Printing head assembly used in small thermal transfer printer

Abstract

The utility model discloses a printing head assembly used in a small thermal transfer printer. A printing head is electrically connected with external control in a limited space. Comprising a substrate, a heating wire and a thermal control circuit, a power supply path for providing a power supply for the heating wire and a signal path for sending a control instruction to the thermal control circuit are led out through a long-strip-shaped FPC circuit board connected to one side of the substrate, and the two ends of the FPC circuit board are provided with internal connection terminals arranged on a power supply circuit and a signal circuit. And the internal connection terminal is electrically connected with a corresponding external connection terminal arranged on a shell of the printer. A hard extension socket which is used for electrically connecting and leading out a printing head power supply and a signal channel in the prior art is improved into an FPC circuit board which is electrically connected and led out, and the led-out FPC circuit board is bent upwards. The thermal transfer printer has the advantages that the conductive performance is stable, the arrangement of long and many electrified wires and hard extension sockets in a narrow space is avoided, the utilization rate of the space in the shell can be effectively improved, and the miniaturization of the thermal transfer printer is facilitated.

Description

Technical Field

[0001] The utility model relates to a thermal transfer printer, in particular to a print head assembly in a small thermal transfer printer. Background Art

[0002] The existing small thermal transfer printers include a machine shell, a print head assembly arranged in the machine shell, a ribbon cassette assembly, a printing rubber roller, a main control circuit board and a power battery. The machine shell includes a machine cover and a machine base, and the ribbon cassette assembly is arranged between the print head assembly and the printing rubber roller.

[0003] In order to ensure that the printer is stably placed on the workbench during use without tipping over, it is required that the total weight of the components arranged in the machine base is sufficient to keep the center of gravity of the printer within the machine base after the machine cover is opened. Usually, heavier components are installed in the machine base, such as the power battery and the main control circuit board. There are two ways to install the print head:

[0004] 1. One way is to arrange the print head assembly, the power battery and the main control circuit board in the machine base, and arrange the printing rubber roller on the machine cover (such as the Chinese invention patent, patent number: CN202011054431.8, publication date: January 28, 2022, title: A Thermal Transfer Printer).

[0005] This structure has the following deficiencies:

[0006] 1) Assembling heavier and larger components in the machine base results in the inner space of the machine cover not being fully utilized, making it difficult to miniaturize the volume of this type of printer.

[0007] 2) Since the heat generating line of the print head is arranged upwards, during use, if there is some dust on the printing medium, this dust will fall on the upper surface of the print head, and large particles of dust are very likely to scratch the print head during the printing process, especially during outdoor use.

[0008] 3) The transmission mechanism between the driving device for driving the printing rubber roller to operate and the printing rubber roller occupies a large space inside the shell.

[0009] 2. The other way is to arrange the printing rubber roller, the power battery and the main control circuit board in the machine base, and arrange the print head assembly on the machine cover.

[0010] This structure has the following deficiencies:

[0011] 1) The wire harness (including the power supply wire and the signal wire) for controlling the heat generating wire of the print head assembly to work needs to be electrically connected to the main control circuit board through a male-female busbar plug structure. This wire harness needs to be connected from the machine cover through the machine base to the circuit board, and additional parts are required to complete the above functions, greatly increasing the volume and structural complexity.

[0012] 2) The wire harness (including the power supply wire and the signal wire) that controls the heating wire of the print head assembly is concentrated together with a relatively large diameter. If the up-and-down wiring connection method is adopted inside the machine case, it will hinder the normal operation of some components inside the machine case. If the wire is arranged through the hinge shaft between the machine cover and the machine base, the diameter of the hinge shaft is relatively large, increasing the volume of the machine and making it impossible to achieve miniaturization.

[0013] In both of the above two methods, the rigid hard row socket 5 is installed at the rear side of the ceramic substrate 21 of the print head (see Figure 10 as shown), and then the circuit of the print head is led out through the connection method of the male and female row sockets, and then electrically connected to the main control circuit board of the printer through the wire harness. This method cannot further reduce the size of the printer in the width direction (i.e., the front and back direction of the ceramic substrate). Utility Model Content

[0014] The technical problem to be solved by the present utility model is to provide a print head assembly for a small thermal transfer printer that realizes the electrical connection between the print head and the external control within a limited space.

[0015] To solve the above technical problem, the technical solution adopted by the present utility model is as follows:

[0016] The print head assembly for a small thermal transfer printer of the present utility model includes a substrate made of ceramic material, a heating wire and a thermal control circuit arranged on the substrate. It is characterized in that: the power supply path for supplying power to the heating wire and the signal path for sending control instructions to the thermal control circuit are led out through an FPC circuit board in a strip shape connected to one side of the substrate. At both ends of the FPC circuit board, a power supply circuit and a signal circuit are arranged on an integrated internal connection terminal, or the power supply circuit and the signal circuit are respectively arranged on different internal connection terminals, and the internal connection terminal is electrically connected to a corresponding external connection terminal arranged on the machine case of the printer.

[0017] The internal connection terminal and the external connection terminal are respectively a male row socket and a female row socket. The internal connection terminal is arranged on the support frame on the side of the machine cover of the printer, and the external connection terminal is arranged corresponding to the internal connection terminal up and down on the base frame of the power supply chamber on the side of the machine base of the printer.

[0018] The internal connection terminal and the external connection terminal are respectively an elastic contact pin and a rigid contact plate, or the internal connection terminal and the external connection terminal are respectively a rigid contact disc and an elastic contact pin; the internal connection terminal is arranged on the support frame on the side of the machine cover of the printer, and the external connection terminal is arranged corresponding to the internal connection terminal up and down on the base frame of the power supply chamber on the side of the machine base of the printer.

[0019] The internal connection terminal and the external connection terminal are both elastic contact pins. The internal connection terminal is arranged on the support frame on the side of the machine cover of the printer, and the external connection terminal is arranged corresponding to the internal connection terminal up and down on the base frame of the power supply chamber on the side of the machine base of the printer.

[0020] Both the internal connection terminal and the external connection terminal are in rigid contact. The internal connection terminal is arranged on the support frame on the side of the printer cover, and the external connection terminal corresponds to the internal connection terminal up and down and is arranged on the base frame of the power supply chamber on the side of the printer base.

[0021] There are two groups of the internal connection terminals, which are respectively arranged on the support frames on both sides of the printer cover. Correspondingly, there are also two groups of the external connection terminals, which are respectively arranged on the base frames of the power supply chambers on both sides of the printer base; the electrical connection terminal composed of a group of internal connection terminals and the corresponding group of external connection terminals includes a plurality of power supply connection channels and electrical signal transmission channels.

[0022] The elastic contact pin consists of a conductive column cavity, a compression spring placed in the conductive column cavity, and a conductive column. The compression spring is placed in the conductive column cavity and is between the top end of the conductive column and the top surface in the conductive column cavity. The conductive column is in contact with the inner wall of the conductive column cavity and can move up and down in the conductive column cavity.

[0023] The shape of the rigid contact plate is a flat plate or a concave plate with an arc-shaped curved surface.

[0024] The utility model improves the hard row plug used for electrically connecting and leading out the print head power supply and signal channels in the prior art to be electrically connected and led out by an FPC circuit board. After being led out, the FPC circuit board bends upward. At the same time, the print head is electrically connected to the main control circuit board arranged in the base by the electrical connection between the internal connection terminals arranged on both sides of the FPC circuit board and the external connection terminals arranged on the base. With the above settings, the conductivity is stable, avoiding the arrangement of long and numerous energized wires and hard row plugs in a narrow space, effectively improving the utilization rate of the space inside the shell, and greatly reducing the shell size of the thermal transfer printer in the width direction, which is beneficial to the miniaturization of the thermal transfer printer. Description of the Drawings

[0025] Figure 1 It is a schematic external view of the small thermal transfer printer of the utility model.

[0026] Figure 2 is Figure 1 a schematic view after the printer cover in [Figure number] is opened.

[0027] Figure 3 is Figure 1 a schematic view of the printer cover in [Figure number].

[0028] Figure 4 is Figure 3 a schematic view of the bottom view of the printer cover in [Figure number].

[0029] Figure 5 is Figure 4 an exploded schematic view of [Figure number].

[0030] Figure 6 For Figure 5 The connection schematic diagram of the print head and the FPC circuit board led out in

[0031] Figure 7 For Figure 6 Exploded schematic diagram of

[0032] Figure 8 For Figure 1 Front view plane schematic diagram of the printer of

[0033] Figure 9 For Figure 8 Cross-sectional view in the A-A direction in

[0034] Figure 10 Schematic diagram of the print head circuit in the thermal transfer printer in the prior art

[0035] The reference numerals are as follows:

[0036] Printer 1, housing 11, cover 12, base 13, side cover 14, ribbon cassette assembly 15, power compartment 16, support frame 17 、 Base frame 18, print head assembly 2, substrate 21 、 FPC circuit board 3, internal connection terminal 31, external connection terminal 32, elastic contact pin 4, conductive column cavity 41, compression spring 42, conductive column 43, concave plate 44, rigid row socket 5. Specific embodiments

[0037] As Figures 1-5 , Figure 8 shown, the small thermal transfer printer 1 (hereinafter also referred to as printer 1) of the present utility model has an external dimension of length × width × height of (220mm - 320mm) × (50mm - 75mm) × (40mm - 57), preferably length × width × height of 317mm × 73.6mm × 51.5mm; its weight is 500g - 1000g, preferably 800g, and the printing width of the printing medium is 220mm - 260mm. Since the present utility model has the advantages of being small, light in weight and having a large effective printing width, with a width utilization rate as high as 82% (formula: printing width of the printing medium 260 / external dimension length 317 * 100%), the width utilization rate of the small thermal transfer printer 1 in the prior art (see Chinese invention patent, patent number: CN202011054431.8) is only 67% (formula: printing width of the printing medium 210 / external dimension length 310 * 100%), it is a printer 1 that is very popular among people who often need to print blank printing media on-site when working outside.

[0038] The small thermal transfer printer 1 of the present utility model is particularly suitable for printing on printing media such as single - sheet labels with self - adhesive paper, single - sheet aluminum - plastic labels or single - sheet nameplates, etc., which are required by field workers in the fields of electric power, communication, petrochemical industry, and transportation when they need to casually make and replace electric power signs and traffic signs on the go.

[0039] The casing 11 is composed of a machine cover 12, a machine base 13 and two machine side covers 14 on the left and right. The print head and ribbon cassette assembly 15 is arranged in the cavity formed by enclosing the machine cover 12, the machine base 13 and the two machine side covers 14. The machine cover 12 is connected to the machine base 13 in a single - side hinged manner, and the diameter of the hinge shaft is between 0.8 mm and 2.5 mm, preferably 2.0 mm.

[0040] The power transmission mechanism for controlling the lifting of the print head, the winding of the ribbon cassette, and the rotation of the paper - feeding rubber roller and the printing rubber roller is centrally arranged in the power chamber 16 on the left and right sides of the machine base 13 inside the casing 11 (taking the Figure 2 paper surface direction as an example, the left side is the left, the right side is the right, the same below).

[0041] The printer 1 of the present utility model has the following improvements compared with the small thermal transfer printer 1 in the prior art:

[0042] 1. The setting of the print head assembly 2 and the main control circuit board.

[0043] The print head assembly 2 is arranged on the inner surface of the machine cover 12 of the printer 1, and the main control circuit board assembly and the power battery are arranged at the bottom inside the machine base 13 of the printer 1, which can make full use of the space inside the casing 11. Thus, it is beneficial to the miniaturization of the printer 1. When the machine cover 12 and the machine base 13 are buckled together, the ribbon cassette assembly 15 is placed inside the casing 11 and is located between the print head assembly 2 and the main control circuit board assembly, and the printing rubber roller is placed between the ribbon cassette assembly 15 and the main control circuit board assembly.

[0044] 2. The electrical connection between the print head assembly and the main control circuit board.

[0045] After the two are separately arranged, setting the power line and signal line (hereinafter collectively referred to as the wire harness) between the print head assembly 2 and the main control circuit board assembly in the limited - space casing 11 becomes a very troublesome problem. Since the wire harness is concentrated together and has a large diameter, if the up - and - down wiring connection method is adopted inside the casing 11, it will hinder the normal operation of some components inside the casing 11. If the wire is set through the hinge shaft connecting the machine cover 12 and the machine base 13, because the diameter of this hinge shaft is small (since this is a small printer 1 in the present utility model, the diameter of this hinge shaft is between 0.8 mm and 2.5 mm, preferably 2.0 mm), the connection method of passing the wire through cannot be adopted. Therefore, the present utility model adopts the following structure for the electrical connection between the print head assembly 2 and the main control circuit board:

[0046] The print head assembly 2 includes a substrate 21 made of ceramic material, a heating wire and a thermal control circuit disposed on the substrate 21 (the heating wire and the thermal control circuit are not shown in the figure, and the thermal control circuit is a circuit printed on the substrate 21 for controlling the operation of the heating wire). In the present utility model, the power supply wire for supplying power to the heating wire and the signal wire for sending control instructions to the thermal control circuit are led out through an FPC circuit board 3 which is connected to the rear side of the substrate 21 (taking Figure 6 the paper surface direction as an example, the left side is the front and the right side is the rear, the same below) and is in a long strip shape. After being led out, the FPC circuit board 3 is bent upward (see Figures 5-7 as shown), so as to complete the external connection of the thermal control circuit in the narrow front-rear direction inside the casing 11. At the same time, internal connection terminals 31 for external connection of the power supply circuit and the signal circuit are provided at both ends of the FPC circuit board 3. The internal connection terminals 31 can be two terminals with the power supply circuit and the signal circuit separately arranged, or the power supply circuit and the signal circuit can be arranged together on an internal connection terminal 31 having multiple channels. The internal connection terminals 31 are electrically connected to corresponding external connection terminals 32 provided on the casing 11 of the printer 1. This setting method can effectively reduce the size of the casing 11 in the width direction.

[0047] The internal connection terminals 31 are in two groups and are respectively arranged on the support frames 17 on both sides of the printer cover 12 of the printer 1. Correspondingly, the external connection terminals 32 are also in two groups and are respectively arranged on the base frames 18 of the power supply chambers 16 on both sides of the printer base 13 of the printer 1; the electrical connection terminals composed of a group of internal connection terminals 31 and the corresponding group of external connection terminals 32 include a plurality of power supply connection channels and electrical signal transmission channels.

[0048] When the print head is pressed against the printing rubber roller through the ribbon, the internal connection terminals 31 are electrically connected to the corresponding external connection terminals 32.

[0049] The internal connection terminals 31 and the external connection terminals 32 of the present utility model preferably adopt the following several structures:

[0050] 1. The internal connection terminals 31 and the external connection terminals 32 are respectively a male row plug and a female row plug. The internal connection terminals 31 are arranged on the support frame 17 on the side of the printer cover 12 of the printer 1, and the external connection terminals 32 are vertically corresponding to the internal connection terminals 31 and are arranged on the base frame 18 of the power supply chamber 16 on the side of the printer base 13 of the printer 1.

[0051] 2. One of the internal connection terminals 31 and the external connection terminals 32 adopts the elastic contact pin 4, and the other is a fixed rigid contact plate. The internal connection terminals 31 / external connection terminals 32 are arranged on the support frame 17 on the side of the printer cover 12 of the printer 1. Correspondingly, the external connection terminals 32 / internal connection terminals 31 are arranged on the base frame 18 of the power supply chamber 16 on the side of the printer base 13 of the printer 1 in a manner vertically corresponding to the internal connection terminals 31 / external connection terminals 32 arranged on the support frame 17.

[0052] As Figure 9 shown, the elastic contact pin 4 is composed of a conductive post cavity 41, a compression spring 42 placed in the conductive post cavity 41, and a conductive post 43. The compression spring 42 is placed in the conductive post cavity 41 and is between the top end of the conductive post 43 and the top end surface in the conductive post cavity 41. The conductive post 43 is in contact with the inner wall of the conductive post cavity 41 and can move up and down in the conductive post cavity 41.

[0053] The shape of the rigid contact plate can be a flat surface or a concave plate 44 with an arc-shaped curved surface. The present invention preferably uses the concave plate 44 with an arc-shaped curved surface.

[0054] When the internal terminal 31 is connected to the external terminal 32, the conductive post 43 in one elastically abuts against the concave plate 44 in the other, thereby achieving electrical connection.

[0055] 3. Both the internal terminal 31 and the external terminal 32 are the elastic contact pins 4 as described above. The internal terminal 31 is arranged on the support frame 17 on the side of the printer 1 cover 12, and the external terminal 32 is arranged corresponding to the internal terminal 31 up and down and is arranged on the base frame 18 of the power compartment 16 on the side of the printer 1 base 13.

[0056] When the internal terminal 31 is connected to the external terminal 32, the conductive posts 43 in both elastically abut against each other, thereby achieving electrical connection.

[0057] 4. Both the internal terminal 31 and the external terminal 32 are the rigid contacts as described above. The internal terminal 31 is arranged on the support frame 17 on the side of the printer 1 cover 12, and the external terminal 32 is arranged corresponding to the internal terminal 31 up and down and is arranged on the base frame 18 of the power compartment 16 on the side of the printer 1 base 13.

[0058] When the internal terminal 31 is connected to the external terminal 32, the rigid contacts in both abut against each other, thereby achieving electrical connection.

Claims

1. A print head assembly for a small thermal transfer printer, comprising a ceramic substrate (21), a heating wire and a thermal control circuit arranged on the substrate (21), characterized in that: A power supply path for providing power to the heating wire and a signal path for sending control instructions to the thermal control circuit are led out through a long FPC circuit board (3) connected to one side of the substrate (21). A power supply circuit and a signal circuit are arranged on internal terminals (31) of an integral structure at both ends of the FPC circuit board (3), or the power supply circuit and the signal circuit are arranged on different internal terminals (31) respectively. The internal terminals (31) are electrically connected to corresponding external terminals (32) arranged on the housing (11) of the printer (1).

2. The print head assembly for a small thermal transfer printer according to claim 1, characterized in that: The internal terminal (31) and the external terminal (32) are respectively a male plug and a female plug. The internal terminal (31) is arranged on a support frame (17) on the side of the cover (12) of the printer (1). The external terminal (32) corresponds to the internal terminal (31) in upper and lower positions and is arranged on a base frame (18) of a power compartment (16) on the side of the base (13) of the printer (1).

3. The print head assembly for a small thermal transfer printer according to claim 1, characterized in that: The internal terminal (31) and the external terminal (32) are respectively an elastic contact pin (4) and a rigid contact plate, or the internal terminal (31) and the external terminal (32) are respectively a rigid contact plate and an elastic contact pin (4); the internal terminal (31) is arranged on a support frame (17) on the side of a cover (12) of the printer (1), and the external terminal (32) corresponds to the internal terminal (31) in upper and lower positions and is arranged on a base frame (18) of a power chamber (16) on the side of a base (13) of the printer (1).

4. The print head assembly for a small thermal transfer printer according to claim 1, characterized in that: The internal terminal (31) and the external terminal (32) are both elastic contact pins (4); the internal terminal (31) is arranged on a support frame (17) on the side of the printer (1) cover (12); the external terminal (32) corresponds to the internal terminal (31) in upper and lower positions and is arranged on a base frame (18) of a power chamber (16) on the side of the printer (1) base (13).

5. The print head assembly for a small thermal transfer printer according to claim 1, characterized in that: The internal terminals (31) and the external terminals (32) are both in rigid contact. The internal terminals (31) are arranged on a support frame (17) on the side of the printer (1) cover (12), and the external terminals (32) correspond to the internal terminals (31) in upper and lower positions and are arranged on a base frame (18) of a power chamber (16) on the side of the printer (1) base (13).

6. The print head assembly for a small thermal transfer printer according to any one of claims 1 to 5, characterized in that: The internal terminals (31) are in two groups, which are respectively arranged on the support frames (17) on both sides of the printer (1) cover (12); correspondingly, the external terminals (32) are also in two groups, which are respectively arranged on the base frame (18) of the power compartment (16) on both sides of the printer (1) base (13); the electrical connection terminals composed of a group of internal terminals (31) and a corresponding group of external terminals (32) include a plurality of power supply connection channels and electrical signal transmission channels.

7. The print head assembly for a small thermal transfer printer according to claim 3, characterized in that: The elastic contact pin (4) is composed of a conductive column cavity (41), a compression spring (42) and a conductive column (43) disposed in the conductive column cavity (41); the compression spring (42) is disposed in the conductive column cavity (41) and is between the top end of the conductive column (43) and the top end surface in the conductive column cavity (41); the conductive column (43) contacts the inner wall of the conductive column cavity (41) and can move up and down in the conductive column cavity (41).

8. The print head assembly for a small thermal transfer printer according to claim 7, characterized in that: The rigid touch panel is in the shape of a concave panel (44) with a flat surface or an arc surface.

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