Various embodiments of the inventions described herein relate to the field of components, devices, systems and methods for printed media sensing and printing.
Having a printer feed, register and print accurately upon a printable media sheet comprising one or more labels disposed above an underlying backing layer can present certain difficulties, especially if the printable media sheet comprises multiple labels, sections of varying width, or portions having offset top edges. Accurately detecting and determining the locations of multiple side edge locations, multiple top edge, locations, multiple labels, and multiple no media or no label locations presents formidable technical challenges. What is needed is a sensing device and corresponding method capable of overcoming these challenges in a cost-effective manner.
In some embodiments, there is provided a printable media sensing device comprising a printed media path having a printed media substrate, the printed media substrate being configured to accept thereon and have fed therealong substantially parallel to an axis of transport a printable media sheet comprising one or more labels disposed above an underlying backing layer, the printable media sheet comprising at least a first top edge, and at least first and second side edges defining a first width of the sheet, an array of light emitters configured to project light beams therefrom towards a first side of the printable media sheet, an array of light sensors configured to receive and sense at least portions of the projected light beams transmitted through the printable media sheet to a second side thereof, the second side opposing the first side, the light sensors generating output signals representative of differences in optical transmissivity detected by the respective light sensors corresponding thereto, and a processor configured to control and drive the array of light emitters, and further configured to receive output signals from the array of light sensors and, on the basis of the received output signals, to determine at least one of the width of the sheet and a first location corresponding to the first top edge.
In other embodiments there is provided a method of printing on a printable media, sheet with a printable media sensing device, the sheet comprising one or more labels disposed above an underlying backing layer, at least a first top edge, and at least first and second side edges defining a first width, the printable media sensing device comprising a printed media substrate configured to accept thereon and have fed therealong substantially parallel to an axis of transport the printable media sheet, an array of light emitters configured to project light beams therefrom towards a first side of the printable media sheet, an array of light sensors configured to receive and sense at least portions of the projected light beams transmitted through the printable media sheet to a second side thereof, the second side opposing the first side, the light sensor generating output signals representative of differences in optical transmissivity detected by the respective light sensors corresponding thereto, a processor configured to control and drive the array of light emitters, and further configured to receive output signals from the array of light sensors and, on the basis of the received output signals, to determine at least one of the width of the sheet and a first location corresponding to the first top edge, the method comprising determining at least one of the width of the sheet and the first location. The method may further comprise sending data to a host processor concerning the width of the sheet and the first location.
Further embodiments are disclosed herein or will become apparent to those skilled in the art after having read and understood the specification and drawings hereof.
Different aspects of the various embodiments of the invention will, become apparent from the following specification, drawings and claims in which:
The drawings are not necessarily to scale. Like numbers refer to like parts or steps throughout the drawings, unless otherwise noted.
Disclosed and described herein are various embodiments of a printed media sensing device, system and method which employ an array of light emitters in conjunction with an array of light sensors to detect, variations in the amount of light transmitted through various layers in a printable media sheet (e.g., index marks, backing, and labels). These variations arise from different locations or portions, of the sheet having different light transmittance characteristics, which are associated with the differing number and type of layers present in the sheet at such different locations or portions. Light is transmitted through one side of the sheet as the sheet is fed beneath or over the array of light emitters, and the light transmitted to the opposite side of the sheet is detected by the array of light sensors.
The sensed light signals are employed to determine one or more of:
The various embodiments of printable media sensing devices, systems and methods disclosed herein work on a through-beam principle, and allow increased flexibility in customer application design, as well as other advantages discussed below. Detecting the width of a printable media sheet can permit, automatic media selection through the use of appropriate controlling software, which eliminates the need for a user to select the media width, and also avoid incorrect media selection. Detecting Top Of Form (TOF) or Bottom of Form (BOF) of a printable media sheet, where TOF for BOF may be the top leading or bottom trailing edge of a printable media sheet or the leading or trailing edge of a label disposed on backing of the printable media sheet permits appropriate controlling software to ensure that printing, upon the printable media sheet begins at the correct location on sheet and does not run over the trailing, inside or outside edges of the printable media sheet.
According to some embodiments, the positions of different portions of a printable media sheet may be detected with great accuracy, and hence enable correspondingly accurate printing on desired portions of the printable media sheet, such as on labels disposed thereon. Some embodiments can be configured to permit labels to be differentiated from the backing of the printable media sheet, with or without the use of an index mark (such as a black ink mark printed on the underside, of the backing paper, as employed by some printable media sheet manufacturers, e.g., BROTHER™). Some embodiments are configured to detect printable media sheet TOF locations, widths and/or label locations without the need to employ printable media sheets haying no registration or index marks, thereby eliminating the costs associated with providing printable media sheets having such marks, simplifying manufacturing processes for printable media sheets having labels disposed thereon, and increasing the versatility of ink jet, laser and other types of printers which incorporate the devices, systems and methods described and disclosed herein.
Note that printable media sheets are not limited to sheets having adhesive labels and an underlying backing, but include paper, cardboard, film, construction paper, or any other medium capable of being formed into a sheet and fed into the devices, systems and printers disclosed herein.
Note further that the printable media sensing devices, systems and methods disclosed herein typically provide input signals to a larger printing system having a host processor or microcontroller, or directly to a computer (such as a personal computer) for further processing and decision making.
Referring now to
Continuing to refer to
A processor (not shown in
Note that sheet 20 in
As illustrated in the embodiments of
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In the embodiments illustrated in
In one embodiment, the individual light sources or emitters of array 50 are AVAGO TECHNOLOGIES™ HLMP-FW67 LEDs, and the individual light sensors of array 70 are AVAGO TECHNOLOGIES™ APDS-9005 light detectors. These products are described in greater detail in the following Data Sheets: (1) Data Sheet for HLMP-CWxx Precision Optical Performance White LED Lamps, AV02-0368EN, Apr. 1, 2008, and (2) Data Sheet for APDS-9005, Miniature Surface-Mount Ambient Light Photo Sensor, AV02-0080EN—Jan. 16, 2007, both of which Data Sheets, are thereby, incorporated by reference herein, each in its respective entirety.
As shown in the embodiment of
Referring now to
Table 1 below shows individual LED light activation, test results obtained using printable media-sensing device 10 of
Table 2 below shows multiple LED light activation test results obtained using printable media sensing device 10 of
Table 3 below shows output signal results obtained by sensors 71 (9005-1 in Table 3), 72 (9005-2 in Table 3), 73 (9005-3 in Table 3), 74 (9005-4 in Table 3), 75 (9005-5 in Table 3) and 76 (9005-6 in Table 3) as sheet 20 was moved through device 10 into successive Positions 1, 2, 3, 4 and 5, where all of LEDs 51, 52, 53, 54, 55 and 56 were activated. Successive positioning of sheet 20 in positions 1, 2, 3; 4 and 5 was obtained as follows. Processor 80 provided information regarding the detection of TOF, the edges of sheet 20, and label versus no media portions of sheet 20 was employed to a host processor of a printer, which in turn used such information to control and drive a printer transport mechanism to feed and set positions 1, 2, 3, 4 and 5 of sheet 20. See
The printable media devices and systems-disclosed herein may be configured to calibrate or auto-calibrate the light-sensors of light sensor array 70 using appropriate calibration software. Such calibration can be employed to compensate for variations in ambient lighting, the ageing of light emitter and light sensors, and dirt or contamination accumulating in device 10 over time.
Calibration functionality permits the light sensors to work at optimal accuracy at all times. Should there be a problem or failure with any one of the light sensors or light emitters, device 10 would be able to detect such problems or failures during the calibration process, and notify the user of the problem and/or store error codes for later retrieval by a service or maintenance engineer.
According to one embodiment, a system “power-on” initiates self calibration of the light sensors and light emitters. Device 10 cycles through each pair of LEDs and light sensors and measures their received power. The measurement obtained from each light sensor is compared to a reference valve stored in processor 80. Any LED with low power output has its drive current adjusted to maintain a consistent light output, such as can happen when LED power is reduced due to dirt, contamination or age. By way of example, the new post-calibration value for the LED drive is stored in a register of processor 80.
In operation, processor 80 cycles through the LEDs, activating each LED in turn, and measuring, the output of each light sensor. Using these values, the width and TOF of a label can be determined.
Included within the scope of the present invention are methods of making and having made the various components, devices and systems described herein.
Various embodiments of the invention are contemplated in addition to those disclosed hereinabove. The above-described embodiments should be considered as examples of the present invention, rather than as limiting the scope of the invention. In addition to the foregoing embodiments of the invention, review of the detailed description and accompanying drawings will show that there are other embodiments of the invention. Accordingly, many combinations, permutations, variations and modifications of the foregoing embodiments of the invention not set forth explicitly herein will nevertheless fall within the scope of the invention.