Direct thermal printer, direct thermal printing method and conveyor for recording material

Abstract: A color thermal printer a conveyor (37) for conveying a color thermosensitive recording sheet (24) along a conveying path (226). A thermal head (41) thermally records a full-color image to the recording sheet being conveyed. A fixer lamp (39, 40, 80, 81) applies ultraviolet rays of a predetermined range of wavelength to the recording sheet being conveyed, for optically fixing the recording sheet. In the thermal printer, a printer casing (11) has a small height, and includes a front panel (16) oriented vertically. An insertion opening (25) in the front panel is adapted to insertion of the recording sheet before the recording, and ejection of the recording sheet after the recording. An air inlet (26) and an air outlet (27) are formed in the front panel. The insertion opening is disposed between the air inlet and the air outlet. An air passageway (64) is disposed in the printer casing, and communicates from the air inlet to the air outlet via at least a portion of the conveying path. A fan unit (65) is disposed in the air passageway, and causes air from the air inlet to flow along the air passageway, to cause heat generated in the printer casing to exit from the air outlet.

Description: The present invention relates to a thermal printer, a thermal printing method and a conveyor for recording material. More particularly, the present invention relates to a thermal printer which can be easily combined with a personal computer, a video player or the like, and a thermal printing method and a conveyor for recording material used with the thermal printer. A tower type of personal computer has been recently used widely. The personal computer of this type has a feature of high extensibility, and includes a plurality of so-called bays, or spaces for setting respective relevant devices such as a flexible disk (FD) drive device, a hard disk device, a compact disk (CD) drive device and an MO drive device. Each bay can contain such a peripheral unit which is approximately 146 mm wide, 41 mm high, and 220 mm deep. There is another suggestion of the personal computer in which a scanner is set in the bay with intention of extension, the scanner previously having been connected externally to a computer in a conventional manner. With the scanner or other peripheral units incorporated in the body of the personal computer, convenience and ease in use of them is increased. There is no need of externally connecting operation. Furthermore peripheral units to be installed do not require installing spaces in a room, although such are still required by external peripheral units. It is conceived to combine a color printer with the personal computer of the tower type as one of the peripheral units, because the color printer will be usable with high frequency and much convenience. However there is no color printer which could be mounted in the bay of the personal computer, because the color printer in the prior art is too large and cannot be constructed in a small size suitable to the bay. There is a color thermal printer of a sublimation type or wax transfer type, which is used with ink ribbon. The ink ribbon is wound in a roll form, which inevitably has a size of 25-30 mm at the minimum. It is impossible to construct the printer with a thickness equal to or less than 41 mm. Moreover the ink ribbon, when used up, must be renewed. If the bay contained the color thermal printer of this type, the entirety of the printer must be pulled out and opened for the purpose of renewal of the ink ribbon. There is no ink jet printer which would be mounted in the bay of the personal computer, because sizes of an ink tank and a recording head of an ink jet printer cannot be reduced and are inconsistent to the smallness of the bay. The ink jet printer has a mechanical system of a serial printer, and also requires a mechanism for moving the recording head. Also the ink jet printer must be supplied with ink periodically. A body of the ink jet printer must be drawn and opened before the ink can be supplied. Both the head moving mechanism and supply of ink cause problems in failure of obtaining compactness of the body. Among various types of color printers, there is a color thermal printer in which color thermosensitive recording material of direct thermal recording is heated to develop color by itself. The color thermal printer does not use ink ribbon, ink or other expendable material, and does not need to be open for the purpose of supplying anything expendable. Therefore this type of the color thermal printer has suitability to being contained in the bay of the personal computer. The recording material includes a support, and a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer, all of which are overlaid on the support. Among the three layers, the yellow coloring layer, which lies the farthest from the support, has the highest heat sensitivity. In the color thermal printer, a thermal head is pressed against the recording material, to print a yellow image to the yellow coloring layer line by line at first. Then a yellow fixer applies ultraviolet rays to the yellow coloring layer to fix the yellow image. The thermal head prints a magenta image to the magenta coloring layer next. A magenta fixer applies ultraviolet rays to the magenta coloring layer to fix the magenta image. Finally the thermal head prints a cyan image to the cyan coloring layer, so as to obtain a full-color image. The thermal recording and the fixation are effected while the recording material is conveyed in a manner relative to the thermal head and the fixer unit. An example of various structures for conveying the recording material is a back-and-forth moving structure. The color thermal printer with this structure includes a recording material conveyor device or a conveyor roller set, which is constituted by a capstan roller and a pinch roller. The capstan roller is driven by a motor to rotate. The pinch roller has a diameter smaller than that of the capstan roller. The conveyor roller set nips the recording material and conveys it back and forth, while the thermal head pressurizes and heats the recording material to develop the three colors sequentially, that are yellow, magenta and cyan. However there is no known color thermal printer which would be mounted in the bay of the personal computer, because of considerable largeness of parts and components in a color thermal printer and a large space required for their arrangement. For the three coloring layers, temperature at which each coloring layer starts being colored is different. Therefore the color thermal printer of the direct recording type inevitably has the maximum heating temperature higher than that of a wax transfer type of thermal printer, in which the temperature at which each coloring layer starts being colored is equal between the coloring layers. In the direct recording type, generated heat is considerably much due to the heating temperature. The problem of considerable generated heat should be solved in mounting the color thermal printer in the bay of the personal computer, in addition to the dimensional problems of the color thermal printer and its parts. In view of the foregoing problems, an object of the present invention is to provide a thermal printer having a sufficiently small size and easily combined with a personal computer, a video player or the like, and a thermal printing method and a conveyor for recording material used with the thermal printer. Another object of the present invention is to provide a thermal printer in which generated heat can be removed in an effective manner, and a thermal printing method and a conveyor for recording material used with the thermal printer. US 5 585 832 discloses a thermal printer for recording an image to thermo-sensitive recording material, said thermal printer including a conveyor for conveying said recording material along a conveying path, a thermal head for thermally recording said image to said recording material being conveyed, and a fixer lamp for applying electromagnetic rays of a predetermined range of wavelength to said recording material being conveyed, for optically fixing said recording material. The present invention is characterised over US 5 585 832 in that said thermal printer comprises a printer casing having a box shape and including a front face oriented substantially vertically to a direction of the height of said printer casing, and a rear face opposite to said front face; an insertion opening, formed in said front face, and adapted to insertion of said recording material therethrough before said recording, and ejection of said recording material therethrough after said recording; an air inlet and an air outlet, formed in said front face, said insertion opening being disposed between said air inlet and said air outlet; an air passageway, disposed in said printer casing, for communicating from said air inlet to said air outlet via at least a portion of said conveying path; and a fan unit, disposed in said air passageway, for causing air from said air inlet to flow along said air passageway, to cause heat generated in said printer casing to exit from said air outlet. Moreover, a partition may be disposed to extend along the conveying path, for defining first and second portions of the air passageway on respective sides thereof by partitioning an inside of the printer casing, the first portion extending from the air inlet, and the second portion communicating with the first portion at an edge of the partition, and extending to the air outlet. Consequently in the thermal printer, generated heat can be removed in an effective manner. The thermal printer can have a sufficiently small size and be easily combined with a personal computer, a video player or the like. The above features of the present invention will become more apparent from the following detailed description when read in connection with the accompanying drawings, in which: Fig. 1 is a vertical section illustrating a color thermal printer; Fig. 2 is a perspective illustrating the thermal printer and a personal computer of a tower type; Fig. 3 is a top plan illustrating the thermal printer of which the top is open; Fig. 4 is a block diagram illustrating relevant circuits in the thermal printer; Fig. 5 is a flow chart illustrating operation of the thermal printer; and Fig. 6 is an explanatory view in a top plan, illustrating another preferred embodiment of fixer lamps. In Fig. 1, a color thermal printer 10 is illustrated in section. The thermal printer 10 is constituted by a printer casing 11, a printing unit 12, a printed circuit board 13 and a heat remover unit or cooler unit 14. In Fig. 2, the printer casing 11 is constituted by a casing component 17 and a front panel 16, and generally has a shape of a box or rectangular parallelepiped and with a small thickness. There are screws (not shown) which secure the front panel 16 to the casing component 17. The casing component 17 has a shape and size suitable to be mounted in a bay 19 of a personal computer 18 of a tower type. In the present embodiment the casing component 17 is 146 mm wide, 41 mm high, and 220 mm deep. In Fig. 1, the casing component 17 is constituted by lower and upper casing halves 17a and 17b, which make it easy to incorporate the printing unit 12, the printed circuit board 13 and the heat remover unit 14. The rear of the printer casing 11 has a connector 20. When the thermal printer 10 is mounted in the bay 19 of Fig. 2, the connector 20 is connected with a connector included in the personal computer 18, so that the printer can be supplied with electric power, and can send and receive data including control data and image data. Note that the casing component 17 may be formed as a box with a lid without splitting into the casing halves 17a and 17b. In Fig. 2, the front panel 16 has an insertion opening 25 formed in the center to extend horizontally, and adapted to insertion of color thermosensitive recording material or sheet 24. The insertion opening 25 lies offset to the right as viewed in the front. As will be described later, an internal conveying path or passageway in connection with the insertion opening 25 is offset to the right for the purpose of simplifying construction of the apparatus. Also a space for accommodating a drive unit 42 is maintained inside the printer casing 11 by offsetting the insertion opening 25. The recording sheet 24, as is well known in the art, includes a support, and a cyan thermosensitive coloring layer, a magenta thermosensitive coloring layer, and a yellow thermosensitive coloring layer, all of which are overlaid on the support. Among the three layers, the yellow coloring layer, which lies the farthest from the support, has the highest heat sensitivity. The yellow coloring layer and the magenta coloring layer have characteristics of optical fixability to ultraviolet rays of wavelength ranges respectively peaking at 420 nm and 365 nm. When each of the coloring layers is optically fixed, its ability to develop the associated color is destroyed. There an air inlet 26 and an air outlet 27 formed in the front panel 16. The air inlet 26 is located above the insertion opening 25. The air outlet 27 is located below the insertion opening 25. The air inlet 26 includes plural vertical slits arranged horizontally at a regular pitch. The air outlet 27 is constituted by plural openings being relatively great, rectangular, arranged horizontally. In the air outlet 27 is disposed a heat remover 28, which is constituted by an extension of a securing bracket 58. To be precise, the heat remover 28 includes air outlet slits or air sub-outlets 29 and heat dissipator fins 30, which are arranged horizontally at regular pitches. In Fig. 1, the printed circuit board 13 is secured to a bottom inner face of the printer casing 11 by securing bosses 31 and securing screws 32 in combination. The printing unit 12 is secured to the printed circuit board 13 by securing screws (not shown) in a unified manner. Circuits for controlling relevant components are included in the printed circuit board 13. There are integrated circuits (IC), transistors, resistors, capacitors and the like, which are mounted on the printed circuit board 13 for incorporating the circuits. The printed circuit board 13 has a greater thickness than that used conventionally and is resistant to flexing force, because the printing unit 12 is secured to it. The printing unit 12 is a unit constituted by a chassis 35 containing a supply roller set 36, a conveyor roller set 37, a platen roller 38, yellow and magenta fixer lamps 39 and 40 in an optical fixer unit, a thermal head 41, and the drive unit 42, all of which are arranged in the chassis 35. In Fig. 3, the chassis 35 is constituted by lateral plates 35a and 35b and a stay 35c for connecting them. Between the lateral plates 35a and 35b are disposed the supply roller set 36, the conveyor roller set 37 and the platen roller 38 and the thermal head 41. An interval between the lateral plates 35a and 35b is slightly greater than a width of the recording sheet 24, so that the lateral plates 35a and 35b guide lateral edges of the recording sheet 24. In Fig. 1, lamp securing holes 45 are formed in the lateral plates 35a and 35b. The fixer lamps 39 and 40 are inserted in the lamp securing holes 45 to secure them to the lateral plates 35a and 35b. In Fig. 3, sockets 46 are disposed on ends of the fixer lamps 39 and 40. The sockets 46 are connected to the printed circuit board 13 by use of codes and connectors. In Fig. 1, reflectors 47 and 48 are associated with the fixer lamps 39 and 40, and reflect rays from the fixer lamps 39 and 40 toward the recording sheet 24 in such a manner that rays are efficiently applied to the recording sheet 24. The yellow fixer lamp 39 is adapted to the yellow color, emits near ultraviolet rays being visible in a wavelength range peaking at 420 nm, and applies the rays to the recording sheet 24 to fix the yellow coloring layer, which is prevented from further developing the yellow color in the course of the magenta recording. The magenta fixer lamp 40 is adapted to the magenta color, emits ultraviolet rays in a wavelength range peaking at 365 nm, and applies the rays to the recording sheet 24 to fix the magenta coloring layer, which is prevented from further developing the magenta color in the course of the cyan recording. In Fig. 3, the fixer lamps 39 and 40 have a long tubular shape with a small diameter. Their middle portions between lamp ends 39a, 39b, 40a and 40b have a feature of emitting rays at a uniform amount. In each of the lamp ends 39a, 39b, 40a and 40b, rays are emitted only at a decreased amount. The lateral plates 35a and 35b are disposed in positions for separating those middle portions from the lamp ends 39a, 39b, 40a and 40b. The lamp ends 39a and 40a are bent at angle of 90 degrees, for the purpose of preventing a width of the thermal printer from being great due to them which emits only rays at the smaller amount. The lamp ends 39b and 40b of the fixer lamps 39 and 40 are straight without bends. A space adjacent to the lamp ends 39b and 40b with a reduced amount of rays contains the drive unit 42. The drive unit 42 is disposed on the outside of the lateral plate 35a. The drive unit 42 is constituted by a stepping motor 50, a gear train 51 as a transmission, and a cover 52. The gear train 51 transmits rotation of the stepping motor 50 to the supply roller set 36, the conveyor roller set 37 and the platen roller 38 in such a manner as to keep constant the peripheral speeds of the supply roller set 36, the conveyor roller set 37 and the platen roller 38. The supply roller set 36, the conveyor roller set 37 and the platen roller 38 rotate in either of a supply direction A and a printing direction B indicated in Figs. 1 and 3. In Fig. 1, the supply roller set 36 is constituted by a drive roller 36a and a push roller 36b. The conveyor roller set 37 is constituted by a capstan roller 37a and a pinch roller 37b. Inside the chassis 35 are disposed an upper front guide plate 53, a lower front guide plate 55 and a rear guide plate 56, all of which guides the recording sheet 24 toward the supply roller set 36, the conveyor roller set 37, the platen roller 38 and the thermal head 41. In Fig. 1, the thermal head 41 is secured to the lateral plates 35a and 35b via the securing bracket 58. The platen roller 38 is caused by a lifter mechanism 59 to shift between a push position and a retracted position. See Fig. 4. The platen roller 38, when in the push position, causes heating element array 41a of the thermal head 41 to push the recording sheet 24. The heating element array 41a includes a great number of heating elements arranged in parallel with an axial direction of the platen roller 38. In the thermal recording the heating elements are driven in accordance with image data, to record a full-color image in a three-color frame-sequential manner. In Fig. 1, the securing bracket 58 operates as a heat dissipator of the thermal head 41. The securing bracket 58 is arranged along the conveying path of the recording sheet 24, is extended under it, and includes heat dissipator fins 58a, which protrude from it and are arranged at a certain interval. A distal end of the securing bracket 58 is located near to the air outlet 27, to constitute the heat remover 28. Note that it is possible to form an opening in a stepped portion 58b of the securing bracket 58, for the purpose of flow of air from a fan unit 65 toward the fixer lamps 39 and 40. A partition 60 is constituted by a combination of the front guide plates 53 and 55, the securing bracket 58 and the rear guide plate 56. The partition 60 splits the inside of the printer casing 11 into an upper portion or chamber 61 and a lower portion or chamber 62. A suitable number of gaps 63 with an edge are defined at an end of the rear guide plate 56, to communicate the upper chamber 61 with the lower chamber 62. An air passageway 64 including the chambers 61 and 62 is defined by a combination of the partition 60 and the gaps 63 in a channel shape inside the printer casing 11. Note that the gaps 63 may have any suitable shapes such as openings, holes, slots and the like. The fan unit 65 is disposed under the rear guide plate 56 at the gaps 63. The fan unit 65 is fixedly secured to the printed circuit board 13. The fan unit 65 is a type called a cross flow fan which has a cage shape, and takes in air through the air inlet 26, and exhausts the air through the air outlet 27 to the outside of the casing. Thus the heat from the thermal head 41 is dissipated by the heat remover 28 and the heat dissipator fins 58a of the securing bracket 58. The heat remover unit 14 consists of a combination of the air inlet 26, the partition 60, the fan unit 65, the securing bracket 58 and the air outlet 27. Note that the cross flow fan for the fan unit 65 consists of a housing and a cage-shaped rotor or impeller. The cage-shaped rotor or impeller includes a number of long blades arranged in a cylindrical manner, and is rotatable about a shaft, which is extended crosswise to the conveying direction of the recording sheet 24. The fixer lamps 39 and 40 are close to each other to keep the printer size compact. In Fig. 4, an irradiance sensor 66 is disposed between the fixer lamps 39 and 40 to measure irradiance of the fixer lamps 39 and 40. A signal generated from the irradiance sensor 66 is sent to a lamp inverter circuit 67, which adjusts voltage to the fixer lamps 39 and 40 to regulate the irradiance at an unchanged value. Fig. 4 is a block diagram in which electric circuits of the thermal printer 10 are depicted. The thermal printer 10 is connected to a personal computer component 69 of the personal computer 18 via an I/O interface 68. A controller 70 consists of a microcomputer well known in the art, receives printing control data and image data transferred from the personal computer component 69, and controls drivers 71 and 72, the lifter mechanism 59, a printing control unit 73, the lamp inverter circuit 67 and a counter 74. The thermal printer 10 does not have an operation panel, but executes the printing operation in accordance with the printing control data sent from the personal computer component 69. The controller 70 sends the driver 71 a rotational direction signal and drive pulses. The gaps 63 cause the stepping motor 50 to rotate forwards or backwards, so that the drive roller 36a of the supply roller set 36 and the capstan roller 37a of the conveyor roller set 37 are rotated in the supply direction or the printing direction. The counter 74 starts a counting operation upon receipt of a rear end detecting signal from a rear end sensor 75, and steps up when the stepping motor 50 rotates forwards to convey the personal computer 18 in the printing direction B, and steps down when the stepping motor 50 rotates backwards to convey the personal computer 18 in the supply direction A. In Fig. 1, the rear end sensor 75 is disposed between the supply roller set 36 and the conveyor roller set 37 and near to the conveyor roller set 37. The lifter mechanism 59 includes a solenoid or the like, moves up and down the platen roller 38 to shift it between a push position and a retracted position. The printing control unit 73 includes a head driver and a memory, which stores three-color image data constituting one frame. The printing control unit 73 drives the respective heating elements of the heating element array 41a in accordance with the three-color image data. The heating elements are caused to develop heat according to each designated one of the colors and the color image data of the color, to develop color of the recording sheet 24 at intended density. The lamp inverter circuit 67 controls the fixer lamps 39 and 40 at an unchanged amount of rays in accordance with detecting signals from the irradiance sensor 66. It is to be noted that the memory does not require capacity of one frame. The memory may have capacity only sufficient for storing a number of lines. It is preferable that the personal computer may successively send image data by a unit amount of plural lines in a timely manner associated with a printing sequence. The operation of the present embodiment is described with reference to Fig. 5. When the personal computer component 69 is operated to command a printing operation, at first a motor for the fan unit 65 is rotated by the driver 72. Air is taken into the printer casing 11 through the air inlet 26. The air flows through the air passageway 64 in the printer casing 11 and is exhausted through the air outlet 27. Thus the heat emitted from the thermal head 41 is caused to flow out of the printer casing 11, inside which the temperature is kept from rising. Then a command of supply of the recording sheet is input. The thermal printer 10 comes to stand by for the sheet supply. While the thermal printer 10 stands by, the stepping motor 50 causes the supply roller set 36, the conveyor roller set 37 and the platen roller 38 to rotate in the direction indicated by the arrow A. A user manually inserts a front end of the recording sheet 24 into the supply roller set 36. Therefore the recording sheet 24 is pulled into the printing unit 12, until a rear end of the recording sheet 24 is detected by the rear end sensor 75. Upon the detection, the recording sheet 24 is stopped. Then a rotational direction of the stepping motor 50 is changed, to rotate the supply roller set 36, the conveyor roller set 37 and the platen roller 38 in the printing direction of the arrow B. The controller 70 causes the counter 74 to count the number of drive pulses of the stepping motor 50 in an incremental manner. According to the counted number of the counter 74, the controller 70 recognizes a position of starting the push of the thermal head 41, a position of starting the thermal recording, a position of stopping the thermal recording, a position of starting retreat of the thermal head 41, and a position of stopping conveyance of the recording sheet 24. The full-color image is recorded in the three-color frame-sequential manner in the order of yellow, magenta and cyan colors in the sequence known in the field of the thermal printing. During the yellow recording, the yellow fixer lamp 39 is turned on to fix the yellow coloring layer, which is prevented from developing further color in the course of the magenta recording and the cyan recording. Similarly during the magenta recording, the magenta fixer lamp 40 is turned on to fix the magenta coloring layer. Additionally the magenta fixer lamp 40 is turned on during the cyan recording, to bleach a non-printing margin which has had yellowish appearance. After the cyan recording, the recording sheet is sent out through the insertion opening 25, to finish the full-color printing operation. In the present embodiment, the recording sheet is manually inserted. Alternatively the thermal printer may be used with a sheet supply cassette and a supply mechanism, which may be mounted on the insertion opening in a removable manner, for automatically supplying the printer with recording sheets. A roll of continuous recording material may be prepared and set in a supply station. The continuous recording material may be cut into separate sheets. Moreover it is possible to combine the manual insertion, the use of the sheet supply cassette, and/or the use of the roll. Of course the positions of the thermal head 41 and the conveyor roller set 37 are not limited to the above examples, but changeable in a suitable manner. The printing sequence is not limited to the above example. The yellow fixation may be conducted during the conveyance in the supply direction after the yellow printing in the printing direction. Moreover the yellow fixation may be conducted during the conveyance both in the printing direction and in the supply direction, namely during and after the yellow printing. In the above embodiment, the printing unit 12 is fixed on the printed circuit board 13. Alternatively each of the printing unit 12 and the printed circuit board 13 may be secured to the printed circuit board 13 in a separate manner. In the above embodiment the fixer lamps 39 and 40 are connected to the printed circuit board 13 via the sockets 46. Instead, the fixer lamps 39 and 40 are connected to it in a direct manner by use of a securing plate. Otherwise the sockets 46 may be directly mounted on the printed circuit board 13. The fixer lamps may be placed on the printed circuit board 13 in a removable manner. In the above embodiment, the lamp ends 39a and 40a of the fixer lamps 39 and 40 are bent at the right angle to keep the printer size compact. It is possible to use fixer lamps 80 and 81 of a U-shape of Fig. 6. The fixer lamps 80 and 81 have lamp ends 80a and 81a from which rays are emitted only at a decreased amount. The lamp ends 80a and 81a can be collectively located, so that a printed circuit board 77 can have a reduced size. This is favorable in reducing the size of the entirety of the thermal printer. Note that a combination of plural arranged fixer lamps of the U-shape may be used for fixation of each color. This is typically effective in avoiding shortage in the amount of fixing rays. In the above embodiment, the thermal printer 10 is mounted in the bay 19 of the personal computer 18 as depicted in Fig. 2. Alternatively a thermal printer may be mounted in a bay of a personal computer of a horizontal type being widely used. Furthermore a thermal printer may be mounted in a bay of a personal computer of a display-panel-combined type. Also a thermal printer may be mounted on any imaging apparatus such as a television set or a video player. In any of them, heat from the thermal head is kept from remaining within the apparatus, which can be constructed in a compact manner. In the present invention, it is also possible that the printer casing 11 is oriented in a upright direction instead of a horizontal direction.

Claims: A thermal printer for recording an image to thermo-sensitive recording material (24), said thermal printer including a conveyor (37) for conveying said recording material along a conveying path, a thermal head (41) for thermally recording said image to said recording material being conveyed, and a fixer lamp (39, 40, 80, 81) for applying electromagnetic rays of a predetermined range of wavelength to said recording material being conveyed, for optically fixing said recording material, characterised in that said thermal printer comprises: a printer casing (11) having a box shape and including a front face (16) oriented substantially vertically to a direction of the height of said printer casing, and a rear face opposite to said front face; an insertion opening (25), formed in said front face, and adapted to insertion of said recording material therethrough before said recording, and ejection of said recording material therethrough after said recording; an air inlet (26) and an air outlet (27), formed in said front face, said insertion opening being disposed between said air inlet and said air outlet; an air passageway (64), disposed in said printer casing, for communicating from said air inlet to said air outlet via at least a portion of said conveying path; and a fan unit (65), disposed in said air passageway, for causing air from said air inlet to flow along said air passageway, to cause heat generated in said printer casing to exit from said air outlet. A thermal printer as defined in claim 1, further comprising a partition, disposed to extend along said conveying path, for defining first and second portions of said air passageway (64) on respective sides thereof by partitioning an inside of said printer casing (11), said first portion extending from said air inlet (26), and said second portion communicating with said first portion at an edge of said partition, and extending to said air outlet (27). A thermal printer as defined in claim 2, wherein said partition includes: a front guide plate, extended from said insertion opening (25) to said thermal head (41) along said conveying path , for supporting said recording material (24) being conveyed; a bracket for supporting said thermal head; and a rear guide plate, extended from said thermal head toward said rear face of said printing casing along said conveying path, for supporting said recording material being conveyed, wherein said second portion of said air passageway (64) communicates with said first portion at a rear edge of said rear guide plate. A thermal printer as defined in claim 2, wherein said air inlet (26) is disposed above said insertion opening (25), and said air outlet (27) is disposed below said insertion opening. A thermal printer as defined in claim 4, wherein said recording material (24) includes a support, and at least first, second and third thermosensitive coloring layers, overlaid on said support, for developing respective colors being different from one another, wherein said first coloring layer is disposed at a recording surface, said third coloring layer is disposed most deeply from said recording surface, and said first and second coloring layers have fixability to electromagnetic rays of respectively first and second ranges of wavelength; wherein said fixer lamp (39, 40, 80, 81) comprises: a first fixer lamp, having a long shape, disposed to extend crosswise to conveyance of said recording material, for emitting electromagnetic rays of said first range of wavelength; and a second fixer lamp, having a long shape, disposed so that said first fixer lamp is disposed between said second fixer lamp and said thermal head (41), extended substantially in parallel with said first fixer lamp, for emitting electromagnetic rays of said second range of wavelength. A thermal printer as defined in claim 5, wherein said fan unit (65) comprises a cross flow fan, and disposed at a bottom of said rear edge of said rear guide plate. A thermal printer as defined in claim 5, further comprising a plurality of first heat dissipator fins, disposed on said bracket to project into said air passageway (64). A thermal printer as defined in claim 7, wherein said air outlet (27) comprises a plurality of air sub-outlets; further comprising a plurality of second heat dissipator fins, disposed on an end portion of said bracket to project toward an outside of said air sub-outlets. A thermal printer as defined in claim 8, wherein said conveyor (37) includes a conveyor roller set for nipping said recording material (24), conveying said recording material plural times in a first direction and a second direction reverse to said first direction, subjecting said recording material plural times to said thermal recording and said optical fixation, to record said full-color image by three-color frame-sequential manner. A thermal printer as defined in claim 9, wherein said fixer lamps and said conveyor roller set are disposed between said insertion opening (25) and said thermal head (41). A thermal printer as defined in claim 5, further comprising two lateral plates, disposed in said printer casing (11) substantially in parallel with each other, said fixer lamps being so extended that distal ends thereof are disposed beyond outer sides of said lateral plates, wherein said lateral plates exclude said distal ends from confrontation with said recording material (24) for applying said electromagnetic rays in a uniformed manner, wherein a platen member, said thermal head (41) and said conveyor roller set are disposed between said lateral plates. A thermal printer as defined in claim 11, wherein each of said fixer lamps has a U-shape including first and second portions, disposed substantially in parallel with each other, and extended crosswise to said conveying path. A thermal printer as defined in claim 11, wherein each of said fixer lamps includes one end bent in an L-shape substantially in parallel with conveyance of said recording material (24), to have an increased length containable in a given space. A thermal printer as defined in claim 13, further comprising a drive unit for driving said conveyor roller set, said drive unit being disposed at least partially between an inside of said printer casing (11) and one of said lateral plates opposite to said bent end of said fixer lamps. A thermal printer as defined in claim 14, wherein said drive unit includes: a stepping motor, disposed under said rear guide plate and between said lateral plates; and a gear train, disposed between said inside of said printer casing (11) and said one of said lateral plates, for transmitting rotation of said stepping motor to said conveyor roller set. A thermal printer as defined in claim 1, wherein said printer casing (11) has a size insertable in a bay of a personal computer of a tower type.

Inventors: GOTO SATORU, SASAKI HIDEMI, TAKATORI NAOKI, GOTO, SATORU, SASAKI, HIDEMI, TAKATORI, NAOKI, Goto, Satoru, c/o Fuji Photo Film Co., Ltd., Sasaki, Hidemi, c/o Fuji Photo Film Co., Ltd., Takatori, Naoki, c/o Fuji Photo Film Co., Ltd.
Applicants: FUJI PHOTO FILM CO LTD, FUJI PHOTO FILM CO., LTD.
Application year: 1998
Main classification: B41J2
IPC codes: B41M5, B41J29, B41J2, B41J13