JP3782201B2 - Image recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present inventionImage recording deviceIn particular, a sample and hold circuit was used.Image recording deviceAbout.
[0002]
[Prior art]
A digital / analog converter (hereinafter referred to as a DA converter) that converts an input digital signal into an analog signal has a high cost per channel. In a system that requires a large number of DA converters, the cost of the entire system is low. Becomes higher.
[0003]
In order to solve such a problem, conventionally, as shown in FIG. 9, an analog switch 34 is connected to an output terminal of a DA converter 32 that converts a digital signal for one channel into an analog signal._n(N is 1 to N, the same applies hereinafter), capacitor 36_nAnd buffer amplifier 38_nAre connected in parallel for the number of channels (N channels in FIG. 9), and a digital signal corresponding to each channel is divided and input to the input end of the DA converter 32 for each channel. A timing generation circuit 46 generates a sampling signal at a timing synchronized with the timing, and each analog switch 34 for each channel by the sampling signal._nThe analog signal for each channel output from the DA converter 32 is converted into a capacitor 36 by controlling on / off switching of the capacitor 36._nEach buffer amplifier 38 of the analog signal for each sampled and held channel._nOutput signals (1ch to Nch) from the channel 1 were used as analog signals for each channel.
[0004]
[Problems to be solved by the invention]
However, in the above conventional technique, since the digital signal is divided and inputted to the DA converter for each channel, the output start timing of the output signal of each channel is shifted for each channel, and the output is started at the same timing. There is a problem that it cannot be applied to a system that requires the above.
[0005]
  The present invention has been made to solve the above-described problems, and can perform multi-channel digital / analog conversion and output simultaneously with only one channel of DA converter.Image recording deviceThe purpose is to provide.
[0006]
[Means for Solving the Problems]
  In order to achieve the above object,Image recording deviceIs one channelimage dataA digital / analog converter that converts the signal to an analog signal, and the digital / analog converterimage dataAnd a plurality of input / output means for dividing and inputting each of the analog signals for each channel output from the digital / analog converter. A first sample-and-hold circuit ofA plurality of second sample holds connected to the output terminals of the plurality of first sample hold circuits and simultaneously sample and hold the analog signals sampled and held by the plurality of first sample hold circuits. A counter of a counter that counts up in a cycle of dividing one cycle of a pixel clock signal indicating one cycle when performing image recording for one pixel into N (divided into the number of channels). The output is input to an N-output decoder, and each output signal of the decoder is input to the corresponding first sample-and-hold circuit as a sampling signal corresponding to each channel of the first sample-and-hold circuit. The out signal is used as a sampling signal corresponding to the plurality of second sample and hold circuits. It is intended to simultaneously input to the plurality of second sample-and-hold circuit.
[0007]
  Claim 1Image recording deviceAccording to one channelimage dataFor digital / analog converters that convert analog signals into analog signals, the input meansimage dataAre input for each channel. Therefore, the analog signal output from the digital / analog converter is divided for each channel.
[0008]
The analog signals divided for each channel output from the digital / analog converter are each sampled and held by a plurality of first sample hold circuits.
[0009]
  Thereafter, each analog signal sampled and held by the plurality of first sample and hold circuits isSimultaneous sample and hold by multiple second sample and hold circuitsIs done.
Here, in the present invention, the counter of the counter that counts up by a period of dividing N periods (divided into the number of channels) of one period of the pixel clock signal indicating one period when image recording for one pixel is performed by the input means. An output is input to an N-output decoder, and each output signal of the decoder is input to a corresponding first sample-and-hold circuit as a sampling signal corresponding to each channel of the first sample-and-hold circuit. The out signal is simultaneously input to the plurality of second sample and hold circuits as sampling signals corresponding to the plurality of second sample and hold circuits.
[0010]
  Thus, according to claim 1Image recording deviceAccording to the analog signal for each channel sampled and held by the plurality of first sample and hold circuits,Second sample and hold circuitTherefore, multi-channel digital / analog conversion can be performed only by one-channel digital / analog converter, and the output timing of each channel can be made simultaneously.
[0012]
  Also,Claim 1Described inImage recording deviceAccording toThe secondIn parallel with the sampling of the analog signal to the second sample and hold circuit, the next analog signal can be sampled to the first sample and hold circuit.,placeIt is possible to build a system with high speed.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
  In this embodiment, the present inventionImage recording deviceIs applied to an image recording apparatus that records light on a photosensitive material by controlling light emission of an LED chip based on image data.
[0019]
(Overall configuration "Appearance")
1 to 3 show an image recording apparatus 100 according to the present embodiment.
[0020]
The image recording apparatus 100 reads image data recorded on a CD-ROM 102 or an FD (floppy disk) 104 (see FIG. 3), exposes an image based on the image data onto the photosensitive material 106, and the photosensitive material 106. Is an apparatus for transferring and outputting the image recorded on the plain paper (image receiving paper 108).
[0021]
The upper part of the front surface (left side in FIG. 3) of the box-shaped casing 110 is an inclined surface, and an operation display unit 112 is provided.
[0022]
As shown in FIG. 2, the operation display unit 112 is classified into a monitor unit 114 located on the right side and an input unit 116 located on the left side. The monitor unit 114 is configured to project the read image.
[0023]
The input unit 116 includes a plurality of operation keys 118 and an input data confirmation display unit 120. Data necessary for image recording, such as the number of recordings, size setting, color balance adjustment, and negative / positive selection. Can be entered.
[0024]
A deck unit 122 is disposed below the operation display unit 112. The deck unit 122 includes a CD-ROM deck unit 124 positioned on the right side of FIG. 2 and an FD deck unit 126 positioned on the left side.
[0025]
The CD-ROM deck unit 124 can open and close the tray 130 by pressing an open / close button 128. By placing the CD-ROM 102 on the tray 130, the CD-ROM 102 can be loaded into the apparatus.
[0026]
On the other hand, the FD deck unit 126 is provided with an FD insertion throttle 132, and by inserting the FD 104, the drive system inside the apparatus operates to draw in the FD 104. Note that when the FD 104 is taken out, the FD 104 can be pulled out by pressing the operation button 134.
[0027]
The CD-ROM deck unit 124 and the FD deck unit 126 are provided with access lamps 136 and 138, respectively, and these access lamps 136 and 138 are lit while being accessed in the apparatus.
[0028]
A discharge tray 140 is disposed further below the deck portion 122. The discharge tray 140 is normally accommodated in the apparatus, and can be pulled out by placing a finger on the grip portion 142 (see FIG. 1).
[0029]
On the discharge tray 140, the image receiving paper 108 on which the image is recorded is discharged.
[0030]
The image receiving paper 108 is previously stored in a layer on the tray 144, and the tray 144 is loaded into a tray loading port 146 provided on the upper surface of the casing 110. The image receiving paper 108 is taken out one by one from the tray 144 loaded in the tray loading port 146, transferred to the image, and then guided to the discharge tray 140.
[0031]
Two circular cover members 148 and 150 are attached to the right side surface of the casing 110 (the front side in FIG. 1). The cover members 148 and 150 can be individually attached and detached. As shown in FIG. 3, the roll photosensitive material 106 is wound around the inside of the apparatus along the axial direction of the cover members 148 and 150. A reel 152 and a take-up reel 154 are provided, and these reels can be taken out or loaded with the cover members 148 and 150 removed.
[0032]
(Image receiving paper transport system)
As shown in FIG. 3, the tray 144 loaded in the tray loading port 146 is configured such that the upper surface of the front end of the tray 144 faces the meniscal roller 156.
[0033]
The half-moon roller 156 has a part of the circumferential surface cut away in a plane parallel to the axis. Normally, the cutout 158 is opposed to the uppermost image receiving paper 108 in the tray 144 at a predetermined interval. ing. Here, when the half-moon roller 156 rotates, the uppermost image-receiving paper 108 and the peripheral surface of the half-moon roller 156 come into contact with each other, and the half-moon roller 156 rotates once to slightly pull out the image-receiving paper 108. The pulled-out image receiving paper 108 is sandwiched between the first roller pair 160 and is completely pulled out from the tray 144 by the driving force of the first roller pair 160.
[0034]
A second roller pair 162, a guide plate 164, and a third roller pair 166 are sequentially arranged on the downstream side of the first roller pair 160, and the image receiving paper 108 is sandwiched between the first roller pair 160. After that, it is sandwiched between the second roller pair 162, guided by the guide plate 164, and sandwiched by the third roller pair 166.
[0035]
In the third roller pair 166, the photosensitive material 106 is also superimposed. That is, the third roller pair 166 is also used as a conveyance path for the photosensitive material 106.
[0036]
(Photosensitive material transport system)
The photosensitive material 106 is loaded into the apparatus in a long form wound in layers on a supply reel 152. The supply reel 152 can be loaded at a predetermined position by removing the cover member 150 (on the rear side of the apparatus) and inserting it in the axial direction.
[0037]
In a state where the photosensitive material 106 is loaded at a predetermined position, the outermost layer is pulled out and loaded along a predetermined conveyance path as an initial setting. In the loading procedure, the outermost layer is pulled out from the supply reel 152 and is sandwiched between the fourth roller pair 168 in the vicinity of the loading position of the supply reel 152, and the third roller pair is interposed via the reservoir 170 and the guide plate 172. After being pinched by 166, it is wound around the heat roller 174 and wound around the take-up reel 154. In this case, a leader tape having a length necessary for loading may be provided at the front end portion of the photosensitive material 106 wound around the supply reel 152.
[0038]
An exposure unit 176 is provided between the fourth roller pair 168 and the reservoir unit 170 in the conveyance path of the photosensitive material 106. A water application unit 178 is provided between the reservoir unit 170 and the guide plate 172. Although details of the exposure unit 176 and the water application unit 178 will be described later, as a process, after the image is exposed on the photosensitive material 106 by the exposure unit 176, the third is performed in a state where water is applied to the emulsion surface (exposure surface). The pair of rollers 166 is overlapped with the image receiving paper 108.
[0039]
(Heat roller)
The heat roller 174 is a heat development transfer portion of the apparatus, and includes a cylindrical roller main body 180 and a heater 182 provided along the axis inside the roller main body 180. By the operation, the surface of the roller main body 180 is heated and has a function of applying heat to the members (the photosensitive material 106 and the image receiving paper 108) wound around the roller main body 180. By this heating, heat development transfer processing is performed, and the image recorded on the photosensitive material 106 is transferred to the image receiving paper 108.
[0040]
A peeling roller 184 and a peeling claw 186 are provided in the vicinity of the lower left of the heat roller 174. The image receiving paper 108 wound about 1/3 around the heat roller 174 is peeled off from the photosensitive material 106, and the image is received in the direction of the discharge tray 140. The paper 108 is guided.
[0041]
On the other hand, the photosensitive material 106 is wound around the heat roller 174 by about ½, and is turned 180 ° to be guided to a position where the take-up reel 154 is loaded.
[0042]
(Water application part)
As shown in FIG. 3, the water application unit 178 has a function of applying water as an image forming solvent to the photosensitive material 106 or the image receiving paper 108, bringing the two overlapping surfaces into close contact, and performing heat development. The coating piece 188 is long along the width direction of the photosensitive material 106 and a tank 190 for storing water.
[0043]
The application piece 188 is a highly absorbent member such as felt or sponge and has an appropriate hardness so that the photosensitive material 106 contacts with a predetermined pressure during conveyance. An appropriate amount of water in the tank 190 is always transferred to the application piece 188 by utilizing a capillary phenomenon. When the photosensitive material 106 and the application piece 188 come into contact with each other, the application piece 188 makes a photosensitive action. In this configuration, water is applied to the surface (emulsion surface) of the material 106.
[0044]
Further, since the application piece 188 is in contact with the photosensitive material 106 with an appropriate pressure, water is applied uniformly.
[0045]
The water in the tank 190 is replenished by removing the entire water application unit 178. However, water may always be supplied from outside the apparatus by providing piping.
[0046]
In the present embodiment, water is used as the image forming solvent. However, this water is not limited to pure water, but includes water in the sense that it is widely used. Further, it may be a mixed solvent of water and a low boiling point solvent such as methanol, DMF, acetone, diisoptyl ketone or the like. Further, it may be a solution containing an image formation accelerator, an antifoggant, a development stopper, a hydrophilic thermal solvent, and the like.
[0047]
(Exposure part)
FIG. 4 shows an exposure unit 176 according to the present embodiment.
[0048]
The exposure unit 176 is connected to the controller 202 with the light source unit 200 provided above the conveyance path of the photosensitive material 106 as a main component. The controller 202 stores image data (image data read from the CD-ROM 102 or the FD 104), and a full-color image forming light source unit 204 as a light emitting unit in the light source unit 200 is provided in accordance with the image data. It is designed to light up. Note that the configuration of the part for turning on the full-color image forming light source unit 204 in the controller 202 particularly related to the present invention will be described later.
[0049]
The light source unit 200 can be moved in the width direction (main scanning direction) of the photosensitive material 106 by driving a main scanning unit 206, which will be described later, and the main light source unit 200 is stopped when the photosensitive material 106 is moved stepwise through the exposure unit 176. Scanning is performed.
[0050]
The light source unit 200 of the exposure unit 176 is covered with a box-type exposure casing 214, and a full-color image forming light source unit 204 is disposed on the upper end surface of the exposure casing 214. The light emitting surface is directed to the opening portion side of the exposure casing 214. On the light emitting surface side of the light source portion 204 for full color image formation, an aperture 216 provided with a rectangular aperture for each emission color is disposed, and R (red), G (green), and B (blue) are provided. The spread of light from the R-LED chip 208R, G-LED chip 208G, and B-LED chip 208B (11 for each color, see FIG. 5) that emits light in each color is limited.
[0051]
A lens 212 is disposed at the center of the exposure casing 214 on the downstream side of the aperture 216, and has a function of condensing the light from the full-color image forming light source unit 204 and forming an image in the vicinity of the photosensitive material 106. Yes. In addition, the resolution of the imaged light is about 300 to 400 dpi. Further, although the lens 212 is shown alone in the drawing, a single lens system may be configured by combining a plurality of lenses.
[0052]
Here, the lens 212 is composed of a plurality of lenses and an aperture, and when the lens 212 has a characteristic that the magnification does not change even if the height of the image plane changes to some extent, It is possible to absorb minute errors due to scanning movement and the attachment state of the LED chip 208.
[0053]
The focus is always adjusted by an autofocus mechanism (not shown).
[0054]
The light source unit 200 is supported by a pair of parallel guide shafts 218 that constitute a part of the main scanning unit 206. The guide shaft 218 is disposed along the width direction of the photosensitive material 106 (the direction of the arrow W in FIG. 4), and the full-color image forming light source unit 204 is guided by the guide shaft 218 to be photosensitive material 106. It is possible to move in the width direction.
[0055]
A part of an endless timing belt 220 is fixed to the exposure casing 214 of the full-color image forming light source unit 204. Both ends of the timing belt 220 are wound around sprockets 222 located near both ends of the guide shaft 218, respectively. The rotating shaft of one sprocket 222 is connected to the rotating shaft of the stepping motor 226 via the transmission 224, and the full-color image forming light source unit 204 is moved along the guide shaft 218 by the reciprocating rotation of the stepping motor 226. It is reciprocated.
[0056]
The driving of the stepping motor 226 is controlled by the controller 202 and is synchronized with the step movement of the photosensitive material 106. That is, in a state where the photosensitive material 106 has moved and stopped by one step, the stepping motor 226 starts to rotate, and the full-color image forming light source unit 204 moves on the photosensitive material 106 along the width direction of the photosensitive material 106. After confirming the predetermined pulse, the full-color image forming light source unit 204 returns to the original position by rotating the stepping motor 226 in the reverse direction. The next movement of the photosensitive material 106 is started simultaneously with the returning operation of the full-color image forming light source unit 204.
[0057]
A photodiode 228 is disposed on the light output side of the light source unit 200, on the surface facing the photosensitive material 106 and in the vicinity of the main scanning start position, and outputs a signal corresponding to the light amount of the light source from the light source unit 204 for full color image formation. It is like that. The photodiode 228 is connected to the light amount correction unit 230, and the signal is input to the light amount correction unit 230.
[0058]
The light amount correction unit 230 has a function of comparing the detected light amounts from the LED chips 208 of the respective colors, adjusting the light amount and the color balance, and outputting a correction value to the controller 202. Based on this correction value, the image data sent to the full-color image forming light source unit 204 is corrected, and each LED chip 208 is lit with an appropriate amount of light.
[0059]
As shown in FIG. 5, the full-color image forming light source unit 204 includes a B-LED chip 208 </ b> B, a G-LED chip 208 </ b> G, and an R-LED chip 208 </ b> R. Along the width direction (main scanning direction) 106, they are attached according to the same arrangement rule. That is, eleven B-LED chips 208B are arranged in two rows and zigzag at the right end in a plan view of the substrate 210, and eleven R-LED chips 208R are arranged in two rows at the left end. Arranged in a zigzag pattern, 11 G-LED chips 208G are arranged in a zigzag pattern in the middle, and a total of 6 LED chips are arranged in the center.
[0060]
The substrate 210 is provided with predetermined wiring by an etching process or the like, but is covered with metal so as not to short-circuit between the wirings, and has a heat dissipation function. For this reason, the heat_generation | fever by lighting of the LED chip 208 can be suppressed, and the fluctuation | variation of emitted light amount can be suppressed. The outer dimension (xx) of the LED chip 208 is about 360 * 360 [mu] m.
[0061]
By the way, as shown in FIG. 5, the pitch between columns (the pitch in the main scanning direction) P of the same color of the LED chips 208 to be mounted on the substrate 210 is 600 μm, and the row pitch (the pitch in the sub scanning direction) L of each column. Is preferably 520 μm, the step size D is 260 μm, and the gap size G between the colors is preferably the same between RG and GB. The hatched portion of the LED chip 208 shown in FIG. 5 is a region that actually emits light, and the boundaries of the light emitting regions between adjacent rows in the staggered LEDs of the same light emitting color are matched.
[0062]
With the full-color image forming light source unit 204 having the above-described structure, 11 main scanning lines can be recorded on the photosensitive material 106 by one main scanning for each color. Note that there is an even number 10 between the main scanning line pitches.
[0063]
Here, in this embodiment, as shown in FIG. 6, the step movement of the photosensitive material 106 is such that the current first main scanning line recorded on the photosensitive material 106 is the previous sixth and seventh. It is controlled to repeat the sub-scanning drive and stop at a pitch (5.5 line pitch) that comes to the middle position of the main scanning line. In FIG. 6, the thin solid line is 11 main scanning lines formed by the previous main scanning, the chain line is 11 main scanning lines formed by the current main scanning, and the thick solid line is the next time. 11 main scanning lines formed by main scanning.
[0064]
In this way, by setting the odd number of LED chips 208, the number of main scan lines is even (that is, 10 intervals), and half the main scan lines are further formed to form main scan lines. It has increased by a factor of two. As described above, since the odd number of LED chips 208 is provided for each emission color, the spacing between the LED chips 208 is an even number, and the scanning lines are formed for each half of the main scanning lines, the same sub-scanning pitch can be set. it can. In addition, the first to fifth main scanning lines at the time of the first main scanning drive are not written for control purposes.
[0065]
Next, with reference to FIG. 7, the configuration of the part that turns on the full-color image forming light source unit 204 in the controller 202 particularly related to the present invention will be described in detail.
[0066]
The controller 202 includes an image memory 10 that temporarily stores input image data, and an output end of the image memory 10 is connected to an input end of a DA converter 32 that converts a digital signal for one channel into an analog signal. Has been.
[0067]
The output end of the DA converter 32 is branched into a plurality (33, which corresponds to the number of LED chips 208 in the present embodiment), and each analog switch 34 is branched._nEach analog switch 34 is connected to one end of a switch unit (n is 1 to N, N = 33 in the present embodiment, and so on)._nThe other end of the switch portion is a capacitor 36._nAnd one end of the buffer amplifier 38_nIs connected to the non-inverting input terminal. Capacitor 36_nThe other end of is grounded.
[0068]
On the other hand, the buffer amplifier 38_nThe output terminal is the buffer amplifier 38_nInverting input terminal and analog switch 40_nIs connected to one end of the switch portion of the analog switch 40_nThe other end of the switch part is a capacitor 42._nOne end, and buffer amplifier 44_nIs connected to the non-inverting input terminal. Further, the capacitor 42_nThe other end of is grounded.
[0069]
On the other hand, the buffer amplifier 44_nOutput terminal of the buffer amplifier 44_nAnd an output terminal (1ch to 33ch) to the full-color image forming light source unit 204 of the controller 202, each output terminal being a full-color image forming light source unit shown in FIG. Each of them is connected to 33 LED chips 208 in 204. (Connection lines from each output end to each LED chip 208 are not shown.)
In addition, the analog switch 34_nEach switch switching input terminal is connected to the output terminal of the sampling signal 46A corresponding to each channel of the timing generation circuit 46, and the analog switch 40 is connected._nEach switch switching input terminal is connected to the same output terminal of the sampling signal 46B of the timing generation circuit 46.
[0070]
  Thus, the analog switch 34_n, Capacitor 36_nAnd buffer amplifier 38_nThe first-stage sample and hold circuit (corresponding to the first sample and hold circuit of the present invention) is_n, Capacitor 42_nAnd buffer amplifier 44_nThe second stage sample and hold circuit (the present inventionThe first2 corresponding to the sample and hold circuit 2).
[0071]
The controller 202 includes a CPU 12 that is connected to the light amount correction unit 230 and the image memory 10 and corrects image data stored in the image memory 10 based on correction values input from the light amount correction unit 230. Yes.
[0072]
The CPU 12 is further connected to a stepping motor 226 and a timing generation circuit 46 to control the step movement of the full-color image forming light source unit 204 and to the timing generation circuit 46 by one pixel in the main scanning direction. A pixel clock signal 12A (see FIG. 8) indicating one cycle when the image recording is performed is output.
[0073]
The timing generation circuit 46 is further connected to the image memory 10, and inputs the image data stored in the image memory 10 to the DA converter 32 based on the pixel clock signal 12 </ b> A input from the CPU 12. Therefore, the timing generation circuit 46 corresponds to the input means of the present invention.
[0074]
  The analog switch 34_n, 40_nFor example, an FET switch or a reed relay can be applied. Further, a portion (a portion surrounded by an alternate long and short dash line in FIG. 7) 30 constituted by the DA converter 32 and the two-stage sample hold circuit for 33 channels and the timing generation circuit 46 is provided.ManyCorresponds to a channel digital / analog converter. In addition, the portion constituted by the multi-channel DA converter 30 and the full-color image forming light source unit 204 isManyIt corresponds to a channel light emitting device.
[0075]
(Reservoir part)
As described above, the reservoir unit 170 is disposed between the exposure unit 176 and the water application unit 178, and includes two pairs of sandwiching rollers 192 and 194 and one dancer roller 196. The photosensitive material 106 is stretched over two pairs of sandwiching rollers 192 and 194, and a substantially U-shaped slack is provided in the photosensitive material 106 between them. In response to this slack, the dancer roller 196 is moved up and down to hold the photosensitive material 106 in the slack portion.
[0076]
In the exposure unit 176, the photosensitive material 106 moves stepwise, but in the water application unit 178, it is necessary to transport the photosensitive material 106 at a constant speed for uniform application of water. For this reason, a conveyance speed difference of the photosensitive material 106 occurs between the exposure unit 176 and the water application unit 178. In order to absorb this speed difference, the dancer roller 196 is moved up and down to adjust the slack amount of the photosensitive material 106 so that the photosensitive material 106 can be moved stepwise and at a constant speed simultaneously.
[0077]
The operation of this embodiment will be described below.
First, the overall flow for image recording will be described.
[0078]
The tray 144 is loaded in the tray loading port 146, the supply reel 152 with the photosensitive material 106 wound up and the take-up reel 154 in the empty state are loaded at predetermined positions, respectively, and the loading is completed. When the print start key of the display unit 112 is operated, the controller 202 reads image data from the CD-ROM 102 or the FD 104 and stores it in the image memory 10.
[0079]
When image data is stored by the controller 202, the supply reel 152 is driven to start conveying the photosensitive material 106.
[0080]
When the photosensitive material 106 reaches a predetermined position of the exposure unit 176, the photosensitive material 106 is temporarily stopped, and image data is output from the controller 202 to the full-color image forming light source unit 204. This image data is output every 11 lines, and the full-color image forming light source unit 204 is guided by the guide shaft 218 by the driving of the stepping motor 226 and moves along the width direction of the photosensitive material 106 (main scanning).
[0081]
Before starting the output of the image data, the light amount of each color from the light source unit 204 for full color image formation is detected by the photodiode 228, and the light amount correction unit 230 sets a correction value for adjusting the density, the color balance, and the like. The data is supplied to the CPU 12 of the controller 202 and the image data is corrected. This correction is performed for each image.
[0082]
As shown in FIG. 6, when one main scanning is completed, the photosensitive material 106 is stopped by moving one step (5.5 line pitch), and the second main scanning is performed. By repeating this, an image for one frame is recorded on the photosensitive material 106. That is, the main scanning line is formed at a pitch that is half the arrangement pitch of the LED chips 208, and the resolution is improved. In this case, the upper five lines at the time of the first main scanning drive on one screen and the lower five lines at the time of the last main scanning driving may be unexposed (the LED chip 208 is turned off).
[0083]
The photosensitive material 106 that has been recorded is wound around the dancer roller 196 by driving only the pair of nip rollers 192 on the upstream side of the reservoir unit 170 (the pair of nip rollers 194 on the downstream side is stopped). It is held in a slack state and does not reach the water application part 178.
[0084]
When the photosensitive material 106 having a length of one image is accumulated in the reservoir unit 170, the pair of nipping rollers 194 on the downstream side of the reservoir unit 170 starts to be driven. As a result, the photosensitive material (image recorded) 106 is conveyed to the water application unit 178. In the water application unit 178, the photosensitive material 106 is conveyed at a constant speed, and water is uniformly applied by the application piece 188.
[0085]
The application piece 188 is constantly supplied with water from the tank 190 and presses the photosensitive material 106 with a predetermined pressure, so that an appropriate amount of water is applied to the photosensitive material 106.
[0086]
The photosensitive material 106 coated with water is guided by the guide plate 172 and conveyed to the third roller pair 166.
[0087]
On the other hand, when the half moon roller 156 rotates once, the peripheral surface of the half moon roller 156 comes into contact with the leading edge of the image receiving paper 108, and the uppermost image receiving paper 108 is pulled out, and the first receiving roller 108 160. By the driving of the first roller pair 160, the image receiving paper 108 is pulled out from the tray 144 and waits for the arrival of the photosensitive material 106 while being sandwiched between the second roller pair 162.
[0088]
In synchronism with the passage of the photosensitive material 106 through the guide plate 172, the driving of the first roller pair 160 and the second roller pair 162 is started, and the image receiving paper 108 is guided by the guide plate 164 and the third roller pair 160 is driven. It is conveyed to the roller pair 166.
[0089]
In the third roller pair 166, the photosensitive material 106 and the image receiving paper 108 are nipped in an overlapped state and sent to the heat roller 174. At this time, the two are brought into close contact with water applied to the photosensitive material 106.
[0090]
The photosensitive material 106 and the image receiving paper 108 in a superposed state are wound around a heat roller 174 and receive heat from the heater 182 to be subjected to heat development transfer processing.
That is, the image recorded on the photosensitive material 106 is transferred to the image receiving paper 108 and visualized.
[0091]
The heat development transfer is completed in a state of being wound about 1/3 around the heat roller 174, and the image receiving paper 108 is peeled off from the photosensitive material 106 by the peeling roller 184 and the peeling claw 186 and wound around the peeling roller 184. Is discharged onto the discharge tray 140.
[0092]
On the other hand, the photosensitive material 106 is wound about 1/2 on the heat roller 174, moves in the tangential direction, and is taken up on the take-up reel 154.
[0093]
Next, the operation of the multi-channel DA converter 30 (see FIG. 7) in the controller 202 when the full-color image forming light source 204 is turned on, which is particularly related to the present invention, will be described with reference to the time chart of FIG.
[0094]
When the pixel clock signal 12A input from the CPU 12 goes high, the timing generation circuit 46 in the multi-channel DA converter 30 is divided into N sections (divided into the number of channels) by one time division of the pixel clock signal 12A. The analog switch 34 corresponding to each channel_nAre generated in order of channels, and a sampling signal 46A is generated, and each analog switch 34 of the sampling signal 46A is generated._nStart applying to. At the same time, the timing generation circuit 46 uses the analog switch 40 for one cycle of the pixel clock signal 12A._nOf the timing signal 46B generated to turn off the analog switch 40_nStart applying to. Note that the analog switch 34 used in the present embodiment._n, 40_nIs turned on when the signal applied to the switch switching input terminal is at a low level.
[0095]
Each analog switch 34 of the sampling signal 46A_nTo the switch switching input terminal and each analog switch 40 of the sampling signal 46B._nIs applied to the switch switching input terminal, the timing generation circuit 46 receives N channels of image data from the image memory 10 to the DA converter 32, that is, N pieces of data provided in the light source unit 204 for full color image formation. Input of image data for causing the LED chip 208 to emit light is started. At this time, the image data of each channel is input within the period when the sampling signal 46A corresponding to each channel is at a low level, as shown in FIG._nThe capacitors 36 that fall within the period when the signal is on and correspond to each channel_nThe image data of each channel is divided and inputted for each channel so as to cover a period during which the sample data can be sampled and held.
Each analog switch 34 of the sampling signal 46A described above._nAre applied to the switch switching input terminal, and image data is input to the DA converter 32, whereby each analog switch 34 is switched._nCapacitor 36 connected to_nThe voltage corresponding to the image data of each channel is sampled, and each capacitor 36 is sampled._nEach buffer amplifier 38 connected to_n8, that is, the output voltage of the first-stage sample and hold circuit starts rising substantially simultaneously with the input of the image data of each channel to the DA converter 32 as shown in FIG. When the application of the low level of the signal 46A is finished, the output voltages corresponding to the image data of all the channels are held.
[0096]
Thereafter, the timing generation circuit 46 outputs the sampling signal 46B to the analog switch 40._nIs turned on, that is, at a low level.
[0097]
Thus, the analog switch 40_nSampling signal 46B for turning on each analog switch 40_nAre simultaneously applied to all switch switching input terminals of the buffer amplifier 44._nThe output at the output terminal of the second stage, that is, the output terminal of each sample and hold circuit in the second stage, is started simultaneously. Therefore, the buffer amplifier 44_nA signal corresponding to the image data is simultaneously applied to each LED chip 208 connected to each output terminal.
[0098]
Thereafter, the timing generation circuit 46 sets the sampling signal 46B to the high level and the analog switch 40._nAfter the sample hold operation of the second-stage sample hold circuit is finished, the sample hold operation of the next image data to the first-stage sample hold circuit is started.
[0099]
In addition, as a method of generating the sampling signals 46A and 46B in the timing generation circuit 46, for example, the counter output of a counter that counts up in a cycle of dividing one cycle of the pixel clock signal 12A into N is input to an N-output decoder. For example, the output signal of the decoder may be a sampling signal 46A corresponding to each channel, and the carry-out signal of the counter may be a sampling signal 46B.
[0100]
As described in detail above, the multi-channel DA converter according to the present embodiment includes two stages of sample and hold circuits corresponding to the number of channels, and the voltage corresponding to the image data of each channel is obtained by the first stage sample and hold circuit. Since the sample-and-hold voltage is sampled and held in a time-division manner and the sample-and-hold voltage is simultaneously output by the second-stage sample-and-hold circuit, multi-channel digital / analog conversion can be performed only by one channel of DA converter, and each channel The output timing can be made simultaneously.
[0101]
In the present embodiment, the case of performing digital / analog conversion for 33 channels using 33 sets of two-stage sample-and-hold circuits has been described. However, the present invention is not limited to this, and two more stages are provided. By additionally connecting the sample and hold circuit in parallel to the output terminal of the DA converter 30, it is possible to realize a DA converter corresponding to more channels according to the number of additional connections.
[0102]
In the present embodiment, the case where the multi-channel DA converter of the present invention is applied to the controller 202 in the exposure unit 176 of the image recording apparatus 100 has been described. However, the present invention is not limited to this, and It can be applied to any device that requires simultaneous analog output.
[0103]
【The invention's effect】
  Claim 1Image recording deviceAccording to the analog signal for each channel sampled and held by the plurality of first sample and hold circuits,Second sample and hold circuitTherefore, the multi-channel digital / analog conversion can be performed only by the digital / analog converter for one channel, and the output timing of each channel can be made simultaneously.
[0104]
  Also,Claim 1DescribedImage recording deviceAccording toThe secondIn parallel with the sampling of the analog signal to the second sample and hold circuit, the next analog signal can be sampled to the first sample and hold circuit.,placeThe effect is that a system with a high speed can be constructed.
[Brief description of the drawings]
FIG. 1 is a perspective view of an image recording apparatus according to an embodiment.
FIG. 2 is a front view of the image recording apparatus according to the present embodiment.
FIG. 3 is a side sectional view showing an internal configuration of the image recording apparatus according to the present embodiment.
FIG. 4 is a front view showing a schematic configuration of an exposure unit.
FIG. 5 is a plan view showing an arrangement state of LED chips in a light source unit.
FIG. 6 is a plan view of a photosensitive material showing a state of a main scanning line and a sub-scanning pitch.
FIG. 7 is a circuit diagram showing a circuit configuration of a portion for turning on a light source unit in a controller.
FIG. 8 is a time chart for explaining the operation of the multi-channel DA converter.
FIG. 9 is a circuit diagram showing a circuit configuration of a conventional multi-channel DA converter.
[Explanation of symbols]
30 Multi-channel DA converter
32 DA converter
34_n  Analog switch
36_n  Capacitor
38_n  Buffer amplifier
40_n  Analog switch
42_n  Capacitor
44_n  Buffer amplifier
46 Timing generation circuit (input means)
100 Image recording apparatus
202 controller
204 Light source for full color image formation (light emitting means)
208 LED chip (light emitter)

Claims (1)

A digital / analog converter that converts 1-channel image data into an analog signal;
Input means for dividing and inputting image data of a plurality of channels into the digital / analog converter for each channel;
A plurality of first sample-and-hold circuits connected in parallel to the output terminals of the digital / analog converter and each sample-and-hold an analog signal for each channel output from the digital / analog converter;
A plurality of second sample and hold circuits connected to the output terminals of the plurality of first sample and hold circuits and simultaneously sample and hold the analog signals sampled and held by the plurality of first sample and hold circuits. Circuit,
Have
The input means outputs a counter output of a counter that counts up in a cycle of dividing one cycle of a pixel clock signal indicating one cycle at the time of image recording for one pixel into N (divides the number of channels) into an N-output decoder. Each of the output signals of the decoder is input to the corresponding first sample and hold circuit as a sampling signal corresponding to each channel of the first sample and hold circuit, and the carry-out signal of the counter is input to the plurality of second output signals. Simultaneously input to the plurality of second sample and hold circuits as sampling signals corresponding to the two sample and hold circuits
Image recording device .

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