JPH0623758U - Thermal printer - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a small thermal printer capable of forming a printed image of extremely high printing quality on a thermal paper or the like by uniformly dissipating heat of a heat sink into the atmosphere. A thermal head includes a head substrate 1 having a plurality of heating resistors 2, a heat radiating plate 4 supporting the head substrate 1 on an upper surface thereof, and a frame 4a attached to the lower surface thereof, and the heat radiating plate. 4 and the cooling fan 5 that blows air into the lower surface frame 4a of the heat dissipation plate 4, when the air is blown to the lower surface of the heat dissipation plate 4 by the cooling fan 5, the wind inside the lower surface frame 4a of the heat dissipation plate 4 The convection occurs and the heat can be evenly and efficiently dissipated from the entire heat dissipation plate 4 into the atmosphere.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a thermal printer used for a printer mechanism such as a word processor and a facsimile.

[0002]

[Prior art]

 Conventionally, a thermal printer used for a printer mechanism such as a word processor has a plurality of heating resistors 12 made of tantalum nitride or the like on the upper surface and a pair of conductive members made of aluminum or the like, as shown in FIGS. 3 (a) and 3 (b). A head substrate 11 made of an electrically insulating material such as aluminum ceramics, to which the layer 13 is adhered, a heat dissipation plate 14 that supports the head substrate 11 and absorbs part of the heat of the head substrate 11, and the heat dissipation. The cooling fan 15 is arranged below the plate 14 and dissipates the heat of the radiator plate 14 into the atmosphere by blowing a certain amount of air onto the radiator plate 14. A constant wind is blown to the lower surface of 14 and electric power is applied between the pair of conductive layers 13 to cause Joule heat generation of the heating resistor 12, and the generated heat is conducted to a thermal paper or the like. Functions as a thermal printer by forming printed images on the thermosensitive paper.

[0003]

[Problems to be solved by the device]

 However, in this conventional thermal printer, when the length of the head substrate 11 and the heat dissipation plate 14 supporting the head substrate 11 is A4 size, it is about 230 mm, and the size of the cooling fan 15 (the diameter of the fan) Longer than about 100 mm) and the bottom surface of the heat sink 14 is flat. Therefore, power is applied to the heating resistor 12 while blowing air through the cooling fan 15 onto the bottom surface of the heat sink 14. When a printed image is formed on heat-sensitive paper by applying the applied heat to the heat-sensitive paper, the cooling fan 15 blows air locally to the heat sink 14, resulting in a variation in the temperature of the heat sink 14. The temperature of the head substrate 11 supported on the upper surface of the heat dissipation plate 14 also fluctuates, and it is impossible to form a printed image of extremely high printing quality on a thermal paper or the like. The had.

Further, in order to solve the above-mentioned drawbacks, it is conceivable that the cooling fan 15 is made large so that a wind having a substantially uniform strength can be blown to the entire lower surface of the heat dissipation plate 14.

However, if the cooling fan 15 is increased in size, the entire structure of the thermal printer becomes extremely large, and it becomes difficult to mount it on a word processor, a facsimile, or the like, which has recently been reduced in size, and the cooling fan 15 is operated. It induces the drawback of requiring a very large power supply to activate.

[0006]

[The purpose of the device]

 The present invention has been devised in view of the above-mentioned drawbacks, and its purpose is to dissipate the heat of a heat sink evenly into the atmosphere and to form a printed image of extremely high print quality on a thermal paper or the like. To provide a thermal printer.

[0007]

[Means for Solving Problems]

 The thermal printer of the present invention comprises a head substrate having a plurality of heating resistors, a heat radiating plate which supports the head substrate on an upper surface thereof, and a frame body is attached to a lower surface thereof, and a lower frame body of the heat radiating plate. It is characterized by being composed of a cooling fan for blowing air on.

[0008]

【Example】

 Next, the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show an embodiment of a thermal printer of the present invention, 1 is a head substrate, 4 is a heat radiating plate, and 5 is a cooling fan.

The head substrate 1 is made of an electrically insulating material such as alumina ceramics, and is connected to a plurality of heating resistors 2 and both ends of the heating resistors 2 via a heat storage layer 1 a made of glass or the like on the upper surface thereof. A pair of conductive layers 3 are deposited.

When the head substrate 1 is made of, for example, alumina ceramics, it is formed by mixing a ceramic raw material powder such as alumina, silica, magnesia, etc. with an appropriate organic solvent and a solvent to form a sludge shape. A ceramic green sheet is formed by employing a blade method, a calendar roll method, or the like, and then the ceramic green sheet is punched into a predetermined shape and baked at a high temperature (about 1600 ° C.).

Further, a heat storage layer 1a made of glass or the like is deposited on the upper surface of the head substrate 1, and the heat storage layer 1a stores the heat generated by the heating resistor 2 to reduce the temperature of the thermal printer for a short time. The temperature is adjusted to the temperature required to form a printed image on thermal paper.

The heat storage layer 1a is obtained by applying a well-known screen printing method or the like to a predetermined area on the upper surface of the head substrate 1 by using a glass paste obtained by adding and mixing an appropriate organic solvent to glass powder. It is applied by printing, and then baked at a high temperature, for example, a temperature of about 700 ° C. to be applied to the upper surface of the head substrate 1.

Further, a plurality of heating resistors 2 are deposited and arranged on the upper surface of the heat storage layer 1a, and a pair of conductive layers 3 are connected to each heating resistor 2.

Since the heating resistor 2 is made of, for example, tantalum nitride or the like and has a predetermined electric resistance, it generates Joule heat when electric power is applied through the pair of conductive layers 3. It is raised and generates heat at a temperature necessary to form a printed image, for example, a temperature of 250 to 400 ° C.

The pair of conductive layers 3 connected to the heating resistor 2 are made of metal such as aluminum and have a function of applying a predetermined electric power required to cause Joule heating to the heating resistor 2. Do

The heating resistor 2 and the pair of conductive layers 3 are adhered to the head substrate 1 with a predetermined thickness by using a conventionally known sputtering method or the like, and a photolithography technique is further adopted. As a result, it is processed into a predetermined pattern.

The heating resistor 2 and the pair of conductive layers 3 are worn on the upper surfaces of the heating resistor 2 and the pair of conductive layers 3 by sliding thermal paper, moisture in the atmosphere, thermal paper, etc. A protective film 6 is applied to effectively prevent corrosion due to contaminants such as chlorine ions and sodium ions contained in.

The protective layer 6 is made of, for example, silicon nitride or the like, and is deposited to a predetermined thickness on the upper surface of the heating resistor 2 or the like by adopting a conventionally known sputtering method or the like.

The head substrate 1 having the heating resistor 2 and the pair of conductive layers 3 adhered to the upper surface thereof is also brought into contact with the upper surface of the heat dissipation plate 4 made of aluminum or the like at its lower surface, whereby the head substrate 1 1 is supported on the heat dissipation plate 4.

The heat dissipation plate 4 conducts and absorbs a part of the heat of the head substrate 1 and effectively prevents the head substrate 1 from being excessively heated by the heat generated by the heat-generating antibody 2.

The heat dissipation plate 4 is manufactured by forming an ingot (lump) made of aluminum or the like into a predetermined shape by using a conventionally known metal working method.

A frame 4a is attached to the outer periphery of the lower surface of the heat radiating plate 4, and air is blown into the frame 4a by a cooling fan 5 described later.

Since the frame body 4 a is attached to the outer periphery of the lower surface of the heat dissipation plate 4, when the cooling fan 5 blows air into the frame body 4 a, the wind convects in the frame body 4 a to release heat. The heat of the plate 4 is evenly dissipated into the atmosphere from the entire lower surface thereof, and as a result, the temperature of the entire heat dissipation plate 4 is made uniform and the temperature of the head substrate 1 supported on the upper surface of the heat dissipation plate 4 is also made uniform. Eggplant For this reason, in this thermal printer, since the temperature of the head substrate 1 is uniform, when forming a print image on a thermal paper or the like, there is almost no uneven density on the thermal paper or the like. It is possible to form various printed images.

When the heat dissipation plate 4 is manufactured by a conventionally well-known metal working method, the frame 4a has a frame shape of a predetermined thickness and a predetermined height along the edge of the bottom surface of the heat dissipation plate 4. It is attached to the lower surface of the heat radiating plate 4 by forming the projecting portion as a unit.

Further, if the height h of the frame body 4a is set to 10 mm or more, the air blown from the cooling fan 5 is satisfactorily convected to the lower surface of the heat dissipation plate 4 so that the heat of the heat dissipation plate 4 is released. It can be diffused into the atmosphere evenly over its entirety. Therefore, the frame body 4a preferably has a height h of 10 mm or more.

Furthermore, a cooling fan 5 is arranged below the heat dissipation plate 4, and the cooling fan 5 cools the heat dissipation plate 4 by blowing air into the lower frame 4 a of the heat dissipation plate 4. To maintain an appropriate temperature.

The cooling fan 5 has a frame 4a attached to the lower surface of the heat dissipation plate 4, and air is convected in the frame 4a. Therefore, it is not necessary to prepare a large amount of air. No Therefore, it is possible to use a cooling fan 5 that is small and operates with a small amount of electric power, which makes it possible to reduce the overall shape of the thermal printer and mount it on a word processor, facsimile, etc., which is becoming smaller in recent years. .

Thus, the above-described thermal printer applies Joule heat to the heating resistor 2 to a predetermined temperature by applying a predetermined electric power between the pair of conductive layers 3 while blowing a wind on the lower surface of the heat dissipation plate 4 by the cooling fan 5. At the same time, the generated heat is conducted to thermal paper or the like to form a printed image on the thermal paper or the like, thereby functioning as a thermal printer.

The present invention is not limited to the above embodiments, and various modifications and improvements can be made without departing from the gist of the present invention. The plate and frame were integrally molded to attach the frame to the lower surface of the heat sink.However, the frame was attached to the lower surface of the heat sink by an adhesive or the like to attach it to the lower surface of the heat sink. It doesn't matter.

[0031]

[Effect of device]

 According to the thermal printer of the present invention, since the frame is attached to the lower surface of the heat dissipation plate that supports the head substrate, when the cooling fan blows air on the lower surface of the heat dissipation plate, the lower surface frame of the heat dissipation plate. Wind convection occurs in the body, and heat can be evenly and efficiently dissipated from the entire heat sink into the atmosphere. As a result, the heat sink has a uniform temperature and is supported on the upper surface of the heat sink. The temperature of the head substrate becomes uniform, and when forming a printed image on thermal paper, there is almost no uneven density on the thermal paper, and it is possible to form a clear printed image with extremely high print quality. Become.

[Brief description of drawings]

FIG. 1A is a perspective view of a thermal printer of the present invention seen from above, and FIG. 1B is a perspective view seen from below.

2A is a perspective view of a head substrate of a thermal printer of the present invention, and FIG. 2B is a sectional view taken along line XX of FIG.

FIG. 3A is a perspective view of a conventional thermal printer seen from above, and FIG. 3B is a perspective view seen from below.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Head substrate 1a ... Heat storage layer 2 ... Heating resistor 3 ... A pair of conductive layers 4 ... Heat dissipation plate 4a ... Frame 5 ... Cooling fan 6 ... Protective film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 8906-2C B41J 3/20 110

Claims (1)

[Scope of utility model registration request] 1. A head substrate having a plurality of heating resistors, a heat radiating plate supporting the head substrate on its upper surface and having a frame attached to its lower surface, and a wind on the lower frame of said heat radiating plate. A thermal printer consisting of a cooling fan for spraying.