JPH07323607A - Image recording apparatus - Google Patents

Abstract

PURPOSE:To provide an image recording apparatus capable of recording a high-grade image on various materials to be recorded by setting the optimum recording conditions corresponding to the kind or use of a material to be recorded. CONSTITUTION:The recording due to either one of a reflection mode and a transmission mode to an OHP film is indicated by the operation of an operation mode and, when the reflection mode is indicated, a main CPU 100 allows a recording head to perform recording scanning once per one recording width of the OHP film and, when the transmission mode is indicated, the CPU 100 allows the recording head to perform recording scanning twice per one recording width of the OHP film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus capable of recording an image on various recording materials such as transparent or translucent sheets for overhead projectors, and more particularly, ink as a recording liquid. Is discharged from the discharge port as a small droplet,
The present invention relates to an image recording apparatus suitable for use in an ink jet recording system in which recording is performed by flying and depositing the droplets on a recording surface of a recording material.

[0002]

2. Description of the Related Art As one of image recording methods, for example,
The ink jet recording method is one in which ink is ejected onto a recording material according to a recording signal to perform recording, and the running cost is low and it is widely used as a quiet recording method. Then, by using a recording head in which a large number of nozzles are formed on a straight line so as to be orthogonal to the relative movement direction of the recording material and the recording head, one relative scanning of the recording head and the recording material is performed. With this, it is possible to print an image of a width corresponding to the number of nozzles formed at one time, and it is possible to relatively easily achieve high-speed printing.

As a recording material on which recording is carried out by such an ink jet recording system, in addition to paper usually used, for example, coated paper having a low transparency or OHP.
There is a transparent film for (overhead projector) (hereinafter, referred to as "OHP film") and the like. The former coated paper is a dispersion in which silica or calcium carbonate as a filler is dispersed in a binder made of PVA (polyvinyl alcohol) or oxidized starch in order to quickly absorb ink droplets ejected from the inkjet recording head. The mixture is coated on the base paper. On the other hand, the latter O
The film for HP is obtained by coating a transparent film such as PET (polyethylene terephthalate) with a water-absorbent resin such as PVA or ultrafine particles such as silica or alumina having a particle size of several tens to several hundreds of angstroms. An ink absorption layer is formed on the surface.

In particular, the OH
When a color image is recorded on a P film, a transmissive image having high color saturation and vivid color can be obtained. Therefore, the demand for the OHP film has recently increased.

By the way, OHP for ink jet recording
As a film for use, in addition to the ink absorption characteristics of quickly absorbing the recording ink recorded on the surface thereof so that the ink does not flow out or bleed, the recording density is high and sufficient density gradation is obtained. There are many things, such as excellent color clarity and color reproducibility as a color record, and excellent water resistance, light resistance, indoor storability, and abrasion resistance of images as the storage stability of the record. Characteristics are required. In particular, in order to prevent ink from flowing out or bleeding due to insufficient ink absorption amount or insufficient ink absorption speed on the surface of the OHP film, a sufficient ink absorption as a coating layer coated on the surface of the OHP film. Amount and sufficient absorption speed are required. Therefore, the thickness of the coating layer coated on the surface of the OHP film is about several μm to 50 μm, and in particular, the thickness of the coating layer for the OHP film for pictorial full color recording is set to be thicker. There is.

However, when the coating layer on the OHP film is thickened in this manner, it becomes difficult to form the layer by coating the film such as PET once, and the coating process is divided into a plurality of times. Since it is necessary to use a large amount of coating material, the production cost of the OHP film is increased as a result, and the transparency of the OHP film itself is lowered, and the OHP film is recorded on the film. There has been a problem that the quality of the projected image is deteriorated when the image is projected by the overhead projector.

Therefore, in the prior art, as shown in FIG.
The coating layer on the HP film has a thickness capable of maintaining the limit recording ink amount Q _max (pl / mm ² ).
That is, even if recording ink droplets are recorded on the surface of the OHP film by the ink jet recording head, ink does not flow out or bleed, that is, the maximum recording ink amount Q ₁ (pl / mm ² ) by the recording head is recorded. The ink absorption capacity Q (pl / mm ² ) is ensured in order to maintain the limit recording ink amount Q _max (pl / mm ² ) (Q ₁ <Q _max ) such that the ink does not flow out even if
By setting the thickness of the coating layer of the OHP film, the cost of the OHP film itself is further reduced. The recording ink amount Q changes according to the image signal S input to the recording apparatus. Also, Q ₁ is 1
It is the maximum print ink amount in one print scan, and Q _max is 1.
This is the limit recording ink amount in one recording scan. Then, as shown in FIG. 13, a sufficient recorded value density D ₁ is achieved on the OHP film, and the OHP film has sufficient transparency when projected by an overhead projector.

[0008]

However, with respect to the OHP film provided with the ink absorbing layer on the surface to such an extent that the ink does not flow out or bleed out as described above,
When an OHP film is recorded by an inkjet recording head and then the recorded image is projected by a reflection type overhead projector, a sufficient recording density can be obtained, but when it is projected by a transmission type overhead projector. However, the density of the projected recorded image is lower than that of the reflective type, and a satisfactory projected image cannot be obtained.

An object of the present invention is to provide an image recording apparatus capable of recording high-quality images on various recording materials by setting optimum recording conditions according to the type and application of the recording material. To provide.

[0010]

According to a first aspect of an image recording apparatus of the present invention, recording means for recording an image on a recording material on the basis of image data, and the recording means and the recording material are relatively disposed. And a control unit capable of changing the number of recording operations of the recording unit in the same recording range of the recording material by controlling the recording unit and the moving unit. To do.

A second aspect of the image recording apparatus of the present invention is recording means for recording an image on a recording material based on image data, and moving means for relatively moving the recording means and the recording material. And a control unit capable of changing the recording density of the recorded image by controlling the recording unit.

[0012]

The first aspect of the image recording apparatus of the present invention is a recording operation in the same recording range for recording materials of various types and applications, such as recording materials used in reflective or transmissive overhead projectors. By changing the number of times, the recording density, and the like, a high-quality image suitable for the type of recording material and its application is recorded.

[0013]

Embodiments of the present invention will now be described in detail and specifically with reference to the drawings.

(Embodiment 1) FIG. 1 is a schematic configuration diagram for explaining the entire image recording apparatus of the present embodiment. The image recording apparatus of the present embodiment reads a color image of an original to obtain a digital color image. A color image scanner unit (hereinafter referred to as "reader unit") 1 for outputting data, and a printer unit 2 for recording a color image on a recording material 4 based on digital color image data output from the reader unit 1. It consists of and.

In the reader unit 1, an exposure lamp, a lens, and an image sensor 3 (a CCD sensor is used in this embodiment) capable of reading a line image in full color on a glass platen of an original table, which are not shown. The image of the placed document is read by the length of the CCD sensor corresponding to the recording width by the recording head 10 described later. The main CPU 100 controls the serial scan operation of the image sensor 3 and the control of the entire apparatus.
Further, the main CPU 100 includes a printer control CPU 102 that controls a control operation of the printer unit 2, a reader control CPU 104 that controls a read control operation, a main image processing unit 106 that processes an image processing operation, and an operation as an input unit by an operator. The unit 108 is connected to the operation unit 1.
08 is used to specify whether the image recording on the OHP film is performed in the reflection mode or the transmission mode as described later.

The main image processing unit 106 described above performs image processing such as masking, black extraction, multi-valued conversion, and gamma correction.
Further, the printer control CPU 102 and the main image processing unit 1
The synchronous memory 110 is connected to 06. The synchronous memory 110 is for absorbing the time variation of the input operation and for correcting the delay due to the mechanical arrangement of the recording head 10 described above. Then, this synchronous memory 11
The output of 0 is output to the recording head 10 from the head driver 115 controlled by the printer control CPU 102.

The printer control CPU 102 is connected to a printer unit drive system 114 that controls the input drive of the printer unit 2.

Further, the reader control CPU 104 includes an input system image processing unit 116 for performing correction processing necessary for the reading system such as shading correction, color correction, and γ correction, and a reader unit drive system 118 for controlling input driving of the reader. Connected to.

Further, the input system image processing unit 116 has a CCD
The sensor 3 is connected to the input system image processing unit 11
Reference numeral 6 is connected to the main image processing unit 106.

FIG. 2 is a perspective view for explaining the printer unit 2. The printer unit 2 is roughly divided into two guide rails 15a and 15b and an ink jet recording head 10.
And a carriage 11 on which the carriage 11 is mounted, an ink supply device, a head recovery device 20, and an electrical system. An image is recorded on the recording material.

The ink supply device is for storing ink and supplying it to the head 10 in a required amount, and has an ink tank 14 and an ink pump 13. The apparatus and the head 10 are connected by an ink supply tube 12, and normally, ink is automatically supplied to the head 10 by a capillarity as much as the amount of ink ejected from the head 10. Also,
At the time of a head recovery operation as described later, ink is forcibly supplied to the head 10 using the ink pump 13.
In addition, 12aB, 13B, and 14B are tubes, pumps, and tanks for black ink.
C, 13C, 14C are for cyan ink, 12aM, 13
M, 14M are for magenta ink, 12aY, 13Y, 1
4Y is for yellow ink.

The head 10 and the ink supply device are
They are mounted on the head carriage 11 and the ink carriage, respectively. The carriages have pulleys 17
The belt 16 provided between a and 17b is connected, and the shaft 18 of the motor 19 is further connected to the pulley 17b. In response to the rotation of the motor 19, those carriages are guided along the guide rails 15a and 15b by arrows. It is configured to reciprocate in the S direction (main scanning direction).

The head recovery device 20 includes the head 1 at the home position HP in order to maintain the stability of the head.
It is provided at a position facing 0, and specifically, the following operation is performed. When not operating, the head 10 is moved forward in the direction of the arrow f ₁ to cap the head 10 at the home position HP to prevent evaporation of ink from inside the nozzles of the head 10 (capping operation), or bubbles in front of the nozzles before image recording is started. In order to discharge dust and the like, an operation of pressurizing the ink flow path in the head 10 by using an ink pump to forcibly discharge the ink from the nozzle is performed (pressure recovery operation). Further, at that time, it also has a function of collecting the discharged ink.

FIG. 3 is a perspective view showing a schematic structure of the ink jet recording head 10. The head 10 is an electric film formed on the substrate 21 through semiconductor manufacturing process steps such as etching, vapor deposition and sputtering. Heat converter 2
2, the electrode 23, the nozzle wall 24, and the top plate 25. The recording ink is supplied from the aforementioned ink tank 14 into the common liquid chamber 26 of the recording head 10 through the ink supply tube 12. Reference numeral 27 in the figure denotes a supply pipe connector. The ink supplied into the common liquid chamber 26 is supplied into the liquid passage 28 forming the nozzle by a capillary phenomenon, and is stably held by forming a meniscus at the discharge port surface 29 at the tip of the nozzle.

Here, the electrothermal converter 2 is passed through the electrode 23.
By energizing No. 2, the ink on the surface of the electrothermal converter 23 is heated, a bubbling phenomenon occurs in the ink, and the energy of the bubbling causes ink droplets to be ejected from the ejection port surface 29.

With the above-mentioned configuration, the nozzle density is set to a high density nozzle arrangement of 16 nozzles / mm,
It is possible to manufacture a multi-nozzle inkjet recording head having 128 nozzles or 256 nozzles.

FIG. 4 shows the image recording apparatus of the present embodiment.
It is a figure for demonstrating the difference of recording density in the case of recording on the OHP film for inkjet recording in a reflection mode and a transmission mode which will be described later. The density of the image recorded on the OHP film by the recording head 10 changes depending on the input image signal. In the figure, A indicates a change in the reflection mode and B indicates a change in the transmission mode. . In the present invention, as will be described later, in the transmissive mode, an image is recorded so that the maximum recording density D _{2 in} that case is higher than the maximum recording density D _{1 in} the reflective mode. Sufficient projected image density is obtained even when the recorded image of the OHP film is projected by the transmission type overhead projector.

FIGS. 5 and 6 are timing charts for explaining the recording operation of this embodiment. In this embodiment, when recording an image on the OHP film, either the reflection mode or the transmission mode is selected by the operation unit 108, and the serial scanning operation of image reading by the reader unit 1 and the printer are performed accordingly. The control content of the serial scan operation of image recording by the unit 2 is switched. That is, when the image recording on the OHP film is performed in the reflection mode, as shown in FIG. 5, the recording width of the recording head 10 is the same as the case of recording the image on the coated paper for normal inkjet recording. Images per minute are recorded on the OHP film by one serial scan operation of the reader unit 1 and the printer unit 2. On the other hand, in the transmissive mode, as shown in FIG. 6, an image per recording width of the recording head 10 is recorded on the OHP film by two serial scan operations of the reader unit 1 and the printer unit 2. As a result, the recording ink droplets corresponding to the same image data are generated a plurality of times (twice in this embodiment).
It is ejected and overlaps. The recording operation in each mode will be specifically described below. In this embodiment, the so-called unidirectional recording method is used in which recording is performed only when the printer unit 2 moves in the forward direction.

(Recording Operation in Reflection Mode) When recording an image on the OHP film in the reflection mode, the reader unit 1 and the printer unit 2 perform serial scanning while reading the original image and recording the image. 1 for motion and 1 for motion
I try to correspond to each time.

Explaining with reference to FIG. 5, first, when the scanning operation of the reader unit 1 in the forward direction is started at timing t ₁ , the movement of the printer unit 2 in the forward direction is started at timing t _2. . Then, at time t ₃ , the reading operation of the original image by the CCD sensor 3 mounted on the reader unit 1 is started, and thereafter, based on the image recording signal corresponding to the read signal of the CCD sensor 3, the timing t ₄
With the recording head 10 mounted in the printer unit 2, the OHP
The recording operation of the image on the film for use is started.

Then, at timing t ₅ , the CCD sensor 3
When the reading operation of the original image by means of is completed, the recording operation of the image by the recording head 10 is completed at timing t ₆ ,
At timing t ₇ , the scanning operation of the reader unit 2 in the forward direction is stopped, and then the reader unit 1 and the document are relatively moved by the sub-scanning motor of the reader unit 1 in the sub-scanning direction by the width of the next image reading. It At the same time, after the printer unit 2 stops the moving operation in the forward direction at the timing t ₈ , the printer unit 2 and the OHP film are moved in the sub-scanning direction by the sub-scanning motor of the printer unit 2 for the next image recording width. It is moved relatively.

When the relative movement of the reader unit 1 and the document in the sub-scanning direction is completed at timing t ₉ , this time, the backward movement operation of the reader unit 1, that is, the back scan operation is started. Printer unit 2 at timing t ₁₀
After the relative movement of the film and the OHP film in the sub scanning direction is completed, the backward movement operation of the printer unit 2, that is, the back scan operation is started. During these back scan operations, the reader unit 1 does not read the original image,
The printer unit 2 does not perform the recording operation.

At timings t ₁₁ and t ₁₂ , the back scan operation of the reader unit 1 and the printer unit 2 in the backward direction is completed one after another, and the first reciprocating scan of the reader unit 1 and the printer unit 2 (hereinafter, " The image reading operation and the image recording operation by the "first scan") are completed.

After that, at timings t ₁₃ and t ₁₄ , the reader unit 1 and the printer unit 2 carry out the second scan similarly to the first scan.
The image reading operation of the scan and the image recording operation are started, and the same operation is repeated thereafter to complete the recording of the image on the OHP film.

(Recording Operation in Transmission Mode) Next, OHP
When recording an image in transmissive mode on a film for printing,
As shown in FIG. 6, in the first scan, the relative movement of the reader unit 1 and the original in the sub-scanning direction and the relative movement of the printer unit 2 and the OHP film in the sub-scanning direction are not performed, and the reader is The unit 1 and the printer unit 2 repeat the image reading operation and the image recording operation twice for the same recording width.

That is, at the timings t ₁ and t ₂ , the scanning operation of the first scan in the forward direction of the reader unit 1 and the printer unit 2 is started in the same manner as in the reflection mode described above, and the timing t ₁₁ , T ₁₂ leader section 1,
After the scan operation of the first scan of the printer unit 2 is completed, the conveyance operations of the reader unit 1 and the printer unit 2 for the image reading width and the image recording width in the sub-scanning direction are not performed, and the backward movement is performed. Back scan to. After that, at timings t ₁₅ and t ₁₆ , the image reading operation of the second scan and the image recording operation of the reader unit 1 and the printer unit 2 are restarted. As a result, the same image is recorded twice in a single recording width on the OHP film. After that, at timings t ₁₇ and t ₁₈ , the image reading operation and the image recording operation of the second scan of the reader unit 1 and the printer unit 2 are completed, and at the timings t ₁₉ and t ₂₀ , those scanning operations in the forward direction are completed. After that, the reader unit 1 and the printer unit 2 are driven by those sub-scanning motors.
The feeding operation for the image reading width and the image recording width in the sub-scanning direction is performed. When the conveying operation of the reader unit 1 and the printer unit 2 in the sub-scanning direction is completed at timings t ₂₁ and t ₂₂ , the back-scan operation in the backward direction is started, and at the timings t ₂₃ and t ₂₄ , the backward scanning operation is performed. The back scan operation is completed, and the image reading operation and the image recording operation of the second scan of the reader unit 1 and the printer unit 2 are completed.

As described above, when the image recording operation on the OHP film is performed, either the reflection mode or the transmission mode is selected. In the transmission mode, the reader unit 1,
The conveyance operation of the printer unit 2 in the sub-scanning direction is performed for each of a plurality of scan operations in the main scanning direction (in the above example, 2).
By performing once for each scan operation),
Images of the same image reading width are recorded on the OHP film a plurality of times (twice in the above example) to increase the total recording ink amount per unit area on the OHP film. This makes it possible to create an OHP film having a sufficient projected image density even when projected by a transmissive OHP projector.

(Embodiment 2) FIG. 7 is a timing chart for explaining the recording operation of the second embodiment of the image recording apparatus of the present invention. In the present embodiment, when the image recording on the OHP film is performed in the transmissive mode, the recorded images corresponding to the same image data are recorded a plurality of times within the one recording width on the OHP film (twice in the present embodiment). When recording again, a predetermined waiting time (stop period) T _wait is set between the first image recording operation and the start of the second image recording operation.
Is provided.

That is, in the present embodiment, after the scanning operation of the first scan of the reader unit 1 and the printer unit 2 is completed at the timings t ₁₁ and t ₁₂ , the waiting time T _wait is awaited, and , After the ink droplets landed on the OHP film in the first scan are sufficiently absorbed in the OHP film, the image reading operation of the second scan similar to the first scan at timings t ₁₃ and t ₁₄ . , The image recording operation is restarted.

During the stop period, the recording head 10 is dried,
In order to prevent the adhesion of dust, the recovery device 20 may perform capping or a recovery process.

As in this embodiment, the printer unit 2
By providing a waiting time _Twait for the image recording time between the second and the second image recording operations, the ink flows out when the ink droplets during the second image recording are not sufficiently absorbed on the surface of the OHP film. It is possible to prevent the occurrence of bleeding and bleeding.

(Third Embodiment) FIGS. 8 and 9 are views for explaining a third embodiment of the image recording apparatus of the present invention.

In the present embodiment, when the image recording on the OHP film is performed in the transmissive mode, the images read from the reader unit 1 are superposed on the OHP film a plurality of times (twice in the present embodiment). When recording and further recording images by the second image recording operation after the first image recording operation on the OHP film, at the time of the second image recording operation, as shown in FIG. Leader section 1
The value of the output image signal S'to the printer unit 2 corresponding to the image read signal S of is set to be smaller than that in the first image recording operation. As a result, the second image recording operation causes the OH
The amount of ink landed on the P film is reduced. The signal conversion operation at the time of the first and second image recording operations as shown in FIG. 8 is performed by the table provided in the main image processing unit 106 of FIG. 1 described above.

By the way, in the case of an OHP film having poor ink absorbability, the limit recording ink amount Q _max (pl / mm ² ) for an area where no recording has been performed yet.
That is, as compared with the limit ink amount of the OHP film during the print operation of the first scan, the limit print ink amount Q ′ _max (pl / mm
² ) That is, the OHP during the recording operation of the second scan
The amount of recording ink for recording film is especially small (Q
_max > Q ' _max ). For such an OHP film, the maximum recording ink amount Q ₂ of the second scan by the recording head (pl / mm ²⁾ of the first scan maximum recording ink amount Q ₁ (pl / mm ²⁾ Less (Q ₁
> Q ₂ ) It is necessary.

Therefore, with respect to an image (recorded image at the time of the second image recording operation) to be overlaid and recorded on the OHP film as in this embodiment, the value of the output image signal S'is set as the recording condition. By reducing the amount of the ink ejected onto the OHP film, the OHP film, which does not have good ink absorptivity, does not cause the ink to flow out or bleed on the surface of the film. High-quality images can be recorded with high quality.

(Embodiment 4) FIG. 10 is a schematic block diagram for explaining the fourth embodiment of the image recording apparatus of the present invention. In this embodiment, the original read by the reader unit 1 is shown. The main CPU 100 controls the printer control CPU 102 and the head driver 115 so that the image data is temporarily stored in the image memory 111, and the image data stored in the image memory 111 is recorded on the OHP sheet by the printer unit 2.

That is, the image data for one scan read by the reader unit 1, that is, the image data for the image reading width is temporarily stored in the image memory 111, and the image data for one scan is repeatedly stored in the printer unit 2. By recording, the scanning operation of the reader unit 1 can be performed only once for the two scanning operations of the printer unit 2. As a result, the problem that occurs when the reader unit 1 repeatedly reads the same area of the document, that is, the deterioration of the image quality of the recorded image due to the misalignment of the read pixels can be prevented, and the exposure lamp and the movable unit of the reader unit 1 can be prevented. The durability of can also be improved.

FIG. 11 is a timing chart for explaining the recording operation of this embodiment. At timings t ₁₁ and t ₁₂ , the image reading operation of the first scan of the reader unit 1 and the printer unit 2 and the image recording operation are performed. After the completion, _wait for the waiting time T _wait for the ink to be absorbed into the OHP film, while the ink droplets landed in the OHP film during the first scan are sufficiently absorbed in the OHP film. After that, the second image recording operation of the printer unit 2 is started at timing t ₁₃ . Then, at timing t ₁₄ , the image recording operation of the image data stored in the image memory 111, that is, the image data read by the first image reading operation of the reader unit 1 is started.

After that, the printer unit 2 at the timing t ₁₅
After the end of the image recording operation and the end of the scanning operation of the printer unit 2 in the forward direction at the timing t ₁₆ , the conveyance of the printer unit 2 in the sub-scanning direction is started at the timing t _17.
When the conveyance in the sub-scanning direction ends at this time, the back scan operation in the backward direction starts this time, and after the back scan operation in the backward direction ends at timing t ₁₈ , the timing t
_{At 19} , the image reading operation for the next image reading width by the reader unit 1 is started.

(Fifth Embodiment) FIGS. 14, 15 and 16 are views for explaining a fifth embodiment of the present invention.

FIG. 14 is a perspective view schematically showing a structural example of an ink jet recording apparatus to which the present invention is applied. 14
In the above, the roll-wound film for OHP (hereinafter referred to as “recording material”) 505 is the conveyance roller 50.
The sheet feeding roller pair 503 is sandwiched between the sheet feeding rollers 1, 502, and is fed in the direction of the arrow f as the sub-scanning motor 515 connected to the sheet feeding roller pair 503 is driven. Guide rails 506 and 507 are installed in parallel across the recording material 505, and a main scanning carriage 508 is guided and supported along the guide rails 506 and 507 so as to be capable of reciprocating left and right. A plurality of carriages 508 (four)
Recording heads 509Y, 509C, 509C, 509B
k is installed. In the case of color recording, these recording heads are selected to record with ink colors of yellow, magenta, cyan and black, for example. In the following description, the recording heads 509Y, 509C, 5 will be described.
09C and 509Bk, or any one of them, simply means the recording means 509 or the recording head 5.
09 will be shown.

Each recording head 509 is composed of a replaceable cartridge in which an ink tank is integrated. The recording material 505 is intermittently fed in the direction of arrow f by the recording width (height of one line) of the recording head 509 (sub-scanning), and the carriage 508 is moved while the recording material 5 is stopped. The carriage 508 is moved in the direction of arrow P.
The recording is performed by ejecting ink from each recording head 509 in synchronization with the movement (main scanning) of the recording head 509. That is, the entire recording is performed by alternately repeating the sub-scanning and the main scanning of the recording material 505.

FIG. 15 is a block diagram of the image recording apparatus of this embodiment.

In FIG. 15, reference numeral 521 denotes an input image signal,
522 is a buffer memory, 523 is a discriminating means, 524 is a γ control signal, 525 is a γ conversion unit, 526 is a scan control signal, 527 is a scan control unit, 528 is a main scanning motor drive signal, and 529 is a sub scanning motor drive. Traffic light, 530
Is a main scanning motor, 531 is a sub-scanning motor, 532 is a converted signal, 533 is a head driving circuit, 534 is a head driving signal, 535 is a recording head, 536 is selecting means, 5
37 is a select signal.

The input image signal 521 is temporarily stored in the buffer memory 522 which is an image memory for one scan,
Then, it is sent to the discrimination means 523.

When the value of the scan control signal 526 is "0", the scan control unit 527 performs the main scan once and then the sub-scan, as in the usual case. 530, the sub-scanning motor 531 is controlled. When the value of the scan control signal 526 is “1”,
The motors 530 and 531 are controlled so that the main scanning is performed twice and the sub-scanning is performed once. Drive circuit 53
3 inputs the image signal after the γ conversion, and the recording head 53
The drive pulse 534 for 5 is output. Recording head 5
The reference numeral 35 ejects ink droplets in response to the drive pulse 534, and the ink droplets perform image recording on the recording material 505.

When the reflection mode is selected, the γ conversion table A shown in FIG. 16 is used as will be described later, and image recording is performed by a normal single scan.

The selector means 536 is used for designating which one of the two modes, the transmissive mode or the reflective mode, in which image recording is to be performed. The designation is made by the user of the image recording apparatus from the outside through a select switch or the like. Is performed by operating. The select signal 537 is sent to the discriminating means 523 as a select signal for those modes.

(Recording Operation in Reflection Mode) When the reflection mode is selected, it is not necessary to increase the recording density. In this case, the determination unit 523 outputs the value “0” as the γ control signal 524 and the scan control signal 526. The γ conversion unit 525 is a table ROM, and performs γ conversion using a conversion table that differs depending on the value of the γ control signal 524. When the value of the γ control signal 524 is “0”, the conversion characteristic table of A in FIG. 16 (hereinafter, “table A”).
If the value of the γ control signal is “1”, the conversion characteristic table of B in FIG. 16 (hereinafter referred to as “table B”) is selected.

(Recording Operation in Transparent Mode) When the transparent mode is selected, the discrimination means 523 monitors the image data for one scan and outputs the control signal according to the monitoring result. That is, the determining unit 523 determines whether or not there is data having a value of "128" or more in the image data (8-bit data) for one line once stored in the buffer memory, that is, the pixels in one line. It is determined whether or not there is a value of "128" or more in the data of the value corresponding to each recording density, and if there is no data of a value of "128" or more, the value of the γ control signal 524 is set to "1". And the value of the scan control signal 526 is set to "0". Therefore, in this case, the γ conversion table B is used to perform image recording in one scan. The maximum value of the image data is “255”.

If the image of one line has data of "128" or more, the value of the γ control signal 524 is set to "0" and the value of the scan control signal 526 is set to "1". Therefore, in this case, the γ conversion table A is used and the image is recorded by two scans.

Therefore, when the double recording density can be obtained only by changing the γ conversion table A to B, that is, 1
If there is no data with a value of "128" or more in the line image data, only the γ conversion table is changed (change to table B) without ejecting ink drops twice by two scans. If the double print density cannot be obtained unless the ink droplets are ejected twice by two scans, that is, the data of "128" or more in the image data for one line. If there is, the ink droplet is ejected twice by two scans with the γ conversion table A kept. As a result, the recording operation for the OHP film used in the transmission type overhead projector can be performed in the necessary minimum time, and a sufficient recording density can be obtained.

(Embodiment 6) In this embodiment, the light quantity of the light source of the overhead projector, that is, "brightness" of the light source,
The "gamma" conversion table can be changed by "dark".

The block diagram of this embodiment is shown in FIG.
5, but the selecting means 536 selects “dark in reflection mode”, “bright in reflection mode”, and “dark in transmission mode”.
It is possible to switch between four levels of "transparent mode bright". The γ conversion unit 525 has six γ conversion tables of conversion characteristics C, D, E, F, G, and H shown in FIG. 17 (hereinafter, these are referred to as “tables C, D, E, F, G, and H”). Is prepared. In Tables C, D, E, and F, the value of the 8-bit input signal (image data) is "25".
5 "," 212 "," 170 "," 128 ",
It is a conversion table that makes the output the maximum value "255".

Further, the tables G and H are converted such that a value obtained by doubling the output becomes the output of the tables E and D within a range in which the double value of the output does not exceed the maximum value "255". It's a table.

When "dark reflection mode" is selected,
That is, when recording is performed on the recording material 505 for the reflection type overhead projector whose light source is relatively dark, the conversion table C is selected, and the image is recorded by one scan using this conversion table C.

When "brightness of reflection mode" is selected,
That is, when recording is performed on the recording material 505 for the reflection type overhead projector whose light source is relatively bright, it is determined whether or not the image data of one scan includes data having a value of "212" or more. If it is not included, the table D is selected, and the image is recorded by one scan using the table D. on the other hand,
If data with a value of "212" or more is included,
The table H is selected, and the image is recorded by two scans using the table H.

When "Dark in transmission mode" is selected,
That is, when recording is performed on the recording material 505 for the transmission type overhead projector in which the light source is relatively dark, it is determined whether or not the data of the value of “170” or more is included in the image data of one scan, If it is not included, the table E is selected, and the image is recorded by one scan using the table E. On the other hand, when data having a value of “170” or more is included, the table G is selected, and the image recording is performed by two scans using the table G.

When "transparent mode bright" is selected,
That is, when recording is performed on the recording material 505 for a transmission type overhead projector whose light source is relatively bright, it is the same as in the above-described sixth embodiment. However, the tables A and B in the sixth embodiment correspond to the tables C and F in this embodiment.

In this way, by configuring so that a plurality of modes can be selected according to the light amount of the projector,
The recording density can be adjusted more finely.

(Embodiment 7) In this embodiment, an OHP as a recording material 505 when projected by a projector is used.
The γ conversion table is also changed depending on the distance between the work sheet and the screen.

That is, generally, as the distance between the recording material 505 and the screen increases, the density of the projected image decreases. In the present embodiment, this is corrected.

In the present embodiment, in each of the reflection mode and the transmission mode, "near reflection mode", "far reflection mode",
The selecting means 536 selects four types of modes, "near the transmission mode" and "far the transmission mode". The γ conversion table to be prepared is the same as that in FIG. 17, and similarly to the sixth embodiment described above, the γ conversion table is selected according to the selection of each mode and the determination result of the value of the image data during one scan. Then, one scan recording or two scan recording is selected.

In the above embodiments, 5, 6 and 7 are described by taking the ink jet recording apparatus as an example, but the same can be applied to recording apparatuses of other recording systems such as sublimation type thermal transfer and fusion type thermal transfer. .

(Others) In addition, in the above-described embodiment, an example in which the recording conditions for a recording material such as an OHP sheet is changed has been described. However, the above-mentioned OHP is further applied to the recording mode for recording material such as normal paper. It may be configured to have a recording mode for the sheet for use. In the recording mode on paper, sufficient color development can be obtained at a density lower than the recording density in the reflection mode described above.

In the present invention, particularly in the ink jet recording system, a means (for example, an electrothermal converter or a laser beam) for generating heat energy as energy used for ejecting ink is provided. The effect is excellent in a recording head and a recording apparatus of a system that causes a change in ink state by energy. This is because such a system can achieve high density recording and high definition recording.

Regarding the typical structure and principle thereof, see, for example, US Pat. Nos. 4,723,129 and 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal in a one-to-one correspondence
It is effective because bubbles can be formed inside. Due to the growth and contraction of the bubbles, the liquid (ink) is ejected through the ejection opening to form at least one droplet. It is more preferable to make this drive signal into a pulse shape, because the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) with excellent responsiveness can be achieved. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in JP-A-59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum width of a recording medium which can be recorded by the recording apparatus. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the apparatus main body, or the electrical connection with the apparatus main body or the ink from the apparatus main body by being attached to the apparatus main body The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add ejection recovery means of the recording head, preliminary auxiliary means and the like because the effects of the present invention can be further stabilized. Specifically, heating is performed by using a capping unit, a cleaning unit, a pressure or suction unit for the recording head, an electrothermal converter or a heating element other than this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type and number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change of the ink from the solid state to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by. In any case, by applying thermal energy such as ink that is liquefied by applying thermal energy according to the recording signal and liquid ink is ejected, or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In this case, the ink is
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent No. 1260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as a form of the ink jet recording apparatus of the present invention, in addition to the one used as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function can be used. It may be a form or the like.

[0085]

As described above, the first embodiment of the image recording apparatus of the present invention is applicable to recording materials of various types and applications, such as recording materials used in reflective or transmissive overhead projectors. By changing the number of recording operations for the same recording range, it is possible to record a high-quality image suitable for the type of recording material and its application.

Further, when a plurality of recording operations are performed in the same recording range, a predetermined waiting time is set between the recording operations to ensure that the recording material such as ink is fixed to the recording material. It can be anything.

Further, when the recording operation is performed a plurality of times in the same recording range, the fixing property of the recording material such as ink is not good by changing the recording condition (for example, recording density) of each recording operation. It is possible to record a high-quality image on a recording material.

Further, by temporarily recording the image data output from the document image reading means in the storage means, when performing the recording operation a plurality of times in the same recording range,
The durability of the movable part of the reading means can be improved without increasing the number of reading operations of the reading means.

According to the second aspect of the image recording apparatus of the present invention, a high-quality image suitable for the type of recording material and its application can be recorded by changing the density of the recorded image.

Further, the optimum recording condition can be automatically obtained by changing the recording density or the number of recording operations in the same recording range according to the value corresponding to the recording density of the image data.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic perspective view of a recording head portion shown in FIG.

FIG. 3 is an exploded perspective view of a main part of the recording head shown in FIG.

FIG. 4 is an explanatory diagram of a relationship between the number of recording operations and recording density in the first embodiment of the present invention.

FIG. 5 is a timing chart for explaining an example of a recording operation in the first embodiment of the present invention.

FIG. 6 is a timing chart for explaining another example of the recording operation in the first embodiment of the present invention.

FIG. 7 is a timing chart for explaining the recording operation of the second embodiment of the present invention.

FIG. 8 is an explanatory diagram of a conversion table according to the third embodiment of this invention.

FIG. 9 is an explanatory diagram of a relationship between the number of recording operations and recording density according to the third embodiment of the present invention.

FIG. 10 is a block diagram showing a fourth embodiment of the present invention.

FIG. 11 is a timing chart for explaining the recording operation of the fourth embodiment of the present invention.

FIG. 12 is an explanatory diagram of an ink absorption capacity of an OHP sheet.

FIG. 13 is an explanatory diagram of a relationship between a recording density of an OHP sheet and an image signal.

FIG. 14 is a perspective view showing a schematic configuration of a fifth embodiment of the present invention.

FIG. 15 is a block diagram showing a fifth embodiment of the present invention.

FIG. 16 is an explanatory diagram of a conversion table according to the fifth embodiment of this invention.

FIG. 17 is an explanatory diagram of a conversion table according to the sixth embodiment of this invention.

[Explanation of symbols]

 1 Reader Section 2 Printer Section 10 Recording Head 22 Electrothermal Converter (Electrothermal Converter)

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Claims (10)

[Claims] 1. A recording means for recording an image on a recording material based on image data, a moving means for relatively moving the recording means and the recording material, and controlling the recording means and the moving means. An image recording apparatus comprising: a control unit capable of changing the number of recording operations of the recording unit for the same recording range of the recording material. 2. The control means can set a predetermined waiting period between each recording operation when the recording operation of the recording means is performed a plurality of times for the same recording range of the recording material. The image recording apparatus according to claim 1, wherein 3. The control means, when the recording operation of the recording means is performed a plurality of times for the same recording range of the recording material, it is possible to change the recording condition by each recording operation. The image recording apparatus according to claim 1 or 2, which is characterized in that. 4. A reading means for reading an original image, and a storage means for storing image data output from the reading means, wherein the control means stores in the storage means at each recording operation of the recording means. The image recording apparatus according to claim 1, wherein the stored image data is read. 5. The image recording apparatus according to claim 3, wherein the control unit can change a recording density as the recording condition. 6. A recording unit for recording an image on a recording material based on image data, a moving unit for relatively moving the recording unit and the recording material, and a recording unit for controlling the recording unit to record an image. An image recording apparatus comprising: a control unit capable of changing a recording density. 7. The image recording apparatus according to claim 6, wherein the control unit can change the recording density based on a value corresponding to the recording density of the image data. 8. The control means is capable of changing the number of recording operations of the recording means for the same recording range of the recording material together with the recording density based on a value corresponding to the recording density of the image data. The image recording apparatus according to claim 6, wherein the image recording apparatus is provided. 9. The recording means reciprocates in a direction substantially orthogonal to a relative movement direction of the recording means and the recording material.
The image recording device according to 4, 5, 6, 7 or 8. 10. The recording means has an inkjet recording head for ejecting ink, and the recording head generates thermal energy for causing film boiling in the ink as energy used for ejecting ink. An electrothermal conversion element is provided, The claim 1, 2,
The image recording device according to 3, 4, 5, 6, 7, 8 or 9.