Patent Application
20070284447
The field of the present invention relates generally to systems and methods for data reading. More particularly, it relates to systems, methods, and apparatus for varying the illumination in a data reader or data reading system.
Image capture and other data reading devices are used to read optical codes, acquire data, and capture a variety of images. One common data acquisition device is an optical code reader. Optical codes typically comprise a pattern of dark elements and light spaces. There are various types of optical codes, including 1-D codes (such as UPC and EAN/JAN barcodes) and 2-D codes (such as PDF-417 and Maxicode). It should be understood, however, that the embodiments described herein may be useful for readers used in connection with any type of code or symbol, including fingerprint capture, and nothing herein should be construed as limiting this disclosure to optical codes or any other particular type of code.
One type of data reader is an imaging reader that employs an imaging device or sensor array, such as a CCD (charge coupled device) or CMOS device. Imaging readers can be configured to read both 1-D and 2-D optical codes, as well as other types of optical codes, symbols, and images of other items. When an imaging reader is used to read an optical code, an image of the optical code or portion thereof is focused onto a detector array. Though some imaging readers are capable of using ambient light illumination, many imaging readers utilize an illumination source to illuminate the item being read and thereby provide the required signal response in the imaging device. For example, optical code readers using image sensor technology are often provided with supplemental illumination. Such extra illumination may be provided for the purpose of delineating the reader field of view to allow the user to aim the device. Supplemental reader illumination may also facilitate low-noise image capture.
In some situations, the amount of supplemental illumination required for effectiveness may be substantial, and the present inventor has recognized that the cycling of this illumination on and off may be irritating to the operator and may also result in fatigue. The present inventor has therefore determined that it would be desirable to provide a data reader that improves on these or other such limitations.
Understanding that drawings depict only certain preferred embodiments and are not therefore to be considered to be limiting in nature, the preferred embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
In the following description, numerous specific details are provided for a thorough understanding of specific preferred embodiments. However, those skilled in the art will recognize that embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, etc.
In some cases, well-known structures, materials, or operations are not shown or described in detail in order to avoid obscuring aspects of the preferred embodiments. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
Disclosed herein are embodiments of methods, systems, and apparatus for varying the illumination in a data reader or data reading system. In one embodiment, a data reading system may have a plurality of configurable illumination modes available that the user may select among. In one of the available modes, the intensity of the illumination source perceived by the user may be gradually increased. Various methods may be used to gradually increase the intensity of the illumination source perceived by the user, such as, for example: (1) increasing the actual intensity of the illumination source; or (2) gradually increasing the duty cycle of the illumination-driving waveform, which may be particularly useful with digital illumination sources.
In some embodiments, the rate at which the perceived intensity increases may be adjusted by the user. The rate at which the perceived intensity is increased may vary considerably as desired. In some embodiments, the range for the rate of increase between actuating a ramping control and reaching a perceived maximum intensity may be between about 0.1 seconds and about 1.5 seconds). In other embodiments, the range for the rate of increase may be between about 0.5 seconds and about 1 second.
Likewise, the profile of the increase as a function of time may also be configurable by the user in some embodiments. For example, the profile may be selected as linear, exponential, sinusoidal, etc. Any of the foregoing profiles may be used permanently in a given embodiment, or may be selected as desired by a user in other embodiments. For example, the data reader may be configured to initiate the perceived illumination intensity increase with a control, such as a trigger control.
Some embodiments may also, or alternatively, allow for a gradual decrease in the intensity of the illumination perceived by the user. In embodiments providing for both a gradual increase and decrease in perceived illumination intensity, the same control may be used to initiate the increase and the decrease or, alternatively, a separate control from the control used to initiate the increase may be used to initiate the decrease sequence. In embodiments utilizing the same control for both functions, the control may be “single-clicked” to initiate an increase sequence and “double-clicked” to initiate a decrease sequence, for example. Alternatively, the device may be configured to automatically initiate a decrease sequence whenever the control is activated during an increase sequence, or while the illumination source is on, for example.
By making the transitions during which the illumination source is turned on and/or turned off gradual, user fatigue and irritation may be reduced. As mentioned above, the rate of the increases/decreases may be configurable in some embodiments, such that the user may select a reasonable tradeoff between the amount of fatigue reduction and the effect of the selected transition rate on other characteristics of the device, such as reading performance and power consumption.
“On/off” control 114 may be used to turn the illumination source 110 on or off. In “standard” mode, activation of control 114 may be used to immediately turn illumination source 110 on at its highest intensity. In “ramping” mode, activation of control 114 may instead cause illumination source 110 to gradually increase in intensity (or at least in intensity perceived by the user) in accordance with a desired profile and/or rate. Rate control 116 allows the user to vary the rate with which the intensity (or perceived intensity) of illumination source 110 increases (or decreases). Profile control 118 likewise allows the user to adjust the profile of the increase with respect to time. For example, profile control 118 may allow a user to select between linear, exponential, and sinusoidal intensity profiles.
In some embodiments, the imaging sensor of the reader may be synchronized with the illumination source, such that the integration of the image on the sensor corresponds to a specific, desired portion of the illumination sequence. For sensors that expose all pixels of an image simultaneously, the integration of the image on the sensor may start at or near the beginning of the illumination sequence.
It should be understood that the term “illumination source” is intended to encompass sources used for aiming a scanner, in addition to those used for adding ambient light and/or for improving the quality of a captured image. Illumination sources used for aiming may be referred to as aiming or pointer beams. In some embodiments, the perceived intensity of the pointer beams may be increased and/or decreased, as described above in connection with ambient illumination sources.
Those of ordinary skill in the art will also appreciate that a control for activating scanning or imaging by a user may also control the illumination source. Thus, a user may activate scanning by activating the control, which may then automatically ramp up the perceived intensity of the illumination source to a desired level. Then, following scanning, the illumination source may be ramped back to zero. In some embodiments, the decrease ramping may be triggered upon release of the scanning control, such as a trigger. Alternatively, reactivation of the control, or activation of a separate control, may be used to initiate the downward ramping.
Those of ordinary skill in the art will also appreciate that the inventive principles set forth herein are applicable to a variety of different devices. For example, some embodiments of the invention may comprise hand-held scanners/readers. Other embodiments of the invention may comprise fixed or “handable” imaging scanners, which typically sit on a retail counter. Some fixed scanners do not include a trigger or switch for activation at all. Instead, the scanner may sense when an item is brought within its range and automatically activate the illumination. Of course, some hand-held scanners may be placed in a holder or stand and thereby operate in a similar mode to the fixed scanners, whereby the illumination source is activated when an object is sensed in a field-of-view. In any of the foregoing embodiments, once a label is read, or a time period has passed, the illumination may be configured to be automatically deactivated, rather than deactivated manually, if desired.
Each of the illumination sources described herein are examples of means for illuminating an optical code on an item. Each of the imaging devices set forth herein, including optical/imaging sensors and sensor arrays, are examples of means for reading the optical code. Examples of means for activating an illumination source or a means for illuminating include buttons, switches, triggers, dials, and the like. Examples of means for ramping the intensity of an illumination source or a means for illuminating perceptible to a user include circuitry for modifying an illumination-driving waveform, such as by gradually increasing the duty cycle of the waveform.
The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that numerous variations and modifications can be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the invention should therefore be determined only by the claims, and their equivalents.
This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Patent Application No. 60/808,413, filed May 25, 2006, and titled “Variable Illumination Scanning,” hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60808413 | May 2006 | US |
