The present disclosure relates generally to an arrangement for, and a method of, assessing reading performance during reading of coded symbols to be electro-optically decoded and read by image capture, and, more particularly, to displaying a symbol image of the symbol that took the longest decode time period to be successfully decoded, thereby enabling a cause of the slow, sluggish reading performance to be determined.
Handheld readers and hands-free readers, such as flat bed or horizontal slot readers, vertical slot readers, and bi-optical readers, have all been used to electro-optically read targets, such as one-dimensional bar code symbols, particularly of the Universal Product Code (UPC) type, and two-dimensional bar code symbols, such as PDF417 and QR codes, in many different venues, such as at full-service or self-service, point-of-transaction, retail checkout systems operated by checkout clerks or customers, and located at supermarkets, warehouse clubs, department stores, and other kinds of retailers, as well as at many other types of businesses, for many years. Handheld readers are typically held in a user's hand and aimed at products bearing, or associated with, identifying target symbols. For hands-free readers having a scan window, such products with their target symbols are typically slid by a user across the scan window in a “swipe” mode, or the user merely presents the target symbols momentarily steady at the scan window in a “presentation” mode. The choice depends on the type of target, on user preference, and on the layout of the system.
Imager-based readers have one or more solid-state imagers, or image sensors, analogous to those conventionally used in consumer digital cameras. Each imager has a one- or two-dimensional array of photocells or light sensors (also known as pixels), and an imaging lens assembly for capturing return light scattered and/or reflected from a target being imaged through a scan window over a field of view, and for projecting the return light onto the sensor array to initiate capture of an image of the target over a range of working distances in which the target can be read. The target may be a symbol, as described above, either printed on a label or displayed on a display screen of an electronic device, such as a smart phone. The target may also be a form, such as a document, label, receipt, signature, driver's license, employee badge, or payment/loyalty card, etc., each bearing alphanumeric characters, as well as a picture, to be imaged. Such an imager may include a one- or two-dimensional charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) device and associated circuits for producing and processing electrical signals corresponding to a one- or two-dimensional array of pixel data over the field of view. These electrical signals are decoded and/or processed by a programmed microprocessor or controller into target data related to the target being electro-optically read, e.g., decoded data identifying the product, and enabling information, such as the product's price, to be retrieved from a price database, or into a picture of a target other than a symbol.
The above-described imager-based readers, employed in either handheld and/or hands-free modes of operation, typically decode and read a symbol in an optimum decode time, e.g., less than about 200 milliseconds (ms), and this is generally considered to be responsive, aggressive, and satisfactory in most applications. Upon a successful decode, the controller typically energizes an auditory annunciator, e.g., a beeper, and/or a visual indicator, such as a light, to alert the user that the target has been successfully decoded. There are times, however, when such decode times are not routinely realized. For example, a symbol may be poorly printed, or covered up with extraneous markings or dirt. Or, a label bearing the symbol may be torn, or overlain with a transparent plastic film or dirt, or placed incorrectly on its product. Alternatively, sunlight or ambient bright lights may cause specular reflections or bright spots to appear on the symbol. The scan window itself may be dirty or scratched, which may interfere with a quick, responsive reading. An inexperienced user may be performing an incorrect scanning technique, thereby delaying reading. All of these factors, and more, either singly or in combination, can deleteriously impair reading performance and can slow down the decode time to exceed the optimum decode time of about 200 ms, and, in some cases, to exceed about 3 seconds, thereby causing the reader to time out without having read the symbol. Such a slow, sluggish performance is unacceptable, particularly in the retail industry, where retailers value fast checkout transactions, and where getting a customer checked out faster generally results in higher revenues.
At present, some retailers try to discover any symbols that read poorly (slowly) by instructing their clerks to take note of each such sluggish performance. Typically, this is done by manually collecting a second physical specimen of the product with the symbol that scanned slowly, because the first physical specimen of the product has already been purchased and removed from the retailer's premises by the customer. In this way, the retailers can inspect the second physical specimen and possibly determine, for example, the source of the slow decode time and possibly see if there is any consistent pattern to the poor performance. However, this technique is ineffective in practice. A clerk may either conveniently or inadvertently forget the retailer's instructions, or simply not wish to be bothered to retrieve a second physical specimen. Not every clerk will have the same mental determination as to what amount of decode time is slow or fast. Due to the subjective, labor-intensive, and extra cost and effort associated with this technique, most retailers do not optimize their checkout times at all, or not as regularly or frequently as they would like.
Accordingly, there is a need to assess reading performance in an automatic, accurate, and inexpensive manner, and to readily determine the cause of poor (slow) reading performance so that corrective measures can be quickly implemented.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and locations of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The method and arrangement components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.