JP2004117825A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a stable light quantity and to reduce light emission variance of an element when an organic EL element is used as a light emitting element of an image forming apparatus. <P>SOLUTION: Pixels Sb and Se on a pixel line Wx shown in Fig.(d) are print parts and pixels Sa, Sc, and Sd are non-print parts. In an area Ex, Three light emitting lines U1, U2 and U3 are arranged in a vertical scanning direction X. When multiple exposure is carried out, organic EL elements Ra corresponding to the non-print parts are turned on during one horizontal scan in (a). In (b), organic EL elements Rg corresponding to the non-print parts are turned on during one horizontal scan and in (c), organic EL elements RI corresponding to the non-print parts are turned on during one horizontal scan in (c). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image forming apparatus having a configuration in which a stable light amount is obtained when an organic EL element is used as a light emitting element in a line head, and light emission variation of the element is reduced.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an image forming apparatus for writing a latent image on an image carrier, an image forming apparatus using an LED array as a writing unit is known. A line head in which light emitting elements such as LEDs are arranged in a plurality of rows has been developed. Patent Document 1 describes an example of such a line head.
[0003]
When the application of the driving pulse to the EL element ends, the afterglow decreases. Therefore, when a drive pulse is applied after a long non-emission, the time required to reach a predetermined light intensity becomes longer, and the amount of light emitted at one time also becomes smaller. Therefore, the above-mentioned conventional example describes that an auxiliary pulse is applied at least once during one main scan, and the EL element is fully lit.
[0004]
In this way, a predetermined light intensity can be obtained in a short time even after no light emission for a long time. The auxiliary pulse is set to such a degree that the photoconductor is not exposed, and to a size that causes afterglow. That is, the light emission operation is started from the state where the afterglow exists.
[0005]
[Patent Document 1]
Patent Publication No. 2534364
[0006]
[Problems to be solved by the invention]
As described above, in the above-described conventional example, an auxiliary pulse having a magnitude enough to generate afterglow is applied to the EL element of the printing unit. However, since no auxiliary pulse is applied to the EL element in the non-printing portion, a temperature difference occurs between the EL elements. The organic EL element has a characteristic that the amount of emitted light changes due to a change in temperature.
[0007]
That is, when an organic EL element is used as the light emitting element, the amount of emitted light increases when a voltage is applied and the temperature rises, and the amount of emitted light changes when the temperature of the organic EL element changes. For this reason, when an organic EL element that emits light and an organic EL element that does not emit light coexist, there is a problem that light emission varies due to a difference in temperature between the elements. In addition, although organic EL elements are accelerated by light emission, if light-emitting organic EL elements and non-light-emitting organic EL elements coexist, the degree of deterioration of each element differs and the amount of emitted light also changes from this aspect. There was a problem.
[0008]
The present invention has been made in view of such problems of the prior art. It is an object of the present invention to provide an image forming apparatus configured to obtain a stable amount of light when an organic EL element is used as a light emitting element in a line head and to reduce light emission variation of the element.
[0009]
[Means for Solving the Problems]
According to the image forming apparatus of the present invention that achieves the above object, a plurality of light emitting element lines in which a plurality of organic EL elements are arranged in the main scan of the image carrier are provided in the sub-scanning direction, and the organic EL elements are arranged two-dimensionally. Image writing means, and a control unit for the organic EL element,
The control unit turns on at least one organic EL element and at least one organic EL element for forming a latent image of the same dot by multiple exposure at least once during one main scan. . Here, the organic EL element includes one corresponding to a printing part, and one corresponding to a non-printing part or a non-image forming part. As described above, since all the organic EL elements have a chance to be turned on, the temperature of each organic EL element rises and the temperature difference decreases. Therefore, variation in light emission of the organic EL element is reduced. In addition, since all the organic EL elements have an opportunity to be turned on, the degree of deterioration of each organic EL element can be equalized, and the change in the amount of emitted light can be suppressed.
[0010]
Further, in the invention, it is preferable that the control section turns on the organic EL element corresponding to the non-printing section or the non-image forming section at least once during one main scan. As described above, since only one organic EL element corresponding to the non-printing portion or the non-image forming portion is turned on, the latent image formed on the photoreceptor does not form a toner image, and does not affect image formation. Has no effect. Therefore, the temperature of the organic EL element can be increased regardless of image formation, and a stable light amount can be obtained. Further, the organic EL elements corresponding to the non-printing portion or the non-image forming portion are uniformly lit, and the temperature difference between the organic EL device and the printing portion can be reduced. For this reason, a change in the amount of emitted light can be suppressed.
[0011]
Further, the present invention provides an image writing unit in which a plurality of light emitting element lines in which a plurality of organic EL elements are arranged in the main scanning of the image carrier are provided in the sub-scanning direction, and the organic EL elements are arranged two-dimensionally. Having a control unit for the organic EL element
The control unit turns on at least one of the light emitting element lines arranged in the main scanning direction, and switches the lines to be turned on at predetermined intervals. Therefore, all the organic EL elements are turned on in units of one line, so that all lighting control can be easily performed. Further, since a toner image is not formed on the latent image formed on the photoconductor, a stable light amount can be obtained without affecting image formation.
[0012]
Further, in the invention, it is preferable that the control section turns on all the organic EL elements of one light-emitting element line once during the one main scan, and changes the line to be turned on every main scan. . For this reason, all the organic EL elements of the multiple exposure can be turned on evenly and only in the same time. Further, the light amount is stabilized in all the organic EL elements.
[0013]
Further, in the invention, it is preferable that the control unit increases the number of times of full lighting for the organic EL element of the light emitting element line arranged at a position farther from the center axis of the rod lens array. In an organic EL element, the light amount variation tends to be larger in a peripheral element that is farther from the center axis of the rod lens array. However, by increasing the number of times of full lighting of the organic EL element in the peripheral portion in this way, it is possible to reduce the variation in the amount of light.
[0014]
Further, in the invention, it is preferable that the control unit changes a light emitting element line that is fully lit every time an image of each page is formed when forming an image of one page. For this reason, since the light emitting element line of the full lighting control is switched on a page basis, the full lighting control of the organic EL element can be easily performed.
[0015]
Further, the invention is characterized in that the organic EL element is connected to an active matrix type driving circuit. Therefore, there is an advantage that the organic EL element maintains light emission even when the switching TFT is turned off due to disturbance or the like. Also, when one pixel is overprinted and multiplex-recorded, light emission is maintained even during transfer of image data from the storage means to the next storage means, so that the pixel can be exposed with high luminance.
[0016]
Further, the present invention provides a state in which a line head provided with an organic EL element for performing the control is mounted on an image carrier cartridge, and a charging unit, an exposure unit, a developing unit, and a transfer unit are arranged around the image carrier. Wherein the toner image formed on the image carrier is transferred to a transfer medium. Therefore, it is possible to configure an image forming apparatus in which the light emission amount of the image writing unit does not change and the image quality does not vary.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the image forming apparatus of the present invention will be described with reference to the drawings. FIG. 8 is a schematic cross-sectional view showing the overall configuration of an embodiment of the image forming apparatus to which the present invention is applied. In this embodiment, an intermediate transfer belt is used as a transfer belt. 8, the image forming apparatus 1 includes a housing body 2, a first opening / closing member 3 mounted on the front surface of the housing body 2 so as to be openable and closable, and a second opening / closing member 3 mounted on the upper surface of the housing body 2 so as to be openable and closable. Opening / closing member (also serving as a paper discharge tray) 4. Further, the first opening / closing member 3 is provided with an opening / closing lid 3 ′ which is attached to the front surface of the housing body 2 so as to be openable and closable, and the opening / closing lid 3 ′ is interlocked with the first opening / closing member 3 or independently. It can be opened and closed.
[0018]
An electrical component box 5 containing a power supply circuit board and a control circuit board, an image forming unit 6, a blower fan 7, a transfer belt unit 9, and a paper feed unit 10 are provided in the housing body 2, and a first opening / closing member is provided. A secondary transfer unit 11, a fixing unit 12, and a recording medium transporting unit 13 are provided in 3. The consumables in the image forming unit 6 and the paper supply unit 10 are configured to be detachable from the main body. In this case, the consumables including the transfer belt unit 9 can be removed and repaired or replaced. It has become.
[0019]
A first opening / closing member 3 is attached to the housing main body 2 so as to be openable and closable on both sides of a front lower portion of the housing main body 2 via a rotating shaft 3b. The transfer belt unit 9 includes a driving roller 14 disposed below the housing body 2 and driven to rotate by a driving source (not shown), a driven roller 15 disposed obliquely above the driving roller 14, and the two rollers. An intermediate transfer belt 16 that is stretched between 14 and 15 and driven to circulate in the direction of the arrow in the drawing is provided with a cleaning unit 17 that is brought into contact with and separated from the surface of the intermediate transfer belt 16. The driven roller 15 and the intermediate transfer belt 16 are disposed in a direction inclined leftward in FIG. As a result, the belt surface 16a in which the belt conveyance direction when the intermediate transfer belt 16 is driven is directed downward is located below.
[0020]
The driving roller 14 and the driven roller 15 are rotatably supported by a support frame 9a, and a rotating portion 9b is formed at a lower end of the supporting frame 9a. The support frame 9a is rotatably mounted on the housing main body 2 by being fitted to a shaft (rotation fulcrum) 2b. A lock lever 9c is rotatably provided at the upper end of the support frame 9a, and the lock lever 9c can be locked by a lock shaft 2c provided on the housing body 2. The drive roller 14 also serves as a backup roller for the secondary transfer roller 19 that constitutes the secondary transfer unit 11. In addition, the driven roller 15 is also used as a backup roller of the cleaning unit 17. The cleaning unit 17 is provided on the belt surface 16a facing downward in the transport direction.
[0021]
On the back surface of the belt surface 16a facing downward in the transport direction of the intermediate transfer belt 16, a primary transfer member 21 composed of a plate spring electrode is opposed to the image carrier 20 of each of the image forming stations Y, M, C, and K by its elastic force. The transfer bias is applied to the primary transfer member 21. On the support frame 9 a of the transfer belt unit 9, a test pattern sensor 18 is installed near the drive roller 14. The test pattern sensor 18 is a sensor for positioning each color toner image on the intermediate transfer belt 16, detecting the density of each color toner image, and correcting a color shift and an image density of each color image. The image forming unit 6 includes a plurality of (four in this embodiment) image forming stations Y (for yellow), M (for magenta), C (for cyan), and K (for black) that form images of different colors. In each of the image forming stations Y, M, C, and K, an image carrier 20 composed of a photosensitive drum and a charging unit 22, an image writing unit 23, and a developing unit are provided around the image carrier 20. Means 24.
[0022]
The charging unit 22, the image writing unit 23, and the developing unit 24 are given the drawing numbers only for the image forming station Y, and the drawing numbers are omitted because the other image forming stations have the same configuration. The arrangement order of the image forming stations Y, M, C, and K is arbitrary. Then, the image carriers 20 of the image forming stations Y, M, C, and K are brought into contact with the belt surface 16a of the intermediate transfer belt 16 that faces downward in the transport direction. As a result, each of the image forming stations Y, M , C, and K are also disposed in a direction inclined leftward in FIG. The image carrier 20 is driven to rotate in the transport direction of the intermediate transfer belt 16 as shown by the arrow in the figure.
[0023]
The charging means 22 is composed of a conductive brush roller connected to a high voltage generation source, and has a brush outer periphery in the opposite direction to the image carrier 20 which is a photosensitive member, and at a peripheral speed of 2 to 3 times. The surface of the image carrier 20 is uniformly charged by the rotation. Further, when such a conductive brush roller is used in an image forming apparatus having a cleaner-less configuration as in this embodiment, a bias having the same polarity as the charged polarity of the toner is applied to the brush roller during non-image formation. Then, the transfer residual toner adhered to the brush roller is discharged to the image carrier 20, transferred to the intermediate transfer belt 16 in the primary transfer unit, and collected by the cleaning unit 17 of the intermediate transfer belt 16. .
[0024]
The image writing unit 23 uses an organic EL array exposure head in which organic EL light emitting elements are arranged in a row in the axial direction of the image carrier 20. The organic EL array exposure head has an advantage that it has a shorter optical path length than a laser scanning optical system, is compact, can be disposed close to the image carrier 20, and can be downsized as a whole. The Y, M, C, and K image carriers 20, the charging unit 22, and the image writing unit 23 of each image forming station are unitized as one image carrier unit 25. The transfer belt unit 9 and the support frame 9a can be exchanged to maintain the position of the organic EL array exposure head with respect to the image carrier 20. Further, when the image carrier unit 25 is replaced, the image carrier unit 25 is replaced including the organic EL array exposure head.
[0025]
Next, the details of the developing unit 24 will be described using the image forming station K as a representative. The developing unit 24 includes a toner storage container 26 for storing toner (hatched portion in the figure), a toner storage unit 27 formed in the toner storage container 26, and a toner stirring member disposed in the toner storage unit 27. 29, and a partition member 30 partitioned and formed above the toner storage section 27.
[0026]
Further, the toner supply roller 31 disposed above the partition member 30, the blade 32 provided on the partition member 30 and abutting on the toner supply roller 31, and the blade 32 abutting on the toner supply roller 31 and the image carrier 20. Are provided, and a regulating blade 34 which is in contact with the developing roller 33 is provided. The image carrier 20 is rotated in the transport direction of the intermediate transfer belt 16, and the developing roller 33 and the supply roller 31 are driven to rotate in a direction opposite to the rotation direction of the image carrier 20, as indicated by arrows in the drawing. The stirring member 29 is driven to rotate in a direction opposite to the rotation direction of the supply roller 31.
[0027]
The toner stirred and carried by the stirring member 29 in the toner storage unit 27 is supplied to the toner supply roller 31 along the upper surface of the partition member 30, and the supplied toner rubs against the blade 32 and is supplied to the toner supply roller 31. It is supplied to the surface of the developing roller 33 by the mechanical adhesion to the surface irregularities and the adhesion by the friction band power. The toner supplied to the developing roller 33 is regulated to a predetermined thickness by the regulating blade 34, and the thinned toner layer is conveyed to the image carrier 20 so that the developing roller 33 contacts the image carrier 20. The latent image portion of the image carrier 20 is developed in the nip portion and the vicinity thereof.
[0028]
The developing roller 33, the toner supply roller 31, and the contact portion between the developing roller 33 and the regulating blade 34 on the side facing the image carrier 20 are not buried in the toner in the toner storage section 27. With this configuration, it is possible to prevent the fluctuation of the contact pressure of the regulating blade 34 against the developing roller 33 due to the decrease of the stored toner, and the excess toner scraped off from the developing roller 33 by the regulating blade 34 falls into the toner storing section 27. Therefore, filming of the developing roller 33 can be prevented.
[0029]
The toner returned to the toner storage unit 27 is stirred by the stirring member 29 with the toner in the toner storage unit 27, and is again supplied to the toner introduction unit near the supply roller 31 by the stirring member 29. Therefore, the surplus toner is dropped to the lower portion without congestion in the rubbing portion between the supply roller 31 and the developing roller 33 and the contact portion between the developing roller 33 and the regulating blade 34 to agitate the toner in the toner storage portion 27. It is possible to prevent the deterioration of the toner in the developing unit from gradually progressing, and a sharp change in image quality from occurring immediately after the replacement of the developing unit.
[0030]
The paper supply unit 10 includes a paper supply unit including a paper supply cassette 35 on which recording media P are stacked and held, and a pickup roller 36 for feeding the recording media P from the paper supply cassette 35 one by one. I have. Inside the first opening / closing member 3, a pair of registration rollers 37 that regulates the timing of feeding the recording medium P to the secondary transfer section, and a secondary transfer unit that is pressed against the drive roller 14 and the intermediate transfer belt 16. The image forming apparatus includes a secondary transfer unit 11, a fixing unit 12, a recording medium conveying unit 13, a pair of paper discharge rollers 39, and a conveying path 40 for double-sided printing.
[0031]
The fixing unit 12 is provided with a heating roller 45 that is rotatable with a built-in heating element such as a halogen heater, a pressure roller 46 that presses and urges the heating roller 45, and is slidably provided on the pressure roller 46. And a heat-resistant belt 49 stretched between the pressure roller 45 and the belt stretching member 47. The color image secondarily transferred to the recording medium is fixed on the recording medium at a predetermined temperature at a nip formed by the heating roller 45 and the heat-resistant belt 49.
[0032]
In this embodiment, the fixing unit 12 can be disposed in a space formed obliquely above the intermediate transfer belt 16, in other words, in a space opposite to the image forming unit 6 with respect to the intermediate transfer belt 16. Thus, heat transfer to the electrical component box 5, the image forming unit 6, and the intermediate transfer belt 16 can be reduced, and the frequency of performing the color misregistration correction operation for each color can be reduced.
[0033]
The outline of the operation of the entire image forming apparatus of the present embodiment as described above is as follows. (1) When a print command signal (image forming signal) from a not-shown host computer or the like (a personal computer or the like) is input to a control circuit in the electrical component box 5, each of the image forming stations Y, M, C, and K is sent. The image carrier 20, the rollers of the developing unit 24, and the intermediate transfer belt 16 are driven to rotate. (2) The surface of the image carrier 20 is uniformly charged by the charging unit 22.
[0034]
(3) In the image forming stations Y, M, C, and K, the surface of the uniformly charged image carrier 20 is selectively exposed in accordance with the image information of each color by the image writing means 23, so that each color is An electrostatic latent image is formed. (4) The developing unit 24 develops the toner images of the electrostatic latent images formed on the respective image carriers 20.
[0035]
(5) To the primary transfer member 21 of the intermediate transfer belt 16, a primary transfer voltage having a polarity opposite to the charging polarity of the toner is applied, and the toner image formed on the image carrier 20 is transferred to the intermediate transfer belt 16 at the primary transfer portion. Are sequentially transferred onto the intermediate transfer belt 16 in an overlapping manner. (6) The recording medium P stored in the paper feed cassette 35 is fed to the secondary transfer roller 19 via the registration roller pair 37 in synchronization with the movement of the intermediate transfer belt 16 on which the primary image has been primarily transferred. .
[0036]
(7) The primary transfer image is synchronized with the recording medium at the secondary transfer portion, and is pressed by the pressing mechanism toward the drive roller 14 of the intermediate transfer belt 16, and is opposite to the primary transfer image. The primary transfer image formed on the intermediate transfer belt 16 with the polarity bias applied is secondarily transferred to a synchronously fed recording medium.
[0037]
(8) The transfer residual toner in the secondary transfer is conveyed in the direction of the driven roller 15 and is scraped off by the cleaning unit 17 arranged opposite to the roller 15, and the intermediate transfer belt 16 is refreshed. Again, the above cycle can be repeated. (9) The toner image on the recording medium is fixed by passing the recording medium through the fixing unit 12, and then the recording medium is directed to a predetermined position (or, if it is not double-sided printing, toward the paper output tray 4 and double-sided printing is performed). In this case, the sheet is conveyed toward the double-sided printing conveyance path 40).
[0038]
FIG. 9 is a partial cross-sectional view near the image carrier 20 of FIG. The image carrier unit 25 includes four images of image forming stations Y, M, C, and K in a case 50 made of an opaque metal plate or the like having an open side in contact with the intermediate transfer belt 16. A carrier (photosensitive drum) 20 is rotatably supported.
[0039]
A conductive brush roller of a charging unit 22 is supported so as to rotate at a predetermined position of each image carrier 20, and an image writing unit 23 including an organic EL array exposure head is provided downstream of the charging unit 22. Each image carrier 20 is positioned and supported in parallel with the image carrier 20. An opening 51 is provided on the wall surface of the case 50 on the downstream side of the image writing unit 23 so as to contact the developing roller 33 of the developing unit 24 corresponding to each image carrier 20. A shielding part 52 of the case 50 is left between each opening 51 and the image writing means 23, and a shielding part 53 of the case 50 is left between the charging means 22 and the image writing means 23. I have.
[0040]
The shielding portions 52 and 53, particularly the shielding portion 52 between the opening 51 and the image writing unit 23, prevent ultraviolet rays from reaching the light emitting unit made of the organic EL material in the image writing unit 23 from the outside. Reference numeral 54 denotes a cleaning pad that wipes off the gradient index rod lens array 55 that covers the organic EL light emitting element array 56 from the front surface when it becomes dirty. The cleaning pad 54 is reciprocated by a handle (not shown).
[0041]
FIG. 10 is a schematic perspective view of the line head showing the image writing means 23 in an enlarged manner. FIG. 10 shows details of a line head provided in the image writing unit 23. A mechanism for accurately positioning the image writing means 23 with respect to each image carrier (photoconductor drum) 20 attached to the image carrier unit 25 is shown. The image carrier 20 is rotatably mounted in the case 50 of the image carrier unit 25 by its axis.
[0042]
On the other hand, the organic EL light emitting element array 61 is held in a long housing 60. The positioning pins 69 provided at both ends of the long housing 60 are fitted into the opposite positioning holes of the case 50, and the fixing screws are inserted into the screw holes of the case 50 through the screw insertion holes 68 provided at both ends of the long housing 60. By screwing and fixing, each image writing means 23 is fixed at a predetermined position.
[0043]
The image writing unit 23 has the light emitting unit 63 of the organic EL light emitting element array 61 mounted on a glass substrate 62 and is driven by a TFT 71 formed on the same glass substrate 62. The gradient index rod lens array 65 constitutes an imaging optical system, and has a stack of gradient index rod lenses 65 ′ arranged on the front surface of the light emitting unit 63.
[0044]
Reference numeral 60 denotes a housing, and 66 denotes a cover. The housing 60 covers the periphery of the glass substrate 62, and the side facing the image carrier 20 is open. In this way, light rays are emitted from the gradient index rod lens 65 ′ to the image carrier 20. A light-absorbing member (paint) is provided on a surface of the housing 60 facing the end surface of the glass substrate 62.
[0045]
FIG. 11 is a plan view partially showing the line head. In FIG. 11, the rod lens array 65 has rod lenses 65a to 65e arranged in two rows in a staggered manner. 81 to 87 are light emitting element lines in which a plurality of light emitting elements are arranged in each of the lines 0.3 to -0.3.
[0046]
In this example, the center line (center axis) C. Light emitting element lines 81 to 87 made of light emitting elements of the same size are arranged at positions symmetrical with respect to L. That is, the light emitting element lines 81 and 87 are arranged at symmetrical positions with respect to the central axis. Further, the light emitting element lines 82 and 86, and 83 and 85 are also arranged at symmetrical positions with respect to the central axis. In this manner, in the example of FIG. 11, a plurality of light emitting element lines 81 to 87 are arranged in parallel in the sub-scanning direction of the image carrier as light emitting element rows capable of exposing the entire image area.
[0047]
Further, the distances between the light emitting element lines are arranged equally. Therefore, when performing multiplex printing of pixels using each light emitting element line, the timing for moving the image carrier and the timing for switching from the previously emitted light emitting element line to the next light emitting element line and emitting light are all defined. Since the same timing can be set for the light emitting element lines, control can be easily performed.
[0048]
Also, in the example of FIG. Light emitting element lines 84 are also arranged on L. Therefore, when performing multiple exposure, the light emission timing in the sub-scanning direction can be controlled with reference to the light emitting element line on the central axis, so that the configuration of the control circuit is simplified.
[0049]
Next, another embodiment of the image forming apparatus according to the present invention will be described. FIG. 12 is a configuration diagram of an image forming apparatus to which the present invention is applied. 12, the image forming apparatus 160 includes, as main components, a developing device 161 having a rotary configuration, a photosensitive drum 165 functioning as an image carrier, an image writing unit 167 provided with an organic EL array, and an intermediate transfer belt. 169, a paper transport path 174, a heating roller 172 of a fixing device, and a paper feed tray 178 are provided.
[0050]
In the developing device 161, the developing rotary 161 a rotates in the arrow A direction about the shaft 161 b. The inside of the developing rotary 161a is divided into four parts, and image forming units for four colors of yellow (Y), cyan (C), magenta (M), and black (K) are provided. 162a to 162d are arranged in the image forming units of the four colors, and are developing rollers that rotate in the direction of arrow B, and 163a to 163d are toner supply rollers that rotate in the direction of arrow C. Reference numerals 164a to 164d denote regulating blades for regulating the toner to a predetermined thickness.
[0051]
165 is a photosensitive drum functioning as an image carrier as described above, 166 is a primary transfer member, 168 is a charger, and 167 is an image writing means provided with an organic EL array. The photosensitive drum 165 is driven in a direction indicated by an arrow D opposite to the developing roller 162a by a drive motor (not shown), for example, a step motor.
[0052]
The intermediate transfer belt 169 is stretched between a driven roller 170b and a drive roller 170a, and the drive roller 170a is connected to a drive motor of the photosensitive drum 165 to transmit power to the intermediate transfer belt. By driving the drive motor, the drive roller 170a of the intermediate transfer belt 169 is rotated in the direction of arrow E opposite to the direction of the photosensitive drum 165.
[0053]
The paper transport path 174 is provided with a plurality of transport rollers and a pair of paper discharge rollers 176 and the like, and transports the paper. The image (toner image) on one side carried on the intermediate transfer belt 169 is transferred to one side of the sheet at the position of the secondary transfer roller 171. The secondary transfer roller 171 is separated from and brought into contact with the intermediate transfer belt 169 by a clutch, is brought into contact with the intermediate transfer belt 169 when the clutch is turned on, and an image is transferred to a sheet.
[0054]
Next, the sheet on which the image has been transferred as described above is subjected to a fixing process by a fixing device having a fixing heater H. The fixing device is provided with a heating roller 172 and a pressure roller 173. The sheet after the fixing process is drawn into the sheet discharge roller pair 176 and advances in the direction of arrow F. When the sheet discharge roller pair 176 rotates in the reverse direction from this state, the sheet reverses direction and advances in the double-sided printing conveyance path 175 in the direction of arrow G. 177 is an electrical component box, 178 is a paper feed tray for storing paper, and 179 is a pickup roller provided at the exit of the paper feed tray 178.
[0055]
In the paper transport path, a low-speed brushless motor is used as a drive motor for driving the transport rollers. The intermediate transfer belt 169 uses a stepping motor because color shift correction and the like are required. These motors are controlled by signals from control means (not shown).
[0056]
In the state shown in the figure, a yellow (Y) electrostatic latent image is formed on the photosensitive drum 165, and a high voltage is applied to the developing roller 62a, whereby a yellow image is formed on the photosensitive drum 165. When all the images on the back and front sides of yellow are carried on the intermediate transfer belt 169, the developing rotary 161a rotates 90 degrees in the arrow A direction.
[0057]
The intermediate transfer belt 169 makes one rotation and returns to the position of the photosensitive drum 165. Next, two cyan (C) images are formed on the photosensitive drum 165, and this image is carried on the yellow image carried on the intermediate transfer belt 169. Hereinafter, the rotation of the developing rotary 161 by 90 degrees and the one-rotation process after the image is carried on the intermediate transfer belt 169 are similarly repeated.
[0058]
The intermediate transfer belt 169 rotates four times to carry four color images, and thereafter the rotation position is further controlled to transfer the image to the sheet at the position of the secondary transfer roller 171. The sheet fed from the sheet feed tray 178 is conveyed through a conveyance path 174, and the color image is transferred to one side of the sheet at the position of the secondary transfer roller 171.
[0059]
The sheet on which the image has been transferred to one side is inverted by the pair of sheet discharging rollers 176 as described above, and stands by on the conveyance path. Thereafter, the sheet is conveyed to the position of the secondary transfer roller 171 at an appropriate timing, and the color image is transferred to the other surface. The housing 180 is provided with an exhaust fan 181.
[0060]
FIG. 4 is a block diagram showing an example of a control mechanism for controlling the organic EL element of the present invention. In FIG. 4, reference numeral 95 denotes a main body controller of the image forming apparatus, and reference numeral 90 denotes a line head controller. The control unit 90 includes a control circuit 91, a drive circuit 92, a light emitting element 93 using an organic EL element, and a memory 94.
[0061]
The main body controller 95 forms image data and transmits the image data to the control circuit 91. The control circuit 91 forms a control signal corresponding to the amount of light emitted from each light emitting element 93, and energizes a drive circuit 92 composed of a TFT (Thin Film Transistor) or the like. The memory 94 stores the light emission amount of each light emitting element.
[0062]
As described above, since the light emission amount of each light emitting element is stored in the memory 94, the light emission amount can be controlled for each selected light emitting element. Note that the memory 94 can be installed on the image forming apparatus main body side. In this case, there is an advantage that the line head can be downsized.
[0063]
FIG. 5 is a block diagram showing an example of the control circuit of FIG. In FIG. 5, the control circuit 91 has a data processing unit 91a and an auxiliary pulse control unit 91b. The data processing unit 91a performs processes such as color separation, gradation processing, development of image data into a bitmap, and color shift adjustment based on the print data transmitted from the main body controller 95.
[0064]
The line heads 92a to 92d correspond to yellow (Y), magenta (M), cyan (C), and black (K), respectively, and form a color image on a photoconductor. Each of the line heads 92a to 92d is provided with a plurality of rows of organic EL elements in the sub-scanning direction of the image carrier.
[0065]
For example, in the line head 92a corresponding to yellow (Y), a light emitting element line in which a plurality of organic EL elements are arranged in the main scanning direction Y of the image carrier has four rows of L1 to L4. They are arranged in the scanning direction X. By arranging the light emitting element lines L1 to L4, the light emitting elements in each column of the four lines are configured to be capable of performing multiple exposure in which the light emitting elements are exposed to the same pixel.
[0066]
The data processing unit 91a outputs a print data signal Ds for each light emitting element line of each of the line heads 92a to 92d. The auxiliary pulse control unit 91b outputs an auxiliary pulse signal Dt for each light emitting element line of each of the line heads 92a to 92d. Reference numerals 91p to 91s denote AND circuits, which open a gate when the print data signal Ds and the auxiliary pulse signal Dt are input, and transmit a drive signal Dr to a selected light emitting element line.
[0067]
As will be described later, individual organic EL elements arranged in each light emitting element line of each of the line heads 92a to 92d can be operated by an active matrix type driving circuit. For this reason, although not shown in FIG. 5, it is possible to emit light by further providing a means for selecting an individual organic EL element in the selected light emitting element line.
[0068]
FIG. 1 is an explanatory diagram according to the embodiment of the present invention. It is assumed that the pixel line Wx of the image carrier includes pixels Sa, Sc, and Sd of a non-printing portion and pixels Sb and Se of a printing portion. Lines U1, U2, and U3 in which a plurality (five) of organic EL elements are arranged in the main scanning direction Y of the image carrier are arranged in a plurality of rows (three rows) in the sub-scanning direction X.
[0069]
Thus, the predetermined image forming region Ex is provided by arranging the organic EL elements two-dimensionally. In FIG. 1A, one light emitting element line U1 is provided with organic EL elements Rb and Re corresponding to the pixels in the printing part and organic EL elements Ra, Rc and Rd corresponding to the pixels in the non-printing part. Have been.
[0070]
In the state of FIG. 1A, during one main scan, a pulse is applied to the organic EL elements Ra corresponding to the pixels in the non-printed area and the organic EL elements Rb and Re corresponding to the pixels in the printed area to light up. Next, the image carrier is moved in the sub-scanning direction X to the state shown in FIG. 1B, and the pixel line Wx is made to correspond to the light emitting element line U2. In this state, during one main scan, a pulse is applied to the organic EL elements Rg corresponding to the pixels in the non-printed area and the organic EL elements Rf and Ri corresponding to the pixels in the printed area to light up. Subsequently, the image carrier is moved in the sub-scanning direction X to the state shown in FIG. 1C, and the pixel line Wx is made to correspond to the light emitting element line U3. In this state, during one main scan, a pulse is applied to the organic EL elements Rk corresponding to the pixels in the non-printing portion and the organic EL elements Rj and Rl corresponding to the pixels in the printing portion to light up.
[0071]
Thus, in FIGS. 1A to 1C, at least one organic EL element for forming a latent image of the same dot by multiple exposure is turned on at least once during one main scan. This processing includes the organic EL element in the printing section and the organic EL element in the non-printing section. For this reason, since there is a chance that all the organic EL elements are turned on, it is possible to prevent a temperature difference from occurring between the organic EL elements and to suppress a variation in light emission.
[0072]
Further, as shown in FIG. 1D, the exposure amounts of the pixels Sa, Sc, and Sd in the non-printing portion are each (（). That is, at the time of multiple exposure, the organic EL elements corresponding to the non-printed portions are uniformly lit, and the temperature difference between the organic EL elements in the printed portion and the organic EL elements can be reduced. For this reason, a change in the amount of emitted light can be suppressed. At this time, the organic EL element of the non-printing portion that is turned on is changed for each main scan so that an image is not formed on the image carrier. In addition, since all the organic EL elements have an opportunity to be turned on, the degree of deterioration of each organic EL element can be equalized, and the change in the amount of emitted light can be suppressed.
[0073]
Further, since only one organic EL element corresponding to the non-printing portion is turned on, the latent image formed on the photosensitive member does not form a toner image, and does not affect image formation. Therefore, the temperature of the organic EL element can be increased regardless of image formation, and a stable light amount can be obtained. In the above example, the control of the organic EL element in the non-printing portion has been described. However, the above control can be applied to the control of the organic EL element corresponding to the non-image forming portion such as a margin.
[0074]
FIG. 2 is an explanatory diagram of another embodiment of the present invention. Parts corresponding to those in FIG. 1 are denoted by the same reference numerals. In the state of FIG. 2A, the pixel line Wx corresponds to the light emitting element line U1. In this state, all the organic EL elements Ra to Re of the non-printing portion and the printing portion, that is, one light emitting element line U1 are turned on during one main scan. In the state of FIG. 2B, the pixel line Wx is made to correspond to the light emitting element line U2, and the organic EL elements Rf and Ri of the printing unit are turned on during one main scan. In the state of FIG. 2C, the pixel line Wx is made to correspond to the light emitting element line U3, and in this state, the organic EL elements Rj and Rl of the printing unit are turned on during one main scan.
[0075]
Also in this case, as shown in FIG. 2D, the exposure amounts of the pixels Sa, Sc, and Sd in the non-print portion are each (１ ／). That is, the organic EL elements corresponding to the non-printed portions are uniformly lit, and the temperature difference from the organic EL elements in the printed portion can be reduced. For this reason, a change in the amount of emitted light can be suppressed. In addition, since all the organic EL elements are turned on in units of one line, the lighting control of the organic EL elements can be easily performed.
[0076]
FIG. 3 is an explanatory diagram illustrating an example of control of an organic EL element according to another embodiment of the present invention. FIG. 3 shows the line head 92a of FIG. 5 as an example. In the example of FIG. 3 as well, a plurality of light emitting element lines in which a plurality of organic EL elements are arranged in the main scan of the image carrier are provided in the sub-scanning direction, and the organic EL elements are arranged two-dimensionally. 1 shows an organic EL element. .. Y1, Y2, Y3,... Form an organic EL element group when multiple exposures are performed by repeatedly striking the same pixel while moving the image carrier in the sub-scanning direction X. That is, the organic EL element group has a function of forming a latent image of the same dot when performing multiple exposure. In the example of FIG. 3, four multiple exposures are performed on the same pixel by the organic EL element groups Y1, Y2, Y3,... Arranged on four lines of the light emitting element lines L1 to L4.
[0077]
As shown in FIG. 3, the line head 92a is provided with a plurality of organic EL elements two-dimensionally arranged in the main scanning direction Y and the sub-scanning direction X of the image carrier. The organic EL elements form an organic EL element group (Y1, Y2, Y3,...) For forming a latent image of the same dot as described above. In this embodiment, at least one organic EL element in the organic EL element group is turned on in a non-printing portion such as a space between characters and a line or a non-image forming portion (blank paper portion). Is what you do.
[0078]
As described above, since only one organic EL element is turned on, a toner image is not formed on the latent image formed on the photoconductor as described above, and the image formation is not affected. Therefore, the temperature of the organic EL element can be increased regardless of image formation, and a stable light amount can be obtained. In addition, the degree of deterioration due to light emission of the organic EL element becomes substantially the same, and variation in light emission of the organic EL element is reduced.
[0079]
In the example of FIG. 3, at least one organic EL element in the organic EL element group is turned on at least once during one main scan. For example, the organic EL elements Y1-L1, Y2-L2, Y3-L3, Y4-L4,... Are turned on during the first main scanning. Subsequently, during the second main scanning, the organic EL elements are turned on like Y1-L2, Y2-L3, Y3-L4, and Y4-L5. In order to perform such control, the auxiliary pulse signal Dt in FIG. 3 is transmitted from the data processing means 91a. At this time, the movement timing of the image carrier and the lighting timing of the organic EL element are adjusted so that an image is not formed on the non-printing portion of the image carrier. In this case, there is an advantage that all the organic EL elements can be turned on uniformly.
[0080]
In another embodiment of the present invention, at least one line in the main scanning direction is completely turned on in a non-printing portion or a non-image forming portion (blank portion) such as a character space or a line space, and at a predetermined interval, for example, a paper interval. , To switch all the lit lines. In the example of FIG. 1, the light emitting element lines L1 to L4 are all turned on at predetermined intervals. In this case, since all the organic EL elements are turned on in units of one line, the whole lighting control can be easily performed. Further, since the toner image is not formed on the latent image formed on the photoconductor, it does not affect the image formation.
[0081]
In another embodiment of the present invention, one line of the organic EL element is fully lit once during one main scan, and the lit line is changed for each main scan. In the example of FIG. 1, all the light emitting element lines L1 are turned on during the first main scanning. Further, the light emitting element line L1 is turned on during the second main scanning. Hereinafter, all the light emitting element lines are sequentially turned on. By performing such control, all the organic EL elements of the multiple exposure can be turned on evenly and in the same time only. Therefore, the amount of light is stabilized in all the organic EL elements.
[0082]
In another embodiment of the present invention, the number of times of full lighting increases as the organic EL element is arranged in a light emitting element line in a peripheral portion that is farther away from the center axis of the rod lens array. In the example of FIG. 3, for example, it is assumed that the light emitting element line L <b> 1 arranges the organic EL elements in the peripheral part that is separated from the center axis of the rod lens array. In this case, the number of times of lighting of the light emitting element line L1 is set to be larger than that of the other light emitting element lines L2 and L3 near the center axis of the rod lens array.
[0083]
In general, in an organic EL element, a light amount variation tends to be larger in a peripheral element that is farther away from the center axis of the rod lens array. As in this embodiment, by increasing the number of times of full lighting of the organic EL elements in the peripheral portion, it is possible to reduce variations in the amount of light.
[0084]
In another embodiment of the present invention, when forming image data of one page, the light emitting element lines that are turned on all the time are changed every time image formation of each page is performed. For example, when forming the image of the first page, all the organic EL elements of the first line are turned on. When forming an image on the next page, all the organic EL elements on a line different from the first line are turned on. As described above, since the line to be lit is changed for each page, the lighting control of the organic EL element can be easily performed.
[0085]
FIG. 6 is a block diagram showing an image forming apparatus according to another embodiment of the present invention. In the example of FIG. 6, the light emitting element is driven by an active matrix method. In FIG. 6, Z is a single light emitting unit in which the light emitting element of the organic EL element and its driving circuit are formed by an active matrix.
[0086]
For example, in the yellow line head 128Y, light emitting element lines 128p to 128t are arranged in five rows. Shift registers 124p to 124t are arranged corresponding to the respective light emitting element lines 128p to 128t. Further, a line selector 134 is connected to the data processing device 123.
[0087]
135a is a supply line for image data wired from the data processing device 123 to the shift register, 135b is a control line wired from the data processing device 123 to the line selector 134, and 136a to 136e are from the line selector 134 to each shift register 124p to Command lines 137a to 137e for commanding the operation of 124t are scanning lines on which a signal from the line selector 134 is supplied to the light emitting element of each line, and 138a to 138k are individual lines and columns for each line from the shift registers 124p to 124t. Signal line for supplying an operation signal to the light emitting element (organic EL element).
[0088]
The operation of FIG. 6 will be described. With a control signal supplied from the data processing device 123 via the control line 135b, the line selector 134 selects the scanning line 137a and supplies a signal to the light emitting element line 128p. Further, the shift register 124p is operated by the signal of the command line 136a. When the shift register 124p activates the signal lines 138a to 138k and sends an output signal of image data to all the organic EL elements on the light emitting element line 128p, the organic EL elements on the light emitting element line 128p emit light to expose the pixels. .
[0089]
By switching the scanning line 137 and the command line 136 with the signal from the line selector 134, the above operation is also performed for the light emitting element lines 128q, 128r, 128s, and 128t, and the light emitting elements of all the light emitting element lines emit light. Expose the pixel.
[0090]
Next, the image data in the shift register 124s is transferred to the shift register 124t. Similarly, the image data is sequentially transferred from the shift register 124r to the shift register 124s, from the shift register 124q to the shift register 124r, from the shift register 124p to the shift register 124q. To transfer. Image data is transferred from the data processing unit 123 to the shift register 124p via the signal line 135a. During this time, the image carrier moves by the pixel pitch.
[0091]
At this time, since the light emitting elements of the light emitting section Z maintain light emission by the action of the active matrix, even when image data is being transferred by the shift register, the light emitting elements are not turned off and the pixels are exposed with high brightness. can do. In this manner, by repeatedly transmitting image data from the shift register 124 to the light emitting elements, transferring image data between the shift registers, and moving the image carrier, the image data is continuously exposed on the image carrier. I can do it.
[0092]
For this reason, in the example of FIG. 6, each pixel is exposed with five times the amount of light when exposed by a single light emitting element, and the amount of light required for exposure of each pixel can be obtained at high speed. . The number of columns in the sub-scanning direction of the line on which the light emitting elements are arranged, that is, the multiple of the amount of light obtained when a pixel is exposed by a single light emitting element can be appropriately selected as needed.
[0093]
In the above description, all the organic EL elements in the light emitting element line are controlled to emit light at the same time. However, by selecting and energizing the signal lines 138a to 138k, the organic EL element group as described in FIG. The organic EL elements of Y1, Y2, Y3,... Can be turned on. Further, by selecting and energizing the scanning lines 137a to 137e, the light emitting element lines 128a to 128t are specified. Therefore, it is possible to perform a full lighting control by selecting a specific one of the organic EL elements two-dimensionally arranged on a plane.
[0094]
Once the data processing unit 123 of the image forming apparatus main body forms the data of the first line, the data processing unit 123 thereafter holds the image data of the first line in the storage unit (shift register), and stores the image data in the storage unit. , The operation of all the light emitting elements of the line head can be controlled. Therefore, the data processing means does not need to generate data of the light emitting elements of all the line heads, and can simplify the circuit configuration. Further, data processing can be performed at high speed.
[0095]
The light emitting portion of the organic EL element can be driven by an active matrix type driving circuit. FIG. 7 is a circuit diagram for operating the light emitting unit Z in an active matrix. In FIG. 7, an organic EL element (EL) is used as a light emitting element, K is its cathode terminal, and A is its anode terminal. The cathode terminal K is connected to a power supply not shown.
[0096]
As the scanning line to which the select signal Ta is input, for example, the scanning line 137a in FIG. 6 can be used. The control signal Dx for selecting an individual light emitting element can be supplied from, for example, the signal line 138a in FIG. The select signal Ta is supplied to the gate Ga of the switching TFT (Tr1).
[0097]
The control signal Dx is supplied to the drain Da of the switching TFT. Va is a power supply line, and Ca is a storage capacitor. The source Sb of the driving TFT (Tr2) of the organic EL element is connected to the power supply line Va, and the drain Db is connected to the anode terminal A of the organic EL element. Further, the gate Gb of the driving TFT (Tr2) is connected to the source Sa of the switching TFT (Tr1).
[0098]
Next, the operation of the circuit diagram of FIG. 7 will be described. When the scanning line and the signal line are energized in a state where the voltage of the power supply line Va is applied to the source of the switching TFT, the switching TFT (Tr1) is turned on. Therefore, the gate voltage of the driving TFT (Tr2) decreases, the voltage of the power supply line Va is supplied from the source of the driving TFT (Tr2), and the driving TFT (Tr2) becomes conductive. As a result, the organic EL element operates and emits light with a predetermined light amount. The storage capacitor Ca is charged with the voltage of the power supply line Va.
[0099]
Even when the switching TFT (Tr1) is turned off, the driving TFT (Tr2) is in the conductive state based on the electric charge charged in the storage capacitor Ca, and the organic EL element maintains the light emitting state. Therefore, when the active matrix is applied to the driving circuit of the light emitting element, even when the switching TFT is turned off to transfer the image data by the shift register, the operation of the organic EL element continues to emit light. In addition, the pixels can be exposed with high luminance.
[0100]
As described above, in the active matrix driving circuit, the light emitting state of the organic EL element can be held by the capacitor and the transistor provided around the organic EL element. Therefore, when one pixel is overprinted and multiplex-recorded, light emission is maintained even during transfer of image data from the storage means to the next storage means, so that the pixel can be exposed with high luminance.
[0101]
As described above, the image forming apparatus of the present invention has been described based on some embodiments, but the present invention is not limited to these embodiments, and various modifications are possible.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a configuration of the present invention.
FIG. 2 is an explanatory diagram showing another embodiment of the present invention.
FIG. 3 is an explanatory diagram showing another embodiment of the present invention.
FIG. 4 is a block diagram illustrating a schematic configuration of a control unit.
FIG. 5 is a block diagram illustrating an example of a control circuit in FIG. 2;
FIG. 6 is a block diagram illustrating an example using a shift register.
FIG. 7 is a circuit diagram showing a driving circuit of the organic EL element.
FIG. 8 is a schematic cross-sectional view illustrating an example of the entire configuration of an image forming apparatus.
FIG. 9 is an enlarged sectional view showing a part of FIG. 5;
FIG. 10 is a perspective view showing an example of a line head.
FIG. 11 is a plan view partially showing a line head.
FIG. 12 is a schematic sectional view showing another example of the image forming apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2 ... Housing main body, 5 ... Electric component box, 6 ... Image forming unit, 9 ... Transfer belt unit, 10 ... Paper feeding unit, 11 ... Secondary transfer unit, 12 ... Fixing unit, 13 ... Recording Medium transfer means, 16: intermediate transfer belt, 19: secondary transfer roller, 20: image carrier, 21: primary transfer member, 22: charging means, 23: image writing means, 24: developing means, 25: image carrying Body unit (image carrier cartridge), 61: organic EL light emitting element array, 62: glass substrate, 63: light emitting unit, 64: cover glass, 65: refractive index distribution type rod lens array, 65 ': refractive index distribution type rod Lenses, 65a to 65h: refractive index distribution type rod lens, 71: TFT, 90: control unit of line head, 91: control circuit, 91a: data processing means, 91b: auxiliary pulse system Control means, 91p-91s AND circuit, 92 drive circuit, 92a-92d line head, 93 organic EL element, 94 memory, 95 main body controller, 123 data processing means, 124p-124t shift register, 128y: line head, 128p to 128t: light emitting element line, 134: line selector, 160: image forming device, 161: developing device, 165: photosensitive drum, 167: image writing means, 168: charging device, 169: intermediate transfer Belt, 171 secondary transfer roller, 172 heating roller, 174 conveyance path, 177 electrical component box, Z light emitting unit,

Claims (8)

Image writing means in which a plurality of light emitting element lines in which a plurality of organic EL elements are arranged in the main scanning of the image carrier are provided in the sub-scanning direction, and the organic EL elements are two-dimensionally arranged; And having
The image forming apparatus, wherein the control unit turns on at least one organic EL element for forming a latent image of the same dot by multiple exposure at least once during one main scan. 2. The control unit according to claim 1, wherein among the organic EL elements, an organic EL element corresponding to a non-printing unit or a non-image forming unit is turned on at least once during one main scan. Image forming apparatus. Image writing means in which a plurality of light emitting element lines in which a plurality of organic EL elements are arranged in the main scanning of the image carrier are provided in the sub-scanning direction, and the organic EL elements are two-dimensionally arranged; An image forming apparatus, wherein the control unit turns on at least one of the light emitting element lines arranged in the main scanning direction, and switches the line to be turned on at predetermined intervals. 4. The control unit according to claim 3, wherein the control unit turns on all the organic EL elements of one light emitting element line once during the one main scan, and changes the line to be turned on every main scan. 5. Image forming apparatus. 4. The image forming apparatus according to claim 3, wherein the control unit increases the number of times of full lighting for the organic EL element of the light emitting element line located farther from the center axis of the rod lens array. 5. apparatus. 4. The image forming apparatus according to claim 3, wherein the control unit changes a light emitting element line that is fully lit every time an image of one page is formed. 5. The image forming apparatus according to claim 1, wherein the organic EL element is connected to an active matrix type driving circuit. A line head provided with an organic EL element for controlling according to any one of claims 1 to 7, mounted on an image carrier cartridge, and a charging unit, an exposure unit, and a developing unit around the image carrier. An image forming apparatus wherein a toner image formed on the image carrier is transferred to a transfer medium in a state where transfer means is provided.

Images