Printing apparatus and method

Abstract

Printing apparatus (100) comprising a first printing device (110) comprising one or more first printheads (111) and configured to print at a respective first printing area (112), a second printing device (120) comprising one or more second printheads (121) and configured to print at a respective second printing area (122), said first printing area (112) and second printing area (122) being spaced apart, an ink distribution system (150) connected to both said first printing device (110) and second printing device (120) to distribute said ink to the first printing device (110) and to the second printing device (120).

Description

[0001] PRINTING APPARATUS AND METHOD

[0002] DESCRIPTION

[0003] The present invention relates to a printing apparatus and method.

[0004] The invention is applicable in all fields where printing on items is required, in particular on substantially flat surfaces of said items, preferably with a limited flexibility.

[0005] The items can be boxes, containers, wrappers, cardboard or plastic packages and their lids or closures, for the packaging of small individual or loose items, e.g. for the food industry (boxes for sweets, chocolates), for the pharmaceutical industry (blister packs, individual vials or strips, pill boxes), or for the tobacco industry (wrappers, containers of tobacco for oral use). Items may also concern more general component sectors, such as electrical components, or the card sector, in particular personalised cards.

[0006] The invention finds a preferred application in the card printing sector, in particular for printing on personalised cards, such as identity cards, health cards, telephone cards, credit cards, bank cards, driving licences, gift cards, access cards, a sector to which specific reference will be made below without losing generality.

[0007] This invention is preferably, though not exclusively, applicable in the field of low-volume personalisation. Furthermore, this invention is equally preferably applicable in the field of item personalisation systems, and in particular cards, from medium to high volumes.

[0008] Identity cards, health cards, telephone cards, credit cards, bank cards, driving licences, gift cards, access cards and various other types of personalised cards are generally made from plastic, paper, metal or hybrid material composition (e.g. metal and plastic), and generally have surfaces including plastic material.

[0009] On their respective surfaces, personalised cards contain personalisation data that can be printed or embedded in the card in different ways, depending on functionality and security level requirements.

[0010] Personalisation data include data belonging to the cardholder such as first name, last name, address, telephone number, bank account number, insurance number, identification image. Other personalisation data include personalised strings, images, messages, card number, card expiry date, linear or two-dimensional codes, logos, names.

[0011] Known card personalisation systems include a card printing apparatus to print some of the personalisation data on the card.

[0012] Said printing apparatus may include one or more Drop-on-Demand (DoD) inkjet printers, which is capable of printing by means of one or more respective printheads with selected colours (e.g. black, white, cyan, yellow, magenta) on the surfaces of the card, or on part of it.

[0013] The DoD inkjet printer can print using thermal inkjet technology or piezoelectric inkjet technology where pressure waves are used to eject selected amounts of ink from the printhead nozzles.

[0014] Ink formulation may vary depending on the type of printhead and substrate characterising the cards to be printed. Ultraviolet and LED dryable inks are especially suitable for printing on plastic material. In particular, ultraviolet dryable ink is preferred as it provides instant drying, light fastness, high print quality, adhesion, scratch resistance, colour density, no volatile organic compounds. In recent years, water-based inks, which adhere to various types of plastic substrates subjected to corona treatment, with good mechanical and moisture resistance, high colour performance and high graphic quality, have also been developed.

[0015] The printer of the printing apparatus can also support so-called “over the edge” printing or “edge- to-edge” or “complete edge-to-edge” printing, where the complete surface of the card is printed, leaving no visible unprinted edge or blank margin. Over the edge printing allows to obtain a card having a high quality result, which is obviously more interesting to the end user.

[0016] To ensure cards printed with a high quality standard, the known card printing apparatus may also include one or more card surface treatment stations to properly treat the card surfaces prior to printing. A surface treatment station may include air cleaning devices, corona treatment devices, plasma treatment devices, air plasma treatment devices, gas plasma treatment devices, as nonlimiting examples.

[0017] Data that is not printed can be incorporated into the card, e.g. by encoding a chip or magnetic strip that is present in the card.

[0018] To this end, the card personalisation system can also include processing stations to perform chip programming or magnetic strips encoding.

[0019] Security elements, holograms, embossed elements are non-limiting examples of additional features of the cards, for which processing stations, comprising, as non-limiting examples, special coating devices, text embossing devices, laser markers, laser engravers, are required to be included in the card personalisation system.

[0020] Card personalisation systems that include card printing apparatuses are used to treat and print up to thousands of cards per hour.

[0021] The important requirements to be fulfilled in this field are to ensure a high quality printing standard while maintaining a high system productivity in terms of cards printed per hour. In addition, both surfaces of a plastic card need to be printed and treated.

[0022] An example of a known printing apparatus suitable for processing a large number of items, and in particular cards, is a printing apparatus that is capable of processing cards in parallel. Such a configuration requires two or more printing devices to operate independently of each other, not cooperating functionally with each other. This configuration allows to obtain a high degree of operational flexibility, as the printing devices, operating independently, are able to perform separate and disjointed printing processes on the items, at the same time or at different times, at the same frequency or at a different frequency, thus increasing the volume and productivity, meaning the number of items printed per hour, as well as optimising the printing of even different items fed at the same time to the printing devices.

[0023] In order to ease understanding of the present invention, the meaning of certain terms and expressions, as used in this description and in the appended claims, are set forth below.

[0024] In a printing apparatus, two printing devices operate "independently" when they perform their respective printing processes in a mutually unrelated manner, i.e. each according to its own workflow, in other words, they are configured to perform separate and disjointed printing processes, at the same moment or at different moments, at the same frequency or at a different frequency. In a printing apparatus, two printing devices are placed “side by side” when they are arranged in relative alignment along a direction transverse to an advancement direction of the items to at least one of the printing devices.

[0025] In a printing apparatus where an item moves forward along a path or itinerary, a first device is defined as "upstream" of a second device when said first device precedes said second device in relation to the advancement of the item, conversely a second device is defined as "downstream" of a first device when said second device follows said first device in relation to said advancement.

[0026] In general, two devices or two systems are independent of each other, i.e. they operate independently, when there is no mutual correlation or dependency between the processes performed by one and the other device or by one and the other system.

[0027] In a printing apparatus, in particular, ink is distributed to two printing devices independently when the ink is fed to the printing devices via respective and separate control systems, so that the two printing devices can print their respective print jobs without any mutual correlation or dependency between the printing processes performed by one and the other device.

[0028] The term “print frequency” of a printing device means a number of items printed in the unit of time, e.g. a number of items printed per minute or a number of items printed per hour.

[0029] The term “horizontal” refers to an orientation extended substantially perpendicular to the vertical direction of gravity.

[0030] The Applicant observed that a printing apparatus wherein, in order to increase productivity, several printing devices operating independently of each other are arranged, offers a solution which, on the one hand, ensures a high degree of flexibility but, on the other hand, proves to be economically unprofitable due to the costs and space involved. In fact, such a printing apparatus requires that each separate and disjointed printing process uses dedicated resources, i.e. that each printing device is provided with components all suitable for properly performing printing processes, these components including, for example, the printhead assembly, the ink distribution system and the print process control system for driving the printheads.

[0031] In more detail, the ink distribution system of a printing device typically comprises one or more main ink tanks, specifically one main ink tank for each ink colour, and for each main tank a supply duct and in some cases a recirculation duct. Each supply duct connects, via a supply pump and valve system, the respective main tank to an inlet of the printing device for ink supply. Similarly, each recirculation duct connects, via a recirculation pump and valve system, an outlet of the printing device (other than the printhead nozzles) to the main tank or to a junction with the respective supply duct, in order to keep the ink in recirculation, e.g. when the ink comprises particulate material, in order to improve the printing result. Pumps and valves for ink supply and recirculation in the printing device are controlled by the printing process control system or by an additional control system of the printing device itself.

[0032] The Applicant has thus ascertained that providing a printing apparatus wherein the printing devices operate independently of each other can ensure a high degree of flexibility in performing the printing processes, which can improve productivity, however resulting in a high overall dimension of the apparatus and a consequent increase in overall costs.

[0033] The Applicant therefore perceived the need to provide a printing apparatus wherein several printing devices could share, as far as possible, certain resources and functionalities, without, however, losing the operational flexibility found in printing apparatuses with independently operating printing devices.

[0034] The Applicant has therefore found that a printing apparatus, wherein two printing devices share and are connected to an ink distribution system configured to distribute ink to each of said printing devices, and wherein said ink distribution system in particular is configured to distribute ink to one and the other printing device independently, allows to effectively reduce the dimension and / or costs of the printing apparatus, while ensuring a wide flexibility in performing printing processes so as to ensure high productivity, with obvious advantage in high volume production.

[0035] In other words, the Applicant has understood that two printing devices operating independently while sharing some resources allow to maintain the flexibility of two devices with costs and / or dimensions comparable to or slightly higher than a single printing device.

[0036] The invention, in a first aspect thereof, relates to a printing apparatus to print on items.

[0037] Preferably said printing apparatus comprises a first printing device.

[0038] Preferably said first printing device comprises one or more first printheads.

[0039] Preferably said first printing device is configured to print at a respective first printing area.

[0040] Preferably said printing apparatus comprises a second printing device.

[0041] Preferably said second printing device comprises one or more second printheads.

[0042] Preferably said second printing device is configured to print at a respective second printing area.

[0043] Preferably said first printing area and second printing area are spaced apart.

[0044] Preferably said printing apparatus comprises an ink distribution system.

[0045] Preferably, said ink distribution system is connected to both said first printing device and second printing device to distribute said ink to the first printing device and to the second printing device.

[0046] The Applicant has verified that such a printing apparatus allows a high flexibility in printing on items, that may also be different from each other and subjected to different printing processes, at the same time or not, with the result of obtaining a high productivity of the apparatus in terms of items printed per hour, while reducing the overall dimensions, due to the effect of sharing certain functionalities that reduce the number of components of the apparatus, in particular the number of pumps and valves for the supply and recirculation of the ink in the printing device, with a consequent reduction of the related costs.

[0047] The invention, in a second aspect thereof, relates to a method for printing on items in a printing apparatus.

[0048] Preferably, the method comprises arranging a first printing device.

[0049] Preferably, the method comprises providing in said first printing device one or more first printheads to print at a respective first printing area.

[0050] Preferably the method comprises arranging a second printing device.

[0051] Preferably, the method comprises providing in said second printing device one or more second printheads to print at a respective second printing area. Preferably the method comprises spacing apart said first printing area from said second printing area.

[0052] Preferably the method comprises arranging an ink distribution system.

[0053] Preferably, the method comprises distributing ink to the first printing device and to the second printing device via said ink distribution system.

[0054] The present invention in at least one of the aspects mentioned above may have at least one of the features set forth below.

[0055] In a preferred embodiment, said ink distribution system is configured to distribute said ink to the first printing device and to the second printing device independently.

[0056] Preferably said printing apparatus comprises a first control system to drive said one or more first printheads.

[0057] Preferably said apparatus comprises a second control system to drive said one or more second printheads.

[0058] Preferably said second control system is distinct from said first control system.

[0059] In a preferred embodiment, said one or more first printheads and said one or more second printheads are configured as Drop-on-Demand inkjet printheads.

[0060] In a preferred embodiment, said one or more first printheads and said one or more second printheads are mounted on a common support frame.

[0061] By providing a common support frame, which is shared with the first and second printing devices, the apparatus is constructively simplified and ensures greater precision of relative alignment between the printheads of the printing devices, ensuring high quality in the print jobs obtained in performing the apparatus printing processes.

[0062] In a preferred embodiment, said one or more first printheads and said one or more second printheads are arranged side by side on said support frame.

[0063] In a preferred embodiment, said printing apparatus comprises a conveyor device for conveying said items along a first conveying path in the direction of said first printing area of said first printing device and along a second conveying path in the direction of said second printing area of said second printing device.

[0064] Preferably said first conveying path and second conveying path are straight and parallel to each other.

[0065] Preferably, said first conveying path and second conveying path belong to a same advancement itinerary along which said items are driven in a forward movement. Preferably said conveyor device is configured to convey said items from said first printing device to said second printing device along said advancement itinerary.

[0066] Preferably one component of said advancement itinerary downstream of said first printing device is subject to at least one inversion in direction along said advancement route. More preferably, said a component of said advancement movement downstream of said first printing device is subject to a first inversion in direction and a second inversion in direction along said advancement itinerary. Thanks to the conveyor device that conveys items from the first printing device to the second printing device, a same item can be subjected to a first printing process and then a second printing process independent of the first. For example, the same item can expose a first face to the printing process and be printed on that first face by the first printing device, then be manipulated with suitable devices to expose a second face to the printing process downstream of the first printing device and be printed on that second face by the second printing device, with the obvious advantage of reducing the processing time of the entire item and thus further increasing the productivity of the printing apparatus.

[0067] Preferably said one or more first printheads are aligned along a first direction parallel to said first conveying path.

[0068] Preferably said one or more second printheads are aligned along a second direction parallel to said second conveying path.

[0069] In a preferred embodiment, said printing apparatus comprises a power supply device configured to supply power to said first printing device and to said second printing device.

[0070] In a preferred embodiment, said method comprises distributing said ink to the first printing device and to the second printing device independently.

[0071] In a preferred embodiment, said method comprises arranging a first control system to drive said one or more first printheads of the first printing device.

[0072] In a preferred embodiment, said method comprises arranging a second control system to drive said one or more second printheads of the first printing device.

[0073] Preferably the method comprises printing with said first printing device and said second printing device independently of each other via said respective first control system and second control system.

[0074] In a preferred embodiment, said first printing device and said second printing device print at different moments or at the same moment.

[0075] In a preferred embodiment, said first printing device and said second printing device print at different frequencies or at the same frequency.

[0076] In a preferred embodiment, said first printing device and said second printing device print on respective surface portions of a same item or print on respective items different from each other.

[0077] In a preferred embodiment, said method comprises printing on an item via said first printing device, leading said printed item to the second printing device and printing on said item via said second printing device.

[0078] In a preferred embodiment, said one or more first printheads are controlled by the respective first control system for performing a same printing process.

[0079] In a preferred embodiment, said one or more second printheads are controlled by the respective second control system for performing a same printing process.

[0080] In a preferred embodiment, said first printing area is defined by one or more first printing subareas associated with said one or more first printheads respectively. In a preferred embodiment, said second printing area is defined by one or more second print subareas associated with said one or more second printheads respectively.

[0081] Preferably the printing process carried out by the first or second printing device on a respective item is completed after said item has passed at respectively all the one or more first or second printheads.

[0082] Preferably the first printing device is configured to print on a first item and the second printing device is configured to print on a second item.

[0083] Preferably said apparatus comprises a shared ink tank, said shared tank being connected to both said first printing device and said second printing device.

[0084] The characteristics and advantages of the invention will better appear from the detailed description of a preferred embodiment thereof, illustrated, by way of non-limiting example, with reference to the appended drawings wherein:

[0085] Figure l is a schematic representation of an example of a printing apparatus made according to the present invention,

[0086] Figure 2 is a schematic plan view of a detail of the printing apparatus in Figure 1,

[0087] Figure 3 is a schematic view of an example of a printing apparatus according to the prior art and including two printing devices,

[0088] Figure 4 is a schematic view of a design variant of the apparatus shown in Figure 3 wherein a conveying path for the items to be printed is provided between the two printing devices which differs from the one shown in Figure 3,

[0089] Figure 5 is a schematic view of a further example of a printing apparatus according to the invention, having a conveying path for the items to be printed similar to the one in Figure 4.

[0090] Referring initially to Figure 1, an example of a printing apparatus made according to the present invention is overall denoted by 100 and schematically represented in the figure. It is also configured to operate according to the method of the present invention.

[0091] The printing apparatus 100 is made to print on items 101, which can be of various types, as shown in Figure 1, wherein small cards and containers with different shapes are shown for merely exemplary purposes.

[0092] The printing apparatus 100 comprises a first printing device 110 comprising a plurality of first printheads, all denoted by 111, configured to print at a respective first printing area 112.

[0093] In this embodiment, the first printing device 110 is provided with five first printheads 111, each dedicated to printing one of the colours cyan, magenta, yellow, black and white.

[0094] The printing apparatus 100 further comprises a second printing device 120 comprising a plurality of second printheads, all denoted by 121, configured to print at a respective second printing area 122.

[0095] The second printing device 120 is also provided with five printheads 121, similarly to what provided in the first printing device 120.

[0096] In addition to the first and second printing devices 110, 120, the apparatus 100 further comprises a third printing device 130 and a fourth printing device 140, both of which are structurally and functionally configured similarly to the printing devices 110, 120 and bearing respective third and fourth printheads 131, 141, which are arranged to print at a respective third and fourth printing area, marked by 132 and 142, respectively.

[0097] In the representation in Figure 1, the printing devices 110, 120, 130, 140 can be schematically identified within the rectangular blocks represented with dot-and-dash lines, which are arranged side by side.

[0098] It is understood that a different number (equal to or greater than two) of printing devices may be provided in the apparatus 100, in any configuration that may be envisaged, the inventive concept underlying the present invention being equally applicable.

[0099] The printing devices 110, 120, 130, 140 are configured as Drop-on-Demand (DoD) inkjet printers, and are capable of printing with selected colours on item surfaces, or portions thereof.

[0100] Each printing area 112,122,132,142, whose respective width is schematically enclosed by the rectangular perimeter represented with a dotted line in Figure 2, is formed by the sum of respective printing sub-areas within which the respective printheads of the respective printing device 110, 120, 130, 140 print.

[0101] The printing areas 112, 122, 132, 142 are spaced apart as shown in the detail in Figure 2.

[0102] A conveyor device, only schematically represented partially in Figure 1, which is arranged to convey the items 101 at the first printing device 110, along a conveying path, whose trajectory is identified by the line marked as 115, is referred to as 114.

[0103] In one embodiment, the conveyor device 114 may comprise a rail system extending along the conveying path 115 and a shuttle moved on said rail system by means of an actuating device, for example a motor. In another embodiment, the conveyor device 115 may comprise a conveyor belt on which the items 101 are supported and held in place, e.g. by suction means with vacuum or electro-adhesive systems.

[0104] The movement of the items 101 towards the printing devices 120, 130 and 140 takes place similarly to what described for the printing device 110, and for this purpose, conveyor devices 124, 134, 144 are respectively arranged to convey the items 101 to the respective second printing device 120, third printing device 130 and fourth printing device 140, along respective conveying paths, whose trajectory is identified by the lines marked 125, 135 and 145 in the figures respectively.

[0105] The movement of the items 101 takes place along the respective conveying paths 115, 125, 135, 145, which in the example described herein are contained in a horizontal plane (parallel to the plane of the sheet) and extend straight and parallel to each other.

[0106] In one embodiment, the items 101 are moved by the respective conveyor device 114, 124, 134, 144 lined up in a row one after the other, in the respective advancement direction along the respective trajectory, and are led through the respective printing areas 112, 122, 132 142 to print on a surface of the items.

[0107] As shown in Figure 2, the printheads 111, 121, 131, 141 of each of the printing devices 110, 120, 130 and 140 are aligned along the respective trajectory of the conveying path 115, 125, 135, 145.

[0108] In addition, the printheads of each printing device 110, 120 130, 140 are arranged side by side with the corresponding printheads of the printing device adjacent thereto, according to the configuration shown in Figure 2. Preferably, the printheads 111, 121, 131, 141 of each printing device associated with a same ink colour are arranged in relative alignment along a direction, denoted by L in Figure 2, directed perpendicular to the straight extension directions of the trajectories 115, 125, 135 and 145.

[0109] Furthermore, all the printheads 111, 121, 131, 141 of the respective printing devices 110, 120, 130 and 140 are mounted on a common support frame 105, schematically represented in Figure 2.

[0110] According to the invention, the printing apparatus 100 comprises an ink distribution system 150, which is connected with each printing devices 110, 120, 130 and 140 to distribute ink to each of said printing devices 110, 120, 130 and 140 .

[0111] The distribution system 150 is configured to be shared with all the printing devices 110, 120, 130 and 140 provided in the printing apparatus. Said distribution system 150 comprises a main ink tank 155, which is connected, via a supply duct 156, to a shared tank 157.

[0112] It is understood that, for each ink base colour supplying the printing apparatus, a respective main tank 155 is provided for containing the respective ink and each tank 155 is connected to a respective shared tank 157 of the distribution system.

[0113] Each shared tank 157, adapted to contain the ink of a respective colour, is in turn connected to each of the respective printheads 111, 121, 131, 141 provided for printing that respective colour in each of the printing devices 110, 120, 130 and 140. Ducts, all denoted by 158, are arranged to connect the shared tank 157 with an inlet of the printing devices for ink supply to respective nozzles (not shown) provided in the corresponding printheads 111, 121, 131, 141 of the printing devices.

[0114] A pressure source, from which the pressure suitable for the operation of the distribution system 150 is brought to the distribution system 150 along a duct 160, is marked as 159.

[0115] The distribution system 150 is also provided with the parts and components suitable to prepare the ink intended to be delivered to the printhead nozzles, e.g. with the correct flow rate, pressure and temperature values. For this purpose, the distribution system 150 is provided with suitable pressure regulating devices and ink heating devices.

[0116] The printing apparatus 100 also comprises, for each printing device 110, 120, 130, 140 a respective control system for driving the printheads of the respective printing device.

[0117] In more detail, a first control system (also technically identifiable by the term “controller”), denoted by 118, is provided to drive the first printheads 111 of the first printing device 110.

[0118] Similarly, the apparatus comprises a second control system 128, separate from the first control system 118, for driving the second printheads 121 of the second printing device 120.

[0119] The apparatus also comprises a third and a fourth control system, denoted by 138 and 148 respectively, to drive the third printheads 131 and the fourth printheads 141 respectively.

[0120] The control systems 118, 128, 138 and 148 are all separate from each other and are connected, via respective electrical and electronic connection lines 119, 129, 139, 149, to the respective printheads 111, 121, 131, 141 of the corresponding printing devices 110, 120, 130, 140.

[0121] In each control system 118, 128, 138 and 148, it is implemented the control logic by means of which the printheads of the respective printing device 110, 120, 130, 140 are controlled, in particular for controlling the opening and closing of the nozzles in order to deliver the ink according to the intended printing process for printing a selected print job on the items 101.

[0122] By providing each printing device with a respective and separate control system, the printing devices operate independently, each according to its own workflow, i.e. they are configured to carry out separate and distinct printing processes, at the same moment or at different moments, at the same frequency or at a different frequency.

[0123] The printing apparatus 100 further comprises a power supply device, denoted by 170, which is shared between the printing devices 110, 120, 130, 140 and is configured to supply power to each printhead 111, 121, 131, 141 of the respective printing device via a power supply line 175.

[0124] Devices for controlling the activation of each individual line of items 101 to be moved to the respective printing device 110, 120, 130, 140 are marked by 180. A preferred configuration provides the presence of a pair of activating devices 180 operatively associated with each respective conveyor device 114, 124, 134, 144.

[0125] In the operation of the printing apparatus 110, individual rows of items 101 are moved to the respective printing devices 110, 120, 130, 140, where the printing of the selected print job is carried out on each item 101 according to the respective printing process controlled by the control system of the respective printing device.

[0126] The printing devices 110, 120, 130, 140 operate performing respective printing processes independently, i.e. they perform their respective printing processes in a mutually unrelated manner, i.e. each according to its own workflow. They are configured to carry out separate and disjointed printing processes, at the same moment or at different moments, at the same frequency or at a different frequency.

[0127] The printing devices 110, 120, 130, 140 are arranged to print on respective surface portions of a same item or can print on respective different items, with a wide range of functional flexibility.

[0128] In addition, it can be provided that printing on an item is completed by a same printing device, or the item, once printed by one printing device, is led to another of the printing devices to undergo another printing process.

[0129] This high degree of flexibility in printing processes achievable with the printing apparatus of the invention is combined with a sharing of resources and functionality between the printing devices, as described above, obtaining the advantages stated with reference to known solutions.

[0130] In order to highlight the main features of the printing apparatus according to the present invention, compared to the prior art, reference is made to Figures 3-5 hereinafter analysed.

[0131] Figure 3 schematically shows a printing apparatus according to the prior art comprising a first and a second printing device, denoted by Pl and P2, which are arranged one after the other along a single, substantially straight, conveying path of the items to be printed. Along said conveying path, the second printing device P2 is placed downstream of the first printing device Pl, with respect to the advancement direction of the items denoted by F, so that the outlet section of the first printing device faces the inlet section of the second printing device.

[0132] The two printing devices Pl, P2 are functionally independent of each other, i.e. they are conceived to perform their respective printing processes in a mutually unrelated manner, i.e. each one according to its own workflow, in other words they are configured to carry out separate and disjointed printing processes, at the same moment or at different moments, at the same frequency or at a different frequency.

[0133] In addition, if surface treatment stations are provided upstream and / or downstream of each printing device, such a configuration requires each printing device to be provided with its own respective treatment stations, thus requiring their duplication within the printing apparatus.

[0134] Figure 4 schematically shows a printing apparatus in a design variant of Figure 3, wherein the first and the second printing devices Pl and P2 retain their functional independence, as in the apparatus of Figure 3, and a different item conveying path is provided between the two printing devices. This conveying path configuration is described in the Italian Patent Application No.102023000025200, on behalf of the same Applicant, to which reference is made for any details not expressly referred to herein.

[0135] In more detail, the conveying path, denoted by T is designed to extend from the outlet section of the first printing device Pl and undergo a first 180° inversion and a subsequent further 180° inversion, so that the items are led to the inlet section of the second printing device P2. This configuration allows the advancement directions F of the items in the respective inlet sections to be concordant with each other, just as the respective advancement directions of the items from the respective outlet sections are concordant with each other. This configuration, together with the side-by-side arrangement of the printing devices, allows for reduced dimensions and can also allow sharing of the surface treatment stations at the inlet and / or outlet of the printing devices, thus avoiding duplication thereof, which can be bulky and expensive. It should be noted that the two printing devices are functionally fully equivalent to those provided in the known configuration in Figure 3, since in both embodiments the two printing devices are configured to maintain their functional independence.

[0136] In Figure 4, the items 101 are exemplified as cards bearing opposite surfaces, denoted by A and B. C denotes a flipping device by means of which the cards leaving the first printing device Pl, where printing is performed on surface A, are flipped by 180° so that the other opposite surface B is directed to the printheads of the second printing device P2, in order to print on surface B when they are fed to the second printing device P2.

[0137] Figure 4 shows card surface treatment stations, in particular a first treatment station SI arranged upstream of printing devices Pl, P2, and a treatment station S2 arranged downstream of printing devices Pl, P2. The configuration of the path T shown in Figure 4 can allow sharing treatment stations SI, S2 between both printing devices Pl, P2 due to the side-by-side position of said printing devices.

[0138] Figure 5 schematically shows a printing apparatus according to the present invention, including a first and a second printing device (marked by 110 and 120 respectively, in line with the numbering of the example described above) between which an item conveying path T is provided having the same configuration as in Figure 4. Details similar to those in Figure 3 are marked with the same numerical references. In much the same way as provided in the embodiments of Figures 3 and 4, the two printing devices also in this case maintain their functional independence from each other.

[0139] Thanks to this functional independence, the printing apparatus according to the invention allows to obtain, on the one hand, a high flexibility in printing on items, even different from each other and subjected to different printing processes, simultaneously or not, with the result of obtaining a high productivity of the apparatus in terms of items printed per hour, and on the other hand, it allows to reduce, at the same time, the overall dimensions, due to the effect of sharing certain devices or components, in particular in the ink distribution system, which reduces the number of components of the apparatus, in particular the number of pumps and valves for supplying and recirculating the ink in the printing device, with a consequent reduction in related costs. The side-by-side arrangement of the printing devices and the conveying path with a double 180° inversion of the conveying direction also allow to share the surface treatment stations at the inlet and / or outlet of the printing devices, thus avoiding duplication thereof, which can be bulky and expensive.

Claims

CLAIMS1. Printing apparatus (100) for printing on items (101), said printing apparatus comprising: a first printing device (110) comprising one or more first printheads (111) and configured to print at a respective first printing area (112), a second printing device (120) comprising one or more second printheads (121) and configured to print at a respective second printing area (122), said first printing area (112) and second printing area (122) being spaced apart, an ink distribution system (150) connected to both said first printing device (110) and second printing device (120) to distribute said ink to the first printing device (110) and to the second printing device (120).

2. Printing apparatus according to claim 1, wherein said ink distribution system (150) is configured to distribute said ink to the first printing device (110) and to the second printing device (120), independently.

3. Printing apparatus according to claim 1 or 2, comprising a first control system (118) for driving said one or more first printheads (111) and a second control system (128), distinct from said first control system (118), for driving said one or more second printheads (121).

4. Printing apparatus according to any one of the preceding claims, wherein said one or more first printheads (111) and said one or more second printheads (121) are configured as Drop-on Demand inkjet printheads.

5. Printing apparatus according to any one of the preceding claims, wherein said one or more first printheads (111) and said one or more second printheads (121) are mounted on a common support frame (105).

6. Printing apparatus according to claim 5, wherein said one or more first printheads (111) and said one or more second printheads (121) are arranged side by side on said support frame (105).

7. Printing apparatus according to any one of the preceding claims, comprising a conveyor device (114, 124) for conveying said items (101) along a first conveying path (115) in the direction of said first printing area (112) of the first printing device (110) and along a second conveying path (125) in the direction of said second printing area (122) of said second printing device (120).

8. Printing apparatus according to claim 7, wherein said first conveying path (115) and said second conveying path (125) are straight and parallel to each other.

9. Printing apparatus according to claim 8, wherein said one or more first printheads (111) are aligned along a first direction parallel to said first conveying path (115) and said one or more second printheads (121) are aligned along a second direction parallel to said second conveying path (125).

10. Printing apparatus according to any one of the preceding claims, comprising a power supply device (170) configured to supply power to said first printing device (110) and said second printing device (120).

11. Method for printing on items (101) in a printing apparatus (100), the method comprising: arranging a first printing device (110) provided with one or more first printheads (111) to print at a respective first printing area (112), arranging a second printing device (120) comprising one or more second printheads (121) to print at a respective second printing area (122), distancing said first printing area (112) from said second printing area (122), arranging an ink distribution system (150) and distributing ink to the first printing device (110) and to the second printing device (120) via said ink distribution system (150).

12. Method according to claim 11, comprising distributing said ink to the first printing device (110) and to the second printing device (120) independently.

13. Method according to claim 11 or 12, comprising: arranging a first control system (118) to drive said one or more first printheads (111) of the first printing device (110), arranging a second control system (128) to drive said one or more second printheads (121) of the second printing device (120), printing with said first printing device (110) and said second printing device (120) independently of each other via said respective first control system (118) and said second control system (128).

14. Method according to any one of claims 11 to 13, wherein said first printing device (110) and said second printing device (120) print at different moments or at the same moment.

15. Method according to any one of claims 11 to 14, wherein said first printing device (110) and said second printing device (120) print at different frequencies or at the same frequency.

16. Method according to any one of claims 11 to 15, wherein said first printing device (110) and said second printing device (120) print on respective surface portions of the same item (101) or print on respective different items (101).

17. Method according to any one of claims 11 to 15, comprising printing on an item (101) through said first printing device (110), leading said printed item (101) to the second printing device (120) and printing on said item (101) through said second printing device (120).

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