JP7189788B2 - image forming device - Google Patents

Description

The present invention relates to an image forming apparatus.

2. Description of the Related Art An inkjet printer in which an air inlet is provided in a housing of a carriage and air flows into the carriage so that a substrate inside the carriage can be cooled is known (Patent Document 1). Further, there is conventionally known a structure in which openings are provided on both sides in the moving direction of the print head, air is taken into the inside of the print head, and a substrate inside the print head is cooled (Patent Document 2).

JP-A-10-44386 JP-A-2-252573

Conventionally, the substrate inside the carriage or printhead is in contact with the entrained air for cooling. However, an image forming apparatus that employs the inkjet method ejects minute amounts of ink to perform printing. As ink droplets are ejected from the nozzles of the print head, ink mist, which is finer ink droplets, is generated. In addition to dust, the air around the carriage or printhead contains ink mist.

Therefore, when air is introduced into the inside of the carriage and the inside of the print head to cool the substrate, as in the past, foreign substances such as ink mist and dust come into contact with the circuits and electronic components on the substrate, causing short circuits and damage to electronic components. There was a risk of causing trouble.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an image forming apparatus capable of cooling a substrate while protecting it from foreign matter.

In order to solve the above-mentioned problems, the present invention provides a carriage movable in a scanning direction, a substrate provided on the carriage on which a drive circuit for an inkjet head is mounted, a cover covering at least part of the drive circuit, and and an exposed portion exposed to the outside from a cover, wherein the exposed portion includes a radiator plate installed on the substrate.

The present invention can provide an image forming apparatus capable of cooling a substrate while protecting it from foreign matter.

1 is an external perspective view showing a printing apparatus according to an embodiment; FIG. 1 is a block diagram of a printing device according to an embodiment; FIG. 4 is a perspective view from the front of the carriage according to the embodiment; FIG. In order to facilitate understanding, the mechanism, parts, etc. inside the carriage are shown through. Also, the upper cover is illustrated in a disassembled state upward. 4 is a perspective view from the rear of the carriage according to the embodiment; FIG. In order to facilitate understanding, the mechanism, parts, etc. inside the carriage are shown through. Also, the upper cover is illustrated in a disassembled state upward. 4 is a top view of the carriage according to the embodiment; FIG. To facilitate understanding, illustration of the upper cover is omitted. It is a perspective view of (a) a rear cover and (b) a front cover according to the embodiment. 4 is a side view of the carriage according to the embodiment; FIG. FIG. 11 is a rear perspective view of a carriage according to a modification; In order to facilitate understanding, the mechanism, parts, etc. inside the carriage are shown through. Also, the upper cover and the lower cover are shown in an exploded state upward. FIG. 11 is a side view of a carriage according to a modified example;

<Embodiment>
A printing apparatus 1, which is an embodiment of the image forming apparatus of the present invention, will be described with reference to FIGS. 1 to 7. FIG. The printing device 1 is an inkjet printer, and is a device for performing printing by ejecting ink onto a printing medium 9 (paper, film, cloth, etc.). As shown in FIGS. 1 and 2, the printing apparatus 1 includes a transport mechanism section 2, a control section 3, and a carriage 4. As shown in FIGS. As shown in FIG. 1, in the printing apparatus 1, three mutually orthogonal directions are defined as a vertical direction, a front-back direction, and a left-right direction. Note that, hereinafter, the front-rear direction may be referred to as the transport direction, and the left-right direction may be referred to as the main scanning direction.

Note that the “inkjet method” in the embodiments and modifications means a liquid supply method that supplies the liquid to a target position by ejecting fine droplets of liquid such as ink or photocurable resin. do. Various methods, such as a thermal method or a piezoelectric element method, can be adopted as a method of forming droplets.

The printing apparatus 1 mainly includes a body portion 10 and guide rails 11 . Openings are formed in the front and rear surfaces of the main body 10, and the openings are opened and closed by respective covers. FIG. 1 shows a state in which a cover for opening and closing the front opening of the main body 10 is removed. The guide rail 11 is a shaft-shaped member and is attached to the main body 10 so as to extend in the left-right direction.

The transport mechanism unit 2 transports the print medium 9 in the front-rear direction, and includes a transport roller (not shown) that is a driving roller and a pinch roller 22 that is a driven roller (FIG. 1). . The conveying roller is rotatable by being powered by a motor (not shown). The print medium 9 can be transported in the front-rear direction by rotating the transport rollers while the print medium 9 is sandwiched between the transport rollers and the pinch rollers 22 .

The control unit 3 is for controlling the printing apparatus 1 . The control unit 3 is communicably connected to the transport mechanism unit 2 and the carriage 4, and has a function of controlling the operations of these units. The configuration of the control unit 3 is not particularly limited, but in this embodiment, an interface (I/F) for receiving print data (raster data) and the like from an external device, a ROM for storing programs, and a It mainly includes a CPU, a RAM that provides a work area for processing by the CPU, and an NVRAM that is a non-volatile memory and stores various data. The control unit 3 controls the transport mechanism unit 2 and the carriage 4 of the printing device 1 based on the received print data.

The carriage 4 has various components for performing ink jet printer type printing. Specifically, as shown in FIGS. 3 and 4, the carriage 4 includes a housing 41, a substrate 42, radiator plates 43A and 43B, and a head section 44. As shown in FIGS. The carriage 4 is movably engaged with the guide rail 11 in the main scanning direction, and has a function of executing printing by ejecting ink onto the print medium 9 . Four types of ink, ie, yellow ink Y, magenta ink M, cyan ink C, and black ink K are used.

<Case>
The housing 41 is a member forming the outer shell of the carriage 4 and includes an upper wall 410 , a front cover 411 , a rear cover 412 , an upper cover 413 , side walls 414 and a lower wall 415 .

The upper wall 410 , the side walls 414 , and the lower wall 415 constitute the lower portion and the rear portion of the carriage 4 and have the function of supporting mechanisms and parts inside the carriage 4 such as the substrate 42 and the head portion 44 . The upper wall 410 is a substantially rectangular plate-shaped member extending in the left-right direction and the front-rear direction, and is arranged above the guide rail 11 with a predetermined space therebetween. The upper surface of the upper wall 410 supports the substrate 42 and also supports the front cover 411 and the rear cover 412 .

The side wall 414 is a plate-like member connected to the front end of the upper wall 410 and provided to hang down from the front end of the upper wall 410 . The side wall 414 is formed in a substantially rectangular shape when viewed in the front-rear direction. 414 A of engaging parts are fixed to the rear surface of the side wall 414 (FIG. 3, FIG. 4). The engaging portion 414A is supported movably in the main scanning direction with respect to the guide rail 11 .

The lower wall 415 is a substantially rectangular plate-like member that is connected to the lower end of the side wall 414 and extends forward. The head portion 44 is provided on the lower wall 415 so as to vertically penetrate the lower wall 415 .

<Case, front cover>
As shown in FIGS. 3-7 , front cover 411 is positioned to cover the top surface of top wall 410 , the front surface of side walls 414 , and the top surface of bottom wall 415 . Also, the front cover 411 abuts on the upper surface of the upper wall 410 , the front surface of the side walls 414 , and the upper surface of the lower wall 415 . The front cover 411 is a member configured by a plurality of plate-like members and forming an internal space, and accommodates a part of the substrate 42 and the head section 44 in the internal space. The front cover 411 includes two side plates 411A, wall-opening plates 411Ba and 411Bb, a rear plate 411C, upper plates 411E and 411F, and a front plate 411G. It is fixed (FIG. 6(b)).

The two side plates 411A are plate-like members formed in the same shape, and constitute left and right outer walls of the front cover 411, respectively. The lower portion of the side plate 411A is formed to have substantially the same shape as the upper surface of the upper wall 410, the front surface of the side wall 414, and the upper surface of the lower wall 415 when viewed in the left-right direction. Therefore, the lower portion of the side plate 411A is in contact with the upper surface of the upper wall 410, the front surface of the side wall 414, and the upper surface of the lower wall 415 without gaps.

The wall-opening plates 411Ba and 411Bb are plate-like members, and are arranged on the left and right sides of the rear plate 411C (FIG. 6(b)). Specifically, the wall-opening plate 411Ba is arranged on the right side of the rear plate 411C, and the wall-opening plate 411Bb is arranged and fixed on the left side of the rear plate 411C. The wall plates 411Ba and 411Bb extend vertically and are arranged to form a predetermined angle with respect to the main scanning direction. Specifically, the open wall plates 411Ba and 411Bb are arranged so as to incline forward as they go outward in the main scanning direction of the front cover 411 when viewed from above (FIG. 5). The wall-opening plates 411Ba and 411Bb each form a notch portion 411H (FIG. 6(b)). The upper end of the notch portion 411H is formed so as to be flush with the upper surface of the substrate 42 . Therefore, the upper surface of the substrate 42 is in contact with the wall plates 411Ba and 411Bb without gaps.

The rear plate 411C is a plate-like member arranged to extend vertically and horizontally. The lower end of the rear plate 411C is formed so as to be flush with the upper surface of the substrate 42, so that the lower end of the rear plate 411C contacts the upper surface of the substrate 42 without any gap. The rear plate 411C is fixed to the wall-opening plates 411Ba and 411Bb arranged on the left and right sides thereof, and forms a continuous rear surface of the front cover 411 together with the wall-opening plates 411Ba and 411Bb. The rear plate 411C forms a rectangular opening 411D.

The upper plate 411E is a plate-like member formed in a substantially trapezoidal shape, and is arranged to extend in the front-rear and left-right directions. The rear end of the upper plate 411E is fixed to the upper end of the rear plate 411C, and the left and right ends of the upper plate 411E are fixed to the upper end of the side plate 411A and the upper ends of the wall plates 411Ba and 411Bb. The upper plate 411E is arranged above the substrate 42 with a predetermined distance therebetween.

The upper plate 411F is a substantially rectangular plate-like member that is arranged to be inclined when viewed in the left-right direction. The rear end of the top plate 411F is fixed to the front end of the top plate 411E, and the left and right ends of the top plate 411F are fixed to the side plates 411A, respectively. The upper plate 411F is inclined downward toward the front. The upper plate 411F is arranged at a predetermined distance from the front portion of the upper wall 410, the side walls 414 and the lower wall 415. As shown in FIG.

The front plate 411G is a substantially rectangular plate member arranged to extend vertically and horizontally. The upper end of the front plate 411G is fixed to the front end of the upper plate 411F, and the left and right ends of the front plate 411G are fixed to the front ends of the side plates 411A. A lower end portion of the front plate 411G is in contact with the upper surface of the lower wall 415 without any gap. The front plate 411G is arranged with a predetermined distance from the side wall 414 and the head portion 44 .

<Case, rear cover>
As shown in FIGS. 3-7, the rear cover 412 is arranged to cover the top surface of the top wall 410 . A lower end portion of the rear cover 412 is in contact with the upper surface of the upper wall 410 . The rear cover 412 is a member that forms an internal space, and accommodates the rear portion of the substrate 42 in the internal space. The rear cover 412 includes two side plates 412A, wall opening plates 412Ba and 412Bb, a front plate 412C, an upper plate 412E, and a rear plate 412G. (Fig. 6(a)).

The two side plates 412A are substantially rectangular plate members formed in the same shape, and constitute left and right outer walls of the rear cover 412, respectively. A lower end portion of the side plate 412A is in contact with the upper surface of the upper wall 410 without any gap.

The wall-opening plates 412Ba and 412Bb are plate-like members, and are arranged on the left and right sides of the front plate 412C. Specifically, the wall-opening plate 412Ba is arranged on the right side of the front plate 412C, and the wall-opening plate 412Bb is arranged on the left side of the front plate 412C and fixed. The wall plates 412Ba and 412Bb extend vertically and are arranged to form a predetermined angle with respect to the main scanning direction. Specifically, the wall-opening plates 412Ba and 412Bb are arranged so as to incline rearward as they go outward in the main scanning direction of the rear cover 412 when viewed from above (FIG. 5).

The wall plates 412Ba and 412Bb each form a notch 412H (FIG. 6(a)). The upper end of the notch portion 412H is formed so as to be flush with the upper surface of the substrate 42 . Therefore, the upper surface of the substrate 42 is in contact with the wall plates 412Ba and 412Bb without gaps.

The front plate 412C is a plate-like member arranged to extend vertically and horizontally. The lower end of the front plate 412C is formed so as to be flush with the upper surface of the substrate 42, so that the lower end of the front plate 412C contacts the upper surface of the substrate 42 without any gap. The front plate 412C is fixed to the wall-opening plates 412Ba and 412Bb arranged on the left and right sides thereof, and forms a continuous front surface of the rear cover 412 together with the wall-opening plates 412Ba and 412Bb. The front plate 412C forms a rectangular opening 412D (FIG. 6(a)).

The upper plate 412E is a plate-like member formed in a substantially trapezoidal shape and extends front and rear and left and right. The front end of the upper plate 412E is fixed to the upper end of the front plate 412C, and the left and right ends of the upper plate 412E are fixed to the upper end of the side plate 412A and the upper ends of the wall plates 412Ba and 412Bb. The upper plate 412E is arranged above the substrate 42 with a predetermined distance therebetween.

The rear plate 412G is a substantially rectangular plate member arranged to extend vertically and horizontally. The upper end of the rear plate 412G is fixed to the rear end of the upper plate 412E, and the left and right ends of the rear plate 412G are fixed to the rear ends of the side plates 412A. A lower end portion of the rear plate 412G is in contact with the upper surface of the upper wall 410 without any gap.

<Upper cover>
The upper cover 413 is a substantially rectangular plate-like member extending in the horizontal direction, and spans the front cover 411 and the rear cover 412 . The front part of the upper cover 413 is fixed to the upper surface of the upper plate 411E, and the rear part of the upper cover 413 is fixed to the upper surface of the upper plate 412E. The center portion of the upper cover 413 in the front-rear direction vertically faces the substrate 42 with a predetermined distance therebetween.

<Substrate>
As shown in FIGS. 3, 4 and 7, the substrate 42 is placed substantially horizontally above the upper wall 410 via four substantially cylindrical supports 45 . The substrate 42 includes a drive circuit 421 arranged on the upper surface of the substrate 42, driver elements 422 and 423, and four FFCs 424 and 425. FIG. Both FFC424 and FFC425 are flat cables made by sandwiching a conductor between films from above and below.

The drive circuit 421 is a circuit used to drive the head section 44 and is formed over substantially the entire upper surface of the substrate 42 . The drive circuit 421 is electrically connected to the driver elements 422 and 423 . In addition to the driver elements 422 and 423, the driving circuit 421 includes a plurality of elements (not shown), which are electrically connected to each other. The drive circuit 421 has a front circuit 421A arranged on the front side, a rear circuit 421C arranged on the rear side, and a central circuit 421B arranged between the front circuit 421A and the rear circuit 421C (see FIG. 7).

A driver element 422 is provided in the front circuit 421A. The front circuit 421A is covered with the front cover 411 and housed inside the front cover 411 . The front part circuit 421A is electrically connected to the head part 44 via the FFC 424 .

A driver element 423 is provided in the rear circuit 421C. The rear circuit 421C is covered with the rear cover 412 and housed inside the rear cover 412 . 421 C of rear circuits are electrically connected with the control part 3 via FFC425.

The central circuit 421B is composed of a circuit that electrically connects the front circuit 421A and the rear circuit 421C, and has no elements. Central circuit 421 B is exposed from both front cover 411 and rear cover 412 . The central circuit 421B is covered with a resist from above and protected from the outside air.

In addition, the cover 416 covering the lower portion of the central circuit 421B prevents the cooling air from entering the covers 411 and 412 . Specifically, the cover 416 includes covers 416A and 416B that cover the lower portions of the left and right ends of the substrate 42, and prevents cooling air from entering the covers 411 and 412 from the lower portion of the substrate 42 (FIGS. 3, 4 and 7). . The covers 416A and 416B are rectangular plate members when viewed from the left and right sides. The upper ends of the covers 416A and 416B both contact the lower surface of the substrate 42, and the lower ends of the covers 416A and 416B contact the upper surface of the upper wall 410. As shown in FIG. The front end and rear end of the cover 416A abut on the wall opening plate 411Bb and the wall opening plate 412Bb, respectively. The front end and rear end of the cover 416B abut on the wall opening plate 411Ba and the wall opening plate 412Ba, respectively.

The driver element 422 is a driver IC element on the high side gate side and is electrically connected to the front circuit 421A. The driver element 422 is composed of four driver elements 422Y, 422M, 422C and 422K. Each element corresponds to four heads 44Y, 44M, 44C, and 44K (described later) that constitute the head section 44, and has a function of adjusting the supply voltage to the corresponding heads. The driver elements 422Y, 422M, 422C, and 422K stand vertically with respect to the substrate 42, and their rear surfaces are supported and fixed to the front surface of the radiator plate 43A.

The driver element 423 is a driver IC element on the low side gate side and is electrically connected to the rear circuit 421C. The driver element 423 is composed of four driver elements 423Y, 423M, 423C and 423K. Each element corresponds to four heads 44Y, 44M, 44C, and 44K (described later) that constitute the head section 44, and has a function of adjusting the supply voltage to the corresponding heads. The driver elements 423Y, 423M, 423C, and 422K stand vertically with respect to the substrate 42, and their front surfaces are supported and fixed to the rear surface of the radiator plate 43B.

<Heat sink>
The heat sinks 43A and 43B are members that release heat generated by the driver elements 422 and 423 and the substrate 42 to the outside, and are made of metal with high thermal conductivity such as aluminum or copper. The radiator plates 43A and 43B are erected so as to be perpendicular to the upper surface of the substrate 42, respectively. The heat sinks 43A and 43B are formed to have approximately the same shape and size as the openings 411D and 412D, respectively, when viewed from the front or rear.

43 A of heat sinks are located in front of the heat sink 43B, and are arrange|positioned so that the opening part 411D may be closed. The rear surface of the heat sink 43A is exposed to the outside through the opening 411D, and the front surface of the heat sink 43A is housed inside the front cover 411. As shown in FIG. The radiator plate 43B is arranged so as to close the opening 412D. The front surface of the heat sink 43B is exposed to the outside through the opening 412D, and the rear surface of the heat sink 43B is housed inside the rear cover 412. As shown in FIG.

The rear surface of the heat sink 43A and the front surface of the heat sink 43B face each other in the transport direction or the front-rear direction. The front surface of the radiator plate 43A is formed smooth, and contacts and supports the rear surfaces of the driver elements 422Y, 422M, 422C, and 422K. The rear surface of the radiator plate 43B is formed smooth, and contacts and supports the front surfaces of the driver elements 423Y, 423M, 423C, and 423K. Note that the components to be supported are not limited to the driver elements 422 and 423, and other elements, components, and the like may be supported. Although the rear surface of the heat sink 43A and the front surface of the heat sink 43B are shown smooth, they may have a plurality of protrusions or the like in order to increase the surface area and facilitate heat dissipation. In addition, the heat sink is an example of the exposed portion in the present invention.

<Wind path>
As shown in FIGS. 3 to 5, an air passage W is formed between the front cover 411 and the rear cover 412. As shown in FIG. The air passage W extends in the main scanning direction or the left-right direction, and a left opening L and a right opening R open to the outside are formed at both left and right ends of the air passage W, respectively. Therefore, the radiator plates 43A and 43B communicate with the openings L and R via the air passage W. As shown in FIG. The left opening L is an opening formed by the wall-opening plate 411Bb and the wall-opening plate 412Bb, and is formed so as to expand toward the left. The right opening R is an opening formed by the wall-opening plate 411Ba and the wall-opening plate 412Ba, and is formed so as to expand toward the right. In other words, each of the right opening R and the left opening L is formed to expand outward from the front cover 411 or the rear cover 412 in the main scanning direction.

Specifically, as shown in FIG. 5, the air passage W is formed between the heat sink 43A and the heat sink 43B. Furthermore, the air passage W is also formed between the wall-opening plates 411Ba, 411Bb, the rear plate 411C, and the wall-opening plates 412Ba, 412Bb, and the front plate 412C. The upper and lower portions of the air passage W are defined by the lower surface of the upper cover 413 and the upper surface of the substrate 42 .

<Head part>
The head unit 44 includes four heads that eject ink and are arranged side by side in the main scanning direction. Specifically, the head section 44 is composed of heads 44Y, 44M, 44C, and 44K corresponding to ink colors to be ejected.

Each of the heads 44Y, 44M, 44C, and 44K has a substantially rectangular parallelepiped shape, and a plurality of nozzles (not shown) for ejecting ink droplets are arranged and formed in the transport direction on the lower surface of each. .

The heads 44Y, 44M, 44C, and 44K are supported by the lower wall 415 and penetrate the lower wall 415 vertically. The upper parts of the heads 44Y, 44M, 44C and 44K are all accommodated inside the front cover 411. As shown in FIG. The heads 44Y, 44M, 44C, and 44K are electrically connected to the driving circuit 421 via the FFC 424, respectively.

<Printing work>
The operation of the printing apparatus 1 configured as described above when executing printing will be described below. The control unit 3 controls the carriage 4 and the transport mechanism unit 2 to eject ink droplets from the head unit 44 in accordance with print data to form an image on the print medium 9 . In the printing operation, the carriage 4 moves in the main scanning direction using a power source (not shown), and at the same time ejects ink droplets from the head section 44 toward the printing medium 9 . When ink is ejected, an ink mist that is finer than the ink droplets is generated. Therefore, in the air around the carriage 4 or the head unit 44, ink mist, which is finer than the ink droplets, is generated in addition to dust.

As the carriage 4 moves in the main scanning direction, cooling air, which is a relative air flow to the carriage 4 , is generated around the carriage 4 . Cooling air flows through the air path W as indicated by the white arrows in FIG. 5 to cool the radiator plates 43A and 43B. Since the left and right openings L and R expand outward from the housing 41 in the main scanning direction, a large amount of cooling air can be taken into the air passage W. The heat generated in the driver elements 422, 423 and the heat generated in the substrate 42 are conducted to the radiator plates 43A, 43B and released to the outside through the cooling air.

The front circuit 421A and the driver element 422 are shielded from the outside air by the front cover 411 and the radiator plate 43A. Also, the rear circuit 421C and the driver element 423 are shielded from the outside air by the rear cover 412 and the radiator plate 43B. Therefore, foreign substances in the air such as dust and ink mist are prevented from contacting the front circuit 421A and the rear circuit 421C, especially the driver elements 422 and 423. FIG. Also, since the central circuit 421B is covered with resist, it is prevented from coming into contact with foreign matter in the air.

<effect>
The printing apparatus 1 of the above embodiment has a carriage 4 that can move in the main scanning direction, and a substrate 42 that is provided on the carriage 4 and on which a drive circuit 421 for the head section 44 is mounted. Further, the printing apparatus 1 includes a front cover 411 or a rear cover 412 covering the front circuit 421A or the rear circuit 421C, and a radiator plate 43A or a radiator plate 43B installed on the substrate 42 and exposed to the outside from these covers. .

In the above configuration, the substrate 42, particularly the front circuit 421A and the rear circuit 421C, are shielded from the outside air and protected from foreign substances such as dust and ink mist in the air. Moreover, since the heat sinks 43A and 43B are exposed to the outside, the heat generated in the substrate 42 can be efficiently radiated to the outside air through the heat sinks 43A and 43B.

The front cover 411 or the rear cover 412 forms an opening L or an opening R that expands toward the outside of the front cover 411 or the rear cover 412 in the main scanning direction. It communicates with the openings L and R.

Since the openings L and R have a shape that expands outward, the cooling air can be efficiently collected and circulated to the radiator plates 43A and 43B. By efficiently collecting the cooling air, the amount of air contacting the radiator plate 43A or the radiator plate 43B is increased, and the heat radiation efficiency is improved.

The substrate 42 has driver elements 422 and 423 electrically connected to the drive circuit 421 . The heat sink 43A holds the driver element 422 on the front side, and the heat sink 43B holds the driver element 423 on the rear side. The front surface of the heat sink 43A or the rear surface of the heat sink 43B are covered with a front cover 411 and a rear cover 412, respectively.

In the above configuration, the driver elements 422 and 423 are covered with the front cover 411 and the rear cover 412 and protected from foreign matter. At the same time, the heat generated in the driver elements 422 and 423 is efficiently radiated to the outside because it is conducted directly to the radiator plates 43A and 43B.

The rear surface of the heat sink 43A or the front surface of the heat sink 43B is parallel to the main scanning direction.

In the above configuration, the radiator plates 43A and 43B are parallel to the cooling air circulation direction, so that the cooling air is not obstructed and the heat can be efficiently dissipated.

The radiator plates 43A and 43B are provided so as to face each other.

In the above configuration, the cooling air flow path can be provided at one location between the radiator plates 43A and 43B, and there is no need to provide a plurality of flow paths. Therefore, the carriage 4, the front cover 411, the rear cover 412, and the like can be made smaller.

The printing apparatus 1 includes a front cover 411 exposing the heat sink 43A to the outside and a rear cover 412 exposing the heat sink 43B to the outside. The printing apparatus 1 has an air passage W between the front cover 411 and the rear cover 412 formed by the heat sink 43A and the heat sink 43B.

With the above configuration, the cooling air flow path can be provided at one location between the front cover 411 and the rear cover 412, and there is no need to provide a plurality of flow paths. Therefore, the carriage 4, the front cover 411, the rear cover 412, and the like can be made smaller.

The printing apparatus 1 includes an upper cover 413 that spans the front cover 411 and the rear cover 412 and forms an air passage W together with the front cover 411 and the rear cover 412 .

In the above configuration, the upper cover 413 prevents the cooling air collected in the air passage W from escaping upward.

<Modification>
In the above embodiment, the upper cover 413 has a flat plate shape, but the present invention is not limited to such a configuration. For example, as shown in the modified carriage 5 of FIGS. 8 and 9, it may further have an upper cover 513 or a lower cover 516 . Other configurations of the carriage 5 are the same as those of the carriage 4 according to the embodiment.

Specifically, the upper cover 513 is made up of a plate-like member, and its central portion is arranged substantially horizontally. A front end portion of the upper cover 513 is in contact with the front cover 411 and the radiator plate 43A without a gap. Also, the rear end of the upper cover 513 is in contact with the rear cover 412 and the radiator plate 43B without gaps. Further, the upper cover 513 is inclined upward at both left and right ends as it extends outward. Along with this, the left and right openings L and R have a shape that also expands upward toward the outside in the main scanning direction. Therefore, a large amount of cooling air is taken into the air passage W, and the heat dissipation efficiency of the heat sinks 43A and 43B can be improved.

The lower cover 516 is arranged to cover the upper portion of the central circuit 421B. The lower cover 516 is composed of a plate-like member, and its central portion is arranged substantially horizontally. A front end portion of the lower cover 516 is in contact with the front cover 411 and the radiator plate 43A without a gap. Also, the rear end of the lower cover 516 is in contact with the rear cover 412 and the radiator plate 43B without gaps. Therefore, the central circuit 421B is shielded from the outside air by the lower cover 516 .

Both left and right ends of the lower cover 516 are formed to be inclined downward toward the outside. Therefore, the left and right openings L and R are formed so as to expand downward toward the outside. Therefore, a large amount of cooling air is taken into the air passage W, and the heat dissipation efficiency of the heat sinks 43A and 43B can be improved.

Also, the entire substrate 42 including the central circuit 421B is shielded from air containing dust and ink mist by the front cover 411, the rear cover 412, and the lower cover 516. FIG. Therefore, electronic components can be arranged also in the central circuit 421B.

Although the cover is composed of a plurality of members in the above embodiments and modifications, the present invention is not limited to this, and the cover may be integrally formed. In addition, the rear surface of the front cover 411 and the front surface of the rear cover 412 do not necessarily have to be polygonal when viewed from above, and may be formed of smooth curved surfaces, for example.

The above embodiments are presented as examples of the invention and do not limit the scope of the invention. Various omissions, replacements, and modifications can be made to the above configuration without departing from the scope of the invention. The above-described embodiments and modifications thereof are included in the invention described in the claims and their equivalents, as well as being included in the scope and gist of the invention.

1 Printing Device 2 Conveyance Mechanism Section 3 Control Section 4 Carriage 5 Carriage 41 Housing 42 Boards 43A, 43B Radiation Plate 44 Head Section 411 Front Cover 412 Rear Cover 413 Upper Cover 513 Upper Cover 516 Lower Cover

Claims (6)

a carriage movable in the main scanning direction;
a substrate provided on the carriage and carrying an inkjet head drive circuit;
a cover that covers at least part of the drive circuit;
and an exposed portion exposed to the outside from the cover,
The exposed portion includes a heat sink installed on the substrate,
The substrate has a driver element electrically connected to the drive circuit,
The image forming apparatus , wherein the heat sink has one surface exposed to the outside from the cover and the other surface opposite to the one surface, covered by the cover, for holding the driver element . the cover forms an opening that expands outward in the main scanning direction;
2. The image forming apparatus according to claim 1, wherein the exposed portion communicates with the opening. 3. The image forming apparatus according to claim 1 , wherein the one surface is parallel to the main scanning direction. 4. The image forming apparatus according to any one of claims 1 to 3 , wherein the exposed portions are provided as a pair of a first exposed portion and a second exposed portion facing each other. The cover is
a first cover that exposes the first exposed portion to the outside;
A second cover that exposes the second exposed portion to the outside,
5. The image forming apparatus according to claim 4 , wherein an air passage formed by said first exposed portion and said second exposed portion is provided between said first cover and said second cover. . The cover is
5. The air conditioner further comprises a third cover that is bridged between the first cover and the second cover and forms the air passage together with the first cover and the second cover. The image forming apparatus according to .

Images