JPH09204083A - Image recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent image blurring in a lateral stripe state by selectively contacting and separating a resist roller on the upstream side of a medium carrying means and increasing a carrying quantity by the resist roller on the upstream side so that a recording medium may be curved in a loop state. SOLUTION: The resist roller 42 is allowed to contact with and separate from a carrying roller 40 by actuating a switching mechanism consisting of a motor and a cam. In order to prevent the recording medium 37 fed from a paper supply mechanism 30 from being strongly tensioned between the resist roller 41 and an attractive roller 83 in the carrying direction of the recording medium 37, the roller 42 is moved to a position shown by a broken line so as to make the carrying quantity of the recording medium 37 by the rollers 40 and 41 a little larger than that by a carrier belt 19. As a result, the recording medium 37 largely floats between the rollers 83 and 40 and is curved along a guide 81 in the loop state. Thus, the fluctuation of the carrying speed and the carrying pitch of the recording medium is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording device.

[0002]

2. Description of the Related Art Conventionally, in an image recording apparatus, for example, a color recording apparatus, each of yellow, magenta, cyan, and black image forming means having a recording head formed by arranging recording elements in a line is provided. The recording medium is adsorbed on the conveyor belt and conveyed in a direction perpendicular to the direction in which the recording elements are arranged. Based on each color image data, yellow, magenta, cyan, and black toners are used to produce color images line by line. Are sequentially stacked.

In this case, the recording medium is discriminated and fed out one by one from the accommodating portion by the paper feed roller and the discriminating means, and the fed recording medium is adsorbed to the conveyor belt by electrostatic force to form each image formation. It is adapted to be sequentially conveyed to the means.

[0004]

However, in the conventional image recording apparatus described above, the recording medium is fed by the paper feed roller and the discriminating means even while the image is formed by each image forming means. The frictional load (tension) is applied by the paper feed roller and the discriminating means, but when the trailing edge of the recording medium is separated from the discriminating portion between the paper feed roller and the discriminating means, the frictional load is not applied.

Therefore, the conveying speed of the recording medium changes at the moment when the trailing edge of the recording medium separates from the discriminating portion, and the conveying pitch of the recording medium changes before and after this. As a result, horizontal streak image blurring occurs in the image formed on the recording medium. Further, in particular, in the color recording apparatus, since a color image is formed by superposing a plurality of colors, color misregistration occurs as the conveyance pitch of the recording medium changes, Accurate color expression is not possible.

Therefore, the recording medium is curved in a loop between the image forming means and the discriminating portion which are arranged on the most upstream side in the conveying direction of the recording medium, and the recording medium is sent to the image forming means. It is conceivable to keep the transport speed constant. However, when the recording medium is a cardboard, envelope, or other thick paper, it is extremely difficult to form the recording medium into a loop, and not only the load on the recording medium transport system becomes large, but also the recording medium is curled. However, the image forming unit cannot be operated smoothly thereafter.

It is conceivable to increase the distance between the image forming means and the discriminating portion so that the recording medium does not have a curl tendency, but the image recording apparatus becomes large. The present invention solves the problems of the conventional image recording apparatus described above, prevents horizontal image blurring in an image from occurring, and allows the image forming unit to operate smoothly even when the recording medium is thick paper. It is an object of the present invention to provide an image recording device that can be used.

[0008]

To this end, in the image recording apparatus of the present invention, a printing mechanism section composed of at least one printing mechanism and a recording medium at a conveyance speed set in the printing mechanism section are used. For conveying the recording medium, a first roller pair disposed upstream of the medium conveying means in the recording medium conveying direction, and one roller of the first roller pair is selectively selected from the other rollers. The recording medium sent from the discriminating means is fed at an upstream side of the contacting / separating means and the first roller pair in the conveying direction of the recording medium, and the conveying amount is greater than the conveying amount by the medium conveying means. A large number of set second roller pairs and a manual paper feeding portion arranged upstream of the first roller pair in the recording medium conveying direction for manually feeding the recording medium are provided. That.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, a color recording device will be described. FIG. 1 shows a first color recording apparatus according to an embodiment of the present invention.
2 is a second schematic view of the color recording apparatus according to the embodiment of the present invention, and FIG. 3 is a perspective view of the color recording apparatus according to the embodiment of the present invention.

As shown in the figure, the color recording device 11 includes first to fourth printing mechanisms P1 to P1 constituting a printing mechanism section.
P4 is sequentially arranged from the upstream side (insertion side) to the downstream side (discharge side) in the transport direction of the recording medium 37. The first
-The fourth printing mechanisms P1 to P4 are electrophotographic LEDs
(Light emitting diode) It has a printing mechanism, and since it has the same structure, respectively, only the 1st printing mechanism P1 is demonstrated, and it explains by giving the same code | symbol about the 2nd-4th printing mechanisms P2-P4. Omit it.

The first printing mechanism P1 includes an image forming section 1
2. LED head 13 that performs exposure according to image data,
And a transfer roller 14 that transfers the toner image formed by the image forming unit 12 onto the recording medium 37.
The image forming unit 12 includes a photoconductor drum 16 that is rotated about a shaft 15 in the direction of arrow a, a charging roller 17 that uniformly and uniformly charges the surface of the photoconductor drum 16, and a developing device 18. To be done. The developing device 18 includes a developing roller 18a made of a semiconductive rubber material, a developing blade 18b, and a developing blade 18b having an appropriate amount of toner.
And a toner tank 18d for storing a non-magnetic single component toner. The toner tank 18d is replaced when the toner runs out.

Then, the toner in the toner tank 18d is sent to the developing blade 18b via the sponge roller 18c, and is made to adhere to the surface of the developing roller 18a in a thin layer, so that the developing roller 18a and the photosensitive drum 16 are connected to each other. Reach the contact surface of. When the toner is thinned, the toner is strongly rubbed (rubbed) by the developing roller 18a and the developing blade 18b to be triboelectrically charged. In this embodiment, the toner is frictionally charged to a negative polarity.

The LED head 13 comprises an LED array (not shown), a substrate 13a on which a drive IC (not shown) for driving the LED array is mounted, a rod lens array 13b for focusing the light of the LED array, and the like. Then, when an image data signal is input from the interface section, which will be described later, the LED head 13 causes the LED array to emit light in accordance with the image data signal to expose the photoconductor drum 16 to expose the photoconductor drum 16. On the surface,
An electrostatic latent image including an image portion and a non-image portion is formed.

Next, the toner on the surface of the developing roller 18a is adhered to the image portion of the electrostatic latent image by electrostatic force, and the electrostatic latent image becomes a toner image. An endless carrier belt 19 is run between the photosensitive drum 16 and the transfer roller 14. The toner tank 18d of the developing device 18 in the first printing mechanism P1 contains yellow toner, and the toner tank 18d of the developing device 18 in the second printing mechanism P2 contains magenta toner. Cyan toner is stored in the toner tank 18d of the developing device 18 in the printing mechanism P3, and black toner is stored in the toner tank 18d of the developing device 18 in the fourth printing mechanism P4.

The LED head 13 of the first printing mechanism P1 receives the yellow image signal of the color image signal, and the LED head 13 of the second printing mechanism P2 receives the magenta image signal of the color image signal. L of 3 printing mechanism P3
The cyan image signal of the color image signal is input to the ED head 13, and the black image signal is input to the LED head 13 of the fourth printing mechanism P4.

Then, as shown in FIG. 3, the image forming portions 12 of the first to fourth printing mechanisms P1 to P4 are housed in a case 50 to form a color image forming unit 25. As shown in FIGS. 1 and 2, the color image forming unit 25 is supported by supports 28 and 29, positioned in the color recording apparatus 11, and the color recording apparatus 1
It can be attached to and detached from one.

Further, the case 50 has a window hole 50a for irradiating light from each LED head 13 and each L.
Guide pin holes 50b and 50c for positioning the ED head 13 with respect to the color image forming unit 25 are formed, respectively. The carrier belt 19 is made of a semiconductive plastic film having a high resistance value, and is stretched between a driving roller 20, a driven roller 21 and a stretching roller 22. The resistance value allows the recording medium 37 to be adsorbed to the carrier belt 19 by static electricity, and further, when the recording medium 37 is separated from the carrier belt 19, the static electricity remaining on the carrier belt 19 is removed. It is set to a range that allows static elimination to occur naturally.

The drive roller 20 is connected to a motor (not shown), and is rotated in the direction of arrow b by driving the motor. Since the tension roller 22 is urged in the direction of arrow c by a spring (not shown), the carrier belt 19 is always tensioned. The upper half 19a of the carrier belt 19 is provided with first to fourth printing mechanisms P.
1 to P4, and between the transfer rollers 14. As a result, the carrier belt 1
9, the recording medium 37 can be conveyed at the set conveying speed. The carrier belt 19, the driving roller 20, the driven roller 21, and the suction roller 83 constitute a medium conveying means.

A cleaning blade 23 is arranged between the driving roller 20 and the carrier belt 19 so that the cleaning blade 23 can hold the carrier belt 19.
Pressed to. The cleaning blade 2
Reference numeral 3 is formed of a flexible rubber material, a plastic material, or the like. In this way, since the tip of the cleaning blade 23 is pressed against the carrier belt 19, the residual toner adhering to the surface of the carrier belt 19 can be scraped off and dropped into the waste toner tank 24.

In this embodiment, each photosensitive drum 16 and each transfer roller 14 are connected to a carrier belt 19.
Be contacted with. A sheet feeding mechanism 30 is arranged on the lower right side of the color recording apparatus 11 in FIG. The paper feed mechanism 30 includes a paper storage cassette 30A and a hopping mechanism 3
0B, the transport roller 40, and the first and second registration rollers 41 and 42 arranged to face the transport roller 40.
Consists of The sheet storage cassette 30A comprises a recording medium storage box 31, a push-up plate 32 and a pressing means 33, and the hopping mechanism 30B comprises a discriminating means 34, a spring 35 and a paper feed roller 36. The discrimination means 34
Is pressed against a paper feed roller 36 by a spring 35 and forms a discriminator between the paper feed roller 36 and the paper feed roller 36. The transport roller 40 and the second registration roller 42 form a first roller pair, and the transport roller 40 and the first registration roller 41 form a second roller pair. In the present embodiment, the transport roller 40 is the first,
The second roller pair is commonly provided, but can be separately provided.

In the paper feeding mechanism 30, first, the recording medium 37 stored in the recording medium storage box 31 is pressed against the paper feeding roller 36 via the push-up plate 32 by the pressing means 33. In this state, when a motor (not shown) is driven to rotate the paper feed roller 36 in the direction of arrow e,
The recording medium 37 sandwiched between the paper feed roller 36 and the discriminating means 34 is fed out of the discriminating section while being discriminated, guided by guides 38 and 39,
0 and the first registration roller 41.

When a motor (not shown) is driven to rotate the carrying roller 40 in the direction of the arrow f, the recording medium 37 causes the carrying roller 40 and the second registration roller 42 to move.
Is transported in the direction of arrow d, guided by guides 81 and 82, and sent between the suction roller 83 and the carrier belt 19. The suction roller 83 is the driven roller 2
1 is pressed against the recording medium 37 and the recording medium 37 sent by the paper feeding mechanism 30 is charged, and the carrier belt 1
It is adsorbed to 9 by electrostatic force. Therefore, the suction roller 83 is formed of a semiconductive rubber material having a high resistance value. Further, a photo interrupter 70 that detects the leading end of the recording medium 37 is disposed between the suction roller 83 and the first printing mechanism P1 in the conveyance direction of the recording medium 37.

The second registration roller 42 operates in the direction indicated by arrow g by operating a switching mechanism (not shown) including a motor and a cam so that the second registration roller 42 takes the solid line position and the broken line position shown in FIG. Has become. That is, the second registration roller 42 is brought into pressure contact with the conveying roller 40 at the solid line position, and is conveyed at the broken line position.
Separated from zero.

Further, reference numeral 84 is a manual feed tray which constitutes a manual paper feed section, and an operator can manually insert the recording medium 37 along the manual feed tray 84 and the guide 85. A photo interrupter 86 detects the recording medium 37 manually inserted. In this case, the manually inserted recording medium 37 is transported by the transport roller 40 and the second registration roller 42, is similarly guided by the guides 81 and 82, and reaches between the suction roller 83 and the carrier belt 19. .

By the way, the recording medium 37 sent from the paper feeding mechanism 30 is for preventing a strong tension from being applied between the first registration roller 41 and the suction roller 83 in the conveying direction of the recording medium 37. In addition, when an image is formed by the first printing mechanism P1, it is curved in a loop shape as shown by a broken line in FIG. Therefore, the guide 81 is arranged so as to be inclined. Then, while the recording medium 37 is curved, the second registration roller 42 is moved to the broken line position.

A static eliminator 43 is arranged so as to face the upper half 19a of the carrier belt 19 on the drive roller 20 side. The static eliminator 43 neutralizes the recording medium 37 adsorbed and conveyed by the carrier belt 19, cancels the attracted state, and facilitates separation of the recording medium 37 from the carrier belt 19. A photo interrupter 71 for detecting the rear end of the recording medium 37 is arranged on the left side of the static eliminator 43 in FIG.

Further, a guide 44 and a fixing device 45 are arranged on the left side of the static eliminator 43 in the figure. The fixing device 45 is conveyed by the carrier belt 19 and fixes the toner image on the recording medium 37 on which the toner image is formed. To this end, the fixing device 45 has a heat roller 46 for heating the toner on the recording medium 37 and a pressure roller 47 for pressing the recording medium 37 together with the heat roller 46.

A discharge port 48 is provided on the left side of the fixing device 45 in the drawing, and a discharge stacker 4 is provided outside the discharge port 48.
The recording medium 37 on which an image is formed and printing is completed is discharged to the discharge stacker 49. next,
The control circuit of the color recording apparatus 11 having the above configuration will be described. FIG. 4 is a block diagram of a control circuit of the color recording apparatus according to the embodiment of the present invention.

In the figure, 51 is a control circuit comprising a microprocessor or the like, and the control circuit 51 controls the overall operation of the color recording apparatus 11 (FIGS. 1 and 2). The control circuit 51 includes the first to fourth printing mechanisms P1 to P4.
SP bias power sources 52Y, 52M, 52 for applying voltages to the sponge rollers 18c of the developing devices 18, respectively.
DB bias power sources 53Y, 53M, 53C, and 53B for applying voltages to the developing rollers 18a of the first to fourth printing mechanisms P1 to P4, respectively. ~ P4 charging power supply 54Y, 54M, 54C, 5 for applying a voltage to each charging roller 17 respectively
4B is connected to transfer power supplies 55Y, 55M, 55C and 55B for applying a voltage to charge the transfer rollers 14 of the first to fourth printing mechanisms P1 to P4, respectively.

Further, the control circuit 51 is provided with a suction charging power source 56 for applying a charging voltage to the suction roller 83.
A static elimination power source 57 for applying a high static elimination voltage to the static eliminator 43
Are respectively connected. The driven roller 21 is grounded to a ground (not shown), and the driven roller 21 and the suction roller 8 are
The recording medium 37 is attracted to the carrier belt 19 by the electrostatic force due to the potential difference with the recording medium 37.

The SP bias power sources 52Y and 5Y, 5
2M, 52C, 52B, DB bias power supplies 53Y, 5
3M, 53C, 53B, respective charging power sources 54Y, 54M,
54C, 54B, transfer power supplies 55Y, 55M, 55
C, 55B, adsorption charging power source 56, and static elimination power source 57
Is controlled on / off by an instruction from the control circuit 51.

Further, the control circuit 51 includes the first to the fourth parts.
The print control circuits 58Y, 58M, 58C and 58B are connected to the print mechanisms P1 to P4, respectively. Then, the print control circuits 58Y, 58M, 58C, 58B
Receives the yellow image signal, the magenta image signal, the cyan image signal, and the black image signal among the color image signals from the memories 59Y, 59M, 59C, and 59B, respectively, and instructs each LED head 13 to issue an instruction from the control circuit 51. Then, the exposure time of the LED array (not shown) is controlled to form an electrostatic latent image on the surface of each photosensitive drum 16.

Therefore, when the interface section 60 receives an image data signal transmitted from an external device (not shown), for example, a host computer, the interface section 60 separates the image data signal by color, and a yellow image signal, a magenta image signal, A cyan image signal and a black image signal are generated, the yellow image signal is stored in the memory 59Y, the magenta image signal is stored in the memory 59M, and the cyan image signal is stored in the memory 5.
9C, the black image signal is stored in the memory 59B.

Then, the fixing device driver 61 is used for the fixing device 4
A heater (not shown) in the heat roller 46 is turned on / off so as to keep the heat roller 46 in 5 at a predetermined temperature. Further, the motor drive circuit 62 drives the motor 63 that rotates the paper feed roller 36, and also the photosensitive drums 16, the charging rollers 17, and the developing rollers 18a of the first to fourth printing mechanisms P1 to P4. , Each sponge roller 1
8c, a motor 64 for rotating each transfer roller 14, the drive roller 20 and the heat roller 46, and a motor 65 for moving the second registration roller 42 in the direction of arrow g.
Drive.

The first to the first rotating by the motor 64
Each photosensitive drum 16, each charging roller 17, each developing roller 18a, each sponge roller 18c, each transfer roller 14, the driving roller 20, and the heat roller 46 of the fourth printing mechanisms P1 to P4 are formed by gears or belts not shown. Be connected. Then, the sensor receiver driver 66 actuates each photo interrupter 70, 71, 86 and sends a signal of an output waveform of each photo interrupter 70, 71, 86 to the control circuit 51.

Next, the operation of the color recording apparatus 11 having the above structure will be described. First, when the power source (not shown) of the color recording apparatus 11 is turned on, the control circuit 51 performs a predetermined initialization and then drives the fixing device driver 61 to set the heat roller 46 in the fixing device 45 to a predetermined temperature. Warm up until the temperature reaches, and then keep at a predetermined temperature.

When the heat roller 46 reaches a predetermined temperature, the control circuit 51 drives the motor 64 via the motor drive circuit 62 to rotate the drive roller 20 and run the carrier belt 19 in the direction of arrow d. Let When the carrier belt 19 is run slightly longer than one rotation, the motor 64 is stopped, and the carrier belt 19 is also stopped. As a result, the residual toner, dust and the like adhering to the surface of the carrier belt 19 are scraped off by the cleaning blade 23 and the waste toner tank 24 is removed.
Is dropped.

When the initial setting of the color recording apparatus 11 is completed in this way, the interface section 60 waits for the image data signal to be transmitted from the external apparatus. Then, when the interface unit 60 receives the image data signal, the control circuit 51 causes the interface unit 60 to operate.
And an instruction to each of the memories 59Y, 59M, 59C, 59B, and based on the instruction, the interface unit 60
Separates the received image data signal by color and stores the yellow image signal of the image data signal in the memory 59Y.
The magenta image signal is stored in the memory 59M, the cyan image signal is stored in the memory 59C, and the black image signal is stored in the memory 59B. In this case, the memories 59Y, 59M,
Each of 59C and 59B stores one page of each yellow image signal, magenta image signal, cyan image signal, and black image signal to be printed on the recording medium 37.

Next, the operation of forming an image on the recording medium 37 housed in the paper feeding mechanism 30 will be described. In this case, it is assumed that the recording medium 37 housed in the paper feeding mechanism 30 is thin paper used in a normal printer. When thick paper is used as the recording medium 37, the recording medium 37 is inserted from the manual feed tray 84.

FIG. 5 is a diagram showing a first state when the recording medium is sucked in the embodiment of the present invention, and FIG. 6 is a diagram showing a second state when the recording medium is sucked in the embodiment of the present invention. Reference numeral 7 is a third portion when inhaling the recording medium in the embodiment of the present invention.
It is a figure which shows the state of. First, the control circuit 51 (FIG. 4)
Drives the motor 63 via the motor drive circuit 62,
The paper feed roller 36 is rotated. When the paper feed roller 36 rotates, the discriminating means 34 and the paper feed roller 36 sort out the recording medium 37 accommodated in the recording medium accommodating box 31 (FIG. 1) and feed only one sheet. Then, the fed recording medium 37 is guided by guides 38 and 39, and the leading end of the recording medium 37 is conveyed by the conveyance roller 40 and the first registration roller 41.
It is reached during the period between and, but after that, it is further transported by a small amount.

As a result, the leading edge of the recording medium 37 comes into contact with the transport roller 40 and the first registration roller 41 and is slightly bent (flexed), and the skew of the recording medium 37 is corrected by this bending. Next, the control circuit 51 drives the motor 64 via the motor drive circuit 62 to
0, and the photosensitive drums 16 of the first to fourth printing mechanisms P1 to P4 (FIG. 2), the charging rollers 17, the developing rollers 18a, the sponge rollers 18c, the transfer rollers 14,
The drive roller 20 and the heat roller 46 of the fixing device 45 are rotated. At the same time, the control circuit 51 turns on the suction charging power supply 56 and applies a voltage to the suction roller 83.

Therefore, as shown in FIG. 5, the conveying roller 40 is rotated in the direction of the arrow f, and the recording medium 37 is
It is conveyed by the first and second registration rollers 41 and 42 and guided by guides 81 and 82. as a result,
The tip of the recording medium 37 reaches between the suction roller 83 and the carrier belt 19. Then, the leading edge of the recording medium 37 is attracted to the carrier belt 19 by the electrostatic force generated between the attraction roller 83 and the driven roller 21.

Further, when the conveying roller 40 is rotated in the direction of arrow f, as shown in FIG.
Is conveyed in the direction of arrow d while being attracted to the carrier belt 19. Then, the contacting / separating means (not shown) of the control circuit 51 drives the motor 65 via the motor drive circuit 62 when the front end of the recording medium 37 is detected by the photo interrupter 70 via the sensor receiver driver 66.
The second registration roller 42 is moved away from the conveyance roller 40 to the position indicated by the broken line.

Subsequently, the paper feed roller 36 is moved in the direction of arrow e,
When the conveyance roller 40 is further rotated in the direction of arrow f and the driven roller 21 is further rotated in the direction of arrow b, the second registration roller 42 is separated from the conveyance roller 40 as shown in FIG. Between the suction roller 83 and the conveyance roller 40, a large amount is floated and curved in a loop shape to form a space in the shaded portion L. Therefore, the carry amount of the carry roller 40 is slightly larger than the carry amount of the recording medium 37 by the drive roller 20 and the carrier belt 19.

When the recording medium 37 is curved in this way, no extra tension is applied to the recording medium 37 that is attracted to the carrier belt 19 and conveyed, so that the conveyance speed of the recording medium 37 is prevented from changing. can do. Therefore, it is possible to prevent the conveyance pitch of the recording medium 37 from changing. When the rear end of the recording medium 37 moves away from the discrimination section, the control circuit 51 stops the motor 63 via the motor drive circuit 62.

Then, when the photo interrupter 70 detects the leading end of the recording medium 37, the control circuit 51 causes each charging roller 17, each developing roller 18a, and each sponge roller 1 to operate.
In order to apply a voltage to 8c, each SP bias power source 52
Y, 52M, 52C, 52B, each DB bias power source 53
Y, 53M, 53C, 53B and respective charging power sources 54Y,
Turn on 54M, 54C and 54B respectively.

In this way, in each of the first to fourth printing mechanisms P1 to P4, the surface of each photoconductor drum 16 is uniformly charged via each charging roller 17, and each sponge roller 18c and each sponge roller 18c is charged. A predetermined high voltage is applied to the developing roller 18a to charge it. Next, the control circuit 51 issues a command to the memory 59Y, reads a yellow image signal for one line from the memory 59Y, and sends the yellow image signal to the print control circuit 58Y. The print control circuit 58Y receives a command from the control circuit 51 to cause the memory 5
The yellow image signal sent from 9Y is converted into a form that can be transferred to the LED head 13 of the first printing mechanism P1 and transferred to the LED head 13.

Then, the LED head 13 of the first printing mechanism P1 turns on the LED array (not shown) corresponding to the yellow image signal transferred from the printing control circuit 58Y,
An electrostatic latent image for one line corresponding to the yellow image signal is formed on the surface of the charged photosensitive drum 16. In this way, an electrostatic latent image is formed on the photosensitive drum 16 according to the yellow image signal read from the memory 59Y for each line, and the electrostatic latent image is formed according to the yellow image signal for the length in the sub-scanning direction. The exposure is terminated when is formed. Then, yellow toner adheres to the surface of the photosensitive drum 16 on which the electrostatic latent image is formed by the electrostatic force of the charged developing roller 18a.
Therefore, as the photosensitive drum 16 rotates, the electrostatic latent image is sequentially developed with the yellow toner and becomes a yellow toner image.

When the leading end of the recording medium 37 reaches between the photosensitive drum 16 of the first printing mechanism P1 and the transfer roller 14, the control circuit 51 causes the transfer power supply 55Y of the first printing mechanism P1. Turn on. As a result, the yellow toner image on the photosensitive drum 16 is transferred line by line onto the recording medium 37 by the transfer roller 14, and the yellow toner image for one page is recorded as the photosensitive drum 16 rotates. It is transferred to the medium 37.

When the trailing edge of the recording medium 37 reaches between the photoconductor drum 16 and the transfer roller 14, the control circuit 51 causes the transfer power source 55Y and the charging power source 54Y of the first printing mechanism P1. The SP bias power source 52Y and the DB bias power source 53Y are turned off. Then, the carrier belt 19 is continuously run, the recording medium 37 moves from the first printing mechanism P1 to the second printing mechanism P2, and then the magenta toner image is recorded in the second printing mechanism P2. It is transferred to the medium 37.

That is, the control circuit 51 has a memory 59M.
To read the magenta image signal for one line from the memory 59M and send the magenta image signal to the print control circuit 58M. The print control circuit 58M includes a control circuit 5
The magenta image signal sent from the memory 59M in response to the command from 1 is converted into a form that can be transferred to the LED head 13 of the second printing mechanism P2, and is transferred to the LED head 13.

Then, the LED head 13 of the second printing mechanism P2 turns on the LED array (not shown) corresponding to the magenta image signal transferred from the print control circuit 58M,
An electrostatic latent image for one line corresponding to the magenta image signal is formed on the surface of the charged photosensitive drum 16. In this manner, an electrostatic latent image is formed on the photosensitive drum 16 according to the magenta image signal read from the memory 59M line by line, and the electrostatic latent image is formed according to the length of the magenta image signal in the sub-scanning direction. Is formed, the exposure ends. Then, magenta toner is attached to the surface of the photosensitive drum 16 on which the electrostatic latent image is formed by the electrostatic force of the charged developing roller 18a.
Therefore, as the photosensitive drum 16 rotates, the electrostatic latent image is sequentially developed with magenta toner to form a magenta toner image.

When the leading end of the recording medium 37 reaches between the photosensitive drum 16 and the transfer roller 14 of the second printing mechanism P2, the control circuit 51 causes the second printing mechanism P2 to operate.
The transfer power source 55M is turned on. As a result, the magenta toner image on the photoconductor drum 16 is transferred line by line to the recording medium 37 by the transfer roller 14, and a magenta toner image for one page is recorded as the photoconductor drum 16 rotates. It is transferred to the medium 37.

When the trailing edge of the recording medium 37 reaches between the photosensitive drum 16 and the transfer roller 14, the control circuit 51 causes the transfer power source 55M of the second printing mechanism P2 to operate.
The charging power source 54M, the SP bias power source 52M, and the DB bias power source 53M are turned off. Next, the recording medium 37
Further moves from the second printing mechanism P2 to the third printing mechanism P3, and the cyan toner image is transferred to the recording medium 37 in the third printing mechanism P3.

Then, the cyan toner image is recorded on the recording medium 37.
Is transferred to the fourth printing mechanism P4 from the third printing mechanism P3 to the fourth printing mechanism P4.
The black toner image is transferred to the recording medium 37 at the time. As described above, the toner images of the respective colors are superimposedly transferred onto the recording medium 37, and become the color toner images. Subsequently, the recording medium 37 is sent to the static eliminator 43 by the carrier belt 19. Here, the control circuit 51 turns on the charge elimination power supply 57 to eliminate the charge on the recording medium 37.

As a result, the recording medium 37 is easily separated from the carrier belt 19, separated from the carrier belt 19 above the driving roller 20, guided by the guide 44, and sent to the fixing device 45. And the recording medium 3
When 7 is separated from the static eliminator 43, the control circuit 51 turns off the static elimination power source 57. In the fixing device 45, the heat roller 46 which has already reached a predetermined temperature at which fixing can be performed,
And a pressure roller 4 that is pressed against the heat roller 46
By 7, the color toner image is fixed on the recording medium 37 to form a color image. When the fixing is completed, the recording medium 37 is discharged to the discharge stacker 49. The control circuit 51 knows that the recording medium 37 is ejected by the photo interrupter 71 detecting the rear end of the recording medium 37.

When the discharge of the recording medium 37 is completed in this way, the control circuit 51 stops the motor 64 via the motor drive circuit 62. Further, the control circuit 51
The contacting / separating means drives the motor 65 via the motor drive circuit 62 to return the second registration roller 42 to the position indicated by the solid line in FIG. In addition, each of the first to fourth printing mechanisms P1 to P1
At P4, when the transfer of the toner image is completed, each charging power source 54Y, 54M, 54C, 54B, each SP bias power source 52Y, 52M, 52C, 52B, each DB bias power source 53Y, 53M, 53C, 53B and each transfer power source The power supplies 55Y, 55M, 55C, 55B are turned off.

In this way, a color image can be formed on the recording medium 37 fed by the paper feeding mechanism 30. In this case, it is possible to prevent the conveyance speed of the recording medium 37 from changing, and also to prevent the conveyance pitch of the recording medium 37 from changing. as a result,
A horizontal streak-like image blur does not occur in the image formed on the recording medium 37.

Further, since the conveyance pitch of the recording medium 37 does not change, color misregistration does not occur and accurate color expression can be performed. Next, a case where the recording medium 37 is thick paper will be described. In this case, the recording medium 37 is inserted from the manual feed tray 84 to form an image.

FIG. 8 is a diagram showing a state during manual insertion according to the embodiment of the present invention. First, when the operator sets the recording medium 37 on the manual feed tray 84, the control circuit 51
(FIG. 4) detects the recording medium 37 by the photo interrupter 86 via the sensor receiver driver 66, and then drives the motor 64 via the motor drive circuit 62.
Conveyor roller 40 and each of the first to fourth printing mechanisms P1
(FIG. 1) to P4 (FIG. 2), each photosensitive drum 16, each charging roller 17, each developing roller 18a, each sponge roller 1
8c, each transfer roller 14, drive roller 20, and fixing device 4
5 heat rollers 46 are rotated. At the same time, the control circuit 51 turns on the adsorption charging power source 56 to apply a voltage to the adsorption roller 83.

As a result, since the carrying roller 40 is rotated in the direction of the arrow f, the recording medium 37 inserted from the manual feed tray 84 is carried by the carrying roller 40 and the second registration roller 42 and guided by the guide 81. , 82
Guided by, the tip reaches between the suction roller 83 and the carrier belt 19. At this time, the tip of the recording medium 37 is attracted to the carrier belt 19 by the electrostatic force generated between the attraction roller 83 and the driven roller 21. Further, when the transport roller 40 is rotated in the direction of the arrow f, the recording medium 37 is transported in a linear state in the direction of the arrow d while being attracted to the carrier belt 19. As a result, the control circuit 51 knows, via the sensor receiver driver 66, that the front end of the recording medium 37 has been detected by the photo interrupter 70.

At this point, the control circuit 51 drives the motor 65 via the motor drive circuit 62 to separate the second registration roller 42 from the conveyance roller 40 and place it at the broken line position. Therefore, even if the transport roller 40 is rotated in the direction of the arrow f, the recording medium 37 is hardly affected. As a result, while being conveyed to the recording medium 37 by the suction roller 83 and the carrier belt 19,
Since no extra tension is applied, it is possible to prevent the conveyance speed of the recording medium 37 from changing and also prevent the conveyance pitch of the recording medium 37 from changing. As a result, horizontal streak image blurring does not occur in the image formed on the recording medium 37.

Further, in the color recording apparatus 11, since the conveyance pitch of the recording medium 37 does not change, color misregistration does not occur and accurate color expression can be performed.
As described above, when the recording medium 37 is thin paper, the second registration roller 42 is separated from the conveying roller 40, and the recording medium 37 fed by the paper feeding mechanism 30 is largely curved.

On the other hand, when the recording medium 37 is thick paper,
Not only is the recording medium 37 manually inserted linearly, but also the second registration roller 42 is separated from the conveyance roller 40. In this case, the recording medium 37
Since an excessive tension is not applied to the recording medium 37 while being conveyed by the suction roller 83 and the carrier belt 19, it is possible to prevent the conveyance speed of the recording medium 37 from changing and the conveyance pitch of the recording medium 37. Can be prevented from changing. As a result, horizontal streak image blurring does not occur in the image formed on the recording medium 37.

Further, in the color recording apparatus 11, since the conveyance pitch of the recording medium 37 does not change, color misregistration does not occur and accurate color expression can be performed.
In the present embodiment, when the recording medium 37 is fed by the paper feeding mechanism 30, the second registration roller 42 is separated from the conveyance roller 40, but it is not always necessary to separate it.

In the present embodiment, the LED head 1 is used to form an electrostatic latent image on each photosensitive drum 16.
Although 3 is used, a laser, a liquid crystal shutter, or the like can be used instead of the LED head 13. further,
Although the electrophotographic color recording apparatus 11 is described in the present embodiment, it can be applied not only to a monochromatic recording apparatus such as a monochrome printer but also to a line type inkjet printer, a thermal transfer printer, or the like. You can also

Further, in the present embodiment, the recording medium 37 is attracted to the carrier belt 19 by applying a voltage to the attraction roller 83. On the contrary, the attraction roller 83 is grounded to a ground not shown. However, it is also possible to apply a voltage to the driven roller 21.

In the present embodiment, the manual paper feeding section in which one recording medium 37 is manually fed is described. However, a paper feeding mechanism for accommodating a plurality of recording media 37 is provided. It may be a manual paper feeding unit. In addition,
The present invention is not limited to the above-mentioned embodiments, and various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0069]

As described above in detail, according to the present invention, in the image recording apparatus, the printing mechanism section including at least one printing mechanism and the transport set in the printing mechanism section are provided. A medium conveying unit that feeds a recording medium at a speed, a first roller pair arranged upstream of the medium conveying unit in the recording medium conveying direction, and one roller of the first roller pair is The recording medium sent from the discriminating means is fed at the contacting / separating means for selectively separating from the roller and the upstream side of the first roller pair in the conveying direction of the recording medium, and the conveying amount is the medium conveying means. And a second roller pair that is set to be larger than the transport amount of the recording medium, and a manual paper feed that is disposed upstream of the first roller pair in the transport direction of the recording medium and manually feeds the recording medium. With the door.

When the recording medium is thin paper,
The recording medium is delivered while being discriminated by the discriminating means and is sent to the first roller pair. Then, the recording medium is sent to the medium carrying means by the first roller pair, and further sent to the printing mechanism section by the medium carrying means. At this time, since the transport amount of the recording medium by the second roller pair is set to be larger than the transport amount by the medium transport means,
The recording medium is curved and conveyed in a loop shape.

Therefore, since no excessive tension is applied to the recording medium conveyed by the medium conveying means, it is possible not only to prevent the conveying speed of the recording medium from changing but also to change the conveying pitch of the recording medium. Can be prevented. As a result, horizontal streak image blurring does not occur in the image formed on the recording medium.

Further, in the color recording apparatus, since the conveyance pitch of the recording medium does not change, color misregistration does not occur and accurate color expression can be performed. On the other hand, when the recording medium is thick paper, the recording medium is sent from the manual paper feeding unit to the first roller pair. Then, the recording medium is sent to the medium carrying means by the first roller pair, and further sent to the printing mechanism section by the medium carrying means.

At this time, if the contacting / separating means selectively separates one roller from the other roller in the first roller pair, no extra tension is applied to the recording medium conveyed by the medium conveying means. It is possible to prevent the conveyance speed of the recording medium from changing. Then, it is possible to prevent the conveyance pitch of the recording medium from changing.

As a result, horizontal stripe image blurring does not occur in the image formed on the recording medium. Further, in the color recording apparatus, since the conveyance pitch of the recording medium does not change, color misregistration does not occur and accurate color expression can be performed.

[Brief description of drawings]

FIG. 1 is a first schematic diagram of a color recording apparatus according to an embodiment of the present invention.

FIG. 2 is a second schematic diagram of the color recording apparatus in the embodiment of the present invention.

FIG. 3 is a perspective view of the color recording apparatus according to the embodiment of the present invention.

FIG. 4 is a block diagram of a control circuit of the color recording apparatus according to the embodiment of the present invention.

FIG. 5 is a diagram showing a first state when a recording medium is sucked in the embodiment of the present invention.

FIG. 6 is a diagram showing a second state when a recording medium is sucked in the embodiment of the present invention.

FIG. 7 is a diagram showing a third state when the recording medium is sucked in the embodiment of the present invention.

FIG. 8 is a diagram showing a state at the time of manual insertion in the embodiment of the present invention.

[Explanation of symbols]

 11 Color Recording Device 19 Carrier Belt 20 Driving Roller 21 Driven Roller 34 Discriminating Means 37 Recording Medium 40 Conveying Roller 41 First Registration Roller 42 Second Registration Roller 83 Adsorption Roller 84 Manual Feed Tray P1 to P4 First to Fourth Printing mechanism

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location G03G 15/01 G03G 15/01 N (72) Inventor Masato Sakai 4-11 Shibaura, Minato-ku, Tokyo No.22 Stock Company Oki Data

Claims (3)

[Claims] 1. A printing mechanism section comprising (a) at least one printing mechanism, and (b) a medium carrying means for feeding a recording medium at a carrying speed set in the printing mechanism section.
(C) a first roller pair arranged upstream of the medium conveying means in the recording medium conveying direction, and (d) one roller of the first roller pair is selectively selected from the other rollers. Contacting / separating means for separating, and (e) upstream of the first roller pair in the transport direction of the recording medium,
The recording medium sent from the discriminating means is fed, and the second roller pair is set so that the carrying amount is larger than the carrying amount by the medium carrying means, and (f) the first roller pair in the carrying direction of the recording medium. An image recording apparatus, comprising: a manual paper feeding unit arranged upstream of a roller pair for manually feeding a recording medium. 2. The medium carrying means is provided with an endless carrier belt that runs along a printing mechanism section, and is arranged so as to face the carrier belt, and an electrostatic force for attracting a recording medium to the carrier belt is applied. The image recording apparatus according to claim 1, further comprising a suction roller that generates the image. 3. The image recording apparatus according to claim 1, wherein the contacting / separating unit separates the one roller from the other roller when the recording medium reaches the medium conveying unit.