JP2005300838A - Printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer whose image unevenness is reduced by suppressing variation in conveying speed of a recording medium small. <P>SOLUTION: The printer which writes a latent image by a fixed image write part by expanding a developer while conveying an instant film sheet is equipped with a gear train 39 having a 1st sub-gear train 39_10 which transmits a turning drive force from a DC motor 406 to a halfway point, a 2nd sub-gear train 39_20 which receives the turning drive force directly from the 1st sub-gear train 39_10 and transmits the turning drive force to a couple of conveyor rollers 31 and 32, and a 3rd sub-gear train 39_30 which receives the turning drive force from the 1st sub-gear train 39_10 and transmits the turning drive force to a couple of expansion rollers 33 and 34. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention transports a recording medium having a developer reservoir at the front end in a predetermined transport direction, on which a latent image is formed by exposure and a visualized image is recorded by the development of the developer in the developer reservoir. The present invention also relates to a printer that performs development by writing a latent image on the recording medium by light irradiation and crushing the developer reservoir to develop the developer.

  As such a printer, there is a printer that records a color image on an instant film sheet. This printer emits red (R), green (G), and blue (B) light that constitutes an image writing unit while conveying the instant film sheet with both sides of the instant film sheet sandwiched between a pair of conveying rollers. A latent image is written on the instant film sheet by cyclically irradiating three colored lights from light-emitting elements having colors, and a pair of developments arranged downstream of the pair of conveyance rollers in the instant film sheet conveyance direction. Development is carried out by developing the developer by crushing the developer reservoir with the roller sandwiching the instant film sheet over the entire width.

Here, the developing roller has a load variation caused by an intrusion of an instant film sheet having a developer pool, a breakdown of the developer pool, a fluid resistance of the developer, a non-uniform thickness of the instant film sheet itself, and the like. . When the magnitude of the load exceeds the torque generated by the motor, the film transport speed temporarily decreases, and after overcoming the level difference, the load decreases and the film transport speed temporarily increases. Thus, the rotation speed of the developing roller is not stabilized by changing the load. This speed fluctuation is transmitted to the conveying roller through the film and the gear train. When the variation in the conveyance speed of the instant film sheet at the image writing position is large, the printing timing is shifted and streaky unevenness occurs in the image. In view of this, a technique has been proposed in which the development roller is held elastically so as to be movable in the instant film sheet conveyance direction, thereby minimizing fluctuations in the conveyance speed of the instant film sheet at the image writing position (see Patent Document 1). ). Also, a technique has been proposed in which a latent image is written on an instant film sheet while the instant film sheet is sufficiently held by a conveyance roller (see Patent Document 2). Further, a technology has been proposed in which a plurality of irregularities are provided on the conveying roller to perform printing based on a roller that accurately and surely conveys an instant film sheet and an encoder signal attached to the roller (see Patent Document 3). .
Japanese Patent Laid-Open No. 2001-13658 International Publication No. WO00 / 077753 Pamphlet Japanese Patent Laid-Open No. 2002-221761

  As described above, it is important how the fluctuation of the developing roller is not transmitted to the conveying roller, and how the film conveyance in the conveying roller unit is stabilized and the speed in the printing unit is stabilized. However, the technique proposed in Patent Document 1 described above has a problem that the configuration is complicated. Further, in the technique proposed in Patent Document 2, if there is rotation unevenness on the transport roller, the unevenness is transmitted to the instant film sheet as it is, but a technique for correcting the rotation unevenness of the transport roller is not shown. Further, in the technique proposed in Patent Document 3, there is a method of allowing fluctuations in the film conveyance speed by providing a plurality of irregularities on the conveyance roller and providing an encoder on the roller that accurately conveys and printing in synchronization with the encoder signal. Although presented, if the fluctuation is rapid and large, the printing timing cannot be controlled in time, and streaky irregularities are generated.

  Here, it is conceivable to separately provide a motor for driving the conveying roller and a motor for driving the developing roller, but this causes a problem that the apparatus becomes large and the cost increases.

  In view of the above circumstances, an object of the present invention is to provide a printer in which fluctuations in the conveyance speed of a recording medium are suppressed to reduce image unevenness.

The printer of the present invention that achieves the above object has a developer reservoir at the front end in a predetermined transport direction, a latent image is formed by exposure, and a developed image is received by developing the developer in the developer reservoir. In a printer that develops a developer by developing a developer by crushing the developer reservoir by writing a latent image on the recording medium by light irradiation while conveying the recording medium to be recorded,
A pair of transport rollers for transporting the recording medium across both sides of the recording medium;
A pair of developing rollers arranged downstream of the pair of conveying rollers in the recording medium conveying direction, and crushing the developer reservoir by sandwiching the recording medium over the entire width, and developing the developer;
A motor for applying a rotational driving force to both the conveying roller and the developing roller;
A gear train for transmitting the rotational driving force of the motor to the conveying roller and the developing roller;
A first sub-gear train in which the gear train transmits the rotational driving force from the motor partway, and a rotational driving force transmitted directly from the first sub-gear train to the conveying roller. A second sub-gear train for transmission, and a third sub-gear train for receiving the rotational driving force directly from the first sub-gear train and transmitting the rotational driving force to the developing roller. Features.

  In the printer of the present invention, when the rotational driving force from the motor is transmitted to the conveying roller and the developing roller, the rotational driving force from the motor transmitted halfway through the first sub gear train is transmitted to the second sub gear. Since the rotational driving force is transmitted separately to the conveying roller and the developing roller, such as being transmitted by the row and transmitted to the developing roller by the third sub-gear row, load fluctuations on the developing roller are applied to the conveying roller. Transmission through the gear train is reduced, fluctuations in the conveyance speed of the recording medium in the printing unit are suppressed, and image unevenness is reduced.

  Here, the motor is preferably a DC motor.

  If the motor is a direct current motor, the cost can be reduced as compared with the case where an expensive stepping motor is employed.

  The encoder preferably includes an encoder that generates an encode signal composed of a pulse train synchronized with the rotation of the transport roller, and a controller that performs printing in synchronization with the encode signal.

  In this way, gentle speed fluctuations do not occur as uneven printing.

  According to the printer of the present invention, the rotational driving force from the motor transmitted halfway through the first sub gear train is transmitted to the transport roller through the second sub gear train, and to the developing roller through the third sub gear train. Therefore, the load fluctuation in the developing roller is not directly transmitted to the conveyance roller, and hence the fluctuation in the conveyance speed of the recording medium in the printing unit is suppressed to be small, and the image unevenness is reduced.

  Hereinafter, embodiments of the present invention will be described.

  FIG. 1 is a perspective view of a printer according to an embodiment of the present invention as viewed obliquely from the front.

  The printer 1 is used in combination with a mobile phone or the like. A plurality of instant film sheets (here, a latent image is formed by exposure and a developer is developed and visualized at the time of delivery (here). In this example, the stacked instant film packs are loaded into the medium loading chamber, and the developer is developed on the instant film sheet while exposing the instant film sheet according to the image data and sending it to the outside. is there. This instant film sheet corresponds to an example of the recording medium referred to in the present invention.

  Some mobile phones can perform infrared communication conforming to IrDA (Infrared Data Association). Using this infrared communication, you can send your information to other information devices. If there is, the image data can be transmitted to the printer 1. When the printer 1 receives image data representing an image taken with the camera-equipped cellular phone or image data transmitted to the cellular phone by e-mail or the like, the printer 1 transmits the image data to the printer 1 using infrared communication. An image is recorded on the instant film sheet based on the image data, and the repeat switch described later can be used without re-recording the image based on the transmitted image data from the mobile phone. It can be performed on another instant film sheet with a simple operation of operating.

  The printer 1 is a portable printer having a thin, light, and small structure as shown in FIG. 1, and includes two 3V primary batteries. An instant film pack is loaded in the casing 1a of the printer 1, and an image is recorded on each of the ten instant film sheets stacked in the instant film pack.

  On the upper surface of the casing 1a of the printer 1, as operation buttons, a power switch (hereinafter referred to as a power SW) 11 for instructing to turn on and off the power of the printer 1 and an image replay based on the transmitted image data. A repeat switch (hereinafter referred to as repeat SW) 12 for recording is provided. A counter 13 indicating the remaining number of instant film sheets is provided on the upper surface of the housing 1a. The counter 13 is a mechanical counter, and when an unused instant film pack is loaded, a numerical value “10” indicating that the remaining number is 10 is displayed. Hereinafter, each time an image is recorded on the instant film sheet, a numerical value indicating the remaining number is displayed, and when the image is recorded on the tenth instant film sheet, the remaining number is zero. A numerical value “0” indicating this is displayed. When the instant film pack is removed, a blank state is displayed in which nothing is displayed.

  A transmission / reception unit 14 is provided at the end of the printer 1. The transmission / reception unit 14 receives the image data transmitted by the infrared communication described above, and transmits a signal for notifying the other party that the image data has been received.

  In addition, the casing 1a of the printer 1 is turned on when the power is turned on and also flashes when the infrared communication is performed, and the communication error LED 16 is turned on when an error occurs in the infrared communication, and the built-in battery voltage. When the battery voltage decreases, a low-battery display LED 17 that is lit to prompt the user to replace the battery is provided.

  Further, the side face of the printer 1 is provided with a film door opening switch 18 provided on the lower surface side of the printer 1 for opening a film door, which will be described later, and the corner portion is provided with a strap attaching portion 1b. ing.

  FIG. 2 is a diagram illustrating a state in which an instant film sheet on which an image is recorded based on image data from a camera-equipped mobile phone is discharged in the printer illustrated in FIG.

  With the infrared communication unit of the camera-equipped mobile phone 2 facing the transmission / reception unit 14 of the printer 1, the camera-equipped mobile phone 2 is operated to transmit image data representing an image taken by the camera-equipped mobile phone 2 by infrared communication. Is transmitted to the printer 1. The printer 1 receives image data transmitted by infrared communication, and records the latent image based on the received image data on the instant film sheet 1001 by exposure, while visualizing the instant film sheet 1001. The paper is gradually discharged from the outlet 19 of the printer 1 to the outside. Thereafter, when the repeat SW 12 is operated, the same image as that image is re-recorded on another instant film sheet.

  FIG. 3 is a perspective view of the lower surface side of the printer shown in FIG. 1 as viewed obliquely from above.

  A film door 20 that is opened by the operation of the film door opening switch 18 shown in FIG. 2 is provided on the lower surface side of the printer 1, and the film door 20 is opened, and an instant film pack is loaded into the medium loading chamber. Is done. The film door 20 is provided with a pack presence / absence confirmation window 20a for confirming whether or not an instant film pack is loaded. Further, a battery cover 21 that is opened to mount a battery that serves as a power source of the printer 1 is also provided adjacent to the film door 20.

  FIG. 4 is a perspective view of the printer shown in FIG. 3 with the film door opened.

  The above-described pack presence / absence confirmation window 20a and spring members 20b and 20c are provided inside the film door 20, and the instant film sheets stacked in the instant film pack by the spring members 20b and 20c are printed on the printer. 1 is pressed to the upper surface side.

  The printer 1 is also provided with a medium loading chamber 22 for loading an instant film pack. On the right side in FIG. 4 outside the medium loading chamber 22, an image writing section 300 and a medium transport developing section 30 for writing an image on the transported instant film sheet are provided. Details of the image writing unit 300 and the medium transporting and developing unit 30 will be described later. Further, a claw 24 for sending the instant film sheet to the image writing unit 300 and the medium conveying / developing unit 30 side is provided below the medium loading chamber 22 in FIG. With such a configuration, the image writing unit while the instant film sheet on the uppermost surface side of the printer 1 among the instant film sheets in the instant film pack is pushed up by the nail 24 and conveyed by the medium conveying / developing unit 30. At 300, an image is written and developed. In the state where the film door 20 is opened, the image writing unit 300 is exposed, so that the image writing unit 300 can be cleaned.

  FIG. 5 is a perspective view of the printer shown in FIG. 4 with the housing removed.

  FIG. 5 shows a medium conveying / developing system including a DC motor 406 (corresponding to an example of the motor according to the present invention) and a gear train 39 for transmitting a rotational driving force from the DC motor 406 to a conveying roll and a developing roll described later. Part 30 is shown. The details of the medium transporting and developing unit 30 will be described later. FIG. 5 also shows the above-described claw 24 provided in the medium loading chamber 22 and a rib 26 that is pressed by loading the instant film pack.

  FIG. 6 is a configuration block diagram showing a control system inside the printer.

  A schematic diagram of the printer 1 shown in FIG. 1 is shown on the right end side of FIG. 6, and a configuration showing a control system of the printer 1 is shown in the entire area excluding the right end portion. Note that the arrows shown in FIG. 6 indicate the arrangement relationship of the components indicating the control system in the printer 1.

  The printer 1 includes a main board unit 100, a sub board unit 200, an image writing unit 300, an FPI unit 401, an ENCPI unit 402, a COUNTPI unit 403, a cam switch 404, and the transmission / reception unit 14 described above. The IrDA transmission / reception unit 405 provided on the DC motor 406 and the DC motor 406 described above are provided.

  The sub-board unit 200 includes the power supply SW 11, the repeat SW 12, and the display LED unit 201 described above. The display LED unit 201 includes the power LED 15, the communication error LED 16, the low battery display LED 17, and the counter backlight LED (not shown) provided on the back side of the counter 13. Yes.

  The image writing unit 300 includes an optical head unit 301 having a light guide, a liquid crystal shutter (LCS), and the like, flexible cables 302 and 303 that connect the optical head unit 301 and the main substrate unit 100, and a flexible cable 303. Light-emitting elements (LEDs) 304, 305, and 306 having emission colors of red (R), green (G), and blue (B) are provided. This image writing unit 300 is provided with three R, G, and B from the LEDs 304, 305, and 306 based on the image data received by the transmission / reception unit 14 in synchronization with the writing instruction pulse on the instant film sheet being conveyed. A latent image is written on the instant film sheet by cyclically irradiating two colored lights. The printer 1 includes two primary batteries 407 for 3V.

  Hereinafter, the main substrate unit 100 will be described. A power supply voltage VB of 6V from the primary battery 407 connected in series is applied to the main substrate unit 100. The main board unit 100 includes an MPU (Micro Processor Unit) 101, an oscillator 102, a reset circuit 103, a flash memory (FLASH) 104, and an SDRAM 105.

  The MPU 101 comprehensively controls the operation of the printer 1.

  The oscillator 102 generates an oscillation signal having a predetermined frequency and supplies it to the MPU 101 as an operation clock signal.

  The reset circuit 103 outputs a reset signal for initializing the MPU 101.

  The flash memory 104 is a non-volatile memory, and the flash memory 104 stores adjustment values for solid difference adjustment that are determined depending on a mechanism or the like unique to the printer 1.

  The SDRAM 105 is a volatile memory, and the SDRAM 105 stores image data from the camera-equipped mobile phone 2.

  The main board 100 is supplied with a power supply voltage VB of 6V, a power supply 106 for outputting a voltage of 2.5V, a power supply 107 for outputting a voltage of 3.3V, and a voltage of 15V. A DC / DC converter 108 is provided. Further, a power supply control unit 109 that controls the power supply units 106 and 107 and the DC / DC converter 108 in response to an instruction from the MPU 101 is also provided. Here, a voltage of 2.5 V is supplied to the MPU 101 and a voltage of 3.3 V is supplied to peripheral circuits other than the MPU 101. Moreover, the voltage of 15V is used for LCD drive mentioned later.

  In order to extend the life of the primary battery 407, the printer 1 includes the MPU 101 having a standby mode which is a low power consumption mode, and the MPU 101 completes the initial process even when the power switch 12 is pressed. At that time, it becomes standby mode. When infrared communication is performed from the outside in this state, the standby mode is shifted to the normal operation mode, an image is recorded on the instant film sheet, and the normal operation mode is quickly shifted to the standby mode. Also, when the repeat SW 12 is pressed, after the image is recorded on the instant film sheet, the standby mode is set. Further, the MPU 101 controls the power supply units 106 and 107 and the DC / DC converter 108 via the power supply control unit 109 so that power is supplied to each unit only when necessary. In this way, the printer 1 can be used for a long time with the built-in primary battery 407.

  Further, the main substrate unit 100 includes a BC unit 110, a TPG unit 111, a temperature detection unit 112, an oscillator 113, an IrDA / LCS control unit 114, and a head LED driving unit 115.

  The BC unit 110 checks whether or not the power supply voltage VB of the primary battery 407 has decreased below a predetermined value. When the MPU 101 determines that the power supply voltage VB of the primary battery 407 is lower than a predetermined value with reference to the check result, the MPU 101 turns on the low battery display LED 17 to prompt the user to replace the battery. .

  The TPG unit 111 turns on and off the 15 V voltage output from the DC / DC converter 108.

  The temperature detection unit 112 detects the temperature of the image writing unit 300. The MPU 101 controls the shutter speed of each shutter unit of the liquid crystal shutter in the optical head unit 301 in accordance with the detection signal from the temperature detection unit 112.

  The oscillator 113 generates an oscillation signal having a predetermined frequency and supplies it to the IrDA / LCS control unit 114.

  The IrDA / LCS control unit 114 controls the IrDA transmission / reception unit 405 and the optical head unit 301 based on the oscillation signal from the oscillator 113. The IrDA transmission / reception unit 405 includes a light projecting element and a light receiving element for performing infrared communication, and the IrDA / LCS control unit 114 sends data photoelectrically converted by the light receiving element to the MPU 101 or from the MPU 101. Data for notifying an external device to that effect is transmitted to the outside via the light projecting element. Further, the IrDA / LCS control unit 114 controls a liquid crystal shutter provided in the optical head unit 301 via the flexible cable 302 based on an instruction from the MPU 101.

  The head LED drive unit 115 drives the LEDs 304, 305, and 306 by flowing a current based on an instruction from the MPU 101 to the LEDs 304, 305, and 306 via the flexible cable 303.

  The printer 1 according to the present embodiment is configured such that the instant film sheet is fed in a predetermined sub-scanning direction (direction in which the instant film sheet is sent out) by the DC motor 406, and the R, G, B on the instant film sheet with respect to the sub-scanning direction. In the main scanning direction that intersects with the sub-scanning direction, the same color is simultaneously written for all the pixels arranged in the main scanning direction on the instant film sheet. This is a printer that records color images.

  In recording a color image, a control signal corresponding to image data is supplied from the IrDA / LCS control unit 114 to the optical head unit 301 constituting the image writing unit 300 via the flexible cable 302. This control signal controls the shutter speed of each shutter section of the liquid crystal shutter in the optical head section 301. The shutter speed of each shutter unit is controlled according to the image data, and light corresponding to each of RGB from the LEDs 304, 305, and 306 provided in the flexible cable 303 is irradiated onto the instant film sheet, and the width of the instant film sheet A latent image consisting of a number of light spots (dots) in the direction is recorded. The width direction, that is, the direction in which the shutter portions are arranged one-dimensionally is the main scanning direction. Accordingly, each shutter portion is electronically scanned in the main scanning direction, and a light spot (all pixels) for one line is recorded on the instant film sheet. By the electronic scanning of the optical head unit 301, light spots composed of a large number of dots are recorded in the main scanning direction of the instant film sheet. As described above, in this embodiment, the instant film sheet is fed in the sub-scanning direction by the DC motor 406. Accordingly, the light spot is sequentially recorded for each of a large number of dots by the image writing unit 300 also in the sub-scanning direction.

  Further, the main board unit 100 is provided with a PI driving unit 116. The PI driving unit 116 drives the FPI unit 401, the ENCPI unit 402, and the COUNTPI unit 403. Here, the FPI unit 401, the ENCPI unit 402, and the COUNTPI unit 403 will be described.

  The FPI unit 401 is a photo interrupter for detecting the presence or absence of an instant film sheet.

  The ENCPI unit 402 is a photo interrupter for outputting an encode signal composed of a pulse train synchronized with the rotation of the DC motor 406.

  The COUNTPI unit 403 is a photointerrupter for the counter 13 to detect a reset state (a state where the instant film pack is removed).

  A cam switch 404 is connected to the main board portion 100. The cam switch 404 is a switch for monitoring an initial position in the transport mechanism of the printer 1.

  Further, the main board part 100 is provided with a motor driving part 117. The motor drive unit 117 and the MPU 101 play the role of the conveyance speed control unit according to the present invention. The motor drive unit 117 and the MPU 101 have a predetermined time interval of the pulse train of the encode signal output from the ENCPI unit 402. The rotational speed of the DC motor 406 is controlled so that the time interval is equal to.

  FIG. 7 is a perspective view showing an exposure surface of the instant film sheet, and FIG. 8 is a perspective view showing an observation surface of the instant film sheet.

  FIG. 7 shows an exposure surface 1001_1 of the instant film sheet 1001. The exposure surface 1001_1 includes a developer reservoir 1001a disposed at the leading end of the instant film sheet 1001 in the conveyance direction, an exposure unit 1001b on which an image is exposed, a blank portion 1001c, and a trap unit that absorbs excess developer. 1001d. Further, FIG. 8 shows the observation surface 1001_2 side of the instant film sheet 1001. The observation surface 1001_2 is provided with an observation unit 1001e for observing an image formed by exposure and having a latent image formed thereon and developed by the developer, and a blank portion 1001f.

  FIG. 9 is a cross-sectional view of the medium conveying and developing unit.

  The medium conveying and developing unit 30 includes a pair of conveying rollers 31 and 32 that convey the instant film sheet 1001 with both side portions of the instant film sheet 1001 being sandwiched. The conveyance roller 32 is urged toward the conveyance roller 31 by a spring member 35_1.

  In addition, the medium transport / development unit 30 is disposed downstream of the pair of transport rollers 31 and 32 in the transport direction of the instant film sheet 1001, and holds the developer film 1001 a across the entire width of the instant film sheet 1001. A pair of developing rollers 33 and 34 for crushing and developing the developer are provided. The developing roller 34 is urged toward the developing roller 33 by a spring member 35_2.

  Further, the medium transport developing unit 30 includes a control plate 36, a film guide plate 37, and an instant film, which are positioned between the transport rollers 31, 32 and the developing rollers 33, 34 for controlling the developing agent. A film guide frame 38 for guiding the sheet 1001 is provided. An image writing unit 300 is provided near the exit of the instant film pack 25.

  The printer 1 according to the present embodiment transfers the instant film sheet 1001 on the uppermost surface side of the printer 1 out of the instant film sheets 1001 in the instant film pack 25 from the predetermined conveyance start point Ps to the nail 24 (FIG. 4, 5), the image writing unit 300 writes an image at the fixed writing point Pf while being conveyed by the conveying rollers 31 and 32. Further, the printer 1 conveys the instant film sheet 1001 with the conveying rollers 31 and 32 while writing an image on the instant film sheet 1001, and develops the developer by crushing the developer reservoir 1001 a with the developing rollers 33 and 34. The developing agent being developed is controlled by the control plate 36 to perform development, and the developer is conveyed to a predetermined conveyance end point Pe. Here, the developing rollers 33 and 34 for developing the developer have a thickness of the instant film sheet 1001 itself, the rush of the instant film sheet 1001 having the developer pool 1001a, the destruction of the developer pool 1001a, the fluid resistance of the developer, and the thickness of the instant film sheet 1001 itself. There is a load fluctuation caused by non-uniformity or the like. This load fluctuation is transmitted to the gear train 39. Hereinafter, a description will be given with reference to FIGS. 10 and 11.

  FIG. 10 is a perspective view of the medium transport developing unit, and FIG. 11 is a diagram of the medium transport developing unit viewed from the front.

  10 and 11 includes the pair of transport rollers 31 and 32 and the pair of development rollers 33 and 34 described above. In addition, the medium conveying and developing unit 30 includes a DC motor 406 and a gear train 39 for transmitting the rotational driving force of the DC motor 406 to the conveying rollers 31 and 32 and the developing rollers 33 and 34. Further, the medium transporting and developing unit 30 includes an ENCPI 402 that is a transmissive photo interrupter including a light projecting element and a light receiving element, and an encoder 40 having a disk-shaped member 41. The disk-shaped member 41 is attached to the transport roller 31. The disk-shaped member 41 is provided with a large number of slots. When the disk-shaped member 41 rotates as the transport roller 31 rotates, the ENCPI unit 402 passes through the slots. When the light from the light projecting element is received by the light receiving element, an encode signal composed of a pulse train synchronized with the rotation of the transport roller 31 is generated. The generated encode signal is input to the MPU 101 via the PI drive unit 116 shown in FIG. 6, whereby the rotation of the DC motor 406 is monitored by the MPU 101, and the rotation of the DC motor 406 is monitored by the motor drive unit 117. Feedback control for constant control is performed.

  The gear train 39 includes a first sub-gear train 39_10 that transmits the rotational driving force from the DC motor 406 halfway. The first sub gear train 39_10 includes a worm gear 39_11 that is pivotally supported by the DC motor 406, and gears 39_12, 39_13, 39_14, 39_15, and 39_16 that sequentially transmit the rotational driving force from the worm gear 39_11.

  The gear train 39 includes a second sub gear train 39_20 that receives the rotational driving force directly from the first sub gear train 39_10 and transmits the rotational driving force to the transport roller 31. The second sub-gear train 39_20 includes a gear 39_21 that rotates in response to the transmission of the rotational driving force from the gear 39_15 constituting the first sub-gear train 39_10, and a gear 39_22 that meshes with the gear 39_21. .

  Further, the gear train 39 includes a third sub gear train 39_30 that receives the rotational driving force directly from the first sub gear train 39_10 and transmits the rotational driving force to the developing rollers 33 and 34. The third sub gear train 39_30 includes a gear 39_31 that rotates in response to the transmission of the rotational driving force from the gear 39_16 constituting the first sub gear train 39_10, and a gear 39_32 that transmits the rotational driving force from the gear 39_31. 39_33, 39_34, 39_35.

  As shown in FIGS. 10 and 11, the printer 1 of the present embodiment transmits the rotational driving force from the DC motor 406 partway through the first sub gear train 39_10, and the rotational drive from the first sub gear train 39_10. The force is transmitted to the conveying roller 31 by the second sub gear train 39_20 and also transmitted to the developing rollers 33 and 34 by the third sub gear train 39_30. Therefore, the conveying roller 31 is routed via the second sub gear train 39_20. Thus, the rotational driving force from the DC motor 406 is transmitted. On the other hand, the rotational driving force from the DC motor 406 is transmitted to the developing rollers 33 and 34 via the third sub gear train 39_30. As described above, since the path of the rotational driving force transmitted between the conveying roller 31 and the developing rollers 33 and 34 is different and the gear train has backlash, the variation is difficult to be transmitted with a large number of gear trains. The fluctuations in the load on the developing rollers 33 and 34 are not directly transmitted to the conveying roller 31, and fluctuations in the conveying speed of the instant film sheet 1001 are suppressed to reduce image unevenness.

  FIG. 12 is a perspective view illustrating a part of a medium transport and development unit as a comparative example.

  FIG. 12 includes a gear train 390 that constitutes a medium conveying and developing unit as a comparative example. The gear train 390 includes a worm gear 390_1 pivotally supported by the DC motor 406 and gears 390_2, 390_3, 390_4, 390_5, 390_6, 390_7, 390_8, 390_9, 390_10, 390_11 that sequentially transmit the rotational driving force from the worm gear 390_1. It is composed of Here, the gears 390_10 and 390_11 are driving roller driving gears, and the gear 390_7 is a conveying roller driving gear.

  In the medium conveying and developing unit as the comparative example, when a load fluctuation occurs in the developing roller, the load fluctuation is transmitted to the gears 390_8 and 390_9 via the developing roller driving gears 390_10 and 390_11, and further via the gear 390_8. Then, it is transmitted to the gear 390_7 for driving the conveying roller. Variations in the conveyance speed of the instant film sheet 1001 due to feed unevenness (gear backlash) for each tooth of the gear are large, and thus image unevenness occurs.

  FIG. 13 is a diagram illustrating fluctuations in the conveyance speed of the instant film sheet in the printer of this embodiment.

  FIG. 13 shows the conveyance speed fluctuation of the instant film sheet 1001 with respect to the rotation angle (200 degrees to 300 degrees) of the cam that completes a series of sequences by rotating from 0 degrees to 360 degrees in the printer 1. . In addition, A in FIG. 13 shows the conveyance speed fluctuation | variation with respect to one tooth of a gear. As shown in FIG. 13, the fluctuation in the conveyance speed of the printer 1 of this embodiment is about ± 5% at most. On the other hand, the fluctuation in the conveyance speed of the printer using the medium conveyance development unit as a comparative example shown in FIG. 12 is about ± 10%.

  The printer 1 according to the present embodiment divides / parallels the drive system of the developing roller for developing the developing solution and the drive system of the conveying roller so that the load fluctuation in the developing roller is not transmitted to the conveying roller, and stable printing is performed. Is what you get. Here, the printer 1 of the present embodiment performs printing based on the encode signal ENC that detects the rotation of the transport roller, that is, the transport speed of the film. If the technique for separately transmitting the rotational driving force is not applied, the reason why the film conveyance becomes unstable and streaky unevenness occurs will be described with reference to FIG.

  FIG. 14 is a diagram for explaining the reason why streaky unevenness occurs in a printer to which the technology for separately transmitting the rotational driving force to the conveying roller and the developing roller, which is a feature of this embodiment, is not applied.

  14A includes a pair of transport rollers 31, 32, a spring member 35_1, a gear 39_22 and a disk-shaped member 41 attached to the transport roller 31, and an ENCPI 402 which is a transmission type photo interrupter. It has been. The disk-shaped member 41 rotates with the rotation of the transport roller 31, and as a result, the ENCPI unit 402 outputs an encode signal ENC composed of a pulse train synchronized with the rotation of the transport roller 31, as shown in FIG. Is done. In a printer to which the technology for separately transmitting the rotational driving force to the conveying roller and the developing roller, which is a feature of the present embodiment, is not applied, the RGB signals are sequentially written at regular time intervals in response to the encode signal ENC. For this reason, the 'R' print has good followability to the encode signal ENC, but the 'B' print is separated from the encode signal ENC in terms of time, so that a shift occurs with respect to the speed fluctuation. Here, as shown in FIG. 14B, an example is shown in which streaks occur due to a momentary decrease in speed.

  Here, if the encode signal ENC is multiplied by 3 to generate the encode signal ENC for each RGB, the above phenomenon does not occur, but the encode signal ENC in this embodiment is about 150 P (pulse) / rotation. Since the slit width is about 100 μm, in order to output a triple signal, the slit width is about 30 μm, the productivity is lowered and the cost is increased, or the diameter of the encoder is increased, so that the size of the device is increased.

It is the perspective view which looked at the printer of one Embodiment of this invention from diagonally forward. FIG. 2 is a diagram illustrating a state in which an instant film sheet on which an image is recorded based on image data from a camera-equipped mobile phone is discharged in the printer illustrated in FIG. 1. It is the perspective view which looked at the lower surface side of the printer shown in FIG. 1 from diagonally upward. FIG. 4 is a perspective view of the printer shown in FIG. 3 in a state where a film door is opened. FIG. 5 is a perspective view of the printer shown in FIG. 4 with a housing removed. FIG. 2 is a configuration block diagram showing a control system inside the printer. It is a perspective view which shows the exposure surface of an instant film sheet. It is a perspective view which shows the observation surface of an instant film sheet. It is sectional drawing of a medium conveyance expansion | deployment part. It is a perspective view of a medium conveyance expansion part. It is the figure which looked at the medium conveyance deployment part from the front. It is a perspective view which shows a part of medium conveyance expansion | deployment part as a comparative example. It is a figure which shows the conveyance speed fluctuation | variation of the instant film sheet in the printer of this embodiment. FIG. 5 is a diagram for explaining the reason why streaky unevenness occurs in a printer to which a technique for separately transmitting a rotational driving force to a conveying roller and a developing roller, which is a feature of the present embodiment, is not applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 1a Case 1b Strap attachment part 2 Cellular phone with camera 11 Power switch (Power SW)
12 Repeat switch (repeat SW)
13 Counter 14 Transceiver 15 Power LED
16 Communication error LED
17 LED for low battery display
18 Film door opening switch 19 Outlet 20 Film door 20a Pack presence / absence confirmation window 20b, 20c, 35_1, 35_2 Spring member 21 Battery cover 22 Medium loading chamber 23 Transport roller 24 Claw (claw)
25 Instant Film Pack 26 Rib 30 Medium Conveyance Development Unit 31, 32 Conveyance Roller 33, 34 Development Roller 36 Control Plate 37 Film Guide Plate 38 Film Guide Frame 39 Gear Train 39_10 First Sub Gear Train 39_11 Worm Gear 39_12, 39_13, 39_14, 39_15 , 39 — 16, 39 — 21, 39 — 22, 39 — 31, 39 — 32, 39 — 33, 39 — 34, 39 — 35 Gear 39 — 20 Second sub gear train 39 — 30 Third sub gear train 40 Encoder 41 Disc-shaped member 100 Main board portion 101 MPU
102, 113 Oscillator 103 Reset circuit 104 Flash memory 105 SDRAM
106, 107 Power supply unit 108 DC / DC converter 109 Power supply control unit 110 BC unit 111 TPG unit 112 Temperature detection unit 114 IrDA / LCS control unit 115 Head LED drive unit 116 PI drive unit 117 Motor drive unit 200 Sub-board unit 201 For display LED unit 300 Image writing unit 301 Optical head unit 302, 303 Flexible cable 304, 305, 306 Light emitting element (LED)
401 FPI part 402 ENCPI part 403 COUNTPI part 404 Cam switch 405 IrDA transmission / reception part 406 DC motor 407 Primary battery 1001 Instant film sheet 1001_1 Exposure surface 1001_2 Observation surface 1001a Development pool 1001b Exposing part 1001c, 1001f White part

Claims (3)

The recording medium is conveyed while transporting a recording medium having a developer reservoir at the front end in a predetermined transport direction, a latent image is formed by exposure, and a developed image is recorded by developing the developer in the developer reservoir. In a printer that performs development by writing a latent image on a medium by light irradiation and crushing the developer reservoir to develop the developer,
A pair of transport rollers for transporting the recording medium across both sides of the recording medium;
A pair of developing rollers disposed downstream of the pair of conveying rollers in the recording medium conveying direction, and crushing the developer reservoir by sandwiching the recording medium over the entire width, and developing the developer;
A motor for applying a rotational driving force to both the conveying roller and the developing roller;
A gear train that transmits the rotational driving force of the motor to the transport roller and the developing roller;
The gear train receives a rotational driving force directly from the first sub-gear train and a first sub-gear train that transmits the rotational driving force from the motor halfway. A second sub-gear train for transmission, and a third sub-gear train for receiving the rotational driving force directly from the first sub-gear train and transmitting the rotational driving force to the developing roller. Features printer.   The printer according to claim 1, wherein the motor is a DC motor. An encoder that generates an encode signal composed of a pulse train synchronized with the rotation of the transport roller;
The printer according to claim 1, further comprising a control unit that performs printing in synchronization with the encode signal.

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