Patent Publication Number: US-11662177-B2

Title: Target dot sight having target illumination sensor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is continuation of U.S. non-provisional patent application Ser. No. 17/152,745, titled “TARGET DOT SIGHT HAVING TARGET ILLUMINATOR SENSOR,” filed Jan. 19, 2021, which is a non-provisional of and claims benefit from U.S. provisional patent application No. 62/962,696, titled “TARGETING DOT SIGHT HAVING TARGET ILLUMINATION SENSOR,” filed Jan. 17, 2020, the disclosures of both of which are incorporated herein by reference in their entirety. 
    
    
     FIELD 
     This disclosure relates to a target dot sight for a firearm, and, more particularly, to a system for controlling the brightness of the target dot sight. 
     BACKGROUND 
     A target dot sights project a target dot, such as a red dot, at a target. Early red dot sights included a single, static, brightness setting. Since the ambient light of the environment in which the shooter is operating may vary, manufacturers began offering user-controlled brightness settings. This allowed the user to manually increase the brightness of the target dot in bright conditions, and to reduce the brightness in dark conditions. Next came automatic brightness adjusters, where, based off readings from an ambient light sensor on the sight, the target dot would automatically increase brightness when the ambient light is brighter, and reduce the brightness of the target dot when there is less ambient light. A problem, exists in these automatic adjustment systems, however, in that the target itself may have a different brightness level than the ambient light gathered by the light sensor. For instance, the target may be brightly lit at the far end of a dark room. In such a condition, the ambient sensor correctly senses that the room is dark, and therefore reduces the target dot brightness accordingly. In this example, the target dot may not even be visible at the bright target because the ambient sensor caused the sight to reduce the brightness of the target dot. 
     Embodiments of the disclosure address these and other limitations of the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a perspective view of a target dot sight having a target illumination sensor and automatic brightness control according to embodiments of the invention. 
         FIG.  2    is a side view of the target dot sight illustrated in  FIG.  1    according to embodiments. 
         FIG.  3    is a front view of the target dot sight illustrated in  FIG.  1    according to embodiments. 
         FIG.  4    is a functional block diagram illustrating example operations of a brightness control of the target dot sight of  FIG.  1   , according to embodiments. 
         FIG.  5    is a functional block diagram illustrating example operations of a brightness control of another target dot sight according to embodiments. 
         FIG.  6    is a flowchart illustrating example operations of a brightness control of the target dot sight of  FIG.  1   , according to embodiments. 
         FIG.  7    is a block diagram illustrating example components of a brightness control system according to embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In embodiments, a target dot sight includes a target illumination sensor that senses the amount of illumination at a target, rather than merely sensing the ambient sight of the entire operating environment. Then, based on the sensed target illumination, the target dot sight automatically compensates for the brightness of the target. Further, in some embodiments, the brightness of the target dot generated by the sight is not just a function of the input of the sensor, but rather includes logic to control the brightness in an intelligent way. 
       FIG.  1    is a perspective view of a target dot sight  100  having a target illumination sensor  110  and automatic brightness control according to embodiments of the invention. 
       FIG.  2    is a side view of the target dot sight  100  illustrated in  FIG.  1    according to embodiments. This view shows that the sensor  110  sits within a recess  112 , rather than being mounted at the front of the housing of the sight  100 , such as an ambient light sensor would be. The recess  112  blocks ambient light from entering the sensor  110 , and instead the sensor  110  senses light from the target itself. The shape and depth of the recess  112  may be implementation specific. In other words, for some embodiments, a deeper recess  112  provides better overall operation of the automatic brightness control of the sight  100 . In other embodiments, a shallower recess  112  may be used. In some embodiments the recess  112  may extend between 2 and 10 mm from the front surface of the sight  100 , with the sensor  110  mounted at the rear-most end of the recess, as illustrated in  FIG.  2   . In preferred embodiments the recess  112  may be 5-6 mm in length. In some embodiments the recess  112  is not a recess at all, but instead may be a protrusion from the sight  200  that functions to block ambient light from the sensor  110 . 
     In some embodiments a light pipe or fiber optic  116  may be mounted in the recess  112  to convey light from the target to the sensor  110 . The light pipe or fiber optic  116  carries light from a front end of the pipe to the sensor  110 , so that the sensor  110  may sense the light at the target, without having ambient light interfere with the sensor measurement. 
     In yet other embodiments a lens  118  may be mounted at or near the front opening of the recess  112 . In those embodiments, the lens  118  operates to focus the light from the target to the sensor  110  to minimize intrusion of ambient light. In some embodiments the lens  118  may be a Fresnel lens or have the same or similar function as a Fresnel lens to further block ambient light. Some embodiments include both a lens  118  as well as the light pipe (or fiber optic)  116  in the recess  112 . 
       FIG.  2    also illustrates a light generating device  130 , such as an LED. When the LED  130  is ON, it generates light that shines through a lens  140  toward the target. A brightness control circuit  150  drives the LED  130  to generate different amounts of light, depending on the operating conditions, as described in detail below. 
       FIG.  3    is a front view of the target dot sight illustrated in  FIG.  1    according to embodiments, which shows the sensor  110  within the recess  112  in the body of the sight  100 , as well as the lens  140  that focuses the light signal from the light generating device  130  on the target. 
       FIG.  4    is a functional block diagram illustrating example components and operations of a brightness control of a target dot sight  200 , which may be an example of the sight  100  described above, according to embodiments. In  FIG.  4   , a variable output target light  230  may have the same function as the light generating device  130  of  FIG.  2   . For example, the target light  230  may generate a light signal  232 , such as a red dot, and projects the red dot onto a target  290 . In other embodiments the target light  230  may generate another color dot, or may generate a pattern, such as a target pattern. A target illumination sensor  210  may have the same function as the sensor  110  of  FIG.  2   , which is to sense the illumination, or brightness level, or the lux, of the target  290 . As described above, the target illumination sensor  210  sits in a recess  212  sized and shaped so that the light from the target  290  is sensed more than the ambient light that is near the sight  200 . 
     In some embodiments, the target light  230  has multiple brightness settings, and the brightness of the light generated by the target light  230  is controlled by a brightness control  250 . The brightness control  250  may be controlled by user inputs  260 , or by an automatic adjuster  270 , or may be controlled by a combination of both of these at different times of operation. When the brightness control  250  is controlled by the user inputs  260 , the brightness control  250  causes the target light  230  to shine more brightly when the user increases the brightness level, and to shine less brightly when the user decreases the brightness level. Typically the user inputs  260  are a manual process, such as a pair of up/down buttons, or a single button that cycles through a number of predetermined power settings before repeating the brightness levels. In other embodiments the user inputs  260  may include a menu and menu selector. In an automatic mode, when the brightness control  250  is controlled by the automatic adjuster  270 , the user-set brightness level is not enabled and the brightness of the target light  230  is automatically set at a level determined by the automatic adjuster  270 . In some embodiments the sight  200  will alternate between the brightness control  250  being controlled by user inputs  260 , or by the automatic adjuster  270 , according operations as described below. In other embodiments the automatic adjustor  270  may store the present user setting and revert to the stored setting under certain conditions. 
       FIG.  5    is a functional block diagram illustrating example components and operations of another brightness control of a target dot sight  300 , which may be an example of the sight  100  described above, according to embodiments. The target dot sight  300  differs from the target dot sight  200  in that the target dot sight  300  further includes, in addition to the components of the target sight  200 , an ambient illumination sensor  380 . Differently than the target illumination sensor  310 , the ambient illumination sensor  380  sits at or near the front edge of the sight  300 . In this way the ambient illumination sensor  380  may sense light more near the target dot sight  300  itself than does the target illumination sensor,  310 , which instead senses light from the target  390 . 
     A user may use the user inputs  360  to control which illumination sensor is operative on the target dot sight  300 . In other words, the user may select to use the target illumination sensor  310  or the ambient illumination sensor  380 . In other embodiments the user may select to use a combination of both of the sensors  310  and  380 . In yet other embodiments the user may set the sensors  310 ,  380  to a desired relative weighting level. For instance, the user may set the target dot sight  300  to weight the target illumination sensor at  310  at 35% and the ambient illumination sensor  380  at 65%. 
       FIG.  6    is a flowchart illustrating example operations of a brightness control flow  400  of the target dot sight of  FIG.  1   , according to embodiments. In general, after an initialization, the sight senses an amount of illumination from the target through a target illumination sensor, such as the sensor  210  of  FIG.  4   , in an operation  402 . These sensed values are periodically stored in a series of the sensed values in an operation  408 , such as in a circular buffer, although other memory schema may be used. In some embodiments the stored illumination values are averaged in an operation  406  in a continually adjusting manner, as the target illumination changes. In some embodiments the average is determined by only those values stored in the circular buffer. In other embodiments the average may include historical values that have already been overwritten in the circular buffer, i.e., values that are older than the number of storage locations in the circular buffer. 
     Then, in an operation  408 , the flow  400  checks to see if the brightness control is currently in a light saturation mode or not. Light saturation mode means that the target is much more brightly illuminated than it previously was, whereas not being in saturation mode means that the target is not much more brightly illuminated than it previously was. In some embodiments, the level of brightness difference between saturation mode and non-saturation mode is user adjustable. The sight may change from non-saturation mode to saturation mode when another light source is suddenly directed to the target, such as from a flashlight, or other light source, for example. Note that the operation  408  determines whether the brightness controller is presently in the saturation mode. Causing the brightness controller to enter or leave the saturation mode is controlled by operations  414  and  422  described below. 
     If the sight is not already in saturation mode, the flow  400  leaves the comparison  408  in the NO direction. Next, the process  400  compares an instantaneous reading from the illumination sensor to the present average of the stored values in a comparison operation  410 . If the instantaneous light reading is much greater than the running average, determined in the comparison  410 , then the flow  400  exits the comparison  410  in the YES direction. In some embodiments, the definition of “much greater than the running average” means exceeding the running average by 25 Lux, but different embodiments can use different threshold levels depending on the implementation. 
     After exiting operation  410  in the YES direction, the flow  400  stores the present brightness, which may have been a user-selected brightness level, in an operation  412  and sets the brightness value of the device to maximum brightness in an operation  414 . The flow  400  sets the brightness value to maximum brightness because the target was suddenly illuminated very brightly, i.e., the present brightness value greatly exceeds the average brightness value, and the sight is responsive to bring up the brightness value of the target dot quickly. The flow  400  also changes its mode to “currently in light saturation mode” so that the operation  408  will be answered correctly the next time the process loops through the flow  400 . Then the flow  400  progresses to a wait state  416 , and waits until the next sampling interval occurs before repeating the process. In some embodiments the sampling interval is 100 ms. In other embodiments the sampling interval may be set to an interval between 10 ms and 500 ms. In some embodiments the interval is user controllable. 
     Returning back to operation  408 , if the sight is not presently in light saturation mode and the outcome of the comparison in operation  410  is NO, then this means the instantaneous sensor reading is higher than the average reading, but does not exceed the average by the threshold amount, such as 25 Lux. In this case, the flow  400  exits operation  410  in the NO direction to the wait state  416  before repeating the analysis again. This process provides a hysteresis effect to the operation of the flow  400 . 
     Returning back to operation  408  once more, if the sight  200  is presently in light saturation mode, the flow  400  exits comparison  408  in the YES direction to another comparison  420 . Comparison  420  determines whether the running average of the light readings is much greater than the instantaneous light reading. In some embodiments, the definition of “much greater than the instantaneous light reading” means exceeding the instantaneous light reading by 25 Lux, but different embodiments can use different threshold levels depending on the implementation. If the running average is much greater than the instantaneous light reading, then the flow  400  exits operation  420  in the YES direction, which indicates that the illumination of the target has suddenly dropped from its previous illumination. In this case, the brightness level is set in an operation  422  to the level previously stored in the operation  412 , meaning that the brightness level of the target light returns to the level previously set by the user, and is no longer in the maximum brightness mode (unless the user had previously set the brightness level to its maximum). The operation  422  also resets the saturation mode of the brightness controller to not being in saturation mode. 
     Although particular values, such as 25 Lux and 100 ms are used in the example flow  400  above, embodiments of the invention may work with values different from those given here, and instead may be varied depending on implementation details. 
       FIG.  7    is a block diagram of an example processor system  550 , which may perform the main operations described in the flow  400  of  FIG.  6   , and may also control operation of the target light output. In some embodiments the example processor system  550  may be used as the brightness control system  150  described above. 
     The processor system  550  includes a central processor or microcontroller  510  configured or programmed to perform the brightness control operations described above. Although only one processor  510  is shown in  FIG.  1    for ease of illustration, as will be understood by one skilled in the art, any number of processors or microcontrollers  510  of varying types may be used in combination, rather than a single processor. 
     The processor or microcontroller  510  may be configured to execute instructions from a memory  520  and may perform any methods and/or associated steps indicated by such instructions, such as reading brightness values, averaging values, storing present brightness values, etc. The memory  520  may be implemented as processor cache, random access memory (RAM), read only memory (ROM), solid state memory, non-volatile memory, hard disk drive(s), or any other memory type. In some embodiments the memory  520  is integrated with the processor or microcontroller  510 . The memory  520  acts as a medium for storing data, computer program products, and other instructions. 
     User inputs  580  are coupled to the one or more processors  510 . User inputs  580  may include one or more pushbuttons, a selectable menu, touchscreen, and/or any other controls employable by a user to interact with the sight. In some embodiment the user inputs  580  may be made on another device, such as a mobile phone or computer and sent through a communication channel, wired or wireless, to the processor system  550 . 
     A target light sensor  530  may operate as any of the target light sensors described above. In general, the target light sensor  530  creates an output signal reading indicative of the amount of light striking the target light sensor. As described above, the target light sensor is positioned to minimize reading of ambient light while maximizing the reading the light striking a target. The target light sensor  530  output is fed to the processor or microcontroller  510 . After the processor or microcontroller  510  determines at which output to drive the target light, a signal is fed to a target light output  590  to generate the target dot or target light at the brightness level controlled by the processor or microcontroller  510 . 
     The aspects of the present disclosure are susceptible to various modifications and alternative forms. Specific aspects have been shown by way of example in the drawings and are described in detail herein. However, one should note that the examples disclosed herein are presented for the purposes of clarity of discussion and are not intended to limit the scope of the general concepts disclosed to the specific aspects described herein unless expressly limited. As such, the present disclosure is intended to cover all modifications, equivalents, and alternatives of the described aspects in light of the attached drawings and claims. 
     References in the specification to aspect, example, etc., indicate that the described item may include a particular feature, structure, or characteristic. However, every disclosed aspect may or may not necessarily include that particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same aspect unless specifically noted. Further, when a particular feature, structure, or characteristic is described in connection with a particular aspect, such feature, structure, or characteristic can be employed in connection with another disclosed aspect whether or not such feature is explicitly described in conjunction with such other disclosed aspect. 
     EXAMPLES 
     Illustrative examples of the technologies disclosed herein are provided below. An example of the technologies may include any one or more, and any combination of, the examples described below. 
     Example 1 is a targeting sight, comprising a light generating source structured to generate a target light and project it toward a target, a target light sensor disposed in the targeting sight and structured to sense a brightness value of the target while excluding ambient light from the target light sensing, and a brightness controller structured to control the light generating source based at least in part on the brightness value sensed by the target light sensor. 
     Example 2 is a targeting sight according to Example 1 above, in which the targeting sight comprises an aperture, and in which the target light sensor is disposed in the aperture. 
     Example 3 is a targeting sight according to Examples 1 and 2 above, in which the aperture is structured to block at least a portion of ambient light from reaching the target light sensor. 
     Example 4 is a targeting sight according to Examples 1 and 2 above, further comprising a light pipe disposed in the aperture. 
     Example 5 is a targeting sight according to Examples 1 and 2 above, further comprising a fiber optic disposed in the aperture. 
     Example 6 is a targeting sight according to any of the Examples above, in which the brightness controller stores historic target brightness levels. 
     Example 7 is a targeting sight according to Example 6, in which the brightness controller determines an average of historic target brightness values. 
     Example 8 is a targeting sight according to Example 7, in which the brightness controller compares a present target light value to the average of historic target brightness values. 
     Example 9 is a method for controlling a target light generator in a targeting sight, comprising reading a present brightness of a target, generating an average brightness value from two or more target brightness readings, comparing the present brightness of the target to the average brightness value, and generating a target light generator control signal based on the comparison of the present brightness of the target to the average brightness value. 
     Example 10 is a method according to Example 9 above, further comprising determining whether the target light generator is in a saturation mode. 
     Example 11 is a method according to Examples 9-10 above, further comprising setting the target light generator to the saturation mode when the present brightness of the target exceeds the average brightness value by 25 Lux or more. 
     Example 12 is a method according to Examples 9-11 above, further comprising storing a present level of the target light generator control signal level prior to setting the target light generator to the saturation mode. 
     Example 13 is a method according to Examples 9-12 above, further comprising entering a restoration setting mode when the target light generator is in the saturation mode, but when the present brightness of the target is below the average brightness value by 25 Lux or more. 
     Example 14 is a method according to Examples 9-13 above, further comprising, when entering the restoration setting mode, setting the target light generator control signal to a previously stored light generator control signal level. 
     Additionally, this written description refers to particular features. One should understand that the disclosure in this specification includes all possible combinations of those particular features. For example, where a particular feature is disclosed in the context of a particular aspect, that feature can also be used, to the extent possible, in the context of other aspects. 
     All features disclosed in the specification, including the claims, abstract, and drawings, and all the steps in any method or process disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. Each feature disclosed in the specification, including the claims, abstract, and drawings, can be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. 
     In addition, when this application refers to a method having two or more defined steps or operations, the defined steps or operations can be carried out in any order or simultaneously, unless the context excludes those possibilities. 
     Although specific embodiments have been illustrated and described for purposes of illustration, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure.