 
     It is worth to mention that the light source  204  is preferably LED due to the benefit of high intensity and low power requirement thereof. The light source  204  may also be a traditional light bulb or any other light sources which can be applied on the flash light. 
     As mentioned above, the lens  202  of the light arrangement is preferably a convex lens, such that the convent lens  202  and the light source  204  is able to provide a relatively wider range of the illumination angle to illuminate a larger area when the distance between the lens  202  and the light source  204  is minimized. The lens  202  may be made by the resin material to form a durable optical resin lens  202  with high light transmitting property. 
     The front cover  12  reinforcingly retaining the lens  202  at the front end  102  of the housing  100  may be detachably coupling with the front end  102 , such as via threaded portion at the peripheral edge of the front cover  12  to engage threaded portion of the surrounding wall within the light cavity  106  to spirally or rotationally detach from or attach to the front end  102  of the housing  100 , in such a manner that the structure of the light arrangement  200  can be easily assembled and dissembled, so as to easily change the LED or light bulb of light source  204 . 
     Thus, the structure of the conductive holder  214 , tubular conductor  218 , sleeve actuator  210 , light supporter  208 , light source  204 , and the lens  202  of the light arrangement  200  can be simply assembled via the threaded portions and the detachable arrangements, so as to minimize the manufacturing cost. 
     The present invention not only can selectively adjust the illumination angles of the light beam without altering the fixed total length of the housing  100 , but also provide a durable and stable electrical connection between the power source and the light source to prevent the happing of short-circuit. 
     One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. 
     It will thus be seen that the objects of the present invention have been fully and effectively accomplished. The embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.