Ink-jet recording head, ink-jet recording apparatus, and electronic equipment

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an ink-jet recording head and an ink-jet recording apparatus wherein a plurality of nozzle rows for discharging ink of different colors are arrayed in approximately a straight line in approximately the same direction as the transporting direction of a recording medium. The present invention also relates to electronic equipment comprising an ink-jet recording apparatus.

2. Description of the Related Art

The ink-jet recording method performs recording of dots by forming flying droplets of ink which is a recording liquid and landing these on a recording medium such as paper or the like, and has a low noise factor due to being a non-contact method. Also, high resolution and high-speed recording is enabled by the increased density of the ink discharge nozzles, and further, no special processing such as developing or fixing is necessary for recording media such as plain paper or the like, so high-quality images can be obtained at low costs. Accordingly, this method has become widespread in recent years.

Particularly, on-demand type ink-jet recording apparatuses can be easily arranged to deal with color, and further the apparatus itself can be easily reduced in size and complexity, so widespread demand thereof in the future is expected. Also, as such color becomes commonplace, even higher image quality and speed is being required.

With such ink-jet recording apparatuses, serial scan apparatuses comprise a carriage upon which are mounted a recording head and ink tanks, and a transporting device for transporting the recording medium, wherein the recording head upon which multiple ink discharging orifices (nozzles) are arrayed in the transporting direction of the recording medium (i.e., the sub-scanning direction) is serially scanned in a direction orthogonal to the sub-scanning direction (i.e., the main scanning direction) using the carriage, and following completion of recording one line, the recording medium is transported by an amount equivalent to one pitch, following which the next image is recorded on the recording medium which has stopped again, and this is repeated, until recording is carried out on the entire recording medium.

Also, in the case of color recording, a recording head for the three colors yellow (Y), magenta (M), and cyan (C), or the four colors of these with black (B), and ink tanks thereof, are mounted on the carriage to carry out recording.

There are two types of nozzle row array configurations for such color recording heads; parallel types wherein the color nozzle rows are arrayed in parallel, and inline types wherein the color nozzle rows are arrayed inline.

Parallel types wherein the color nozzle rows are arrayed in parallel in the carriage scanning direction are generally suitable for high-speed printing, though this depends on the length of the nozzle rows. This is due to the fact that each of the colors can be discharged and overlaid in a single scan of the carriage. However, the parallel type has a problem in that the order in which the droplets of ink land differs between scanning in one direction and scanning in the returning direction, in the event that recording is performed both coming and going, so the coloring changes depending on the direction in which the carriage is traveling. There also is a problem with types which discharge ink using thermal energy in that driving heater boards must be arrayed in high precision for each of the color nozzle rows.

On the other hand, inline types wherein the color nozzle rows are arrayed inline in the transporting direction of the recording medium are advantageous with regard to reduction in the size of the head itself, and also manufacturing is relatively easy, which is advantageous in the area of costs as well.

Thus, inline type recording heads are generally advantageous regarding reduction in size and costs.

Now, in recent years, there have been increased demands for printers for PDAs, digital cameras, etc., requiring further reduction in size and increase in speed of the recording heads for ink-jet recording apparatuses.

While inline type recording heads are suitable for reduced size as described above, there are the following problems which occur in the event that the recording head scanning speed is increased (i.e., the driving frequency is increased) to perform high-speed printing.

Increased head scanning speed means that the amount of time from the current scan to the next scan is reduced, and accordingly the time from discharging ink of one color to the time of discharging the next ink color is also reduced. Consequently, bleeding at the boundary between the dots on the recording medium, or mixing of colors on the recording head face at the time of suctioning recovery, occurs, markedly deteriorating the image quality.

SUMMARY OF THE INVENTION

The present invention has been made in light of the above-described problems with the conventional art, and accordingly it is an object of the present invention to provide an ink-jet recording head, ink-jet recording apparatus, and electronic equipment, capable of preventing bleeding on the recording medium and mixing of colors on the recording head in cases of printing at high speeds with in-line type recording heads, so as to obtain high-quality images at low costs with simple modifications.

According to a first aspect of the present invention, an ink-jet recording head comprises a plurality of nozzle rows for discharging ink of different colors arrayed in approximately a straight line in approximately the same direction as a transporting direction of a recording medium, with images being recorded on the recording medium by scanning in a direction orthogonal to the arrayed direction of the nozzle rows, wherein, of the nozzle rows of different colors for discharging ink, the positioning spacing of the nozzle rows of different colors is set so as to be greater than the shortest nozzle row.

With the present invention, the positioning spacing of the nozzle rows for each color is set so as to be greater than the length of the nozzle rows of different colors for discharging ink, so a great amount of time can be purchased between the current scan and the next scan, thereby preventing bleeding on the recording medium and mixing of colors on the recording head.

A dummy nozzle may be positioned between nozzle rows for discharging ink of different colors.

The positioning spacing of the nozzle rows of different colors converted into the number of nozzles, and the length of the nozzle rows of different colors converted into the number of nozzles, may be set so as to be multiples of a natural number n, and also the amount of transporting the recording medium per time converted into the number of nozzles may be a multiple of the natural number n.

The plurality of nozzles arrayed in each of the nozzle rows may be disposed in a staggered array.

According to another aspect of the present invention, an ink jet recording apparatus comprises the above-described ink-jet recording head.

Further objects, features and advantages of the present invention will become apparent from the following description of the preferred embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

is a frontal view of a camera with a built-in printer, to which the present invention can be applied;

FIG. 2

is a perspective view illustrating the camera shown in

FIG. 1

from a frontal diagonal direction;

FIG. 3

is a perspective view illustrating the camera shown in

FIG. 1

from a rear diagonal direction;

FIG. 4

is a perspective view illustrating a media pack mountable to the camera shown in

FIG. 1

;

FIG. 5

is a perspective view illustrating the positional relation of the primary components disposed within the camera shown in

FIG. 1

;

FIG. 6

is a perspective view illustrating the printer unit shown in

FIG. 5

;

FIG. 7

is a perspective view illustrating the printer unit shown in

FIG. 6

partially removed;

FIG. 8

is a perspective view illustrating the carriage in the printer unit shown in

FIG. 6

;

FIG. 9

is a perspective view illustrating the components of the printing media transporting system in the printing unit shown in

FIG. 6

;

FIG. 10

is a perspective view illustrating the components of the ink supplying system in the printing unit shown in

FIG. 6

;

FIG. 11

is a plan view illustrating a state wherein the media pack is mounted to the components of the ink supplying system shown in

FIG. 10

;

FIG. 12

is a schematic block configuration diagram of the camera unit and printer unit in the camera shown in

FIG. 1

;

FIG. 13

is an explanatory diagram of signal processing in the camera unit shown in

FIG. 12

;

FIG. 14

is an explanatory diagram of signal processing in the printer unit shown in

FIG. 12

;

FIG. 15

is a plan view showing a blown-up view of the ink discharging orifice face of the recording head; and

FIG. 16

is a diagram illustrating change in the overlapping of the colors according to transporting of the recording medium.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following is a description of the embodiments of the present invention, with reference to the drawings.

In the present specification, the term “print” (or sometimes referred to as “record”) implies a broad definition of the forming of images, designs, patterns, and so forth on a printing medium or processing a printing medium with regard to such images, designs, patterns, and so forth, regardless of whether meaningful information such as characters, shapes, etc., are formed, i.e., regardless of whether that which is formed is meaningful or not, and regardless of whether that which is formed is manifested so as to be perceivable by the human eye.

Also, the term “printing medium” implies not only paper commonly used with printing apparatuses, but also broadly covers any article capable of receiving ink, such as textiles, plastic film, metal plates and the like, glass, ceramics, wood, leather, and so forth, but in the following will be referred to as “sheets” or simply “paper”.

Also, in the present specification, the term “camera” implies equipment or devices for optically taking images and converting the optical images into electric signals, and will also be referred to as “image taking unit” in the following description.

Further, the term “link” (also referred to as “liquid”) should be accorded the broadest interpretation as with the above term “print”, and implies any liquid which could be provided for the forming of images, designs, patterns, and so forth on a printing medium, for processing a print medium with regard to such images, designs, patterns, and so forth, and for processing ink (e.g., coagulation or non-solvency of color material within ink provided to a printing medium).

Now, one form of the head suitably used with the present invention is an arrangement wherein thermal energy generated by an electro-thermal converter is used to cause film boiling in a liquid and form bubbles.

Basic Configuration

First, the basic configuration of an apparatus according to the present invention will be described with reference to

FIGS. 1 through 14

. The apparatus described with reference to the present example comprises information processing equipment, having an image taking unit for optically taking images and converting the images into electric signals (hereafter also referred to as a “camera unit”), and an image recording unit for recording images based on the electric signals obtained by taking the image (hereafter also referred to as a “printer unit”). In the following description, the information processing equipment described with the present example will be referred to as a “camera with built-in printer”.

With an apparatus main unit A

001

, a printer unit (recording device) B

100

is integrally assembled to the rear side of a camera unit A

100

. The printer unit B

100

records images using ink and printing media supplied from a media pack C

100

. With the present configuration, as can be clearly understood from

FIG. 5

which observes the apparatus main unit A

001

from the rear side with the outer housing removed, the media pack C

100

is inserted to the right-hand side of the apparatus main unit A

001

in the drawing, and the printer unit B

100

is disposed to the left-hand side of the apparatus main unit A

001

in the drawing. In the event of the printer unit B

100

recording, the apparatus main unit A

001

may be positioned such that a later-described liquid crystal display unit A

105

of the camera unit A

100

faces upwards and a lens A

101

faces downwards. In this recording position, a later-described recording head B

120

of the printer unit B

100

assumes an attitude for discharging ink downwards. Recording may be performed in the same position as that assumed for photographing with the camera unit A

100

, and is not restricted to the above recording position, but this recording position wherein ink is discharged downwards is preferable from the perspective of stability during the recording operation.

In the following, description of the basic mechanical configuration of the apparatus according to the present example will be made separately for A “camera unit”, B “media pack”, and C “printer unit”, and the basic configuration of the signal processing system will be described as D: “signal processing system”.

A: Camera Unit

The camera unit A

100

is basically configured as a common digital camera, and is integrally assembled with the later-described printer unit B

100

to the apparatus main unit A

001

so as to make up a digital camera with a printer built in, having the external look such as shown in

FIGS. 1 through 3

. In

FIGS. 1 through 3

, reference numeral A

101

denotes a lens, A

102

denotes a viewfinder, A

102

a

denotes a viewfinder window, A

103

denotes a strobe, A

104

denotes a release button, and A

105

denotes a liquid crystal display unit (external display unit). As described later, the camera unit A

100

processes data taken using a CCD, stores images to a compact flash memory card (CF card) A

107

, displays images, exchanges various types of data with the printer unit B

100

, and so forth. Reference numeral A

109

denotes a discharging unit for discharging a printing medium C

104

upon which the taken images are recorded. Reference numeral A

108

shown in

FIG. 5

is a battery serving as a power source of the camera unit A

100

and the printer unit B

100

.

B: Media Pack

The media pack C

100

is detachable from the apparatus main unit A

001

, and with the present embodiment, is mounted to the apparatus main unit A

001

as shown in

FIG. 1

by being inserted in an insertion portion A

002

of the apparatus main unit A

001

(see FIG.

3

). The insertion portion A

002

is closed as shown in

FIG. 3

in the event that there is no media pack C

100

mounted thereto, and opens when a media pack C

100

is mounted.

FIG. 5

illustrates the apparatus main unit A

001

with the media pack C

100

mounted and the outer housing removed. As shown in

FIG. 4

, a pack main unit C

101

of the media pack C

100

has a shutter C

102

which is slidable in the direction indicated by the arrow D. The shutter C

102

slides to the position indicated by the two-dot broken line in

FIG. 4

in the state that the media pack C

100

is not mounted to the apparatus main unit A

001

, and slides to the position indicated by the solid line in

FIG. 4

in the state that the media pack C

100

is mounted to the apparatus main unit A

001

.

Stored in the pack main unit C

101

are an ink pack C

103

and a printing medium C

104

. In

FIG. 4

, the ink pack C

103

is stored below the printing medium C

104

. In the case of the present example, the ink pack C

103

individually stores three inks, Y (yellow), M (magenta), and C (cyan), and around

20

sheets are stacked and stored for the printing medium C

104

. The ink and the printing medium C

104

are stored in the same media pack C

100

, the combination thereof having been selected beforehand so as to be most suitable for recording images. Accordingly, various types of media packs C

100

with differing combinations of ink and printing media might be prepared, such as media packs for super-high quality, for normal images, for decals (pre-cut stickers), and so forth, so that the user can select a media pack C

100

to mount to the apparatus main unit A

001

according to the object of the user and the type of image to be recorded, thereby recording the image as the user intends using an optimal combination of ink and printing medium. Also, a later-described EEPROM (identifying IC) is provided to the media pack C

100

, and the EEPROM stores identification data regarding the types of ink and printing medium which the media pack stores, the amount remaining, and so forth.

In the state that the media pack C

100

is mounted to the apparatus main unit A

001

, the ink pack C

103

is connected to a later-described ink supply system at the apparatus main unit A

001

side by three joints C

105

corresponding to the respective inks Y, M, and C. On the other hand, the printing medium C

104

is separated one sheet at a time by an unshown separating mechanism, and then fed in the direction of the arrow C by a later-described feeding roller C

110

(see FIG.

9

). The driving force of the feeding roller C

110

is supplied from a later-described transporting motor M

002

(see

FIG. 9

) provided to the apparatus main unit A

001

side, via a linking unit C

110

a.

Also, provided to the pack main unit C

101

are a wiper C

106

for wiping a later-described recording head of the printer unit, and an ink absorbing member C

107

for absorbing waste ink discharged from the printer unit. The recording head in the printer unit reciprocally moves in the main scanning direction indicated by the arrow A, as described later. In the state that the media pack C

100

is removed from the apparatus main unit A

001

, the shutter C

102

slides to the portion indicated by the two-dot broken line in

FIG. 4

, and thus protects the joints C

105

, wiper C

106

, ink absorbing member C

107

, and so forth.

C: Printer Unit

The printer unit B

100

according to the present example is a serial type using an ink-jet recording head. This printer unit B

100

will be described in the separate sections of C-1 “printing action unit”, C-2 “printing medium transporting system”, and C-3 “ink supplying system”.

C-1: Printing Action Unit

FIG. 6

is a perspective view of the entire printer unit B

100

, and

FIG. 7

is a perspective view with a part of the printer unit B

100

removed.

As shown in

FIG. 5

, the tip portion of the media pack C

100

mounted to the apparatus main unit A

001

is situated at a predetermined position within the main unit of the printer unit B

100

. The printing media C

104

fed out from the media pack C

100

in the direction of the arrow C is nipped by an LF roller B

101

and an LF pinch roller B

102

of the later-described printing media transporting system, and is thus transported in the sub-scanning direction over the platen B

103

in the direction indicated by the arrow B. Reference numeral B

104

denotes a carriage reciprocally driven in the main scanning direction indicated by the arrow A following a guide shaft B

105

and a lead screw B

106

.

Provided to the carriage B

104

are, as shown in

FIG. 8

, a bearing B

107

for the guide shaft B

105

and a bearing B

108

for the lead screw B

106

. As shown in

FIG. 7

, a screw ping B

109

protruding to the inner side of the bearing B

108

is attached to a predetermined position of the carriage B

104

by means of a spring B

110

. The tip of the screw pin B

109

fits into the screw threads formed on the perimeter of the lead screw B

106

, such that rotation of the lead screw B

106

is converted into reciprocal motion of the carriage B

104

.

Also, mounted on the carriage B

104

are an ink-jet recording head B

120

capable of discharging ink of the colors Y, M, and C, and a sub-tank (not shown) for storing ink to be supplied to the ink-jet recording head B

120

. The ink-jet recording head B

120

has multiple ink discharging orifices B

121

(see

FIG. 8

) formed along a direction intersecting the main scanning direction of the arrow A (in the case of the present example in the direction orthogonal thereto). The ink discharging orifices B

121

have nozzles capable of discharging ink supplied from the sub-tank. Electro-thermal converters provided for each nozzle can be used for energy generating means for discharging the ink. The electro-thermal converters are driven to generate heat, which causes air bubbles in the ink within the nozzles, and the ink is discharged as droplets from the ink discharging orifices B

121

by the bubble-generating energy.

The sub-tank has a capacity smaller than the ink-pack C

103

stored in the media pack C

100

, and stores an amount of ink necessary for recording an image on at least one sheet of the printing medium C

104

. At the ink storing portions for the Y, M, and C inks in the sub-tank, ink supplying portions and negative pressure introduction portions are formed for each, and three hollow needles B

122

are individually connected to the corresponding ink supplying portions, with the negative pressure introduction portions of each being connected to a shared supply air opening B

123

. Ink is supplied to such a sub-tank from the ink pack C

103

of the media pack C

100

at the point that the carriage B

104

moves to the home position as shown in

FIG. 6

, which will be described later.

With the carriage B

104

shown in

FIG. 8

, reference numeral B

124

denotes a needle cover, and in the event that the needles B

122

and the joints C

105

are not linked the needle cover B

124

moves by the pressing force of a spring to a position protecting the needles B

122

, but in the event that the needles B

122

and the joints C

105

are linked the needle cover B

124

is pressed upwards in the figure against the pressing force of the spring to a position disengaging protection of the needles B

122

. The position to which the carriage B

104

moves is detected by the encoder sensor B

131

at the carriage B

104

side and a linear scale B

132

(see FIG.

6

) at the printer unit B

100

main unit side. Also, in the event that the carriage B

104

moves to the home position, this is detected by a HP (Home Position) flag B

133

at the carriage B

104

side, and a HP sensor B

134

(see

FIG. 7

) at the printer unit B

100

main unit side.

In

FIG. 7

, both ends of the guide shaft B

105

are provided with supporting shafts (not shown) at positions eccentric from the center axis thereof. The position of the carriage

104

is adjusted by the guide shaft B

105

being rotatably adjusted on the supporting shaft, thereby adjusting the distance between the recording head B

120

and the printing medium C

104

on the platen B

103

(this distance also referred to as “sheet distance”). Also, the lead screw B

106

is rotatably driven by a carriage motor M

001

via a screw gear B

141

, idler gear B

142

, and motor gear B

143

. Also, reference numeral B

150

denotes a flexible cable for electrically connecting the recording head B

120

to a later-described control system.

The recording head B

120

records one line of image on the printing medium upon the platen B

103

by discharging ink from the ink discharging orifices B

121

according to image signals while moving in the main scanning direction of the arrow A along with the carriage B

104

. Repeating the one-line recording action of such a recording head B

120

and the transporting action of the printing medium by a predetermined amount in the sub-scanning direction of the arrow B by a later-described printing media transporting system sequentially records images on the printing medium.

C-2: Printing Medium Transporting System

FIG. 9

is a perspective view of the components of the printing medium transporting system in the printer unit B

100

. In

FIG. 9

, reference numeral B

201

denotes a pair of discharging rollers, with the one discharging roller B

201

at the upper side in the drawing being driven by a transporting motor M

002

via a discharging roller gear B

202

and intermediate gear B

203

. In the same way, the aforementioned LF roller B

101

is driven by the transporting motor M

002

via a LF roller gear B

204

and the intermediate gear B

203

. The discharging roller B

201

and LF roller B

101

transport the printing medium C

104

in the sub-scanning direction of the arrow B by the driving force of the transporting motor M

002

rotating forward.

On the other hand, in the event that the transporting motor M

002

rotates in reverse, a platen head B

213

and a locking mechanism not shown are driven via a switching slider B

211

and switching cam B

212

, while driving force is transmitted to the feeding roller C

110

at the media pack C

100

side. That is to say, the platen head B

213

passes through a window portion C

102

A (see

FIG. 4

) in the shutter C

102

of the media pack C

100

and presses the printing medium C

401

collected within the media pack C

100

downwards in

FIG. 4

, by the driving force of the transporting motor M

002

rotating in reverse. Thus, the printing medium C

104

at the bottommost position in

FIG. 4

is pressed downwards upon the feeding roller within the media pack C

100

. Also, an unshown locking mechanism locks the media pack C

100

to the apparatus main unit A

001

by the driving force of the transporting motor M

002

rotating in reverse, thereby keeping the media pack C

100

from being removed. Also, the feeding roller C

110

at the media pack side C

100

receives transmission of driving force of the transporting motor M

002

rotating in reverse, thereby transporting the one sheet of printing medium C

104

at the bottommost position in

FIG. 4

in the direction indicated by the arrow C.

Thus, a single sheet of the printing media C

104

is extracted in the direction of the arrow C from the media pack C

100

by the transporting motor M

002

rotating in reverse, and subsequently the printing media C

104

is transported in the direction of the arrow B by forward rotation of the transporting motor M

002

.

C-3: Ink Supplying System

FIG. 10

is a perspective view of the components of the ink supplying system in the printer unit B

100

, and

FIG. 11

is a plan view illustrating the state in which the media pack C

100

is mounted to the components of the ink supplying system.

The joints C

105

of the media pack c

100

mounted to the printer unit B

100

are situated blow the needles B

122

(see

FIG. 8

) at the side of the carriage B

104

which has moved to the home position. Provided to the main unit of the printer unit B

100

is a joint fork B

301

(see

FIG. 10

) positioned below the joints C

105

, and moving the joints C

105

upwards thereby connects the joints C

105

to the needles B

122

. Thus, ink supply channels are formed between the ink pack C

103

of the media pack C

100

and the ink supplying portion of the sub-tank on the side of the carriage B

104

. Also, a supplying joint B

302

situated below the supply air opening B

123

(see

FIG. 8

) of the carriage B

104

which has moved to the home position is provided to the main unit of the printer unit B

100

. The supplying joint B

302

is connected to a pump cylinder B

304

serving as a negative pressure generating source, via a supplying tube B

303

. The supplying joint B

302

is moved upwards by a joint lifter B

305

to be connected to the supply air opening B

123

at the carriage B

104

side. Thus, a negative pressure introducing channel is formed between the negative pressure introducing portion of the sub-tank at the carriage B

104

side and the pump cylinder B

304

. The joint lifter B

305

vertically moves the supplying joint B

302

and the joint fork B

301

by the driving force of a joint motor M

003

.

An air-liquid separating member (not shown) for permitting air to pass but preventing passage of ink is provided at the negative pressure introducing portion of the sub-tank. The air-liquid separating member passage of air within the sub-tank suctioned through the negative pressure introducing channel, and thus ink is supplied from the media pack C

100

to the sub-tank. Preventing passage of ink by the air-liquid separating member at the point that ink is sufficiently filled, i.e., till the ink within the sub-tank reaches the air-liquid separating member, automatically stops filling of the ink. A air-liquid separating member is provided for the ink supplying portion in the ink storing portion for each color ink in he sub-tank, and filling of ink is automatically stopped for each ink storing portion.

Also, provided to the printer unit B

100

main unit is a suctioning cap B

310

capable of capping the recording head B

120

(se

FIG. 8

) at the carriage B

104

side which has moved to the home position. The suctioning cap B

310

is capable of suctioning discharging of ink from the ink discharging orifices B

121

of the recording head B

120

by the negative pressure being introduced from the pump cylinder B

304

via the suctioning tube B

311

to the interior thereof (i.e., performing suctioning recovery processing). Also, the recording head B

120

discharges ink not contributing to recording of the image into the suctioning cap B

310

as necessary (preliminary discharging processing). Ink within the suctioning cap B

310

passes from the pump cylinder B

304

through the waste liquid tube B

312

and the waste liquid joint B

313

, and is discharged into an ink absorbing member C

107

in the media pack C

110

.

The pump cylinder B

304

configures a pump unit B

315

along with the pump motor M

004

for reciprocal driving hereof. The pump motor M

004

functions as a driving source for vertically moving a wiper lifter B

316

(see FIG.

10

). The wiper lifter B

316

lifts a wiper C

106

of the media pack C

100

mounted to the printer unit B

100

, thereby moving the wiper C

106

to a position at which wiping of the recording head B

120

can be performed.

In

FIGS. 10 and 11

, reference numeral B

321

denotes a pump HP sensor for detecting that the operating position of the pump configured of the pump cylinder B

304

is at the home position. Also, reference numeral B

322

denotes a joint HP sensor detecting that the above-described ink supplying channels and negative pressure introducing channel have been formed. Also, reference numeral B

323

denotes a chassis configuring the main unit of the printer unit B

100

.

D: Signal Processing System

FIG. 12

is a schematic block configuration diagram of the camera unit A

100

and the printer unit B

100

.

With the camera unit A

100

, reference numeral

101

denotes a CCD serving as an image-taking device,

102

denotes a microphone for input of audio,

103

denotes an ASIC for performing hardware processing,

104

denotes a first memory for temporarily storing image data and the like,

105

denotes a CF card for storing images that have been taken (equivalent to the CF card A

107

),

106

denotes an LCD for displaying images that have been taken or reproduced images (equivalent to the liquid crystal display unit A

105

), and

120

denotes a first CPU for controlling the camera unit A

100

.

In the printer unit B

100

reference numeral

210

denotes an interface between the camera unit A

100

and the printer unit B

100

.

201

denotes an image processing unit (including a binarization processing unit for binarizing images),

202

denotes second memory to be used for image processing,

203

denotes a band memory control unit,

204

denotes band memory,

205

denotes mask memory,

206

denotes a head control unit,

207

denotes a recording head (equivalent to the recording head B

120

),

208

denotes an encoder (equivalent to the encoder sensor B

131

),

209

denotes an encoder counter,

220

denotes a second CPU for controlling the printer unit B

100

,

221

denotes a motor driver,

222

denotes a motor (equivalent to the motors M

001

, M

002

, M

003

, and M

004

),

223

denotes a sensor (including the HP sensors B

134

, B

321

, and B

322

),

224

denotes an EEPROM built into the media pack C

100

,

230

denotes an audio encoder unit, and

250

denotes an electric power source for supplying electric power to the entire apparatus (equivalent to the battery A

108

).

FIG. 13

is an explanatory diagram describing the signal processing of the camera unit A

100

. In the photography mode, images taken by the CCD

101

through the lens

107

are subjected to signals processing by the ASIC

103

(i.e., CCD signal processing), and converted into YUV brightness two-color difference signals. Further, the images are resized to a predetermined resolution, subjected to JPEG compressing, and recorded in the CF card

105

. Also, audio is input from the microphone

102

, and recorded in the CF card

105

via the ASIC

103

. The audio recording may be performed simultaneously with taking the images, or as after-recording following taking the images. In the replay mode, the JPEG images are read out from the CF card

105

, subjected to JPEG expansion by the ASIC

103

, resized to the display resolution, and displayed on the LCD

106

.

FIG. 14

is an explanatory diagram for describing the signals processing at the printer unit B

100

.

Images reproduced at the camera unit A

100

side, i.e., read out of the CF card

105

, are subjected to JPEG expansion by the ASIC

103

as shown in

FIG. 13

, and resized to a resolution suitable for printing. The resized data (YUV) is then sent to the printer unit B

100

via the interface unit

210

. The printer unit B

100

performs image processing for the image data sent from the camera unit A

100

with the image processing unit

201

as shown in

FIG. 14

, and performs: conversion of the image signals into RGB signals; input ã correction according to properties of the camera; color correction and color conversion using a look-up table (LUT); and conversion into binary signals for printing. At the time of the binarization processing, the second memory

202

is used as error memory for error dispersion (ED) processing which is performed. In the present example, the binarization processing unit on the image processing unit

201

performs error dispersion processing, but other processing may be performed, such as binarization processing using dither patterns, or the like. The binarized print data is temporarily stored in the band memory

204

by the band memory control unit

203

. The encoder counter

209

of the printer unit B

100

receives input of encoder pulses from the encoder

208

each time the carriage B

104

upon which the recording head

207

and the encoder

208

are mounted moves a predetermined distance. Synchronously with these encoder pulses, print data is read out from the band memory

204

and the mask memory

205

, and based on the print data thereof, the head control unit

206

controls the recording head

207

to perform recording.

The band memory control in

FIG. 14

is as described next.

The multiple nozzles on the recording head

207

are formed in rows with a density of 1200 dpi, for example. In the event of scanning the carriage one time to record an image using such a recording head

207

, there is the need to create beforehand recording data for the number of nozzles in the sub-scanning direction (hereafter also referred to as “vertical (Y-direction)”) and the recording area in the main scanning direction (hereafter also referred to as “horizontal (X-direction)”), i.e., recording data for one scan. The recording data is created by the image processing unit

201

, and then temporarily stored in the band memory

204

by the band memory control unit

203

. Following storing one scan of recording data in the band memory

204

, the carriage is scanned in the main scanning direction. At this time, the encoder pulses input by the encoder

208

are counted by the encoder counter

209

, recording data is read out from the band memory

204

following the encoder pulses, and ink droplets are discharged from the recording head based on the image data thereof. In the event of performing recording of the image with the recording head

207

scanning in both directions, i.e., both when going and when returning, image data is read out from the band memory according to the scanning direction of the recording head

207

. For example, in the event of recording in the going direction, the address of the image data read out from the band memory

204

is sequentially incremented, and in the event of recording in the return direction, the address of the image data read out from the band memory

204

is sequentially decremented.

In reality, at the point that the image data (C, M, Y) created by the image processing unit

201

is written to the band memory

204

, and one band of image data has been prepared, the recording head

207

can be scanned. The recording head

207

is thus scanned, the image data is read out of the band memory

204

, and the recording head

207

records the image based on the image data. Image data to be recorded next is created by the image processing unit

201

during the recording operation, and the image data is written to the area of the band memory

204

corresponding to the recording position thereof.

Thus, the band memory control switches between the task of writing the recording data (C, M, Y) created by the image processing unit

201

to the band memory

204

, and the task of reading out the recording data (C, M, Y) to send to the head control unit

206

along with the scanning action of the carriage.

The following is a description of the mask memory control in FIG.

14

.

This mask memory control is necessary in the event that multi-pass recording is used. In the case of multi-pass recording, one line of recording image having a width equivalent to the length of a nozzle row of the recording head

207

is recorded by multiple scans of the recording head

207

. That is to say, the amount of transporting of the printing medium which is intermittently transported in the sub-scanning direction is set a 1/N of the length of the nozzle row, and in the event that, for example, N=2, one line of recording image is recorded by two scans (2-pass recording), and in the event that N=4, one line of recording image is recorded by four scans (4-pass recording). In the same way, in the event that N=8, one line of recording image is recorded by eight scans, and in the event that N=16, by sixteen scans. Accordingly, one line of recording image is completed by multiple scans of the recording head

207

.

In reality, mask data for appropriating the image data to multiple scans of the recording head

207

is stored in the mask memory

205

, and the recording head

207

discharges ink and records images based on the logical product (AND) data of the mask data and image data.

Also, in

FIG. 14

, the audio data stored in the CF card

105

is sent to the printer unit B

100

via the interface

210

, in the same manner as with the image data. The audio data sent to the printer unit B

100

is encoded at the audio encoder

230

and recorded in the image to be printed as code data. In the event that there is no need to include audio data in the printed image, or in the event that an image with no audio data is to be printed, the encoded audio data is not printed, with only the image being printed, as a matter of course.

With the present embodiment, description has been made regarding a camera with a built-in printer, wherein the camera unit A

100

and printer unit B

100

are integrally formed. However, the same functions can be realized in an arrangement wherein the camera unit A

100

and printer unit B

100

are separate and individual devices, connected by the interface

210

.

Characteristic Configurations

Next, description will be made regarding an embodiment of a characteristic configuration of the present invention.

FIG. 15

is a plan view showing a blown-up view of the ink discharging orifice face

1

of the recording head B

120

shown in FIG.

8

.

As shown in

FIG. 15

, the recording head B

120

has multiple ink discharging orifices B

121

arrayed following the direction intersecting the main scanning direction (arrow I) (in the case of the present embodiment, a direction generally orthogonal), in other words, in approximately a straight line in approximately the same direction as the transporting direction of the printing medium (recording medium) C

104

(arrow II). These ink discharging orifices B

121

configure nozzles capable of discharging ink supplied from the sub-tank.

This recording head B

120

discharges ink of the three colors of Y (yellow), M (magenta), and C (cyan), as described above.

The nozzle row for yellow (Y) ink is configured of 64 ink nozzles Y

1

through Y

64

for contributing to image formation by discharging yellow ink onto the printing medium C

104

, and eight dummy nozzles YD

1

through YD

8

(solid fill-in) arrayed four each on either side thereof.

The nozzle row for magenta (M) ink is configured of 64 ink nozzles M

1

through M

64

for contributing to image formation by discharging magenta ink onto the printing medium C

104

, and eight dummy nozzles MD

1

through MD

8

(solid fill-in) arrayed four each on either side thereof.

The nozzle row for cyan (C) ink is configured of 64 ink nozzles C

1

through C

64

for contributing to image formation by discharging cyan ink onto the printing medium C

104

, and eight dummy nozzles CD

1

through CD

8

(solid fill-in) arrayed four each on either side thereof.

The nozzle rows of each color have 32 nozzles arrayed on one side at the same pitch, and have 32 nozzles arrayed on the other side half a pitch off, so as to make a so-called staggered array, thereby realizing a 1200 dpi high-density array.

Also, the nozzle rows of each color are of an inline type wherein the rows are arrayed in approximately a straight line in approximately the same direction as the transporting direction of the recording medium C

104

(arrow II).

Also, the dummy nozzles YD

1

through YD

8

, MD

1

through MD

8

, and CD

1

through CD

8

, are arrayed so as to allow bubbles generated in the adjacent end ink nozzles Y

1

, Y

2

, Y

63

, Y

64

, M

1

, M

2

, M

63

, M

64

, C

1

, C

2

, C

63

, C

64

, and so forth, to escape to the nozzle dummies, or to keep the ink discharging properties of the end ink nozzles the same as those of the others by arrayed nozzles on either side of the end nozzles.

Now, the arraying spacing W of the nozzle rows of each color is set so as to be longer than the length L of the ink nozzle rows for discharging ink of each of the colors. That is to say, W>L holds. The dummy nozzles are positioned in the spacing W of the nozzle rows of each color.

With the present embodiment, the spacing W between the nozzle rows of each color is the equivalent of the space occupied by 72 nozzles, when converted into an equivalent number of nozzles. That is to say, the length L of the nozzle row of each color is the equivalent of the space occupied by 64 nozzles, and conversely the spacing W of the gap between nozzle rows of each color is longer than L (i.e., the equivalent of the space occupied by 72 nozzles).

Also, in this case, the transporting amount Δp of the recording medium C

104

each time performed during scanning of the carriage B

104

, is the equivalent of the space occupied by 32 nozzles.

FIG. 16

is a diagram illustrating change in the overlapping of the colors according to transporting of the recording medium C

104

in the event that the above transporting amount Δp is the equivalent of the space occupied by 32 nozzles.

In this case, let us say that for example, 2-pass multi-pass printing is performed. Multi-pass printing is performed by setting the sheet feeding amount to 1/N of the nozzles used (64 in this case) and printed N times with data subjected to complementary thinning out, thereby printing one raster line using multiple (an N number of) nozzles. In this case, one line worth, that is a recording image of 64 nozzles worth, is divided into two scans and recorded (the two scans being the traversing and returning scans).

Incidentally, in the event that multi-pass printing is not to be performed, recording may be performed using all nozzles each time that transporting is performed by 2 Δp worth (the equivalent of the space occupied by 64 nozzles).

In this way, the recording head B

120

is a linear type, so the colors each land at different positions during each scan. Finally, the recording medium C

104

is transported by 2 Δp worth following the scan.

At this time, according to this recording head B

120

, the spacing W between the colors is great, so time can be purchased until the ink lands during the next scan. Accordingly, time can be secured for the ink which has already landed to be sufficiently fixed. Thus, bleeding on the recording medium in high-speed recording can be prevented.

Also, the spacing W between the colors is great, so mixing of ink colors on the face

1

of the recording head B

120

can be prevented. Accordingly, this arrangement is also advantageous regarding mixing of colors at the time of recovery processing of the recording head, such as suctioning recovery and preliminary discharging. Further, this enables using inline recording heads for reactive inks, which has been difficult conventionally.

Also, according to this recording head, the nozzle rows for each color are configured of 64 nozzles, and the spacing W for the nozzle rows for each color is the equivalent of the space occupied by 72 nozzles, and further the transporting amount of the recording medium C

104

each time is Δp (which is the equivalent of the space occupied by 32 nozzles), each of these being multiples of 8.

This is since the band memory

204

shown in

FIG. 14

is managed in increments of band buffers storing eight scanning lines of discharging data, and the band memory

204

contains band buffers for at least 8 by 3 pieces of recording data and band buffers for three pieces of dummy nozzle data, thereby facilitating managing of the data by making the number of nozzles, the spacing between the nozzles, and the transporting amount of the recording medium, to be multiples of 8.

Now, in the above embodiment, the nozzle array is staggered, but the nozzle array may be in a straight line, or may be in yet another array.

With the present embodiment, description has been made regarding an arrangement wherein the nozzle row spacing for each of the colors is longer than the nozzle lengths of all, but with the present embodiment, it is sufficient that the nozzle row spacing be wider than the shortest nozzle row length. That is, depending on the type of ink used, not all inter-color spacings need to be longer than the nozzle rows, such as with cases wherein there is a nozzle row discharging ink with excellent fixing properties.

The present invention has been made regarding a three-color head of the colors yellow, magenta, and cyan, but the present invention is not restricted to this, and is also advantageous for an arrangement wherein a black nozzle row is added to the above three colors. In this case, it is advantageous from the perspective of recording speed to have the black nozzle row longer than the color nozzles.

Also, the recording head according to the present invention is also applicable to the so-called bubble jet method wherein thermal energy is generated to discharge ink, or the piezo method using piezo devices.

Thus, as described above, according to the present invention, the array spacing of nozzle rows of each color is greater than the nozzle row length L for discharging ink of each of the colors, so high-quality recording with little bleeding, mixing of colors, etc., can be provided at low costs, even when using very small heads or printing at high speeds.

While the present invention has been described with reference to what are presently considered to be the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modification and equivalent structures and functions.

Number	Name	Date	Kind
5640183	Hackleman	Jun 1997	A
5796416	Silverbrook	Aug 1998	A
5943072	Robert et al.	Aug 1999	A
5956056	Kaneko et al.	Sep 1999	A
6229565	Bobry	May 2001	B1

Ink-jet recording head, ink-jet recording apparatus, and electronic equipment

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

Priority Claims (1)

US Referenced Citations (5)