WO1999003683A1 - Densitometre monte sur chariot - Google Patents

Densitometre monte sur chariot Download PDF

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Publication number
WO1999003683A1
WO1999003683A1 PCT/US1998/012655 US9812655W WO9903683A1 WO 1999003683 A1 WO1999003683 A1 WO 1999003683A1 US 9812655 W US9812655 W US 9812655W WO 9903683 A1 WO9903683 A1 WO 9903683A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
media
printing system
light source
densitometer
Prior art date
Application number
PCT/US1998/012655
Other languages
English (en)
Inventor
Deane Gardner
Herman Ferrier
Original Assignee
Topaz Technologies, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Topaz Technologies, Inc. filed Critical Topaz Technologies, Inc.
Priority to AU82584/98A priority Critical patent/AU8258498A/en
Publication of WO1999003683A1 publication Critical patent/WO1999003683A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/46—Measurement of colour; Colour measuring devices, e.g. colorimeters
    • G01J3/50—Measurement of colour; Colour measuring devices, e.g. colorimeters using electric radiation detectors
    • G01J3/51—Measurement of colour; Colour measuring devices, e.g. colorimeters using electric radiation detectors using colour filters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J29/00—Details of, or accessories for, typewriters or selective printing mechanisms not otherwise provided for
    • B41J29/38—Drives, motors, controls or automatic cut-off devices for the entire printing mechanism
    • B41J29/393—Devices for controlling or analysing the entire machine ; Controlling or analysing mechanical parameters involving printing of test patterns
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
    • H04N1/46—Colour picture communication systems
    • H04N1/56—Processing of colour picture signals
    • H04N1/60—Colour correction or control
    • H04N1/603—Colour correction or control controlled by characteristics of the picture signal generator or the picture reproducer
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/46—Measurement of colour; Colour measuring devices, e.g. colorimeters
    • G01J3/50—Measurement of colour; Colour measuring devices, e.g. colorimeters using electric radiation detectors
    • G01J3/501—Colorimeters using spectrally-selective light sources, e.g. LEDs

Definitions

  • the inventions relate to the field of printing systems, and more specifically to ink jet printing systems.
  • An ink-jet printing system is a type of non-impact image recording device that forms characters and images on a medium by controllably discharging ink from printheads or cartridges disposed on a print carriage.
  • Two well known types of ink-jet printing systems are printers and plotters.
  • the print carriage includes multiple printheads or cartridges (referred to herein as the Printheads) each of which is dedicated to printing a specific color.
  • the colors are generally magenta, cyan, yellow and black. These colors are selected because their combinations can yield a wide range of colors.
  • Each printhead controllably ejects ink in the form of droplets through either a single nozzle or through multiple nozzles, depending on the type of printhead.
  • the ejected droplets travel through an air gap and onto the media. Shortly thereafter, the ink droplets dry on the medium to form images or words through their combination.
  • Printhead apparatuses attempt to generate variable volume ink drops using various methods.
  • the amplitude or shape of an electrical drive signal which is applied to the ink jet printer transducers is manipulated to vary the volume of the ink drop.
  • An example of such a method and apparatus is disclosed in copending U.S. Patent Applications Serial No. 08/808,608, which is incorporated herein by reference in its entirety.
  • the one or more printheads employed in printing systems may have life expectancies that are considerably less than that of the entire printing system. Therefore, the printheads may be designed to be replaceable during the life of the printer system.
  • a known drawback of ink-jet printing systems is that printheads will discharge different droplet volumes and densities at different times, even in response to a signal instructing the same amount of discharge.
  • the absolute volume of ink ejected from the printhead is not well controlled, and may vary with time, ambient temperature, or other environmental factors. Also, the use of different combinations of ink and media by the user may result in prints which are too light or dark.
  • Variations in the volume of ink discharged from the printheads result in the printing of lesser quality images on the medium since the expected volume of ink is not discharged.
  • images can be less or more dense than expected, or the color tones can be different than those which were desired by the user.
  • the size may be variable in both length and width, or in length or width individually. Determination of the media size by the printing system can be input by the user through a printer interface. Such an interface can be a key pad on the printer, an on-screen menu on a computer or other input devices. However, it would be desirable to have a printer which can automatically determine the size of the media and print images with consistent quality on media of different sizes without user intervention.
  • a printing system comprises a printing mechanism adapted for printing on a substrate, a first light source adapted for emitting light onto a surface of the substrate, a second light source adapted for emitting light onto the surface of the substrate, and a photosensor adapted to detect light emitted by the first light source and the second light source which is reflected from the surface of the substrate.
  • One aspect of the printing system includes a carriage mounted densitometer.
  • the densitometer is preferably designed to detect densities of inks having different colors.
  • the densitometer is also capable of being used to determine the width of media inserted into the printing system, as well as the type of media.
  • Another aspect of the present invention comprises a print carriage including at least two printheads, each of the at least two printheads discharging ink of a different color onto a media.
  • a densitometer for measuring a separate ink density for each ink color discharged from the at least two printheads onto the media, the densitometer comprising a media type detector that determines a type of the media.
  • Yet another aspect of the present invention comprises a method for calibrating ink discharge levels in a printing system, by printing a test pattern on a media in the printing system, the test pattern comprising at least two areas each being a different color; illuminating the test pattern with light; detecting an intensity of the light after reflection from the test pattern; converting the intensity into an electrical signal; and altering the amount of ink discharged on a next discharge according to the intensity of the light determined.
  • the present invention is directed toward a non-impact printing system.
  • the non-impact printing system comprises a platen, a guide rail disposed above the platen, a print carriage disposed upon the guide rail, at least two printheads, each of the at least two printheads discharging ink of a different color onto a media.
  • the printing system also includes a densitometer, the densitometer measuring a separate ink density for each ink color discharged from the at least two printheads onto the media.
  • the densitometer also includes comprising a media type detector that determines the type of the media.
  • the printing system further includes means for moving the print carriage along the guide rail.
  • the densitometer is capable of acting as a media width detection system for extremely glossy and matte-surface media.
  • Fig. 1 is a front perspective of a preferred embodiment of a printing system constructed according to the present invention.
  • Fig. 2 is a side elevational view of a preferred embodiment of a preferred densitometer apparatus constructed according to the present invention.
  • Fig. 3 is a view of a surface of a preferred densitometer apparatus.
  • Fig. 4 is a diagram showing the angle of incidence and reflection for a preferred densitometer.
  • Fig. 5 is a block diagram of the preferred electrical components of a densitometer apparatus constructed in accordance with the present invention.
  • Fig. 6 is a diagram of a preferred calibration system.
  • Fig. 7 shows a preferred test pattern for determining the density of an image area on the media using the preferred densitometer apparatus.
  • Fig. 8 is a flow chart of the operation of a preferred color densitometer.
  • Fig. 9 is a flow chart showing calibration of a preferred printing system.
  • Fig. 10 is a top view of a preferred apparatus for determining the location of an edge of a diffuse surface media.
  • Fig. 11 shows the angles of incidence and reflection for a preferred embodiment of a preferred edge detection system used for glossy media.
  • Fig. 12 is a flow chart showing the operation of a preferred media width detection system.
  • Fig. 13 is a flow chart showing the operation of a preferred media type detection system.
  • a printer 5 is shown.
  • Medium 10 is disposed on the surface of platen 20.
  • Platen 20 is disposed inside printer 5.
  • the platen 20 defines the maximum width of media that can be inserted into printer 5.
  • Print carriage 40 which is above platen 20, is slidably connected to a guide rail 50. Print carriage 40 moves along guide rail 50 in a direction substantially perpendicular to the movement of media 10 being fed through the printer 5. Movement of print carriage 40 is accomplished by mechanical drive assembly 52, which includes a wire, chain, belt or the like 53 mechanically coupled to print carriage 40, and wound around opposing pulleys 54, and a motor 56 which powers one of the pulleys. Many other configurations of mechanical drive assemblies are useable with the present system.
  • a code strip 58 having a plurality of equally spaced markings 57 thereon is disposed along the width of printer 5 and above guide rail 50. Code strip 58 contains positional information which is read by an encoder module 59 on print carriage 40.
  • the encoder module 59 preferably includes an optical reader that uses the markings 57 provided on code strip 58 to determine the appropriate position for discharging ink in response to appropriate commands. Although only one arrangement of code strip 58 and encoder module 59 is shown, any other configuration that can be used with a print carriage can be used by the present invention without deviating from the scope and teachings of the present invention.
  • Print carriage 40 preferably includes a first printhead 60, a second printhead 61, a third printhead 62, and a fourth printhead 63.
  • each printhead 60, 61, 62, and 63 is dedicated to ejecting ink of a different color.
  • the printheads 60, 61, 62, and 63 can be arranged in a variety of configurations. Possible arrangements of the printheads 60, 61, 62, and 63 include a single horizontal row aligned along the axis of guide rail 40, two side-by-side vertical columns, a matrix configuration or any other configuration that is capable of creating uniform images on a media.
  • printheads 60, 61, 62, and 63 are a single horizontal row aligned parallel to the guide rail 50, with each printhead being slightly offset from its nearest neighbor.
  • Each individual printhead 60, 61, 62, and 63 is selectively used to discharge ink.
  • the ink which is discharged from the printheads 60, 61, 62, and 63 travels through an air gap 70 in the form of droplets until striking the media 10.
  • the droplets of ink discharged are substantially spherical in shape prior to the moment that they come in contact with the media 10.
  • the size of the droplets is relatively small compared to size of the paper.
  • the printer or plotter delivers a resolution of 360 or 720 dpi (Dots Per Inch) .
  • the printheads are preferably of a piezoelectric type which eject ink in response to mechanical deformation of the printhead structure upon the application of electrical signals.
  • a preferred embodiment of a printhead is disclosed in copending U.S. Patent Application Serial No. 08/703,924, entitled “Ink Jet Printhead Apparatus", and is hereby incorporated herein by reference in its entirety.
  • Densitometer 80 can be used for performing multiple functions, including determining the density of a particular pattern printed on the media. As will be described in greater detail below, the density of a particular ink pattern is a measurement that is represented by the negative logarithm of the average reflectance over an area on the media. The density information as measured by densitometer 80 can in turn be used to calibrate the amount of ink discharged from a particular printhead 60, 61, 62, or 63. Because it is carriage mounted, densitometer 80 can be used to calibrate the color at any time without having to remove the media from the printer to use an external densitometer.
  • the interior of densitometer 80 preferably comprises a first light source 100, a second light source 110, and a third light source 120.
  • light sources 100, 110, and 120 are light emitting diodes (LEDs) .
  • LEDs light emitting diodes
  • light sources 100, 110, and 120 can be photoemmiters, laser diodes, super luminescent diodes, fiber optic light sources, or other suitable light sources.
  • the light sources preferably have an emitted spectrum with strong peaks in the red, green or blue wavelengths of the visible light spectrum.
  • the light sources 100, 110 and 120 emit light signals which are reflected by the surface of the media and detected by photosensor 130.
  • photosensor 130 is a light-to-frequency converter.
  • a light-to-frequency converter will output a signal with a frequency proportional to the intensity of the detected light.
  • One such light-to-frequency converter is a TSL235 photosensor manufactured by Texas Instruments, Corp. It is possible, however, to construct photosensor 130 with photo diodes, logarithmic amplifiers and A/D converters in combinations which could be created by one skilled in the art.
  • An advantage of using light-to-frequency converters includes their compact size and the reduced cost of using a single component instead of a multi-component apparatus.
  • A/D converters and log amplifiers increases the difficulty of device calibration, as well as making the device more sensitive to temperature changes.
  • any apparatus which can generate an electrical signal in response to light can be used by the present invention without deviating from the scope and teachings of the present invention.
  • Frequency counter 140 determines the intensity of the light received by the photosensor 130 by counting the number of pulses within a specific time period.
  • frequency counter 140 is a Peripheral Interface Controller (PIC) 16C74 manufactured by Microchip Technology, Inc.
  • PIC Peripheral Interface Controller
  • Frequency counter is preferably located on the print carriage 40, but can be located anywhere within printer 5.
  • the magnitude of the intensity of the light detected by photosensor 130 is proportional to the reflectance of the pattern printed on the media. That is, the lesser the ink density on the medium, the greater the magnitude of the reflected light intensity detected by the photosensor.
  • the resulting light intensity levels can be used to calibrate the amount of ink that should be discharged from a printhead or the number of ink droplets printed in a given area to obtain the desired printed density for the specific image.
  • the intensity can either be maintained as a reflectance value or converted into a density value depending on the software, drivers and/or system used.
  • Densitometer 80 further includes an additional light source 150.
  • the specular reflections of light emitted by the additional light source 150 are capable of detection by photosensor 130.
  • the additional light source 150 can be used to determine the width of the media inserted into printer 5, as will be described with respect to Fig. 13 below.
  • First light source 100, second light source 110 and third light source 120 are the three light sources that are included in a preferred densitometer 80.
  • the light sources are preferably aligned with respect to photosensor 130 so that a substantial portion of the light that is detected by the photosensor is a diffuse reflection from the media 10 of light emitted by the light source 100, 110 or 120.
  • the alignment of each light source 100, 110, and 120 is preferably less than fifteen degrees (15°) from a line perpendicular to the surface of the media 10, as shown in Fig. 4.
  • First light source 100, second light source 110, and third light source 120 are preferably light emitting diodes that each emit a light signal of a different wavelength and therefore a light signal of a different color.
  • the light emitting diodes preferably emit light in a narrow frequency band associated with the specific color (The band is preferably lOnm for each color) .
  • the use of light emitting diodes prevents several problems associated with incandescent light sources used in standard densitometers such as limited lifetime and color drift with time.
  • the colors selected for the light sources are strongly absorbed by an ink color used in the printer, then the selection is made such that for every color of ink, there is one light source color which has a wavelength that is substantially absorbed by the ink color.
  • a preferred densitometer uses only three color diodes since the color black is actually the absence of all color (i.e. it absorbs all wavelengths of light) and any of the three diodes can be used when calibrating black ink patterns or printheads.
  • a presently preferred correspondence of light emitting diodes to ink colors is shown in Table 1 below.
  • the system can be readily adapted to be used with a single color printer by using only one light source to measure density.
  • an ink jet printer which only uses black ink can use a red light emitting diode for density measurements.
  • an additional light source 150 is arranged at an equal angle to the media as the detector can be retained on the densitometer for purposes of retaining the functionality of the system as a whole.
  • Controller 300 can be comprised of a microprocessor, microcontroller, software, memory, or any combination of these components. Controller 300 directs operation of the printer 5. Examples of such functions include controlling the amount of ink emitted by the printheads 60, 61, 62, and 63, movement of the carriage 40, the timing (i.e., when the light sources are turned on and for how long) , the amount of light emitted by the light sources 100, 110, and 120, and the editing of a tonal pattern look up table for the tonal adjustments (which is discussed below) .
  • controller 300 operates frequency counter 130, and the light source driver 310.
  • the functions of the frequency counter 130 and the light source driver 310 can be performed by separate components if desired.
  • the light sources 100, 110, and 120 emit light for a fixed period of time. In a preferred embodiment, this fixed period of time is a whole number multiple of a half cycle of the Alternating Current ("A/C") mains power supply signal. This is done to compensate for the flicker of the lights in the room in which the printer operates, which are also reflected from the surface of the media and generally operate using the same A/C mains power supply signal. While a light source 100, 110 or 120 emits light for the fixed period, the light is reflected from media 10 and detected by photosensor 130.
  • A/C Alternating Current
  • the photosensor 130 then creates an electrical signal with a frequency proportional to the intensity of the reflected light.
  • the output signal from the photosensor 130 feeds the frequency counter 140.
  • Frequency counter 140 transmits information corresponding to the light intensity to controller 300 which uses the transmitted information to calibrate the printing system.
  • a tonal value look up table 450 which provides the density correction control signals for driving printer 5.
  • a preferred tonal value look up table 450 comprises a first tonal value look up table 452, a second tonal value look up table 453, a third tonal value look up table 454 and a fourth tonal value look up table 455, where each tonal value look up table 452, 453, 454, 455 corresponds to a specific ink color used in a printhead.
  • the tonal value look up table 450 can be initially a set of preprogrammed values, or can be calculated as a first step prior to printer use. Tonal value look up tables 451-454 are created by various algorithms using the information obtained from densitometer 80.
  • Tonal value look up table 450 can reside in a general purpose computer memory magnetic storage, or any other storage media accessible to the controller 300.
  • the information contained in tonal value look up table 450 is used to determine the ink discharged, and is variable and dependent on the latest calibration values.
  • a test pattern 500 be printed on the media 10 which is the same for each density calibration operation.
  • a preferred test pattern 500 is shown.
  • swaths 510, 520, 530 and 540 is created for each color, with each individual patch having a different density. The density is determined by the number of dots created by ink discharge in a specific area.
  • the number of patches created for each color is preferably the same, although it is possible to use a different number of patches according to user or printer specification.
  • twelve patches of varying densities for each color are created within one swath.
  • the preferred densities of the test patterns for each color are tonal values of approximately 0%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95% and 100% of the maximum printed density.
  • the patches preferably have an area large enough to allow the densitometer 80 take a density or reflectance reading.
  • a calibration command is input to the printer (Step 600) .
  • the calibration command can be input by a user at any time, a regular function performed by the printer at power up, a regular function when new media or ink is placed in the printer, or, when the halftone screen patterns or printed resolution are changed and/or performed at specified time intervals during printer use.
  • the carriage Upon receiving the calibration command (Step 605) , the carriage is moved to a position above the media and the photosensor determines the intensity of the light reflected from the media prior to using any of the light sources 100, 110, and 120 (Step 610) .
  • Step 610 is not always necessary and may be substituted by measuring the reflectance. However, step 610 is preferred since any reflectance that is a result of the ambient light should be subtracted from the any values obtained during calibration. Next, the requisite number of patches for each color are printed upon the media
  • Step 620 see Fig. 7.
  • the densitometer 80 is then positioned above a swath (Step 630) .
  • the appropriate light source 100, 110 or 120 is illuminated (Step 640) .
  • the diffuse reflection is detected by the photosensor 130 for the particular illuminated light source (Step 650) .
  • the process is then repeated for each patch of a same color (Step 660) .
  • the tonal value look up table for each color is created (Step 670) .
  • the process is then repeated for each color.
  • the tonal value look up table preferably contains a series density increments or reflectance increments and a corresponding print value for each density increment or reflectance.
  • the density increments or reflectance increments are variable and a function of the system and software used.
  • a preferred density look up table contains 256 density increments.
  • the print value represents the percentage of dots per square inch that are required to achieve the corresponding density increment. The print value is used by the computer or work station during rasterization of an image to determine the amount of ink to discharge at various positions on the media.
  • the measured density values are matched with the appropriate print value (Step 675) . These measured density values are then stored as the density values for the appropriate print value (Step 680) .
  • the remaining density values for the density values which were not one of the tonal values printed are obtained using interpolation (Step 685) .
  • the print values can be calculated using methods which are known to one of skill in the art. Alternatively, the system can operate using reflectance values as opposed to density values. In this situation, the tonal correction look up tables are created and function using reflectance values. The use of reflectance measurements are preferred over density measurements, since the output of the frequency counter 140 is in fact a reflectance intensity, and converting the reflectance intensity values into a density value requires processing overhead.
  • diffuse reflections 700 but not the specular reflections 710 created by first light source 100, second light source 110, and third light source 120, are detected by photosensor 130.
  • a diffuse reflection is one where the angle of incidence for all the rays of light is different than the angle of reflection.
  • specular reflection is one where the angle of incidence is exactly equal to the angle of reflection. Since media surfaces are generally "rough" (not mirror like) , there is always some diffuse reflection decreased by photosensor 130, even when the additional light source 150 is used.
  • the diffuse reflections 700 can be used to determine whether or not there is media in the printer as well as to determine the position of the edge of the media. However, not all media produce sufficient diffuse reflections using the geometry of the preferred densitometer. For instance, transparent media (such as Mylar) produce little if any diffuse reflections which could be detected by photosensor 130. Such a media, however, can produce sufficient specular reflections that are detectable by the photosensor.
  • additional light source 150 is used in determining the width of media 10 in the printer 5. Specifically, additional light source 150 is aligned so that the angle of incidence 730 of the light beams emitted from additional light source 150 is approximately 45° from an axis 740 which perpendicular to the surface of the media 10.
  • this alignment allows the angle of reflection 750 to also be 45°. Therefore, the angle of reflection is approximately equal to the angle of incidence.
  • the alignment shown in Fig. 10 allows for sufficient intensity of reflections to be detected by photosensor 130. Specular reflections of light emitted by the additional light source 150 have sufficient magnitude because the critical angle (the minimum angle of incidence at which reflection occurs) for media in current use is generally less than 45°, thereby allowing light emitted by additional light source 150 and reflected from the surface of a media to be detected by the photodetector 130.
  • the media 10 is inserted into a printer or plotter (Step 800) .
  • one edge of the media 10 is positioned at a known, fixed location. This known location is usually aligned with the left edge of the media.
  • the carriage 40 is then moved to a position over the platen 20 which is left of the left edge of the media (Step 810) .
  • the light sources 100, 110, 120 and 150 are illuminated in sequence and the highest intensity of the reflection is determined (Step 820) . This intensity is then used as reference value such that when the same intensity at step 820 is received again, the system can determine the edge of the media.
  • the carriage 40 is then moved using a constant velocity along the guide rail 50.
  • the light source 100, 110, 120 or 150 which had the highest intensity at step 820 produces light pulses at regular intervals.
  • the intensity of the specular reflections are detected by the photosensor 130 (Step 830) .
  • the intensity of the specular reflections is approximately equal to the intensity collected at step 830, it is then known that the edge of the media is found.
  • the position of the carriage 40 is then determined by having the position encoder 59 determine the position of the carriage 40 from the code strip 58 (Step 840) .
  • the distance between the fixed edge and the carriage 40 is determined which allows the calculation of the width of the media (Step 850) .
  • media of any width can be inserted into the printer, regardless of whether it is a standard or a non-standard size. This is due to the fact that the width of the media is actually measured. The width is not determined using a look up table of media sizes nor provided by the user.
  • a media is inserted into the printing system by a user. Then the densitometer is moved to a position above the media (Step 910) .
  • the position where densitometer is located can be determined by using a position which is located above the minimum media size that the printer can use.
  • Each of the light sources 100, 110, 120 and additional light source 150 is illuminated in sequentially, and the intensity of the reflected light for each light source (Step 920) .
  • the intensity values determined at step 920 are compared to each other (Step 930) . If the reflected intensity from the additional light source 150 is greater than the reflected intensity from light sources 100, 110 and 120, then media type is classified as a film type media (Step 940) . If the reflected intensity from any of the light sources 100, 110 and 120 is greater than the reflected intensity from the additional light source 150, then media type is classified as a paper type media (Step 950) .
  • the media type detection can be performed as a single step during the process of width detection at step 820. This can be done, since at step 820 of Fig. 12 all the light sources are illuminated and the intensity of each reflectance is obtained. This can eliminate the need for a separate media type detection process, and is preferred over using a separate process of media detection.
  • the processes described in Fig. 12 and Fig. 13 can also be run concurrently. While the embodiments, applications and advantages of the present invention have been depicted and described, there are many more embodiments, applications and advantages possible without deviating from the spirit of the inventive concepts described herein. The invention should therefore should only be restricted in accordance with the spirit of the claims appended hereto and is not restricted by the preferred embodiments, specification or drawings.

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  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • General Physics & Mathematics (AREA)
  • Ink Jet (AREA)

Abstract

Ce système d'impression comporte un chariot d'impression (40) pourvu d'au moins deux têtes d'impression dont chacune (60, 61) porte au moins une buse. Chaque buse décharge de l'encre provenant de la tête d'impression. Un densitomètre (80) situé sur le chariot d'impression est capable, pour différentes encres de couleur, de mesurer la densité d'une image imprimée. Ce densitomètre comporte un détecteur de type de support déterminant le type du support.
PCT/US1998/012655 1997-07-16 1998-07-06 Densitometre monte sur chariot WO1999003683A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU82584/98A AU8258498A (en) 1997-07-16 1998-07-06 Carriage mounted densitometer

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US89604897A 1997-07-16 1997-07-16
US08/896,048 1997-07-16

Publications (1)

Publication Number Publication Date
WO1999003683A1 true WO1999003683A1 (fr) 1999-01-28

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PCT/US1998/012655 WO1999003683A1 (fr) 1997-07-16 1998-07-06 Densitometre monte sur chariot

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AU (1) AU8258498A (fr)
TW (1) TW397777B (fr)
WO (1) WO1999003683A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1182047A1 (fr) * 2000-08-26 2002-02-27 Hewlett-Packard Company, A Delaware Corporation Procédé et appareil pour imprimer un motif d'essai
EP2462426A1 (fr) * 2009-08-05 2012-06-13 Georg Fritzmeier GmbH + Co. KG Dispositif de mesure pour la détermination d'une valeur d'indice de végétation de plantes
JP2016198899A (ja) * 2015-04-08 2016-12-01 富士フイルム株式会社 インクジェット記録装置
CN112020435A (zh) * 2018-05-16 2020-12-01 惠普发展公司，有限责任合伙企业 确定光源的反射光强度

Citations (9)

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EP1182047A1 (fr) * 2000-08-26 2002-02-27 Hewlett-Packard Company, A Delaware Corporation Procédé et appareil pour imprimer un motif d'essai
EP2462426A1 (fr) * 2009-08-05 2012-06-13 Georg Fritzmeier GmbH + Co. KG Dispositif de mesure pour la détermination d'une valeur d'indice de végétation de plantes
JP2016198899A (ja) * 2015-04-08 2016-12-01 富士フイルム株式会社 インクジェット記録装置
CN112020435A (zh) * 2018-05-16 2020-12-01 惠普发展公司，有限责任合伙企业 确定光源的反射光强度
EP3774345A4 (fr) * 2018-05-16 2021-11-17 Hewlett-Packard Development Company, L.P. Détermination des intensités de lumière réfléchie de sources de lumière
US11285733B2 (en) 2018-05-16 2022-03-29 Hewlett-Packard Development Company, L.P. Determining reflected light intensities of light sources

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